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:
Feb. 17, 2004
Filed:
Jan. 31, 2001
Edgar D. Sheh, San Jose, CA (US);
Hemant Melkote, San Jose, CA (US);
Vinay K. Agarwal, Cupertino, CA (US);
Western Digital Technologies, Inc., Lake Forest, CA (US);
Abstract
The present invention may be embodied in a method and a disk drive for improving head position accuracy during track following through real-time identification of external vibration. A selected track is followed using a servo control loop having a nominal gain and being responsive to position error signal samples generated based on a difference between head position samples and a reference head position value. A spectral power value within a predetermined frequency band is determined from a sequence of the position error signal samples. If a property of the spectral power value exceeds a threshold, the gain of the servo control loop is increased within the predetermined frequency band to attenuate the effect of external vibration on the position of the head over the selected track during track following.