JPS61279919A - Input switch for handwritten coordinate detector - Google Patents

Abstract

PURPOSE:To obtain an input switch for detection of handwritten coordinates which excels in the hermetic properties, the electric conductivity and durability, by combining prescribed elements. CONSTITUTION:The electrodes 2 and 2' orthogonal to each other are provided on both sides of the electrically insulated substrates, e.g., polyester films 1 and 1' together with carbon resistors 3 and 3' formed on the entire surface of both films. Thus electric circuits are formed on both films 1 and 1'. Then the striped insulated patterns 4 and 4' having <=0.1mm line width and >=0.1mm spaces are provided in parallel to the electrodes 2 and 2' on both resistors 3 and 3' respectively. Then the pressure-sensitive conductor layers 5 and 5' are set on both patterns 4 and 4' so that both electrodes 2 and 2' are set orthogonal to each other. Thus it is possible to obtain an input switch for detection of handwritten coordinates which excels in the hermetic properties, the electric conductivity and durability.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an input switch for a handwritten coordinate detection device, and particularly to a handwritten coordinate detection device with a novel structure that has excellent airtightness, conductivity, and durability. This invention relates to an input switch for a detection device.

[Technical Background of the Invention] Recently, various input switches using pressure-sensitive conductive rubber sheets have been widely used as electronic components. An example of an input switch using a pressure-sensitive conductive rubber sheet is the general 0N
In addition to the -OFF switch, input switches for handwritten coordinate detection devices are known.

Pressure-sensitive conductive rubber is made by dispersing metal particles in insulating rubber. By controlling the degree of dispersion, when pressure above a certain value is applied, the metal particles come into contact with each other and become conductive. It has the property of being electrically conductive because a path is formed.

Pressure-sensitive conductive rubber sheets currently on the market have a particle size of 5.
Ni powder of about 0 to 100 μm is used, which is quite large for particles to be filled into insulating rubber. Due to this, it has the disadvantage of poor durability against repeated pressurization. That is, this is because the dispersion state of particles within the pressure-sensitive coating changes as a result of dispersing large and hard particles.

Another characteristic required of the pressure-sensitive conductive rubber seals 1 to 1 used as input switch components for handwritten coordinate detection devices is that they respond with good sensitivity when pressure is applied to a small area such as a pen, and vice versa. It has so-called resistance to touch, which means that it is not sensitive to large areas such as the palm or elbow.

Japanese Patent Application Laid-Open No. 56-91302 discloses that the particle size is 30 to 15.
A mixture of 0 μm magnetic metal powder with a particle size of 7 μl/1 g and 5 to 40% by weight of magnetic fine powder is dispersed in a liquid elastomer and formed into a sheet in a magnetic field to produce a pressure-sensitive conductive rubber sheet. It describes how to do this. This conventional method is characterized by blending a suitable matrix of magnetic fine particles in a method in which magnetic metal powder (the particles are quite large) is dispersed by molding in a magnetic field. It is possible to respond to a constant pressing force per unit area, regardless of the pressing area. However, this conventional method requires very special equipment because it is necessary to perform the molding while applying a magnetic field, and has the disadvantage that it lacks versatility and can only be applied to sheet-shaped molded products. For this reason, when used in a handwritten coordinate detection device, it can be small or horizontal, but it has to be large or vertical like a blackboard.It also has the disadvantage that it is difficult to fix it. . Furthermore, the durability against repeated pressurization is about 100,000 times, which is still insufficient for a switch.

[Object of the Invention] The present invention has been made to eliminate the above-mentioned drawbacks, and provides a handwritten coordinate detection device having a novel structure, excellent airtightness, and excellent electrical conductivity and durability. It attempts to provide an input switch.

[Structure 1 of the Invention In other words, the present invention provides an electrical circuit configured on a first electrically insulating substrate, and a second electrically insulating substrate arranged at a distance from the electrical circuit on the first substrate. an electric circuit whose projection intersects with the electric circuit of the first substrate; and an electric circuit which is adhered to the first and second substrates with input contact portions of the electric circuit remaining, and whose line width is It is characterized by comprising a striped insulating pattern with an interval of 0.1 aon or less and an interval of more than 0.1 mm, and a pressure-sensitive conductive layer deposited on the first and second substrates forming the insulating pattern. This is an input switch for a handwritten coordinate detection device.

The electrically insulating substrate used in the present invention may be either plate-like or film-like, and may be either rigid or flexible. Examples include laminates and molded products made of phenol resin, epoxy resin, polyester resin, silicone resin, polyimide resin, etc., and only the part to which pressure is applied,
In order to transmit the pressure to the pressure-sensitive conductive layer, it is preferable that the layer be flexible and have a thickness of 2 mm or less. Also 0,015
If it is less than mm, durability is poor.

Further, the electric circuit configured on the above-mentioned substrate is, for example, provided with parallel electrodes on both ends, further provided with a resistor connected to the electrodes and covering almost the entire surface of the substrate, and thus connected to the first and second substrates. Two types of electric circuits are formed such that the projections of their respective electrode portions form a right angle.
The electrode parts used in the above electric circuit are made of metals such as silver and copper,
Alternatively, it may be formed using a conductive paste or the like.

Further, the resistor used in the electric circuit is formed of carbon paste or the like.

Next, the insulating patterns provided on the electric circuits of the first and second substrates are made of silicone resin or silicone rubber that has adhesive properties to the base material because of their excellent workability, heat resistance, and durability. It is suitable to form with a type of insulating adhesive. This insulating pattern is provided to provide resistance to touching, and is striped, and the insulating patterns on the first and second substrates are formed so that their projections intersect with each other. This striped insulating pattern has a line width of 0.1n+m or less and an interval of 0.11111 so that it can be input with a pen tip of 0.1 to 0.5a+m and so as not to reduce the resolution ability. It is necessary to overcome it. Furthermore, the intersection angle is preferably a right angle in terms of design. The thickness of the insulating pattern is 2μ
It is preferable that the thickness is not less than m and less than 80 μm.

If it is less than 2 .mu.m, even a large area of contact will cause input, resulting in poor resistance to hand contact, and if it is 80 .mu.m or more, the decomposition ability will decrease.

Further, the pressure-sensitive conductive layer deposited on the first and second substrates having an insulating pattern structure is made of silicone rubber, silver, etc.
A material in which one or more types of conductive particles such as copper, nickel, and carbon are dispersed is suitable. In particular, a composition previously discovered by the present inventors in which metal powder such as nickel powder is surface-treated with a platinum compound and then dispersed in polyorganosiloxane (JP-A-59-98
No. 164) is advantageous in that the resistance value varies greatly depending on the operating pressure. Furthermore, since the nickel powder used in this composition has a small average particle size of 7 μm or less, it is superior in durability compared to conventional products. In addition, this composition can have adhesive properties to the substrate and can also be applied directly to the electrodes using methods such as screen printing, which eliminates the problem of conventional fixation when vertically mounted. Problems and size limitations can be easily resolved.

The thickness of the pressure-sensitive conductive layer is suitably 10 μm or more and less than 80 μm from the viewpoint of pressure-sensitive conductivity, preferably 30 to 60 μm.
It is. In addition, if the thickness is less than the thickness of the insulating pattern, the insulating pattern becomes protruding, creating fine irregularities on the input switch, making it difficult to input. The larger the thickness the better.

By combining the above-described components according to the present invention, an input switch for a handwritten coordinate detection device is provided.

[Examples of the Invention] The present invention will be described in detail with reference to Examples below, but the present invention is not limited to the Examples without departing from the gist of the present invention.

Example 1 Electrodes 2 were provided in parallel on both sides of a polyester film 1 with a size of 210 x 295 mm and a thickness of 75 μm using a polyester resin containing silver particles, and a sheet resistance of 1 was provided on the entire surface.
A carbon resistor 3 of Ω/mouth was provided.

Two sheets were prepared: one with electrodes in the vertical direction [Fig. 1(a)] and one with electrodes in the horizontal direction [Fig. 1(b)].
A cross section of each electric circuit is shown in FIGS. 2 and 3.

Next, the insulating pattern 4 was formed to a thickness of 20 mm using an additive liquid silicone rubber [TSE3360 manufactured by Toshiba Silicone Corporation].
It was set in μm. This insulating pattern 4 has a line width of 0.0
A striped pattern of 9 nv and an interval of 0.3 mm was formed. This striped pattern is provided on both the carbon resistor with electrodes in the vertical direction [Fig. 1(a)] and the carbon resistor with electrodes in the horizontal direction [Fig. 1(b)]. are at right angles to each other. Cross-sectional views of the insulating pattern formed thereon are shown in FIGS. 4 and 5, respectively.

Next, a pressure-sensitive conductive silicone rubber B5 containing N1 powder having an average particle size of 5 μm was provided to a thickness of 60 μm on the carbon resistor provided with the insulating pattern (FIGS. 4 and 5). Cross-sectional views of the structure on which the pressure-sensitive conductive layer 5 is formed are shown in FIGS. 6 and 7, respectively.

Next, as shown in FIG. 8, an electric circuit film having a pressure-sensitive conductive layer and having electrodes in the vertical direction [FIG. 6] and an electric circuit film having electrodes in the horizontal direction [FIG. 7], The overlapping switch was constructed so that the electrode parts were orthogonal to each other.

Zebra Co., Ltd. for this switch! ! ! When I measured the switching characteristics with a ballpoint pen, the insulation resistance was 10.
It operated with a switching load of 100 g, with a conduction resistance of 0 MΩ or more and a conduction resistance of 2.5 Ω or less. In addition, in order to measure the resistance to hand contact, pressure was applied using a brass rod with a diameter of 20 mm.
No input was made even though I applied a pressure of 5k (l).Furthermore, with the above ballpoint pen, I applied a pressure of 200g and made a round trip of 100.
After 10,000 sweeps, we measured the switching characteristics and found that
The result was exactly the same as the initial value.

Example 2 The insulating pattern of Example 1 was made with a line width of 0. oysmra,
The switch was constructed in the same manner as in Example 1, except that it was formed in a striped pattern with an interval of 0.21111.

When we measured the switching characteristics of this switch using a Zebra Co., Ltd. ballpoint pen, we found that the insulation resistance was 100MΩ.
As described above, the operation was performed with a conduction resistance of 2 Ω or less and a switching load of 50 g. Furthermore, the same results as in Example 1 were obtained in the handling resistance and durability tests.

[Brief explanation of drawings]

Figure 1 (a) is a plan view of an electric circuit film with carbon resistors on the entire surface and vertical electrodes, Figure 1 (b)
Figure 2 is a plan view of an electric circuit film with carbon resistors on the entire surface and horizontal electrodes, and Figure 2 is the IF of Figure 1 (a).
- A schematic cross-sectional view along the IF line, FIG. 3 is the [
[Schematic cross-sectional view taken along line -111, Figure 4 is similar to Figure 1 (a
5 is a schematic cross-sectional view of a substrate film with an insulating pattern provided on the carbon resistor of FIG. 1(b), and FIG. is a schematic cross-sectional view of a substrate film in which a pressure-sensitive conductive layer is provided on the carbon resistor and insulating pattern shown in FIG.
FIG. 7 is a schematic cross-sectional view of a substrate film in which a pressure-sensitive conductive layer is provided on the carbon resistor and insulating pattern shown in FIG.
The figure is a schematic cross-sectional view showing an input switch for a handwritten coordinate detection device according to the first embodiment. 1.1'...Substrate polyester film, 2゜2'
...Electrode, 3,3'...Carbon resistor, 4゜4'...Insulating pattern, 5,5'...Pressure-sensitive conductive layer. Figure 1 Figure 2 Figure 13 Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] 1. An electrical circuit configured on a first electrically insulating substrate, and a second electrical circuit disposed at a distance from the electrical circuit on the first substrate.
an electrical circuit configured on an electrically insulating substrate and whose projection intersects with the electrical circuit on the first substrate; a striped insulating pattern with a line width of 0.1 mm or less and an interval of more than 0.1 mm; and a pressure-sensitive conductive layer deposited on the first and second substrates forming the insulating pattern. An input switch for a handwritten coordinate detection device, comprising: 2. The method according to claim 1, wherein the first and second electrically insulating substrates are flexible insulating substrate films or resin plates each having a thickness of 0.015 to 2 mm. Input switch for handwritten coordinate detection device. 3. Electric circuits configured on first and second electrically insulating substrates both have parallel electrodes on both ends and have a resistor on the entire surface, 2. The input switch for a handwritten coordinate detection device according to claim 1, wherein the input switch is arranged such that the projections of the input switches are arranged at right angles to each other. 4. The input switch for a handwritten coordinate detection device according to claim 1, wherein the insulating pattern is formed of a silicone resin or silicone rubber-based insulating adhesive. 5. The input switch for a handwritten coordinate detection device according to claim 1, wherein the thickness of the insulating pattern is 2 μm or more and less than 80 μm. 6 The insulating patterns formed on the electric circuits of the first and second substrates are striped, and the projections of the insulating patterns on the first and second substrates are at right angles to each other. An input switch for a handwritten coordinate detection device according to claim 1, characterized in that: 7. Handwritten coordinate detection according to claim 1, wherein the pressure-sensitive conductive layer is formed of a paste in which surface-treated conductive metal powder is dispersed in silicone rubber. Input switch for equipment. 8. The handwritten coordinates according to claim 1, wherein the pressure-sensitive conductive layer has a thickness of 10 μm or more and less than 80 μm, and is the same as or thicker than the insulating pattern. Input switch for detection device.