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. 30, 2010
Filed:
Sep. 05, 2007
Applicants:
Kenichiro Saisho, Kanagawa, JP;
Yoshinori Hayashi, Kanagawa, JP;
Kohji Sakai, Tokyo, JP;
Inventors:
Assignee:
Ricoh Company, Ltd., Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
G02B 26/08 (2006.01);
U.S. Cl.
CPC ...
Abstract
A diffractive-optical element that is transparent includes a diffraction surface that is formed by a step. A width of the step is set substantially equal to a common multiple of λ/{n(λ)−1} for two or more wavelengths, where λ(i=1, 2, . . . ) is a wavelength and n(λ) is a refractive index with respect to the wavelength λ.