JPH05281516A - Active matrix input-output device - Google Patents

Abstract

PURPOSE:To provide an active matrix input-output device capable of acting as an input device as well as acting as a display device. CONSTITUTION:One end of gate bus lines X1 to Xm is connected with a gate driver 11, respectively, and one end of source bus lines Y1 to Yn is connected with a source driver 12 respectively. The other end of the gate bus lines X1 to Xm is connected with a controller 13 through a detecting circuit 14 respectively. The other end of the source bus lines Y1 to Yn is connected with the controller 13 through a detecting circuit 15, respectively. A gate driver 11 and a source driver 12 are connected with a controller, respectively. A picture element includes a liquid crystal layer 16 is arranged in matrix form. For every each picture element, a parallel circuit of the electrode of the liquid crystal layer 16 and an accumulation capacity 17 is connected with TFT 18 for driving the picture element. For every each picture element, an MIS diode 19 which is a photosensitive element is connected in parallel with TFT 18. One end of the MIS diode 19 is connected with the gate bus lines.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active matrix input / output device having a function as an input device in addition to a function as a display device.

[0002]

2. Description of the Related Art FIG. 11 is a circuit diagram of a conventional active matrix display device. FIG. 12 is a plan view of the substrate of the active matrix display device of FIG. 13 is shown in FIG.
2 is a cross-sectional view taken along line AA of FIG.

As shown in FIG. 11, the conventional active matrix display device is arranged such that the gate bus lines X _{1 to} X _m and the source bus lines Y _{1 to} Y _n are orthogonal to each other. The gate bus lines X _{1 to} X _m are connected to the gate driver 201, and the source bus lines Y ₁ to X _m are connected.
Y _n is connected to the source driver 202.

Gate driver 201 and source driver 20
2 are connected to the controller 203, respectively.

The picture elements 204 are arranged in a matrix, and a parallel circuit of the picture element 204 and the storage capacitor 205 is connected to a thin film transistor (TFT) 206 for each picture element.

In FIG. 12, reference numerals 211 and 212 denote gate bus lines and source bus lines which are orthogonal to each other. Reference numerals 213 and 214 are lines for storage capacitors and storage capacitors. The pixel electrodes 215 are arranged in a matrix. The TFT 216 made of amorphous silicon (a-Si) has a gate electrode 217 and a drain electrode 21.
8 and a source electrode 219 are provided.

As shown in FIG. 13, the conventional active matrix display device includes glass substrates 221 and 222.

A gate electrode 223, a gate insulating film 224 made of tantalum oxide (Ta ₂ O ₅ ), a gate insulating film 225, and a pixel electrode are formed on a glass substrate 221 on which a TFT 240 is formed.
226, alignment film 227, drain electrode 228, source electrode 229
, N-type amorphous silicon (a-Si (n ⁺ )) layer 2
30 and 231, a semiconductor layer 232 made of a-Si, and a protective film 233 are provided.

A glass substrate facing the glass substrate 221
222 above the black stripe 234, color filter
235, a counter electrode 236 and an alignment film 237 are provided.

A liquid crystal layer 238 is formed by injecting liquid crystal between the two substrates on which the electrodes, layers, films, etc. are thus formed and sealing with a sealing resin.

In such a configuration, the storage capacitor 205 improves the off characteristics of the TFT 206 and the deterioration of the contrast due to the off resistance of the liquid crystal. Crosstalk is reduced, and the number of scanning lines is not limited. Therefore, as compared with the simple matrix type, a display with a large capacity and high image quality can be obtained.

[0012]

Such a conventional active matrix display device has only a function as a display device, and does not have a function as a signal input device.

For this reason, when this active matrix display device is used as a display device for a word processor, a computer, etc., it is general to input information from the outside usually via a keyboard. In this case, in order to perform processing in conjunction with the display screen on the display screen, an additional input work from a keyboard, a mouse, a track board, or the like is required, and there is a problem that the work becomes complicated.

Further, in order to make an input on the display screen,
It is necessary to install a touch panel or the like having a configuration that can be overlapped with the display device, and there is a problem that a new device such as a touch panel must be prepared.

Accordingly, it is an object of the present invention to provide an active matrix input / output device which can function not only as a display device but also as an input device.

[0016]

A plurality of picture elements each having an electrode, a drive element for driving the plurality of picture elements, a plurality of signal lines arranged in a row or column direction, and a plurality of signal lines A plurality of scanning lines arranged to intersect the signal line of
A photosensitive element that is connected to a plurality of signal lines and a plurality of scanning lines and that converts light from the outside into an electric signal, and a detection means for detecting changes in signals passing through the plurality of signal lines and the plurality of scanning lines. It has and.

[0017]

According to the signals from the plurality of scanning lines, the voltage is applied to the electrodes of the plurality of picture elements by connecting the signal lines corresponding to the electrodes of the plurality of picture elements, and the picture elements are optically The image is displayed after being modulated. In addition, in a plurality of picture elements irradiated with light from the outside in a state where the driving element is turned on and off by a scanning signal, a photocurrent flows and signals on a plurality of signal lines and a plurality of scanning lines change. The detection means detects this signal change by extracting it from each of the plurality of signal lines and the plurality of scanning lines. Therefore, not only the function as the display device but also the function as the input device can be achieved.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a circuit diagram of a first embodiment when an active matrix input / output device according to the present invention is applied to a liquid crystal display device.

As shown in the figure, in the liquid crystal display device of this embodiment, the gate bus lines X _{1 to} X _m and the source bus lines Y _{1 to} Y _n are arranged so as to be orthogonal to each other.

_One ends of the gate bus lines X _{1 to} X _m are connected to the gate driver 11, respectively, and _one ends of the source bus lines Y _{1 to} Y _n are connected to the source driver 12, respectively.

[0022] The other end of the gate bus line X ₁ ~X _m, the gate bus line X ₁ ~ input from the gate driver 11
Each is connected to the controller 13 via a detection circuit 14 that detects a change in a signal passing through X _m . The other end of the source bus lines Y ₁ to Y _n are connected to the controller 13 via the detection circuit 15 for detecting a change in a signal passing through the source bus line Y ₁ to Y _n inputted from the source driver 12 ..

Gate driver 11 and source driver 12
Are respectively connected to the controller 13.

The picture elements including the liquid crystal layer 16 are arranged in a matrix, and for each picture element, a parallel circuit of the electrodes of the liquid crystal layer 16 and the storage capacitor 17 is an amorphous material for driving the picture elements. It is connected to the TFT 18 made of silicon (a-Si).

In addition, in parallel with the TFT 18 for each picture element, a metal-insulating film-semiconductor (M
IS) diode 19 is connected.

One end of the MIS diode 19 is connected to the gate bus line.

MI, which is a photosensitive element provided in each picture element
When the S-diode 19 is irradiated with spot-shaped light from the outside, an internal electric field is generated inside the S-diode 19 due to the generation of photocarriers by the incident light. Therefore, a photocurrent flows in the picture element which is irradiated with light in a state in which the TFT 18 is turned on and off by the scanning signal, and a photocurrent flows, so that the gate bus lines X _{1 to} X _m and the source bus lines Y _{1 to} Y _n are exposed. Signal changes. This signal change is taken out from the output terminal of each bus line, and the detection circuits 14 and 1
5, respectively.

The picture element containing the liquid crystal layer 16 is one embodiment of the plurality of picture elements of the present invention. The detection circuits 14 and 15 are an example of the detection means of the present invention. The TFT 18 is an example of the driving element of the present invention. The MIS diode 19 is an embodiment of the photosensitive element of the present invention. Gate bus line X _{1 to} X
_m is an embodiment of the plurality of scan lines of the present invention. Source bus lines Y ₁ to Y _n is one embodiment of a plurality of signal lines of the present invention.

FIG. 2 is a plan view of a substrate for explaining the structure of a photosensitive element included in the active matrix input / output device according to the present invention.

In the figure, reference numerals 21 and 22 are a source bus line and a gate bus line which are orthogonal to each other. Reference numerals 23 and 29 are lines for storage capacitors and storage capacitors. The pixel electrodes 24 are connected to the source bus lines 21 via the TFTs 25 and arranged in a matrix. The TFT 25 is provided with a gate electrode 26 and a drain electrode 27.

Since the photosensitive element 28 is used as the semiconductor layer of the MIS diode similarly to the slightly n-type semiconductor a-Si used in the TFT 25, it can be formed simultaneously with the TFT 25. In order to obtain photosensitivity, the photosensitive element 28 does not include a metal layer that is a source / drain electrode. The electrodes are a transparent electrode and n-type amorphous silicon (a) doped with phosphorus (P) for n-type.
-Si (n ⁺ )) layer is used.

FIG. 3 is a sectional view taken along line BB of FIG. 2 showing the structure of the active matrix input / output device according to the present invention.

As shown in the figure, the active matrix input / output device of this embodiment has glass substrates 31 and 42, a gate electrode 32, gate insulating films 33 and 55 made of tantalum oxide (Ta ₂ O ₅ ), and silicon nitride. A gate insulating film 34 made of (SiN _x ), semiconductor layers 35 and 51 made of a-Si, source / drain electrodes 36, a-Si (n ⁺ ) layers 37 and 53,
SiN _x layers 38 and 58, pixel electrodes 39, alignment films 40 and 46, S
iN _x protective films 41 and 57, a color filter 43, black stripe layers 44 and 59, a transparent electrode 45, a liquid crystal layer 47,
It has a gate bus line 56 and a hole 60 for incident light.

The gate electrode 32 and the gate bus line 56 formed on the transparent glass substrate 31 are made of tantalum (Ta), and the surfaces of the gate electrode 32 and the gate bus line 56 are oxidized by the anodic oxidation method. Gate insulating films 33 and 55 made of Ta ₂ O ₅ are formed respectively.

Glass substrate 31 and gate insulating films 33 and 55
On top, SiN is formed by plasma enhanced chemical vapor deposition (CVD).
_A gate insulating film 34 made of _x is formed, and the gate insulating film 34 forms a two-layer gate insulating film together with the gate insulating films 33 and 55.

A semiconductor layer 35 made of a-Si is formed on the gate insulating film 34 above the gate electrode 32 and the gate insulating film 33.
A semiconductor layer 51 made of a-Si is formed on the gate insulating film 34 above the gate bus line 56 and the gate insulating film 55 by the plasma CVD method.

The gate insulating film 34 and the a-Si (n ⁺ ) layer 37
Source / drain electrodes made of titanium (Ti)
36 is formed, and the a-Si (n ⁺ ) 37 is the semiconductor layer 35.
And the source / drain electrode 36 by plasma CVD.

The channel portion is provided with SiN _x layers 38 and 58 in order to suppress damage during the manufacturing process.

The pixel electrode 39 is a transparent electrode and is made of tin-doped indium oxide (ITO).

Source / drain electrodes 36 constituting the TFT
A protective film 41 made of SiN _x is formed on the top.

On the side opposite to the glass substrate 31, on the transparent glass substrate 42, a color filter 43, black stripe layers 44 and 59 made of chrome (Cr) serving as a light shielding layer, and ITO. A transparent electrode 45 is formed.

The glass substrate 31 side on which the TFT is formed,
Also, on both of the glass substrate 42 side where the transparent electrode 45 which is the counter electrode is formed, alignment films 40 and 46 are formed respectively, and liquid crystal is injected between both substrates and sealed with a sealing resin. As a result, the liquid crystal layer 47 is formed.

A hole 60 for transmitting light is provided in a portion of the black stripe facing the photosensitive element.

In this embodiment, an a-Si TFT was used as the active element, but in addition to this, a polysilicon TFT, a crystalline silicon TFT, a TFT using a compound semiconductor such as CdSe, a diode, and a PINa-Si diode are used. The same input / output device can be realized by using it.

Therefore, according to the above-mentioned embodiment of the active matrix input / output device, it is possible to perform not only the function as the display device but also the function as the input device.

FIG. 4 is a circuit diagram of a second embodiment when the active matrix input / output device according to the present invention is applied to a liquid crystal display device.

As shown in the figure, in the liquid crystal display device of this embodiment, the gate bus lines X _{1 to} X _m and the source bus lines Y _{1 to} Y _n are arranged so as to be orthogonal to each other.

_One ends of the gate bus lines X _{1 to} X _m are connected to the gate driver 61, respectively, and _one ends of the source bus lines Y _{1 to} Y _n are connected to the source driver 62, respectively.

The gate bus the other end of the line X ₁ ~X _m, the gate bus line X ₁ ~ input from the gate driver 61
Each is connected to a counter circuit 66 via a detection circuit 64 that detects a change in a signal passing through X _m .

The other ends of the source bus lines Y _{1 to} Y _n are connected to the source bus lines Y ₁ to Y _n input from the source driver 62.
Each is connected to a counter circuit 66 via a detection circuit 65 that detects a change in a signal passing through Y _n .

The gate driver 61, the source driver 62, the counter circuit 66 and the feedback circuit 67 are connected to the controller 63, respectively.

The counter circuit 66 is constructed so that it can detect the positions of the picture elements arranged in a matrix with reference to a predetermined start signal.

The feedback circuit 67 is configured to feed back the signal to the input side of the bus line, that is, the gate driver 61 and the source driver 62, in order to correct the disturbance of the signal passing through the bus line due to light irradiation.

The picture elements including the liquid crystal layer 68 are arranged in a matrix, and for each picture element, a parallel circuit of the electrode of the liquid crystal layer 68 and the storage capacitor 69 is used to drive the picture element. -Si
Connected to the TFT 70.

In addition, a MIS diode 71 made of a-Si which is a photosensitive element is connected in parallel with the TFT 70 for each picture element.

One end of the MIS diode 71 is connected to the gate bus line.

MI, which is a light-sensitive element provided in each picture element
When the S-diode 71 is irradiated with spot-shaped light from the outside, an internal electric field is generated inside the S-diode 71 due to the generation of photocarriers due to the incident light. Therefore, a photocurrent flows in the picture element which is irradiated with light in a state where the TFT 70 is turned on and off by the scanning signal, and a photocurrent flows, which causes the gate bus lines X _{1 to} X _m and the source bus lines Y _{1 to} Y _{n to} move. Signal changes. This signal change is taken out from the output terminal of each bus line and detected by the detection circuits 64 and 65, respectively.

The picture element containing the liquid crystal layer 68 is one embodiment of the plurality of picture elements of the present invention. The detection circuits 64 and 65 are an embodiment of the detection means of the present invention. The TFT 70 is an example of the driving element of the present invention. The MIS diode 71 is an embodiment of the photosensitive element of the present invention. Gate bus line X _{1 to} X
_m is an embodiment of the plurality of scan lines of the present invention. Source bus lines Y ₁ to Y _n is one embodiment of a plurality of signal lines of the present invention. The counter circuit 66 is an embodiment of the position detecting means of the present invention. The feedback circuit 67 is an embodiment of the feedback means of the present invention.

Although a-SiTFTs are used as active elements in this embodiment, polysilicon TFTs, crystalline silicon TFTs, TFTs using compound semiconductors such as CdSe, diodes, and PINa-Si diodes are also used. The same input / output device can be realized by using it.

Therefore, according to the above-described embodiment of the active matrix input / output device, not only the function as the display device but also the function as the input device can be achieved. Further, according to this embodiment, the feedback circuit 67 is provided, and the feedback circuit 67 feeds back the correction signal to the gate driver 61 and the source driver 62 in order to correct the disturbance of the signal passing through the bus line due to irradiation. With this configuration, it is possible to suppress the influence on the display due to the disturbance of the signal passing through the bus line.

FIG. 5 is a circuit diagram of a third embodiment in which the active matrix input / output device according to the present invention is applied to a liquid crystal display device.

As shown in the figure, in the liquid crystal display device of this embodiment, the gate bus lines X _{1 to} X _m and the source bus lines Y _{1 to} Y _n are arranged so as to be orthogonal to each other.

_One ends of the gate bus lines X _{1 to} X _m are connected to the gate driver 81, respectively, and _one ends of the source bus lines Y _{1 to} Y _n are connected to the source driver 82, respectively.

[0064] The other end of the gate bus line X ₁ ~X _m, the gate bus line X ₁ is input from the gate driver 81 to
Each of them is connected to a controller 83 via a detection circuit 84 which detects a change in a signal passing through X _m . The other end of the source bus lines Y ₁ to Y _n are connected to the controller 83 via the detection circuit 85 for detecting a change in a signal passing through the source bus line Y ₁ to Y _n inputted from the source driver 82 ..

Gate driver 81 and source driver 82
Are respectively connected to the controller 83.

The picture elements including the liquid crystal layer 86 are arranged in a matrix, and for each picture element, a parallel circuit of the electrodes of the liquid crystal layer 86 and the storage capacitor 87 is used to drive the picture elements. -Si
Is connected to the TFT 88.

In addition, a MIS diode 89 made of a-Si which is a photosensitive element is connected in parallel with the TFT 88 for each picture element.

One end of the MIS diode 89 is connected to the source bus line.

MI, which is a photosensitive element provided in each picture element
When the S-diode 89 is irradiated with spot-shaped light from the outside, an internal electric field is generated inside the S-diode 89 due to the generation of photocarriers by the incident light. Therefore, a photocurrent flows in the picture element which is irradiated with light in a state where the TFT 88 is turned on and off by the scanning signal, and a photocurrent flows, so that the gate bus lines X _{1 to} X _m and the source bus lines Y _{1 to} Y _n are exposed. Signal changes. This signal change is taken out from the output terminal of each bus line and detected by the detection circuits 84 and 85, respectively.

The picture element containing the liquid crystal layer 86 is one embodiment of the plurality of picture elements of the present invention. The detection circuits 84 and 85 are an embodiment of the detection means of the present invention. The TFT 88 is an example of the driving element of the present invention. The MIS diode 89 is an example of the photosensitive element of the present invention. Gate bus line X _{1 to} X
_m is an embodiment of the plurality of scan lines of the present invention. Source bus lines Y ₁ to Y _n is one embodiment of a plurality of signal lines of the present invention.

FIG. 6 is a substrate plan view for explaining the structure of the photosensitive element included in the active matrix input / output device according to the present invention.

In the figure, reference numerals 91 and 92 denote a gate bus line and a source bus line which are orthogonal to each other. Reference numerals 93 and 99 are a storage capacity line and a storage capacity. The picture element electrodes 94 are connected to the source bus lines 92 via the TFTs 95 and arranged in a matrix. A source / drain electrode 96 is provided on the TFT 95.

Since the photosensitive element 98 is used as the semiconductor layer of the MIS diode similarly to the slightly n-type semiconductor a-Si used in the TFT 95, it can be formed simultaneously with the TFT 95. In order to obtain photosensitivity, the photosensitive element 98 does not include a metal layer that is a source / drain electrode, and the transparent electrode and the n-type phosphorus (P) -doped a-Si (n ⁺ ) are used as electrodes. Layers and are used.

FIG. 7 is a sectional view taken along line CC of FIG. 6 showing the configuration of the active matrix input / output device according to the present invention.

As shown in the figure, the active matrix input / output device of this embodiment has glass substrates 101 and 102,
Gate electrode 103, gate insulating film 104 made of Ta ₂ O ₅
, SiN _x protective film 105, a-Si semiconductor layer 106, SiN _x gate insulating film 107, a-
Si (n ⁺ ) layer 108, transparent electrodes 109 and 113, source electrode 110, ITO electrode 111, black stripe layer 112,
Alignment films 114 and 115, liquid crystal layer 116, and holes for incident light
It has 117.

The gate electrode 103 formed on the transparent glass substrate 101 is made of Ta, and the gate insulating film 104 made of Ta ₂ O ₅ oxidized by the anodic oxidation method is formed on the surface of the gate electrode 103, respectively. Has been formed.

On the gate insulating film 104 on the side of the photosensitive element 120, a semiconductor layer 106 made of a-Si is formed by the plasma CVD method.

On the semiconductor layer 106, a gate insulating film 107 made of SiN _x , an a-Si (n ⁺ ) layer 108, and ITO.
A transparent electrode 109 made of SiN _x is sequentially formed, and a protective film 105 made of SiN _x is further formed on the transparent electrode 109.

The gate insulating film 107 and the gate insulating film 104 form a two-layer gate insulating film.

A source electrode 110 made of Ti and a transparent ITO electrode 111 are formed on the gate electrode 103 on the TFT side.

The gate insulating film 107 made of SiN _x formed in the channel portion is also effective for suppressing damage during the manufacturing process.

On the side opposite to the glass substrate 101, on the transparent glass substrate 102, C which functions as a light shielding layer is provided.
A black stripe layer 112 made of r and a transparent electrode 113 made of ITO are formed.

Glass substrate 101 on which TFT is formed
On both the side and the glass substrate 102 side on which the transparent electrode 113 which is the counter electrode is formed, alignment films 114 and 115 are formed respectively, and liquid crystal is injected between both substrates and sealed with a sealing resin. By being stopped, the liquid crystal layer 116 is formed.

A hole 117 for transmitting light is provided on the side facing the light sensitive element 120.

Although a-SiTFTs are used as active elements in this embodiment, polysilicon TFTs, crystalline silicon TFTs, TFTs using compound semiconductors such as CdSe, diodes, and PINa-Si diodes are also used. The same input / output device can be realized by using it.

Therefore, according to the above-described embodiment of the active matrix input / output device, not only the function as the display device but also the function as the input device can be achieved.

Further, as the conventional light receiving element, a charge coupled element (CCD), an image pickup element and the like can be mentioned, but it is difficult to increase the size of any of these elements from the viewpoint of cost and has not been put to practical use. However, according to the above-described embodiment, not only the function as the display device but also the function as the input device can be achieved at the same time, so that the screen size can be increased.

FIG. 8 is a circuit diagram of a fourth embodiment when the active matrix input / output device according to the present invention is applied to a liquid crystal display device.

As shown in the figure, in the liquid crystal display device of this embodiment, the gate bus lines X _{1 to} X _m and the source bus lines Y _{1 to} Y _n are arranged so as to be orthogonal to each other.

_One ends of the gate bus lines X _{1 to} X _m are respectively connected to the gate driver 131, and _one ends of the source bus lines Y _{1 to} Y _n are respectively connected to the source driver 132.

The other ends of the gate bus lines X _{1 to} X _m are connected to the gate bus line X ₁ input from the gate driver 131.
It is connected to the controller 133 via the detection circuit 134 for detecting a signal change through to X _m. The other end of the source bus lines Y ₁ to Y _n via the detection circuit 135 for detecting a change in a signal passing through the source bus line Y ₁ to Y _n inputted from the source driver 132 Controller 133
Respectively connected to.

Gate driver 131 and source driver 13
2 are connected to the controller 133, respectively.

The picture elements including the liquid crystal layer 136 are arranged in a matrix, and a storage capacitor 137 and a MIS diode 139 made of a-Si which is a photosensitive element are connected in series for each picture element. And this series connected storage capacitor 13
7 and the MIS diode 139 and the parallel circuit of the electrodes of the liquid crystal layer 136 are made of a-Si for driving the picture elements.
It is connected to the FT138.

When the spot light from the outside is applied to the MIS diode 139, an internal electric field is generated inside the MIS diode 139 due to the generation of photocarriers by the incident light. Therefore, a photocurrent flows in the picture element which is irradiated with light in a state in which the TFT 138 is turned on and off by the scanning signal, and a photocurrent flows on the pixel bus lines X _{1 to} X _m and the source bus lines Y _{1 to} Y _n . Signal changes. Extract this signal change from the output terminal of each bus line,
The detection circuits 134 and 135 respectively detect.

In this embodiment, since the storage capacitor 137 is connected as the load of the TFT 138 by the light irradiation, the input signal of the source or the gate is dulled by the increase of the bus line load (capacity). There is a possibility that it will end up. To avoid this, the detection circuits 134 and 135 may be connected to the input sides of the gate driver 131 and the source driver 132, respectively.

The picture element containing the liquid crystal layer 136 is one embodiment of the plurality of picture elements of the present invention. The detection circuits 134 and 135 are an embodiment of the detection means of the present invention. The storage capacity 137 is an embodiment of the storage capacity of the present invention. The TFT 138 is an example of the driving element of the present invention. The MIS diode 139 is an embodiment of the photosensitive element of the present invention. Gate bus lines X ₁ to X _m is one embodiment of a plurality of scan lines of the present invention.
Source bus lines Y ₁ to Y _n is one embodiment of a plurality of signal lines of the present invention.

FIG. 9 is a plan view of a substrate for explaining the structure of a photosensitive element included in the active matrix input / output device according to the present invention.

In the figure, reference numerals 141 and 142 denote a gate bus line and a source bus line which are orthogonal to each other. Reference numeral 143 is a storage capacity. Picture element electrode 14
4 are connected to the source bus line 142 via the TFT 145 and arranged in a matrix. TFT145
A gate electrode 146 is provided in the.

The photosensitive element 147 includes a semiconductor layer 148 made of a-Si and an a-Si (n ⁺ ) layer 149. Since the photosensitive element 147 is used as the semiconductor layer of the MIS diode similarly to the slightly n-type semiconductor a-Si used in the TFT 145, it can be formed simultaneously with the TFT 145. In order to obtain photosensitivity, the photosensitive element 147 does not include a metal layer that is a source / drain electrode, and the electrode is a transparent electrode and a-Si (n ⁺ ) doped with n-type phosphorus (P). Layers and are used.

FIG. 10 is a sectional view taken along line DD in FIG. 9 showing the structure of the active matrix input / output device according to the present invention.

As shown in the figure, the active matrix input / output device of this embodiment has glass substrates 151 and 152,
Gate electrode 153, gate insulating film 154 made of Ta ₂ O ₅
, A gate insulating film 155 made of SiN _x , a semiconductor layer 156 made of a-Si, transparent electrodes 157, 158 and 165, a-
Si (n ⁺ ) layers 159 and 161, protective film made of SiN _x
160, alignment films 162 and 166, a color filter 163, a black stripe layer 164, a liquid crystal layer 167, and a hole 168 for incident light.

The gate electrode 153 formed on the transparent glass substrate 151 is made of Ta, and the gate insulating film 154 made of Ta ₂ O ₅ oxidized by the anodic oxidation method is formed on the surface of the gate electrode 153, respectively. Has been formed.

A gate insulating film 155 made of SiN _x is formed on the glass substrate 151 and the gate insulating film 154 by the plasma CVD method. The gate insulating film 155 is a two-layer gate insulating film together with the gate insulating film 154. Is forming.

The gate insulating film 155 in the portion of the photosensitive element 170
A semiconductor layer 156 made of a-Si is formed on the upper surface of the plasma CV.
It is formed by the D method.

A transparent electrode 157 made of ITO is formed on the gate insulating film 155 near the pixel electrode 171.

A transparent electrode 158 made of ITO is formed on the gate insulating film 155 in the storage capacitor 172 portion.

An a-Si (n ⁺ ) layer 159 is formed on the portion where the gate insulating film 155 and the semiconductor layer 156 are laminated, and the transparent electrode 157 is formed from the portion of the pixel electrode 171 to a. It extends above the —Si (n ⁺ ) layer 159.

On the transparent electrode 157 and the semiconductor layer 156,
A protective film 160 made of SiN _x is formed.

Between the semiconductor layer 156 and the transparent electrode 158,
An a-Si (n ⁺ ) layer 161 is formed.

An alignment film 162 is formed on the transparent electrode 158 in the storage capacitor 172.

On the side facing the glass substrate 151, on the transparent glass substrate 152, a color filter 163 and a black stripe layer made of Cr which functions as a light shielding layer.
164 and a transparent electrode 165 made of ITO are formed.

Glass substrate 151 on which TFTs are formed
And the glass substrate 152 side on which the transparent electrode 165 which is a counter electrode is formed, alignment films 162 and 166 are formed respectively, and liquid crystal is injected between both substrates and sealed with a sealing resin. The liquid crystal layer 167 is formed by being stopped.

Photosensitive element 170 of black stripe 164.
A hole 168 for transmitting light is provided in a portion facing to.

In this embodiment, the a-Si TFT was used as the active element, but in addition to this, a polysilicon TFT, a crystalline silicon TFT, a TFT using a compound semiconductor such as CdSe, a diode, and a PINa-Si diode are used. The same input / output device can be realized by using it.

Therefore, according to the above-described embodiment of the active matrix input / output device, not only the function as the display device but also the function as the input device can be achieved.

Further, as a conventional light receiving element, a CCD, an image pickup element and the like can be mentioned, but it is difficult to increase the size of any of these elements from the viewpoint of cost and they have not been put to practical use.
However, according to the above-described embodiment, not only the function as the display device but also the function as the input device can be achieved at the same time, so that the screen size can be increased.

[0117]

As described above, according to the present invention, a plurality of picture elements each having an electrode, a driving element for driving the plurality of picture elements, and a plurality of driving elements arranged in the row or column direction are provided. Signal lines, a plurality of scanning lines arranged to intersect the plurality of signal lines, and a photosensitivity connected to the plurality of signal lines and the plurality of scanning lines to convert light from the outside into an electric signal. Since the device and the detection means for detecting the change of the signal passing through the plurality of signal lines and the plurality of scanning lines are provided,
Not only the function as the display device but also the function as the input device can be achieved.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a first embodiment when an active matrix input / output device according to the present invention is applied to a liquid crystal display device.

FIG. 2 is a plan view of a substrate for explaining the configuration of a photosensitive element included in the active matrix input / output device according to the present invention.

FIG. 3 is a sectional view taken along line BB of FIG. 2 showing the configuration of the active matrix input / output device according to the present invention.

FIG. 4 is a circuit diagram of a second embodiment when the active matrix input / output device according to the present invention is applied to a liquid crystal display device.

FIG. 5 is a circuit diagram of a third embodiment when the active matrix input / output device according to the present invention is applied to a liquid crystal display device.

FIG. 6 is a substrate plan view for explaining a configuration of a photosensitive element included in the active matrix input / output device according to the present invention.

7 is a cross-sectional view taken along the line CC of FIG. 6 showing the configuration of the active matrix input / output device according to the present invention.

FIG. 8 is a circuit diagram of a fourth embodiment when the active matrix input / output device according to the present invention is applied to a liquid crystal display device.

FIG. 9 is a plan view of a substrate for explaining the configuration of a photosensitive element included in the active matrix input / output device according to the present invention.

10 is a cross-sectional view taken along the line DD of FIG. 9 showing the configuration of the active matrix input / output device according to the present invention.

FIG. 11 is a circuit diagram of a conventional active matrix display device.

12 is a plan view of a substrate of the active matrix display device of FIG.

13 is a cross-sectional view taken along the line AA of FIG.

[Explanation of symbols]

11, 61, 81, 131 Gate driver 12, 62, 82, 132 Source driver 13, 63, 83, 133 Controller 14, 15, 64, 65, 84, 85, 134, 135 Detection circuit 16, 47, 68, 86 , 116, 136, 167 Liquid crystal layer 17, 29, 69, 87, 99, 137, 143, 172 Storage capacity 18, 25, 70, 88, 95, 138, 145 TFT 19, 71, 89, 139 MIS diode 21, 92, 142, Y _{1 to} Y _n source bus lines 22, 56, 91, 141, X _{1 to} X _m gate bus lines 23, 93 storage capacitance lines 24, 39, 94, 144, 171 pixel electrodes 26, 32 , 103, 146, 153 Gate electrode 27 Drain electrode 28, 98, 120, 147, 170 Photosensitive element 31, 42, 101, 102, 151, 152 Glass substrate 33, 34, 55, 104, 107, 154, 155 Gate Insulating films 35, 51, 106, 148, 156 Semiconductor layers 36, 96 Source / drain electrodes 37, 53, 108, 149, 159, 161 a-Si (n ⁺ ) layers 38, 58 SiN _x layers 40, 46, 114 , 115, 162, 166 Alignment films 41, 57, 105, 160 Protective film 43, 163 Color filter 44, 59, 112, 164 Black stripe layer 45, 109, 113, 157, 158, 165 Transparent electrode 60, 117, 168 Hole 66 Counter circuit 67 Feedback circuit 110 Source electrode 111 ITO electrode

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hitoshi Uzumasa 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Within Sharp Corporation (72) Inventor Makoto Miyago 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Osaka Incorporated (72) Inventor Kiyoshi Nakazawa 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (72) In-house Masayuki Katakami 22-22, Nagaike-cho, Abeno-ku, Osaka, Osaka 72) Inventor Takehisa Sakurai 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Prefecture Sharp Corporation (72) Katsuhiro Kawai, 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Prefecture

Claims (5)

[Claims] 1. A plurality of picture elements each having an electrode,
A driving element for driving the plurality of picture elements, a plurality of signal lines arranged in a row or column direction, and a plurality of scanning lines arranged so as to intersect the plurality of signal lines, A photosensitive element that is connected to the plurality of signal lines and the plurality of scanning lines and converts light from the outside into an electric signal, and detects a change in a signal passing through the plurality of signal lines and the plurality of scanning lines. An active matrix input / output device comprising: 2. The active matrix input / output device according to claim 1, wherein the detection means includes position detection means for detecting the positions of the plurality of picture elements. 3. The feedback for feeding back a correction signal obtained by the detection means to the plurality of signal lines and the plurality of scanning lines based on a change in a signal passing through the plurality of detected signal lines and the plurality of scanning lines. The active matrix input / output device according to claim 1, further comprising means. 4. The active matrix input / output device according to claim 1, wherein the photosensitive element is connected to the electrodes of the plurality of picture elements in parallel with the driving element. 5. The active matrix input / output according to claim 1, further comprising a storage capacitor connected to the driving element via a photosensitive element in parallel with the electrodes of the plurality of picture elements. apparatus.