CN109753852B - Optical assembly for object texture, display assembly and electronic equipment - Google Patents

Abstract

The present application provides an optical component, a display component and an electronic device for object texture, which belong to the technical field of display. The optical assembly is applied to an electronic device having a display panel, and the optical assembly includes a light source, a light guide device and a photodetector array. Among them, the light source is used to emit light, the light guide device is used to make the light emitted by the light source propagate in the light guide device, and guide the light to the display side of the display panel, and the area of the light guide device is greater than or equal to the area of the display panel, and the light The detector array is used to receive the light reflected by the object to be identified when there is an object to be identified on the display side of the display panel, and generate light for indicating the image of the object to be identified according to the received light reflected from the object to be identified Signal, the present application solves the problem that the related technology cannot realize full-screen fingerprint recognition, affects user experience, and has poor reliability, realizes full-screen recognition, improves user experience, and improves the reliability of texture recognition, and is used in electronic equipment.

Description

Optical components, display components and electronic equipment for object texture

technical field

The present application relates to the field of display technology, and in particular, to an optical component, a display component and an electronic device used for object textures.

Background technique

At present, organic light-emitting diode (English: Organic Light-Emitting Diode; abbreviated: OLED) display device plays an increasingly important role in personal life due to its advantages of self-luminescence, high contrast, thin thickness, wide viewing angle and fast response speed. More important, users often store a lot of important personal information and office materials in the display device, and therefore, the security of the display device becomes particularly important. A common way to improve the security of the display device is to set a password for the display device, and the password can be in the form of a password, a graphic, or a combination of a password and a graphic. However, the above method has some problems in practical application. For example, if the password is simple, it is easy to be leaked or cracked, and if the password is complex, it is difficult for the user to remember.

In the related art, in order to improve the security of the display device, the display component of the display device adopts the fingerprint identification technology, among which, the optical fingerprint identification technology is widely used in the fingerprint identification technology. For example, a display component for fingerprint identification using optical fingerprint identification technology includes a light source, a light detector and a display panel. Both the light source and the light detector are set at the designated position, the light source is used to emit light, and the light detector is used to receive the light reflected by the user's finger when there is a user's finger on the display side of the display panel, and generate a fingerprint for identifying the fingerprint according to the received light. The light signal of the fingerprint image.

However, the above-mentioned display components cannot realize full-screen fingerprint recognition, which affects the user experience and causes poor recognition reliability.

SUMMARY OF THE INVENTION

The present application provides an optical component, a display component and an electronic device for object textures, which can solve the problems that the related technologies cannot realize full-screen fingerprint recognition, affect user experience, and have poor recognition reliability. The technical solution is as follows:

In a first aspect, an optical assembly for object texture is provided, which is applied to an electronic device having a display panel, including: a light source, a light guide device and a photodetector array. Among them, the light source is used to emit light, and the light guide device is used to make the light emitted by the light source propagate in the light guide device and guide the light to the display side of the display panel. The area of the light guide device is greater than or equal to the area of the display panel. When there is an object to be identified on the display side of the display panel, the device array is used to receive the light reflected by the object to be identified, and to generate an optical signal indicating the image of the object to be identified according to the received light reflected from the object to be identified . For example, the object to be identified may be a fingerprint or a palm print.

In the present application, the light guide device can propagate the light emitted by the light source in the light guide device and guide the light to the display side of the display panel, and the area of the light guide device is greater than or equal to that of the display panel. In this way, an object at any position on the display side of the display panel can be detected, so that any position of the display panel can complete the texture recognition, realizing full-screen recognition. At the same time, the use of the light guide device can also reduce the demand for the number of light sources, thereby reducing the cost of the display assembly.

The light source, light guide device and photodetector array of the optical assembly can be arranged in various positions. For example, the light source can be arranged below one end of the display panel or directly below the display panel; the photodetector array can be arranged On the non-display side of the display panel; the light guide device may be arranged between the photodetector array and the display panel, or may be arranged under the cover plate or the polarizer of the display panel.

For example, the electronic device to which the optical component can be applied may be a product or component with a display function, such as a smart phone, a tablet computer, a TV, a monitor, a notebook computer, a wearable device, a digital photo frame, a navigator, and the like. The display panel of the electronic device may be an OLED display panel.

The photodetector array of the optical component includes a plurality of photodetectors, for example, 500 photodetectors can be correspondingly arranged per inch of the display panel, and the photodetector array can cover the entire display panel. For example, the photodetector may be a high-resolution image sensor, such as a CMOS, a CCD, or the like.

Optionally, the light guide device includes a light guide plate and a diffractive optical device, and the diffractive optical device is disposed on the light guide plate. Wherein, both sides of the light guide plate are provided with light refraction layers, and the refractive index of the light refraction layers is smaller than that of the light guide plate. Diffractive optics are used to direct light propagating in the light guide plate to the display side of the display panel.

The refractive index of the light refraction layers on both sides of the light guide plate is smaller than that of the light guide plate, so that the light incident on the light guide plate can be totally reflected at the interface between the light guide plate and the light refraction layer, so that the light emitted by the light source is reflected in the light guide plate. spread in the device.

Optionally, the light refraction layer is formed of air or optical glue. The light guide plate may be made of a material with high transmittance to light, for example, the light guide plate may be made of PC, PMMA, PDMS or glass material.

Optionally, the display panel has a plurality of pixels arranged in a matrix, and each pixel includes a plurality of sub-pixels. For example, each pixel may include 3 sub-pixels, or may include 5 sub-pixels. When each pixel includes 3 sub-pixels, the 3 sub-pixels may be red sub-pixels, green sub-pixels and blue sub-pixels. The diffractive optical device includes a plurality of diffraction gratings arranged in a matrix, and the light passing through each diffraction grating passes through the gaps between the plurality of sub-pixels in the display panel, so as to prevent the picture displayed by the display assembly from being affected. Optionally, by adjusting the position of the diffraction grating, or by controlling the exit angle of the diffracted light emitted by the diffraction grating, the light passing through each diffraction grating can pass through the gaps between the plurality of sub-pixels in the display panel. .

In the present application, the exit angle of the diffracted light emitted by the diffractive optical device may be smaller than a preset angle value, so that the diffracted light does not undergo total reflection at the interface between the cover plate of the display panel and the air.

In addition, the exit angle of the diffracted light emitted by the diffractive optical device may also be greater than or equal to a preset angle value, so that the diffracted light is totally reflected at the interface between the cover plate of the display panel and the air. When the diffracted light is totally reflected at the interface between the cover plate and the air of the display panel, compared with the diffracted light that does not undergo total reflection at the interface between the cover plate and the air of the display panel, the clarity of the image of the object to be recognized can be improved, and further Improve the accuracy of texture recognition. For example, by setting the grating period of the diffraction grating and adjusting the incident angle of light incident on the diffraction grating, the exit angle of the diffracted light emitted by the diffractive optical device may be greater than or equal to a preset angle value.

Wherein, the preset angle value θ1 satisfies: θ1=arcsin(n2*sinθ2/n1), n1 is the refractive index of the light guide plate, n2 is the refractive index of the cover plate, and θ2 is the incidence of diffracted light on the interface between the cover plate and the air Angle, θ2 satisfies: θ2>arcsin(n3/n2), n3 is the refractive index of air.

The exit angle of the diffracted light emitted by the diffractive optical device is greater than or equal to the preset angle value, the diffracted light is totally reflected at the interface between the cover plate and the air of the display panel, the reflectivity of the diffracted light is 100%, and the interface between the cover plate and the air reflects In this way, the difference between the optical signal generated by the photodetector array based on the light reflected from the interface between the cover plate and the air and the optical signal generated based on the light reflected from the interface between the cover plate and the object to be identified is greater. Therefore, the processor can form a higher-definition image of the object to be identified based on the two more different optical signals generated by the photodetector array.

Assuming that the object to be recognized is a fingerprint, in order to further improve the clarity of the fingerprint image, the difference between the intensity of the light reflected by the second interface and the intensity of the light reflected by the first interface can be increased. The second interface refers to the interface between the cover plate of the display panel and the air (ie, the air existing between the fingerprint valley and the cover plate), and the first interface refers to the interface between the cover plate and the fingerprint ridge. In order to increase the difference between the intensity of the light reflected by the second interface and the intensity of the light reflected by the first interface, the exit angle of the diffracted light emitted by the diffractive optical device can be greater than or equal to the preset angle value, so that the diffracted light is at the second interface. The interface, that is, the interface between the cover plate of the display panel and the air, undergoes total reflection. Since the difference between the intensity of the light reflected by the second interface and the intensity of the light reflected by the first interface is larger, the optical signal generated by the photodetector array according to the light reflected by the second interface and the light signal generated by the light reflected by the first interface The optical signals are more different, allowing the processor to form a higher definition fingerprint image based on the two more different optical signals generated by the photodetector array.

Generally, a display panel includes an array substrate, an encapsulation layer for covering and protecting the array substrate, a polarizer, an optically transparent adhesive and a cover plate sequentially arranged on the side of the encapsulation layer away from the array substrate. The cover plate may be a glass cover plate. The light guide device of the optical assembly may be disposed between the photodetector array and the display panel, or may be disposed under the cover plate or the polarizer of the display panel.

Optionally, the light source may be disposed below one end of the display panel. Disposing the light source below one end of the display panel can reduce the thickness of the optical assembly, the thickness of the display assembly including the optical assembly, and the thickness of the electronic device including the display assembly, thereby meeting the user's needs for the use of the electronic device.

Further, in order to improve the light utilization rate of the light source and further improve the accuracy of pattern recognition, the optical assembly may further include: an optical path collimator, the optical path collimator is arranged between the light source and the light guide device, and the optical path collimator is used for alignment. The light emitted by the light source is collected and coupled into the light guide device. The light emitted by the light source is coupled into the light guide device through the optical path collimator, so that the light guide device can make more light emitted by the light source propagate in the light guide device, and guide the light to the display side of the display panel, so that the light The intensity of the light reflected by the object to be recognized received by the detector array is higher, the light utilization rate of the light source is improved, and the accuracy of pattern recognition is further improved.

Optionally, the optical path collimator includes a converging lens and a coupling grating. The light source is arranged at the focal length of the converging lens, and the coupling grating is arranged between the converging lens and the light guide device. The converging lens is used for converging the light emitted by the light source into a collimated light beam; the coupling grating is used for coupling the collimated light beam into the light guide device. The light emitted by the light source is coupled into the light guide device through the converging lens and the coupling grating, so that the light guide device can transmit more light emitted by the light source in the light guide device and guide the light to the display side of the display panel.

For example, a nano-imprinting process may be used to form a coupling grating on the side of the light guide plate away from the display panel.

Optionally, the light source of the optical assembly used for the texture of the object can also be disposed on the side wall of the light guide device. In this case, the optical assembly does not need to be provided with an optical path collimator, which simplifies the structure of the optical assembly.

Optionally, the light source may include multiple sub-light sources, the converging lens may include multiple sub-lenses, and the multiple sub-light sources are in one-to-one correspondence with the multiple sub-lenses. Exemplarily, the sub-lens may be a microlens, a cylindrical lens or a collimator, and the collimator includes a fast-axis collimator and a slow-axis collimator.

In addition, the light source can also be a laser, the converging lens can be a microlens or a cylindrical lens, and the laser is arranged at the focal length of the microlens or the cylindrical lens.

Optionally, the plurality of diffraction gratings are arranged in a matrix shape at equal intervals, and the arranged interval is 20 micrometers to 400 micrometers.

Optionally, each diffraction grating has a length of 5 μm to 30 μm and a width of 5 μm to 30 μm.

In addition, for the future full-screen fingerprint identification technology, the optical component can make the thickness of the mobile terminal screen smaller, and can obtain a clearer fingerprint image that meets the needs of fingerprint identification, and can be well applied to the future full-screen fingerprint identification technology. Adapt to technological trends.

In a second aspect, a display assembly is provided, including a display panel and the optical assembly described in the first aspect. Since the optical assembly can transmit the light emitted by the light source in the light guide device and guide the light to the display side of the display panel, when there is an object to be identified on the display side of the display panel, the photodetector array receives the reflected light from the object to be identified. light, and generate a light signal for indicating the image of the object to be identified according to the received light reflected by the object to be identified. The area of the light guide device is greater than or equal to the area of the display panel, so any position of the display panel can Completed texture recognition, realized full-screen recognition, improved user experience, and improved the reliability of texture recognition. At the same time, the use of the light guide device can also reduce the demand for the number of light sources, thereby reducing the cost of the display assembly. In addition, arranging the light source below one end of the display panel can reduce the thickness of the electronic device, meet the user's demand for the use of the electronic device, further improve the light utilization rate of the light source, and improve the accuracy of pattern recognition.

Optionally, the display panel is an OLED display panel.

In a third aspect, an electronic device is provided, including the display component of the second aspect and a processor (eg, a CPU), where the processor is configured to form an image of an object to be recognized according to an optical signal obtained by an optical component of the display component. Since the display assembly of the electronic device includes the optical assembly for the texture of the object, the light guide device of the optical assembly can propagate the light emitted by the light source in the light guide device, and guide the light to the display side of the display panel, and the photodetector array When there is an object to be identified on the display side of the display panel, the light reflected by the object to be identified is received, and a light signal indicating the image of the object to be identified is generated according to the received light reflected by the object to be identified, and the light is guided. The area of the device is greater than or equal to the area of the display panel, so any position of the display panel can complete the pattern recognition, which realizes the full-screen recognition, improves the user experience, and improves the reliability of the pattern recognition. At the same time, the use of the light guide device can also reduce the demand for the number of light sources, thereby reducing the cost of electronic equipment. In addition, arranging the light source below one end of the display panel can reduce the thickness of the electronic device, meet the user's demand for the use of the electronic device, further improve the light utilization rate of the light source, and improve the accuracy of pattern recognition.

In a fourth aspect, a method for manufacturing an optical component for object texture is provided, the method comprising: forming a light source, a light guide device and a photodetector array respectively. Among them, the light source is used to emit light, and the light guide device is used to make the light emitted by the light source propagate in the light guide device and guide the light to the display side of the display panel. The area of the light guide device is greater than or equal to the area of the display panel. The device array is used to receive the light reflected by the object to be identified when there is an object to be identified on the display side of the display panel, and to generate a light signal indicating an image of the object to be identified according to the received light reflected from the object to be identified. For example, the object to be identified may be a fingerprint or a palm print.

The light guide device formed by the manufacturing method can propagate the light emitted by the light source in the light guide device and guide the light to the display side of the display panel. The area of the light guide device is greater than or equal to that of the display panel, so any The texture recognition can be completed at all positions, realizing full-screen recognition, improving user experience, and improving the reliability of identifying textures. At the same time, the formation of light guide devices can also reduce the demand for the number of light sources, thereby reducing the cost of display components.

Optionally, the light guide device includes a light guide plate and a diffractive optical device. Correspondingly, forming the light guide device includes: forming a diffractive optical device on the light guide plate, and then forming light on both sides of the light guide plate on which the diffractive optical device is formed. Refraction layer, the refractive index of the light refraction layer is smaller than that of the light guide plate, and the diffractive optical device is used to guide the light propagating in the light guide plate to the display side of the display panel.

Optionally, the display panel has a plurality of pixels arranged in a matrix, each pixel includes a plurality of sub-pixels, and the diffractive optical device includes a plurality of diffraction gratings arranged in a matrix. Correspondingly, the diffractive optical device is formed on the light guide plate, It may include: forming a plurality of diffraction gratings on the light guide plate, and the light passing through each diffraction grating passes through the gaps between the plurality of sub-pixels in the display panel, so as to prevent the picture displayed by the display assembly from being affected. Optionally, by adjusting the position of the diffraction grating, or by controlling the exit angle of the diffracted light emitted by the diffraction grating, the light passing through each diffraction grating can pass through the gaps between the plurality of sub-pixels in the display panel. .

Optionally, forming a plurality of diffraction gratings on the light guide plate may include: forming a plurality of diffraction gratings on the light guide plate through a nanoimprint process. Exemplarily, the plurality of diffraction gratings are arranged in a matrix shape at equal intervals, and the arranged interval may be 20 micrometers to 400 micrometers. The length of each diffraction grating 021 may be 5 micrometers to 30 micrometers, and the width may be 5 micrometers to 30 micrometers.

Optionally, forming the photodetector array includes: forming the photodetector array on the non-display side of the display panel. For example, 500 photodetectors may be formed per inch on the non-display side of the display panel. The photodetector array covers the entire display panel.

Generally, the display panel includes a cover plate and a polarizer. Correspondingly, forming a light guide device may include: forming a light guide device on a side of the display panel close to the photodetector array, and the light guide device is located between the photodetector array and the display panel. Alternatively, a light guide device is formed on the side of the display panel away from the photodetector array, and the light guide device is located under the cover plate or the polarizer of the display panel.

Optionally, forming the light source may include: forming the light source under one end of the display panel so that the outermost edge of the light source is located outside the outermost edge of the vertical projection of the display panel. Forming the light source under one end of the display panel can reduce the thickness of the optical component, reduce the thickness of the display component including the optical component, and further reduce the thickness of the electronic device including the display component, so as to meet the needs of the user for the use of the electronic device.

In addition, a light source may be formed at one end of the display panel, and the light source and the display panel may be located on the same layer.

Optionally, the optical assembly further includes: an optical path collimator. Correspondingly, after the light source is formed under one end of the display panel, the method may further include: forming an optical path collimator between the light source and the light guide device, and the optical path collimator is formed. The straightener is used for condensing the light emitted by the light source and coupling it into the light guide device.

The light emitted by the light source is coupled into the light guide device through the optical path collimator, so that the light guide device can make more light emitted by the light source propagate in the light guide device, and guide the light to the display side of the display panel, so that the light The intensity of the light reflected by the object to be recognized received by the detector array is higher, the light utilization rate of the light source is improved, and the accuracy of pattern recognition is further improved.

Optionally, the optical path collimator includes a converging lens and a coupling grating. Correspondingly, forming an optical path collimator between the light source and the light guide device includes: forming a converging lens between the light source and the light guide device, so that the light source is located in the converging device. The focal length position of the lens; a coupling grating is formed between the converging lens and the light guide device, the converging lens is used for converging the light emitted by the light source into a collimated light beam, and the coupling grating is used for coupling the collimated light beam into the light guide device. For example, a nano-imprinting process may be used to form a coupling grating on the side of the light guide plate away from the display panel.

The beneficial effects brought by the technical solution provided by the application are:

Since the light guide device can transmit the light emitted by the light source in the light guide device and guide the light to the display side of the display panel, when there is an object to be recognized on the display side of the display panel, the photodetector array receives the reflected light from the object to be recognized. light, and generate a light signal for indicating the image of the object to be identified according to the received light reflected by the object to be identified. Since the area of the light guide device is greater than or equal to the area of the display panel, any position of the display panel is It can complete texture recognition, realize full-screen recognition, improve user experience, and improve the reliability of texture recognition. At the same time, the use of the light guide device can also reduce the demand for the number of light sources.

Description of drawings

1 is a schematic structural diagram of an optical component and a display panel for object texture provided by an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of another optical component for object texture and a display panel provided by an embodiment of the present invention;

3 is a side view of a light guide device provided by an embodiment of the present invention;

Figure 4-1 is a schematic structural diagram of a diffraction grating;

Figure 4-2 is a schematic diagram of the propagation path of light incident on the diffraction grating shown in Figure 4-1;

5-1 is a schematic structural diagram of another optical component and display panel for object texture provided by an embodiment of the present invention;

5-2 is a schematic diagram of a fingerprint reflected light provided by an embodiment of the present invention;

Figure 5-3 is a top view of the optical assembly shown in Figure 5-1;

6 is a schematic structural diagram of a diffraction grating provided by an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of still another optical assembly for object texture and a display panel provided by an embodiment of the present invention;

8-1 is a schematic diagram of a propagation path of light incident on a light guide plate provided by an embodiment of the present invention;

Figure 8-2 is a schematic diagram of the working process of the optical assembly when the diffracted light is totally reflected at the interface between the cover plate and the air of the display panel;

8-3 is a schematic diagram of a fingerprint reflected light provided by an embodiment of the present invention;

8-4 is a schematic structural diagram of an OLED display panel in the related art;

9-1 is a schematic structural diagram of another optical component and display panel for object texture provided by an embodiment of the present invention;

9-2 is a schematic diagram of a mobile terminal screen provided with a fingerprint identification area;

10-1 is a flowchart of forming a light guide device according to an embodiment of the present invention;

10-2 is a flowchart of forming a light refraction layer on both sides of a light guide plate formed with diffractive optical devices according to an embodiment of the present invention.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present application clearer, the embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

At present, a common way to improve the security of a display device is to set a password for the display device. For example, the password may be in the form of a password, a graphic, or a combination of a password and a graphic. However, these methods all have some problems in practical application. For example, if the password is simple, it is easy to be leaked or cracked; if the password is complex, it is difficult for users to remember. In the related art, in order to improve the security of the display device, the display component of the display device often adopts the fingerprint identification technology. The fingerprint identification technology provides users with great convenience and improves the user experience.

The current fingerprint identification technology mainly includes three kinds: capacitive fingerprint identification technology, ultrasonic fingerprint identification technology and optical fingerprint identification technology. Compared with capacitive fingerprint recognition technology and ultrasonic fingerprint recognition technology, optical fingerprint recognition technology has attracted more attention. At present, the display components that use the optical fingerprint identification technology for fingerprint identification include a light source, a light detector and a display panel. Both the light source and the light detector are set at the designated position, the light source is used to emit light, and the light detector is used to receive the light reflected by the user's finger when there is a user's finger on the display side of the display panel, and generate a fingerprint for identifying the fingerprint according to the received light. The light signal of the fingerprint image. After that, a processor (such as a CPU) forms a fingerprint image according to the light signal obtained by the display assembly. Since the light source and the light detector are set at the specified position, only partial recognition can be achieved, and full-screen fingerprint recognition cannot be achieved.

However, the optical assembly for object texture provided by the embodiment of the present invention includes a light guide device, the light guide device can transmit the light emitted by the light source in the light guide device, and guide the light to the display side of the display panel, and the light guide device The area of the device is greater than or equal to the area of the display panel. In this way, an object at any position on the display side of the display panel can be detected, so that any position of the display panel can complete the texture recognition, realizing full-screen recognition.

FIG. 1 is a schematic structural diagram of an optical assembly for object texture and a display panel according to an embodiment of the present invention, where the optical assembly is applied to an electronic device having a display panel. For example, the electronic device may be a product or component with a display function, such as a smart phone, a tablet computer, a television, a monitor, a notebook computer, a wearable device, a digital photo frame, a navigator, and the like.

The optical assembly includes: a light source 21 , a light guide device 22 and a photodetector array 23 . The light source 21 , the light guide device 22 and the photodetector array 23 of the optical assembly can be placed in various positions. For example, the light source can be placed under one end of the display panel, or directly under the display panel; the photodetector The array can be arranged on the non-display side of the display panel; the light guide device can be arranged between the photodetector array and the display panel, or can be arranged under the cover plate or the polarizer of the display panel. The arrangement of the light source below one end of the display panel means that the outermost edge of the light source is located outside the outermost edge of the vertical projection of the display panel. In FIG. 1 , the light source 21 is arranged below one end of the display panel 00 , the photodetector array 23 is arranged on the non-display side of the display panel 00 , and the light guide device 22 is arranged between the photodetector array 23 and the display panel 00 as an example. illustrate.

Referring to FIG. 1, a light source 21 is used to emit light.

The light guide device 22 is used to make the light emitted by the light source 21 propagate in the light guide device 22 and guide the light to the display side of the display panel 00 , wherein the area of the light guide device 22 is greater than or equal to that of the display panel 00 . FIG. 1 exemplarily shows that the area of the light guide device 22 is larger than that of the display panel 00 .

The photodetector array 23 is used to receive the light reflected by the object to be identified when there is an object to be identified 001 on the display side of the display panel 00, and to generate a signal for indicating the object to be identified according to the received light reflected from the object to be identified image light signal. The photodetector array 23 includes a plurality of photodetectors. For example, the display panel may have 500 photodetectors per inch, and the photodetector array 23 may cover the entire display panel, that is, the area where the photodetector array 23 is located The area is equal to the area of the display panel.

For example, the object to be identified may be a fingerprint or a palm print. The display panel may be an OLED display panel.

The light guide device shown in FIG. 1 can propagate the light emitted by the light source in the light guide device and guide the light to the display side of the display panel. The area of the light guide device is greater than or equal to that of the display panel. When there is an object to be identified on the display side of the display panel, the photodetector array receives the light reflected by the object to be identified, and generates an optical signal for indicating the image of the object to be identified according to the received light reflected from the object to be identified . After that, the processor forms an image of the object to be recognized according to the light signal, and compares the image of the object to be recognized with the image stored in the image library in advance. If the two match, the recognition is successful. Since the area of the light guide device is greater than or equal to the area of the display panel, the pattern recognition can be completed at any position of the display panel, realizing full-screen recognition. At the same time, the use of the light guide device can also reduce the demand for the number of light sources, thereby reducing the cost of the display assembly. In addition, arranging the light source below one end of the display panel can reduce the thickness of the optical component, reduce the thickness of the display component including the optical component, and further reduce the thickness of the electronic device including the display component, so as to meet the needs of the user for the use of the electronic device.

The identification operation of the optical component can be used for applications such as unlocking of electronic devices, quick payment, and quick login software. Taking the unlocking application of an electronic device as an example, if the identification is successful, the user can use the electronic device.

It should be noted that, for the process that the processor forms an image of the object to be recognized according to the optical signal, and recognizes the texture of the object to be recognized based on the image of the object to be recognized, reference may be made to the related art, which is not repeated in this embodiment of the present invention.

To sum up, in the optical assembly for object texture provided by the embodiment of the present invention, since the light guide device can propagate the light emitted by the light source in the light guide device, and guide the light to the display side of the display panel, the photodetector array When there is an object to be identified on the display side of the display panel, the light reflected by the object to be identified is received, and an optical signal indicating the image of the object to be identified is generated according to the received light reflected by the object to be identified. The area of the device is greater than or equal to the area of the display panel, so any position of the display panel can complete the pattern recognition, which realizes the full-screen recognition, improves the user experience, and improves the reliability of the pattern recognition. At the same time, the use of the light guide device can also reduce the demand for the number of light sources. In addition, arranging the light source below one end of the display panel can reduce the thickness of the electronic device and meet the user's requirement for using the electronic device.

2 is a schematic structural diagram of another optical component for object texture and a display panel provided by an embodiment of the present invention. The optical component is applied to an electronic device with a display panel. As shown in FIG. 2 , the optical component includes: a light source 21. Light guide device 22 and photodetector array 23. In FIG. 2 , the light source 21 is arranged below one end of the display panel 00 , the photodetector array 23 is arranged on the non-display side of the display panel 00 , and the light guide device 22 is arranged between the photodetector array 23 and the display panel 00 as an example. illustrate.

Referring to FIG. 2, a light source 21 is used to emit light.

The light guide device 22 is used to make the light emitted by the light source 21 propagate in the light guide device 22 and guide the light to the display side of the display panel 00 , wherein the area of the light guide device 22 is greater than or equal to that of the display panel 00 . FIG. 2 exemplarily shows that the area of the light guide device 22 is larger than that of the display panel 00 . The display panel 00 includes a cover plate 231 .

The photodetector array 23 is used to receive the light reflected by the object to be identified when there is an object to be identified 001 on the display side of the display panel 00, and to generate a signal for indicating the object to be identified according to the received light reflected from the object to be identified. The light signal of the image. The photodetector array 23 includes a plurality of photodetectors, for example, 500 photodetectors are arranged per inch on the display panel, and the photodetector array 23 can cover the entire display panel. The object to be recognized can be a fingerprint or a palm print.

Optionally, the photodetector may be a high-resolution image sensor, for example, the photodetector may be a complementary metal oxide semiconductor (Complementary Metal Oxide Semiconductor, CMOS), a charge-coupled device (Charge-coupled Device, CCD), or the like.

Referring to FIG. 2 , the light guide device 22 may include a light guide plate 221 and a diffractive optical device 222 , and the diffractive optical device 222 is disposed on the light guide plate 221 .

Both sides of the light guide plate 221 are provided with light refraction layers 2210 , and the refractive index of the light refraction layers 2210 is smaller than that of the light guide plate 221 . Diffractive optics are used to direct light propagating in the light guide plate to the display side of the display panel.

The light guide plate may be made of a material with high transmittance to light. For example, the light guide plate may be made of polycarbonate (Polycarbonate, PC), polymethylmethacrylate (PMMA), polydimethylmethacrylate Siloxane (polydimethylsiloxane, PDMS) or glass material. The light guide plate with high transmittance facilitates the light reflected by the object to be recognized to reach the photodetector array through the light guide plate.

The refractive index of the light refraction layers 2210 on both sides of the light guide plate 221 is smaller than that of the light guide plate 221, so that the light incident on the light guide plate 221 can be totally reflected at the interface between the light guide plate 221 and the light refraction layer 2210, so that the light source The emitted light propagates in the light guide. Assuming that the light guide plate is made of PC material with a refractive index of 1.585 and the refractive index of the light refraction layer is 1.3, the critical angle of total reflection of light in the light guide plate at the interface between the light guide plate and the light refraction layer is C1=arcsin(1.3/1.585) ≈55°, therefore, when the incident angle of the light incident on the light guide plate on the interface between the light guide plate and the light refraction layer is greater than 55°, such as the incident angle of the light incident on the light guide plate on the interface between the light guide plate and the light refraction layer When it is 60°, the light can be totally reflected at the interface between the light guide plate and the light refraction layer.

Exemplarily, the light refraction layer may be formed of air or optical glue, that is, as shown in FIG. 2 , an air layer may be disposed between the light guide plate 221 and the display panel 00 and the photodetector array 23, respectively, and the air layer is light refraction layer. Alternatively, an optical adhesive layer may be disposed between the light guide plate 221 and the display panel 00 and the photodetector array 23 respectively, and the optical adhesive layer is a light refraction layer. The embodiment of the present invention does not limit the formation method of the light refraction layer.

As shown in FIG. 2 , the diffractive optical device 222 is used to guide the light propagating in the light guide plate 221 to the display side of the display panel 00 . In order for the photodetector array 23 to receive the light reflected by the object to be identified when there is an object to be identified on the display side of the display panel 00, and to generate a signal for indicating the object to be identified according to the received light reflected from the object to be identified. The light signal of the image. The guiding direction of the light is the direction indicated by u in FIG. 2 .

Optionally, the display panel has a plurality of pixels arranged in a matrix, and each pixel includes a plurality of sub-pixels. For example, each pixel may include 3 sub-pixels, or may include 5 sub-pixels. When each pixel includes 3 sub-pixels, the 3 sub-pixels may be red sub-pixels, green sub-pixels and blue sub-pixels.

FIG. 3 shows a side view of the light guide device, which includes a light guide plate 221 and a diffractive optical device 222 . The diffractive optical device 222 may include a plurality of diffraction gratings 021 arranged in a matrix, and the light passing through each diffraction grating 021 passes through the gaps between the plurality of sub-pixels in the display panel, in this way, the picture displayed by the display assembly is avoided. affected. Optionally, by adjusting the position of the diffraction grating, or by controlling the exit angle of the diffracted light emitted by the diffraction grating, the light passing through each diffraction grating can pass through the gaps between the plurality of sub-pixels in the display panel. .

In order to enable readers to understand the embodiments of the present invention more deeply, the structure and principle of the diffraction grating will now be briefly described. First, referring to FIG. 4-1, FIG. 4-1 shows a schematic structural diagram of a diffraction grating 021. The diffraction grating belongs to an optical component, which includes a plurality of periodically arranged grating teeth 0211. The grating period d of the diffraction grating refers to the distance between the centers of any two adjacent grating teeth, and the magnitude of the grating period is the same as the magnitude of the light wavelength. The magnitude of the height H of each grating tooth 0211 of the diffraction grating is also of the same magnitude as that of the wavelength of light. The grating period of the diffraction grating and the height of each grating tooth can be set according to actual requirements. For example, the grating period of the diffraction grating can be 300 nanometers, and the height of each grating tooth can be 300 nanometers.

为入射至衍射光栅的光的入射角，θ为入射至衍射光栅的光在衍射光栅上发生衍射时的衍射角，d为衍射光栅的光栅周期。由图4-2可以得到，

θ和d之间存在如下关系：

其中，λ为入射至衍射光栅的光的波长，m为入射至衍射光栅的光在衍射光栅上发生衍射时的衍射级次，m可以等于0、±1、±2等。m等于+1时的衍射为正一级衍射(正一级衍射的光称为正一级衍射光)；m等于-1时的衍射为负一级衍射，依次类推，m等于+2时的衍射为正二级衍射。在衍射过程中，多级衍射可以同时存在。可选的，在实际应用中，可以通过调整衍射光栅的光栅齿的高度、光栅齿的占空比(占空比＝c1/(c1+p1)，c1为一个光栅齿的宽度，p1为与该光栅齿相邻的一个间隙的宽度)等参数的大小来调整每级衍射光的强度。而由公式

可知，当采用衍射光栅对入射角为

的光产生垂直于衍射光栅的正一级衍射光，也即是，θ＝0°时，则有：

所以有：

也即是，当θ＝0°时，衍射光栅的光栅周期与入射至衍射光栅的光的波长、入射至衍射光栅的光的入射角有关。Figure 4-2 shows a schematic diagram of the propagation path of light incident on the diffraction grating shown in Figure 4-1. In Figure 4-2, both R1 and R2 are light incident on the diffraction grating.

is the incident angle of the light incident on the diffraction grating, θ is the diffraction angle when the light incident on the diffraction grating is diffracted on the diffraction grating, and d is the grating period of the diffraction grating. It can be obtained from Figure 4-2,

There is the following relationship between θ and d:

Among them, λ is the wavelength of the light incident on the diffraction grating, m is the diffraction order when the light incident on the diffraction grating is diffracted on the diffraction grating, and m can be equal to 0, ±1, ±2, etc. When m is equal to +1, the diffraction is positive first-order diffraction (the light with positive first-order diffraction is called positive first-order diffracted light); when m is equal to -1, the diffraction is negative first-order diffraction, and so on, when m is equal to +2 Diffraction is positive second order diffraction. During the diffraction process, multiple orders of diffraction can exist simultaneously. Optionally, in practical applications, the height of the grating teeth of the diffraction grating and the duty cycle of the grating teeth can be adjusted (duty ratio=c1/(c1+p1), c1 is the width of one grating tooth, and p1 is the The intensity of each order of diffracted light is adjusted by the size of parameters such as the width of a gap adjacent to the grating teeth). And by the formula

It can be seen that when the diffraction grating is used for the incident angle as

The light of , produces positive first-order diffracted light perpendicular to the diffraction grating, that is, when θ=0°, there are:

F:

That is, when θ=0°, the grating period of the diffraction grating is related to the wavelength of light incident on the diffraction grating and the incident angle of the light incident on the diffraction grating.

的光经过衍射光学器件222所产生的0级衍射光携带了绝大部分的光能量，0级衍射光仍按照光原来的方向传播，在导光板内发生全反射，并在导光器件中传播。而入射角为

的光经过衍射光学器件222所产生的正一级衍射光携带了少量的光能量，该正一级衍射光按照垂直于导光板221的方向朝显示面板的显示侧射出，其被导向显示面板的显示侧，进而到达待识别物体001，也即是，图4-2中入射至衍射光栅的光在衍射光栅上发生衍射时的衍射角θ为0°。假设，入射至衍射光栅的光的入射角

为60°，入射至衍射光栅的光的波长λ为532纳米，那么基于公式

可以得到，衍射光栅的光栅周期d＝532/sin60°＝614.3，即衍射光栅的光栅周期为614.3纳米。As shown in FIG. 2, when the light incident on the light guide plate 221 reaches the diffractive optical device 222, the incident angle is

The 0th-order diffracted light generated by the diffractive optical device 222 carries most of the light energy, and the 0th-order diffracted light still propagates in the original direction of the light, is totally reflected in the light guide plate, and propagates in the light guide device . and the angle of incidence is

The positive first-order diffracted light generated by the diffractive optical device 222 carries a small amount of light energy, and the positive first-order diffracted light is emitted toward the display side of the display panel in a direction perpendicular to the light guide plate 221, and is directed to the display side of the display panel. The display side, and then reaches the object to be identified 001, that is, the diffraction angle θ when the light incident on the diffraction grating in FIG. 4-2 is diffracted on the diffraction grating is 0°. Assuming that the incident angle of light incident on the diffraction grating

is 60°, and the wavelength λ of the light incident on the diffraction grating is 532 nm, then based on the formula

It can be obtained that the grating period of the diffraction grating is d=532/sin60°=614.3, that is, the grating period of the diffraction grating is 614.3 nm.

In another achievable manner, in order to improve the light utilization rate of the light source and further improve the accuracy of texture identification, the optical component used for the texture of the object may further include an optical path collimator, and the optical path collimator is used for the light emitted by the light source. Condensed and coupled into the light guide. For example, the optical assembly may be as shown in FIG. 5-1 . The optical assembly includes: a light source 21 , a light guide device 22 and a photodetector array 23 . In FIG. 5-1 , the light source 21 is also arranged below one end of the display panel 00 , the photodetector array 23 is arranged on the non-display side of the display panel 00 , and the light guide device 22 is arranged between the photodetector array 23 and the display panel 00 Take an example to illustrate.

Among them, the light source 21 is used for emitting light.

The light guide device 22 is used to propagate the light emitted by the light source in the light guide device 22 and guide the light to the display side of the display panel 00 , wherein the area of the light guide device 22 is greater than or equal to that of the display panel 00 . FIG. 5-1 exemplarily shows that the area of the light guide device 22 is larger than that of the display panel 00 .

The photodetector array 23 is used to receive the light reflected by the object to be identified when there is an object to be identified 001 on the display side of the display panel 00, and to generate a signal for indicating the object to be identified according to the received light reflected from the object to be identified image light signal.

The light guide device 22 may include a light guide plate 221 and a diffractive optical device 222 , and the diffractive optical device 222 is disposed on the light guide plate 221 . Diffractive optics are used to direct light propagating in the light guide plate to the display side of the display panel. The diffractive optical device 222 may include a plurality of diffraction gratings 021 arranged in a matrix. Both sides of the light guide plate 221 are provided with light refraction layers 2210 , and the refractive index of the light refraction layers 2210 is smaller than that of the light guide plate 221 .

The optical assembly further includes: an optical path collimator 24 , and the optical path collimator 24 is arranged between the light source 21 and the light guide device 22 . The optical path collimator 24 is used for condensing the light emitted by the light source 21 and coupling it into the light guide device 22 .

The light emitted by the light source is coupled into the light guide device through the optical path collimator, so that the light guide device can make more light emitted by the light source propagate in the light guide device, and guide the light to the display side of the display panel, so that the light The intensity of the light reflected by the object to be recognized received by the detector array is higher, the light utilization rate of the light source is improved, and the accuracy of pattern recognition is further improved.

Optionally, as shown in FIG. 5-1 , the optical path collimator 24 may include a converging lens 241 and a coupling grating 242 . The light source 21 is arranged at the focal length position of the converging lens 241 , and the coupling grating 242 is arranged between the converging lens 241 and the light guide device 22 .

The converging lens 241 is used to condense the light emitted by the light source 21 into a collimated light beam.

The coupling grating 242 is used to couple the collimated light beam into the light guide device 22 .

The light emitted by the light source is coupled into the light guide device through the converging lens and the coupling grating, so that the light guide device can transmit more light emitted by the light source in the light guide device and guide the light to the display side of the display panel.

Exemplarily, as shown in FIG. 5-1 , a nano-imprinting process may be used to form a coupling grating on the side of the light guide plate away from the display panel. In addition, in practical applications, the size of the area that the coupling grating needs to occupy on the light guide plate can also be determined according to the size of the converging lens.

Assuming that the object to be recognized on the display side of the display panel is a fingerprint, the working process of the optical assembly shown in Figure 5-1 can be as follows: the light source 21 emits light, and the focusing lens 241 converges the light emitted by the light source 21 into a collimated beam, coupling The grating 242 couples the collimated light beam into the light guide plate 221 of the light guide device 22 . The light incident on the light guide plate 221 is totally reflected at the interface between the light guide plate 221 and the light refraction layer 2210, and the totally reflected light passes through the diffraction grating 021 to generate positive first-order diffracted light that propagates perpendicular to the diffraction grating (the propagation direction is direction indicated by u in Figure 5-1). The positive first-order diffracted light passes through the display panel and reaches the interface between the cover plate 231 of the display panel 00 and the fingerprint 001 . Fingerprints are innate, unique and invariable features of the human body that can be distinguished from others. Fingerprints are composed of a series of fingerprint ridges and fingerprint valleys on the skin surface of the fingertips. The composition details of these fingerprint ridges and fingerprint valleys are usually Including details such as the bifurcation of the fingerprint ridge, the end of the fingerprint ridge, the arch, the tent-like arch, left-handed, right-handed, spiral or double-turned, these details determine the uniqueness of the fingerprint image. As shown in FIG. 5-2 , when a finger touches the surface of the cover plate 231 , the fingerprint ridges are in contact with the cover plate 231 , and there is air between the fingerprint valleys and the cover plate 231 . Since the refractive index of the fingerprint ridges in contact with the surface of the cover plate 231 of the display panel 00 is greater than the refractive index of the air between the cover plate 231 and the fingerprint valleys, the intensity of the light reflected by the fingerprint ridges is different from that of the fingerprint valleys. , in this way, the intensity of the light reflected by the fingerprint 001 carries the area information of the fingerprint, and the area information is used to indicate the fingerprint ridge or fingerprint valley. Finally, as shown in Fig. 5-1, the optical signal generated by the photodetector array 23 based on the light reflected by the fingerprint ridges is different from the optical signal generated by the light reflected by the fingerprint valleys, so that the processor can be based on the photodetector. The two optical signals generated by the array 23 form a fingerprint image.

Refer to Figure 2 for the meanings of other symbols in Figure 5-1.

Fig. 5-3 shows a top view of the optical assembly shown in Fig. 5-1. As shown in Fig. 5-3, the optical path collimator 24 is disposed between the light source 21 and the light guide plate 221 of the light guide device. The optical path collimator 24 includes a converging lens 241 and a coupling grating 242 , and the light source 21 is arranged at the focal length of the converging lens 241 . The diffractive optical device includes a plurality of diffraction gratings 021 arranged in a matrix.

Optionally, as shown in FIG. 5-3 , the light source 21 may include a plurality of sub-light sources 211 , the converging lens 241 may include a plurality of sub-lenses 2411 , and the sub-light sources correspond to the plurality of sub-lenses one-to-one. Exemplarily, the sub-lens may be a microlens, a cylindrical lens or a collimator, and the collimator includes a fast-axis collimator and a slow-axis collimator. The embodiment of the present invention does not limit the type of the sub-lens.

In addition, the light source can also be a laser, the converging lens can be a microlens or a cylindrical lens, and the laser is arranged at the focal length of the microlens or the cylindrical lens.

Optionally, as shown in FIG. 5-3 , the plurality of diffraction gratings 021 are arranged in a matrix shape at equal intervals, and the arranged interval D may be 20 micrometers to 400 micrometers. In practical applications, a plurality of diffraction gratings included in the diffractive optical device can be used in conjunction with a display panel with a resolution of 600 pixels per inch (Pixel Per Inch, PPI). The higher the resolution of the display panel, the smaller the pitch of the diffraction grating arrangement included in the diffractive optical device.

For example, as shown in FIG. 6 , the length a of each diffraction grating 021 may be 5 μm˜30 μm, and the width b may be 5 μm˜30 μm.

In yet another implementation manner, in order to simplify the structure of the optical assembly shown in FIG. 5-1, the light source of the optical assembly used for the texture of the object can be arranged on the side wall of the light guide device. In this case, Optical components do not need to set optical path collimators. Exemplarily, the optical assembly may be as shown in FIG. 7 , and the optical assembly includes: a light source 21 , a light guide device 22 and a photodetector array 23 . FIG. 7 illustrates an example in which the photodetector array 23 is disposed on the non-display side of the display panel 00 and the light guide device 22 is disposed between the photodetector array 23 and the display panel 00 . Referring to FIG. 7 , since the light source 21 is disposed on the side wall of the light guide device 22 , the light source 21 and the light guide device 22 are located on the same layer, so that the optical assembly does not need to be provided with an optical path collimator.

For the meanings of other marks in Fig. 7, please refer to Fig. 2 and Fig. 5-1.

It should be supplemented that, in the first aspect of the optical component used for the texture of the object in the embodiment of the present invention, the exit angle of the diffracted light emitted by the diffractive optical device (that is, when the light incident on the diffraction grating is diffracted on the diffraction grating) Diffraction angle) can be smaller than the preset angle value, so that the diffracted light will not be totally reflected at the interface between the cover plate of the display panel and the air. In the second aspect, the exit angle of the diffracted light emitted by the diffractive optical device can be greater than or equal to the preset angle value, so that the diffracted light is totally reflected at the interface between the cover plate and the air of the display panel. When total reflection occurs at the interface of the air, compared with the first aspect, the clarity of the image of the object to be recognized can be improved, thereby improving the accuracy of texture recognition.

Wherein, the preset angle value θ1 described in the first aspect and the second aspect satisfies: θ1=arcsin(n2*sinθ2/n1), n1 is the refractive index of the light guide plate, n2 is the refractive index of the cover plate, and θ2 is the diffracted light The angle of incidence at the interface of the cover plate and air. The incident angle θ2 satisfies: θ2>arcsin(n3/n2), where n3 is the refractive index of air.

Assuming that the object to be recognized is a fingerprint, in order to further improve the clarity of the fingerprint image, the difference between the intensity of the light reflected by the second interface and the intensity of the light reflected by the first interface can be increased. The second interface refers to the interface between the cover plate of the display panel and the air (ie, the air existing between the fingerprint valley and the cover plate), and the first interface refers to the interface between the cover plate and the fingerprint ridge. In order to increase the difference between the intensity of the light reflected by the second interface and the intensity of the light reflected by the first interface, the exit angle of the diffracted light emitted by the diffractive optical device can be greater than or equal to the preset angle value, so that the diffracted light is at the second interface. The interface, that is, the interface between the cover plate of the display panel and the air, undergoes total reflection.

使衍射光学器件发出的衍射光的出射角大于或等于预设角度值。图8-1示出了入射至导光板221的光的传播路径示意图。如图8-1所示，盖板231中射向盖板231和空气的界面上的光的入射角为θ2，盖板231的折射率为n2，空气的折射率为n3，导光板221的折射率为n1，光折射层2210的折射率为n4，衍射光学器件发出的衍射光的出射角对应的预设角度值为θ1，光折射层2210中射向光折射层2210与显示面板00的界面上的光的入射角为ω，那么当θ2满足：θ2>arcsin(n3/n2)时，盖板231中射向盖板231和空气的界面上的光便可以发生全反射。示例的，盖板231的折射率n2为1.51，空气的折射率n3为1.0，那么当θ2>arcsin(1/1.51)，也即是，θ2大于41.5°，比如为50°时，盖板231中射向盖板231和空气的界面上的光线便可以发生全反射。Illustratively, by setting the grating period d of the diffraction grating and adjusting the incident angle of the light incident on the diffraction grating

The exit angle of the diffracted light emitted by the diffractive optical device is greater than or equal to the preset angle value. FIG. 8-1 shows a schematic diagram of the propagation path of light incident on the light guide plate 221 . As shown in Figure 8-1, the incident angle of the light incident on the interface between the cover plate 231 and the air in the cover plate 231 is θ2, the refractive index of the cover plate 231 is n2, the refractive index of the air is n3, and the light guide plate 221 has a refractive index of n3. The refractive index is n1, the refractive index of the light refraction layer 2210 is n4, and the preset angle corresponding to the exit angle of the diffracted light emitted by the diffractive optical device is θ1. The incident angle of the light on the interface is ω, then when θ2 satisfies: θ2>arcsin(n3/n2), the light from the cover plate 231 on the interface between the cover plate 231 and the air can be totally reflected. For example, the refractive index n2 of the cover plate 231 is 1.51, and the refractive index n3 of air is 1.0, then when θ2>arcsin(1/1.51), that is, when θ2 is greater than 41.5°, such as 50°, the cover plate 231 The light incident on the interface between the cover plate 231 and the air can be totally reflected.

为60°，衍射光学器件发出的衍射光的出射角为46.9°，入射至衍射光栅的光的波长λ为532纳米，则由

(m等于+1)可以得到：衍射光栅的光栅周期d＝532/(sin60°-sin46.9°)≈3911，也即是，衍射光栅的光栅周期为3911纳米。因此，如果将衍射光栅的光栅周期d设置为3911纳米，并将入射至衍射光栅的光的入射角

设置为60°时，便可以使衍射光学器件发出的衍射光的出射角等于预设角度值即46.9°，进而使得衍射光在显示面板的盖板和空气的界面发生全反射，从而提高了指纹图像的清晰度。In the related art, it is assumed that light is emitted from the first medium to the interface between the first medium and the second medium, the refractive index of the first medium is m1, the refractive index of the second medium is m2, and the incident angle of light on the interface is ζ1. , the refraction angle is ζ2, then there are: m1*sinζ1=m2*sinζ2, which is called the formula of the law of refraction. The formula of the law of refraction corresponds to Fig. 8-1, there is: n1*sinθ1=n4*sinω=n2*sinθ2, so there is: θ1=arcsin(n2*sinθ2/n1). For example, the refractive index n2 of the cover plate 231 is 1.51, the refractive index n1 of the light guide plate 221 is 1.585, and the incident angle θ2 of the light incident on the interface between the cover plate 231 and the air in the cover plate 231 is 50°, then the preset The angle value θ1=arcsin(n2*sinθ2/n1)=46.9, that is, the preset angle corresponding to the exit angle of the diffracted light emitted by the diffractive optical device is 46.9°. When the exit angle of the diffracted light emitted by the diffractive optical device is greater than or equal to 46.9°, the light emitted from the cover plate 231 toward the interface between the cover plate 231 and the air can be totally reflected. Assuming the incident angle of light incident on the diffraction grating

is 60°, the exit angle of the diffracted light emitted by the diffractive optical device is 46.9°, and the wavelength λ of the light incident on the diffraction grating is 532 nm, then by

(m is equal to +1), it can be obtained that the grating period of the diffraction grating is d=532/(sin60°-sin46.9°)≈3911, that is, the grating period of the diffraction grating is 3911 nm. Therefore, if the grating period d of the diffraction grating is set to 3911 nm, and the incident angle of light incident on the diffraction grating is set to

When set to 60°, the exit angle of the diffracted light emitted by the diffractive optical device can be equal to the preset angle value, which is 46.9°, so that the diffracted light can be totally reflected at the interface between the cover plate of the display panel and the air, thereby improving the fingerprinting performance. Image clarity.

8-2 shows a schematic diagram of the working process of the optical assembly when the diffracted light is totally reflected at the interface of the cover plate of the display panel and the air. In FIG. 8-2, the light source 21 is arranged below one end of the display panel 00. , the photodetector array 23 is disposed on the non-display side of the display panel 00 , and the light guide device 22 is disposed between the photodetector array 23 and the display panel 00 as an example to illustrate. Assuming that the object to be recognized is a fingerprint, the working process of the optical assembly can be as follows: the light source 21 emits light, the focusing lens 241 converges the light emitted by the light source 21 into a collimated beam, and the coupling grating 242 couples the collimated beam to the guide of the light guide device. inside the light plate 221 . The light incident on the light guide plate 221 is totally reflected at the interface between the light guide plate 221 and the light refraction layer 2210, and the totally reflected light passes through the diffraction grating 021 to generate positive first-order diffracted light that propagates toward the display side of the display panel. The exit angle of the first-order diffracted light is greater than the preset angle value. As shown in Figure 8-3, the positive first-order diffracted light is divided into two parts: the first part of the positive first-order diffracted light and the second part of the positive first-order diffracted light. The first part of the positive first-order diffracted light passes through the display panel 00 to reach the interface between the cover plate 231 of the display panel 00 and the air (that is, the air existing between the fingerprint valley and the cover plate), and the exit angle of the first part of the positive first-order diffracted light is greater than the preset angle value, so the first part of the positive first-order diffracted light is totally reflected at the interface between the cover plate 231 and the air. Assuming that the intensity of the first part of the positive first-order diffracted light reaching the interface between the cover plate 231 and the air is q1, the intensity of the light reflected by the interface between the cover plate 231 and the air is also q1. The second part of the positive first-order diffracted light reaches the interface between the cover plate 231 and the fingerprint ridge. Since the refractive index of the cover plate 231 is close to that of the fingerprint ridge, the cover plate 231 and the fingerprint ridge do not satisfy the total reflection condition. Part of the positive first-order diffracted light will not be totally reflected at the interface between the cover plate 231 and the fingerprint ridge, and most of the second part of the positive first-order diffracted light will be directed and leaked into the fingerprint ridge. Assuming that the intensity of the second part of the positive first-order diffracted light reaching the interface between the cover plate 231 and the fingerprint ridge is q2, if q3 is used to represent the intensity of the light reflected by the interface between the cover plate 231 and the fingerprint ridge, then: q2> q3>0.

Since the difference between the intensity of the light reflected by the second interface (ie, the interface between the cover plate and the air) and the intensity of the light reflected by the first interface (ie, the interface between the cover plate and the fingerprint ridge) is larger, the photodetector array is based on the first interface. The difference between the optical signal generated by the light reflected by the second interface and the optical signal generated according to the light reflected by the first interface is greater, so that the processor can form a more clear optical signal based on the two more different optical signals generated by the photodetector array. High fingerprint image. Other labels in Figure 8-2 can refer to Figure 5-1.

Therefore, in the second aspect, the exit angle of the diffracted light emitted by the diffractive optical device is greater than or equal to the preset angle value, so that the diffracted light can be totally reflected at the interface between the cover plate of the display panel and the air, and the reflectance of the diffracted light is 100%, the intensity of the light reflected by the interface between the cover plate and the air is greater, so that the light signal generated by the photodetector array according to the light reflected from the interface between the cover plate and the air, and the light signal generated by the interface between the cover plate and the object to be recognized The difference between the optical signals generated by the reflected light is greater, so that the processor can form a higher definition image of the object to be identified based on the two more different optical signals generated by the photodetector array.

Further, based on the second aspect, the light passing through the diffraction grating can pass through the gaps between the plurality of sub-pixels in the display panel by controlling the exit angle of the diffracted light emitted by the diffraction grating, so as to prevent the display component from displaying the light. The screen is affected.

The optical assembly for object texture provided in the embodiment of the present invention may be applied to an electronic device having a display panel, for example, the display panel may be an OLED display panel. 8-4 shows a schematic structural diagram of an OLED display panel in the related art. The display panel includes: an array substrate 831, an encapsulation layer 832 for covering and protecting the array substrate 831, and the encapsulation layer 832 is sequentially arranged on the encapsulation layer 832 away from the array. The polarizer 833 , the optically transparent adhesive 834 and the cover plate 231 on one side of the substrate 831 .

Optionally, the light guide device of the optical component used for the texture of the object can be arranged under the cover plate 231 of the display panel shown in FIG. below the polarizer, that is, between the polarizer and the encapsulation layer. 9-1 exemplarily shows a schematic structural diagram of the optical assembly when the light guide device 22 is disposed under the cover plate 231 of the display panel 00 . The optical assembly includes a light source 21 , a light guide device and a photodetector array 23 .

The photodetector array 23 may be disposed on the non-display side of the display panel 00 , and the light source 21 may be disposed at one end of the display panel 00 , that is, the light source 21 and the display panel 00 are located on the same layer.

The light guide device may include a light guide plate 221 and a diffractive optical device, and the diffractive optical device is disposed on the light guide plate 221 . The diffractive optical device may include a plurality of diffraction gratings 021 arranged in a matrix, and light passing through each diffraction grating passes through the gaps between the plurality of sub-pixels in the display panel. Both sides of the light guide plate 221 are provided with light refraction layers 2210 , and the refractive index of the light refraction layers 2210 is smaller than that of the light guide plate 221 .

For example, in order to improve the clarity of the image of the object to be recognized, the exit angle of the diffracted light emitted by the diffractive optical device may be greater than or equal to a preset angle value, so that the diffracted light is totally reflected at the interface between the cover plate of the display panel and the air.

Further, referring to FIG. 5-1 , the display assembly may further include: an optical path collimator, and the optical path collimator is disposed between the light source and the light guide device. The optical path collimator is used to collect the light emitted by the light source and couple it into the light guide device. The optical path collimator may include a converging lens and a coupling grating. The light source is arranged at the focal length of the converging lens, and the coupling grating is arranged between the converging lens and the light guide device. The converging lens is used for converging the light emitted by the light source into a collimated light beam, and the coupling grating is used for coupling the collimated light beam into the light guide device.

In addition, as shown in FIG. 7 , the light source 21 can also be arranged on the side wall of the light guide plate 221 to simplify the structure of the optical assembly and omit the setting process of the optical path collimator.

Other reference numbers in Figure 9-1 may refer to Figure 2 and Figure 5-1.

In the optical assembly for object texture provided by the embodiment of the present invention, the light guide device propagates the light emitted by the light source in the light guide device, and guides the light to the display side of the display panel, and the area of the light guide device is greater than or equal to the area of the display panel. area. When there is an object to be identified on the display side of the display panel, the photodetector array receives the light reflected by the object to be identified, and generates an optical signal for indicating the image of the object to be identified according to the received light reflected from the object to be identified , to achieve full-screen recognition. At the same time, the use of the light guide device can also reduce the demand for the number of light sources, thereby reducing the cost of the display assembly. In addition, arranging the light source below one end of the display panel can reduce the thickness of the optical component, thereby reducing the thickness of the electronic device, so as to meet the needs of the user for the use of the electronic device. Further, through the optical path collimator, the intensity of the light reflected by the object to be identified received by the photodetector array is higher, the light utilization rate of the light source is improved, and the texture identification accuracy is improved.

It should be added that for mobile terminals, full-screen fingerprint recognition technology is the development trend of fingerprint recognition technology in the future. The goal of full-screen fingerprint recognition technology is to complete fingerprint detection and recognition in any area of the mobile terminal screen. The full-screen fingerprint recognition technology can increase the screen ratio of the mobile terminal (the screen ratio refers to the ratio of the area of the mobile terminal screen to the area of the front panel of the mobile terminal), and can provide users with a better fingerprint unlocking experience. At present, the three main problems faced by full-screen fingerprint recognition technology are: 1. When the fingerprint sensor is integrated with the display component, the screen of the mobile terminal cannot be too thick; 2. After the light reflected by the fingerprint passes through the complex laminated structure of the screen of the mobile terminal A clearer fingerprint image needs to be formed; 3. As shown in Figure 9-2, when the fingerprint identification area is set on the screen of the mobile terminal, the screen of the mobile terminal should not be too thick. However, the optical component for object texture provided by the embodiment of the present invention is aimed at the future full-screen fingerprint recognition technology, which can make the thickness of the screen of the mobile terminal smaller, and can obtain a clearer fingerprint image that meets the needs of fingerprint recognition. The components can be well applied to the future full-screen fingerprint recognition technology to adapt to the technological development trend.

To sum up, in the optical assembly for object texture provided by the embodiment of the present invention, since the light guide device can propagate the light emitted by the light source in the light guide device, and guide the light to the display side of the display panel, the photodetector array When there is an object to be identified on the display side of the display panel, the light guide device receives the light reflected by the object to be identified, and generates an optical signal for indicating the image of the object to be identified according to the received light reflected from the object to be identified. The area of the display panel is greater than or equal to the area of the display panel, so any position of the display panel can complete the pattern recognition, realize the full screen recognition, improve the user experience, and improve the reliability of the pattern recognition. At the same time, the use of the light guide device can also reduce the demand for the number of light sources, thereby reducing the cost of the display assembly. In addition, arranging the light source below one end of the display panel can reduce the thickness of the electronic device, meet the user's demand for the use of the electronic device, further improve the light utilization rate of the light source, and improve the accuracy of pattern recognition.

An embodiment of the present invention further provides a display assembly, which may be shown in FIG. 1 , FIG. 2 , FIG. 5-1 , FIG. 7 , FIG. 8-2 or FIG. 9-1 , including a display panel and corresponding diagrams Optical components shown. Wherein, the display panel may be an OLED display panel.

An embodiment of the present invention further provides an electronic device, which may include the display component and the processor shown in FIG. 1, FIG. 2, FIG. 5-1, FIG. 7, FIG. 8-2 or FIG. 9-1 (eg CPU), the processor is configured to form an image of the object to be identified according to the light signal obtained by the optical component of the display component.

For example, the electronic device may be a product or component with a display function, such as a smart phone, a tablet computer, a television, a monitor, a notebook computer, a wearable device, a digital photo frame, a navigator, and the like.

To sum up, in the electronic device provided by the embodiments of the present invention, since the display component of the electronic device includes an optical component for object texture, the light guide device of the optical component can propagate the light emitted by the light source in the light guide device, The light is guided to the display side of the display panel, and when there is an object to be identified on the display side of the display panel, the photodetector array receives the light reflected by the object to be identified, and generates light for the object to be identified according to the received light reflected by the object to be identified. The light signal indicating the image of the object to be recognized, and the area of the light guide device is greater than or equal to the area of the display panel, so any position of the display panel can complete the pattern recognition, realize the full-screen recognition, improve the user experience, and improve the Texture recognition reliability. At the same time, the use of the light guide device can also reduce the demand for the number of light sources, thereby reducing the cost of electronic equipment. In addition, arranging the light source below one end of the display panel can reduce the thickness of the electronic device, meet the user's demand for the use of the electronic device, further improve the light utilization rate of the light source, and improve the accuracy of pattern recognition.

Embodiments of the present invention also provide a method for manufacturing an optical component for object texture, the method may include:

A light source, a light guide device and a photodetector array are formed respectively.

Among them, the light source is used to emit light. The light guide device is used to make the light emitted by the light source propagate in the light guide device and guide the light to the display side of the display panel, and the area of the light guide device is greater than or equal to that of the display panel. The photodetector array is used to receive the light reflected by the object to be identified when there is an object to be identified on the display side of the display panel, and to generate an image indicating the object to be identified according to the received light reflected from the object to be identified. light signal.

Taking FIG. 1 as an example, the light source 21, the light guide device 22 and the photodetector array 23 can be formed respectively, and then the formed light guide device 22 and the photodetector array 23 are sequentially formed on the non-display side of the display panel. 21 is formed below one end of the display panel.

Optionally, as shown in FIG. 2, the light guide device 22 may include a light guide plate 221 and a diffractive optical device 222. Correspondingly, as shown in FIG. 10-1, a light guide device is formed, including:

Step 1001 , forming a diffractive optical device on the light guide plate.

As shown in FIG. 3 , the diffractive optical device 222 is formed on the light guide plate 221 .

Optionally, the display panel has a plurality of pixels arranged in a matrix, each pixel includes a plurality of sub-pixels, and the diffractive optical device may include a plurality of diffraction gratings arranged in a matrix, correspondingly, as shown in Figure 3 and Figure 10-2 As shown, step 1001 may include:

A plurality of diffraction gratings 021 are formed on the light guide plate 221, and the light passing through each diffraction grating passes through the gaps between the plurality of sub-pixels in the display panel, so as to prevent the picture displayed by the display assembly from being affected. Optionally, by adjusting the position of the diffraction grating, or by controlling the exit angle of the diffracted light emitted by the diffraction grating, the light passing through each diffraction grating can pass through the gaps between the plurality of sub-pixels in the display panel. .

For example, forming a plurality of diffraction gratings on the light guide plate may include: forming a plurality of diffraction gratings on the light guide plate through a nano-imprinting process.

Exemplarily, the plurality of diffraction gratings are arranged in a matrix shape at equal intervals, and the arranged interval may be 20 micrometers to 400 micrometers. The length of each diffraction grating 021 may be 5 micrometers to 30 micrometers, and the width may be 5 micrometers to 30 micrometers.

Step 1002 , forming light refraction layers on both sides of the light guide plate on which the diffractive optical device is formed.

As shown in FIG. 10-2 , light refraction layers 2210 are formed on both sides of the light guide plate 221 on which the diffractive optical devices 222 are formed.

The refractive index of the light refraction layer is smaller than that of the light guide plate, and the diffractive optical device is used to guide the light propagating in the light guide plate to the display side of the display panel.

The light source, the light guide device and the photodetector array included in the optical assembly can be formed in various positions. For example, referring to FIG. 2 , FIG. 5-1 , FIG. 7 , FIG. 8-2 or FIG. 9-1 , the photodetector array is formed. It may include: forming the photodetector array 23 on the non-display side of the display panel 00 . For example, 500 photodetectors may be formed per inch on the non-display side of the display panel. The photodetector array covers the entire display panel.

For example, referring to FIG. 1 , FIG. 2 , FIG. 5-1 , FIG. 7 or FIG. 8-2 , forming the light guide device may include:

A light guide device 22 is formed on the side of the display panel 00 close to the photodetector array 23 , and the light guide device 22 is located between the photodetector array 23 and the display panel 00 .

Referring to FIG. 8-4, the display panel includes a cover plate 231 and a polarizer 833. Therefore, referring to FIG. 9-1, a light guide device 22 is formed on the side of the display panel 00 away from the photodetector array 23, and the light guide device 22 is located at the side of the display panel 00. Below the cover plate 231 of the display panel 00 .

The light guide device 22 in FIG. 9-1 may also be located below the polarizer of the display panel.

For example, referring to FIG. 1 , FIG. 2 , FIG. 5-1 or FIG. 8-2 , forming the light source may include: forming the light source 21 under one end of the display panel 00 so that the outermost edge of the light source is located at the outermost side of the vertical projection of the display panel outside the edge. Forming the light source under one end of the display panel can reduce the thickness of the optical component, reduce the thickness of the display component including the optical component, and further reduce the thickness of the electronic device including the display component, so as to meet the needs of the user for the use of the electronic device.

7, the light source 21 is formed on the side wall of the light guide 22, and the light source 21 and the light guide device 22 are located on the same layer, which simplifies the manufacturing process of the optical assembly shown in FIG. 5-1.

9-1, a light source 21 is formed at one end of the display panel 00, and the light source 21 and the display panel 00 are located on the same layer.

Further, as shown in FIG. 5-1, the optical assembly may further include: an optical path collimator 24. Correspondingly, after the light source is formed under one end of the display panel, the method may further include:

An optical path collimator 24 is formed between the light source 21 and the light guide device 22 , and the optical path collimator 24 is used for condensing the light emitted by the light source 21 and coupling it into the light guide device 22 . The light emitted by the light source is coupled into the light guide device through the optical path collimator, so that the light guide device can make more light emitted by the light source propagate in the light guide device, and guide the light to the display side of the display panel, so that the light The intensity of the light reflected by the object to be recognized received by the detector array is higher, the light utilization rate of the light source is improved, and the accuracy of pattern recognition is further improved.

Optionally, as shown in FIG. 5-1, the optical path collimator 24 includes a converging lens 241 and a coupling grating 242. Correspondingly, an optical path collimator is formed between the light source and the light guide device, including:

A condensing lens 241 is formed between the light source 21 and the light guide device 22 , so that the light source 21 is located at the focal length of the condensing lens 241 .

A coupling grating 242 is formed between the condensing lens 241 and the light guide device 22 .

The converging lens 241 is used for converging the light emitted by the light source 21 into a collimated light beam, and the coupling grating 242 is used for coupling the collimated light beam into the light guide device 22 . For example, a nano-imprinting process may be used to form a coupling grating on the side of the light guide plate away from the display panel.

Exemplarily, the light source may include multiple sub-light sources, the converging lens may include multiple sub-lenses, and the multiple sub-light sources correspond to the multiple sub-lenses one-to-one. Exemplarily, the sub-lens may be a microlens, a cylindrical lens or a collimator, and the collimator includes a fast-axis collimator and a slow-axis collimator.

To sum up, the method for manufacturing an optical assembly for object texture provided by the embodiment of the present invention forms a light guide device that can propagate the light emitted by the light source in the light guide device, and guide the light to the display side of the display panel, When there is an object to be identified on the display side of the display panel, the photodetector array receives the light reflected by the object to be identified, and generates an optical signal for indicating the image of the object to be identified according to the received light reflected from the object to be identified , Since the area of the light guide device is greater than or equal to the area of the display panel, the pattern recognition can be completed at any position of the display panel, realizing full-screen recognition, improving user experience, and improving the reliability of pattern recognition. Simultaneously forming the light guide device can also reduce the demand for the number of light sources, thereby reducing the cost of the display assembly. In addition, forming the light source under one end of the display panel can reduce the thickness of the electronic device and meet the needs of the user for the use of the electronic device. Further, the formed optical path collimator also improves the light utilization rate of the light source and improves the texture. recognition accuracy.

Those skilled in the art can clearly understand that, for the convenience and brevity of description, for the specific steps of the method described above, reference may be made to the corresponding process in the foregoing apparatus embodiments, and details are not repeated here.

The above descriptions are only optional embodiments of the present application, and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the protection of the present application. within the range.

Claims (20)

1. an optical assembly for object texture, is characterized in that, is applied to the electronic equipment with display panel, comprises: light source, light guide device and photodetector array, the light source is used to emit light; The light guide device is used to make the light emitted by the light source propagate in the light guide device and guide the light to the display side of the display panel, wherein the area of the light guide device is greater than or equal to the display the area of the panel; The photodetector array is used to receive the light reflected by the object to be identified when there is an object to be identified on the display side of the display panel, and to generate a signal for indicating the object to be identified according to the received light reflected from the object to be identified. Describe the light signal of the image of the object to be identified; Wherein, the light guide device includes a light guide plate and a diffractive optical device, the diffractive optical device is arranged on the light guide plate, and the orthographic projection of the diffractive optical device on the display panel is located in the pattern recognition of the display panel In the region, the diffractive optical device includes a plurality of diffraction gratings arranged in a matrix, and each of the diffraction gratings is used for decomposing the light propagating in the light guide plate and entering the diffraction grating into light in the guide plate. diffracted light propagating in the light plate and diffracted light propagating to the display side of the display panel, so that the diffractive optical device guides the light propagating in the light guide plate to the display side of the display panel, the photodetector array for receiving the light reflected by the object to be recognized based on the diffracted light propagating to the display side of the display panel, and generating an image indicating the object to be recognized according to the received light reflected by the object to be recognized light signal. 2. The optical assembly of claim 1, wherein Both sides of the light guide plate are provided with a light refraction layer, and the refractive index of the light refraction layer is smaller than that of the light guide plate. 3. The optical assembly according to claim 2, wherein the display panel has a plurality of pixels arranged in a matrix, and each of the pixels comprises a plurality of sub-pixels, Light passing through each of the diffraction gratings passes through the gaps between the plurality of sub-pixels in the display panel. 4. The optical assembly of claim 2, wherein The exit angle of the diffracted light emitted by the diffractive optical device is smaller than a preset angle value, so that the diffracted light is not totally reflected at the interface between the cover plate of the display panel and the air. 5. The optical assembly of claim 2, wherein The exit angle of the diffracted light emitted by the diffractive optical device is greater than or equal to a preset angle value, so that the diffracted light is totally reflected at the interface between the cover plate of the display panel and the air. 6. The optical assembly according to claim 4 or 5, characterized in that, The preset angle value θ1 satisfies: θ1=arcsin(n2*sinθ2/n1), the n1 is the refractive index of the light guide plate, the n2 is the refractive index of the cover plate, and the θ2 is the The incident angle of diffracted light on the interface between the cover plate and the air, the θ2 satisfies: θ2>arcsin(n3/n2), and the n3 is the refractive index of air. 7. The optical assembly according to any one of claims 1 to 5, wherein, The photodetector array is disposed on the non-display side of the display panel. 8. The optical assembly according to claim 7, wherein the display panel comprises a cover plate and a polarizer, The light guide device is arranged between the photodetector array and the display panel, Alternatively, the light guide device is disposed below the cover plate or the polarizer of the display panel. 9. The optical assembly according to any one of claims 1 to 5, wherein, The light source is disposed below one end of the display panel. 10. The optical assembly according to any one of claims 1 to 5, wherein the optical assembly further comprises: an optical path collimator, the optical path collimator is arranged between the light source and the light guide device between, The light path collimator is used for condensing the light emitted by the light source and coupling it into the light guide device. 11. The optical assembly according to claim 10, wherein the optical path collimator comprises a converging lens and a coupling grating, the light source is arranged at a focal length position of the converging lens, and the coupling grating is arranged at the focal length of the converging lens. between the converging lens and the light guide device, the converging lens is used for converging the light emitted by the light source into a collimated light beam; The coupling grating is used to couple the collimated light beam into the light guide device. 12 . The optical assembly according to claim 11 , wherein the light source comprises a plurality of sub-light sources, the converging lens comprises a plurality of sub-lenses, and the plurality of sub-light sources correspond to the plurality of sub-lenses one-to-one. 13 . 13. The optical assembly of claim 12, wherein The sub-lens is a microlens, a cylindrical lens or a collimator, and the collimator includes a fast-axis collimator and a slow-axis collimator. 14 . The optical component according to claim 3 , wherein the plurality of diffraction gratings are arranged in a matrix shape at equal intervals, and the arranged interval is 20 μm˜400 μm. 15 . 15. The optical assembly of claim 3, wherein Each of the diffraction gratings has a length of 5 to 30 microns and a width of 5 to 30 microns. 16. The optical assembly of claim 2, wherein The light guide plate is made of polycarbonate PC, polymethyl methacrylate PMMA, polydimethylsiloxane PDMS or glass material. 17. The optical assembly of claim 2, wherein the light refraction layer is formed of air or optical glue. 18. A display assembly, comprising a display panel and the optical assembly according to any one of claims 1 to 17. 19. The display assembly of claim 18, wherein the display panel is an organic light emitting diode (OLED) display panel. 20. An electronic device, characterized by comprising the display assembly according to claim 18 or 19 and a processor, wherein the processor is configured to form an image of an object to be identified according to an optical signal obtained by an optical assembly of the display assembly.

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