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. 13, 2009
Filed:
Sep. 22, 2004
Takeshi Iwasaki, Yokohama, JP;
Soichi Oikawa, Tokyo, JP;
Futoshi Nakamura, Ichikawa, JP;
Tomoyuki Maeda, Kawasaki, JP;
Hiroshi Sakai, Ichihara, JP;
Akira Sakawaki, Ichihara, JP;
Kenji Shimizu, Chiba, JP;
Takeshi Iwasaki, Yokohama, JP;
Soichi Oikawa, Tokyo, JP;
Futoshi Nakamura, Ichikawa, JP;
Tomoyuki Maeda, Kawasaki, JP;
Hiroshi Sakai, Ichihara, JP;
Akira Sakawaki, Ichihara, JP;
Kenji Shimizu, Chiba, JP;
Showa Denko K.K., Tokyo, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
To make possible high density recording by making the structure of the perpendicular magnetic recording layer finer. A perpendicular magnetic recording mediumincludes at least a nonmagnetic under layer, a perpendicular magnetic layer, and a protective layer which are stacked on a nonmagnetic substrate, wherein the perpendicular magnetic layer includes ferromagnetic crystal grains and nonmagnetic crystal grain boundary regions, wherein the crystal grain boundary region includes at least two kinds of oxide.