Touch sensor

Abstract

The present invention provides a touch sensor capable of reducing its own vertical direction parasitic capacitance. The touch sensor of the present invention is a touch sensor having a structure in which a display panel having a plurality of pixel electrodes respectively provided corresponding to each of a plurality of pixels and a common electrode (32) provided commonly to the plurality of pixels, and a touch panel for detecting a position of at least one of a finger and a pen are overlapped in a vertical direction. The common electrode (32) has a hole (H) that reduces an area of the common electrode (32), whereby the area of the common electrode (32) that constitutes a majority of an electrode of one of vertical direction capacitances can be reduced, and thus the vertical direction parasitic capacitance itself can be reduced.

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 overlapping in a vertical direction. Background Technology

[0002] Touch sensors are known to have a structure in which a touch panel for detecting the position of a finger or pen is disposed on a display panel. In such touch sensors, the structure in which the display panel and the touch panel are integrally formed is called an "on-cell type," and the structure in which the display panel and the touch panel are formed separately is called an "out-cell type." Hereinafter, these "on-cell type" and "out-cell type" will be collectively referred to as "touch sensors."

[0003] In touch sensors, parasitic capacitance is generated between the touch panel and the display panel, independently of the parasitic capacitance generated between the sensor electrodes within the touch panel. Hereinafter, this latter parasitic capacitance will be 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. Thus, the display drive signal reaching the touch panel becomes noise affecting touch panel movements, reducing the detection accuracy of fingers and styluses.

[0004] Patent documents 1 and 2 disclose techniques for preventing such a decrease in detection accuracy. Specifically, Patent document 1 discloses a display-side processing technique to reduce the aforementioned noise by changing the driving method of multiple pixel electrodes according to the content of the image data and the polarity of each pixel electrode. Patent document 2 discloses a technique to reduce the effects of the aforementioned noise by providing a charge equivalent to the amount of parasitic capacitance in the vertical direction to the charge amplifier of the touch sensor.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: International Publication No. 2019 / 087332

[0008] Patent Document 2: Japanese Patent Application Publication No. 2011-222013 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] However, according to the technology described in Patent Documents 1 and 2 above, although noise can be reduced, the vertical parasitic capacitance itself cannot be reduced. In order to detect the position of a finger or pen as unaffected as possible by the display, it is preferable to reduce the vertical parasitic capacitance itself.

[0011] Therefore, one of the objectives of this invention is to provide a touch sensor that can reduce its own parasitic capacitance in the vertical direction.

[0012] Methods for solving problems

[0013] The touch sensor of the present invention has a structure in which a display panel and a touch panel are arranged overlapping in a vertical direction. The display panel has a plurality of pixel electrodes respectively disposed corresponding to each of a plurality of pixels and a common electrode disposed in common to the plurality of pixels. The touch panel is used to detect the position of at least one of a finger and a pen. The common electrode has a conductor area suppression portion that reduces the area of ​​the common electrode.

[0014] Invention Effects

[0015] According to the present invention, it is possible to reduce the area of ​​most of the common electrode of one of the electrodes constituting the vertical capacitance, thereby reducing the vertical parasitic capacitance itself. Attached Figure Description

[0016] Figure 1 This is a diagram showing the structure of an electronic device 1 including the touch sensor 2 according to the first embodiment of the present invention.

[0017] Figure 2 yes Figure 1 The top view of the display panel 4 shown.

[0018] Figure 3 This is a diagram showing the circuit structure of each organic light emitting diode (OLED) unit PX.

[0019] Figure 4 (a) is with Figure 2 The sectional view of the display panel 4 corresponding to line AA shown is (b) with Figure 2 The BB line shown is a cross-sectional view of the display panel 4.

[0020] Figure 5 It is shown Figure 4 (a) and Figure 4 (b) is a diagram of the planar structure of the common electrode 32.

[0021] Figure 6 This is a diagram showing the planar structure of the common electrode 32 in a first modified example of the first embodiment of the present invention.

[0022] Figure 7 (a) is with Figure 6 The cross-sectional view of the display panel 4 corresponding to the CC line shown is (b) and is the same as Figure 6The DD line shown is a cross-sectional view of the display panel 4.

[0023] Figure 8 This is a diagram showing the planar structure of the common electrode 32 in a second variation of the first embodiment of the present invention.

[0024] Figure 9 This is a diagram showing the planar structure of the common electrode 32 in a third variation of the first embodiment of the present invention.

[0025] Figure 10 This is a diagram showing the planar structure of the common electrode 32 in a fourth variation of the first embodiment of the present invention.

[0026] Figure 11 This is a diagram showing the planar structure of the common electrode 32 included in the touch sensor 2 according to the second embodiment of the present invention.

[0027] Figure 12 (a) is with Figure 11 The cross-sectional view of the display panel 4 corresponding to the EE line shown is (b) with Figure 11 The FF line shown is a cross-sectional view of the display panel 4.

[0028] Figure 13 This is a diagram showing the planar structure of the common electrode 32 in the first variation of the second embodiment of the present invention.

[0029] Figure 14 This is a diagram showing the planar structure of the common electrode 32 in a second variation of the second embodiment of the present invention. Detailed Implementation

[0030] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0031] Figure 1 This is a diagram showing the structure of an electronic device 1 including the touch sensor 2 of this embodiment. In this diagram, only the portion showing the touch sensor 2 is shown as a vertical cross-sectional view of the panel structure. The electronic device 1 is, for example, a personal information device such as a tablet terminal, smartphone, or laptop computer, and is configured to include a main processor 50, a memory 51, and a sensor controller 52 in addition to the touch sensor 2.

[0032] The main processor 50 is the central processing unit of the electronic device 1. The memory 51 is a storage device configured to store arbitrary data, and includes main storage devices such as DRAM (Dynamic Random Access Memory) and auxiliary storage devices such as hard disks. The main processor 50 is configured to execute the operating system of the electronic device 1 and various applications that describe applications by reading and executing programs stored in the memory 51. The memory 51 functions as the working memory of the main processor 50 and also stores data generated by the main processor 50.

[0033] The sensor controller 52 is an integrated circuit that uses the touch panel 6 to detect the positions of fingers and pens on the touch surface 2a (described later). Details of the processing performed by the sensor controller 52 will be described later. There are no particular limitations on the specific method of detecting the positions of fingers and pens, but for example, finger position detection can be performed using capacitive methods, and pen detection can be performed using active electrostatic methods or electromagnetic induction methods. Hereinafter, the explanation will continue based on the premise that finger position detection is performed using capacitive methods and pen position detection is performed using active electrostatic methods.

[0034] Touch sensor 2 is classified as an on-cell type touch sensor as described above, and has a structure in which the display panel 4 and the touch panel 6 are integrally formed. More specifically, as... Figure 1 As shown, the structure comprises 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) stacked sequentially. The surface of the glass substrate 9 forms a touch surface 2a for the user to slide their finger or pen. Hereinafter, "above" of the touch sensor 2 refers to the touch surface 2a side, and "below" of the touch sensor 2 refers to the opposite side of the touch surface 2a (the surface of the glass substrate 3).

[0035] The display panel 4 is an organic electroluminescence (EL) display disposed on the glass substrate 3, and has a structure in which multiple OLED units, each constituting a 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 functions to display images generated by the main processor 50 by driving each OLED unit individually based on display drive signals supplied from the main processor 50.

[0036] The touch panel 6 is a sensor for detecting the position of at least one of a finger and a pen, disposed on the upper surface of the display panel 4 (more specifically, the upper surface of the common electrode 32, described later) across a glass substrate 5. The glass substrate 5 is a transparent insulator with a thickness of d2 and a specified dielectric constant ε. The specific value of the thickness d2 is, for example, a value smaller than tens of μm.

[0037] Multiple sensor electrodes (not shown) are disposed within the touch panel 6 and are respectively connected to the sensor controller 52. Among these multiple sensor electrodes, there are multiple first linear conductors (not shown) that extend parallel to one side of the rectangular touch panel 6 and are arranged at equal intervals, and multiple second linear conductors (not shown) that extend in a direction orthogonal to the aforementioned side and are arranged at equal intervals. Both the first and second linear conductors are made of transparent conductors such as indium tin oxide (ITO).

[0038] The sensor controller 52 performs processing to detect the pen's position and receive data sent by the pen through bidirectional communication with the pen using multiple sensor electrodes included in the touch panel 6. Additionally, the sensor controller 52 performs processing to detect the finger's position by supplying a finger detection signal to each of a plurality of first linear conductors and receiving the finger detection signal using each of a plurality of second linear conductors. The sensor controller 52 sequentially supplies the detected pen or finger position and the data received from the pen to the main processor 50. The main processor 50 performs processing to generate an image based on the supplied position and data and supplies a display drive signal for displaying the generated image to the display panel 4. The image generated by the main processor 50 includes a pointer displayed at a position corresponding to the finger or pen position, stroke data indicating the trajectory of the finger or pen position, etc.

[0039] A polarizing plate 7, used to improve the outdoor visual visibility of the display panel 4, is disposed on the upper surface of the touch panel 6. A glass substrate 9, a flat and transparent insulator, is disposed on the polarizing plate 7 through an air gap 8. Alternatively, a resin layer may be used in place of or together with the air gap 8. The distance d1 between the touch panel 6 and the touch surface 2a is the sum of the thicknesses of the polarizing plates 7, the air gap 8, and the glass substrate 9. The larger the distance d1, the longer the distance between the multiple sensor electrodes included in the touch panel 6 and the finger or pen, and the worse the position detection accuracy of the sensor controller 52 becomes; therefore, the distance d1 is preferably minimized.

[0040] Here, in addition to the distance d1, the thickness d2 of the glass substrate 5 also affects the accuracy of the position detection of the sensor controller 52. That is, the display drive signal leaking from the display panel 4 reaches the touch panel 6 via the aforementioned vertical parasitic capacitance (parasitic capacitance generated between the touch panel 6 and the display panel 4). The display drive signal reaching the touch panel 6 overlaps with the signals transmitted and received between the sensor controller 52 and the pen, as well as the aforementioned finger detection signal, as noise. Therefore, it is preferable to minimize the intensity of the display drive signal reaching the touch panel 6. For this purpose, it is preferable to increase the thickness d2 to reduce the vertical parasitic capacitance. However, from the viewpoint of minimizing the height of the touch sensor 2 and visually confirming the display panel 4, it is preferable to reduce the thickness d2. In fact, the thickness d2 is trending towards reduction. If the thickness d2 becomes smaller, the aforementioned distance d1 becomes relatively larger. As a result, the accuracy of the position detection of the sensor controller 52 deteriorates. Therefore, it is desirable to pursue techniques to reduce the vertical parasitic capacitance by means other than increasing the thickness d2.

[0041] This invention reduces the parasitic capacitance in the vertical direction by studying the structure within the display panel 4 and using methods other than increasing the thickness d2. Hereinafter, refer to... Figures 2-5 A detailed description of the structure of the display panel 4 that reduces vertical parasitic capacitance without relying on thickness d2.

[0042] Figure 2 This is a top view of display panel 4. As shown in the figure, display panel 4 has a matrix structure of multiple OLED units PX (pixels) arranged along the x and y directions as illustrated. It should be noted that... Figure 2 The rectangular area shown for each OLED unit PX represents the range of light emission.

[0043] exist Figure 2 In the figures described below, OLED unit PX labeled "R" is configured to emit red light, OLED unit PX labeled "G" is configured to emit green light, and OLED unit PX labeled "B" is configured to emit blue light. Figure 2 As shown, in the x-direction, groups of three OLED unit PXs corresponding to "R", "G", and "B" are repeatedly arranged from left to right. Additionally, in the y-direction, OLED unit PXs of the same color are repeatedly arranged.

[0044] Furthermore, the display panel 4 is configured to have multiple gate lines GL, multiple source lines SL, and multiple power lines VL. Each gate line GL is provided with a common ground for multiple OLED cells PX arranged in the x-direction and is connected to the corresponding OLED cell PX. Additionally, each source line SL and each power line VL are provided with a common ground for multiple OLED cells PX arranged in the y-direction and are connected to the corresponding OLED cell PX.

[0045] Figure 3 This diagram illustrates the circuit structure of each OLED cell PX. As shown, each OLED cell PX comprises a switching transistor Ts, a driving transistor Td, an organic light-emitting diode (OLED) EL, and a capacitor C. The gate of the switching transistor Ts is connected to the corresponding gate line GL, and its source is connected to the corresponding source line SL. 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 its cathode is grounded.

[0046] The OLED cells PX are driven in a row-by-row matrix manner. Specifically, the main processor 50 first determines the luminous intensity of each of the series of OLED cells PX arranged in the x-direction based on the image of the displayed object, and provides a potential corresponding to the determined luminous intensity to each source line SL. Next, the corresponding gate line GL is activated, thereby turning on the switching transistor Ts of the corresponding series of OLED cells PX. As a result, the potential of the corresponding source line SL is supplied to the gate of the driving transistor Td, and the driving transistor Td becomes conductive. The power supply line VL is connected to a power supply with a specified voltage. When the driving transistor Td becomes conductive, a current corresponding to the potential of the source line SL is supplied to the organic light-emitting diode EL. As a result, the organic light-emitting diode EL emits light at the determined luminous intensity.

[0047] Figure 4 (a) is with Figure 2 The sectional view of the display panel 4 corresponding to line AA shown. Figure 4 (b) is with Figure 2 The BB line shown is a cross-sectional view of the display panel 4. Hereinafter, refer to this... Figure 4 (a) and Figure 4 (b) describes the stacked structure of the display panel 4.

[0048] First, the display panel 4 is configured to have six insulating layers 10-15 sequentially from the bottom. A gate 20 for a switching transistor Ts, a gate 24 for a driving transistor Td, and a gate line GL are formed on the upper surface of the insulating layer 10. The gate 20 and the gate line GL are connected via a conductor formed on the upper surface of the insulating layer 10 (in... Figure 4 (Not present in the middle) but interconnected. In addition, a channel 21 for the switching transistor Ts and a channel 25 for the driving transistor Td are formed on the upper surface of the insulating layer 11.

[0049] The upper surface of the insulating layer 12 has the source 22 and drain 23 of the switching transistor Ts, the drain 26 and source 27 of the driving transistor Td, the source line SL, and the power line VL. The source 22 is connected to one end of the channel 21 through a via conductor penetrating the insulating layer 12. The drain 23 is connected to the other end of the channel 21 through a via conductor penetrating the insulating layer 12, and is also connected to the gate 24 through via conductors penetrating the insulating layers 11 and 12. The drain 26 is connected to one end of the channel 25 through a via conductor penetrating the insulating layer 12. The source 27 is connected to the other end of the channel 25 through a via conductor penetrating the insulating layer 12. Figure 3 The capacitor C shown is composed of parasitic capacitance formed between the source 27 and the gate 24.

[0050] A pixel electrode 30, equivalent to the anode of an organic light-emitting diode (OLED), is formed on the upper surface of the insulating layer 14. The pixel electrode 30 is connected to the drain electrode 26 through a conductive via penetrating the insulating layers 13 and 14. Figure 4 As shown in (b), an insulating layer 33 is formed between two adjacent pixel electrodes 30 in the y-direction, thereby ensuring insulation between the two adjacent pixel electrodes 30 in the y-direction. On the other hand, as Figure 4 As shown in (a), two adjacent pixel electrodes 30 in the x direction are insulated by an insulating layer 15.

[0051] The insulating layer 15 is thicker than the insulating layer 33, and in the x-direction, two adjacent insulating layers 15 form a valley-like structure where the pixel electrode 30 and the insulating layer 33 are alternately exposed on the bottom surface. A light-emitting layer 31 is formed at the bottom of this valley with a certain thickness. The light-emitting layer 31 is made of a material that emits light according to the potential difference between the corresponding pixel electrode 30 and the common electrode 32. Furthermore, a common electrode 32, equivalent to the cathode of an organic light-emitting diode (OLED), is formed on the upper surface of the light-emitting layer 31.

[0052] A common electrode 32 is also formed on the side surface of the valley formed by the insulating layer 15 and the upper surface of the insulating layer 15, forming a rectangular solid conductor that covers the entire display panel 4, not each pixel. Thus, the common electrode 32 constitutes most of one electrode of the vertical capacitance. The common electrode 32 is formed using a solid conductor to minimize its resistance. Normally, it is impossible to create holes in the common electrode 32, but in this embodiment, one or more holes H are provided in the common electrode 32. These one or more holes H function as conductor area suppression portions that reduce the area of ​​the common electrode 32, thus reducing the area of ​​the common electrode 32 as a whole. The touch sensor 2 of this embodiment reduces the area of ​​the common electrode 32 by providing one or more holes H in the solid conductor, thereby reducing the vertical parasitic capacitance.

[0053] Figure 5 This is a diagram showing the planar structure of the common electrode 32. The dashed lines in the diagram represent the light-emitting range of each pixel. As shown in the diagram, the common electrode 32 is connected to a constant voltage power supply supplied with ground potential GND via one or more power supply lines. Figure 5 In the example, two power cables (four in total) are provided at one end and the other end of the display panel 4 in the x direction.

[0054] like Figure 5 As shown, the holes H of the common electrode 32 in this embodiment are formed in regions corresponding to multiple pixels when viewed in the horizontal direction. More specifically, the common electrode 32 is provided with multiple holes H, each hole H being formed in each of the multiple regions corresponding to two adjacent pixels in the x direction, extending in the y direction. However, each of the multiple regions corresponding to two adjacent pixels in the x direction is also provided with several bridges Ha (parts without holes H), thereby electrically connecting the portions of the common electrode 32 located on both sides of the holes H in the x direction.

[0055] according to Figure 5 The arrangement of the aperture H shown allows for maintaining a state where at least a portion or all of the multiple pixels are covered by the shared electrode 32. Therefore, the aperture H can be configured in a manner that does not affect the uniformity of the transmittance of light emitted from the light-emitting layer 31. Furthermore, in Figure 5 In the example, since several bridges Ha are provided in each of the multiple regions between two adjacent pixels in the x direction, it is possible to avoid a portion of the common electrode 32 becoming a floating conductor without a ground potential due to not being electrically connected to more than one power supply line.

[0056] As explained above, the touch sensor 2 according to this embodiment can reduce the area of ​​most of the common electrode 32 that constitutes one of the electrodes in the vertical direction capacitance, thereby reducing the vertical parasitic capacitance itself. Therefore, even if the distance d2 cannot be increased, the position detection accuracy of the sensor controller 52 can be prevented from deteriorating due to the display drive signal. In addition, the aperture H can be provided in a manner that does not affect the uniformity of the transmittance of light emitted from the light-emitting layer 31, and it is also possible to prevent a portion of the common electrode 32 from becoming a floating conductor without a supplied ground potential.

[0057] It should be noted that the location of the hole H on the common electrode 32 is not limited to... Figure 4 (a) and Figure 5 The location shown. For example, in Figure 4 (a) and Figure 5 In the example, the aperture H is configured regularly, but it can also be configured randomly. In the case of randomly configuring the aperture H, it is preferable to configure the aperture H in such a way that the number (or total area or total extension) of the aperture H between the two pixels corresponding to the color is substantially the same for each combination of colors of two adjacent pixels.

[0058] For example, it is preferable to configure the aperture H in such a way that the total number T1 of aperture H between pixels corresponding to red and pixels corresponding to green, the total number T2 of aperture H between pixels corresponding to green and pixels corresponding to blue, and the total number T3 of aperture H between pixels corresponding to blue and 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 of T1, T2, and T3 is less than 50% of one-third of the sum of T1, T2, and T3. In this way, color differences caused by regions (color unevenness) can be suppressed.

[0059] Figure 6 This is a diagram showing the planar structure of the common electrode 32 in the first modified example of this embodiment. Additionally, Figure 7 (a) is with Figure 6 The cross-sectional view of the display panel 4 corresponding to the CC line shown. Figure 7 (b) is with Figure 6 The DD line shown is a cross-sectional view of the display panel 4. This variant example differs from others in that each of the plurality of regions corresponding to two adjacent pixels in the y-direction has a hole H extending in the x-direction. Figure 5 The example shown is different. The fact that several bridges Ha are set in each of multiple regions equivalent to two adjacent pixels in the y-direction is different. Figure 5The example shown is the same. In addition, two power lines for supplying ground potential GND to the common electrode 32 are provided at one end and the other end in the y direction of the display panel 4.

[0060] This modified example also allows the state in which at least part or all of the multiple pixels are covered by the common electrode 32 to be maintained, thus enabling the aperture H to be provided in a manner that does not affect 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 two adjacent pixels in the y direction, it is possible to prevent a portion of the common electrode 32 from becoming a floating conductor without a ground potential.

[0061] Figure 8 This is a diagram showing the planar structure of the common electrode 32 in a second variation of this embodiment. In this example, apertures H are randomly or regularly arranged in a portion of the region corresponding to the area between two adjacent pixels in the x-direction and a portion of the region corresponding to the area between two adjacent pixels in the y-direction. However, to prevent a portion of the common electrode 32 from becoming a floating conductor without a ground potential, the size and position of the apertures H are adjusted so as not to create a portion entirely surrounded by the apertures H. Through this example, it is also possible to set the apertures H in a manner that does not affect the uniformity of the transmittance of light emitted from the light-emitting layer 31, and to prevent a portion of the common electrode 32 from becoming a floating conductor without a ground potential.

[0062] Figure 9 This is a diagram showing the planar structure of the common electrode 32 in the third variation of this embodiment. In this example, the aperture H is provided in such a way that it covers a portion of the pixel. If the aperture H hardly affects the uniformity of the transmittance of light emitted from the light-emitting layer 31, then the aperture H can also be provided in such a way that it covers a portion of the pixel.

[0063] Figure 10 This diagram illustrates the planar structure of the common electrode 32 in the fourth variation of this embodiment. This variation is an example of a situation where the hole H must be provided in the common electrode 32 regardless of the pixel arrangement, such as after the display panel 4 is completed. In this case, to minimize the impact of the hole H on image quality, such as... Figure 10 As shown, it is preferable to form the hole H with an area smaller than that of a pixel. Furthermore, it is preferable to use methods such as... Figure 10 As shown, the holes H are arranged regularly and uniformly relative to each of the red, green, and blue pixels. Furthermore, it is preferable to arrange the holes H such that the x-direction spacing X2 of the regularly arranged holes H is not a multiple or approximation of the x-direction spacing X1 of the pixels, and the y-direction spacing Y2 of the regularly arranged holes H is not a multiple or approximation of the y-direction spacing Y1 of the pixels, so as to prevent moiré patterns from forming.

[0064] Figure 11 This is a diagram showing the planar structure of the common electrode 32 included in the touch sensor 2 according to the second embodiment of the present invention. Additionally, Figure 12 (a) is with Figure 11 The cross-sectional view of the display panel 4 corresponding to the EE line shown. Figure 12 (b) is with Figure 11 The image shows a cross-sectional view of the display panel 4 corresponding to the FF line. The touch sensor 2 of this embodiment differs from the touch sensor 2 of the first embodiment in that the display panel 4 has one or more auxiliary electrodes 35 (hereinafter collectively referred to as "auxiliary electrodes 35"). Hereinafter, the structure of the display panel 4 of this embodiment will be described in detail, focusing on the differences from the touch sensor 2 of the first embodiment.

[0065] The auxiliary electrode 35 is a transparent conductor provided for reducing the resistance of the common electrode 32, such as... Figure 12 (a) and Figure 12 As shown in (b), a transparent insulator, i.e., a protective layer 34, is formed on the upper surface of the common electrode 32. The auxiliary electrode 35 and the common electrode 32 are connected to each other by one or more through-hole conductors 35a passing through the protective layer 34 at a position corresponding to above the insulating layer 15. By providing the auxiliary electrode 35, the resistance of the common electrode 32 can be reduced; on the other hand, the parasitic capacitance in the vertical direction increases compared to the case where the auxiliary electrode 35 is not provided.

[0066] like Figure 12 As shown in (a), the hole H in this embodiment is formed in a manner that allows the auxiliary electrode 35, the protective layer 34, and the common electrode 32 to pass through. Therefore, when viewed in the horizontal direction, the position where one or more holes H are provided does not have either the common electrode 32 or the auxiliary electrode 35.

[0067] In order to prevent the auxiliary electrode 35 from becoming a floating conductor due to the lack of a grounding potential, one or more holes H in this embodiment are formed in such a way that the hole conductor 35a remains at least within the range where the auxiliary electrode 35, which is a floating conductor, is not generated. Figure 11 The arrangement of the holes H shown is an example of such a hole H configuration. In this example, the holes H are arranged in a manner that rows of holes H are arranged between pixels corresponding to red and green, rows of holes H are arranged between pixels corresponding to green and blue, and rows of holes H are arranged between pixels corresponding to blue and red, repeating sequentially from one end of the display panel 4 in the y-direction. This prevents portions of the auxiliary electrode 35 from becoming floating conductors.

[0068] As explained above, the touch sensor 2 according to this embodiment can reduce the area of ​​most of the common electrode 32 and auxiliary electrode 35 that constitute one of the electrodes in the vertical direction capacitance. Therefore, even when the auxiliary electrode 35 is provided in the display panel 4, the vertical parasitic capacitance itself can be reduced. Therefore, even if it is not possible to increase the vertical parasitic capacitance... Figure 1 The distance d2 shown also prevents the position detection accuracy of the sensor controller 52 from deteriorating due to the display drive signal.

[0069] Furthermore, 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. Therefore, the common electrode 32, needless to say, and the auxiliary electrode 35 can also avoid becoming a floating conductor due to lack of ground potential. Moreover, since the holes H are uniformly arranged for each of the red, green, and blue, color differences (color unevenness) caused by regional variations can also be suppressed.

[0070] Figure 13 This is a diagram showing the planar structure of the common electrode 32 in the first modified example of this embodiment. In this modified example, a hole H with a width in the x direction approximately equal to that of a pixel is provided between two adjacent pixels in the y direction. Therefore, while leaving all the via conductor 35a intact, the holes H can be uniformly arranged relative to each of the three colors. Thus, it is possible to suppress color differences (color unevenness) caused by regions while avoiding the formation of floating conductor portions on the auxiliary electrode 35.

[0071] Figure 14 This is a diagram showing the planar structure of the common electrode 32 in the second variation of this embodiment. In this variation, H-shaped holes H are formed using the area between two adjacent pixels in the y-direction and the areas on both sides of these two pixels. When viewed in the x-direction, these H-shaped holes H are arranged in the y-direction with every other column. Furthermore, in the columns of two adjacent H-shaped holes H in the x-direction, the positions of the holes H are offset by one pixel. By adopting such a structure, this variation can also suppress color differences (color unevenness) caused by regions while avoiding the formation of a floating conductor portion on the auxiliary electrode 35.

[0072] The preferred embodiments of the present invention have been described above, but the present invention is not limited to such embodiments in any way. The present invention can certainly be implemented in various ways without departing from its spirit.

[0073] For example, in the embodiments described above, examples of applying the present invention to a touch sensor 2 having a display panel 4 as an organic EL display have been described. However, the present invention can also be applied to a touch sensor 2 having a display panel 4 as other types of displays. For example, if the display panel 4 is a liquid crystal display, in this example, each of the plurality of pixels includes a material (specifically a liquid crystal layer) that controls the passage of light based on the potential difference between the corresponding pixel electrode and the common electrode. Furthermore, the aperture H is formed in such a way that at least a portion of each of the plurality of pixels is covered by the common electrode. In this way, as in the embodiments described above, even if the distance d2 cannot be increased, the accuracy of the position detection of the sensor controller 52 due to the display drive signal can be prevented from deteriorating. In addition, the aperture H can be provided in a way that does not affect the uniformity of the transmittance of light emitted from the light-emitting layer 31, and it is also possible to prevent a portion of the common electrode 32 from becoming a floating conductor without a supplied ground potential.

[0074] Furthermore, while examples of applying the present invention to an on-cell type touch sensor 2 have been described in the above embodiments, the present invention can also be applied to an out-cell type touch sensor in the same way.

[0075] Furthermore, while the second embodiment described above illustrates an example where the auxiliary electrode 35 is formed on the upper side of the common electrode 32, the present invention can also be applied to the case where the auxiliary electrode is formed on the lower side of the pixel electrode 30. In this case, the hole H is formed similarly to that in the second embodiment, preferably with a residual via conductor connecting the common electrode 32 and the auxiliary electrode within a range that does not generate a floating conductor in the auxiliary electrode, while simultaneously penetrating the common electrode 32. In this case, it is not necessarily necessary to form the hole H in a manner that also penetrates the auxiliary electrode, but it is also permissible to form the hole H in a manner that also penetrates the auxiliary electrode.

[0076] Furthermore, while the above embodiments illustrate the use of the aperture H as a conductor area suppression section, other structures can also be used to reduce the area of ​​the common electrode 32 (and auxiliary electrode). For example, a portion of the common electrode 32 (and auxiliary electrode) can be made highly resistive through ion implantation of impurities, thereby forming a conductor area suppression section.

[0077] Label Explanation

[0078] 1. Electronic equipment

[0079] 2. Touch sensor

[0080] 2a Touch surface

[0081] 3 Glass substrate

[0082] 4. Display panel

[0083] 5. Glass substrate

[0084] 6 Touch Panel

[0085] 7 polarizing plate

[0086] 8. Air gap

[0087] 9. Glass substrate

[0088] 10-15 Insulation layers

[0089] 20, 24 gate

[0090] 21, 25 channels

[0091] 22, 27 Source poles

[0092] 23, 26 Drain

[0093] 30-pixel electrode

[0094] 31. Emissive layer

[0095] 32 Common electrode

[0096] 33 Insulation layer

[0097] 34 Protective Layer

[0098] 35 Auxiliary Electrode

[0099] 35a Through-hole Conductor

[0100] 50 main processors

[0101] 51 Memory

[0102] 52 Sensor Controller

[0103] EL Organic Light Emitting Diode

[0104] GL gate line

[0105] GND ground potential

[0106] H hole

[0107] Ha Bridge

[0108] PX OLED unit

[0109] SL source line

[0110] Td driving transistor

[0111] Ts switching transistor

[0112] VL power cord

Claims

1. A touch sensor having a structure in which a display panel and a touch panel are arranged in a vertical direction in a superposed manner, the display panel having a plurality of pixel electrodes provided in correspondence with each of a plurality of pixels, respectively, and a common electrode provided in common to the plurality of pixels, the touch panel serving to detect a position of at least one of a finger and a pen, wherein the touch sensor has an auxiliary electrode formed on an upper surface of the common electrode through a protective layer, and connected to the common electrode through a via conductor that penetrates the protective layer, the common electrode has a conductor area suppression portion that suppresses an area of the common electrode, the conductor area suppression portion is constituted by one or more holes provided so as to penetrate the common electrode, the protective layer, and the auxiliary electrode, respectively.

2. The touch sensor according to claim 1, wherein the one or more holes are formed in a manner that maintains a state in which at least a portion of each of the plurality of pixels is covered by the common electrode.

3. The touch sensor according to claim 2, wherein the one or more holes are formed in regions corresponding to spaces between the plurality of pixels when viewed in a horizontal direction, respectively.

4. The touch sensor according to claim 1 or 2, wherein the common electrode is connected to a constant voltage power supply through one or more power supply lines, the one or more holes are formed in a manner that does not generate a portion within the common electrode that is not electrically connected to any of the one or more power supply lines.

5. The touch sensor according to claim 1, wherein the one or more holes are formed in an area smaller than each of the plurality of pixels, respectively, and are regularly arranged in a pitch that is not a multiple or a submultiple of a pitch of the plurality of pixels.

6. The touch sensor according to any one of claims 1 to 3, wherein the plurality of pixels each contain a material that emits light in accordance with a potential difference between the pixel electrode corresponding thereto and the common electrode.

7. The touch sensor according to any one of claims 1 to 3, wherein the plurality of pixels each contain a material that controls passage of light in accordance with a potential difference between the pixel electrode corresponding thereto and the common electrode.

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