Title:
データ記憶装置及びその制御方法
Document Type and Number:
Japanese Patent JP4289670
Kind Code:
B2
Abstract:
Embodiments of the invention are directed to detecting an abnormality in head flying height. In one embodiment, an AGC controller establishes the gain of the reproduced signal through gain adjustment using the servo AGC of the servo signal. A digital filter performs filtering processing by use of the obtained gain data g and the gain data of previous sectors. A comparative judgment section obtains filtered gain data G from the digital filter and compares the gain data G with a reference value CRITERIA to determine whether the flying height is normal or abnormal. If the gain G is larger than the reference value CRITERIA, then the data write operation is inhibited. The filter parameters of the digital filter are programmable parameters which can be set and changed.
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Inventors:
Tetsuo Ueda
Kazuyuki Ishibashi
Satoshi Ishii
Masaaki Noguchi
Kazuyuki Ishibashi
Satoshi Ishii
Masaaki Noguchi
Application Number:
JP2004049284A
Publication Date:
July 01, 2009
Filing Date:
February 25, 2004
Export Citation:
Assignee:
Hitachi Global Storage Technologies Netherlands BV
International Classes:
G11B21/21; G11B5/60; G11B20/18; G11B21/02; G11B27/36
Domestic Patent References:
| JP2001229637A | ||||
| JP9139040A | ||||
| JP2000030388A |
Attorney, Agent or Firm:
Yoshinobu Shindo