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:
Mar. 09, 2021
Filed:
Jan. 03, 2019
Applicant:
Canon Kabushiki Kaisha, Tokyo, JP;
Inventors:
Masato Tanaka, Tokyo, JP;
Makoto Kojima, Atsugi, JP;
Tomonao Nakayasu, Kawasaki, JP;
Yukinobu Okura, Tokyo, JP;
Assignee:
CANON KABUSHIKI KAISHA, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B 5/18 (2006.01); B29D 11/00 (2006.01);
U.S. Cl.
CPC ...
G02B 5/1852 (2013.01); B29D 11/00269 (2013.01); B29D 11/00932 (2013.01); G02B 5/1876 (2013.01);
Abstract
An optical member having a concentric diffraction surface facing the outside, wherein the projection having a inclined surface concentric to the diffraction surface having an angle of inclination θ smaller than the angle of inclination ϕ is provided outside the diffraction surface having the largest ϕ, so that an interference of a cutting tool is avoided, and simultaneously, deterioration of a surface roughness may be restrained.