Optical device including a spatial optical modulator and an optical element

摘要

A lens is arranged to form a spatially varying intensity distribution at a photoreceptor within a pixel region so as to form a charge pattern thereon. The photoreceptor is associated with a liquid crystal device such that the presence of a suitable recording voltage across the photoreceptor and liquid crystal device causes regions of the liquid crystal device to switch to an opaque state when the light intensity on an associated region of the photoreceptor exceeds a threshold value lth. Removal of the recording voltage allows the image held in the liquid crystal device to be stored in a non-volatile manner and to be replayed by illumination with a read beam. An analog image having a grey scale can be reproduced from the pixel region. A plurality of pixel regions can be provided as an array so as to record and replay monochrome images.