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:
Aug. 02, 2005
Filed:
Apr. 15, 2003
Tetsuya Kanbe, Yokohama, JP;
Yuzuru Hosoe, Hino, JP;
Ichiro Tamai, Hachioji, JP;
Yoshio Takahashi, Koganei, JP;
Kiwamu Tanahashi, Fujisawa, JP;
Satoshi Matsunuma, Kamakura, JP;
Yoshihiro Shiroishi, Hachioji, JP;
Tetsuya Kanbe, Yokohama, JP;
Yuzuru Hosoe, Hino, JP;
Ichiro Tamai, Hachioji, JP;
Yoshio Takahashi, Koganei, JP;
Kiwamu Tanahashi, Fujisawa, JP;
Satoshi Matsunuma, Kamakura, JP;
Yoshihiro Shiroishi, Hachioji, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A magnetic storage device has a magnetic layer, the magnetic crystal grains of which are separated by a nonmagnetic phase. The typical crystal grain is in the approximate shape of a sphere or an ellipsoid. The thickness of the magnetic crystal grains, which is in the direction perpendicular to the surface or the film, is smaller than that of the thickness of the magnetic film. The ratio of the coercive force, which is measured in the circumferential direction, to the coercive force, which is measured in the radial direction, (the orientation ratio of the coercive force), is larger than 1.0, but preferably nor greater than 3.0. Further, the area fraction of the magnetic grains having an extended axis within 30° from the circumferential direction is equal to or more than 45%.