JP6529827B2 - Display device - Google Patents

Description

  The present invention relates to a display device provided with an illuminance sensor that measures the illuminance around a display screen.

  In portable electronic devices such as mobile phones and digital cameras having liquid crystal panels, an illuminance sensor for detecting the illuminance of external light is mounted so that the light emission amount of the backlight of the liquid crystal panel can be controlled according to the illuminance of external light. ing. For example, Patent Document 1 discloses a portable terminal device that makes the display device easy-to-see luminance according to the brightness of the surrounding environment of the background.

JP, 2011-028183, A (February 10, 2011 release)

  By the way, in the conventional mobile device (mobile phone 201), as shown in FIG. 12 (FIG. 1 of Patent Document 1), the illuminance sensor (light measuring sensor 237) is formed in the vicinity of the display surface (display 234). In recent smartphones, there is a tendency to reduce the frame portion in order to make the display surface as large as possible, and there are cases where layout constraints are large on the design of the housing and it can not be placed in the expected position.

  The present invention has been made in view of the above problems, and an object thereof is to provide a display device capable of appropriately acquiring visual environment illuminance information without impairing the design.

  In order to solve the above-mentioned subject, a display concerning one mode of the present invention is a display provided with an illumination intensity sensor which detects illumination intensity of exterior light, and a back light module which irradiates light from the back of a display surface of a display panel. In the apparatus, the backlight module includes a light guide plate disposed on a back surface of the display surface of the display panel to guide light emitted from the light source to the back surface of the display surface, and the illuminance sensor includes It is characterized in that it is disposed at a position where the outside light is received through the light guide plate.

  According to one aspect of the present invention, it is possible to appropriately obtain visual environment illuminance information without impairing the design.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic structure perspective view of the display apparatus which concerns on Embodiment 1 of this invention. It is a schematic block diagram of a display shown in FIG. It is a flowchart which shows the flow of the illumination intensity acquisition process in the display apparatus shown in FIG. It is a figure which shows an example of the timing chart of illumination intensity information acquisition in the display apparatus shown in FIG. It is a figure which shows an example of the timing chart of illumination intensity information acquisition in the display apparatus shown in FIG. It is a figure which shows an example of the timing chart of illumination intensity information acquisition in the display apparatus shown in FIG. It is a schematic structure perspective view of the display apparatus which concerns on Embodiment 2 of this invention. It is a figure which shows the example of the screen display at the time of the illumination intensity acquisition in the display apparatus shown in FIG. It is a schematic structure perspective view of a display concerning a 3rd embodiment of the present invention. It is a schematic block diagram of a display shown in FIG. It is a schematic structure perspective view of the display apparatus which concerns on Embodiment 4 of this invention. (A) and (b) are the top views of the display apparatus which showed the example of the arrangement | positioning position of a general illumination intensity sensor.

Embodiment 1
The embodiment of the present invention is described in detail as follows. In this embodiment, an example in which the display device of the present invention is applied to a liquid crystal display device will be described.
(Overview of Liquid Crystal Display Device 101)
FIG. 1 is a schematic perspective view of a liquid crystal display device 101.

  As shown in FIG. 1, the liquid crystal display device 101 includes a liquid crystal panel (display panel) 1 and a backlight module 2 for irradiating backlight from the back side of the liquid crystal panel 1.

  The liquid crystal panel 1 may be any liquid crystal panel as long as it is a light transmissive liquid crystal panel. The drive system of the liquid crystal panel 1 is not particularly limited.

  The backlight module 2 is disposed on the back of the display surface of the liquid crystal panel 1 with a plurality of LED light sources 21 as light sources, and guides the light emitted from each LED light source 21 to the back of the display surface as backlight A light guide plate 22 for emitting light is provided.

  The light guide plate 22 has substantially the same size as the display surface of the liquid crystal panel 1, and guides the light emitted from the plurality of LED light sources 21 arranged at one end to the back surface of the display surface as backlight. ing. The shape of the light guide plate 22 may be plate-like or trapezoidal, and is not particularly limited.

  In the liquid crystal display device 101 configured as described above, an illuminance sensor 3 for detecting the illuminance of external light is adjacent to the LED light source 21 so that the light emission amount in the backlight module 2 can be controlled according to the illuminance of external light. It is arranged. That is, the illuminance sensor 3 receives external light incident from the display surface of the liquid crystal panel 1 through the light guide plate 22 of the backlight module 2. Thereby, the display surface of the liquid crystal panel 1 disposed on the front surface of the light guide plate 22 becomes an area for receiving the external light of the illuminance sensor 3.

  The illuminance sensor 3 may be disposed at a position for receiving the external light through the light guide plate 22, but may be disposed at a position for receiving the external light from the end of the light guide plate 22, and As shown in FIG. 1, the end of the light guide plate 22 may be disposed on the side where the LED light source 21 is disposed.

  The signal detected by the illuminance sensor 3 is used for drive control of the backlight module 2.

(Schematic block diagram of the liquid crystal display device 101)
As shown in FIG. 2, the liquid crystal display device 101 stores image data to be displayed on the liquid crystal panel 1 when the illuminance is detected by the liquid crystal panel 1, the control unit 4 for controlling driving of the backlight module 2, and the illuminance sensor 3. The image data storage unit 5 is further provided.

  The control unit 4 includes a CPU, and obtains illuminance information from a detection signal from the display control unit 41 that controls the display of the liquid crystal panel 1, the backlight drive control unit 42 that controls the drive of the backlight module 2, and the illuminance sensor 3. The illumination information acquisition unit 43 is included.

  The illumination information acquisition unit 43 acquires illumination information from the detection value of the illumination sensor 3 when the backlight drive control unit 42 stops driving the backlight module 2. The control unit 4 instructs the backlight drive control unit 42 to stop the driving of the backlight module 2 when acquiring the illuminance information if there is a request for acquiring the illuminance information to the illuminance information acquiring unit 43. Thus, the detection by the illuminance sensor 3 can be performed while avoiding the time when the backlight module 2 is driven, that is, the time when the backlight module 2 emits the backlight light. Outside light can be received by the illuminance sensor 3 without being disturbed. Therefore, the illuminance information acquisition unit 43 can acquire appropriate illuminance information on the display surface side of the liquid crystal display device 101.

  In addition, the backlight drive control unit 42 further causes the illuminance information acquisition unit 43 to properly acquire the illuminance information, so that the normal image (normally displayed as wallpaper etc.) displayed on the liquid crystal panel 1 is acquired when the illuminance information is acquired. The display control unit 41 outputs an instruction signal for switching the current image or the image that has been displayed up to the image for acquiring the illuminance information (image for measuring the illuminance: hereinafter referred to as “measurement image”) Do. That is, when the display control unit 41 receives an instruction signal (backlight module stop instruction signal) from the backlight drive control unit 42, at least a part of the image being displayed on the liquid crystal panel 1 is displayed in white. Switch to the measurement image of.

  In the above description, the display control unit 41 performs the process of switching the image being displayed by the instruction signal (backlight module stop instruction signal) from the backlight drive control unit 42, but the present invention is limited thereto. Alternatively, the instruction signal may be received directly from the control unit 4 to switch the image being displayed. In addition to the display control unit 41, the backlight drive control unit 42 and the illuminance information acquisition unit 43 may be directly controlled by the control unit 4.

  Here, as a measurement image to be switched by the display control unit 41, an image in white display in which light is transmitted through the entire surface of the liquid crystal panel 1 is preferable, and any display image in which the influence of liquid crystal display is small may be used. The measurement image is stored in the image data storage unit 5.

  In addition, when the illuminance information acquisition unit 43 finishes acquiring the illuminance information, the control unit 4 instructs the display control unit 41 to switch from the measurement image to the normal image, and the backlight drive control unit 42. In response to this, an instruction is issued to resume driving of the backlight module 2.

(Illumination information acquisition processing)
Here, the flow of the acquisition process of the illuminance information will be described below with reference to the flowchart shown in FIG.

  First, in step S11, if there is an illuminance acquisition request (Yes), the control unit 4 turns off the backlight (step S12). Here, the control unit 4 instructs the backlight drive control unit 42 to stop the driving of the backlight module 2.

  Next, the control unit 4 displays the measurement image (step S13). Here, the control unit 4 instructs the display control unit 41 to switch from the normal image displayed on the liquid crystal panel 1 to the measurement image stored in the image data storage unit 5.

  Subsequently, the illuminance information acquisition unit 43 measures the illuminance (step S14). Specifically, the illuminance information acquisition unit 43 receives external light incident from the display surface of the liquid crystal panel 1 on which the measurement image is displayed through the light guide plate 22 in a state in which the backlight module 2 does not emit backlight light. The illuminance sensor 3 receives light, and acquires illuminance information from the detection value output from the illuminance sensor 3.

  Next, the control unit 4 displays a normal image (step S15). Specifically, when the acquisition of the illuminance information by the illuminance information acquiring unit 43 is completed, the control unit 4 causes the display control unit 41 to switch the measurement image displayed on the liquid crystal panel 1 to the normal image.

  Further, the control unit 4 turns on the backlight (step S16), and ends the process. Specifically, when the acquisition of the illuminance information by the illuminance information acquisition unit 43 is completed, the control unit 4 causes the backlight drive control unit 42 to resume the driving of the backlight module 2 and perform the illuminance information acquisition process. finish.

  It is preferable to synchronize the timing of acquiring the illuminance information with the refresh of the liquid crystal panel 1. That is, the backlight drive control unit 42 performs the driving stop of the backlight module 2 in synchronization with the refresh of the liquid crystal panel 1.

  The timing of acquiring the illuminance information will be described below. Here, the following three patterns will be described.

(Illumination information acquisition timing (1))
Normally, since the illuminance can not be measured accurately while the backlight is on, the illuminance measurement is performed when the backlight is off as in the above-described illuminance information acquisition process. Then, at the time of illuminance measurement, in order to minimize the influence of liquid crystal display, an ambient light transmission color (for example, white display) is displayed as a measurement image. Since the backlight is off, it is difficult for the user to visually recognize. The illuminance information acquisition timing at this time is shown in FIG.

  FIG. 4 is a timing chart showing an example of the illuminance information acquisition timing. Here, the drive (BL drive) timing of the backlight module 2 when the illuminance information acquisition timing (period of illuminance measurement) by the illuminance information acquisition unit 43 is the refresh cycle (60 Hz cycle) of the liquid crystal panel 1; It shows the switching timing of the display image of the liquid crystal panel 1.

  In this case, for example, as shown in (a) and (b) of FIG. 12, it is possible to obtain illuminance information without arranging a dedicated window for illuminance measurement in the frame area.

  By the way, when the still image is displayed in a cycle of 60 Hz at which the illuminance information acquisition timing is displayed, there is a possibility that the user may recognize the illuminance measurement (backlights off, measurement image display). That is, the user may feel that the screen is flickering when performing the illuminance information acquisition process.

(Illumination information acquisition timing (2))
Therefore, to prevent the user from recognizing the illuminance measurement (backlights off, measurement image display), the illuminance information acquisition timing is shorter than the refresh cycle of the liquid crystal panel 1 when the illuminance measurement is not performed, for example, a 60 Hz cycle. For example, a so-called high-speed refresh drive is performed to set a cycle of 120 Hz (a refresh cycle of double speed) which is 1/2 times. Specifically, the backlight drive control unit 42 synchronizes the driving stop of the backlight module 2 with 1⁄2 (120 Hz) of the refresh cycle (60 Hz) when the illuminance is not measured.

  FIG. 5 is a timing chart showing an example of the illuminance information acquisition timing. Here, when the illuminance information acquisition timing (period of illuminance measurement) by the illuminance information acquiring unit 43 is a cycle of 120 Hz (a period of refresh of the liquid crystal panel 1 which is 1/2 times when illuminance is not measured). The timing for driving the backlight module 2 (BL driving) and the timing for switching the display image of the liquid crystal panel 1 are shown.

  As described above, when the backlight is turned on / off in a short cycle such as 120 Hz, it becomes difficult to recognize flicker. Moreover, since the illuminance information acquisition cycle is short, it is possible to react promptly to changes in ambient environment illuminance.

  In the above description, the refresh cycle at the time of measuring the illuminance is 120 Hz. However, the present invention is not limited to this, and the refresh cycle may be set short to the extent that flicker is not felt.

(Lighting information acquisition timing (3))
By the way, when ambient environment illumination does not change for a certain period, it is not necessary to acquire illumination information by a fixed cycle. For example, when the ambient environment illuminance does not change rapidly, such as putting the liquid crystal display device 101 face down (place the display surface on a desk or the like) or putting it in a pocket, the illuminance measurement interval is thinned. Specifically, the backlight drive control unit 42 stops the driving of the backlight module 2 at a constant cycle (60 Hz, 120 Hz, etc.), and the detected value by the illuminance sensor 3 is compared with the previous detected value. When it is a value within a predetermined range, control is performed so as not to stop driving of the backlight module 2 next time.

  FIG. 6 is a timing chart showing an example of the illuminance information acquisition timing. Here, timing of illuminance information acquisition (decimation of measurement interval), timing of driving of the backlight module 2 (BL driving), and timing of switching of the display image of the liquid crystal panel 1 by the illuminance information acquiring unit 43 are shown. As described above, by thinning the measurement interval and widening the measurement interval, it is possible to save power by reducing the drive processing load.

Second Embodiment
It will be as follows if other embodiment of this invention is described. In addition, about the member which has the same function as the member demonstrated in the said embodiment for convenience of explanation, the same code | symbol is appended and the description is abbreviate | omitted.
(Outline of Liquid Crystal Display Device 102)
FIG. 7 is a schematic perspective view of the liquid crystal display device 102. As shown in FIG.

  As shown in FIG. 7, the liquid crystal display device 102 has almost the same configuration as the liquid crystal display device 101 shown in FIG. 1, but the number of illuminance sensors 3 is different. That is, although the illuminance sensor 3 is one in the liquid crystal display device 101 shown in FIG. 1, in the liquid crystal display device 102 shown in FIG. 7, there are plural (three in FIG. 7) illuminance sensors 3. As shown in FIG. 7, the illuminance sensors 3 are alternately arranged with the LED light sources 21. The arrangement of the illuminance sensors 3 may not be alternately arranged with the LED light sources 21, but it is preferable to be arranged at equal intervals.

  In the liquid crystal display device 102 configured as described above, each illuminance sensor 3 detects the illuminance. The detection values detected by the respective illumination sensors 3 become illumination information in the following two ways.

(Average of detected value)
The illuminance information acquisition unit 43 acquires an average value of detection values of the plurality of illuminance sensors 3 as illuminance information.

(Except for the minimum value of detected values, averaging)
The illuminance information acquisition unit 43 acquires, as illuminance information, the average value of the remaining detection values excluding the minimum detection value among the detection values of the plurality of illuminance sensors 3.

  As described above, by arranging a plurality of illuminance sensors 3, it is possible to reduce the influence of external factors such as covering the display surface of the liquid crystal panel 1 with the hand on the illuminance measurement.

  Further, the measurement image may be changed depending on the arrangement position of the illuminance sensor 3. This example is shown in FIG. (A) of FIG. 8 is a measurement image in the case where the entire display surface is displayed in white (hereinafter referred to as “entirely white display”), and (b) is in the case where a portion of the lower portion of the display surface is displayed in white ( Hereinafter, measurement images (1) and (c) of "lower part white display" are displayed when white display of a part of the lower part of the display surface (hereinafter referred to as "lower part white display") The measurement image (2) is shown.

  As shown to (a) of FIG. 8, when a measurement image is a white display on the whole surface, in order to measure an illuminance effectively, it is preferable to arrange each illuminance sensor 3 at equal intervals as shown in FIG. .

  When the measurement image is partially white in the lower part and the whole area in the width direction of the lower part is the measurement area as shown in (b) of FIG. It is preferable to arrange the respective illuminance sensors 3 at equal intervals, as in the case of the entire surface white display shown in 2.).

  On the other hand, when the measurement image is partially white in the lower part and only the left side of the lower part is the measurement area as shown in (c) of FIG. 8, the illuminance sensor 3 is used to effectively measure the illuminance. It is preferable to arrange on the lower left side. However, as shown in FIG. 7, the illuminance sensors 3 may be arranged at equal intervals.

  The measurement image is not limited to only three examples shown in FIG. 8 and may be measurement images of other patterns. Also, a plurality of measurement images may be switched as needed. The switching of the measurement image may be performed by the user or may be performed based on the detection value from the illuminance sensor 3.

  By the way, in the examples shown in the first and second embodiments, when the display surface of the liquid crystal panel 1 is covered with a hand or a finger, there is a possibility that the illuminance is detected unintentionally as low. As a countermeasure, the liquid crystal panel 1 is provided with a touch panel, cooperates with the sensing information of the touch panel, and it is determined that the area where the user touches the touch panel is covered with the user's finger or hand. It is conceivable to acquire illuminance information of a point (area) determined not to be covered by a finger or a hand. In the following embodiment 3, an example in which the touch information of the touch panel is linked will be described.

Third Embodiment
It will be as follows if other embodiment of this invention is described. In addition, about the member which has the same function as the member demonstrated in the said embodiment for convenience of explanation, the same code | symbol is appended and the description is abbreviate | omitted.
(Overview of Liquid Crystal Display Device 103)
FIG. 9 is a schematic perspective view of the liquid crystal display device 103.

  The liquid crystal display device 103 has almost the same configuration as the liquid crystal display device 102 shown in FIG. 7 as shown in FIG. 9, but differs in that the liquid crystal panel 11 includes a touch panel. That is, as shown in FIG. 10, the liquid crystal display device 103 differs from the liquid crystal display device 102 shown in FIG. 7 in that the liquid crystal display device 103 includes the liquid crystal panel 11 including a touch panel. That is, when the user touches the display surface of the liquid crystal panel 11, coordinate information indicating the touch position of the touch panel included in the liquid crystal panel 11 is acquired by the display control unit 41, and the acquired coordinate information is acquired from the display control unit 41 It is sent to the illuminance information acquisition unit 43. The illuminance information acquisition unit 43 specifies the illuminance sensor 3 to be a target of illuminance detection from the transmitted coordinate information, and does not use the detected value from the specified illuminance sensor 3 but detects the detected value from another illuminance sensor 3 Acquired as illuminance information.

  As described above, when the liquid crystal panel 1 includes the touch panel, the illuminance information acquisition unit 43 is positioned at a position corresponding to the light guide path of the light guide plate 22 corresponding to the touch position (coordinates obtained from the coordinate information) of the touch panel. The detection value of the remaining illuminance sensor 3 excluding the detection value of the arranged illuminance sensor 3 may be acquired as the illuminance information. Thereby, as shown in FIG. 9, when a part of the left side of the screen is covered with a hand, the corresponding part is displayed in black, and the illuminance information of the part is not acquired.

  As a result, by not detecting the illuminance of the area where the accuracy of the illuminance detection is low, that is, the region touched by the user, it is possible to acquire more accurate illuminance information.

  As described above, according to the liquid crystal display devices 101 to 103 of the first to third embodiments, the region receiving external light for the illuminance sensor 3 is the entire area or a part of the display screen of the liquid crystal panels 1 and 11 As compared with the conventional illuminance sensor, the light receiving area can be received in a wide area, and is not easily affected by a shield such as a user's finger.

  Further, according to the above configuration, since it is not necessary to provide an opening for the illuminance sensor 3 on the frame, it is possible to eliminate the restriction of the design for the arrangement of the illuminance sensor 3. Moreover, since the direction in which the external light for illuminance detection is received is the same as the direction in which the user looks at the display screen, the visual environment illuminance information can be appropriately acquired.

[Modification]
In the first to third embodiments, the arrangement position of the LED light source 21 which is a light source is only at one end side of the light guide plate 22. This is because the liquid crystal display devices 101 to 103 assume mobile devices whose display screen size is as small as 5 to 6 inches, such as a smartphone, so the LED light source 21 is disposed on one end side of the light guide plate 22 This is also because the display screen can be uniformly irradiated with backlight light.

  However, the present invention is not limited to the above configuration, and is also applicable to the case where the LED light sources 21 are disposed at both ends of the light guide plate 22 as in the liquid crystal display device 104 shown in FIG. In the liquid crystal display device 104, the illuminance sensors 3 are disposed adjacent to the LED light sources 21 disposed at both ends of the light guide plate 22, respectively. In this case, since the illumination light of the LED light source 21 is incident on the light guide plate 22 from both ends of the light guide plate 22 and emitted as backlight light, the illuminance sensor 3 is disposed when external light is also incident on the light guide plate 22 The light guide plate 22 is led to both ends of the light guide plate 22. In the example of FIG. 11, since one illuminance sensor 3 is disposed at each end of the light guide plate 22, the illuminance information acquisition unit 43 acquires the average value of the detection values of the two acquired illuminance sensors 3 as illuminance information. Do. When a plurality of illuminance sensors 3 are disposed at both ends of the light guide plate 22, as obtained in the second embodiment, the average value excluding the minimum value is acquired as illuminance information. That is, in the liquid crystal display device 104, the LED light source 21 and the illuminance sensor 3 are disposed at both ends of the light guide plate 22 only in the first to third embodiments, and the illuminance information acquiring process is performed in the embodiment described above. The same processing as 1 to 3 can be applied. Therefore, the example shown in FIG. 11 is suitable when the light guide plate is large as in a device such as a television or a monitor for a personal computer having a light guide display of 20 inches or more.

  Moreover, although the above description demonstrated the example which arrange | positioned the illumination intensity sensor 3 in the edge part (one end, both ends) of the light-guide plate 22 in all, it is not limited to this, For example, the back surface of the light-guide plate 22 The illumination sensor 3 may be disposed on the That is, it may be disposed at a position where the outside light is received through the light guide plate 22.

[Example of software implementation]
The control block (in particular, the display control unit 41, the backlight drive control unit 42, and the illuminance information acquisition unit 43) of the control unit 4 of the display device is realized by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like. It may be realized by software using a CPU (Central Processing Unit).

  In the latter case, the control unit 4 of the display device is a CPU that executes instructions of a program that is software that implements each function, and a ROM (Read Only) in which the program and various data are readable by a computer (or CPU). Memory or storage device (these are referred to as "recording media"), and RAM (Random Access Memory) for developing the program. The object of the present invention is achieved by the computer (or CPU) reading the program from the recording medium and executing the program. As the recording medium, a “non-transitory tangible medium”, for example, a tape, a disk, a card, a semiconductor memory, a programmable logic circuit or the like can be used. The program may be supplied to the computer via any transmission medium (communication network, broadcast wave, etc.) capable of transmitting the program. The present invention can also be realized in the form of a data signal embedded in a carrier wave, in which the program is embodied by electronic transmission.

[Summary]
A display device according to aspect 1 of the present invention is a display comprising an illuminance sensor 3 for detecting the illuminance of external light, and a backlight module 2 for emitting light from the back of the display surface of the display panel (liquid crystal panels 1 and 11). In the device (liquid crystal display devices 101 to 104), the backlight module 2 is disposed on the back of the display surface of the display panel (liquid crystal panels 1 and 11), and light emitted from a light source (LED light source 21) The light guide plate 22 guides the light to the back surface of the display surface, and the light intensity sensor 3 is disposed at a position where the outside light is received through the light guide plate 22.

  According to the above configuration, the illuminance sensor is disposed at the position where the outside light is received through the light guide plate of the backlight module, so the display surface of the display panel disposed on the front of the light guide plate is the illuminance sensor It becomes an area for receiving external light. Thus, it becomes possible to receive external light from the display surface of the display panel to the illuminance sensor without arranging a dedicated window for illuminance measurement in the frame area of the display panel as in the prior art.

  Therefore, as compared with the conventional illuminance sensor, the area for the illuminance sensor to receive the external light becomes wider, so that the effect of being hardly affected by the shield such as the finger is exhibited.

  The specific arrangement position of the illumination sensor 3 is as follows. In the display device according to aspect 2 of the present invention, in the above aspect 1, the illuminance sensor 3 may be disposed at a position where the outside light is received from the end of the light guide plate 22.

  Furthermore, the preferable arrangement of the illuminance sensor 3 is as follows. In the display device according to aspect 3 of the present invention, in the above aspect 2, the illuminance sensor 3 may be disposed on the side where the light source (the LED light source 21) is disposed. According to the above configuration, by providing the illuminance sensor 3 on the same side as the LED light source 21, there is no need to secure a space for separately arranging the illuminance sensor 3, so the size of the existing backlight module 2 can be maintained. .

  In the display device according to aspect 4 of the present invention, in any one aspect of the above aspects 1 to 3, an illuminance information acquisition unit 43 for acquiring illuminance information from a detection value of the illuminance sensor 3 and driving of the backlight module 2 The illumination information acquisition unit 43 detects the illumination information from the detection value of the illumination sensor 3 when the backlight drive control unit 42 stops the driving of the backlight module 2. You just need to get

  According to the above configuration, it is possible to detect the illuminance without being affected by the backlight light, so it is possible to improve the accuracy of illuminance detection.

  In the display device according to aspect 5 of the present invention, in the above aspect 4, the backlight drive control unit 42 performs the driving stop of the backlight module 2 in synchronization with the refresh of the display panel (liquid crystal panel 1). May be

  According to the above configuration, since the illuminance can be detected at a timing that does not affect the display, the user does not have to feel much of the display change due to the illuminance detection.

  In the display device according to aspect 6 of the present invention, in the aspect 5, the refresh cycle of the display panel (liquid crystal panel 1) may be set shorter than the refresh cycle when the illuminance is not measured. According to the above configuration, the illuminance can be detected in a state where the influence on the display is further reduced, and therefore the user hardly feels the change in the display due to the illuminance detection. That is, since the flickering of the screen at the time of illuminance detection can be eliminated, the user hardly feels a change in display due to the illuminance detection.

  In the display device according to the seventh aspect of the present invention, in the fourth aspect, the backlight drive control unit 42 stops the driving of the backlight module at a constant cycle, and the detection value of the illuminance sensor 3 is the previous detection value. When the value is within the predetermined range as compared with the above, it is not necessary to stop the driving of the backlight module 2 next time. According to the above configuration, the detection operation of the illuminance in a state where the change in the illuminance is small is not performed, and the detection of the illuminance is performed only when necessary, so unnecessary illuminance detection does not have to be performed.

  The display device according to aspect 8 of the present invention further includes a display control unit 41 that performs display control of the display panel (liquid crystal panel 1) according to any one of the aspects 4 to 7, and the display control unit 41 When an instruction signal for stopping the backlight module 2 is received from the backlight drive control unit 42, an image being displayed on the display panel (liquid crystal panel 1) is converted into an illuminance measurement image at least a part of which is displayed in white. You may switch. According to the above configuration, since the display is switched to the illuminance measurement image at the time of illuminance detection, the detection accuracy of the illuminance is improved.

  In the display device according to aspect 9 of the present invention, in any one of the above aspects 1 to 8, a plurality of the illuminance sensors 3 may be arranged. According to the above configuration, since illuminance information is acquired using each detection value obtained from the plurality of illuminance sensors 3, highly accurate illuminance information can be obtained.

  The display device according to aspect 10 of the present invention further includes an illuminance information acquisition unit 43 for acquiring illuminance information from the detection value of the illuminance sensor 3 according to aspect 9, and the display panel (liquid crystal panel 1) includes a touch panel. The illuminance information acquisition unit 43 detects the remaining detection values of the illuminance sensor 3 excluding the detection value of the illuminance sensor 3 disposed at the position corresponding to the light guide path of the light guide plate 22 corresponding to the touch position of the touch panel. It may be acquired as illuminance information. According to the above configuration, the detection value of the illuminance sensor 3 corresponding to the area covered by the user's hand or the like is not used, and the illuminance information is acquired using the detection values of the remaining illuminance sensor 3. Illuminance information can be obtained.

  The display device according to aspect 11 of the present invention further includes an illuminance information acquisition unit 43 that acquires illuminance information from the detection value of the illuminance sensor 3 in aspect 9, and the illuminance information acquisition portion 43 includes the plurality of illuminances. The average value of the detection values of the sensor 3 may be acquired as illumination information. According to the above configuration, it is possible to obtain highly accurate illuminance information only by using the average value of the detection values from the plurality of illuminance sensors 3 as the illuminance information.

  The display device according to aspect 12 of the present invention further includes an illuminance information acquisition unit 43 that acquires illuminance information from the detection value of the illuminance sensor 3 in the above-mentioned aspect 9, and the illuminance information acquisition unit 43 Among the detection values of the sensor 3, the average value of the remaining detection values excluding the minimum detection value may be acquired as illumination information. According to the above configuration, since the smallest detected value is excluded, the accuracy of the illuminance information acquisition is improved as compared to the case where the illuminance information is acquired using all of the detected values of all the illuminance sensors 3. Can.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment.

  INDUSTRIAL APPLICABILITY The present invention can be applied to a display device using a backlight, in particular, a portable information terminal such as a smartphone having a restriction on the arrangement position of the illuminance sensor like a display device with a narrow frame.

Reference Signs List 1 liquid crystal panel, 2 backlight module, 3 illuminance sensor, 4 control unit, 5 image data storage unit, 11 liquid crystal panel (display panel), 21 LED light source (light source), 22 light guide plate, 41 display control unit, 42 backlight Drive control unit, 43 Illuminance information acquisition unit, 101 to 104 liquid crystal display device (display device)

Claims (8)

A display device comprising: an illuminance sensor for detecting the illuminance of external light; and a backlight module for emitting light from the back of the display surface of the display panel,
The above backlight module is
A light guide plate disposed on the back of the display surface of the display panel and guiding light emitted from the light source to the back of the display surface;
The illuminance sensor is disposed at a position to receive the outside light through the light guide plate ,
An illuminance information acquisition unit that acquires illuminance information from the detection value of the illuminance sensor;
A backlight drive control unit that controls driving of the backlight module;
The illuminance information acquisition unit
When the driving of the backlight module is stopped by the backlight driving control unit, illuminance information is acquired from the detection value of the illuminance sensor,
The above backlight drive control unit
Drive stop of the backlight module in synchronization with the refresh of the display panel,
A display device characterized in that a refresh cycle at the time of measuring the illuminance of the display panel is set shorter than a refresh cycle at the time of not measuring the illuminance . And a display control unit that performs display control of the display panel,
The display control unit
When receiving a back light module stop instruction signal from the backlight drive control unit, according to claim 1 in which the image under display in the display panel, and at least a part is switched to a white display illumination measurement image The display device as described in. The display device according to any one of claims 1 and 2 , wherein a plurality of the illuminance sensors are arranged. A display device comprising: an illuminance sensor for detecting the illuminance of external light; and a backlight module for emitting light from the back of the display surface of the display panel,
The above backlight module is
A light guide plate disposed on the back of the display surface of the display panel and guiding light emitted from the light source to the back of the display surface;
A plurality of the illuminance sensors are disposed at positions where the outside light is received through the light guide plate;
It further comprises an illuminance information acquisition unit that acquires illuminance information from the detection value of the illuminance sensor,
The display panel includes a touch panel;
The illuminance information acquisition unit
A display device characterized by acquiring detection values of remaining illuminance sensors excluding illuminance detection values of illuminance sensors arranged at positions corresponding to light guide paths of a light guide plate corresponding to touch positions of the touch panel as illuminance information. . An illuminance information acquisition unit that acquires illuminance information from the detection value of the illuminance sensor;
A backlight drive control unit that controls driving of the backlight module;
The illuminance information acquisition unit
5. The display device according to claim 4 , wherein illuminance information is acquired from a detection value of the illuminance sensor when the backlight drive control unit stops driving the backlight module. The above backlight drive control unit
Stop driving the backlight module at a constant cycle,
The display device according to claim 5 , wherein the driving stop of the next backlight module is not performed when the detection value by the illuminance sensor is a value within a predetermined range in comparison with a previous detection value. The display device according to any one of claims 1 to 6, wherein the illuminance sensor is disposed at an end of the light guide plate. The display device according to claim 7 , wherein the illuminance sensor is disposed on the side where the light source is disposed.

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