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:
Apr. 09, 2002
Filed:
May. 14, 1999
Raffi Codilian, Irvine, CA (US);
George S. Bouchaya, Mission Viejo, CA (US);
Western Digital Technologies, Inc., Lake Forest, CA (US);
Abstract
A method for controlling the current applied to a voice coil motor (VCM) prevents overheating of a coil in the VCM. The method includes the steps of defining an acceleration interval for measuring the distance traveled by a head moved by the VCM. The method also defines a distance traveled during the acceleration interval which can be used as a reference for indicating that the coil is being overheated. The VCM is driven for the acceleration interval and the distance traveled during the interval is measured and compared to the reference distance. If the difference exceeds a threshold, then the current being applied to the coil is controlled to maintain the coil temperature within a limit. If, however, the difference does not exceed the threshold, the current being applied to the coil is controlled to meet a performance requirement.