Capacitive key

Claim 2

A key for producing an electrical signal between capacitor electrodes comprising a static capacitor electrode, a dynamic capacitor electrode and a dielectric layer therebetween, said dynamic electrode being mounted for flexing movement relative to the static electrode to effect a change in capacitance therebetween, a spacer peripherally interposed between the dynamic electrode and said dielectric layer to separate the dynamic electrode from said dielectric layer and define an aperture through which the dynamic electrode may approach the static electrode, said dynamic electrode being formed of a flexible deformable conductive material overlying said spacer and the aperture to enter said aperture and increase the capacitance between the electrodes upon actuation of the dynamic electrode.

Claim 3

The capacitive key as claimed in claim 1 wherein said dynamic electrode is provided with a cut located to place an essentially isolated dynamic electrode segment over the aperture, said cut further being shaped to size said dynamic electrode segment for entry of the aperture and produce the capacitive change upon dynamic electrode actuation.

Claim 4

The capacitive key as claimed in claim 1 wherein said static and dynamic electrodes and the dielectric layer form a generally planar layered structure of extended dimensions to encompass a plurality of generally coplanar signal producing pairs of static and dynamic capacitor electrodes and wherein said spacer is in the form of a lattice structure having a plurality of apertures aligned between pairs of statIc and dynamic capacitor electrodes.

Claim 5

The capacitive key as claimed in claim 1 and further including a manually operable key actuating mechanism for flexing said dynamic electrode into the aperture towards the static electrode, said mechanism being formed of a projectile poised to strike against the dynamic electrode and flex it into said aperture, cooperatively mounted magnetic latching elements located to magnetically retain the projectile away from the dynamic electrode, and a keystem which is spring biased mounted with the projectile, said keystem being mounted for movement towards the projectile against the spring bias to apply a force against the projectile in the direction of the dynamic electrode sufficient to overcome said magnetic retention and fire the projectile against the dynamic electrode to impart an abrupt momentary flexure thereto and produce an electrical signal having a steep waveform.

Claim 6

The capacitive key as claimed in claim 4 wherein one of said magnetic latching elements is selectively spaced from the dynamic electrode to recapture the projectile for magnetic retention upon rebounding after impact upon said dynamic electrode.

Claim 7

The capacitive key as claimed in claim 5 wherein the spring biased keystem further includes a single spring coupling the keystem to the projectile to spring bias the keystem in an inactive position and spring bias the projectile towards the dynamic electrode.

Claim 8

The capacitive key as claimed in claim 6 wherein the projectile is further provided with a bumper element formed of an insulating material and mounted for contact with the dynamic electrode upon firing of the projectile.

Claim 9

The capacitive key as claimed in claim 3 wherein said lattice shaped spacer is formed of a generally rectangular grid.

Claim 10

A key as in claim 8 wherein said lattice is formed of an insulating material.

Claim 11

The capacitive key as claimed in claim 3 wherein said dynamic electrode is provided with a plurality of cuts shaped to form generally isolated dynamic electrode segments located in alignment with respective apertures for entry thereof upon respective individual actuation.

Claim 12

A capacitive key as claimed in claim 4 wherein said dynamic electrode is provided with two separated oppositely arranged cuts to form a dynamic electrode segment which is connected with spans to the remainder of the dynamic electrode, said segment being located in the path of the fired projectile for impact thereby, said segment being bent by the projectile towards the static electrode while leaving the remainder of dynamic electrode substantially in its normal spaced position from the static electrode.

Claim 13

The capacitive key as claimed in claim 4 and further comprising an apertured mechanical-impact protective layer interposed between said dynamic electrode and said projectile, said protective layer having an opening in alignment with the apertures in the spacer to enable said projectile to impact upon the dynamic electrode.

Claim 14

A capacitive key for producing an electrical signal between capacitor electrodes comprising a multilayered structure formed of a static electrode layer, a dynamic capacitor electrode layer and a dielectric layer therebetween said dynamic electrode layer being formed of a flexible material, a spacer layer in the form of a lattice structure having a plurality of apertures sized to receive overlying segments of the dynamic electrode for a variation in capacitance, a plurality of key actuating mechanisms disposed over the dynamic electrode layer in alignment with respective segments thereof, said mechanisms including each a projectile poised to strike against the aligned segment of the dynamic electrode to flex it into an aperture, cooperatively mounted magnetic latching elements located to magnetically retain the projectile away from the dynamic electrode and a keystem which is spring biased mounted with the projectile, said keystem being mounted for movEment towards the projectile against the spring bias to apply a force against the projectile in the direction of the underlying dynamic electrode segment sufficient to overcome said magnetic retention and fire the projectile against the dynamic electrode to impart an abrupt momentary flexure thereto into an aperture for the production of an electrical signal.

Claim 15

A capacitive key for producing an electrical signal between capacitor electrodes comprising a multilayered structure formed of a static electrode layer, a dynamic capacitor electrode layer and a dielectric layer therebetween said dynamic electrode layer being formed of a flexible material, a spacer layer in the form of a lattice structure having a plurality of apertures sized to receive overlying segments of the dynamic electrode for a variation in capacitance, a plurality of key actuating mechanisms disposed over the dynamic electrode layer in alignment with respective segments thereof, said mechanisms including each a projectile poised to strike against the aligned segment of the dynamic electrode to flex it into an aperture, cooperatively mounted magnetic latching elements located to magnetically retain the projectile away from the dynamic electrode and a keystem which is spring biased mounted with the projectile, said keystem being mounted for movEment towards the projectile against the spring bias to apply a force against the projectile in the direction of the underlying dynamic electrode segment sufficient to overcome said magnetic retention and fire the projectile against the dynamic electrode to impart an abrupt momentary flexure thereto into an aperture for the production of an electrical signal.

Claim 16

The capacitive key as claimed in claim 13 wherein each segment is provided with a cut shaped to enhance flexibility thereof and effectively isolate adjacent segments from each other.