Display device

Abstract

To provide a display device capable of suppressing change in luminance due to touch in the display device having a touch panel.SOLUTION: A display device includes: a liquid crystal display panel 11 that has a screen and displays an image on the screen; a touch sensor 12 that is disposed to overlap the screen of the liquid crystal display panel and detects a position touched on the screen; a backlight 20 that is disposed on a back surface of the liquid crystal display panel and has a plurality of light sources 21; and a controller 30 that controls luminance of the backlight. The controller changes luminance of the light source at a position corresponding to a touched position among the plurality of light sources based on sensing results from the touch sensor.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a display device including a touch panel.

Background Art

[0002] In a display device in which a liquid crystal display panel and a touch panel are laminated, when the screen is touched, the gap of the liquid crystal display panel may change, and display disturbances such as a change in luminance may occur. Patent Document 1 discloses a method for manufacturing a display device having a structure for suppressing such display disturbances.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present disclosure is to provide a display device including a touch panel that can suppress a change in luminance due to touch.

Means for Solving the Problems

[0005] The display device of the present disclosure includes a liquid crystal display panel having a screen and displaying an image on the screen, a touch sensor disposed so as to overlap the screen of the liquid crystal display panel and detecting a position touched on the screen, a backlight disposed on the back surface of the liquid crystal display panel and having a plurality of light sources, and a controller that controls the luminance of the backlight. The controller changes the luminance of the light source at a position corresponding to the touched position among the plurality of light sources based on the sensing result from the touch sensor.

Effects of the Invention

[0006] According to the display device of an embodiment of the present disclosure, it is possible to suppress the change in luminance due to touch.

Brief Description of the Drawings

[0007]

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Embodiments for Carrying Out the Invention

[0008] (First Embodiment) Embodiments of the present disclosure will be described based on the drawings. The present disclosure is not limited to the following embodiments, and design changes can be appropriately made within the scope that satisfies the configuration of the present disclosure. Further, in the following description, the same reference numerals are commonly used among different drawings for the same part or parts having the same or similar functions, and repeated descriptions thereof may be omitted. Also, each configuration described in the embodiments and modification examples may be appropriately combined or changed without departing from the gist of the present disclosure. For the sake of easy understanding of the description, in the drawings referred to below, the configuration may be shown in a simplified or schematic manner, or some constituent members may be omitted. Also, the dimensional ratios between the constituent members shown in each figure do not necessarily represent the actual dimensional ratios. FIG. 1 is a schematic configuration diagram of a display device 101 according to the present embodiment. The display device 101 is, for example, a smartphone, a tablet terminal, a smartwatch, an in-vehicle information display, and a personal computer.

[0009] The display device 101 includes a liquid crystal display panel 11, a touch panel 14, a backlight 20, and a controller 30. The display device 101 also includes a gate driver 40, a source driver 50, an LED driver 60, and a touch panel controller 70. The display device 101 may further include a host computer 150 that controls the whole.

[0010] The liquid crystal display panel 11 has a screen 11a for displaying an image, and the touch panel 14 is disposed so as to overlap the screen 11a. The backlight is disposed on the back surface 11b of the liquid crystal display panel 11 on the side opposite to the screen 11a. The screen 11a means the surface on which an image is displayed and does not mean a specific surface.

[0011] The touch panel 14 may have any structure as long as it has the function of detecting the position touched on the screen 11a. Specifically, the touch panel 14 may have any of the structures of the out-cell method, the on-cell method, and the in-cell method. When the touch panel is of the out-cell method, it may be a touch panel using any of the detection methods of the resistive film method, the capacitance method, the electromagnetic induction method, and the optical method. Also, when it is of the capacitance method, the touch panel may be a surface type or a projection type. Further, when it is of the projection type, the touch panel may be a self-capacitance method or a mutual-capacitance method. Also, when the touch panel is of the in-cell method, it may be a touch panel using any of the detection methods of the capacitance method, the liquid crystal capacitance method, the optical method, and the micro switch method.

[0012] In this embodiment, the touch panel 14 includes a touch sensor 12 that detects the touch position on the screen 11a and is incorporated in the liquid crystal display panel 11. The liquid crystal display panel 11 in which the touch panel 14 is incorporated is called a touch screen 10. In this embodiment, the touch screen 10 is a self-capacitance type full in-cell touch panel driven in the horizontal electric field mode.

[0013] FIG. 2 is a schematic cross-sectional view of an example of the touch screen 10. The touch screen 10 includes a first substrate 110, a second substrate 120, and a liquid crystal layer 130 positioned between the first substrate 110 and the second substrate 120.

[0014] The second substrate 120 includes a glass substrate 122, a color filter 121, and a transparent electrode 140. The color filter 121 is disposed on a surface of the glass substrate 122 facing the liquid crystal layer 130. On the other hand, the transparent electrode 140 is disposed on a surface of the glass substrate 122 opposite to the surface facing the liquid crystal layer 130. The transparent electrode 140 is formed of a transparent conductor such as, for example, ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide), and is connected to, for example, a reference potential. When the touch screen 10 is driven in the horizontal electric field mode, since no common electrode is provided on the second substrate 120, charges accumulate on the second substrate 120, and the charges accumulated on the second substrate 120 affect the liquid crystal layer 130, making it easy for display abnormalities due to static electricity to occur. By providing the transparent electrode 140, the accumulation of charges on the second substrate 120 can be suppressed.

[0015] The second substrate 120 may further include a protective film provided on the transparent electrode 140 and a glass substrate.

[0016] The first substrate 110 is an active matrix substrate. The first substrate 110 includes a glass substrate 111, a TFT layer 112, an insulating layer 113, a plurality of pixel electrodes 114, an insulating layer 115, and a plurality of touch sensor electrodes 116. A TFT layer 112 including TFTs for driving each pixel is disposed on the glass substrate 111, and pixel electrodes 114 are disposed via the insulating layer 115. An insulating layer 113 is disposed to cover the pixel electrodes 114, and touch sensor electrodes 116 are disposed on the insulating layer 115.

[0017] FIG. 3 and FIG. 4 are circuit diagrams showing the configuration of the TFT layer 112. The TFT layer 112 includes a plurality of gate bus lines 117 and a plurality of source bus lines 118. The plurality of gate bus lines 117 extend, for example, in the row direction, and the plurality of source bus lines 118 extend in the column direction so as to be orthogonal to the plurality of gate bus lines 117.

[0018] The TFT layer 112 includes a plurality of TFTs. As shown in FIG. 4, each TFT is connected to one of a plurality of gate bus lines 117 and one of a plurality of source bus lines 118. Specifically, the gate G and source S of the TFT are connected to the gate bus line 117 and the source bus line 118 respectively, and the drain D is connected to the pixel electrode 114.

[0019] The plurality of gate bus lines 117 are connected to the gate driver 40 disposed outside the display region DR. Also, the plurality of source bus lines 118 are connected to the source driver 50.

[0020] FIG. 5 is a schematic plan view showing the arrangement of a plurality of touch sensor electrodes 116 on the first substrate 110. The plurality of touch sensor electrodes 116 are arranged in a matrix of rows and columns. The touch sensor electrodes 116 are made of a transparent conductor such as ITO or IZO.

[0021] The plurality of touch sensor electrodes 116 function as counter electrodes (common electrodes) in the liquid crystal display panel 11 and also function as touch sensors for detecting touch positions in the touch panel 14. Each touch sensor electrode 116 is connected to the source driver 50 by a touch sensor line 119.

[0022] The backlight 20 includes a plurality of light sources 21 arranged in a matrix of rows and columns. The light sources 21 are, for example, LEDs and are arranged at a surface density according to the use or specifications of the display device. For example, a backlight capable of local dimming drive such as a direct-lit backlight, a mini-LED backlight, or a backlight with white LEDs spread out in a plane can be used. The plurality of light sources 21 are connected to the LED driver 60.

[0023] The controller 30 includes an image processing unit 31, a local dimming unit 32, and a touch synchronization processing unit 33. The host computer 150 outputs a video data signal of an image to be displayed on the screen 11a of the liquid crystal display panel 11 to the controller 30. The video data signal is input to the image processing unit 31 and the local dimming unit 32 in the controller 30. The image processing unit 31 generates a gate start pulse signal, a source start pulse signal, and a data signal based on the video data signal. The gate driver 40 receives the gate start pulse signal, generates a gate signal, and outputs the generated gate signal to the gate bus line 117. The source driver 50 receives the source start pulse signal and the data signal, generates a source signal, and outputs the generated source signal to the source bus line 118. Thereby, an image based on the video data signal is displayed on the screen 11a.

[0024] The source driver 50 also controls the touch panel 14. In the present embodiment, the source driver 50 drives each touch sensor electrode 116 via the touch sensor line 119 according to the self-capacitance method, and detects a voltage change due to an increase in capacitance caused by a touch with a finger or the like. The detection signal is output to the touch panel controller 70.

[0025] The touch panel controller 70 obtains the touch position P on the screen 11a from the detection signal. For example, the touch panel controller 70 generates touch coordinate data represented by detection coordinates (xp, yp) as the touch position P, and outputs the generated touch coordinate data to the local dimming unit 32 and the host computer 150. Further, the touch panel controller 70 exchanges synchronization signals in order to synchronize the signal processing timing with the touch synchronization processing unit 33.

[0026] The host computer 150 receives the touch coordinate data, and controls a smartphone or a tablet terminal, which is the display device 101, so as to perform an operation related to the image information indicated at the touched position. Based on the sensing result from the touch sensor electrode 116, the local dimming unit 32 changes the luminance of the light source 21 at the position corresponding to the touched position among the plurality of light sources 21.

[0027] When the screen 11a of the touch screen 10 is touched with a finger or the like, the distance between the first substrate 110 and the second substrate 120 that forms the space of the liquid crystal layer 130 changes in the vicinity of the touched position, and the alignment of the liquid crystal is disturbed. In addition, when the first substrate 110 and the second substrate 120 are locally bent, the alignment direction of the liquid crystal in the vicinity of these substrates changes. As a result, among the images displayed on the screen 11a, the amount of light transmitted from the backlight 20 at the touched position fluctuates, and the luminance changes. The change in luminance may be a case where the luminance decreases, a case where the luminance increases, and a case where the luminance decreases and increases according to the position and time.

[0028] The local dimming unit 32 changes the luminance of the backlight 20 in the vicinity of the touch position so as to compensate or offset the luminance change occurring in the vicinity of the touch position, or at least to reduce the luminance change. For example, when the luminance of the screen 11a decreases in the vicinity of the touch position due to the touch, the luminance of the light source 21 in the vicinity of the touch position is increased so as to compensate for the decrease in luminance. Also, when the luminance of the screen 11a increases in the vicinity of the touch position due to the touch, the luminance of the light source 21 in the vicinity of the touch position is decreased so as to compensate for the increase in luminance.

[0029] For this purpose, the local dimming unit 32 stores in advance position correspondence information indicating the relationship between the detection coordinates of the touch sensor and the light source 21 of the backlight 20 at the position corresponding to the detection coordinates. The local dimming unit 32 determines the light source 21 whose luminance is to be changed based on the sensing result from the touch sensor, that is, the detection coordinates, and the stored position correspondence information. The position correspondence information may be, for example, a table based on a combination of the detection coordinates of the touch sensor and the light source 21 at the corresponding position. Alternatively, the local dimming unit 32 may store a function that specifies the corresponding light source 21 when the detection coordinates of the touch sensor are input.

[0030] The change in the luminance of the screen 11a caused by the touch, that is, the decrease or increase in luminance, may continue while the touch continues, or the luminance may change significantly immediately after the touch and then return to the original luminance as the disturbance in the liquid crystal alignment recovers. The local dimming unit 32 preferably controls the light source 21 of the backlight 20 according to the characteristics of the luminance change of the screen 11a due to such a touch. Specifically, it is preferable to adjust the luminance of the light source 21 according to the duration of the luminance change caused by the touch. For example, while the touch on the screen 11a continues, the local dimming unit 32 may maintain a state in which the luminance of the light source 21 at the position corresponding to the touched position among the plurality of light sources 21 is changed based on the sensing result from the touch sensor. Alternatively, when there is a touch on the screen 11a, the local dimming unit 32 may change the luminance of the light source 21 at the position corresponding to the touched position among the plurality of light sources 21 for a certain period and then return it to the original luminance.

[0031] The local dimming unit 32 sets, for example, the plurality of light sources 21 to the luminance value B, and as shown in FIG. 1, changes the luminance value of the light source 21p at the position corresponding to the detection coordinate P, which is determined using the position correspondence information, by the change amount δ from B. The number of light sources 21 whose luminance is changed may be 1 or more. Also, when changing the luminance of the plurality of light sources 21, the change amount δ may be the same or different. For example, when the luminance of the screen 11a decreases due to touch, the luminance value of the light source 21p is set to B + δ. The local dimming unit 32 outputs the data of the set luminance value to the LED driver 60.

[0032] The LED driver 60 generates a drive current based on the received luminance value data, and supplies the generated drive current to each light source 21. When pulse-driving the light source 21, the local dimming unit 32 may change the duty ratio of the pulse signal based on the luminance value.

[0033] The local dimming unit 32 may further perform general local dimming. Specifically, the local dimming unit 32 may determine the luminance of each of the plurality of light sources based on the video data signal input from the host computer 150 and the sensing result from the touch sensor, and drive the light source 21 with the magnitude of the current corresponding to the determined luminance.

[0034] FIG. 6 is a schematic diagram for explaining local dimming. The video data signal of the image to be displayed has luminance information for each pixel, and the image I displayed on the liquid crystal display panel 11 is based on the luminance information for each pixel of the video data signal. For example, the image I includes a bright region A1 with a luminance value of B1 and a dark region A2 with a luminance value of B2 (B2 < B1) lower than B1. The local dimming unit 32 receives the video data signal and determines the luminance of the plurality of light sources 21 based on the luminance information for each pixel. For example, the luminance value of the light source 21-A1 in the bright region A1 is set to B1', and the luminance value of the light source 21-A2 in the dark region A2 is set to B2' (B2' < B1') lower than B1'. Further, as described above, the luminance value of the light source 21p-A1 at the position corresponding to the detection coordinate P which is the touch position is changed by an amount of change δ from B1'. For example, the luminance value of the light source 21p-A1 is set to B1' + δ. The local dimming unit 32 outputs the data of the set luminance value to the LED driver 60. The LED driver 60 generates a drive current based on the received data of the luminance value and supplies the generated drive current to each light source 21.

[0035] As a result, the light source 21-A1 is lit at a high luminance, and the light source 21-A2 is lit at a low luminance. Also, the luminance value of the light source 21p-A1 is lit at a luminance higher by δ than the surrounding light source 21-A1. By such local dimming, the image can be displayed with high contrast and low power consumption. Also, as described above, the luminance change due to the touch on the screen 11a can be suppressed.

[0036] FIG. 7 is a flowchart showing an example of a control method of the backlight 20 in the display device 101 according to the present embodiment.

[0037] The touch panel 14 detects a touch on the screen 11a, and the touch panel controller 70 determines the detection coordinate P (step S101). The local dimming unit 32 determines the light source 21p whose luminance is to be changed corresponding to the detection coordinate P using the position correspondence information stored in advance (step S102).

[0038] Further, the local dimming unit 32 receives the video data signal of the image to be displayed, and sets the luminance of the plurality of light sources 21 based on the luminance information of each pixel of the video data signal. Further, the luminance of the light source 21p is set so that the luminance change due to touch is suppressed (step S103).

[0039] The local dimming unit 32 outputs the data of the set luminance value to the LED driver 60. The LED driver 60 generates a drive current based on the received data of the luminance value, and supplies the generated drive current to each light source 21 (step S104).

[0040] As described above, according to the present embodiment, in a display device provided with a touch panel, it is possible to suppress the change in luminance due to touch.

[0041] (Second Embodiment) FIG. 8 is a schematic configuration diagram of the display device 102 according to the present embodiment. The display device 102 is different from the first embodiment in that it further includes a pressure sensor 13 in addition to the touch sensor 12. In the present embodiment, the touch sensor 12 and the pressure sensor 13 integrally form a touch panel 14, and the touch panel 14 is disposed on the screen 11a of the liquid crystal display panel 11. The touch panel 14 is an on-cell type or an out-cell type.

[0042] FIG. 9 is a schematic cross-section showing an example of the touch panel 14. The touch panel 14 includes a first substrate 201, a first electrode layer 210 supported by the first substrate 201, a second substrate 202, a second electrode layer 220 supported by the second substrate 202, and an insulating layer 203 positioned between the first electrode layer 210 and the second electrode layer 220. FIG. 10 is a schematic plan view of the first electrode layer 210. FIG. 11 is a schematic plan view of the second electrode layer 220. The cross-section at the position of the line A-A in FIGS. 10 and 11 is shown in FIG. 9.

[0043] The first electrode layer 210 includes a plurality of drive electrodes 211 and a plurality of floating island electrodes 212. Each drive electrode 211 has a shape in which a plurality of rhombus-shaped electrodes are connected in the row direction. The plurality of floating island electrodes 212 are arranged spaced apart from each other and are in a floating state not connected to any potential.

[0044] The second electrode layer 220 includes a plurality of position detection electrodes 221, a plurality of pressure detection electrodes 222, and a plurality of shield electrodes 223. Each position detection electrode 221 has a shape in which a plurality of rhombus-shaped electrodes are connected in the column direction. Also, each pressure detection electrode 222 has a shape in which a plurality of rhombus-shaped electrodes are connected in the column direction. The plurality of position detection electrodes 221 and the plurality of pressure detection electrodes 222 are alternately arranged in the row direction. Each shield electrode 223 extends in the column direction and is arranged between adjacent position detection electrodes 221 and pressure detection electrodes 222.

[0045] The first electrode layer 210 and the second electrode layer 220 face each other with an elastic insulating layer 203 therebetween. Specifically, in a plan view, the drive electrodes 211 of the first electrode layer 210 overlap a part of the pressure detection electrodes 222 of the second electrode layer 220, and the floating island electrodes 212 of the first electrode layer 210 overlap a part of the position detection electrodes 221 of the second electrode layer 220.

[0046] As shown in FIG. 9, when the indicator F contacts the first substrate 201, as indicated by the broken line L1, the drive electrode 211 and the floating island electrode 212 are capacitively coupled with a capacitance C1. At this time, as indicated by the broken line L3, the floating island electrode 212 and the position detection electrode 221 are capacitively coupled with a capacitance C3. Therefore, due to the touch of the indicator F, a combined capacitance of the capacitance C1 and the capacitance C3 is formed, and the signal obtained from the position detection electrode 221 changes.

[0047] Also, as shown by the dashed line L2 in FIG. 9, the drive electrode 211 and the pressure detection electrode 222 are capacitively coupled with a capacitance C2. Here, when a pressure (load) is applied to the first substrate 201 by the indicator F, since the insulating layer 203 is made of an elastic material, the distance between the drive electrode 211 and the pressure detection electrode 222 becomes shorter at the pressed portion. As a result, the capacitance C2 between the drive electrode 211 and the pressure detection electrode 222 increases, and the signal obtained from the pressure detection electrode 222 changes.

[0048] In this embodiment, the touch panel 14 detects the touch position and the touch pressure on the screen 11a by the mutual capacitance method. Specifically, the source driver 50 outputs a drive signal to the drive electrode 211 and receives the sensing results (signal changes) obtained from the position detection electrode 221 and the sensing results (signal changes) obtained from the pressure detection electrode 222. The received sensing results of position detection and pressure detection are input to the touch panel controller 70.

[0049] As described in the first embodiment, the touch panel controller 70 generates touch coordinate data represented by detection coordinates P(xp, yp) as the touch position from the sensing result of position detection, and outputs the generated touch coordinate data to the local dimming unit 32 and the host computer 150. Also, the touch panel controller 70 generates pressure data indicating a pressure value from the sensing result of pressure detection, and outputs the generated pressure data to the local dimming unit 32 and the host computer 150.

[0050] As described in the first embodiment, the local dimming unit 32 determines a light source 21p that changes the luminance corresponding to the detection coordinates P using the position correspondence information stored in advance. The local dimming unit 32 also stores in advance, as pressure correspondence information, the correspondence between the touch pressure and the amount of change in luminance. For example, when the amount of change in luminance increases as the touch pressure value increases, combinations of the pressure value Pn and the amount of change in luminance γn that appears on the screen 10a at that pressure value are stored for a plurality of different pressure values ((Pn, γn) n = 1, 2, 3 ···). The local dimming unit 32 determines the amount of change in luminance γi due to the touch using the pressure correspondence information from the pressure value indicated by the pressure data received from the touch panel controller 70.

[0051] For example, the local dimming unit 32 sets the luminance values of a plurality of light sources 21 to the luminance value B, and changes the luminance value of the light source 21p at the position corresponding to the detection coordinates P, which is determined using the position correspondence information, by the amount of change γi from B. For example, when the luminance of the screen 11a decreases due to a touch, the luminance value of the light source 21p is set to B + γi. The local dimming unit 32 outputs the data of the set luminance value to the LED driver 60. The LED driver 60 generates a drive current based on the received luminance value data and supplies the generated drive current to each light source 21.

[0052] As a result, even when the luminance changes at the touched position on the screen, the luminance of the corresponding light source 21 applied to the position is changed according to the degree of luminance change due to the touch pressure, and the luminance change due to the touch on the screen 11a can be suppressed. In particular, according to the present embodiment, when the degree of luminance change differs depending on the strength of the touch, the backlight is controlled so that the luminance change is more suppressed.

[0053] (Other forms) As described in the above embodiments, the touch panel in the display device of the present disclosure is not limited to a specific driving method, a specific detection method, and a specific structure. As long as the coordinates of the touch position can be obtained from the touch panel, the touch panel may have any structure of an out-cell method, an on-cell method, and an in-cell method, and may also adopt any detection method such as a resistive film method, a capacitance method, an electromagnetic induction method, and an optical method.

[0054] In addition, the sensor electrodes of the touch panel described in the first and second embodiments are merely examples, and the touch sensor electrodes, position detection electrodes, and pressure detection electrodes may have shapes different from those in the above embodiments.

[0055] Moreover, there is no particular limitation on the driving method of the liquid crystal display panel, and a liquid crystal display panel driven by a driving method other than the horizontal electric field mode can also be suitably used in the display device of the present disclosure.

[0056] The display device of the present disclosure can also be described as follows.

[0057] The display device according to the first configuration is a liquid crystal display panel having a screen and displaying an image on the screen, a touch sensor disposed so as to overlap the screen of the liquid crystal display panel and detecting a position touched on the screen, a backlight disposed on the back surface of the liquid crystal display panel and having a plurality of light sources, a controller for controlling the luminance of the backlight, and the controller changes the luminance of the light source at the position corresponding to the touched position among the plurality of light sources based on the sensing result from the touch sensor.

[0058] According to the first configuration, since the luminance of the light source disposed at the position corresponding to the touch position is changed, it is possible to reduce the luminance change caused by the touch.

[0059] In the display device according to the second configuration, in the first configuration, the controller stores in advance position correspondence information indicating the relationship between the detection coordinates of the touch sensor and the light source corresponding to the detection coordinates, and the controller may determine a light source whose luminance is to be changed based on the sensing result from the touch sensor and the position correspondence information.

[0060] The display device according to the third configuration, in the first configuration, further includes a pressure sensor that is disposed so as to overlap the screen of the liquid crystal display panel and detects the pressure of the touch, and the controller may include changing the luminance of the light source corresponding to the touched position by an amount of change corresponding to the pressure of the touch based on the sensing result of the pressure sensor. According to the third configuration, even when the degree of change in luminance varies depending on the pressing strength, it is possible to more appropriately reduce the luminance change caused by the touch.

[0061] The display device according to the fourth configuration, in the third configuration, the controller stores in advance pressure correspondence information indicating the correspondence relationship between the pressure of the touch and the amount of change in luminance, and the controller may determine the amount of change based on the sensing result from the pressure sensor and the pressure correspondence information.

[0062] The display device according to the fifth configuration, in the first configuration, the controller may receive the video data signal of the image to be displayed and determine the luminance of each of the plurality of light sources based on the video data signal and the sensing result from the touch sensor.

[0063] The display device according to the sixth configuration, in the third configuration, the controller may receive the video data signal of the image to be displayed and determine the luminance of each of the plurality of light sources based on the video data signal, the sensing result from the touch sensor, and the sensing result from the pressure sensor.

Explanation of Reference Numerals

[0064] 10… Touch screen, 10a… Screen, 11… Liquid crystal display panel, 12… Touch sensor, 13… Pressure sensor, 14… Touch panel, 20… Backlight, 21… Light source, 30… Controller, 31… Image processing unit, 32… Local dimming unit, 33… Touch synchronization processing unit, 40… Gate driver, 50… Source driver, 60… LED driver, 70… Touch panel controller, 101, 102… Display device, 110, 210… First substrate, 111… Glass substrate, 112… TFT layer, 113… Insulating layer, 114… Pixel electrode, 115, 203… Insulating layer, 116… Touch sensor electrode, 117… Gate bus line, 118… Source bus line, 119… Touch sensor line, 120, 220… Second substrate, 121… Color filter, 122… Glass substrate, 130… Liquid crystal layer, 140… Transparent electrode, 210… First electrode layer, 211… Drive electrode, 212… Floating island electrode, 220… Second electrode layer, 221… Position detection electrode, 222… Pressure detection electrode, 223… Shield electrode

Claims

1. A liquid crystal display panel having a screen and displaying an image on the screen, A touch sensor disposed to overlap the screen of the liquid crystal display panel and detecting a position touched on the screen, A backlight disposed on the back surface of the liquid crystal display panel and having a plurality of light sources, A controller for controlling the brightness of the backlight, comprising The controller changes the brightness of the light source at the position corresponding to the touched position among the plurality of light sources based on the sensing result from the touch sensor. A display device.

2. The controller stores in advance position correspondence information indicating the relationship between the detection coordinates of the touch sensor and the light source corresponding to the detection coordinates, and the controller determines the light source whose brightness is to be changed based on the sensing result from the touch sensor and the position correspondence information. The display device according to claim 1.

3. Further comprising a pressure sensor disposed to overlap the screen of the liquid crystal display panel and detecting the pressure of the touch, The controller changes the brightness of the light source at the position corresponding to the touched position by an amount of change corresponding to the pressure of the touch based on the sensing result from the pressure sensor. The display device according to claim 1.

4. The controller stores in advance pressure correspondence information indicating the correspondence between the pressure of the touch and the amount of change in brightness, and the controller determines the amount of change based on the sensing result from the pressure sensor and the pressure correspondence information. The display device according to claim 3.

5. The controller receives the video data signal of the image to be displayed, Determining the luminance of each of the plurality of light sources based on the video data signal and the sensing result from the touch sensor The display device according to claim 1.

6. The controller receives a video data signal of the image to be displayed, Determining the luminance of each of the plurality of light sources based on the video data signal, the sensing result from the touch sensor, and the sensing result from the pressure sensor The display device according to claim 3.

Images