Patent ID: 6188455
Filing Date: 2001-02-13
Classification: G02F

Abstract:
A liquid crystal display device comprising:a drive liquid crystal cell having a pair of substrates disposed to face each other with a predetermined gap therebetween, and a liquid crystal layer disposed between the pair of substrates, wherein each substrate has an electrode on one surface thereof and liquid crystal molecules of the liquid crystal layer are controlled by a voltage applied between the electrodes;a pair of polarizers disposed outside of said drive liquid crystal cell; andan optical compensation unit disposed between said drive liquid crystal cell and one of the pair of polarizers;wherein said optical compensation unit comprises a left-twist liquid crystal layer of liquid crystal molecules having a chirality in a left-twist direction and a right-twist liquid crystal layer of liquid crystal molecules having a chirality in a right-twist direction;wherein: d.sub.r /P.sub.r =d.sub.l /P.sub.l, where P.sub.r is a chiral patch and d.sub.r is a thickness, respectively, of the right-twist liquid crystal layer, and P.sub.l, is a chiral pitch and d.sub.l is a thickness, respectively, of the left-twist liquid crystal layer;wherein .DELTA.n.sub.h.multidot.d.sub.h.congruent..DELTA.n.sub.r.multidot.d.sub.r =.DELTA.n.sub.l, and d.sub.r /p.sub.r =d.sub.l /p.sub.l >0.5, where .DELTA.n.sub.h, .DELTA.n.sub.l and .DELTA.n.sub.r are values of refractive index anisotropies, respectively, of said drive liquid crystal cell, said left-twist liquid crystal layer and said right-twist liquid crystal layer, and d.sub.h is a thickness of said drive liquid crystal cell.