Liquid crystal device alignment

摘要

PCT No. PCT/GB96/00107 Sec. 371 Date Aug. 8, 1997 Sec. 102(e) Date Aug. 8, 1997 PCT Filed Jan. 22, 1996 PCT Pub. No. WO96/24880 PCT Pub. Date Aug. 15, 1996A liquid crystal display cell comprises two cell walls spaced apart to enclose a layer of liquid crystal material. The cell walls carry electrode structures, e.g. arranged in rows and columns to give an x, y matrix of addressable elements or pixels. The liquid crystal material is aligned by a grating (grooved) structure on one or both cell walls. This grating structure is a bigrating with one symmetrical grating and an asymmetric grating which may be orthogonal to the symmetric grating. The grooves of the asymmetric grating varying their depth or asymmetry along the lengths to give a locally varying pretilt whose longer range average provides a pretilt in a preferred range, e.g. about 2-24 degrees.