JPH0677131U - Switch element of seat switch - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a switch element for a seat switch, which does not cause a failure even after long-term use and does not malfunction even if rainwater enters. [Structure] A plurality of elongated conductive films 4 and 4 are attached to one surface of a flexible electrode sheet 3 of an insulating material or an electrode plate 6 of an insulating material substantially in parallel, and one end of each conductive film 4 is attached. And a silver-carbon electrode is connected over at least one side edge portion.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a switch element of a sheet switch used for, for example, a so-called calculator or a personal identification code input panel of an electric lock, and more particularly to a switch element of a sheet switch having a long life and reliable operation.

[0002]

[Prior art]

 The sheet switch used for the above-mentioned calculator and the secret code input panel of the electric lock is called a so-called ten-key switch, and the main part thereof is configured as shown in FIG. 2, for example.

That is, in FIG. 2, reference numeral 1 indicates a first switch element, reference numeral 2 indicates a second switch element, and the first switch element 1 is a thin electrode sheet 3 made of an insulating material and having flexibility. Plural parallel (four in FIG. 2) elongated conductive films 4 and 4 are attached to one surface (the lower surface in FIG. 2), and the routing electrode 5 is connected to one end of each conductive film 4. .

In FIG. 2, the conductive films 4, 4 and the routing electrodes 5, 5 provided on the lower surface of the electrode sheet 3 appear to be provided on the upper surface because the electrode sheet 3 is made of a transparent material. This is because the.

On the other hand, three parallel conductive films 4 and 4 are attached to the upper surface of a transparent electrode plate 6 made of an insulating material such as a thin glass plate, and the conductive electrodes are connected to one end of each conductive film. 5 is connected to form the second switch element 2.

Then, as shown in FIG. 2, the first switch element 1 and the second switch element 2 are arranged so that the surfaces to which the conductive films 4 are attached face each other, and The conductive films 4 and 4 are arranged so as to be substantially orthogonal to each other, and a spacer 7 made of an insulating material is sandwiched between the two switch elements 1 and 2, and these are integrally joined by, for example, an adhesive or the like. Constitute.

The sheet switch configured as described above is superimposed and fixed on the surface of a liquid crystal display device having a display unit arranged in a grid, for example, to form a ten-key switch or the like.

The spacer 7 has, for example, a rectangular opening at a portion corresponding to an intersection of the conductive films of the first and second switch elements 1 and 2, and a number displayed so as to be aligned with the opening. And the like are pushed from the first switch element 1 side by a finger or the like, the conductive film 4 selected in the first switch element 1 is selected in the second switch element 2 by the deformation of the electrode sheet 3. By inputting signals from the selected conductive films 4 and 4 to the arithmetic circuit as coordinate signals from the corresponding routing electrodes 5 and 5, the selected code is input. To do.

It should be noted that the thickness of the spacer in FIG. 2 is exaggeratedly shown in a large scale for the sake of clarity.

[0010]

[Problems to be solved by the device]

 When the sheet switch configured as described above is used for a long period of time, the conductive sheet 4 is cracked due to repeated elastic deformation of the electrode sheet 3 and the conductive film 4 integrated with the sheet.

There is almost no problem when the crack runs along the length direction of the conductive film 4, but when the crack crosses the conductive film in the width direction, a region on the opposite side of the routing electrode 5 with respect to the crack. The signal of is blocked by the crack and cannot be taken out from the routing electrode 5. In other words, the seat switch fails.

Further, as shown in FIG. 3, the signal of each switch portion A of the sheet switch is supplied to the microcomputer 8 by dividing the power supply voltage Vcc by the pull-up resistor R1 and the contact resistor R2 of the sheet switch. However, the contact resistance R2 of the conventional sheet switch has a high value of, for example, about 50 K ohms.

Therefore, the value of the pull-up resistor R1 must be set high, for example, about 450 K ohms.

When the conventional sheet switch configured as described above is installed outdoors, for example, as a constituent member of a personal identification code input panel of an electric lock, the switch is not turned ON when rainwater enters. In addition, the resistance of the portion A in FIG. 3 becomes several tens of K ohms, which is the same as when the switch is turned ON, which causes a malfunction.

It is an object of the present invention to solve the above-mentioned inconvenience, to provide a switch element of a seat switch which does not cause a failure even after long-term use and does not malfunction even if rainwater enters. .

[0016]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, a device according to claim 1 is characterized in that a plurality of elongated conductive films are attached to one surface of an electrode plate made of an insulating material substantially in parallel, and at least one end portion of each conductive film is provided. A feature is that a silver-carbon electrode is connected over one side edge portion.

The invention according to claim 2 is characterized in that a plurality of elongated conductive films are attached in parallel to one surface of a thin electrode sheet made of an insulating material and having flexibility, and one end of each conductive film is attached. And a silver-carbon electrode is connected over at least one side edge portion.

[0018]

[Action]

 In the switch element configured as described above, both the switch element described in claim 1 and the switch element described in claim 2 have a silver-carbon electrode connected to at least one side edge of the conductive film. Since the coordinate signal generated in the conductive film is a so-called bypass, even if a crack crosses the conductive film due to long-term use, the coordinate signal generated in the conductive film is transmitted to the routing electrode through this bypass. .

Further, for the same reason, the contact resistance of the switch section is significantly reduced. As a result of the experiment, it was confirmed that the contact resistance decreased by about two digits. This means that the contact resistance will be several hundred ohms.

[0020]

【Example】

 In FIG. 1, reference numeral 1 indicates a first switch element of the sheet switch, and reference numeral 2 indicates a second switch element.

The electrode sheet 3 which is the base of the first switch element 1 uses a polyester film having a thickness of about 150 μm, for example.

On one surface of the polyester film, four parallel parallel transparent conductive films 4 of indium tin oxide are attached by, for example, vapor deposition.

A silver-carbon electrode is connected over one end of each conductive film 4 and at least one side edge, and this silver-carbon electrode is used as a lead electrode 5.

In order to connect the silver-carbon electrode to the end portion and the side edge portion of the conductive film 4, the silver-carbon electrode is printed, for example, so as to overlap the end portion and the side edge portion of the conductive film 4.

Specifically, fine particles of silver and carbon are dispersed in an appropriate vehicle and printed on the conductive film 4 in the same manner as silk screen printing. Since the printing of this electrode is similar to the connection of the leading electrode 5 at the end of the conductive film of the conventional switch element, a more detailed description will be omitted.

Alternatively, the silver electrode may be printed first, and the carbon electrode may be printed so as to polymerize on the silver electrode.

The significance of using a silver-carbon electrode as an electrode is that it complements the disadvantages of silver that is easily rusted but is tough and carbon that is brittle but not easily rusted, and enhances the performance as an electrode by utilizing its advantages.

It should be noted that the electrode plate 6 which is the base of the second switch element 2 uses a thin glass plate as in the conventional one shown in FIG. 2, which is an essential component of the present invention. Instead of the electrode plate 6 of the second switch, a flexible electrode sheet 3 similar to that of the first switch element 1 may be used.

However, a hard electrode plate is not suitable for the base of the first switch element 1 that is operated by fingers. This is because the electrode plate is less likely to be deformed and the smooth operation of the sheet switch cannot be expected.

In addition, in the illustrated embodiment described above, the electrode sheet 3 or the electrode plate 6 is transparent. This is because it is assumed that the sheet switch will be transparent and will be used by being superimposed on another liquid crystal display device. However, the electrode sheets and the electrode plates of the first and second switch elements can be made of an opaque material by marking the reference numerals to be input on the surface of the first switch element that is pushed by the fingers.

[0031]

[Effect of device]

 As is clear from the above description, in the present invention, the silver-carbon electrode is connected not only to the end portion of the conductive film but also to at least one side edge thereof, so that a crack crosses the conductive film due to long-term use. However, no failure occurs and the reliability of the seat switch can be significantly improved.

Further, the resistance value of the contact resistance of the switch portion is remarkably reduced, and therefore the pull-up resistance value can be set to several kilo-ohms, so that even if rainwater enters the seat switch, the switch portion Since the resistance value is at most several tens of K ohms, while the pull-up resistance value is several kilo ohms, the partial pressure is sufficiently high and no malfunction occurs.

[Brief description of drawings]

FIG. 1 is an external perspective view showing a main part of a seat switch using a switch element according to an embodiment of the present invention, in which constituent members are developed.

FIG. 2 is an external perspective view similar to FIG. 1, showing a main part of a conventional seat switch.

FIG. 3 is a block diagram showing an example of a method of extracting a signal from a seat switch.

[Explanation of symbols]

 1 1st switch element 2 2nd switch element 3 Electrode sheet 4 Conductive film 5 Routing electrode 6 Electrode plate 7 Spacer 8 Microcomputer

Claims (5)

[Scope of utility model registration request] 1. A plurality of elongated conductive films are attached to one surface of an electrode plate made of an insulating material substantially parallel to each other, and silver-carbon is spread over one end and at least one side edge of each conductive film. A switch element for a sheet switch, which is characterized by connecting electrodes. 2. A plurality of elongated conductive films are attached in parallel to one surface of a thin electrode sheet which is made of an insulating material and has flexibility, and is formed on one end and at least one side edge of each conductive film. A switch element of a sheet switch, characterized in that a silver-carbon electrode is connected across the sheet. 3. The switch element for a sheet switch according to claim 1, wherein the electrode plate is made of a transparent material. 4. The switch element for a sheet switch according to claim 2, wherein the electrode sheet is made of a transparent material. 5. The switch element for a sheet switch according to claim 1, wherein the conductive film is a vapor-deposited film of indium tin oxide.