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:
Apr. 26, 2016
Filed:
Aug. 31, 2011
Taku Hatano, Tokyo, JP;
Kenichi Harai, Tokyo, JP;
Taku Hatano, Tokyo, JP;
Kenichi Harai, Tokyo, JP;
ZEON CORPORATION, Tokyo, JP;
Abstract
A step of forming a layered body including a resin layer (a) containing a resin A having positive intrinsic birefringence and a resin layer (b) containing a resin B having negative intrinsic birefringence, the resin layer (b) being provided on one side of the resin layer (a); a first stretching step of stretching the layered body in one direction at a temperature T1; and a second stretching step of, after the first stretching step, stretching the layered body in another direction that is approximately orthogonal to the previous stretching direction at a temperature T2 which is lower than the temperature T1 to obtain a phase difference plate are performed. By these steps, a phase difference plate wherein a slow axis of the resin layer (a) after the stretching treatment and a slow axis of the resin layer (b) after the stretching treatment are approximately parallel to each other, and in-plane retardation Rea and NZ coefficient NZa in the resin layer (a) after the stretching treatment, and in-plane retardation Reb and NZ coefficient NZb in the resin layer (b) after the stretching treatment satisfy specific relationship is obtained.