JPS63307626A - Transparent flat switch - Google Patents

Abstract

PURPOSE:To raise the mounting density with simple construction by performing shrink coating in such a way that the film thickness is uneven part to part, and by forming transparent insulation film on an electrode. CONSTITUTION:Transparent insulation is shrink coated on at least either of a movable electrode 22 and a stationary electrode 28 in the thickness below 1mum, which differes from part to part, and thus films are provided as spacers 25, 31. The two electrodes 22, 28 are in mechanical contact through a shrink coated film having uneven thickness, while they are out of continuity in electrical terms, but put in continuity with application of external force, whose magnitude varies depending upon the material of the film and its coated condition. This can eliminate pressure insensitive zone with simple construction, and coordinates data in follow up to the handwriting without breaks even though the mounting density is raised.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a contact type transparent flat switch that utilizes the displacement of a transparent insulating sheet due to pressure.

[Conventional technology]

FIG. 8 is a cross-sectional view showing a conventional transparent flat switch shown on page 8 of "Touch Input System Development Trends and Application Development" published by Japan Industrial Technology Center, 9th to 12th.
The figure is a plan view or a sectional view showing each component of the switch.

8 to 10, 1 is a transparent first insulating sheet that is easily displaced in the thickness direction due to stress, and 2 is a transparent conductive film provided on one side of the first insulating sheet 1. 3 is a first movable lead which is one signal extraction electrode of the movable electrode 2, 4 is a second movable lead which is the other signal extraction electrode of the movable electrode 2, and 5 is a first insulating sheet. 1, a movable electrode 2 and a first. The second movable lead 3.4 shows a movable electrode sheet, and the eighth. .

In the figures xx and r2, 6 is a transparent second insulating sheet corresponding to the first insulating sheet l, 7 is a fixed electrode formed of a transparent conductive film and provided on one side of the second insulating sheet 6, 8 is a first fixed lead that is one signal extraction electrode of the fixed electrode 7; 9 is a second fixed lead that is the other signal extraction electrode of the fixed electrode 7; 10 is the second insulating sheet 6; the fixed electrode 7; and a fixed electrode sheet composed of both fixed leads 8 and 9; 11 indicates an insulating tod spacer formed of an insulating material and provided on the fixed electrode 7;

Next, the operation will be explained. The transparent flat switch configured as shown in FIG.
When pressed, the movable electrode 2 along with the first insulating sheet 1
moves downward, and the movable electrode 2 and fixed electrode 7 come into contact and become energized.

Next, when the external stress applied to the first insulating sheet 1 decreases, the first insulating sheet 1. The movable electrode 2 begins to return to its original state, and finally the movable electrode 2 and the fixed electrode become non-conductive, and the first insulating sheet l.

The movable electrode 2 returns to its original state.

As described above, by applying or removing external stress to the first insulating sheet 1, both electrodes 2.7 are brought into a conductive state or a non-conductive state, and this state can be detected by an external circuit. Furthermore, since both electrodes 2 and 7 are configured to have a uniform resistance distribution, for example, the 14th electrode
As shown in the figure, when a transparent flat switch is connected to a constant current source S, the current ratio flowing into both movable leads 3.4 (X coordinate) and the current ratio flowing out from both fixed leads 8.9 (Y coordinate) By calculating these and converting them from analog to digital, the coordinates of the pressed position (X.

Y) is obtained from the following formula.

1=il+12=i3+i4 Here, a; dimension between both movable leads 3.4 b; dimension between both fixed leads 8.9! ;Total current 11;Inflow current 12 from the first movable lead 3;Inflow current i3 from the second movable lead 4;First fixed lead 8
Outflow current i4; outflow current from the second fixed lead 9 Note that even if the transparent flat switch is connected to a constant voltage source, the coordinates (X, Y) of the pressed position can be determined in the same way.

[Problem that the invention seeks to solve]

As mentioned above, in the conventional transparent flat switch, since the insulating tod spacer 11 exists on the fixed electrode 7, both electrodes 2.
7 could not be connected, resulting in a dead band N (FIG. 13). Another problem is that as the insulation pitch of the transparent flat switch, that is, the pitch of the insulation dot spacers 11 is kept constant, and the number of divisions between the insulation dot spacers 11 is increased to increase the mounting density, the number of dead zones N also increases. was there.

As a countermeasure against the increase in the dead band N mentioned above, for example, if the shape of the insulating dot spacer is made smaller, it will be slightly improved. Even if the shape is made smaller, it cannot be a fundamental countermeasure because the insulating tod spacer exists on the fixed electrode.

This invention was made to solve the above problems, and includes spraying, dipping, roll coating,
It has a simple structure in which a thin film of transparent insulator is applied to the electrode by applying methods such as spinner coating and silk printing, so that the film thickness is uneven depending on the area.
The purpose of the present invention is to obtain a transparent flat switch that can easily increase the packaging density, is inexpensive, and has high reliability.

[Means to solve the problem]

In order to solve the above-mentioned problems, the transparent flat switch of the present invention includes a transparent insulator on at least one of the movable electrode and the fixed electrode. A spacer is provided with a shrink-painted thin film having a thickness of less than um and whose thickness is uneven depending on the portion.

[Effect].

Since the transparent flat switch of the present invention is equipped with the above-mentioned spacer, both electrodes are mechanically in contact via a thin film of an unrestricted thickness coated on the electrodes, but electrically there is a large contact resistance between the electrodes. Because it exists between them, it is in a non-conducting state. However, when external stress is applied, the contact resistance between the electrodes decreases, resulting in a conductive state. The value of external stress (operating force) that causes this conduction state varies depending on the material of the thin film, the coating state, etc.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

In Fig. 1.2.3, 21 is a material that is easily displaced in the thickness direction due to stress, such as plastic.

A transparent first layer made of glass or the like in the form of a film or plate.
22 is a planar movable electrode formed of a transparent conductive film provided on one side of a transparent first insulating sheet 21; 23 is a first signal extraction electrode of one of the movable electrodes 22;
24 is a second movable lead which is provided opposite to the first movable lead 23 and is the other signal extraction electrode of the movable electrode 22; 25 is both movable leads 2 of the movable electrode 22;
A first spacer made of a thin transparent insulator coated with shrinkage and having a thickness of 1 μm or less and whose thickness is uneven depending on the portion, provided on the surface excluding the 3°24 portion;
26 is the first insulating sheet 21° movable electrode 221 and both movable leads 23, 24. This is a movable electrode sheet composed of spacers 25. In Fig. 1.4.5, 27 is a first insulating sheet, and 28 is a transparent second insulating sheet made of plastic, glass, etc. in the form of a film or plate, corresponding to 21; 2 is a planar fixed electrode provided on one side of the insulating sheet 27 and formed of a transparent conductive film, 29 is a first fixed lead which is one signal extraction electrode of the fixed electrode 28, and 30 is a first fixed lead. A second fixed lead 31 is provided opposite to the fixed electrode 29 and is the other signal extraction electrode of the fixed electrode 28, and a second fixed lead 31 is provided on the surface of the fixed electrode 27 excluding the portions between the fixed leads 29 and 30, and has a thickness of 1 μm or less. (32 is the transparent second insulating sheet)27. This is a fixed electrode sheet consisting of fixed electrodes 282, fixed leads 29, 30, and spacers 31.

The transparent flat switch of this embodiment is constructed by overlapping the above-mentioned movable electrode sheet 26 on the fixed electrode sheet 32 as shown in FIG. The resistance RC between the two electrodes (Fig. 6), which was more than several 10KΩ, begins to decrease as shown in Fig. 7 due to external stress, and finally reaches a stable value of 2 to 3Ω. By detecting this stable resistance value between both electrodes 22, 28, the conductive state can be defined.

By the way, the resistance value between both electrodes 22 and 28 is equal to that of both spacers 2
5.31, the contact resistance changes due to external stress, and the above resistance value changes. In other words, by adding both spacers 25.31, pressure-sensitive characteristics are imparted between both electrodes 22°28, and both spacers 25.31 with this pressure-sensitive characteristics
is provided on almost the entire surface of both electrodes 22 and 28, so
Pressure-sensitive characteristics appear the same everywhere.

When the external stress decreases, the resistance value between both electrodes 22:28 increases, and eventually the non-conducting state returns to several tens of Ω.

The electrodes 22, 28 are made of gold, silver, copper, carbon, nickel, tin, indium oxide, tin oxide, iodized steel, palladium, chromium, etc., and the spacers 25.31 are made of acrylic, silicon, etc. In the example, the spacer is connected to both electrodes 22.28.
However, it may be provided on either one of the electrodes.

〔Effect of the invention〕

According to this invention, at least one of the movable electrode and the fixed electrode is coated with a thin film of a transparent insulator with a thickness of 1 μm or less, and the thickness is uneven depending on the part, and is used as a spacer. With this configuration, an insensitive pressure band can be created, and coordinate data that follows handwriting can be obtained without interruption even when the packaging density is increased, and it is possible to easily expand the area at low cost.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a transparent flat switch according to an embodiment of the present invention, Fig. 2 is a plan view of the movable electrode sheet of Fig. 1, Fig. 3 is a sectional view taken along the line m-m of Fig. 2, and Fig. 4 is a plan view of the fixed electrode sheet in FIG. 1, FIG. 5 is a sectional view taken along the line V-V in FIG. 4, and FIG. 6 is an equivalent circuit diagram of the transparent flat switch of the present invention.
Fig. 7 is a characteristic diagram showing changes in contact resistance with respect to external stress, Fig. 8 is a sectional view of the conventional example, Fig. 9 is a plan view of the movable electrode sheet of Fig. 8, and Fig. 1O is the x of Fig. 9. -X sectional view, FIG. 11 is a plan view of the fixed electrode sheet shown in FIG. 8, FIG. 12 is a sectional view taken along line XII-XII of FIG. FIG. 14 is an equivalent circuit diagram in which a transparent flat switch is connected to a constant current source. 21-...First insulation sheet, 22...
Movable electrode, 23...First movable lead, 24.
...Second movable lead, 25...First spacer, 26...Movable electrode sheet, 27...
...Second insulating sheet, 28...Pa fixed electrode, 29...First fixed lead, 30...
- Second fixed lead, 31... second spacer, 32... fixed electrode sheet. Agent Masuo Daikun (and 2 others) Figure 1 21: 1st tl! , sparse sheet shi・movable tj&23
: 1st/1st Tsubasa D Lead 24 Sensation 2/'1 Possible 1st Force 1 Note 25, Name 1 Syasa Cup OJ electrode sheet 27; Term 32 shape ]? ° Fixing the 2 sheets 2nd drawing 3rd drawing 4th figure 5th figure 612] 7th figure 13 procedural amendment form 1. Indication of the incident: Patent Application No. 143781/1986 2,
Name of the invention Transparent flat switch 3, Person making the amendment Representative Moriya Shiki 4, Agent 5, Detailed explanation of the invention to be amended. Correct the word “insulation sheet” to “insulation sheet”. (2) In the same book, page 3, line 6, page 5, line 7, line 18, line 20, 73. Correct it with "do, cut spacer". (3) In the same book, page 9, line 12, "connection resistance" is corrected to "contact resistance."that's all

Claims (1)

[Scope of Claims] A movable electrode sheet including a movable electrode and a pair of opposing movable leads on one side of a first transparent insulating sheet having elasticity, and a fixed electrode on one side of a second transparent insulating sheet. In a transparent flat switch, the transparent flat switch is composed of a fixed electrode sheet provided with a fixed lead and a pair of opposing fixed leads, and a spacer that separates the two electrodes, and a transparent insulating material with a thickness of 1 μm is applied to at least one of the two electrodes.
A transparent flat switch characterized in that the spacer is a thin film coated with shrinkage and having a thickness as follows, and the thickness is uneven depending on the portion.