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. 21, 2017
Filed:
May. 25, 2016
Hgst Netherlands B.v., Amsterdam, NL;
Michael Konrad Grobis, San Jose, CA (US);
Virat Vasav Mehta, San Jose, CA (US);
Gregory John Parker, San Jose, CA (US);
Hal Jervis Rosen, Los Gatos, CA (US);
Bruce David Terris, Sunnyvale, CA (US);
HGST Netherlands B.V., Amsterdam, NL;
Abstract
A heat-assisted magnetic recording (HAMR) disk has multiple independent data layers, each data layer being a continuous non-patterned layer of magnetizable material. Each data layer can store data independent and not related to the data stored in the other data layers. The data layers are separated by a nonmagnetic spacer layer (SL) and each data layer is formed of high-anisotropy (K) material so that the coercivities of lower and upper data layers (RL1 and RL2) are greater than the magnetic write field. At a high laser power both RL1 and RL2 are heated to above their respective Curie temperatures and data is recorded in both RL1 and RL2. At low laser power only upper RL2 is heated to above its Curie temperature and data is recorded only in RL2. The SL prevents lower RL1 from being heated to above its Curie temperature at low laser power.