Thermally addressed cholesteric-smectic liquid crystal device

摘要

A visual display device is featured which uses a new thermal addressing technique to provide a dark image upon a lighter background. The display is capable of being multiplexed to a large number of rows. The device comprises a cholesteric-smectic liquid crystal material mixed with a pleochroic dye of high order parameter. When the material experiences a transition from a higher to a lower, smectic thermal phase, two different textures or light states are developed; a transparent state and a light absorbing state. The transparent state is developed by applying a sensitizing voltage to certain portions of the medium. The pleochroic dye absorbs the light passing through the unsensitized portions of medium to provide the dark image. The row electrodes are made diffusely reflective so as to provide a double light pass through the medium to improve contrast.