Patent ID: 6144432
Filing Date: 2000-11-07
Classification: G02F

Abstract:
A reflective liquid crystal display device comprising:a liquid crystal cell comprising a liquid crystal layer, having a thickness dLC, of liquid crystal, having a birefringence of .DELTA.nLC, sealed between a first substrate and a second substrate, the liquid crystal cell having a first substrate side and a second substrate side;a polarizer layer disposed on the first substrate side of said liquid crystal cell;two sheets of retardation layer disposed between said polarizer layer and said liquid crystal layer;at least one scattering layer disposed between said polarizer layer and said liquid crystal layer; andan optical reflector disposed on the second substrate side of the said liquid crystal layer;wherein a twisting angle of said liquid crystal is between 220.degree. and 260.degree., a multiple .DELTA.nLC.multidot.dLC of said birefringence .DELTA.nLC of said liquid crystal multiplied by said liquid crystal layer thickness dLC is between 700 nm and 1000 nm, and the liquid crystal display device satisfies formula 2 and one of set of formulae 3-5 or set of formulae 8-10:.vertline.Rfilm(2)-Rfilm(1).vertline..ltoreq.200 nm (2)100.degree..ltoreq..o slashed.F1-.o slashed.LC.ltoreq.140.degree.(3)-70.degree..ltoreq..o slashed.F2-.o slashed.F1.ltoreq.-50.degree.(4)-70.degree..ltoreq..o slashed.p-.o slashed.F2.ltoreq.-50.degree.(5)75.degree..ltoreq..o slashed.F1-.o slashed.LC.ltoreq.115.degree.(8)-70.degree..ltoreq..o slashed.F2-.o slashed.F1.ltoreq.-50.degree.(9)-40.degree..ltoreq..o slashed.p-.o slashed.F2.ltoreq.10.degree.(10)where:Rfilm(i) (retardation in retardation layer i)={nx(i)-ny(i)}.multidot.d(i)i=1 for the retardation layer relatively closer to said liquid crystal cell;i=2 for the retardation layer relatively farther from said liquid crystal cell;nx(i)=an extraordinary light refractive index of retardation layer i within a face of the layer;ny(i)=an ordinary light refractive index of retardation layer i;d(i)=a thickness of retardation layer i;.o slashed.LC=an angle of an alignment direction of molecules of said liquid crystal contacting said first substrate;.o slashed.p=an angle of an absorption axis of said polarizer layer;.o slashed.F1=an angle of slow axis direction of said retardation layer relatively closer to said liquid crystal cell; and.o slashed.F2=an angle of slow axis direction of said retardation layer relatively farther from said liquid crystal cell;wherein all angles are measured from a reference direction parallel to a face of said liquid crystal cell, and a twisting direction of said liquid crystal from said second substrate to said first substrate is considered to be a positive direction.