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:
Oct. 21, 2003
Filed:
Oct. 12, 2000
Hai T. Ho, Westminster, CO (US);
Seagate Technology LLC, Scotts Valley, CA (US);
Abstract
An apparatus and method for canceling nonrepeatable runout position error in a disc drive. Pursuant to the method, a frequency of a specified nonrepeatable runout disturbance is determined. A position error signal indicative of a position of a read/write head relative to a track is received. A signal is generated based upon the frequency of the specified nonrepeatable runout disturbance and the received position error signal. The generated signal is applied to the servo loop. Applying the generated signal to the servo loop cancels a component of the position error signal arising from the specified nonrepeatable runout disturbance. In an illustrative embodiment, applying the generated signal to the servo loop produces a notch in an error sensitivity function relating the position error signal to a general nonrepeatable runout disturbance, the notch being centered at the frequency of the specified nonrepeatable runout disturbance.