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. 25, 2008
Filed:
Feb. 16, 2007
Applicants:
Hideaki Hirai, Kanagawa, JP;
Shigeru Ohuchida, Tokyo, JP;
Inventors:
Hideaki Hirai, Kanagawa, JP;
Shigeru Ohuchida, Tokyo, JP;
Assignee:
Ricoh Company, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B 7/00 (2006.01); G02B 27/14 (2006.01);
U.S. Cl.
CPC ...
Abstract
An optical pickup unit includes first and second light sources of first and second wavelengths, respectively, a diachronic element, a phase plate, and an objective lens. One of the first and second light sources is selected so that information recording or reproduction is performed by converging a light beam emitted from the selected one of the first and second light sources on an optical recording medium via the diachronic element, the phase plate, and the objective lens.