Patent Number: 7,786,981

Title: Circular touch sensor

Abstract: A circular touch sensor has three or more sensors arranged in an iris pattern. Each pad is defined by continuous edges that spiral outward about a center point. The unique geometric shape allows measurement of relative amounts of contact on adjoining sensors. In one implementation, the sensors measure relative capacitance of two or more sensors, thereby enabling high precision identification of the point of contact. With as few as three pads, the circular touch sensor is less expensive than traditional 12-pad to 16-pad circular sensors.

Inventors: Proctor; David W. (Bellevue, WA)

Assignee: Microsoft Corporation

International Classification: G06F 3/044 (20060101)

Expiration Date: 8/31/12018