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:
Oct. 13, 2020
Filed:
Mar. 04, 2019
Sharp Kabushiki Kaisha, Sakai, Osaka, JP;
Akira Sakai, Sakai, JP;
Masahiro Hasegawa, Sakai, JP;
Koji Murata, Sakai, JP;
Yuichi Kawahira, Sakai, JP;
Takako Koide, Sakai, JP;
Kiyoshi Minoura, Sakai, JP;
SHARP KABUSHIKI KAISHA, Sakai, Osaka, JP;
Abstract
A circularly polarizing plate includes: a first retardation layer having negative refractive index anisotropy; a second retardation layer having positive refractive index anisotropy; and a linear polarizer, the first retardation layer and the second retardation layer being disposed such that their optical axes are parallel to each other, the first retardation layer providing an in-plane retardation whose absolute value is |R1(λ)| to light having a wavelength of λ nm, the second retardation layer providing an in-plane retardation whose absolute value is |R2(λ)| to light having a wavelength of λ nm, the first retardation layer and the second retardation layer satisfying the following formulas (1) to (4):|R1(450)|>|R1(550)|>|R1(650)|  (1)|R2(550)|>|R1(550)|  (2)|R2(550)|−|R1(550)|>|R2(450)|−|R1(450)|  (3)|R2(650)|−|R1(650)|>|R2(550)|−|R1(550)|  (4).