JP2011107454A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device which detects a position designated by a user on a display panel with higher accuracy. <P>SOLUTION: The display device includes a plurality of pixels 90 arranged in a display panel 30 and a light detection part for detecting illuminance of light made incident on the display panel 30. The light detection part includes a photodiode 52 disposed in the display panel 30, and a photochromic layer 50 disposed in a position where light made incident on a semiconductor layer 44 of the photodiode 52 passes. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a semiconductor device or a display device including a thin film transistor (TFT) and an optical sensor.

  Conventionally, a wide variety of display devices have been developed, one of which is a glasses-type display device. A glasses-type display device is a type of display device in which a display unit such as a liquid crystal display panel or a lens is incorporated in a glasses-type frame, and a user wearing the frame directly views a video or an image displayed on the display unit. is there.

  An example of a glasses-type display device is described in Patent Document 1. The display device of Patent Document 1 is a glasses-type image display device having a function of adjusting the amount of external light. FIG. 9 is a perspective view illustrating the configuration of the video display device 10 of Patent Document 1, and FIG. 10 is a cross-sectional view of the video display device 10.

  As shown in FIGS. 9 and 10, the video display device 10 includes a condenser lens L1, a mirror M1, a half mirror M2, a lens 11, a photochromic thin film 12, a spectacle-type frame 13, a side light shielding panel 14, a liquid crystal panel 15, a back surface. A light 16, a liquid crystal driving circuit 17, an optical sensor 18, and an input jack 19 are provided.

  The video displayed on the liquid crystal panel 15 according to the video signal from the input jack 19 passes through the condenser lens L1, the mirror M1, and the half mirror M2, and is superimposed on the external light incident through the lens 11 to be used by the user. Delivered to. At this time, the intensity of external light is adjusted by the photochromic thin film 12 covering the lens 11. Moreover, the light quantity of external light is measured by the optical sensor 18, and the brightness of the backlight 16 is adjusted according to the measurement result.

  The photochromic thin film 12 is a thin film having a photochromic effect purified by baking a mixture of titanium oxide and a metal oxide. Here, the photochromic effect is a concentration change in response to ultraviolet rays in the range of 300 nm to 400 nm. It is said that it is an effect to cause. Details of a material having photochromic properties including titanium oxide are described in Patent Document 2.

  Patent Documents 3 and 4 include a touch panel type display device that includes an optical sensor in the display device, recognizes that a user's finger or the like has touched the display surface, and specifies and outputs the detection position. Is described.

JP 9-43563 A JP 2009-132858 A JP 2009-093050 A JP 2009-237711 A

  One of optical sensors for measuring the illuminance of external light is an amorphous photosensor (APS). FIG. 11 is a diagram schematically showing a cross-sectional configuration of a portion (photodiode portion 80) where the photodiode 52 is disposed in the liquid crystal panel 15 including the amorphous photosensor. The photodiode 52 is a TFT type photodiode formed in the TFT substrate 40 of the liquid crystal panel 15.

  As shown in FIG. 11, the liquid crystal panel 15 includes a TFT substrate 40, a counter substrate 60 disposed to face the TFT substrate 40, and a liquid crystal layer 70 disposed between the TFT substrate 40 and the counter substrate 60. ing.

  The TFT substrate 40 includes a glass substrate 41, a gate (gate electrode) 42 formed on the glass substrate 41, and a gate laminated on the glass substrate 41 (on the liquid crystal layer 70 side) so as to cover the gate 42. An insulating film 43; a semiconductor layer 44 formed on the gate insulating film 43; a drain (drain electrode) 45 and a source (source electrode) 55 formed so as to cover a part of the semiconductor layer 44; Formed on the first protective film 46 formed to cover the layer 44, the drain 45, and the source 55, the second protective film 47 formed on the first protective film 46, and the second protective film 47. The transparent conductive film 48 and an alignment film 49 formed on the transparent conductive film 48 are provided.

  The gate 42, the gate insulating film 43, the semiconductor layer 44, the drain 45, and the source 55 constitute a photodiode 52. The drain 45 and the gate 42 are electrically connected to each other, and both function as an anode of the diode, and the source 55 functions as a cathode of the diode.

  The TFT substrate 60 includes a glass substrate 61, a black matrix (BM) 62 stacked on the glass substrate 61 (on the liquid crystal layer 70 side), and an alignment film disposed so as to cover the glass substrate 61 and the black matrix 62. 63. Although not shown in FIG. 11, the glass substrate 61 includes a color filter and a counter electrode.

  Incident light 72 incident on the liquid crystal panel 15 from the counter substrate 60 side enters the semiconductor layer 44 of the photodiode 52 through the opening 64 of the black matrix 62, and corresponds to the illuminance of the incident light 72 received by the semiconductor layer 44. Electrons and holes are generated inside the semiconductor layer 44, and the current (Id) flowing from the drain 45 to the source 55 changes. The illuminance (or light amount) of the incident light 72 is measured by measuring the change in the current (or the voltage associated therewith).

  However, it has been found that when the illuminance of light incident on the semiconductor layer 44 exceeds a certain value, a problem that an appropriate output cannot be obtained from the amorphous optical sensor occurs. This is because if the illuminance of light incident on the semiconductor layer 44 is too strong, the threshold value of the diode (transistor) shifts in the + direction. Even if it does not return. Therefore, even if the same amount of light is irradiated before and after the threshold value shifts, the output voltage value differs depending on the detection, and accurate detection cannot be performed.

  FIG. 12 shows changes in the diode characteristics of the photodiode 52. The vertical axis in FIG. 12 represents the current (Id) flowing from the drain 45 to the source 55, and the horizontal axis represents the gate voltage. Further, a in FIG. 12 represents a preferable diode characteristic when the illuminance of light incident on the semiconductor layer 44 is in an appropriate range, and b is when the illuminance of light incident on the semiconductor layer 44 is too strong. It represents undesirable diode characteristics.

  As shown in FIG. 12, when the diode characteristics change, it becomes difficult to accurately measure the illuminance by the amorphous light sensor, and it becomes impossible to accurately grasp the change of the external light (incident light).

  This invention is made | formed in view of said problem, The objective is to provide the display apparatus which can detect the illumination intensity of the light which injects into a display part more correctly.

  A display device according to the present invention includes a plurality of pixels disposed on a display panel, and a light detection unit that detects an illuminance of light incident on the display panel, and the light detection unit is disposed in the display panel. And a photochromic layer disposed at a position where light incident on the semiconductor layer of the photodiode passes.

  In one embodiment, the photochromic layer is disposed so as to cover the semiconductor layer when viewed from a direction perpendicular to the display surface of the display panel.

  In one embodiment, the display panel includes a TFT substrate including a TFT arranged for each of a plurality of pixels arranged in a matrix, a counter substrate arranged to face the TFT substrate, and the TFT substrate. A liquid crystal layer is provided between the counter substrate and the photodiode is formed in the TFT substrate.

  In one embodiment, the counter substrate is disposed so as to cover the TFT, and includes a black matrix that blocks light incident on the TFT substrate, and light incident on the semiconductor layer of the photodiode is incident on the black matrix. The light enters the semiconductor layer through the provided opening.

  In one embodiment, the photodiode is formed in the same layer as the plurality of TFTs in the TFT substrate.

  In one embodiment, each of the photodiodes is arranged to correspond to three of the plurality of pixels.

  In one embodiment, the display device is a touch sensor type display device that detects a position on a display surface designated by a user.

  Note that the display device according to the present invention may include not only a liquid crystal display device but also a display device such as a display device using TFTs as switching elements, and an imaging device.

  ADVANTAGE OF THE INVENTION According to this invention, the change of the diode characteristic by incident light is prevented, and it becomes possible to provide the display apparatus which has an optical sensor with the stable sensitivity.

1 is a perspective view schematically illustrating a configuration of a display device 100 according to an embodiment of the present invention. 3 is a cross-sectional view schematically illustrating a configuration of a touch panel in the display device 100. FIG. 4 is a cross-sectional view schematically showing a configuration of a photodiode portion 80 in the liquid crystal panel 30 in the display device 100. FIG. 4 is a plan view schematically showing a configuration of a liquid crystal panel 30. FIG. 4 is a plan view schematically showing the configuration of an amorphous optical sensor 86 in the liquid crystal panel 30. FIG. 4 is a flowchart showing a method for forming a photochromic layer 50 in an amorphous optical sensor 86. FIG. 6 is a diagram showing the relationship between the illuminance of light incident on a photodiode 52 and the diode characteristics of the photodiode 52. 6 is a diagram showing the relationship between the illuminance of light incident on a photodiode 52 and the output voltage of an amorphous optical sensor 86. FIG. 1 is a perspective view illustrating a configuration of a video display device 10 of Patent Document 1. FIG. 1 is a cross-sectional view of a video display device 10. FIG. 4 is a cross-sectional view schematically showing a configuration of a photodiode portion 80 in the liquid crystal panel 15. FIG. FIG. 6 is a diagram showing changes in diode characteristics of a photodiode 52 in the liquid crystal panel 15

  Hereinafter, a display device according to an embodiment of the present invention will be described with reference to the drawings. However, the scope of the present invention is not limited to the following embodiments.

(Embodiment)
FIG. 1 is a perspective view schematically illustrating the configuration of a touch panel display device 100 according to the embodiment, and FIG. 2 is a cross-sectional view schematically illustrating the configuration of the touch panel in the display device 100.

  The display device 100 is an active matrix type liquid crystal display device. As shown in FIG. 1, a liquid crystal panel (display panel) 30 comprising a TFT substrate 40, a counter substrate (CF substrate) 60, and a liquid crystal layer 70, and a TFT substrate. Polarizing plates 26 and 27 disposed on the outer sides of 40 and the counter substrate 60, and a backlight 28 disposed on the opposite side of the polarizing plate 26 from the TFT substrate 40.

  As will be described later with reference to FIG. 4, a plurality of scanning lines (gate bus lines) Gn and a plurality of signal lines (data bus lines) Sm are arranged on the TFT substrate 40 so as to be orthogonal to each other. . A TFT 92, which is an active element, is formed for each pixel 90 in the vicinity of each intersection of the plurality of scanning lines Gn and the plurality of signal lines Sm. The plurality of scanning lines Gn and the plurality of signal lines Sm are respectively connected to the scanning line driving circuit 22 and the signal line driving circuit 23 shown in FIG. 1, and the scanning line driving circuit 22 and the signal line driving circuit 23 are controlled. The circuit 24 is connected. In accordance with control by the control circuit 24, a scanning signal for switching on / off of the TFT 90 is supplied from the scanning line driving circuit 22 to the scanning line Gn. Further, in accordance with control by the control circuit 24, a display signal (voltage applied to the pixel electrode) is supplied from the signal line driving circuit 23 to the plurality of signal lines Sm.

  As shown in FIG. 2, the liquid crystal panel 30 includes a plurality of pixels 90 and an optical sensor (touch sensor) including a plurality of photodiodes 52 provided adjacent to the plurality of pixels 90 arranged in a matrix. Has been. A light shielding layer 88 is formed on the side of the backlight 28 of the photodiode 52 so that the light 29 irradiated from the backlight 28 to the photodiode 52 is shielded. As the optical sensor, an amorphous optical sensor (light detection unit) 86, which will be described later with reference to FIG. 4, is used.

  Incident light 72 is incident on the photodiode 52 from the counter substrate 60 side. However, when the user's finger touches the display surface or approaches the vicinity of the display surface, the incident light 72 enters the photodiode 52 below the display surface. The light 72 is blocked, and a difference occurs between the illuminance of light incident on the photodiode 52 and the illuminance of light incident on the photodiode 52 at another position. Therefore, the touch position by the user on the display surface is specified by detecting the outputs of the plurality of arranged photodiodes 52. In this way, an optical sensing touch panel is realized.

  FIG. 3 is a cross-sectional view of the liquid crystal panel 30 in a portion (photodiode portion 80) where the photodiode 52 of the optical sensor is formed. Note that the same reference numerals are assigned to the same constituent members or constituent elements having the same functions as those of the liquid crystal panel 15 shown in FIG.

  As shown in FIG. 3, the TFT substrate 40 of the liquid crystal panel 30 includes a glass substrate 41, a gate (gate electrode) 42 formed on the glass substrate 41, and a glass substrate 41 (on the liquid crystal layer 70 side). A gate insulating film 43 laminated to cover the gate 42, a semiconductor layer 44 formed on the gate insulating film 43, and a drain (drain electrode) formed to cover a part of the semiconductor layer 44. 45, the source (source electrode) 55, the first protective film 46 formed so as to cover the semiconductor layer 44, the drain 45, and the source 55, and the second protective film 47 formed on the first protective film 46. A transparent conductive film 48 formed on the second protective film 47, a photochromic layer 50 disposed between the second protective film 47 and the transparent conductive film 48, and the transparent conductive film 48. The alignment film 49 Eteiru.

  The gate 42, the gate insulating film 43, the semiconductor layer 44, the drain 45, and the source 55 constitute a photodiode 52. The photodiode 52 is a TFT type photodiode. The drain 45 and the gate 42 are electrically connected to each other, and both function as an anode of the diode, and the source 55 functions as a cathode of the diode.

  The photochromic layer 50 is a thin film having a photochromic effect formed by baking a mixture of titanium oxide and metal oxide, for example, and changes its concentration according to the illuminance (or light amount) of incident light 72, and its transmittance To change. The photochromic layer 50 is formed and disposed so as to cover the semiconductor layer 44 at a position where the incident light 72 incident on the semiconductor layer 44 passes above the semiconductor layer 44 of the photodiode 52. With such a configuration, all the incident light 72 directed toward the semiconductor layer 44 enters the semiconductor layer 44 after passing through the photochromic layer 50.

  The counter substrate 60 includes a glass substrate 61, a black matrix (BM) 62 laminated on the glass substrate 61 (on the liquid crystal layer 70 side), and an alignment film disposed so as to cover the glass substrate 61 and the black matrix 62. 63. Although not shown in FIG. 3, the glass substrate 61 includes a color filter and a counter electrode.

  Incident light 72 incident on the liquid crystal panel 30 from the counter substrate 60 side enters the semiconductor layer 44 of the photodiode 52 through the opening 64 of the black matrix 62, and the illuminance (or light quantity) of the incident light 72 received by the semiconductor layer 44. ), The current flowing from the drain 45 to the source 55 changes. The illuminance of the incident light 72 is detected by measuring the change in the current (or the voltage associated therewith).

  All of the light incident on the semiconductor layer 44 passes through the photochromic layer 50, but the transmittance of the photochromic layer 50 changes depending on the illuminance of the incident light (the illuminance of light irradiated on the photochromic layer 50). When the illuminance of incident light exceeds a certain value, the color density of the photochromic layer 50 becomes strong, so that the amount of light incident on the semiconductor layer 44 is limited. Thereby, since the change of the diode characteristic of the photodiode 52 is suppressed, an inappropriate signal output from the amorphous optical sensor 86 is prevented.

  FIG. 4 shows the circuit configuration of the TFT substrate 40 in the liquid crystal panel 30 and the arrangement of the black matrix 62. FIG. 5 shows a circuit configuration of the amorphous optical sensor 86.

  As shown in FIG. 4, the liquid crystal panel 30 has a plurality of pixels 90 arranged in a matrix, and the TFT substrate 40 has a plurality of scanning lines (gate bus lines) Gn and a plurality of signal lines (data bus lines). ) Sm are arranged so as to be orthogonal to each other. A TFT 92 that is an active element is formed for each pixel 90 in the vicinity of each intersection of the plurality of scanning lines Gn and the plurality of signal lines Sm. In each pixel, a pixel electrode (transparent conductive film) made of, for example, ITO (Indium Tin Oxide) electrically connected to the drain electrode of the TFT 92 is disposed.

  A storage capacitor line (also called a storage capacitor line or Cs line) Csn is arranged between two adjacent scanning lines Gn in parallel with the scanning line Gn. In each pixel, when a signal (voltage) is supplied from the signal line Sm to the pixel electrode, the auxiliary capacitance Cs is provided between the auxiliary capacitance electrode connected to the auxiliary capacitance line Csn and the auxiliary capacitance counter electrode connected to the pixel electrode. A liquid crystal capacitor C is formed by the pixel electrode and the counter electrode sandwiching the liquid crystal layer 70.

  The plurality of scanning lines Gn and the plurality of signal lines Sm are respectively connected to the scanning line driving circuit 22 and the signal line driving circuit 23 shown in FIG. 1, and the scanning line driving circuit 22 and the signal line driving circuit 23 are control circuits. 24. In accordance with control by the control circuit 24, a scanning signal for switching on / off of the TFT 92 is supplied from the scanning line driving circuit 22 to the scanning line Gn. Further, in accordance with control by the control circuit 24, a display signal (voltage applied to the pixel electrode) is supplied from the signal line driving circuit to the plurality of signal lines Sm.

  The counter substrate 60 includes a color filter and a common electrode. In the case of displaying three primary colors, the color filter includes an R (red) filter, a G (green) filter, and a B (blue) filter, each of which is arranged corresponding to the pixel 90. The common electrode is formed so as to cover the plurality of pixel electrodes. In accordance with the potential difference applied between the common electrode and each pixel electrode, the liquid crystal molecules between both electrodes are aligned for each pixel, and display is performed.

  When viewed perpendicular to the surface of the TFT substrate 40 or the counter substrate 60, the black matrix 62 of the counter substrate 50 is disposed so as to cover the TFT 92. The black matrix 62 basically covers the amorphous light sensor 86, but the opening 64 of the black matrix 62 is formed only on the photodiode 52.

  A plurality of amorphous optical sensors 86 (hereinafter also simply referred to as optical sensors 86) are formed on the TFT substrate 40 so as to correspond to the three pixels 90. Note that the correspondence relationship between the photosensors 86 and the pixels 90 is not limited to this, and when the sensor arrangement density may be low, the photosensors 86 are associated with more than three pixels 90. You may arrange. The output of the optical sensor 86 is used in the same manner as the sensor output by a normal touch panel, for example, for detecting the position or coordinates on the display surface where the user's finger contacts.

  In the TFT substrate 40, the photodiode 52 and the TFT 92 are formed in the same layer. The semiconductor layer 44 of the photodiode 52 and the semiconductor layer of the TFT 92 both include an amorphous silicon layer, and both are formed simultaneously in the same process. Further, the gate 42 of the photodiode 52, the gate electrode of the TFT 92, the scanning line Gn, the wiring Vrstn, and the wiring Vrwn are simultaneously formed in the same process, and the drain 45 and the source 55 of the photodiode 52, and the source electrode and the drain electrode of the TFT 92 are formed. The signal line Sm, the wiring Vsm, and the wiring Vom are formed simultaneously in the same process.

  As shown in FIGS. 4 and 5, the amorphous optical sensor 86 includes a photodiode 52, a capacitor 81 that holds the output of the photodiode 52, and an output amplifier 82 that amplifies the output of the photodiode 52. The drain 45 and the gate 42 of the photodiode 52 are connected to the wiring Vrstn, and the source 55 of the photodiode 52 is connected to one terminal of the capacitor 81 and the base of the output amplifier. The other terminal of the capacitor 81 is connected to the wiring Vrwn. A pair of terminals of the output amplifier 82 are connected to the wiring Vsm and the wiring Vom, respectively, and the output signal of the amorphous optical sensor 86 is supplied to the liquid crystal driving circuit included in the control circuit 24 by both wirings.

  In general, when a transistor is formed on a TFT substrate, the transistor is covered with a black matrix of a counter substrate so that the transistor characteristics do not change due to the influence of external light and the transistor member does not deteriorate. Do not irradiate the transistor directly. However, in this embodiment, the photodiode 52 receives the incident light 72 and operates as an optical sensor. Therefore, the semiconductor layer 44 of the photodiode 52 is not covered with the black matrix 62, and the black on the semiconductor layer 44 is black. An opening 64 of the matrix 62 is formed. However, a photochromic layer 50 is formed on the semiconductor layer 44 in order to prevent light with an illuminance above a certain level from entering the semiconductor layer 44, thereby suppressing fluctuations in diode characteristics.

  Note that the photochromic layer 50 only needs to be formed on the semiconductor layer 44, and is not necessarily disposed between the second protective film 47 and the transparent conductive film 48. The photochromic layer 50 may be formed between the TFT substrate 40 and the liquid crystal layer 70, between the counter substrate 60 and the liquid crystal layer 70, or inside the counter substrate 60. However, if the photochromic layer 50 is formed in the transmissive region of the pixel 90, the backlight is prevented from being transmitted and the display luminance is lowered. Therefore, the photochromic layer 50 is formed avoiding the transmissive region.

  Next, the process of forming the photochromic layer 50 will be described with reference to FIG.

  First, in step S1, a gate 42, a gate insulating film 43, a semiconductor layer 44, a drain 45, a source 55, a first protective film 46, and a second protective film 47 are formed on a glass substrate 41 of the TFT substrate 40. It is formed using a manufacturing method. Next, in step S2, a photochromic solution containing the material of the photochromic layer 50 is applied on the second protective film 47 by a spin coating method. Thereafter, in step 3, the applied photochromic solution is heated and fired to obtain a layer obtained by sintering the photochromic material. Next, in step S <b> 4, this layer is patterned to selectively form a photochromic layer 50 on the semiconductor layer 44. Thereafter, in step S5, a transparent conductive film 48 is formed so as to cover the photochromic layer 50.

  Next, the effects obtained by the display device 100 according to the present embodiment will be described with reference to FIGS.

  FIG. 7 shows the relationship between the illuminance (L) of the incident light 72 incident on the photodiode 52 and the characteristics of the photodiode 52 (threshold shift amount (dM)). The threshold shift means that the threshold value of the transistor (the voltage value at which the transistor starts to operate) changes due to the factor of external light (or long-term application of DC voltage, heat, etc.). The amount (dM) means a change amount of the threshold value before and after the change.

  As shown in FIG. 7, the threshold value does not change when the illuminance of the incident light 72 is smaller than a certain value L1, but when the illuminance of the incident light 72 exceeds L1 (for example, when the illuminance is L2), the threshold value varies. appear. The variation in the threshold value increases as the illuminance of the incident light 72 increases.

  FIG. 8 is a graph showing the relationship (LV characteristics) between the illuminance (L) of the incident light 72 incident on the photodiode 52 and the output voltage (V) of the optical sensor 86. In this graph, Va represents the LV characteristic of the photodiode 52 in which the threshold shift has occurred, and Vb represents the LV characteristic of the photodiode 52 in which no threshold shift has occurred. Yes.

  As shown in FIG. 8, the output voltage of the optical sensor 86 decreases as the illuminance (L) of the incident light 72 increases. However, when the illuminance (L) exceeds a certain level, the decrease in the output voltage (V) stops. . At this time, there is a difference in the decrease in the output voltage (V) between Va and Vb, and Vb shows a voltage value lower than Va. This is because, in the photodiode 52 having the LV characteristic of Va, the threshold value shift causes the sensitivity of the photodiode 52 to light to decrease, and the output voltage (V) of the photosensor 86 decreases accordingly. It is because it becomes difficult to do.

  As described above, when the illuminance of the incident light 72 to the photodiode 52 exceeds a certain value L1, the threshold value of the photodiode 52 is shifted, and accordingly, the sensitivity of the photosensor 86 is lowered. It becomes difficult to accurately specify the detection position based on V).

  According to the display device 100 according to the present invention, since the photochromic layer 50 is disposed on the semiconductor layer 44 of the photodiode 52, incident light 72 incident on the semiconductor layer 44 due to a spontaneous concentration change of the photochromic layer 50. Is prevented from exceeding a certain value. Therefore, the threshold shift of the photodiode 52 and the fluctuation of the characteristics accompanying it are prevented, and the voltage reflecting the accurate detection result is supplied from the amorphous optical sensor 86. This makes it possible to accurately grasp the position specified by the user's finger or the like.

  The present invention relates to a liquid crystal display device including an active matrix substrate having a thin film transistor, an organic electroluminescence (EL) display device, a display device such as an inorganic electroluminescence display device, an imaging device such as a flat panel X-ray image sensor device, and the like. It is suitably used for an image input device such as a contact image input device or a fingerprint reader.

DESCRIPTION OF SYMBOLS 10 Image display apparatus 11 Lens 12 Photochromic thin film 13 Eyeglass-type frame 14 Side light shielding panel 15 Liquid crystal panel 16 Backlight 17 Liquid crystal drive circuit 18 Optical sensor 19 Input jack 22 Scan line drive circuit 23 Signal line drive circuit 24 Control circuit 26, 27 Polarization Plate 28 Backlight 30 Liquid crystal panel 40 TFT substrate 41 Glass substrate 42 Gate 43 Gate insulating film 44 Semiconductor layer 45 Drain 46 First protective film 47 Second protective film 48 Transparent conductive film 49 Alignment film 50 Photochromic layer 52 Photodiode 55 Source 60 Counter substrate 61 Glass substrate 62 BM (Black matrix)
63 Alignment film 64 Aperture 70 Liquid crystal layer 72 Incident light 80 Photodiode part 81 Capacitor 82 Output amplifier 86 Amorphous photosensor (APS)
88 shading layer 90 pixels 92 TFT
100 Display device

Claims (7)

A plurality of pixels arranged on the display panel;
A light detection unit that detects the illuminance of light incident on the display panel,
The light detection unit includes a photodiode disposed in the display panel, and a photochromic layer disposed at a position where light incident on a semiconductor layer of the photodiode passes.   The display device according to claim 1, wherein the photochromic layer is disposed so as to cover the semiconductor layer when viewed from a direction perpendicular to a display surface of the display panel. The display panel includes a TFT substrate including TFTs arranged for each of a plurality of pixels arranged in a matrix, a counter substrate arranged to face the TFT substrate, and the TFT substrate and the counter substrate. With a liquid crystal layer arranged in between,
The display device according to claim 2, wherein the photodiode is formed in the TFT substrate. The counter substrate is disposed so as to cover the TFT, and includes a black matrix that blocks incident light on the TFT substrate,
The display device according to claim 3, wherein light incident on the semiconductor layer of the photodiode enters the semiconductor layer through an opening provided in the black matrix.   The display device according to claim 3, wherein the photodiode is formed in the same layer as the plurality of TFTs in the TFT substrate.   6. The display device according to claim 1, wherein each of the photodiodes is disposed so as to correspond to three of the plurality of pixels.   The display device according to claim 1, wherein the display device is a touch sensor type display device that detects a position on a display surface designated by a user.

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