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:
Aug. 12, 2014
Filed:
Mar. 19, 2014
Hgst Netherlands B.v., Amsterdam, NL;
Charles Mathew Mate, San Jose, CA (US);
HGST Netherlands B.V., Amsterdam, NL;
Abstract
In a magnetic recording disk drive, a disk with equally angularly spaced regions that have topography different from the other regions of the disk is used to detect head-disk contact. In one embodiment of a bit-patterned media (BPM) disk, equally angularly spaced servo sectors have topography different from the data regions of the disk. A head-disk spacing sensor detects the topography of the servo sectors as the servo sectors pass the sensor during rotation of the disk. This results in the head-disk spacing sensor generating an output signal with a fundamental frequency f=NX/60 Hz, where N is the number of servo sectors and X is the disk rotation rate in RPM. A second or higher harmonic or harmonics of the fundamental frequency fare filtered from the output of the head-disk spacing sensor and used to identify the initiation of head-disk contact.