WO2016104003A1

WO2016104003A1 - Touch panel

Info

Publication number: WO2016104003A1
Application number: PCT/JP2015/082619
Authority: WO
Inventors: 横山　崇; 中村　一男; 奥村　健治; 聖子平井
Original assignee: 日本写真印刷株式会社
Priority date: 2014-12-26
Filing date: 2015-11-19
Publication date: 2016-06-30
Also published as: JP2016126471A

Abstract

[Problem] To achieve low retardation in a touch panel wherein an intermediate substrate film is arranged between electrodes. [Solution] A touch panel 1 that is provided with a first transparent electrode 15, a second transparent electrode 17, a first intermediate substrate film 19, and a second intermediate substrate film 21. The second transparent electrode 17 is arranged so as to face the first transparent electrode 15. The first intermediate substrate film 19 and the second intermediate substrate film 21 are arranged between the first transparent electrode 15 and the second transparent electrode 17 and achieve low resistance as a result of the combined arrangement of the slow axes A, B thereof.

Description

Touch panel

The present invention relates to a touch panel.

Conventionally, PDAs, portable terminals such as handy terminals, OA devices such as copy machines, facsimiles, smartphones, mobile phones, portable game devices, electronic dictionaries, car navigation systems, small PCs, digital cameras, video cameras, portable MDs (PMD) In many cases, a touch panel is used for a liquid crystal display window of an electronic device. Among several types of touch panels, it has a multi-touch function that enlarges and reduces images by tapping, flipping, and picking the screen with your fingertips, and it has excellent visibility and durability. The popularity of touch panels is high.

An example of a capacitive touch panel is described in Patent Document 1. In Patent Document 1, the touch panel is realized as a capacitive film sensor 30 that is disposed on the liquid crystal display window of the above-described electronic device and adhered to the back surface of the cover panel 12 having translucency that functions as a dielectric. ing.
In 3rd Embodiment of patent document 1, the film sensor 30 is laminated | stacked on the other side of the base film 32, the 1st electrode part 40 formed on the surface 32a of the base film 32, and the base film 32. And the second electrode part 45 formed on the surface 33a of the another base film 33.

JP 2013-214173 A

Since the cover panel is generally thick, it is necessary to ensure a long distance between the electrodes in order to improve the sensor sensitivity of the touch panel. Therefore, an intermediate base film may be further provided between the two base films of the film sensor. For such an intermediate substrate film, a material having a low retardation or a high retardation is used for improving the visibility when using polarized sunglasses. On the other hand, since the intermediate base film is highly rigid when the thickness for increasing the sensitivity is increased by using a material having high retardation, for example, a UV curable adhesive is used for bonding the base materials. Will be used. This is to reduce the mixing of bubbles in the bonded portion of the high-rigidity touch panel, and to allow the substrates to be bonded to each other in a touch panel having a curved surface, for example. Thus, when the thickness is further increased using a material having a high retardation, the adhesive material is limited.
When a low retardation material is used, since the thickness between the electrodes is set large as described above, it is difficult to realize low retardation as a result.
The inventors of the present invention have sought the cause of the above problem and devised an invention for solving the problem as follows.

An object of the present invention is to realize low retardation in a touch panel in which an intermediate base film is disposed between electrodes.

Hereinafter, a plurality of modes will be described as means for solving the problem. These aspects can be arbitrarily combined as necessary.

A touch panel according to an aspect of the present invention includes a first detection electrode, a second detection electrode, and a plurality of resin films. The second detection electrode is disposed to face the first detection electrode. A resin film is arrange | positioned between a 1st detection electrode and a 2nd detection electrode, and implement | achieves low retardation by combining arrangement | positioning of slow axes. The number of resin films is not particularly limited. Moreover, the combination of arrangement | positioning of slow axis will not be specifically limited if low retardation is realizable.
In this touch panel, low retardation is realized by combining the arrangement of slow axes of a plurality of resin films. Further, by providing a plurality of resin films, it is possible to realize a reduction in rigidity compared to the case of providing a single resin film.

The retardation of the plurality of resin films may be 250 nm or less.

The plurality of resin films may have two resin films whose slow axes are orthogonal to each other.

In the touch panel according to the present invention, low retardation of the intermediate substrate film is realized.

The typical block diagram of the touch panel of 1st Embodiment. The typical perspective view which shows the slow axis of an intermediate | middle base film. The typical block diagram of the touch panel of 2nd Embodiment. The typical perspective view which shows the slow axis of an intermediate | middle base film.

1. First Embodiment An embodiment of a capacitive touch panel according to a first embodiment will be described with reference to FIG. FIG. 1 is a schematic configuration diagram of a touch panel according to a first embodiment.
The touch panel 1 according to an aspect of the present invention includes a first transparent electrode 15 (an example of a first detection electrode), a second transparent electrode 17 (an example of a second detection electrode), and a first intermediate base film 19 (resin An example of a film) and a second intermediate substrate film 21 (an example of a resin film).
Specifically, the touch panel 1 includes the cover panel 3 and the above-described configuration (first transparent electrode 15, second transparent electrode 17, first intermediate substrate film 19 and second intermediate substrate film) attached to the back surface thereof. 21). The film sensor 5 may be either a self-capacitance (Self Capacitance) method or a mutual capacitance (Mutual Capacitance) method.

For the cover panel 3, a cover glass made of a glass plate or a plastic cover made of a plastic plate is usually used. Examples of the resin used for the plastic plate include polymethyl methacrylate (PMMA), polycarbonate, cyclic olefin polymer, alicyclic methacrylate, HEMA hydroxyethyl methacrylate (PHEMA), etc. Then, the thermoplastic resin which hardens is mentioned. In addition, thermosetting resins that chemically change into a net-like molecular structure by heat, such as diethylene glycol diallyl carbonate (ADC) and siloxanyl methacrylate (SiMA), and photo-curing resins that cure at room temperature with ultraviolet rays or the like may be used. it can. Among these, PMMA and PC are generally well known as representative examples of transparent plastics used for optics. PMMA is excellent in transparency, birefringence, which is an optical distortion, is small, and PC has high heat resistance.
The cover panel 3 has a thickness in the range of 500 μm to 2000 μm.

The film sensor 5 is affixed to the back side of the cover panel 3. In the present embodiment, the first adhesive layer 7 is provided on the back surface of the cover panel 3. For example, a transparent optical adhesive is used for the first adhesive layer 7. An example of this is a pressure sensitive adhesive (hereinafter referred to as “PSA”). The material of the first adhesive layer 7 is, for example, acrylic, silicone, epoxy adhesive, or urethane adhesive.
The second base film 13 is disposed so as to face the first base film 11. Specifically, the first base film 11 is disposed on the cover panel 3 side, and the second base film 13 is disposed away from the cover panel 3.

The first transparent electrode 15 is formed on the first base film 11. Specifically, the first transparent electrode 15 has a conductor arranged in a predetermined pattern on the surface of the first base film 11. The second transparent electrode 17 is formed on the second base film 13. The second transparent electrode 17 has a conductor disposed in a predetermined pattern on the surface of the second base film 13. The first transparent electrode 15 and the second transparent electrode 17 are connected to the detection circuit 51.
The first intermediate substrate film 19 and the second intermediate substrate film 21 are disposed between the first transparent electrode 15 and the second transparent electrode 17. The first intermediate base film 19 and the second intermediate base film 21 achieve low retardation by combining the arrangement of the slow axes. The number of resin films is not particularly limited. Moreover, the combination of arrangement | positioning of slow axis will not be specifically limited if low retardation is realizable.

In this touch panel 1, low retardation is realized by combining the arrangement of slow axes of a plurality of resin films. Specifically, the low retardation value is 0 nm to 250 nm, and preferably 100 nm or less. More preferably, the retardation value is 10 nm or less. As an example, a retardation value of 6 nm can be realized by combining two base films having a retardation value of 100 nm.
Further, by providing a plurality of resin films, it is possible to realize a reduction in rigidity compared to the case of providing a single resin film. For example, the flexural modulus is preferably 1.5 GPa or less, more preferably 1.0 GPa or less.

More specifically, as shown in FIG. 2, the slow axis A of the first intermediate substrate film 19 and the slow axis B of the second intermediate substrate film 21 are orthogonal to each other in plan view. FIG. 2 is a schematic perspective view showing a slow axis of the intermediate base film. Here, the orthogonality includes ranges of 90 degrees and 90 degrees ± several degrees. Note that both slow axes may cross each other so as to form another angle instead of being orthogonal.
The first intermediate substrate film 19 and the second intermediate substrate film 21 may be formed by being divided from the same substrate film. In that case, the properties unique to the base film are leveled.
However, the first intermediate base film and the second intermediate base film may be manufactured from different base films, respectively.
The thickness of the first intermediate substrate film 19 and the second intermediate substrate film 21 may be the same or different.

As materials for the first base film 11, the second base film 13, the first intermediate base film 19, and the second intermediate base film 21, transparent polyester (PET), polyimide (PI), and polyether are used. Films such as sulfone (PES), polyether ether ketone (PEEK), polycarbonate (PC), polypropylene (PP), polyamide (PA), polyacryl (PAC), norbornene-based thermoplastic transparent resin, or their lamination The body is used. A cycloolefin polymer (COP) and a cycloolefin copolymer (COC) can also be used.
The thicknesses of the first base film 11, the second base film 13, the first intermediate base film 19 and the second intermediate base film 21 are in the range of 25 μm to 500 μm.

The material of the first transparent electrode 15 and the second transparent electrode 17 preferably exhibits a light transmittance (translucency) of 80% or more and a surface resistance value (conductivity) of several mΩ to several hundred Ω. The film can be formed using metal oxides such as indium oxide, tin oxide, indium tin oxide (ITO), and tin antimonic acid, and metals such as gold, silver, copper, platinum, palladium, aluminum, and rhodium. As a method for forming the first transparent electrode 15 and the second transparent electrode 17 made of these materials, a transparent conductive film is formed by a PVD method such as a sputtering method, a vacuum deposition method, or an ion plating method, or a CVD method or a coating method. There are a method of patterning by etching after forming, a printing method, and the like.

A second adhesive layer 31 is provided between the first base film 11 and the first intermediate base film 19. A third adhesive layer 33 is provided between the first intermediate substrate film 19 and the second intermediate substrate film 21. A fourth adhesive layer 35 is provided between the second intermediate base film 21 and the second base film 13. The same material as the first adhesive layer 7 can be used for the second adhesive layer 31, the third adhesive layer 33, and the fourth adhesive layer 35.
The thickness of each adhesive layer is in the range of 25 μm to 175 μm.

In the touch panel having the configuration of the first embodiment, the flexural modulus and the retardation value were measured. The thickness of each layer is as follows.
First adhesive layer 7: 175 μm
First base film 11: 75 μm
Second adhesive layer 31: 75 μm
First intermediate base film 19: 400 μm
Third adhesive layer 33: 75 μm
Second intermediate substrate film: 400 μm
Fourth adhesive layer: 75 μm
Second substrate film: 75 μm
The obtained measurement value had a retardation value of 10 nm or less and a flexural modulus of 0.85 GPa or less.

2. Second Embodiment In the above embodiment, the number of intermediate substrate films is two, but the number is not particularly limited. An embodiment in which the number of intermediate substrate films is three will be described below with reference to FIG. FIG. 3 is a schematic configuration diagram of the touch panel according to the second embodiment. The basic structure is the same as that of the first embodiment.
As shown in FIG. 3, a first intermediate base film 19 </ b> A, a second intermediate base film 21 </ b> A, and a third intermediate base film 37 are disposed between the first transparent electrode 15 and the second transparent electrode 17. Has been. A third adhesive layer 33A is provided between the first intermediate substrate film 19A and the second intermediate substrate film 21A. A fourth adhesive layer 35 </ b> A is provided between the second intermediate base film 21 </ b> A and the third intermediate base film 37. A fifth adhesive layer 39 is provided between the third intermediate base film 37 and the second base film 13.

As shown in FIG. 4, the slow axis A of the first intermediate substrate film 19 and the slow axis C of the third intermediate substrate film are at the same angle, and the slow axis of the second intermediate substrate film 21 is relative thereto. The phase axes B are orthogonal to each other in plan view. FIG. 4 is a schematic perspective view showing a slow axis of the intermediate base film.
Here, the retardation value of the first intermediate substrate film 19A is set to 200 nm, the retardation value of the third intermediate substrate film 37 is set to 100 nm, and the retardation value of the second intermediate substrate film 21A is set to 400 nm. Here, the orthogonality includes ranges of 90 degrees and 90 degrees ± several degrees. Note that the slow axes may cross each other so as to form another angle instead of being orthogonal to each other.
There are no particular restrictions on the way in which the above intermediate substrate films are arranged, each retardation value, thickness, and the like.

3. Common Items The first and second embodiments have the following configurations and functions in common.

The touch panel (for example, touch panel 1) of the present embodiment includes a first detection electrode (for example, the first transparent electrode 15), a second detection electrode (second transparent electrode 17), and a plurality of resin films (for example, the first one). An intermediate base film 19, a second intermediate base film 21, a first intermediate base film 19A, a second intermediate base film 21A, and a third intermediate base film 37). The second detection electrode is disposed to face the first detection electrode. A resin film is arrange | positioned between a 1st detection electrode and a 2nd detection electrode, and implement | achieves low retardation by combining arrangement | positioning of slow axes.
In this touch panel, low retardation is realized by combining the arrangement of slow axes of a plurality of resin films. Further, by providing a plurality of resin films, it is possible to realize a reduction in rigidity compared to the case of providing a single resin film.

4). Other Embodiments Although a plurality of embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. In particular, a plurality of embodiments and modifications described in this specification can be arbitrarily combined as necessary.
Any base film is not limited to a single layer resin film, and may be a laminate of a plurality of resin films.
Further, in the layer configuration of the touch panel, that is, the film sensor, the number, type, position, thickness, and the like of the layer are not limited to the above embodiment.

The present invention can be widely applied to touch panels.

1: Touch panel 3: Cover panel 15: First transparent electrode 17: Second transparent electrode 19: First intermediate substrate film 19A: First intermediate substrate film 21: Second intermediate substrate film 21A: Second intermediate substrate Film 37: Third intermediate substrate film

Claims

A first detection electrode;
A second detection electrode disposed opposite to the first detection electrode;
A plurality of resin films that are arranged between the first detection electrode and the second detection electrode, and achieve a low retardation by combining the arrangement of the slow axes,
Touch panel equipped with.
2. The touch panel according to claim 1, wherein retardation of the plurality of resin films is 250 nm or less.
The touch panel according to claim 1 or 2, wherein the plurality of resin films have two resin films whose slow axes are orthogonal to each other.