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. 07, 2004
Filed:
Jul. 26, 2000
Applicant:
Inventor:
Takehiko Nakai, Kawasaki, JP;
Assignee:
Canon Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B 5/18 ;
U.S. Cl.
CPC ...
G02B 5/18 ;
Abstract
A diffraction optical element wherein a plurality of diffraction gratings formed of at least two kinds of materials differing in dispersion are laminated, at least two of the plurality of diffraction gratings are formed on a curved surface and adjacent to each other, and these two adjacent diffraction gratings are equal to each other in the shape of a curved tip plane in which the tips of respective grating portions are ranged.