Patent Publication Number: US-11379066-B2

Title: Touch sensor including rounded corner and sensing electrode including rounded edge corresponding to rounded corner, and display device including the same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation of U.S. patent application Ser. No. 16/806,400, filed Mar. 2, 2020, which issued as U.S. Pat. No. 10,936,105, which is a Continuation of U.S. patent application Ser. No. 15/868,964, filed Jan. 11, 2018, which issued as U.S. Pat. No. 10,579,191, which claims priority to and the benefit of Korean Patent Application No. 10-2017-0081992, filed Jun. 28, 2017, each of which is hereby incorporated by reference for all purposes as if fully set forth herein. 
    
    
     BACKGROUND 
     Field 
     The disclosure generally relates to a touch sensor and a display device including the same. 
     Discussion 
     Display devices may include an information input function along with an image display function. The information input function may be generally implemented by a touch sensor for receiving user input. The touch sensor may be attached to one surface of a display panel that displays an image or may be integrally formed with the display panel. A user may input information by pressing, touching, or otherwise interacting with the touch sensor while viewing an image displayed on the display panel. 
     The above information disclosed in this section is only for understanding the background of the inventive concepts, and, therefore, may contain information that does not form prior art. 
     SUMMARY 
     Some exemplary embodiments are capable of providing a touch sensor having a decreased difference in touch sensitivity. 
     Some exemplary embodiments are capable of providing a display device including the touch sensor. 
     Additional aspects will be set forth in the detailed description which follows, and, in part, will be apparent from the disclosure, or may be learned by practice of the inventive concepts. 
     According to one or more exemplary embodiments, a touch sensor includes a base, first sensing electrode columns, and second sensing electrode columns. The base includes a sensing region including a rounded corner, and a non-sensing region outside the sensing region. The first sensing electrode columns extend in a first direction on the base, each first sensing electrode column among the first sensing electrode columns including first sensing electrodes, each first sensing electrode among the first sensing electrodes including sub-electrodes. The second sensing electrode columns are alternately disposed with the first sensing electrode columns on the base, each second sensing electrode column among the second sensing electrode columns including second sensing electrodes. Sub-electrodes of one of adjacent first sensing electrodes among the first sensing electrodes are electrically connected to respective sub-electrodes of another of the adjacent first sensing electrodes. A sub-electrode closest to the rounded corner among the sub-electrodes includes a rounded edge corresponding to the rounded corner. A second sensing electrode closest to the rounded corner among the second sensing electrodes includes a rounded edge corresponding to the rounded corner, and a protrusion part protruding toward the sub-electrode including the rounded edge. 
     According to one or more exemplary embodiments, a touch sensor includes a base, first sensing electrode columns, second sensing electrode columns, and a third sensing electrode. The base includes a sensing region including a rounded corner, and a non-sensing region outside the sensing region. The first sensing electrode columns extend in a first direction on the base, each first sensing electrode column among the first sensing electrode columns including first sensing electrodes, each first sensing electrode among the first sensing electrodes including sub-electrodes. The second sensing electrode columns are alternately disposed with the first sensing electrode columns on the base, each second sensing electrode column among the second sensing electrode columns including second sensing electrodes. The third sensing electrode is closest to the rounded corner among the first sensing electrodes and the second sensing electrodes. Sub-electrodes of one of adjacent first sensing electrodes among the first sensing electrodes are electrically connected to respective sub-electrodes of another of the adjacent first sensing electrodes. 
     According to one or more exemplary embodiments, a display device includes a display panel and a touch sensor. The display panel is configured to display an image. The touch sensor is on the display panel. The touch sensor includes a sensing region including a rounded corner, and a non-sensing region outside the sensing region. The touch sensor further includes first sensing electrode columns, and second sensing electrode columns. The first sensing electrode columns extend in a first direction, each first sensing electrode column among the first sensing electrode columns including first sensing electrodes, each first sensing electrode among the first sensing electrodes including sub-electrodes. The second sensing electrode columns are alternately disposed with the first sensing electrode columns, each second sensing electrode column among the second sensing electrode columns including second sensing electrodes. Sub-electrodes of one of adjacent first sensing electrodes among the first sensing electrodes are electrically connected to respective sub-electrodes of another of the adjacent first sensing electrodes. A sub-electrode closest to the rounded corner among the sub-electrodes includes a rounded edge corresponding to the rounded corner. A second sensing electrode closest to the rounded corner among the second sensing electrodes includes a rounded edge corresponding to the rounded corner, and a protrusion part protruding toward the sub-electrode including the rounded edge. 
     According to one or more exemplary embodiments, a display device includes a display panel and a touch sensor. The display panel is configured to display an image. The touch sensor includes a sensing region including a rounded corner, and a non-sensing region outside the sensing region. The touch sensor further includes first sensing electrode columns, second sensing electrode columns, and a third sensing electrode. The first sensing electrode columns extend in a first direction, each first sensing electrode column among the first sensing electrode columns including first sensing electrodes, each first sensing electrode among the first sensing electrodes including sub-electrodes. The second sensing electrode columns are alternately disposed with the first sensing electrode columns, each second sensing electrode column among the second sensing electrode columns including second sensing electrodes. The third sensing electrode is closest to the rounded corner among the first sensing electrodes and the second sensing electrodes. Sub-electrodes of one of adjacent first sensing electrodes among the first sensing electrodes are electrically connected to respective sub-electrodes of another of the adjacent first sensing electrodes. 
     The foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the claimed subject matter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the inventive concepts, and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the inventive concepts, and, together with the description, serve to explain principles of the inventive concepts. 
         FIG. 1  is an exploded perspective view illustrating a display device including a touch sensor according to some exemplary embodiments. 
         FIG. 2  is a sectional view of the display device shown in  FIG. 1  according to some exemplary embodiments. 
         FIG. 3  is an enlarged view of region EA 1  shown in  FIG. 2  according to some exemplary embodiments. 
         FIG. 4  is a plan view illustrating the touch sensor shown in  FIG. 1  according to some exemplary embodiments. 
         FIG. 5  is a plan view illustrating an arrangement of sensing electrodes of the touch sensor shown in  FIG. 1  according to some exemplary embodiments. 
         FIG. 6  is an enlarged view of region EA 2  of  FIG. 5  according to some exemplary embodiments. 
         FIG. 7  is a plan view illustrating first sensing electrodes of a first sensing electrode column and first sensing lines shown in  FIG. 5  according to some exemplary embodiments. 
         FIG. 8  is a plan view illustrating second sensing electrodes of a second sensing electrode column and second sensing lines shown in  FIG. 5  according to some exemplary embodiments. 
         FIG. 9  is a plan view illustrating a connection relationship of first sensing electrodes, second sensing electrodes, first sensing lines, second sensing lines, and a sensing line connection part according to some exemplary embodiments. 
         FIG. 10  is a sectional view illustrating a connection relationship of the sensing lines and the sensing line connection part of  FIG. 9  according to some exemplary embodiments. 
         FIG. 11  is an enlarged view of region EA 3  of  FIG. 6  according to some exemplary embodiments. 
         FIG. 12  is a plan view illustrating a first sensing electrode and a second sensing electrode that are provided at a rounded corner of the touch sensor shown in  FIG. 5  according to some exemplary embodiments. 
         FIG. 13  is an enlarged view of region EA 4  of  FIG. 12  according to some exemplary embodiments. 
         FIGS. 14 and 15  are plan views illustrating examples of a first sensing electrode and a second sensing electrode that are provided at a rounded corner of a touch sensor according to various exemplary embodiments. 
         FIGS. 16, 17, 18, and 19  are plan views illustrating examples of a first sensing electrode and a second sensing electrode that are provided at a rounded corner of a touch sensor according to various exemplary embodiments. 
         FIGS. 20, 21, 22, and 23  are plan views illustrating a first sensing electrode and a second sensing electrode that are provided at a rounded corner of a touch sensor according to various exemplary embodiments. 
         FIGS. 24 and 25  are plan views illustrating a first sensing electrode and a second sensing electrode that are provided at a rounded corner of a touch sensor according to some exemplary embodiments. 
     
    
    
     DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS 
     In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of various exemplary embodiments. It is apparent, however, that various exemplary embodiments may be practiced without these specific details or with one or more equivalent arrangements. In other instances, well-known structures and devices are shown in block diagram form in order to avoid unnecessarily obscuring various exemplary embodiments. Further, various exemplary embodiments may be different, but do not have to be exclusive. For example, specific shapes, configurations, and characteristics of an exemplary embodiment may be implemented in another exemplary embodiment without departing from the spirit and the scope of the disclosure. 
     Unless otherwise specified, the illustrated exemplary embodiments are to be understood as providing exemplary features of varying detail of some exemplary embodiments. Therefore, unless otherwise specified, the features, components, modules, layers, films, panels, regions, aspects, etc. (hereinafter individually or collectively referred to as “elements”), of the various illustrations may be otherwise combined, separated, interchanged, and/or rearranged without departing from the spirit and the scope of the disclosure. 
     The use of cross-hatching and/or shading in the accompanying drawings is generally provided to clarify boundaries between adjacent elements. As such, neither the presence nor the absence of cross-hatching or shading conveys or indicates any preference or requirement for particular materials, material properties, dimensions, proportions, commonalities between illustrated elements, and/or any other characteristic, attribute, property, etc., of the elements, unless specified. Further, in the accompanying drawings, the size and relative sizes of elements may be exaggerated for clarity and/or descriptive purposes. When an exemplary embodiment may be implemented differently, a specific process order may be performed differently from the described order. For example, two consecutively described processes may be performed substantially at the same time or performed in an order opposite to the described order. Also, like reference numerals denote like elements. 
     When an element is referred to as being “on,” “connected to,” or “coupled to” another element, it may be directly on, connected to, or coupled to the other element or intervening elements may be present. When, however, an element is referred to as being “directly on,” “directly connected to,” or “directly coupled to” another element, there are no intervening elements present. To this end, the term “connected” may refer to physical, electrical, and/or fluid connection. Further, the D1-axis, the D2-axis, and the D3-axis are not limited to three axes of a rectangular coordinate system, and may be interpreted in a broader sense. For example, the D1-axis, the D2-axis, and the D3-axis may be perpendicular to one another, or may represent different directions that are not perpendicular to one another. For the purposes of this disclosure, “at least one of X, Y, and Z” and “at least one selected from the group consisting of X, Y, and Z” may be construed as X only, Y only, Z only, or any combination of two or more of X, Y, and Z, such as, for instance, XYZ, XYY, YZ, and ZZ. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
     Although the terms “first,” “second,” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used to distinguish one element from another element. Thus, a first element discussed below could be termed a second element without departing from the teachings of the disclosure. 
     Spatially relative terms, such as “beneath,” “below,” “under,” “lower,” “above,” “upper,” “over,” “higher,” “side” (e.g., as in “sidewall”), and the like, may be used herein for descriptive purposes, and, thereby, to describe one element&#39;s relationship to another element(s) as illustrated in the drawings. Spatially relative terms are intended to encompass different orientations of an apparatus in use, operation, and/or manufacture in addition to the orientation depicted in the drawings. For example, if the apparatus in the drawings is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the exemplary term “below” can encompass both an orientation of above and below. Furthermore, the apparatus may be otherwise oriented (e.g., rotated 90 degrees or at other orientations), and, as such, the spatially relative descriptors used herein interpreted accordingly. 
     The terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting. As used herein, the singular forms, “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Moreover, the terms “comprises,” “comprising,” “includes,” and/or “including,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, components, and/or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It is also noted that, as used herein, the terms “substantially,” “about,” and other similar terms, are used as terms of approximation and not as terms of degree, and, as such, are utilized to account for inherent deviations in measured, calculated, and/or provided values that would be recognized by one of ordinary skill in the art. 
     Various exemplary embodiments are described herein with reference to sectional and/or exploded illustrations that are schematic illustrations of idealized exemplary embodiments and/or intermediate structures. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, exemplary embodiments disclosed herein should not be construed as limited to the particular illustrated shapes of regions, but are to include deviations in shapes that result from, for instance, manufacturing. In this manner, regions illustrated in the drawings are schematic in nature and shapes of these regions may not illustrate the actual shapes of regions of a device, and, as such, are not intended to be limiting. 
     Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure is a part. Terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense, unless expressly so defined herein. 
       FIG. 1  is an exploded perspective view illustrating a display device including a touch sensor according to some exemplary embodiments.  FIG. 2  is a sectional view of the display device shown in  FIG. 1  according to some exemplary embodiments.  FIG. 3  is an enlarged view of region EA 1  shown in  FIG. 2  according to some exemplary embodiments. FIG.  4  is a plan view illustrating the touch sensor shown in  FIG. 1  according to some exemplary embodiments.  FIG. 5  is a plan view illustrating an arrangement of sensing electrodes of the touch sensor shown in  FIG. 1  according to some exemplary embodiments. 
     Referring to  FIGS. 1 to 5 , the display device may include a display panel  100  and a touch sensor  200 . 
     The display panel  100  may display an image, and, as such, may be any suitable form of display panel. For example, self-luminescent display panels, such as an organic light emitting display panel (OLED panel), may be used as the display panel  100 . In addition, non-luminescent display panels, such as a liquid crystal display panel (LCD panel), an electrophoretic display panel (EPD panel), and/or an electro-wetting display panel (EWD panel), may be used as the display panel  100 . When a non-luminescent display panel is used as the display panel  100 , the display device may include a backlight unit (not shown) that supplies light to the display panel  100 . For convenience, a case where an OLED panel is used as the display panel  100  is described. 
     The display panel  100  may have various planar shapes. For example, the display panel  100  may have a closed polygonal shape including at least one linear side. In addition, the display panel  100  may have shapes, such as a circle and an ellipse, which include curved (or arcuate) sides. In addition, the display panel  100  may have shapes, such as a semicircle and a semi-ellipse, which include linear and curved sides. 
     In some embodiments, when the display panel  100  has linear sides, at least some of corners of a polygonal shape may be formed in a curve. For example, when the display panel  100  has a rectangular shape, corners of the rectangular shape may have a rounded (or arcuate) shape. That is, the display panel  100  may have rounded corners. For instance, a portion at which adjacent linear sides meet each other may be replaced with a curve having a determined curvature. The corner of the rectangular shape may be formed with a curved side having both adjacent ends respectively connected to two adjacent linear sides, the curved side having a determined curvature. The curvature may be differently set depending on positions. For example, the curvature may be changed depending on a position at which the curve is started, a length of the curve, etc. It is also contemplated that compound or polynomial curves may be utilized in association with exemplary embodiments. 
     The display panel  100  may include a display region and a non-display region provided at a periphery (or outside) of the display region. The display region may have a shape corresponding to that of the display panel  100 . For example, the display region may have a closed polygonal shape including linear sides. In addition, the display region may have shapes, such as a circle and an ellipse, which include curved sides. In addition, the display region may have shapes, such as a semicircle and a semi-ellipse, which include linear and curved sides. 
     In some embodiments, when the display panel  100  has linear sides, at least some of corners of a polygonal shape may be formed in a curve. That is, the display region may have rounded corners. In more detail, when the display region has a rectangular shape, a portion at which adjacent linear sides meet each other may be replaced with a curve having a determined curvature. That is, the corner of the rectangular shape may be formed with a curved side having both adjacent ends respectively connected to two adjacent linear sides, the curved side having a determined curvature. The curvature may be differently set depending on positions. For example, the curvature may be changed depending on a position at which the curve is started, a length of the curve, etc. It is also contemplated that compound or polynomial curves may be utilized in association with exemplary embodiments. 
     Although not illustrated, a plurality of pixels may be provided in the display region. Each pixel may be any one of a red pixel, a green pixel, a blue pixel, and a white pixel, but embodiments are not limited thereto. For example, the pixel may be any one of a magenta pixel, a cyan pixel, a yellow pixel, etc. 
     In addition, the display panel  100  may include a driving unit (not shown) that is provided at one side of a substrate SUB and drives the pixels. The driving unit may be a chip-on-glass (COG) type of driving element; however, embodiments are not limited thereto. 
     Each of the pixels may include at least one thin film transistor TFT provided on the substrate SUB and a display element OLED connected to the thin film transistor TFT. The display element OLED may be an organic light emitting element. 
     The substrate SUB may include a transparent insulating material that enables light to be transmitted therethrough. The substrate SUB may be a rigid substrate and/or a flexible substrate. The rigid substrate (or substrate portion) may include a glass substrate, a quartz substrate, a glass ceramic substrate, and a crystalline glass substrate. The flexible substrate (or substrate portion) may include a film substrate and a plastic substrate that include a polymer organic material. For example, the flexible substrate may include at least one of polyethersulfone (PES), polyacrylate (PA), polyetherimide (PEI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyarylate (PAR), polyimide (PI), polycarbonate (PC), triacetate cellulose (TAC), and cellulose acetate propionate (CAP). Also, the flexible substrate may include fiber glass reinforced plastic (FRP). The material applied as the substrate SUB may have resistance (e.g., heat resistance) against high processing temperature in a manufacturing process of the display device. 
     A buffer layer BFL may be provided between the substrate SUB and the thin film transistor TFT. The buffer layer BFL may include an inorganic insulating material. For example, the buffer layer BFL may include at least one of silicon oxide, silicon nitride, and silicon oxynitride. Also, the buffer layer BFL may have a single or multi-layered structure. For example, the buffer layer BFL may have a single-layered structure including one of silicon oxide, silicon nitride, and silicon oxynitride. The buffer layer BFL may include a silicon oxide layer and a silicon nitride layer disposed on the silicon oxide layer. The buffer layer BFL may include three or more insulating layers that are sequentially stacked. The buffer layer BFL may prevent impurities from being diffused into the thin film transistor TFT from the substrate SUB. Also, the buffer layer BFL may planarize a surface of the substrate SUB. 
     The thin film transistor TFT may be connected to a gate line (not shown) and a data line (not illustrated). The thin film transistor TFT may include a semiconductor (or active) layer SCL, a gate electrode GE, a source electrode SE, and a drain electrode DE. 
     The semiconductor layer SCL may be disposed on the buffer layer BFL. The semiconductor layer SCL may include at least one of amorphous silicon, polycrystalline silicon, oxide semiconductor, and organic semiconductor. In the semiconductor layer SCL, regions connected to the source electrode SE and the drain electrode DE may be source and drain regions into which impurities are doped or injected. A region between the source region and the drain region may be a channel region. Although not shown, when the semiconductor layer SCL includes an oxide semiconductor, a light blocking layer for blocking light incident into the semiconductor layer SCL may be disposed on the top or bottom of the semiconductor layer SCL. 
     A gate insulating layer GI may be disposed on the semiconductor layer SCL. The gate insulating layer GI may cover the semiconductor layer SCL, and may insulate the semiconductor layer SCL and the gate electrode GE from each other. The gate insulating layer GI may include at least one of an organic insulating material and an inorganic insulating material. For example, the gate insulating layer GI may include at least one of silicon oxide and silicon nitride. 
     The gate electrode GE may be disposed on the gate insulating layer GI. The gate electrode GE may be connected to the gate line. The gate electrode GE may include a low-resistance conductive material, and overlap with the semiconductor layer SCL. 
     An interlayer insulating layer ILD may be disposed over the gate electrode GE. The interlayer insulating layer ILD may include at least one of an organic insulating material and an inorganic insulating material. For example, the interlayer insulating layer ILD may include at least one of silicon oxide and silicon nitride. The interlayer insulating layer ILD may insulate the source electrode SE and the drain electrode DE from the gate electrode GE. 
     Contact holes passing through the gate insulating layer GI and the interlayer insulating layer ILD may expose the source region and the drain region of the semiconductor layer therethrough. 
     The source electrode SE and the drain electrode DE may be disposed on the interlayer insulating layer ILD to be spaced apart from each other. The source electrode SE and the drain electrode DE may include a low-resistance conductive material. One end of the source electrode SE may be connected to the data line. The other end of the source electrode SE may be connected to the source region of the semiconductor layer SCL through one of the contact holes. One end of the drain electrode DE may be connected to the drain region through the other of the contact holes. The other end of the drain electrode DE may be connected to the display element OLED. 
     Although a case where the thin film transistor TFT is a thin film transistor having a top gate structure has been described and illustrated as an example, embodiments are not limited thereto. For example, the thin film transistor TFT may be a thin film transistor having a bottom gate structure, a dual gate structure, etc. 
     A protective layer PSV may be provided over the thin film transistor TFT. The protective layer PSV may cover the thin film transistor TFT. A portion of the protective layer PSV may be removed to expose one of the source electrode SE and the drain electrode DE, e.g., the drain electrode DE, therethrough. The protective layer PSV may include at least one layer. For example, the protective layer PSV may include an inorganic protective layer and an organic protective layer disposed on the inorganic protective layer. The inorganic protective layer may include at least one of silicon oxide and silicon nitride. The organic protective layer may include at least one of acryl, polyimide (PI), polyamide (PA), and benzocyclobutene (BCB). Also, the organic protective layer may be a planarization layer that is transparent and flexible to reduce and planarize winding (or undulations) of a lower structure. 
     The display element OLED may be provided on the protective layer PSV. The display element OLED may include a first electrode AE connected to the thin film transistor TFT, an emitting layer EML disposed on the first electrode AE, and a second electrode CE disposed on the emitting layer EML. One of the first electrode AE and the second electrode CE may be an anode electrode, and the other of the first electrode AE and the second electrode CE may be a cathode electrode. For example, the first electrode AE may be an anode electrode, and the second electrode CE may be a cathode electrode. 
     In addition, at least one of the first electrode AE and the second electrode CE may be a transmissive electrode. For example, when the display element OLED is a bottom emission type organic light emitting element, the first electrode AE may be a transmissive electrode, and the second electrode CE may be a reflective electrode. When the display element OLED is a top emission type organic light emitting element, the first electrode AE may be a reflective electrode, and the second electrode CE may be a transmissive electrode. When the display element OLED is a double-sided emission type organic light emitting element, both of the first electrode AE and the second electrode CE may be transmissive electrodes. For convenience, a case where the display element OLED is a top emission type organic light emitting element and the first electrode AE is an anode electrode is described and illustrated as an example. 
     In each pixel, the first electrode AE may be disposed on the protective layer PSV. The first electrode AE may include a reflective layer (not shown) configured to reflect light and a transparent conductive layer (not shown) disposed on the top or bottom of the reflective layer. At least one of the reflective layer and the transparent conductive layer may be connected to the drain electrode DE. 
     The reflective layer may include a material that reflects incident light. For example, the reflective layer may include at least one of aluminum (Al), silver (Ag), chromium (Cr), molybdenum (Mo), platinum (Pt), nickel (Ni), and any alloy thereof. 
     The transparent conductive layer may include transparent conductive oxide. For example, the transparent conductive layer may include at least one transparent conductive oxide, such as at least one of indium tin oxide (ITO), indium zinc oxide (IZO), aluminum zinc oxide (AZO), gallium doped zinc oxide (GZO), zinc tin oxide (ZTO), gallium tin oxide (GTO), and fluorine doped tin oxide (FTO). 
     A pixel defining layer PDL may be disposed over the first electrode AE. The pixel defining layer PDL is provided between pixel regions, and may expose the first electrode AE therethrough. The pixel defining layer PDL may overlap with an edge portion of the first electrode AE. In this manner, the pixel defining layer PDL may allow a majority of a surface of the first electrode AE to be exposed therethrough. The pixel defining layer PDL may include an organic insulating material. For example, the pixel defining layer PDL may include at least one of polystyrene, polymethyl methacrylate (PMMA), polyacrylonitrile (PAN), polyamide (PA), polyimide (PI), polyarylether (PAE), heterocyclic polymer, parylene, epoxy, benzocyclobutene (BCB), siloxane based resin, and silane based resin. 
     The emitting layer EML may be disposed on the exposed surface of the first electrode AE. The emitting layer EML may have a multi-layered thin film structure including at least a light generation layer (LGL). For example, the emitting layer EML may include a hole injection layer (HIL) for injecting holes and a hole transport layer (HTL) having a hole transporting property such that the HTL increases opportunity for holes and electrons to be re-combined by suppressing movement of electrons that fail to be combined in the LGL, the LGL for emitting light through the re-combination of the injected electrons and holes. The emitting layer EML layer additionally include a hole blocking layer (HBL) for suppressing the movement of holes that fail to be combined in the LGL, an electron transport layer (ETL) transporting electrons to the LGL, and an electron transport layer (EIL) for injecting electrons. The HIL, the HTL, the HBL, the ETL, and the EIL may be common layers connected in adjacent light emitting regions. 
     The color of light generated from the LGL may be one of red, green, blue, and white, but embodiments are not limited thereto. For example, the color of light generated from the LGL of the emitting layer EML may also be at least one of magenta, cyan, yellow, etc. 
     The second electrode CE may be disposed on the emitting layer EML. The second electrode CE may be a semi-transmissive reflective layer. For example, the second electrode CE may be a thin metal layer having a thickness through which light can be transmitted. The second electrode CE may allow a portion of the light emitted from the LGL to be transmitted therethrough, and reflect the rest of the light emitted from the LGL. The second electrode CE may include a material having a low work function as compared with the transparent conductive layer, e.g., as compared with the first electrode AE. For example, the second electrode CE may be include at least one of molybdenum (Mo), tungsten (W), silver (Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca), and any alloy thereof. 
     A portion of the light emitted from the emitting layer EML may not be transmitted through the second electrode CE, and the light reflected from the second electrode CE may be again reflected from the reflective layer of the first electrode AE. That is, the light emitted from the emitting layer EML may resonate between the reflective layer and the second electrode CE. The light extraction efficiency of the display element OLED can be improved by the resonance of the light. 
     A distance between the reflective layer and the second electrode CE may be changed depending on a color of light emitted from the LGL. That is, the distance between the reflective layer and the second electrode CE may be adjusted to correspond to a resonance distance, depending on the color of the light emitted from the LGL. 
     An encapsulation layer ECL may be provided over the second electrode CE. The encapsulation layer ECL covers the display element OLED and may prevent oxygen and moisture from penetrating into the display element OLED. The encapsulation layer ECL may include a plurality of insulating layers. For example, the encapsulation layer ECL may include a plurality of inorganic layers (not shown) and a plurality of organic layers (not shown). For example, the encapsulation layer ECL may include a first inorganic layer on the second electrode CE, an organic layer on the first inorganic layer, and a second inorganic layer on the organic layer. Here, the inorganic layer may include at least one of silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, titanium oxide, zirconium oxide, and tin oxide. The organic layer may include at least one of acryl, polyimide (PI), polyamide (PA), and benzocyclobutene (BCB). 
     Although a case where the encapsulation layer ECL is applied so as to isolate the display element OLED from an external environment is described and illustrated as an example, embodiments are not limited thereto. To isolate the display element OLED from the external environment, an encapsulation substrate may be applied instead of (or in addition to) the encapsulation layer ECL. The encapsulation substrate may be joined with the substrate SUB through a sealant. When the display element OLED is isolated from the external environment using the encapsulation substrate, the encapsulation layer ECL may be omitted. 
     The touch sensor  200  may have a shape corresponding to that of the display panel  100 . For example, the touch sensor  200  may have a closed polygonal shape including linear sides. In addition, the touch sensor  200  may have shapes, such as a circle and an ellipse, which include curved sides. In addition, the touch sensor  200  may have shapes, such as a semicircle and a semi-ellipse, which include linear and curved sides. 
     In some embodiments, when the touch sensor  200  has linear sides, at least some of corners of a polygonal shape may be formed in a curve. That is, the touch sensor  200  may have rounded (or arcuate) corners. In more detail, when the touch sensor  200  has a rectangular shape, a portion at which adjacent linear sides meet each other may be replaced with a curve having a determined curvature. That is, a vertex portion of the rectangular shape may be formed with a curved side having both adjacent ends respectively connected to two adjacent linear sides, the curved side having a determined curvature. The curvature may be differently set depending on positions. For example, the curvature may be changed depending on a position at which the curve is started, a length of the curve, etc. It is also contemplated that compound or polynomial curves may be utilized in association with exemplary embodiments. 
     The touch sensor  200  may include a sensing region SA corresponding to the display region and a non-sensing region NSA outside the sensing region SA, e.g., the non-sensing region NSA may be provided at the periphery of the sensing region SA. 
     The sensing region SA may have a shape corresponding to that of the touch sensor  200 . For example, the sensing region SA may have a closed polygonal shape including linear sides. In addition, the sensing region SA may have shapes, such as a circle and an ellipse, which include curved sides. In addition, the sensing region SA may have shapes, such as a semicircle and a semi-ellipse, which include linear and curved sides. 
     In some embodiments, when the sensing region SA has linear sides, at least some of corners of a polygonal shape may be formed in a curve. That is, the sensing region SA may have rounded corners. For instance, when the sensing region SA has a rectangular shape, a portion at which adjacent linear sides meet each other may be replaced with a curve having a determined curvature. That is, a vertex portion of the rectangular shape may be formed with a curved side having both adjacent ends respectively connected to two adjacent linear sides, the curved side having a determined curvature. The curvature may be differently set depending on positions. For example, the curvature may be changed depending on a position at which the curve is started, a length of the curve, etc. 
     The touch sensor  200  may be provided on at least one of both surfaces of the display panel  100 . For example, the touch sensor  200  may be provided on the encapsulation layer ECL. That is, the encapsulation layer ECL of the display panel  100  may be a base that supports the touch sensor  200 . The touch sensor  200  may include a first insulating layer  210  provided on the encapsulation layer ECL, an electrode layer  220  on the first insulating layer  210 , and a cover layer  230  on the electrode layer  220 . 
     The first insulating layer  210  may include at least one of an organic insulating material and an inorganic insulating material. For example, the first insulating layer  210  may include at least one of silicon oxide and silicon nitride. 
     The electrode layer  220  may include a plurality of first sensing electrode columns TSC 1  that are provided in the sensing region SA and include a plurality of first sensing electrodes TSE 1 , a plurality of second sensing electrode columns TSC 2  that are provided in the sensing region SA, are alternately disposed with the first sensing electrode columns TSC 1 , and include a plurality of second sensing electrodes TSE 2 . The electrode layer  220  may also include a plurality of first sensing lines SL 1  that are connected to the first sensing electrodes TSE 1  and are provided in the non-sensing region NSA, a plurality of second sensing lines SL 2  that are connected to the second sensing electrodes TES 2  and are provided in the non-sensing region NSA, and a pad unit (or area) PDA that electrically connects the first sensing electrodes TSE 1  and the second sensing electrodes TSE 2  to an external driving circuit (not shown) through the first sensing lines SL 1  and the second sensing lines SL 2 , and is provided in the non-sensing region NSA. One of the first sensing electrodes TSE 1  and the second sensing electrodes TSE 2 , e.g., the first sensing electrodes TSE 1 , may be touch driving electrodes that receive touch driving signals, and the other of the first sensing electrodes TSE 1  and the second sensing electrodes TSE 2 , e.g., the second sensing electrodes TSE 2 , may be touch receiving electrodes that output touch sensing signals. As such, the electrode layer  220  may detect a touch of a user based on a change in capacitance of a first capacitor formed between the first sensing electrodes TSE 1  and the second sensing electrodes TSE 2 . 
     Both of the first sensing electrode columns TSC 1  and the second sensing electrode columns TSC 2  may extend in one direction. In addition, the first sensing electrodes TSE 1  may be arranged in the direction in which the first sensing electrode columns TSC 1  extend, and the second sensing electrodes TSE 2  may be arranged in the direction in which the second sensing electrode columns TSC 2  extend. The first sensing electrodes TSE 1  and the second sensing electrodes TSE 2  may sense a change in capacitance from a touch input of a an object, such as a portion of the body of the user, a stylus pen, etc. In addition, the first sensing electrodes TSE 1  and the second sensing electrodes TSE 2  may include a conductive material to sense the change in capacitance. 
     The first sensing lines SL 1  and the second sensing lines SL 2  may transmit the change in capacitance, which is sensed via the first sensing electrodes TSE 1  and the second sensing electrodes TSE 2 , to an external circuit through the pad unit PDA. In addition, the first sensing lines SL 1  and the second sensing lines SL 2  may include the same material as the first sensing electrodes TSE 1  and the second sensing electrodes TSE 2 . The pad unit PDA may include a plurality of pads PD. The pads PD may be electrically connected to the first sensing electrodes TSE 1  and the second sensing electrodes TSE 2  through the first sensing lines SL 1  and the second sensing lines SL 2 . 
     The cover layer  230  may be provided on the electrode layer  220  to protect the exposed surface of the touch sensor  200 , e.g., the electrode layer  220 . The cover layer  230  may include at least one of an organic insulating material and an inorganic insulating material. For example, the cover layer  230  may include at least one of silicon oxide and silicon nitride. 
     Although a case where the cover layer  230  is provided on the electrode layer  220  is described and illustrated as an example, embodiments are not limited thereto. For example, the cover layer  230  may be replaced with (or supplemented by) a transparent window disposed on the electrode layer  220 . The window may be a high-strength transparent plastic substrate or a high-strength transparent glass substrate. 
       FIG. 6  is an enlarged view of region EA 2  of  FIG. 5  according to some exemplary embodiments.  FIG. 7  is a plan view illustrating first sensing electrodes of a first sensing electrode column and first sensing lines shown in  FIG. 5  according to some exemplary embodiments.  FIG. 8  is a plan view illustrating second sensing electrodes of a second sensing electrode column and second sensing lines shown in  FIG. 5  according to some exemplary embodiments.  FIG. 9  is a plan view illustrating a connection relationship of first sensing electrodes, second sensing electrodes, first sensing lines, second sensing lines, and a sensing line connection part according to some exemplary embodiments.  FIG. 10  is a sectional view illustrating a connection relationship of the sensing lines and the sensing line connection part of  FIG. 9  according to some exemplary embodiments.  FIG. 11  is an enlarged view of region EA 3  of  FIG. 6  according to some exemplary embodiments. 
     Referring to  FIGS. 6 to 11 , the electrode layer  220  may include a plurality of first sensing electrode columns TSC 1  that extend in one direction and are parallel to one another, and a plurality of second sensing electrode columns TSC 2  that extend in parallel to the first sensing electrode columns TSC 1  and are alternately disposed with the first sensing electrode columns TSC 1 . 
     The first sensing electrode columns TSC 1  may include a plurality of first sensing electrodes TSE 1 . For example, one first sensing electrode column TSC 1  may include m (m is a natural number of 2 or more) first sensing electrodes TSE 1 . The first sensing electrodes TSE 1  may be arranged in the direction in which the first sensing electrode columns TSC 1  extend. 
     Each of the first sensing electrodes TSE 1  may include a plural number of sub-electrodes, e.g., N sub-electrodes SUE 1 , SUE 2 , SUE 3 , and SUE 4  disposed to be spaced apart from each other, where N is an integer greater than or equal to 2. In some embodiments, each of the first sensing electrodes TSE 1  may include four sub-electrodes SUE 1 , SUE 2 , SUE 3 , and SUE 4 . That is, each of the first sensing electrodes TSE 1  may include a first sub-electrode SUE 1 , a second sub-electrode SUE 2 , a third sub-electrode SUE 3 , and a fourth sub-electrode SUE 4 . Here, the sub-electrodes SUE 1 , SUE 2 , SUE 3 , and SUE 4  may be sequentially arranged in the extending direction of the first sensing electrode columns TSC 1 . That is, among the sub-electrodes SUE 1 , SUE 2 , SUE 3 , and SUE 4 , the first sub-electrode SUE 1  may be disposed most distant from the pad unit PDA, and the fourth sub-electrode SUE 4  may be disposed closest to the pad unit PDA. 
     The sub-electrodes SUE 1 , SUE 2 , SUE 3 , and SUE 4  may be connected to first sensing lines SL 1 . The first sensing lines SL 1  may be disposed in a region in which the first sensing electrode columns TSC 1  and the second sensing electrode columns TSC 2  are disposed. In addition, the sub-electrodes SUE 1 , SUE 2 , SUE 3 , and SUE 4  of one of adjacent first sensing electrodes TSE 1  may be electrically connected to the sub-electrodes SUE 1 , SUE 2 , SUE 3 , and SUE 4  of the other of the adjacent first sensing electrodes TSE 1  through the first sensing lines SL 1 , respectively. 
     For example, if each of the first sensing electrodes TSE 1  includes N sub-electrodes SUE 1 , SUE 2 , SUE 3 , and SUE 4 , a J-th sub-electrode of one first sensing electrode TSE 1  may be electrically connected an (N−J+1)-th sub-electrode of an adjacent first sensing electrode TSE 1  through a first sensing line SL 1 , where J is a positive integer less than or equal to N. Therefore, if the number of sub-electrodes SUE 1 , SUE 2 , SUE 3 , and SUE 4  included in the first sensing electrode TSE 1  is N, the number of first sensing lines SL 1  corresponding to one first sensing electrode column TSC 1  may be N. 
     For instance, if each of the first sensing electrodes TSE 1  includes four sub-electrodes SUE 1 , SUE 2 , SUE 3 , and SUE 4 , a first sub-electrode SUE 1  of one first sensing electrode TSE 1  and a fourth sub-electrode SUE 4  of an adjacent first sensing electrode TSE 1  may be electrically connected to each other through a first, first sensing line SL 11 . A second sub-electrode SUE 2  of the one first sensing electrode TSE 1  and a third sub-electrode SUE 3  of the adjacent first sensing electrode TSE 1  may be electrically connected to each other through a second, first sensing line SL 12 . A third sub-electrode SUE 3  of the one first sensing electrode TSE 1  and a second sub-electrode SUE 2  of the adjacent first sensing electrode TSE 1  may be electrically connected to each other through a third, first sensing line SL 13 . A fourth sub-electrode SUE 4  of the one first sensing electrode TSE 1  and a first sub-electrode SUE 1  of the adjacent first sensing electrode TSE 1  may be electrically connected to each other through a fourth, first sensing line SL 14 . Therefore, the number of first sensing lines SL 1  corresponding to each of the first sensing electrode columns TSC 1  may be four. 
     If the number of first sensing electrodes TSE 1  in one first sensing electrode column TSC 1  is M, the number of sub-electrodes SUE 1 , SUE 2 , SUE 3 , and SUE 4  in one first sensing electrode TSE 1  is N, and the sub-electrodes SUE 1 , SUE 2 , SUE 3 , and SUE 4  and the first sensing lines SL 1  correspond to each other one-by-one, the number of first sensing lines SL 1  corresponding to the one first sensing electrode column TSC 1  may be M×N, where M is an integer greater than or equal to 2. If the number of first sensing electrode columns TSC 1  is P, the electrode layer  220  may include P×M×N first sensing lines SL 1 , where P is an integer greater than or equal to 2. Therefore, in regions between the first sensing electrodes TSC 1  and the second sensing electrodes TSC 2 , the number of first sensing lines SL 1  may increase as the first sensing lines SL 1  become closer to the pad unit PDA. In the regions between the first sensing electrodes TSC 1  and the second sensing electrodes TSC 2 , electromagnetic interference, e.g., noise caused by signals applied to the first sensing lines SL 1  may increase as the number of first sensing lines SL 1  increases. If the noise increases, the mutual capacitance between the first sensing electrode TSE 1  and the second sensing electrode TSE 2  may decrease. Therefore, the touch sensitivity of the electrode layer  220  may decrease as a distance to the pad unit PDA decreases in the electrode layer  220 . Also, in the electrode layer  220 , the touch sensitivity of a region distant from the pad unit PDA and the touch sensitivity of a region close to the pad unit PDA may be different from each other. 
     However, in some embodiments, sub-electrodes SUE 1 , SUE 2 , SUE 3 , and SUE 4  of adjacent first sensing electrodes TSE 1  may be electrically connected through the same first sensing lines SL 1 . That is, the sub-electrodes SUE 1 , SUE 2 , SUE 3 , and SUE 4  of the adjacent first sensing electrodes TSE 1  may share the first sensing lines SL 1 . Since the number of first sensing lines SL 1  corresponding to the first sensing electrode column TSC 1  is equal to that of sub-electrodes SUE 1 , SUE 2 , SUE 3 , and SUE 4  included in each first sensing electrode TSE 1 , the number of first sensing lines SL 1  corresponding to the first sensing electrode column TSC 1  may be less than that of sub-electrodes SUE 1 , SUE 2 , SUE 3 , and SUE 4  included in the first sensing electrode column TSC 1 . Thus, the number of first sensing lines SL 1  disposed in the regions between the first sensing electrode columns TSC 1  and the second sensing electrode columns TSC 2  can decrease, and the area in which the first sensing lines SL 1  are occupied in the regions between the first sensing electrode columns TSC 1  and the second sensing electrode columns TSC 2  can decrease. 
     In some embodiments, the number of first sensing lines SL 1  disposed in the regions between the first sensing electrode columns TSC 1  and the second sensing electrode columns TSC 2  decreases, and, as such, electromagnetic interference between the second sensing electrodes TSE 2  and the first sensing electrodes TSE 1  and first sensing lines SL 1  can decrease. Thus, the touch sensitivity of the electrode layer  220  can be improved. 
     In some embodiments, the number of first sensing lines SL 1  disposed in the regions between the first sensing electrode columns TSC 1  and the second sensing electrode columns TSC 2  decreases, and, as such, the area in which the first sensing lines SL 1  are occupied in the regions between the first sensing electrode columns TSC 1  and the second sensing electrode columns TSC 2  can decrease. Given that the area in which the first sensing lines SL 1  are occupied in the regions between the first sensing electrode columns TSC 1  and the second sensing electrode columns TSC 2  decreases, the area of the first sensing electrodes TSE 1  or the second sensing electrodes TSE 2  can increase. By increasing the area of the first sensing electrodes TSE 1  or the second sensing electrodes TSE 2 , the touch sensitivity of the electrode layer  220  can be improved. 
     The second sensing electrode columns TSC 2  may include a plurality of second sensing electrodes TSE 2 . For example, one second sensing electrode column TSC 2  may include q second sensing electrodes TES 2 , where q is an integer greater than or equal to 2. The second sensing electrodes TSE 2  may be arranged in the direction in which the second sensing electrode columns TSC 2  extend. 
     The second sensing electrodes TES 2  may be connected to second sensing lines SL 2 , respectively. Therefore, the number of second sensing lines SL 2  corresponding to one second sensing electrode column TSC 2  may be equal to that of the second sensing electrodes TSE 2 . That is, the number of second sensing lines SL 2  corresponding to the one second sensing electrode column TSC 2  may be q. The second sensing lines SL 2  may be disposed in the regions between the second sensing electrode columns TSC 2  and the first sensing electrode columns TSC 1 . 
     The second sensing lines SL 2  may be alternately disposed at left and right sides of the second sensing electrode columns TSC 2 . For example, the second sensing line SL 2  connected to one of adjacent second sensing electrodes TSE 2  may be disposed at the right side of the second sensing electrode column TSC 2 . In addition, the second sensing line SL 2  connected to the other of the adjacent second sensing electrodes TSE 2  may be disposed at the left side of the second sensing electrode column TSC 2 . Therefore, the numbers of second sensing lines SL 2  disposed in the regions between the first sensing electrode columns TSC 1  and the second sensing electrode columns TSC 2  may be equal to one another. 
     In some embodiments, the first sensing lines SL 1  connected to the sub-electrodes SUE 1 , SUE 2 , SUE 3 , and SUE 4  disposed at the same positions in the first sensing electrode columns TSC 1  may be electrically connected to each other through a first sensing line connection part CNL 1 . For example, the J-th first sensing lines SL 1  connected to the J-th sub-electrodes of the first sensing electrodes TSE 1  in one first sensing electrode column TSC 1  may be electrically connected to the J-th first sensing lines SL 1  connected to the J-th sub-electrodes of the first sensing electrodes TSE 1  in another first sensing electrode column TSC 1 . Here, the other first sensing electrode column TSC 1  may be a first sensing electrode column TSC 1  that is not adjacent to the one first sensing electrode column TSC 1 , but is spaced apart from the one first sensing electrode column TSC 1  the among the first sensing electrode columns TSC 1 . 
     For example, the electrode layer  220  may include the first sensing line connection part CNL 1  provided on the first insulating layer  210  shown in  FIG. 10 , a second insulating layer  225  provided over the first sensing line connection part CNL 1 , and the first sensing electrodes TSE 1 , the second sensing electrodes TSE 2 , the first sensing lines SL 1 , and the second sensing lines SL 2 , which are provided on the second insulating layer  225 . 
     The second insulating layer  225  may include at least one of an organic insulating material and an inorganic insulating material. The second insulating layer  225  may include a first contact hole CNT 1  that exposes the first sensing line connection part CNL 1  therethrough. The first sensing line connection part CNL 1  and the first sensing lines SL 1  may be electrically connected to each other through the first contact hole CNT 1 . 
     The first sensing lines SL 1  connected to the first sensing line connection part CNL 1  may be electrically connected to the same pad PD among the pads PD of the pad unit PDA. Thus, given that the first sensing lines SL 1  are electrically connected to each other through the first sensing line connection part CNL 1 , the total number of pads PD electrically connected to the first sensing electrodes TSE 1  may decrease. 
     In addition, since the J-th first sensing lines SL 1  of the first sensing electrode columns TSC 1  are electrically connected to each other, the J-th sub-electrodes connected to the J-th first sensing lines SL 1  may be applied with the same signal, e.g., a touch driving signal, through the same pad PD. In addition or alternatively, the J-th sub-electrodes connected to the J-th first sensing lines SL 1  may output the same signal, e.g., a touch sensing signal, through the same pad PD. 
     Although a case where the first sensing line connection parts CNL 1  are provided in a lower layer of the first sensing electrodes TSE 1 , the second sensing electrodes TSE 2 , the first sensing lines SL 1 , and the second sensing lines SL 2  is described and illustrated as an example, embodiments are not limited thereto. The first sensing line connection part CNL 1  may be provided in an upper layer of the first sensing electrodes TSE 1 , the second sensing electrodes TSE 2 , the first sensing lines SL 1 , and the second sensing lines SL 2 . 
     The second sensing lines SL 2  connected to second sensing electrodes TSE 2  disposed at the same positions in the second sensing electrode columns TSC 2  may be electrically connected to each other. For example, an i-th second sensing line SL 2  connected to an i-th second sensing electrode TSE 2  in each of four adjacent second sensing electrode columns TSC 2  may be connected to a second sensing line connection part CNL 2  through a second contact hole CNT 2 , where i is a positive integer less than or equal to q. Like the first sensing line connection part CNL 1 , the second sensing line connection part CNL 2  may be provided on the first insulating layer  210 . In addition, the connection structure of the second sensing lines SL 2  and the second sensing line connection parts CNL 2  may be identical to that of the first sensing lines SL 1  and the first sensing line connection parts CNL 1 . 
     Since the i-th second sensing lines SL 2  of the second sensing electrode columns TSC 2  are electrically connected to each other, four second sensing electrodes TSE 2  connected to the i-th second sensing lines SL 2  in four adjacent second sensing electrode columns TSC 2  may be electrically connected to each other. 
     According to some embodiments, the second sensing lines SL 2  connected to second sensing electrodes TSE 2  disposed at the same positions in the second sensing electrode columns TSC 2  may be electrically connected to the same pad PD among the pads PD of the pad unit PDA. Since the i-th second sensing lines SL 2  are electrically connected to each other, the i-th second sensing electrodes TSE 2  connected to the i-th second sensing lines SL 2  may be applied with the same signal, e.g., a touch driving signal, through the same pad PD. In addition or alternatively, the i-th second sensing electrodes TSE 2  connected to the i-th second sensing lines SL 2  may output the same signal, e.g., a touch sensing signal, through the same pad PD. 
     Since the second sensing lines SL 2  connected to second sensing electrodes TSE 2  disposed at the same positions in the second sensing electrode columns TSC 2  are electrically connected to each other, the number of pads PD electrically connected to the second sensing electrodes TSE 2  may decrease. 
     Although a case where the second sensing electrodes TSE 2  disposed at the same positions in four adjacent second sensing electrode columns TSC 2  are connected to one pad PD is described and illustrated as an example, embodiments are not limited thereto. For example, the second sensing electrodes TSE 2  disposed at the same positions in two or three adjacent second sensing electrode columns TSC 2  may be connected to one pad PD. 
     According to some embodiments, the sub-electrodes SUE 1 , SUE 2 , SUE 3 , and SUE 4  and the second sensing electrodes TSE 2 , as shown in  FIG. 11 , may include a plurality of conductive fine lines CFL. For example, the sub-electrodes SUE 1 , SUE 2 , SUE 3 , and SUE 4  and the second sensing electrodes TSE 2  may include a plurality of first conductive fine lines CFL 1  that extend in one direction and are parallel to one another, and a plurality of second conductive fine lines CFL 2  that extend in a direction intersecting the first conductive fine lines CFL 1  and are parallel to one another. That is, the second sensing electrodes TSE 2  and the sub-electrodes SUE 1 , SUE 2 , SUE 3 , and SUE 4  may have a mesh structure. 
     The mesh structure may include a plurality of openings, e.g., regions formed as the first conductive fine lines CFL 1  and the second conductive fine lines CFL 2  intersect each other. The openings can decrease the area in which the sub-electrodes SUE 1 , SUE 2 , SUE 3 , and SUE 4  and the second sensing electrodes TSE 2  overlap with the display panel  100 . By reducing the area in which the sub-electrodes SUE 1 , SUE 2 , SUE 3 , and SUE 4  and the second sensing electrodes TSE 2  overlap with the display panel  100 , it is possible to prevent (or at least reduce) electromagnetic interference between the sub-electrodes SUE 1 , SUE 2 , SUE 3 , and SUE 4  and second sensing electrodes TSE 2  and the display panel  100 . Thus, the touch sensitivity of the electrode layer  220  can be improved. In addition, by reducing the area in which the sub-electrodes SUE 1 , SUE 2 , SUE 3 , and SUE 4  and the second sensing electrodes TSE 2  overlap with the display panel  100 , the number of obstacles on (or in) a path along which light emitted from the display panel  100  is transferred to a viewer can be reduced. Thus, the display quality of the display device including the touch sensor  200  and the display panel  100  can be improved. 
     The first conductive fine lines CFL 1  and the second conductive fine lines CFL 2  may include at least one of aluminum (Al), copper (Cu), chromium (Cr), nickel (Ni), gold (Au), platinum (Pt), and any alloy thereof. Also, the first conductive fine lines CFL 1  and the second conductive fine lines CFL 2  may include a transparent conductive oxide. 
     Although a case where the first sensing electrodes TSE 1  and the second sensing electrodes TSE 2  are provided on the second insulating layer  225  is described and illustrated as an example, embodiments are not limited thereto. For example, the first conductive fine lines CFL 1  and the second conductive fine lines CFL 2 , which are included in the first sensing electrodes TSE 1  and the second sensing electrodes TSE 2 , may include a first conductive layer provided on the first insulating layer  210  and a second conductive layer provided on the second insulating layer  225 , and the first conductive layer and the second conductive layer may be electrically connected to each other through a contact hole. 
       FIG. 12  is a plan view illustrating a first sensing electrode and a second sensing electrode that are provided at a rounded corner of the touch sensor shown in  FIG. 5  according to some exemplary embodiments.  FIG. 13  is an enlarged view of region EA 4  of  FIG. 12  according to some exemplary embodiments.  FIGS. 14 and 15  are plan views illustrating examples of a first sensing electrode and a second sensing electrode that are provided at a rounded corner of a touch sensor according to various exemplary embodiments. The plan views of  FIGS. 14 and 15  illustrate similar regions as region EA 4 , but with respect to modified touch sensors. As such, primarily differences will be described below to avoid obscuring exemplary embodiments. 
     Referring to  FIGS. 12 to 15 , the touch sensor  200  (see  FIGS. 1 to 11 ) may have a closed polygonal shape including linear sides, and at least some corners of the polygonal shape may be formed in a curve. That is, the touch sensor  200  may have rounded corners. For example, when the touch sensor  200  has a rectangular shape, a portion at which adjacent linear sides meet each other may be replaced with a curve having a determined curvature. That is, the corner of the rectangular shape may be formed with a curved side having both adjacent ends respectively connected to two adjacent linear sides, the curved side having a determined curvature. 
     The touch sensor  200  may include a sensing region SA and a non-sensing region NSA provided at the periphery of the sensing region SA. The sensing region SA may have a shape corresponding to that of the touch sensor  200 . For example, the sensing region SA may have a rectangular shape, and a corner of the rectangular shape may be formed with a curved side having both adjacent ends respectively connected to two adjacent linear sides, the curved side having a determined curvature. 
     A plurality of first sensing electrode columns TSC 1  and a plurality of second sensing electrode columns TSC 2  alternately disposed with the first sensing electrode columns TSC 1  may be provided in the sensing region SA. 
     The first sensing electrode columns TSC 1  and the second sensing electrode columns TSC 2  may include a plurality of first sensing electrodes TSE 1  and a plurality of second sensing electrodes TSE 2  or TSE 2 _ 1 . For example, one first sensing electrode column TSC 1  and one second sensing electrode column TSC 2  may include M first sensing electrodes TSE 1  and M second sensing electrodes TSE 2  or TSE 2 _ 1 , M is an integer greater than or equal to 2. The first sensing electrodes TSE 1  and the second sensing electrodes TSE 2  or TSE_ 2  may be arranged in the direction in which the first sensing electrode columns TSC 1  and the second sensing electrode columns TSC 2  extend. 
     Each of the first sensing electrodes TSE 1  may include a plural number of sub-electrodes, e.g., N (N is a natural number of 2 or more) sub-electrodes SUE 1  (or SUE 1 _ 1 ), SUE 2 , SUE 3 , and SUE 4  disposed to be spaced apart from each other. For example, each of the first sensing electrodes TSE 1  may include first to fourth sub-electrodes SUE 1  (or SUE 1 _ 1 ), SUE 2 , SUE 3 , and SUE 4 . The first to fourth sub-electrodes SUE 1  (or SUE 1 _ 1 ), SUE 2 , SUE 3 , and SUE 4  may be sequentially arranged in the extending direction of the first sensing electrode columns TSC 1 . 
     The sub-electrodes SUE 1  (or SUE 1 _ 1 ), SUE 2 , SUE 3 , and SUE 4  may be connected to first sensing lines SL 1 . In addition, the sub-electrodes SUE 1 , SUE 2 , SUE 3 , and SUE 4  of one of adjacent first sensing electrodes TSE 1  may be electrically connected to the sub-electrodes SUE 1 , SUE 2 , SUE 3 , and SUE 4  of the other of the adjacent first sensing electrodes TSE 1  through the first sensing lines SL 1 , respectively. 
     The second sensing electrodes TSE 2  (or TSE 2 _ 1 ) may be connected to second sensing lines SL 2 . 
     Since the sensing region SA has a rounded corner, edges of the first sub-electrode SUE 1  (or SUE 1 _ 1 ) and the second sensing electrode TSE 2  (or TSE 2 _ 1 ), which correspond to the rounded corner, may have a rounded shape. That is, the first sub-electrode SUE 1  (or SUE 1 _ 1 ) and the second sensing electrode TSE 2  (or TSE 2 _ 1 ) may have a shape in which a portion of a quadrangular shape, e.g., a region at the outside of a curved side, is removed. Therefore, the area of the first sub-electrode SUE 1  (or SUE 1 _ 1 ) may be smaller than those of the other sub-electrodes, e.g., the second to fourth sub-electrodes SUE 2 , SUE 3 , and SUE 4 . In addition, the sum of the areas of the first to fourth sub-electrodes SUE 1  (or SUE 1 _ 1 ), SUE 2 , SUE 3 , and SUE 4  of the first sensing electrode TSE 1  may be different from the area of the second sensing electrode TSE 2  or TSE 2 _ 1 . 
     As shown in  FIG. 13 , the first sub-electrode SUE 1  and the second sensing electrode TSE 2  have a shape having a portion removed therefrom, and, as such, the capacitance of a capacitor formed between the first sub-electrode SUE 1  and the second sensing electrode TSE 2  may decrease. This is because the areas of the first sub-electrode SUE 1  and the second sensing electrode TSE 2  are smaller. In some embodiments, a decrease in area of the second sensing electrode TSE 2  is larger than that in area of the first sub-electrode SUE 1 , and, therefore, the capacitance of the capacitor formed between the first sub-electrode SUE 1  and the second sensing electrode TSE 2  may decrease in proportion to the decrease in area of the second sensing electrode TSE 2 . As the capacitance decreases, the touch sensitivity of the touch sensor  200  may be deteriorated. 
     Meanwhile, as shown in  FIGS. 14 and 15 , the second sensing electrode TSE 2 _ 1  has a shape protruding to the first sub-electrode SUE 1 _ 1  such that the area of the first sub-electrode SUE 1 _ 1  may decrease, but the area of the second sensing electrode TSE 2 _ 1  may increase. Therefore, the sum of the areas of the first to fourth sub-electrodes SUE 1 _ 1 , SUE 2 , SUE 3 , and SUE 4  of the first sensing electrode TSE 1  may be substantially the same as or similar to the area of the second sensing electrode TSE 2 _ 1 . 
     At least because the second sensing electrode TSE 2 _ 1  has a shape protruding towards the first sub-electrode SUE 1 _ 1 , the area in which the first sub-electrode SUE 1 _ 1  and the second sensing electrode TSE 2 _ 1  can form a capacitor may increase. As the area in which the first sub-electrode SUE 1 _ 1  and the second sensing electrode TSE 2 _ 1  form the capacitor increases, the capacitance of the capacitor may increase. As the capacitance increases, the touch sensitivity of the touch sensor  200  can be improved. 
     Hereinafter, the first sub-electrode SUE 1 _ 1  and the second sensing electrode TSE 2 _ 1 , which are provided at the rounded corner of the touch sensor shown in  FIGS. 14 and 15  will be described in more detail. 
     The edges of the first sub-electrode SUE 1 _ 1  and the second sensing electrode TSE 2 _ 1 , which are provided at the rounded corner of the sensing region SA in the touch sensor  200 , may have a rounded shape, corresponding to the rounded corner of the sensing region SA. 
     In addition, the second sensing electrode TSE 2 _ 1  may include a protrusion part PTA protruding in a direction perpendicular or inclined with respect to the direction in which the second sensing electrode columns TSC 2  extend. The protrusion part PTA may protrude toward the first sub-electrode SUE 1 _ 1  of the first sensing electrode TSE 1 . Here, by the protrusion part PTA, the boundary between the first sub-electrode SUE 1 _ 1  and the second sensing electrode TSE 2 _ 1  may be inclined in the direction in which the first sensing electrode columns TSC 1  and the second sensing electrode columns TSC 2  extend. In addition, the protrusion part PTA may extend to the inside of the first sensing electrode column TSC 1 . For instance, the protrusion part PTA may extend into a notched, concave, or otherwise patterned portion of the first sub-electrode SUE 1 _ 1 . 
     If the protruding part PTA extends to the inside of the first sensing electrode column TSC 1 , the area of the second sensing electrode TSE 2 _ 1  provided at the rounded corner of the sensing region SA may increase due to the protrusion part PTA. However, the area of the first sub-electrode SUE 1 _ 1  may decrease due to the protrusion part PTA. For example, the area of the first sub-electrode SUE 1 _ 1  may decrease in proportion to the area of the protrusion part PTA protruding toward the first sensing electrode TSE 1 . Therefore, the sum of the areas of the first to fourth sub-electrodes SUE 1 _ 1 , SUE 2 , SUE 3 , and SUE 4  of the first sensing electrode TSE 1  may be equal or similar to the area of the second sensing electrode TSE 2 _ 1 . 
     In addition, although the area of the first sub-electrode SUE 1 _ 1  decreases, the area of the second sensing electrode TSE 2 _ 1  increases, and, as such, the area in which the first sub-electrode SUE 1 _ 1  and the second sensing electrode TSE 2 _ 1  form a capacitor may increase. Therefore, the capacitance of the capacitor formed between the first sub-electrode SUE 1 _ 1  and the second sensing electrode TSE 2 _ 1  may increase. 
     At least one of the first sensing lines SL 1  connected to the sub-electrodes SUE 1 _ 1 , SUE 2 , SUE 3 , and SUE 4  and the second sensing lines SL 2  connected to the second sensing electrode TSE 2 _ 1  may be provided between the protrusion part PTA of the second sensing electrode TSE 2 _ 1  and the first sub-electrode SUE 1 _ 1 . In addition, a dummy pattern DMP may be provided between the protrusion part PTA of the second sensing electrode TSE 2 _ 1  and the first sub-electrode SUE 1 _ 1 . The dummy pattern DMP may prevent (or at least reduce) a region between the first sub-electrode SUE 1 _ 1  and the second sensing electrode TSE 2 _ 1  from being viewed by a user. 
     At the rounded corner, the touch sensor  200  shown in  FIG. 14  may not include the first sensing lines SL 1 , the second sensing lines SL 2 , and the dummy pattern DMP between the protrusion part PTA of the second sensing electrode TSE 2 _ 1  and the first sub-electrode SUE 1 _ 1 . Therefore, at the rounded corner, the touch sensor  200  shown in  FIG. 14  may increase the area of the second sensing electrode TSE 2 _ 1  and the area of the first sub-electrode SUE 1 _ 1 , and decrease the distance between the protrusion part PTA of the second sensing electrode TSE 2 _ 1  and the first sub-electrode SUE 1 _ 1 . 
     As the area of the second sensing electrode TSE 2 _ 1  and the area of the first sub-electrode SUE 1 _ 1  increase, and the distance between the protrusion part PTA of the second sensing electrode TSE 2 _ 1  and the first sub-electrode SUE 1 _ 1  decreases, the touch sensitivity of the touch sensor  200  can be improved. That is, at the rounded corner, the touch sensitivity of the touch sensor  200  shown in  FIG. 14  can be better than the touch sensitivity of the touch sensor  200  shown in  FIG. 15 . 
       FIGS. 16, 17, 18, and 19  are plan views illustrating examples of a first sensing electrode and a second sensing electrode that are provided at a rounded corner of a touch sensor according to various exemplary embodiments. The plan views of  FIGS. 16 to 19  illustrate similar regions as region EA 4 , but with respect to modified touch sensors. As such, primarily differences will be described below to avoid obscuring exemplary embodiments. 
     Referring to  FIGS. 16 to 19 , the sensing region SA of the touch sensor  200  (see  FIGS. 1 to 11 ) may have a rounded corner. 
     A plurality of first sensing electrode columns TSC 1  and a plurality of second sensing electrode columns TSC 2  alternately disposed with the first sensing electrode columns TSC 1  may be provided in the sensing region SA. The first sensing electrode columns TSC 1  and the second sensing electrode columns TSC 2  may include a plurality of first sensing electrodes TSE 1  and a plurality of second sensing electrodes TSE 2 _ 2  or TSE 2 _ 3 . 
     Each of the first sensing electrodes TSE 1  may include first to fourth sub-electrodes SUE 1 _ 2  (or SUE 1 _ 3 ), SUE 2 , SUE 3 , and SUE 4  that are sequentially disposed to be spaced apart from each other. The sub-electrodes SUE 1 _ 2  (or SUE 1 _ 3 ), SUE 2 , SUE 3 , and SUE 4  may be connected to first sensing lines SL 1 _ 1  or SL 1 _ 2 . In addition, the sub-electrodes SUE 1 _ 2  (or SUE 1 _ 3 ), SUE 2 , SUE 3 , and SUE 4  of one of adjacent first sensing electrodes TSE 1  may be electrically connected to the sub-electrodes SUE 1 _ 2  (or SUE 1 _ 3 ), SUE 2 , SUE 3 , and SUE 4  of the other of the adjacent first sensing electrodes TSE 1  through the first sensing lines SL 1 _ 1  or SL 1 _ 2 , respectively. 
     The second sensing electrodes TSE 2 _ 2  or TSE 2 _ 3  may be connected to second sensing lines SL 2 _ 1  or SL 2 _ 2 . 
     Edges of the first sub-electrode SUE 1 _ 2  or SUE 1 _ 3  and the second sensing electrode TSE 2 _ 2  or TSE 2 _ 3 , which are provided at the rounded corner of the sensing region SA, may have a shape corresponding to that of the rounded shape of the sensing region SA. 
     In addition, the second sensing electrode TSE 2 _ 2  or TSE 2 _ 3  may include a protrusion part PTA_ 1  or PTA_ 2  protruding in a direction perpendicular or inclined with respect to the direction in which the second sensing electrode columns TSC 2  extend. The protrusion part PTA_ 1  or PTA_ 2  may protrude toward the first sub-electrode SUE 1 _ 2  or SUE 1 _ 3  of the first sensing electrode TSE 1 . Here, by the protrusion part PTA_ 1  or PTA_ 2 , a portion of the boundary between the first sub-electrode SUE 1 _ 2  or SUE 1 _ 3  and the second sensing electrode TSE 2 _ 2  or TSE 2 _ 3  may be inclined in the direction in which the first sensing electrode columns TSC 1  and the second sensing electrode columns TSC 2  extend. In addition, the boundary may have at least one bending point. As shown in  FIGS. 16 and 17 , the boundary between the first sub-electrode SUE 1 _ 2  and the second sensing electrode TSE 2 _ 2  may have one bending point. As shown in  FIGS. 18 and 19 , the boundary between the first sub-electrode SUE 1 _ 3  and the second sensing electrode TSE 2 _ 3  may have two bending points. 
     The length of the boundary between the first sub-electrode SUE 1 _ 2  or SUE 1 _ 3  and the second sensing electrode TSE 2 _ 2  or TSE 2 _ 3  may be increased by the bending point. In addition, the capacitance of a capacitor formed between the first sub-electrode SUE 1 _ 2  or SUE 1 _ 3  and the second sensing electrode TSE 2 _ 2  or TSE 2 _ 3  may be in proportion to the length of the boundary between the first sub-electrode SUE 1 _ 2  or SUE 1 _ 3  and the second sensing electrode TSE 2 _ 2  or TSE 2 _ 3 . Therefore, as the length of the boundary between the first sub-electrode SUE 1 _ 2  or SUE 1 _ 3  and the second sensing electrode TSE 2 _ 2  or TSE_ 3  increases, the capacitance may be increased. As the capacitance of the capacitor formed between the first sub-electrode SUE 1 _ 2  or SUE 1 _ 3  and the second sensing electrode TSE 2 _ 2  or TSE 2 _ 3  increases, the touch sensitivity at the rounded corner of the touch sensor  200  can be improved. 
     At least one of the first sensing lines SL 1 _ 1  or SL 1 _ 2  connected to the sub-electrodes SUE 1 _ 2  (or SUE 1 _ 3 ), SUE 2 , SUE 3 , and SUE 4  and the second sensing lines SL 2 _ 1  or SL 2 _ 2  connected to the second sensing electrode TSE 2 _ 2  or TSE 2 _ 3  may be provided between the protrusion part PTA_ 1  or PTA_ 2  of the second sensing electrode TSE 2 _ 2  or TSE 2 _ 3  and the first sub-electrode SUE 1 _ 2  or SUE 1 _ 3 . In addition, a dummy pattern DMP_ 1  or DMP_ 2  may be provided between the protrusion part PTA_ 1  or PTA_ 2  of the second sensing electrode TSE 2 _ 2  or TSE 2 _ 3  and the first sub-electrode SUE 1 _ 2  or SUE 1 _ 3 . 
     At the rounded corner, the touch sensor  200  shown in  FIGS. 16 and 18  may not include the first sensing lines SL 1 _ 1  or SL 1 _ 2 , the second sensing lines SL 2 _ 1  or SL 2 _ 2 , and the dummy pattern DMP_ 1  or DMP_ 2  between the protrusion part PTA_ 1  or PTA_ 2  of the second sensing electrode TES 2 _ 2  or TSE_ 3  and the first sub-electrode SUE 1 _ 2  or SUE_ 3 . As such, at the rounded corner, the touch sensor  200  shown in  FIGS. 16 and 18  may increase the area of the second sensing electrode TSE 2 _ 2  or TSE 2 _ 3  and the area of the first sub-electrode SUE 1 _ 2  or SUE 1 _ 3 , and decrease the distance between the protrusion part PTA_ 1  or PTA_ 2  of the second sensing electrode TSE 2 _ 2  or TSE 2 _ 3  and the first sub-electrode SUE 1 _ 2  or SUE 1 _ 3 . 
     As the area of the second sensing electrode TSE 2 _ 2  or TSE 2 _ 3  and the area of the first sub-electrode SUE 1 _ 2  or SUE 1 _ 3  increase, and the distance between the protrusion part PTA_ 1  or PTA_ 2  of the second sensing electrode TSE 2 _ 2  or TSE 2 _ 3  and the first sub-electrode SUE 1 _ 2  or SUE 1 _ 3  decreases, the touch sensitivity of the touch sensor  200  can be improved. That is, at the rounded corner, the touch sensitivity of the touch sensor  200  shown in  FIGS. 16 and 18  can be better than as compared with the touch sensitivity of the touch sensor  200  shown in  FIGS. 17 and 19 . 
       FIGS. 20, 21, 22, and 23  are plan views illustrating a first sensing electrode and a second sensing electrode that are provided at a rounded corner of a touch sensor according to various exemplary embodiments. The plan views of  FIGS. 20 to 23  illustrate similar regions as region EA 4 , but with respect to modified touch sensors. As such, primarily differences will be described below to avoid obscuring exemplary embodiments. 
     Referring to  FIGS. 20 to 23 , the sensing region SA of the touch sensor  200  (see  FIGS. 1 to 11 ) may have a rounded corner. A plurality of first sensing electrode columns TSC 1  and a plurality of second sensing electrode columns TSC 2  alternately disposed with the first sensing electrode columns TSC 1  may be provided in the sensing region SA. The first sensing electrode columns TSC 1  and the second sensing electrode columns TSC 2  may include a plurality of first sensing electrodes TSE 1  and a plurality of second sensing electrodes TSE 2 . 
     Each of the first sensing electrodes TSE 1  may include first to fourth sub-electrodes SUE 1 _ 4  (or SUE 1 _ 5 ), SUE 2 , SUE 3 , and SUE 4  that are sequentially disposed to be spaced apart from each other. The sub-electrodes SUE 1 _ 4  (or SUE 1 _ 5 ), SUE 2 , SUE 3 , and SUE 4  may be connected to first sensing lines SL 1 _ 3  or SL 1 _ 4 . In addition, the sub-electrodes SUE 1 _ 4  (or SUE 1 _ 5 ), SUE 2 , SUE 3 , and SUE 4  of one of adjacent first sensing electrodes TSE 1  may be electrically connected to the sub-electrodes SUE 1 _ 4  (or SUE 1 _ 5 ), SUE 2 , SUE 3 , and SUE 4  of the other of the adjacent first sensing electrodes TSE 1  through the first sensing lines SL 1 _ 3  or SL 1 _ 4 , respectively. 
     The second sensing electrodes TSE 2 _ 4  or TSE 2 _ 5  may be connected to second sensing lines SL 2 _ 3  or SL 2 _ 4 . 
     Edges of the first sub-electrode SUE 1 _ 4  or SUE 1 _ 5  and the second sensing electrode TSE 2 _ 4  or TSE 2 _ 5 , which are provided at the rounded corner of the sensing region SA, may have a shape corresponding to that of the rounded shape of the sensing region SA. That is, the edges of the first sub-electrode SUE 1 _ 4  or SUE 1 _ 5  and the second sensing electrode TSE 2 _ 4  or TSE 2 _ 5 , which correspond to the rounded corner of the sensing region SA, may have a rounded shape. In addition, the second sensing electrode TSE 2 _ 4  or TSE 2 _ 5  may include a protrusion part PTA_ 3  or PTA_ 4  protruding in a direction perpendicular or inclined with respect to the direction in which the second sensing electrode columns TSC 2  extend. The protrusion part PTA_ 3  or PTA_ 4  may protrude toward the first sub-electrode SUE 1 _ 4  or SUE_ 5  of the first sensing electrode TSE 1 . The protrusion part PTA_ 3  or PTA_ 4  may be more adjacent to the rounded corner than the first sub-electrode SUE 1 _ 4  or SUE 1 _ 5  having the rounded edge. 
     At least a portion of the boundary between the first sub-electrode SUE 1 _ 4  or SUE 1 _ 5  and the second sensing electrode TSE 2 _ 4  or TSE 2 _ 5  may have a curved shape. For example, as shown in  FIGS. 20 and 21 , the boundary between the protrusion part PTA_ 3  of the second sensing electrode TSE 2 _ 4  and the first sub-electrode SUE 1 _ 4  may have a curved shape. In addition, as shown in  FIGS. 22 and 23 , the boundary between the protrusion part PTA_ 4  and the second sensing electrode TSE 2 _ 5  may have a shape including curves at both ends thereof and a connection line (or portion) that connects the curves between the curves at both the ends thereof. The connection line may be formed in the shape of a bent line having at least one bending point. 
     In some embodiments, at least a portion of the boundary between the first sub-electrode SUE 1 _ 4  or SUE 1 _ 5  and the second sensing electrode TSE 2 _ 4  or TSE 2 _ 5  has a curved shape, and, as such, the length of the boundary between the first sub-electrode SUE 1 _ 4  or SUE 1 _ 5  and the second sensing electrode TSE 2 _ 4  or TSE 2 _ 5  may increase. As the length of the boundary between the first sub-electrode SUE 1 _ 4  or SUE 1 _ 5  and the second sensing electrode TSE 2 _ 4  or TSE 2 _ 5  increases, the capacitance of a capacitor formed between the first sub-electrode SUE 1 _ 4  or SUE 1 _ 5  and the second sensing electrode TSE 2 _ 4  or TSE 2 _ 5  may increase. As the capacitance of the capacitor formed between the first sub-electrode SUE 1 _ 4  or SUE 1 _ 5  and the second sensing electrode TSE 2 _ 4  or TSE 2 _ 5  increases, the touch sensitivity in a region adjacent to the rounded corner of the touch sensor  200  can be improved. 
     At least one of the first sensing lines SL 1 _ 3  or SL 1 _ 4  connected to the sub-electrodes SUE 1 _ 4  (or SUE 1 _ 5 ), SUE 2 , SUE 3 , and SUE 4  and the second sensing lines SL 2 _ 3  or SL 2 _ 4  connected to the second sensing electrode TSE 2 _ 4  or TSE 2 _ 5  may be provided between the protrusion part PTA_ 3  or PTA_ 4  of the second sensing electrode TSE 2 _ 4  or TSE 2 _ 5  and the first sub-electrode SUE 1 _ 4  or SUE 1 _ 5 . In addition, a dummy pattern DMP_ 3  or DMP_ 4  may be provided between the protrusion part PTA_ 3  or PTA_ 4  of the second sensing electrode TSE 2 _ 4  or TSE 2 _ 5  and the first sub-electrode SUE 1 _ 4  or SUE 1 _ 5 . 
     At the rounded corner, the touch sensor  200  shown in  FIGS. 20 and 22  may not include the first sensing lines SL 1 _ 3  or SL 1 _ 4 , the second sensing lines SL 2 _ 3  or SL 2 _ 4 , and the dummy pattern DMP_ 3  or DMP_ 4  between the protrusion part PTA_ 3  or PTA_ 4  of the second sensing electrode TES 2 _ 4  or TES 2 _ 5  and the first sub-electrode SUE 1 _ 4  or SUE 1 _ 5 . Therefore, at the rounded corner, the touch sensor  200  shown in  FIGS. 20 and 22  may increase the area of the second sensing electrode TSE 2 _ 4  or TSE 2 _ 5  and the area of the first sub-electrode SUE 1 _ 4  or SUE 1 _ 5 , and decrease the distance between the protrusion part PTA_ 3  or PTA_ 4  of the second sensing electrode TSE 2 _ 4  or TSE 2 _ 5  and the first sub-electrode SUE 1 _ 4  or SUE 1 _ 5 . 
     As the area of the second sensing electrode TSE 2 _ 4  or TSE 2 _ 5  and the area of the first sub-electrode SUE 1 _ 4  or SUE 1 _ 5  increases, and the distance between the protrusion part PTA_ 3  or PTA_ 4  of the second sensing electrode TSE 2 _ 4  or TSE 2 _ 5  and the first sub-electrode SUE 1 _ 4  or SUE 1 _ 5  decreases, the touch sensitivity of the touch sensor  200  can be improved. That is, at the rounded corner, the touch sensitivity of the touch sensor  200  shown in  FIGS. 20 and 22  can be better than as compared with the touch sensitivity of the touch sensor  200  shown in  FIGS. 21 and 23 . 
       FIGS. 24 and 25  are plan views illustrating a first sensing electrode and a second sensing electrode that are provided at a rounded corner of a touch sensor according to some exemplary embodiments. The touch sensor of  FIGS. 24 and 25  is similar to the touch sensor  200  of  FIGS. 1 to 11 . As such, primarily differences will be described below to avoid obscuring exemplary embodiments. 
     Referring to  FIGS. 24 and 25 , the sensing region SA of the touch sensor  200  (see  FIGS. 1 to 11 ) may have a rounded corner. A plurality of first sensing electrode columns TSC 1  and a plurality of second sensing electrode columns TSC 2  alternately disposed with the first sensing electrode columns TSC 1  may be provided in the sensing region SA. The first sensing electrode columns TSC 1  and the second sensing electrode columns TSC 2  may include a plurality of first sensing electrodes TSE 1  and a plurality of second sensing electrodes TSE 2 _ 6 . 
     Some of the first sensing electrodes TSE 1  may include first to fourth sub-electrodes SUE 1 , SUE 2 , SUE 3 , and SUE 4  that are sequentially disposed to be spaced apart from each other. The first sub-electrode SUE 1  of the first sensing electrode TSE 1  provided at (or near) the rounded corner and a region of the second sensing electrode TSE 2 _ 6  corresponding to the first sensing electrode SUE 1  at (or near) may be omitted. That is, the first sensing electrode TSE 1  provided at the rounded corner may include only the second to fourth sub-electrodes SUE 2 , SUE 3 , and SUE 4 . In this manner, a third sensing electrode TSE 3  may be provided in the region in which the first sub-electrode SUE 1  and the region of the second sensing electrode TSE 2 _ 6  corresponding to the first sub-electrode SUE 1  are omitted. That is, the third sensing electrode TSE 3  may be provided at the rounded corner. In addition, an edge corresponding to the rounded corner of the third sensing electrode TSE 3  may have a rounded shape. 
     The third sensing electrode TSE 3  may be a self-capacitance type sensing electrode. For example, as shown in  FIG. 24 , the third sensing electrode TSE 3  may not form a capacitor with the first sensing electrode TSE 1  and the second sensing electrode TSE 2 _ 6 . 
     In some embodiments, as shown in  FIG. 25 , the third sensing electrode TSE 3  may form a capacitor with at least one of the first sensing electrode TSE 1  and the second sensing electrode TSE 2 _ 6 . For example, the third sensing electrode TSE 3  may form a capacitor with the second sensing electrode TSE 2 _ 6 . Therefore, the third sensing electrode TSE 3  along with the second sensing electrode TSE 2 _ 6  may operate as a sensing electrode of a mutual capacitance type touch sensor. 
     The sub-electrodes SUE 1 , SUE 2 , SUE 3 , and SUE 4  may be connected to the first sensing lines SL 1 . In addition, the sub-electrodes SUE 1 , SUE 2 , SUE 3 , and SUE 4  of one of adjacent first sensing electrodes TSE 1  may be electrically connected to the sub-electrodes SUE 1 , SUE 2 , SUE 3 , and SUE 4  of the other of the adjacent first sensing electrodes TSE 1  through the first sensing lines SL 1 , respectively. The second sensing electrodes TSE 2 _ 6  may be connected to second sensing lines SL 2 , and the third sensing electrodes TSE 3  may be connected to third sensing lines SL 3 . 
     According to various exemplary embodiments, a touch sensor and a display device can prevent (or reduce) the sensitivity at a rounded corner from being decreased. Thus, the touch sensor and display device can decrease a difference in touch sensitivity between regions. 
     Although certain exemplary embodiments and implementations have been described herein, other embodiments and modifications will be apparent from this description. Accordingly, the inventive concepts are not limited to such embodiments, but rather to the broader scope of the presented claims and various obvious modifications and equivalent arrangements.