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. 19, 2002
Filed:
Aug. 17, 1999
Sony Corporation, Tokyo, JP;
Abstract
Disclosed is an optical disc apparatus compatible with both ROM type and RAM type optical discs having high density and large capacity. An optical disc apparatus includes: a disc control device including an optical disc (a magneto-optical disc), a spindle motor for rotating the optical disc, an objective lens for forming a light spot on the optical disc, and a control drive device which controls and drives the objective lens in the tracking direction of the optical disc, a semiconductor laser serving as a light source, a signal light transfer having a polarization-preserving optical fiber for guiding output light from the semiconductor laser to the objective lens, ¼ wave plates provided in optical paths on both sides of the polarization-preserving optical fiber, and signal detecting devices (polarization beam splitter and photo detectors) for detecting a servo signal, etc. from the reflected light from the optical disc.