Abstract:
A display device includes a first substrate, a second substrate, a transistor, a display element, a first touch electrode, a second touch electrode, a spacer, and a light reflector. The second substrate overlaps the first substrate. The transistor is positioned between the first substrate and the second substrate. The display element is electrically connected to the transistor. The first touch electrode contacts the second substrate. The second touch electrode contacts the second substrate and is insulated from the first touch electrode. The spacer overlaps the first touch electrode and is positioned between the first touch electrode and the first substrate. The light reflector overlaps the second touch electrode, is positioned between the second touch electrode and the first substrate, and is spaced from the spacer. A distance between the light reflector and the second touch electrode is greater than a distance between the spacer and the first touch electrode.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to and the benefit of Korean Patent Application No. 10-2016-0006914 filed in the Korean Intellectual Property Office on Jan. 20, 2016; the entire contents of the Korean Patent Application are incorporated herein by reference. 
       BACKGROUND 
       [0002]    (a) Field 
         [0003]    The technical field relates to a display device. 
         [0004]    (b) Description of the Prior Art 
         [0005]    A display device may include a touch screen (or touchscreen) structure for receiving user input. The touch screen structure may include touch electrodes for sensing touches. 
         [0006]    In the display device, a touch electrode and a display element (e.g., cathode) may become substantially close to each other and therefore generating significant parasitic capacitance. Such parasitic capacitance may cause errors in touch sensing. 
       SUMMARY 
       [0007]    Embodiments may be related to a display device with minimum undesirable parasitic capacitance. 
         [0008]    An embodiment may be related to a display device that includes the following elements: a first base substrate including a plurality of pixel areas; display elements disposed in the pixel areas; a second base substrate facing the first base substrate; a plurality of spacers disposed between the pixel areas and configured to maintain a gap between the first base substrate and the second base substrate; a plurality of touch electrodes provided in the second base substrate and including at least one first region (or first touch electrode set) and at least one second region (or second touch electrode set) electrically insulated from the first region; and light reflection patterns (or light reflection structures) disposed on the first base substrate to correspond to the second region. 
         [0009]    In an embodiment, the plurality of spacers may be disposed to correspond to the first region. 
         [0010]    In an embodiment, the light reflection patterns may include the same material as the plurality of spacers. 
         [0011]    In an embodiment, the light reflection patterns may have a different shape from the plurality of spacers. 
         [0012]    In an embodiment, the light reflection patterns may have a lower height than the plurality of spacers. 
         [0013]    In an embodiment, at least one portion of the light reflection patterns may include a pattern of protrusions and depressions that are curved. 
         [0014]    In an embodiment, at least one portion of the light reflection patterns may include a protruding portion that protrudes toward the plurality of touch electrodes. 
         [0015]    In an embodiment, at least one portion of the light reflection patterns may include a recessed portion that is recessed toward the first base substrate. 
         [0016]    In an embodiment, the second region may have a shape that surrounds the first region when viewed on the plane. 
         [0017]    In an embodiment, the display elements may include a first electrode provided in the pixel area; a pixel defining layer disposed between the pixel areas and exposing at least one portion of the first electrode to the outside; an emission layer disposed on the first electrode and emitting light; and a second electrode disposed on the emission layer. 
         [0018]    In an embodiment, the plurality of touch electrodes may include first conductive lines extending in one direction; and second conductive lines extending in a direction crossing the first conductive lines. 
         [0019]    In an embodiment, the light reflection patterns may be disposed in the second region in which the first conductive lines and the second conductive lines cross each other. 
         [0020]    In an embodiment, the light reflection patterns may have a shape that protrudes toward the second base substrate from the pixel defining layer. 
         [0021]    In an embodiment, the light reflection patterns may have a shape in the second region that is recessed inward of the first base substrate from the pixel defining layer. 
         [0022]    In an embodiment, the display elements may be disposed in regions where the first conductive lines and the second conductive lines cross each other. 
         [0023]    In an embodiment, the second electrode may be provided between the plurality of spacers and the second base substrate. 
         [0024]    An embodiment may be related to a display device. The display device may include a first substrate, a second substrate, a transistor, a display element, a first touch electrode, a second touch electrode, a spacer, and a light reflector. The second substrate may overlap the first substrate. The transistor may be positioned between the first substrate and the second substrate. The display element may be electrically connected to the transistor. The first touch electrode may directly contact the second substrate. The second touch electrode may directly contact the second substrate and may be electrically insulated from the first touch electrode. The spacer may overlap (and/or be covered by) the first touch electrode and may be positioned between the first touch electrode and the first substrate. The light reflector may overlap (and/or be covered by) the second touch electrode, may be positioned between the second touch electrode and the first substrate, and may be spaced from the spacer. The minimum distance between the light reflector and the second touch electrode may be greater than the minimum distance between the spacer and the first touch electrode. 
         [0025]    The shape/structure of the light reflector may be different from the shape/structure of the spacer. 
         [0026]    A material of the spacer may be identical to a spacer of the light reflector. 
         [0027]    The display device may include a pixel defining layer. The pixel defining layer may include an opening and may include at least one of a first protrusion, a second protrusion, and a recess. The display element may include a light emission layer. The light emission layer may be positioned inside the opening. The spacer may include the first protrusion. The light reflector may include the second protrusion and/or the recess. The second protrusion may be shorter than the first protrusion if the light reflector includes the second protrusion. 
         [0028]    The display element may include a display-element electrode. The minimum distance between the display-element electrode and the first touch electrode may be less than the minimum distance between the spacer and the first touch electrode. 
         [0029]    The spacer may be narrower than the first touch electrode in a direction parallel to the first substrate. 
         [0030]    The spacer may be taller than the light reflector in a direction perpendicular to the first substrate. 
         [0031]    The display element may include a display-element electrode. The spacer may be positioned between a first portion of the display-element electrode and a second portion of the display-element electrode and may directly contact each of the first portion of the display-element electrode and the second portion of the display-element electrode. 
         [0032]    A third portion of the display-element may directly contact the spacer and may be positioned between the spacer and the first touch electrode. 
         [0033]    The display device may include an insulating layer. The spacer, the first portion of the display-element electrode, and the second portion of the display-element electrode may be positioned between a first portion of the insulating layer and a second portion of the insulating layer. 
         [0034]    A third portion of the insulating layer may be positioned between a third portion of the display-element electrode and the first touch electrode and may directly contact each of the third portion of the display-element electrode and the first touch electrode. 
         [0035]    The light reflector may be positioned between a fourth portion of the display-element electrode and a fifth portion of the display-element electrode and may directly contact each of the fourth portion of the display-element electrode and the fifth portion of the display-element electrode. 
         [0036]    The light reflector, the fourth portion of the display-element electrode, and the fifth portion of the display-element electrode may be positioned between a fourth portion of the insulating layer and a fifth portion of the insulating layer. 
         [0037]    A sixth portion of the insulating layer may be positioned between a sixth portion of the display-element electrode and the second touch electrode, may directly contact the sixth portion of the display-element electrode, and may be spaced from the second touch electrode. 
         [0038]    A recessed portion of the display-element electrode may be positioned inside a recessed portion of the light reflector and may be positioned between the second touch electrode and the recessed portion of the light reflector. 
         [0039]    A recessed portion of the insulating layer may be positioned inside the recessed portion of the display-element electrode and may be positioned between the second touch electrode and the recessed-portion of the display-element electrode. 
         [0040]    The light reflector may have a recess, which may be recessed toward the first substrate. 
         [0041]    The light reflector may include a protrusion and a recess. The protrusion protrudes toward the second substrate. The recess may be recessed toward the first substrate. 
         [0042]    The light reflector may include two protrusions. The display element may include a display-element electrode. A portion of the display-element electrode may be positioned between the two protrusions and may be positioned between the second touch electrode and the first substrate. 
         [0043]    The light reflector may include two protrusions. The display element may include a display-element electrode. Two portions of the display-element electrode may directly contact the two protrusions, may be positioned between the two protrusions, and may be oriented not parallel to each other. 
         [0044]    The display device may include an insulating layer. Two portions of the insulating layer may be positioned between the two portions of the display-element electrode and may be oriented at an acute angle with respect to each other. 
         [0045]    The display device may include a third touch electrode, a fourth touch electrode, and a fifth touch electrode, which may directly contact the second substrate, may be spaced from one another, and may be spaced from each of the first touch electrode and the second touch electrode. The display device may include a first additional light reflector, which may overlap the third touch electrode and may be positioned between the third touch electrode and the first substrate. The display device may include a second additional light reflector, which may overlap the fourth touch electrode and may be positioned between the fourth touch electrode and the first substrate. The display device may include a third additional light reflector, which may overlap the fifth touch electrode and may be positioned between the fifth touch electrode and the first substrate. The spacer may be positioned between the light reflector and the first additional light reflector and may be positioned between the second additional light reflector and the third additional light reflector. The light reflector, the spacer, and the first additional light reflector may be aligned in a first direction. The second additional light reflector, the spacer, and the third additional light reflector may be aligned in a second direction different from the first direction. 
         [0046]    The spacer may be not identical to any of the light reflector, the first additional light reflector, the second light reflector, and the third light reflector in shape and/or structure. The light reflector, the first additional light reflector, the second light reflector, and the third light reflector may be identical to one another in shape and/or structure. The spacer, the light reflector, the first additional light reflector, the second light reflector, and the third light reflector may be formed of the same material. 
         [0047]    According to embodiments, one or more spacers in a display device can maintain a sufficient gap between touch electrodes and display elements. Advantageously, undesirable parasitic capacitance between the touch electrodes and the display elements can be minimized. 
         [0048]    According to embodiments, the light reflection structure may enable the spacer to be substantially inconspicuous to users. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0049]      FIG. 1  is a perspective view of a display device according to an embodiment. 
           [0050]      FIG. 2  is a top plan view of a display unit of the display device illustrated in  FIG. 1  according to an embodiment. 
           [0051]      FIG. 3  is a top plan view of a touch unit of the display device illustrated in  FIG. 1  according to an embodiment. 
           [0052]      FIG. 4  is a top plan view of a region corresponding to a touch electrode illustrated in  FIG. 3  according to an embodiment. 
           [0053]      FIG. 5  is a top plan view of the portion A 1  indicated in  FIG. 4  according to an embodiment. 
           [0054]      FIG. 6  is a cross-sectional view taken along the line I-I′ indicated in  FIG. 5  according to an embodiment. 
           [0055]      FIG. 7  is a cross-sectional view taken along the line II-II′ indicated in  FIG. 5  according to an embodiment. 
           [0056]      FIG. 8  is a cross-sectional view of a display device according to an embodiment. 
           [0057]      FIG. 9  is a cross-sectional view of a display device according to an embodiment. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0058]    An embodiment relates to a display device that is capable of displaying an image and sensing a user&#39;s touch. The display device according to the current embodiment may sense a touch event provided by a user&#39;s hand, a stylus, and/or another input means and, in response to the touch event, may display or transmit image information. 
         [0059]    Embodiments are described with reference to the drawings. 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 may be used to distinguish one element from another element. Thus, a first element discussed below may be termed a second element without departing from teachings of one or more embodiments. The description of an element as a “first” element may not require or imply the presence of a second element or other elements. The terms “first”, “second”, etc. may also be used herein to differentiate different categories or sets of elements. For conciseness, the terms “first”, “second”, etc. may represent “first-category (or first-set)”, “second-category (or second-set)”, etc., respectively. In this application, “pattern” may mean “structure” or “member”; “connect” may mean “electrically connect”; “insulate” may mean “electrically insulate”. 
         [0060]      FIG. 1  is a perspective view of a display device according to an embodiment,  FIG. 2  is a top plan view of the display unit of  FIG. 1  according to an embodiment, and  FIG. 3  is a top plan view of a touch unit of  FIG. 1  according to an embodiment. 
         [0061]    Referring to  FIGS. 1 to 3 , the display device may have one or more of various shapes, for example, a rectangular shape with two pairs of parallel sides. One of the two pairs of sides may be longer than the other pair. 
         [0062]    For better understanding and ease of description, an extending direction of the short sides is denoted as a first direction D 1 , and an extending direction of the long sides denoted as a second direction D 2 . 
         [0063]    The display device includes a display unit  100 , in which display elements for displaying an image are provided, and a touch unit  200  for sensing a touch. 
         [0064]    The display device includes a display area DA in which an image is displayed, a sensing area SA for sensing a user&#39;s touch and/or pressure in the touch unit  200  when a touch event occurs, and a peripheral area PA neighboring and/or abutting the display area DA and/or the sensing area SA. The sensing area SA may overlap the display area DA, and may be as large as or larger than the display area DA. 
         [0065]    The display unit  100  may display visual information, for example, one or more of text, video, a photo, a two-dimensional or a three-dimensional image, etc. Hereinafter, the visual information is denoted as “image”. The display unit  100  may be implemented using one or more technologies for displaying an image. 
         [0066]    The display unit  100  includes the display area DA and the peripheral area PA. The display area DA may include a plurality of pixel areas in which display elements are provided. The peripheral area PA may be a non-display area, which may not dynamically display images, and may be disposed adjacent to the display area DA. 
         [0067]    The display unit  100  may include a plurality of signal wires and a plurality of thin film transistors connected to the plurality of signal wires. Each of the display elements may be electrically connected to one of the thin film transistors. 
         [0068]    Each of the display elements may include a first electrode connected to the thin film transistor, an emission layer disposed on the first electrode, and a second electrode disposed on the emission layer. The emission layer may include a light generation layer from which light is generated by combining electrons and holes injected through the first and second electrodes. 
         [0069]    The touch unit  200  may be provided on a front side of the display unit  100 , that is, a side where the image is displayed to a user, and may also be provided integrally with the display unit  100 . During manufacturing, the touch unit  200  may be provided on top of the display unit  100 . 
         [0070]    The touch unit  200  includes a sensing area SA and a peripheral area PA. The sensing area SA may correspond to the display area DA of the display unit  100 . The peripheral area PA may be disposed adjacent to the sensing area SA. The peripheral area PA may correspond to the peripheral area PA of the display unit  100 . 
         [0071]    The touch unit  200  may include a touch sensing unit that is provided in the sensing area SA, and a wire portion that is provided in the peripheral area PA. 
         [0072]    The touch sensing unit may sense a touch event provided to the display device via a user&#39;s hand or separate input means. In an embodiment, the touch sensing unit may be a capacitive touch sensor in which a change in capacitance between two sensing electrodes is sensed. 
         [0073]    The touch sensing unit includes touch electrodes  220  that are provided in the sensing area SA. In the touch unit  200 , the touch electrodes  220  are disposed on a surface that faces the display unit  100 , and may be connected to a pad area PDA via sensing lines  230 . The touch electrodes  220  may be arranged in various ways according to embodiments. 
         [0074]    In an embodiment, some of the touch electrodes  220  may include a plurality of sensing electrode rows that are electrically connected to and parallel to each other in a first direction D 1 ; some of the touch electrodes  220  may include a plurality of sensing electrode columns that are connected in a direction D 2  and are parallel to each other. 
         [0075]    The wire portion connects the touch sensing unit with a driving circuit (not shown) that may drive the touch unit  200 . The driving circuit may include a position detection circuit. The wire portion may transmit a sensing input signal from the driving circuit to the plurality of touch electrodes  220 , and/or may transmit a sensing output signal from the plurality of touch electrodes  220  to the driving circuit. The wire portion may include the sensing lines  230  that are connected to the plurality of touch electrodes  220 . 
         [0076]      FIG. 4  is a top plan view of a region corresponding to a touch electrode illustrated in  FIG. 3  according to an embodiment,  FIG. 5  is a top plan view of the portion A 1  indicated in  FIG. 4  according to an embodiment,  FIG. 6  is a cross-sectional view of  FIG. 5  taken along the line I-I′ according to an embodiment, and  FIG. 7  is a cross-sectional view of  FIG. 5  taken along the line II-II′ according to an embodiment. 
         [0077]    Referring to  FIGS. 3 to 7 , the display device includes the following elements: a display unit  100  in which display elements  300  are provided; spacers SP disposed between adjacent display elements  300 ; and a touch unit  200  disposed on the display unit  100 . The touch unit  200  includes a substrate  210  and touch electrodes  220  (including  221  and  223 ) disposed on a surface of the substrate  210  that faces the display unit  100 . 
         [0078]    The display unit  100  may include a display area DA and a peripheral area PA. The display area DA may include a plurality of pixel areas. The peripheral area PA, which is a non-display area that does not dynamically display images, may be disposed adjacent to the display area DA. In an embodiment, the display unit  100  may include a first base substrate  110 , one or more thin film transistors (TFT) disposed in/near the pixel areas on the first base substrate  110 , and the display elements  300 . 
         [0079]    The first base substrate  110  can transmit light since it includes a transparent insulating material. In an embodiment, the first base substrate  110  may be a rigid substrate or a flexible substrate. The rigid substrate may include at least one of a glass substrate, a quartz substrate, a glass-ceramic substrate, and a crystalline glass substrate. The flexible substrate may include at least one of a film substrate and a plastic substrate that include a polymer organic material. During a manufacturing process of the display device, it is desirable that a material of the first base substrate  110  has resistance against high processing temperatures (or high heat resistance). 
         [0080]    A buffer layer  115  may be disposed between the first base substrate  110  and the thin film transistors (TFT). The buffer layer  115  may include at least one of a silicon oxide and a silicon nitride. 
         [0081]    A semiconductor pattern  120  may be provided on the buffer layer  115 . The semiconductor pattern  120  is formed of a semiconductor material, and acts as an active layer of the thin film transistor (TFT). The semiconductor pattern  110  may include a source region  120   b , a drain region  120   c , and a channel region  120   a  provided between the source region  120   b  and the drain region  120   c . An inorganic semiconductor or an organic semiconductor may be selected to form the semiconductor pattern  120 . The source region  120   b  and the drain region  120   c  may be doped with n-type or p-type impurities. 
         [0082]    An interlayer insulating layer  125  may be disposed on the semiconductor pattern  120 . The interlayer insulating layer  125  may cover the semiconductor pattern  120 , and may insulate the semiconductor pattern  120  from the gate electrode  130 . The interlayer insulating layer  125  may include at least one of a silicon oxide and a silicon nitride. 
         [0083]    The gate electrode  130  may be disposed on the interlayer insulating layer  125 . The gate electrode  130  may include a low resistance conductive material, and may be provided to cover a region corresponding to the channel region  120   a  of the semiconductor pattern  120 . 
         [0084]    The gate electrode  130  may be, for example, made of a single kind of metal, various kinds of metals, or an alloy. Specifically, the gate electrode  130  may be made of one or more of molybdenum (Mo), tungsten (W), aluminum neodymium (AlNd), titanium (Ti), aluminum (Al), silver (Ag), and an alloy. The gate electrode  130  may include a material mixture that forms a single layer. The gate electrode  130  may have a dual layer structure or a multilayer structure formed of at least a low resistance material, such as molybdenum (Mo), aluminum (Al), and/or silver (Ag), to reduce wire resistance. 
         [0085]    A gate insulating layer  135  may be provided on the gate electrode  130 . The gate insulating layer  135  may include the same material as the interlayer insulating layer  125 . The gate insulating layer  135  may insulate the source electrode  140   a  and the drain electrode  140   b  from the gate electrode  130 . 
         [0086]    Openings (or contact holes) penetrating through the interlayer insulating layer  125  and the gate insulating layer  135  may expose the source region  120   b  and the drain region  120   c  of the semiconductor pattern  120 . 
         [0087]    The source electrode  140   a  and the drain electrode  140   b  may be provided on the gate insulating layer  135 . The source electrode  140   a  and the drain electrode  140   b  may be disposed to be separated from each other on the gate insulating layer  135 . 
         [0088]    The source electrode  140   a  and the drain electrode  140   b  may be formed of a single kind of metal, but may be formed of two or more kinds of metal or an alloy of two or more kinds of metals. In an embodiment, the source electrode  140   a  and the drain electrode  140   b  may be formed as a single layer, which is made of at least one of molybdenum (Mo), tungsten (W), molybdenum tungsten (MoW), aluminum neodymium (AlNd), titanium (Ti), aluminum (Al), silver (Ag), and an alloy or a material mixture. In an embodiment, the electrodes  140   a  and  140   b  may have a dual layer structure or a multilayer structure formed of at least a low resistance material, such as molybdenum (Mo), aluminum (Al), and/or silver (Ag), to reduce wire resistance. 
         [0089]    One end of the source electrode  140   a  may be connected to a data line (not shown). The other end of the source electrode  140   a  may contact the source region  120   b  through one of the openings. One end of the drain electrode  140   b  may contact the drain region  120   c  through the other one of the openings. The other end of the drain electrode  140   b  may be connected to one of the display elements  300 . 
         [0090]    In an embodiment, the thin film transistor (TFT) is a thin film transistor having a top gate structure. In an embodiment, the thin film transistor (TFT) may be a thin film transistor that has a bottom gate structure. 
         [0091]    A passivation layer  145  may be provided on the first base substrate  110  in which the thin film transistor (TFT) is disposed. The passivation layer  145  covers the thin film transistor (TFT), and may include at least one layer. In an embodiment, the passivation layer  145  may include an organic insulating material that can planarize a surface by reducing unevenness of the lower structure. One or more of an acrylic resin, benzocyclobutene (BCB), polyimide (PI), polyamide (PA), and a phenolic resin may be included in the organic insulating material. 
         [0092]    In the passivation layer  145 , a contact hole exposing a part of the drain electrode  140   b  is formed using a photolithography process and/or a different process. 
         [0093]    The display elements  300  may be provided on the passivation layer  145 . The display elements  300  may include a first electrode  150  connected to the drain electrode  140   b , an emission layer  160  disposed on the first electrode  150 , and a second electrode  170  disposed on the emission layer  160 . 
         [0094]    One of the first electrode  150  and the second electrode  170  may be an anode, and the other may be a cathode. For example, the first electrode  150  may be an anode, and the second electrode  170  may be a cathode. 
         [0095]    In an embodiment, at least one of the first electrode  150  and the second electrode  170  may be a transmissive electrode (or transparent electrode). In an embodiment, the display elements  300  are bottom-emission organic light emitting diodes, the first electrode  150  may be a transmissive electrode, and the second electrode  170  may be a reflective electrode. In an embodiment, the display elements  300  are top-emission organic light emitting diodes, the first electrode  150  may be a reflective electrode, and the second electrode  170  may be a transmissive electrode. In an embodiment, the display elements  300  are dual-emission organic light emitting diodes, each of the first electrode  150  and the second electrode  170  may be a transmissive electrode. In an embodiment, the display elements  300  are top-emission organic light emitting diodes, and the first electrode  150  is an anode. 
         [0096]    In each pixel area, a first electrode  150  may be disposed on the passivation layer  145 . The first electrode  150  may include a reflective layer (not shown) that can reflect light, and a transparent conductive layer (not shown) disposed above or below the reflective layer. At least one of the transparent conductive layer and the reflective layer may be connected to the drain electrode  140   b.    
         [0097]    The reflective layer may include a material that can reflect 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 an alloy. 
         [0098]    The transparent conductive layer may include a transparent conductive oxide. For example, the transparent conductive layer may include 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). 
         [0099]    A pixel defining layer  155  may be provided on the first electrode  150 . The pixel defining layer  155  may include an opening that exposes the first electrode  150 . In an embodiment, the pixel defining layer  155  may overlap an edge portion of the first electrode  150 . The opening of the pixel defining layer  155  may expose most of a surface of the first electrode  150  that faces the touch unit  200 . 
         [0100]    The pixel defining layer  155  may include an organic insulating material. For example, the pixel defining layer  155  may include at least one of polystyrene, polymethyl methacrylate (PMMA), polyacrylonitrile (PAN), polyamide (PA), polyimide (PI), polyarylether (PAE), a heterocyclic polymer, parylene, epoxy, benzocyclobutene (BCB), a siloxane-based resin, and a silane-based resin. 
         [0101]    The spacers SP and the light reflection patterns  400  may be disposed (directly) on the pixel defining layer  155 . 
         [0102]    The spacers SP may protrude toward the touch unit  200  from the pixel defining layer  155  such that a gap between the display unit  100  and the touch unit  200  is maintained. Even if an external pressure is applied to the display unit  100  or the touch unit  200 , the spacers SP may prevent the touch unit  200  from contacting the display elements  300 , such that the display elements  300  are not damaged. 
         [0103]    The spacers SP are provided such that display characteristics of the display elements  300  are not significantly affected by an external impact, and may be regularly or randomly disposed in the display area DA. 
         [0104]    The light reflection patterns  400  (or light reflectors  400 ) may protrude toward the touch unit  200  from the pixel defining layer  155 , and may be provided in regions where no spacers SP are disposed. 
         [0105]    The spacers SP and the light reflection patterns  400  may each include an organic insulating material. For example, the spacers SP and the light reflection patterns  400  may include the same material as the pixel defining layer  155 . In an embodiment, the pixel defining layer  155  and the spacers SP may be sequentially or separately formed, and/or may be separate structures that are made of different materials. In an embodiment, the pixel defining layer  155  and the light reflection patterns  400  may be sequentially or separately formed, and/or may be separate structure that are made of different materials. 
         [0106]    The pixel defining layer  155 , the spacers SP, and the light reflection patterns  400  may be formed through an exposure process using a halftone mask. In an embodiment, the light reflection patterns  400  may be lower, thinner, and/or shorter than the plurality of spacers SP. 
         [0107]    The emission layer  160  may be disposed inside an opening of the layer  155  on the surface of the first electrode  150  that is exposed by the opening. The emission layer  160  may have a multi-layered thin film structure that includes at least a light generation layer (LGL). A color of the light generated from the light generation layer may be one of red, green, blue, and white, and/or one of other colors. 
         [0108]    The second electrode  170  may be provided on the emission layer  160 . The second electrode  170  may extend to the pixel defining layer  155  and the spacers SP. The second electrode  170  may be a transflective layer. In an embodiment, the second electrode  170  may be a thin metal layer, which is thin enough to transmit light. 
         [0109]    The second electrode  170  may include a material that has a lower work function than that of a transparent conductive layer. For example, the second electrode  170  may 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 an alloy. 
         [0110]    Some of the light emitted from the emission layer  160  may not be transmitted through the second electrode  170 , and the light reflected from the second electrode  170  may be reflected again from the reflective layer of the electrode  150 . That is, the light emitted from the emission layer  160  may be resonated between the reflective layer and the second electrode  170 . Light efficiency of the display elements  300  may be improved by the resonance of the light. 
         [0111]    A capping layer  175  (or insulating layer  175 ) may be provided on the second electrode  170 . The capping layer  175  allows a gap between the second electrode  170  and the touch unit  200  to be maintained. The capping layer  175  may include an insulating material that can insulate the second electrode  170  from the touch unit  200 . 
         [0112]    The touch unit  200  may separate the display elements  300  from an external environment. In an embodiment, the touch unit  200  may include a second base substrate  210  that includes the same material as the first base substrate  110 , and touch electrodes  220  that are disposed on the second base substrate  210 . The second base substrate  210  may be bonded to the first base substrate  110  by a sealant. 
         [0113]    The touch unit  200  may include a sensing area SA, and a peripheral area PA disposed adjacent to the sensing area SA. The sensing area SA may correspond to the display area DA of the display unit  100 . The peripheral area PA may correspond to the peripheral area of the display unit  100  PA. 
         [0114]    The touch electrodes  220  may be disposed in the sensing area SA (directly) on a surface of the substrate  210  that faces the display unit  100 . 
         [0115]    The touch electrodes  220  may include at least one first region  220   a  (or first touch electrode set  220   a ), and a second region  220   b  (or second touch electrode set  220   b ) electrically insulated from the first region  220   a . In the plan view, the second region  220   b  (or second touch electrode set  220   b ) may substantially or completely surround the first region  220   a  (or first touch electrode set  220   a ). That is, the first region  220   a  may have an isolated island shape that is surrounded by the second region  220   b.    
         [0116]    The touch electrodes  220  may include a metal mesh. More In an embodiment, the touch electrodes  220  may include a plurality of conductive lines that cross each other. 
         [0117]    The plurality of conductive lines may include a plurality of first conductive lines  221  that extend in a direction D 1 , and a plurality of second conductive lines  223  that extend in a direction D 2  different from (e.g., perpendicular to) the direction D 1 . 
         [0118]    Regions formed at/near intersections of the first conductive lines  221  and the second conductive lines  223  may correspond to the pixel area. In an embodiment, the display elements  300  may be disposed in/near intersections of the first conductive lines  221  and the second conductive lines  223 . 
         [0119]    The plurality of conductive lines in the first region  220   a  (or first touch electrode set  220   a ) may be electrically separated from the plurality of conductive lines that are in the second region  220   a  (or second touch electrode set  220   b ). The first conductive lines  221  in the first region  220   a  may be electrically separated from the first conductive lines  221  in the second region  220   b , and the second conductive lines  223  in the first region  220   a  may be electrically separated from the second conductive lines  223  in the second region  220   b . In an embodiment, first conductive lines  221  disposed in the first region  220   a  and the second conductive lines  223  may be electrically separated from each other. 
         [0120]    In an embodiment, the spacers SP may be disposed only in a region corresponding to the first region  220   a  (or first touch electrode set  220   a ), and may not be disposed in a region corresponding to the second region  220   b  (or second touch electrode set  220   b ). In an embodiment, the light reflection patterns  400  may be disposed only in the region corresponding to the second region  220   b  (or second touch electrode set  220   b ), and may not be disposed in the region corresponding to the first region  220   a  (or first touch electrode set  220   a ). In an embodiment, the spacers SP may be disposed only in the region corresponding to the first region  220   a , and the light reflection patterns  400  may be disposed only in the region corresponding to the second region  220   b.    
         [0121]    The light reflection patterns  400  may be lower, thinner, and/or shorter than the spacers SP as a result of a manufacturing process, e.g., an exposure process. In an embodiment, a shape/structure of each of the light reflection patterns  400  may be different from a shape/structure of each of the spacers SP. 
         [0122]    In an embodiment, a distance between the display element  300  and the touch electrode  220  in the second region  220   b  may be different from that between the display element  300  and the touch electrode  220  in the first region  220   b . In an embodiment, the distance between the display element  300  and the touch electrode  220  in the second region  220   b  may be greater than the distance between the display element  300  and the touch electrode  220  in the first region  220   a  by a difference between heights of the light reflection pattern  400  and the spacer SP. According to embodiments, the distance between the display element  300  and the touch electrode  220  in the second region  220   b  is sufficient secured, and undesirable parasitic capacitance generated between the display element  300  and the touch electrode  220  may be minimized. 
         [0123]    If only the spacers SP are disposed in the region corresponding to the first region  220   a , and if no light reflection patterns  400  are disposed in the region corresponding to the second region  220   b , when external light is incident on the display unit  100 , the light may be reflected by the spacers SP, such that the spacers SP may be significantly conspicuous to a user. As a result, the user may perceive unsatisfactory image quality. 
         [0124]    In embodiments, the light reflection patterns  400 , which reflect light t in a way similar to how the spacers SP reflect light, may be disposed in the second region  220   b  that surrounds the first region  220   a . As a result, reflected light may be visible throughout substantially the entire region of the display unit  100 . Advantageously, reflected light can be substantially uniformly provided, and satisfactory image quality may be perceived by the user. 
         [0125]      FIG. 8  is a cross-sectional view of a display device according to an embodiment. I 
         [0126]    Referring to  FIG. 8 , the display device includes a display unit  100 ′ (which includes a display element  300 ′) and a touch unit  200  disposed on the display unit  100 ′. Touch electrodes ((analogous/identical to electrodes  220  of  FIG. 7 ) are disposed on a surface of the touch unit  200  facing the display unit  100 ′. 
         [0127]    The display unit  100 ′ may include a first base substrate  110 , at least one or more thin film transistors (TFTs) disposed in a pixel area on the first base substrate  110 , and the display elements  300 ′. 
         [0128]    Each of the display elements  300 ′ may include a first electrode  150  connected to the thin film transistor (TFT), an emission layer  160  disposed on the first electrode  150 , and a second electrode  170  disposed on the emission layer  160 ′. 
         [0129]    The pixel defining layer  155 ′ may be provided on the first electrode  150 . The pixel defining layer  155 ′ may be provided with an opening, which is disposed between the pixel areas and exposes the first electrode  150 . In an embodiment, the pixel defining layer  155 ′ may include a light reflection pattern  400 ′ that is recessed toward the first base substrate  110  in a region corresponding to the first conductive lines  221  of the touch electrode  220 . 
         [0130]    In an embodiment, the light reflection pattern  400 ′ has a recessed portion that is recessed toward the first base substrate  110  from the pixel defining layer  155 . In an embodiment, the recessed portion of the light reflection pattern  400 ′ may have a round shape (or curved shape), as shown in the drawing. 
         [0131]    Due to the light reflection pattern  400 , a distance between the touch electrodes  220  of the touch unit  200  and the second electrode  170 ′ of the display unit  100  may increase such that the gap between the touch electrodes  220  and the second electrode  173  is sufficiently maintained. As a result, parasitic capacitance between the touch electrodes  220  and the second electrode  170 ′ may be minimized. 
         [0132]    Table 1 below shows values of parasitic capacitance between a touch electrode and a second electrode (or a display-element electrode) according to sizes of a gap between the touch electrode and the second electrode. 
         [0000]    
       
         
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                   
                 Gap 
                   
                 Gap 
                   
               
               
                   
                 between 
                 Gap between 
                 between 
                 Gap between 
               
               
                   
                 touch 
                 touch 
                 touch 
                 touch 
               
               
                 Parasitic 
                 electrode 
                 electrode 
                 electrode 
                 electrode and 
               
               
                 capacitance 
                 and second 
                 and second 
                 and second 
                 second 
               
               
                 values 
                 electrode is 
                 electrode is 
                 electrode is 
                 electrode is 
               
               
                 (pF) 
                 2 μm 
                 4 μm 
                 6 μm 
                 8 μm 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Experimental 
                 0.17 
                 0.157 
                 0.15 
                 0.146 
               
               
                 group 
                   
                   
                   
                   
               
               
                 Embodiment 
                 0.07 
                 0.05 
                 0.03 
                 0.03 
               
               
                 illustrated in 
                   
                   
                   
                   
               
               
                 FIG. 7 
                   
                   
                   
                   
               
               
                 Embodiment 
                 0.05 
                 0.03 
                 0.03 
                 0.02 
               
               
                 illustrated in 
                   
                   
                   
                   
               
               
                 FIG. 8 
               
               
                   
               
             
          
         
       
     
         [0133]    In Table 1, the experimental group may represent a structure in which spacers are uniformly disposed across the entire region of the display device. The embodiment illustrated in  FIG. 7  may represent a structure in which spacers are disposed in a specific region of the display device (e.g., the first region ( 220   a  of  FIG. 5 )), and light reflection patterns having a lower height than the spacers are disposed in regions other than the specific region. The embodiment illustrated in  FIG. 8  may represent a structure in which spacers are disposed in a specific region of the display device, and light reflection patterns having a recessed portion downward from the pixel defining layer are disposed in regions other than the specific region. 
         [0134]    Table 1 shows that as the gap between touch electrode and the second electrode increases, related parasitic capacitance decreases. 
         [0135]    Table 1 further shows that the embodiments including light reflection patterns, compared with experimental group including no light reflection pattern, produce lower parasitic capacitance between the touch electrode and the second electrode. 
         [0136]    According to embodiments, spacers are disposed only in specific regions of the display device, and light reflection patterns are disposed in regions other than the specific regions. Therefore, sufficient gaps between touch electrodes and second electrodes are reinforced in the regions where the light reflection patterns are formed. Advantageously, parasitic capacitance may be minimized. 
         [0137]      FIG. 9  is a cross-sectional view of a display device according to an embodiment. an 
         [0138]    Referring to  FIG. 9 , the display device includes a display unit  100 ″ (which includes display elements  300 ″) and a touch unit  200  disposed on the display unit  100 ″. Touch electrodes (analogous/identical to electrodes  220  of  FIG. 7 ) are disposed on a surface of the touch unit  200  facing the display unit  100 ″. 
         [0139]    The display unit  100 ″ may include a first base substrate  110 , one or more thin film transistors (TFT) disposed in a pixel area on the first base substrate  110 , and the display elements  300 ″. 
         [0140]    Each of the display elements  300 ″ may include a first electrode  150  connected to the thin film transistor (TFT), an emission layer  160  disposed on the first electrode  150 , and a second electrode  170 ″ disposed on the emission layer  160 . 
         [0141]    A pixel defining layer  155 ″ may be provided on the first electrode  150 . The pixel defining layer  155 ″ may be disposed between the pixel areas and may include an opening that exposes at least one portion of the first electrode  150 . In an embodiment, the pixel defining layer  155 ″ may include at least one portion that has protrusions and depressions in a region corresponding to the first conductive lines  221  of the touch electrode  220 . 
         [0142]    In an embodiment, the protrusions and depressions may form a light reflection pattern  400 ″. The protrusions (or protruding portions) may protrude toward the touch unit  200  from the pixel defining layer  155 ″. In an embodiment, the depressions (or recessed portions) may be recessed toward the first base substrate  110  from the pixel defining layer  155 ″. 
         [0143]    The protruding portions and the recessed portions of the light reflection pattern  400 ″ may be formed using one or more of various methods such as one or more of laser processing, wet or dry etching, an imprint process, etc. In embodiments, the protruding portion and the recessed portion of the light reflection pattern  400 ″ may be formed using a halftone mask process. 
         [0144]    The display device may include spacers analogous to or identical to some of the previously described spacers. Accordingly, a gap between the touch electrodes  220  and the second electrode  170 ″ may be sufficiently maintained. Therefore, undesirable parasitic capacitance formed between the touch electrodes  220  and the second electrode  170 ″ may be minimized or prevented. 
         [0145]    It will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit within the scope defined by the claims.