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:
Jun. 10, 2014
Filed:
Feb. 28, 2012
Jiangang Liang, San Jose, CA (US);
Jeng-yu Wang, Fremont, CA (US);
Siri S. Weerasooriya, Campbell, CA (US);
Duc H. Banh, San Jose, CA (US);
Jiangang Liang, San Jose, CA (US);
Jeng-Yu Wang, Fremont, CA (US);
Siri S. Weerasooriya, Campbell, CA (US);
Duc H. Banh, San Jose, CA (US);
Western Digital Technologies, Inc., Irvine, CA (US);
Abstract
A servo writer is disclosed operable to write servo sectors on a disk to define non-circular servo tracks. The servo writer comprises control circuitry including a servo control system operable to measure a position of a head over the disk to generate a position signal, generate a position error signal (PES) representing a difference between the position signal and a reference signal, process the PES with a servo compensator to generate a control signal, and position the head over the disk in response to the control signal. A disturbance is induced into the servo control system, and while positioning the head over the disk in response to the control signal, a plurality of servo sectors are written on the disk to define a servo track, wherein the disturbance induced into the servo control system causes the servo track to be non-circular relative to a rotation axis of the disk.