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. 27, 2005
Filed:
Mar. 08, 2001
Applicant:
Hiroaki Yukawa, Chiba, JP;
Inventor:
Hiroaki Yukawa, Chiba, JP;
Assignee:
Sony Corporation, , JP;
Primary Examiner:
Int. Cl.
CPC ...
G11B007/00 ;
U.S. Cl.
CPC ...
Abstract
An optical pickup device is adapted to read information signals from optical recording media of two different types such as a 'DVD' and a 'CD' for which two light beams with different wavelengths are used and comprises a photodetector having a single light receiving section that can be shared by optical recording media of two different types. Both the light beam reflected from the signal recording surface of the “DVD”and the light beam reflected from the signal recording surface of the “CD”are diffracted by the diffraction elementand focussed to a same spot on the light receiving surface of the photodiode of a photodetector