CN211015464U

CN211015464U - Touch sensor, window stack structure including the same, and image display device

Info

Publication number: CN211015464U
Application number: CN202020137839.0U
Authority: CN
Inventors: 李喆勋; 梁珍福
Original assignee: Dongwoo Fine Chem Co Ltd
Current assignee: Dongwoo Fine Chem Co Ltd
Priority date: 2019-01-28
Filing date: 2020-01-21
Publication date: 2020-07-14
Anticipated expiration: 2030-01-21
Also published as: CN111488085A; WO2020159120A1; KR20200093280A; KR102526899B1

Abstract

A touch sensor, comprising: a substrate layer; first sensing electrodes arranged in a row direction on a substrate layer, each of the first sensing electrodes including protrusions at both ends thereof; a second sensing electrode arranged in a column direction on the substrate layer, the second sensing electrode including connection portions at both ends thereof, the second sensing electrode being integrally connected with the connection portions in the column direction; and a bridge electrode electrically connected to the projections adjacent in the row direction. The protrusions are spaced about the connecting portion to face each other, and the connecting portion includes a recess. A window stack structure and an image display device including the touch sensor are also provided.

Description

Touch sensor, window stack structure including the same, and image display device

Technical Field

The utility model relates to a touch sensor, including its window stacked structure and image display device. More particularly, the present invention relates to a touch sensor including a plurality of conductive layers, and a window stack structure and an image display device including the same.

Background

The display device may include a flat panel display device such as a liquid crystal display (L CD) device, a Plasma Display Panel (PDP) device, an electro-luminescence display device, an organic light emitting diode (O L ED) display device, and the like.

A touch panel or a touch sensor capable of inputting a user's instruction by selecting an instruction displayed on a screen with a finger or an input tool has also been developed. The touch panel or the touch sensor may be combined with a display device so that display and information input functions can be implemented in one electronic apparatus.

The touch sensor includes a sensing electrode for converting a touch input from a user into an electrical signal by a capacitance change. The sensing electrode is disposed in a display region of the image display device, and thus when a user recognizes the sensing electrode, the quality of an image realized from the image display device may be degraded.

For example, as disclosed in korean patent application publication No. 2014-0092366, various image display devices combined with a touch screen panel including a touch sensor have recently been developed. However, a configuration of the sensing electrode for preventing recognition of the sensing electrode without degrading electrical performance and sensitivity of the touch sensor is required.

Disclosure of Invention

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

According to an aspect of the present invention, there is provided an image display device including a touch sensor having improved optical and electrical properties.

According to an aspect of the present invention, there is provided a window stack structure including a touch sensor having improved optical and electrical properties.

The above aspects of the present invention are to be achieved by the following features or configurations:

(1) a touch sensor, comprising: a substrate layer; first sensing electrodes arranged in a row direction on the substrate layer, each of the first sensing electrodes including protrusions at both ends thereof; second sensing electrodes arranged in a column direction on the substrate layer, the second sensing electrodes including connection portions at both ends thereof, the second sensing electrodes being integrally connected with the connection portions in the column direction; and a bridge electrode electrically connected to the protrusions adjacent in the row direction, wherein the protrusions are spaced apart with respect to the connection portion to face each other, and the connection portion includes a recess.

(2) The touch sensor according to the above (1), wherein the protrusion is inserted into the recess.

(3) The touch sensor according to the above (2), wherein the connection portion includes: a first portion adjacent to both ends of the second sensing electrode; and a second portion having a reduced width relative to a width of the first portion due to the recess.

(4) The touch sensor according to the above (3), wherein a length of the concave portion in the column direction is in a range of 70 μm to 200 μm.

(5) The touch sensor according to the above (3), wherein the width of the second portion is in a range of 50 μm to 150 μm.

(6) The touch sensor according to the above (1), further comprising an insulating layer at least partially covering the first and second sensing electrodes on the substrate layer.

(7) The touch sensor according to the above (6), wherein the bridge electrode intersects the recess on the insulating layer.

(8) The touch sensor according to the above (7), wherein the bridge electrode is formed through the insulating layer to directly contact the protrusion of the first sensing electrode.

(9) The touch sensor according to the above (1), wherein the corner portions of the protrusions and the connecting portions have a rounded shape.

(10) The touch sensor according to the above (1), wherein a corner of the bridge electrode has a shape of a rounded corner.

(11) A window stack structure comprising: a window substrate; and the touch sensor according to any one of the above (1) to (10), the touch sensor being on the window substrate.

(12) The window stack-up structure of (11) above, further comprising a polarizing layer between the window substrate and the touch sensor or on the touch sensor.

(13) An image display apparatus comprising: a display panel; and the touch sensor according to any one of the above (1) to (10), the touch sensor being on the display panel.

In the touch sensor according to the exemplary embodiments of the present invention, the pattern shape in the intersection region of, for example, the column direction sensing electrode and the row direction sensing electrode may be changed, so that the electrode recognition or visibility at the intersection region due to the overlapping of the electrode patterns may be prevented.

In some embodiments, the pattern shape may include a rounded portion so that electrode recognition may be further prevented.

Drawings

Fig. 1 is a schematic top plan view showing an example of an electrode arrangement in a capacitance type touch sensor.

Fig. 2 and 3 are a top plan view and a cross-sectional view, respectively, illustrating an intersection area of a touch sensor according to an exemplary embodiment.

Fig. 4 is a top plan view illustrating an intersection area of a touch sensor according to some example embodiments.

Fig. 5 is a schematic cross-sectional view illustrating a window stack structure and an image display device according to an exemplary embodiment.

Fig. 6 and 7 are graphs showing the results of measuring the channel resistance according to the width of the connection portion.

Fig. 8 is a graph illustrating the result of measuring the channel resistance according to the length of the recess included in the connection portion.

Detailed Description

According to an exemplary embodiment of the present invention, there is provided a touch sensor including protrusions and recesses at intersection regions of sensing electrodes, so that electrode visibility may be suppressed. Further, an image display device including the touch sensor is provided.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. However, it should be understood by those skilled in the art that such embodiments described with reference to the accompanying drawings are provided for further understanding of the spirit of the present invention and do not limit the claimed subject matter as disclosed in the detailed description and the appended claims.

The terms "row direction" and "column direction" as used herein are used to relatively designate two directions crossing each other, and do not denote absolute directions.

Referring to fig. 1, the touch sensor includes, for example, a first sensing electrode 50 and a second sensing electrode 60 disposed on a substrate layer 100.

The substrate layer 100 may include a support layer, an insulating interlayer, and a film type substrate for forming the

sensing electrodes

50 and 60. For example, the substrate layer 100 may include a film material commonly used in touch sensors. For example, the substrate layer 100 may include glass, polymer, and/or inorganic insulating materials. The polymer may include, for example, 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), Polyethersulfone (PES), cellulose Triacetate (TAC), Polycarbonate (PC), Cyclic Olefin Copolymer (COC), Polymethylmethacrylate (PMMA), and the like. The inorganic insulating material may include, for example, an oxide of silicon, a nitride of silicon, silicon oxynitride, a metal oxide, or the like.

In some embodiments, a layer or a film member in an image display device to which the touch sensor is applied may also be used as the substrate layer 100. For example, an encapsulation layer or a passivation layer included in the display panel may be used as the substrate layer 100.

The first sensing electrode 50 and the second sensing electrode 60 may be arranged along two different crossing directions. For example, the first sensing electrodes 50 may be arranged along a row direction (or X direction) of the upper surface of the substrate layer 100. The second sensing electrodes 60 may be arranged along a column direction (or Y direction) of the upper surface of the substrate layer 100.

The second sensing electrodes 60 adjacent in the column direction may be connected to each other through a connection portion 65. The connection portion 65 may be integrally connected to the second sensing electrode 60, and may be substantially provided as an integral member.

The plurality of second sensing electrodes 60 may be integrally connected to each other by connection portions 65 to define a second sensing electrode column. The plurality of second sensing electrode columns may be arranged along the row direction.

Each of the first sensing electrodes 50 may have an independent island pattern shape. The first sensing electrodes 50 adjacent in the row direction may be electrically connected to each other via the bridge electrode 55.

Thus, a first sensing electrode row including a plurality of first sensing electrodes 50 connected to each other via the bridge electrode 55 may be defined. The plurality of first sensing electrode rows may be arranged along a column direction.

The first and

second sensing electrodes

50 and 60, and/or the bridge electrode 55 may include a transparent conductive oxide, such as Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), zinc oxide (ZnO), Indium Zinc Tin Oxide (IZTO), Cadmium Tin Oxide (CTO), etc., or a transparent conductive material, such as silver nanowire (AgNW), Carbon Nanotube (CNT), graphene, metal mesh, conductive polymer, etc.

In some embodiments, the bridge electrode 55 may include a metal such as 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), molybdenum (Mo), calcium (Ca), or an alloy thereof.

In some embodiments, the first and

second sensing electrodes

50 and 60 and/or the bridging electrode 55 may include a stacked structure of transparent conductive oxide layers and metal layers.

In some embodiments, the bridge electrode 55 may be formed to include a low resistance metal to reduce channel resistance through the first row of sense electrodes. In some embodiments, the first and

second sensing electrodes

50 and 60 may include a transparent conductive oxide as described above to improve transmittance of the touch sensor.

A trace may extend from each of the first row and the second column of sense electrodes. For example, a first trace 70 may extend from each first sensing electrode row and a second trace 80 may extend from each second sensing electrode column.

The ends of the first and

second traces

70, 80 can be collected into a bonding area allocated at one end of the substrate layer 100. The end portion may be bonded to a Flexible Printed Circuit Board (FPCB) through, for example, an Anisotropic Conductive Film (ACF). The touch sensor driving IC chip may be electrically connected to the first and

second traces

70 and 80 via a flexible printed circuit board.

The first and

second traces

70 and 80 may 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), molybdenum (Mo), calcium (Ca), or an alloy thereof (e.g., silver-palladium-copper (APC)). These may be used alone or in combination.

In a plan view, the bridge electrode 55 and the connection portion 65 may overlap and cross each other at an intersection area C indicated by a dotted circle in fig. 1. As shown in fig. 3, the bridge electrode 55 and the connection portion 65 may face each other with respect to the insulating layer 120 interposed therebetween.

Therefore, for example, interface reflection due to the difference in refractive index between layers increases, and a color sensation difference may be caused in the intersection region C, and thus electrode recognition by a user may be caused.

Fig. 2 and 3 are a top plan view and a cross-sectional view, respectively, illustrating an intersection area of a touch sensor according to an exemplary embodiment. Specifically, fig. 3 is a cross-sectional view taken along line I-I' of fig. 2 in the thickness direction.

Referring to fig. 2 and 3, as described with reference to fig. 1, the first sensing electrodes 110 may be physically spaced apart from each other with respect to the connection portions 135 integrally connected to the second sensing electrodes 130. The bridge electrode 115 may overlap and cross the connection portion 135 on the insulating layer 120 in a plan view.

In an exemplary embodiment, the protrusions 112 may be formed at both ends of the first sensing electrode 110 in the row direction. The protrusions 112 of the adjacent first sensing electrodes 110 may be spaced apart to face each other in the row direction.

The second sensing electrodes 130 may be integrally connected to each other via connection portions 135 formed at both ends of the second sensing electrodes 130 in the column direction. In an exemplary embodiment, the connection portion 135 may include a recess 132 that may be recessed in a row direction.

As shown in fig. 2, a pair of concave portions 132 facing each other in the row direction may be formed in one connecting portion 135. The connecting portion 135 may include a central portion having a width reduced by the recess 132.

For example, the connection portion 135 may include a first portion 135a and a second portion 135 b. The first portion 135a may include both ends of the connection portion 135 directly connected to the second sensing electrode 130. The second portion 135b may include a portion narrowed by the recess 132. In an exemplary embodiment, a pair of first portions 135a may be connected to both ends of the second portion 135 b.

In some embodiments, the protrusion 112 included in the first sensing electrode 110 may be inserted into the recess 132 included in the connection portion 135 of the second sensing electrode 130. A pair of protrusions 112 adjacent in the row direction may face each other with respect to the connection portion 135 or the second portion 135 b.

The insulating layer 120 may at least partially cover the first and

second sensing electrodes

110 and 130. The bridge electrode 115 may be formed on the insulating layer 120 to electrically connect the first sensing electrodes 110 adjacent in the row direction.

As shown in fig. 3, the bridge electrode 115 may include a contact portion 115a that may be formed through the insulating layer 120 and may contact the first sensing electrode 110. In an exemplary embodiment, the contact portion 115a included in the bridge electrode 115 may directly contact the top surface of the protrusion 112 of the first sensing electrode 110.

A passivation layer 140 covering the bridge electrode 115 may be formed on the insulating layer 120. The insulating layer 120 and the passivation layer 140 may include an organic insulating material such as a siloxane resin, an acrylic resin, or the like, or an inorganic insulating material such as silicon oxide, silicon nitride, silicon oxynitride, or the like.

As described above, the electrode occupying area at the intersection region C shown in fig. 1 may be reduced by the protrusion 112 of the first sensing electrode 110 and the recess 132 or the second portion 135b of the second sensing electrode 130. Therefore, electrode visibility caused at the intersection region C can be reduced or avoided.

In addition, the length of the bridge electrode 115 may be reduced by reducing the distance between the protrusions 112 using the recesses 132. Therefore, electrode visibility due to overlapping of electrode layers can be suppressed or reduced.

The area of the first portion 135a may be relatively increased in the connection portion 135 to prevent the channel resistance in the second sensing electrode column from being excessively increased by the second portion 135 b.

Therefore, the area or size of the electrode overlapping in the intersection region C can be reduced to suppress electrode visibility, while preventing channel resistance from increasing to maintain an appropriate signal transmission rate.

Referring again to fig. 2, the width (b) of the second portion 135b of the connection portion 135 may be less than the width (a) of the first portion 135a of the connection portion 135. In some embodiments, the width (width in the row direction) (b) of the second portion 135b of the connection portion 135 may be about 50 to 150 μm. For example, if the width of the second portion 135b is less than about 50 μm, the channel resistance of the second sensing electrode column may excessively increase. If the width of the second portion 135b exceeds about 150 μm, the above-described effect of preventing the visibility of the electrode may be difficult to achieve, and the effect of reducing the channel resistance may be reduced. In one embodiment, the width of the second portion 135b may be about 50 μm to about 100 μm.

In some embodiments, the length (length in the column direction) (c) of the recess 132 may be about 70 μm to about 200 μm. If the length of the recess 132 is less than about 70 μm, the width of the protrusion 112 may also be excessively reduced, thereby increasing the channel resistance of the first sensing electrode row. Further, a sufficient gap may not be obtained between the protrusion 112 and the connection portion 135, thereby causing mutual signal interference.

If the length of the recess 132 exceeds about 200 μm, the length of the second sensing electrode column may excessively increase, resulting in an increase in channel resistance.

Preferably, the length of the recess 132 may be about 100 μm to about 200 μm.

Referring to fig. 4, the corner of the protrusion 113 included in the first sensing electrode 110 and the recess 132 formed in the connection portion 137 of the second sensing electrode 120 may have a rounded shape. Therefore, the corners of the first and

second portions

137a and 137b in the connection portion 137 may also have a rounded shape.

The corners of the electrodes are rounded so that the recognition or visibility of the electrodes due to abrupt pattern profile changes can be further prevented. In addition, with the introduction of the rounded profile, a moire phenomenon caused by overlapping with electrodes and lines of a display panel on which the touch sensor is mounted may be reduced.

In some embodiments, the corners of the bridge electrodes 117 may also be rounded, so that prevention of electrode recognition and moire may be more effectively achieved.

Referring to fig. 5, according to the exemplary embodiment as described above, the window stack structure 250 may include the window substrate 230, the polarizing layer 210, and the touch sensor 200.

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

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

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

The polarizing layer 210 may be directly attached to the surface of the window substrate 230, or may be attached via the first adhesive layer 220.

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

As shown in fig. 5, the window substrate 230, the polarizing layer 210, and the touch sensor 200 may be sequentially positioned from the viewer side. In this case, the electrode layer of the touch sensor 200 may be disposed under the polarizing layer 210, so that it is possible to effectively prevent a viewer from recognizing the electrode pattern. As described above, electrode recognition can be further prevented by the electrode structure at the intersection region C.

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

The image display apparatus may include a display panel 360 and a window stack structure 250 disposed on the display panel 360.

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.

A pixel circuit including a Thin Film Transistor (TFT) may be formed on the panel substrate 300, and an insulating layer covering the pixel circuit may be formed. The pixel electrode 310 may be electrically connected to, for example, a drain electrode of a TFT on the insulating layer.

The pixel defining layer 320 may be formed on the insulating layer, and the pixel electrode 310 may be exposed through the pixel defining layer 320, so that a pixel region may be defined. 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.

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

In some embodiments, the display panel 360 and the window stack structure 250 may be bonded to each other by the adhesive layer 260. For example, the thickness of the adhesive layer 260 may be greater than each of the thicknesses of the first adhesive layer 220 and the second adhesive layer 225. The viscoelasticity of the adhesive layer 260 may be about 0.2MPa or less at a temperature ranging from-20 ℃ to 80 ℃. In this case, noise from the display panel 360 may be blocked, and interface stress when bent may be relieved, so that damage to the window stack structure 250 may be avoided. In one embodiment, the viscoelasticity of the adhesive layer 260 may be in a range of about 0.01MPa to about 0.15 MPa.

Hereinafter, preferred embodiments are presented to more specifically describe the present invention. However, the following examples are given only for illustrating the present invention, and it will be clearly understood by those skilled in the relevant art that these examples are not limited to the appended claims, but various changes and modifications may be made within the scope and spirit of the present invention. Such changes and modifications are properly included in the appended claims.

Experimental example 1:measuring channel resistance according to the width of the connection portion (second portion)

A first sensing electrode and a second sensing electrode, each having a size of 4mm × mm, are formed on a COP substrate, the second sensing electrode is integrally connected by a connection portion, and a recess is formed such that the connection portion includes a second portion having a reduced width, as shown in FIG. 2.

Specifically, contact holes having a size of 30 μm × 30 μm are formed through the insulating layer, a conductive layer filling the contact holes is formed on the insulating layer, and then patterned to form bridge electrodes.

Channel resistances of the first sensing electrode row and the second sensing electrode column of the touch sensor manufactured as described above are measured.

Specifically, fig. 6 shows that when the bridge electrode is formed of ITO having a sheet resistance of 40 μ/□ to have a width of 60 μm (the width (a) of the first portion included in the connection portion of the second sensing electrode is fixed to 250 μm, and the length (c) of the recess is fixed to 90 μm), the channel resistance varies according to the variation of the width (b) of the second portion. Fig. 7 shows the variation of channel resistance under the same conditions as fig. 6 except that the bridge electrode is formed of a metal having a sheet resistance of 0.2 Ω/□ to have a width of 4 μm.

Referring to fig. 6 and 7, the channel resistance (x resistance) through the first sensing electrode row is kept constant, and the channel resistance (y resistance) through the second sensing electrode column has a gradually decreasing tendency.

Experimental example 2: measuring channel resistance according to length of recess

Fig. 8 is a graph showing the result of measuring the channel resistance according to the length of the concave portion included in the connection portion.

Specifically, the sensing electrode and the ITO bridge electrode were formed to have the same material and size as those of experimental example 1. When the width (a) of the first portion was fixed to 250 μm and the width (b) of the second portion was fixed to 75 μm, the change in channel resistance was measured from the change in the length (c) of the concave portion. The width of the protrusion included in the first sensing electrode is increased at the same rate of changing the length of the recess.

Referring to fig. 8, when the length of the recess is increased to more than about 70 μm, the decrease and increase in resistance by the first and second sensing electrodes are balanced, so that the increase in the total resistance is suppressed. When the length of the recess is about 100 μm or more, the total resistance is maintained substantially constant.

As described with reference to fig. 6 to 8, an increase in channel resistance is prevented by adjusting the sizes of the connection portions and the recesses, while also preventing visibility of the electrodes.

Claims

1. A touch sensor, comprising:

a substrate layer;

first sensing electrodes arranged in a row direction on the substrate layer, each of the first sensing electrodes including protrusions at both ends thereof;

second sensing electrodes arranged in a column direction on the substrate layer, the second sensing electrodes including connection portions at both ends thereof, the second sensing electrodes being integrally connected with the connection portions in the column direction; and

bridge electrodes electrically connected to the protrusions adjacent in the row direction,

wherein the protrusions are spaced apart with respect to the connection portion to face each other, and the connection portion includes a recess.

2. The touch sensor of claim 1, wherein the protrusion is inserted into the recess.

3. The touch sensor according to claim 2, wherein the connection portion comprises:

a first portion adjacent to both ends of the second sensing electrode; and

a second portion having a reduced width relative to a width of the first portion due to the recess.

4. The touch sensor according to claim 3, wherein a length of the concave portion in the column direction is in a range of 70 μm to 200 μm.

5. The touch sensor of claim 3, wherein the width of the second portion is in a range of 50 μm to 150 μm.

6. The touch sensor of claim 1, further comprising an insulating layer at least partially covering the first and second sense electrodes on the substrate layer.

7. The touch sensor of claim 6, wherein the bridge electrode intersects the recess on the insulating layer.

8. The touch sensor of claim 7, wherein the bridge electrode is formed through the insulating layer to directly contact the protrusion of the first sensing electrode.

9. The touch sensor according to claim 1, wherein the corner of the protrusion and the connection portion have a rounded shape.

10. The touch sensor of claim 1, wherein corners of the bridge electrodes have a rounded shape.

11. A window stack, comprising:

a window substrate; and

the touch sensor of claim 1, on the window substrate.

12. The window stack-up of claim 11, further comprising a polarizing layer between the window substrate and the touch sensor or on the touch sensor.

13. An image display apparatus, comprising:

a display panel; and

the touch sensor of claim 1, the touch sensor being on the display panel.