Touch sensor

Abstract

To provide a touch sensor capable of minimizing a vertical direction parasitic capacitance itself.SOLUTION: A touch sensor in accordance with the present invention has a display panel, which includes plural pixel electrodes associated with respective pixels disposed in a matrix form and a common electrode shared across the plural pixels, and a touch panel, which is used to detect a position of at least one of a finger and pen, in a structure in which the display panel and the touch panel are superposed on each other in a vertical direction. The common electrode has plural H-shaped holes arrayed in a second direction on every other line of the matrix seen in a first direction. Each of the H-shaped holes is formed using an area between two pixels adjoining in the second direction and areas on both sides in the first direction of the two pixels. On a line having two H-shaped holes adjoining in the first direction, the positions of the H-shaped holes are displaced from each other by one pixel.SELECTED DRAWING: Figure 14

Description

[Technical field]

[0001] The present invention relates to a touch sensor having a structure in which a display panel and a touch panel are arranged so as to overlap each other in the vertical direction. [Background technology]

[0002] There is known a touch sensor having a structure in which a touch panel for detecting the position of a finger or a pen is disposed on a display panel. Among these types of touch sensors, those in which the display panel and the touch panel are integrally formed are called "on-cell type," and those in which the display panel and the touch panel are formed separately are called "out-cell type." In the following, these "on-cell type" and "out-cell type" are collectively referred to simply as "touch sensor."

[0003] In a touch sensor, in addition to the parasitic capacitance occurring between sensor electrodes in the touch panel, a parasitic capacitance also occurs between the touch panel and the display panel. Hereinafter, the latter parasitic capacitance is referred to as "vertical parasitic capacitance." The display drive signal supplied from the computer to the display panel also reaches the touch panel via this vertical parasitic capacitance. The display drive signal thus reaching the touch panel becomes noise in the operation of the touch panel, reducing the detection accuracy of a finger or pen.

[0004] Patent Documents 1 and 2 disclose techniques for preventing such a decrease in detection accuracy. Specifically, Patent Document 1 discloses a technique for reducing the above-mentioned noise by a process on the display side that changes the driving method of a plurality of pixel electrodes according to the contents of image data and the polarity of each pixel electrode. Patent Document 2 discloses a technique for reducing the influence of the above-mentioned noise by providing a charge equivalent to the vertical parasitic capacitance to a charge amplifier of a touch sensor. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2019 / 087332 [Patent Document 2] JP 2011-222013 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, although the techniques described in the above Patent Documents 1 and 2 can reduce noise, they cannot reduce the vertical parasitic capacitance itself. In order to detect the position of a finger or pen with as little influence as possible from the display, it is preferable to reduce the vertical parasitic capacitance itself.

[0007] Therefore, one object of the present invention is to provide a touch sensor that can reduce the vertical parasitic capacitance itself. [Means for solving the problem]

[0008] The touch sensor according to the present invention is a touch sensor having a structure in which a display panel having a plurality of pixel electrodes corresponding to each of a plurality of pixels and a common electrode provided in common to the plurality of pixels, and a touch panel for detecting the position of at least one of a finger and a pen are arranged vertically superimposed on one another, and the common electrode has a conductor area suppression portion that reduces the area of ​​the common electrode. Effect of the Invention

[0009] According to the present invention, since the area of ​​the common electrode which constitutes most of one electrode of the vertical capacitance can be reduced, it becomes possible to reduce the vertical parasitic capacitance itself. [Brief description of the drawings]

[0010] [Figure 1]1 is a diagram showing a configuration of an electronic device 1 including a touch sensor 2 according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view of the display panel 4 shown in FIG. [Diagram 3] FIG. 2 is a diagram showing a circuit configuration of an individual OLED cell PX. [Figure 4] 2. FIG. 3(a) is a cross-sectional view of the display panel 4 corresponding to the line AA shown in FIG. 2, and FIG. 3(b) is a cross-sectional view of the display panel 4 corresponding to the line BB shown in FIG. [Diagram 5] FIG. 5 is a diagram showing a planar configuration of the common electrode 32 shown in FIGS. 4(a) and 4(b). [Figure 6] FIG. 13 is a diagram showing a planar configuration of a common electrode 32 according to a first modified example of the first embodiment of the present invention. [Figure 7] 7A is a cross-sectional view of the display panel 4 corresponding to the line CC shown in FIG. 6, and FIG. 7B is a cross-sectional view of the display panel 4 corresponding to the line DD shown in FIG. [Figure 8] FIG. 13 is a diagram showing a planar configuration of a common electrode 32 according to a second modified example of the first embodiment of the present invention. [Figure 9] FIG. 13 is a diagram showing a planar configuration of a common electrode 32 according to a third modified example of the first embodiment of the present invention. [Figure 10] FIG. 13 is a diagram showing a planar configuration of a common electrode 32 according to a fourth modified example of the first embodiment of the present invention. [Figure 11] 13 is a diagram showing a planar configuration of a common electrode 32 included in a touch sensor 2 according to a second embodiment of the present invention. FIG. [Figure 12] 11. FIG. 14(a) is a cross-sectional view of the display panel 4 corresponding to the EE line shown in FIG. 11, and FIG. 14(b) is a cross-sectional view of the display panel 4 corresponding to the FF line shown in FIG. [Figure 13] FIG. 13 is a diagram showing a planar configuration of a common electrode 32 according to a first modified example of the second embodiment of the present invention. [Figure 14] FIG. 13 is a diagram showing a planar configuration of a common electrode 32 according to a second modified example of the second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0012] 1 is a diagram showing the configuration of an electronic device 1 including a touch sensor 2 according to the present embodiment. In the figure, only the portion of the touch sensor 2 is shown in a vertical cross-sectional view showing the panel structure. The electronic device 1 is a personal information device such as a tablet terminal, a smartphone, or a notebook computer, and is configured to include a host processor 50, a memory 51, and a sensor controller 52 in addition to the touch sensor 2.

[0013] The host processor 50 is a central processing unit of the electronic device 1. The memory 51 is a storage device configured to be able to store any data, and includes a main storage device such as a dynamic random access memory (DRAM) and an auxiliary storage device such as a hard disk. The host processor 50 is configured to be able to execute various applications including the operating system and drawing applications of the electronic device 1 by reading and executing programs stored in the memory 51. The memory 51 functions as a work memory for the host processor 50, and also has a role of storing data generated by the host processor 50.

[0014] The sensor controller 52 is an integrated circuit that detects the positions of a finger and a pen on the touch surface 2a (described later) using the touch panel 6. Details of the processing performed by the sensor controller 52 will be described later. The specific detection method for the positions of the finger and the pen is not particularly limited, but for example, the finger position detection is performed by a capacitance method, and the pen detection is performed by an active electrostatic method or an electromagnetic induction method. In the following, the explanation will be continued on the assumption that the finger position detection is performed by a capacitance method, and the pen position detection is performed by an active electrostatic method.

[0015] The touch sensor 2 is classified as an on-cell type touch sensor, and has a structure in which a display panel 4 and a touch panel 6 are integrally formed. More specifically, as shown in FIG. 1, the touch sensor has a structure in which a glass substrate 3 (bottom glass), a display panel 4, a glass substrate 5 (top glass), a touch panel 6, a polarizing plate 7, an air gap 8, and a glass substrate 9 (window glass) are laminated in this order. Of these, the surface of the glass substrate 9 constitutes a touch surface 2a on which a user slides a finger or a pen. Hereinafter, the upper side of the touch sensor 2 refers to the touch surface 2a side, and the lower side of the touch sensor 2 refers to the opposite side of the touch surface 2a (the surface of the glass substrate 3).

[0016] The display panel 4 is an organic EL display arranged on a glass substrate 3, and has a structure in which a plurality of OLED (Organic Light Emitting Diode) cells, each constituting one pixel (subpixel), are arranged in a matrix. The structure of the display panel 4 will be described in more detail later. The display panel 4 plays a role in displaying an image generated by the host processor 50 by individually driving each OLED cell based on a display drive signal supplied from the host processor 50.

[0017] The touch panel 6 is a sensor for detecting the position of at least one of a finger and a pen, and is disposed on the upper surface of the display panel 4 (more specifically, on the upper surface of the common electrode 32 described later) via a glass substrate 5. The glass substrate 5 is a transparent insulator having a predetermined dielectric constant ε and a thickness d2. A specific value of the thickness d2 is, for example, a value smaller than several tens of μm.

[0018] A plurality of sensor electrodes (not shown) each connected to the sensor controller 52 are disposed within the touch panel 6. The plurality of sensor electrodes include a plurality of first linear conductors (not shown) extending parallel to one side of the rectangular touch panel 6 and arranged at equal intervals, and a plurality of second linear conductors (not shown) each extending in a direction perpendicular to the one side and arranged at equal intervals. Both the first and second linear conductors are made of a transparent conductor such as indium tin oxide (ITO).

[0019] The sensor controller 52 performs a process of detecting the position of the pen and receiving data transmitted by the pen by performing two-way communication with the pen using a plurality of sensor electrodes included in the touch panel 6. The sensor controller 52 also performs a process of detecting the position of the finger by supplying a finger detection signal to each of a plurality of first linear conductors and receiving the signal by each of a plurality of second linear conductors. The sensor controller 52 sequentially supplies the position of the pen or finger thus detected and the data received from the pen to the host processor 50. The host processor 50 performs a process of generating an image based on the position and data thus supplied, and supplying a display drive signal for displaying the generated image to the display panel 4. The image generated by the host processor 50 includes a cursor displayed at a position corresponding to the position of the finger or pen, stroke data indicating the trajectory of the position of the finger or pen, and the like.

[0020] The polarizing plate 7 is disposed on the upper surface of the touch panel 6 to improve the outdoor visibility of the display panel 4. The glass substrate 9 is a flat and transparent insulator, and disposed on the polarizing plate 7 via an air gap 8. A resin layer may be used in place of or in addition to the air gap 8. The distance d1 between the touch panel 6 and the touch surface 2a is the total value of the thicknesses of the polarizing plate 7, the air gap 8, and the glass substrate 9. The greater the distance d1, the longer the distance between the multiple sensor electrodes included in the touch panel 6 and the finger or pen, which deteriorates the accuracy of position detection by the sensor controller 52. Therefore, it is preferable to make the distance d1 as small as possible.

[0021] Here, the accuracy of position detection by the sensor controller 52 is affected by the thickness d2 of the glass substrate 5 as well as the distance d1. That is, the display drive signal leaking from the display panel 4 reaches the touch panel 6 via the above-mentioned vertical parasitic capacitance (parasitic capacitance occurring between the touch panel 6 and the display panel 4). The display drive signal that reaches the touch panel 6 is superimposed as noise on the signal transmitted and received between the sensor controller 52 and the pen and on the above-mentioned finger detection signal, so it is preferable to reduce the intensity of the display drive signal that reaches the touch panel 6 as much as possible, and for this purpose, it is preferable to increase the thickness d2 to reduce the vertical parasitic capacitance. However, from the viewpoint of reducing the height of the touch sensor 2 and the visibility of the display panel 4, it is preferable to reduce the thickness d2, and the actual thickness d2 is rather tending to decrease. If the thickness d2 decreases, the above-mentioned distance d1 becomes relatively large, and as a result, the accuracy of position detection by the sensor controller 52 deteriorates, so a technology for reducing the vertical parasitic capacitance by a method other than increasing the thickness d2 is required.

[0022] The present invention realizes a reduction in the vertical parasitic capacitance by a method other than increasing the thickness d2, by devising an internal structure of the display panel 4. Hereinafter, the structure of the display panel 4 that realizes a reduction in the vertical parasitic capacitance regardless of the thickness d2 will be specifically described with reference to Figs. 2 to 5.

[0023] Fig. 2 is a plan view of the display panel 4. As shown in the figure, the display panel 4 has a configuration in which a plurality of OLED cells PX (pixels) are arranged in a matrix along the x direction and y direction shown in the figure. Note that the area (rectangular area) of each OLED cell PX shown in Fig. 2 represents the range of light emission.

[0024] In Fig. 2 and the figures shown later, an OLED cell PX marked with "R" is an OLED cell PX configured to emit red light, an OLED cell PX marked with "G" is an OLED cell PX configured to emit green light, and an OLED cell PX marked with "B" is an OLED cell PX configured to emit blue light. As shown in Fig. 2, a set of three OLED cells PX corresponding to "R", "G", and "B" from the left is repeatedly arranged in the x direction. In addition, OLED cells PX of the same color are repeatedly arranged in the y direction.

[0025] The display panel 4 is configured to have a plurality of gate lines GL, a plurality of source lines SL, and a plurality of power lines VL. Each gate line GL is provided in common to a plurality of OLED cells PX arranged in the x direction, and is connected to each corresponding OLED cell PX. Each source line SL and each power line VL is provided in common to a plurality of OLED cells PX arranged in the y direction, and is connected to each corresponding OLED cell PX.

[0026] FIG. 3 is a diagram showing the circuit configuration of an individual OLED cell PX. As shown in the figure, the OLED cell PX is configured to have a switching transistor Ts, a driving transistor Td, an organic light-emitting diode EL, and a capacitor C. Of these, the gate of the switching transistor Ts is connected to the corresponding gate line GL, and the source is connected to the corresponding source line SL. In addition, the source of the driving transistor Td is connected to the corresponding power line VL. The drain of the switching transistor Ts is connected to the gate of the driving transistor Td. The gate of the driving transistor Td is also connected to its own source via the capacitor C. The anode of the organic light-emitting diode EL is connected to the drain of the driving transistor Td, and the cathode is grounded.

[0027] The OLED cells PX are driven in units of rows of the matrix. Specifically, the host processor 50 first determines the emission intensity of each of the series of OLED cells PX arranged in the x direction based on the image to be displayed, and supplies a potential corresponding to the determined emission intensity to each source line SL. Next, the corresponding gate line GL is activated to turn on the switching transistor Ts of the corresponding series of OLED cells PX. This causes the potential of the corresponding source line SL to be supplied to the gate of the drive transistor Td, turning on the drive transistor Td. The power supply line VL is connected to a power supply of a predetermined voltage, and when the drive transistor Td is turned on, a current of an amount corresponding to the potential of the source line SL is supplied to the organic light-emitting diode EL. This causes the organic light-emitting diode EL to emit light with the determined emission intensity.

[0028] Fig. 4(a) is a cross-sectional view of the display panel 4 corresponding to the line AA shown in Fig. 2, and Fig. 4(b) is a cross-sectional view of the display panel 4 corresponding to the line BB shown in Fig. 2. Hereinafter, the layered structure of the display panel 4 will be described with reference to Figs. 4(a) and 4(b).

[0029] First, the display panel 4 is configured to have six insulating layers 10 to 15 in this order from the bottom. On the upper surface of the insulating layer 10, a gate 20 of the switching transistor Ts, a gate 24 of the driving transistor Td, and a gate line GL are formed. Among these, the gate 20 and the gate line GL are connected to each other via a conductor (not shown in FIG. 4) formed on the upper surface of the insulating layer 10. In addition, on the upper surface of the insulating layer 11, a channel 21 of the switching transistor Ts and a channel 25 of the driving transistor Td are formed.

[0030] On the upper surface of the insulating layer 12, a source 22 and a drain 23 of the switching transistor Ts, a drain 26 and a source 27 of the driving transistor Td, a source line SL, and a power supply line VL are formed. Of these, the source 22 is connected to one end of the channel 21 by a via conductor that penetrates the insulating layer 12. The drain 23 is connected to the other end of the channel 21 by a via conductor that penetrates the insulating layer 12, and is also connected to the gate 24 by a via conductor that penetrates the insulating layers 11 and 12. The drain 26 is connected to one end of the channel 25 by a via conductor that penetrates the insulating layer 12. The source 27 is connected to the other end of the channel 25 by a via conductor that penetrates the insulating layer 12. The capacitor C shown in FIG. 3 is constituted by a parasitic capacitance formed between the source 27 and the gate 24.

[0031] A pixel electrode 30 corresponding to the anode of the organic light-emitting diode EL is formed on the upper surface of the insulating layer 14. The pixel electrode 30 is connected to the drain 26 by a via conductor penetrating the insulating layers 13 and 14. As shown in FIG. 4(b), an insulating layer 33 is formed between two pixel electrodes 30 adjacent in the y direction, thereby ensuring insulation between the two pixel electrodes 30 adjacent in the y direction. On the other hand, as shown in FIG. 4(a), two pixel electrodes 30 adjacent in the x direction are insulated from each other by an insulating layer 15.

[0032] The insulating layer 15 is formed thicker than the insulating layer 33, and a valley-like structure is formed between two insulating layers 15 adjacent in the x direction, with the pixel electrodes 30 and the insulating layers 33 alternately exposed at the bottom. A light-emitting layer 31 is formed at the bottom of this valley with a constant thickness. The light-emitting layer 31 is made of a material that emits light in response to the potential difference between the corresponding pixel electrode 30 and common electrode 32. In addition, a common electrode 32 that corresponds to the cathode of the organic light-emitting diode EL is formed on the upper surface of the light-emitting layer 31.

[0033] The common electrode 32 is also formed on the side of the valley formed by the insulating layer 15 and on the upper surface of the insulating layer 15, and forms a rectangular solid conductor that covers the entire display panel 4, not for each pixel. As a result, the common electrode 32 forms a large portion of one electrode of the vertical capacitance. The reason why the common electrode 32 is formed of a solid conductor is to reduce the resistance of the common electrode 32 as much as possible. Normally, holes are not formed in the common electrode 32, but in this embodiment, one or more holes H are provided in the common electrode 32. Each of these one or more holes H functions as a conductor area suppressing portion that reduces the area of ​​the common electrode 32, and plays a role of reducing the area of ​​the common electrode 32 as a whole. The touch sensor 2 according to this embodiment thus realizes a reduction in the vertical parasitic capacitance by reducing the area of ​​the common electrode 32 by providing one or more holes H in the solid conductor.

[0034] Fig. 5 is a diagram showing the planar configuration of the common electrode 32. The dashed lines in the figure indicate the light emission range of each pixel. As shown in the figure, the common electrode 32 is connected to a constant voltage power supply to which a ground potential GND is supplied by one or more power supply wirings. In the example of Fig. 5, a total of four power supply wirings are provided, two at each end in the x direction of the display panel 4.

[0035] 5, the holes H of the common electrode 32 according to the present embodiment are formed in regions corresponding to spaces between a plurality of pixels when viewed in the horizontal direction. More specifically, the common electrode 32 is provided with a plurality of holes H, and each hole H is formed to extend in the y direction in each of a plurality of regions corresponding to spaces between two pixels adjacent in the x direction. However, several bridges Ha (portions where no holes H are formed) are also provided in each of the plurality of regions corresponding to spaces between two pixels adjacent in the x direction, so that the portions of the common electrode 32 located on both sides of the holes H in the x direction are electrically connected to each other.

[0036] 5, it is possible to maintain a state in which at least a part or all of each of the multiple pixels is covered with the common electrode 32. Therefore, it is possible to provide the holes H without affecting the uniformity of the transmittance of the light emitted from the light-emitting layer 31. In addition, in the example of FIG. 5, several bridges Ha are provided in each of the multiple regions corresponding to the spaces between two pixels adjacent in the x direction, so that it is possible to prevent a part of the common electrode 32 from being electrically connected to any of one or more power supply wirings and becoming a floating conductor to which no ground potential is supplied.

[0037] As described above, according to the touch sensor 2 of this embodiment, the area of ​​the common electrode 32 constituting most of one electrode of the vertical capacitance can be reduced, so that the vertical parasitic capacitance itself can be reduced. Therefore, even if the distance d2 cannot be increased, it is possible to prevent the accuracy of the position detection by the sensor controller 52 from being deteriorated due to the display drive signal. In addition, the hole H can be provided so as not to affect the uniformity of the transmittance of the light emitted from the light-emitting layer 31, and it is also possible to prevent a part of the common electrode 32 from becoming a floating conductor to which no ground potential is supplied.

[0038] The positions of the holes H provided in the common electrode 32 are not limited to those shown in Fig. 4(a) and Fig. 5. For example, although the holes H are arranged with a regularity in the examples of Fig. 4(a) and Fig. 5, the holes H may be arranged randomly. When the holes H are arranged randomly, it is preferable to arrange the holes H so that for each combination of the colors of two adjacent pixels, the number (or the total area or total length) of the holes H arranged between the two pixels corresponding to the colors is substantially the same value.

[0039] For example, it is preferable to arrange the holes H so that the total number T1 of holes H arranged between the pixels corresponding to red and the pixels corresponding to green, the total number T2 of holes H arranged between the pixels corresponding to green and the pixels corresponding to blue, and the total number T3 of holes H arranged between the pixels corresponding to blue and the pixels corresponding to red are substantially the same value. However, "substantially the same value" here means that the maximum absolute value of the difference between any two numbers among T1, T2, and T3 is a number smaller than 50% of 1 / 3 of the total of T1, T2, and T3. This makes it possible to suppress color differences (color unevenness) depending on the area.

[0040] FIG. 6 is a diagram showing a planar configuration of the common electrode 32 according to a first modified example of the present embodiment. FIG. 7(a) is a cross-sectional view of the display panel 4 corresponding to the CC line shown in FIG. 6, and FIG. 7(b) is a cross-sectional view of the display panel 4 corresponding to the DD line shown in FIG. 6. This modified example is different from the example shown in FIG. 5 in that a hole H extending in the x direction is provided in each of a plurality of regions corresponding to between two adjacent pixels in the y direction. As in the example shown in FIG. 5, several bridges Ha are provided in each of a plurality of regions corresponding to between two adjacent pixels in the y direction. Also, two power supply wirings for supplying a ground potential GND to the common electrode 32 are provided at each of one end and the other end of the display panel 4 in the y direction.

[0041] This modification also allows the state in which at least a part or all of each of the multiple pixels is covered with the common electrode 32 to be maintained, so that it is possible to provide the holes H without affecting the uniformity of the transmittance of light emitted from the light-emitting layer 31. In addition, since several bridges Ha are provided in each of the multiple regions corresponding to between two pixels adjacent in the y direction, it is possible to prevent a part of the common electrode 32 from becoming a floating conductor to which no ground potential is supplied.

[0042] 8 is a diagram showing a planar configuration of the common electrode 32 according to the second modified example of the present embodiment. In this example, holes H are arranged randomly or with a certain regularity in a part of the region between two pixels adjacent in the x direction and in a part of the region between two pixels adjacent in the y direction. However, in order to prevent a part of the common electrode 32 from becoming a floating conductor to which no ground potential is supplied, the size and position of the holes H are adjusted so that no part is entirely surrounded by the holes H. This example also allows the holes H to be provided without affecting the uniformity of the transmittance of the light emitted from the light emitting layer 31, and prevents a part of the common electrode 32 from becoming a floating conductor to which no ground potential is supplied.

[0043] 9 is a diagram showing a planar configuration of a common electrode 32 according to a third modified example of the present embodiment. In this example, holes H are provided so as to cover almost the entirety of some pixels. If the holes H have almost no effect on the uniformity of the transmittance of light emitted from the light-emitting layer 31, it is also possible to provide the holes H in this way so as to cover almost the entirety of some pixels.

[0044] FIG. 10 is a diagram showing a planar configuration of the common electrode 32 according to a fourth modified example of the present embodiment. This modified example is an example of a case where the holes H must be provided in the common electrode 32 regardless of the arrangement of the pixels, such as when the holes H are drilled in the common electrode 32 after the display panel 4 is completed. In this case, in order to prevent the holes H from affecting the image quality as much as possible, it is preferable to form the holes H with an area smaller than that of the pixels, as shown in FIG. 10. It is also preferable to arrange the holes H regularly as shown in FIG. 10 so that the holes H are uniformly arranged for each of red, green, and blue. It is also preferable to arrange the holes H so that the pitch X2 of the regularly arranged holes H in the x direction is not a multiple or divisor of the pitch X1 of the pixels in the x direction, and the pitch Y2 of the regularly arranged holes H in the y direction is not a multiple or divisor of the pitch Y1 of the pixels in the y direction, in order to prevent moire from occurring.

[0045] Fig. 11 is a diagram showing a planar configuration of a common electrode 32 included in a touch sensor 2 according to a second embodiment of the present invention. Fig. 12(a) is a cross-sectional view of a display panel 4 corresponding to an EE line shown in Fig. 11, and Fig. 12(b) is a cross-sectional view of a display panel 4 corresponding to an FF line shown in Fig. 11. The touch sensor 2 according to this embodiment differs from the touch sensor 2 according to the first embodiment in that the display panel 4 has an auxiliary electrode 35. The structure of the display panel 4 according to this embodiment will be described in detail below, focusing on the differences from the touch sensor 2 according to the first embodiment.

[0046] The auxiliary electrode 35 is a transparent conductor provided to reduce the resistance of the common electrode 32, and is formed on the upper surface of the common electrode 32 via a protective layer 34, which is a transparent insulator, as shown in Figures 12(a) and 12(b). The auxiliary electrode 35 and the common electrode 32 are connected to each other by a via conductor 35a that penetrates the protective layer 34 at a position corresponding to above the insulating layer 15. By providing the auxiliary electrode 35, it is possible to reduce the resistance of the common electrode 32, but the vertical parasitic capacitance becomes larger than when the auxiliary electrode 35 is not provided.

[0047] 12(a), the hole H according to the present embodiment is formed so as to penetrate the auxiliary electrode 35, the protective layer 34, and the common electrode 32. Therefore, neither the common electrode 32 nor the auxiliary electrode 35 is disposed at a position where one or more holes H are provided as viewed in the horizontal direction.

[0048] In order to prevent the auxiliary electrode 35 from being supplied with a ground potential and becoming a floating conductor, one or more holes H according to the present embodiment are formed so as to leave the via conductor 35a at least in a range where the auxiliary electrode 35, which is a floating conductor, does not occur. The arrangement of the holes H shown in FIG. 11 is an example of such an arrangement of the holes H. In the example of the same figure, the holes H are arranged so that a row in which a hole H is arranged between a pixel corresponding to red and a pixel corresponding to green, a row in which a hole H is arranged between a pixel corresponding to green and a pixel corresponding to blue, and a row in which a hole H is arranged between a pixel corresponding to blue and a pixel corresponding to red are repeatedly arranged in order from one end side in the y direction of the display panel 4. This can prevent the auxiliary electrode 35 from becoming a floating conductor.

[0049] As described above, according to the touch sensor 2 of the present embodiment, the areas of the common electrode 32 and the auxiliary electrode 35 constituting most of one electrode of the vertical capacitance can be reduced, so that the vertical parasitic capacitance itself can be reduced even when the auxiliary electrode 35 is provided inside the display panel 4. Therefore, even if the distance d2 shown in FIG. 1 cannot be increased, it is possible to prevent the accuracy of position detection by the sensor controller 52 from being deteriorated due to the display drive signal.

[0050] Moreover, according to the touch sensor 2 of this embodiment, the electrical connection between the auxiliary electrode 35 and the common electrode 32 can be maintained, so that it is possible to prevent the occurrence of a portion that is not supplied with a ground potential and becomes a floating conductor not only for the common electrode 32 but also for the auxiliary electrode 35. Furthermore, since the holes H are uniformly arranged for each of red, green, and blue, it is also possible to suppress color differences (color unevenness) depending on the region.

[0051] 13 is a diagram showing a planar configuration of a common electrode 32 according to a first modified example of the present embodiment. In this modified example, a hole H whose width in the x direction is approximately equal to that of a pixel is provided between two pixels adjacent in the y direction. This makes it possible to uniformly arrange holes H for each of the three colors while leaving all of the via conductors 35a. This makes it possible to prevent the auxiliary electrode 35 from having a portion that becomes a floating conductor and to suppress color differences (color unevenness) depending on the region.

[0052] 14 is a diagram showing a planar configuration of a common electrode 32 according to a second modified example of the present embodiment. In this modified example, an H-shaped hole H is formed by utilizing a region between two pixels adjacent in the y direction and regions on both sides of these two pixels. The H-shaped holes H are arranged in the y direction, every other row as viewed in the x direction. In addition, the positions of the holes H are shifted by one pixel between two rows of H-shaped holes H adjacent in the x direction. With the above configuration, this modified example also makes it possible to prevent the auxiliary electrode 35 from having a portion that becomes a floating conductor, while suppressing color differences (color unevenness) depending on the region.

[0053] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and it goes without saying that the present invention can be embodied in various forms without departing from the spirit of the present invention.

[0054] For example, in each of the above embodiments, the present invention is applied to a touch sensor 2 having a display panel 4 that is an organic EL display. However, the present invention is also applicable to a touch sensor 2 having a display panel 4 that is another type of display. For example, in the case where the display panel 4 is a liquid crystal display, each of the pixels includes a material (specifically, a liquid crystal layer) that controls the passage of light depending on the potential difference between the corresponding pixel electrode and the common electrode. Then, the hole H is formed so that at least a part of each of the pixels is kept covered by the common electrode. By doing so, as in each of the above embodiments, even if the distance d2 cannot be increased, it is possible to prevent the accuracy of position detection by the sensor controller 52 from being deteriorated due to the display drive signal. In addition, the hole H can be provided so as not to affect the uniformity of the transmittance of the light emitted from the light emitting layer 31, and it is also possible to prevent a part of the common electrode 32 from becoming a floating conductor to which no ground potential is supplied.

[0055] Furthermore, in each of the above embodiments, an example in which the present invention is applied to an on-cell type touch sensor 2 has been described, but the present invention can also be applied to an out-cell type touch sensor in the same manner.

[0056] In the above-mentioned second embodiment, an example in which the auxiliary electrode 35 is formed above the common electrode 32 has been described, but the present invention is also applicable to a case in which the auxiliary electrode is formed below the pixel electrode 30. In this case, similar to the second embodiment, it is preferable that the hole H is formed so as to penetrate the common electrode 32 while leaving a via conductor connecting the common electrode 32 and the auxiliary electrode to an extent that no floating conductor is generated in the auxiliary electrode. In this case, it is not necessarily required to form the hole H so as to penetrate the auxiliary electrode, but the hole H may be formed so as to penetrate the auxiliary electrode.

[0057] In addition, in each of the above embodiments, an example has been described in which the hole H is used as the conductor area suppressing portion, but the area of ​​the common electrode 32 (and the auxiliary electrode) may be reduced by other means. For example, the conductor area suppressing portion may be formed by increasing the resistance of a part of the common electrode 32 (and the auxiliary electrode) by ion implantation of impurities. [Explanation of symbols]

[0058] 1 Electronic equipment 2 Touch Sensor 2a Touch surface 3. Glass substrate 4 Display Panel 5. Glass substrate 6 Touch Panel 7 Polarizing Plate 8 Air Gap 9. Glass Substrate 10~15 Insulation layer 20,24 Gate 21,25 Channel 22,27 Source 23,26 Drain 30 Pixel electrode 31 Light-emitting layer 32 Common electrode 33 Insulating layer 34 Protective layer 35 Auxiliary electrode 35a Via conductor 50 Host Processor 51 Memory 52 Sensor Controller EL Organic Light Emitting Diode GL Gate line GND Ground potential H hole Ha Bridge PX OLED Cell SL Source Line Td Drive transistor Ts Switching transistor VL power line

Claims

1. a display panel including a plurality of pixel electrodes provided corresponding to a plurality of pixels arranged in a matrix shape along a first direction and a second direction perpendicular to the first direction, and a common electrode provided in common to the plurality of pixels; a touch panel for detecting the position of at least one of a finger and a pen; A touch sensor having a structure in which the common electrode has a plurality of H-shaped holes arranged in the second direction, on every other column of the matrix as viewed in the first direction; each of the plurality of H-shaped holes is formed using a region between two of the pixels adjacent to each other in the second direction and regions on both sides of the two pixels in the first direction; In two rows of the H-shaped holes adjacent to each other in the first direction, the positions of the H-shaped holes are shifted by one pixel. Touch sensor.

2. The common electrode is connected to a constant voltage power supply by one or more power supply wirings; the plurality of H-shaped holes are formed such that no portion that is not electrically connected to any of the one or more power supply wirings is generated in the common electrode; The touch sensor of claim 1 .

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