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:
Nov. 16, 2010
Filed:
Oct. 01, 2004
Kuniaki Ishibashi, Ibaraki, JP;
Kazuki Tsuchimoto, Ibaraki, JP;
Hiroyuki Yoshimi, Ibaraki, JP;
Nitto Denko Corporation, Ibaraki-shi, Osaka, JP;
Abstract
A birefringent film with excellent uniformity in in-plane retardation, retardation in the thickness direction, and alignment axis is provided. The birefringent film is produced in such a manner that, in the step of stretching a polymer film, the polymer film is stretched in a width direction while being shrunk in a longitudinal direction, and assuming that lengths in the width direction and the longitudinal direction of the polymer film before being stretched are 1, a change ratio (STD) of the length in the width direction of the polymer film resulting from the stretching and a change ratio (SMD) of the length in the longitudinal direction of the polymer film resulting from the shrinking satisfy the following formula (1).(1/)<1  (1)