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:
Nov. 20, 1990
Filed:
Dec. 11, 1987
Applicant:
Inventors:
Naoya Eguchi, Tokyo, JP;
Osamu Kawakubo, Saitama, JP;
Hitoshi Okada, Chiba, JP;
Tamotsu Maeda, Kanagawa, JP;
Susumu Tosaka, Tokyo, JP;
Assignee:
Sony Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ; G11B / ;
U.S. Cl.
CPC ...
369013 ; 360114 ;
Abstract
A rotation control for a magnet used in a magneto-optical recording system having a first coil that rotates a permanent magnet to invert the polarity of its magnetic field applied to an optical recording type disc and a second coil provided at the position displaced from the central line of the first coil and for applying a driving force to the permanent magnet when the permanent magnet begins to rotate, wherein the permanent magnet can be settled in quite a short time after it is inverted in polarity by controlling a drive current applied to the second coil.