Touch sensor and window stack structure including the same and image display apparatus

Abstract

A touch sensor according to an embodiment of the present application includes a substrate layer, a bridge electrode provided on a top surface of the substrate layer, an auxiliary electrode provided around the bridge electrode to be physically spaced apart from the bridge electrode, first sensing electrodes electrically connected to each other via the bridge electrode, and second sensing electrodes electrically separated from the first sensing electrodes and arranged in a direction different from an arrangement direction of the first sensing electrodes. With the auxiliary electrode, resistance can be reduced and visual recognition of the bridge electrode can be suppressed.

Description

[0001] Cross-reference to related applications and priority claims

[0002] This application claims priority to Korean Patent Application No. 10-2019-0173843, filed on December 24, 2019, with the Korean Intellectual Property Office (KIPO), the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] This invention relates to a touch sensor and an image display device including the touch sensor. More specifically, this invention relates to a touch sensor including patterned sensing electrodes and an image display device including the touch sensor. Background Technology

[0004] With the development of information technology, there is an increasing demand for display devices that are thinner, lighter, and more energy efficient. These display devices can include flat panel displays such as liquid crystal displays (LCDs), plasma display panels (PDPs), electroluminescent displays, and organic light-emitting diode (OLEDs).

[0005] Touch panels or touch sensors have also been developed that allow users to input instructions by selecting commands displayed on the screen using their fingers or input tools. These touch panels or touch sensors can be integrated with display devices to enable both display and information input functions within a single electronic device.

[0006] In touch sensors, sensing electrodes formed of a conductive material, such as a metal used for touch sensing, can be arranged on a substrate. However, when a touch sensor is inserted into a display device, the image quality realized from the image display device may be degraded by the sensing electrodes. For example, the sensing electrodes may be visually identifiable to the user as interfering with the image.

[0007] Furthermore, low channel resistance of the sensing electrodes can be advantageous for achieving high-resolution and high-sensitivity touch sensing. Therefore, there is a need to construct sensing electrodes with improved optical properties to enhance the image quality and electrical characteristics of touch sensing.

[0008] For example, as disclosed in Korean Patent Application Publication No. 2014-0092366, various image display devices combined with touch screen panels including touch sensors have recently been developed. However, as mentioned above, there remains a need for touch sensors or touch panels with improved optical properties. Summary of the Invention

[0009] According to one aspect of the present invention, a touch sensor with improved optical properties and electrical reliability is provided.

[0010] According to an aspect of the present application, there is provided an image display apparatus including the touch sensor.

[0011] The above aspects of the present inventive concept will be achieved by the following features or configurations:

[0012] (1) A touch sensor comprising: a substrate layer; a bridge electrode disposed on a top surface of the substrate layer; an auxiliary electrode disposed around the bridge electrode to be physically spaced apart from the bridge electrode; first sensing electrodes electrically connected to each other via the bridge electrode; and second sensing electrodes electrically separated from the first sensing electrodes and arranged in a direction different from an arrangement direction of the first sensing electrodes.

[0013] (2) The touch sensor according to the above (1), wherein the auxiliary electrode comprises a first auxiliary electrode and a second auxiliary electrode, wherein the first sensing electrodes are superimposed on the first auxiliary electrode and the second sensing electrodes are superimposed on the second auxiliary electrode in a plan view.

[0014] (3) The touch sensor according to the above (2), wherein the first sensing electrodes comprise first etching regions therein and the second sensing electrodes comprise second etching regions therein.

[0015] (4) The touch sensor according to the above (3), wherein the auxiliary electrode has a mesh shape comprising unit cells gathered therein.

[0016] (5) The touch sensor according to the above (4), wherein the unit cells of the first auxiliary electrode are arranged to be offset from the first etching regions in a plan view, and the unit cells of the second auxiliary electrode are arranged to be offset from the second etching regions in a plan view.

[0017] (6) The touch sensor according to the above (4), further comprising separation electrodes arranged between the first auxiliary electrode and the second auxiliary electrode adjacent to each other.

[0018] (7) The touch sensor according to the above (6), wherein each of the separation electrodes has a fragment shape from one side of each of the unit cells.

[0019] (8) The touch sensor according to the above (2), wherein the first auxiliary electrode physically contacts the first sensing electrodes, and the second auxiliary electrode physically contacts the second sensing electrodes.

[0020] (9) The touch sensor according to the above (1), wherein the bridge electrode has a curved shape or a wavy shape.

[0021] (10) The touch sensor according to the above (9), wherein the auxiliary electrode has a mesh shape comprising unit cells gathered therein, and a side surface of the unit cells has a curved shape or a wavy shape.

[0022] (11) The touch sensor according to the above (1), wherein the auxiliary electrode has a mesh shape including unit cells gathered therein, and a side of the unit cell has the same shape or the same spatial frequency as the bridge electrode.

[0023] (12) The touch sensor according to the above (1), further comprising an insulating pattern partially covering the bridge electrode, wherein the first sensing electrodes and the second sensing electrodes are disposed on the auxiliary electrode, the bridge electrode, and the insulating pattern.

[0024] (13) The touch sensor according to the above (12), wherein the bridge electrode and the auxiliary electrode include a metal, and the first sensing electrodes and the second sensing electrodes include a multi-layer structure of a transparent conductive oxide layer and a metal layer.

[0025] (14) The touch sensor according to the above (1), further comprising an insulating pattern partially covering the second sensing electrodes, wherein the bridge electrode connects adjacent ones of the first sensing electrodes on the insulating pattern, and the auxiliary electrode is disposed on the first sensing electrodes and the second sensing electrodes.

[0026] (15) The touch sensor according to the above (14), wherein the bridge electrode and the auxiliary electrode include a metal, and the first sensing electrodes and the second sensing electrodes include a transparent conductive oxide.

[0027] (16) A window stack structure comprising: a window substrate; and a touch sensor according to the above embodiment, stacked on the window substrate.

[0028] (17) An image display apparatus comprising: a display panel; and a touch sensor according to the above embodiment, stacked on the display panel.

[0029] The touch sensor according to the embodiment of the present application can include an auxiliary electrode disposed around a bridge electrode. The auxiliary electrode can prevent the bridge electrode from being visually recognized by a user by shifting the optical environment around the bridge electrode to a spatial frequency environment including a high frequency component.

[0030] In an exemplary embodiment, the auxiliary electrode can directly contact the sensing electrode, and can function as a catalyst electrode that facilitates current flow through the bridge electrode. Accordingly, high sensitivity touch sensing can be provided by reducing channel resistance.

[0031] In an exemplary embodiment, an etching region can be included in the sensing electrode, and electrode visual recognition of the sensing electrode can be reduced or inhibited by the etching region. In a plan view, the auxiliary electrode can be disposed to be offset from the etching region. Accordingly, improved conductivity can be provided while inhibiting parasitic capacitance due to the addition of the auxiliary electrode. Attached Figure Description

[0032] Figure 1 This is a schematic cross-sectional view illustrating a touch sensor according to an exemplary embodiment.

[0033] Figures 2 to 4 This is a schematic top plan view illustrating the construction of the bridging electrode and auxiliary electrode of a touch sensor according to an exemplary embodiment.

[0034] Figure 5 This is a schematic top plan view illustrating the insulating pattern of a touch sensor according to an exemplary embodiment.

[0035] Figure 6 This is a schematic top plan view illustrating the construction of the sensing electrodes of a touch sensor according to an exemplary embodiment.

[0036] Figure 7 This is a schematic top plan view illustrating the arrangement of the first electrode, the first auxiliary electrode, and the bridging electrode according to an exemplary embodiment.

[0037] Figure 8 This is a schematic top plan view illustrating the arrangement of the second electrode and the second auxiliary electrode according to an exemplary embodiment.

[0038] Figure 9 This is a schematic top-view plan view illustrating a touch sensor according to an exemplary embodiment.

[0039] Figure 10 This is a schematic cross-sectional view illustrating a window stacking structure and an image display device according to an exemplary embodiment. Detailed Implementation

[0040] According to an exemplary embodiment of the present invention, a touch sensor is provided, which includes a sensing electrode, a bridging electrode, and an auxiliary electrode, and has reduced electrode visibility and improved conductivity and sensitivity. Furthermore, a window stacking structure and an image display device including the touch sensor are provided.

[0041] The invention will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that such embodiments described with reference to the drawings are provided to further understand the spirit of the invention and not to limit the subject matter to be protected as disclosed in the detailed description and the appended claims.

[0042] In the accompanying drawings, two directions parallel to the top surface of the touch sensor or substrate 100 and intersecting each other are defined as the first direction and the second direction. For example, the first direction and the second direction may be perpendicular to each other.

[0043] The terms "first", "second", "row direction", and "column direction" used herein are used to relatively designate different elements and directions crossing each other, not to indicate absolute order and direction.

[0044] Figure 1 is a schematic cross-sectional view illustrating a touch sensor according to an exemplary embodiment. For example, Figure 1 Examples of a touch sensor having a bottom bridge configuration are provided.

[0045] Referring to Figure 1 The touch sensor can include a bridge electrode 110, auxiliary electrodes 120 and 130, an insulating pattern 140, and sensing electrodes 150 and 160 on a base layer 100.

[0046] The base layer 100 can include a support layer or a film-type substrate for forming the above-described electrodes. For example, the base layer 100 can include a film material commonly used for a touch sensor. For example, the base layer 100 can include glass, a polymer, and / or an inorganic insulating material. The polymer can include, for example, a cyclic olefin polymer (COP), polyethylene terephthalate (PET), polyacrylate (PAR), polyetherimide (PEI), polyethylene naphthalate (PEN), polyphenylene sulfide (PPS), polyallylate (polyallylate), polyimide (PI), cellulose acetate propionate (CAP), polyether sulfone (PES), cellulose triacetate (TAC), polycarbonate (PC), cyclic olefin copolymer (COC), polymethyl methacrylate (PMMA), or the like. The inorganic insulating material can include, for example, silicon oxide, silicon nitride, silicon oxynitride, metal oxide, or the like.

[0047] In some embodiments, a layer or a film member in an image display apparatus to which the touch sensor is applied can also be used as the base layer 100. For example, an encapsulation layer or a passivation layer included in a display panel can be used as the base layer 100.

[0048] The bridge electrode 110 can be disposed on the base layer 100. The auxiliary electrodes 120 and 130 can be disposed on the base layer 100 together with the bridge electrode 110.

[0049] In an exemplary embodiment, the auxiliary electrodes 120 and 130 can be distributed to completely surround the bridge electrode 110, and can be physically spaced apart from the bridge electrode 110.

[0050] In some embodiments, the bridge electrode 110 and the auxiliary electrodes 120 and 130 can include a metal. For example, the bridge electrode 110 and the auxiliary electrodes 120 and 130 can include silver (Ag), gold (Au), copper (Cu), aluminum (Al), platinum (Pt), palladium (Pd), chromium (Cr), titanium (Ti), tungsten (W), niobium (Nb), tantalum (Ta), vanadium (V), iron (Fe), manganese (Mn), cobalt (Co), nickel (Ni), zinc (Zn), tin (Sn), molybdenum (Mo), calcium (Ca), or an alloy containing at least two of them (e.g., silver-palladium-copper (APC) or copper-calcium (CuCa)).

[0051] In one embodiment, the bridge electrode 110 and the auxiliary electrodes 120 and 130 can substantially consist of a metal layer. In this case, current flow can be facilitated, and channel resistance can be easily reduced through the bridge electrode 110 and the auxiliary electrodes 120 and 130.

[0052] Reference will be made later to FIGS. 2A and 2B. Figures 2 to 4 The arrangement and configuration of the bridge electrode 110 and the auxiliary electrodes 120 and 130 will be described in more detail.

[0053] The bridge electrode 110 can be partially covered by the insulating pattern 140. In some embodiments, the insulating pattern 140 can cover a portion other than both end portions (e.g., contact portions) of the bridge electrode 110.

[0054] The insulating pattern 140 can include an inorganic insulating material such as silicon dioxide or silicon nitride, or an organic insulating material such as an epoxy-based resin, an acrylic-based resin, a siloxane-based resin, or a polyimide-based resin.

[0055] The sensing electrodes 150 and 160 can be disposed on the bridge electrode 110 and the auxiliary electrodes 120 and 130. For example, the sensing electrodes 150 and 160 can be arranged to operate in a mutual capacitance type.

[0056] The first sensing electrodes 150 can be arranged along a first direction (e.g., a row direction or a width direction). Each first sensing electrode 150 can have an independent island-like pattern shape, and first sensing electrodes 150 adjacent in the first direction can be electrically connected to each other by the bridge electrode 110. For example, adjacent first sensing electrodes 150 can be electrically connected to each other by contact portions of the bridge electrode 110 exposed from the insulating pattern 140.

[0057] Accordingly, first sensing electrode rows extending in the first direction can be defined, and a plurality of first sensing electrode rows can be arranged along a second direction (e.g., a column direction or a length direction).

[0058] The second sensing electrodes 160 can be arranged along the second direction. Adjacent second sensing electrodes 160 in the second direction can be connected to each other by connection portions 167 (see FIG. 2B). The second sensing electrodes 160 and the connection portions 167 can be integrally connected to each other to be provided as substantially a single member. In this case, the second sensing electrodes 160 and the connection portions 167 can be formed by a same conductive layer through a patterning process, and can be located at a same layer or a same level. Figure 6 ) The second sensing electrodes 160 and the connection portions 167 can be integrally connected to each other to be provided as substantially a single member. In this case, the second sensing electrodes 160 and the connection portions 167 can be formed by a same conductive layer through a patterning process, and can be located at a same layer or a same level.

[0059] Thus, a second sensing electrode column extending in the second direction can be defined, and a plurality of second sensing electrode columns can be arranged along the first direction.

[0060] In some embodiments, the sensing electrodes 150 and 160 can contact the auxiliary electrodes 120 and 130. Thus, current flow can be facilitated by the auxiliary electrodes 120 and 130 to reduce channel resistance.

[0061] The shape and structure of the sensing electrodes 150 and 160 will be described in more detail later with reference to FIGS. 3A and 3B. Figure 6 The shape and structure of the sensing electrodes 150 and 160 will be described in more detail later with reference to FIGS. 3A and 3B.

[0062] In an exemplary embodiment, the sensing electrodes 150 and 160 can include a transparent conductive oxide to have enhanced transmittance. For example, the transparent conductive oxide can include indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium zinc tin oxide (IZTO), or cadmium tin oxide (CTO), etc. These can be used alone or in combination.

[0063] In some embodiments, the sensing electrodes 150 and 160 can include a multi-layer structure including a transparent conductive oxide layer and a metal layer. For example, the first and second electrode layers can each have a double-layer structure of a transparent conductive oxide-metal layer or a triple-layer structure of a transparent conductive oxide layer-metal layer-transparent conductive oxide layer. In this case, flexibility can be enhanced by the metal layer, and resistance can be reduced, so that signal transmission speed can also be improved. In addition, the transparent conductive oxide layer can enhance corrosion resistance and transparency.

[0064] The touch sensor can further include a passivation layer 160 covering the sensing electrodes 150 and 160. The passivation layer can include an organic insulating material such as an epoxy-based resin, an acrylic-based resin, a siloxane-based resin, a polyimide-based resin, etc., or an inorganic insulating material such as silicon oxide or silicon nitride.

[0065] As described above with reference to Figure 1 , the touch sensor can have a bottom bridge structure. Alternatively, the touch sensor can have a top bridge structure.

[0066] In this case, the sensing electrodes 150 and 160 can be formed on the base layer 100, and the insulating pattern 140 can be formed to cover the connection portion 167 included in the second sensing electrode 160. The bridge electrode 110 can electrically connect the adjacent first sensing electrodes 150 on the insulating pattern 140, and the auxiliary electrodes 120 and 130 can be distributed around the bridge electrode 110 and disposed on the sensing electrodes 150 and 160.

[0067] In the case of the touch sensor having the top bridge structure, the sensing electrodes 150 and 160 can include the transparent conductive oxide described above, and the bridge electrode 110 and the auxiliary electrodes 120 and 130 can include metal.

[0068] Hereinafter, the electrode structure / arrangement of the touch sensor will be described in more detail based on the touch sensor having the bottom bridge structure.

[0069] Figures 2 to 4 is a schematic top plan view illustrating a configuration of a bridge electrode and auxiliary electrodes of a touch sensor according to an exemplary embodiment. Specifically, Figure 2 The bridge electrode and the auxiliary electrodes are shown together. Figure 3 is a single top plan view of a first auxiliary electrode. Figure 4 is a single top plan view of a second auxiliary electrode.

[0070] Reference Figures 2 to 4 As described above, the bridge electrode 110 and the auxiliary electrodes 120 and 130 can be formed together on the top surface of the base layer 100.

[0071] For example, the bridge electrode 110 can have a curved shape or a wave shape. The auxiliary electrodes 120 and 130 can surround the bridge electrode 110, and can be physically separated from the bridge electrode 110.

[0072] The auxiliary electrodes 120 and 130 can have a mesh shape in which unit cells are gathered. In some embodiments, the unit cells can be arranged in a zigzag shape such that vertices of adjacent unit cells are offset or staggered. Accordingly, irregularity in the arrangement of the unit cells can be provided, such that a moire phenomenon due to overlapping with pixels included in a display panel below the touch sensor can be reduced.

[0073] Each side of the unit cell can have a curved shape or a wave shape. In an exemplary embodiment, each side of the unit cell can have substantially the same or similar shape as the bridge electrode 110.

[0074] According to an exemplary embodiment, the side of the unit cell can be formed to have the same spatial frequency as the bridge electrode 110.

[0075] The auxiliary electrodes 120 and 130 can include a first auxiliary electrode 120 and a second auxiliary electrode 130. The first auxiliary electrode 120 and the second auxiliary electrode 130 can be electrically and physically separated from each other.

[0076] As Figure 3 independently shown in

[0077] As Figure 4 independently shown in

[0078] As Figure 3 and Figure 4 shown, the division electrodes 125 and 135 having a fragment shape of one side of a cell can be arranged to surround the periphery of the first auxiliary electrode 120 and the second auxiliary electrode 130, and to be separated from each other between the first auxiliary electrode 120 and the second auxiliary electrode 130.

[0079] For example, the first division electrode 125 can be arranged to surround the periphery of the first auxiliary electrode 120. The second division electrode 135 can be arranged to surround the periphery of the second auxiliary electrode 130.

[0080] As described above, the auxiliary electrodes 120 and 130 including a side having substantially the same or similar spatial frequency or shape as the bridge electrode 110 can be disposed around the bridge electrode 110 including metal. Accordingly, the surrounding environment of the bridge electrode 110 can be filled with a high frequency component, and can be transferred to a spatial frequency range that cannot be visually recognized by a user. Accordingly, electrode visual recognition due to the bridge electrode 110 can be reduced or suppressed.

[0081] Figure 5 is a schematic top plan view showing an insulating pattern of a touch sensor according to an exemplary embodiment.

[0082] Referring to Figure 5 , the insulating pattern 140 can have substantially the same or similar shape as the bridge electrode 110. For example, the insulating pattern 140 can also have a curved shape or a wavy shape.

[0083] As described above, the insulating pattern 140 can expose both ends of the bridge electrode 110 and cover the bridge electrode 110.

[0084] Figure 6 is a schematic top plan view illustrating a configuration of sensing electrodes of a touch sensor according to an exemplary embodiment.

[0085] Reference Figure 6 As described with reference to Figure 1 , the touch sensor can include first sensing electrodes 150 and second sensing electrodes 160. The second sensing electrodes 160 can be integrally connected to each other along a second direction by connection portions 167. The first sensing electrodes 150 can be arranged to be spaced apart from each other in a first direction.

[0086] In an exemplary embodiment, etching regions 155 and 165 can be formed inside the sensing electrodes 150 and 160. The first etching regions 155 can be formed inside the first sensing electrodes 150, and the second etching regions 165 can be formed inside the second sensing electrodes 160.

[0087] The term "etching region" used in the present application can refer to a region or space removed by etching the inside of a conductive layer or a conductive pattern of a predetermined shape. In an exemplary embodiment, the etching region can have a shape such as a slit, a hole, or an opening.

[0088] In some embodiments, the etching regions 155 and 165 can be formed as slits having a curved or curvilinear shape. The curvilinear shape of the etching regions 155 and 165 can include a sinusoidal curve, a cosinusoidal curve, a conic curve, a catenary, a tractrix curve, a trochoid, a cycloid, a cardioid, etc.

[0089] The etching regions 155 and 165 can be regularly and repeatedly arranged. For example, the etching regions 155 and 165 can be arranged along the sides of an imaginary rectangle (e.g., an imaginary square).

[0090] As Figure 6 indicated, the etching regions 155 and 165 can have a shape in which a water wave corresponding to one period is divided between the vertices of an imaginary square. In one embodiment, the imaginary square can be arranged in a zigzag such that the vertices are offset or staggered.

[0091] The dummy pattern 170 can be formed between the first sensing electrodes 150 and the second sensing electrodes 160 adjacent to each other. The dummy pattern 170 can be defined by a separation region 172 extending along the periphery of the first sensing electrodes 150 and the second sensing electrodes 160. The separation region 172 can have substantially the same or similar waveforms as the first and second etching regions 155 and 165. Accordingly, the dummy pattern 170 can have a shape substantially the same or similar to the shape of the conductive pattern inside the sensing electrodes 150 and 160 (e.g., a quadrilateral having four sides converted into water waves).

[0092] In addition, the shape of the conductive pattern inside the sensing electrodes 150 and 160 can be similar to that of the unit cells included in the auxiliary electrodes 120 and 130 (see FIG. 1B). Thus, the uniformity of the electrode structure in the touch sensor can be improved, so that visual recognition of the electrodes by a user can be prevented due to local deviation of the pattern shape. Figure 2 and Figure 3 ) included in the auxiliary electrodes 120 and 130. Thus, the uniformity of the electrode structure in the touch sensor can be improved, so that visual recognition of the electrodes by a user can be prevented due to local deviation of the pattern shape.

[0093] According to the above-described exemplary embodiments, the etching regions 155 and 165 can be formed inside each of the sensing electrodes 150 and 160. Thus, the moire phenomenon caused by the regular overlap of the sensing electrodes 150 and 160 with the pixel structure included in the display panel can be prevented or reduced. For example, the spatial frequency generated by the overlap between the sensing electrodes 150 and 160 and the pixel structure can be suppressed or canceled by the etching regions 155 and 165.

[0094] In addition, the etching regions 155 and 165 can function as light slits, so that the moire phenomenon can be more effectively suppressed by light diffraction or scattering, and the sensing electrodes 150 and 160 can be prevented from being visually recognized by a user.

[0095] Figure 7 is a schematic top plan view illustrating an arrangement of a first electrode, a first auxiliary electrode, and a bridge electrode according to an exemplary embodiment.

[0096] Referring to Figure 7 In the plan view, the first sensing electrode 150 can be superimposed on the first auxiliary electrode 120. In the exemplary embodiment, the first sensing electrode 150 can contact the first auxiliary electrode 120. Thus, the first auxiliary electrode 120 can facilitate the current flow through the first sensing electrode 150, and can function as a catalyst electrode that can concentrate or facilitate the current flow through the bridge electrode 110.

[0097] In some embodiments, in the plan view, each side of the unit cell included in the first auxiliary electrode 120 can not overlap the first etching region 155 included in the first sensing electrode 150. For example, each side of the unit cell included in the first auxiliary electrode 120 can be offset or symmetrical to the first etching region 155. The first auxiliary electrode 120 can be arranged to avoid the first etching region 155, so that parasitic capacitance caused by the addition of the first auxiliary electrode 120 can be prevented without reducing the optical slit effect of the first etching region 155.

[0098] Figure 8 is a schematic top plan view illustrating an arrangement of a second electrode and a second auxiliary electrode according to an exemplary embodiment.

[0099] Referring to Figure 8In a plan view, the second sensing electrode 160 can be superimposed on the second auxiliary electrode 130. In an exemplary embodiment, the second sensing electrode 160 can contact the second auxiliary electrode 130. Accordingly, the second auxiliary electrode 130 can function as a catalyst electrode, which can facilitate the current flow through the second sensing electrode 160.

[0100] In some embodiments, in a plan view, each side of the unit cell included in the second auxiliary electrode 130 can not overlap the second etched region 165 included in the second sensing electrode 160. For example, each side of the unit cell included in the second auxiliary electrode 130 can be offset or symmetrical with the second etched region 165. The second auxiliary electrode 130 can be arranged to avoid the second etched region 165, such that parasitic capacitance caused by the addition of the second auxiliary electrode 130 can be prevented without reducing the optical slit effect of the second etched region 165.

[0101] Figure 9 FIG. 1 is a schematic top plan view illustrating a touch sensor according to an exemplary embodiment. Specifically, Figure 9 FIG. 1 is a schematic top plan view illustrating a touch sensor according to an exemplary embodiment. Specifically,

[0102] Reference will now be made in detail to Figure 9 As described above, the auxiliary electrodes 120 and 130 can contact the sensing electrodes 150 and 160 around the bridge electrode 110, and can be arranged to be offset from the etched regions 155 and 165.

[0103] Accordingly, the arrangement of the conductive patterns in a plan view of the touch sensor can be completely converted into a high frequency component that can not be recognized by a user, such that electrode visual recognition can be effectively suppressed.

[0104] Figure 10 FIG. 2 is a schematic cross-sectional view illustrating a window stack structure and an image display apparatus according to an exemplary embodiment.

[0105] Reference will now be made in detail to Figure 10 The window stack structure 250 can include the window substrate 230, the polarizing layer 210, and the touch sensor 200 according to an exemplary embodiment as described above.

[0106] The window substrate 230 can include, for example, a hard coat film. In one embodiment, a light-shielding pattern 235 can be formed on a peripheral portion of a surface of the window substrate 230. The light-shielding pattern 235 can include a color-printed pattern, and can have a single layer or a multi-layer structure. A bezel portion or a non-display area of the image display apparatus can be defined by the light-shielding pattern 235.

[0107] The polarizing layer 210 can include a coated polarizer or a polarizing plate. The coated polarizer can include a liquid crystal coating layer, which can include a liquid crystal compound that can be cross-linked and a dichroic dye. In this case, the polarizing layer 210 can include an alignment layer for providing orientation of the liquid crystal coating layer.

[0108] For example, the polarizing plate can include a polyvinyl alcohol-based polarizer and a protective film attached to at least one surface of the polyvinyl alcohol-based polarizer.

[0109] The polarizing layer 210 can be directly attached to a surface of the window substrate 230 or can be attached via the first adhesive layer 220.

[0110] The touch sensor 200 can be included in the window stack structure 250 as a film or a panel. In one embodiment, the touch sensor 200 can be combined with the polarizing layer 210 via the second adhesive layer 225.

[0111] As shown in FIG. 2B, from the viewer side, the window substrate 230, the polarizing layer 210, and the touch sensor 200 can be sequentially positioned. In this case, the sensing electrode of the touch sensor 200 can be disposed under the polarizing layer 210, so that the electrode pattern can be effectively prevented from being recognized by the viewer. Figure 10

[0112] If the touch sensor 200 includes a substrate, the substrate can include, for example, triacetyl cellulose, a cyclic olefin, a cyclic olefin copolymer, a polynorbornene copolymer, or the like, and preferably can have an in-plane retardation value of ±2.5 nm or less.

[0113] In one embodiment, the touch sensor 200 can be directly transferred to the window substrate 230 or the polarizing layer 210. In one embodiment, from the viewer side, the window substrate 230, the touch sensor 200, and the polarizing layer 210 can be sequentially positioned.

[0114] The image display apparatus can include a display panel 360 and the window stack structure 250 disposed on the display panel 360.

[0115] The display panel 360 can include a pixel electrode 310 disposed on a panel substrate 300, a pixel definition layer 320, a display layer 330, a counter electrode 340, and an encapsulation layer 350.

[0116] A pixel circuit including a thin film transistor (TFT) can be formed on the panel substrate 300, and an insulating layer covering the pixel circuit can be formed. The pixel electrode 310 can be electrically connected to a drain electrode of the TFT on the insulating layer, for example.

[0117] ​The pixel definition layer 320 may be formed on the insulating layer, and the pixel electrode 310 may be exposed through the pixel definition layer 320 to allow for the definition of pixel regions. The display layer 330 may be formed on the pixel electrode 310, and the display layer 330 may include, for example, a liquid crystal layer or an organic light-emitting layer.

[0118] A counter electrode 340 may be disposed on the pixel defining layer 320 and the display layer 330. The counter electrode 340 may be used as a common electrode or cathode, for example, in an image display device. An encapsulation layer 350 may be disposed on the counter electrode 340 to protect the display panel 360.

[0119] In some embodiments, the display panel 360 and the window stack structure 250 can be combined with each other via an adhesive layer 260. For example, the thickness of the adhesive layer 260 may be greater than the thickness of each of the first adhesive layer 220 and the second adhesive layer 225. The viscoelasticity of the adhesive layer 260 may be about 0.2 MPa or less in a temperature range of -20°C to 80°C. In this case, noise from the display panel 360 can be blocked, and interface stress during bending can be reduced, thus preventing damage to the window stack structure 250. In one embodiment, the viscoelasticity of the adhesive layer 260 may be in the range of about 0.01 MPa to about 0.15 MPa.

[0120] The touch sensor 200 may include an auxiliary electrode and a sensing electrode configuration according to the exemplary embodiments described above, which enables improved touch sensitivity while preventing degradation of image quality from the display panel 360.

[0121] Preferred embodiments are presented below to describe the invention in more detail. However, the following embodiments are given only to illustrate the invention, and those skilled in the art will clearly understand that various changes and modifications are possible within the scope and spirit of the invention. Such changes and modifications are formally included in the appended claims.

[0122] Example

[0123] A metal film (copper alloy film) is patterned on a COP substrate to form a structure such as... Figure 2 The diagram shows a bridging electrode and an auxiliary electrode with wavy lines. The bridging electrode and auxiliary electrode have a linewidth of 4 μm and a thickness of [missing information].

[0124] In addition, an acrylic insulating pattern is formed that partially covers the bridging electrode, and an ITO layer is deposited and patterned to form the first and second sensing electrodes (thickness: ), thus possessing Figure 6 and Figure 9 The shape is shown. Each linewidth of the etched region formed in the sensing electrode is 10 μm.

[0125] Comparative Example

[0126] A touch sensor was manufactured by the same method as in the example, except that the auxiliary electrode was omitted.

[0127] A current was applied to each of the touch sensors of the example and the comparative example to measure the parasitic capacitance, the resistance of the first sensing electrode, and the resistance of the second sensing electrode. The results are shown in Table 1.

[0128] [Table 1]

[0129] Parasitic capacitance (pF) Resistance of the first sensing electrode (Ω) Resistance of the second sensing electrode (Ω) Example 0.85 30.5 44.0 Comparative Example 0.84 58.8 78.5

[0130] Referring to Table 1, while the resistance of the sensing electrode was significantly reduced, the increase in parasitic capacitance due to the addition of the auxiliary electrode was substantially suppressed.

Claims

1. A touch sensor comprising: a base layer; a bridge electrode disposed on a top surface of the base layer; an auxiliary electrode disposed around the bridge electrode to be physically spaced apart from the bridge electrode, and the auxiliary electrode has a mesh shape including unit cells gathered therein; first sensing electrodes electrically connected to each other via the bridge electrode, and the first sensing electrodes include first etching regions therein; and second sensing electrodes electrically separated from the first sensing electrodes and arranged in a direction different from an arrangement direction of the first sensing electrodes, and the second sensing electrodes include second etching regions therein, wherein the auxiliary electrode includes a first auxiliary electrode contacting the first sensing electrodes and a second auxiliary electrode contacting the second sensing electrodes, wherein unit cells of the first auxiliary electrode are arranged to be offset from the first etching regions in a plan view, and unit cells of the second auxiliary electrode are arranged to be offset from the second etching regions in a plan view, and wherein the auxiliary electrode facilitates current flow through the bridge electrode. In a plan view, the first sensing electrodes are superimposed on the first auxiliary electrodes, and the second sensing electrodes are superimposed on the second auxiliary electrodes.

2. The touch sensor of claim 1, wherein, 3.The touch sensor of claim 1, further comprising separation electrodes arranged between the first auxiliary electrodes and the second auxiliary electrodes adjacent to each other. Each of the separation electrodes has a fragment shape from one side of each of the unit cells.

4. The touch sensor of claim 3, wherein, The bridge electrode has a curved shape.

5. The touch sensor of claim 1, wherein, The auxiliary electrode has a mesh shape including unit cells gathered therein, and sides of the unit cells have a curved shape.

6. The touch sensor of claim 5, wherein, The auxiliary electrode has a mesh shape including unit cells gathered therein, and sides of the unit cells have the same shape or the same spatial frequency as the bridge electrode.

7. The touch sensor of claim 1, wherein, 8.The touch sensor of claim 1, further comprising an insulating pattern partially covering the bridge electrode, the first sensing electrodes and the second sensing electrodes are disposed on the auxiliary electrode, the bridge electrode, and the insulating pattern. wherein The bridge electrode and the auxiliary electrode include a metal, and the first sensing electrodes and the second sensing electrodes include a multi-layer structure of a transparent conductive oxide layer and a metal layer.

9. The touch sensor of claim 8, wherein, 10.The touch sensor of claim 1, further comprising an insulating pattern partially covering the second sensing electrodes, the bridge electrode connects adjacent first sensing electrodes among the first sensing electrodes on the insulating pattern, and the auxiliary electrode is disposed on the first sensing electrodes and the second sensing electrodes. wherein The bridge electrode and the auxiliary electrode include a metal, and the first sensing electrodes and the second sensing electrodes include a transparent conductive oxide.

11. The touch sensor of claim 10, wherein, 12.A window stack structure comprising: a window substrate; and the touch sensor of claim 1 stacked on the window substrate. 13.An image display apparatus comprising: a display panel; and the touch sensor of claim 1. ​ ​ The touch sensor according to claim 1 is stacked on the display panel.

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