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:
Nov. 13, 2012
Filed:
Mar. 28, 2008
Teiichiro Umezawa, Singapore, SG;
Masafumi Ishiyama, Singapore, SG;
Kenji Ayama, Singapore, SG;
Tokichiro Sato, Singapore, SG;
Teiichiro Umezawa, Singapore, SG;
Masafumi Ishiyama, Singapore, SG;
Kenji Ayama, Singapore, SG;
Tokichiro Sato, Singapore, SG;
WD Media (Singapore) Pte. Ltd., Singapore, SG;
Abstract
A vertical magnetic recording disc () includes a base (), a magnetic recording layer (), and a medium protection layer (). The magnetic recording layer () is a ferromagnetic layer having a granular structure where a granular portion is formed. The medium protection layer () contains nitrogen (N) atoms and carbon (C) atoms with a number ratio (N/C) in a range from 0.050 to 0.150. In a Raman spectrum obtained by exciting the medium protection layer () by argon ion laser light of wavelength 514.5 nm, from which a fluorescence is removed, the peak ratio Dh/Gh is in a range from 0.70 to 0.95, when a D peak Dh appearing in the vicinity of 1350 cmis separated from G peak Gh appearing in the vicinity of 1520 cmby the Gauss function.