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. 07, 1988
Filed:
Sep. 26, 1986
Yoshiro Yoda, Tokyo, JP;
Olympus Optical Co., Ltd., Tokyo, JP;
Abstract
In an apparatus for generating a magnetic field, first and second electromagnetic coils are linearly arranged on a yoke. The coils face one surface of an optical disk. An optical head is positioned above the other surface of the optical disk. A track address for denoting a track on the optical disk is picked up from the optical disk by the optical head and an information signal processor. A first and/or second energizing signal is generated from a switching circuit in accordance with the track address. Thus, one or both of coil drive circuits are driven in response to the energizing signals, energizing one or both of the coils, so that a predetermined magnetic field is applied to the optical disk from the selected coil or coils.