Patent ID: 7317437

Claim:
An active matrix liquid crystal display including a plurality of active components each for driving a corresponding one of a plurality of pixels of said display, said display comprising: a layer of cholesteric liquid crystal material including a plurality of pixels that produce images having various levels of light reflectance including a level of minimum reflectance, a level of maximum reflectance and levels of reflectance therebetween, said level of maximum reflectance and said level of minimum reflectance being stable in the absence of an electric field; an active matrix array including conductive active elements each of which corresponds to one of said plurality of pixels of said liquid crystal layer; and drive electronics adapted to provide signals to the active elements of said active matrix display in order to: a) cause some subset of said active matrix active elements to apply voltage pulses for updating a corresponding first subset of said pixels when information intended to be displayed by said first subset of pixels has changed from previous information displayed by said first subset of pixels; and b) at the same time as a), enable said active matrix array to maintain previous information displayed by a second subset of-said pixels when information intended to be displayed by said second subset of said pixels has not changed from said previous information displayed by said second subset of said pixels, wherein said pixels are thereby updated and maintained at said levels of reflectance.