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:
Feb. 08, 1994
Filed:
May. 24, 1991
Toyokazu Okada, Osaka, JP;
Kazuaki Sakakura, Osaka, JP;
Koji Higashi, Osaka, JP;
Akiko Shimizu, Osaka, JP;
Sumitomo Chemical Co., Ltd., Osaka, JP;
Abstract
A phase retarder and a process for producing the same are disclosed. The phase retarder is obtained by shrinking a uniaxially stretched thermoplastic high polymer film in the direction perpendicular to the stretching direction at a lengthwise shrink of at least 2%. The phase retarder has a ratio of a retardation value (R.sub.30) measured on the phase retarder being inclined at a angle of 30.degree. with respect to the orientation axis as an axis of rotation to a retardation value (R.sub.0) measured on the phase retarder being held horizontally, each measured with a polarizing microscope, (R.sub.30 /R.sub.0) of not more than 1.10, and preferably not more than 1.07. A liquid crystal display fitted with the phase retarder exhibits broad viewing angle characteristics while achieving a satisfactory B/W display level.