Patent ID: 8269745

Claim:
A 5-wire touch screen system comprising: (a) a 5-wire touch screen sensor including (1) a substantially transparent, substantially conductive wiper layer, (2) a substantially transparent resistive layer aligned with the wiper layer, the resistive layer including first, second, third, and fourth contact terminals, and (3) a plurality of thin spacers separating the wiper layer and the resistive layer, wherein a touch on the wiper layer presses a small portion of the wiper layer against the resistive layer to form a resistive contact area having a touch resistance between the wiper layer and the resistive layer, the touch resistance being inversely proportional to an intensity of the touch; and (b) a controller coupled to the touch screen sensor, including (1) touch screen driver circuitry for selectively coupling the wiper layer and the various contact terminals to first and second reference voltages, respectively, to generate first and second analog touch location voltages and an analog touch voltage on the resistive layer at the resistive contact area, (2) analog to digital conversion circuitry having an input coupled to the touch screen driver circuitry, and (3) multiplexing circuitry in the controller for selectively coupling the wiper layer and the various contact terminals to the input of the analog to digital conversion circuitry so as cause it to convert the first and second analog touch location voltages and the analog touch voltage to digital representations thereof, respectively.