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. 29, 2000
Filed:
Nov. 17, 1997
Haruhiko Izumi, Kawasaki, JP;
Ken Tamanoi, Kawasaki, JP;
Masaharu Moritsugu, Kawasaki, JP;
Miyozo Maeda, Kawasaki, JP;
Toshio Sugimoto, Kawasaki, JP;
Koji Matsumoto, Kawasaki, JP;
Motonobu Mihara, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A magneto-optical recording medium adapted for reproduction of a high resolution signal without the necessity of a reproducing magnetic field. The magneto-optical recording medium comprises a transparent substrate and deposits of a reproducing layer, a switch layer and a recording layer formed on the transparent substrate successively. The reproducing layer is a perpendicular magnetization film at a room temperature but is turned to an in-plane magnetization film when heated beyond a predetermined temperature. Each of the switch layer and the recording layer is a perpendicular magnetization film. The respective Curie temperatures Tc1, Tc2 and Tc3 of the reproducing layer, the switch layer and the recording layer satisfy the relationship of Tc1>Tc3>Tc2. When a reproducing laser beam is irradiated to the recording medium, the switched connection between the reproducing layer and the recording layer is interrupted in a high temperature region heated beyond the Curie temperature of the switch layer, whereby the reproducing layer is caused to present in-plane magnetization.