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:
Aug. 08, 1995
Filed:
Sep. 22, 1992
Zenta Kikuchi, Hamura, JP;
Takashi Miyashita, Hachioji, JP;
Casio Computer Co., Ltd., Tokyo, JP;
Abstract
A polarizer and an analyzer are respectively arranged on the incident and exit sides of a twisted nematic liquid crystal cell, and at least one biaxial retardation plate is arranged between the polarizer and the analyzer. The biaxial retardation plate is arranged such that its phase delay axis is parallel or perpendicular to the aligning treatment direction of an aligning film on the incident side of the liquid crystal cell. The polarizer is arranged such that its light-transmitting axis is parallel or perpendicular to the incident-side aligning treatment direction. The light-transmitting axis of the analyzer is set to be perpendicular to the light-transmitting axis of the polarizer. A liquid crystal material sealed in the twisted nematic liquid crystal cell is twisted at about 90.degree.. The biaxial retardation plate has a refractive index n.sub.X in an extending direction of the retardation plate, a refractive index n.sub.Y in a direction perpendicular to the extending direction, and a refractive index n.sub.Z in a direction of thickness, which satisfy the relation n.sub.Y <n.sub.Z <n.sub.X. A product .DELTA.n.multidot.d of a refractive index anisotropy .DELTA.n and a thickness d of the biaxial retardation plate falls within the range of approximately 300 to 400 nm.