Patent ID: 7705834

Claim:
A touch sensor, comprising: a display device having a first substrate on which at least one display electrode is disposed, and a second substrate on which at least one display electrode is disposed, for the display of a shape on the display device; an interface coupled to the at least one display electrode on the first substrate for receiving display data to the display device, the display data providing a voltage value between the at least one display electrode on the first substrate and the at least one display electrode on the second substrate; a measuring circuit coupled to the at least one display electrode on the first substrate; and switching means for connecting the interface to the at least one display electrodes on the first and second substrates when the switching means is in a first state of operation and for connecting the measuring circuit to the at least one display electrode on the first substrate when the switching means is in a second state of operation, wherein: the measuring circuit is configured to detect a change in capacitance or resistance measured at the at least one display electrode on the first substrate; and the switching means is configured to preserve the voltage value between the at least one display electrode on the first substrate and the at least one display electrode on the second substrate when the switching means is in the second state of operation.