Patent Publication Number: US-2022238849-A1

Title: Touch display device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. application Ser. No. 16/924,017, filed on Jul. 8, 2020 which claims the benefit of Korean Patent Application No 10-2019-0160326, filed on Dec. 5, 2019, which is hereby incorporated by reference as if fully set forth herein. 
    
    
     BACKGROUND 
     Technical Field 
     The present disclosure relates to a touch display device, and more particularly to a touch display device exhibiting low reflectivity. 
     Description of the Related Art 
     A touch screen is an input device through which a user may input a command by selecting instructions displayed on a screen of a display device using a hand or an object. That is, a touch screen converts a contact position that directly contacts a human hand or an object into an electrical signal and receives selected instructions based on the contact position as an input signal. Such a touch screen may substitute for a separate input device that is connected to a display device and operated, such as a keyboard or a mouse, and thus the range of application of the touch screen is continually increasing. 
     A touch screen includes a plurality of touch electrodes formed of an opaque material. A polarizing plate is disposed on the touch screen in order to prevent deterioration in visibility due to reflection of light incident from outside by the touch electrodes formed of the opaque material. However, the polarizing plate incurs an increase in the thickness of a product, an increase in manufacturing costs, and a decrease in transmissivity. 
     BRIEF SUMMARY 
     Accordingly, in some embodiments of the present disclosure, a touch display device that substantially obviates one or more problems due to limitations and disadvantages of the related art is provided. 
     The present disclosure provides a touch display device exhibiting low reflectivity. 
     Additional advantages, technical benefits, and features of the disclosure will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the disclosure. The benefits and other advantages of the disclosure may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. 
     To achieve these benefits and other advantages and in accordance with the purpose of the disclosure, as embodied and broadly described herein, a touch display device includes a light-blocking stack composed of at least two light-blocking color layers overlapping a plurality of touch electrodes disposed on an encapsulation unit, and a low-reflection layer disposed on the light-blocking stack, thereby absorbing external light without a separate polarizing plate, thus exhibiting low reflectivity. 
     It is to be understood that both the foregoing general description and the following detailed description of the present disclosure are examples and explanatory and are intended to provide further explanation of the disclosure as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the disclosure and together with the description serve to explain the principle of the disclosure. In the drawings: 
         FIG. 1  is a perspective view showing a touch display device according to the present disclosure; 
         FIG. 2  is a plan view showing a touch display device according to a first embodiment of the present disclosure; 
         FIG. 3  is an enlarged plan view of region A in  FIG. 2 ; 
         FIG. 4  is a cross-sectional view of the touch display device taken along line I-I′ in  FIG. 2 ; 
         FIG. 5  is a cross-sectional view showing another embodiment of the light-blocking stack shown in  FIG. 4 ; 
         FIG. 6  is a plan view showing the low-reflection layer shown in  FIGS. 4 and 5 ; 
         FIG. 7  is a cross-sectional view showing the relationships between the line widths of the light-blocking stack and the low-reflection layer according to the present disclosure and the line width of a polarizing plate according to a comparative example; and 
         FIG. 8  is a cross-sectional view showing a touch display device according to a second embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to the one or more embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. 
       FIG. 1  is a perspective view of a touch display device according to the present disclosure. 
     A touch display device shown in  FIG. 1  senses the presence or absence of a touch and a touch position by sensing a variation in mutual capacitance Cm (e.g., a touch sensor) in response to a user touch through touch electrodes  152   e  and  154   e  shown in  FIG. 2  for a touch period. An organic light-emitting display device having the touch sensor shown in  FIG. 1  displays an image through a unit pixel UP (refer to  FIG. 3 ) including a light-emitting element  120 . 
     To this end, the touch display device includes a unit pixel UP composed of a plurality of subpixels SP arranged in a matrix form on a substrate  111 , an encapsulation unit  140  disposed on the plurality of subpixels SP, and a touch sensor Cm disposed on the encapsulation unit  140 . 
     The unit pixel UP is composed of red (R), green (G) and blue (B) subpixels SP, which are arranged in a row. Alternatively, as shown in  FIG. 1 , the unit pixel UP is composed of red (R), green (G), blue (B) and white (W) subpixels SP. Alternatively, as shown in  FIG. 3 , the unit pixel UP is formed in a Pentile structure including one red subpixel, one blue subpixel, and two green subpixels. 
     Each of the subpixels SP includes a pixel-driving circuit and a light-emitting element  120  connected to the pixel-driving circuit. 
     The pixel-driving circuit includes a switching transistor T 1 , a driving transistor T 2 , and a storage capacitor Cst. In the present disclosure, a structure in which the pixel-driving circuit includes two transistors T and one capacitor C is described by way of example, but the present disclosure is not limited thereto. That is, a pixel-driving circuit having a  3 T 1 C structure or  3 T 2 C structure in which three or more transistors T and one or more capacitors C are provided may be used. 
     The switching transistor T 1  is turned on when a scan pulse is supplied to a scan line SL, and supplies a data signal supplied to a data line DL to the storage capacitor Cst and a gate electrode of the driving transistor T 2 . 
     The driving transistor T 2  controls the current I supplied from a high-voltage (VDD) supply line to the light-emitting element  120  in response to the data signal supplied to the gate electrode of the driving transistor T 2 , thereby adjusting the amount of light emitted from the light-emitting element  120 . Even when the switching transistor T 1  is turned off, the driving transistor T 2  maintains the emission of light by the light-emitting element  120  by supplying a constant amount of current thereto using the voltage charged in the storage capacitor Cst until the data signal of the next frame is supplied. 
     The driving thin-film transistor T 2   130 , as shown in  FIG. 4 , includes a semiconductor layer  134  disposed on a buffer layer  112 , a gate electrode  132  overlapping the semiconductor layer  134  with a gate insulating film  102  interposed therebetween, and source and drain electrodes  136  and  138  formed on an interlayer insulating film  114  so as to be in contact with the semiconductor layer  134 . The semiconductor layer  134  is formed of at least one of an amorphous semiconductor material, a polycrystalline semiconductor material, or an oxide semiconductor material. 
     The light-emitting element  120  includes an anode  122 , a light-emitting stack  124  formed on the anode  122 , and a cathode  126  formed on the light-emitting stack  124 . 
     The anode  122  is electrically connected to the drain electrode  138  of the driving thin-film transistor T 2  ( 130 ), which is exposed through a pixel contact hole that penetrates a pixel planarization layer  118 . 
     At least one light-emitting stack  124  is formed on the anode  122  in an emission area that is defined by a bank  128 . The at least one light-emitting stack  124  is formed by stacking a hole-related layer, an organic emission layer, and an electron-related layer on the anode  122  in that order or in the reverse order. In addition, the light-emitting stack  124  may include first and second light-emitting stacks, which face each other with a charge generation layer interposed therebetween. In this case, the organic emission layer of any one of the first and second light-emitting stacks generates blue light, and the organic emission layer of the other one of the first and second light-emitting stacks generates yellow-green light, whereby white light is generated through the first and second light-emitting stacks. Since the white light generated in the light-emitting stack  124  is incident on a color filter located above the light-emitting stack  124 , a color image may be realized. Alternatively, colored light corresponding to each subpixel may be generated in each light-emitting stack  124  without a separate color filter in order to realize a color image. That is, the light-emitting stack  124  of the red (R) subpixel may generate red light, the light-emitting stack  124  of the green (G) subpixel may generate green light, and the light-emitting stack  124  of the blue (B) subpixel may generate blue light. 
     The cathode  126  is formed so as to face the anode  122 , with the light-emitting stack  124  interposed therebetween. The cathode  126  is connected to a low-voltage (VSS) supply line. 
     The encapsulation unit  140  prevents foreign materials including but not limited to external moisture or oxygen from entering the light-emitting element  120 , which is vulnerable to external moisture or oxygen. To this end, the encapsulation unit  140  includes a plurality of inorganic encapsulation layers  142  and  146  and an organic encapsulation layer  144  disposed between the plurality of inorganic encapsulation layers  142  and  146 . The inorganic encapsulation layer  146  is disposed at the top of the encapsulation unit  140 . In this case, the encapsulation unit  140  includes at least two inorganic encapsulation layers  142  and  146  and at least one organic encapsulation layer  144 . In the present disclosure, the structure of the encapsulation unit  140  in which the organic encapsulation layer  144  is disposed between the first and second inorganic encapsulation layers  142  and  146  will be described by way of example. 
     The first inorganic encapsulation layer  142  is formed on the substrate  111 , on which the cathode  126  has been formed, at the position that is the closest to the light-emitting element  120 . The first inorganic encapsulation layer  142  is formed of an inorganic insulating material that is capable of being deposited at a low temperature, such as silicon nitride (SiN x ), silicon oxide (SiO x ), silicon oxynitride (SiON), or aluminum oxide (Al 2 O 3 ). Thus, since the first inorganic encapsulation layer  142  is deposited in a low-temperature atmosphere, it is possible to prevent damage to the light-emitting stack  124 , which is vulnerable to a high-temperature atmosphere, during the process of depositing the first inorganic encapsulation layer  142 . 
     The organic encapsulation layer  144  serves to dampen the stress between the respective layers due to bending of the organic light-emitting display device and to increase planarization performance. The organic encapsulation layer  144  is formed of an organic insulating material, such as acrylic resin, epoxy resin, polyimide, polyethylene, or silicon oxycarbide (SiOC). 
     When the organic encapsulation layer  144  is formed through an inkjet method, at least one dam  106  is disposed in order to prevent the organic encapsulation layer  144 , which is in a liquid state, from spreading to an edge of the substrate  111 . The at least one dam  106  may prevent the organic encapsulation layer  144  from spreading to a pad area formed at the outermost portion of the substrate  111 , in which a touch pad  170  and a display pad  104  are disposed. To this end, the at least one dam  106  may be formed so as to completely surround the active area, in which the light-emitting element  120  is disposed, as shown in  FIG. 2 , or may be formed only between the active area and the pad area. When the pad area, in which the touch pad  170  and the display pad  104  are disposed, is disposed at one side of the substrate  111 , the at least one dam  106  is disposed only on the one side of the substrate  111 . When the pad area, in which the touch pad  170  and the display pad  104  are disposed, is disposed at opposite sides of the substrate  111 , the at least one dam  106  is disposed on the opposite sides of the substrate  111 . The at least one dam  106  is formed in a single-layered or multi-layered structure. The at least one dam  106  is formed simultaneously with at least one of the pixel planarization layer  118 , the bank  128 , or the spacer using the same or substantially the same material. 
     The second inorganic encapsulation layer  146  is formed on the substrate  111 , on which the organic encapsulation layer  144  has been formed, so as to cover the top and side surfaces of each of the organic encapsulation layer  144  and the first inorganic encapsulation layer  142 . Accordingly, the second inorganic encapsulation layer  146  reduces or prevents permeation of external moisture or oxygen into the first inorganic encapsulation layer  142  and the organic encapsulation layer  144 . The second inorganic encapsulation layer  146  is formed of an inorganic insulating material, such as silicon nitride (SiN x ), silicon oxide (SiO x ), silicon oxynitride (SiON), or aluminum oxide (Al 2 O 3 ). 
     A touch sensor Cm is disposed on the encapsulation unit  140 . The touch sensor Cm includes a touch insulating film  156 , and further includes a touch-sensing line  154  and a touch-driving line  152  disposed so as to intersect each other, with the touch insulating film  156  interposed therebetween. The touch sensor charges an electric charge using a touch-driving pulse supplied to the touch-driving line  152 , and discharges the electric charge to the touch-sensing line  154 . 
     The touch-driving line  152  includes a plurality of first touch electrodes  152   e  and first bridges  152   b  electrically connecting the first touch electrodes  152   e  to each other. 
     The first touch electrodes  152   e  are spaced apart from each other at regular intervals in an X direction, which is a first direction, on the touch insulating film  156 . Each of the first touch electrodes  152   e  is electrically connected to a neighboring first touch electrode  152   e  via the first bridge  152   b.    
     The first bridge  152   b  is disposed on the touch insulating film  156 , which is coplanar with the second touch electrode  154   e , and thus is electrically connected to the second touch electrode  154   e  without a separate contact hole. 
     The touch-sensing line  154  includes a plurality of second touch electrodes  154   e  and second bridges  154   b  electrically connecting the second touch electrodes  154   e  to each other. 
     The second touch electrodes  154   e  are spaced apart from each other at regular intervals in a Y direction, which is a second direction, on the touch insulating film  156 . Each of the second touch electrodes  154   e  is electrically connected to a neighboring second touch electrode  154   e  via the second bridge  154   b.    
     The second bridge  154   b  is formed on a touch buffer film  148 , which is formed of an insulating material. The second bridge  154   b  is exposed through a touch contact hole  158  that penetrates the touch insulating film  156 , and is electrically connected to the first touch electrode  152   e.    
     As shown in  FIG. 3 , the first and second touch electrodes  152   e  and  154   e  and the first bridge  152   b  are formed in a mesh type such that they do not overlap the emission area of each subpixel SP and overlap the bank  128 . The second bridge  154   b  is formed in a V shape or an inverse V shape so as to avoid overlapping the emission area of each subpixel SP but to overlap the bank  128 . Accordingly, it is possible to prevent an aperture ratio and transmissivity from being deteriorated by the first and second touch electrodes  152   e  and  154   e  and the first and second bridges  152   b  and  154   b.    
     The first and second touch electrodes  152   e  and  154   e  and the first and second bridges  152   b  and  154   b  have higher conductivity than a transparent conductive film, and thus are formed as low-resistance electrodes. The first and second touch electrodes  152   e  and  154   e  and the first and second bridges  152   b  and  154   b  are formed in a single-layered or multi-layered structure together with routing lines  160  using a touch metal layer formed of a material having high corrosion resistance and acid resistance and excellent conductivity, such as Ta, Ti, Cu, or Mo. For example, the first and second touch electrodes  152   e  and  154   e , the first and second bridges  152   b  and  154   b , and the routing lines  160  are formed in a three-layered structure such as a stack of Ti/Al/Ti, MoTi/Cu/MoTi, or Ti/Al/Mo. Accordingly, the resistances and capacitances of the first and second touch electrodes  152   e  and  154   e , the first and second bridges  152   b  and  154   b , and the routing lines  160  are reduced. As a result, RC delay is reduced, thus improving touch sensitivity. 
     According to the present disclosure, each of the touch-driving line  152  and the touch-sensing line  154  is connected to a touch-driving unit (not shown) via the routing line  160  and the touch pad  170 . 
     The touch pad  170  is connected to a signal transmission film (not shown), on which the touch-driving unit is mounted. The touch pad  170  is composed of first and second touch pad electrodes  172  and  174 . 
     The first touch pad electrode  172  is disposed on at least one of the substrate  111 , the buffer layer  112 , or the interlayer insulating film  114 , which is disposed below the encapsulation unit  140 . The first touch pad electrode  172  is formed of the same or substantially the same material as at least one of a gate electrode  132 , a source electrode  136 , or a drain electrode  138  of a driving transistor T 2  ( 130 ) in the same plane, and has a single-layered or multi-layered structure. For example, since the first touch pad electrode  172  is formed of the same or substantially the same material as the source and drain electrodes  136  and  138  and is disposed on the interlayer insulating film  114 , the first pad electrode  172  is formed through the same mask process as the source and drain electrodes  136  and  138 . 
     The second touch pad electrode  174  is electrically connected to the first touch pad electrode  172 , which is exposed through a pad contact hole  176  that penetrates a pixel protective film  108 , the touch buffer film  148 , and the touch insulating film  156 . Since the second touch pad electrode  174  is formed through the same mask process as the routing line  160 , the second touch pad electrode  174  is formed of the same or substantially the same material as the routing line  160  in the same plane. 
     The second touch pad electrode  174  extends from the routing line  160 , and is connected to a signal transmission film (not shown), on which the touch-driving unit is mounted, via an anisotropic conductive film (not shown). 
     A display pad  104  is also disposed in a non-active area (a bezel), in which the touch pad  170  is disposed. For example, as shown in  FIG. 2 , display pads  104  may be disposed between touch pads  170 , or the touch pads  170  may be disposed between the display pads  178 . Alternatively, the touch pad  170  may be disposed at one side of the display panel, and the display pad  104  may be disposed at the opposite side of the display panel. However, the arrangement of the touch pad  170  and the display pad  104  is not limited to the structure shown in  FIG. 2 , and may be variously changed depending on the design requirements of the display device. 
     The display pad  104  is formed in a stack structure different from that of the touch pad  170 , or is formed in the same stack structure as the touch pad  170 , as shown in  FIG. 3 . 
     The routing line  160  transmits a touch-driving pulse generated in the touch-driving unit to the touch-driving line  152  through the touch pad  170 , and transmits a touch signal from the touch-sensing line  154  to the touch-driving unit through the touch pad  170 . Accordingly, the routing line  160  is formed between each of the first and second touch electrodes  152   e  and  154   e  and the touch pad  170  to electrically connect each of the first and second touch electrodes  152   e  and  154   e  to the touch pad  170 . As shown in  FIG. 2 , the routing line  160  extends from the first touch electrode  152   e  to at least one of the left side or the right side of the active area AA, and is connected to the touch pad  170 . In addition, the routing line  160  extends from the second touch electrode  154   e  to at least one of the upper side or the lower side of the active area, and is connected to the touch pad  170 . This arrangement of the routing line  160  may be variously changed depending on the design requirements of the display device. The routing line  160  is disposed above first and second dams  162  and  164  so as to overlap with the first and second dams  162  and  164 . 
     A color filter array is disposed so as to cover the routing lines  160 , the touch electrodes  152   e  and  154   e , and the bridges  152   b  and  154   b.    
     The color filter array includes a touch planarization layer  190 , a color filter  192 , a light-blocking stack  194 , a low-reflection layer  196 , and a touch protective film  198 . 
     The touch planarization layer  190  is formed of an organic insulating material, and flattens the substrate  111 , on which the routing lines  160 , the touch electrodes  152   e  and  154   e , and the bridges  152   b  and  154   b  have been formed. 
     The color filter  192  is disposed so as to overlap the emission area exposed by the bank  128  of each subpixel area. A red (R) color filter  192  is formed on the touch planarization layer  190  of the red subpixel area, a green (G) color filter  192  is formed on the touch planarization layer  190  of the green subpixel area, and a blue (B) color filter  192  is formed on the touch planarization layer  190  of the blue subpixel area. 
     The light-blocking stack  194  is disposed so as to overlap the bank  128  between the color filters  192 . The light-blocking stack  194  serves to distinguish between the subpixel areas and to prevent optical interference and light leakage between adjacent subpixel areas. In addition, the light-blocking stack  194  is formed such that the reflectivity thereof has a single-digit percentage (%). As such, the light-blocking stack  194  absorbs external light, thereby reducing or minimizing deterioration in visibility and brightness. 
     The light-blocking stack  194  is formed by stacking at least two light-blocking color layers  194   a  and  194   b  that realize different colors from each other. That is, the light-blocking stack  194  is formed by stacking first and second light-blocking color layers  194   a  and  194   b , as shown in  FIG. 4 , or is formed by stacking first to third light-blocking color layers  194   a ,  194   b  and  194   c , as shown in  FIG. 5 . The first light-blocking color layer  194   a  is formed of the same or substantially the same material as any one of the red (R), green (G), and blue (B) color filters  192 . Since the second light-blocking color layer  194   b  is formed of the same or substantially the same material as the color filter  192 , which realizes a color different from that of the first light-blocking color layer  194   a , the second light-blocking color layer  194   b  absorbs light that has passed through the first light-blocking color layer  194   a , among the light generated by the light-emitting element  120 . The third light-blocking color layer  194   c  is formed of the same or substantially the same material as the color filter  192 , which realizes a color different from that of the first and second light-blocking color layers  194   a  and  194   b . The third light-blocking color layer  194   c  absorbs light that has passed through the first and second light-blocking color layers  194   a  and  194   b , among the light generated by the light-emitting element  120 . 
     For example, in the case of the light-blocking stack  194  having the two-layered structure shown in  FIG. 4 , since the first light-blocking color layer  194   a  is formed of the same or substantially the same material as the red (R) or green (G) color filter  192 , the first light-blocking color layer  194   a  is formed through the same mask process as the red (R) or green (G) color filter  192 . Since the second light-blocking color layer  194   b  is formed of the same or substantially the same material as the blue (B) color filter  192 , the second light-blocking color layer  194   b  is formed through the same mask process as the blue (B) color filter  192 . In the case of the light-blocking stack  194  having the three-layered structure shown in  FIG. 5 , the first light-blocking color layer  194   a  is formed through the same mask process as the red (R) color filter  192  using the same or substantially the same material as the red (R) color filter  192 . The second light-blocking color layer  194   b  is formed through the same mask process as the green (G) color filter  192  using the same or substantially the same material as the green (G) color filter  192 . The third light-blocking color layer  194   c  is formed through the same mask process as the blue (B) color filter  192  using the same or substantially the same material as the blue (B) color filter  192 . 
     As described above, the light-blocking stack  194  of the present disclosure is composed of at least two light-blocking color layers, rather than black resin. In this case, the present disclosure does not use a chemical solution (e.g., a developer), which is used to pattern black resin. Accordingly, in the present disclosure, the second touch pad electrode  174  and the routing line  160  do not react with a chemical solution (a developer), which is used to pattern black resin. Thus, it is possible to prevent corrosion of the second touch pad electrode  174  and the routing line  160 . Further, the second touch pad electrode  174  and the routing line  160  have resistance to corrosion by a chemical solution used to pattern the light-blocking stack  194 . Thus, it is possible to prevent the second touch pad electrode  174  and the routing line  160  from being corroded by the chemical solution used to pattern the light-blocking stack  194 . 
     As shown in  FIG. 6 , the low-reflection layer  196  is formed in the region other than the region where the color filter  192  of each subpixel SP is located. That is, since the low-reflection layer  196  is disposed on the light-blocking stack  194  so as to cover the top and side surfaces of the light-blocking stack  194 , the low-reflection layer  196  overlaps the touch electrodes  152   e  and  154   e  and the bridges  152   b  and  154   b . The low-reflection layer  196  is formed of a low-reflection material having reflectivity having a single-digit percentage (%). For example, the low-reflection layer  196  is formed in a single-layered or multi-layered structure using at least one of TiO x , CuN x , CuMg, CuS, AlON, AlTiN, MoTaO x , or MoTiON. Since the low-reflection layer  196  absorbs external light, it is possible to reduce or minimize deterioration in visibility and brightness. 
     As shown in  FIG. 7 , since the low-reflection layer  196  and the light-blocking stack  194  of the present disclosure are disposed under the touch protective film  198 , the spacing distance from the bank  128  is shorter than the spacing distance between the bank  128  and a light-blocking unit  96  of a conventional polarizing plate disposed on the touch protective film  198 . In this case, even when the line widths of the low-reflection layer  196  and the light-blocking stack  194  are increased so as to be larger than that of the light-blocking unit  96  of the conventional polarizing plate by 1 to 2 μm, the light generated by the light-emitting element  120  is emitted without being blocked by the low-reflection layer  196  or the light-blocking stack  194 . Accordingly, the low-reflection layer  196  and the light-blocking stack  194  of the present disclosure are capable of being formed to be wider than the light-blocking unit  96  of the conventional polarizing plate by a predetermined width W, thereby preventing the occurrence of color mixing and a reduction in viewing angle. 
     The touch protective film  198  is formed on the substrate  111 , on which the touch sensor, the color filter  192 , the light-blocking stack  194 , and the low-reflection layer  196  have been formed, so as to expose the display pad  104  and the touch pad  170 . The touch protective film  198  prevents the touch sensor, the color filter  192 , the light-blocking stack  194 , and the low-reflection layer  196  from being damaged by external shocks or moisture. 
       FIG. 8  is a cross-sectional view showing a touch display device according to a second embodiment of the present disclosure. 
     The touch display device shown in  FIG. 8  includes the same components as the touch display device shown in  FIG. 4 , except that at least one of a light-blocking stack  194  or a low-reflection layer  196  is disposed on a routing line  160 . Thus, a description of the same components will be omitted. 
     The light-blocking stack  194  is disposed so as to overlap the bank  128  between color filters  192 . Further, the light-blocking stack  194  is disposed above the routing line  160  so as to overlap the routing line  160 . The light-blocking stack  194  serves to distinguish between the subpixel areas and to prevent optical interference and light leakage between adjacent subpixel areas. In addition, the light-blocking stack  194  is formed such that the reflectivity thereof has a single-digit percentage (%). As such, the light-blocking stack  194  absorbs external light, thereby reducing or minimizing deterioration in visibility and brightness. The light-blocking stack  194  is formed by stacking at least two light-blocking color layers  194   a  and  194   b , which realize different colors from each other. 
     As described above, the light-blocking stack  194  of the present disclosure is composed of at least two light-blocking color layers  194   a  and  194   b , rather than black resin. In this case, the present disclosure does not use a chemical solution (e.g., a developer), which is used to pattern black resin. Accordingly, in the present disclosure, the second touch pad electrode  174  does not react with a chemical solution (e.g., a developer), which is used to pattern black resin. Thus, it is possible to prevent corrosion of the second touch pad electrode  174 . 
     As shown in  FIG. 8 , since the low-reflection layer  196  is disposed on the light-blocking stack  194  so as to cover the top and side surfaces of the light-blocking stack  194 , the low-reflection layer  196  overlaps the routing line  160 , the touch electrodes  152   e  and  154   e , and the bridges  152   b  and  154   b . The low-reflection layer  196  is formed of a low -reflection material having reflectivity having a single-digit percentage (%). For example, the low-reflection layer  196  is formed in a single-layered or multi-layered structure using at least one of TiO x , CuN x , CuMg, CuS, AlON, AlTiN, MoTaO x , or MoTiON. Since the low-reflection layer  196  absorbs external light, it is possible to reduce or minimize deterioration in visibility and brightness. 
     Although the present disclosure has been described by exemplifying the mutual-capacitance-type touch sensor, which includes the touch-sensing line  154  and the touch-driving line  152  intersecting each other, with the touch insulating film  156  interposed therebetween, the present disclosure may also be applied to a self-capacitance-type touch sensor. Since each of a plurality of self-capacitance-type touch electrodes has electrically independent self-capacitance, it is used as a self-capacitance-type touch sensor, which senses variation in capacitance in response to a user touch. That is, the light-blocking stack  194  and the low-reflection layer  196  are disposed so as to overlap a plurality of self-capacitance-type touch electrodes and the routing line  160 . Accordingly, the light-blocking stack  194  and the low-reflection layer  196  absorb external light, thereby reducing or minimizing deterioration in visibility and brightness. 
     A touch display device according to various embodiments of the present disclosure may be described as follows. 
     The touch display device according to the present disclosure includes a light-emitting element disposed on a substrate, an encapsulation unit disposed on the light-emitting element, a plurality of touch electrodes disposed on the encapsulation unit, a light-blocking stack including at least two light-blocking color layers overlapping the plurality of touch electrodes, and a low-reflection layer disposed on the light-blocking stack. 
     In addition, the touch display device according to the present disclosure further includes red, green, and blue color filters overlapping the light-emitting element. 
     The at least two light-blocking color layers realize different colors from each other. 
     Specifically, a first embodiment of the at least two light-blocking color layers include a first light-blocking color layer formed of the same or substantially the same material as one of the red and green color filters, and a second light-blocking color layer disposed on the first light-blocking color layer and formed of the same or substantially the same material as the blue color filter. 
     A second embodiment of the at least two light-blocking color layers include a first light-blocking color layer formed of the same or substantially the same material as the red color filter, a second light-blocking color layer formed of the same or substantially the same material as the green color filter, and a third light-blocking color layer formed of the same or substantially the same material as the blue color filter. 
     The low-reflection layer is formed in a single-layered or multi-layered structure using at least one of TiO x , CuN x , CuMg, CuS, AlON, AlTiN, MoTaO x , or MoTiON. 
     In addition, the touch display device further includes a routing line connected to the touch electrodes and disposed along the side surface of the encapsulation unit, and a touch pad connected to the routing line. 
     In addition, the touch display device further includes a touch protective film disposed on the low-reflection layer and on the substrate in a region other than the region where the touch pad is located. For example, a touch protective film is on the low-reflection layer and on the substrate in a region spaced apart from the touch pad. 
     At least one of the light-blocking stack or the low-reflection layer overlaps the routing line. 
     As is apparent from the above description, in a touch display device according to the present disclosure, a light-blocking stack composed of at least two light-blocking color layers realizing different colors from each other and a low-reflection layer disposed on the light-blocking stack are formed so as to overlap at least one of a touch electrode formed of opaque metal, a bridge, or a routing line. Accordingly, it is possible to prevent external light from being reflected by the touch electrode, the bridge, and the routing line, and thus the present disclosure is capable of exhibiting low reflectivity. 
     In addition, the touch display device according to the present disclosure is capable of exhibiting low reflectivity without a separate polarizing plate, thereby reducing manufacturing costs and preventing a reduction in transmissivity. 
     It will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure without departing from the spirit or scope of the disclosure. Thus, it is intended that the present disclosure covers the modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalents. 
     The various embodiments described above can be combined to provide further embodiments. These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.