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:
Jan. 30, 2007
Filed:
Dec. 16, 2002
Hisao Kawai, Tokyo, JP;
Teiichiro Umezawa, Tokyo, JP;
Hirotaka Tanaka, Tokyo, JP;
Masaki Uemura, Tokyo, JP;
Hisao Kawai, Tokyo, JP;
Teiichiro Umezawa, Tokyo, JP;
Hirotaka Tanaka, Tokyo, JP;
Masaki Uemura, Tokyo, JP;
Hoya Corporation, Tokyo, JP;
Hoya Magnetics Singapore Pte. Ltd., Singapore, SG;
Abstract
In a magnetic recording medium including a glass substrate () having a principal surface on which at least a magnetic layer () is formed, the magnetic recording medium has a coercive force of 2500 oersted or more in a circumferential direction thereof. The principal surface of the glass substrate is provided with a texture having a predetermined surface roughness so that the magnetic layer is given circumferential magnetic anisotropy. The magnetic recording medium further includes a magnetic anisotropy inducing layer () formed between the glass substrate and the magnetic layer so that the magnetic recording medium has an oriented ratio (OR) of 1.1 or more. The oriented ratio (OR) is defined as a ratio of a magnetic characteristic in circumferential direction to another magnetic characteristic in the radial direction.