Patent ID: 6177918
Filing Date: 2001-01-23
Classification: G02F,G06F

Abstract:
In a liquid crystal display having a plurality of cells each comprising a first substrate having a common electrode integrated thereon, a second substrate having a pixel electrode integrated thereon, liquid crystal material disposed between said common electrode and said pixel electrode, a device for determining contact position of a touch input device with said first substrate comprising:a signal layer and guard plane layer integrated into said first substrate and disposed between said first substrate and said common electrode, the signal layer being capacitively coupled to the common electrode, and the guard layer being disposed between the signal layer and the common electrode;a first signal generator for applying a first signal to said signal layer;a second signal generator for applying a second signal to said guard plane layer to thereby lower capacitive coupling of noise between said signal layer and said common electrode; andposition determining means for determining contact position of said touch input based upon response to said first signal.