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:
Jul. 09, 2002
Filed:
Aug. 24, 1999
Naoyuki Takagi, Gifu, JP;
Atsushi Yamaguchi, Ogaki, JP;
Sanyo Electric Co., Ltd., Osaka, JP;
Abstract
A laser beam is directed from an optical head ( ) while an alternating magnetic field is applied from a magnetic head ( ). A reproduced signal from the optical head ( ) is input to a reproduced signal detecting circuit ( ) through a reproduced signal amplifying circuit ( ). The detected signal (CK) of discontinuous regions provided at prescribed intervals in the groove of a magneto-optical recording medium ( ) is input to an external synchronous signal generating circuit ( ) and, in response, an external synchronous signal (SYN) is generated. In synchronization with the external synchronous signal (SYN), the reproduced signal detecting circuit ( ) calculates a difference between the reproduced signal generated when a magnetic field for magnetic domain magnification is applied and the reproduced signal generated when a magnetic field for magnetic domain erasure is applied. The difference is detected as a reproduced signal (RF). Accordingly, low frequency “winding” included in the reproduced signal from the optical head ( ) is offset, resulting in a correct reproduced signal (RF).