JPS6059689B2 - conductive rubber switch - Google Patents

Description

[Detailed description of the invention] .

The present invention relates to a conductive rubber switch having a built-in series resistor in a switch portion.

The basic structure of a conductive rubber switch is as shown in FIG.
12 and a conductive rubber plate 13 formed thereon. By pressing the conductive rubber plate 13 as shown by the arrow, the electrodes 11 and 12 are short-circuited via the conductive rubber plate 13. It is something.

There are various possible applications for such conductive rubber switches.
For example, it may be used to control the state of a flip-flop circuit 20 as shown in FIG.

That is, the contacts 21, 22, 22' constitute a changeover switch S, the common contact 21 is grounded, and the contacts 22, 22' are connected to power supply terminals 23, 23' via resistors R, R', respectively. , are located at the two input terminals of the flip-flop circuit 20. In this case, if the output of the flip-flop circuit 20 is supplied as a power source to a load with low power consumption such as an IC, the circuit shown in FIG. It can be used as a power supply circuit with a small amount of power.

Furthermore, the flip-flop circuit 20 can also be considered as a latch circuit that stores the state of the non-lock conductive rubber switch S. By the way, in the circuit of FIG. 2, a resistor R,
Although R' is necessary, it is not a good idea to prepare these resistors R and R' as individual components, considering the reduction in the number of parts and the number of wiring lines.

This invention has been made in view of the above points, and provides a conductive rubber switch that has a built-in resistor connected in series with the switch part and can reduce the number of parts and wiring when applied to various circuit devices. It is something. That is, the present invention is characterized in that a third electrode is added in addition to the first and second electrodes used as switch contacts, and the connection between the second and third electrodes is used as a resistor in series with the switch part. It is said that

Hereinafter, the present invention will be explained in detail with reference to the drawings. Third
The figure shows the structure of a conductive rubber switch according to an embodiment of the present invention, in which first electrodes 31, 3'' are formed in the center on an insulating substrate 30, and a relatively short electrode is formed on the outside of the first electrodes 31, 3''. Second electrodes 32, 32'' are formed at a distance apart, and third electrodes 33, 33'' are formed at a relatively long distance outside of the second electrodes 32, 32''.

A conductive rubber plate 34 having an appropriate resistance value is formed astride over these electrodes 31-33, 31''-33''. Note that the conductive comb plate 34 has electrodes 31,
The electrodes 3", 32, and 32" are always in non-contact with a predetermined gap, and the electrodes 33 and 33" are always in contact. However, in this embodiment, an insulating film 35 for insulation from the outside is integrally formed on the conductive rubber plate 34, and the gap between the first and second electrodes 31 and 32 on this insulating film 35 is , 3"-32", pressure receiving portions 36, 36'' are provided.

Here, the first electrodes 31, 3'' correspond to the common contact 21 in FIG. 2, and are commonly connected on the substrate 3 or externally.

Further, the second electrodes 32, 32'' are the contact points 2 in FIG.
2,22''.Furthermore, the third electrode 33,3
3″ corresponds to the power terminals 23, 23″ in FIG.
A common connection is made on the substrate 30 or externally. That is, when the pressure receiving part 36 or 36'' is pressed as shown by the arrow, the resistance value of the area between the electrodes 31 and 32 of the conductive rubber plate 34 and between 3' and 32' decreases greatly, and the resistance value of the area between the electrodes 31, 32, and 3'
, 32'' are in contact with the conductive rubber plate 34, so that a short circuit is created between them.

Therefore, the space between them operates as a switch section. On the other hand, between the electrodes 32 and 33 of the conductive rubber plate 34, 32''-33''
The area between these areas is pressed and the resistance is always kept high, so the area between these acts as resistances R and R'' in FIG. 2. In the above embodiment, the electrodes 32-32
``'' is connected via the conductive rubber plate 34, but this distance is long and has a sufficiently high resistance, so there is no problem. Further, when using this conductive rubber switch to control the flip-flop circuit 20 as shown in FIG. 2, if the flip-flop circuit 20 is constructed of CMOS, the electrode 32-3
Even if the values of the resistors R and R'' formed between 3 and 32'' and 33'' differ by about 1:10, the purpose can be sufficiently achieved and there is no problem.

As explained above, according to the present invention, it is possible to provide a conductive rubber switch that includes a resistor in series with the switch part by using a part of the conductive comb board that originally provides the switching action. This makes it possible to reduce the number of parts and wiring in circuit equipment including switches, which also contributes to improved reliability.

In the above embodiments, a change-over type switch has been described, but a simple on-type switch with only one each of the first to third electrodes may be used.
Of course, the present invention can also be applied to an off switch.

Furthermore, a multi-contact type changeover switch can also be configured.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional conductive rubber switch, FIG. 2 is a circuit diagram showing an example of the use of the conductive rubber switch, and FIG. 3 is a sectional view of a conductive rubber switch according to an embodiment of the present invention. 30... Insulating substrate, 31, 63 "...
・First electrode, 32, 32″...Second electrode, 33
, 33''... Third electrode, 34... Conductive rubber plate, 35... Insulator film, 36, 36''...
...Pressure receiving part.

Claims (1)

[Scope of Claims] 1. An insulating substrate, first to third electrodes formed on the substrate at a distance from each other, and one end having a predetermined gap with respect to the first and second electrodes. a conductive rubber plate disposed on the third electrode in a state in which the electrode is always in contact with the third electrode; and a pressure receiving part provided on the conductive rubber plate at a position above the first and second electrodes. The conductive rubber plate is used as a switch section for opening and closing between the first and second electrodes, and the section between the second and third electrodes is used as a resistor connected in series with the switch section. Characteristic conductive rubber switch. 2. The conductive rubber switch according to claim 1, wherein the conductive rubber plate has an insulating film integrally formed on the pressure receiving part side.