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:
Dec. 09, 2014
Filed:
Nov. 19, 2012
Hgst Netherlands B.v., Amsterdam, NL;
Sripathi V. Canchi, Santa Clara, CA (US);
Michael K. Grobis, San Jose, CA (US);
Bruno Marchon, Palo Alto, CA (US);
Erhard Schreck, San Jose, CA (US);
HGST Netherlands B.V., Amsterdam, NL;
Abstract
A data storage device and method for enabling dynamic fly height control which is insensitive to off-track motions is described. In some embodiments, a hard disk drive acquires signal data from neighboring overlapping tracks which are unwritten, thermally erased, or AC demagnetized. Side-to-side (off-track) positional errors or oscillations of the read head do not affect the signal which arises solely from the magnetic domains on the disk. Thus, signal variations may only arise from changes in the fly height. In other embodiments, neighboring overlapping data tracks are prewritten with reference data. The width of the neighboring overlapping tracks exceeds any expected side-to-side positional errors of the read head, thus signal variations may only arise from changes in the fly height. For all embodiments, the noise or reference data signal may serve as a reliable dynamic measure of the fly height with no effects arising from off-track motions.