US Patent 7250940 Touch screen apparatus and method therefore

Methods and apparatus are provided for an apparatus for inputting data. The apparatus comprises a detection circuit for providing a first reference voltage to a first and a second electrode of a first conductive layer of a resistive touch screen and providing a second reference voltage to a first and a second electrode of a second conductive layer of the resistive touch screen. The detection circuit maintains the first and second reference voltages under quiescent conditions and when the first and second conductive layers couple together. The method includes applying substantially equal voltages to the first and second electrodes of the first conductive layer of the resistive touch screen. Substantially equal voltages are applied to the first and second electrodes of the second conductive layer of the resistive touch screen. Approximately zero current is conducted in the first and second conductive layers under quiescent conditions.