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. 25, 2009
Filed:
Sep. 01, 2005
Lou Shrinkle, Leucadia, CA (US);
David HU, Los Altos, CA (US);
Peter Crill, Encinitas, CA (US);
Matthew Yee, Milpitas, CA (US);
Lou Shrinkle, Leucadia, CA (US);
David Hu, Los Altos, CA (US);
Peter Crill, Encinitas, CA (US);
Matthew Yee, Milpitas, CA (US);
Headway Technologies, Inc., Milpitas, CA (US);
Abstract
A method for operating a head testing apparatus (spin stand) using a mounted hard disk that has had its servo track information pre-written in an external servo-writing apparatus rather than in the testing apparatus itself. This insures more accurate servo-track writing and renders the testing operation more efficient. The problem of repeatable runout (RRO) associated with the transfer of a disk written in one machine to another is eliminated by forming a corrected position error signal (PES) by subtracting the average offset of one or more servo sector locations previously calculated using limited bandwidth operation of the servomechanism, from the position error signal generated during full bandwidth servo operation of the apparatus.