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:
Mar. 25, 2008
Filed:
Apr. 12, 2005
Applicants:
Yoshiaki Kawato, Tokyo, JP;
Masaaki Futamoto, Shiroyama, JP;
Kazuhiro Nakamoto, Tokyo, JP;
Inventors:
Assignee:
Hitachi Global Storage Technologies Japan, Ltd., Kanagawa-ken, JP;
Primary Examiner:
Int. Cl.
CPC ...
G11B 5/66 (2006.01); G11B 5/70 (2006.01);
U.S. Cl.
CPC ...
Abstract
An improved perpendicular magnetic recording medium and an improved magnetic storage apparatus are provided, which are suitable for high speed and high density magnetic recording. A magnetic under layer of a two-layered perpendicular magnetic recording medium includes three layers: a ferromagnetic layer; a non-magnetic layer; and a ferromagnetic layer, wherein the ferromagnetic layers are antiferromagnetically coupled with each other, thereby preventing a magnetic flux from a magnetic wall in a magnetic under layer from entering a read back head.