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:
Mar. 02, 1999
Filed:
Oct. 30, 1997
Yoshihiro Muto, Miyagi, JP;
Sony Corporation, Tokyo, JP;
Abstract
The present invention provides a method for producing a magneto-optical recording medium capable of optical intensity modulation direct overwriting, which method enables to easily form an initialization layer having an excellent stability against the magnetization inversion during the optical intensity modulation direct overwriting. When producing a magneto-optical recording medium at least a memory layer 1 which is magnetized according to a recording signal, a recording layer 2 whose magnetization direction is temporarily changed according to a recording signal during a recording, a switch layer 3 which is temporarily demagnetized during a recording, and an initialization layer 4 whose magnetization direction is not changed during a recording; the memory layer 1 is formed by forming at least a first magnetic layer 1a having a residual magnetization Mr smaller than a saturation magnetization Ms and a second magnetic layer 1b having a ratio Mr/Ms between the residual magnetization Mr and the saturation magnetization Ms greater than that of the first magnetic layer. Moreover, when forming the second magnetic layer 1b, an external magnetic field is applied almost in the vertical direction to the film surface.