Variable capacitance type push-button switch
First Claim
1. In a variable capacitance type push-button switch comprising a case made of an insulating material;
- an insulating substrate held to said case and carrying stationary electrodes;
a key stem movable vertically within said case; and
a movable member carried by the lower end of said key stem;
the improvement wherein said movable member includes a holding member made of an elastic material of high compressibility and having a lower surface substantially convex in section, a movable electrode made of an electrically conductive and flexible material held to said lower surface of said holding member, and a dielectric film carried by said movable electrode and comprised of a synthetic resin of a fluoride type having a relative premittivity of at least eight; and
means for depressing said key stem to bring said movable member into engagement with said substrate to deform said lower surface into a more planar configuration and press said dielectric film into pressed contact with said stationary electrodes.
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Accused Products
Abstract
A capacitance type push-button switch which includes a movable member carried by the lower end of a key stem and including a holding member made of an elastic material of high compressibility and having a convex lower surface, a movable electrode made of an electrically conductive and flexible material held to the lower surface of the holding member, a dielectric film carried by the movable electrode and comprised of a synthetic resin of a fluoride type which can be brought into contact with two stationary electrodes to vary the capacitance therebetween, means including a pair of suspending pieces each carrying at their lower end portions a respective pawl adapted to engage the holding member when it is raised to its upper position for holding it in place, and means for releasing the pawls to bring the dielectric film into pressed contact with the stationary electrodes.
14 Citations
13 Claims
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1. In a variable capacitance type push-button switch comprising a case made of an insulating material;
- an insulating substrate held to said case and carrying stationary electrodes;
a key stem movable vertically within said case; and
a movable member carried by the lower end of said key stem;
the improvement wherein said movable member includes a holding member made of an elastic material of high compressibility and having a lower surface substantially convex in section, a movable electrode made of an electrically conductive and flexible material held to said lower surface of said holding member, and a dielectric film carried by said movable electrode and comprised of a synthetic resin of a fluoride type having a relative premittivity of at least eight; and
means for depressing said key stem to bring said movable member into engagement with said substrate to deform said lower surface into a more planar configuration and press said dielectric film into pressed contact with said stationary electrodes. - View Dependent Claims (2, 3, 4, 5, 6, 7)
- an insulating substrate held to said case and carrying stationary electrodes;
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8. A variable capacitance type push-button switch comprising a case made of an insulating material;
- an insulating substrate held to said case and carrying stationary electrodes;
a key stem movable vertically within said case; and
a movable member carried by the lower end of said key stem;
the improvement wherein said movable member includes a holding member made of an elastic material of high compressibility, a movable electrode made of an electrically conductive and flexible material held to said holding member, and a dielectric film formed on the lower surface of said movable electrode and comprised of a synthetic resin of a fluoride type;
means including a pair of suspending pieces extending downwardly from a top surface of said case and each carrying at their lower end portions a respective pawl adapted to engage said holding member when it is raised to its upper position for holding it in place; and
means for depressing said key stem to release said holding member from said pawls to bring said movable member into engagement with said substrate to bring said dielectric film into pressed contact with said stationary electrodes. - View Dependent Claims (9, 10, 11, 12, 13)
- an insulating substrate held to said case and carrying stationary electrodes;
Specification