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:
Feb. 14, 2012
Filed:
Jun. 09, 2006
Migaku Takahashi, Sendai, JP;
Masahiro Oka, Ichihara, JP;
Akira Kikitsu, Minato-ku, JP;
Tohoku University, Miyagi-ken, JP;
Showa Denko K.K., Tokyo, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
The invention provides a magnetic recording medium, and a magnetic recording and reproducing apparatus. The magnetic recording medium includes a substrate, an under layerformed on the substrate, a magnetic recording layerformed on the under layer, and a protective layerformed on the magnetic recording layer. The magnetic recording layeris composed of a primary recording layerand a secondary recording layerwhich are mutually exchange-coupled. The primary recording layerhas magnetic grains and a nonmagnetic material that surrounds the magnetic grains, and has a perpendicular magnetic anisotropy. The secondary recording layeris made of a material having a negative crystal magnetic anisotropy and its easy plane of the magnetization is a plane of the medium.