Patent ID: 6204835
Filing Date: 2001-03-20
Classification: G09G

Abstract:
A method of addressing bistable chiral nematic liquid crystal material disposed between opposed substrates, wherein one of the substrates has a first plurality of electrodes facing a second plurality of electrodes on the other substrate, and wherein the intersection of the first and the second plurality of electrodes forms a plurality of pixels, and wherein the chiral nematic liquid crystal material may be driven to a focal conic texture having a low reflectance, a planar texture having a high reflectance or a combination of the focal conic and planar textures having a gray scale reflectance anywhere between the high and low reflectances, the method comprising the steps of:a) applying a preparation voltage across the first and second plurality of electrodes with the liquid crystal material in either the focal conic texture, the planar texture, or a combination of the focal conic and planar textures to partially drive the liquid crystal material toward the focal conic texture;b) subsequently applying a selection voltage across the first and second plurality of electrodes; andc) repeating steps a) and b) until the material exhibits a desired reflectance anywhere between and including the low reflectance and the high reflectance.