Title:
POSITION SIGNAL DEMODULATION METHOD, POSITION SIGNAL DEMODULATOR, AND MAGNETIC DISK UNIT
Document Type and Number:
Japanese Patent JP3813971
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a position signal demodulation method, a position signal demodulator and a magnetic disk unit for digitally demodulating a position signal.
SOLUTION: In the magnetic disk unit, a servo demodulation part performs digital sampling of first and second servo burst signals read by a head with frequency of double of burst signal frequency or more, respectively, calculates a cosine coefficient and a sine coefficient of predetermined signal components by using a digital sampling value for each of the first and second servo burst signals, calculates pieces of amplitude information of the first and second servo burst signals by calculating square roots of square-sum of the cosine coefficient and the sine coefficient, respectively, calculates difference between the pieces of amplitude information of the first and second servo burst signals and defines the difference as the position signal.
Inventors:
Koichi Aikawa
Application Number:
JP2004302636A
Publication Date:
August 23, 2006
Filing Date:
October 18, 2004
Export Citation:
Assignee:
富士通株式会社
International Classes:
G11B21/10; (IPC1-7): G11B21/10
Domestic Patent References:
| JP9312073A | ||||
| JP5234288A | ||||
| JP7222347A |
Attorney, Agent or Firm:
Chimitsu Saito
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