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:
Dec. 03, 1996
Filed:
Mar. 25, 1993
Masahisa Fujino, Musashino, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
Recording of information on and/or reproduction of information from a magnetooptical recording medium is effected as follows. A light beam from an objective lens is irradiated on a track of the recording medium. The objective lens is driven in a direction perpendicular to the track such that the beam spot and the track have a predetermined positional relationship therebetween. A magnetic field modulated according to information to be recorded is applied to the beam spot irradiated position of the recording medium by a magnetic field applying device. A relative position between the objective lens and the magnetic field applying device in the direction perpendicular to the track is detected. The recording of information is effected on the recording medium by applying the magnetic field according to the information while changing the beam spot irradiated position on the recording medium with respect to the track. The movable range of the objective lens, in which a level of a reproduction signal obtained in the reproduction of information exceeds a predetermined level, in the direction perpendicular to the track, in the recording operation, is detected on the basis of a detection result of the relative position, so that a driver for the objective lens is controlled on the basis of the detected movable range.