JP2005141325A - Transparent touch panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate blocking with a display device, static electricity, and a trouble due to static electricity in a light-weight, hardly-breakable transparent touch panel attached to a display device. <P>SOLUTION: This transparent touch panel is constructed of double-layer plastic base plate made of a movable base plate and a fixed base plate. Fine irregularities are arranged on a face opposite to a face having an electrode in the fixed base plate, and a transparent conductive layer is arranged on the fine irregularities. The transparent conductive layer and a conduction part on a display face in a display device are stuck to each other by bonding their circumferences fully or partially via a conductive adhesive, and the the display device and a ground potential are matched together. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a transparent touch panel disposed in a display unit of a display device.

  Transparent touch panels can be broadly classified into digital types and analog types, but analog types that can handle character input have become mainstream. Each of the analog type transparent touch panels has a transparent conductive layer on the surface, electrodes on both ends of the analog touch panel, a touch-side movable substrate and a non-touch-side fixed substrate, the transparent conductive layer is opposite, and the electrode directions are orthogonal They are arranged and stacked. The movable substrate and the fixed substrate are held between the substrates with a double-sided adhesive tape or the like.

FIG. 3 is an explanatory diagram of an example of a conventional transparent touch panel in which the fixed substrate is made of glass.
The movable substrate 10 having the transparent conductive layer 11 and the fixed substrate 20 having the transparent conductive layer 21 are fixed with an adhesive 30 around the periphery. Although not shown, gaps are maintained between the transparent conductive layers with dot-like spacers so that they do not come into contact with each other at the time of non-input. Then, it is fixed to the peripheral portion 52 of the display device 50 with the adhesive material 40.

FIG. 4 is an explanatory diagram of an example of a conventional transparent touch panel in which the movable substrate and the fixed substrate are made of a film. (For example, Patent Document 1)
Unlike FIG. 3, the fixed substrate 20 is made of a film and is entirely bonded to the support 25 with a transparent adhesive. The support 25 is fixed to the peripheral portion 52 of the display device 50 with the adhesive material 40.

FIG. 5 is an explanatory diagram of another example of a conventional transparent touch panel in which the movable substrate and the fixed substrate are made of a film. (For example, Patent Document 2)
Unlike FIG. 4, the fixed substrate 20 is bonded to the entire surface of the display device 50 with a transparent adhesive, and the surface of the display device 50 also serves as a support.

JP 2000-89914 A (FIG. 1) JP 09-230102 (FIG. 1)

  The problem to be solved is to provide a transparent touch panel that is composed of two layers of a movable substrate and a fixed substrate in view of manufacturing cost, is lightweight and does not break, and does not require a support.

In order to achieve the above object, the transparent touch panel of the invention of claim 1
Each transparent conductive layer has a transparent conductive layer on the surface of the transparent plastic substrate, and the transparent conductive layer faces the movable substrate and the fixed substrate provided with position detection electrodes at substantially both ends of the transparent conductive layer with a predetermined gap therebetween. In the transparent touch panel in which the electrodes are arranged so as to be orthogonal to each other and arranged on the display surface of the display device, a transparent conductive layer is also provided on the opposite surface of the surface having the electrodes of the fixed substrate, and the display of the display device The surface and the periphery are bonded together.

A transparent touch panel according to a second aspect of the invention is characterized in that in the transparent touch panel according to the first aspect, the movable substrate and the fixed substrate are made of a transparent plastic substrate made of the same material.

A transparent touch panel according to a third aspect of the present invention is the transparent touch panel according to any one of the first and second aspects, wherein the movable substrate and the fixed substrate have a thickness of 0.1 mm or more, and the total thickness of the movable substrate and the fixed substrate. Is 1 mm or less.

A transparent touch panel according to a fourth aspect of the invention is characterized in that in the transparent touch panel according to any one of the first to third aspects, the thickness of the fixed substrate is equal to or greater than the thickness of the movable substrate.

A transparent touch panel according to a fifth aspect of the present invention is characterized in that in the transparent touch panel according to any one of the first to fourth aspects, fine irregularities are formed on a surface opposite to the surface having the electrodes of the fixed substrate.

A transparent touch panel according to a sixth aspect of the present invention is the transparent touch panel according to any one of the first to fifth aspects, wherein the resistance value of the transparent conductive layer on the surface opposite to the surface having the electrodes of the fixed substrate is the movable substrate and the fixed substrate. It is more than the resistance value of the transparent conductive layer of the surface which has this electrode.

A transparent touch panel according to a seventh aspect of the present invention is the transparent touch panel according to any one of the first to sixth aspects, wherein the transparent conductive layer on the opposite side of the surface having the electrodes of the fixed substrate and the conductive portion of the display surface of the display device These are characterized in that the periphery of the transparent touch panel or a part of the periphery is bonded with a conductive adhesive.

The transparent touch panel according to an eighth aspect of the present invention is used for a portable terminal in the transparent touch panel according to any one of the first to seventh aspects.

As described above, the transparent touch panel of the present invention has the following effects.
Since it consists of a two-layer plastic substrate of a movable substrate and a fixed substrate, it is lightweight and does not break like glass. In addition, since a support is not required, the number of bonding steps is reduced, naturally, foreign matter biting is reduced and the yield is improved. Further, the unevenness on the surface opposite to the surface having the electrodes of the fixed substrate does not cause blocking with the display device or deterioration of visibility. In addition, the conductive layer on the back surface opposite to the surface having the electrodes of the fixed substrate reduces static electricity and obstacles caused by the static electricity, and reduces the obstacles related to potential mismatch by matching the ground potential with the display device.

  Embodiments of the present invention will be described below. Since each drawing is drawn so that the configuration is easy to understand, it is not an actual size ratio but is partially enlarged or reduced.

(Embodiment 1)
FIG. 1 is an explanatory diagram of an example of a transparent touch panel according to the present invention. The movable substrate 10 having the transparent conductive layer 11 and the fixed substrate 20 having the transparent conductive layers 21 and 22 are fixed with an adhesive 30 around the periphery. Although not shown, gaps are maintained between the transparent conductive layers with dot-like spacers so that they do not come into contact with each other at the time of non-input.

Movable substrate As the movable substrate 10 of the transparent touch panel of the present invention, various plastic films having transparency can be used. Specifically, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersal Phon (PES), polyether ether ketone (PEEK), polycarbonate (PC), polypropylene (PP), polyamide (PA), polyacryl (PAC), norbornene-based thermoplastic transparent resin, or laminates thereof can give. Moreover, the elasticity, durability, and visibility at the time of input can be improved by laminating a polarizing plate, a retardation plate, a hard coat film, a fine uneven film, and the like. The thickness of the film base is usually 100 to 500 μm, preferably 150 to 500 μm.

Fixed substrate The same material as the movable substrate 10 is used as the fixed substrate 20. In some cases, the layers are laminated for the purpose of reinforcing durability. The thickness of the film base is usually 100 to 500 μm, preferably 150 to 500 μm. When the thickness is less than 100 μm, there is no stiffness, and in order to match the physical properties of the expansion coefficient and the contraction coefficient with the movable substrate 10, it is preferable to use substrates of the same material and the same thickness.

Unevenness processing of fixed substrate Although not shown, unevenness processing may be performed on the surface opposite to the surface having the electrodes of the fixed substrate 20 to prevent blocking with the display device.
The unevenness is generally processed by adding silica or an acrylic filler to an acrylic hard coat. As for the surface roughness, the maximum height (Rmax) is desirably 0.05 to 3 μm. As another method, unevenness may be provided by embossing.

Transparent conductive layer Next, the transparent conductive layers 11 and 21 are formed. As a general method for forming the transparent conductive layer on the film substrate, a sputtering method, a vacuum deposition method, an ion plating method, and the like are used. There are PVD methods such as CVD method, coating method, printing method and the like. The material for forming the transparent conductive layer is not particularly limited, and examples thereof include indium-tin composite oxide (ITO), tin oxide, copper, aluminum, nickel, and chromium. May be formed. Further, before forming the transparent conductive layer, an undercoat layer for improving transparency and adhesion may be provided. The surface resistance of the transparent conductive layers 11 and 21 is usually 200Ω / □ to 2000Ω / □.

Similarly, the transparent conductive layer 22 is provided on the surface of the fixed substrate 20 opposite to the surface having the electrodes. The surface resistance of the transparent conductive layer 22 may be higher than the surface resistance of the transparent conductive layers 11 and 21, and avoids a large decrease in transmittance with a low resistance. When the surface opposite to the surface having the electrodes of the fixed substrate 20 is uneven, the transparent conductive layer 22 is also uneven.

Transparent conductive layer pattern and electrodes The transparent conductive layer 11 of the movable substrate 10 and the transparent conductive layer 21 of the fixed substrate 20 are separated from each other at the periphery of each substrate. If necessary, the transparent conductive layer 22 of the fixed substrate 20 may be peeled off at the periphery of the substrate.
In the peeling method, a desired pattern-shaped mask is formed on the surface of the transparent conductive layer, and thereafter, etching with an acid solution is performed to peel only unnecessary portions of the transparent conductive layer, and then the patterned mask is removed with a stripping agent such as an alkaline solution. Is removed by dissolution or the like. The transparent conductive layer 21 and the transparent conductive layer 22 of the fixed substrate 20 can be subjected to acid treatment and alkali treatment at the same time. There is also a method of removing the transparent conductive layer into a linear shape or a planar shape with a laser without performing etching with an acid solution.

  Next, electrodes are formed on both ends of the transparent conductive layers 11 and 21 with conductive ink, and dot spacers are provided on or around the transparent conductive layer pattern 21 of the fixed substrate.

Bonding <br/> then bonded via the adhesive 30 made of the movable substrate 10 and the stationary substrate 20 from the double-sided adhesive tape. Double-sided adhesive tape is made by applying adhesive on the upper and lower surfaces with a core material film in between. Polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polyethersulfone (PES), etc. are used as the core material. A plastic film is used. As the adhesive, acrylic, silicon, urethane, or a mixture thereof is used. You may apply | coat and print an adhesive, without using a double-sided adhesive tape.
The routing circuit from the electrodes of the movable substrate 10 and the fixed substrate 20 is connected to the flexible connector by thermocompression bonding and guided to an external circuit.

Mounting to display device Fig. 2 is an explanatory diagram of mounting the transparent touch panel according to the present invention to the display device.
The transparent conductive layer 22 of the fixed substrate 20 of the touch panel is fixed to the peripheral portion 52 of the display device 50 with the conductive adhesive material 41. At the time of pressing input, the fixed substrate 20 may warp and the transparent conductive layer 22 and the surface of the display device 50 may come into contact with each other. However, since the transparent conductive layer 22 has fine irregularities (not shown), blocking with the display device is possible. Does not occur.

As a movable substrate, a PET film having a thickness of 250 μm was hard-coated on both sides, and a transparent conductive layer made of ITO and having a surface resistance of 250Ω / □ was provided on one side by sputtering.
As a fixed substrate, a PET film having a thickness of 250 μm was subjected to double-sided hard coat treatment, and the surface not contacting the movable substrate (back surface) was added with fine particles to form an uneven surface. A transparent conductive layer having a surface resistance of 250Ω / □ was provided on the side in contact with the movable substrate by sputtering, and a transparent conductive layer having a surface resistance of 1000Ω / □ was provided on the back surface by sputtering.

A transparent touch panel having a length of 80 mm * width of 56 mm was prepared using both substrates. Since the circumference | surroundings of both board | substrates were bonded together with the double-sided adhesive tape, the thickness of the transparent touch panel was 0.6 mm. This transparent touch panel was disposed on the display surface side of the liquid crystal display device, and the back surface of the transparent touch panel and the peripheral portion of the liquid crystal display device made of metal were bonded and attached with a conductive adhesive. As the conductive adhesive, a product (# 8530AD) manufactured by Dainippon Ink & Chemicals, Inc. in which a 30 μm conductive adhesive was arranged on both surfaces of a 30 μm aluminum foil was used.

After mounting, the appearance at the time of pen input was visually observed with a load of 500 grams. No blocking or Newton ring occurred between the transparent touch panel and the liquid crystal display device, which was good.
Next, the static electricity of the peripheral part of the liquid crystal display device which consists of a transparent touch panel and a metal after pen input 200 times with a load of 500 grams was measured. It was good at 0.0 KV.

Comparative Example 1
A fixed substrate having the same processing as that of the movable substrate of Example 1 having no conductive layer and unevenness on the back surface was used.
Otherwise, a transparent touch panel was prepared in the same manner as in Example 1, and was similarly attached to the liquid crystal display device.

After mounting, the appearance at the time of pen input was visually observed with a load of 500 grams. Blocking and Newton rings occurred between the transparent touch panel and the liquid crystal display device.
Next, the static electricity of the peripheral part of the liquid crystal display device which consists of a transparent touch panel and a metal after pen input 200 times with a load of 500 grams was measured. A voltage of 0.3 KV was generated.

It can be applied to a transparent touch panel that is lightweight and hard to break.

An explanatory view of an example of a transparent touch panel by the present invention. Explanatory drawing of mounting | wearing to the display apparatus of the transparent touch panel by this invention. Explanatory drawing of an example of the conventional transparent touch panel from which a fixed board | substrate consists of glass. Explanatory drawing of an example of the conventional transparent touch panel from which a movable substrate and a fixed substrate consist of films. An explanatory view of other examples of the conventional transparent touch panel in which a movable substrate and a fixed substrate consist of films.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Movable board | substrate 11, 21 Transparent conductive layer 20 Fixed board | substrate 22 Transparent conductive layer 25 Support body 30,40 Adhesive 41 Conductive adhesive 50 Display apparatus 51 Display part
52 peripheral area

Claims (8)

Each has a transparent conductive layer on the surface of the transparent plastic base material, and a movable substrate and a fixed substrate provided with position detection electrodes at substantially both ends of the transparent conductive layer,
In the transparent touch panel in which the transparent conductive layer faces through a predetermined gap, the electrodes are arranged to be orthogonal, and are arranged on the display surface of the display device.
A transparent touch panel having a transparent conductive layer on the surface opposite to the surface having the electrodes of the fixed substrate, and bonding the display surface and the periphery of the display device. The transparent touch panel according to claim 1, wherein the movable substrate and the fixed substrate are made of a transparent plastic base material made of the same material. The transparent touch panel according to claim 1, wherein a thickness of the movable substrate and the fixed substrate is 0.1 mm or more, and a total thickness of the movable substrate and the fixed substrate is 1 mm or less. The transparent touch panel according to claim 1, wherein a thickness of the fixed substrate is equal to or greater than a thickness of the movable substrate. The transparent touch panel according to any one of claims 1 to 4, further comprising fine irregularities on a surface opposite to the surface having the electrodes of the fixed substrate. The resistance value of the transparent conductive layer on the surface opposite to the surface having the electrode of the fixed substrate is equal to or higher than the resistance value of the transparent conductive layer on the surface having the electrode of the movable substrate and the fixed substrate. The transparent touch panel according to any one of 5. The transparent conductive layer on the surface opposite to the surface having the electrode of the fixed substrate and the conductive portion of the display surface of the display device are bonded with a conductive adhesive to a periphery or a part of the periphery. The transparent touch panel in any one of Claims 1-6. It is used for a portable terminal, The transparent touch panel in any one of Claims 1-7 characterized by the above-mentioned.

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