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:
Feb. 16, 1993
Filed:
May. 19, 1992
Katsutarou Ichihara, Tokyo, JP;
Hiromichi Kobori, Yokohama, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A magneto-optical information storage medium includes a substrate, a recording layer formed on the substrate and having an axis of easy magnetization extending in the direction perpendicular to its surface, a nonmagnetic layer formed on the recording layer, and a bias layer, formed on the nonmagnetic layer, for generating bias magnetic field H.sub.B (T) in accordance with a temperature. The magnetization of the recording layer is reversed by bias magnetic field H.sub.B (T) in first and second magnetization reversal temperature regions T.sub.W and T.sub.E (T.sub.W >T.sub.E). Information is recorded on such a magneto-optical information storage medium by radiating a first laser beam having a first power level for heating an irradiated portion to a temperature in region T.sub.W. In addition, information erasing is performed by radiating a second laser beam having a second power level which is lower than the first power level and heats an irradiated portion to a temperature in region T.sub.E. Overwrite is performed by power-modulating between the first and second power levels and radiating the modulated laser beam onto a previously recorded area of the medium.