Patent Publication Number: US-2022236823-A1

Title: Touch sensor and display apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application is Bypass Continuation of International Application No. PCT/JP2019/004083, filed on Feb. 5, 2019, which claims priority from Japanese Application No. JP2018-060420 filed on Mar. 27, 2018. The contents of these applications are hereby incorporated by reference into this application. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a touch sensor and a display device having a touch sensor. 
     2. Description of the Related Art 
     As shown in  FIG. 8 , International Publication No. 2015/182473 discloses a touch panel device including: an electrode extending in a lateral direction in which electrodes adjacent to each other are connected to each other via a connection unit; an electrode extending in a longitudinal direction in which the electrodes adjacent to each other are connected to each other via the connection unit; a voltage application unit  110 , and a charge detection unit  100 . The touch panel device detects a position touched by a finger or the like that approaches an electrode extending in the longitudinal direction, based on a change in the amount of electric charges detected by the charge detection unit  100 . 
     Further, International Publication No. 2015/182473 discloses that an edge of a corner portion is curved. The electrode includes a rectangular reference electrode pair disposed in the vicinity of the center and a deformed electrode pair disposed in the vicinity of the curved edge and having a shape in which a part of the rectangle is missing. It is disclosed that the touch panel device has a correction unit that amplifies the output of the deformed electrode pair to the same level as that of the output of the reference electrode pair. 
     SUMMARY OF THE INVENTION 
     In the above-described configuration in the related art, only the electrodes disposed at the edge of the touch panel device have a shape different from that of the electrodes disposed at the center, and the reference electrode pair electrically connected to the deformed electrode pair and the reference electrode pair that is not connected to the deformed electrode pair are mixed. Therefore, even when the correction unit amplifies the output of the electrode including the deformed electrode pair of the charge detection unit  100 , the output of the reference electrode pair connected to the deformed electrode pair is also amplified, and thus, it was not possible to correct the touched coordinate with high accuracy. 
     An object of the present invention is to provide a touch sensor having a curved edge and a display device having a touch sensor, that is, a touch sensor having improved detection accuracy of the touched coordinates and a display device having a touch sensor. 
     According to one aspect of the present invention, there is provided a touch sensor. The touch sensor includes a touch detection area with at least a part of a curved area having a curved edge. In the touch detection area, a plurality of first electrodes and second electrodes disposed side by side in a first direction and in a second direction are disposed. A plurality of first electrodes disposed side by side in the first direction are connected to each other. A plurality of second electrodes disposed side by side in the second direction are connected to each other. In the curved area, distances between the plurality of first electrodes and the second electrodes in the first direction gradually change in the second direction. 
     According to another aspect of the present invention, there is provided a display device having a touch sensor. The display device includes a display unit in which a light emitting element and a plurality of pixels having transistors are disposed in a matrix shape, a touch sensor having a plurality of first electrodes and second electrodes disposed side by side in a first direction and in a second direction, and the display unit being overlapped in a plan view and a curved area having a curved edge at least at a part thereof. A plurality of first electrodes disposed side by side in a first direction are connected to each other. A plurality of second electrodes disposed side by side in the second direction are connected to each other. In the curved area, distances between the plurality of first electrodes and the second electrodes in the first direction gradually change in the second direction. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a schematic plan view of a display device according to a first embodiment; 
         FIG. 1B  is a schematic plan view of the display device according to the first embodiment; 
         FIG. 2  is an enlarged plan view of the inside of a frame of a one-dot chain line in  FIG. 1A ; 
         FIG. 3  is a schematic sectional view showing a section taken along line III-III line in  FIG. 1A ; 
         FIG. 4A  is an enlarged sectional view of a first electrode and a second electrode; 
         FIG. 4B  is an enlarged sectional view of the first electrode and the second electrode; 
         FIG. 5  is a view showing a functional configuration of a control unit; 
         FIG. 6A  is a schematic plan view of a display device according to a second embodiment; 
         FIG. 6B  is a schematic plan view of the display device according to the second embodiment; 
         FIG. 7A  is a schematic plan view of a display device according to a third embodiment; 
         FIG. 7B  is a schematic plan view of the display device according to the third embodiment; and 
         FIG. 8  is a schematic plan view of a display device according to the related art. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Hereinafter, each embodiment of the invention will be described with reference to the drawings. Noted that the disclosure is merely an example, and those skilled in art can easily think of appropriate modifications while keeping the gist of the invention, and it is needless to say that the modifications are included in the scope of the invention. Further, in order to make the description clearer, there is a case where the width, thickness, shape, and the like of each part are schematically represented as compared with the embodiments, but these are merely an example, and the interpretation of the invention is not limited thereto. In the specification and each drawing, the same elements as those described above with reference to the drawings already described will be given the same reference numerals, and the detailed description thereof will be appropriately omitted. 
     Furthermore, in the detailed description of the present invention, when defining the positional relationship between a certain configuration element and another configuration element, the terms “above” and “below” mean not only a case of being positioned immediately above or below the configuration element but also a case where another configuration element is further interposed therebetween unless otherwise specified. 
     First Embodiment 
       FIG. 1A  is a plan view of a display device  1  according to a first embodiment.  FIG. 1B  is a view schematically showing a position  14  where a first connection line  23  described later is disposed in an entire touch sensor  20 .  FIG. 2  is an enlarged view of the inside of a frame of a one-dot chain line shown in  FIG. 1A . An organic EL display device is given as an example of the display device  1 . The display device  1  includes a full-color pixel by combining unit pixels (sub-pixels) of a plurality of colors including, for example, red, green, and blue, and displays a full-color image. 
     A periphery area  11  (frame area) is formed outside a display area  15  of a display unit  10 . An integrated circuit chip  12  for driving pixels is mounted on the periphery area  11 , and an FPC  13  (flexible print board) for electrical connection to the outside is connected thereto. In the following description, the direction along the side of the periphery area  11  to which the FPC  13  is connected is a first direction, and the direction orthogonal thereto is a second direction. The first direction and the second direction may be opposite to each other. 
     The display device  1  has a curved area  16  having a curved edge at least at a part thereof. Specifically, the display device  1  has a shape obtained by rounding a corner portion having a rectangular shape. The display device  1  has linear edges along the first direction and the second direction, and curved edges on the upper right, lower right, upper left, and lower left, respectively. 
     The shape of the display device  1  is not limited to the shape shown in  FIG. 1A , and may be any other shape as long as the shape includes the curved area  16 . For example, the display device  1  may have a shape in which some of the four corners of a rectangle are rounded, or may have a circular shape or an elliptical shape. 
     In the following description, as shown in  FIG. 1A , the rectangular area adjacent to the curved area  16  in the first direction and in the second direction is referred to as a first area  17 . A rectangular area adjacent to the first area  17  in the second direction is referred to as a second area  18 . The first area  17  and the second area  18  may not be included in the display device  1  depending on the shape of the display device  1 . 
     The curved area  16  is an area surrounded by a first side that linearly extends in the first direction, a second side that linearly extends in the second direction, and a curved side. Specifically, the curved area  16  includes a curved side along the curved edge, and a first side that linearly extends in the first direction and a second side that linearly extends in the second direction from a boundary between the curved edge and a straight edge. In other words, the first side is a boundary line between the curved area  16  and the first area  17  adjacent to the curved area  16  in the second direction. The second side is a boundary line between the curved area  16  and the second area  18  adjacent to the curved area  16  in the first direction. In  FIG. 1A , in order to clarify the area, it is described that there is a gap between the curved area  16 , the first area  17 , and the second area  18 , but in reality, two areas adjacent to each other are in contact with each other. 
     The display device  1  includes the display unit  10  and the touch sensor  20  that is formed to overlap the display unit  10  in a plan view. Specifically, in the display unit  10 , a plurality of pixels including a light emitting element and a transistor are disposed in a matrix shape. The display unit  10  displays an image when a plurality of pixels emit light. The touch sensor  20  has a plurality of first electrodes  21  and second electrodes  22  disposed side by side in the first direction and in the second direction, respectively, and overlaps the display unit  10  in a plan view. In the touch sensor  20 , an area that overlaps the display unit  10  in a plan view is a touch detection area. 
     The touch detection area is an area where the coordinates touched by the user or the like are detected. Specifically, the touch detection area has a curved area  16  having a shape inscribed in a rectangle and having a curved edge, at least at a part thereof. For example, the touch detection area of a touch sensor or a display device having a touch sensor of the related art has a rectangular shape, but the touch detection area of the invention has a shape in which four corners of the rectangular shape are rounded. In the touch detection area, the plurality of first electrodes and second electrodes disposed side by side in the first direction and in the second direction are disposed. 
     As shown in  FIG. 1A , each of the first electrode  21  and the second electrode  22  is formed in a rectangular shape having a first direction and a second direction intersecting the first direction as diagonal directions (refer to  FIGS. 4A and 4B ). In addition, a part of the first electrode  21  and the second electrode  22  which are in contact with the edge of the display device  1  is formed in a triangular shape. 
     The plurality of first electrodes  21  disposed side by side in the first direction are connected to each other. Specifically, as shown in  FIGS. 1A and 2 , the plurality of first electrodes  21  are two-dimensionally arranged side by side in the first direction and in the second direction, respectively. Among these first electrodes  21 , the first electrodes  21  adjacent to each other in the first direction are connected to each other via the first connection line  23 , and the first electrodes  21  adjacent to each other in the second direction are not connected to each other. In other words, the plurality of first electrodes  21  respectively form a plurality of electrode rows that extend in the first direction by connecting the first electrodes  21  adjacent to each other in the first direction via the first connection line  23 , each electrode row is electrically separated from each other in the second direction. 
     The plurality of second electrodes  22  disposed side by side in the second direction are connected to each other. Specifically, the plurality of second electrodes  22  are two-dimensionally arranged side by side in the first direction and in the second direction, respectively. Among these second electrodes  22 , the second electrodes  22  adjacent to each other in the second direction are connected to each other via a second connection line  24  intersecting the first connection line  23  in a plan view, and the second electrodes  22  adjacent to each other in the first direction are not connected to each other. In other words, the plurality of second electrodes  22  forma plurality of electrode rows that extend in the second direction by connecting the second electrodes  22  adjacent to each other in the second direction via the second connection line  24 , each electrode row is electrically separated from each other in the first direction. The first connection line  23  is provided on the upper layer of the connected second electrodes  22 , but may be provided on the lower layer. 
     Each second electrode  22  is disposed so as to be surrounded by the first electrode  21  in a plan view. For example, each of the second electrodes  22  is disposed between the first electrodes  21  adjacent to each other in a direction (for example, a direction of 45 degrees or −45 degrees) intersecting both the first direction and the second direction, and is surrounded by four first electrodes  21 . The first electrode  21  and the second electrode  22  are electrically separated from each other by leaving a distance so as not to come into contact with each other. 
     In the curved area  16  and the first area  17 , the distances between the plurality of first electrodes  21  and the second electrodes  22  in the first direction gradually change in the second direction. Specifically, as shown in  FIG. 1B , in the curved area  16  on the side where the FPC  13  of the display device  1  is provided (lower side of  FIG. 1B ), the distances between the connection lines  23  aligned in the first direction (left-right direction of  FIG. 1B ) gradually increase as going in the second direction (upward direction of  FIG. 1B ). Therefore, in the curved area  16  on the side where the FPC  13  of the display device  1  is provided, the distances between the plurality of first electrodes  21  and the second electrodes  22  in the first direction gradually increase in the second direction. Therefore, in the first area  17  adjacent to the curved area  16  in the first direction on the side where the FPC  13  of the display device  1  is provided, the distances between the plurality of first electrodes  21  and the second electrodes  22  in the first direction gradually increase in the second direction. 
     In the curved area  16  on the side (upper side of  FIG. 1B ) opposite to the side where the FPC  13  of the display device  1  is provided, the distances between the connection lines  23  aligned in the first direction (left-right direction of  FIG. 1B ) gradually decrease as going in the second direction (upward direction of  FIG. 1B ). Therefore, in the first area  17  adjacent to the curved area  16  in the first direction on the side opposite to the side where the FPC  13  of the display device  1  is provided, the distances between the plurality of first electrodes  21  and the second electrodes  22  in the first direction gradually decrease in the second direction. 
     Meanwhile, the distances between the plurality of first electrodes  21  and the second electrodes  22  in the second direction are constant. Specifically, as shown in  FIG. 1B , in any area (the curved area  16 , the first area  17 , and the second area  18 ) of the touch sensor  20 , the distances between the connection lines  23  aligned in the second direction (up-down direction of  FIG. 1B ) are constant. Therefore, in all areas of the touch sensor  20 , the distances between the plurality of first electrodes  21  and the second electrodes  22  in the second direction are constant. 
       FIG. 3  shows a sectional view when cut along line III-III shown in  FIG. 1A . In  FIG. 3 , hatching of some layers such as a substrate  30 , a flattening film  51 , and a pixel separation film  55  is omitted in order to make it easy to see the sectional structure. Further, the description of the integrated circuit chip  12  is omitted. In the following description regarding  FIG. 3 , the laminating direction is the upward direction. 
     The substrate  30  is made of, for example, glass or a flexible resin such as polyimide. The substrate  30  is covered with an undercoat layer  31 . A semiconductor layer  41  is formed on the undercoat layer  31 , and the semiconductor layer  41  is covered with a gate insulating film  33 . A gate electrode  43  is formed on the gate insulating film  33 , and the gate electrode  43  is covered with a passivation film  35 . A drain electrode  45  and a source electrode  47  penetrate the gate insulating film  33  and the passivation film  35  and are connected to the semiconductor layer  41 . The semiconductor layer  41 , the gate electrode  43 , the drain electrode  45 , and the source electrode  47  form a thin film transistor  40 . The thin film transistor  40  is provided so as to correspond to each of the plurality of unit pixels. The undercoat layer  31 , the gate insulating film  33 , and the passivation film  35  are formed of, for example, an inorganic insulating material such as SiO2, SiN, or SiON, and may have a laminated structure having a plurality of layers in addition to the single layer including the above-described inorganic insulating material. The undercoat layer  31  may include a resin layer in a layer that is not in contact with the substrate  30  and the semiconductor layer  41 . 
     On the passivation film  35 , in addition to the drain electrode  45  and the source electrode  47 , a wiring  49  is formed on the periphery area  11 . The illustrated wiring  49  is a wiring for electrically connecting the touch sensor  20  and the FPC  13  to each other. The drain electrode  45 , the source electrode  47 , and the wiring  49  are covered with the flattening film  51 , and the flattening film  51  is covered with an inorganic insulating film  53 . The drain electrode  45 , the source electrode  47 , and the wiring  49  are formed of a conductive material containing, for example, Al, Ag, Cu, Ni, Ti, and Mo. The flattening film  51  is formed of an organic insulating material such as acrylic resin and has a flat upper surface. The inorganic insulating film  53  is formed of an inorganic insulating material such as SiO2, SiN, or SiON. 
     A pixel electrode  61  (for example, an anode) is formed on the inorganic insulating film  53 . The pixel electrode  61  penetrates the flattening film  51  and the inorganic insulating film  53  and is connected to the source electrode  47 . The pixel electrode  61  is provided so as to correspond to each of the plurality of unit pixels. The pixel electrode  61  is formed as a reflective electrode. Further, in the periphery area  11 , a first terminal  67  and a second terminal  68  exposed from the inorganic insulating film  53  and the like are formed on the upper surface of the substrate  30 , penetrate the flattening film  51  and the inorganic insulating film  53 , and are respectively connected to both end portions of the wiring  49 . The second terminal  68  is disposed at a position farther from the display area  15  than the first terminal  67 . In other words, the second terminal  68  is disposed at a position farther from a light emitting element  60  which will be described later than the first terminal  67 . 
     The pixel electrode  61 , the first terminal  67 , and the second terminal  68  are formed by including a conductive material containing, for example, Al, Ag, Cu, Ni, Ti, and Mo. Further, since the first terminal  67  and the second terminal  68  are often exposed to the atmosphere during the process, a material that hardly causes surface oxidation or the like, for example, an indium-based oxide such as ITO or IZO may be included. In other words, the first terminal  67  and the second terminal  68  may have a two-layer structure of a conductive material containing Al, Ag, Cu, Ni, Ti, and Mo, and an indium-based oxide that hardly causes surface oxidation and the like. 
     In a case where the first terminal  67  and the second terminal  68  include indium-based oxide on the surface side thereof, when a first inorganic insulating film  71 , a second inorganic insulating film  75 , an interlayer insulating film  83  and the like are etched and removed, the indium-based oxide has a small selection ratio with respect to the etching solution, and thus, it is desirable that the shapes of the first terminal  67  and the second terminal  68  can be maintained. Further, in a case where the display device  1  is the bottom emission type, the pixel electrode  61  needs to be formed as a transmissive electrode, and in this case, the above-described indium-based oxide can be used. 
     The pixel separation film  55  is disposed around the pixel electrode  61 . The pixel separation film  55  is also called a rib or a bank. On the pixel separation film  55 , a first opening  55   a  is formed such that the pixel electrode  61  is exposed at the bottom. An inner edge part of the pixel separation film  55  that forms the first opening  55   a  is placed at a circumferential edge part of the pixel electrode  61 , and has a tapered shape that becomes wider outward in the upward direction. The pixel separation film  55  is formed in the display area  15  and in the vicinity of the boundary between the periphery area  11  and the display area  15 . The pixel separation film  55  is formed of an organic insulating material such as acrylic resin. 
     On the pixel electrode  61  exposed at the bottom of the first opening  55   a  of the pixel separation film  55 , a light emitting layers  63  are formed separately from each other. The light emitting layer  63  emits light in a plurality of colors of, for example, red, green, and blue corresponding to each of the plurality of unit pixels. At least one of a positive hole transport layer, a positive hole injection layer, an electron transport layer, and an electron injection layer may be formed together with the light emitting layer  63 . The light emitting layer  63  is individually formed by vapor deposition using a mask. The light emitting layer  63  may be formed by vapor deposition as a uniform film in the entire display area  15 . In this case, the light emitting layer  63  emits light of a single color (for example, white), and each component of a plurality of colors of red, green, and blue is extracted by a color filter  103  or a color conversion layer. The light emitting layer  63  is not limited to the formation by vapor deposition and may be formed by coating. 
     The light emitting layer  63  and the pixel separation film  55  are covered with a counter electrode  65  (for example, cathode). The counter electrode  65  is formed as a uniform film in the entire display area  15 . The light emitting element  60  is configured with the light emitting layer  63  and the pixel electrode  61  and the counter electrode  65  sandwiching the light emitting layer  63 , and the light emitting layer  63  emits light by a current that flows between the pixel electrode  61  and the counter electrode  65 . The counter electrode  65  is formed of a transparent conductive material such as ITO or a metal thin film such as MgAg. In a case where the display device  1  is a top emission type, the counter electrode  65  needs to be formed as a transmissive electrode, and in a case where a metal thin film is used, it is necessary to reduce the film thickness to the extent that light is transmitted. 
     The pixel separation film  55  and the counter electrode  65  are sealed by being covered with a sealing film (passivation film)  70 , and are shielded from moisture. The sealing film  70  has a three-layer laminated structure including, for example, the first inorganic insulating film  71 , the organic insulating film  73 , and the second inorganic insulating film  75  in this order from the bottom. The first inorganic insulating film  71  and the second inorganic insulating film  75  are formed of an inorganic insulating material such as SiO2, SiN, or SiON. The organic insulating film  73  is formed of an organic insulating material such as acrylic resin, and flattens the top surface of the sealing film  70 . The display unit  10  is configured of each layer of the substrate  30  to the sealing film  70 . 
     The display device  1  has the touch sensor  20  on the sealing film  70 . Specifically, a protective insulating film  81  is formed on the sealing film  70 , and the plurality of first electrodes  21  and the plurality of second electrodes  22  that are two-dimensionally arranged are formed on the protective insulating film  81 . An interlayer insulating film  83  is formed on the first electrode  21  and the second electrode  22 . The first electrode  21  and the second electrode  22  configure a drive electrode and a detection electrode of the electrostatic capacity type touch sensor  20 . The protective insulating film  81  and the interlayer insulating film  83  are formed of an organic insulating material such as acrylic resin. The protective insulating film  81  may be omitted, and in this case, the first electrode  21  and the second electrode  22  are formed on the sealing film  70 . 
     In the present embodiment, the first electrode  21  and the second electrode  22  have a laminated structure including a first layer containing a material such as Ag or MoW that makes ohmic contact with the indium-based material and a second layer provided on the first layer and containing indium-based oxide such as ITO, IZO, and IGZO. 
     In the present embodiment, the plurality of first electrodes  21  and the plurality of second electrodes  22  are disposed in the same layer between the sealing film  70  and the interlayer insulating film  83 , but the present invention is not limited thereto, and the plurality of first electrodes  21  and the plurality of second electrodes  22  may be disposed on layers different from each other. In other words, one of the first electrode  21  and the second electrode  22  may be disposed below the interlayer insulating film  83 , and the other may be disposed above the interlayer insulating film  83 . Further, both the first electrode  21  and the second electrode  22  may be disposed on the interlayer insulating film  83 . 
     As shown in  FIGS. 2 to 4B , the first connection line  23  and the second connection line  24  intersect each other in a plan view. The interlayer insulating film  83  is interposed between the first connection line  23  and the second connection line  24  that intersect each other in a plan view, and both the first connection line  23  and the second connection line  24  are electrically separated from each other. 
     The first connection line  23  is a so-called bridge wiring disposed on the interlayer insulating film  83 . Specifically, as shown in  FIGS. 3 and 4A , the first connection line  23  is connected to the first electrode  21  through a through hole  90  formed in the interlayer insulating film  83 . Meanwhile, the second connection line  24  is formed continuously with the second electrode  22  under the interlayer insulating film  83 . Note that  FIG. 4A  is an enlarged view of the first electrode  21  and the second electrode  22  in the second area  18  of  FIG. 1A . 
     The first connection line  23  is formed of a conductive material containing, for example, Al, Ag, Cu, Ni, Ti, and Mo. The first connection line  23  may have, for example, a three-layer structure of Ti, Al, and Ti, or may have a three-layer structure of Mo, Al, and Mo. By forming the first connection line  23  with such a laminated structure, it is possible to achieve low resistance of the first connection line  23  and suppress the occurrence of delay caused by time constant in the detection in the touch sensor  20 . The second connection line  24  has a laminated structure including a first layer containing a material such as Ag or Mow that makes ohmic contact with the indium-based material and a second layer provided on the first layer and containing indium-based oxide such as ITO, IZO, and IGZO. 
     The first electrode  21  and the second electrode  22  may be rectangular electrodes having a uniform thickness, or may have a shape having a third opening  91  in an area that emits light from a plurality of pixels. Specifically, as shown in  FIG. 4A , each of the plurality of first electrodes  21  and the plurality of second electrodes  22  may be formed in a rectangular uniform thickness. Further, as shown in  FIG. 4B , the plurality of first electrodes  21  and the second electrodes  22  may each be formed in a mesh shape having the plurality of third openings  91 . Each third opening  91  is formed at a position overlapping the area (that is, the first opening  55   a ) that emits light of a plurality of pixels in a plan view. Accordingly, reflection, absorption, and the like of light emitted by the pixel due to the first electrode  21  and the second electrode  22  can be reduced, and the brightness of the display device  1  can be improved. 
     Further, the second connection line  24  may be disposed as a bridge wiring on the interlayer insulating film  83 , and the first connection line  23  may be formed continuously with the first electrode  21  under the interlayer insulating film  83 . Further, an intersection unit where the first connection line  23  intersects the second connection line  24  as a bridge wiring and an intersection unit where the second connection line  24  intersects the first connection line  23  as a bridge wiring may be mixed. 
     A lead wire  25  is disposed on the interlayer insulating film  83  from the circumferential edge portion of the display area  15  to the periphery area  11 . Specifically, the lead wire  25  has, for example, a three-layer structure of Ti, Al, and Ti, or Mo, Al, and Mo. The lead wire  25  is connected to the first electrode  21  or the second electrode  22  through a second opening  83   a  formed on the interlayer insulating film  83 . The lead wire  25  is formed over the end surface of the first inorganic insulating film  71 , the second inorganic insulating film  75 , and the interlayer insulating film  83 , and is connected to the exposed upper surface of the first terminal  67 . The lead wire  25  is connected to the wiring  49  disposed below the light emitting element  60  via the first terminal  67 . 
     The FPC  13  is connected to the second terminal  68  disposed on the side separated from the display area  15 . In the periphery area  11 , a terminal (third terminal) (not shown) is also provided. The terminal is electrically connected to the light emitting element  60 , and the FPC  13  is connected to this terminal (not shown). The terminal (not shown) is electrically connected to the light emitting element  60  via the thin film transistor  40  and the integrated circuit chip  12 . 
     Furthermore, the FPC  13  is connected to both the second terminal  68  electrically connected to the touch sensor  20  and a terminal (third terminal) (not shown) electrically connected to the light emitting element  60 . Therefore, a single FPC  13  can supply signals to both the touch sensor  20  and the light emitting element  60  from the outside. 
     Next, an example of a control unit  105  that calculates the touched position on the touch sensor  20  will be described.  FIG. 5  is a view showing a functional configuration of the control unit  105 . The control unit  105  includes an I-V conversion unit  101 , an analog-digital conversion unit  102  (ADC), a filter  103 , and a signal processing unit  104 . 
     The I-V conversion unit  101  converts the amount of change in the current value, which appears depending on whether or not the first electrode  21  is touched, into the amount of change in the voltage value. Specifically, the I-V conversion unit  101  is electrically connected to the first electrode  21  via the lead wire  25 . Further, the second electrode  22  is electrically connected to the voltage application unit  110  (not shown) via the lead wire  25 . For example, a pulse signal is input to the second electrode  22  by the voltage application unit  110 . The voltage of the first electrode  21  changes via the electrostatic capacity formed between the first electrode  21  and the second electrode  22 . At this time, charges move between the first touch electrode and the I-V conversion unit  101 . In other words, a current flows from a first touch electrode to the I-V conversion unit  101 . This current value differs depending on whether or not the first electrode  21  is touched. The I-V conversion unit  101  converts the current supplied from the first touch electrode into a voltage. The first electrode  21  and the second electrode  22  may be exchangeable, the first electrode  21  may be connected to the voltage application unit  110 , and the second electrode  22  may be connected to the I-V conversion unit  101 . 
     The analog-digital conversion unit  102  converts the analog voltage value converted by the I-V conversion unit  101  into a digital voltage value. 
     The filter  103  measures the voltage converted to digital a predetermined number of times and averages the voltages. Specifically, for example, the filter  103  performs processing of averaging the voltage values measured four times per second. The filter  103  may perform processing of excluding the maximum value and the minimum value from the voltage values measured a predetermined number of times and averaging the other voltage values. 
     The filter  103  may be provided between the I-V conversion unit  101  and the first electrode  21 , or between the I-V conversion unit  101  and the analog-digital conversion unit  102 . In this case, the filter  103  may be configured by a low pass filter  103 , a band pass filter  103 , or the like. 
     The signal processing unit  104  calculates the touched coordinates of the touch sensor  20  based on the voltage value output by the filter  103 . Specifically, based on the relationship between the position of the plurality of first electrodes  21  and the voltage value calculated from the output of each first electrode  21 , the signal processing unit  104  calculates a function that approximates the relationship between the position and the voltage value. The signal processing unit  104  calculates the touched coordinate in the second direction according to the peak value of the function. Further, based on the relationship between the position of the second electrode  22  into which the pulse signal is input and the voltage value calculated from the output of each first electrode  21 , the signal processing unit  104  calculates a function that approximates the relationship between the position and the voltage value. The signal processing unit  104  calculates the touched coordinate in the first direction according to the peak value of the function. 
     The control unit  105  is included in an IC (not shown) disposed on the FPC  13 . Further, the control unit  105  may be included in the integrated circuit chip for driving the pixel. 
     As described above, in the first embodiment, in the curved area  16  and the first area  17 , the first electrode  21  and the second electrode  22  disposed at the same coordinates in the second direction are formed in the first direction at constant distances. Therefore, unlike the related art, only the electrodes disposed along the edge of the display device  1  do not have a unique shape. Therefore, when the signal processing unit  104  calculates the touched coordinates, the influence of the first electrode  21  and the second electrode  22  having a unique shape can be averaged in the first direction. Accordingly, the calculation accuracy of the coordinates in the first direction can be improved. 
     Second Embodiment 
     Subsequently, a second embodiment of the present invention will be described. The description of the same configuration as those of the first embodiment will be omitted.  FIG. 6A  is a plan view of the display device  1  according to the second embodiment of the present invention.  FIG. 6B  is a view schematically showing a position where the connection line  23  is disposed in the entire touch sensor  20 . 
     In the second embodiment, in the first area  17  and the second area  18 , the distances between the plurality of first electrodes  21  and the second electrodes  22  in the first direction and in the second direction are constant. In other words, the first electrode  21  and the second electrode  22  disposed in the area other than the curved area  16  are both formed in the same rhombus shape. In addition, a part of the first electrode  21  and the second electrode  22  disposed to be in contact with the edge of the display device  1  of the first area  17  is formed in a triangular shape. 
     Meanwhile, in the curved area  16 , the distances between the plurality of first electrodes  21  and the second electrodes  22  in the first direction gradually change in the second direction. Specifically, as shown in  FIG. 6B , in the curved area  16  on the side (lower side of  FIG. 6B ) where the FPC  13  of the display device  1  is provided, the distances between the connection lines  23  aligned in the first direction (left-right direction of  FIG. 6B ) gradually increase as going in the second direction (upward direction of  FIG. 6B ). Therefore, in the curved area  16 , the distances between the plurality of first electrodes  21  and the second electrodes  22  in the first direction gradually increase in the second direction. 
     In the curved area  16  on the side (upper side of  FIG. 6B ) opposite to the side where the FPC  13  of the display device  1  is provided, the distances between the connection lines  23  aligned in the first direction (left-right direction of  FIG. 6B ) gradually decrease as going in the second direction (upward direction of  FIG. 6B ). 
     Further, in the curved area  16 , the distances between the plurality of first electrodes  21  and the second electrodes  22  in the second direction gradually change in the first direction. Specifically, as shown in  FIG. 6B , in the curved area  16  on the left side of  FIG. 6B , the distances between the connection lines  23  aligned in the second direction (up-down direction of  FIG. 6B ) gradually increase as going in the first direction (rightward direction of  FIG. 6B ). Therefore, in the curved area  16 , the distances between the plurality of first electrodes  21  and the second electrodes  22  in the second direction gradually increase in the first direction. 
     In the curved area  16  on the right side of  FIG. 6B , the distances between the connection lines  23  aligned in the second direction (up-down direction of  FIG. 6B ) gradually decrease as going in the first direction (rightward direction of  FIG. 6B ). Therefore, in the curved area  16 , the distances between the plurality of first electrodes  21  and the second electrodes  22  in the second direction gradually decrease in the first direction. 
     As described above, in the second embodiment, the first electrode  21  and the second electrode  22  are disposed at constant distances in the first direction and in the second direction in the area other than the curved area  16 . Accordingly, the detection accuracy in the curved area  16  can be improved in the same manner as in the first embodiment while maintaining the coordinate detection accuracy similar to that in the technique of the related art in the area other than the curved area  16 . 
     Third Embodiment 
     Subsequently, a third embodiment of the present invention will be described. The description of the same configuration as those of the first embodiment will be omitted.  FIG. 7A  is a plan view of the display device  1  according to the third embodiment of the present invention.  FIG. 7B  is a view schematically showing a position where the connection line  23  is disposed in the entire touch sensor  20 . 
     In the third embodiment, in the curved area  16 , the first area  17 , and the second area  18 , the distances between the plurality of first electrodes  21  and the second electrodes  22  in the first direction gradually change in the second direction, and the distances between the plurality of first electrodes  21  and the second electrodes  22  in the second direction gradually change in the first direction. 
     Specifically, as shown in  FIG. 7B , in an area below the center of the display device  1 , the distances between the connection lines  23  aligned in the first direction (left-right direction of  FIG. 7B ) gradually increase as going in the second direction (upward direction of  FIG. 7B ). Therefore, in an area below the center of the display device  1 , the distances between the plurality of first electrodes  21  and the second electrodes  22  in the first direction gradually increase in the second direction. 
     In an area above the center of the display device  1 , the distances between the connection lines  23  aligned in the first direction (left-right direction of  FIG. 7B ) gradually decrease as going in the second direction (upward direction of  FIG. 7B ). Therefore, in an area above the center of the display device  1 , the distances between the plurality of first electrodes  21  and the second electrodes  22  in the first direction gradually decrease in the second direction. 
     In an area on the left of the center of the display device  1 , the distances between the connection lines  23  aligned in the second direction (up-down direction of  FIG. 7B ) gradually increase as going in the first direction (rightward direction of  FIG. 7B ). Therefore, in an area on the left of the center of the display device  1 , the distances between the plurality of first electrodes  21  and the second electrodes  22  in the second direction gradually increase in the first direction. 
     In an area on the right of the center of the display device  1 , the distances between the connection lines  23  aligned in the second direction (up-down direction of  FIG. 7B ) gradually decrease as going in the first direction (rightward direction of  FIG. 7B ). Therefore, in an area on the right of the center of the display device  1 , the distances between the plurality of first electrodes  21  and the second electrodes  22  in the second direction gradually decrease in the first direction. 
     As described above, in the third embodiment, in the entire area of the display device  1 , the distances between the first electrode  21  and the second electrode  22  gradually change respectively in the first direction and in the second direction. Accordingly, the influence of the curved edge of the display device  1  is dispersed over the entire display device  1 , and thus the detection accuracy of the touched coordinate can be improved. 
     In each of the above-described embodiments, a case of an organic EL display device is illustrated as a disclosure example, but as another application example, any flat panel type display device  1  such as a liquid crystal display device, another self-luminous display device, or an electronic paper type display device including an electrophoretic element or the like, can be used. It is needless to say that the present invention can be applied to small, medium, and large sizes without any particular limitation. 
     Further, in the above-described embodiments, an example in which the display device integrally is formed with the touch sensor  20  so as to be superimposed on the display area has been described as an example, but it is needless to say that the invention can also be applied to the touch sensor  20  alone, that is, the touch panel device itself. 
     While there have been described what are at present considered to be certain embodiments of the invention, it will be understood that various modifications may be made thereto, and it is intended that the appended claims cover all such modifications as fall within the true spirit and scope of the invention.