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:
Nov. 30, 2004
Filed:
Oct. 10, 2001
Yuuko Kawaguchi, Osaka, JP;
Motoyoshi Murakami, Osaka, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A multilayer film including a first magnetic layer, a second magnetic layer, and a third magnetic layer in the stated order is formed so that a Curie temperature T of the second magnetic layer is set to be lower than a Curie temperature T of the first magnetic layer and a Curie temperature T of the third magnetic layer and that the third magnetic layer is a perpendicular magnetization film. In at least a part of a region at a temperature lower than T , the first magnetic layer is perpendicularly magnetized by exchange coupling with the second magnetic layer, and the magnetization of the third magnetic layer is transferred to the first magnetic layer via the second magnetic layer because of the exchange coupling. The second magnetic layer is made of a magnetic layer that remains in an in-plane magnetization state at room temperature and is perpendicularly magnetized in a temperature range from a critical temperature T higher than room temperature to the Curie temperature T of the same. Thus, in a magneto-optical recording medium to which the magnetic-domain enlarging-reproducing method is applied, upon reproduction of information utilizing the magnetic-domain enlargement, magnetic influences from tracks adjacent to a target track are suppressed.