Liquid crystal reflective display apparatus

摘要

A flat screen, electrically controlled, reflective display device is provided that utilizes a very thin layer of a positive dielectric anisotropy liquid crystalline material of the nematic type. The selected liquid crystal material is one whose optical phase shift transmission is a sensitive function of the electric field within it, allowing controlled optical transmission in conjunction with an optical circular polarizer. The nematic material is placed in a very thin layer in a flat-sided cell between transparent planar cell wall elements that accurately define the thickness of the nematic layer. Birefringence of the nematic liquid crystal is controlled by voltages applied to interleave arrays of alternate parallel electrodes coated on the inner surface of only one of the transparent cell elements. The invention includes novel means for holding constant and uniform the thickness of the thin nematic layer and for reducing undesired parallax and multiple image effects.