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. 02, 2005
Filed:
Aug. 30, 2002
Hemant Melkote, San Jose, CA (US);
Robert L. Cloke, Santa Clara, CA (US);
Vinay K. Agarwal, Cupertino, CA (US);
Hemant Melkote, San Jose, CA (US);
Robert L. Cloke, Santa Clara, CA (US);
Vinay K. Agarwal, Cupertino, CA (US);
Western Digital Technologies, Inc., Lake Forest, CA (US);
Abstract
A method is disclosed for writing servo patterns for tracks on a rotating magnetic disk medium of a disk drive. Servo patterns are written on a reference track of the disk medium. Track following of the written servo patterns on the reference track is performed using a servo loop having a closed-loop response. A position error signal is generated for the reference track based on the track following. A correction signal is generated based on the track following using an observer of a one-dimensional state model that is equivalent to a two-dimensional state model of the servo loop. Servo patterns are written on a target track during track following of the reference track. The position error signal of the servo loop is adjusted based on the correction signal to reduce radial error propagation from the reference track to the target track.