Patent ID: 7696971
Filing Date: 2010-04-13
Classification: G02F,G09G

Abstract:
1. A method for the grey-scale control of a reflective bistable cholesteric display, comprising: (a) applying clearing pulses to initially induce the cholestericnematic transition, (b) allowing the cholesteric liquid crystal molecules to relax to the planar texture, (c) setting the grey scale brightness level of a pixel by using a sequence of high and low pulses to modulate the cholesteric domain size and helical axis orientation, said grey scale brightness level being determined by the position in which one or more high pulses appear in said sequence of high and low pulses, and (d) allowing a relaxation period for stabilizing the coexistence of the planar and focal-conic textures; wherein step (c) is carried out after step (b) and before step (d).