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:
May. 07, 2002
Filed:
Mar. 07, 2001
Satoru Ohnuki, Toride, JP;
Norio Ohta, Ibaraki, JP;
Katsusuke Shimazaki, Ibaraki, JP;
Masafumi Yoshihiro, Ibaraki, JP;
Hiroki Takao, Ibaraki, JP;
Hitoshi Watanabe, Ibaraki, JP;
Hitachi Maxell, Ltd., Ibaraki, JP;
Abstract
A magneto-optic recording medium includes a second auxiliary magnetic film, a first auxiliary magnetic film and a magneto-optic recording film on a substrate. The auxiliary magnetic films change from in-plane magnetization to vertical magnetization at critical temperatures T and T . Since they have the relation T >T , the magnetic domain transferred from the magneto-optic recording film to the first auxiliary magnetic film at the time of reproduction is expanded in diameter and is transferred to the second auxiliary magnetic film when the temperature profiles of the auxiliary magnetic films inside an optical spot are utilized. The magnetic domain of the magneto-optic recording film can be expanded and transferred, too, by means of magnetostatic coupling by using a non-magnetic film in place of the first auxiliary magnetic film. Pulse reproduction light subjected to power modulation in synchronism with a reproduction clock can be used at the time of reproduction. Even when a very small magnetic domain is recorded, the intensity of an amplified reproduction signal can be detected and excellent C/N can be obtained.