OPTICAL COMPENSATOR FOR SUPER-TWIST NEMATIC LIQUID CRYSTAL DISPLAYS

摘要

An improved normally white super-twist nematic (OMI) liquid crystal display (200) exhibits a dramatically improved horizontal viewing angle as compared to conventional OMI displays. The display's liquid crystal cell has a twist angle greater than about 180 DEG and less than about 270 DEG , preferably between 220 DEG and 250 DEG , and a phase retardation of between 500 nanometers (nm) and 850 nm. The improved display includes a novel compensator which incorporates, as one of its compensation elements, a positively birefringent oblique compensator layer (250) (referred to as an O-plate compensator layer). Additionally, a positively birefringent A-plate compensator layer (245) and one or more negatively birefringent C-plate compensator layers (210, 240) may be used in the display.