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:
Dec. 12, 1995
Filed:
Apr. 12, 1994
Sumitomo Chemical Company, Ltd., Tokyo, JP;
Abstract
A process for continuously producing a phase retarder film or sheet comprising continuously supplying a stretched thermoplastic resin film or sheet to a heating zone in parallel with the stretching direction of the film or sheet and heating the film or sheet to a temperature not lower than the glass transition temperature of the resin while applying pressure to the surface of the film or sheet passing through the heating zone, thereby continuously subjecting the film or sheet to thermal relaxation while suppressing the expansion of the film or sheet in a direction parallel to the surface of the film or sheet and perpendicular to the stretching axis. According to the present invention, a phase retarder film or sheet having a low angular dependence of retardation can be produced continuously. By using the phase retarder film(s) or sheet(s) thus obtained as optical compensator(s), the viewing angle characteristics of liquid crystal display devices can remarkably be improved.