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:
Mar. 20, 2001
Filed:
Feb. 16, 1999
NEC Corporation, Tokyo, JP;
Abstract
The present invention provides a magnetic disc apparatus comprising a vertical two-layered magnetic recording (MR) medium and a mono-pole/MR composite head or ID/MR composite head, wherein the vertical two-layered magnetic recording medium includes a vertical magnetization film formed on an undercoat soft magnetic film having no magnetic domain wall structure. This eliminates the fatal defect of a conventional vertical two-layered medium that an undercoat soft magnetic film domain wall is easily shifted by an external magnetic field generated by motors for disc rotation and head positioning, causing demagnetization of the recording magnetization to lower the output. The magnetic disc apparatus according to the present invention enables to obtain a high output stability.