Abstract: A keyboard switch includes a plurality of spaced piezoelectric transducers secured to a common strike plate which is selectively impacted to actuate all of the transducers in response to switch actuation. The switch includes a snap action spring member carrying an impact member which impacts the strike plate as the spring member snaps to its actuated state when the switch is depressed . The spring member causes the impact member to maintain a compressive force against the strike plate, maintaining the transducers actuated while the key remains depressed and for a short interval after the key is released. An array of such switches on a keyboard is disposed over a plurality of parallel data lines which electrically contact one or more transducers at each switch in accordance with a switch indentification code. The parallel binary number appearing on the lines is received by processing circuitry which identifies each depressed key by its code.
Type:
Grant
Filed:
December 20, 1983
Date of Patent:
December 8, 1987
Assignees:
Aaron J. Gellman, Samuel H. Levinson
Inventors:
Austin Boldridge, Jr., Scott Buell, James M. Graham