JP2004086530A - Transparent touch panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transparent touch panel with other peripheral edges than input possible areas in a smaller size for contributing to a smaller size or a pocket size of portable personal computer, cellphone, or personal digital assistant. <P>SOLUTION: The transparent touch panel comprises a first planar board and a second planer board and a pressure sensitive adhesive double coated tape for firmly holding the first planar board and the second planer board without covering electrodes and pull circuits. The electrodes and the pull circuits are arranged in parallel to the inside of the pressure sensitive adhesive double coated tape and the pressure sensitive adhesive double coated tape are thinner and narrower. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a transparent touch panel of a resistive film type used for a portable personal computer, a mobile phone, a portable information terminal, and the like, and further relates to a technique of expanding an input area of the transparent touch panel.
[0002]
[Prior art]
Transparent touch panels can be broadly classified into digital and analog types, but analog types capable of character input are becoming mainstream. Each of the analog transparent touch panels has a transparent conductive film on the surface, and a first planar substrate on the touch side and a second planar substrate on the non-touch side having electrodes on opposite ends thereof. They are arranged so that they face each other and the electrode directions are orthogonal to each other. The first planar substrate and the second planar substrate are firmly held around the substrate by a double-sided adhesive tape.
[0003]
FIG. 3 is an exploded view of an example of a conventional transparent touch panel. As shown in FIG. 3, the transparent touch panel is configured by laminating a first planar substrate 110 and a second planar substrate 130 via a spacer 140 made of a double-sided adhesive tape. The thickness of the double-sided pressure-sensitive adhesive tape is usually about 100 μm to cover the electrodes. The first planar substrate 110 receives an input from an operator using a finger or an input pen on the transparent touch panel. Reference numeral 120 denotes a connector unit connected to internal electrodes.
[0004]
The spacer 140 is formed in a continuous frame shape except for a portion where the connector portion 120 is mounted and a cutout portion 141 of a corner opposite to the portion, and the first planar substrate 110 and the second planar substrate 130 are formed. It is stuck on the periphery. In the cutout 141, since no spacer member is interposed, a gap is formed between the first planar substrate 110 and the second planar substrate 130, which acts as an internal air vent hole. When the air vent hole is not required, the cutout 141 need not be provided.
[0005]
In the gap between the first planar substrate 110 and the second planar substrate 130 inside the spacer 140, dot-shaped spacers 160 are provided at predetermined intervals. On the main surface on the side facing the two-surface substrate 130, a transparent conductive film 111 is formed on substantially the entire surface. Further, electrodes 112 are provided on two opposing sides of the transparent conductive film 111. A pair of electrode ends 114, 114 for connecting to the pair of connection electrodes 122, 122 on the connector 120 is formed in the remaining area of the main surface facing the connector 120. The electrode ends 114, 114 and the electrodes 112, 112 provided on the two sides of the resistance film 111 are connected to each other by routing circuits 113, 113.
[0006]
On the main surface of the second planar substrate 130 on the side facing the first planar substrate 110, a transparent conductive film 131 is provided on substantially the entire surface. The electrodes 132 and 132 are provided on two sides of the transparent conductive film 131 opposite to each other in a direction perpendicular to the facing direction of the electrodes 112 and 112 formed on the transparent conductive film 111 of the first planar substrate 110. 132 are formed. In the remaining area of the main surface, similarly to the first planar substrate 110, a pair of electrode ends 134, 134 connected to the pair of connection electrodes 123, 123 on the connector section 120 side is formed. Routing circuits 133 and 133 for connecting the extreme portions 134 and 134 and the electrodes 132 and 132 provided on two sides of the transparent conductive film 131 are formed.
[0007]
In the connector section 120, connection electrodes 122, 122, 123, 123 connected to the electrode ends 114, 114, 134, 134 of the first and second planar substrates 110, 130 are exposed and formed on upper and lower surfaces. In a state where the transparent touch panel is assembled, the first planar substrate connection electrodes 122, 122 are the first planar substrate electrode ends 114, 114, and the second planar substrate connection electrodes 123, 123 are the second planar substrate electrodes. It is connected to the extreme portions 134, 134 by thermocompression bonding or the like.
[0008]
Japanese Patent Application Laid-Open No. 11-95925 discloses an example of a transparent touch panel in which a wiring circuit is provided on one substrate and a double-sided adhesive tape is provided so as to cover a bus bar (electrode) and the wiring circuit. It is shown.
[0009]
Japanese Patent Application Laid-Open No. H10-310244 discloses a transparent touch panel in which a routing circuit is provided on one substrate and a transparent touch panel in which a routing circuit is provided on each substrate. Is provided with a double-sided adhesive tape. While the double-sided pressure-sensitive adhesive tape holds the substrate with a pressure-sensitive adhesive and covers the silver ink to exhibit an insulating effect, the double-sided pressure-sensitive adhesive tape has been wide and thick.
[0010]
In the conventional transparent touch panel, the fact that the double-sided pressure-sensitive adhesive tape is wide means that the peripheral portion other than the inputtable area portion is wide. The thick double-sided pressure-sensitive adhesive tape means that, as shown in FIG. 4, when the first planar substrate 10 immediately adjacent to the double-sided pressure-sensitive adhesive tape 30 was input with the input pen 40, the first planar substrate 10 was greatly deformed. If this large deformation slides the first planar substrate 10 near the double-sided adhesive tape 30 many times with a pen, the transparent conductive film of the first planar substrate 10 is damaged and the resistance value changes. It became unusable.
[0011]
That is, in the conventional transparent touch panel, since the double-sided adhesive tape 30 is arranged so as to cover the silver electrode 11, it is difficult to make the double-sided adhesive tape 30 narrow. Since it was difficult to ensure sufficient sliding durability of the planar substrate 10, the periphery of the transparent touch panel other than the inputtable area could not be reduced.
[0012]
[Problems to be solved by the invention]
However, there is a strong demand for miniaturization of transparent touch panels. Particularly in portable information devices, there is a growing demand for transparent touch panels that have a small peripheral edge other than the input area of the transparent touch panel even if it is only one side. Was. Therefore, an object of the present invention is to provide a transparent touch panel in which a peripheral portion other than an input-capable area portion is reduced in order to reduce the size and pocket size of a portable personal computer, a cellular phone, a portable information terminal, and the like.
[0013]
[Means for Solving the Problems]
The transparent touch panel according to the invention of claim 1 includes a touch-side first planar substrate and a non-touch-side second planar substrate each having a transparent conductive film on the surface and having electrodes on two opposing sides thereof, In a rectangular transparent touch panel in which transparent conductive films are disposed so as to face each other and the electrode directions are orthogonal to each other, and the entire periphery between the substrates is fixed with a double-sided adhesive tape, at least one of the four sides of the transparent touch panel has the electrodes and / or Alternatively, a wiring circuit from an electrode is disposed inside the double-sided pressure-sensitive adhesive tape, and the thickness of the electrode and / or the wiring circuit from the electrode is smaller than the thickness of the double-sided pressure-sensitive adhesive tape.
[0014]
A transparent touch panel according to a second aspect of the present invention is the transparent touch panel according to the first aspect of the present invention, wherein the first planar substrate and the electrode of the second planar substrate and / or a circuit drawn from the electrode overlap the first planar substrate. It is characterized in that the sum of the thicknesses of the electrodes of the planar substrate and the electrodes of the second planar substrate and / or the circuit drawn from the electrodes is smaller than the thickness of the double-sided adhesive tape.
[0015]
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 to second aspects, wherein the first planar substrate and the electrode of the second planar substrate and / or a circuit extending from the electrode are: It is characterized by comprising a conductive agent and an insulating agent covering the conductive agent.
[0016]
A transparent touch panel according to a fourth aspect of the present invention is the transparent touch panel according to any one of the first to third aspects, wherein the thickness of the double-sided adhesive tape is 20 μm to 60 μm.
[0017]
According to a fifth aspect of the present invention, in the transparent touch panel according to any one of the first to fourth aspects, the width of the double-sided adhesive tape on one side of the first planar substrate is 0.2 mm to 0.6 mm. It is characterized by.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments of the present invention will be described below. First, as the planar substrate used in the present invention, transparent glass, polyethylene terephthalate (PET), polyether sulfone (PES), polyether ether ketone (PEEK), polycarbonate (PC), polypropylene (PP) A plastic film such as polyamide (PA), polyacryl (PAC), norbornene-based thermoplastic transparent resin, or a laminate thereof is used. The first planar substrate on the touch side is usually a plastic film substrate having a thickness of 20 to 500 μm, and the second planar substrate on the non-touch side is typically a glass substrate or a plastic film substrate having a thickness of 500 to 2000 μm. Are often used.
[0019]
Next, a method for forming a transparent conductive film is a general method for forming a transparent conductive film on a film or a glass substrate, such as a PVD method such as a sputtering method, a vacuum deposition method, or an ion plating method, or a CVD method. , Coating method, printing method and the like. The material for forming the transparent conductive film is not particularly limited, and examples thereof include indium-tin composite oxide (ITO), tin oxide, copper, aluminum, nickel, and chromium. May be formed. Before forming the transparent conductive film, an undercoat layer for improving transparency, adhesion, and the like may be provided.
[0020]
Next, the patterning of the transparent conductive film is performed. In general, a desired pattern-like mask is formed on the conductive film surface of the transparent conductive film, followed by etching with an acid solution to remove only unnecessary portions of the conductive film. After peeling, the pattern mask is removed by dissolving or the like with a peeling agent such as an alkaline solution.
[0021]
Next, electrodes are formed on both ends of the transparent conductive film with conductive ink. As the conductive ink, a conductive printable paste such as silver, carbon ink, or copper ink is used, and silver and carbon may be mixed or overcoated. The electrode width is generally 0.2 mm to several mm, and the thickness is generally several μm to several tens μm. Thereafter, an insulating ink may be applied to a necessary portion of the transparent conductive film or the electrode as a measure to ensure insulation or prevent migration. As the insulating ink, acrylic resin, urethane resin, epoxy resin, silicon resin, or the like is used. The routing circuit is usually formed at the same time.
[0022]
The support is often made of polycarbonate, an acrylic resin substrate, or a polyolefin resin substrate, and glass can also be used. The thickness of the support is generally 0.5 to 5 mm, and the shape is often flat and the center is convex.
[0023]
The bonding of the first planar substrate and the second planar substrate is performed using a pressure-sensitive adhesive or a double-sided pressure-sensitive adhesive tape, and substantially only the peripheral portion is bonded. The double-sided pressure-sensitive adhesive tape has a core material film sandwiched between top and bottom surfaces, and the core material is plastic such as polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polyethersulfone (PES) A film is used. Acrylic, silicone, urethane, and mixtures thereof are used as the adhesive.
[0024]
In addition, it is more preferable to bond the entire surface of the support and the second planar substrate from the viewpoint of visibility than to the peripheral portion.
[0025]
Next, an embodiment of the present invention will be described below. Each drawing has been drawn so as to make the configuration easy to understand, and is therefore not drawn to scale but partially enlarged or reduced. As the double-sided adhesive tape, an acrylic resin type of Lintec was used.
[0026]
A transparent touch panel was made as shown in FIGS. 1 and 2 using the electrodes on the opposite side of the connector of the first planar substrate in FIG. Conventionally, a double-sided adhesive tape covers the electrode 112 as shown in FIG. 3 with respect to the electrode side, but in FIG. 1 there is an electrode 11 made of silver ink inside the double-sided adhesive tape 30, and in FIG. Has an electrode 11 made of silver ink and an insulating ink 12 inside. 1 and 2, the double-sided pressure-sensitive adhesive tape and the electrode 11 have a structure having no overlap. 1 and 2, the transparent conductive films of the first planar substrate 10 and the second planar substrate 20 are omitted.
[0027]
(Example 1) In FIG. 1, the first planar substrate is made of PET having a thickness of 188 μm, the conductive surface is made of an ITO film having a surface resistance of 350Ω / □, and the opposite surface is made of a hard coat. The second planar substrate is 0.5 mm glass, and the conductive surface is an ITO film having a surface resistance of 500Ω / □. Both were patterned, and the electrodes and the routing circuit were formed with silver ink.
[0028]
Produce a transparent touch panel with a 0.6 mm wide double-sided adhesive tape at 0.3 mm from the edge of the second planar substrate, and a 0.3 mm wide electrode on the first planar substrate with an interval of 0.2 mm. did. The double-sided pressure-sensitive adhesive tape had a thickness of 60 μm, and the electrode thickness was 10 μm.
[0029]
The prepared transparent touch panel was subjected to a sliding test at a speed of 3 reciprocations per second by applying a load of 2.45 N with a normal input pen (made of polyacetal, pen tip R = 0.8 mm). When the transparent touch panel is connected to the monitor and a pen is input, a straight line is displayed before the sliding test, but the straight line is distorted if the transparent touch panel deteriorates in the sliding test. The value obtained by dividing the strain length by the length of the transparent touch panel in the same direction as the strain was defined as the linearity degradation value.
[0030]
As a result, it was favorable that the linearity degradation value was within 1.5% after sliding 10,000 times at 2.4 mm from the edge of the second planar substrate, that is, at 1.5 mm from the double-sided adhesive tape.
[0031]
(Example 2) In FIG. 2, the same base material as in Example 1 was used, both were patterned, electrodes and wiring circuits were formed with silver ink, and the silver ink was covered with an acrylic insulating ink. A double-sided adhesive tape having a width of 0.6 mm is placed at 0.3 mm from the edge of the second planar substrate, and a transparent touch panel is formed on the first planar substrate with a silver ink electrode having a width of 0.3 mm at an interval of 0.2 mm. Produced. The double-sided pressure-sensitive adhesive tape had a thickness of 60 μm, and the electrode covered with the insulating ink had a thickness of 20 μm. The prepared transparent touch panel was subjected to a sliding test in the same manner as in Example 1. As a result, it was favorable that the linearity degradation value was within 1.5% after sliding 10,000 times at 2.4 mm from the edge of the second planar substrate, that is, at 1.5 mm from the double-sided adhesive tape.
[0032]
(Example 3) A transparent touch panel was manufactured in the same manner as in Example 1 except that the thickness of the double-sided pressure-sensitive adhesive tape was set to 30 µm. The prepared transparent touch panel was subjected to a sliding test in the same manner as in Example 1. The results were as good as in Example 1.
[0033]
Example 4 A transparent touch panel was manufactured in the same manner as in Example 2 except that the first planar substrate was a 188 μm norbornene-based arton film manufactured by JSR (“ARTON” is a registered trademark of JSR). The prepared transparent touch panel was subjected to a sliding test in the same manner as in Example 2. The results were as good as in Example 2.
[0034]
(Example 5) A transparent touch panel was produced in the same manner as in Example 3 except for the width of the double-sided adhesive tape. A transparent touch panel is prepared with a double-sided adhesive tape with a width of 0.2 mm at 0.3 mm from the edge of the second planar substrate and a 0.3 mm-wide electrode on the first planar substrate with an interval of 0.2 mm. did. The prepared transparent touch panel was subjected to a sliding test in the same manner as in Example 1. As a result, at a position of 2.0 mm from the edge of the second planar substrate, that is, at a position of 1.5 mm from the double-sided pressure-sensitive adhesive tape, sliding was performed 10,000 times, and the linearity degradation value was good within 1.5%.
[0035]
(Example 6) In FIG. 2, the same base material as in Example 5 was used, both were patterned, electrodes and wiring circuits were formed with silver ink, and the silver ink was covered with an acrylic insulating ink. A transparent touch panel with a double-sided adhesive tape having a width of 0.2 mm at a distance of 0.3 mm from the edge of the second planar substrate and a silver ink electrode having a width of 0.3 mm on the first planar substrate with an interval of 0.2 mm. Was prepared. The prepared transparent touch panel was subjected to a sliding test in the same manner as in Example 1. As a result, at a position of 2.0 mm from the edge of the second planar substrate, that is, at a position of 1.5 mm from the double-sided pressure-sensitive adhesive tape, sliding was performed 10,000 times, and the linearity degradation value was good within 1.5%.
[0036]
Comparative Example 1 A transparent touch panel was manufactured in the same manner as in Example 2 except that the thickness of the double-sided pressure-sensitive adhesive tape was set to 100 μm. The prepared transparent touch panel was subjected to a sliding test in the same manner as in Example 1. As a result, at 3.4 mm from the edge of the second planar substrate, that is, at 2.5 mm from the double-sided pressure-sensitive adhesive tape, sliding was performed 10,000 times, and the linearity deterioration value was within 1.5%. At a distance of 2.0 mm from the tape, the linearity degradation value exceeded 20% after sliding 5,000 times, and at a distance of 1.5 mm from the double-sided adhesive tape, the linearity degradation value exceeded 20% after sliding 100 times.
[0037]
Comparative Example 2 A transparent touch panel was manufactured in the same manner as in Example 2 except that the thickness of the double-sided pressure-sensitive adhesive tape was 25 μm. The prepared transparent touch panel was subjected to a sliding test in the same manner as in Example 1. As a result, at 2.4 mm from the edge of the second planar substrate, that is, at 1.5 mm from the double-sided pressure-sensitive adhesive tape, sliding was performed 10,000 times, and the linearity deterioration value was within 1.5%. Partially occurred.
[0038]
【The invention's effect】
The present invention is implemented in the form described above, and has an effect of reducing the peripheral portion other than the inputtable area of the transparent touch panel used for a notebook computer, a mobile phone, a portable information terminal, or the like.
[Brief description of the drawings]
FIG. 1 shows a first embodiment of the present invention.
FIG. 2 shows a second embodiment of the present invention.
FIG. 3 is an explanatory view of a conventional transparent touch panel.
FIG. 4 is an explanatory view of a pen input immediately before a double-sided adhesive tape on a conventional transparent touch panel.
[Explanation of symbols]
Reference Signs List 10 first planar substrate 11 electrode 12 made of silver ink 12 insulating ink 20 second planar substrate 21 dot-shaped spacer 30 spacer 40 made of double-sided adhesive tape input pen 100 transparent touch panel 110 first planar substrate 111, 131 transparent conductive Membrane 112, 132 Electrode 113, 133 Routing circuit 120 Connector part 130 Second planar substrate 140 Spacer 160 made of double-sided adhesive tape 160 Dot-shaped spacer

Claims (5)

Each of the first planar substrate on the touch side and the second planar substrate on the non-touch side, each having a transparent conductive film on the surface and having electrodes on two opposite sides thereof, is opposed to the transparent conductive film and the electrode direction is orthogonal. In a rectangular transparent touch panel, which is fixed so that the entire periphery between the substrates is fixed with double-sided adhesive tape,
Arranging at least one of the four sides of the transparent touch panel with the electrodes and / or a circuit extending from the electrodes inside the double-sided adhesive tape,
A transparent touch panel, wherein a thickness of the electrode and / or a circuit drawn from the electrode is smaller than a thickness of the double-sided adhesive tape. When the electrodes of the first planar substrate and the electrodes of the second planar substrate and / or the circuits drawn from the electrodes overlap, pulling from the electrodes and / or the electrodes of the first planar substrate and the second planar substrate is performed. 2. The transparent touch panel according to claim 1, wherein the sum of the thicknesses of the circulating circuits is smaller than the thickness of the double-sided adhesive tape. The electrode of the first planar substrate and the second planar substrate and / or a circuit extending from the electrode includes a conductive agent and an insulating agent covering the conductive agent. The transparent touch panel according to Crab. The transparent touch panel according to claim 1, wherein a thickness of the double-sided pressure-sensitive adhesive tape is 20 μm to 60 μm. 5. The transparent touch panel according to claim 1, wherein the width of the double-sided adhesive tape on one side of the first planar substrate is 0.2 mm to 0.6 mm. 6.

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