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. 04, 2025
Filed:
Sep. 30, 2020
Dai Nippon Printing Co., Ltd., Tokyo, JP;
Shosei Kubota, Kashiwa, JP;
Yoshiko Tanaka, Tokorozawa, JP;
Norio Ishii, Nagareyama, JP;
Takashi Kuroda, Moriya, JP;
Hiroaki Segawa, Nagareyama, JP;
Akinobu Ushiyama, Moriya, JP;
DAI NIPPON PRINTING CO., LTD., Tokyo, JP;
Abstract
Provided is an optical film that can suppress rainbow unevenness when viewed with the naked eyes without increasing the in-plane phase difference. The optical film has a low-refractive index layer on a plastic film, the plastic film is a biaxially stretched plastic film with an in-plane phase difference of 2500 nm or less, the low-refractive index layer is located on the outermost surface, and the optical film has a region in which ΔEab satisfies specific conditions, wherein the ΔEab is calculated from the differences between the L* value, the a* value, and the b* value obtained by measuring a laminate 1 including the optical film, the polarizer, and the surface light source under specific conditions and the L* value, the a* value, and the b* value obtained by measuring a laminate 2 including the polarizer and the surface light source under specific conditions, respectively.