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:
Jan. 06, 2009
Filed:
Jun. 26, 2006
Applicants:
Takenori Atsumi, Ibaraki, JP;
Atsushi Okuyama, Kanagawa, JP;
Shinsuke Nakagawa, Ibaraki, JP;
Inventors:
Assignee:
Hitachi Global Storage Technologies Netherlands B.V., Amsterdam, NL;
Primary Examiner:
Int. Cl.
CPC ...
G11B 5/596 (2006.01);
U.S. Cl.
CPC ...
Abstract
In a magnetic disk device, oscillation occurring at a frequency higher than Nyquist frequency is suppressed. In one embodiment, a multi-late filter having a resonance point at a frequency higher than the intended Nyquist frequency is introduced in a previous stage of a controlled object. At that time, since a resonance characteristic of the multi-rate filter is aliased by a sampler, the multi-rate filter is designed such that the resonance point after the aliasing is stabilized in phase by a following compensator.