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. 25, 2009
Filed:
Apr. 13, 2005
Masahiko Sega, Kanagawa, JP;
Yoshio Soyama, Kanagawa, JP;
Takashi Kouno, Ibaraki, JP;
Toshihiro Arisaka, Kanagawa, JP;
Masahiko Sega, Kanagawa, JP;
Yoshio Soyama, Kanagawa, JP;
Takashi Kouno, Ibaraki, JP;
Toshihiro Arisaka, Kanagawa, JP;
Hitachi Global Storage Technologies Netherlands B.V., Amsterdam, NL;
Abstract
A magnetic disk drive is to be provided wherein oscillations in thrust, conical and translational modes of a spindle caused by disturbance are to be damped to diminish a positioning error and thereby attain a high recording density and improved accessing performance. In one embodiment, there is provided a compensation circuit using acceleration or angular acceleration sensors, the sensors being disposed on a base, a cover or a PCB (printed circuit board) of a magnetic disk drive so that they can detect disturbance effectively, and wherein a mechanical system transfer characteristic of and other parameters in thrust, conical, or translational mode of a spindle are acquired or calculated by a processor and unnecessary oscillation in each mode is compensated. In another embodiment, to measure a transfer characteristic of the spindle in thrust mode and other parameters after installation of the magnetic disk drive in a case, piezoelectric elements are provided as one of oscillating means. The measurement may be made repeatedly at predetermined intervals.