The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 08, 2001
Filed:
Jun. 21, 1999
Asahi Glass Company Ltd., Tokyo, JP;
Abstract
A color liquid crystal display device has a liquid crystal layer of nematic liquid crystal having positive dielectric anisotropy and including a chiral material, which is interposed between two substrates disposed substantially in parallel, each provided with a transparent electrode and an aligning layer. The twist angle of the liquid crystal layer of liquid crystal molecules determined by the aligning layer of each of the substrates is 160°-300°. A pair of polarizing plates disposed outside the liquid crystal layer. A driving circuit applies a driving voltage across the transparent electrodes. A birefringent plate is disposed between the liquid crystal layer and an upper polarizing plates and a product &Dgr;n,·d,of a refractive index anisotropy &Dgr;n,of the liquid crystal in the liquid crystal layer and a thickness d,of the liquid crystal layer is 1.2 &mgr;m-2.5 &mgr;m. The birefringent plate is formed to have a relation of nx≧n,≧n,wherein n,and n,respectively represent a refractive index (n,>n,) in a film plane direction of the birefringent plate, and n,represents a refractive index in the thickness direction of the birefringent plate (except for a case of n,=n,=n,). The birefringent plate has the sum &Dgr;n,·d,of the refractive index anisotropy between a slow axis (a direction of n,in the film plane) and a fast axis (a direction of n,in the film plane), and birefringence in the thickness direction is 1.2 &mgr;m-2.5 &mgr;m. At least three voltage values are selected to be applied across the transparent electrodes by multiplexing driving.