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:
Jul. 12, 2011
Filed:
Aug. 20, 2009
Kenji Shimizu, Ichihara, JP;
Junichi Kishimoto, Ichihara, JP;
Kenji Shimizu, Ichihara, JP;
Junichi Kishimoto, Ichihara, JP;
Showa Denko K.K., Tokyo, JP;
Abstract
A magnetic recording medium comprises a nonmagnetic substrate on which is disposed at least a vertical magnetic layer. The vertical magnetic layer comprises at least three layers including a lower layer, an intermediate layer and an upper layer from the substrate side. The lower, intermediate and upper magnetic layers are bound by ferro-coupling and are constituted of magnetic particles which are columnar crystals extending continuously from the lower layer to the upper layer. A nonmagnetic layer is between the lower and intermediate magnetic layers or between the intermediate and upper magnetic layers. The upper layer has a magnetic anisotropic constant (Ku) from 0.8×10to 4×10(erg/cc), the intermediate layer has a magnetic anisotropic constant (Ku) from 2×10to 7×10(erg/cc) and the lower layer has a magnetic anisotropic constant (Ku) from 1×10to 4×10(erg/cc).