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. 20, 2013
Filed:
Aug. 28, 2008
Migaku Takahashi, Sendai, JP;
Shin Saito, Sendai, JP;
Gohei Kurokawa, Ichihara, JP;
Yuzo Sasaki, Ichihara, JP;
Tatsu Komatsuda, Ichihara, JP;
Atsushi Hashimoto, Chiba, JP;
Akihiko Takeo, Minato-ku, JP;
Tomoyuki Maeda, Kawasaki, JP;
Migaku Takahashi, Sendai, JP;
Shin Saito, Sendai, JP;
Gohei Kurokawa, Ichihara, JP;
Yuzo Sasaki, Ichihara, JP;
Tatsu Komatsuda, Ichihara, JP;
Atsushi Hashimoto, Chiba, JP;
Akihiko Takeo, Minato-ku, JP;
Tomoyuki Maeda, Kawasaki, JP;
Abstract
A perpendicular magnetic recording medium including at least a soft under layer, an orientation control layer, a magnetic recording layer and a protective layer on a non-magnetic substrate, wherein the orientation control layer is composed of three or more layers including a seed layer, a first intermediate layer and a second intermediate layer sequentially, formed in that order from the substrate side, the crystal grains that constitute the first intermediate layer are epitaxially grown on the crystal grains of the seed layer, the crystal grains that constitute the second intermediate layer are epitaxially grown on the crystal grains of the first intermediate layer, and the crystal grains that constitute the second intermediate layer are finer than the crystal grains that constitute the first intermediate layer.