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:
May. 26, 1992
Applicant:
Inventors:
Assignee:
Sumitomo Chemical Co., Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B32B / ;
U.S. Cl.
CPC ...
428156 ; 428212 ; 428333 ; 428910 ; 528205 ; 359484 ; 359249 ;
Abstract
An optical film having high optical uniformity is disclosed, including a thermoplastic resin film having no periodic thickness variation of sine waveform having a pitch of 50 mm or less and a thickness change of 0.5 .mu.m or more on continuous thickness measurement in the machine direction, and an optical film having a retardation value of 1200 nm or less with a fluctuation of not more than 10% and a rate of change of not more than 1.3%/cm, which is obtained by stretching said thermoplastic resin film. The optical film is laminated on a polarizing sheet to serve as a phase retarder.