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:
May. 16, 2017
Filed:
Feb. 20, 2015
Tokai Optical Co., Ltd., Okazaki-Shi, JP;
Hirotoshi Takahashi, Okazaki, JP;
Tokai Optical Co., Ltd., Okazaki-Shi, JP;
Abstract
An optical product includes an optical multilayer film on an optical product base, a color of reflected light of the optical multilayer film satisfies a condition of 0.27≦x≦0.31 and 0.30≦y≦0.36 in a chromaticity diagram (x,y,Y) of a CIE color system, reflectance is always 1 percent or less in a wavelength range from 420 nanometers (nm) to 680 nm, both inclusive, Y is 0.5 percent or less, and the optical multilayer film has a total of seven layers, in which a first layer is counted from an optical product base side, and odd layers are low refractive index layers and even layers are high refractive index layers, and an optical film thickness of a sixth layer is greater than or equal to 0.530λ, and not greater than 0.605λ when λ represents a design wavelength (any value in a range from 480 nm to 520 nm, both inclusive).