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:
Dec. 01, 2020
Filed:
Jul. 30, 2018
Canon Kabushiki Kaisha, Tokyo, JP;
Kenichi Iwata, Fujisawa, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
There is provided a diffraction optical element which comprises a base material, and in which a first resin layer having a diffraction grating shape and a second resin layer are laminated on the base material. The diffraction grating shape forms a plurality of concentric annular sections when planarly viewed from a lamination direction of the diffraction optical element. The second resin layer comprises a first portion and a second portion, and the first portion is provided on a first annular section of the first resin layer. The second portion is continuously provided from above the first portion to above a region including a periphery of the first resin layer. A difference between a refractive index of the second portion on a center of the first annular section and a refractive index of the second portion on a circumference of the first annular section is within 0.0005.