Oki Electric Industry Co., Ltd.

Spyrus, Inc.

Paul Waihung Chau

Jeffrey P Copeland

Gerald W Vandenengel

A compact key input apparatus interface includes a resistive element and a number of key contacts on the resistive element. The keys of a key input apparatus are disposed to provide electrical contact between a voltage source and the resistive element at a particular contact point when a corresponding key is depressed, such that a path from the voltage source to ground is made through the resistive element. The keys are arranged along the length of the resistive element so that the depression of any key provides a different conductive path to ground and therefore a different magnitude of current through the conductive path. A corresponding sense voltage measured at a sampling point provides a single-line input to a key decoder, which determines which key is depressed based on the level of the sense voltage.

Growing community of inventors

Nashua, NH, United States of America

Paul Waihung Chau