Patent ID: 6577363
Filing Date: 2003-06-10
Classification: G02F

Abstract:
An improved VCT liquid crystal device comprising;a nematic or chiral nematic liquid crystal material of negative dielectric anisotropy; two containing cell walls, spaced apart and carrying electrodes or other means to impose a field on the liquid crystal layer; an aligning surface treatment at one cell wall providing a substantially planar alignment of the liquid crystal with a defined azimuthal alignment direction; an aligning surface treatment on the second cell wall providing a preferred, substantially homeotropic alignment (z) of the adjacent liquid crystal material, and also providing a defined azimuthal alignment direction (y) to the adjacent liquid crystal, when said liquid crystal near the second cell wall is caused to depart significantly from the said preferred, substantially homeotropic alignment; means for distinguishing between two different optical states; and one or more birefringent compensator layers disposed adjacent one or on both cell walls in order to improve the viewing characteristics of the display.