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:
Nov. 12, 2002
Filed:
Jan. 23, 2001
Hisanori Yamaguchi, Ishikawa, JP;
Tomoaki Sekime, Ishikawa, JP;
Yoshio Iwai, Ishikawa, JP;
Tetsu Ogawa, Ishikawa, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
In a reflective liquid crystal display device with a single polarizing film and two retardation films located in between the polarizing film and liquid crystal cell, the angle of twist of nematic liquid crystal is 45°˜90°, the product of the birefringence of the liquid crystal and the thickness of the liquid crystal layer is 0.20 &mgr;m˜0.30 &mgr;m, the retardation value of the retardation film on the polarizing film side is 0.13 &mgr;m˜0.18 &mgr;m, the retardation value of the retardation film on the liquid crystal cell side is 0.13 &mgr;m˜0.18 &mgr;m, and the Z coefficient of each of two retardation films is 0.3˜1.0. This invention is featured by the following optical relations, that is, Ø 75°˜195°, Ø −Ø , 105°˜115°, and Ø −Ø , 165°˜175°, where Ø , Ø and Ø are angles formed by the reference line and respectively the direction of the absorption axis of the polarizing film, the direction of the slow axis of the retardation film on the polarizing film side, and the direction of the slow axis of the retardation film on the liquid crystal cell side. With the foregoing construction, a high contrast display of bright achromatic white and achromatic black is achieved.