05008497 is referenced by 255 patents and cites 15 patents.

A touch controller is presented that comprises a touch sensor employing a resistive membrane, and an analog electronic circuit that accurately measures the touch position and the touch pressure on the sensor. Several variations of the electronic circuit are presented based on the principle of providing a constant current through the touch sensor, measuring the position with a differential amplifier, and measuring the touch pressure at the output of the current regulator. The touch sensors that may be used include resistive coatings such are used in overlays for computer displays, and force-sensing resistors. The circuits are simple, accurate and low-cost, yet provide measurements of the touch position that are fully decoupled from the pressure measurement, without approximation. The result is that the useful range of touch sensitivity is extended to include very light touches, without sacrificing position accuracy.

Title
Touch controller
Application Number
7/497691
Publication Number
5008497
Application Date
March 22, 1990
Publication Date
April 16, 1991
Inventor
David J Asher
P.O. Box 8748, Albany, 12208
NY, US
IPC
G08C 21/00
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