WO2025141448A1 - Electronic device and program - Google Patents

Abstract

The present invention provides an electronic device having an authentication function. The electronic device has a display unit. The display unit has a plurality of light-emitting elements and a plurality of light-receiving elements. The light-receiving element receives light emitted from the light-emitting element and then reflected from a subject. When the illuminance of external light is equal to or less than a first value, the light-emitting element emits light at a first illuminance and the light-receiving element receives light during a first detection period. When the illuminance of the external light is higher than the first value, the light-emitting element emits light at a second illuminance higher than the first illuminance, and the light-receiving element receives light during a second detection period shorter than the first detection period.

Description

Electronic devices and programs

One aspect of the present invention relates to an electronic device. One aspect of the present invention relates to a program to be executed by an electronic device. One aspect of the present invention relates to an operation method of an electronic device. One aspect of the present invention relates to an authentication method for an electronic device.

Note that one embodiment of the present invention is not limited to the above technical field. Examples of technical fields of one embodiment of the present invention disclosed in this specification and the like include semiconductor devices, display devices, light-emitting devices, power storage devices, memory devices, electronic devices, lighting devices, input devices, input/output devices, driving methods thereof, and manufacturing methods thereof. A semiconductor device refers to any device that can function by utilizing semiconductor characteristics.

In recent years, information terminal devices such as mobile phones such as smartphones, tablet information terminals, and notebook PCs (personal computers) have become widespread. Such information terminal devices often contain personal information, and various authentication technologies have been developed to prevent unauthorized use.

For example, Patent Document 1 discloses an electronic device that has a fingerprint sensor in the push button switch section.

US Patent Application Publication No. 2014/0056493

An object of one embodiment of the present invention is to provide a display unit having a light detection function. Another object is to provide a high-definition display unit having a light detection function. Another object is to provide a display device having a light detection function. Another object is to provide a high-definition display device having a light detection function. Another object is to provide an electronic device having a display function. Another object is to provide an electronic device having a light detection function. Another object is to provide an electronic device having an authentication function typified by fingerprint authentication. Another object is to provide an electronic device with high security. Another object is to provide an electronic device with high operability. Another object is to provide a multi-function electronic device. Another object is to provide a new electronic device. Another object is to provide an electronic device having a high security authentication method. Another object is to provide an electronic device having a new operation method. Another object is to provide an electronic device having a new authentication method.

Another object of one embodiment of the present invention is to provide a program to be executed on a highly secure electronic device. Another object is to provide a program to be executed on a new electronic device. Another object is to provide a new program.

Note that the description of these problems does not preclude the existence of other problems. Note that one embodiment of the present invention does not necessarily solve all of these problems. Note that problems other than these can be extracted from the description in the specification, drawings, claims, etc.

One aspect of the present invention is an electronic device having a display unit, the display unit having a plurality of light-emitting elements and a plurality of light-receiving elements, the light-receiving elements receiving light emitted from the light-emitting elements and reflected from a subject, the light-receiving elements receiving light during a first detection period when the illuminance of external light is equal to or lower than a first value, the light-emitting elements emitting light at a first luminance during the first detection period, and when the illuminance of external light is higher than the first value, the light-receiving elements receiving light during a second detection period that is shorter than the first detection period, and the light-emitting elements emitting light at a second luminance that is higher than the first luminance during the second detection period.

Furthermore, in the above aspect, it is preferable that the light receiving element receives light during a first detection period when the illuminance of external light is equal to or lower than a first value, and receives light during a second detection period when the illuminance of external light is higher than the first value.

Or one aspect of the present invention is a display unit having a display unit having a plurality of pixel circuits and a plurality of second elements, the pixel circuits having a first element and a current control unit, the first element having a first electrode and a second electrode, and a first light-emitting layer located between the first electrode and the second electrode, the current control unit having a first terminal and a second terminal connected to the second electrode, the first electrodes of the first elements of the plurality of pixel circuits are connected to each other, the first terminals of the current control units of the plurality of pixel circuits are connected to each other, and the second elements are illuminated from the first elements. An electronic device that receives reflected light from a subject of light emitted from the light source, and when the illuminance of external light is equal to or less than a first value, the second element receives light for a first detection period, and during the first detection period, the first element emits light at a first luminance, and when the illuminance of external light is higher than the first value, the second element receives light for a second detection period that is shorter than the first detection period, and during the second detection period, the first element emits light at a second luminance that is higher than the first luminance, and the potential difference between the first terminal and the first electrode when emitting light at the second luminance is greater than the potential difference between the first terminal and the first electrode when emitting light at the first luminance.

In the above aspect, it is preferable that the current control unit has a first transistor, one of the source and drain of the first transistor is connected to a first terminal, and the other of the source and drain of the first transistor is connected to a second terminal.

In the above aspect, it is preferable that the current control unit has a first transistor, and when the first element emits light, a potential corresponding to the first terminal is applied to one of the source and drain of the first transistor, and the current of the first element is controlled by the first transistor.

Furthermore, in the above aspect, it is preferable that the product of the first luminance and the length of the first detection period is 0.8 to 1.2 times the product of the second luminance and the length of the second detection period.

In the above aspect, it is preferable that the subject is a first finger that is in contact with or close to the surface of the display unit, and that the device has a function of acquiring fingerprint information of the first finger.

In the above aspect, it is preferable that the device has a memory unit, the subject is a first finger that is in contact with or close to the surface of the display unit, the memory unit has fingerprint information of a second finger, and has a function of acquiring the fingerprint information of the first finger and a function of matching the fingerprint information of the first finger with the fingerprint information of the second finger.

Furthermore, in the above aspect, it is preferable that the second element has a third electrode, a fourth electrode, and an active layer located between the third electrode and the fourth electrode, the third electrodes of the second elements are connected to each other, and the same potential is applied to the third electrodes of the second elements and the first electrodes of the first elements of the pixel circuits.

In the above aspect, it is preferable that the second element has a second light-emitting layer, and the second light-emitting layer is located between the third electrode and the fourth electrode.

In the above aspect, it is preferable that the first element has a function of emitting light of one color selected from the three colors of red, green, and blue, and the second element has a function of emitting light of another color selected from the three colors and a function of receiving visible light.

Furthermore, in the above aspect, it is preferable that the first element has a function of emitting light of one color selected from the three colors of red, green, and blue, and the second element has a function of emitting light of another color selected from the three colors and a function of receiving infrared light.

Furthermore, in the above aspect, it is preferable that the potential of the first electrode when emitting light of the second brightness is lower than the potential of the first electrode when emitting light of the first brightness.

Furthermore, in the above aspect, it is preferable that the potential of the first terminal when emitting light of the second luminance is higher than the potential of the first terminal when emitting light of the first luminance.

Or, one aspect of the present invention is an electronic device having a display unit and a camera, the display unit having a plurality of pixel circuits and a plurality of second elements, the pixel circuit having a first element and a current control unit, in a first operation mode, the second element receives reflected light from a subject of light emitted from the first element, when the illuminance of external light is equal to or lower than a first value, the first element emits light at a first luminance, the second element receives light during a first detection period, when the illuminance of external light is higher than the first value, the first element emits light at a second luminance higher than the first luminance, and the second element receives light during a second detection period shorter than the first detection period, in a second operation mode, the first element emits light at a third luminance, and an image is captured using the camera with the light emission at the third luminance as a flashlight, and the third luminance is lower than the second luminance.

Furthermore, in the above aspect, it is preferable that the first element has a first electrode and a second electrode, and a light-emitting layer located between the first electrode and the second electrode, the current control unit has a first terminal and a second terminal connected to the second electrode, the first electrodes of the first elements of the multiple pixel circuits are connected to each other, the first terminals of the current control units of the multiple pixel electrodes are connected to each other, and the potential difference between the first terminal and the first electrode is greater during emission of the second luminance than during emission of the first luminance, and the potential difference between the first terminal and the first electrode is greater during emission of the second luminance than during emission of the third luminance.

Or one aspect of the present invention is a program for executing an electronic device, the electronic device having a display unit having a display function and a detection function, and a memory unit, and the program includes a first step of placing a first finger in contact with or in close proximity to a surface of the display unit, a second step of displaying a first region of a first image on the display unit at a first luminance, performing detection during a first detection period using the first region of the first image as a light source, and obtaining a first captured image of the first finger, a third step of selecting whether or not to adopt the first captured image, and if the captured image is not adopted in the third step, displaying the first region of the first image on the display unit at a second luminance higher than the first luminance, and obtaining a first captured image of the first finger using the first region of the first image as a light source. This program has a fourth step of performing detection in a second detection period that is shorter than the detection period and acquiring a second captured image of the first finger, a fifth step of selecting whether or not to adopt the second captured image, a sixth step of extracting fingerprint information of the first finger from the first captured image if the captured image is adopted in the third step, and extracting fingerprint information of the first finger from the second captured image if the captured image is adopted in the fifth step, and a seventh step of comparing the fingerprint information of the first finger extracted in the sixth step with the fingerprint information of the second finger held in the memory unit, and proceeds to the sixth step without performing the fourth and fifth steps if the captured image is adopted in the third step.

Furthermore, in the above aspect, it is preferable that the product of the first luminance and the length of the first detection period is 0.8 to 1.2 times the product of the second luminance and the length of the second detection period.

One aspect of the present invention has a display unit, a memory unit, and an illuminance sensor, the display unit has a plurality of pixel circuits and a plurality of light receiving elements, the pixel circuit has a light emitting element and a current control unit, the light receiving element receives light reflected from a subject of light emitted from the light emitting element, the memory unit has first biometric information, the illuminance sensor detects illuminance corresponding to external light received by the display unit, when the illuminance detected by the illuminance sensor is equal to or lower than a first value, the light receiving element receives light during a first detection period, during the first detection period, the light emitting element emits light at a first luminance, and when the illuminance detected by the illuminance sensor is higher than the first value, the light receiving element The electronic device has a function of acquiring processing contents based on an authentication code and a function of acquiring second biometric information and approving the processing contents based on a comparison with the first biometric information, the authentication code being acquired by using an image including the authentication code as a first subject and detecting reflected light from the first subject with multiple light receiving elements, and the second biometric information being acquired by using a finger or palm as a second subject and detecting reflected light from the second subject with multiple light receiving elements.

Furthermore, in the above aspect, the light-emitting element has a first electrode and a second electrode, and a first light-emitting layer located between the first electrode and the second electrode, the current control unit has a first terminal and a second terminal connected to the second electrode, the first electrodes of the light-emitting elements of the multiple pixel circuits are connected to each other, the first terminals of the current control units of the multiple pixel circuits are connected to each other, and it is preferable that the difference between the potential of the first terminal and the potential of the first electrode when emitting light of the second luminance is greater than the difference between the potential of the first terminal and the potential of the first electrode when emitting light of the first luminance.

In the above aspect, it is preferable that the current control unit has a first transistor, one of the source and drain of the first transistor is connected to a first terminal, and the other of the source and drain of the first transistor is connected to a second terminal.

In the above aspect, it is preferable that the current control unit has a first transistor, and when the light-emitting element emits light, a potential corresponding to the first terminal is applied to one of the source and drain of the first transistor, and the current of the light-emitting element is controlled by the first transistor.

In the above embodiment, it is preferable that the authentication code is a barcode or a two-dimensional code.

Furthermore, in the above aspect, it is preferable that the product of the first luminance and the length of the first detection period is 0.8 to 1.2 times the product of the second luminance and the length of the second detection period.

Furthermore, in the above aspect, it is preferable that the light receiving element has a third electrode, a fourth electrode, and an active layer located between the third electrode and the fourth electrode, the third electrodes of each of the light receiving elements are connected to each other, and the same potential is applied to each of the third electrodes of the light receiving element and the first electrodes of each of the light emitting elements of the multiple pixel circuits.

In the above aspect, it is preferable that the light receiving element has a second light emitting layer, and the second light emitting layer is located between the third electrode and the fourth electrode.

In the above embodiment, it is preferable that the light-emitting element has a function of emitting light of one color selected from the three colors of red, green, and blue, and the light-receiving element has a function of emitting light of another color selected from the three colors and a function of receiving visible light.

In the above embodiment, it is preferable that the light-emitting element has a function of emitting light of one color selected from the three colors of red, green, and blue, and the light-receiving element has a function of emitting light of another color selected from the three colors and a function of receiving infrared light.

Furthermore, in the above aspect, it is preferable that the potential of the first electrode when emitting light of the second brightness is lower than the potential of the first electrode when emitting light of the first brightness.

Furthermore, in the above aspect, it is preferable that the potential of the first terminal when emitting light of the second luminance is higher than the potential of the first terminal when emitting light of the first luminance.

Or one aspect of the present invention is a program to be executed by an electronic device, the electronic device having a display unit having a plurality of light receiving elements and a memory unit, and including a first step of displaying an image including an authentication code as a first subject on the display unit at a first brightness using the light source as a light source, and detecting reflected light from the first subject of the light source by the plurality of light receiving elements in a first detection period, a second step of acquiring an image of the authentication code using the reflected light detected in the first step, a third step of displaying a first processing content based on the authentication code on the display unit, a fourth step of placing a first finger in contact with or in close proximity to the display unit, and a fourth step of displaying a second image including the first finger as a second subject on the display unit at a second brightness using the light source as a light source, and detecting reflected light from the first subject of the light source as a light source in a first detection period. The program has a fifth step in which a plurality of light receiving elements detect reflected light from the first finger during a second detection period; a sixth step in which an image of the first finger is acquired using the reflected light detected in the fifth step; a seventh step in which fingerprint information of the first finger is acquired from the image of the first finger and compared with the fingerprint information of the second finger stored in the storage unit; and an eighth step in which the fingerprint information of the first finger and the fingerprint information of the second finger are confirmed to match by the comparison and a first processing content is performed. The program verifies the image quality of the image acquired in the sixth step, and if it is determined that the image needs to be acquired again, the fifth and sixth steps are performed again, and in the second fifth step, the second luminance is higher and the second detection period is shorter than in the first step.

Furthermore, in the above aspect, it is preferable that the product of the first luminance and the length of the first detection period is 0.8 to 1.2 times the product of the second luminance and the length of the second detection period.

According to one aspect of the present invention, a display unit having a light detection function can be provided. Or, a high-definition display unit having a light detection function can be provided. Or, a display device having a light detection function can be provided. Or, a high-definition display device having a light detection function can be provided. Or, an electronic device having a display function can be provided. Or, an electronic device having a light detection function can be provided. Or, an electronic device having an authentication function such as fingerprint authentication can be provided. Or, an electronic device with high security can be provided. Or, an electronic device with high operability can be provided. Or, a multi-function electronic device can be provided. Or, a new electronic device can be provided. Or, an electronic device having a high security authentication method can be provided. Or, an electronic device having a new operation method can be provided. Or, an electronic device having a new authentication method can be provided.

Alternatively, according to one aspect of the present invention, it is possible to provide a program to be executed by a highly secure electronic device. Or, it is possible to provide a program to be executed by a new electronic device. Or, it is possible to provide a new program.

Note that the description of these effects does not preclude the existence of other effects. Note that one embodiment of the present invention does not necessarily have to have all of these effects. Note that effects other than these can be extracted from the description in the specification, drawings, claims, etc.

Fig. 1A is a diagram showing a configuration example of an electronic device, Fig. 1B is a diagram showing a configuration example of an electronic device, and Figs. 1C and 1D are diagrams showing examples of pixel circuits.
FIG. 2 is a diagram illustrating an example of the operation of the electronic device.
3A and 3B are diagrams illustrating an example of the operation of the electronic device.
FIG. 4 is a flow chart illustrating an example of a method of operating an electronic device.
5A and 5B are diagrams illustrating an example of the operation of the electronic device.
6A and 6B are diagrams showing a configuration example of a display unit, and FIGS. 6C to 6F are diagrams showing a configuration example of a pixel.
7A and 7B are timing charts showing an example of the operation of the electronic device, and FIG. 7C is a diagram showing an example of a pixel circuit.
FIG. 8 is a flowchart illustrating an example of a method of operating an electronic device.
9A to 9C are diagrams illustrating an example of the operation of the electronic device.
10A and 10B are diagrams illustrating an example of the operation of the electronic device.
FIG. 11 is a diagram showing an example of the operation of the electronic device.
12A to 12D are diagrams showing configuration examples of electronic devices.
13A to 13D are diagrams showing configuration examples of electronic devices.
14A to 14C are diagrams showing an example of an electronic device.
15A and 15B are diagrams illustrating an example of the configuration of an electronic device.
16A and 16B are diagrams illustrating an example of the configuration of an electronic device.
17A and 17B are diagrams illustrating an example of the configuration of an electronic device.
18A to 18D are diagrams showing configuration examples of electronic devices.
Fig. 19A is a diagram showing an example of a subject, Fig. 19B is a diagram showing a configuration example of an electronic device, and Fig. 19C is a diagram showing the electronic device and a subject.
Fig. 20A is a diagram showing an electronic device and a subject, Fig. 20B and Fig. 20C are diagrams showing examples of the configuration of the electronic device.
21A to 21I are diagrams showing examples of pixels.
22A and 22B are circuit diagrams showing an example of a pixel circuit, and Fig. 22C is a timing chart showing an example of the operation of the pixel circuit.
Fig. 23A is a diagram showing a configuration example of a display device, and Fig. 23B is a circuit diagram showing an example of a pixel circuit.
24A to 24C are circuit diagrams showing examples of pixel circuits.
25A and 25B are circuit diagrams showing examples of pixel circuits.
26A, 26B, and 26D are cross-sectional views showing an example of a display device, 26C and 26E are diagrams showing example images, and 26F to 26H are top views showing example pixels.
Fig. 27A is a cross-sectional view showing a configuration example of a display device, Fig. 27B to Fig. 27D are top views showing examples of pixels, and Fig. 27E is a diagram showing an example of an image.
28A is a cross-sectional view showing a configuration example of a display device, and FIGS. 28B to 28I are top views showing an example of a pixel.
29A to 29F are diagrams showing configuration examples of light-emitting elements.
30A and 30B are diagrams showing configuration examples of a light emitting element and a light receiving element.
31A and 31B are diagrams showing a configuration example of a display device.
32A to 32D are diagrams showing configuration examples of the display device.
33A to 33C are diagrams showing configuration examples of a display device.
34A to 34D are diagrams showing configuration examples of the display device.
35A to 35F are diagrams showing configuration examples of the display device.
36A to 36F are diagrams showing configuration examples of a display device.
FIG. 37 is a diagram showing an example of the configuration of a display device.
Fig. 38A is a cross-sectional view showing an example of a display device, and Fig. 38B is a cross-sectional view showing an example of a transistor.
39A to 39F are diagrams showing configuration examples of electronic devices.

The following describes the embodiments with reference to the drawings. However, it will be readily understood by those skilled in the art that the embodiments can be implemented in many different ways, and that the form and details can be modified in various ways without departing from the spirit and scope of the invention. Therefore, the present invention should not be interpreted as being limited to the description of the embodiments below.

In the configuration of the invention described below, the same parts or parts having similar functions are denoted by the same reference numerals in different drawings, and repeated explanations will be omitted. Also, when referring to similar functions, the same hatching pattern may be used and no particular reference numeral may be used.

Note that in each figure described in this specification, the size of each component, the thickness of a layer, or the area may be exaggerated for clarity. Therefore, the figures are not necessarily limited to the scale.

Note that ordinal numbers such as "first" and "second" are used in this specification to avoid confusion between components and do not limit the number.

In the following, expressions indicating directions such as "up" and "down" are basically used in accordance with the directions in the drawings. However, for the purpose of facilitating explanation, the directions that "up" and "down" refer to in the specification may not match those in the drawings. As an example, when explaining the stacking order (or formation order) of a laminate, etc., even if the surface on which the laminate is provided (the surface to be formed, the supporting surface, the adhesive surface, the flat surface, etc.) is located above the laminate in the drawings, it may be expressed as "the surface to be formed is below" and "the laminate is above."

In this specification, the display unit has the function of displaying (outputting) images, etc. on a display surface. Therefore, the display unit is one aspect of an output device.

Furthermore, in this specification, a display panel has a function of displaying (outputting) images, etc. on a display surface. Therefore, a display panel is one aspect of an output device.

In this specification, a display panel having a connector such as an FPC (Flexible Printed Circuit) or TCP (Tape Carrier Package) attached to the substrate, or an IC mounted on the substrate using a method such as COG (Chip On Glass), may be referred to as a display panel module, display module, or simply a display panel.

Note that in this specification, a touch panel has a function of displaying an image or the like on a display surface, and a function as a touch sensor that detects when a detectable object such as a finger or stylus touches, presses, or approaches the display surface. Therefore, a touch panel is one aspect of an input/output device.

A touch panel can also be called, for example, a display panel (or display device) with a touch sensor or a display panel (or display device) with a touch sensor function. A touch panel can also have a configuration that includes a display panel and a touch sensor panel. Alternatively, the touch panel can have a function as a touch sensor inside or on the surface of the display panel.

In this specification, a touch panel substrate on which one or more components selected from a connector, an IC, etc. are mounted may be referred to as a touch panel module, a display module, or simply a touch panel.

(Embodiment 1)
In this embodiment, an electronic device according to one embodiment of the present invention will be described.

The electronic device of one embodiment of the present invention has a display unit. The display unit has a function of emitting light and a function of receiving light. In addition, it is preferable that the display unit has a function of detecting a touch operation.

The display unit can display an image. The display unit can also receive light using the displayed image as a light source. For example, the displayed image can be used as a light source to receive light reflected from a subject (object), and information such as the light intensity and wavelength can be obtained.

The display unit has a plurality of light-emitting elements and a plurality of light-receiving elements. It is preferable that the plurality of light-emitting elements are arranged in a matrix. It is also preferable that the plurality of light-receiving elements are arranged in a matrix.

A subject can be imaged using a number of light receiving elements arranged in a matrix. Light emitting elements can be arranged around each of the light receiving elements arranged in a matrix. The light receiving elements can receive reflected light emitted from the light emitting elements arranged around them.

The display unit may also be configured to include a plurality of pixels arranged in a matrix. Each of the plurality of pixels may, for example, include one or more light-emitting elements and light-receiving elements. Each of the plurality of pixels may, for example, include one or more light-emitting elements and one or more light-receiving elements. Alternatively, each of the plurality of pixels may be configured to include only one of a light-emitting element and a light-receiving element. When a pixel includes a plurality of light-emitting elements, the pixel may, for example, include a plurality of light-emitting elements that emit light in different wavelength ranges. When a pixel includes a plurality of light-receiving elements, the pixel may, for example, include a plurality of light-receiving elements that correspond to different wavelength ranges.

The electronic device may have a sensor unit.

Part of the light emitted by the light-emitting element in the display unit is reflected by the subject, and the reflected light is incident on the light-receiving element. The light-receiving element can output an electrical signal depending on the intensity of the incident light. Therefore, by having light-receiving elements arranged in a matrix, the display unit can obtain (also referred to as capturing) positional information and shape of a subject touching or approaching the display unit as data. In other words, the display unit has the function of displaying images, and can also function as an image sensor panel or an optical sensor. Therefore, the display unit is sometimes described as functioning as part of the sensor unit of the electronic device.

The sensor unit can have a touch sensor, an illuminance sensor, or the like. The display unit of one embodiment of the present invention can function as an optical sensor, and can detect contact with or proximity to the surface of the display unit using the optical sensor. Thus, it can be said that the display unit functions as a touch sensor.

The sensor unit can also be configured to have a touch sensor that is not included in the display unit.

An electronic device according to one embodiment of the present invention has a function of capturing an image of a subject touching or approaching the display using multiple light-receiving elements arranged on the display.

An electronic device according to one aspect of the present invention has a function for acquiring authentication information from a captured image.

Biometric information can be acquired as authentication information. For example, authentication information can be acquired when the subject of an image is a finger, a palm, or the like. When the subject is a finger, a fingerprint image can be used as authentication information. When the subject is a palm, a palm print image can be used as authentication information.

For example, an image including an authentication code can be used as a subject to acquire authentication information based on the authentication code. Examples of authentication codes include barcodes and two-dimensional codes. Furthermore, the authentication information is not limited to these codes. The authentication information can include character information. An image of the character information can be captured, and character recognition can be performed in the control circuit of the electronic device to extract character data, and authentication can be performed using the extracted character data.

Note that authentication information such as an authentication code may have an area that can be decrypted using a code. Code information can be stored in the memory unit of an electronic device according to one embodiment of the present invention, and the authentication information can be read by combining the code with the authentication code when reading the authentication code.

For example, by including information linked to a user in an area that can be decrypted using a code, it becomes possible to protect and manage personal information. Furthermore, to improve convenience, authentication information such as an authentication code may also include an area that can be decrypted without using a code. This allows information that is desired to be widely disclosed, for example information that is widely shared among multiple users and does not contain confidential information such as personal information, to be decrypted without using a code.

<Configuration Example 1 of Electronic Device>
1A shows a block diagram of an electronic device 420 of one embodiment of the present invention. The electronic device 420 includes a control circuit unit 401, a display unit 422, a sensor unit 403, and a memory unit 404. The control circuit unit 401 includes an authentication unit 407. The display unit 422 includes a light-emitting element 405 and a light-receiving element 406. The electronic device 420 can be used in, for example, a portable information terminal.

In the drawings attached to this specification, the components are classified by function and shown in block diagrams as independent blocks. However, in reality, it is difficult to completely separate components by function, and one component may be involved in multiple functions. Also, one function may be realized by multiple components.

The control circuit section 401 has a function of controlling the entire system of the electronic device 420. The control circuit section 401 also has a function of controlling each component of the electronic device 420 in an integrated manner. The control circuit section 401 can be configured to include a scanning line driver circuit and a signal line driver circuit.

The control circuit unit 401 functions as, for example, a central processing unit (CPU). The control circuit unit 401 performs various data processing or program control by interpreting and executing commands from various programs using a processor. Programs that can be executed by the processor may be stored in a memory area of the processor, or may be stored in the storage unit 404.

The control circuit unit 401 has functions such as generating image data to be output to the display unit 422, processing authentication information input from the light receiving element 406 of the display unit 422, and controlling the lock state of the electronic device 420.

The authentication unit 407 has the function of performing authentication processing using authentication information.

The display unit 422 has a function of displaying an image using the light-emitting element 405 based on image data input from the control circuit unit 401. The display unit 422 can capture an image of a subject touching the display unit 422 or a subject close to the display unit 422. For example, part of the light emitted by the light-emitting element 405 is reflected by the subject, and the reflected light is incident on the light-receiving element 406. The light-receiving element can output an electrical signal according to the intensity of the incident light, and the display unit 422 has multiple light-receiving elements 406 arranged in a matrix, so that position information and shape of the subject can be obtained as data (imaged). The display unit 422 can be said to have a function as an image sensor panel or an optical sensor.

The display unit 422, which has the function of an optical sensor, can obtain information on the color of the light in addition to information on the intensity of the light. Thus, the display unit 422 can obtain information on the color of the subject. By using the color information, the accuracy of authentication can be improved and security can be enhanced. When obtaining information on the color of the light, for example, a color filter can be provided on the light receiving element, and the colors corresponding to the color filter can be obtained. Alternatively, in an image used as a light source, light of different wavelengths can be turned on in sequence, and the imaging data corresponding to each lighting period can be analyzed to obtain information on the color of the light.

The sensor unit 403 has an illuminance sensor. The illuminance sensor can acquire the intensity of external light illuminating the environment in which the electronic device 420 is used, more specifically, the illuminance of external light illuminating the display unit 422, for example. Furthermore, the illuminance sensor can acquire information such as the color and wavelength of the external light in addition to the illuminance of the external light.

The sensor unit 403 can also have an ultrasonic sensor, an optical sensor, a capacitance sensor, or the like. These sensors can be used as touch sensors, for example. These sensors can also be used to obtain information about the subject. For example, if the subject is a finger, information about the finger can also be obtained.

An ultrasonic sensor emits ultrasonic waves and detects the waves reflected by the subject, thereby obtaining three-dimensional information about the unevenness of the subject. Because ultrasonic waves pass through the skin, when the subject is a human finger, it can detect blood flow inside the skin in addition to the unevenness (fingerprint) of the finger. After obtaining a first captured image of the finger's fingerprint as first authentication information using the light receiving element of the display unit 422, an ultrasonic sensor may be used to obtain a second captured image of the finger's fingerprint as second authentication information. Security can be increased by obtaining authentication information using multiple different methods.

The control circuit unit 401 has the function of performing approved processing when the authentication performed by the authentication unit 407 is approved.

The authentication unit 407 has a function of locking the system of the electronic device 420. It also has a function of transitioning from a locked state of the system of the electronic device to a state in which the system is unlocked and the electronic device 420 can be used. Fingerprint authentication can be used for this authentication.

When fingerprint authentication is performed in the control circuit unit 401, the control circuit unit 401 may have a function of generating image data including an image showing the position where the user is to touch with their finger (also called an image informing the touch position) and outputting the image data to the display unit 422.

When the subject to be imaged is a finger, the display unit 422 has a function of acquiring user authentication information using the light receiving element 406 and outputting the authentication information to the control circuit unit 401. For example, an image of the fingerprint of the user who touches the display unit 422 (also referred to as an imaged image or imaged data) can be used as the authentication information. The display unit 422 can acquire the authentication information by capturing an image of the fingerprint of the user who has touched the display unit 422 using the light receiving element 406.

Since the display unit 422, which has the function of an optical sensor, can obtain color information of the subject, color information may be included in the authentication information. For example, if the subject is a finger, skin color information can be obtained as authentication information in addition to fingerprint information.

The memory unit 404 has a function of storing user information of pre-registered users. For example, the user's fingerprint information can be used as the user information. The memory unit 404 can output the user information to the authentication unit 407 in response to a request from the control circuit unit 401.

The storage unit 404 can hold fingerprint information of the fingers used by the user for authentication, and can freely register information for one or more fingers. For example, it can hold fingerprint information for two fingers, the index finger of the user's right hand and the index finger of the left hand. The user can freely register fingerprint information for one or more of the index finger, middle finger, ring finger, little finger, and thumb, and the storage unit 404 can hold information for all registered fingerprints.

The authentication unit 407 has a function of executing a process (authentication process) of comparing the authentication information input from the display unit 422 with the information stored in the memory unit 404 and determining whether they match.

The authentication process can use, for example, a template matching method that compares two images and uses the similarity between them, or a pattern matching method. The authentication process can also use a minutia method that compares feature points (minutia) such as the endpoints and branching points of the image patterns. The authentication process can also use inference using machine learning. In particular, it is preferable to perform inference using a neural network.

FIG. 1B is a perspective view showing an example of an electronic device 420. The electronic device 420 shown in FIG. 1B has a housing 421 and a display unit 422. The electronic device 420 has a control circuit unit 401, a sensor unit 403, and a memory unit 404 within the housing 421.

The sensor unit 403 has an illuminance sensor 432. The illuminance sensor 432 is located, for example, on the surface of the housing 421 on which the display unit 422 is provided, or in the vicinity of the surface. The illuminance sensor 432 can detect the illuminance corresponding to the external light received by the display unit 422.

The electronic device 420 has a camera 431. The electronic device 420 has a function of capturing still images or videos using the camera 431 and storing them in a storage unit, a function of displaying the captured images on a display unit, etc.

The camera 431 is located, for example, on the surface of the housing 421 on which the display unit 422 is provided, or in the vicinity of the surface. The camera 431 may be called an in-camera. It is preferable that the camera 431 includes a wide-angle lens. The camera 431 can be suitably used when capturing an image of a subject that is farther away from the display unit 422 than the subject captured using the light receiving element of the display unit 422.

An image can be displayed on the display unit 422, and the image can be used as a flashlight to capture an image with the camera 431. FIG. 2 shows an example in which the user 433 displays an image on the display unit 422 of the electronic device 420, uses the image as a flashlight, and captures an image including the user 433 himself using the camera 431. FIG. 2 shows an example in which the region 483 in the display unit 422 is turned on and used as a flashlight. FIG. 2 shows an example in which the region 483 is the entire surface of the display unit 422, but the region 483 may be a partial region of the display unit 422. In the region 483, all pixels may be turned on, or a regular pattern such as a houndstooth check pattern or a striped pattern may be displayed. In addition, for example, a white display may be used for display as a flashlight. In addition, when displaying as a flashlight, the color temperature of the color to be displayed may be set. For example, it may be possible to select from two or more predetermined color temperatures. By setting the color temperature to a reddish color temperature, for example, a person's skin color may look more natural, which may be preferable.

In an electronic device and a display portion according to one embodiment of the present invention, the luminance of a light-emitting element may refer to, for example, the average luminance in an area including multiple pixels.

[Pixel circuit]
A pixel has one or more pixel circuits. One pixel circuit includes one light-emitting element. Alternatively, one pixel circuit includes one light-receiving element. Alternatively, one pixel circuit may include one light-emitting element and one light-receiving element. Furthermore, the pixel circuit may include two or more light-emitting elements. Furthermore, the pixel circuit shown in FIG. 1C may be widely used for display elements. For example, it may be used for liquid crystal elements. Furthermore, it is not limited to display elements, and may be used for memory elements that hold a state according to data.

It is preferable that the pixel circuit has one or more transistors.

Figure 1C shows pixel circuit PX1 as a pixel circuit including a light-emitting element, and pixel circuit PX2 as a pixel circuit including a light-receiving element.

In FIG. 1C, pixel circuit PX1 has a light-emitting element EM and a current control unit CU. The current control unit CU has a function of controlling the current of the light-emitting element EM. Pixel circuit PX1 also has a signal supply unit SE. The signal supply unit SE has a function of supplying to the current control unit CU a signal based on a scanning signal provided from a line GL and an image signal provided from a line SL. The line GL may be called a scanning line, and the line SL may be called a signal line.

One terminal of the light-emitting element EM is connected to the wiring CAT. The potential of the wiring CAT is sometimes called the cathode potential.

One terminal of the current control unit CU is connected to the wiring ANO. The potential of the wiring ANO is sometimes called the anode potential. The other terminal of the current control unit CU is connected to the other terminal of the light-emitting element EM.

The current control section has a current control transistor. The current control transistor can also be called a drive transistor. The current control transistor has the function of controlling the current of the light-emitting element EM. By controlling the current of the light-emitting element EM, for example, the brightness of the light-emitting element EM can be controlled.

Pixel circuit PX2 has a light receiving element IG. One terminal of the light receiving element IG is connected to wiring CAT.

Figure 1D shows an example of pixel PX1 in which transistor M2 is used as the current control unit and transistor M1 is used as the signal supply unit.

In FIG. 1D, one of the source and drain of the transistor M2 is connected to the light-emitting element, but one or more transistors may be connected between the light-emitting element and one of the source and drain of the transistor M2. In FIG. 1D, the other of the source and drain of the transistor M2 is connected to the wiring ANO, but one or more transistors may be connected between the transistor M2 and the wiring ANO.

An example of the operation method of pixel circuit PX1 will be described. Here, FIG. 1D is used as an example. First, in the first period, a potential that turns on transistor M1, such as a high-level potential, is applied to wiring GL, and an image signal is applied to wiring SL, thereby turning on transistor M1 and applying an image signal to the gate of transistor M2. At this time, if a reset signal is applied to the other terminal of the light-emitting element EM, the light-emitting element EM can be put into a non-emitting state.

In the subsequent second period, a signal that turns off the transistor M1, for example a low-level potential, is applied to the wiring GL. The gate potential of the transistor M2 is maintained, and a current corresponding to the gate potential of the transistor M2 flows through the light-emitting element EM. In the second period, writing is performed on the next row and onwards.

It is also possible for one pixel circuit to have both a light-emitting element and a light-receiving element. In that case, the pixel circuit has a circuit area corresponding to the light-emitting element and a circuit area that controls the light-receiving element.

Also, adjacent pixel circuits may share some parts. For example, wiring, electrodes, etc. may be shared.

In the display portion of one embodiment of the present invention, the transistors in the pixel circuit PX1 and the transistors in the pixel circuit PX2 can be provided in the same layer, and the light-emitting element EM and the light-receiving element IG can be provided on the layer in which the transistors are provided. With this configuration, the heights of the regions in which the light-emitting element EM and the light-receiving element IG are arranged can be roughly the same. By shortening the distance between the light-emitting element and the light-receiving element, the detection performance of the light-receiving element can be improved.

When a configuration is used in which the light-emitting element has two pairs of electrodes (e.g., a lower electrode and an upper electrode) and a light-emitting layer located between them, and the light-receiving element has two pairs of electrodes (e.g., a lower electrode and an upper electrode) and an active layer located between them, one electrode of the light-emitting element (e.g., the upper electrode) and one electrode of the light-receiving element (e.g., the upper electrode) can be a common electrode. The common electrode can be provided across multiple light-emitting elements and multiple light-receiving elements.

A pixel can be configured to include multiple sub-pixels. Each sub-pixel can have a pixel circuit. In this specification, the term "sub-pixel" may refer to a pixel circuit.

The electronic device of one embodiment of the present invention has a circuit for driving pixels. Examples of such circuits include a scan line driver circuit and a signal line driver circuit.

The display device can be applied to an electronic device according to one embodiment of the present invention. For example, the display device can include a display portion, a scanning line driver circuit, and a signal line driver circuit. The scanning line driver circuit and the signal line driver circuit do not have to be included in the display device. For example, the display device may not include part or all of the signal line driver circuit.

The display device may also include, for example, a touch sensor panel as the touch sensor. Note that the touch sensor does not necessarily have to be included in the display device.

<Example 1 of operation method>
The following describes an example of a method of operating electronic device 420. Here, the operation of capturing an image of a subject will be described.

Figures 3A and 3B are schematic diagrams illustrating the operation of the light receiving element detecting light that is emitted from the display unit 422 and reflected from the subject when the brightness of the external light is different. Figures 3A and 3B show an example in which the subject 460 is a user's finger. Figure 3A shows operation outdoors on a sunny day as an example when the illuminance of the external light is high, and Figure 3B shows operation under indoor lighting as an example when the illuminance of the external light is lower than that of Figure 3A.

In FIG. 3A, the illuminance of external light is higher than in FIG. 3B, so it is preferable to further increase the detection sensitivity of the light receiving element. For example, the detection sensitivity can be further increased by increasing the brightness of the light emitted from the light emitting element.

A flowchart of the operation of electronic device 420 is shown in Figure 4.

In step S500, processing of this flow begins.

Next, in step S501, the subject is detected. For example, the electronic device detects that the subject has touched the surface of the display unit, or that the subject has been placed close to the surface of the display unit. It is also possible that the subject does not need to be detected. In that case, for example, in step S501, the electronic device displays instructions on the display unit to place the subject, and the user places the subject according to the instructions.

The instruction may, for example, display a position image to inform the user of the subject's placement position.

Next, in step S502, the number of processing times x (x is an integer equal to or greater than 1) is set to 1, and in step S503, the luminance L of the area used as the light source for imaging and the time t, which is the length of the detection period of the light receiving element 406, are set in the first image to be displayed on the display unit. The length of the detection period of the light receiving element 406 may be expressed as the exposure time. The luminance L set here is set to L(1), and the time t is set to t(1).

Next, in step S503, the area in the first image used as a light source for imaging is displayed on the display unit with luminance L. The light emitted from the light-emitting element 405 can be used as a light source when imaging with the light-receiving element 406. Therefore, the light emitted by the light-emitting element 405 that is lit in the area used as a light source for imaging when displaying the first image can be light of a color that can be received by the light-receiving element 406. For example, if the display unit 422 has light-emitting elements 405 of three colors, red (R), green (G), and blue (B), any one, any two, or all three of these light-emitting elements 405 can be lit.

In step S503, all of the light-emitting elements 405 of the display unit 422 may be turned on, or some of the light-emitting elements 405 of the display unit 422 may be turned on. In Figures 3A and 3B, an area in the display unit 422 used as a light source for imaging is shown as area 425. Figures 3A and 3B show an example in which all of the light-emitting elements 405 of the display unit 422 are turned on as area 425. Area 425 can be used as a light source for imaging. In Figures 3A and 3B, the first image can be said to be an image that displays white or a predetermined color over the entire surface of the display unit 422. Area 425 is an area in which subject detection is performed in the following step S504, and the user can obtain a captured image by holding the subject over area 425 or by having the subject touch area 425.

Luminance L can be the luminance in region 425.

When some of the light-emitting elements 405 of the display unit 422 are turned on, that is, when part of the display unit 422 is the area 425, the user can obtain a captured image by holding a subject over the area 425 or by having the subject touch the area 425. The light-emitting elements 405 outside the area 425 may be turned off. Since the light-emitting elements 405 that are turned on in the area 425 are covered by the subject, it is possible to prevent the user from viewing bright light. For example, in a dark usage environment, if the user directly views the display light of the first image, the user will feel dazzled and there is also a risk of the light damaging the eyes. Therefore, by making the area 425 only a part of the display unit, the burden on the user can be reduced. Note that any image may be displayed in an area other than the area 425.

Figure 5A shows an example in which the light-emitting elements 405 in region 425 of the display unit 422 are turned on and the other regions are turned off. In Figure 5A, the first image can be said to be an image in which white or a specified color is displayed over the entire area of region 425 of the display unit 422, and black is displayed in the other regions. Note that, instead of black, a color darker than region 425 may be displayed in the regions other than region 425. It is preferable that the regions other than region 425 have a lower brightness than region 425.

When a pixel has light-emitting elements corresponding to the three colors red (R), green (G), and blue (B), for example, all of the R, G, and B pixels in region 425 can be lit. Alternatively, none of the R, G, or B pixels can be lit. For example, a single color, R, G, or B, can be lit.

Also, not all pixels in region 425 need to be lit. For example, as shown in FIG. 6A, an image in which lit pixels 30 (hereinafter referred to as pixels 30[w]) and unlit pixels 30 (hereinafter referred to as pixels 30[b]) are arranged in a staggered pattern may be displayed in region 425. Alternatively, as shown in FIG. 6B, an image in which pixels 30[w] and pixels 30[b] are arranged in a striped pattern may be displayed in region 425. Alternatively, pixels 30[w] and pixels 30[b] may be arranged randomly. Pixels 30[w] and pixels 30[b] may be arranged so that the light irradiated to the subject is uniform within a range that does not impair the image quality of the captured image.

Figures 6C to 6F show the illuminated states of the sub-pixels of pixel 30. Pixel 30 has sub-pixel R including a light-emitting element corresponding to red, sub-pixel G including a light-emitting element corresponding to green, sub-pixel B including a light-emitting element corresponding to blue, and sub-pixel PS including a light-receiving element.

Figures 6C and 6D show examples of the lighting state of the sub-pixels of pixel 30 (pixel 30[b]) that are turned off in region 425. Figure 6C shows an example in which the light-emitting elements corresponding to all colors are turned off and the light-receiving elements are not driven. Figure 6D shows an example in which the light-emitting elements corresponding to all colors are turned off and the light-receiving elements are driven.

Figures 6E and 6F show examples of the lighting state of the sub-pixels of pixel 30 (pixel 30[w]) that is turned on in region 425. Figure 6E shows an example in which light-emitting elements corresponding to all colors are turned on and the light-receiving element is also driven. Figure 6F shows an example in which only the light-emitting element corresponding to green is turned on among all light-emitting elements and the light-receiving element is also driven.

5B shows an example of using an image as the first image in which white or a predetermined color is displayed over the entire area 425, and information such as text 481 and image 482 is displayed in the other areas. Text 481 can be, for example, a message encouraging the user to place a finger on display unit 422.

Next, in step S504, the first image is used as a light source to capture an image of the subject. In the image capture, the length of the detection period of the light receiving element 406 is time t. In step S504, the electronic device obtains a captured image of the subject using the signal detected by the light receiving element 406.

Next, in step S505, it is determined whether or not the captured image acquired in step S504 can be adopted. Specifically, for example, it is determined whether or not the captured image has sufficient image quality for acquiring information about the subject, and if the image quality is sufficient, the image is adopted, and if the image quality is insufficient, the image is not adopted.

If the captured image is adopted, proceed to step S509; if not, proceed to step S506.

In step S506, 1 is added to the processing count x (x becomes x+1).

In step S507, it is determined whether the number of processing times x is smaller than n (n is an integer equal to or greater than 1). If the number of processing times reaches n, the process proceeds to step S511, where the process ends. In step S511, the control circuit unit of the electronic device receives information indicating that the process has ended as well as information indicating that the captured image has not been obtained. If the number of processing times has not reached n, the process proceeds to step S508.

In step S508, the values of the luminance L of the first image to be displayed on the display unit in step S503 and the time t, which is the length of the detection period of the light receiving element 406, are set again. The luminance L set here is L(x), and the time t is t(x).

In addition to the light emitted from the light emitting element 405 and reflected from the subject, external light also enters the light receiving element 406. The external light can become noise when forming a captured image of the subject. In particular, when the illuminance of the external light is bright as in the example shown in FIG. 3A, there is a concern that the noise components in the captured image will increase, leading to a deterioration in the image quality.

Therefore, when the illuminance of external light is high, it is preferable to relatively reduce the noise components by increasing the brightness of the light-emitting element 405.

In step 508, for example, if the illuminance of external light exceeds a predetermined value, the value of luminance L is set to a value higher than that of the previous process. Furthermore, when luminance L is set to a high value, the intensity of the reflected light incident on the light receiving element 406 can also be increased, and light can be sufficiently detected even in a shorter detection period. Therefore, luminance L is set to a high value and time t is set to a shorter value.

For example, if the luminance L is A times, it is preferable to set each so that the time t is approximately 1/A times. In other words, it is preferable to set each so that the product of the luminance L and the time t is approximately constant. Here, L(x) is A times L(1), and the time t(x) is 1/A times the time t(1).

The product of brightness L and time t can be set to be 0.8 to 1.2 times, or 0.85 to 1.15 times, or 0.9 to 1.1 times the product of brightness L and time t in the previous process.

After step S508, the process returns to step S503, and steps S503 to S505 are repeated. If the captured image is not adopted in step S505, the process proceeds to step S506, and if the captured image is adopted in step S505, the process proceeds to step S509.

In step S509, the selected captured image is acquired, and in step S510, the processing of this flow ends.

In an electronic device and a display portion according to one embodiment of the present invention, the luminance of a light-emitting element may refer to, for example, the average luminance in an area including multiple pixels.

[Luminance L setting]
The setting of the luminance L performed in step S507 will now be described.

The luminance of the light-emitting element EM of the pixel circuit PX1 shown in FIG. 1C is determined, for example, by the potential difference between the wiring ANO and the wiring CAT, and the intensity of the image signal provided from the signal supply unit SE to the current control unit CU. The image signal can be a different signal for each pixel. Furthermore, the light-emitting element can emit light with a gradation that corresponds to the value of the image signal.

On the other hand, each of the wirings ANO and CAT is a wiring shared by multiple pixel circuits, and a common potential is applied to each pixel circuit. Therefore, by changing the potential of the wiring ANO or wiring CAT, the overall brightness of the shared pixel circuits changes.

In applications where the luminance is changed significantly, for example, the potential of the wiring CAT or wiring ANO is changed. As an example, when the luminance of the display unit when the user visually recognizes image information, character information, etc. displayed on the display unit is significantly different from the luminance when the subject is imaged, the potential of the wiring CAT or wiring ANO is changed. For example, as shown in FIG. 3A, when an image of a subject is captured using a light receiving element of the display unit outdoors on a sunny day, in step S508, it is preferable to increase the luminance by increasing the potential difference between the wiring ANO and the wiring CAT by changing the potential of the wiring CAT or wiring ANO from the previous process. For example, when the illuminance of light received from outside light is equal to or greater than the illuminance Q, it is preferable to change the potential of the wiring CAT or wiring ANO, and the illuminance Q is, for example, 1000 lux or more and 50000 lux or less. The illuminance Q is, for example, 1000 lux (lx) or more and 20000 lux or less, more preferably 1000 lux or more and 10000 lux or less, and even more preferably 1000 lux or more and 5000 lux or less, and can be, for example, about 2000 lux. The unit of illuminance, lux, can also be expressed by the unit symbol lx. It can also be expressed as lm/ ^m2 .

On the other hand, as shown in FIG. 3B, under indoor lighting, the potentials of the wiring CAT and wiring ANO do not need to be changed in step S508, and the same conditions can be used, for example. Alternatively, the potential difference between the wiring ANO and wiring CAT can be made smaller compared to outdoors on a clear day. In other words, the range of voltage fluctuations of the wiring ANO and wiring CAT can be made smaller.

Similarly, in an environment in which a flashlight is used when capturing an image as shown in FIG. 2, the illuminance of external light may be lower than, for example, a sunny day outdoors as shown in FIG. 3A. Even in such a case, the potential of wiring CAT and wiring ANO does not need to be changed when displaying an image used as a flashlight. Alternatively, the potential difference between wiring ANO and wiring CAT can be made smaller than when it is outdoors on a sunny day. In other words, the range of voltage fluctuation of wiring ANO and wiring CAT can be made smaller.

The luminance of area 425 of display unit 422 when a fingerprint is captured in a first environment (hereinafter, imaging condition Im1), such as outdoors on a sunny day, is higher than the luminance of area 425 of display unit 422 when a fingerprint is captured in a second environment (hereinafter, imaging condition Im2), such as under indoor lighting. Also, the luminance of area 483 in a third environment (hereinafter, imaging condition Im3) in which a flashlight is used is lower than the luminance in imaging condition Im1, for example.

The brightness of region 425 under imaging condition Im1 is, for example, 1.5 times or more, 1.7 times or more, or 2 times or more than the brightness of region 425 under imaging condition Im2.

The brightness of region 425 under imaging condition Im1 is, for example, 1.5 times or more, 1.7 times or more, or 2 times or more than the brightness of region 483 under imaging condition Im3.

The potential difference between the wiring ANO and the wiring CAT under imaging condition Im1 is, for example, 1.05 times or more, 1.1 times or more, or 1.2 times or more than the potential difference between the wiring ANO and the wiring CAT under imaging condition Im2 or imaging condition Im3. In addition, the potential difference between the wiring ANO and the wiring CAT under imaging condition Im2 may be smaller than the potential difference between the wiring ANO and the wiring CAT under imaging condition Im3.

The potential of the wiring CAT under imaging condition Im1 is, for example, lower than the potential of the wiring CAT under imaging condition Im2 and imaging condition Im3. Also, the difference between the potential of the wiring CAT under imaging condition Im1 and the potential of the wiring CAT under imaging condition Im2 or imaging condition Im3 is, for example, 0.5 to 5 times the potential difference between the gate and source of the current control transistor (drive transistor) of the current control unit CU when the pixel is emitting light under imaging condition Im2 or imaging condition Im3. Also, the potential of the wiring CAT under imaging condition Im2 may be greater than the potential difference of the wiring CAT under imaging condition Im3.

Alternatively, the potential of the wiring ANO under imaging condition Im1 is, for example, lower than the potential of the wiring ANO under imaging condition Im2 and imaging condition Im3. Also, the difference between the potential of the wiring ANO under imaging condition Im1 and the potential of the wiring ANO under imaging condition Im2 or imaging condition Im3 is, for example, 0.5 to 5 times the potential difference between the gate and source of the current control transistor (drive transistor) of the current control unit CU when the pixel is emitting light under imaging condition Im2 or imaging condition Im3. Also, the potential of the wiring ANO under imaging condition Im2 may be smaller than the potential difference of the wiring ANO under imaging condition Im3.

FIG. 7A shows an example in which the potential of the wiring CAT is lowered and the potential difference between the wiring ANO and the wiring CAT is increased when performing the processing of steps S502 and S503 for the xth time in the flow shown in FIG. 4, compared to the processing of steps S502 and S503 for the (x-1)th time. Note that in order to increase the luminance in step S503 for the xth time, the time t, which is the length of the detection period of the light receiving element 406, is shortened compared to step S503 for the (x-1)th time, but information corresponding to the detection period of each light receiving element 406 is omitted in FIG. 7A.

In addition, FIG. 7B shows an example in which the potential of the wiring ANO is increased and the potential difference between the wiring ANO and the wiring CAT is increased when performing the x-th processing of steps S502 and S503 compared to when performing the (x-1)th processing of steps S502 and S503 in the flow shown in FIG. 4.

Here, if the current control transistor in the current control unit CU is a p-channel type, for example, a potential supplied from the wiring ANO is applied to the source of the transistor, and a potential corresponding to the image signal provided by the signal supply unit SE is applied to the gate of the transistor. Changing the potential of the source of the transistor is not preferable because it changes the potential between the gate and source, which may change the operation of the transistor, specifically, the stability of the saturation current flowing in the saturation region of the transistor. Therefore, if the current control transistor is a p-channel type, it is preferable to change the potential of the wiring CAT, as shown in FIG. 7A.

In addition, when the current control transistor of the current control unit CU is an n-channel type, for example, the terminal connected to the light-emitting element EM is connected to the source of the transistor, and a potential corresponding to the image signal provided by the signal supply unit SE is provided to the gate of the transistor. When the current control transistor is an n-channel type, it is preferable to change the potential of the wiring ANO, as shown in FIG. 7B.

Figure 7C shows multiple pixel circuits PX1 and multiple pixel circuits PX2 arranged in a matrix. In the multiple pixel circuits PX1, a common signal is applied to the wiring ANO. In addition, in the multiple pixel circuits PX1 and multiple pixel circuits PX2, a common signal is applied to the wiring CAT.

The wiring CAT is also connected to the pixel circuit PX2, which includes a light receiving element. Therefore, changing the voltage of the wiring CAT also affects the driving conditions of the pixel circuit PX2, which drives the light receiving element. In such a case, it is preferable to appropriately change the voltage of the signals supplied to each wiring in the pixel circuit PX2 in conjunction with changing the wiring CAT.

On the other hand, since the wiring ANO is not connected to the pixel circuit PX2, there is an advantage that when changing the wiring ANO to change the luminance of the light-emitting element, the driving conditions of the pixel circuit PX2 do not need to be taken into consideration.

<Example 2 of operation method>
In the following, an example of an operation for performing authentication in an electronic device according to one embodiment of the present invention will be described by applying the above-described example 1 of the operation method.

A flowchart of the operation of electronic device 420 is shown in Figure 8.

In step S100, processing of this flow begins.

Next, in step S101, an image of the authentication code is acquired. For example, a camera included in the electronic device can be used to acquire the image.

Next, in step S102, authentication code information is obtained from the captured image of the authentication code.

Next, in step S103, information on the process based on the authentication code is displayed on the display unit. The process is, for example, a process performed using the electronic device 420. An example of the process is approval using the authentication code.

Next, in step S104, it is determined whether the processing information displayed on the display unit in step S103 is approved. If it is not approved, the process proceeds to step S199, and the process of this flow ends. If it is approved, the process proceeds to step S105.

Steps S105 to S108 are for verifying user information to confirm the approval of step S104. Here, fingerprint information is used as the user information.

First, in step S105, an image of the first finger is acquired. By performing the flow shown in FIG. 4 with the first finger as the subject, an image of the first finger can be acquired in step S105.

Next, in step S106, the captured image acquired in step S105 is used to acquire fingerprint information of the first finger.

Next, in step S107, the first fingerprint information is compared. For example, the first fingerprint information may be compared with the second fingerprint information stored in the storage unit of the electronic device.

Next, in step S108, it is determined whether the comparison performed in step S107 results in a match. If it is determined that there is a match, the process proceeds to step S109, where the electronic device performs the process approved in step S104. If it is determined that there is no match, the process proceeds to step S199, where the process of this flow ends.

<Example 3 of operation method>
By carrying out the flow shown in FIG. 4 with an image including the authentication code as a subject, a captured image of the authentication code can be acquired in step S101 in FIG.

<Example 4 of operation method>
An example of a method of operation of one embodiment of the present invention will be described with reference to FIG. 9A.

In FIG. 9A, the first image displayed on display unit 422 is an image that can be used as a light source for imaging in the flow shown in FIG. 4 displayed in area 425, an image that can be used as a flashlight displayed in area 483, and a still image or video image captured using camera 431 displayed in area 484.

Area 425 and area 483 can each display white or a specified color. Note that area 425 and area 483 may display the same color or different colors.

In FIG. 9A, the flow shown in FIG. 4 can be performed by placing a finger, which is subject 460, in contact with or close to area 425 and acquiring an image. At this time, while the image is being acquired, area 483 can be used as a flashlight and an image of the user can be captured using camera 431. A still image or video of the user captured by camera 431 can be displayed in area 484.

Facial authentication may be performed by photographing the user's face and comparing it with user information stored in the memory unit of the electronic device 420. Security can be improved by combining authentication using fingerprint information from the subject 460, which is the finger, with facial authentication.

Note that, particularly in the case of still images, the captured image does not have to be displayed in area 484 while the image is being captured by camera 431. Therefore, for example, as shown in FIG. 9C, area 483 used as a flashlight is displayed while the image is being captured, and area 484 displaying the captured image by camera 431 is not displayed, and as shown in FIG. 9B, after the image is captured, area 483 is not displayed, and area 484 is displayed, thereby making it possible to increase the area of each of areas 483 and 484.

Note that, particularly when the illuminance of external light is low, a flashlight can be used to conveniently capture an image of the user. The luminance of region 483 used as a flashlight can be made higher than the luminance of region 425 when used to capture a fingerprint image, for example. For example, the potential of wiring CAT can be made lower. For example, the potential of wiring ANO can be made higher. Here, for region 425, the luminance of imaging condition Im2, driving conditions of the pixel circuit, and the like described above can be referenced, and for region 483, the luminance of imaging condition Im3, driving conditions of the pixel circuit, and the like described above can be referenced.

Alternatively, when the illuminance of external light is high, it may be possible to refer to the description of the luminance of the imaging condition Im1, the driving conditions of the pixel circuit, etc., described above, for area 425.

<Example 5 of Operation Method>
In the first image displayed on display unit 422 in Fig. 10A, an image that can be used as a light source for imaging in the flow shown in Fig. 4 is displayed in area 425 (area 425a and area 425b), and an image or video captured using camera 438 is displayed in area 484. Fig. 10B shows electronic device 420 with the surface of housing 421 opposite to the surface shown as the top surface in Fig. 10A as the top surface. Camera 438 is a camera arranged on the surface of housing 421 opposite to the surface on which display unit 422 is provided.

Area 484 displays a still image or video as a captured image of authentication code 485. Also, in FIG. 10A, two areas (area 425a and area 425b) are shown as area 425. A different finger can be placed on each area. FIG. 10A shows an example in which the user's index finger 460a is placed on area 425a, and the user's middle finger 460b is placed on area 425b.

In the above-mentioned example 3 of the operation method, an example was shown in which an image including an authentication code is acquired in step S101, and then an image of a finger is acquired in step S105, using the flow shown in FIG. 8. However, in the image of the display unit 422 shown in FIG. 10A, for example, both images can be acquired in step S101. Therefore, it may be possible to omit step S105, which is performed later, and the efficiency of the process can be improved.

<Example 6 of Operation Method>
Fig. 11 shows an example of combining the configuration shown in Fig. 9 with the configuration shown in Fig. 10. In Fig. 11, two areas (area 484a and area 484b) are shown as area 484. An image or video captured by camera 438 is displayed in area 484a. A still image or video is displayed as the image of authentication code 485 in area 484b.

This embodiment can be implemented in combination with at least a portion of the other embodiments described in this specification.

(Embodiment 2)
In this embodiment, an example of an electronic device of one embodiment of the present invention will be described.

<Configuration Example 2 of Electronic Device>
12A to 13D are schematic diagrams of the electronic device 420. Fig. 12A to Fig. 13D are cross-sectional views taken along dashed line A-B in Fig. 3A. In Fig. 12A to Fig. 13D, an area 425 and an area 427 are indicated by arrows.

The electronic device 420 has a housing 421, a layer 441, and a layer 443. The layer 441 has a display portion 422. The layer 443 has a sensor portion 403. The region 427 overlaps with the layer 443, and detection can be performed using a sensor included in the sensor portion 403. In the example shown in FIG. 3A, an illuminance sensor 432 is provided. Various sensors other than an illuminance sensor can also be provided in the region 427. A control circuit portion 401 and a memory portion 404 can be provided in a space 445 inside the housing 421. The control circuit portion 401 and the memory portion 404 may be provided in the layer 441 or the layer 443. Although not shown, electronic components such as a communication antenna and a storage battery can be provided in the space 445.

FIG. 12A shows an example in which area 425 is provided on the entire surface of display unit 422, and area 427 is provided on a portion of display unit 422. In other words, area 425 and area 427 have an overlapping area. In the configuration shown in FIG. 12A, the first authentication information can be obtained at any position on display unit 422.

FIG. 12B shows an example in which region 425 is provided in a part of the display unit 422, and region 427 is provided in a part of the display unit 422. By providing region 425 in a part of the display unit 422, only a part of the light-emitting element 405 is turned on, so that the power consumption of the electronic device 420 can be reduced. In FIG. 12B, a configuration in which region 425 and region 427 do not have an overlapping area is shown, but as shown in FIG. 12C, a configuration in which region 425 and region 427 have an overlapping area may also be used.

FIG. 12D shows an example in which area 425 and area 427 are located in the same position. By locating area 425 and area 427 in the same position, the user can obtain first authentication information and second authentication information while keeping a finger touching display unit 422, thereby improving the operability of electronic device 420.

FIGS. 12A to 12D show a configuration in which an area 427 is provided in the display unit 422, and the second authentication information is acquired within the display unit 422. The layer 443 having the sensor unit 403 is preferably fixed to the layer 441 having the display unit 422. For example, the layer 443 is fixed to the layer 441 by an adhesive layer (not shown). It is also preferable that there is no space between the layer 443 and the layer 441. By adopting a configuration in which there is no space (air) between the layer 443 and the layer 441, when a fingerprint sensor using ultrasonic waves is used for the sensor unit 403, attenuation of ultrasonic waves due to air can be suppressed, and the second authentication information can be acquired with high sensitivity.

Figure 13A shows an example in which area 425 is provided on the entire surface of display unit 422, and area 427 is provided outside display unit 422. As shown in Figure 13B, area 425 may be provided in a part of display unit 422. Figures 13A and 13B show a configuration in which area 425 and area 427 do not overlap, and the first authentication information and the second authentication information are obtained on the same surface (display surface) as display unit 422 of electronic device 420.

13A and 13B show a configuration example in which the layer 443 is exposed, but one embodiment of the present invention is not limited to this. The layer 443 may be provided inside the housing 421. In the case where the layer 443 is provided inside the housing 421, the layer 443 is preferably fixed to the housing 421. The layer 443 is fixed to the housing 421 by an adhesive layer (not shown). In addition, it is preferable that there is no space between the layer 443 and the housing 421. By using a configuration in which there is no space (air) between the layer 443 and the housing 421, when a fingerprint sensor using ultrasound is used for the sensor unit 403, attenuation of ultrasound due to air can be suppressed, and the second authentication information can be acquired with high sensitivity.

Figure 13C shows an example in which area 425 is provided on the entire surface of display unit 422, and area 427 is provided on the surface facing display unit 422 of electronic device 420 (surface facing the display surface). As shown in Figure 13D, area 425 may be provided in a part of display unit 422. Figures 13C and 13D show a configuration in which first authentication information is obtained on the same surface (display surface) as display unit 422 of electronic device 420, and second authentication information is obtained on the surface facing display unit 422 (surface facing the display surface).

When the configuration shown in FIG. 13C and FIG. 13D is used, a space (air) may be present between the layer 443 and the layer 441. Note that although the configuration example in which the layer 443 is exposed is shown in FIG. 13C and FIG. 13D, one embodiment of the present invention is not limited to this. The layer 443 may be provided inside the housing 421. When the layer 443 is provided inside the housing 421, the layer 443 is preferably fixed to the housing 421. The layer 443 is fixed to the housing 421 by an adhesive layer (not shown). In addition, it is preferable that there is no space between the layer 443 and the housing 421.

The above is an explanation of an example of the configuration of an electronic device.

Note that the authentication method, processing method, operation method, operation method, display method, etc. executed by the electronic device of one aspect of the present invention can be described, for example, as a program. For example, a program describing the authentication method, processing method, operation method, operation method, display method, etc. executed by the electronic device 420, etc. exemplified above can be stored in a non-transitory storage medium and read and executed by an arithmetic device, etc., possessed by the control circuit unit 401 of the electronic device 420. In other words, a program for executing the authentication method, operation method, etc. exemplified above by hardware, and a non-transitory storage medium in which the program is stored, are one aspect of the present invention.

The electronic device of one embodiment of the present invention may have one or more of a speaker, a microphone, and a camera. The electronic device may also have one or more of a speaker, a microphone, a camera, and a sensor (including a function to sense, detect, or measure force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared light).

Electronic components such as communication antennas and storage batteries can be installed in the space inside the electronic device's housing.

The display unit can have a touch sensor. The touch sensor can use various types, such as a capacitive type, a resistive film type, a surface acoustic wave type, an infrared type, an optical type, or a pressure-sensitive type.

The electronic device 6500 shown in Fig. 14A and Fig. 14B is a portable information terminal that can be used as a smartphone. In the perspective view of Fig. 14A, the display portion 6502 of the electronic device 6500 faces upward, and in the perspective view of Fig. 14B, the surface of the housing 6501 that is located behind the surface on which the display portion 6502 of the electronic device is provided faces upward.

The electronic device 6500 includes a housing 6501, a display portion 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, a camera 6521, a camera 6522, an illuminance sensor 6523, a light source 6508, and the like. The display portion 6502 has a touch panel function.

The display unit 422 described above can be applied to the display unit 6502.

The display unit 6502, the camera 6507, and the illuminance sensor 6523 are arranged on the side of the housing 421 where the display unit 422 is provided. The cameras 6521, 6522, and the light source 6508 are arranged on the rear side.

Camera 6507 can be used to capture an image of the user. Camera 6507 can be called an in-camera, and cameras 6521 and 6522 can be called out-cameras.

When capturing images using the camera 6507, for example, the light-emitting element of the display unit 422 can be used as a flashlight. When capturing images using the cameras 6521 and 6522, for example, the light source 6508 can be used as a flashlight.

Electronic device 6500 can have two or more cameras with different focal lengths. Camera 6521 and camera 6522 are, for example, cameras with lenses with different focal lengths. One can be used for wider-angle imaging and the other for telephoto imaging.

Furthermore, cameras 6507, 6521, and 6522 can suitably capture images of subjects that are farther away than the distance between the subject captured on display unit 422 and the surface of the display unit.

The illuminance sensor 6523 is disposed on the side of the housing 421 where the display unit 422 is provided. Therefore, it is possible to detect illuminance corresponding to external light received by the display unit 422. Note that the illuminance sensor 6523 may be disposed on the rear side of the display unit 422 in the housing 421. In this case, external light irradiated to the display unit 422 passes through the display unit 422 and is irradiated to the illuminance sensor 6523.

Figure 14C is a schematic cross-sectional view including the end of the housing 6501 on the microphone 6506 side.

A transparent protective member 6510 is provided on the display surface side of the housing 6501, and a display panel 6511, optical members 6512, a touch sensor panel 6513, a printed circuit board 6517, a battery 6518, etc. are arranged in the space surrounded by the housing 6501 and the protective member 6510.

The display panel 6511, the optical member 6512, and the touch sensor panel 6513 are fixed to the protective member 6510 by an adhesive layer (not shown).

In an area outside the display portion 6502, a part of the display panel 6511 is folded back, and the FPC 6515 is connected to the folded back part. An IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to a terminal provided on a printed circuit board 6517.

The display device of one embodiment of the present invention can be applied to the display panel 6511. Therefore, an extremely lightweight electronic device can be realized. In addition, since the display panel 6511 is extremely thin, a large-capacity battery 6518 can be mounted thereon while keeping the thickness of the electronic device small. In addition, by folding back a part of the display panel 6511 and arranging a connection portion with the FPC 6515 on the back side of the display portion, an electronic device with a narrow frame can be realized.

Images can be captured using the display unit 6502. For example, a fingerprint can be captured using the display panel 6511 for fingerprint authentication.

When the display unit 6502 further includes a touch sensor panel 6513, the display unit 6502 can have a touch panel function. The touch sensor panel 6513 can use various types, such as a capacitive type, a resistive film type, a surface acoustic wave type, an infrared type, an optical type, or a pressure-sensitive type. Alternatively, the display panel 6511 may function as a touch sensor, in which case the touch sensor panel 6513 does not need to be provided.

<Configuration Example 3 of Electronic Device>
The electronic device 420 shown in FIG. 15A can be used as a portable information terminal that can be attached to a living body or an object.

The electronic device 420 shown in FIG. 15A has a band 435. The electronic device 420 can be attached to a living body or an object using the band 435. The electronic device 420 shown in FIG. 15A also has a fastener 437. The fastener 437 can be used to fasten the attached band 435 to the living body or an object. In the example shown in FIG. 15A, the electronic device 420 is attached to the user's left wrist 461.

The housing 421 has a first surface and a second surface opposite to the first surface. It is preferable that the display unit 422 is provided on the first surface, and the sensor unit 403 is provided on the second surface. Fig. 17A is a perspective view showing the appearance of the first surface (display unit 422) side of the electronic device 420 shown in Fig. 15A. Fig. 17B is a perspective view showing the appearance of the second surface (sensor unit 403) side of the electronic device 420 shown in Fig. 15A. The sensor unit 403 is provided on the second surface to detect the attachment/detachment state of the electronic device 420.

Note that while FIG. 15A shows an example in which the display unit 422 of the electronic device 420 is rectangular, the shape of the display unit 422 is not particularly limited. The design of the electronic device 420 can be improved by having the display unit 422 have a shape other than rectangular. As shown in FIG. 15B, the display unit 422 may be circular. As shown in FIG. 16A, the display unit 422 may be configured so that its display surface is curved and the display is performed along the curved display surface. Also, as shown in FIG. 16B, the electronic device 420 may be cylindrical. FIG. 16B shows the electronic device 420 being worn on a finger 463.

The electronic device 420 may have an operation button 436. The user can operate the electronic device 420 by pressing the operation button 436. The electronic device 420 may have a band 435 and a fastener 437. The electronic device 420 can be attached to a living body or an object by the band 435 and the fastener 437. Note that, although the configuration in which the electronic device 420 has the operation button 436 is shown in FIG. 15A and the like, the electronic device 420 may be configured not to have the operation button 436. Also, although the configuration in which the electronic device 420 has the fastener 437 is shown in FIG. 17A, FIG. 17B and the like, the electronic device 420 may be configured not to have the fastener 437. The electronic device 420 may be configured to be attached to a living body or an object by only the band 435. Also, the electronic device 420 may be configured not to have the band 435.

The electronic device 420 can be configured to communicate hands-free, for example, by communicating with a wireless headset. The electronic device 420 can also transmit data to and from other information terminals and charge itself via a connection terminal (not shown). The charging operation can also be performed by wireless power supply.

Figures 18A and 18B are cross-sectional views taken along dashed line A-B in Figure 15A, and Figure 18C is a cross-sectional view taken along dashed line E-F in Figure 15A. Figure 18D is a cross-sectional view taken along dashed line C-D in Figure 16A. Figures 18B to 18D show enlarged views of the housing 421, display unit 422, and sensor unit 403. Note that Figures 18A to 18D omit the operation button 436 and fastener 437.

The sensor unit 403 can obtain information (first information) on the attachment/detachment state of the electronic device 420 by receiving the reflected light that is incident on the sensor unit 403 after a portion of the emitted light is reflected by a living body or an object. In FIG. 18B, the light emitted from the display unit 422 and the light emitted from the sensor unit 403 are indicated by arrows. As shown in FIG. 18B, it is preferable that the light emitted from the display unit 422 and the light emitted from the sensor unit 403 are in opposite directions. Note that while FIG. 18A shows an example in which the sensor unit 403 is worn on the back of the hand, the method of wearing the electronic device 420 is not limited to this. The sensor unit 403 may also be worn on the palm of the hand.

As shown in FIG. 18D, the display unit 422 may be configured so that its display surface is curved and the display is performed along the curved display surface.

<Example 7 of Operation Method>
In the case where a portable information terminal that can be attached to a living body or an object is used as the electronic device 420, an example of performing authentication using a comparison of an authentication code and user information will be described with reference to the examples of the operation methods shown in FIGS.

[Image of authentication code]
First, a method for acquiring a captured image of an image including an authentication code will be described using the operation method shown in Fig. 4. Note that, in the following, the description of the previous embodiment can be appropriately referred to.

First, in step S500, processing of this flow begins.

Next, in step S501, the subject 460 is detected.

In this step, subject 460 is an image including an authentication code. FIG. 19A shows, as an example, a piece of paper on which an authentication code is printed. The authentication code can also be attached to objects such as merchandise and fixtures, and to structures such as pillars and walls. Subject 460 may also be displayed on an electronic device. For example, an image of the authentication code may be displayed on the display unit of the electronic device.

As an example of the detection in this step, after the user brings the display unit 422 of the electronic device 420 close to the subject 460, the proximity of the subject 460 can be detected using the sensor unit. At this time, a message to start capturing an image of the subject 460 is displayed on the display unit 422 of the electronic device 420, and the user can follow the message and bring the display unit 422 closer to the subject 460. As will be described later, the image may be captured by scanning the display unit 422. At this time, a message to start scanning can be displayed. Note that when such a message is displayed, for example, it is also possible to proceed to the next step after a certain time has passed since the message was displayed, without detecting the proximity of the subject 460.

Next, in step S502, the number of processing times x is set to 1, the luminance L is set to L(1), and the time t is set to t(1).

Next, in step S503, the first image is displayed on the display unit at luminance L.

Next, in step S504, the first image is used as a light source to capture an image of the subject. Here, if the image of the authentication code is larger than the size of the display unit 422 of the electronic device 420, the entire image of the authentication code can be captured by scanning the display unit 422. Figures 19B and 19C show how the display unit 422, which is brought close to the subject 460, is scanned in the direction of the arrow. In Figure 19C, the electronic device 420 is worn on the user's left wrist 461, with the user's palm positioned on the front and the housing 421 of the electronic device 420 worn on the back side, i.e., the back of the user's hand. The user moves the left wrist 461 to scan the display unit 422, and the entire image of the authentication code, which is the subject, can be captured.

Then, in step S504, the electronic device acquires a captured image of the subject using the signal detected by the light receiving element.

Next, in step S505, it is determined whether or not the captured image acquired in step S504 can be adopted. Specifically, for example, it is determined whether or not the captured image has sufficient image quality to acquire information about the subject, and if the image quality is sufficient, it is adopted, and if the image quality is insufficient, it is not adopted.

If the captured image is adopted, proceed to step S509; if not, proceed to step S506.

In step 506, the processing count x is incremented.

In step S507, it is determined whether the number of processing times x is smaller than n. If the number of processing times reaches n, the process proceeds to step S511 and ends the process.

In step S508, the luminance L is set to L(x) and the time t is set to t(x).

After step S508, the process returns to step S503, and steps S503 to S505 are repeated. If the captured image is not adopted in step S505, the process proceeds to step S506, and if the captured image is adopted in step S505, the process proceeds to step S509.

In step S509, the approved captured image is acquired, and in step S510, the processing of this flow ends.

[Finger imaging]
Next, a method for acquiring an image of a user's finger will be described using the operation method shown in Fig. 4. Note that in the following, the description of the previous embodiment can be referred to as appropriate.

First, in step S500, processing of this flow begins.

Next, in step S501, the subject 460 is detected.

In this step, the subject 460 is the user's finger. As an example, FIG. 20A shows an example in which the index finger of the user's right hand touches the display unit 422 of the electronic device 420 worn on the user's left wrist 461.

As an example of the detection in this step, after the user brings the display unit 422 of the electronic device 420 close to the subject 460, the proximity of the subject 460 can be detected using a sensor unit. Alternatively, a message to start capturing an image of the subject 460 can be displayed on the display unit 422 of the electronic device 420, and the user can touch or bring their finger close to the display unit 422 in accordance with the message. When such a message is displayed, for example, it is also possible to proceed to the next step after a certain time has elapsed since the message was displayed, without detecting the proximity of the subject 460.

Next, in step S502, the number of processing times x is set to 1, the luminance L is set to L(1), and the time t is set to t(1).

Next, in step S503, the first image is displayed on the display unit at luminance L.

Next, in step S504, the first image is used as a light source to capture an image of the subject. Also in step S504, the electronic device obtains a captured image of the subject using a signal detected by the light receiving element.

Next, in step S505, it is determined whether or not the captured image acquired in step S504 can be adopted. Specifically, for example, it is determined whether or not the captured image has sufficient image quality to acquire information about the subject, and if the image quality is sufficient, it is adopted, and if the image quality is insufficient, it is not adopted.

If the captured image is adopted, proceed to step S509; if not, proceed to step S506.

In step 506, the processing count x is incremented.

In step S507, it is determined whether the number of processing times x is smaller than n. If the number of processing times reaches n, the process proceeds to step S511 and ends the process.

In step S508, the luminance L is set to L(x) and the time t is set to t(x).

After step S508, the process returns to step S503, and steps S503 to S505 are repeated. If the captured image is not adopted in step S505, the process proceeds to step S506, and if the captured image is adopted in step S505, the process proceeds to step S509.

In step S509, the selected captured image is acquired, and in step S510, the processing of this flow ends.

[certification]
Next, an example of an operation of performing authentication using a portable information terminal that can be attached to a living body or an object as an electronic device according to the flow shown in Fig. 8 will be described. Note that in the following, the description of the previous embodiment can be appropriately referred to.

First, in step S100, processing of this flow begins.

Next, in step S101, an image of the authentication code is acquired. Here, the method described above is used to acquire the image of the authentication code.

By using a portable information terminal that can be attached to a living body or an object as the electronic device, the user can capture an image of the authentication code simply by moving the part of the body where the electronic device is attached, for example, the wrist in Figure 19C. This can minimize hindrance to the user's work. In addition, there is no need to carry the electronic device in a bag, pocket, etc., and there is no need to remove it from a bag, pocket, etc., which improves convenience during work. By minimizing hindrance to work and improving convenience, it is possible to increase the safety of work and improve work efficiency.

Next, in step S102, authentication code information is obtained from the captured image of the authentication code.

Next, in step S103, information about the processing based on the authentication code is displayed on the display unit.

Next, in step S104, it is determined whether the processing information displayed on the display unit in step S103 is approved. If it is not approved, the process proceeds to step S199, and the process of this flow ends. If it is approved, the process proceeds to step S105.

Next, in step S105, an image of the first finger is acquired. Here, the method described above is used to acquire the image of the first finger.

By using a portable information terminal that can be attached to a living body or an object as the electronic device, the user does not need to carry the electronic device in a bag, pocket, etc., and there is no need to remove the electronic device from a bag, pocket, etc., improving convenience during work. In addition, it is possible to minimize hindrance to the user's work. By minimizing hindrance to work and improving convenience, it is possible to increase the safety of work and improve work efficiency.

Next, in step S106, the captured image acquired in step S105 is used to acquire fingerprint information of the first finger.

Next, in step S107, the first fingerprint information is compared. For example, the first fingerprint information may be compared with the second fingerprint information stored in the storage unit of the electronic device.

Next, in step S108, it is determined whether the comparison performed in step S107 results in a match. If it is determined that there is a match, the process proceeds to step S109, where the electronic device performs the process approved in step S104. If it is determined that there is no match, the process proceeds to step S199, where the process of this flow ends.

Note that a sensor that detects the attachment and detachment of electronic device 420 is provided in the sensor unit, and authentication is performed when electronic device 420 is removed from the user's wearing site and then worn again, thereby linking electronic device 420 to the user. The operation performed on electronic device 420 is an operation performed by a terminal that has been approved in advance for first authentication by linking with the user. It can also be expressed as two-stage authentication, with the linking with the user when electronic device 420 is worn being the first stage authentication, and the matching of fingerprint information in step 107 being the second stage authentication. By using two stages of authentication, security can be made extremely high.

When the electronic device 420 is worn, authentication can be performed using an appropriate method such as fingerprint authentication, password authentication including PIN authentication, voiceprint authentication, etc.

[Illuminance sensor]
Fig. 20B is a cross-sectional view taken along dashed line A-B in Fig. 15A, and shows an example in which an illuminance sensor 434 is provided inside the housing 421. The illuminance sensor 434 shown in Fig. 20B is provided so as to overlap the rear surface of the display unit 422. External light irradiated to the display unit 422 is incident on the illuminance sensor 434 via the display unit 422.

In the example shown in FIG. 20C, the illuminance sensor 434 is disposed next to the display unit 422 on the surface of the housing 421.

This embodiment can be implemented in combination with at least a portion of the other embodiments described in this specification.

(Embodiment 3)
In this embodiment, an example of a display device including a light-receiving element or the like according to one embodiment of the present invention will be described. The display device can be applied to an electronic device according to one embodiment of the present invention.

In the display device of this embodiment, a pixel can be configured to have multiple types of subpixels having light-emitting elements with different light-emitting colors. For example, a pixel can be configured to have three types of subpixels. The three subpixels can be subpixels of three colors, red (R), green (G), and blue (B), or subpixels of three colors, yellow (Y), cyan (C), and magenta (M). Alternatively, a pixel can be configured to have four types of subpixels. The four subpixels can be subpixels of four colors, R, G, B, and white (W), or subpixels of four colors, R, G, B, and Y.

There are no particular limitations on the arrangement of the sub-pixels, and various methods can be applied. Examples of the arrangement of the sub-pixels include a stripe arrangement, an S-stripe arrangement, a matrix arrangement, a delta arrangement, a Bayer arrangement, and a pentile arrangement.

The top surface shape of the subpixel may be, for example, a triangle, a quadrangle (including a rectangle and a square), a polygon such as a pentagon, a polygon with rounded corners, an ellipse, or a circle. The top surface shape of the subpixel here corresponds to the top surface shape of the light-emitting region of the light-emitting element.

In a display device having a light-emitting element and a light-receiving element in each pixel, the pixels have a light-receiving function, so that it is possible to detect the contact or proximity of an object while displaying an image. For example, rather than just displaying an image using all of the sub-pixels of the display device, some of the sub-pixels can emit light as a light source, while other sub-pixels can perform light detection, and the image can be displayed using the remaining sub-pixels.

The pixels shown in Figures 21A, 21B, 21C, 21G, 21H, and 21I have subpixels G, B, R, and PS.

The pixels shown in FIG. 21A are arranged in a stripe pattern. The pixels shown in FIG. 21B are arranged in a matrix pattern.

The pixel array shown in FIG. 21C has three subpixels (subpixel R, subpixel G, and subpixel S) arranged vertically next to one subpixel (subpixel B).

The pixel array shown in FIG. 21G shows an example in which subpixels are arranged in two rows. The top row (first row) has three subpixels (subpixel G, subpixel B, and subpixel R) arranged horizontally, and the bottom row has one subpixel (subpixel PS).

Figure 21H shows an example in which subpixels are arranged in three rows. One subpixel (subpixel B) is provided across the first and second rows, and to the left of it, one subpixel (subpixel G) is provided in the first row, one subpixel (subpixel R) is provided in the second row, and one subpixel (subpixel PS) is provided in the third row.

The configuration shown in FIG. 21I has two pixels (hereinafter referred to as pixel 30c and pixel 30d) with different configurations arranged side by side.

Pixel 30c shown in FIG. 21I has subpixel PS in the top row (first row), subpixel G in the bottom row (second row), and subpixel R across the first and second rows. In other words, pixel 30c has subpixel PS and subpixel G in the left column (first column), and subpixel R in the right column (second column).

Pixel 30d shown in FIG. 21I has subpixel PS in the top row (first row), subpixel G in the bottom row (second row), and subpixel B across the first and second rows. In other words, pixel 30d has subpixel PS and subpixel G in the left column (first column), and subpixel B in the right column (second column).

In the configuration shown in FIG. 21I, subpixels R and B are arranged in every two pixels, and the areas of subpixels R and B are larger than the area of subpixel G. With this configuration, the resolution of subpixels G and PS is increased, and the areas of subpixels R and B are increased, thereby increasing the luminance even with lower power consumption, thereby realizing a display device that is high-resolution, has low power consumption, and is highly reliable.

The light receiving area of the subpixel PS may be configured to be smaller than the light emitting areas of the other subpixels. The smaller the light receiving area, the narrower the imaging range, making it possible to suppress blurring in the imaging results and improve the resolution. Therefore, by using the subpixel PS, it is possible to perform imaging with high definition or high resolution.

The pixel shown in Figures 21D, 21E, and 21F has subpixel G, subpixel B, subpixel R, subpixel IRS, and subpixel PS.

Figures 21D, 21E, and 21F show an example in which one pixel is provided in two rows. The top row (first row) has three subpixels (subpixel G, subpixel B, and subpixel R), and the bottom row (second row) has two subpixels (one subpixel PS and one subpixel IRS).

In FIG. 21D, three vertically elongated subpixels G, B, and R are arranged horizontally, and below them, subpixel PS and horizontally elongated subpixel IRS are arranged horizontally. In FIG. 21E, two horizontally elongated subpixels G and R are arranged vertically, and vertically elongated subpixel B is arranged horizontally, and below them, horizontally elongated subpixel IRS and vertically elongated subpixel PS are arranged horizontally. In FIG. 21F, three vertically elongated subpixels R, G, and B are arranged horizontally, and below them, horizontally elongated subpixel IRS and vertically elongated subpixel PS are arranged horizontally. In FIGS. 21E and 21F, the area of subpixel IRS is the largest, and the area of subpixel PS is approximately the same as that of the subpixels, etc.

Note that the layout of the subpixels is not limited to the configurations shown in Figures 21A to 21I.

Subpixel R has a light-emitting element that emits red light. Subpixel G has a light-emitting element that emits green light. Subpixel B has a light-emitting element that emits blue light. Subpixel IRS has a light-emitting element that emits infrared light. Subpixel PS has a light-receiving element. The wavelength of light detected by subpixel PS is not particularly limited, but it is preferable that the light-receiving element of subpixel PS is sensitive to light emitted by the light-emitting element of subpixel R, subpixel G, subpixel B, or subpixel IRS. For example, it is preferable to detect one or more of light in wavelength ranges such as blue, purple, blue-purple, green, yellow-green, yellow, orange, and red, and light in the infrared wavelength range.

The light receiving area of the subpixel PS is smaller than the light emitting area of the other subpixels. The smaller the light receiving area, the narrower the imaging range, making it possible to suppress blurring of the imaging result and improve the resolution. Therefore, by using the subpixel PS, it is possible to perform imaging with high definition or resolution. For example, the subpixel PS can be used to perform imaging for personal authentication using a fingerprint, palm print, iris, pulse shape (including vein shape and artery shape), face, etc.

The subpixel PS can also be used as a touch sensor (also called a direct touch sensor) or a near-touch sensor (also called a hover sensor, hover touch sensor, non-contact sensor, or touchless sensor). For example, it is preferable for the subpixel PS to detect infrared light. This allows touch detection even in dark places.

Here, the touch sensor or near-touch sensor can detect the proximity or contact of an object (such as a finger, hand, or pen). The touch sensor can detect an object by directly contacting the display device with the object. The near-touch sensor can detect the object even if the object does not contact the display device. For example, it is preferable that the display device is configured to detect the object when the distance between the display device and the object is in the range of 0.1 mm to 300 mm, preferably 3 mm to 50 mm. With this configuration, it is possible to operate the display device without the object directly touching it, in other words, it is possible to operate the display device in a non-contact (touchless) manner. With the above configuration, it is possible to reduce the risk of the display device becoming dirty or scratched, or it is possible to operate the display device without the object directly touching the dirt (such as dust or viruses) attached to the display device.

In order to capture high-definition images, it is preferable that the subpixels PS are provided in all pixels of the display device. On the other hand, when used in a touch sensor or near-touch sensor, the subpixels PS do not require high accuracy compared to capturing images of fingerprints, etc., so it is sufficient that they are provided in some of the pixels of the display device. By making the number of subpixels PS in the display device less than the number of subpixels R, etc., the detection speed can be increased.

Figure 22A shows an example of a pixel circuit corresponding to a subpixel having a light receiving element, and Figure 22B shows an example of a pixel circuit corresponding to a subpixel having a light emitting element.

The pixel circuit PIX2 shown in FIG. 22A has a light receiving element PD, a transistor M11, a transistor M12, a transistor M13, a transistor M14, and a capacitance element C2. Here, an example is shown in which a photodiode is used as the light receiving element PD.

The anode of the light receiving element PD is electrically connected to the wiring V1, and the cathode is electrically connected to one of the source and drain of the transistor M11. The gate of the transistor M11 is electrically connected to the wiring TX, and the other of the source and drain is electrically connected to one electrode of the capacitance element C2, one of the source and drain of the transistor M12, and the gate of the transistor M13. The gate of the transistor M12 is electrically connected to the wiring RES, and the other of the source and drain is electrically connected to the wiring V2. The one of the source and drain of the transistor M13 is electrically connected to the wiring V3, and the other of the source and drain is electrically connected to one of the source and drain of the transistor M14. The gate of the transistor M14 is electrically connected to the wiring SEN, and the other of the source and drain is electrically connected to the wiring WX.

Wiring V1 can be the cathode wiring described in the previous embodiment.

A constant potential is supplied to each of the wirings V1, V2, and V3. When the light receiving element PD is driven with a reverse bias, a potential higher than the potential of the wiring V1 is supplied to the wiring V2. The transistor M12 is controlled by a signal supplied to the wiring RES, and has a function of resetting the potential of the node connected to the gate of the transistor M13 to the potential supplied to the wiring V2. The transistor M11 is controlled by a signal supplied to the wiring TX, and has a function of controlling the timing at which the potential of the node changes according to the current flowing through the light receiving element PD. The transistor M13 functions as an amplifying transistor that outputs according to the potential of the node. The transistor M14 is controlled by a signal supplied to the wiring SEN, and functions as a selection transistor for reading out the output according to the potential of the node in an external circuit connected to the wiring WX.

The pixel circuit PIX1 shown in FIG. 22B has a light-emitting element EL, a transistor M15, a transistor M16, a transistor M17, and a capacitance element C3. Here, an example is shown in which a light-emitting diode is used as the light-emitting element EL. In particular, it is preferable to use an organic EL element as the light-emitting element EL.

In FIG. 22B, transistor M16 can function as a current control unit CU.

The gate of transistor M15 is electrically connected to wiring GL, one of the source and drain is electrically connected to wiring SL, and the other of the source and drain is electrically connected to one electrode of the capacitor C3 and the gate of transistor M16. One of the source and drain of transistor M16 is electrically connected to wiring V4, and the other is electrically connected to the anode of the light-emitting element EL and one of the source and drain of transistor M17. The gate of transistor M17 is electrically connected to wiring MS, and the other of the source and drain is electrically connected to wiring OUT2. The cathode of the light-emitting element EL is electrically connected to wiring V5.

Wiring V4 and wiring V5 can be the anode wiring and cathode wiring described in the previous embodiment, respectively.

A constant potential is supplied to the wiring V4 and the wiring V5. The anode side of the light-emitting element EL can be set to a high potential, and the cathode side can be set to a lower potential than the anode side. The transistor M15 is controlled by a signal supplied to the wiring GL, and functions as a selection transistor for controlling the selection state of the pixel circuit PIX1. The transistor M16 also functions as a drive transistor for controlling the current flowing through the light-emitting element EL according to the potential supplied to the gate. When the transistor M15 is in a conductive state, the potential supplied to the wiring SL is supplied to the gate of the transistor M16, and the light emission brightness of the light-emitting element EL can be controlled according to the potential. The transistor M17 is controlled by a signal supplied to the wiring MS, and has the function of outputting the potential between the transistor M16 and the light-emitting element EL to the outside via the wiring OUT2.

Here, it is preferable to use transistors that use metal oxide (oxide semiconductor) in the semiconductor layer in which the channel is formed for the transistors M11, M12, M13, and M14 in the pixel circuit PIX2, and the transistors M15, M16, and M17 in the pixel circuit PIX1.

Transistors using metal oxides that have a wider band gap than silicon and a smaller carrier concentration can achieve an extremely small off-current. Therefore, due to the small off-current, it is possible to hold the charge accumulated in the capacitor connected in series with the transistor for a long period of time. Therefore, it is preferable to use transistors using oxide semiconductors for transistors M11, M12, and M15, which are connected in series with capacitor C2 or capacitor C3 in particular. In addition, by using transistors using oxide semiconductors for other transistors as well, the manufacturing cost can be reduced.

Also, for the transistors M11 to M17, transistors using silicon as the semiconductor in which the channel is formed can be used. In particular, using silicon with high crystallinity such as single crystal silicon or polycrystalline silicon is preferable because it can achieve high field effect mobility and enable faster operation.

In addition, a configuration may be used in which one or more of the transistors M11 to M17 contain an oxide semiconductor, and the remaining transistors contain silicon.

Note that in Figures 22A and 22B, the transistors are shown as n-channel transistors, but p-channel transistors can also be used.

The transistors of pixel circuit PIX2 and the transistors of pixel circuit PIX1 are preferably formed side by side on the same substrate. In particular, it is preferable to have a configuration in which the transistors of pixel circuit PIX2 and the transistors of pixel circuit PIX1 are mixed and periodically arranged in one region.

In addition, it is preferable to provide one or more layers having one or both of a transistor and a capacitance element at a position overlapping the light receiving element PD or the light emitting element EL. This makes it possible to reduce the effective area occupied by each pixel circuit, and to realize a high-definition light receiving section or display section.

A block diagram of the display device 100 is shown in FIG. 23A. The display device 100 has a display unit 11, a drive circuit unit 12, a drive circuit unit 13, a drive circuit unit 14, and a circuit unit 15, etc.

The display unit 11 has a plurality of pixels 30 arranged in a matrix. The pixels 30 have a pixel circuit 21R, a pixel circuit 21G, a pixel circuit 21B, and a pixel circuit 22. The pixel circuit 21R, the pixel circuit 21G, and the pixel circuit 21B each have a light-emitting element that functions as a display element. The pixel circuit 22 has a light-receiving element that functions as a photoelectric conversion element.

The pixel 30 is electrically connected to the wiring GL, the wiring SLR, the wiring SLG, the wiring SLB, the wiring TX, the wiring SEN, the wiring RES, the wiring WX, etc. The wiring SLR, the wiring SLG, and the wiring SLB are electrically connected to the driving circuit unit 12. The wiring GL is electrically connected to the driving circuit unit 13. The driving circuit unit 12 functions as a source line driving circuit (also called a source driver). The driving circuit unit 13 functions as a gate line driving circuit (also called a gate driver).

Pixel 30 has pixel circuit 21R, pixel circuit 21G, and pixel circuit 21B. For example, pixel circuit 21R can function as a subpixel that exhibits red color or as a part of a subpixel, pixel circuit 21G can function as a subpixel that exhibits green color or as a part of a subpixel, and pixel circuit 21B can function as a subpixel that exhibits blue color or as a part of a subpixel. This allows display device 100 to perform full color display. Note that, although an example in which pixel 30 has subpixels of three colors is shown here, pixel 30 may have subpixels of four or more colors.

Pixel circuit 21R has a light-emitting element that emits red light. Pixel circuit 21G has a light-emitting element that emits green light. Pixel circuit 21B has a light-emitting element that emits blue light. Note that pixel 30 may have sub-pixels that have light-emitting elements that emit other light. For example, pixel 30 may have, in addition to the above three sub-pixels, a sub-pixel that has a light-emitting element that emits white light, or a sub-pixel that has a light-emitting element that emits yellow light.

The wiring GL is electrically connected to pixel circuits 21R, 21G, and 21B arranged in the row direction (extension direction of the wiring GL). The wiring SLR, wiring SLG, and wiring SLB are each electrically connected to pixel circuits 21R, 21G, and 21B (not shown) arranged in the column direction (extension direction of the wiring SLR, etc.).

The pixel circuit 22 of the pixel 30 is electrically connected to the wiring TX, wiring SEN, wiring RES, and wiring WX. The wiring TX, wiring SEN, and wiring RES are each electrically connected to the drive circuit unit 14, and the wiring WX is electrically connected to the circuit unit 15.

The driving circuit unit 14 has a function of generating signals for driving the pixel circuits 22 and outputting them to the pixel circuits 22 via the wirings SEN, TX, and RES. The circuit unit 15 has a function of receiving signals output from the pixel circuits 22 via the wirings WX and outputting them to the outside as image data. The circuit unit 15 functions as a readout circuit.

The pixel circuit PIX1 described above can be applied to pixel circuit 21R, pixel circuit 21G, and pixel circuit 21B.

The pixel circuit PIX2 described above can be applied to the pixel circuit 22.

[Example of a method for driving a pixel circuit]
Fig. 22C is a timing chart for explaining an example of a method for driving the sub-pixel PIX2 having the configuration shown in Fig. 22A. Here, by setting the potential of the wiring V2 to a potential lower than the potential of the wiring V1, a reverse bias can be applied to the light receiving element PD. When the potential of the wiring V1 is set to the potential of the wiring V5 of the pixel circuit PIX1, for example, the potential of the cathode wiring, the value of the wiring V2 is set to a potential lower than the potential of the cathode wiring. Note that in Fig. 22B, "H" indicates a high potential and "L" indicates a low potential. The same notation is used in other timing charts. In Fig. 22B, periods T1 to T5 are shown as periods during which the sub-pixel PIX2 is driven.

In period T1, the potentials of the wiring TX and wiring RES are set to high potential, and the potential of the wiring SEN is set to low potential. As a result, transistors M11 and M12 are turned on, and transistor M14 is turned off. When transistor M12 is turned on, the potential of node FD becomes a low potential, which is the potential of wiring V2. In addition, when transistor M12 and transistor M11 are turned on, the potential of wiring V2 is also applied to the potential of one electrode of the light receiving element PD, although this is not shown in FIG. 22A. As a result, the charge accumulated in capacitance C2 is reset. Therefore, period T1 is a reset period, and the operation performed in period T1 can be said to be a reset operation.

In period T2, the potentials of the wiring TX and the wiring RES are set to low potential. This causes the transistors M11 and M12 to be turned off. When light is irradiated onto the light receiving element PD in this state, charge corresponding to the energy of the light incident on the light receiving element PD is accumulated in the light receiving element PD. Therefore, period T2 is an exposure period, and the operation performed in period T2 can be said to be an exposure operation.

The exposure period shown in period T2 is, for example, the detection period of the light receiving element described in the previous embodiment. Note that when exposure is performed using a light emitting element of the display device, it is preferable that the light emitting element is turned on at least during period T2.

In period T3, the potential of the wiring TX is set to a high potential. This turns on the transistor M11, and the charge stored in the light-receiving element PD is transferred to the node FD. This causes the potential of the node FD to rise. Therefore, period T3 is a transfer period, and the operation performed in period T3 can be said to be a transfer operation.

In period T4, the potential of the wiring TX is set to low. This causes the transistor M11 to be turned off, and the transfer of the accumulated charge to the node FD ends.

As a result, the pixel circuit PIX2 acquires image data. Specifically, the potential of the node FD becomes a potential corresponding to the image data. Therefore, the periods T1 to T4 are acquisition periods, and the operations performed during the periods T1 to T4 are acquisition operations.

Next, an example of a driving method in the period T5 will be described. During the period T5, the potential of the wiring SEN is set to a high potential. This causes the transistor M14 to be turned on, and a signal representing the imaging data acquired by the pixel circuit PIX2 is output to the wiring WX. Specifically, the potential of the wiring WX becomes a potential corresponding to the potential of the node FD. This causes the imaging data acquired by the pixel circuit PIX2 to be read out.

As described above, the imaging data acquired by the pixel circuit PIX2 is read out by supplying a high-potential signal to the wiring SEN. In other words, the pixel circuit PIX2 that reads out the imaging data can be selected by the signal supplied to the wiring SEN. Therefore, the signal supplied to the wiring SEN can be said to be a selection signal.

Furthermore, after the imaging data is read out, the potential of the wiring RES is set to a high potential. This turns on the transistor M12, and the imaging data acquired by the pixel circuit PIX2 is reset. Specifically, the potential of the node FD becomes a low potential, which is the potential of the wiring V2. Here, because the transistor M14 is on, the potential of the wiring WX also changes in response to the change in the potential of the node FD. Correlated double sampling may be performed in the readout circuit section electrically connected to the wiring WX. By performing correlated double sampling, noise contained in the read-out imaging data can be reduced.

As described above, the imaging data acquired by the pixel circuit PIX2 is reset by supplying a high-potential signal to the wiring RES. Therefore, the signal supplied to the wiring RES can be said to be a reset signal.

Next, the potential of the wiring RES is set to a low potential to turn off the transistor M12, and the potential of the wiring SEN is set to a low potential to turn off the transistor M14.

The above is an example of a driving method in period T5. In period T5, the imaging data acquired by pixel circuit PIX2 is read out. Therefore, period T5 is a readout period, and the operation performed in period T5 can be said to be a readout operation.

The acquisition of imaging data in pixel circuit PIX2 is preferably performed by a global shutter method. Here, the global shutter method refers to a method of acquiring imaging data simultaneously for all pixels. By acquiring imaging data by the global shutter method, it is possible to ensure the simultaneity of imaging, so that an image with little distortion can be easily obtained even when the subject is moving at high speed.

On the other hand, the reading of the imaging data in the pixel circuit PIX2 is performed, for example, row by row. Therefore, when the imaging data is acquired by the global shutter method, there will be a pixel circuit PIX2 in which the period from acquisition to reading of the imaging data will be long. Therefore, when the imaging data is acquired by the global shutter method, it is preferable to be able to hold the charge transferred from the pixel circuit PIX2 to the node FD for a long period of time.

In order to hold charge in the node FD for a long period of time, it is preferable to use a transistor with low off-state current as a transistor electrically connected to the node FD. As a transistor with low off-state current, an OS transistor can be preferably used. The transistor M11 and the transistor M12 are preferably OS transistors.

If the off-state current is low, OS transistors do not have to be used as transistors M11 and M12. For example, transistors having a semiconductor with a wide band gap may be used. A wide band gap semiconductor may refer to a semiconductor with a band gap of 2.2 eV or more. Examples include silicon carbide, gallium nitride, and diamond.

Note that the transistors M11 and M12 may be transistors having silicon in their channel formation regions (hereinafter, Si transistors), or the like. Si transistors have a higher off-state current than OS transistors. However, even if the off-state currents of the transistors M11 and M12 are high, the image data in the pixel circuit PIX2 may be acquired by a global shutter system by increasing the capacitance value of the capacitor C2, for example. The image data in the pixel circuit PIX2 may be acquired by a rolling shutter system. In this case, even if the transistors M11 and M12 are transistors having a high off-state current, the capacitance value of the capacitor C2 does not need to be increased.

In addition, the transistors M13 and M14 may be Si transistors or OS transistors. For example, when transistors having crystalline silicon (typically, low-temperature polysilicon (also referred to as LTPS), single crystal silicon, or the like) are used as the transistors M13 and M14, the on-state current of the transistors M13 and M14 can be increased. Thus, image data can be read at high speed. On the other hand, when the transistors M11 to M14 are all OS transistors, all the transistors in the pixel circuit PIX2 can be formed in the same layer. Furthermore, when all the transistors in the display device, including the transistors M11 to M14, are OS transistors, all the transistors in the display device can be formed in the same layer. As described above, the manufacturing process of the display device can be simplified. Note that the transistors M11 to M14 may be transistors having amorphous silicon in their channel formation regions. Note that the transistors M11 to M14 may be a combination of a Si transistor (typically an LTPS transistor) and an OS transistor. Note that a configuration in which an LTPS transistor and an OS transistor are combined may be referred to as LTPO. For example, a display device with high display quality can be obtained by using an OS transistor as a transistor that functions as a switch for controlling conduction/non-conduction between wirings and an LTPS transistor as a transistor for controlling current.

When fingerprint authentication is performed using a display device according to one embodiment of the present invention, first, a row driver circuit selects pixels in a specific row of the display unit and reads out first imaging data. This allows, for example, the position on the display unit of a finger that is in contact with or close to the display unit to be detected. Next, the row driver circuit selects only pixels in the row in which the finger is in contact with or close to that row and the rows surrounding that row, and reads out second imaging data, i.e., the user's fingerprint. In this way, the display device according to one embodiment of the present invention performs fingerprint authentication.

Here, when reading out the first imaging data, it is only necessary to detect the position of the finger, and it is not necessary to read out the fingerprint image. Therefore, it is not necessary to read out the first imaging data for all rows and columns of pixels in the display unit. For example, it may be performed for a limited number of pixels every several rows and columns. This makes it possible to shorten the readout period per pixel row compared to when the first imaging data is read out for all pixels in the display unit. On the other hand, when reading out the second imaging data, it is necessary to read out the fingerprint image for all pixels in the specified area, so the readout period per pixel row is longer than when the first imaging data is read out. In the display device of one embodiment of the present invention, the pixels from which the second imaging data is read out for fingerprint authentication can be only a part of the pixels provided in the display unit. Therefore, fingerprint authentication can be performed in a shorter time than when the second imaging data is read out from all pixels.

Furthermore, when a pixel circuit includes a light receiving/emitting element that has both light receiving and emitting functions, the pixel circuit can include a circuit area used for light receiving and a circuit area used for emitting light. FIG. 23B shows an example of a pixel circuit including a light receiving/emitting element SR. When exposure is performed on the light receiving/emitting element SR, the transistors M16 and M17 are turned off. By turning off the transistor M16, it is possible to cut off the electrical connection between the wiring V4, which functions as the anode wiring, and the light receiving/emitting element SR. Furthermore, when light is to be emitted from the light receiving/emitting element SR, for example, a low potential can be applied from the wiring TX to the gate of the transistor M11.

Figures 24A, 24B, 24C, 25A, and 25B show examples of pixel circuits that can be used as pixel circuit 21R, pixel circuit G, and pixel circuit B.

In the pixel circuit 23 shown in FIG. 24A, for example, the transistor 52 and the transistor 54 can function as a current control unit CU of the pixel circuit. Also, the transistor 54 can function as a drive transistor.

In the pixel circuit 23 shown in FIG. 24B, for example, the transistor 54 can function as a current control unit CU of the pixel circuit. The transistor 54 can also function as a drive transistor.

In the pixel circuit 23 shown in FIG. 24C, for example, transistor 61, transistor 62, transistor 63, transistor 65, and capacitor 67 can function as a current control unit CU of the pixel circuit. Also, transistor 63 can function as a drive transistor.

In the pixel circuit 23 shown in FIG. 25A, for example, transistors M2, M3, M4, M5, and capacitance element C1 can function as a current control unit CU of the pixel circuit. Transistor M3 can also function as a drive transistor. FIG. 25A shows an example in which p-type channel transistors are used as the transistors, while FIG. 25B shows an example in which transistors M4 and M6 are replaced with n-type channel transistors.

Note that in the above pixel circuit, the polarity of the transistors is just an example, and n-channel transistors and p-channel transistors may be interchanged as appropriate.

The pixel circuit 23 shown in FIG. 24A has transistors 51 to 54, a capacitor 57, and a capacitor 58.

The gate of transistor 51 is electrically connected to wiring GLa. One of the source and drain of transistor 53 is electrically connected to the other of the source and drain of transistor 52, the other electrode of capacitor 57, and one electrode of light-emitting element 60. The other of the source and drain of transistor 53 is electrically connected to wiring 48. The gate of transistor 53 is electrically connected to wiring GLb.

The transistor 53 has a function as a switch and has a function of controlling the conductive state or non-conductive state between the wiring 48 and one electrode of the light-emitting element 60 based on the potential of the wiring GLb. A reference potential, for example, is supplied to the wiring 48. The reference potential of the wiring 48 supplied via the transistor 53 can suppress variations in the gate-source potential of the transistor 52.

The wiring 48 can also be used to obtain a current value that can be used to set pixel parameters. More specifically, the wiring 48 can function as a monitor line for outputting the current flowing through the transistor 52 or the current flowing through the light-emitting element 60 to the outside of the pixel circuit 23. The current output to the wiring 48 can be converted to a potential by, for example, a source follower circuit. Or, it can be converted to a digital signal by, for example, an A-D converter. Note that when the wiring 48 functions as a monitor line, the display device does not need to have a reference potential generating circuit. Also, when the wiring 48 functions as a monitor line, the pixel circuit 23 can be electrically connected to a different wiring 48 for each column.

It is preferable to use an OS transistor as the transistor 53. As described above, an OS transistor has a higher field effect mobility than, for example, a transistor using amorphous silicon. Therefore, by using an OS transistor as the transistor 53, the display device can be driven at high speed.

One of the source and drain of transistor 52 is electrically connected to one of the source and drain of transistor 54. The other of the source and drain of transistor 54 is electrically connected to wiring ANO. The gate of transistor 54 is electrically connected to wiring GLc. One electrode of capacitor 58 is electrically connected to the other of the source and drain of transistor 52, one of the source and drain of transistor 53, the other electrode of capacitor 57, and one electrode of light-emitting element 60. The other electrode of capacitor 58 is electrically connected to wiring ANO.

The wiring GLc is electrically connected to the scanning line driving circuit. That is, when the pixel circuit 23 has the configuration shown in FIG. 24A, the wiring GLa, the wiring GLb, and the wiring GLc are provided in the display device as the wiring GL.

Transistor 54 functions as a switch and has the function of controlling the conductive state or non-conductive state between wiring ANO and one of the source and drain of transistor 52 based on the potential of wiring GLc.

By turning on the transistor 54, a current having a magnitude corresponding to the gate potential of the transistor 52 flows, for example, from the wiring ANO to the wiring CAT. This causes the light-emitting element 60 to emit light with a luminance corresponding to the gate potential of the transistor 52. On the other hand, by turning off the transistor 54, no current flows through the light-emitting element 60, so that the light-emitting element 60 does not emit light.

It is preferable to use an OS transistor as transistor 54. As described above, an OS transistor has a higher field-effect mobility than, for example, a transistor using amorphous silicon. Therefore, by using an OS transistor as transistor 54, the display device can be driven at high speed.

The pixel circuit 23 shown in FIG. 24B differs from that shown in FIG. 24A in the connection of the transistor 54. Also, in FIG. 24B, the capacitor 58 is not provided.

In FIG. 24B, one of the source and drain of transistor 54 is electrically connected to the other of the source and drain of transistor 51, the gate of transistor 52, and one electrode of capacitor 57. The other of the source and drain of transistor 54 is electrically connected to wiring 49. The gate of transistor 54 is electrically connected to wiring GLc. When pixel circuit 23 has the configuration shown in FIG. 24B, wiring GLa, wiring GLb, and wiring GLc are provided in the display device as wiring GL.

By turning on the transistor 54, the gate potential of the transistor 52 can be set to the potential of the wiring 49. This can prevent current from flowing through the light-emitting element 60, for example, and can prevent the light-emitting element 60 from emitting light.

The pixel circuit 23 shown in FIG. 24C has a transistor 61, a transistor 62, a transistor 63, a transistor 64, a transistor 65, a transistor 66, a capacitor 67, a capacitor 68, and a light-emitting element 60.

One of the source and drain of transistor 61 is electrically connected to wiring ANO. The other of the source and drain of transistor 61 is electrically connected to one of the source and drain of transistor 62. One of the source and drain of transistor 62 is electrically connected to one of the source and drain of transistor 63. The gate of transistor 61 is electrically connected to wiring GLd.

The other of the source and drain of transistor 62 is electrically connected to the gate of transistor 63. The gate of transistor 63 is electrically connected to one electrode of capacitor 67. The gate of transistor 62 is electrically connected to wiring GLe.

One of the source and drain of transistor 64 is electrically connected to wiring SL. The other of the source and drain of transistor 64 is electrically connected to the other of the source and drain of transistor 63. The other of the source and drain of transistor 63 is electrically connected to one of the source and drain of transistor 65. The gate of transistor 64 is electrically connected to wiring GLf.

The other of the source and drain of transistor 65 is electrically connected to one of the source and drain of transistor 66. One of the source and drain of transistor 66 is electrically connected to the other electrode of capacitor 67. The other electrode of capacitor 67 is electrically connected to one electrode of capacitor 68. One electrode of capacitor 68 is electrically connected to one electrode of the light-emitting element 60. The gate of transistor 65 is electrically connected to wiring GLg.

The other of the source and drain of the transistor 66 is electrically connected to the wiring 48. The gate of the transistor 66 is electrically connected to the wiring GLe.

The other electrode of the capacitor 68 is electrically connected to the wiring GLf. The other electrode of the light-emitting element 60 is electrically connected to the wiring CAT.

The wiring GLd, the wiring GLe, the wiring GLf, and the wiring GLg are electrically connected to the scanning line driving circuit. In other words, when the pixel circuit 23 has the configuration shown in FIG. 24C, the wiring GLd, the wiring GLe, the wiring GLf, and the wiring GLg are provided in the display device as the wiring GL.

Transistor 61, transistor 62, transistor 64, transistor 65, and transistor 66 function as switches. Transistor 61 has a function of controlling the conductive state or non-conductive state between wiring ANO and one of the source and drain of transistor 62 and one of the source and drain of transistor 63 based on the potential of wiring GLd. Transistor 62 has a function of controlling the conductive state or non-conductive state between the other of the source and drain of transistor 61 and one of the source and drain of transistor 63 and the gate of transistor 63 and one electrode of capacitor 67 based on the potential of wiring GLe. Transistor 64 has a function of controlling the conductive state or non-conductive state between wiring SL and the other of the source and drain of transistor 63 and one of the source and drain of transistor 65 based on the potential of wiring GLf. The transistor 65 has a function of controlling the conductive state or non-conductive state between the other of the source and drain of the transistor 63 and the other of the source and drain of the transistor 64 and one electrode of the light-emitting element 60 based on the potential of the wiring GLg. The transistor 66 has a function of controlling the conductive state or non-conductive state between the wiring ANO and one electrode of the light-emitting element 60 based on the potential of the wiring GLe.

It is preferable to use OS transistors as transistors 61 to 66. OS transistors have higher field-effect mobility than, for example, transistors using amorphous silicon. Therefore, by using OS transistors as transistors 61 to 66, a display device can be driven at high speed.

The pixel circuit 23 shown in FIG. 25A includes transistors M1 to M7, a capacitor C1, and a light-emitting element EL. To the pixel circuit, wirings GL1 to GL4 functioning as gate lines, wiring SL1 functioning as a source line, wiring VP2 to which a fixed potential is supplied, wiring ANO functioning as an anode wiring, and wiring CAT functioning as a cathode wiring are connected.

The gate of transistor M1 is connected to wiring GL2, one of the source and drain is connected to wiring SL1, and the other of the source and drain is connected to one of the source and drain of transistor M2 and one of the source and drain of transistor M3. The gate of transistor M2 is connected to wiring GL3, and the other of the source and drain is connected to wiring ANO. The gate of transistor M3 is connected to one electrode of capacitance C1, the other of the source and drain of transistor M4, and one of the source and drain of transistor M6, the backgate is connected to wiring ANO, and the other of the source and drain is connected to one of the source and drain of transistor M4 and one of the source and drain of transistor M5. The gate of transistor M4 is connected to transistor GL2. The gate of transistor M5 is connected to wiring GL3, and the other of the source and drain is connected to one electrode of the light-emitting element EL and one of the source and drain of transistor M7. The gate of the transistor M6 is connected to the wiring GL1, and the other of the source and drain is connected to the wiring VP2. The gate of the transistor M7 is connected to the wiring GL4, and the other of the source and drain is connected to the wiring VP2. The other electrode of the capacitor C1 is connected to the wiring ANO.

Here, an example is shown in which all of the transistors M1 to M7 are p-channel transistors, but one or more may be n-channel transistors. Figure 25B shows an example in which the transistors M4 and M6 are replaced with n-channel transistors.

Transistor M3 functions as a drive transistor, and the other transistors function as switches. It is preferable to use a p-channel LTPS transistor for transistor M3. It is preferable to use TG transistors with small parasitic capacitance for transistors M4 and M6, which are greatly affected by noise on capacitance C1. It is also preferable to use vertical transistors or LTPS transistors with large on-current for transistors M1, M2, M5, and M7. When using TG transistors and vertical transistors, it is preferable to use n-channel transistors.

This embodiment can be implemented in combination with at least a portion of the other embodiments described in this specification.

(Embodiment 4)
In this embodiment, a light-receiving and light-emitting device according to one embodiment of the present invention will be described. The light-receiving and light-emitting device or a part of the light-receiving and light-emitting device and the display device or a part of the display device described below can be suitably used in the electronic device described in Embodiment 1. The light-receiving and light-emitting portion of the light-receiving and light-emitting device can be applied to, for example, a display portion included in the electronic device according to one embodiment of the present invention.

The light-receiving and light-emitting portion of the light-receiving and light-emitting device of one embodiment of the present invention has a light-receiving element (also called a light-receiving device) and a light-emitting element. The light-receiving and light-emitting portion has a function of displaying an image using the light-emitting element. Furthermore, the light-receiving and light-emitting portion has one or both of a function of capturing an image and a function of sensing using the light-receiving element. Therefore, the light-receiving and light-emitting device of one embodiment of the present invention can also be expressed as a display device, and the light-receiving and light-emitting portion can also be expressed as a display portion.

Alternatively, the light-receiving and light-emitting device of one embodiment of the present invention may have a light-receiving and light-emitting element (also called a light-receiving and light-emitting device) and a light-emitting element.

First, we will explain the light receiving and emitting device that has a light receiving element and a light emitting element.

The light-receiving and light-emitting device of one embodiment of the present invention has a light-receiving element and a light-emitting element in the light-receiving and light-emitting portion. In the light-receiving and light-emitting device of one embodiment of the present invention, the light-emitting and receiving portion has light-emitting elements arranged in a matrix, and an image can be displayed in the light-receiving and light-emitting portion. The light-receiving and light-emitting portion has light-receiving elements arranged in a matrix, and the light-receiving and light-emitting portion has one or both of an imaging function and a sensing function. The light-receiving and light-emitting portion can be used as an image sensor, a touch sensor, and the like. That is, by detecting light in the light-receiving and light-receiving portion, it is possible to capture an image and detect a touch operation of an object (such as a finger or a pen). Furthermore, in the light-receiving and light-emitting device of one embodiment of the present invention, the light-emitting and receiving device can use the light-emitting element as a light source for a sensor. Therefore, it is not necessary to provide a light-receiving portion and a light source separately from the light-receiving and light-emitting device, and the number of components in an electronic device can be reduced.

In one embodiment of the light-receiving and light-emitting device of the present invention, when light emitted by a light-emitting element in the light-receiving and light-emitting unit is reflected (or scattered) by an object, the light-receiving element can detect the reflected light (or scattered light), making it possible to capture images and detect touch operations even in dark places.

The light-emitting element of the light-receiving and light-emitting device of one embodiment of the present invention functions as a display element (also called a display device).

As the light-emitting element, it is preferable to use an EL element (also called an EL device) such as an OLED or QLED. Examples of the light-emitting substance possessed by the EL element include a substance that emits fluorescence (fluorescent material), a substance that emits phosphorescence (phosphorescent material), and a substance that exhibits thermally activated delayed fluorescence (thermally activated delayed fluorescence (TADF) material). As the light-emitting substance possessed by the EL element, not only organic compounds but also inorganic compounds (such as quantum dot materials) can be used. Furthermore, LEDs such as micro LEDs can also be used as the light-emitting element.

The light-receiving and light-emitting device of one embodiment of the present invention has a function of detecting light using a light-receiving element.

When the light receiving element is used in an image sensor, the light receiving and emitting device can capture an image using the light receiving element. For example, the light receiving and emitting device can be used as a scanner.

An electronic device to which the light-emitting and receiving device of one embodiment of the present invention is applied can acquire data related to biometric information such as a fingerprint or palm print by using the function as an image sensor. In other words, a biometric authentication sensor can be built into the light-emitting and receiving device. By building in a biometric authentication sensor into the light-emitting and receiving device, the number of components in the electronic device can be reduced compared to a case in which a biometric authentication sensor is provided separately from the light-emitting and receiving device, and the electronic device can be made smaller and lighter.

In addition, when the light receiving element is used as a touch sensor, the light receiving and emitting device can detect a touch operation on an object using the light receiving element.

The light receiving element can be, for example, a pn-type or pin-type photodiode. The light receiving element functions as a photoelectric conversion element (also called a photoelectric conversion device) that detects light incident on the light receiving element and generates an electric charge. The amount of electric charge generated by the light receiving element is determined based on the amount of light incident on the light receiving element.

In particular, it is preferable to use an organic photodiode having a layer containing an organic compound as the light receiving element. Organic photodiodes can be easily made thin, lightweight, and large in area, and have a high degree of freedom in shape and design, making them applicable to a variety of devices.

In one embodiment of the present invention, an organic EL element (also called an organic EL device) is used as a light-emitting element, and an organic photodiode is used as a light-receiving element. The organic EL element and the organic photodiode can be formed on the same substrate. Therefore, an organic photodiode can be built into a display device using an organic EL element.

If all the layers constituting an organic EL element and an organic photodiode are fabricated separately, the number of film formation processes becomes enormous. However, since organic photodiodes have many layers that can be configured in common with organic EL elements, the layers that can be configured in common can be formed in one go, thereby preventing an increase in the number of film formation processes.

For example, one of the pair of electrodes (common electrode) can be a layer common to the light receiving element and the light emitting element. Also, for example, at least one of the hole injection layer, the hole transport layer, the electron transport layer, and the electron injection layer can be a layer common to the light receiving element and the light emitting element. In this way, by having a common layer for the light receiving element and the light emitting element, the number of film formations and the number of masks can be reduced, and the number of manufacturing steps and manufacturing costs of the light receiving and emitting device can be reduced. Also, a light receiving and emitting device having a light receiving element can be manufactured using existing manufacturing equipment and manufacturing methods for display devices.

Next, we will explain the light emitting/receiving device having a light emitting/receiving element and a light emitting element. Note that the description of the same functions, actions, effects, etc. as those described above may be omitted.

In the light-receiving and light-emitting device of one embodiment of the present invention, the subpixels that exhibit one of the colors have a light-receiving and light-emitting element instead of a light-emitting element, and the subpixels that exhibit the other colors have a light-emitting element. The light-receiving and light-emitting element has both a function of emitting light (light-emitting function) and a function of receiving light (light-receiving function). For example, when a pixel has three subpixels, a red subpixel, a green subpixel, and a blue subpixel, at least one subpixel has a light-receiving and light-emitting element, and the other subpixels have a light-emitting element. Therefore, the light-receiving and light-emitting portion of the light-receiving and light-emitting device of one embodiment of the present invention has a function of displaying an image using both the light-receiving and light-emitting elements and the light-emitting elements.

By having the light receiving/emitting element function as both a light emitting element and a light receiving element, it is possible to impart a light receiving function to the pixel without increasing the number of sub-pixels included in the pixel. This makes it possible to add one or both of an imaging function and a sensing function to the light receiving/emitting section of the light receiving/emitting device while maintaining the aperture ratio of the pixel (aperture ratio of each sub-pixel) and the definition of the light receiving/emitting device. Therefore, the light receiving/emitting device of one embodiment of the present invention can increase the aperture ratio of the pixel and easily achieve high definition compared to a case in which a sub-pixel having a light receiving element is provided in addition to a sub-pixel having a light emitting element.

In the light-receiving and light-emitting device of one embodiment of the present invention, light-receiving and light-emitting elements and light-emitting elements are arranged in a matrix in a light-receiving and light-emitting portion, and an image can be displayed in the light-receiving and light-emitting portion. The light-receiving and light-emitting portion can be used as an image sensor, a touch sensor, and the like. In the light-receiving and light-emitting device of one embodiment of the present invention, the light-emitting element can be used as a light source for the sensor. Therefore, imaging and detection of touch operations are possible even in a dark place.

The light-receiving element can be produced by combining an organic EL element and an organic photodiode. For example, the active layer of an organic photodiode can be added to the layered structure of an organic EL element to produce a light-receiving element. Furthermore, a light-receiving element produced by combining an organic EL element and an organic photodiode can suppress an increase in the number of film-forming steps by forming layers that can be configured in common with the organic EL element in a single step.

For example, one of the pair of electrodes (a common electrode) can be a layer common to the light-receiving and light-emitting elements. Also, for example, at least one of the hole injection layer, the hole transport layer, the electron transport layer, and the electron injection layer can be a layer common to the light-receiving and light-emitting elements.

The layers of the light-receiving/light-emitting element may have different functions depending on whether the light-receiving/light-emitting element functions as a light-receiving element or as a light-emitting element. In this specification, the components are named based on their functions when the light-receiving/light-emitting element functions as a light-emitting element.

The light-receiving and light-emitting device of this embodiment has a function of displaying an image using a light-emitting element and a light-receiving and light-emitting element. In other words, the light-emitting element and the light-receiving and light-emitting element function as display elements.

The light emitting/receiving device of this embodiment has the function of detecting light using a light emitting/receiving element. The light emitting/receiving element can detect light with a shorter wavelength than the light emitted by the light emitting/receiving element itself.

When the light-emitting/receiving elements are used in an image sensor, the light-emitting/receiving device of this embodiment can capture an image using the light-emitting/receiving elements. Also, when the light-emitting/receiving elements are used in a touch sensor, the light-emitting/receiving device of this embodiment can detect a touch operation on an object using the light-emitting/receiving elements.

The light-receiving and light-emitting element functions as a photoelectric conversion element. The light-receiving and light-emitting element can be produced by adding an active layer of a light-receiving element to the configuration of the light-emitting element described above. For example, the active layer of a pn-type or pin-type photodiode can be used for the light-receiving and light-emitting element.

In particular, it is preferable to use an active layer of an organic photodiode having a layer containing an organic compound for the light-receiving and light-emitting element. Organic photodiodes are easy to make thin, lightweight, and large in area, and have a high degree of freedom in shape and design, making them applicable to a variety of devices.

Below, a display device, which is an example of a light-emitting and receiving device according to one embodiment of the present invention, will be described in more detail with reference to the drawings.

[Display Device Configuration Example 1]
[Configuration Example 1-1]
26A shows a schematic diagram of the display unit 200. The display unit 200 has a substrate 201, a substrate 202, a light receiving element 212, a light emitting element 211R, a light emitting element 211G, a light emitting element 211B, a functional layer 203, and the like.

Light-emitting element 211R, light-emitting element 211G, light-emitting element 211B, and light-receiving element 212 are provided between substrate 201 and substrate 202. Light-emitting element 211R, light-emitting element 211G, and light-emitting element 211B emit red (R), green (G), and blue (B) light, respectively. Note that below, when there is no need to distinguish between light-emitting element 211R, light-emitting element 211G, and light-emitting element 211B, they may be referred to as light-emitting element 211.

The display unit 200 has a plurality of pixels arranged in a matrix. Each pixel has one or more sub-pixels. Each sub-pixel has one light-emitting element. For example, a pixel may have three sub-pixels (three colors: R, G, and B, or three colors: yellow (Y), cyan (C), and magenta (M)), or a pixel may have four sub-pixels (four colors: R, G, B, and white (W), or four colors: R, G, B, and Y). Furthermore, the pixel has a light-receiving element 212. The light-receiving element 212 may be provided in all pixels, or may be provided in some pixels. Also, one pixel may have multiple light-receiving elements 212.

Figure 26A shows a state in which a finger 220 touches the surface of the substrate 202. A portion of the light emitted by the light-emitting element 211G is reflected at the contact point between the substrate 202 and the finger 220. Then, a portion of the reflected light is incident on the light-receiving element 212, making it possible to detect that the finger 220 has touched the substrate 202. In other words, the display unit 200 can function as a touch panel.

The functional layer 203 has a circuit for driving the light-emitting element 211R, the light-emitting element 211G, and the light-emitting element 211B, and a circuit for driving the light-receiving element 212. The functional layer 203 is provided with switches, transistors, capacitance, wiring, and the like. Note that when the light-emitting element 211R, the light-emitting element 211G, the light-emitting element 211B, and the light-receiving element 212 are driven by a passive matrix method, a configuration without switches, transistors, and the like may be used.

The display unit 200 preferably has a function for detecting the fingerprint of a finger 220. Fig. 26B shows a schematic enlarged view of the contact area when the finger 220 is touching the substrate 202. Fig. 26B also shows light-emitting elements 211 and light-receiving elements 212 arranged alternately.

A fingerprint is formed on finger 220 by concave and convex parts. Therefore, the convex parts of the fingerprint are touching substrate 202 as shown in FIG. 26B.

Light reflected from a surface, interface, etc. can be specularly reflected or diffusely reflected. Specularly reflected light is highly directional, with the angle of incidence and angle of reflection being the same, while diffusely reflected light is less directional, with its intensity less dependent on the angle. The light reflected from the surface of the finger 220 is dominated by the diffuse reflection component of the specular and diffuse reflection types. On the other hand, the light reflected from the interface between the substrate 202 and the atmosphere is dominated by the specular reflection component.

The intensity of light reflected by the contact or non-contact surface between finger 220 and substrate 202 and incident on light receiving element 212 located directly below them is the sum of specularly reflected light and diffusely reflected light. As described above, in the concave portions of finger 220, substrate 202 and finger 220 do not come into contact, so specularly reflected light (indicated by solid arrows) is dominant, whereas in the convex portions, they come into contact, so diffusely reflected light (indicated by dashed arrows) from finger 220 is dominant. Therefore, the intensity of light received by light receiving element 212 located directly below the concave portions is higher than that of light receiving element 212 located directly below the convex portions. This allows the fingerprint of finger 220 to be captured.

By setting the spacing between the light receiving elements 212 to be smaller than the distance between two convex parts of a fingerprint, preferably the distance between adjacent convex and concave parts, a clear fingerprint image can be obtained. Since the distance between the concave and convex parts of a human fingerprint is approximately 200 μm, for example, the spacing between the light receiving elements 212 is 400 μm or less, preferably 200 μm or less, more preferably 150 μm or less, even more preferably 100 μm or less, and even more preferably 50 μm or less, and is 1 μm or more, preferably 10 μm or more, and more preferably 20 μm or more.

An example of a fingerprint image captured by the display unit 200 is shown in FIG. 26C. In FIG. 26C, within the imaging range 223, the outline of the finger 220 is shown by a dashed line, and the outline of the contact area 221 is shown by a dashed line. Within the contact area 221, a fingerprint 222 with high contrast can be captured due to differences in the amount of light incident on the light receiving element 212.

The subject may be a palm and authentication may be performed using a palm print. As shown in FIG. 27E, the palm is positioned in the imaging range 223 so that the palm print 222b of the palm 220b is captured.

In the configuration shown in FIG. 26A and the like, an example is shown in which a light-emitting element functioning as a display panel and a light-receiving element functioning as a sensor having a function of reading fingerprints, palm prints, etc. are arranged on the substrate 201, but the light-emitting element and the sensor having a function of reading fingerprints, palm prints, etc. do not have to be formed on the same plane. For example, the sensor having a function of reading fingerprints, palm prints, etc. may be arranged below the display unit. For example, an IC chip equipped with a sensor having a function of reading fingerprints, palm prints, etc. may be arranged below the display unit. However, in such a case, compared to the case in which the display unit itself functions as a sensor as in one embodiment of the present invention, when the sensor is provided separately from the display unit, the volume occupied within the housing increases. Therefore, the degree of freedom in arranging the sensor within the housing is reduced. In addition, if the area of the sensor is limited, the number of fingers to be read is limited.

In an electronic device according to one aspect of the present invention, the display unit itself functions as a sensor, making it possible to read fingerprints, palm prints, and the like at any position on the display unit. Therefore, the area on the display unit where reading is performed can be operated in any shape, such as vertical or horizontal, and suitable reading can be performed at an appropriate position and with any number of fingers, etc.

The display unit 200 can also function as a touch sensor or a pen tablet. Figure 26D shows the tip of the stylus 225 being slid in the direction of the dashed arrow while in contact with the substrate 202.

As shown in FIG. 26D, the diffuse reflected light diffused by the tip of the stylus 225 and the contact surface of the substrate 202 is incident on the light receiving element 212 located at the portion overlapping the contact surface, thereby enabling the position of the tip of the stylus 225 to be detected with high accuracy.

Figure 26E shows an example of the trajectory 226 of the stylus 225 detected by the display unit 200. The display unit 200 is capable of detecting the position of a detectable object such as the stylus 225 with high positional accuracy, and therefore is also capable of performing high-resolution drawing in drawing applications and the like. Also, unlike the case where a capacitive touch sensor, an electromagnetic induction touch pen, or the like is used, the position of even a highly insulating detectable object can be detected, so the material of the tip of the stylus 225 does not matter, and various writing implements (e.g., a brush, a glass pen, a feather pen, etc.) can be used.

Here, Figures 26F to 26H show an example of a pixel that can be applied to the display unit 200.

The pixels shown in Figures 26F and 26G each have a red (R) light-emitting element 211R, a green (G) light-emitting element 211G, a blue (B) light-emitting element 211B, and a light-receiving element 212. The pixels each have a pixel circuit for driving the light-emitting element 211R, the light-emitting element 211G, the light-emitting element 211B, and the light-receiving element 212.

Figure 26F shows an example in which three light-emitting elements and one light-receiving element are arranged in a 2 x 2 matrix. Figure 26G shows an example in which three light-emitting elements are arranged in a row, with one horizontally long light-receiving element 212 arranged below them.

The pixel shown in Figure 26H is an example having a white (W) light-emitting element 211W. Here, four light-emitting elements are arranged in a row, and a light-receiving element 212 is arranged below them.

Note that the pixel configuration is not limited to the above, and various arrangement methods can be used.

[Configuration Example 1-2]
In the following, a configuration example including a light-emitting element that emits visible light, a light-emitting element that emits infrared light, and a light-receiving element will be described.

The display unit 200A shown in FIG. 27A has a light-emitting element 211IR in addition to the configuration exemplified in FIG. 26A. The light-emitting element 211IR is a light-emitting element that emits infrared light IR. In this case, it is preferable to use an element that can receive at least the infrared light IR emitted by the light-emitting element 211IR as the light-receiving element 212. It is more preferable to use an element that can receive both visible light and infrared light as the light-receiving element 212.

As shown in FIG. 27A, when a finger 220 touches the substrate 202, the infrared light IR emitted from the light-emitting element 211IR is reflected by the finger 220, and a portion of the reflected light is incident on the light-receiving element 212, thereby obtaining position information of the finger 220.

Figures 27B to 27D show an example of a pixel that can be used in the display unit 200A.

Figure 27B shows an example in which three light-emitting elements are arranged in a row, and below them, light-emitting element 211IR and light-receiving element 212 are arranged side by side. Also, Figure 27C shows an example in which four light-emitting elements including light-emitting element 211IR are arranged in a row, and below them, light-receiving element 212 is arranged.

Figure 27D shows an example in which three light-emitting elements and a light-receiving element 212 are arranged on all four sides with the light-emitting element 211IR at the center.

Note that in the pixels shown in Figures 27B to 27D, the positions of the light-emitting elements and the light-emitting elements and light-receiving elements can be interchanged.

[Configuration Example 1-3]
In the following, a configuration example including a light-emitting element that emits visible light and a light-receiving/light-emitting element that emits visible light and receives visible light will be described.

The display unit 200B shown in FIG. 28A has a light-emitting element 211B, a light-emitting element 211G, and a light-receiving/light-emitting element 213R. The light-receiving/light-emitting element 213R has a function as a light-emitting element that emits red (R) light, and a function as a photoelectric conversion element that receives visible light. FIG. 28A shows an example in which the light-receiving/light-emitting element 213R receives green (G) light emitted by the light-emitting element 211G. The light-receiving/light-emitting element 213R may receive blue (B) light emitted by the light-emitting element 211B. The light-receiving/light-emitting element 213R may also receive both green and blue light.

For example, it is preferable that the light receiving/emitting element 213R receives light with a shorter wavelength than the light it emits. Alternatively, the light receiving/emitting element 213R may be configured to receive light with a longer wavelength than the light it emits (e.g., infrared light). The light receiving/emitting element 213R may be configured to receive light with a wavelength similar to the light it emits, but in that case, it may also receive the light it emits, which may reduce the light emission efficiency. For this reason, it is preferable that the light receiving/emitting element 213R is configured so that the peak of the emission spectrum and the peak of the absorption spectrum do not overlap as much as possible.

In addition, the light emitted by the light-receiving/light-emitting element is not limited to red light. Furthermore, the light emitted by the light-emitting element is not limited to a combination of green light and blue light. For example, the light-receiving/light-emitting element can be an element that emits green or blue light and receives light of a different wavelength from the light it emits.

In this way, the light receiving/receiving element 213R functions as both a light emitting element and a light receiving element, so the number of elements arranged in one pixel can be reduced. This makes it easier to achieve higher definition, a higher aperture ratio, and higher resolution.

Figures 28B to 28I show an example of a pixel that can be used in the display unit 200B.

Figure 28B shows an example in which light-emitting/receiving element 213R, light-emitting element 211G, and light-emitting element 211B are arranged in a row. Figure 28C shows an example in which light-emitting element 211G and light-emitting element 211B are arranged alternately in the vertical direction, with light-emitting/receiving element 213R arranged next to them.

Figure 28D shows an example in which three light-emitting elements (light-emitting element 211G, light-emitting element 211B, and light-emitting element 211X) and one light-receiving and light-emitting element are arranged in a 2x2 matrix. Light-emitting element 211X is an element that emits light other than R, G, and B. Examples of light other than R, G, and B include white (W), yellow (Y), cyan (C), magenta (M), infrared light (IR), and ultraviolet light (UV). When light-emitting element 211X emits infrared light, it is preferable that the light-receiving and light-emitting element has a function of detecting infrared light or a function of detecting both visible light and infrared light. The wavelength of light detected by the light-receiving and light-emitting element can be determined depending on the application of the sensor.

Two pixels are shown in FIG. 28E. An area including three elements surrounded by dotted lines corresponds to one pixel. Each pixel has a light-emitting element 211G, a light-emitting element 211B, and a light-receiving/light-emitting element 213R. In the left pixel shown in FIG. 28E, the light-emitting element 211G is arranged in the same row as the light-receiving/light-emitting element 213R, and the light-emitting element 211B is arranged in the same column as the light-receiving/light-emitting element 213R. In the right pixel shown in FIG. 28E, the light-emitting element 211G is arranged in the same row as the light-receiving/light-emitting element 213R, and the light-emitting element 211B is arranged in the same column as the light-receiving/light-emitting element 211G. In the pixel layout shown in FIG. 28E, the light-receiving/light-emitting elements 213R, the light-emitting element 211G, and the light-emitting element 211B are arranged repeatedly in both odd and even rows, and in each column, light-emitting elements or light-receiving/light-emitting elements with different emission colors are arranged in the odd and even rows.

Figure 28F shows four pixels to which a Pentile array is applied, with two adjacent pixels having light-emitting or light-receiving elements that emit light of two different colors. Note that Figure 28F shows the top shape of the light-emitting or light-receiving elements.

The upper left pixel and the lower right pixel shown in FIG. 28F have a light receiving/emitting element 213R and a light emitting element 211G. The upper right pixel and the lower left pixel have a light emitting element 211G and a light emitting element 211B. That is, in the example shown in FIG. 28F, a light emitting element 211G is provided in each pixel.

The top surface shape of the light-emitting element and light-receiving element is not particularly limited, and can be a circle, an ellipse, a polygon, a polygon with rounded corners, etc. Figure 28F etc. shows an example in which the top surface shape of the light-emitting element and light-receiving element is a square (diamond) tilted at approximately 45 degrees. Note that the top surface shapes of the light-emitting element and light-receiving element for each color may be different from each other, or may be the same for some or all of the colors.

Furthermore, the size of the light-emitting region (or light-receiving region) of the light-emitting element and light-receiving/light-emitting element of each color may be different from each other, or may be the same for some or all colors. For example, in FIG. 28F, the area of the light-emitting region of the light-emitting element 211G provided in each pixel may be smaller than the light-emitting regions (or light-receiving/light-emitting regions) of the other elements.

Figure 28G is a modified example of the pixel array shown in Figure 28F. Specifically, the configuration in Figure 28G is obtained by rotating the configuration in Figure 28F by 45 degrees. In Figure 28F, it has been described that one pixel has two elements, but as shown in Figure 28G, one pixel can also be considered to be made up of four elements.

Figure 28H is a modified example of the pixel array shown in Figure 28F. The upper left pixel and lower right pixel shown in Figure 28H have light receiving/emitting element 213R and light emitting element 211G. The upper right pixel and lower left pixel have light receiving/emitting element 213R and light emitting element 211B. That is, in the example shown in Figure 28H, each pixel is provided with light receiving/emitting element 213R. Because each pixel is provided with light receiving/emitting element 213R, the configuration shown in Figure 28H can capture images with higher resolution than the configuration shown in Figure 28F. This can improve the accuracy of biometric authentication, for example.

Figure 28I is a modified example of the pixel array shown in Figure 28H, which is obtained by rotating the pixel array by 45 degrees.

In FIG. 28I, it is assumed that one pixel is composed of four elements (two light-emitting elements and two light-receiving and light-emitting elements). In this way, one pixel can capture images with high resolution by having multiple light-receiving and light-emitting elements with light-receiving capabilities. This can improve the accuracy of biometric authentication. For example, the resolution of the image can be set to the root of twice the resolution of the display.

A display device to which the configuration shown in Figure 28H or Figure 28I is applied has p (p is an integer of 2 or more) first light-emitting elements, q (q is an integer of 2 or more) second light-emitting elements, and r (r is an integer greater than p and greater than q) light-receiving and light-emitting elements. p and r satisfy r = 2p. Furthermore, p, q, and r satisfy r = p + q. One of the first light-emitting elements and the second light-emitting elements emits green light, and the other emits blue light. The light-receiving and light-emitting elements emit red light and have a light-receiving function.

For example, when detecting a touch operation using a light-receiving/light-emitting element, it is preferable that the light emitted from the light source is difficult for the user to see. Blue light is less visible than green light, so it is preferable to use a light-emitting element that emits blue light as the light source. Therefore, it is preferable that the light-receiving/light-emitting element has a function of receiving blue light. However, this is not limited, and the light-emitting element to be used as the light source can be appropriately selected depending on the sensitivity of the light-receiving/light-emitting element.

As described above, various pixel arrangements can be applied to the display device of this embodiment.

This embodiment can be implemented in combination with at least a portion of the other embodiments described in this specification.

(Embodiment 5)
In this embodiment, a light-emitting element and a light-receiving element that can be used in a light-receiving and light-emitting device which is one embodiment of the present invention will be described.

In this specification, etc., a device fabricated using a metal mask or an FMM (fine metal mask, high-definition metal mask) may be referred to as a device with an MM (metal mask) structure. Also, in this specification, etc., a device fabricated without using a metal mask or an FMM may be referred to as a device with an MML (metal maskless) structure.

Note that in this specification, a structure in which a separate light-emitting layer is created for each color light-emitting element (here, blue (B), green (G), and red (R)), or the light-emitting layers are painted separately, may be referred to as an SBS (Side By Side) structure. Also, in this specification, a light-emitting element capable of emitting white light may be referred to as a white light-emitting element. Note that a white light-emitting element can be combined with a colored layer (e.g., a color filter) to realize a light-emitting device and electronic device having a full-color display unit.

[Light-emitting element]
Moreover, the light-emitting element can be roughly divided into a single structure and a tandem structure. A single structure device has one light-emitting unit between a pair of electrodes, and the light-emitting unit is preferably configured to include one or more light-emitting layers. To obtain white light emission with a single structure, a light-emitting layer that can produce white light by the emission of each of two or more light-emitting layers can be selected to obtain white light emission. For example, in the case of two colors, a configuration in which the light-emitting element as a whole emits white light can be obtained by making the emission color of the first light-emitting layer and the emission color of the second light-emitting layer have a complementary color relationship. In addition, when white light emission is obtained using three or more light-emitting layers, a configuration in which the emission colors of the three or more light-emitting layers are combined to emit white light as a whole light-emitting device can be used to obtain white light emission.

A device with a tandem structure has two or more light-emitting units between a pair of electrodes, and each light-emitting unit preferably includes one or more light-emitting layers. By using light-emitting layers that emit light of the same color in each light-emitting unit, the luminance per given current can be increased, and a light-emitting element with higher reliability can be obtained compared to a single structure. To obtain white light emission in a tandem structure, a configuration can be used in which light from the light-emitting layers of multiple light-emitting units is combined to obtain white light emission. The combination of light-emitting colors that produces white light emission is the same as in the single structure. In a device with a tandem structure, it is preferable to provide an intermediate layer such as a charge generation layer between the multiple light-emitting units.

In addition, when comparing the above-mentioned white light-emitting element (single structure or tandem structure) with a light-emitting element having an SBS structure, the light-emitting element having an SBS structure can reduce power consumption compared to the white light-emitting element. If you want to keep power consumption low, it is preferable to use a light-emitting element having an SBS structure. On the other hand, the manufacturing process of the white light-emitting element is simpler than that of the light-emitting element having an SBS structure, so it is preferable because the manufacturing cost can be reduced or the manufacturing yield can be increased.

<Configuration example of light-emitting element>
As shown in FIG. 29A , the light-emitting element has an EL layer 790 between a pair of electrodes (a lower electrode 791 and an upper electrode 792). The EL layer 790 can be composed of a plurality of layers, such as a layer 720, a light-emitting layer 711, and a layer 730. The layer 720 can have, for example, a layer containing a substance with high electron injection properties (electron injection layer) and a layer containing a substance with high electron transport properties (electron transport layer). The light-emitting layer 711 has, for example, a light-emitting compound. The layer 730 can have, for example, a layer containing a substance with high hole injection properties (hole injection layer) and a layer containing a substance with high hole transport properties (hole transport layer).

A structure having layer 720, light-emitting layer 711, and layer 730 disposed between a pair of electrodes can function as a single light-emitting unit, and in this specification, the structure in FIG. 29A is referred to as a single structure.

29B is a modified example of the EL layer 790 of the light-emitting element shown in FIG. 29A. Specifically, the light-emitting element shown in FIG. 29B has a layer 730-1 on the lower electrode 791, a layer 730-2 on the layer 730-1, a light-emitting layer 711 on the layer 730-2, a layer 720-1 on the light-emitting layer 711, a layer 720-2 on the layer 720-1, and an upper electrode 792 on the layer 720-2. For example, when the lower electrode 791 is an anode and the upper electrode 792 is a cathode, the layer 730-1 functions as a hole injection layer, the layer 730-2 functions as a hole transport layer, the layer 720-1 functions as an electron transport layer, and the layer 720-2 functions as an electron injection layer. Alternatively, when the lower electrode 791 is a cathode and the upper electrode 792 is an anode, the layer 730-1 functions as an electron injection layer, the layer 730-2 functions as an electron transport layer, the layer 720-1 functions as a hole transport layer, and the layer 720-2 functions as a hole injection layer. By using such a layer structure, it is possible to efficiently inject carriers into the light-emitting layer 711 and increase the efficiency of carrier recombination in the light-emitting layer 711.

Note that a variation of the single structure is a configuration in which multiple light-emitting layers (light-emitting layers 711, 712, 713) are provided between layer 720 and layer 730, as shown in Figures 29C and 29D.

Furthermore, as shown in Figures 29E and 29F, a configuration in which multiple light-emitting units (EL layer 790a, EL layer 790b) are connected in series via an intermediate layer (charge generating layer) 740 is referred to as a tandem structure in this specification. Note that in this specification and the like, the configuration shown in Figures 29E and 29F is referred to as a tandem structure, but is not limited to this, and for example, the tandem structure can also be referred to as a stack structure. Note that by using a tandem structure, it is possible to obtain a light-emitting element that can emit light with high brightness.

In FIG. 29C, light-emitting layers 711, 712, and 713 may be made of light-emitting materials that emit light of the same color.

In addition, different light-emitting materials may be used for the light-emitting layers 711, 712, and 713. When the light emitted by the light-emitting layers 711, 712, and 713 is complementary in color, white light is obtained. Figure 29D shows an example in which a colored layer 795 that functions as a color filter is provided. When white light passes through the color filter, light of the desired color can be obtained.

In addition, in FIG. 29E, the same light-emitting material may be used for the light-emitting layers 711 and 712. Alternatively, light-emitting materials that emit light of different colors may be used for the light-emitting layers 711 and 712. When the light emitted by the light-emitting layers 711 and 712 is a complementary color, white light is obtained. FIG. 29F shows an example in which a colored layer 795 is further provided.

In addition, in Figures 29C, 29D, 29E, and 29F, layers 720 and 730 may have a laminated structure consisting of two or more layers, as shown in Figure 29B.

In addition, in FIG. 29D, the same light-emitting material may be used for light-emitting layers 711, 712, and 713. Similarly, in FIG. 29F, the same light-emitting material may be used for light-emitting layers 711 and 712. In this case, by applying a color conversion layer instead of colored layer 795, light of a desired color different from the light-emitting material can be obtained. For example, by using a blue light-emitting material for each light-emitting layer and transmitting blue light through the color conversion layer, light with a longer wavelength than blue (e.g., red, green, etc.) can be obtained. As the color conversion layer, a fluorescent material, a phosphorescent material, or quantum dots can be used.

A structure that produces different emission colors (here, blue (B), green (G), and red (R)) for each light-emitting element is sometimes called an SBS (Side By Side) structure.

The color of light emitted by the light-emitting element can be red, green, blue, cyan, magenta, yellow, or white, depending on the material that constitutes the EL layer 790. In addition, the color purity can be further improved by imparting a microcavity structure to the light-emitting element.

A light-emitting element that emits white light is preferably configured to include two or more types of light-emitting materials in the light-emitting layer. To obtain white light emission, it is preferable to select light-emitting materials in which the light emitted by the two light-emitting materials has a complementary color relationship, or to select light-emitting materials in which the light emitted by the two or more light-emitting materials is combined to produce a white light. For example, when white light emission is obtained using two light-emitting layers, a light-emitting element that emits white light as a whole can be obtained by making the light-emitting color of the first light-emitting layer and the light-emitting color of the second light-emitting layer complementary colors. In addition, when white light emission is obtained using three or more light-emitting layers, it is preferable to configure the light-emitting element to emit white light as a whole by combining the light-emitting colors of the three or more light-emitting layers.

The light-emitting layer preferably contains two or more luminescent materials that emit light of R (red), G (green), B (blue), Y (yellow), O (orange), etc. Alternatively, it is preferable that the light-emitting layer contains two or more luminescent materials, and the light emitted by each of the luminescent materials contains spectral components of two or more colors of R, G, and B.

Figure 30A shows a schematic cross-sectional view of light-emitting element 750R, light-emitting element 750G, light-emitting element 750B, and light-receiving element 760. Light-emitting element 750R, light-emitting element 750G, light-emitting element 750B, and light-receiving element 760 have upper electrode 792 as a common layer.

Light-emitting element 750R has pixel electrode 791R, layer 751, layer 752, light-emitting layer 753R, layer 754, layer 755, and upper electrode 792. Light-emitting element 750G has pixel electrode 791G and light-emitting layer 753G. Light-emitting element 750B has pixel electrode 791B and light-emitting layer 753B.

Layer 751 includes, for example, a layer containing a substance with high hole injection properties (hole injection layer), etc. Layer 752 includes, for example, a layer containing a substance with high hole transport properties (hole transport layer), etc. Layer 754 includes, for example, a layer containing a substance with high electron transport properties (electron transport layer), etc. Layer 755 includes, for example, a layer containing a substance with high electron injection properties (electron injection layer), etc.

Alternatively, a structure may be used in which layer 751 has an electron injection layer, layer 752 has an electron transport layer, layer 754 has a hole transport layer, and layer 755 has a hole injection layer.

Note that, although layers 751 and 752 are shown separately in FIG. 30A, this is not limiting. For example, when layer 751 has the functions of both a hole injection layer and a hole transport layer, or when layer 751 has the functions of both an electron injection layer and an electron transport layer, layer 752 may be omitted.

Note that the light-emitting layer 753R of the light-emitting element 750R has a light-emitting material that emits red light, the light-emitting layer 753G of the light-emitting element 750G has a light-emitting material that emits green light, and the light-emitting layer 753B of the light-emitting element 750B has a light-emitting material that emits blue light. Note that the light-emitting elements 750G and 750B have a configuration in which the light-emitting layer 753R of the light-emitting element 750R is replaced with the light-emitting layer 753G and the light-emitting layer 753B, respectively, and the other configurations are the same as those of the light-emitting element 750R.

Note that layers 751, 752, 754, and 755 may have the same configuration (material, film thickness, etc.) for the light-emitting elements of each color, or may have different configurations.

The light receiving element 760 has a pixel electrode 791PD, a layer 761, a layer 762, a layer 763, and an upper electrode 792. The light receiving element 760 can be configured without a hole injection layer and an electron injection layer.

Layer 762 has an active layer (also called a photoelectric conversion layer). Layer 762 has the function of absorbing light in a specific wavelength band and generating carriers (electrons and holes).

Layer 761 and layer 763 each have, for example, either a hole transport layer or an electron transport layer. When layer 761 has a hole transport layer, layer 763 has an electron transport layer. On the other hand, when layer 761 has an electron transport layer, layer 763 has a hole transport layer.

In addition, the light receiving element 760 may have the pixel electrode 791PD as the anode and the upper electrode 792 as the cathode, or the pixel electrode 791PD as the cathode and the upper electrode 792 as the anode.

Figure 30B is a modified example of Figure 30A. Figure 30B shows an example in which layer 755 is provided in common between each light-emitting element and each light-receiving element, similar to upper electrode 792. In this case, layer 755 can be called a common layer. In this way, by providing one or more common layers between each light-emitting element and each light-receiving element, the manufacturing process can be simplified, and manufacturing costs can be reduced.

Here, layer 755 functions as an electron injection layer or a hole injection layer for light-emitting element 750R and the like. At this time, layer 755 functions as an electron transport layer or a hole transport layer for light-receiving element 760. Therefore, layer 763 functioning as an electron transport layer or a hole transport layer does not need to be provided in light-receiving element 760 shown in FIG. 30B.

[Light-emitting element]
Here, a specific example of the configuration of the light-emitting element will be described.

The light-emitting element has at least a light-emitting layer. The light-emitting element may further have a layer other than the light-emitting layer, the layer including a substance having high hole injection properties, a substance having high hole transport properties, a hole blocking material, a substance having high electron transport properties, a substance having high electron injection properties, an electron blocking material, or a bipolar substance (a substance having high electron transport properties and hole transport properties).

The light-emitting element may be made of either a low molecular weight compound or a high molecular weight compound, and may contain an inorganic compound. The layers constituting the light-emitting element may be formed by a deposition method (including a vacuum deposition method), a transfer method, a printing method, an inkjet method, a coating method, or the like.

For example, the light-emitting element can have one or more layers selected from the group consisting of a hole injection layer, a hole transport layer, a hole blocking layer, an electron blocking layer, an electron transport layer, and an electron injection layer.

The hole injection layer is a layer that injects holes from the anode to the hole transport layer, and is a layer that contains a material with high hole injection properties. Examples of materials with high hole injection properties include aromatic amine compounds and composite materials that contain a hole transport material and an acceptor material (electron accepting material).

The hole transport layer is a layer that transports holes injected from the anode by the hole injection layer to the light emitting layer. The hole transport layer is a layer that contains a hole transport material. As the hole transport material, a substance having a hole mobility of 1×10 ⁻⁶ cm ² /Vs or more is preferable. Note that other substances can also be used as long as they have a higher hole transport property than electrons. As the hole transport material, a material having a high hole transport property such as a π-electron-rich heteroaromatic compound (e.g., a carbazole derivative, a thiophene derivative, a furan derivative, etc.) and an aromatic amine (a compound having an aromatic amine skeleton) is preferable.

The electron transport layer is a layer that transports electrons injected from the cathode by the electron injection layer to the light-emitting layer. The electron transport layer is a layer that includes an electron transporting material. As the electron transporting material, a substance having an electron mobility of 1×10 ⁻⁶ cm ² /Vs or more is preferable. Note that, other substances can be used as long as they have a higher electron transporting property than holes. As the electron transporting material, in addition to metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, and metal complexes having a thiazole skeleton, oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives having a quinoline ligand, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and other π-electron-deficient heteroaromatic compounds including nitrogen-containing heteroaromatic compounds can be used.

The electron injection layer is a layer that injects electrons from the cathode to the electron transport layer, and is a layer that contains a material with high electron injection properties. As the material with high electron injection properties, an alkali metal, an alkaline earth metal, or a compound thereof can be used. As the material with high electron injection properties, a composite material containing an electron transport material and a donor material (electron donor material) can also be used.

As the electron injection layer, for example, lithium, cesium, ytterbium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF ₂ ), 8-(quinolinolato)lithium (abbreviation: Liq), 2-(2-pyridyl)phenolatolithium (abbreviation: LiPP), 2-(2-pyridyl)-3-pyridinolatolithium (abbreviation: LiPPy), 4-phenyl-2-(2-pyridyl)phenolatolithium (abbreviation: LiPPP), lithium oxide (LiO _x ), alkali metals such as cesium carbonate, alkaline earth metals, or compounds thereof can be used. In addition, the electron injection layer may have a laminated structure of two or more layers. As the laminated structure, for example, a configuration in which lithium fluoride is used in the first layer and ytterbium is provided in the second layer can be used.

Alternatively, a material having electron transport properties may be used for the electron injection layer. For example, a compound having an unshared electron pair and an electron-deficient heteroaromatic ring may be used as the material having electron transport properties. Specifically, a compound having at least one of a pyridine ring, a diazine ring (pyrimidine ring, pyrazine ring, pyridazine ring), and a triazine ring may be used.

The lowest unoccupied molecular orbital (LUMO) level of an organic compound having an unshared electron pair is preferably -3.6 eV or more and -2.3 eV or less. In general, the highest occupied molecular orbital (HOMO) level and the LUMO level of an organic compound can be estimated by CV (cyclic voltammetry), photoelectron spectroscopy, optical absorption spectroscopy, inverse photoelectron spectroscopy, etc.

For example, 4,7-diphenyl-1,10-phenanthroline (abbreviation: BPhen), 2,9-di(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen), 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P), diquinoxalino[2,3-a:2',3'-c]phenazine (abbreviation: HATNA), 2,4,6-tris[3'-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: TmPPPyTz), etc. can be used as an organic compound having an unshared electron pair. Note that NBPhen has a higher glass transition temperature (Tg) and is more heat resistant than BPhen.

The light-emitting layer is a layer that contains a light-emitting substance. The light-emitting layer can have one or more types of light-emitting substances. As the light-emitting substance, a substance that emits light of a color such as blue, purple, blue-purple, green, yellow-green, yellow, orange, or red is appropriately used. In addition, a substance that emits near-infrared light can also be used as the light-emitting substance.

Light-emitting materials include fluorescent materials, phosphorescent materials, TADF materials, quantum dot materials, etc.

Examples of fluorescent materials include pyrene derivatives, anthracene derivatives, triphenylene derivatives, fluorene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, and naphthalene derivatives.

Examples of phosphorescent materials include organometallic complexes (particularly iridium complexes) having a 4H-triazole skeleton, 1H-triazole skeleton, imidazole skeleton, pyrimidine skeleton, pyrazine skeleton, or pyridine skeleton, organometallic complexes (particularly iridium complexes) having a phenylpyridine derivative having an electron-withdrawing group as a ligand, platinum complexes, and rare earth metal complexes.

The light-emitting layer may have one or more organic compounds (host material, assist material, etc.) in addition to the light-emitting substance (guest material). As the one or more organic compounds, one or both of a hole transport material and an electron transport material may be used. In addition, as the one or more organic compounds, a bipolar material or a TADF material may be used.

The light-emitting layer preferably has, for example, a phosphorescent material and a hole-transporting material and an electron-transporting material, which are a combination that easily forms an exciplex. With this configuration, light emission can be efficiently obtained using ExTET (Exciplex-Triple Energy Transfer), which is the energy transfer from the exciplex to the light-emitting material (phosphorescent material). By selecting a combination that forms an exciplex that emits light that overlaps with the wavelength of the lowest energy absorption band of the light-emitting material, the energy transfer becomes smooth and light emission can be efficiently obtained. With this configuration, it is possible to simultaneously achieve high efficiency, low voltage operation, and long life for the light-emitting element.

[Light receiving element]
The active layer of the light receiving element includes a semiconductor. Examples of the semiconductor include inorganic semiconductors such as silicon and organic semiconductors including organic compounds. In this embodiment, an example in which an organic semiconductor is used as the semiconductor of the active layer is shown. By using an organic semiconductor, the light emitting layer and the active layer can be formed by the same method (for example, vacuum deposition method), which is preferable because the manufacturing equipment can be shared.

Examples of the n-type semiconductor material of the active layer include electron-accepting organic semiconductor materials such as fullerene (e.g., C ₆₀ , C ₇₀ , etc.) and fullerene derivatives. Fullerene has a shape like a soccer ball, and this shape is energetically stable. Fullerene has both a deep (low) HOMO level and a LUMO level. Fullerene has a deep LUMO level, so it has extremely high electron-accepting (acceptor) properties. Normally, as in benzene, when the π-electron conjugation (resonance) spreads on a plane, the electron-donating (donor) properties are high, but fullerene has a spherical shape, so it has high electron-accepting properties despite the large spread of the π-electron conjugation. High electron-accepting properties cause charge separation efficiently at high speed, which is beneficial as a light-receiving element. Both _{C 60} and C ₇₀ have wide absorption bands in the visible light region, and C ₇₀ in particular is preferred because it has a larger π-electron conjugation system than C ₆₀ and a wide absorption band in the long wavelength region. Other fullerene derivatives include [6,6]-Phenyl-C ₇₁ -butylic acid methyl ester (abbreviation: PC70BM), [6,6]-Phenyl-C ₆₁ -butylic acid methyl ester (abbreviation: PC60BM), and 1',1'',4',4''-Tetrahydro-di[1,4]methanenaphthaleno[1,2:2',3',56,60:2'',3''][5,6]fullerene-C ₆₀ (abbreviation: ICBA).

In addition, examples of materials for n-type semiconductors include metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, metal complexes having a thiazole skeleton, oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, naphthalene derivatives, anthracene derivatives, coumarin derivatives, rhodamine derivatives, triazine derivatives, and quinone derivatives.

Examples of the p-type semiconductor material in the active layer include electron-donating organic semiconductor materials such as copper (II) phthalocyanine (CuPc), tetraphenyldibenzoperiflathene (DBP), zinc phthalocyanine (ZnPc), tin phthalocyanine (SnPc), and quinacridone.

In addition, examples of p-type semiconductor materials include carbazole derivatives, thiophene derivatives, furan derivatives, and compounds having an aromatic amine skeleton. In addition, examples of p-type semiconductor materials include naphthalene derivatives, anthracene derivatives, pyrene derivatives, triphenylene derivatives, fluorene derivatives, pyrrole derivatives, benzofuran derivatives, benzothiophene derivatives, indole derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, indolocarbazole derivatives, porphyrin derivatives, phthalocyanine derivatives, naphthalocyanine derivatives, quinacridone derivatives, polyphenylenevinylene derivatives, polyparaphenylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, and polythiophene derivatives.

The HOMO level of the electron-donating organic semiconductor material is preferably shallower (higher) than the HOMO level of the electron-accepting organic semiconductor material. The LUMO level of the electron-donating organic semiconductor material is preferably shallower (higher) than the LUMO level of the electron-accepting organic semiconductor material.

It is preferable to use spherical fullerenes as the electron-accepting organic semiconductor material, and an organic semiconductor material with a nearly planar shape as the electron-donating organic semiconductor material. Molecules with similar shapes tend to gather together, and when molecules of the same type aggregate, the energy levels of their molecular orbitals are close, which can increase carrier transport.

For example, the active layer is preferably formed by co-evaporation of an n-type semiconductor and a p-type semiconductor. Alternatively, the active layer may be formed by stacking an n-type semiconductor and a p-type semiconductor.

The light-receiving element may further include a layer containing a material with high hole transport properties, a material with high electron transport properties, or a bipolar material (a material with high electron transport properties and hole transport properties) as a layer other than the active layer. In addition, the light-receiving element may further include a layer containing a material with high hole injection properties, a hole blocking material, a material with high electron injection properties, an electron blocking material, etc., without being limited to the above.

The light receiving element may be made of either a low molecular weight compound or a high molecular weight compound, and may contain an inorganic compound. The layers constituting the light receiving element may be formed by a deposition method (including a vacuum deposition method), a transfer method, a printing method, an inkjet method, a coating method, or the like.

For example, a polymer compound such as poly(3,4-ethylenedioxythiophene)/polystyrenesulfonic acid (abbreviated as PEDOT/PSS) and an inorganic compound such as molybdenum oxide and copper iodide (CuI) can be used as the hole transport material or the electron blocking material. In addition, an inorganic compound such as zinc oxide (ZnO) and an organic compound such as polyethyleneimine ethoxylate (PEIE) can be used as the electron transport material or the hole blocking material. The light receiving element may have, for example, a mixed film of PEIE and ZnO.

In addition, a polymer compound such as poly[[4,8-bis[5-(2-ethylhexyl)-2-thienyl]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl]-2,5-thiophenediyl[5,7-bis(2-ethylhexyl)-4,8-dioxo-4H,8H-benzo[1,2-c:4,5-c']dithiophene-1,3-diyl]] polymer (abbreviation: PBDB-T) or a PBDB-T derivative that functions as a donor can be used in the active layer. For example, a method of dispersing an acceptor material in PBDB-T or a PBDB-T derivative can be used.

The active layer may also contain three or more materials. For example, in order to expand the absorption wavelength range, a third material may be mixed in addition to an n-type semiconductor material and a p-type semiconductor material. In this case, the third material may be either a low molecular weight compound or a high molecular weight compound.

That concludes the explanation of the photodetector.

This embodiment can be implemented in combination with at least a portion of the other embodiments described in this specification.

(Embodiment 6)
In this embodiment, a configuration example of a display device that can be used in an electronic device of one embodiment of the present invention will be described. A display portion of the electronic device of one embodiment of the present invention can include a light-emitting element and a light-receiving element included in the display device.

One aspect of the present invention is a display device having a light-emitting element and a light-receiving element. For example, a full-color display device can be realized by having three types of light-emitting elements that respectively emit red (R), green (G), and blue (B) light.

In one aspect of the present invention, EL layers and EL layers and active layers are processed into fine patterns by photolithography without using a shadow mask such as a metal mask. This makes it possible to realize a display device with high definition and a large aperture ratio, which have been difficult to achieve until now. Furthermore, because the EL layers can be made separately, it is possible to realize a display device that is extremely vivid, has high contrast, and has high display quality.

Regarding the spacing between EL layers of different colors or between an EL layer and an active layer, it is difficult to make it less than 10 μm, for example, using a formation method using a metal mask, but the above method can narrow it to 3 μm or less, 2 μm or less, or 1 μm or less. For example, by using an exposure device for LSI, the spacing can be narrowed to 500 nm or less, 200 nm or less, 100 nm or less, or even 50 nm or less. This allows the area of the non-light-emitting region that may exist between two light-emitting elements or between a light-emitting element and a light-receiving element to be significantly reduced, making it possible to approach an aperture ratio of 100%. For example, the aperture ratio can be 50% or more, 60% or more, 70% or more, 80% or more, or even 90% or more, and it is also possible to achieve less than 100%.

Furthermore, the size of the EL layer and the active layer themselves can be made much smaller than when a metal mask is used. Also, for example, when a metal mask is used to create separate EL layers, the thickness varies between the center and edges of the island-shaped EL layer, so the effective area that can be used as a light-emitting region is small compared to the area of the entire EL layer. On the other hand, with the above manufacturing method, the island-shaped EL layer is formed by processing a film that has been deposited to a uniform thickness, so the thickness can be made uniform, and even if the size of the EL layer is minute, almost the entire area can be used as a light-emitting region. Therefore, with the above manufacturing method, it is possible to achieve both high definition and a high aperture ratio.

Organic films formed using FMM (Fine Metal Mask) often have a very small taper angle (e.g., greater than 0 degrees and less than 30 degrees) with the thickness decreasing toward the end. For this reason, organic films formed using FMM have a continuous connection between the side and top surfaces, making it difficult to clearly identify the side surfaces. On the other hand, one aspect of the present invention has an EL layer processed without using FMM, and therefore has clear side surfaces. In particular, one aspect of the present invention preferably has a portion where the EL layer has a taper angle of 30 degrees or more and 120 degrees or less, preferably 60 degrees or more and 120 degrees or less.

In this specification, the end of an object being tapered means that the angle between the side (surface) and the surface to be formed (bottom surface) in the end region is greater than 0 degrees and less than 90 degrees, and the cross-sectional shape has a continuously increasing thickness from the end. The taper angle refers to the angle between the bottom surface (surface to be formed) and the side (surface) at the end of the object.

More specific examples are provided below.

Figure 31A shows a schematic top view of the display device 100. The display device 100 has multiple light-emitting elements 90R that exhibit red light, multiple light-emitting elements 90G that exhibit green light, multiple light-emitting elements 90B that exhibit blue light, and multiple light-receiving elements 90S. The display device 100 has a substrate 101, and the light-emitting elements 90R, 90G, 90B, and 90S are each provided on the substrate 101. In Figure 31A, to easily distinguish between the light-emitting elements, the symbols R, G, B, and S are assigned within the light-emitting region of each light-emitting element or light-receiving element.

The light-emitting element 90R, the light-emitting element 90G, the light-emitting element 90B, and the light-receiving element 90S are each arranged in a matrix. FIG. 31A shows a configuration in which two elements are arranged alternately in one direction. Note that the method of arranging the light-emitting elements is not limited to this, and arrangement methods such as a stripe arrangement, an S-stripe arrangement, a delta arrangement, a Bayer arrangement, a zigzag arrangement, or a pentile arrangement, diamond arrangement, etc. may also be used.

Furthermore, FIG. 31A shows a connection electrode 111C that is electrically connected to the common electrode 113. The connection electrode 111C is given a potential (e.g., an anode potential or a cathode potential) to be supplied to the common electrode 113. The connection electrode 111C is provided outside the display area where the light-emitting elements 90R and the like are arranged. Furthermore, FIG. 31A shows the common electrode 113 by a dashed line.

The connection electrode 111C can be provided along the outer periphery of the display area. For example, it may be provided along one side of the outer periphery of the display area, or it may be provided over two or more sides of the outer periphery of the display area. In other words, if the top surface shape of the display area is rectangular, the top surface shape of the connection electrode 111C can be strip-shaped, L-shaped, U-shaped (square bracket shaped), square, or the like.

Figure 31B is a schematic cross-sectional view corresponding to dashed lines A1-A2 and C1-C2 in Figure 31A. Figure 31B shows a schematic cross-sectional view of the light-emitting element 90B, the light-emitting element 90R, the light-receiving element 90S, and the connection electrode 111C.

Note that the light-emitting element 90G, which is not shown in the schematic cross-sectional diagram, can be configured in the same manner as the light-emitting element 90B or the light-emitting element 90R, and the following description of these elements can be referred to.

The light-emitting element 90B has a pixel electrode 111, an organic layer 112B, an organic layer 114, and a common electrode 113. The light-emitting element 90R has a pixel electrode 111, an organic layer 112R, an organic layer 114, and a common electrode 113. The light-receiving element 90S has a pixel electrode 111, an organic layer 115, an organic layer 114, and a common electrode 113. The organic layer 114 and the common electrode 113 are provided in common to the light-emitting element 90B, the light-emitting element 90R, and the light-receiving element 90S. The organic layer 114 can also be referred to as a common layer. The pixel electrodes 111 are provided at a distance between each light-emitting element and between the light-emitting element and the light-receiving element.

Organic layer 112R contains a light-emitting organic compound that emits at least red light. Organic layer 112B contains a light-emitting organic compound that emits at least blue light. Organic layer 115 contains a photoelectric conversion material that is sensitive to the wavelength range of visible light or infrared light. Organic layer 112R and organic layer 112B can each be called an EL layer.

The organic layers 112R, 112B, and 115 may each have one or more of an electron injection layer, an electron transport layer, a hole injection layer, and a hole transport layer. The organic layer 114 may be configured not to have a light-emitting layer. For example, the organic layer 114 has one or more of an electron injection layer, an electron transport layer, a hole injection layer, and a hole transport layer.

Here, it is preferable that the uppermost layer of the stacked structure of organic layers 112R, 112B, and 115, i.e., the layer in contact with organic layer 114, is a layer other than the light-emitting layer. For example, it is preferable to provide an electron injection layer, an electron transport layer, a hole injection layer, a hole transport layer, or a layer other than these to cover the light-emitting layer, and to configure the layer in contact with organic layer 114. In this way, by protecting the top surface of the light-emitting layer with another layer when fabricating each light-emitting element, the reliability of the light-emitting element can be improved.

The pixel electrode 111 is provided for each element. The common electrode 113 and the organic layer 114 are provided as a continuous layer common to each light-emitting element. A conductive film having transparency to visible light is used for either one of the pixel electrodes or the common electrode 113, and a conductive film having reflectivity is used for the other. By making each pixel electrode transparent and the common electrode 113 reflective, a bottom emission type display device can be obtained. Conversely, by making each pixel electrode reflective and the common electrode 113 transparent, a top emission type display device can be obtained. Note that by making both the pixel electrodes and the common electrode 113 transparent, a dual emission type display device can also be obtained.

An insulating layer 131 is provided covering the end of the pixel electrode 111. The end of the insulating layer 131 is preferably tapered. In this specification and the like, a tapered end of an object means that the angle between the surface and the surface to be formed in the end region is greater than 0 degrees and less than 90 degrees, and the cross-sectional shape has a continuously increasing thickness from the end.

In addition, by using an organic resin for the insulating layer 131, the surface can be made gently curved. This improves the coverage of the film formed on the insulating layer 131.

Materials that can be used for the insulating layer 131 include, for example, acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimideamide resin, siloxane resin, benzocyclobutene resin, phenolic resin, and precursors of these resins.

Alternatively, the insulating layer 131 may also include an inorganic insulating material. Examples of inorganic insulating materials that can be used for the insulating layer 131 include oxides or nitrides such as silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, aluminum oxide, aluminum oxynitride, and hafnium oxide. In addition, yttrium oxide, zirconium oxide, gallium oxide, tantalum oxide, magnesium oxide, lanthanum oxide, cerium oxide, and neodymium oxide may also be used.

As shown in FIG. 31B, between the light-emitting elements emitting different colors of light and between the light-emitting element and the light-receiving element, the two organic layers are spaced apart with a gap between them. In this way, it is preferable that organic layer 112R, organic layer 112B, and organic layer 115 are arranged so as not to contact each other. This makes it possible to preferably prevent current from flowing through two adjacent organic layers and causing unintended light emission. This makes it possible to increase the contrast and realize a display device with high display quality.

The organic layers 112R, 112B, and 115 preferably have a taper angle of 30 degrees or more. The organic layers 112R, 112G, and 112B preferably have an angle between the side surface (surface) and the bottom surface (surface to be formed) at the end of the organic layers 112R, 112G, and 112B of 30 degrees or more and 120 degrees or less, preferably 45 degrees or more and 120 degrees or less, and more preferably 60 degrees or more and 120 degrees or less. Alternatively, the organic layers 112R, 112G, and 112B preferably each have a taper angle of 90 degrees or close to 90 degrees (for example, 80 degrees or more and 100 degrees or less).

A protective layer 121 is provided on the common electrode 113. The protective layer 121 has the function of preventing impurities such as water from diffusing from above to each light-emitting element.

The protective layer 121 can have, for example, a single-layer structure or a multilayer structure including at least an inorganic insulating film. Examples of the inorganic insulating film include oxide films or nitride films such as a silicon oxide film, a silicon oxynitride film, a silicon nitride oxide film, a silicon nitride film, an aluminum oxide film, an aluminum oxynitride film, and a hafnium oxide film. Alternatively, a semiconductor material such as indium gallium oxide or indium gallium zinc oxide may be used as the protective layer 121.

In addition, a laminated film of an inorganic insulating film and an organic insulating film can also be used as the protective layer 121. For example, it is preferable to have a configuration in which an organic insulating film is sandwiched between a pair of inorganic insulating films. Furthermore, it is preferable that the organic insulating film functions as a planarizing film. This allows the upper surface of the organic insulating film to be flat, improving the coverage of the inorganic insulating film thereon and enhancing the barrier properties. In addition, since the upper surface of the protective layer 121 is flat, it is preferable that when a structure (e.g., a color filter, an electrode of a touch sensor, or a lens array) is provided above the protective layer 121, the influence of the uneven shape caused by the structure below can be reduced.

In the connection portion 130, a common electrode 113 is provided in contact with the connection electrode 111C, and a protective layer 121 is provided covering the common electrode 113. In addition, an insulating layer 131 is provided covering the end of the connection electrode 111C.

Below, we will explain a configuration example of a display device that has a part of the configuration different from that shown in FIG. 31B. Specifically, we will show an example in which the insulating layer 131 is not provided.

Figures 32A to 32D show an example in which the side of pixel electrode 111 roughly coincides with the side of organic layer 112R, organic layer 112B, or organic layer 115.

In FIG. 32A, organic layer 114 is provided to cover the top and side surfaces of organic layer 112R, organic layer 112B, and organic layer 115. Organic layer 114 prevents pixel electrode 111 and common electrode 113 from coming into contact with each other and causing an electrical short circuit.

Figure 32B shows an example having an insulating layer 125 provided in contact with organic layer 112R, organic layer 112G, and organic layer 112B, as well as the side surface of pixel electrode 111. Insulating layer 125 can effectively prevent electrical shorts between pixel electrode 111 and common electrode 113, and leakage current between them.

The insulating layer 125 may be an insulating layer containing an inorganic material. For example, an inorganic insulating film such as an oxide insulating film, a nitride insulating film, an oxynitride insulating film, and a nitride oxide insulating film may be used for the insulating layer 125. The insulating layer 125 may have a single layer structure or a laminated structure. Examples of the oxide insulating film include a silicon oxide film, an aluminum oxide film, a magnesium oxide film, an indium gallium zinc oxide film, a gallium oxide film, a germanium oxide film, an yttrium oxide film, a zirconium oxide film, a lanthanum oxide film, a neodymium oxide film, a hafnium oxide film, and a tantalum oxide film. Examples of the nitride insulating film include a silicon nitride film and an aluminum nitride film. Examples of the oxynitride insulating film include a silicon oxynitride film and an aluminum oxynitride film. Examples of the nitride oxide insulating film include a silicon nitride oxide film and an aluminum nitride oxide film. In particular, by applying an inorganic insulating film such as an aluminum oxide film, a hafnium oxide film, or a silicon oxide film formed by the ALD method to the insulating layer 125, an insulating layer 125 with few pinholes and excellent function of protecting the organic layer can be formed.

Note that in this specification and elsewhere, oxynitride refers to a material whose composition contains more oxygen than nitrogen, and nitride oxide refers to a material whose composition contains more nitrogen than oxygen. For example, silicon oxynitride refers to a material whose composition contains more oxygen than nitrogen, and silicon nitride oxide refers to a material whose composition contains more nitrogen than oxygen.

The insulating layer 125 can be formed by a sputtering method, a CVD method, a PLD method, an ALD method, or the like. It is preferable to form the insulating layer 125 by an ALD method, which has good coverage.

In FIG. 32C, a resin layer 126 is provided between two adjacent light-emitting elements or between a light-emitting element and a light-receiving element to fill the gap between two opposing pixel electrodes and the gap between two opposing organic layers. The resin layer 126 can flatten the surfaces on which the organic layer 114, common electrode 113, etc. are formed, preventing the common electrode 113 from being broken due to insufficient coverage of the step between adjacent light-emitting elements.

As the resin layer 126, an insulating layer having an organic material can be suitably used. For example, as the resin layer 126, acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimideamide resin, silicone resin, siloxane resin, benzocyclobutene resin, phenol resin, and precursors of these resins can be applied. In addition, as the resin layer 126, organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin can be used. In addition, as the resin layer 126, a photosensitive resin can be used. As the photosensitive resin, a photoresist can be used. As the photosensitive resin, a positive material or a negative material can be used.

In addition, the resin layer 126 may be made of a colored material (e.g., a material containing a black pigment) to block stray light from adjacent pixels and suppress color mixing.

In FIG. 32D, an insulating layer 125 and a resin layer 126 are provided on the insulating layer 125. The insulating layer 125 prevents the organic layer 112R and the like from contacting the resin layer 126, preventing impurities such as moisture contained in the resin layer 126 from diffusing into the organic layer 112R and the like, resulting in a highly reliable display device.

In addition, a reflective film (e.g., a metal film containing one or more selected from silver, palladium, copper, titanium, aluminum, etc.) may be provided between the insulating layer 125 and the resin layer 126, and the light emitted from the light-emitting layer may be reflected by the reflective film, thereby providing a mechanism for improving the light extraction efficiency.

Figures 33A to 33C show an example in which the width of pixel electrode 111 is greater than the width of organic layer 112R, organic layer 112B, or organic layer 115. Organic layer 112R and the like are provided inside the end of pixel electrode 111.

Figure 33A shows an example in which an insulating layer 125 is included. The insulating layer 125 is provided to cover the side surfaces of the organic layer of the light-emitting element or light-receiving element, and a part of the upper surface and the side surfaces of the pixel electrode 111.

Figure 33B shows an example in which a resin layer 126 is included. The resin layer 126 is located between two adjacent light-emitting elements or between a light-emitting element and a light-receiving element, and is provided to cover the side of the organic layer and the upper and side surfaces of the pixel electrode 111.

Figure 33C shows an example having both an insulating layer 125 and a resin layer 126. The insulating layer 125 is provided between the organic layer 112R etc. and the resin layer 126.

Figures 34A to 34D show an example where the width of pixel electrode 111 is smaller than the width of organic layer 112R, organic layer 112B, or organic layer 115. Organic layer 112R, etc., extend outward beyond the edge of pixel electrode 111.

Figure 34B shows an example having an insulating layer 125. The insulating layer 125 is provided in contact with the side surfaces of the organic layers of two adjacent light-emitting elements. Note that the insulating layer 125 may be provided to cover not only the side surfaces of the organic layer 112R, etc., but also part of the upper surface.

Figure 34C shows an example having a resin layer 126. The resin layer 126 is located between two adjacent light-emitting elements, and is provided so as to cover part of the side and upper surface of the organic layer 112R, etc. Note that the resin layer 126 may be configured to contact the side surface of the organic layer 112R, etc., and not cover the upper surface.

Figure 34D shows an example having both an insulating layer 125 and a resin layer 126. The insulating layer 125 is provided between the organic layer 112R etc. and the resin layer 126.

Here, we will explain an example of the configuration of the resin layer 126.

The flatter the upper surface of the resin layer 126, the better; however, depending on the uneven shape of the surface on which the resin layer 126 is formed, the conditions under which the resin layer 126 is formed, etc., the surface of the resin layer 126 may have a concave or convex shape.

35A to 36F show an end of the pixel electrode 111R of the light-emitting element 90R, an end of the pixel electrode 111G of the light-emitting element 90G, and an enlarged view of the vicinity thereof. An organic layer 112G is provided on the pixel electrode 111G.

Figures 35A, 35B, and 35C show enlarged views of the resin layer 126 and its vicinity when the upper surface of the resin layer 126 is flat. Figure 35A shows an example where the width of the organic layer 112R etc. is greater than that of the pixel electrode 111. Figure 35B shows an example where these widths are roughly the same. Figure 35C shows an example where the width of the organic layer 112R etc. is smaller than that of the pixel electrode 111.

As shown in FIG. 35A, since the organic layer 112R is provided to cover the end of the pixel electrode 111, it is preferable that the end of the pixel electrode 111 has a tapered shape. This improves the step coverage of the organic layer 112R, resulting in a highly reliable display device.

Figures 35D, 35E, and 35F show an example in which the upper surface of the resin layer 126 is concave. In this case, concave portions that reflect the concave upper surface of the resin layer 126 are formed on the upper surfaces of the organic layer 114, the common electrode 113, and the protective layer 121.

Figures 36A, 36B, and 36C show an example in which the upper surface of the resin layer 126 is convex. In this case, convex portions that reflect the convex upper surface of the resin layer 126 are formed on the upper surfaces of the organic layer 114, the common electrode 113, and the protective layer 121.

Figures 36D, 36E, and 36F show an example in which part of the resin layer 126 covers part of the upper end and upper surface of the organic layer 112R, and part of the upper end and upper surface of the organic layer 112G. In this case, an insulating layer 125 is provided between the resin layer 126 and the upper surface of the organic layer 112R or the organic layer 112G.

36D, 36E, and 36F show an example in which part of the upper surface of the resin layer 126 is concave. In this case, the organic layer 114, the common electrode 113, and the protective layer 121 are formed with an uneven shape that reflects the shape of the resin layer 126.

The above is an explanation of an example of the resin layer configuration.

This embodiment can be implemented in combination with at least a portion of the other embodiments described in this specification.

(Seventh embodiment)
In this embodiment, a configuration example of a display device and a display module that can be applied to an electronic device according to one embodiment of the present invention will be described. Although a display device capable of displaying an image will be described here, the display device can also be used as a light-emitting and receiving device by using a light-emitting element as a light source.

The display device of this embodiment can be a high-resolution display device or a large display device. Therefore, the display device of this embodiment can be used in electronic devices with relatively large screens, such as television devices, desktop or notebook personal computers, computer monitors, digital signage, and large game machines such as pachinko machines, as well as in the display units of digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, smartphones, wristwatch terminals, tablet terminals, personal digital assistants, and audio playback devices.

[Display device 400]
FIG. 37 shows a perspective view of display device 400, and FIG. 38A shows a cross-sectional view of display device 400.

Display device 400 has a configuration in which substrate 452 and substrate 451 are bonded together. In FIG. 37, substrate 452 is shown by a dashed line.

The display device 400 includes a display portion 462, a circuit 464, wiring 465, and the like. FIG. 37 shows an example in which an IC 473 and an FPC 472 are mounted on the display device 400. Therefore, the configuration shown in FIG. 37 can also be called a display module including the display device 400, an IC (integrated circuit), and an FPC. The display portion 462 can include a light-emitting element and a transistor connected to the light-emitting element. The display portion 462 can also include a light-receiving element and a transistor connected to the light-receiving element. The display device 400 can be applied to an electronic device of one embodiment of the present invention, and the circuit 464 and the IC can be included in a control circuit portion of the electronic device of one embodiment of the present invention.

For example, a scanning line driver circuit can be used as the circuit 464.

The wiring 465 has a function of supplying signals and power to the display portion 462 and the circuit 464. The signals and power are input to the wiring 465 from the outside via the FPC 472, or are input to the wiring 465 from the IC 473.

In FIG. 37, an example is shown in which an IC 473 is provided on a substrate 451 by a COG (chip on glass) method or a COF (chip on film) method. For example, an IC having a scanning line driver circuit or a signal line driver circuit can be used as the IC 473. Note that the display device 400 and the display module may not have an IC. Also, the IC may be mounted on an FPC by a COF method or the like.

Figure 38A shows an example of a cross section of the display device 400 when a part of the area including the FPC 472, a part of the circuit 464, a part of the display unit 462, and a part of the area including the connection part are cut. Figure 38A shows an example of a cross section of the display unit 462 when a region including the light-emitting element 430b that emits green light (G) and the light-receiving element 440 that receives reflected light (L) is cut.

The display device 400 shown in FIG. 38A has a transistor 252, a transistor 260, a transistor 258, a light-emitting element 430b, a light-receiving element 440, and the like between a substrate 453 and a substrate 454.

The light-emitting element 430b and the light-receiving element 440 can be the light-emitting element or light-receiving element exemplified above.

Here, when a pixel of a display device has three types of subpixels having light-emitting elements with different light-emitting colors, the three subpixels include subpixels of three colors of red (R), green (G), and blue (B), and subpixels of three colors of yellow (Y), cyan (C), and magenta (M). When a pixel of a display device has four subpixels, the four subpixels include subpixels of four colors of R, G, B, and white (W), and subpixels of four colors of R, G, B, and Y. Alternatively, the subpixels may have light-emitting elements that emit infrared light.

The light receiving element 440 may be a photoelectric conversion element sensitive to light in the red, green, or blue wavelength range, or a photoelectric conversion element sensitive to light in the infrared wavelength range.

The substrate 454 and the protective layer 416 are bonded via an adhesive layer 442. The adhesive layer 442 is provided so as to overlap the light-emitting element 430b and the light-receiving element 440, respectively, and a solid sealing structure is applied to the display device 400. A light-shielding layer 417 is provided on the substrate 454.

The light-emitting element 430b and the light-receiving element 440 have conductive layers 411a, 411b, and 411c as pixel electrodes. The conductive layer 411b is reflective to visible light and functions as a reflective electrode. The conductive layer 411c is transparent to visible light and functions as an optical adjustment layer.

The conductive layer 411a of the light-emitting element 430b is connected to the conductive layer 272b of the transistor 260 through an opening provided in the insulating layer 264. The transistor 260 has a function of controlling the driving of the light-emitting element. On the other hand, the conductive layer 411a of the light-receiving element 440 is electrically connected to the conductive layer 272b of the transistor 258. The transistor 258 has a function of controlling the timing of exposure using the light-receiving element 440, etc.

An EL layer 412G or a photoelectric conversion layer 412S is provided to cover the pixel electrode. An insulating layer 491 is provided in contact with the side surface of the EL layer 412G and the side surface of the photoelectric conversion layer 412S, and a resin layer 492 is provided to fill the recess of the insulating layer 491. An organic layer 414, a common electrode 413, and a protective layer 416 are provided to cover the EL layer 412G and the photoelectric conversion layer 412S. By providing the protective layer 416 to cover the light-emitting element, impurities such as water can be prevented from entering the light-emitting element, and the reliability of the light-emitting element can be improved.

Light G emitted by the light-emitting element 430b is emitted toward the substrate 452. The light-receiving element 440 receives the light L incident through the substrate 452 and converts it into an electrical signal. It is preferable to use a material that is highly transparent to visible light for the substrate 452.

Transistor 252, transistor 260, and transistor 258 are all formed on a substrate 451. These transistors can be manufactured using the same material and the same process.

Note that the transistors 252, 260, and 258 may be fabricated to have different configurations. For example, transistors may be fabricated with or without a back gate, or transistors may be fabricated with different materials and/or thicknesses for the semiconductor, gate electrode, gate insulating layer, source electrode, and drain electrode.

Using a flexible material for the substrate 453 can increase the flexibility of the display device.

When the display device 400 is to have a flexible structure, first, a fabrication substrate on which the insulating layer 262, the transistors, the light-emitting elements, the light-receiving elements, etc. are provided is bonded to a substrate 454 on which a light-shielding layer 417 is provided, using an adhesive layer. Then, the fabrication substrate is peeled off and a substrate 453 is attached to the exposed surface, so that each component formed on the fabrication substrate is transferred to the substrate 453. This can increase the flexibility of the display device 400.

A connection portion 254 is provided in an area of the substrate 453 where the substrate 454 does not overlap. In the connection portion 254, the wiring 465 is electrically connected to the FPC 472 via a conductive layer 466 and a connection layer 292. The conductive layer 466 can be obtained by processing the same conductive film as the pixel electrode. This allows the connection portion 254 and the FPC 472 to be electrically connected via the connection layer 292.

Transistor 252, transistor 260, and transistor 258 each have a conductive layer 271 functioning as a gate, an insulating layer 261 functioning as a gate insulating layer, a semiconductor layer 281 having a channel formation region 281i and a pair of low resistance regions 281n, a conductive layer 272a connected to one of the pair of low resistance regions 281n, a conductive layer 272b connected to the other of the pair of low resistance regions 281n, an insulating layer 275 functioning as a gate insulating layer, a conductive layer 273 functioning as a gate, and an insulating layer 265 covering the conductive layer 273. The insulating layer 261 is located between the conductive layer 271 and the channel formation region 281i. The insulating layer 275 is located between the conductive layer 273 and the channel formation region 281i.

The conductive layer 272a and the conductive layer 272b are each connected to the low resistance region 281n through an opening provided in the insulating layer 265. One of the conductive layer 272a and the conductive layer 272b functions as a source, and the other functions as a drain.

Figure 38A shows an example in which an insulating layer 275 covers the top and side surfaces of the semiconductor layer. The conductive layer 272a and the conductive layer 272b are connected to the low resistance region 281n through openings provided in the insulating layer 275 and the insulating layer 265, respectively.

On the other hand, in the transistor 259 shown in FIG. 38B, the insulating layer 275 overlaps with the channel formation region 281i of the semiconductor layer 281, but does not overlap with the low resistance region 281n. For example, the structure shown in FIG. 38B can be manufactured by processing the insulating layer 275 using the conductive layer 273 as a mask. In FIG. 38B, an insulating layer 265 is provided to cover the insulating layer 275 and the conductive layer 273, and the conductive layer 272a and the conductive layer 272b are each connected to the low resistance region 281n through an opening in the insulating layer 265. Furthermore, an insulating layer 268 may be provided to cover the transistor.

The structure of the transistor included in the display device of this embodiment is not particularly limited. For example, a planar type transistor, a staggered type transistor, an inverted staggered type transistor, or the like can be used. In addition, the transistor structure may be either a top-gate type or a bottom-gate type. Alternatively, a gate may be provided above and below a semiconductor layer in which a channel is formed.

Transistor 252, transistor 260, and transistor 258 are configured to sandwich a semiconductor layer in which a channel is formed between two gates. The two gates may be connected and the same signal may be supplied to drive the transistor. Alternatively, the threshold voltage of the transistor may be controlled by supplying a potential for controlling the threshold voltage to one of the two gates and a potential for driving to the other.

The crystallinity of the semiconductor material used in the semiconductor layer of the transistor is not particularly limited, and any of an amorphous semiconductor, a single crystal semiconductor, or a semiconductor having crystallinity other than single crystal (a microcrystalline semiconductor, a polycrystalline semiconductor, or a semiconductor having a crystalline region in part) may be used. The use of a single crystal semiconductor or a semiconductor having crystallinity is preferable because it can suppress deterioration of the transistor characteristics.

The semiconductor layer of the transistor preferably contains a metal oxide (also referred to as an oxide semiconductor). In other words, the display device of this embodiment preferably uses a transistor in which a metal oxide is used for a channel formation region (hereinafter, referred to as an OS transistor).

The band gap of the metal oxide used in the semiconductor layer of the transistor is preferably 2 eV or more, and more preferably 2.5 eV or more. By using a metal oxide with a large band gap, the off-state current of the OS transistor can be reduced.

The metal oxide preferably contains at least indium or zinc, and more preferably contains indium and zinc. For example, the metal oxide preferably contains indium, M (wherein M is one or more selected from gallium, aluminum, yttrium, tin, silicon, boron, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, and cobalt), and zinc. In particular, M is preferably one or more selected from gallium, aluminum, yttrium, and tin, and more preferably gallium. Note that a metal oxide containing indium, M, and zinc may be referred to as an In-M-Zn oxide hereinafter.

When the metal oxide is In-M-Zn oxide, it is preferable that the atomic ratio of In in the In-M-Zn oxide is greater than or equal to the atomic ratio of M. Examples of atomic ratios of metal elements in such In-M-Zn oxides include In:M:Zn = 1:1:1 or a composition thereabout, In:M:Zn = 1:1:1.2 or a composition thereabout, In:M:Zn = 2:1:3 or a composition thereabout, In:M:Zn = 3:1:2 or a composition thereabout, In:M:Zn = 4:2:3 or a composition thereabout, In:M:Zn = 4:2:4.1 or a composition thereabout, In:M:Zn = 5:1:3 or a composition thereabout, In:M:Zn = 5:1:6 or a composition thereabout, In:M:Zn = 5:1:7 or a composition thereabout, In:M:Zn = 5:1:8 or a composition thereabout, In:M:Zn = 6:1:6 or a composition thereabout, In:M:Zn = 5:2:5 or a composition thereabout, and the like. Note that the term "nearby composition" includes a range of ±30% of the desired atomic ratio. Increasing the atomic ratio of indium in the metal oxide can increase the on-state current or field effect mobility of the transistor.

For example, when the atomic ratio is described as In:Ga:Zn=4:2:3 or a composition close thereto, this includes cases where the content ratio of each element is Ga=1 to 3 and Zn=2 to 4 when In is 4. Also, when the atomic ratio is described as In:Ga:Zn=5:1:6 or a composition close thereto, this includes cases where the content ratio of each element is Ga=0.1 to 2 and Zn=5 to 7 when In is 5. Also, when the atomic ratio is described as In:Ga:Zn=1:1:1 or a composition close thereto, this includes cases where the content ratio of each element is Ga=0.1 to 2 and Zn=0.1 to 2 when In is 1.

In addition, the atomic ratio of In in the In-M-Zn oxide may be less than the atomic ratio of M. Examples of atomic ratios of metal elements in such In-M-Zn oxide include In:M:Zn=1:3:2 or a composition in the vicinity thereof, In:M:Zn=1:3:3 or a composition in the vicinity thereof, and In:M:Zn=1:3:4 or a composition in the vicinity thereof. By increasing the atomic ratio of M in the metal oxide, the band gap of the In-M-Zn oxide can be made larger, and the resistance to a negative bias stress test under light can be improved. Specifically, the change in threshold voltage or the change in shift voltage (Vsh) measured in a NBTIS (Negative Bias Temperature Illumination Stress) test of a transistor can be reduced. The shift voltage (Vsh) is defined as the Vg at which the tangent to the maximum slope of the transistor's drain current (Id)-gate voltage (Vg) curve intersects with the line Id = 1 pA.

Alternatively, the semiconductor layer of the transistor may contain silicon. Examples of silicon include amorphous silicon and crystalline silicon (such as low-temperature polysilicon and single crystal silicon).

In particular, low-temperature polysilicon has a relatively high mobility and can be formed on a glass substrate, and therefore can be suitably used in display devices. For example, a transistor using low-temperature polysilicon in its semiconductor layer can be applied to the transistor 252 in the driver circuit, and a transistor using an oxide semiconductor in its semiconductor layer can be applied to the transistor 260 and the transistor 258 provided in the pixel.

Alternatively, the semiconductor layer of the transistor may have a layered material that functions as a semiconductor. A layered material is a general term for a group of materials that have a layered crystal structure. A layered crystal structure is a structure in which layers formed by covalent or ionic bonds are stacked via bonds weaker than covalent or ionic bonds, such as van der Waals bonds. A layered material has high electrical conductivity within a unit layer, that is, high two-dimensional electrical conductivity. By using a material that functions as a semiconductor and has high two-dimensional electrical conductivity in the channel formation region, a transistor with a large on-current can be provided.

Examples of the layered material include graphene, silicene, and chalcogenides. Chalcogenides are compounds containing chalcogen (an element belonging to Group 16). Examples of the chalcogenides include transition metal chalcogenides and Group 13 chalcogenides. Specific examples of transition metal chalcogenides that can be used as the semiconductor layer of a transistor include molybdenum sulfide (representatively MoS ₂ ), molybdenum selenide (representatively MoSe ₂ ), molybdenum tellurium (representatively MoTe 2 ), tungsten sulfide (representatively WS ₂ ), tungsten selenide (representatively WSe ₂ ), tungsten tellurium (representatively WTe ₂ ), hafnium sulfide (representatively HfS ₂ ), hafnium selenide (representatively HfSe ₂ ), zirconium sulfide (representatively ZrS ₂ ), zirconium selenide (representatively ZrSe ₂ ) _, and the like.

The transistors in the circuit 464 and the transistors in the display portion 462 may have the same structure or different structures. The transistors in the circuit 464 may all have the same structure or may have two or more types. Similarly, the transistors in the display portion 462 may all have the same structure or may have two or more types.

It is preferable to use a material that is difficult for impurities such as water and hydrogen to diffuse into at least one of the insulating layers that covers the transistor. This allows the insulating layer to function as a barrier layer. With this configuration, it is possible to effectively prevent impurities from diffusing into the transistor from the outside, thereby improving the reliability of the display device.

It is preferable to use an inorganic insulating film for each of insulating layers 261, 262, 265, 268, and 275. As the inorganic insulating film, for example, a silicon nitride film, a silicon oxynitride film, a silicon oxide film, a silicon nitride oxide film, an aluminum oxide film, an aluminum nitride film, or the like can be used. In addition, a hafnium oxide film, an yttrium oxide film, a zirconium oxide film, a gallium oxide film, a tantalum oxide film, a magnesium oxide film, a lanthanum oxide film, a cerium oxide film, a neodymium oxide film, or the like may be used. In addition, two or more of the above-mentioned inorganic insulating films may be stacked and used.

Here, organic insulating films often have a lower barrier property than inorganic insulating films. For this reason, it is preferable that the organic insulating film has an opening near the end of the display device 400. This makes it possible to prevent impurities from entering through the organic insulating film from the end of the display device 400. Alternatively, the organic insulating film may be formed so that the end of the organic insulating film is located inside the end of the display device 400, so that the organic insulating film is not exposed at the end of the display device 400.

An organic insulating film is suitable for the insulating layer 264 that functions as a planarizing layer. Materials that can be used for the organic insulating film include acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimideamide resin, siloxane resin, benzocyclobutene resin, phenolic resin, and precursors of these resins.

It is preferable to provide a light-shielding layer 417 on the surface of substrate 454 facing substrate 453. In addition, various optical members can be arranged on the outside of substrate 454. Examples of optical members include a polarizing plate, a retardation plate, a light diffusion layer (such as a diffusion film), an anti-reflection layer, and a light-collecting film. In addition, an antistatic film that suppresses the adhesion of dust, a water-repellent film that makes it difficult for dirt to adhere, a hard coat film that suppresses the occurrence of scratches due to use, an impact absorbing layer, etc. may be arranged on the outside of substrate 454.

Figure 38A shows a connection portion 278. At the connection portion 278, the common electrode 413 and the wiring are electrically connected. Figure 38A shows an example in which the same layered structure as the pixel electrode is applied to the wiring.

The substrate 453 and the substrate 454 can be made of glass, quartz, ceramics, sapphire, resin, metal, alloy, semiconductor, or the like. A semiconductor substrate such as a single crystal semiconductor substrate, a polycrystalline semiconductor substrate, a compound semiconductor substrate such as silicon germanium, or an SOI substrate made of silicon or silicon carbide can be used. A substrate having a circuit including a transistor provided thereon may be used as the substrate 453. A material that transmits light is used for the substrate on the side from which light from a light-emitting element is extracted. When a flexible material is used for the substrate 453 and the substrate 454, the flexibility of the display device can be increased. A polarizing plate may be used as the substrate 453 or the substrate 454.

When substrate 453 and substrate 454 are made of a flexible material, polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyacrylonitrile resin, acrylic resin, polyimide resin, polymethyl methacrylate resin, polycarbonate (PC) resin, polyethersulfone (PES) resin, polyamide resin (nylon, aramid, etc.), polysiloxane resin, cycloolefin resin, polystyrene resin, polyamideimide resin, polyurethane resin, polyvinyl chloride resin, polyvinylidene chloride resin, polypropylene resin, polytetrafluoroethylene (PTFE) resin, ABS resin, cellulose nanofiber, etc. can be used. One or both of substrates 453 and 454 may be made of glass having a thickness sufficient to provide flexibility.

When a circular polarizing plate is laminated on a display device, it is preferable to use a substrate with high optical isotropy as the substrate of the display device. A substrate with high optical isotropy has small birefringence (it can also be said that the amount of birefringence is small).

The absolute value of the retardation (phase difference) value of a substrate with high optical isotropy is preferably 30 nm or less, more preferably 20 nm or less, and even more preferably 10 nm or less.

Examples of films with high optical isotropy include triacetyl cellulose (TAC, also known as cellulose triacetate) film, cycloolefin polymer (COP) film, cycloolefin copolymer (COC) film, and acrylic film.

In addition, when a film is used as the substrate, there is a risk that the film will absorb water, causing changes in shape such as wrinkles on the display panel. For this reason, it is preferable to use a film with low water absorption for the substrate. For example, it is preferable to use a film with a water absorption rate of 1% or less, more preferably 0.1% or less, and even more preferably 0.01% or less.

For the adhesive layer, various curing adhesives can be used, such as photocuring adhesives such as ultraviolet curing adhesives, reactive curing adhesives, heat curing adhesives, and anaerobic adhesives. These adhesives include epoxy resin, acrylic resin, silicone resin, phenolic resin, polyimide resin, imide resin, PVC (polyvinyl chloride) resin, PVB (polyvinyl butyral) resin, and EVA (ethylene vinyl acetate) resin. In particular, materials with low moisture permeability such as epoxy resin are preferable. Two-part mixed resins may also be used. Adhesive sheets, etc. may also be used.

The connection layer 292 can be made of an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), or the like.

Materials that can be used for conductive layers such as the gate, source, and drain of a transistor, as well as various wirings and electrodes that constitute a display device include metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, and tungsten, as well as alloys containing these metals as the main component. Films containing these materials can be used as a single layer or a laminated structure.

In addition, as a conductive material having light transmission, conductive oxides such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, zinc oxide containing gallium, or graphene can be used. Alternatively, metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, and titanium, or alloy materials containing the metal materials can be used. Alternatively, nitrides of the metal materials (for example, titanium nitride) may be used. Note that when using metal materials or alloy materials (or their nitrides), it is preferable to make them thin enough to have light transmission. Also, a laminated film of the above materials can be used as a conductive layer. For example, it is preferable to use a laminated film of an alloy of silver and magnesium and indium tin oxide, because it can increase conductivity. These can also be used for conductive layers such as various wirings and electrodes constituting a display device, and conductive layers (conductive layers that function as pixel electrodes or common electrodes) of light-emitting elements.

Insulating materials that can be used for each insulating layer include, for example, resins such as acrylic resin and epoxy resin, and inorganic insulating materials such as silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, and aluminum oxide.

The configuration examples exemplified in this embodiment and the corresponding drawings, etc. can be combined, at least in part, with other configuration examples or drawings, etc. as appropriate.

This embodiment can be implemented in combination with at least a portion of the other embodiments described in this specification.

(Embodiment 8)
In this embodiment, a metal oxide (also referred to as an oxide semiconductor) which can be used for the OS transistor described in the above embodiment will be described.

The metal oxide used in the OS transistor preferably contains at least indium or zinc, and more preferably contains indium and zinc. For example, the metal oxide preferably contains indium, M (M is one or more selected from gallium, aluminum, yttrium, tin, silicon, boron, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, and cobalt), and zinc. In particular, M is preferably one or more selected from gallium, aluminum, yttrium, and tin, and more preferably gallium.

Metal oxides can also be formed by sputtering, chemical vapor deposition (CVD) such as metal organic chemical vapor deposition (MOCVD), or atomic layer deposition (ALD).

Hereinafter, an oxide containing indium (In), gallium (Ga), and zinc (Zn) will be described as an example of a metal oxide. Note that an oxide containing indium (In), gallium (Ga), and zinc (Zn) may be referred to as an In-Ga-Zn oxide.

<Classification of crystal structures>
Examples of the crystal structure of an oxide semiconductor include amorphous (including completely amorphous), c-axis-aligned crystalline (CAAC), nanocrystalline (nc), cloud-aligned composite (CAC), single crystal, and polycrystalline.

The crystal structure of the film or substrate can be evaluated using an X-ray diffraction (XRD) spectrum. For example, it can be evaluated using an XRD spectrum obtained by a GIXD (Grazing-Incidence XRD) measurement. The GIXD method is also called the thin film method or the Seemann-Bohlin method. In the following, the XRD spectrum obtained by a GIXD measurement may be simply referred to as the XRD spectrum.

For example, in the case of a quartz glass substrate, the shape of the peak in the XRD spectrum is nearly symmetrical. On the other hand, in the case of an In-Ga-Zn oxide film having a crystalline structure, the shape of the peak in the XRD spectrum is asymmetrical. The asymmetric shape of the peak in the XRD spectrum clearly indicates the presence of crystals in the film or substrate. In other words, if the shape of the peak in the XRD spectrum is not symmetrical, the film or substrate cannot be said to be in an amorphous state.

The crystal structure of the film or substrate can be evaluated by a diffraction pattern (also called a nanobeam electron diffraction pattern) observed by nanobeam electron diffraction (NBED). For example, a halo is observed in the diffraction pattern of a quartz glass substrate, and it can be confirmed that the quartz glass is in an amorphous state. In addition, a spot-like pattern is observed in the diffraction pattern of an In-Ga-Zn oxide film formed at room temperature, rather than a halo. For this reason, it is presumed that the In-Ga-Zn oxide formed at room temperature is neither single crystal nor polycrystal, nor in an amorphous state, but is in an intermediate state, and it cannot be concluded that it is in an amorphous state.

<<Structure of oxide semiconductor>>
Note that oxide semiconductors may be classified differently from the above when focusing on their structures. For example, oxide semiconductors are classified into single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors. Examples of non-single-crystal oxide semiconductors include the above-mentioned CAAC-OS and nc-OS. Non-single-crystal oxide semiconductors include polycrystalline oxide semiconductors, amorphous-like oxide semiconductors (a-like OS), amorphous oxide semiconductors, and the like.

Here, we will explain the details of the above-mentioned CAAC-OS, nc-OS, and a-like OS.

[CAAC-OS]
CAAC-OS has a plurality of crystalline regions, and the plurality of crystalline regions are oxide semiconductors whose c-axes are aligned in a specific direction. Note that the specific direction is the thickness direction of the CAAC-OS film, the normal direction of the surface on which the CAAC-OS film is formed, or the normal direction of the surface of the CAAC-OS film. The crystalline regions are regions having periodic atomic arrangement. Note that when the atomic arrangement is regarded as a lattice arrangement, the crystalline regions are also regions with a uniform lattice arrangement. Furthermore, CAAC-OS has a region in which a plurality of crystalline regions are connected in the a-b plane direction, and the region may have distortion. Note that the distortion refers to a portion where the direction of the lattice arrangement is changed between a region with a uniform lattice arrangement and another region with a uniform lattice arrangement in the region in which the plurality of crystalline regions are connected. In other words, CAAC-OS is an oxide semiconductor whose c-axes are aligned and whose orientation is not clearly aligned in the a-b plane direction.

Each of the multiple crystal regions is composed of one or more tiny crystals (crystals with a maximum diameter of less than 10 nm). When a crystal region is composed of one tiny crystal, the maximum diameter of the crystal region is less than 10 nm. When a crystal region is composed of many tiny crystals, the size of the crystal region may be approximately several tens of nm.

In addition, in the In-Ga-Zn oxide, CAAC-OS tends to have a layered crystal structure (also referred to as a layered structure) in which a layer containing indium (In) and oxygen (hereinafter, an In layer) and a layer containing gallium (Ga), zinc (Zn), and oxygen (hereinafter, a (Ga, Zn) layer) are stacked. Note that indium and gallium are mutually substituted. Therefore, the (Ga, Zn) layer may contain indium. Also, the In layer may contain gallium. Note that the In layer may contain zinc. The layered structure is observed as a lattice image in a high-resolution TEM (Transmission Electron Microscope) image, for example.

When a structural analysis is performed on a CAAC-OS film using, for example, an XRD device, a peak indicating c-axis orientation is detected at or near 2θ = 31° in out-of-plane XRD measurement using θ/2θ scan. Note that the position of the peak indicating c-axis orientation (2θ value) may vary depending on the type and composition of the metal elements that make up the CAAC-OS.

Furthermore, for example, multiple bright points (spots) are observed in the electron diffraction pattern of a CAAC-OS film. Note that one spot and another spot are observed at positions that are point-symmetric with respect to the spot of the incident electron beam that has passed through the sample (also called the direct spot).

When the crystal region is observed from the above-mentioned specific direction, the lattice arrangement in the crystal region is based on a hexagonal lattice, but the unit cell is not necessarily a regular hexagon and may be a non-regular hexagon. The above distortion may have a lattice arrangement such as a pentagon or heptagon. Note that in CAAC-OS, no clear grain boundary can be confirmed even in the vicinity of the distortion. In other words, it can be seen that the formation of grain boundaries is suppressed by the distortion of the lattice arrangement. This is thought to be because CAAC-OS can tolerate distortion due to the fact that the arrangement of oxygen atoms in the a-b plane direction is not dense, and the bond distance between atoms changes due to the substitution of metal atoms.

Note that a crystal structure in which clear grain boundaries are observed is called polycrystal. The grain boundaries are likely to become recombination centers and capture carriers, causing a decrease in the on-state current of a transistor and a decrease in field-effect mobility. Therefore, CAAC-OS, in which no clear grain boundaries are observed, is one of the crystalline oxides having a crystal structure suitable for the semiconductor layer of a transistor. Note that a structure containing Zn is preferable for forming CAAC-OS. For example, In-Zn oxide and In-Ga-Zn oxide are suitable because they can suppress the occurrence of grain boundaries more than In oxide.

CAAC-OS is an oxide semiconductor with high crystallinity and no clear crystal grain boundaries. Therefore, it can be said that CAAC-OS is less susceptible to a decrease in electron mobility due to crystal grain boundaries. In addition, since the crystallinity of an oxide semiconductor may decrease due to the inclusion of impurities or the generation of defects, CAAC-OS can be said to be an oxide semiconductor with few impurities and defects (such as oxygen vacancies). Therefore, an oxide semiconductor having CAAC-OS has stable physical properties. Therefore, an oxide semiconductor having CAAC-OS is resistant to heat and highly reliable. In addition, CAAC-OS is stable against high temperatures (so-called thermal budget) in the manufacturing process. Therefore, the use of CAAC-OS in an OS transistor can increase the degree of freedom in the manufacturing process.

[nc-OS]
The nc-OS has periodic atomic arrangement in a microscopic region (e.g., a region of 1 nm to 10 nm, particularly a region of 1 nm to 3 nm). In other words, the nc-OS has microcrystals. Note that the size of the microcrystals is, for example, 1 nm to 10 nm, particularly 1 nm to 3 nm, and therefore the microcrystals are also called nanocrystals. In addition, the nc-OS does not show regularity in crystal orientation between different nanocrystals. Therefore, no orientation is observed in the entire film. Therefore, the nc-OS may be indistinguishable from an a-like OS or an amorphous oxide semiconductor depending on the analysis method. For example, when a structure of the nc-OS film is analyzed using an XRD device, no peak indicating crystallinity is detected in out-of-plane XRD measurement using θ/2θ scanning. When an nc-OS film is subjected to electron diffraction (also referred to as selected area electron diffraction) using an electron beam with a probe diameter larger than that of a nanocrystal (e.g., 50 nm or more), a diffraction pattern such as a halo pattern is observed. On the other hand, when an nc-OS film is subjected to electron diffraction (also referred to as nanobeam electron diffraction) using an electron beam with a probe diameter close to the size of a nanocrystal or smaller than that of a nanocrystal (e.g., 1 nm to 30 nm), an electron diffraction pattern in which multiple spots are observed in a ring-shaped region centered on a direct spot may be obtained.

[a-like OS]
The a-like OS is an oxide semiconductor having a structure between the nc-OS and an amorphous oxide semiconductor. The a-like OS has a void or low-density region. That is, the a-like OS has lower crystallinity than the nc-OS and CAAC-OS. Furthermore, the a-like OS has a higher hydrogen concentration in the film than the nc-OS and CAAC-OS.

<<Configuration of oxide semiconductor>>
Next, the above-mentioned CAC-OS will be described in detail. Note that the CAC-OS relates to a material structure.

[CAC-OS]
CAC-OS is a material in which elements constituting a metal oxide are unevenly distributed in a size range of 0.5 nm to 10 nm, preferably 1 nm to 3 nm, or in the vicinity thereof. Note that in the following, a state in which one or more metal elements are unevenly distributed in a metal oxide and a region containing the metal elements is mixed in a size range of 0.5 nm to 10 nm, preferably 1 nm to 3 nm, or in the vicinity thereof, is also referred to as a mosaic or patch shape.

Furthermore, CAC-OS is a structure in which the material is separated into a first region and a second region, forming a mosaic shape, and the first region is distributed throughout the film (hereinafter, also referred to as a cloud shape). In other words, CAC-OS is a composite metal oxide having a structure in which the first region and the second region are mixed.

Here, the atomic ratios of In, Ga, and Zn to the metal elements constituting CAC-OS in In-Ga-Zn oxide are expressed as [In], [Ga], and [Zn], respectively. For example, in CAC-OS in In-Ga-Zn oxide, the first region is a region where [In] is larger than [In] in the composition of the CAC-OS film. The second region is a region where [Ga] is larger than [Ga] in the composition of the CAC-OS film. Alternatively, for example, the first region is a region where [In] is larger than [In] in the second region and [Ga] is smaller than [Ga] in the second region. The second region is a region where [Ga] is larger than [Ga] in the first region and [In] is smaller than [In] in the first region.

Specifically, the first region is a region whose main component is indium oxide, indium zinc oxide, etc., and the second region is a region whose main component is gallium oxide, gallium zinc oxide, etc. In other words, the first region can be rephrased as a region whose main component is In. The second region can be rephrased as a region whose main component is Ga.

Note that there may be cases where a clear boundary between the first region and the second region cannot be observed.

In addition, CAC-OS in In-Ga-Zn oxide refers to a material composition containing In, Ga, Zn, and O, in which some regions mainly contain Ga and some regions mainly contain In, each of which is in a mosaic shape, and these regions exist randomly. Therefore, it is presumed that CAC-OS has a structure in which metal elements are distributed non-uniformly.

CAC-OS can be formed, for example, by a sputtering method under conditions where the substrate is not heated. When CAC-OS is formed by a sputtering method, any one or more of an inert gas (typically argon), oxygen gas, and nitrogen gas may be used as the film-forming gas. The lower the flow rate ratio of oxygen gas to the total flow rate of film-forming gas during film formation, the more preferable it is. For example, the flow rate ratio of oxygen gas to the total flow rate of film-forming gas during film formation is set to 0% or more and less than 30%, preferably 0% or more and 10% or less.

In addition, for example, in the case of CAC-OS in In-Ga-Zn oxide, it can be confirmed by EDX mapping obtained using energy dispersive X-ray spectroscopy (EDX) that the structure has a region mainly composed of In (first region) and a region mainly composed of Ga (second region) that are unevenly distributed and mixed.

Here, the first region is a region with higher conductivity than the second region. In other words, the first region exhibits conductivity as a metal oxide when carriers flow through it. Therefore, when the first region is distributed in a cloud-like shape in the metal oxide, a high field effect mobility (μ) can be achieved.

On the other hand, the second region has higher insulating properties than the first region. In other words, the second region is distributed in the metal oxide, which can suppress leakage current.

Therefore, when the CAC-OS is used in a transistor, the conductivity due to the first region and the insulating property due to the second region act complementarily, so that the CAC-OS can be given a switching function (on/off function). In other words, the CAC-OS has a conductive function in a part of the material and an insulating function in a part of the material, and the whole material has a function as a semiconductor. By separating the conductive function and the insulating function, both functions can be maximized. Therefore, by using the CAC-OS in a transistor, a high on-current (I _on ), a high field-effect mobility (μ), and a good switching operation can be realized.

In addition, transistors using CAC-OS are highly reliable. Therefore, CAC-OS can improve the reliability of electronic devices to which it is applied.

Oxide semiconductors have a variety of structures, each of which has different characteristics. The oxide semiconductor of one embodiment of the present invention may have two or more of an amorphous oxide semiconductor, a polycrystalline oxide semiconductor, an a-like OS, a CAC-OS, an nc-OS, and a CAAC-OS.

<Transistor Having Oxide Semiconductor>
Next, the case where the oxide semiconductor is used for a transistor will be described.

By using the oxide semiconductor in a transistor, a transistor with high field-effect mobility can be realized. In addition, a highly reliable transistor can be realized.

It is preferable to use an oxide semiconductor having a low carrier concentration for the transistor. For example, the carrier concentration of the oxide semiconductor is 1×10 ¹⁷ cm ⁻³ or less, preferably 1×10 ¹⁵ cm ⁻³ or less, more preferably 1×10 ¹³ cm ⁻³ or less, more preferably 1×10 ¹¹ cm ⁻³ or less, and further preferably less than 1×10 ¹⁰ cm ⁻³ and 1×10 ⁻⁹ cm ⁻³ or more. Note that in the case of lowering the carrier concentration of the oxide semiconductor film, the carrier concentration can be lowered by lowering the impurity concentration in the oxide semiconductor film and lowering the density of defect states. In this specification and the like, a low impurity concentration and a low density of defect states are referred to as high-purity intrinsic or substantially high-purity intrinsic. Note that an oxide semiconductor having a low carrier concentration may be referred to as a high-purity intrinsic or substantially high-purity intrinsic oxide semiconductor.

In addition, a highly pure intrinsic or substantially highly pure intrinsic oxide semiconductor film may have a low density of trap states because of its low density of defect states.

In addition, the charge trapped in the trap states of the oxide semiconductor takes a long time to disappear and may behave as if it were a fixed charge. Therefore, a transistor in which a channel formation region is formed in an oxide semiconductor with a high density of trap states may have unstable electrical characteristics.

Therefore, in order to stabilize the electrical characteristics of a transistor, it is effective to reduce the impurity concentration in the oxide semiconductor. In addition, in order to reduce the impurity concentration in the oxide semiconductor, it is preferable to also reduce the impurity concentration in adjacent films. Examples of impurities include hydrogen, nitrogen, alkali metals, alkaline earth metals, iron, nickel, silicon, and the like. Note that impurities in an oxide semiconductor refer to, for example, anything other than the main component that constitutes the oxide semiconductor. For example, an element with a concentration of less than 0.1 atomic % can be considered an impurity.

<Impurities>
Here, the influence of each impurity in an oxide semiconductor will be described.

When an oxide semiconductor contains silicon or carbon, which is one of Group 14 elements, defect levels are formed in the oxide semiconductor. Therefore, the concentration of silicon or carbon in the oxide semiconductor and the concentration of silicon or carbon in the vicinity of the interface with the oxide semiconductor (concentration obtained by secondary ion mass spectrometry (SIMS)) are set to 2×10 ¹⁸ atoms/cm ³ or less, preferably 2×10 ¹⁷ atoms/cm ³ or less.

In addition, when an oxide semiconductor contains an alkali metal or an alkaline earth metal, defect levels are formed and carriers are generated in some cases. Therefore, a transistor using an oxide semiconductor containing an alkali metal or an alkaline earth metal is likely to have normally-on characteristics. For this reason, the concentration of the alkali metal or the alkaline earth metal in the oxide semiconductor measured by SIMS is set to 1×10 ¹⁸ atoms/cm ³ or less, preferably 2×10 ¹⁶ atoms/cm ³ or less.

Furthermore, when nitrogen is contained in an oxide semiconductor, electrons serving as carriers are generated, the carrier concentration increases, and the semiconductor is likely to become n-type. As a result, a transistor using an oxide semiconductor containing nitrogen as a semiconductor is likely to have normally-on characteristics. Alternatively, when nitrogen is contained in an oxide semiconductor, a trap state may be formed. As a result, the electrical characteristics of the transistor may become unstable. For this reason, the nitrogen concentration in the oxide semiconductor obtained by SIMS is set to less than 5×10 ¹⁹ atoms/cm ³ , preferably 5×10 ¹⁸ atoms/cm ³ or less, more preferably 1×10 ¹⁸ atoms/cm ³ or less, and further preferably 5×10 ¹⁷ atoms/cm ³ or less.

In addition, hydrogen contained in the oxide semiconductor reacts with oxygen bonded to a metal atom to form water, and thus oxygen vacancies may be formed. When hydrogen enters the oxygen vacancies, electrons serving as carriers may be generated. In addition, some of the hydrogen may bond to oxygen bonded to a metal atom to generate electrons serving as carriers. Therefore, a transistor using an oxide semiconductor containing hydrogen is likely to have normally-on characteristics. For this reason, it is preferable that hydrogen in the oxide semiconductor is reduced as much as possible. Specifically, the hydrogen concentration in the oxide semiconductor obtained by SIMS is set to less than 1×10 ²⁰ atoms/cm ³ , preferably less than 1×10 ¹⁹ atoms/cm ³ , more preferably less than 5×10 ¹⁸ atoms/cm ³ , and further preferably less than 1×10 ¹⁸ atoms/cm ³ .

By using an oxide semiconductor with sufficiently reduced impurities in the channel formation region of a transistor, stable electrical characteristics can be achieved.

This embodiment can be implemented in combination with at least a portion of the other embodiments described in this specification.

(Embodiment 9)
This embodiment describes an example of an electronic device according to one embodiment of the present invention.

The electronic device shown in Figures 39A to 39F has a housing 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or an operation switch), a connection terminal 9006, a sensor 9007, a microphone 9008, etc.

The electronic device shown in Figures 39A to 39F has various functions. For example, it can have a function of displaying various information (still images, videos, text images, etc.) on the display unit, a touch panel function, a function of displaying a calendar, date or time, etc., a function of controlling processing by various software (programs), a wireless communication function, a function of reading and processing programs or data recorded on a recording medium, etc. Note that the functions of the electronic device are not limited to these, and it can have various functions. The electronic device may have multiple display units. In addition, the electronic device may have a function of providing a camera or the like to capture still images or videos and store them on a recording medium (external or built into the camera), a function of displaying the captured images on the display unit, etc.

Details of the electronic devices shown in Figures 39A to 39F are described below.

Figure 39A is a perspective view showing a mobile information terminal 9101. The mobile information terminal 9101 can be used as a smartphone, for example. The mobile information terminal 9101 may be provided with a speaker 9003, a connection terminal 9006, a sensor 9007, and the like. The mobile information terminal 9101 can display one or more pieces of text or image information on multiple surfaces. Figure 39A shows an example in which three icons 9050 are displayed. Information 9051 shown in a dashed rectangle can also be displayed on another surface of the display unit 9001. Examples of the information 9051 include notification of incoming e-mail, SNS, telephone call, etc., the title of e-mail or SNS, the sender's name, date and time, time, remaining battery level, radio wave intensity, and the like. Alternatively, an icon 9050 or the like may be displayed at the position where the information 9051 is displayed.

Figure 39B is a perspective view showing a mobile information terminal 9102. The mobile information terminal 9102 has a function of displaying information on three or more sides of the display unit 9001. Here, an example is shown in which information 9052, information 9053, and information 9054 are each displayed on different sides. For example, a user can check information 9053 displayed in a position that can be observed from above the mobile information terminal 9102 while the mobile information terminal 9102 is stored in a breast pocket of a garment. The user can check the display without taking the mobile information terminal 9102 out of the pocket and decide, for example, whether or not to answer a call.

Figure 39C is a perspective view showing a wristwatch-type mobile information terminal 9200. The display surface of the display unit 9001 is curved, and display can be performed along the curved display surface. The mobile information terminal 9200 can also perform hands-free conversation by communicating with, for example, a headset capable of wireless communication. The mobile information terminal 9200 can also perform data transmission with another information terminal or one or more of charging via a connection terminal 9006. Note that charging may be performed by wireless power supply.

Figures 39D to 39F are perspective views showing a foldable mobile information terminal 9201. Figure 39D is a perspective view of the mobile information terminal 9201 in an unfolded state, Figure 39F is a folded state, and Figure 39E is a perspective view of a state in the middle of changing from one of Figures 39D and 39F to the other. The mobile information terminal 9201 has excellent portability when folded, and has excellent display visibility due to a seamless wide display area when unfolded. The display unit 9001 of the mobile information terminal 9201 is supported by three housings 9000 connected by hinges 9055. For example, the display unit 9001 can be bent with a curvature radius of 0.1 mm or more and 150 mm or less.

This embodiment can be combined with other embodiments as appropriate.

ANO: Wiring, CAT: Wiring, CU: Current control unit, EM: Light-emitting element, FD: Node, GL: Wiring, GLa: Wiring, GLb: Wiring, GLc: Wiring, GLd: Wiring, GLe: Wiring, GLf: Wiring, GLg: Wiring, IG: Light-receiving element, IR: Infrared light, IRS: Sub-pixel, M11: Transistor, M12: Transistor, M13: Transistor, M14: Transistor, M15: Transistor, M16: Transistor, M17: Transistor, MS: Wiring, PD: Light-receiving element, PS: Sub-pixel, RES: Wiring, SE: Signal supply unit, SEN: Wiring, SL: Wiring, SLB: Wiring, SLG: Wiring, SLR: Wiring, SR: light emitting/receiving element, TX: wiring, WX: wiring, 11: display section, 12: drive circuit section, 13: drive circuit section, 14: drive circuit section, 15: circuit section, 21B: pixel circuit, 21G: pixel circuit, 21R: pixel circuit, 22: pixel circuit, 23: pixel circuit, 30: pixel, 30c: pixel, 30d: pixel, 48: wiring, 49: wiring, 51: transistor, 52: transistor, 53: transistor, 54: transistor, 57: capacitance, 58: capacitance, 60: light emitting element, 61: transistor, 62: transistor, 63: transistor, 64: transistor, 65: transistor, 66: transistor, 67: capacitance, 68: capacitance, 90 B: light-emitting element, 90G: light-emitting element, 90R: light-emitting element, 90S: light-receiving element, 100: display device, 101: substrate, 111: pixel electrode, 111C: connection electrode, 111G: pixel electrode, 111R: pixel electrode, 112B: organic layer, 112G: organic layer, 112R: organic layer, 113: common electrode, 114: organic layer, 115: organic layer, 121: protective layer, 125: insulating layer, 126: resin layer, 130: connection portion, 131: insulating layer, 200: display portion, 200A: display portion, 200B: display portion, 201: substrate, 202: substrate, 203: functional layer, 211: light-emitting element, 211B: light-emitting element, 211G: light-emitting element, 211IR: light-emitting element child, 211R: light emitting element, 211W: light emitting element, 211X: light emitting element, 212: light receiving element, 213R: light receiving/emitting element, 220: finger, 221: contact portion, 222: fingerprint, 223: imaging range, 225: stylus, 226: trajectory, 252: transistor, 254: connection portion, 258: transistor, 259: transistor, 260: transistor, 261: insulating layer, 262: insulating layer, 264: insulating layer, 265: insulating layer, 268: insulating layer, 271: conductive layer, 272a: conductive layer, 272b: conductive layer, 273: conductive layer, 275: insulating layer, 278: connection portion, 281: semiconductor layer, 281i: channel formation region, 281n : low resistance region, 292: connection layer, 400: display device, 401: control circuit section, 403: sensor section, 404: memory section, 405: light emitting element, 406: light receiving element, 407: authentication section, 411a: conductive layer, 411b: conductive layer, 411c: conductive layer, 412G: EL layer, 412S: photoelectric conversion layer, 413: common electrode, 414: organic layer, 416: protective layer, 417: light shielding layer, 420: electronic device, 421: housing, 422: display section, 425: region, 425a: region, 425b: region, 427: region, 430b: light emitting element, 431: camera, 432: illuminance sensor, 433: user, 434: illuminance sensor, 435: band, 4 36: operation button, 437: fastener, 438: camera, 440: light receiving element, 441: layer, 442: adhesive layer, 443: layer, 445: space, 451: substrate, 452: substrate, 453: substrate, 454: substrate, 460: subject, 461: left wrist, 462: display unit, 463: finger, 464: circuit, 465: wiring, 466: conductive layer, 472: FPC, 473: IC, 483: region, 484: region, 484a: region, 484b: region, 491: insulating layer, 492: resin layer, 711: light emitting layer, 712: light emitting layer, 713: light emitting layer, 720: layer, 730: layer, 750B: light emitting element, 750G: light emitting element, 750R: light emitting element, 751: layer, 752: layer, 753B: light-emitting layer, 753G: light-emitting layer, 753R: light-emitting layer, 754: layer, 755: layer, 760: light-receiving element, 761: layer, 762: layer, 763: layer, 790: EL layer, 790a: EL layer, 790b: EL layer, 791: lower electrode, 791B: pixel electrode, 791G: pixel electrode, 791PD: pixel electrode, 791R: pixel electrode, 792: upper electrode, 795: colored layer, 6500: electronic device, 6501: housing, 6502: display unit, 6503: power button, 6504: button, 6505: speaker, 6506: microphone, 6507: camera, 6508: light source, 6510: protective member, 6511 : Display panel, 6512: Optical member, 6513: Touch sensor panel, 6515: FPC, 6516: IC, 6517: Printed circuit board, 6518: Battery, 6521: Camera, 6522: Camera, 6523: Illuminance sensor, 9000: Housing, 9001: Display unit, 9003: Speaker, 9005: Operation key, 9006: Connection terminal, 9007: Sensor, 9008: Microphone, 9050: Icon, 9051: Information, 9052: Information, 9053: Information, 9054: Information, 9055: Hinge, 9101: Portable information terminal, 9102: Portable information terminal, 9200: Portable information terminal, 9201: Portable information terminal

Claims (32)

A display unit is provided.
the display unit includes a plurality of light-emitting elements and a plurality of light-receiving elements;
The light receiving element receives light emitted from the light emitting element and reflected from a subject;
The light receiving element receives light during a first detection period,
During the first detection period, the light emitting element emits light at a first luminance;
the light receiving element receives light for a second detection period that is shorter than the first detection period;
During the second detection period, the light-emitting element emits light at a second luminance higher than the first luminance.
electronic equipment. In claim 1,
the light receiving element receives light during the first detection period when the illuminance of the external light is equal to or lower than a first value, and receives light during the second detection period when the illuminance of the external light is higher than the first value;
electronic equipment. A display unit is provided.
the display unit includes a plurality of pixel circuits and a plurality of second elements;
the pixel circuit includes a first element and a current control unit;
the first element has a first electrode, a second electrode, and a first light-emitting layer located between the first electrode and the second electrode;
the current control unit has a first terminal and a second terminal connected to the second electrode,
the first electrodes of the first elements of the plurality of pixel circuits are connected to each other;
the first terminals of the current control units of the pixel circuits are connected to each other;
the second element receives light emitted from the first element and reflected from a subject;
When the illuminance of the external light is equal to or less than a first value, the second element receives light for a first detection period;
During the first detection period, the first element emits light at a first intensity;
When the illuminance of the external light is higher than the first value, the first element emits light at a second luminance higher than the first luminance, and the second element receives light for a second detection period shorter than the first detection period;
During the second detection period, the first element emits light at the second intensity;
a difference between a potential of the first terminal and a potential of the first electrode during emission of the second luminance is greater than a difference between a potential of the first terminal and a potential of the first electrode during emission of the first luminance;
electronic equipment. In claim 3,
the current control section includes a first transistor;
one of a source and a drain of the first transistor is connected to the first terminal;
the other of the source and the drain of the first transistor is connected to the second terminal;
electronic equipment. In claim 3,
the current control section includes a first transistor;
When the first element emits light, a potential corresponding to the first terminal is applied to one of a source and a drain of the first transistor, and a current of the first element is controlled by the first transistor.
electronic equipment. In any one of claims 1 to 5,
a product of the first luminance and a length of the first detection period is 0.8 to 1.2 times a product of the second luminance and a length of the second detection period;
electronic equipment. In any one of claims 1 to 5,
the subject is a first finger in contact with or close to a surface of the display unit;
having a function of acquiring fingerprint information of the first finger;
electronic equipment. In any one of claims 1 to 5,
A storage unit is provided.
the subject is a first finger in contact with or close to a surface of the display unit;
the storage unit has fingerprint information of a second finger;
An electronic device having a function of acquiring fingerprint information of the first finger and a function of matching the fingerprint information of the first finger with the fingerprint information of the second finger. In claim 3,
the second element has a third electrode, a fourth electrode, and an active layer located between the third electrode and the fourth electrode;
the third electrodes of the second elements are connected to each other;
the third electrodes of the second elements and the first electrodes of the first elements of the pixel circuits are supplied with the same potential;
electronic equipment. In claim 9,
the second element has a second light-emitting layer;
the second light-emitting layer is located between the third electrode and the fourth electrode;
electronic equipment. In claim 10,
the first element has a function of emitting light of one color selected from three colors of red, green, and blue;
the second element has a function of emitting light of another color selected from the three colors and a function of receiving visible light;
electronic equipment. In claim 10,
the first element has a function of emitting light of one color selected from three colors of red, green, and blue;
the second element has a function of emitting light of another color selected from the three colors and a function of receiving infrared light;
electronic equipment. In claim 3,
a potential of the first electrode during emission of the second luminance is lower than a potential of the first electrode during emission of the first luminance;
electronic equipment. In claim 3,
a potential of the first terminal during emission of the second luminance is higher than a potential of the first terminal during emission of the first luminance;
electronic equipment. A display unit and a camera are included.
the display unit includes a plurality of pixel circuits and a plurality of light receiving elements;
the pixel circuit includes a light emitting element and a current control unit;
In a first mode of operation,
The light receiving element receives light emitted from the light emitting element and reflected from a subject;
When the illuminance of external light is equal to or less than a first value, the light-emitting element emits light with a first luminance, and the light-receiving element receives light for a first detection period;
When the illuminance of the external light is higher than the first value, the light emitting element emits light at a second luminance higher than the first luminance, and the light receiving element receives light for a second detection period shorter than the first detection period,
In a second mode of operation,
the light emitting element emits light at a third brightness;
taking an image using the camera with the light emitted at the third luminance as a flashlight;
The third luminance is lower than the second luminance.
electronic equipment. In claim 15,
The light-emitting element has a first electrode, a second electrode, and a light-emitting layer located between the first electrode and the second electrode,
the current control unit has a first terminal and a second terminal connected to the second electrode,
the first electrodes of the light-emitting elements of the plurality of pixel circuits are connected to each other;
the first terminals of the current control units of the pixel circuits are connected to each other;
a potential difference between the first terminal and the first electrode is larger during emission of the second luminance than during emission of the first luminance;
a potential difference between the first terminal and the first electrode is greater during emission of the second luminance than during emission of the third luminance;
electronic equipment. A program for running an electronic device,
The electronic device has a display unit having a display function and a detection function, and a memory unit,
A first step of placing a first finger on or proximate to a surface of the display;
a second step of displaying a first region of a first image on the display unit at a first luminance, performing detection during a first detection period using the first region of the first image as a light source, and acquiring a first captured image of the first finger;
a third step of selecting whether or not to adopt the first captured image;
a fourth step of displaying the first area of the first image on the display unit at a second luminance higher than the first luminance when the captured image is not adopted in the third step, performing detection in a second detection period shorter than the first detection period using the first area of the first image as a light source, and acquiring a second captured image of the first finger;
a fifth step of selecting whether or not to adopt the second captured image;
a sixth step of extracting fingerprint information of the first finger from the first captured image when the first captured image is adopted in the third step, and extracting fingerprint information of the first finger from the second captured image when the second captured image is adopted in the fifth step;
a seventh step of comparing the fingerprint information of the first finger extracted in the sixth step with fingerprint information of a second finger stored in the storage unit;
having
if the first captured image is adopted in the third step, the fourth step and the fifth step are not performed and the sixth step is performed.
program. In claim 17,
a product of the first luminance and a length of the first detection period is 0.8 to 1.2 times a product of the second luminance and a length of the second detection period;
program. The device has a display unit, a storage unit, and an illuminance sensor,
the display unit includes a plurality of pixel circuits and a plurality of light receiving elements;
the pixel circuit includes a light emitting element and a current control unit;
The light receiving element receives light emitted from the light emitting element and reflected from a subject;
the storage unit has first biological information;
the illuminance sensor detects an illuminance corresponding to external light received by the display unit;
When the illuminance detected by the illuminance sensor is equal to or lower than a first value, the light receiving element receives light for a first detection period,
During the first detection period, the light emitting element emits light at a first luminance;
When the illuminance detected by the illuminance sensor is higher than the first value, the light receiving element receives light for a second detection period that is shorter than the first detection period,
During the second detection period, the light emitting element emits light at a second luminance higher than the first luminance;
a function of acquiring a processing content based on an authentication code, and a function of acquiring second biometric information and approving the processing content based on a comparison with the first biometric information;
the authentication code is acquired by using an image including the authentication code as a first subject and detecting reflected light from the first subject with the plurality of light receiving elements;
the second biometric information is acquired by detecting reflected light from a finger or a palm of a second subject using the plurality of light receiving elements;
electronic equipment. 20. In claim 19,
the light-emitting element has a first electrode, a second electrode, and a first light-emitting layer located between the first electrode and the second electrode;
the current control unit has a first terminal and a second terminal connected to the second electrode,
the first electrodes of the light-emitting elements of the plurality of pixel circuits are connected to each other;
the first terminals of the current control units of the pixel circuits are connected to each other;
a difference between a potential of the first terminal and a potential of the first electrode during emission of the second luminance is greater than a difference between a potential of the first terminal and a potential of the first electrode during emission of the first luminance;
electronic equipment. In claim 20,
the current control section includes a first transistor;
one of a source and a drain of the first transistor is connected to the first terminal, and the other of the source and the drain of the first transistor is connected to the second terminal;
electronic equipment. In claim 20,
the current control section includes a first transistor;
When the light-emitting element emits light, a potential corresponding to the first terminal is applied to one of a source and a drain of the first transistor, and a current of the light-emitting element is controlled by the first transistor.
electronic equipment. In any one of claims 19 to 22,
The authentication code is a barcode or a two-dimensional code.
electronic equipment. In any one of claims 19 to 22,
a product of the first luminance and a length of the first detection period is 0.8 to 1.2 times a product of the second luminance and a length of the second detection period;
electronic equipment. In claim 20,
the light receiving element has a third electrode, a fourth electrode, and an active layer located between the third electrode and the fourth electrode;
the third electrodes of the light receiving elements are connected to each other;
the third electrode of each of the light receiving elements and the first electrode of each of the light emitting elements of the plurality of pixel circuits are given the same potential;
electronic equipment. 26. In claim 25,
the light receiving element has a second light emitting layer,
the second light-emitting layer is located between the third electrode and the fourth electrode;
electronic equipment. 27. In claim 26,
the light-emitting element has a function of emitting light of one color selected from three colors of red, green, and blue,
The light receiving element has a function of emitting light of another color selected from the three colors and a function of receiving visible light.
electronic equipment. 27. In claim 26,
the light-emitting element has a function of emitting light of one color selected from three colors of red, green, and blue,
The light receiving element has a function of emitting light of another color selected from the three colors and a function of receiving infrared light.
electronic equipment. In claim 20,
a potential of the first electrode is lower during emission of the second luminance than during emission of the first luminance;
electronic equipment. In claim 20,
a potential of the first terminal is higher during emission of the second luminance than during emission of the first luminance;
electronic equipment. A program for causing an electronic device to execute the program.
The electronic device includes a display unit having a plurality of light receiving elements and a storage unit,
a first step of displaying the first image at a first luminance on the display unit using an image including an authentication code as a first subject and using the image as a light source, and detecting reflected light from the light source on the first subject by the plurality of light receiving elements during a first detection period;
a second step of acquiring an image of the authentication code by using the reflected light detected in the first step;
a third step of displaying a first process content based on the authentication code on the display unit;
a fourth step of placing a first finger in contact with or adjacent to the display;
a fifth step of displaying a second image at a second luminance on the display unit using the first finger as a second subject and a second light source as a second light source, and detecting reflected light of the second light source from the second subject by the plurality of light receiving elements during a second detection period;
a sixth step of acquiring an image of the first finger by using the reflected light detected in the fifth step;
a seventh step of acquiring fingerprint information of the first finger from the captured image of the first finger and comparing the fingerprint information of the first finger with fingerprint information of a second finger stored in the storage unit;
an eighth step of confirming a match between the fingerprint information of the first finger and the fingerprint information of the second finger by the collation and performing the first process;
having
verifying the image quality of the captured image acquired in the sixth step, and if it is determined that the captured image needs to be reacquired, performing the fifth step and the sixth step again;
In the fifth step performed a second time, the second luminance is higher and the second detection period is shorter than those in the first time.
program. 32. In claim 31,
a product of the first luminance and a length of the first detection period is 0.8 to 1.2 times a product of the second luminance and a length of the second detection period;
program.

Images