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:
Nov. 07, 2006
Filed:
May. 25, 2005
Yoshikatsu Fujii, Kanagawa-ken, JP;
Sadahiro Nishida, Kanagawa-ken, JP;
Osamu Beppu, Kanagawa-ken, JP;
Shinji Matsushita, Kanagawa, JP;
Hidefumi Tominaga, Kanagawa-ken, JP;
Yoshikatsu Fujii, Kanagawa-ken, JP;
Sadahiro Nishida, Kanagawa-ken, JP;
Osamu Beppu, Kanagawa-ken, JP;
Shinji Matsushita, Kanagawa, JP;
Hidefumi Tominaga, Kanagawa-ken, JP;
Hitachi Global Storage Technologies Netherlands B.V., Amsterdam, NL;
Abstract
Embodiments of the invention provide a magnetic disk drive and magnetic disk drive control method for unloading a head safely with a simple configuration when a positioning control signal cannot be detected due, for instance, to a seek error. In one embodiment, when a head cannot detect servo information prerecorded on a disk, a positioning control section resets and starts a time counting section, and switches to an unloading control section for causing the unloading control section to output a position control signal to a VCM driver. The time counting section counts tacho-pulses generated by a motor driver, and outputs time information. The unloading control section receives the time information from the time counting section. In accordance with the received time information, the unloading control section computes the position control signal that the positioning control section outputs to the VCM driver. In this instance, the unloading control section controls the VCM driver to provide such an electrical current profile that the drive current to be supplied to a VCM is small at an initial stage and large at a later stage.