JP2008021208A - Electro-optical device and electronic equipment equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a matrix type touch key of excellent transmittance. <P>SOLUTION: A liquid crystal display device comprises an active matrix substrate 101 and a thin film circuit formed on the substrate. The thin film circuit comprises a plurality of scan lines (201-n); a plurality of data lines (202-m) almost orthogonal to the scan lines; a plurality of pixel switching elements formed at intersection points of the scanning lines and data lines; a plurality of pixel electrodes connected to the pixel switching elements; row sense lines (204-n) arranged parallel with the scan lines; column sense lines (205-m) arranged parallel with the data lines; photo diodes formed at the intersection points of the row sense lines and column sense lines; row sense line terminals (604-n) connected to the row sense lines to output the detection output of optical sensor elements; and column sense line terminals (605-m) connected to the column sense lines to output the detection output of the optical sensor elements. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electro-optical device and an electronic apparatus including the same, and more particularly, to a circuit formed on a substrate using a thin film polysilicon forming technique, a liquid crystal display device using the circuit, and the liquid crystal display device. It relates to electronic equipment.

  In recent years, a display device with a built-in touch key has been developed in which a touch key sensor is mounted on a display device (mainly on a liquid crystal display device) and an icon or a button displayed on the display is touched with a finger or a stylus. It continues to spread due to its excellent operability.

  Generally, a touch key sensor includes a resistance film method, an infrared light shielding method, an ultrasonic surface acoustic wave method, an electromagnetic dielectric method, a capacitance method, and the like, and each is mass-produced. However, each method has its disadvantages. For example, the resistance film type is consumed when used, so the life is short and the quality of the display device is lowered. The infrared shading method is difficult to reduce in size, and the ultrasonic surface acoustic wave method is thick. The electromagnetic induction method requires a dedicated pen. The capacitance method is difficult to input with a finger other than a finger, and it is difficult to reduce the thickness. As described above, the touch key method that satisfies the requirements of (1) no dedicated pen, (2) no deterioration in display quality, and (3) a reduction in size and thickness has not yet been mass-produced.

  Therefore, as disclosed in Patent Document 1, a photo sensor is incorporated on an active matrix substrate constituting a liquid crystal display device, and external light is blocked by a finger or a stylus, or backlight light is reflected by reflection of the finger. A photo sensor type touch key is proposed that detects and uses as a touch key sensor. However, the conventionally proposed configuration method has a problem that a built-in circuit area is large and a decrease in transmittance is unavoidable.

JP 2006-79589 A

  SUMMARY OF THE INVENTION In view of the conventional problems, the present invention provides a touch key with a simpler configuration, thereby realizing a display device with a built-in touch key that has excellent transmittance and does not deteriorate display quality.

  The present invention is an electro-optical device (liquid crystal display device 910) comprising a substrate (active matrix substrate 101) and a thin film circuit formed on the substrate, and the thin film circuit includes a plurality of scanning lines (201-n). ), A plurality of data lines (202-m) substantially orthogonal to the plurality of scanning lines, and a plurality of pixel switching elements (401-) formed at intersections of the plurality of scanning lines and the plurality of data lines. nm), a plurality of pixel electrodes (402-nm) connected to the plurality of pixel switching elements, and a row sense line (204-n) arranged in parallel with the plurality of scanning lines. And a photosensor element (photodiode 410-n) formed at the intersection of the column sense line (205-m) arranged in parallel with the plurality of data lines and the row sense line and the column sense line. -M), A row sense line terminal (604-n) that is connected to the row sense line and outputs a detection output of the photosensor element, and a column sense line that is connected to the column sense line and outputs a detection output of the photosensor element. And a terminal (605-m).

  According to such a configuration, since the photosensor element is disposed on the same substrate as the pixel switching element, the display quality is hardly deteriorated, and the size and thickness can be easily reduced. In addition, a dedicated pen is not required by detecting the blocking or reflection of external light. Also, since the photosensor elements in the column direction are connected by the same column sense line and the photosensor elements in the row direction are connected by the same row sense line, respectively, even if the output from each photosensor element is weak The signal in the entire row sense line / column sense line has sufficient strength, and there is no need to incorporate an amplifier or the like in the display area as in the prior art, and there is an excellent effect that the decrease in transmittance is small.

  The electro-optical device of the present invention is further connected to the row sense line terminal and the column sense line terminal, and based on a detection output of the photosensor element, a light shield (finger) positioned adjacent to the substrate surface. 990, shadow 991) or a position detection circuit (external drive IC 929, coordinate detection processing circuit (785)) for detecting the position of the light emitter, and the position detection circuit detects the position in the row direction from the current flowing through the row sense line. Further, the position of the light shielding body or the light emitting body is detected by calculating the position in the column direction from the current flowing through the column sense line.

  According to the above configuration, the liquid crystal display device with a built-in touch sensor can be provided at a low cost by being employed in an electro-optical device such as a liquid crystal display device.

  The electro-optical device of the present invention further includes a row sense circuit (621) connected to the row sense line terminal and a column sense circuit (622) connected to the column sense line terminal. The circuit includes a first A / D conversion circuit (A / D conversion circuit 501-n) that converts the current flowing through the row sense line into a digital value, and the column sense circuit digitally converts the current flowing through the column sense line. A second A / D conversion circuit (A / D conversion circuit 504-n) for converting to a value, and the row sensing circuit and the column sensing circuit are formed on the same substrate as the plurality of pixel switching elements It is characterized by comprising active elements.

  According to the above configuration, since the A / D conversion circuit exists on the same substrate as the optical sensor, it is difficult for noise to enter, and extra load resistance / capacitance is not applied, so even weak signals can be detected. Excellent in sensing.

  The electro-optical device according to the aspect of the invention further includes a scanning line driving circuit (301) connected to the plurality of scanning lines and a data line driving circuit (302) connected to the plurality of data lines. At least one of the line drive circuit and the data line drive circuit is configured by an active element formed on the same substrate as an active element forming the row sense circuit and the column sense circuit, and the scan line drive circuit and the data line drive circuit The row sense line circuit or the data line driving circuit and the column sense circuit are present on both ends (configuration of FIG. 1) across a display region in which the plurality of pixel switching elements and the plurality of pixel electrodes are arranged. It is characterized by.

  According to the above configuration, by arranging one or both of the scanning line driving circuit and the column sensing circuit or the data line driving circuit and the row sensing circuit on the opposite side, a narrow frame is made possible, and noise from the driving circuit is detected. Sense sensitivity can be improved because it is difficult to be affected.

  In the electro-optical device according to the aspect of the invention, the row sense circuit or the column sense circuit may be the first (A / D conversion circuit 501-n) or the second A / D conversion circuit (A / D conversion circuit). 504-n) includes a serial conversion circuit (row sense circuit 621, column sense circuit 622) for serially converting and outputting the signal.

  According to the above configuration, by converting the results output from the plurality of A / D conversion circuits into serial digital data, it is possible to reduce mounting terminals with the outside, and thus it is possible to cope with cost reduction and narrowing of the frame.

  In addition, the electro-optical device of the present invention further includes a number of row sense lines smaller than the number of the plurality of scanning lines (configurations in FIGS. 12, 16, 17, and 18), and the scanning of the pixel electrodes. The width in the direction perpendicular to the line is different between the pixel electrode overlapping the row sense line and the pixel electrode not overlapping the row sense line (GY2> GY1).

  According to the above configuration, generally, the coordinate resolution as a touch key may be lower than the resolution as a display device. Therefore, by thinning out the row sense lines less than the scanning lines, the light shielding area by the row sense lines can be reduced, and the luminance of the liquid crystal display device can be improved. In addition, by changing the pixel electrode width between the pixels that overlap the row sense lines and the pixels that do not, the aperture ratio of each pixel can be made to be substantially the same, and unevenness can be prevented.

  In addition, the electro-optical device of the present invention further includes column sense lines whose number is smaller than the number of the plurality of data lines (configurations in FIGS. 12, 16, 17, and 18), and the scanning of the pixel electrodes. The width in the direction perpendicular to the line is different between the pixel electrode overlapping with the column sense line and the pixel electrode not overlapping with the column sense line (GX2> GX1).

  The electro-optical device of the present invention is further characterized in that transmission aperture ratios of pixel electrodes having different widths in a direction perpendicular to the scanning line or in a direction perpendicular to the data line are substantially equal to each other.

  According to the above configuration, generally, the coordinate resolution as a touch key may be lower than the resolution as a display device. Therefore, by thinning out the column sense lines less than the data lines, the light shielding area by the column sense lines can be reduced, the luminance of the liquid crystal display device can be improved, and the pixels which overlap with the row sense lines and the column sense lines but do not have the pixels. By changing the pixel electrode width, the aperture ratio of each pixel can be made to be substantially the same, and unevenness can be prevented.

  The electro-optical device according to the present invention is further characterized in that the pixel electrode overlapping the column sense line is a pixel electrode corresponding to blue display.

  According to the above configuration, it is preferable that a part of the plurality of pixel electrodes overlapping with the column sense line is a pixel electrode corresponding to blue display. This is because blue is less visible to humans than green and red, and unevenness due to column sense lines is difficult to see.

  In the electro-optical device according to the aspect of the invention, the number of the row sense lines may be approximately half of the number of the scanning lines (configuration in FIGS. 12, 16, 17, and 18). The pixel switching element connected to the odd-numbered scan line and the pixel switching element connected to the even-numbered scan line are line-symmetric with respect to the scan line direction, and the row sense line is the odd-numbered scan line. The pixel electrode is connected between the pixel electrode connected to the scanning line and the pixel electrode connected to the even-numbered scanning line.

  According to the above configuration, the lowering of the aperture ratio due to the row sense lines can be suppressed to a minimum by inverting the pixels in odd and even numbers and passing every other sense line through the non-display area between the pixel electrodes. Is possible.

  In the electro-optical device according to the aspect of the invention, the number of the column sense lines may be approximately 1/6 of the number of the data lines (configuration of FIGS. 12, 16, 17, and 18). The pixel switching element connected to the odd-numbered data line and the pixel switching element connected to the even-numbered data line are symmetrical with respect to the data line direction, and the column sense line is the odd-numbered data line. The pixel electrode is connected between the pixel electrode connected to the data line and the pixel electrode connected to the even-numbered data line.

  According to the above configuration, the lowering of the aperture ratio due to the row sense lines can be suppressed to a minimum by inverting the pixels in odd and even numbers and passing every other sense line through the non-display area between the pixel electrodes. Is possible.

  In the electro-optical device according to the aspect of the invention, the photosensor element may be divided into a plurality of pixels and may be sub-photosensor elements connected in parallel to each other, and the sub-photosensors may be made of thin film polysilicon. The branch wiring is connected to the row sense line or the column sense line.

  The electro-optical device of the present invention is further characterized in that the row sense line or the column sense line is made of thin film polysilicon.

  According to the above configuration, by dividing the photosensor into a plurality of pixels and arranging them in parallel, it becomes difficult to visually recognize unevenness between the pixels, and the display quality can be improved without reducing the signal intensity. In addition, the number of contact holes can be reduced by connecting a plurality of sub photosensors using a wiring in which an impurity serving as an acceptor or donor is heavily doped in thin film polysilicon. In addition, since the thin film polysilicon transmits light, the amount of light transmission can be reduced less than wiring with metal. By design, if the resistance value is within an allowable range, the entire row sense line or the entire column sense line can be more effectively formed by forming the thin film polysilicon.

  The electro-optical device according to the present invention is further characterized in that the optical sensor is a photodiode comprising a PIN junction diode or a PN junction diode using thin film polysilicon as an active layer.

  According to the above configuration, since the pixel switching element and the active layer can be manufactured in the same manufacturing process, a high-performance photodiode can be manufactured on the substrate without an increase in manufacturing cost.

  The electro-optical device of the present invention further includes a pixel auxiliary electrode made of an n + type or p + type semiconductor resistor configured by implanting ions into the same material as the active layer of the plurality of pixel switching elements. The pixel auxiliary electrode is electrically connected to the pixel electrode, and the auxiliary capacitance line formed of the same material as the scanning line or the scanning line overlaps the pixel auxiliary electrode to form an auxiliary capacitance, and the row The sense line and the scanning line are made of the same material. When the pixel auxiliary electrode is an n + type semiconductor resistor, the row sense line is connected to the cathode electrode of the photodiode, and the pixel auxiliary electrode is a p + type. In the case of a semiconductor resistor, the row sense line is connected to the anode electrode of the photodiode.

  According to the above configuration, the thin film silicon forming the auxiliary capacitance of the pixel and the thin film silicon connected to the row sense line of the photodiode are in the same ion implantation process, and the row sense line and the scanning line or the auxiliary capacitance line are in the same wiring forming process. Can be manufactured. For this reason, the outstanding effect that there is no increase in manufacturing cost can be produced.

  Further, the present invention is an electronic apparatus using the above electro-optical device. As a result, it is possible to provide a low-cost electro-optical device with a built-in touch key that does not require a dedicated pen and does not deteriorate display quality and can be reduced in size and thickness. By using this electronic device, it is possible to reduce the thickness and size while maintaining the display quality, and it is possible to realize an excellent industrially useful electronic device that can be operated without using a dedicated pen such as a finger.

  Embodiments of a liquid crystal display device according to the present invention will be described below with reference to the drawings.

  FIG. 1 is a configuration diagram of an active matrix substrate (101) for realizing the first embodiment of the present invention. On the active matrix substrate (101), 480 scanning lines (201-1 to 480) and 1920 data lines (202-1 to 1920) are formed orthogonally, and 480 auxiliary capacitance lines ( 203-1 to 480) are arranged in parallel with the scanning lines (201-1 to 480). The auxiliary capacitance lines (203-1 to 480) are short-circuited to each other and connected to the common potential input terminal (603). The opposing conductive portion (304) is also connected to the common potential input terminal (603). The scanning lines (201-1 to 480) are connected to the scanning line driving circuit (301) and supplied with driving signals. The data lines (202-1 to 1920) are connected to the data line driving circuit (302) and supplied with video signals. The scanning line driver circuit (301) and the data line driver circuit (302) are connected to a signal input terminal (601), and are supplied with various necessary signals and a power supply potential. The scanning line driving circuit (301) and the data line driving circuit (302) are formed by integrating polysilicon thin film transistors on an active matrix substrate, and are manufactured in the same process as the pixel switching element (401-nm). This is a so-called drive circuit built-in type liquid crystal display device.

  Further, in this embodiment, the row sense lines (204-1 to 480) are arranged in parallel to the direction parallel to the wiring direction of the scanning lines (201-1 to 480), and parallel to the direction parallel to the wiring direction of the data lines. Thus, column sense lines (205-1 to 1920) are arranged. The row sense lines (204-1 to 480) are connected to the row sense line terminals (604-1 to 480), and the column sense lines (205-1 to 1920) are connected to the column sense line terminals (6055-1 to 1920). Connected to.

  FIG. 2 is a circuit diagram in the vicinity of the intersection of the mth data line (202-m) and the nth scanning line (201-n) in the pixel display area indicated by the dotted line (310) in FIG. A pixel switching element (401-nm) made of an N-channel field effect polysilicon thin film transistor is formed at each intersection of the scanning line (201-n) and the data line (202-m), and its gate electrode Are connected to the scanning line (201-n), and the source and drain electrodes are connected to the data line (202-m) and the pixel electrode (402-nm), respectively. When the pixel electrode (402-nm) and the electrode short-circuited to the same potential form an auxiliary capacitance line (203-n) and an auxiliary capacitance capacitor (403-nm), and when assembled as a liquid crystal display device A counter substrate electrode (common electrode, denoted as COM in the figure) and a capacitor are also formed between the liquid crystal elements. Further, the column sense line (205-m) arranged in parallel with the wiring direction of the data line (202-m) and the scanning line (201-n) are arranged in parallel with the wiring direction. A photodiode (410-nm), which is a lateral PIN (p-intrinsic-n) junction diode, is formed at the intersection of the row sense lines (204-n). Here, the photodiode (410-nm), which is a lateral PIN junction diode, has the same film thickness as the polysilicon thin film that is the active layer of the pixel switching element (401-nm), and has the same manufacturing process. Since it is manufactured, there is no increase in manufacturing cost.

  FIG. 3A is a plan view showing an actual configuration of the circuit diagram shown in FIG. As shown in the legend of FIG. 3, the different shaded parts indicate different material wirings, and the same shaded parts indicate the same material wiring. It consists of four layers of chromium thin film (Cr), polysilicon thin film (Poly-Si), molybdenum thin film (Mo), aluminum / neodymium alloy thin film (AlNd), and indium / tin alloy thin film (ITO). Between these layers, any one of silicon oxide, silicon nitride, and organic insulating film or an interlayer insulating film in which these layers are stacked is formed and connected to each other through a contact hole. In this embodiment, the chromium thin film (Cr) is 100 nm thick, the polysilicon thin film (Poly-Si) is 50 nm thick, the molybdenum thin film is 200 nm thick, the aluminum / neodymium alloy thin film is 500 nm thick, indium / tin. The alloy thin film has a thickness of 100 nm. As shown in FIG. 3A, the data line (202-m) is formed of an aluminum-neodymium alloy thin film (AlNd) and is connected to the pixel switching element (401-nm) through a contact hole. The scanning line (201-n) is composed of a molybdenum thin film (Mo) and also serves as the gate electrode of the pixel switching element (401-nm). The auxiliary capacitance line (203-n) is made of the same wiring material as the scanning line (201-n), the pixel electrode (402-n-m) is made of an indium tin alloy thin film, and the pixel switching element (401-n). -M) through the contact hole. Further, the drain electrode of the pixel switching element (401-nm) is also connected to an n + type polysilicon thin film (Poly-Si) heavily doped with phosphorus, and in plan view with the auxiliary capacitance line (203-n). An auxiliary capacitor (403-nm) is formed by overlapping.

  FIG. 3B is a diagram showing a cross-sectional structure of a photodiode (410-nm) which is a lateral PIN junction diode at the line AA ′ in FIG. Note that the scale is not constant in order to make the drawing easier to see. The active matrix substrate (101) is an insulating substrate made of non-alkali glass, and a light shielding film (501) made of a chromium thin film (Cr) is disposed thereon via an insulating film. The light shielding film (501) is provided to shield light from the backlight unit (926) of FIG. Further, a silicon island (502) made of a polysilicon thin film is disposed on the insulating film, and the silicon island (502) is a p + region (502P) doped with boron ions at a high concentration, and phosphorus ions are doped at a high concentration. The n + region (502N), the p + region (502P), and the n + region (502N) formed between the n + region (502N) and the intrinsic semiconductor region (502I) doped with boron ions or phosphorus ions at all or only to a very low concentration. The p + region (502P) is connected to the anode electrode (504), and the n + region (502N) is connected to the cathode electrode (503) via contact holes. The anode electrode (504) and the cathode electrode (503) are formed of an aluminum-neodymium alloy thin film (AlNd). In the lateral type PIN junction diode having such a configuration, the anode according to external light (light from above in FIG. 3B) is applied in a reverse bias state in which a potential of + is applied to the cathode electrode and a potential of − is applied to the anode electrode. While the amount of light leakage flowing between the electrode (504) and the cathode electrode (503) changes, the light from the backlight (light from below in FIG. 3B) is blocked by the light shielding film (501). There is no effect.

  Furthermore, a pixel electrode (402-nm) is present on these via an insulating film. Here, the photodiode (410-nm) is disposed under the pixel electrode (402-nm) because the reliability of the liquid crystal element is improved by the DC electric field component of the anode electrode (504) or the cathode electrode (504). This is to prevent adverse effects.

  FIG. 4 is a perspective configuration view (partially sectional view) of a transmissive VGA resolution liquid crystal display device with a built-in touch key in the first embodiment using the active matrix substrate of FIG. The liquid crystal display device (910) includes an active matrix substrate (101) (first substrate) and a counter substrate (912) (second substrate) which are bonded to each other with a sealant (923) at a predetermined interval, and a nematic phase liquid crystal material (922) is sandwiched. Although not shown, an alignment material made of polyimide or the like is applied onto the active matrix substrate (101) and rubbed to form an alignment film. Although not shown, the counter substrate (912) includes a color filter corresponding to a pixel, a black matrix for preventing light leakage and improving contrast, and a counter electrode (912) made of an ITO film to which a common potential is supplied. ) And an alignment material made of polyimide or the like is applied to the surface in contact with the nematic liquid crystal material (922), and the rubbing process is performed in a direction perpendicular to the rubbing process direction of the alignment film of the active matrix substrate (101). Has been.

  Further, an upper deflection plate (924) is arranged outside the counter substrate (912), and a lower deflection plate (925) is arranged outside the active matrix substrate (101) so that the polarization directions thereof are orthogonal to each other ( (Cross Nicol shape) Further, a backlight unit (926) forming a surface light source is disposed below the lower deflection plate (925). The backlight unit (926) may be a cold cathode tube or LED with a light guide plate or a scattering plate attached thereto, or may be a unit that emits light entirely from an EL element. Although not shown, if necessary, the periphery may be covered with an outer shell, or a protective glass or acrylic plate may be attached on the upper deflection plate (924) to improve the viewing angle. Therefore, an optical compensation film may be attached.

  Further, the active matrix substrate (101) is provided with a projecting portion (927) projecting from the counter substrate (912), and a signal input terminal (601) and a common potential input terminal (counter electrode potential terminal) in the projecting portion (927). ) (603), row sense line terminals (604-1 to 480), column sense line terminals (6055-1 to 1920) (all not shown), FPC (flexible substrate) (928) and external drive An IC (929) is mounted and electrically connected. In FIG. 4, the external drive IC (929) is composed of two ICs, but may be one or three or more. An FPC (flexible board) (928) is connected to a control board (921) having a power supply IC, a signal control IC, a capacitor, a resistor, a ROM, a backlight control unit, etc., and receives a reference potential, a control signal, and video data. Supply to the active matrix substrate (101).

  FIG. 5 is a graph showing the characteristics of the photodiode (410-nm), in which the horizontal axis Vd indicates the voltage applied between the anode electrode and the cathode electrode, and the vertical axis Id indicates the anode electrode-cathode electrode at that time. Current flowing between them is shown. The solid line (A) is data when 1000 lx light is irradiated to the photodiode (410-nm), and the solid line (B) is when 100 lx light is irradiated to the photodiode 410-nm. It is data of. In the region of Vd> 0 · Id> 0, that is, in the forward bias condition region, Id shows a substantially constant value with respect to Vd regardless of the amount of light irradiation, but Vd <0 · Id <0 and Vd> −Vz (where Vz represents a breakdown voltage or a jumping voltage), that is, under a relatively low reverse bias condition, | Id | increases almost in proportion to the amount of light irradiation, and hardly depends on Vd. That is, the current flowing through the photodiode (410-nm) in this region is a constant current source expressed by the following (Equation 1).

Here, L is the amount of light applied to the photodiode (410-nm), T is the temperature of the photodiode (410-nm), Iphoto is a constant, and Ileak (T) Is a function of temperature T representing heat leakage.

  In this embodiment, it is assumed that appropriate voltages are applied to the row sense line terminals (604-1 to 480) and the column sense line terminals (6055-1 to 1920) so that the above (Equation 1) is satisfied. For example, 5 V is uniformly applied to the row sense line terminals (604-1 to 480), and 0 V (GND) is uniformly applied to the column sense line terminals (6055-1 to 1920). Then, a voltage of Vd = −5V is applied to each photodiode (410−n−m). Note that the breakdown voltage or the jump voltage Vz of the photodiode (410-nm) in this example is 10V.

  The temperature of the active matrix substrate (101) is uniformly T, and the amount of light irradiated to the photodiode (410-nm) by the backlight unit (926) is uniformly LB (unit: lux). Assuming that the amount of light from external light irradiated to (410-nm) is represented by LA (n, m), the current IR (n) flowing through the row sense line terminal (604-n) is ( It is represented by Formula 2).

  Similarly, a current IC (m) flowing through the column sense line terminal (605-m) is expressed by the following (formula 3).

  First, consider the case where the liquid crystal display device (910) is used in a relatively strong external light environment, that is, outdoors or under illumination. Here, if there is no light-shielding object on the liquid crystal display device (910) and the external light is uniformly applied, all the LA (n, m) have the same illuminance, so of course all the IR (n) and IC (m) ) Indicates the same value. However, if there is a shield such as a finger or a stylus on the liquid crystal display device (910), a shadow is formed on the liquid crystal display device (910). Then, the illuminance LA (n, m) of the photodiode (410-nm) corresponding to the portion becomes a lower value than the other portions without the shielding.

  For example, as shown in FIG. 6, the case where external light is blocked by the finger (990) and a shadow (991) is formed on the liquid crystal display device (liquid crystal module) (910) will be described as an example. 6 shows that the finger (990) is approaching when the liquid crystal display device (910) is viewed from the side, and the lower side of FIG. 6 is the finger made when looking down at the liquid crystal display device (910). It is a figure which shows the shadow (991). Here, the shadow (991) is in a region corresponding to the column sense lines n1 to n2 and the row sense lines m1 to m2. In other words, the illuminance LA (n, m) of the photodiode 410-nm (n1 ≦ n ≦ n2, m1 ≦ m ≦ m2) in the portion where the shadow (991) is made by the finger (990) is the other shield. It becomes a low value compared with the part without. The length of the shadow (991), that is, the length of the portion where the illuminance LA (n, m) is low is m = mc in the row sense line direction and n = nc in the column sense line direction. It is the longest. Here, assuming that the illuminance LA (n, m) under the shadow (991) is uniform, if the current IR (n) flowing through the row sense line terminals (604-n) is measured, n = nc as shown in FIG. Let's make a graph that draws a minimum. Further, if the current IC (m) flowing through the column sense line terminal (605-m) is measured, a graph can be drawn which draws a minimum at m = mc as shown in FIG.

  That is, the current IR (n) flowing through the row sense line terminal (604-n) and the current IC (m) flowing through the column sense line terminal (605-m) are measured, and IR (n) and IC (m) are minimal. If a point (n = nc, m = mc) is obtained, a set of row sense lines and column sense lines corresponding to the center coordinates of the shadow formed by the finger (990) can be obtained.

  In the above description, the case where the finger makes a shadow has been described. However, when the finger reflects the backlight, the photodiode (410-nm) (n1 ≦ n ≦ n2, Since the illuminance LA (n, m) of m1 ≦ m ≦ m2) is higher than that of the other portions without the finger (990), it is the same if the maximum point of IR (m) · IC (n) is obtained. The center coordinates of the finger (990) can be obtained.

  In this embodiment, since the backlight unit (926) is shielded from light by the light shielding film (501), LB << LA (n, m) and the term LB can be ignored, but the light shielding film (501). ) LB << LA (n, m) and can be detected in the same manner in a situation where the external light is strong, but LB >> LA (n, m) is sufficient in the situation where the external light is weak. Since the case where S / N ratio cannot be taken arises, it is not preferable.

  A specific configuration will be described with reference to FIG. FIG. 9 is a block diagram showing a specific configuration of the electronic apparatus in this embodiment. The liquid crystal display device 910 is a transmissive VGA resolution liquid crystal display device with a built-in touch key described with reference to FIG. 4, and is connected to the row sense line terminals (604-1 to 480) and the column sense terminals (6055-1 to 1920). As described with reference to FIG. 4, the external drive IC (929) thus mounted is mounted. The external drive IC (929) is a digital signal for the current IR (1-480) flowing through the row sense line terminals (604-1 to 480) and the current IC (1-1920) flowing through the column sense terminals (6055-1 to 1920). An A / D conversion circuit for converting the current into a digital value while sampling the current IR (1-480) and the current IC (1-1920) at regular intervals, and transfers the result to the coordinate detection processing circuit (785). .

  The coordinate detection processing circuit (785) has minimum or maximum current IR (n = 1 to 480) and current IC (m = 1 to 1920) flowing through the row sense line terminals (604-n) based on the received digital numerical values. The center coordinates (nc, mc) of the finger are calculated. If the center coordinate (nc, mc) of the finger does not move for a certain period, it is determined that the finger has been touched, and the coordinate (nc, mc) is transferred to the external I / F circuit (782). The external I / F circuit (782) also transfers the input data from the input / output device (783) to the central processing circuit (781). The central processing circuit (781) performs various arithmetic processing based on data from the external I / F circuit (782), and transfers the result as a command to the display information processing circuit (780) or the external I / FIC (782). . The display information processing circuit (780) changes the video signal based on a command from the central processing circuit (781), and outputs a drive signal with a predetermined signal to the external drive circuit (929), whereby the liquid crystal display device (910) is displayed. ) Display image changes. The external I / F circuit (782) also changes the control signal to the input / output device (783) based on the command from the central processing circuit (781), thereby changing the output state of the input / output device (783). . Here, the input / output device (783) is, for example, a keyboard, a mouse, a trackball, an LED, a speaker, an antenna, or the like.

  In this embodiment, the center coordinates (nc, mc) of the finger are calculated by calculating the point at which the current IR (n = 1 to 480) and the current IC (m = 1 to 1920) are minimized or maximized. nc, mc) is determined to have been touched when it has not moved for a certain time. For example, coordinates n1, n2, m1, m2 at which current values IR (n) and IC (m) start to decrease are obtained, and | n2 The case where −n1 | and | m2−m1 | are maximized in time may be determined as touched, and ((n2 + n1) ÷ 2, (m2 + m1) ÷ 2) may be transferred as finger coordinates. Alternatively, it may be determined that the touch is made when the difference between the current value IR (n) with respect to n and the difference between IC (m) with respect to m exceeds a certain threshold (that is, when the illuminance change becomes steep). Moreover, not only the input by a finger but the input by a stylus may be used, and a light pen may be used. In the latter case, the illuminance is always high at the position where the light pen is located.

  As described above, the photodiodes are arranged in a matrix on the active matrix substrate, and the anodes (or cathodes) of the photodiodes arranged in the row direction are connected to the same electrode (= row sense line) and arranged in the column direction. The cathode (or anode) of the photodiode is connected to the same electrode (= column sense line), an appropriate bias is applied to the row sense line / column sense line, and the current values flowing through the row sense line and the column sense line are compared. It functions as a touch key. According to this configuration, even if the current amount of each photodiode is not sufficient, a large current flows in the entire row sense line or column sense line, so that the S / N ratio is excellent. Therefore, even when a photodiode is formed using a silicon thin film having the same structure as the active layer of the transistor, it has sufficient sensitivity. This makes it possible to construct a liquid crystal display device with a built-in touch key in the same manufacturing process as that of a normal liquid crystal display device without a built-in touch key. It has the advantage that it can be manufactured at low cost.

  FIG. 10 is a configuration diagram of an active matrix substrate (101) for realizing the second embodiment of the present invention. On the active matrix substrate (101), 480 scanning lines (201-1 to 480) and 1920 data lines (202-1 to 1920) are formed orthogonally, and 480 auxiliary capacitance lines ( 203-1 to 480) are arranged in parallel with the scanning lines (201-1 to 480). The auxiliary capacitance lines (203-1 to 480) are short-circuited to each other and connected to the common potential input terminal (603). The opposing conductive portion (304) is also connected to the common potential input terminal (603). The scanning lines (201-1 to 480) are connected to the scanning line driving circuit (301) and supplied with driving signals. The data lines (202-1 to 1920) are connected to the data line driving circuit (302) and supplied with video signals. The scanning line driver circuit (301) and the data line driver circuit (302) are connected to a signal input terminal (601), and are supplied with various necessary signals and a power supply potential. The scanning line driving circuit (301) and the data line driving circuit (302) are formed by integrating polysilicon thin film transistors on an active matrix substrate, and in the same process as the pixel switching element (401-nm). A so-called drive circuit built-in type liquid crystal display device is manufactured.

  Further, in the present embodiment, the row sense lines (204-1 to 240) are arranged in parallel to the direction parallel to the wiring direction of the scanning lines (201-1 to 480) and at a rate of one for every two scanning lines. The That is, the nth row sense line (204-n) is arranged next to the n * 2th (201-n * 2) scanning line. In addition, column sense lines (205-1 to 320) are arranged in parallel to the wiring direction of the data lines and at a ratio of one to six data lines. That is, the nth row sense line (205-n) is arranged next to the n * 6th (202-n * 6) data line. The row sense lines (204-1 to 240) are connected to the row sense circuit (621), and the column sense lines (205-320) are connected to the column sense circuit (622). The row sense circuit (621) is connected to a plurality of row sense circuit input / output terminals (604), and is supplied with necessary potentials and signals from the outside and outputs a result sensed by the row sense circuit. Similarly, the column sense circuit (622) is connected to a plurality of column sense circuit input / output terminals (605), and is supplied with necessary potentials and signals from the outside and outputs a result sensed by the column sense circuit. Note that the row sense circuit (621) is arranged on the opposite side across the scanning line driver circuit (301) and the display region (310), and the column sense circuit (622) is displayed in the same manner as the data line driver circuit (302). The row sense circuit (621) and the column sense circuit (622) are affected by the noise of the scanning line driving circuit (301) and the data line driving circuit (302). While making it difficult, narrow frame is realized.

FIG. 11 is a circuit diagram in the vicinity of the intersection of the mth column sense line (205-m) and the nth row sense line (204-n) in the pixel display area indicated by the dotted line 310 in FIG. Unlike the first embodiment, one column sense line (205-m) is arranged for every six data lines (202-1 to 1920), and the row sense line (204-n) is a scanning line (201-1 to 201-1). 480) One is arranged for every two. A lateral PIN junction diode photodiode (410-nm) is arranged at the intersection of the column sense line (205-m) and the row sense line (204-n). One photodiode (410-nm) is arranged for every six pixels in the scanning line direction and one for every two pixels in the data line direction. Here, the photodiodes (410-1 to 240-1 to 320), which are lateral PIN junction diodes, have the same film thickness as the polysilicon thin film that is the active layer of the pixel switching element (401-nm), Since it is manufactured in the same manufacturing process, there is no increase in manufacturing cost.
The other points are the same as those in the first embodiment shown in FIG.

  FIG. 12 is a plan view showing an actual configuration of the circuit diagram shown in FIG. The configuration and film thickness of each wiring represented by the hatching shown in the legend of FIG. 12 are the same as those in the first embodiment, and will not be described. Further, the cross-sectional structure of the photodiode (410-nm) which is a lateral PIN junction diode at the line AA ′ is completely the same as that of FIG.

  As shown in FIG. 12, in this embodiment, the pixel passes through the row sense line (204-n) (here, n = 1 to 240), that is, corresponds to the pixel electrode (402-n * 2-1 to 1920). The pitch in the data line direction differs between the pixel and the other pixels. That is, an interval (indicated by Y2 in FIG. 6) between the scanning line 201-n * 2 and the scanning line (201-n * 2 + 1) and an interval between the scanning line 201-n * 2 + 1 and the scanning line (201-n * 2 + 2) ( Are different from each other, and Y2> Y1. Correspondingly, the width (GY2) of the pixel electrode (402-n * 2-1 to 1920) and the width (GY1) of the pixel electrode (402-n * 2 + 1-1 to 1920) are also different (GY2> GY1). This layout prevents the aperture ratio from being changed for each pixel by the row sense line (204-m).

  Similarly, in this embodiment, the pixels (m = 1 to 320) through which the column sense line (205-m) passes, that is, the pixels corresponding to the pixel electrodes (402-1 to 480-m * 6), The pitch in the scanning line direction is different from other pixels. That is, the interval (indicated by X2 in FIG. 6) between the data line (202−m * 6) and the data line (202−m * 6 + 1) and the other data line (202) (indicated by X1 in FIG. 6). Are different from each other and X2> X1. Correspondingly, the width (GX2) of the pixel electrodes (402-1 to 480-m * 6) and the other pixel electrodes (402-1 to 480-m * 6 + 1, 402-1 to 480-m * 6 + 2,...). , 402-1 to 480-m * 6 + 5), the width (GX1) in the scanning line direction is also different (GX2> GX1). This layout prevents the aperture ratio from being changed for each pixel by the column sense line (205-m).

  As described above, compared with the first embodiment, in this embodiment, one photodiode (410) is arranged not on all pixels but on a fixed number of pixels (6 × 2 pixels in this embodiment). As a result, the number of column sense lines (205) and row sense lines (204) is reduced, and the luminance of the liquid crystal display device (910) is improved by increasing the transmittance of the panel. Further, by changing the pixel pitch between the pixel portion through which the column sense line (205) and the row sense line (204) pass and the other pixels, the aperture ratio does not change between the respective pixels. The vertical and horizontal unevenness does not occur and the display quality is not impaired.

  Further, in this embodiment, the pixel electrodes (402-1 to 480-m * 6) through which the column sense line (205-m) passes are made of a color material on the counter electrode (912) so that the corresponding display color is blue. Deploy. Since human vision is the least insensitive to blue among the three primary colors, it is possible to suppress degradation in display quality due to factors such as light reflected by the column sense line (205) and the photodiode (410). It is. Further, since the photodiode (410) has a good photosensitivity on the shorter wavelength side, the sense sensitivity is improved as compared with the case where it is arranged under the green or red color material.

  In this embodiment, the column sense lines are arranged every 6 pixels and the row sense lines are arranged every 2 pixels. However, these numerical values may be set freely from the sensitivity of the photodiode, the required coordinate resolution, and the like. . As the number of column sense lines (205) and row sense lines (204) is reduced, the luminance of the liquid crystal display device (910) is improved. On the other hand, the position resolution as a touch key sensor is lowered, and the column sense lines Since the amount of current flowing in (205) and the row sense line (204) also decreases, detection becomes difficult.

  13A is a circuit block diagram of the row sense circuit (621), and FIG. 13B is a circuit block diagram of the column sense circuit (622). The row sense circuit (621) has a 240-stage configuration, and the column sense circuit (622) has a 320-stage configuration, except for the number of stages. Hereinafter, the operation of the row sense circuit (621) in FIG. 13A will be described. The row sense line (204-n) is connected to the A / D conversion circuit (501-n), converted into a digital binary, and then output to the input stage (D) of the DFF circuit (502-n). Here, only when the sampling timing signal WRT is HIGH, the A / D conversion circuit (501-n) performs A / D conversion and outputs the result. At this time, the transmission gate (503-n) is closed and the previous stage is output. The output from the DFF circuit (502- [n-1]) is not input to the next stage DFF circuit (502-n). After the writing is completed in this way, the DFF circuit (502-n) sequentially transfers the signal written in each stage by the CLK signal and the XCLK signal. During the transfer, the sampling timing signal WRT signal is LOW, the reverse polarity sampling timing signal (XWR) is HIGH, and the transmission gate (503-n) is open. In other words, after sampling (WRT = HIGH, XWRT = LOW), a sampling result transfer (WRT = LOW, XWRT = HIGH) period continues, and the sampling result is serially converted and output from the OUT terminal to the outside. It has become.

  In the column sense circuit (622) in FIG. 13B, the row sense line (204-n) is the column sense line (205-n), and the A / D conversion circuit (501-n) is the A / D conversion circuit (504). -N), the DFF circuit (502-n) is replaced with the DFF circuit (505-n) and the transmission gate (503-n) is replaced with the transmission gate (506-n), and the number of stages is increased from 240 to 320. Since the operation is the same, the description is omitted.

  Specific examples of the A / D conversion circuit (501-n) in FIG. 13A and the A / D conversion circuit (504-n) in FIG. 13B are shown in FIG. 14A, FIG. 14B, and FIG. 14 (C). 14A and 14B, the capacitor 510 is reset to the initial potential by the reset signal RST, and then the IN terminal (the row sense line (204-n) or the column sense line (205-n)) is reset. The potential of the capacitor (510) fluctuates due to the current flowing from the (connected). This variation is detected by the comparator circuit (511), digitized, and output from the OUT terminal. From the row sense line (204-n) or the column sense line (205-n), the IN terminal Comparator (511) is assumed to be the current flowing through the capacitor, the operating point (inverted potential) of the comparator circuit (511) is V1, the initial potential charged to the capacitor (510) by the reset signal RST is V0, and the capacitance of the capacitor (510) is C. -The time until the output from the circuit (511) is inverted is expressed by the following (Equation 4).

  In the configuration shown in FIG. 14A, V0 and V1 are determined in a self-aligned manner, and V1-V0 hardly depends on the process variation, but it is difficult to increase the difference. In the configuration shown in FIG. Since V1 is determined by 512), V1-V0 is likely to be large, but is likely to depend on process variations. Which configuration is adopted may be determined in consideration of the values of I and C, process fluctuation stability, and the like. In the configuration of FIG. 14C, IV conversion is performed using the saturation characteristics of the transistor (513) whose drain and gate are short-circuited. From the saturation region current equation of the MOS transistor, the potential V of the node (514) is expressed by a linear equation of the square root of the current flowing through the transistor (513). If the potential of this node (514) is input to the comparator (511), it is output whether it is above or below the reference potential, from which it can be converted into a current. In this configuration, the reset signal RST is not necessary. In this configuration, since the output from the comparator (511) is continuous in time, there is a merit that there is no restriction on the sampling time. On the other hand, there is a large error due to variations in threshold values of the transistor (513), and the transistor (513). There is a demerit that the dynamic range is limited by the performance of.

  FIG. 15 shows specific examples of the DFF circuit (502-n) in FIG. 13A and the DFF circuit (505-n) in FIG. 13B. This is a general DFF circuit using a normal CMOS clocked inverter.

  Here, each transistor constituting the row sense circuit (621) and the column sense circuit (622) is formed by integrating polysilicon thin film transistors on an active matrix substrate (101), and a scanning line driving circuit ( 301), the transistors and the pixel switching elements (401-nm) constituting the data line driving circuit (302) are manufactured in the same process, and the manufacturing cost is kept at the same level as the conventional one.

  The row sense circuit (621) and the column sense circuit (622) configured as described above are provided with A / D conversion circuits (501-1 to 240) and A / D conversion at the sampling timing (sampling signal WRT is HIGH timing). The output results of the circuits (504-1 to 320) are serially converted and output as digital signals from the row sense terminals (604-n) or the column sense terminals (605-m) to the external drive IC (929). Thus, the external drive IC (929) can digitally calculate the current IR (n) flowing through the row sense line (204-n) and the current IC (m) flowing through the column sense line (205-m) at the sampling timing. is there. The external drive IC (929) appropriately outputs the calculation result to the coordinate detection processing circuit (785) as digital data.

  The configuration of the liquid crystal display device (910) using the active matrix substrate of the present embodiment, the configuration of the electronic apparatus to which the liquid crystal display device is applied, the operation principle of the touch keys, and the coordinate detection method are the same as in the first embodiment. Omitted.

  In this embodiment, since the external drive IC (929) receives the serial digital data output from the row sense circuit (621) and the column sense circuit (622), the external drive IC (929) is externally driven as compared with the configuration of the first embodiment. Since it is not necessary to insert an A / D conversion circuit on the IC (929), the cost of the external drive IC (929) is reduced and the number of mounting terminals is dramatically reduced, so that the mounting cost is greatly reduced. In addition, since the distance from the photodiode (410) to the A / D converter is shortened, the accuracy can be improved. In particular, it greatly contributes to the conversion accuracy when the output current from the photodiode (410) is low, that is, when the illuminance is low.

  In this embodiment, the A / D conversion circuit is a 1-bit digital output, but this may be a multi-bit digital output. In this case, for example, in the configuration of FIG. 14B, a plurality of comparator circuits 511 are arranged in parallel, a plurality of potentials are taken out from the dividing resistors (512) and connected to each other, and a plurality of comparator circuits (511) are connected. The output may be encoded into binary data to output multi-bit A / D conversion data, and a plurality of D-FF transfer circuits may be provided to perform serial output for the number of bits. Alternatively, the reference potential input to the comparator circuit (511) may be temporally changed while the 1-bit configuration is maintained, and the data at each timing may be latched and encoded.

  FIG. 16 is an enlarged plan view of the pixel display region of the active matrix substrate (101) for realizing the third embodiment of the present invention. The legend is the same as in FIG.

  This embodiment is different from the second embodiment in that the photodiode (410-n-m) is not only under a specific pixel electrode (402- [n * 2]-[m * 6]) but also 6 pixels (402 − [N * 2] − [m * 6−5 to 0]), n + thin film polysilicon resistor cathode branch wiring (452−n−m) in which each cathode is implanted with a high concentration of phosphorus ions The anodes are connected to each other by anode branch wires (451-nm) made of p + thin film polysilicon resistors implanted with boron ions at a high concentration. The cathode branch wiring (452-nm) is the row sense line (204-n), the anode branch wiring (451-nm) is the column sense line (205-m), and the pixel electrode (402- [n]). * 2]-[m * 6]) Only through one contact hole. The pitch of the scanning line (201) and the data line (202) is changed in the pixel portion through which the column sense line (205) and the row sense line (204) pass and other pixels as in the second embodiment ( X1 <X2, Y1 <Y2), and correspondingly, the widths of the pixel electrodes 402 are also different in size (GX1 <GX2, GY1 <GY2). As a result, the aperture ratio of each pixel is adjusted to be substantially the same. In this embodiment, the cathode branch wiring (452-nm) and the anode branch wiring (451-nm) are each formed of thin film polysilicon and transmit light. In comparison, the transmittance of the panel is not greatly reduced. In general, n + / p + thin film polysilicon has a specific resistance several hundred to several thousand times higher than that of a metal thin film, but the photocurrent that originally flows through the photodiode (410-nm) is not large, and the cathode branch wiring ( 452-nm) and the length of the anode branch wiring (451-nm) are about several hundreds of micrometers at most, and the resistance value does not cause the photocurrent to peak. In addition, since the photodiodes (410-nm) are dispersedly arranged in each pixel, even if photodiodes of the same size are made, it is difficult to see compared to the second embodiment, and the display quality of the panel is improved.

  Further, in the present invention, pixel switching elements (pixel transistors) (401-2, 4,... 480-1 to 1920) corresponding to even-numbered scanning lines (210-2, 4,... 480) and odd-numbered scanning lines (210). −1, 3,... 479) and the pixel switching elements (pixel transistors) (401-1, 3,... 479-1 to 1920) are laid out so that the layout is in line contrast with the data line direction. The row sense line (204-n) is arranged between the even-numbered scan line (201-n * 2) and the odd-numbered scan line (201-n * 2 + 1), and the row sense line (204-n). The pixel electrode (402-n * 2-1 to 1920) and the pixel electrode (402-n * 2 + 1-1 to 1920) are separated from each other. Since the gap between the pixel electrodes originally does not contribute to the aperture ratio (transmittance) and is shielded by the black matrix on the counter electrode (912), the aperture ratio decreases due to the row sense line (204-n) by such a layout. Is almost gone.

  In this embodiment, the configuration of the active matrix substrate (101) excluding the pixel display area, the configuration of the liquid crystal display device (910) and the configuration of the electronic apparatus to which it is applied, the method of coordinate detection, etc. are the second embodiment. The explanation is omitted because there is no change.

  FIG. 17 is an enlarged plan view of a pixel display region of an active matrix substrate (101) showing a third alternative embodiment in place of FIG. In this example, the width (GY2) of the pixel electrode (402-n * 2-1 to 1920) and the width of the pixel electrode (402-n * 2 + 1-1 to 1920) in the direction perpendicular to the scanning line (201-n) ( GY1) is the same (GY1 = GY2), and the pixels connected to the even-numbered scanning lines (201-2, 4, 6,..., 480) and the odd-numbered scanning lines (201-1, 3, 5,. Layout. In addition, the row sense line (204-n) is not a metal wiring, but an n + thin film polysilicon resistor, and is directly connected to the photodiode (410-nm), whereby the cathode branch wiring (452-nm). ) Does not exist. According to this layout, since pixels in the scanning line direction are objects of each other, unevenness or the like becomes more difficult to see. Further, by using an n + thin film polysilicon resistor for the row sense line (204-n), the contact holes are reduced and the panel transmittance is increased. Since the n + thin film polysilicon resistor generally has a resistivity several hundred to several thousand times that of the metal wiring, the current flowing through the row sense line (204-n) due to the wiring load resistance as the liquid crystal display device becomes larger. Will be restricted, which will impede sensing at high illuminance. In such a case, the row sense line (204-n) may be replaced with a metal wiring as in the second embodiment, or a double wiring of an n + thin film polysilicon resistor and a metal wiring may be used.

  In this embodiment, the layout is symmetrically arranged in the scanning line direction. However, the layout may be symmetrically arranged in the data line direction. Alternatively, as shown, both the scanning line direction and the data line direction may be symmetrically arranged. Further, not only the row sense line (204-n) but also the column sense may be constituted by a thin film polysilicon film resistor. Such a further alternative embodiment is shown in FIG. In this embodiment, the scanning line direction and the data line direction are symmetrically arranged, and a row sense line (204-n) made of n + type thin film polysilicon and a column sense line made of p + type thin film polysilicon (402) between the pixel electrodes (402). 205-m). The column sense line (205-m) is transferred to the AlNd thin film through a contact hole so as not to be short-circuited at the intersection of the row sense line (204-n) and the column sense line (205-m). As in the previous embodiment, when the resistance of the column sense line (205-m) becomes a problem, the column sense line (205-m) is replaced with a metal wiring, or the p + thin film polysilicon resistor and the metal wiring are doubled. Wiring is sufficient.

  In this embodiment, the row sense line is connected to the cathode electrode, and the column sense line is connected to the anode electrode. However, in this case, the thin film polysilicon film at the portion forming the storage capacitor (403) overlapping the storage capacitor line (203-n) can be manufactured by the same process as the cathode electrode, that is, a p + type thin film polysilicon film. Preferably there is. Even if the anode electrode overlaps with the row sense line (204-n) formed of the same thin film as the scanning line in a plane, the thin film overlapped with the auxiliary capacitance line (203-n) formed of the same thin film as the scanning line. This is because the process of heavily doping polysilicon can be shared, and the manufacturing cost can be reduced.

  In this embodiment, the polysilicon thin film is used for the configuration of the pixel switching element (401-nm) and the photodiode (410-nm), but an amorphous silicon thin film may be used. Although the TN mode has been described as an example of the liquid crystal display mode, it may be applied to other modes such as the VA mode, the FFS mode, or the IPS mode, or may be applied to a transflective / total reflection liquid crystal display device. Further, it may be applied to an organic EL display device or the like instead of a liquid crystal display device.

  In addition, the A / D conversion circuit, the DFF circuit, and the like may be combined with any known circuit configuration in addition to the circuit shown in this embodiment.

  Further, in this embodiment, the coordinate detection processing circuit (785) is arranged outside the liquid crystal display device (910), but it may be arranged inside the liquid crystal display device (910) or similar to the row sense circuit / column sense circuit. Alternatively, a thin film polysilicon may be formed on the active matrix substrate.

1 is a configuration diagram of an active matrix substrate 101 constituting a liquid crystal display device according to a first embodiment of the present invention. 1 is a pixel circuit diagram of an active matrix substrate 101 constituting a liquid crystal display device according to a first embodiment of the present invention. FIG. 2 is a plan view and a cross-sectional view showing an actual configuration of a pixel according to the first embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective configuration diagram (partially sectional view) of a transmissive VGA resolution liquid crystal display device (910) with a built-in touch key in an embodiment of the present invention. The graph which shows the characteristic of the photodiode (410) in the Example of this invention. The side view and overhead view for demonstrating the coordinate detection method of this invention. The graph which shows the electric current value distribution of the row sense line (204) for demonstrating the coordinate detection method of this invention. The graph which shows the electric current value distribution of the column sense line (205) for demonstrating the coordinate detection method of this invention. FIG. 11 is a block diagram illustrating a specific structure of an electronic device in this embodiment. The active matrix 101 board | substrate block diagram which comprises the liquid crystal display device by the 2nd Example of this invention. 1 is a pixel circuit diagram of an active matrix substrate 101 constituting a liquid crystal display device according to a first embodiment of the present invention. The top view which shows the actual structure of the pixel by the 2nd Example of this invention. The block diagram of the row sense circuit (621) and the column sense circuit (622) by the 2nd Example of this invention. The circuit diagram of the A / D conversion circuit (501-n, 504-n) by the 2nd Example of this invention. The circuit diagram of the DFF circuit (502-n, 505-n) by the 2nd Example of this invention. The top view which shows the actual structure of the pixel by the 3rd Example of this invention. The top view which shows the actual structure of the pixel by the 3rd another Example of this invention. FIG. 9 is a plan view showing an actual configuration of a pixel according to a third further alternative embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 ... Active matrix substrate, 201-n ... Scan line, 202-m ... Data line, 203-n ... Auxiliary capacitance line, 204-n ... Row sense line, 205-m ... Column sense line, 301 ... Scan line drive circuit , 302... Data line driving circuit, 304. Opposite conductive portion, 401 -nm, pixel switching element, 402 -nm, pixel electrode, 403, auxiliary capacitor, 410 -nm, photodiode, 451. nm ... anode branch wiring, 452-nm ... cathode branch wiring, 501-n, 504-n ... A / D conversion circuit, 502-n, 505-n ... DFF circuit, 503-n ... transmission gate, 501 ... Light shielding film, 502 ... Silicon island, 502P ... P + region, 502N ... N + region, 502I ... Application semiconductor region, 503 ... Cathode electrode, 504 ... Anode electrode, 5 DESCRIPTION OF SYMBOLS 0 ... Capacitor, 511 ... Comparator circuit, 512 ... Dividing resistor, 513 ... Transistor, 514 ... Node, 601 ... Signal input terminal, 603 ... Common potential input terminal, 604-n ... Row sense line terminal, 605-m ... Column Sense line terminal, 604 ... row sense circuit input / output terminal, 605 ... column sense circuit input / output terminal, 621 ... row sense circuit, 622 ... column sense circuit, 781 ... central processing circuit, 782 ... external I / F circuit, 783 ... Input / output equipment, 785 ... coordinate detection processing circuit, 910 ... liquid crystal display, 912 ... counter electrode, 921 ... control board, 922 ... nematic phase liquid crystal material, 923 ... sealing material, 924 ... upper deflection plate, 925 ... lower deflection plate 926 ... Backlight unit, 927 ... Overhang, 928 ... FPC, 990 ... Finger, 991 ... Shadow, 929 ... External drive IC

Claims (16)

An electro-optical device comprising a substrate and a thin film circuit formed on the substrate,
The thin film circuit is
A plurality of scan lines;
A plurality of data lines substantially orthogonal to the plurality of scanning lines;
A plurality of pixel switching elements formed at intersections of the plurality of scanning lines and the plurality of data lines;
A plurality of pixel electrodes connected to the plurality of pixel switching elements;
A row sense line disposed in parallel with the plurality of scan lines;
Column sense lines arranged in parallel to the plurality of data lines;
A photosensor element formed at the intersection of the row sense line and the column sense line;
A row sense line terminal connected to the row sense line and outputting a detection output of the photosensor element;
An electro-optical device comprising: a column sense line terminal connected to the column sense line and outputting a detection output of the photosensor element. The electro-optical device is further connected to the row sense line terminal and the column sense line terminal, and based on a detection output of the photosensor element, determines a position of a light shielding body or a light emitting body located adjacent to the substrate surface. It has a position detection circuit to detect,
The position detection circuit detects a position of the light shield or light emitter by calculating a position in a row direction from a current flowing in the row sense line and a position in a column direction from a current flowing in the column sense line. The electro-optical device according to claim 1. The electro-optical device further includes a row sense circuit connected to the row sense line terminal;
Comprising a column sense circuit connected to the column sense line terminal;
The row sense circuit includes a first A / D conversion circuit that converts a current flowing through the row sense line into a digital value;
The column sense circuit includes a second A / D conversion circuit that converts a current flowing through the column sense line into a digital value;
3. The electro-optical device according to claim 1, wherein the row sensing circuit and the column sensing circuit are configured by active elements formed on the same substrate as the plurality of pixel switching elements. The electro-optical device further includes a scanning line driving circuit connected to the plurality of scanning lines;
A data line driving circuit connected to the plurality of data lines;
At least one of the scanning line driving circuit and the data line driving circuit is constituted by an active element formed on the same substrate as an active element constituting the row sensing circuit and the column sensing circuit,
The scanning line driving circuit and the row sensing line circuit or the data line driving circuit and the column sensing circuit are present on both ends across a display region in which the plurality of pixel switching elements and the plurality of pixel electrodes are arranged. The electro-optical device according to claim 1, wherein the electro-optical device is provided.   The row sense circuit or the column sense circuit includes a serial conversion circuit for serially converting and outputting a signal output from the first or second A / D conversion circuit. The electro-optical device according to claim 3.   The number of row sense lines is less than the number of the plurality of scan lines, and the width of the pixel electrode in the direction perpendicular to the scan lines is a pixel electrode that overlaps the row sense line and a pixel that does not overlap the row sense line 6. The electro-optical device according to claim 1, wherein the electrodes are different from each other.   The number of column sense lines less than the number of the plurality of data lines, and the width of the pixel electrode in the direction perpendicular to the scanning line is a pixel electrode that overlaps the column sense line and a pixel that does not overlap the column sense line The electro-optical device according to claim 1, wherein the electrodes are different from each other.   8. The electro-optical device according to claim 7, wherein the pixel electrode overlapping the column sense line is a pixel electrode corresponding to blue display.   9. The electro-optic according to claim 6, wherein the transmission aperture ratios of pixel electrodes having different widths in a direction perpendicular to the scanning line or in a direction perpendicular to the data line are substantially equal to each other. apparatus.   The number of the row sense lines is approximately ½ of the number of the scanning lines, and among the scanning lines, the pixel switching elements connected to the odd-numbered scanning lines and the pixel switching connected to the even-numbered scanning lines. The elements are symmetrical with respect to the scanning line direction, and the row sense line is disposed between a pixel electrode connected to the odd-numbered scanning line and a pixel electrode connected to the even-numbered scanning line. 10. The electro-optical device according to claim 1, wherein the electro-optical device is provided.   The number of the column sense lines is approximately ½ of the number of the data lines, and among the data lines, the pixel switching elements connected to the odd-numbered data lines and the pixel switching connected to the even-numbered data lines. The elements are symmetrical with respect to the data line direction, and the column sense lines are arranged between pixel electrodes connected to odd-numbered data lines and pixel electrodes connected to even-numbered data lines. The electro-optical device according to claim 1, wherein the electro-optical device is any one of claims 1 to 10.   The photo sensor element is divided into a plurality of pixels and is composed of sub photo sensor elements connected in parallel to each other. The sub photo sensors are connected to each other by branch wirings made of thin film polysilicon. The electro-optical device according to claim 1, wherein the electro-optical device is connected to the row sense line or the column sense line.   13. The electro-optical device according to claim 1, wherein the row sense line or the column sense line is made of thin film polysilicon.   13. The electro-optical device according to claim 1, wherein the optical sensor is a photodiode including a PIN junction diode or a PN junction diode using thin film polysilicon as an active layer. A pixel auxiliary electrode made of an n + type or p + type semiconductor resistor configured by implanting ions into the same material as the active layer of the plurality of pixel switching elements;
The pixel auxiliary electrode is electrically connected to the pixel electrode;
A storage capacitor is formed by overlapping the storage capacitor line made of the same material as the scanning line or the scanning line and the pixel auxiliary electrode,
The row sense lines and the scanning lines are made of the same material,
When the pixel auxiliary electrode is an n + type semiconductor resistor, the row sense line is connected to the cathode electrode of the photodiode, and when the pixel auxiliary electrode is a p + type semiconductor resistor, the row sense line is the photosensor. The electro-optical device according to claim 14, wherein the electro-optical device is connected to an anode electrode of a diode. An electronic apparatus using the electro-optical device according to claim 1.