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:
Oct. 19, 1999
Filed:
Jul. 30, 1996
Kenji Tanase, Gifu, JP;
Atsushi Yamaguchi, Gifu, JP;
Yoshihisa Suzuki, Aichi, JP;
Satoshi Sumi, Gifu, JP;
Yoshiharu Uchihara, Gifu, JP;
Seiji Murata, Osaka, JP;
Kenji Torasawa, Gifu, JP;
Sanyo Electric., Ltd., Osaka, JP;
Abstract
In magneto-optical recording medium, on a transparent substrate of polycarbonate resin, an SiN film having the thickness of 600 to 800 .ANG. and surface roughness Rmax of at most 10 nm is formed. On the SiN film, a GdFeCo reading layer having the thickness of 800 to 1200 .ANG. with Gd content of 30 to 36 at. % and Co content of 12 to 50 at. % is formed. On the reading layer, a TbFeCo recording layer of which Co content is 10 to 16 at. % is formed. The recording layer is a perpendicular magnetization film, and the reading layer is an in-plane magnetization film. At the time of reading, the reading and recording layers are heated, and the direction of magnetization of the recording layer is transferred to the reading layer only in the prescribed heated area. Information can be read only from the transferred portion, and thus a super resolution effect is obtained. When Kerr rotation angle .theta..sub.K is measured for the light reflected from the reading layer while the temperatures of the reading and recording layers are elevated, .theta..sub.K is approximately in proportion to Cth power of the elevated temperature t, wherein C is at least 8.0.