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:
Feb. 03, 1998
Filed:
Oct. 28, 1996
Yoshiyuki Matsumoto, Tokyo, JP;
Sony Corporation, Tokyo, JP;
Abstract
An optical pickup device for irradiating a laser beam onto an optical recording medium and receiving a return light from the optical recording medium, comprising a semiconductor laser element which is formed on a semiconductor substrate and has first and second light emitting faces, a first reflection portion provided so as to confront the first light emitting face of the semiconductor laser element, a second reflection portion provided so as to provide confront the second light emitting face of the semiconductor laser element, a first photodetector for receiving a return reflection light of the laser beam which is reflected from the first reflection portion and focused on the recording medium, and a second photodetector for receiving a return reflection light of the laser beam which is reflected from the second reflection portion and focused on the recording medium. A recording signal on the recording medium and a focus error signal are detected by the first and second photodetectors.