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:
Jun. 30, 1992
Filed:
Apr. 12, 1990
Olympus Optical Co., Ltd., , JP;
Abstract
Apparatus for recording opto-magnetically information on an opto-magnetic record medium in the form of the direction of the magnetization stored in a magnetic layer including an objective lens for projecting a laser light beam onto the magnetic layer of the opto-magnetic record medium, a device for generating a bias magnetic field which is applied to the magnetic layer in a direction perpendicular thereto, a supporting device for supporting the objective lens movably in a focusing direction parallel to an optical axis of the objective lens as well as in a tracking direction perpendicular both to the optical axis and an information track direction, and a driving device for moving the objective lens in the focusing and tracking directions to perform the focusing and tracking control. The driving device includes a magnetic circuit for generating a driving magnetic field and focusing and tracking coils mechanically coupled with the objective lens, portions of the focusing and tracking coils being inserted into the driving magnetic field to generate forces for moving the objective lens in the focusing and tracking directions. The magnetic circuit is so constructed that a magnetic flux leaked out of the magnetic circuit becomes minimum in a region of the opto-magnetic record medium onto which the laser light beam is focused by the objective lens, so that the leakage of the magnetic flux does not affect the bias magnetic field and thus the recording operation.