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:
Nov. 23, 2004
Filed:
Nov. 20, 2001
Applicant:
Inventors:
Kyu Takada, Otsu, JP;
Takuji Hatano, Suita, JP;
Koji Takahara, Amagasaki, JP;
Koujirou Sekine, Ibaraki, JP;
Assignee:
Minolta Co. Ltd., Osaka, JP;
Primary Examiner:
Int. Cl.
CPC ...
G02B 5/18 ;
U.S. Cl.
CPC ...
G02B 5/18 ;
Abstract
A diffractive optical element has a diffraction grating formed by periodic depressions and projections on the surface of a substrate and a dielectric multilayer film on the diffraction grating. The materials of the respective layers of the film are chosen such that the depth of the depressions is an integral multiple of the sum of the thickness of the layers in one period of the film. As a result, individual layers of the film are continuous across multiple depressions and projections, to provide improved first-order reflectance.