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. 18, 2009
Filed:
Apr. 20, 2007
Sayaka Nojiri, Kanagawa, JP;
Nobuhiko Wasa, Kanagawa, JP;
Sayaka Nojiri, Kanagawa, JP;
Nobuhiko Wasa, Kanagawa, JP;
Hitachi Global Storage Technologies Netherlands B.V., Amsterdam, NL;
Abstract
Embodiments in accordance with the present invention provide a disk drive capable of verifying whether the speed of an actuator is true or not, the speed being detected while the actuator is being moved between a retracted position and a recording surface of a magnetic disk, and to provide a control method for controlling the disk drive. In a particular embodiment, a hard disk drive (HDD) comprises: a head for accessing a disk; an actuator for supporting the head, the actuator being driven by a voice coil motor (VCM); a speed monitor for, on the basis of a cylinder ID written to the disk, monitoring the speed of the actuator while the actuator is being moved between a ramp which is provided outside a data area of the disk and the data area; and a speed verifier for, if an abnormal speed condition of the actuator is detected by the speed monitor, verifying the abnormal speed condition on the basis of the counter electromotive voltage of the VCM. If the speed based on the counter electromotive voltage is also abnormal, the speed verifier records the speed as the overspeed.