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:
Apr. 17, 2012
Filed:
Dec. 03, 2008
Applicant:
Mikio Kobayashi, Utsunomiya, JP;
Inventor:
Mikio Kobayashi, Utsunomiya, JP;
Assignee:
Canon Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B 5/18 (2006.01);
U.S. Cl.
CPC ...
Abstract
A diffractive optical element includes at least one element portion including a base, a diffraction grating, a substrate, and an intermediate layer. The base and the diffraction grating are disposed above the substrate through the intermediate layer, and are formed of a same material. An extinction coefficient for the d-line of the material of the diffraction grating and an extinction coefficient for the d-line of a material of the intermediate layer are properly set to satisfied conditional expressions.