JPH1195926A - Touch panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a touch panel in which the influences of electrostatic noises or the like upon a transparent conductive film can be reduced. SOLUTION: A downside electrode sheet 4 forming a transparent conductive film 2 and a pair of parallel bus bars 3 over all the surface of a transparent board 1 and an upside electrode sheet 8 forming a patterned transparent conductive film 6 and a pair of parallel bus bars 7 on a transparent film 5 a little smaller than the transparent board 1 are mutually overlapped so that the direction between the bus bars 3 on the downside electrode sheet 4 can be orthogonal with the direction between the bus bars 7 on the upside electrode sheet 8 while interposing a spacer 9 between the transparent conductive films 2 and 6, their peripheral edge parts are adhered by an adhesive layer 10, and laying circuits 11 conducted with the bus bars 3 and 7 on the downside and upside electrode sheets 4 and 8 are provided on the upside electrode sheet 8 at least. Concerning such a touch panel of an analog resistant film system, the transparent conductive film 2 of the downside electrode sheet 4 is fringed with an insulating layer 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of inputting a position on a screen such as an LCD (Liquid Crystal Display) or a CRT (CRT) by pressing the screen from above with a finger or a pen in accordance with an instruction on a see-through screen. Is performed on a touch panel.

[0002]

2. Description of the Related Art Conventionally, as a touch panel used in an electronic organizer or a personal computer, as shown in FIG. 3, a transparent conductive film 2 made of indium tin oxide (ITO) or the like and a silver Lower electrode sheet 4 formed with a pair of parallel bus bars 3 made of paste or the like
And a patterned transparent conductive film 6 and bus bar 7 made of the same material as above on a transparent film 5 such as a polyethylene terephthalate film smaller than the transparent plate 1.
Is formed between the transparent conductive films 2 and 6 with a spacer 9 in the form of dots between the bus bars 3 of the lower electrode sheet 4 and the bus bars 7 of the upper electrode sheet 8. Are superimposed so as to be orthogonal to each other, and the peripheral portion thereof is adhered by an adhesive layer 10 such as a double-sided tape or an adhesive, and the routing circuit 11, which is electrically connected to the bus bars 3 and 7 of the lower electrode sheet 4 and the upper electrode sheet 8. 13 is provided on at least the upper electrode sheet 8 in an analog resistance film type.

The reason why the transparent film 5 smaller than the transparent plate 1 is used is that there is a bonding tolerance in the production of a touch panel. Usually, transparent film 5 rather than transparent plate 1
Is smaller in size by about 0.1 to 0.5 mm.

In addition, since the transparent conductive film 2 of the lower electrode sheet 4 is formed over the entire surface, when the routing circuit 13 is provided on the lower electrode sheet 4 as well, a gap between the transparent conductive film 2 and the routing circuit 13 is provided. Was provided with an insulating layer 12a.

Further, since the transparent conductive film 2 of the lower electrode sheet 4 is formed over the entire surface, an insulating layer 12b is also provided in the vicinity corresponding to the connection portion of the film connector 14.
This is because in the manufacturing process of the touch panel, the film connector 14 is often inserted last from the lateral direction, and the adhesive layer 10 and the bus bar 3 of the lower electrode sheet 4 are not provided near the insertion port for easy insertion. In addition, the transparent conductive film 2 of the lower electrode sheet 4 is prevented from being electrically connected to the routing circuit 11 irrelevant to the upper electrode sheet 8.

[0006]

However, in the conventional touch panel, since the transparent film 5 is smaller than the transparent plate 1, the transparent conductive film exposed portion 15 is formed at a portion where the transparent plate 1 protrudes outside the transparent film 5. (See FIG. 4). Since the insulating layers 12a and 12b are formed near the routing circuit 13 of the lower electrode sheet 4 and near the connection with the film connector 14, the transparent conductive film exposed portion 15 is not formed. Is small.

As a result, if the exposed area is large, noise 16 such as static electricity may affect the transparent conductive film 2.

Accordingly, an object of the present invention is to solve the above-mentioned problems, and to provide a touch panel capable of reducing the influence of noise such as static electricity on a transparent conductive film.

[0009]

In order to achieve the above object, a touch panel according to the present invention comprises: a lower electrode sheet having a transparent conductive plate and a pair of parallel bus bars formed on a transparent plate; A transparent conductive film patterned on a small transparent film and an upper electrode sheet having a pair of parallel bus bars formed thereon, a spacer interposed between the transparent conductive films, and a direction between the bus bars of the lower electrode sheet and the upper electrode. The sheet is overlapped so that the direction between the bus bars is orthogonal to each other, the peripheral portion thereof is adhered by an adhesive layer, and a routing circuit that is electrically connected to the bus bars of the lower electrode sheet and the upper electrode sheet is provided on at least the upper electrode sheet. In an analog resistive touch panel, the transparent conductive film of the lower electrode sheet is configured to be bordered by an insulating layer.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a touch panel according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is an exploded view showing an embodiment of the touch panel according to the present invention, and FIG. 2 is a partially enlarged view showing an embodiment of the touch panel according to the present invention. In the figure, 1 is a transparent plate, 2
Is a transparent conductive film, 3 is a bus bar, 4 is a lower electrode sheet, 5
Is a transparent film, 6 is a transparent conductive film, 7 is a bus bar, 8 is an upper electrode sheet, 9 is a spacer, 10 is an adhesive layer, 11
Denotes a routing circuit, 12 denotes an insulating layer, and 13 denotes a routing circuit.

The present invention relates to an analog resistive touch panel in which the transparent conductive film 2 of the lower electrode sheet 4 is formed on the entire surface of the transparent plate 1 and the transparent film 5 of the upper electrode sheet 8 is smaller than the transparent plate 1. As shown in FIG. 1, the transparent conductive film 2 of the lower electrode sheet 4 is bordered by an insulating layer 12.

Examples of the transparent plate 1 include glass plates such as soda glass, borosilicate glass, and tempered glass, engineering plastics such as polycarbonate, polyamide, and polyetherketone, acrylic, polyethylene terephthalate, and polybutylene terephthalate. A transparent resin plate such as a system is used.

The transparent film 5 is more than the transparent plate 1 by 0.1.
Use is made of engineering plastics such as polycarbonate-based, polyamide-based, and polyetherketone-based materials that are slightly smaller by about 1 to 0.5 mm, and transparent films such as acrylic-based, polyethylene-terephthalate-based, and polybutylene-terephthalate-based films. Note that a hard coat layer may be formed on the surface of the transparent film 5 opposite to the surface on which the transparent conductive film 6 is provided. The hard coat layer includes an inorganic material such as a siloxane-based resin or an organic material such as an acrylic epoxy-based or urethane-based thermosetting resin or an acrylate-based photocurable resin. The thickness of the hard coat layer is 1 to 7
About μm is appropriate. The transparent film 5 may be subjected to a non-glare treatment on the surface opposite to the surface on which the transparent conductive film 6 is provided to prevent light reflection. For example, the transparent film 5 and the hard coat layer are processed to have irregularities, or an extender, fine particles such as silica and alumina are mixed in the hard coat layer. Further, the transparent film 5 may be a laminated body in which a plurality of films are stacked instead of a single film.

As the transparent conductive films 2, 6, metal oxide films such as tin oxide, indium oxide, antimony oxide, zinc oxide, cadmium oxide, indium tin oxide (ITO), and composites mainly composed of these metal oxides Membrane, gold,
There are metal films of silver, copper, tin, nickel, aluminum, palladium, and the like. Further, the transparent conductive films 2 and 6 may be formed in multiple layers. The methods for forming the transparent conductive films 2 and 6 include vacuum deposition, sputtering, ion plating, and CV.
D method and the like. Note that due to the characteristics of the touch panel, it is not preferable that the transparent conductive film be electrically connected to a routing circuit provided on the same sheet. Therefore, the upper electrode sheet 8 in FIG.
Since the transparent conductive film 6 has the routing circuit 11 on the upper electrode sheet 8 side, the transparent conductive film 6 was formed in a pattern avoiding the routing circuit 11. On the other hand, the transparent conductive film 2 of the lower electrode sheet 4 in FIG.
However, a wiring circuit 13 was provided over the entire surface and an insulating layer 12 was interposed therebetween. The reason why the transparent conductive film 2 of the lower electrode sheet 4 is not patterned is that the transparent plate 1 on which the transparent conductive film 2 is formed is difficult to handle, and it takes time to pattern. As a method of patterning the transparent conductive film 6, a method of performing an etching process with an acid or the like to remove unnecessary portions is used. Further, a spacer 9 is formed on one of the surfaces of the transparent conductive films 2 and 6. For the spacer, for example, acrylate resin such as melamine acrylate resin, urethane acrylate resin, epoxy acrylate resin, methacryl acrylate resin, acrylate acrylate resin, etc. It can be obtained by forming. Also, a large number of fine dots can be formed by a printing method to form a spacer.

The bus bars 3, 7 and the routing circuit 11,
As 13, a conductive paste such as a metal such as gold, silver, copper, or nickel or carbon is used. As a method for forming the bus bars 3 and 7 and the routing circuits 11 and 13, printing methods such as screen printing, offset printing, gravure printing, and flexographic printing, a photoresist method,
There is a brush coating method. The bus bar 3 and the routing circuit 13 of the lower electrode sheet 4 are bonded to the routing circuit 11 of the upper electrode sheet 8 via a conductive adhesive.

As the insulating layer 12, an insulating resin or film such as a solder resist is used. Examples of the method for forming the insulating layer 12 include printing methods such as screen printing, offset printing, gravure printing, and flexographic printing, brush coating, and film lamination. The insulating layer 1
2 most preferably completely borders the transparent conductive film 2 of the lower electrode sheet 4, but even if there is a part that is not bordered, the effect of reducing the effect of noise is sufficient if the area is small. can get.

As the adhesive layer 10, a double-sided tape is usually used in which a portion corresponding to a panel visible area and a portion corresponding to a portion of a wiring circuit to which a conductive adhesive is applied are used. Further, instead of the double-sided tape, an adhesive, for example, an aqueous or acrylic printing paste may be used.

The routing circuit 1 for the upper electrode sheet 8
1 and the bus bar 3 of the lower electrode sheet 4 and the routing circuit 13
As a conductive adhesive used for conduction with the ink, an ink in which conductive particles such as silver and nickel are dispersed in an epoxy resin or a silicon resin is used, and is applied by a dispenser or the like. There is also a design that does not use a conductive adhesive (spotless). In this case, the film connector 1
Terminals are taken out from the upper electrode sheet 8 and the lower electrode sheet 4 by using a material having a through hole or a metal wire on both surfaces as the material 4.

With the above-described configuration, the touch panel of the present invention is characterized in that the transparent conductive film 2 of the lower electrode sheet 4 is bordered by the insulating layer 12 so that the transparent conductive film 2 protruding outside the transparent film 5 is formed. The exposed area can be substantially eliminated (see FIG. 2), and the influence of noise such as static electricity on the transparent conductive film 2 can be reduced.

The touch panel shown in FIG. 1 is merely an embodiment of the present invention, and the present invention is not limited to this. For example, all the routing circuits that are electrically connected to the bus bars 3 and 7 may be collectively provided on the upper electrode sheet 8 side (not shown).

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a UV-curable acrylic hard coat is applied by gravure printing on one surface of a roll-shaped transparent film made of polyethylene terephthalate, and an ITO film is formed on the opposite surface by sputtering. To obtain an attached ITO film. After the roll film is cut into a sheet shape, an etching resist is applied on the ITO film by screen printing in a pattern except for the peripheral portion of the lower electrode sheet, and unnecessary portions of the ITO are removed with hydrochloric acid.
By removing the film, a rectangular transparent conductive film is formed. After etching, the resist is removed with an alkali, and a pair of bus bars facing each other is formed by screen printing using silver ink on two opposite sides of the transparent conductive film, and at the same time, a circuit is routed to a portion where the transparent conductive film is not formed. It forms and obtains an upper electrode sheet.

On the other hand, a large transparent plate made of soda glass from which a large number of lower electrode sheets can be obtained by cutting is used, and an ITO film is formed on one entire surface by vacuum evaporation to form a transparent conductive film. Using epoxy acrylate photocurable resin on the conductive film to form a fine dot shape by photo process, obtain a spacer, and further border the transparent conductive film of each lower electrode sheet obtained after cutting An insulating layer is formed across a cut line by screen printing using a solder resist. Next, a set of busbars facing each other on the transparent conductive film is formed directly on each part to be the lower electrode sheet by screen printing using silver ink, and at the same time, a wiring circuit is formed on the insulating layer, and then cut. A plurality of lower electrode sheets are obtained by cutting along the line from the surface of the transparent plate on which the transparent conductive film is not formed.

Next, on the surface of the upper electrode sheet on which the transparent conductive film is formed, a double-sided tape obtained by punching a portion corresponding to the panel visible area and a portion corresponding to the portion of the wiring circuit to which the conductive adhesive is applied is applied. A conductive adhesive in which a silver filler is dispersed in silicon is applied to a portion of the wiring circuit where the double-sided tape has come off, using a dispenser.

Next, the upper electrode sheet and the lower electrode sheet are opposed to each other with the surface on which the transparent conductive film is formed so that the direction between the bus bars of the lower electrode sheet and the direction between the bus bars of the upper electrode sheet are orthogonal to each other. A touch panel was obtained by bonding.

The touch panel thus obtained is
Since the transparent conductive film of the lower electrode sheet is bordered by the insulating layer, the influence of noise such as static electricity on the transparent conductive film can be reduced.

[0027]

The touch panel of the present invention has the above-described configuration and operation, and has the following effects.

That is, in the touch panel of the present invention, since the transparent conductive film of the lower electrode sheet is bordered by the insulating layer, the exposed area of the transparent conductive film which protrudes outside the transparent film is almost eliminated, and The effect of noise such as static electricity can be reduced.

[Brief description of the drawings]

FIG. 1 is an exploded view showing an embodiment of a touch panel according to the present invention.

FIG. 2 is a partially enlarged view showing an embodiment of the touch panel according to the present invention.

FIG. 3 is an exploded view showing one embodiment of a touch panel according to the related art.

FIG. 4 is a partially enlarged view showing one embodiment of a touch panel according to the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transparent plate 2 Transparent conductive film 3 Bus bar 4 Lower electrode sheet 5 Transparent film 6 Transparent conductive film 7 Bus bar 8 Upper electrode sheet 9 Spacer 10 Adhesive layer 11 Routing circuit 12 Insulating layer 12a Insulating layer 12b Insulating layer 13 Routing circuit 14 Film connector 15 Transparent conductive film exposed part 16 Noise

Claims (1)

[Claims] 1. A lower electrode sheet having a transparent conductive film and a pair of parallel bus bars formed on the entire surface of a transparent plate, a transparent conductive film patterned on a transparent film smaller than the transparent plate, and a pair of parallel conductive bars. The upper electrode sheet on which the bus bar is formed is overlapped so that the direction between the bus bars of the lower electrode sheet and the direction between the bus bars of the upper electrode sheet are orthogonal to each other with a spacer interposed between the transparent conductive films, and a peripheral portion thereof is provided. Is adhered with an adhesive layer, and in a touch panel of an analog resistive film type wherein at least a routing circuit conducting to a bus bar of the lower electrode sheet and the upper electrode sheet is provided on the upper electrode sheet, the transparent conductive film of the lower electrode sheet is A touch panel characterized by being bordered by an insulating layer.