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. 15, 2000
Filed:
Jun. 24, 1998
Peter Everett Brooks, Rochester, MN (US);
Lance Allen Gabrielson, Rochester, MN (US);
Western Digital Corporation, Irvine, CA (US);
Abstract
A method of centering a disk pack on a base rotatably supporting the disk pack includes performing a series a steps while the disk pack is rotating. A reference timing signal is generated. A first imbalance in the rotating disk pack is detected, and a first imbalance signal is produced. The first imbalance signal is correlated with the reference timing signal to produce a first correlation value, which indicates a location of the first imbalance relative to the reference timing signal. Based upon the first correlation value, a first impact is applied to the base, causing the base to shift relative to the disk pack. As a result of the first impact, the first imbalance moves to a second imbalance. The second imbalance is detected, and a second imbalance signal is produced. The second imbalance signal is correlated with the reference timing signal to produce a second correlation value, which indicates a location of the second imbalance relative to the reference timing signal. A phase compensation value is also determined, based upon the first and second correlation values. The phase compensation value indicates a phase difference between an actual location of the first imbalance and a desired location of the first imbalance when the first impact was applied. Based upon the phase compensation value, a second impact is applied to the base, again causing the base to shift relative to the disk pack.