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. 10, 2015
Filed:
Jul. 20, 2012
Rieko Ren, Kunitachi, JP;
Koji Tasaka, Hino, JP;
Kouji Tashiro, Hachioji, JP;
Konica Minolta, Inc., Tokyo, JP;
Abstract
A circularly polarizing plate has a polarizer and two λ/4 plates (T1, T2) bonded respectively onto both sides of the polarizer so as to face each other, the circularly polarizing plate is characterized in that the in-plane retardation values Ro of the λ/4 plates (T1) and the λ/4 plates (T2) satisfy (a) to (c) below in an environment with a temperature of 23° C. and RH of 55%. (a) The in-plane retardation value Ro of the λ/4 plates (T1), when measured within the range of 450 to 650 nm, is 3.0 to 20.0 nm smaller than the in-plane retardation value Ro of the λ/4 plates (T2). (b) The in-plane retardation value Ro of the λ/4 plates (T1) (450) falls within the range of 110 to 140 nm. (c) The in-plane retardation value Ro of the λ/4 plates (T2) (650) falls within the range of 145 to 165 nm.