Image Number 19 for United States Patent #6961015.
A touch screen display circuit is disclosed which includes means for measuring a voltage at two separate input terminals which represent a location on a touch screen where pressure was applied. The display circuit includes means for defining a time period during which the voltage is measured and means for converting the measured voltage to a digital value. The means for measuring a voltage includes an amplifier and a capacitor which are configured as an integrator. The means for converting comprises a counter that measures an amount of time required for the capacitor to dissipate its charge. A touch screen display system having a touch screen which includes first and second sheets of conductive materials positioned in a spaced apart relationship is disclosed. The touch screen display system utilizes a means coupled to the first and second sheets for measuring a voltage at two separate input terminals, a means for defining a time period during which the voltage is measured and a means for converting the voltage to a digital value.