Importance

Loading Importance Indicators...

Abstract

A touch sensor is disclosed that senses the two-dimensional position and pressure of an object 34, such as a stylus or finger, that is touching its surface. The sensor is comprised of two insulating substrates 28 and 29 which extend over the area to be sensed. A first fixed resistor 33 establishes a potential gradient over the first substrate 29 in a first, or X, position dimension. A second fixed resistor 32 establishes a potential gradient over the second substrate 28 in a second, or Y, position dimension. Between the substrates is a force variable resistor 42 that changes its local resistance under the touch point as a function of the touch pressure. Two touch controllers are also disclosed that comprise the touch sensor 50 and an electronic circuit that accurately measures the resistance values of the touch sensor. The touch controllers output three signals: the X position, the Y position, and the pressure of the touch point. The first touch controller uses a current regulator 51 to supply a constant current through the touch sensor. The second touch controller uses a voltage regulator 67 to supply a constant voltage across the touch sensor.

Loading the Abstract Image...

First Claim