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:
Feb. 15, 2022
Filed:
Oct. 11, 2017
Canon Kabushiki Kaisha, Tokyo, JP;
Mikio Kobayashi, Utsunomiya, JP;
CANON KABUSHIKI KAISHA, Tokyo, JP;
Abstract
A diffractive optical element includes a first lens having a convex surface, a second lens having a concave surface, disposed in such a manner that the concave surface of the second lens faces the convex surface of the first lens, and a diffraction grating section formed between the first and the second lenses and having positive optical power through diffraction. The diffraction grating section includes a first diffraction grating and a second diffraction grating disposed in this order from a side closer to the first lens; the second diffraction grating has a refractive index larger than that of the first diffraction grating, and an inner diameter of a grating wall surface of the diffraction grating section decreases as approaching to the second lens from the first lens.