Touch sensor and image display apparatus including the same

Abstract

A touch sensor according to an embodiment of the present application includes a substrate layer, sensing electrodes arranged on a top surface of the substrate layer, the sensing electrodes having a plurality of protrusions connected in a boundary of the sensing electrodes, and dummy electrodes provided between the sensing electrodes, the dummy electrodes having a plurality of protrusions connected in a boundary of the dummy electrodes. The sensing electrodes include first sensing electrodes arranged in a column direction and second sensing electrodes arranged in a row direction. A radius of curvature of the protrusions in an area in which the first sensing electrodes, the second sensing electrodes, and the dummy electrodes are adjacent to each other is smaller than a radius of curvature of the protrusions in other areas.

Description

[0001] Cross-reference and priority statement of related applications

[0002] This application claims priority to Korean Patent Application No. 10-2020-0008795, filed on January 22, 2020, 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, the demand for display devices with thinner dimensions, lighter weight, and higher power efficiency is increasing. Display devices can include flat panel display devices, such as liquid crystal display (LCD) devices, plasma display panel (PDP) devices, electroluminescent display devices, organic light-emitting diode (OLED) display devices, etc.

[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, enabling display and information input functions to be combined into a single electronic device.

[0006] In touch sensors, sensing electrodes made of a conductive material such as metal can be arranged on a substrate for touch sensing. 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 recognized by the user, thereby interfering with the image.

[0007] Therefore, there is a need for the construction of sensing electrodes that have improved optical and visual properties while maintaining the desired electrical properties for touch sensing.

[0008] For example, as disclosed in Korean Patent Application Publication No. 2014-0092366, various image display devices incorporating touchscreen panels including touch sensors have recently been developed. However, there is a growing need for touch sensors or touch panels with improved optical and visual characteristics. Summary of the Invention

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

[0010] According to one aspect of the present invention, an image display device including a touch sensor is provided.

[0011] The above-mentioned aspects of the present invention will be achieved through the following features or constructions:

[0012] (1) A touch sensor, comprising: a substrate layer; a sensing electrode disposed on a top surface of the substrate layer, the sensing electrode having a boundary in which a plurality of protrusions are connected; and a dummy electrode disposed between the sensing electrodes, the dummy electrode having a boundary in which a plurality of protrusions are connected, wherein the sensing electrode includes a first sensing electrode disposed in a column direction and a second sensing electrode disposed in a row direction, and the radius of curvature of the protrusions in the region where the first sensing electrode, the second sensing electrode and the dummy electrode are adjacent to each other is smaller than the radius of curvature of the protrusions in the region where only two of the first sensing electrode, the second sensing electrode and the dummy electrode are adjacent to each other.

[0013] (2) The touch sensor according to (1) above further includes: a first partition region that separates the first sensing electrode and the second sensing electrode from each other; a second partition region that separates the first sensing electrode and the dummy electrode from each other; and a third partition region that separates the second sensing electrode and the dummy electrode from each other.

[0014] (3) The touch sensor according to (2) above, wherein the protrusion includes: a first protrusion formed in the intersection region of the first partition region, the second partition region and the third partition region; and a second protrusion defined only by the first partition region, the second partition region or the third partition region.

[0015] (4) According to the touch sensor described in (3) above, wherein the radius of curvature of the first protrusion is smaller than the radius of curvature of the second protrusion.

[0016] (5) The touch sensor according to (4) above, wherein the radius of curvature of the first protrusion is less than 0.05.

[0017] (6) The touch sensor according to (1) above, wherein the dummy electrode includes: a first dummy electrode disposed between the first sensing electrode and the second sensing electrode which are adjacent to each other; and a second dummy electrode surrounded by the four sensing electrodes of the sensing electrodes.

[0018] (7) The touch sensor according to (6) above, wherein the second dummy electrode has an X-shape.

[0019] (8) The touch sensor according to (1) above, wherein the boundary between the sensing electrode and the dummy electrode has an amorphous wavy shape.

[0020] (9) The touch sensor according to (1) above further includes a floating electrode formed inside each of the sensing electrodes.

[0021] (10) The touch sensor according to (9) above, wherein the boundary of the floating electrode has an amorphous wavy shape.

[0022] (11) According to the touch sensor described in (1) above, the boundary of the sensing electrode is defined by setting an assembly of imaginary square cells, the side of the imaginary square cells is deformed into a wavy shape, and the area where the vertex of the cell is located is located at the boundary of the assembly.

[0023] (12) The touch sensor according to (1) above, wherein the first sensing electrode includes a plurality of first sensing electrodes and the second sensing electrode includes a plurality of second sensing electrodes, wherein the touch sensor further includes: a bridge electrode that electrically connects the plurality of first sensing electrodes adjacent to each other in the column direction; and a connection portion that integrally connects the plurality of second sensing electrodes adjacent to each other in the row direction.

[0024] (13) A window stack structure, comprising: a window substrate; and a touch sensor according to the above embodiment, the touch sensor being stacked on the window substrate.

[0025] (14) An image display device, comprising: a display panel; and a touch sensor according to the embodiments described above, the touch sensor being stacked on the display panel.

[0026] In a touch sensor according to an embodiment of the present invention, the periphery of the sensing electrode can be formed such that multiple protrusions can be connected, and the periphery may include protrusions with different radii of curvature. Dummy electrodes with a periphery having a random wavy shape may be included between adjacent sensing electrodes.

[0027] The periphery of the sensing electrode can be formed into a substantially random shape, thereby preventing electrode visibility and moiré phenomena caused by the regular repetition of the electrode pattern.

[0028] In an exemplary embodiment, the protrusion of the sensing electrode adjacent to the end of the dummy electrode may have a small radius of curvature. Therefore, electrode visual recognition occurring at the intersection between the sensing electrode and the dummy electrode can be further reduced. Attached Figure Description

[0029] Figure 1 and Figure 2 These are schematic cross-sectional views and schematic top plan views illustrating a touch sensor according to an exemplary embodiment.

[0030] Figure 3 This is a partially enlarged top plan view illustrating the electrode configuration of a touch sensor according to an exemplary embodiment.

[0031] Figure 4 This is a partially enlarged top view of a touch sensor according to an exemplary embodiment.

[0032] Figure 5 This is a schematic cross-sectional view illustrating a window stacking structure and an image display device according to an exemplary embodiment.

[0033] Figure 6 This is a partially enlarged top view used to describe the method of forming the boundary between the sensing electrode and the dummy electrode in the embodiments.

[0034] Figure 7 This is a partially enlarged top view showing the construction of the radius of curvature in the embodiment. Detailed Implementation

[0035] According to an exemplary embodiment of the present invention, a touch sensor is provided, which includes a sensing electrode and a dummy electrode, and has improved visual characteristics while preventing electrode recognition. Furthermore, a window stacking structure including the touch sensor and an image display device are provided.

[0036] The invention will now be described in detail 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 do not limit the subject matter to be protected as disclosed in the detailed specification and appended claims.

[0037] In the accompanying drawings, two directions parallel to the top surface of the touch sensor or substrate layer 100 and intersecting each other are defined as the first direction and the second direction. For example, the first direction and the second direction can be perpendicular to each other.

[0038] The terms “first,” “second,” “row direction,” and “column direction” used here are used to specify different elements and directions that intersect each other in a relative way, rather than to indicate an absolute order and direction.

[0039] Figure 1 and Figure 2 These are schematic cross-sectional views and schematic top plan views illustrating a touch sensor according to an exemplary embodiment, respectively. For example, Figure 1An example of a touch sensor with a top bridge configuration is provided.

[0040] refer to Figure 1 and Figure 2 The touch sensor may include a substrate layer 100 and sensing electrodes 110 and 120 disposed on the substrate layer 100.

[0041] The substrate layer 100 may include a film-type member serving as a base layer for forming the sensing electrodes 110 and 120 or for objects on which the sensing electrodes 110 and 120 are formed. In some embodiments, the substrate layer 100 may refer to a display panel on which the sensing electrodes 110 and 120 are formed directly.

[0042] For example, substrate layer 100 may include substrate or film materials commonly used in touch sensors. For example, substrate layer 100 may comprise glass, polymers, and / or inorganic insulating materials. Polymers may include, for example, cyclic olefin polymers (COP), polyethylene terephthalate (PET), polyacrylate (PAR), polyetherimide (PEI), polyethylene naphthalate (PEN), polyphenylene sulfide (PPS), polyallyl compounds, polyimide (PI), cellulose acetate propionate (CAP), polyethersulfone (PES), cellulose triacetate (TAC), polycarbonate (PC), cyclic olefin copolymers (COC), polymethyl methacrylate (PMMA), etc. Inorganic insulating materials may include, for example, silicon oxide, silicon nitride, silicon oxynitride, metal oxides, etc.

[0043] In some embodiments, the layer or film component in the image display device that incorporates a touch sensor can also be used as the substrate layer 100. For example, an encapsulation layer or passivation layer included in the display panel can be used as the substrate layer 100.

[0044] Sensing electrodes 110 and 120 may include a first sensing electrode 110 and a second sensing electrode 120. For example, sensing electrodes 110 and 120 may be arranged to operate in a mutual capacitance type.

[0045] The first sensing electrodes 110 may be arranged along a first direction (e.g., column direction or length direction). Each first sensing electrode 110 may have an independent island pattern shape, and the first sensing electrodes 110 adjacent to each other along the first direction may be electrically connected to each other via bridge electrodes 140.

[0046] Therefore, a first sensing electrode array extending along a first direction can be defined, and multiple first sensing electrode arrays can be arranged along a second direction.

[0047] The second sensing electrode 120 can be arranged along a second direction. Adjacent second sensing electrodes 120 along the second direction can be connected to each other via a connecting portion 125. The second sensing electrode 120 and the connecting portion 125 can be integrally connected to each other to be substantially a single component. In this case, the second sensing electrode 120 and the connecting portion 125 can be formed by patterning the same conductive layer and can be located on the same layer or at the same level.

[0048] Therefore, a second row of sensing electrodes extending along the second direction can be defined, and multiple rows of second sensing electrodes can be arranged along the first direction.

[0049] An insulating layer 130 covering the sensing electrodes 110 and 120 can be formed on the substrate layer 100. A bridge electrode 140 can be provided on the insulating layer 130 to electrically connect adjacent first sensing electrodes 110 to each other through, for example, a contact region 145 formed in the insulating layer 130.

[0050] A passivation layer 160 covering the bridge electrode 140 can be formed on the insulating layer 130.

[0051] The insulating layer 130 and / or the passivation layer 160 may contain inorganic insulating materials, such as silicon oxide or silicon nitride; or organic insulating materials, such as epoxy resins, acrylic resins, siloxane resins, polyimide resins, etc.

[0052] A dummy electrode 150 may be provided between adjacent sensing electrodes 110 and 120. The dummy electrode 150 may be located on the same layer or at the same level as the sensing electrodes 110 and 120 (e.g., on the top surface of the substrate layer 100).

[0053] The dummy electrode 150 may include: a first dummy electrode 152 disposed between the sides of the first sensing electrode 110 and the second sensing electrode 120 which are adjacent to each other; and a second dummy electrode 154 surrounded by four sensing electrodes 110 and 120 which are adjacent to each other. For example, the second dummy electrode 154 may have a generally X-shaped design.

[0054] In an exemplary embodiment, sensing electrodes 110 and 120, bridge electrode 140, and dummy electrode 150 may each comprise a transparent conductive oxide. For example, the transparent conductive oxide may include indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium zinc tin oxide (IZTO), cadmium tin oxide (CTO), etc. These may be used individually or in combination.

[0055] In some embodiments, sensing electrodes 110 and 120, bridge electrode 140, and dummy electrode 150 may comprise metals. For example, sensing electrodes 110 and 120, bridge electrode 140, and dummy electrode 150 may comprise 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 alloys comprising at least one of them (e.g., silver-palladium-copper (APC) or copper-calcium (CuCa)).

[0056] In some embodiments, sensing electrodes 110 and 120, bridge electrode 140, and dummy electrode 150 may have a multilayer structure including a transparent conductive oxide layer and a metal layer. For example, sensing electrodes 110 and 120, bridge electrode 140, and dummy electrode 150 may each have a two-layer structure of a transparent conductive oxide layer-metal layer or a three-layer structure of a transparent conductive oxide layer-metal layer-transparent conductive oxide layer. In this case, the metal layer can enhance flexibility and reduce resistance, thereby also improving signal transmission speed. Furthermore, the transparent conductive oxide layer can enhance corrosion resistance and transparency.

[0057] Figure 1 An example of a top-bridge type touch sensor is shown, but the touch sensor can have a bottom-bridge structure. In this case, bridge electrodes 140 can be formed on substrate layer 100, and an insulating layer 130 including contact holes that partially expose bridge electrodes 140 can be formed on bridge electrodes 140. Sensing electrodes 110 and 120 and a dummy electrode 150 can be formed on insulating layer 130, and first sensing electrodes 110 adjacent to each other can be electrically connected to each other through contact holes via bridge electrodes 140.

[0058] Figure 3 This is a partially enlarged top plan view illustrating the electrode structure of a touch sensor according to an exemplary embodiment. Specifically, Figure 3 This is an enlarged top view showing the sensing electrodes 110 and 120 around the bridge electrode 140 of the touch sensor and the dummy electrode 150.

[0059] Reference Figure 3 The periphery or boundary of sensing electrodes 110 and 120 may have a substantially amorphous wavy shape. As used in this application, the term "amorphous" refers to a shape that deviates from a regular shape in which a particular waveform repeats regularly with a constant period.

[0060] In an exemplary embodiment, the boundaries of sensing electrodes 110 and 120 and the dummy electrode 150 may each have an amorphous, wavy shape. Therefore, visual electrode recognition due to the regular repetition of electrode boundaries can be prevented. Additionally, moiré patterns arising from the regular overlap of the pixel structure of the display panel on which the touch sensor is mounted can be effectively prevented.

[0061] The first sensing electrode 110, the second sensing electrode 120, and the dummy electrode 150 can be separated by a partition region to define each boundary. For example... Figure 3 As shown, the first sensing electrode 110 and the second sensing electrode 120 can be separated from each other through the first separating region S1. The first sensing electrode 110 and the dummy electrode 150 can be separated from each other through the second separating region S2. The second sensing electrode 120 and the dummy electrode 150 can be separated from each other through the third separating region S3.

[0062] The boundaries of sensing electrodes 110 and 120 may be formed by a plurality of protrusions connected to each other. In an exemplary embodiment, sensing electrodes 110 and 120 may include protrusions with different radii of curvature.

[0063] The protrusion may include a first protrusion C1 and a second protrusion C2. The first protrusion C1 may be a protrusion included in the sensing electrodes 110 and 120 in the region in which the first sensing electrode 110, the second sensing electrode 120 and the dummy electrode 150 are adjacent to each other.

[0064] For example, the first protrusion C1 can be a protrusion of the sensing electrodes 110 and 120 at the intersection of the first separation region S1, the second separation region S2 and the third separation region S3.

[0065] The second protrusion C2 may be a protrusion defined only by the first dividing region S1, the second dividing region S2, or the third dividing region S3.

[0066] In an exemplary embodiment, the radius of curvature of the first protrusion C1 may be smaller than the radius of curvature of the second protrusion C2. For example, the radius of curvature (R) of the first protrusion C1 may be less than 0.05, and the radius of curvature (R) of the second protrusion C2 may be greater than 0.05.

[0067] In some embodiments, the radius of curvature of the first protrusion C1 can be from 0.01 to 0.03, and the radius of curvature of the second protrusion C2 can be from 0.05 to 0.2.

[0068] As described above, the dummy electrode 150 may further include a protrusion along the contour of the first dividing region S2 and the second dividing region S3. The radius of curvature of the protrusion of the dummy electrode 150 at the intersection of the dividing regions S1, S2 and S3 may also be smaller than the radius of curvature of the other protrusions.

[0069] As described above, the radius of curvature of the convex portion at the intersection of the separating regions S1, S2, and S3 can be relatively reduced. Therefore, the convex portion can adequately fill the intersection region to reduce the blank space generated in the intersection region. Thus, visual electrode recognition caused by differences in reflectivity and refractive index in the intersection region can be suppressed.

[0070] Alternatively, a dummy electrode 150 can be added to the space between the first sensing electrode 110 and the second sensing electrode 120, thereby reducing the space without conductive material and effectively suppressing the visual recognition of the electrodes.

[0071] Figure 4 This is a partially enlarged top plan view illustrating a touch sensor according to an exemplary embodiment. References are omitted herein. Figures 1 to 3 A detailed description of the components and structures that are substantially the same or similar.

[0072] refer to Figure 4 Floating electrodes 117 and 127 can be formed inside the sensing electrodes 110 and 120. The first floating electrode 117 can be disposed inside the first sensing electrode 110, and the second floating electrode 127 can be disposed inside the second sensing electrode 120.

[0073] For example, the first sensing electrode 110 and the first floating electrode 117 can be separated and spaced apart from each other by a fourth separating region S4 formed in the first sensing electrode 110. The second sensing electrode 120 and the second floating electrode 127 can be separated and spaced apart from each other by a fifth separating region S5 formed in the second sensing electrode 120.

[0074] Floating electrodes 117 and 127 can be used as regulating electrodes for the capacitance generated by sensing electrodes 110 and 120. For example, the capacitance generated by sensing electrodes 110 and 120 can be finely adjusted by adjusting the area of ​​floating electrodes 117 and 127.

[0075] In some embodiments, the boundaries of the floating electrodes 117 and 127 may also have an amorphous wavy shape including protrusions with different radii of curvature. Therefore, the floating electrodes 117 and 127 can further prevent Moiré phenomena.

[0076] Figure 5 This is a schematic cross-sectional view illustrating a window stacking structure and an image display device according to an exemplary embodiment.

[0077] refer to Figure 5 According to the exemplary embodiment described above, the window stack structure 250 may include a window substrate 230, a polarizing layer 210, and a touch sensor 200.

[0078] The window substrate 230 may include, for example, a hard coating. In one embodiment, a light-shielding pattern 235 may be formed on a peripheral portion of the surface of the window substrate 230. The light-shielding pattern 235 may include a color-printed pattern and may have a single-layer or multi-layer structure. The bezel portion or non-display area of ​​the image display device may be defined by the light-shielding pattern 235.

[0079] The polarizing layer 210 may include a coated polarizer or a polarizing plate. The coated polarizer may include a liquid crystal coating, which may contain a crosslinkable liquid crystal compound and a dichroic dye. In this case, the polarizing layer 210 may include an alignment layer for providing orientation of the liquid crystal coating.

[0080] For example, a polarizing plate may include a polyvinyl alcohol polarizer and a protective film attached to at least one surface of the polyvinyl alcohol polarizer.

[0081] The polarizing layer 210 can be directly attached to the surface of the window substrate 230, or it can be attached via the first adhesive layer 220.

[0082] The touch sensor 200 may be included as a film or panel in the window stack structure 250. In one embodiment, the touch sensor 200 may be bonded to the polarizing layer 210 via a second adhesive layer 225.

[0083] refer to Figure 5 The window substrate 230, polarizing layer 210, and touch sensor 200 can be positioned sequentially from the viewer's side. In this case, the sensing electrodes of the touch sensor 200 can be disposed below the polarizing layer 210, thereby effectively preventing the viewer from recognizing the electrode pattern.

[0084] If the touch sensor 200 includes a substrate, the substrate may contain, for example, triacetyl cellulose, cyclic olefins, cyclic olefin copolymers, polynorbornene copolymers, etc., and preferably, may have an in-plane delay value of ±2.5 nm or less.

[0085] In one embodiment, the touch sensor 200 can be directly transferred to the window substrate 230 or the polarizing layer 210. In another embodiment, the window substrate 230, the touch sensor 200, and the polarizing layer 210 can be positioned sequentially from the viewer's side.

[0086] The image display device may include a display panel 360 and a window stacking structure 250 disposed on the display panel 360.

[0087] The display panel 360 may include a pixel electrode 310, a pixel defining layer 320, a display layer 330, an opposite electrode 340, and an encapsulation layer 350 disposed on the panel substrate 300.

[0088] Pixel circuits including thin-film transistors (TFTs) can be formed on the panel substrate 300, and an insulating layer covering the pixel circuits can be formed. Pixel electrodes 310 can be electrically connected to, for example, the drain of a TFT on the insulating layer.

[0089] A pixel defining layer 320 can be formed on the insulating layer, and the pixel electrode 310 can be exposed through the pixel defining layer 320, thereby defining a pixel area. A display layer 330 can 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.

[0090] An opposite electrode 340 may be provided on the pixel defining layer 320 and the display layer 330. The opposite electrode 340 may be used as a common electrode or cathode, for example, in an image display device. An encapsulation layer 350 may be provided on the opposite electrode 340 to protect the display panel 360.

[0091] In some embodiments, the display panel 360 and the window stack structure 250 can be bonded to each other via an adhesive layer 260. For example, the thickness of the adhesive layer 260 can be greater than the thickness of each of the first adhesive layer 220 and the second adhesive layer 225. At temperatures ranging from -20°C to 80°C, the viscoelasticity of the adhesive layer 260 can be about 0.2 MPa or less. In this case, noise from the display panel 360 can be blocked, and interface stress during bending can be reduced, thereby preventing damage to the window stack structure 250. In one embodiment, the viscoelasticity of the adhesive layer 260 can be in the range of about 0.01 MPa to about 0.15 MPa.

[0092] The touch sensor 200 may include dummy electrodes and sensing electrodes having shapes and configurations according to the exemplary embodiments described above. Therefore, improved visual characteristics can be achieved while minimizing degradation of image quality from the display panel 360.

[0093] Preferred embodiments are presented below to describe the invention in more detail. However, the following examples are given merely to illustrate the invention, and those skilled in the art will clearly understand that various changes and modifications can be made within the scope and spirit of the invention. Such changes and modifications are appropriately included in the appended claims.

[0094] Example

[0095] Figure 6 This is a partially enlarged top view used to describe the method of forming the boundary between the sensing electrode and the dummy electrode in the embodiments. Figure 7 This is a partially enlarged top view showing the construction of the radius of curvature in the embodiment.

[0096] refer to Figure 6 Set up square cells 50, each side of which is converted into water waves (e.g., sine waves). Assemble cells 50 horizontally such that the vertices of the cells are offset or staggered in a zigzag configuration to form an initial boundary through the periphery of the assembled cells.

[0097] Subsequently, as shown by the dashed circle, the corners of each vertex of cell 50 were rounded. The initial rounded boundaries of the assembly can be defined as the boundaries of sensing electrodes 110 and 120, as shown in the reference... Figure 2 and Figure 3 As stated above.

[0098] Specifically, the metal film (APC alloy film, thickness: ) deposited on a COP substrate, and via a reference Figure 6 The described boundary determination method involves etching a metal film to form separated regions. Therefore, with... Figure 3 The shapes shown form a first sensing electrode, a second sensing electrode, and a dummy electrode.

[0099] As in Figure 7 As shown, the radius of curvature of the first protrusion C1 at the intersection of the first dividing region to the third dividing regions S1, S2 and S3 is 0.02, and the radius of curvature of the second protrusion C2 defined only by the first dividing region S1 is 0.06.

[0100] Comparative example

[0101] The touch sensor sample was manufactured using the same method as in the embodiment, except that the radii of curvature of the first protrusion C1 and the second protrusion C2 were both 0.05.

[0102] Experimental Example

[0103] Touch sensor samples from the examples and comparative examples were laminated onto display panel test samples obtained from commercially available mobile display products. The width direction of the display panel test sample was set to 0°, and then the touch sensor sample was tilted while changing the angle clockwise. Moiré patterns were observed based on the tilt angle, and the level of moiré pattern generation was evaluated on a five-level scale from level 0 (minimum moiré pattern) to level 5 (maximum moiré pattern).

[0104] Specifically, the contrast and period of the generated moiré pattern are observed through 10 panels to select a level, and the level values ​​are averaged to evaluate the level of moiré pattern generation.

[0105] The level of moiré pattern formation is evaluated based on the following criteria.

[0106] i) Level 0: No moiré pattern detected

[0107] ii) Level 1: Low contrast / high frequency (approximately 0-1mm moiré period)

[0108] iii) Level 2: Low contrast / medium frequency (approximately 2-3 mm moiré period)

[0109] iv) Level 3: Low contrast / low frequency (approximately 4-5 mm moiré period)

[0110] v) Level 4: Medium contrast / medium frequency (approximately 2-3 mm moiré period)

[0111] vi) Level 5: Medium contrast / low frequency (approximately 4-5mm moiré period)

[0112] In addition, the touch sensor samples of the embodiments and comparative examples were observed through 10 panels, and the electrode visual recognition score was rated from 0 (electrode not recognized) to 10 (electrode shape clearly visible). The average score of the 10 panels was used to evaluate the visibility of the electrodes.

[0113] [Table 1]

[0114] Moirée evaluation Electrode visibility evaluation Example Level 3 5 Comparative example Level 4 6

[0115] Referring to Table 1, in embodiments where the radius of curvature of the first protrusion is relatively reduced, the moiré effect and electrode visual recognition are effectively suppressed.

Claims

1. A touch sensor, comprising: Substrate layer; A sensing electrode is disposed on the top surface of the substrate layer, and a plurality of protrusions are connected in the boundary of the sensing electrode. The sensing electrode includes a first sensing electrode arranged in the column direction and a second sensing electrode arranged in the row direction. A dummy electrode is disposed between the sensing electrodes, and multiple protrusions are connected to the boundary of the dummy electrode. A first dividing region separates the first sensing electrode and the second sensing electrode from each other, wherein the first dividing region does not include the dummy electrode; A second partition region separates the first sensing electrode and the dummy electrode from each other; as well as A third dividing region separates the second sensing electrode and the dummy electrode from each other. The plurality of protrusions include: A first protrusion is formed in the intersection region of the first dividing region, the second dividing region, and the third dividing region; and The second protrusion is defined only by each of the first dividing region, the second dividing region, and the third dividing region. Wherein, the radius of curvature of the first protrusion is smaller than the radius of curvature of the second protrusion, and The outermost boundaries of the sensing electrode and the dummy electrode have an amorphous wavy shape.

2. The touch sensor according to claim 1, wherein, The radius of curvature of the first protrusion is less than 0.

05.

3. The touch sensor according to claim 1, wherein, The dummy electrode includes: A first dummy electrode is disposed between the first sensing electrode and the second sensing electrode, which are adjacent to each other; and The second dummy electrode is surrounded by the four sensing electrodes among the sensing electrodes.

4. The touch sensor according to claim 3, wherein, The second dummy electrode has an X-shape.

5. The touch sensor of claim 1, further comprising a floating electrode formed inside each of the sensing electrodes.

6. The touch sensor according to claim 5, wherein, The boundary of the floating electrode has an amorphous wavy shape.

7. The touch sensor according to claim 1, wherein, The boundary of the sensing electrode is defined by setting up an assembly of imaginary square cells, the sides of which are deformed into a wavy shape, and the rounded corners of the vertices of the cells are located at the boundary of the assembly.

8. The touch sensor according to claim 1, wherein, The first sensing electrode includes a plurality of first sensing electrodes, and the second sensing electrode includes a plurality of second sensing electrodes. The touch sensor further includes: Bridge electrodes, wherein the bridge electrodes electrically connect adjacent first sensing electrodes in the column direction of the plurality of first sensing electrodes; and A connecting portion integrally connects adjacent second sensing electrodes among the plurality of second sensing electrodes in the row direction.

9. A window stacking structure, comprising: Window substrate; and The touch sensor according to claim 1 is stacked on the window substrate.

10. An image display device, comprising: Display panel; and The touch sensor according to claim 1 is stacked on the display panel.

Images