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:
Sep. 28, 2021
Filed:
Nov. 08, 2018
Keiwa Inc., Tokyo, JP;
Yoshitada Namikawa, Tokyo, JP;
Yuki Matsuno, Tokyo, JP;
Keiwa Inc., Tokyo, JP;
Abstract
A backlight unit () includes a light guide sheet () and a light diffusion sheet () provided on the surface of the light guide sheet (). Assuming that the coefficient of static friction between the light guide sheet () and the light diffusion sheet () measured at a temperature of 23° C. and a humidity of 50% in accordance with JIS K 7125 is Y, and the difference in coefficient of linear expansion between the light guide sheet () and the light diffusion sheet () measured in accordance with JIS K 7197 is X, the following relational expression (1) is satisfied.[Math. 1]≤1.00×10−3.43×10+2.35  (1).