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:
Oct. 12, 2004
Filed:
Sep. 06, 2002
Applicant:
Inventors:
Naoki Ikeda, Miyagi, JP;
Seiichi Onodera, Miyagi, JP;
Assignee:
Sony Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B 5/66 ; G11B 5/70 ;
U.S. Cl.
CPC ...
G11B 5/66 ; G11B 5/70 ;
Abstract
Fine projections on a magnetic layer surface are controlled so as to reduce a media noise and improve C/N characteristic. A magnetic recording medium allows reproduction through a MR head or a GMR head. The magnetic layer on a main surface of a non-magnetic base has a coercive force of 80 KA/m or more and 180 KA/m or less. Assuming that a height of the fine projections is h and a diameter of the fine projections at a half-height h/2 is &phgr; , 99% of the fine projections having a height not less than 10 nm satisfy a relationship as expressed by 100 nm≧&phgr; ≧40 nm.