30.1: A New Drive Scheme for Cholesteric Reflective Displays Under Active Matrix Addressing

A novel drive scheme for reflective cholesteric active matrix displays is proposed. This method is composed of two stages, a fast resetting phase which drives the cholesteric to the homeotropic state and a determining phase where different voltages are applied in order to get different gray levels of reflectance. When the determining voltage is low, a bright high reflective planar state is achieved while when the voltage is high, a dark focal conic state is formed. We experimentally demonstrated that the drive scheme works well for video ratio operation.