Capacitance controlled keyswitch

摘要

A tri-state capacitance controlled keyswitch having a deformable concave electrode moveable by means of an actuator toward and away from a pair of capacitor plates underlying a dielectric layer in order to change the capacitive coupling between the capacitor plates. The electrode is normally remote from the dielectric layer in a weak capacitance open circuit position, a first higher capacitance closed circuit position exists when the electrode is undeformed and is in contact with the dielectric layer, and a second highest capacitance closed circuit position exists when the electrode is deformed and is in contact with the dielectric layer.