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. 21, 2005
Filed:
Jul. 19, 2002
Yoshio Soyama, Odawara, JP;
Yuji Hata, Odawara, JP;
Katsumoto Onoyama, Hiratsuka, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In a magnetic disk drive that performs the seek operation of a magnetic head by a VCM, a characteristic that is excellent in fault tolerance that will not generate a fault in severe environment, such as a high temperature and the issue of high frequency command without requiring a special device and special operation and without deteriorating access performance. For this purpose, a VCM current and a VCM voltage are measured and VCM back electromotive force is calculated based on both results. At seek operation, position information located on a magnetic disk is sampled and a traveling velocity is detected from the difference of the sampled result. VCM coil temperature is estimated from the difference between the traveling velocity and the VCM back electromotive force. The magnetic disk drive moves low velocity seek mode when the estimated value of this VCM coil temperature exceeded a specified value.