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:
May. 17, 1994
Filed:
Oct. 30, 1992
Mitsuo Ishii, Nabari, JP;
Tomoyuki Miyake, Nara, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
An external magnetic field generation apparatus is used for a recording and reproduction apparatus which records information on a magneto-optical recording medium based on the magnetic field modulation system and the light modulation system, and applies a magnetic field to the portion of the magneto-optical recording medium where the light beam is projected. The apparatus has the first electro-magnet, used for the magnetic field modulation system, for generating an a.c. magnetic field which is reversed at a high speed. The apparatus has the second electro-magnet, used for the light modulation system, for generating a strong d.c. magnetic field such that power consumption coincides with that of the first electro-magnet. The second electro-magnet is integral with the first electro-magnet. The apparatus has a driver for selecting one of the electro-magnets in response to a switching signal, and the driver supplies power to the selected electro-magnet.