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:
Apr. 14, 2009
Filed:
May. 27, 2005
Curtis Egan, Thornton, CO (US);
David R. Finamore, Louisville, CO (US);
Curtis Egan, Thornton, CO (US);
David R. Finamore, Louisville, CO (US);
Maxtor Corporation, Scotts Valley, CA (US);
Abstract
Methods and structures for detecting touchdown of the read/write head on its recording surface or for detecting other read signal amplitude modulations as proportional to variance of the value of the read channel variable gain amplifier ('VGA'). Variance in the VGA values caused by the standard feedback control electronics associated therewith is proportional to amplitude modulations of the sensed signal picked up by the read channel (or servo read sensor). These amplitude modulations are, in turn, reflective of flying height of the read/write head as well as generally indicative of other parameters of the read channel operation. Touchdown of the read/write head and other parameters of the disk drive operation may therefore be detected as variances in the VGA control values.