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:
Oct. 25, 1983
Filed:
Oct. 17, 1980
Nobutake Imamura, Tokyo, JP;
Chuichi Ota, Fuchu, JP;
Kokusai Denshin Denwa Co., Ltd., Tokyo, JP;
Abstract
Disclosed is a magneto-optic recording medium to which magnetic Kerr effect is applied and characterized by the tracking guide on an even surface free from disorder of linear polarization. Since the tracking guide may be any type if it has a different reflection characteristic from that of the memory area viewing from magneto-optic standpoint, the tracking guide can be produced by a thermal treatment for changing the magnetic property of a part of a thin film with its magnetization easy axis in the direction perpendicular to the film surface. As no difference exists between the memory area and the guide area other than their magnetic properties, they are on the same plane and have no unevenness between their surfaces. Where, the guide area is assumed to have such magnetic property as the magnetization easy axis is parallel to the film surface, or it is perpendicular to the film surface but has no rectangular hysterisis. Such change of magnetic property can be obtained easily by an irradiation of laser beam to an amorphous alloy thin film with perpendicular magnetization easy axis.