JP4894768B2 - Display device and electronic device - Google Patents

Description

  The present invention relates to a display device and an electronic apparatus.

  A touch panel is an auxiliary input device for a display unit (display device) in an electronic device such as a personal computer and a personal digital assistant (PDA), and an operator touches a desired position on the panel surface with a pen or a finger. It is an instruction to input data required by the electronic device.

  As such a touch panel, for example, a device that detects a touch position by arranging a touch panel circuit or a capacitance sensor circuit in an effective pixel and reading a capacitance change due to a finger press (for example, Patent Documents) is disclosed. 1).

JP 2007-48275 A

  By the way, the plurality of capacitor electrodes are formed on the layer where the signal line is formed for each pixel, and are connected across the signal line of each pixel on the layer where the scanning line is formed. However, the contact hole connecting the upper metal wiring and the lower metal wiring has an increased aspect ratio due to miniaturization of semiconductor elements and wiring. For this reason, the possibility of causing a reliability failure such as a contact failure due to insufficient coverage of the wiring due to the fine contact hole becomes very high, and there is a risk that the device reliability and the manufacturing yield are lowered due to the wiring failure. .

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

Application Example 1] A display device comprising a display region, a plurality of sensing areas for detecting and capacitance provided in the display area, and
An element substrate, a counter substrate, a liquid crystal layer sandwiched between the element substrate and the counter substrate, and display pixels provided in the display region corresponding to intersections of a plurality of scanning lines and a plurality of signal lines; A plurality of pixel circuits for driving pixel electrodes forming the display pixels, a first electrode and a second electrode provided in the sensing region, and a capacitance between the first electrode and the second electrode. A sensing circuit that outputs a sensing signal based on the first electrode , wherein the first electrode is formed in the same layer as the pixel electrode , and at least a portion of the first electrode is at least in plan view. A display device which overlaps with one of the signal lines.

  According to this, since one terminal of the capacitance detection element is formed on the same layer as the pixel electrode is formed, a contact hole for each portion overlapping (stranding) the signal line is not necessary, thereby reducing contact failure. can do. This provides a liquid crystal device capable of preventing or suppressing a decrease in wiring quality and maintaining and improving device reliability and manufacturing yield.

Application Example 2 In the display device described above, the first electrode is formed such that a portion overlapping the signal line is narrower than a width of the other portion of the first electrode .

  According to this, the influence of noise from the overlapping signal lines can be reduced, and the sensitivity increases. In addition, an increase in the parasitic capacitance of the signal line can be suppressed. As a result, the sensing performance is improved without degrading the display quality.

Application Example 3 In the display device, the sensing circuit has a gate connected to the first electrode and a power line electrically connected to one of the electrodes to generate a detection current corresponding to the gate potential. A first transistor that is output from the other electrode, and a second transistor that is provided between the gate of the first transistor and the power supply line and is turned on in response to a reset signal supplied to the gate through the first control line. A transistor, a reference capacitance element provided between the first control line and the gate of the first transistor, a second capacitor line provided between the other electrode of the first transistor and the detection line; And a third transistor which is turned on in response to a selection signal supplied to the gate through the display device.

  According to this, the configuration of the sensing circuit that outputs the sensing signal is easy.

Application Example 4 In the display device described above, at least a part of the first electrode overlaps at least one of the first and second control lines in a plan view.

  According to this, the capacitance component of the capacitance detection element increases without lowering the aperture ratio. As a result, the sensing performance is improved without degrading the display quality.

  Application Example 5 Electronic equipment including the display device described above.

  According to this, since the display device is mounted, it is possible to provide an electronic device that prevents or suppresses the deterioration of the wiring quality and realizes the maintenance and improvement of the device reliability and the manufacturing yield.

  Hereinafter, embodiments will be described with reference to the drawings. In each drawing used in the following description, the scale of each member is appropriately changed to make each member a recognizable size. Further, in this specification, a pixel area as a minimum unit is referred to as “sub-pixel”, and a set of a plurality of sub-pixels each having a color filter is referred to as “pixel”. An area between pixel areas is referred to as an “inter-pixel area”.

(First embodiment)
FIG. 1 is a plan view showing an overall configuration of a liquid crystal device 10 as a display device according to the present embodiment. 1A is a plan view, and FIG. 1B is a cross-sectional view taken along the line II of FIG. 1A.

  As shown in FIGS. 1A and 1B, in the liquid crystal device 10 of this embodiment, the element substrate 12 and the counter substrate 14 are bonded together by a sealing material 16, and the region is defined by the sealing material 16. Liquid crystal 18 is enclosed. The liquid crystal 18 is made of a liquid crystal material having positive dielectric anisotropy. A light shielding film (peripheral parting) 20 made of a light shielding material is formed in a region inside the region where the sealing material 16 is formed. In the peripheral circuit area outside the sealing material 16, a signal line driving circuit 22 and an external circuit mounting terminal 24 are formed along one side of the element substrate 12, and scanning line driving is performed along two sides adjacent to the one side. A circuit 26 is formed. On the remaining side of the element substrate 12, a plurality of wirings 28 are provided for connecting the scanning line driving circuits 26 provided on both sides of the image display area (display area) A. In addition, an inter-substrate conductive material 30 for providing electrical continuity between the element substrate 12 and the counter substrate 14 is disposed at a corner portion of the counter substrate 14.

  FIG. 2 is an equivalent circuit diagram of the liquid crystal device 10 according to the present embodiment. Pixel electrodes 32 are respectively formed on a plurality of sub-pixels (display pixels) S arranged in a matrix so as to form the image display area A of the liquid crystal device 10. Further, a TFT (Thin Film Transistor) element 36 that is a pixel switching element (pixel circuit) for performing energization control to the pixel electrode 32 is formed on the side of the pixel electrode 32. A signal line 38 is electrically connected to the source of the TFT element 36. Image signals S1, S2,..., Sn are supplied to the signal lines 38, respectively. The image signals S1, S2,..., Sn may be supplied to each signal line 38 in this order, or may be supplied to each of a plurality of adjacent signal lines 38 for each group.

  The scanning line 40 is electrically connected to the gate of the TFT element 36. The scanning signals G1, G2,..., Gm are supplied to the scanning line 40 in a pulse manner at a predetermined timing. The scanning signals G1, G2,..., Gm are applied sequentially to the respective scanning lines 40 in this order.

  Further, the pixel electrode 32 is electrically connected to the drain of the TFT element 36. When the TFT elements 36 serving as switching elements are turned on for a certain period by the scanning signals G1, G2,..., Gm supplied from the scanning lines 40, the image signals S1, S2,. , Sn are written into the liquid crystal 18 of each sub-pixel S at a predetermined timing.

  Image signals S1, S2,..., Sn written in the liquid crystal 18 are held for a certain period by a liquid crystal capacitance formed between the pixel electrode 32 and the common electrode 34 (see FIG. 1). In order to prevent leakage of the held image signals S1, S2,..., Sn, a storage capacitor 44 is formed between the pixel electrode 32 and the capacitor wiring 42, and is arranged in parallel with the liquid crystal capacitor. . Thus, when a voltage signal is applied to the liquid crystal 18, the alignment state of the liquid crystal molecules changes depending on the applied voltage level.

(Detailed configuration of liquid crystal device)
FIG. 3 is a plan view schematically showing a part of the image display area A of the liquid crystal device 10 according to the present embodiment, and FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. The liquid crystal device 10 in the present embodiment corresponds to the intersection of the plurality of scanning lines 40 and the plurality of signal lines 38, and is provided in the image display area A and the sub-pixels S provided in the image display area A. This is a sensor electrode integrated liquid crystal device having a plurality of inter-pixel regions (sensing regions) C for detecting capacitance. The inter-pixel region C overlaps with the black matrix BM, which is a non-display region where no image is displayed. The sub-pixel S includes a pixel electrode 32, a common electrode 34, and a liquid crystal layer 18 sandwiched between the element substrate 12 and the counter substrate 14, and is bordered by a black matrix BM.

  In the liquid crystal device 10 according to the present embodiment, sensing circuits 46 that detect whether or not the image display area A is touched are provided in a matrix form in the inter-pixel area C. The sensing circuit 46 converts touch information of the image display area A by the user into an electrical signal. The sensing circuit 46 is an electrode between the sensor electrode (one terminal) 50 and the sensor electrode (the other terminal) 52 of the capacitance detection element 48. A detection signal (sensing signal) that bears pressing information on the touch portion in the image display area A is output based on a change in capacitance caused by a user's pressing that occurs between the sensor electrode 50 and the pixel electrode 32. The detection signal output from the sensing circuit 46 is input to a drive circuit (not shown), and the drive circuit generates position information provided with the external pressure based on the detection signal.

  The sensing circuit 46 includes a signal detection element 54 and the like, and is selectively and regularly arranged in a unit region 56 (for example, a range indicated by a one-dot chain line in FIG. 3). That is, the liquid crystal device 10 according to the present embodiment has a so-called touch panel structure, and the liquid crystal device 10 is determined by determining whether or not the user touches an icon displayed in the image display area A. It is possible to input data required for driving.

  As shown in FIG. 4, the element substrate 12 is sequentially stacked on a substrate body 58 made of a light-transmitting material such as glass, quartz, and plastic, and on the inner surface (liquid crystal layer side) of the substrate body 58. The base insulating film 60, the gate insulating film 62, the interlayer insulating film 64, the planarizing film 66, and the alignment film 68 are provided.

  On the substrate body 58, signal lines 38 and scanning lines 40 are formed along the vertical and horizontal boundary regions of the plurality of pixels. In the sub-pixels S that are partitioned in plane by the signal lines 38 and the scanning lines 40, the semiconductor layer 70 disposed on the inner surface of the base insulating film 60 and the inner surface of the gate insulating film 62 are disposed. Gate electrode 72 (a part of scanning line 40), signal line 38 and drain electrode 74 disposed on the inner surface of interlayer insulating film 64, and pixel electrode disposed on the inner surface of planarization film 66 32. The signal line 38 is connected to the source region of the semiconductor layer 70, and the drain electrode 74 is electrically connected to the drain region of the semiconductor layer 70. The pixel electrode 32 is connected to the drain electrode 74 through a contact hole H1 formed in the planarizing film 66. Thus, the TFT element 36 and the pixel electrode 32 connected to the TFT element 36 are configured in the sub-pixel S.

  Further, as shown in FIGS. 3 and 4, in the inter-pixel region C, a sensing circuit 46 and a capacitance detection element 48 for converting unevenness information of the touch part by the user into an electric signal corresponding to a predetermined pixel are provided. Has been placed. The sensing circuit 46 includes a signal detection element 54 that outputs a detection signal that carries touch information. The signal detection element 54 is a MOS transistor including a gate electrode 76, a polycrystalline silicon layer 78, and a source / drain electrode 80. The electrostatic capacitance detection element 48 includes a pair of sensor electrodes 50 and 52 that detect the electrostatic capacitance of the liquid crystal layer 18. The electrostatic capacity is a variable capacity in which the capacity value of the liquid crystal layer 18 changes according to the pressing pressure of the user. The sensor electrode 50 is connected to the gate electrode 76 that controls the opening and closing of the selection transistor, transmits the change in the detection capacitance due to the user's touch to the signal detection element 54, and the drain current flowing through the channel region of the polycrystalline silicon layer 78. The change in electrostatic capacitance (pixel capacitance) can be sensed by the amplification action. The sensor electrode 50 is formed on the layer where the pixel electrode 32 is formed. At least a part of the sensor electrode 50 overlaps at least one signal line 38 in plan view.

  In this embodiment, the signal detection element 54 and the TFT element 36 are exemplified by a three-terminal transistor including a gate terminal (current control terminal), a source terminal (current output terminal), and a drain terminal (current input terminal). However, it is not limited to this.

  In order to manufacture the signal detection element 54 and the TFT element 36 shown in FIG. 4, a base insulating film 60 such as silicon oxide is laminated on the substrate body 58, and amorphous silicon is formed thereon to be crystallized. A crystalline silicon layer 78 and a semiconductor layer 70 are formed. Next, the gate insulating film 62 is formed on the polycrystalline silicon layer 78 and the semiconductor layer 70, the gate electrode 76 is formed on the polycrystalline silicon layer 78, and the gate electrode 72 is formed on the semiconductor layer 70. Then, impurities are implanted and diffused into the polycrystalline silicon layer 78 and the semiconductor layer 70 in a self-aligned manner to form source / drain regions, respectively. Next, the signal detection element 54 and the TFT element 36 are configured by forming the source / drain electrode 80, the signal line 38, and the drain electrode 74 on the interlayer insulating film 64.

  Further, a planarizing film 66 made of a light transmissive material is laminated to open a contact hole H1, and a sensor electrode 50 is formed of a metal material such as Al, and indium tin oxide (hereinafter referred to as “ITO”). After the pixel electrode 32 is formed with a light-transmitting conductive material such as the above, the entire surface is covered with an alignment film 68 made of a resin material such as polyimide, thereby forming the element substrate 12 of this embodiment. Yes. Here, the planarization film 66 ensures flatness on the polycrystalline silicon layer 78 and the semiconductor layer 70 and obtains a desired film thickness. The sensor electrode 50 may be formed simultaneously with the pixel electrode 32 using the same material as the pixel electrode 32.

  In addition, the method for forming a semiconductor element such as a transistor on the substrate body 58 is not limited to the above-described manufacturing method. For example, the semiconductor element such as a transistor is formed on the substrate body 58 by applying a peeling transfer technique. Also good. If the peeling transfer technique is applied, an inexpensive substrate having an appropriate strength such as a plastic substrate or a glass substrate can be adopted as the substrate body 58, so that the mechanical strength of the liquid crystal device 10 can be increased.

  On the other hand, the counter substrate 14 includes, for example, a substrate body 82 made of a light transmissive material such as glass, quartz, and plastic, and color filters CF (R (red), G (green) sequentially formed on the substrate body 82. , B (blue)), the black matrix BM, the planarizing film 84 formed on the entire surface of the substrate body 82 so as to cover the color filter CF and the black matrix BM, and the common formed on the planarizing film 84. The electrode 34 and the sensor electrode 52, and an alignment film 86 that covers the common electrode 34 and the sensor electrode 52 are provided.

  In the pixel region (sub-pixel S), a color filter CF and a common electrode 34 are provided corresponding to the pixel electrode 32 on the element substrate 12 side. Here, the color filter CF is made of a pigment and a photosensitive light-transmitting resin, and the common electrode 34 is made of a light-transmitting conductive material such as ITO, for example, like the pixel electrode 32.

  In the inter-pixel region C, a sensor electrode 52 corresponding to the sensor electrode 50 on the element substrate 12 side and a black matrix BM that functions to insulate the sensor electrode 52 from the common electrode 34 are provided. The sensor electrode 52 is made of a metal material such as Al, for example, like the sensor electrode 50 described above. As a light shielding film, the black matrix BM is formed on the substrate body 82 so as to partition the color filter CF.

  The liquid crystal panel is provided with a pair of polarizing plates 88 and 90 with their transmission axes substantially orthogonal to each other. Here, an optical compensation film (not shown) may be disposed on one or both of the inner sides of the polarizing plates 88 and 90.

  In the above-described configuration, the liquid crystal device 10 of the present embodiment has an electric capacity corresponding to the thickness of the liquid crystal layer 18. For example, when the image display area A is touched by the user's fingertip, the pressure is reduced. The capacitance of the liquid crystal layer 18 changes simultaneously with the bending of the counter substrate 14 according to the pressure, and a pressing signal is output from the sensor electrode 50. When the signal detection element 54 is opened by the gate electrode 76, a detection current determined by the gate potential is output from the signal detection element 54. This detected current is processed as a touch signal. In this way, by detecting whether or not the user's fingertip or the like has been touched on the icon or the like displayed in the image display area A, data required when driving the liquid crystal device 10 can be directly input. It is possible.

(Circuit configuration)
FIG. 5 is a diagram illustrating circuits of the sensing circuit 46 and the capacitance detection element 48 according to the present embodiment. The sensing circuit 46 includes an amplification transistor (first transistor) 54, a reset transistor (second transistor) 92, and a selection transistor (third transistor) 94 as signal detection elements. These transistors are composed of TFT elements similarly to the above-described TFT elements 36 of the pixel circuit, and are formed by the same process.

A reset signal RES is supplied to the gate of the reset transistor 92 via the first control line 96. The drain of the reset transistor 92 is connected to the power supply line 98, and the source is connected to the gate of the amplification transistor 54. A voltage V _RH is supplied to the power line 98.

  The drain of the amplification transistor 54 is connected to the power supply line 98, and its source is connected to the drain of the selection transistor 94. The source of the selection transistor 94 is connected to the detection line 100, and the selection signal SEL is supplied to the gate of the selection transistor 94 via the second control line 102.

  A reference capacitive element 104 is provided between the gate of the amplification transistor 54 and the first control line 96. Further, one terminal of the capacitance detection element 48 is connected to the gate of the amplification transistor 54, and a fixed potential Vx is supplied to the other terminal. In this example, the fixed potential Vx is different from the common potential Vcom. Therefore, even if the common potential Vcom is changed by AC driving, the potential of the amplification transistor 54 does not change, and sensing can be performed independently of the image display. In addition, since it is not necessary to perform sensing in synchronization with the image display cycle of the display device, sensing can be performed as necessary, or sensing can be performed at a longer cycle. As a result, power consumption can be reduced.

(Circuit operation)
Next, the operation of the sensing circuit 46 will be described with reference to FIGS.
FIG. 6 is a timing chart for explaining the operation of the sensing circuit 46 according to the present embodiment. 7 to 9 are diagrams for explaining the operation of the sensing circuit 46 according to the present embodiment. As shown in FIG. 6, the sensing circuit 46 operates with the reset period Tres, the sensing period Tsen, and the readout period Tout as one unit.

(Reset period)
First, in the reset period Tres, the level of the reset signal RES becomes VD, and the reset transistor 92 is turned on. At this time, the selection signal SEL is at a low level, and the selection transistor 94 is turned off. Then, as shown in FIG. 7, the potential of the gate of the amplification transistor 54 is reset to the power supply potential _VRH .

(Sensing period)
Next, in the sensing period Tsen following the reset period Tres, the level of the reset signal RES changes from VD to GND (= 0V). Then, as shown in FIG. 8, the reset transistor 92 is turned off. Since the first control line 96 is connected to one electrode of the reference capacitor 104, the reference capacitor 104 functions as a coupling capacitor, and the gate potential of the amplification transistor 54 changes when the level of the reset signal RES changes. .

  If the capacitance value of the reference capacitance element 104 is Cr, the capacitance value of the capacitance detection element 48 is Cs, and the potential change of the first control line 96 is ΔVgate (= VD), the gate potential of the amplification transistor 54 is The change ΔV is given by the following equation (1). However, the parasitic capacitance is ignored.

ΔV = ΔVgate × Cr / (Cr + Cs) (1)
From equation (1), if the capacitance value Cs of the capacitance detection element 48 is large, the change ΔV due to capacitive coupling is small, and conversely, if the capacitance value Cs is small, the change ΔV is large. Therefore, the capacitance change of the capacitance detection element 48 can be reflected in the gate potential.

(Reading period)
Next, in the reading period Tout, the selection signal SEL changes from the low level to the high level. Then, the selection transistor 94 is turned on as shown in FIG. As a result, a detection current Idet corresponding to the gate potential of the amplification transistor 54 flows through the detection line 100. By the way, it is preferable to precharge the potential of the detection line 100 to the precharge potential Vpre prior to the read period Tout in order to ensure that the selection transistor 94 is turned on in the read period Tout. In this example, as shown in FIG. 6, the reset period Tres and the sensing period Tsen are set as the precharge period Tpre, and the precharge potential Vpre is supplied to the detection line 100 during the period.

Here, the change of the electrostatic capacitance by the electrostatic capacitance detection element 48 will be described with reference to FIG.
FIG. 10 is a diagram for explaining a change in capacitance due to the capacitance detection element 48 according to the present embodiment. As shown in FIG. 10, the capacitance detection element 48 is configured by sandwiching the liquid crystal 18 between the sensor electrode 50 and the sensor electrode 52. In a state where a human finger is not touched, the sensor electrode 50 and the sensor electrode 52 are parallel as shown in FIG. 5A, but when the liquid crystal device 10 is pressed with a finger, as shown in FIG. The sensor electrode 52 is bent, and the distance between the sensor electrode 50 and the sensor electrode 52 is shortened. For this reason, when a person presses the liquid crystal device 10 with a finger, the capacitance value Cs of the capacitance detection element 48 increases. In this way, a change in capacitance is detected.

  Further, the reference capacitor element 104 of this example is configured by using a polycrystalline silicon layer 78 as one electrode, using a gate electrode 76 as the other electrode, and sandwiching a gate insulating film 62 therebetween. The polycrystalline silicon layer 78, the gate electrode 76, and the gate insulating film 62 are formed by the same process as the other transistors 54 and 92. Therefore, a special process is not necessary for forming the reference capacitor element 104, and the manufacturing cost can be reduced.

  According to the present embodiment, since the sensor electrode 50 of the capacitance detection element 48 is formed in the same layer as the pixel electrode 32 is formed, the contact hole H1 for each part overlapping (stranding) the signal line 38 is formed. Contact failure can be reduced because it is not necessary. This provides the liquid crystal device 10 that can prevent or suppress a decrease in wiring quality and can maintain and improve device reliability and manufacturing yield.

(Second Embodiment)
Next, a second embodiment will be described with reference to the drawings.
FIG. 11 is a plan view schematically showing a part of the image display area A of the liquid crystal device 106 according to the present embodiment. The liquid crystal device 106 of the present embodiment is a TFT active matrix type transmissive liquid crystal device, similar to the liquid crystal device 10 according to the first embodiment, and is characterized by the sensor electrode 50 and the signal line 38. It overlaps with. Accordingly, since the basic configuration of the liquid crystal device 106 of the present embodiment is the same as that of the liquid crystal device 10 of the first embodiment, common components are denoted by the same reference numerals, and detailed description thereof is omitted or simplified.

  In the liquid crystal device 106 of this embodiment, as shown in FIG. 11, a portion that overlaps the signal line 38 that supplies a signal voltage to each pixel of the sensor electrode 50 is formed to be narrower than the width of the other portion of the sensor electrode 50. Yes. According to this, the influence of noise from the signal line 38 can be suppressed, and the sensitivity can be increased. In addition, an increase in parasitic capacitance of the signal line 38 can be suppressed.

(Third embodiment)
Next, a third embodiment will be described with reference to the drawings.
FIG. 12 is a plan view schematically showing a part of the image display area A of the liquid crystal device 108 according to the present embodiment. The liquid crystal device 108 according to the present embodiment is a TFT active matrix type transmissive liquid crystal device, similar to the liquid crystal device 10 according to the first embodiment, and is characterized by the sensor electrode 50 and the first And the second control lines 96 and 102 overlap. Accordingly, since the basic configuration of the liquid crystal device 108 of the present embodiment is the same as that of the liquid crystal device 10 of the first embodiment, common components are denoted by the same reference numerals, and detailed description thereof is omitted or simplified.

  In the liquid crystal device 108 of the present embodiment, as shown in FIG. 12, the sensor electrode 50 overlaps at least one of the first and second control lines 96 and 102 in plan view. According to this, the capacity of the storage capacitor 44 can be increased without decreasing the aperture ratio, and the sensitivity can be increased.

(Electronics)
Next, an electronic apparatus using the liquid crystal device according to the present embodiment will be described with reference to FIG.
FIG. 13A is a perspective view showing a configuration of a mobile personal computer 110 that employs the liquid crystal device 10 (106, 108) according to the embodiment as a display unit. The personal computer 110 includes a liquid crystal device 10 (106, 108) as a display unit and a main body 112. The main body 112 is provided with a power switch 114 and a keyboard 116. Menu buttons 118, 120, 122 are displayed on the liquid crystal device 10 (106, 108). Various programs can be assigned to these menu buttons. For example, an e-mail can be assigned to the menu button 118, a browser can be assigned to the menu button 120, and drawing software can be assigned to the menu button 122. Even if the user does not operate the keyboard 116, the user can activate desired software simply by touching the menu button.

  FIG. 13B is a perspective view showing a configuration of a mobile phone 130 to which the liquid crystal device 10 (106, 108) according to the above embodiment is applied. The cellular phone 130 includes a plurality of operation buttons 132, scroll buttons 134, and the liquid crystal device 10 (106, 108) as a display unit. By operating the scroll button 134, the screen displayed on the liquid crystal device 10 (106, 108) is scrolled. Menu buttons 136 and 138 are displayed on the liquid crystal device 10 (106, 108). For example, when the user touches the menu button 136, the phone book is displayed, and when the user touches the menu button 138, the telephone number of the cellular phone is displayed.

  FIG. 13C is a perspective view showing a configuration of a personal digital assistant (PDA) 140 to which the liquid crystal device 10 (106, 108) according to the embodiment is applied. The portable information terminal 140 includes a plurality of operation buttons 142, a power switch 144, and the liquid crystal device 10 (106, 108) as a display unit. When the power switch 144 is operated, menu buttons 146 and 148 are displayed. For example, when the menu button 146 is pressed, the address book is displayed, and when the menu button 148 is pressed, the schedule book is displayed.

  In addition, as an electronic apparatus to which the electro-optical device according to the present embodiment is applied, in addition to those shown in FIGS. 13A to 13C, a digital still camera, a television, a video camera, a car navigation device, an electronic notebook, Examples include electronic paper, a calculator, a word processor, a workstation, a videophone, a scanner, a copier, a video player, and a device equipped with a touch panel.

  The common electrode 34 may be formed on the element substrate 12 side. In this case, the common electrode may be formed through the pixel electrode and the insulating layer, or the common electrode may be formed in the same layer as the pixel electrode. Further, the capacitor electrode may be formed by using any one of the pixel electrode and the common electrode on the element substrate side. Note that in the case where the capacitor electrode is formed on the layer where the common electrode is formed, it is preferable that it does not overlap with the pixel electrode. This is because when the capacitor electrode overlaps with the pixel electrode, a capacitor is formed in the overlapped portion, and when the voltage of the pixel electrode changes due to signal voltage writing, the voltage of the overlapped portion changes, and the capacitance change of Cs cannot be read correctly. Because. Further, in the case where the capacitor electrode is formed on the layer where the pixel electrode is formed, it is preferable that it does not overlap with the common electrode. This is because when the capacitance electrode overlaps the common electrode, a capacitance is formed in the overlapped portion, and the denominator in the equation (1) increases, so that the amount of change in voltage decreases and sensitivity decreases.

  In addition, each of the above embodiments is an example in which the electro-optical device is applied to a liquid crystal device, but it can be applied to an organic EL display device instead.

1 is a plan view showing an overall configuration of a liquid crystal device according to a first embodiment. FIG. 2 is an equivalent circuit diagram of the liquid crystal device according to the first embodiment. FIG. 2 is a plan view schematically showing a part of an image display area of the liquid crystal device according to the first embodiment. Sectional drawing which follows the IV-IV line of FIG. The figure which shows the circuit of the sensing circuit and electrostatic capacitance detection element which concern on 1st Embodiment. The timing chart for demonstrating operation | movement of the sensing circuit which concerns on 1st Embodiment. The figure which shows operation | movement of the sensing circuit which concerns on 1st Embodiment. The figure which shows operation | movement of the sensing circuit which concerns on 1st Embodiment. The figure which shows operation | movement of the sensing circuit which concerns on 1st Embodiment. The figure which shows the change of the electrostatic capacitance by the electrostatic capacitance detection element which concerns on 1st Embodiment. FIG. 6 is a plan view schematically showing a part of a pixel array on an element substrate of a liquid crystal device according to a second embodiment. FIG. 6 is a plan view schematically showing a part of a pixel array on an element substrate of a liquid crystal device according to a third embodiment. The perspective view which shows the structure of the electronic device which employ | adopted the liquid crystal device which concerns on this embodiment as a display part.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Liquid crystal device (display device) 12 ... Element substrate 14 ... Opposite substrate 16 ... Sealing material 18 ... Liquid crystal layer (liquid crystal) 20 ... Shading film (peripheral parting) 22 ... Signal line drive circuit 24 ... External circuit mounting terminal 26 ... Scanning Line drive circuit 28 ... Wiring 30 ... Substrate conductive material 32 ... Pixel electrode 34 ... Common electrode 36 ... TFT element 38 ... Signal line 40 ... Scanning line 42 ... Capacitor wiring 44 ... Storage capacitor 46 ... Sensing circuit 48 ... Capacitance detection Element 50 ... Sensor electrode (one terminal) 52 ... Sensor electrode (the other terminal) 54 ... Signal detection element (amplification transistor) (first transistor) 56 ... Unit region 58 ... Substrate body 60 ... Base insulating film 62 ... Gate insulation Film 64 ... Interlayer insulating film 66 ... Planarizing film 68 ... Alignment film 70 ... Semiconductor layer 72 ... Gate electrode 74 ... Drain electrode 76 ... Gate Electrode 78 ... Polycrystalline silicon layer 80 ... Source / drain electrode 82 ... Substrate body 84 ... Planarizing film 86 ... Alignment film 88, 90 ... Polarizing plate 92 ... Reset transistor (second transistor) 94 ... Selection transistor (third transistor) 96 ... first control line 98 ... power supply line 100 ... detection line 102 ... second control line 104 ... reference capacitance element 106,108 ... liquid crystal device 110 ... personal computer 112 ... main body 114 ... power switch 116 ... keyboard 118,120, 122 ... Menu button 130 ... Mobile phone 132 ... Operation button 134 ... Scroll button 136, 138 ... Menu button 140 ... Mobile information terminal 142 ... Operation button 144 ... Power switch 146, 148 ... Menu button

Claims (5)

A display device comprising: a display area; and a plurality of sensing areas for detecting capacitance provided in the display area,
An element substrate, a counter substrate, and a liquid crystal layer sandwiched between the element substrate and the counter substrate;
Corresponding to the intersection of a plurality of scanning lines and a plurality of signal lines, display pixels provided in the display area,
A plurality of pixel circuits for driving pixel electrodes forming the display pixels;
A first electrode and a second electrode provided in the sensing region;
A sensing circuit that outputs a sensing signal based on a capacitance between the first electrode and the second electrode ;
Including
The first electrode is formed in the same layer as the layer in which the pixel electrode is formed,
At least a part of the first electrode overlaps at least one of the signal lines in a plan view. The display device according to claim 1,
The display device according to claim 1 , wherein a portion of the first electrode that overlaps the signal line is formed to be narrower than a width of another portion of the first electrode . The display device according to claim 1 or 2,
The sensing circuit is
A first transistor having a gate connected to the first electrode and a power line electrically connected to one electrode and outputting a detection current corresponding to the gate potential from the other electrode;
A second transistor provided between the gate of the first transistor and the power supply line and turned on in response to a reset signal supplied to the gate through the first control line;
A reference capacitive element provided between the first control line and the gate of the first transistor;
A third transistor provided between the other electrode of the first transistor and the detection line, and turned on in response to a selection signal supplied to the gate via the second control line;
A display device comprising: The display device according to claim 3,
At least a part of the first electrode overlaps at least one of the first and second control lines in a plan view.   An electronic apparatus comprising the display device according to claim 1.

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