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. 08, 2005
Filed:
Jul. 25, 2001
David Kuo, Palo Alto, CA (US);
Xinwei LI, Milpitas, CA (US);
Jing Gui, Fremont, CA (US);
Seagate Technology LLC, Scotts Valley, CA (US);
Abstract
A magnetic recording medium is formed with a distribution of low coercivity regions functioning as a transition pattern for servo information capable of being sensed by a read/write head by exposing a masked magnetic layer to ions to change the coercivity of the exposed magnetic layer without substantially affecting the topography of the magnetic layer. Embodiments of the present invention include forming a series of substantially radially extending low coercivity regions used to divide the magnetic layer into a plurality of sectors comprising substantially concentric circumferentially extending data tracks by exposing a masked magnetic layer having a high coercivity, i.e. from about 2000 Oe to about 10000 Oe, to one or more heavy atom ion bombardments of gaseous ions, e.g. argon ions, at a dose of about 1×10atoms/cmto about 9×10atoms/cmhaving an implantation energy of about 10 KeV to about 50 KeV.