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:
Jun. 30, 2015
Filed:
Dec. 18, 2013
Canon Kabushiki Kaisha, Tokyo, JP;
Rie Ishimatsu, Utsunomiya, JP;
Takeharu Okuno, Utsunomiya, JP;
CANON KABUSHIKI KAISHA, , JP;
Abstract
An optical element includes a transparent substrate and an antireflection coating on the substrate. The antireflection coating includes an intermediate layer on the substrate, and an undulation layer that is formed on the intermediate layer and has a plurality of convexes arrayed with spacing shorter than a shortest wavelength. The undulation layer has a portion where refractive index increases from a light incident side to the substrate. The intermediate layer has a first layer closest to the substrate, and a second layer formed on the first layer. A refractive index n1 of the first layer, a refractive index n2 of the second layer, and a refractive index ns of the substrate satisfy the following conditional equations:1.75≦≦2.20;1<2; and1<