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:
Sep. 14, 1993
Filed:
Oct. 23, 1991
Hiroyuki Yoshimi, Osaka, JP;
Tatsuki Nagatsuka, Osaka, JP;
Yasuo Fujimura, Osaka, JP;
Tatsuya Osuka, Osaka, JP;
Nitto Denko Corporation, Osaka, JP;
Abstract
A birefringent film in which molecules oriented in a direction parallel to the film plane and molecules oriented in the direction of the thickness of the film are present in a mixed state. Also, a process for producing the birefringent film, which comprises laminating a resin film on one or both sides thereof with a shrinkable film, thereby preparing a laminate, and then heat stretching the laminate, thereby performing stretching treatment of the resin film while imparting to the resin film the ability to shrink in the direction crossing the stretching direction. A retardation film is formed by using at least one birefringent film and has refractive indexes, n.sub.x and n.sub.y, in two directions parallel to the plate plane and crossing each other at right angles and a refractive index, n.sub.z, in the direction of the thickness of the plate, said refractive indexes n.sub.x, n.sub.y, and n.sub.z satisfying the following equation: