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:
Oct. 27, 1992
Filed:
Sep. 19, 1991
Tsuneo Yanagida, Hachiohji, JP;
Kazuyasu Motoyama, Hachiohji, JP;
Olympus Optical Company Limited, Tokyo, JP;
Abstract
A photo-magnetic (magneto-optic) recording device having recording medium in the form of a rotating magnetic disc having magnetic characteristics in a direction perpendicular to its surface has a pickup head (7) disposed on one side of the disc and movable radially of the disc to scan selected areas of the disc. On the side of the disc opposite to that on which the pickup head is located, there are provided a plurality of coils (8) generating a bias-magnetic field applied to the disc. The coils are disposed in overlapping arrangement with their centers disposed on a line extending radially of the disc. The coils are energized by electric circuitry which comprises means for sensing the position of the pickup head and energizing a respective coil located in position to apply a bias-magnetic to the area of the disc scanned by the pickup head.