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:
Jun. 15, 1993
Filed:
Mar. 16, 1990
Hisao Yokokura, Hitachi, JP;
Teruo Kitamura, Katsuta, JP;
Akio Mukoh, Mito, JP;
Junichi Hirakata, Hitachi, JP;
Yasuhiko Kando, Mobara, JP;
Isoji Sakai, Kobe, JP;
Yasuo Fujimura, Ashiya, JP;
Noboru Masutani, Ashiya, JP;
Hitachi, Ltd., Tokyo, JP;
Denko Corporation, Osaka, JP;
Abstract
A liquid crystal display device comprising: a liquid crystal display element formed by holding, between two substrates at least one of which has a light-permeable electrode, a liquid crystal layer in which liquid crystal molecules of a nematic liquid crystal having positive dielectric anisotropy and containing an optically active substance has a helical axis perpendicular to the substrates between the substrates and are helically oriented, and the liquid crystal molecules between the substrates have a twist angle of 180 to 270 degrees, and a phase plate formed by stacking water surface development films of an organic polymer with changing the orientation axes thereof at a constant angle, wherein the contrast ratio, a ratio between brightness in white display and brightness in black display, is remarkably excellent over that of a device obtained by stacking plastic films, and the transmissivity, a quotient of background brightness and light source brightness, is equivalent to that of a conventional double layer structure liquid crystal display device.