Patent ID: 7843516

Claim:
A liquid crystal display (LCD) device configured to operate under at least a normal display mode and a touchscreen mode comprising: a casing; a transparent touchscreen surface held into place by the casing; a liquid crystal (LC) layer disposed within the casing behind the touchscreen surface, at least part of the LC layer being partitioned according to a plurality of touchscreen keys; at least one probe light sensor disposed within the casing behind the LC layer and configured to detect user contact with at least one of the plurality of touchscreen keys using a light sensing operation while the device is in the touchscreen mode and not detect user contact while the device is in a display mode; and one or more probe light emitters disposed within the casing behind the LC layer, each probe light emitter configured to emit consubstantial light that impinges upon the at least one of the plurality of touchscreen keys to be detected by the light sensing operation.