Patent Document ID: 4733222
Application ID: 06853428
Patent Status: 1

Claim One:
1. A capacitance-variation-sensitive touch sensing array system comprising an array of electrodes with each electrode including a connected series of conductive tabs; an array of keys with each key overlying at least one tab of at least one of said electrodes for varying the capacitance between said electrode and ground upon the key being touched by an operator; an array of drive lines capacitively coupled to the electrodes, with individual drive lines being coupled to a plurality of the electrodes; drive means for applying drive signals to the drive lines to drive the electrodes coupled thereto; an array of sense lines capacitively coupled to the electrodes, to derive sense signals from the electrodes when drive signals are applied to the drive lines, with each of said sense lines being so coupled to a plurality of the electrodes as to be interconnected via unique combinations of electrodes to said drive lines such that the sense lines derive unique combined patterns of variations in said sense signals in response to actuation of each of the keys; means coupled to the sense lines for sensing said patterns of variations in said sense signals; and means coupled to the sensing means for processing the sense signals to provide information associated with any particular key that is touched by an operator; whereby the number of keys exceeds the product of the number of drive lines and the number of sense lines.