JP2017003613A - Display device - Google Patents

Abstract

Provided is a display device capable of appropriately obtaining visual environment illumination information without impairing design. In a liquid crystal display device (101), a backlight module (2) is disposed on the back surface of the display surface of the liquid crystal panel 1, and guides light emitted from an LED light source (21) to the back surface of the display surface. An illuminating light guide plate (22), and the illuminance sensor (3) is disposed at a position for receiving external light via the light guide plate (22). [Selection] Figure 1

Description

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

  Portable electronic devices such as mobile phones and digital cameras that have a liquid crystal panel are equipped with an illuminance sensor that detects the illuminance of external light so that the amount of light emitted from 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 it easy to see the display device according to the brightness of the surrounding environment of the background.

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

  By the way, in the conventional mobile device (cell phone 201), as shown in FIG. 12 (FIG. 1 of Patent Document 1), the illuminance sensor (photometric 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. Due to the design of the housing, there are cases where the placement restrictions are large, and there is a case where it cannot be placed at the expected position.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a display device that can appropriately obtain visual environment illumination information without impairing design.

  In order to solve the above problems, a display device according to one embodiment of the present invention includes a illuminance sensor that detects the illuminance of external light and a backlight module that emits light from the back surface of the display surface of the display panel. The backlight module is disposed on the back surface of the display surface of the display panel, and includes a light guide plate that guides and irradiates light emitted from a light source to the back surface of the display surface. It is characterized by being arranged at a position for receiving the external light via the light guide plate.

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

1 is a schematic configuration perspective view of a display device according to Embodiment 1 of the present invention. It is a schematic block diagram of the display apparatus 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 the illumination intensity information acquisition in the display apparatus shown in FIG. It is a figure which shows an example of the timing chart of the illumination intensity information acquisition in the display apparatus shown in FIG. It is a figure which shows an example of the timing chart of the 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 the display apparatus which concerns on Embodiment 3 of this invention. It is a schematic block diagram of the display apparatus 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 position of a general illuminance sensor.

Embodiment 1
The embodiment of the present invention will be 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.
(Outline of the liquid crystal display device 101)
FIG. 1 is a schematic configuration perspective view of the 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 light 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 transmission type liquid crystal panel. The driving method of the liquid crystal panel 1 is not particularly limited.

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

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

  In the liquid crystal display device 101 having the above configuration, the illuminance sensor 3 that detects the illuminance of the external light is adjacent to the LED light source 21 so that the amount of light emitted from the backlight module 2 can be controlled according to the illuminance of the external light. Has been placed. That is, the illuminance sensor 3 receives external light incident from the display surface of the liquid crystal panel 1 via the light guide plate 22 of the backlight module 2. As a result, the display surface of the liquid crystal panel 1 disposed on the front surface of the light guide plate 22 becomes a region for receiving external light of the illuminance sensor 3.

  The illuminance sensor 3 only needs to be disposed at a position where external light is received via the light guide plate 22, but may be disposed at a position where external light is received from the end of the light guide plate 22. As shown in FIG. 1, 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 driving 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 sensor 3 detects illuminance, and the control unit 4 for controlling the driving of the liquid crystal panel 1 and the backlight module 2. An image data storage unit 5 is further provided.

  The control unit 4 includes a CPU, and obtains illuminance information from the 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 performs drive control of the backlight module 2, and the illuminance sensor 3. An illuminance information acquisition unit 43 is included.

  The illuminance information acquisition unit 43 acquires illuminance information from the detection value of the illuminance sensor 3 when the backlight drive control unit 42 stops driving the backlight module 2. If there is an illuminance information acquisition request to the illuminance information acquisition unit 43, the control unit 4 instructs the backlight drive control unit 42 to stop driving the backlight module 2 when acquiring the illuminance information. As a result, detection by the illuminance sensor 3 can be performed while the backlight module 2 is being driven, that is, when the backlight module 2 is irradiating the backlight light. External light can be received by the illuminance sensor 3 without being obstructed. Therefore, the illuminance information acquisition unit 43 can acquire appropriate illuminance information on the display surface side of the liquid crystal display device 101.

  Further, the backlight drive control unit 42 further displays a normal image (such as wallpaper) displayed on the liquid crystal panel 1 when the illuminance information is acquired so that the illuminance information acquisition unit 43 appropriately acquires the illuminance information. An instruction signal for switching to a display for acquiring illuminance information (illuminance measurement constant image: hereinafter referred to as “measurement image”). To 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 screen.

  In the above description, the display control unit 41 performs a process of switching an image being displayed by an instruction signal (backlight module stop instruction signal) from the backlight drive control unit 42, but is not limited thereto. Instead of this, the above instruction signal may be received directly from the control unit 4 and processing for switching the image being displayed may be performed. 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, the measurement image to be switched by the display control unit 41 is preferably a white display image in which the entire surface of the liquid crystal panel 1 transmits light, and may be a display image that is less affected by the liquid crystal display. The measurement image is stored in the image data storage unit 5.

  Further, when the illuminance information acquisition by the illuminance information acquisition unit 43 is completed, the control unit 4 instructs the display control unit 41 to switch from the measurement image to the normal image, and to the backlight drive control unit 42. An instruction is given to resume driving of the backlight module 2.

(Illuminance information acquisition process)
Here, the flow of the illuminance information acquisition process 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 driving the backlight module 2.

  Next, the control part 4 displays a 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 performs illuminance measurement (step S14). Specifically, the illuminance information acquisition unit 43 transmits external light incident from the display surface of the liquid crystal panel 1 displayed on the measurement image via the light guide plate 22 in a state where the backlight module 2 does not irradiate 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 acquisition of illuminance information by the illuminance information acquisition 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 a normal image.

  Moreover, the control part 4 lights a backlight (step S16) and complete | finishes a process. Specifically, when acquisition of illuminance information by the illuminance information acquisition unit 43 is completed, the control unit 4 causes the backlight drive control unit 42 to resume driving the backlight module 2 and performs illuminance information acquisition processing. finish.

  The timing of obtaining the illuminance information is preferably synchronized with the refresh of the liquid crystal panel 1. That is, the backlight drive control unit 42 stops driving the backlight module 2 in synchronization with the refresh of the liquid crystal panel 1.

  Hereinafter, the timing of obtaining illuminance information will be described. Here, the following three patterns will be described.

(Illuminance information acquisition timing (1))
Normally, since the illuminance cannot be accurately measured while the backlight is lit, the illuminance is measured when the light is turned off as in the above illuminance information acquisition process. In order to minimize the influence of the liquid crystal display during illuminance measurement, an external light transmission color (for example, white display) is displayed as a measurement image. Since the backlight is turned off, it is difficult for the user to visually recognize. Illuminance information acquisition timing at this time is shown in FIG.

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

  In this case, for example, as shown in FIGS. 12A and 12B, it is possible to acquire illuminance information without arranging a dedicated window for illuminance measurement in the frame area.

  By the way, when the illuminance information acquisition timing is displaying a still image with a cycle of 60 Hz, etc., there is a possibility that the user may recognize illuminance measurement (backlight extinguishing, measurement image display). That is, the user may feel as if the screen is flickering during the illuminance information acquisition process.

(Illuminance information acquisition timing (2))
Therefore, in order to prevent the user from recognizing illuminance measurement (backlight off, measurement image display), the illuminance information acquisition timing is set to a refresh cycle of the liquid crystal panel 1 when the illuminance measurement is not performed, for example, a refresh cycle shorter than a 60 Hz cycle, For example, so-called high-speed refresh driving is performed in which the cycle is ½ times 120 Hz (double-speed refresh cycle). Specifically, the backlight drive control unit 42 synchronizes the drive stop of the backlight module 2 with 1/2 the refresh cycle (60 Hz) when the illuminance is not measured (120 Hz).

  FIG. 5 is a timing chart showing an example of illuminance information acquisition timing. Here, as an example, the illuminance information acquisition timing (illuminance measurement cycle) by the illuminance information acquisition unit 43 is set to 120 Hz cycle (1/2 times the refresh cycle of the liquid crystal panel 1 when the illuminance measurement is not performed). 4 shows the drive timing (BL drive) of the backlight module 2 and the switching timing of the display image on the liquid crystal panel 1.

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

  In the above description, the refresh cycle at the time of illuminance measurement has been described as 120 Hz. However, the present invention is not limited to this, and the refresh cycle may be set short enough that flicker is not felt.

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

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

[Embodiment 2]
The following will describe another embodiment of the present invention. For convenience of explanation, members having the same functions as those described in the embodiment are given the same reference numerals, and descriptions thereof are omitted.
(Outline of the liquid crystal display device 102)
FIG. 7 is a schematic configuration perspective view of the liquid crystal display device 102.

  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, the liquid crystal display device 101 shown in FIG. 1 has one illuminance sensor 3, but the liquid crystal display device 102 shown in FIG. 7 has a plurality of illuminance sensors 3 (three in FIG. 7). The illuminance sensor 3 is arranged alternately with the LED light sources 21 as shown in FIG. The illuminance sensor 3 may not be arranged alternately with the LED light source 21, but is preferably arranged at equal intervals.

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

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

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

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

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

  As shown in FIG. 8A, when the measurement image is white display on the entire surface, in order to effectively measure the illuminance, it is preferable to arrange the illuminance sensors 3 at equal intervals as shown in FIG. .

  In the case where the measurement image is a partial white display at the lower part and the entire width direction of the lower part is set as the measurement region as shown in FIG. Similarly to the full white display shown in FIG.

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

  The measurement images are not limited to the three examples shown in FIG. 8 and may be measurement images of other patterns. Also, a plurality of measurement images may be switched as necessary. 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 example shown in the said Embodiment 1, 2, when the display surface of the liquid crystal panel 1 has covered the hand and the finger | toe, there exists a possibility of detecting that the illumination intensity fell unintentionally. As a countermeasure for this, a touch panel is provided on the liquid crystal panel 1, and it is determined that the area touched by the user on the touch panel is covered with the user's finger or hand in cooperation with the sensing information of the touch panel. It is conceivable to obtain illuminance information of a point (area) determined not to be covered with a finger or a hand. In the following third embodiment, an example in which the touch panel sensing information is linked will be described.

[Embodiment 3]
The following will describe another embodiment of the present invention. For convenience of explanation, members having the same functions as those described in the embodiment are given the same reference numerals, and descriptions thereof are omitted.
(Outline of the liquid crystal display device 103)
FIG. 9 is a schematic configuration perspective view of the liquid crystal display device 103.

  As shown in FIG. 9, the liquid crystal display device 103 has almost the same configuration as the liquid crystal display device 102 shown in FIG. 7, but is different in that the liquid crystal panel 11 includes a touch panel. That is, the liquid crystal display device 103 is different from the liquid crystal display device 102 shown in FIG. 7 in that the liquid crystal display device 103 includes a liquid crystal panel 11 including a touch panel as shown in FIG. 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 identifies the illuminance sensor 3 that is the target of illuminance detection from the sent coordinate information, and uses the detected value from the other illuminance sensors 3 without using the detected value from the identified illuminance sensor 3. Obtained as illuminance information.

  Thus, when the liquid crystal panel 1 includes a touch panel, the illuminance information acquisition unit 43 is located 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. You may make it acquire the detection value of the remaining illumination sensor 3 except the detection value of the arrange | positioned illumination sensor 3 as illumination information. Thus, 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 that part is not acquired.

  Thereby, it is possible to acquire more accurate illuminance information by not detecting the illuminance of the area where the illuminance detection is inaccurate, that is, the area touched by the user.

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

  Moreover, according to the said structure, since it is not necessary to provide the opening for the illumination intensity sensors 3 on a flame | frame, the restrictions of the design for arrangement | positioning of the illumination intensity sensors 3 can be eliminated. And since the direction which receives the external light for illumination detection and the direction which a user looks at a display screen become the same, visual recognition environment illumination information can be acquired appropriately.

[Modification]
In the first to third embodiments, the arrangement position of the LED light source 21 that is a light source is only one end side of the light guide plate 22. This is because the liquid crystal display devices 101 to 103 are assumed to be mobile devices whose display screen size is as small as, for example, 5 to 6 inches such as a smartphone. Therefore, the LED light source 21 is arranged on one end side of the light guide plate 22. This is because the backlight can be irradiated evenly to the display screen.

  However, the present invention is not limited to the above configuration, and can also be applied to the case where the LED light sources 21 are arranged 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. In this case, since the light emitted from 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 guided to both ends of the light guide plate 22. In the example of FIG. 11, since one illuminance sensor 3 is arranged 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 obtained illuminance sensors 3 as illuminance information. To do. When a plurality of illuminance sensors 3 are arranged at both ends of the light guide plate 22, as obtained in the second embodiment, the average value excluding the average value and 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 arranged at both ends of the light guide plate 22 only different from the first to third embodiments, and the illuminance information acquisition process is the same as the first embodiment. 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, such as a television or a monitor for a personal computer having a conductive display screen of 20 inches or more.

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

[Example of software implementation]
The control blocks (particularly 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 are realized by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like. Alternatively, it may be realized by software using a CPU (Central Processing Unit).

  In the latter case, the control unit 4 of the display device includes a CPU that executes instructions of a program that is software that realizes each function, and a ROM (Read Only) in which the program and various data are recorded so as to be readable by the computer (or CPU). Memory) or a storage device (these are referred to as “recording media”), a RAM (Random Access Memory) for expanding the program, and the like. And the objective of this invention is achieved when a computer (or CPU) reads the said program from the said recording medium and runs it. As the recording medium, a “non-temporary tangible medium” such as 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 an arbitrary transmission medium (such as a communication network or a broadcast wave) that can transmit 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 includes a display including an illuminance sensor 3 that detects the illuminance of external light, and a backlight module 2 that emits light from the back of the display surface of the display panel (liquid crystal panels 1 and 11). It is a device (liquid crystal display devices 101-104), Comprising: The said backlight module 2 is arrange | positioned in the back surface of the display surface of the said display panel (liquid crystal panel 1, 11), and the light irradiated from the light source (LED light source 21) The illumination sensor 3 is arranged at a position to receive the external light through the light guide plate 22.

  According to the above configuration, since the illuminance sensor is disposed at a position for receiving external light via the light guide plate of the backlight module, the display surface of the display panel disposed on the front surface of the light guide plate is the illuminance sensor. This is a region for receiving external light. As a result, it is possible to receive external light from the display surface of the display panel to the illuminance sensor without disposing a dedicated window for measuring illuminance 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 external light is widened, so that the effect of being hardly influenced by a shielding object such as a finger is obtained.

  The specific arrangement position of the illuminance sensor 3 is as follows. In the display device according to aspect 2 of the present invention, in the aspect 1, the illuminance sensor 3 may be disposed at a position where external light is received from an 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 aspect 2, the illuminance sensor 3 may be disposed on the side where the light source (LED light source 21) is disposed. According to the above configuration, since the illuminance sensor 3 is provided on the same side as the LED light source 21, it is not necessary to secure a space for separately arranging the illuminance sensor 3, so the size of the existing backlight module 2 can be kept. .

  In any one of the first to third aspects, the display device according to the fourth aspect of the present invention is an illuminance information acquisition unit 43 that acquires illuminance information from the detection value of the illuminance sensor 3, and the driving of the backlight module 2. The illuminance information acquisition unit 43 is configured to detect illuminance information from the detection value of the illuminance sensor 3 when the backlight drive control unit 42 stops driving the backlight module 2. Just get it.

  According to the above configuration, since the illuminance can be detected without being affected by the backlight light, the accuracy of the illuminance detection can be improved.

  In the display device according to aspect 5 of the present invention, in the aspect 4, the backlight drive control unit 42 stops driving the backlight module 2 in synchronization with 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 feel much change in the display due to the illuminance detection.

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

  In the display device according to aspect 7 of the present invention, in the aspect 4, the backlight drive control unit 42 stops driving the backlight module at a constant cycle, and the detection value by the illuminance sensor 3 is the previous detection value. When the value is within the predetermined range, the drive of the backlight module 2 need not be stopped next time. According to the above configuration, since the detection operation of the illuminance is not performed in a state where the change in the illuminance is small and the illuminance is detected only when necessary, it is not necessary to perform a useless illuminance detection.

  In any one of the above aspects 4 to 7, 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), and the display control unit 41 includes: When the stop instruction signal for the backlight module 2 is received from the backlight drive control unit 42, the image being displayed on the display panel (liquid crystal panel 1) is changed to an illuminance measurement image at least partly displaying white. It may be switched. According to the above configuration, when detecting illuminance, the display is switched to the illuminance measurement image, so that the illuminance detection accuracy 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 the illuminance information is obtained using each detection value obtained from the plurality of illuminance sensors 3, illuminance information with high accuracy can be obtained.

  The display device according to aspect 10 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 aspect 9, and the display panel (liquid crystal panel 1) includes a touch panel. The illuminance information acquisition unit 43 obtains the detection values of the remaining illuminance sensors 3 excluding the detection values of the illuminance sensor 3 arranged at the position corresponding to the light guide path of the light guide plate 22 corresponding to the touch position of the touch panel. What is necessary is just to acquire as illumination intensity information. According to the above configuration, the detection value of the illuminance sensor 3 corresponding to the area covered with the user's hand or the like is not used, and the illuminance information is acquired using the remaining detection values of the illuminance sensor 3, so that high accuracy 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 the aspect 9, and the illuminance information acquisition unit 43 includes the plurality of illuminances. You may acquire the average value of the detected value of the sensor 3 as illumination intensity information. According to the above configuration, it is possible to obtain highly accurate illuminance information only by using the average value of detection values from the plurality of illuminance sensors 3 as 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 aspect 9, and the illuminance information acquisition unit 43 includes the plurality of illuminances. Of the detection values of the sensor 3, an average value of the remaining detection values excluding the minimum detection value may be acquired as illuminance information. According to the above configuration, since the minimum detected value is excluded, the illuminance information acquisition accuracy is improved as compared to the case where the illuminance information is acquired using all the detected values of all the illuminance sensors 3. Can do.

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

  INDUSTRIAL APPLICABILITY The present invention can be used for an information portable terminal such as a smartphone having a restriction on the position of an illuminance sensor, such as a display device using a backlight, particularly a narrow frame display device.

DESCRIPTION OF SYMBOLS 1 Liquid crystal panel, 2 Backlight module, 3 Illuminance sensor, 4 Control part, 5 Image data storage part, 11 Liquid crystal panel (display panel), 21 LED light source (light source), 22 Light guide plate, 41 Display control part, 42 Backlight Drive control unit, 43 Illuminance information acquisition unit, 101-104 Liquid crystal display device (display device)

Claims (10)

A display device comprising an illuminance sensor that detects the illuminance of external light, and a backlight module that irradiates light from the back of the display surface of the display panel,
The above backlight module
A light guide plate that is disposed on the back surface of the display surface of the display panel and guides and radiates light emitted from a light source to the back surface of the display surface,
The display device, wherein the illuminance sensor is arranged at a position for receiving the external light through the light guide plate.   The display device according to claim 1, wherein the illuminance sensor is disposed at an end of the light guide plate.   The display device according to claim 2, wherein the illuminance sensor is disposed on a side where the light source is disposed. An illuminance information acquisition unit that acquires illuminance information from the detection value of the illuminance sensor;
A backlight drive control unit for controlling the drive of the backlight module,
The illuminance information acquisition unit
4. The display device according to claim 1, wherein illuminance information is acquired from a detection value of the illuminance sensor when driving of the backlight module is stopped by the backlight drive control unit. 5. The backlight drive control unit is
The display device according to claim 4, wherein the drive of the backlight module is stopped in synchronization with refresh of the display panel.   6. The display device according to claim 5, wherein a refresh cycle when measuring the illuminance of the display panel is set shorter than a refresh cycle when illuminance is not measured. The backlight drive control unit is
Stop driving the backlight module at regular intervals,
5. The display device according to claim 4, wherein when the detected value by the illuminance sensor is a value within a predetermined range compared to the previous detected value, the driving of the backlight module is not stopped next time. A display control unit for performing display control of the display panel;
The display control unit
5. The illuminance measurement image, at least a part of which is displayed on the display panel, is switched to an illuminance measurement image that is displayed in white when the backlight module stop instruction signal is received from the backlight drive control unit. The display device according to any one of? 7.   The display device according to claim 1, wherein a plurality of the illuminance sensors are arranged. 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
The detection value of the remaining illuminance sensors excluding the detection value of the illuminance sensor arranged at a position corresponding to the light guide path of the light guide plate corresponding to the touch position of the touch panel is acquired as illuminance information. 9. The display device according to 9.

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