Title:
DISK DRIVE, AND DEVICE AND METHOD FOR ITS PHASE DEMODULATION
Document Type and Number:
Japanese Patent JP3245343
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To prevent the demodulating process for position signal from becoming complicated and to accurately demodulate the position signal while performing a fast seek operation a head by providing a selection part and selecting the outputs from a 1st and a 2nd phase difference detection part according to operation conditions.
SOLUTION: The 1st phase difference detection part 3A uses a zerocross signal and a master cross, uses a servo pattern 9 for N units of (N: integer larger than 2) cylinders, and discriminates polarity information in the servo pattern 9, thereby outputting phase difference information. The 2nd phase difference detection part 3B uses a servo pattern which is a half the servo pattern 9 for the N units of cylinders and outputs phase difference information without discriminating the polarity information. The selection part 4 outputs the phase difference information from the 1st phase difference detection part 3A under seek operation conditions and outputs the phase difference information from the 2nd phase difference detection part 3B under on-track control conditions. A phase difference information integration part 5 integrates the selected phase difference information from the selection part 4 and outputs a signal for positioning control over the head 7.
Inventors:
Tatsuhiko Kosugi
Application Number:
JP34312695A
Publication Date:
January 15, 2002
Filing Date:
December 28, 1995
Export Citation:
Assignee:
富士通株式会社
International Classes:
G11B21/10; G11B5/55; G11B5/596; G11B19/28; G11B21/08; (IPC1-7): G11B21/10
Domestic Patent References:
| JP6010472A | ||||
| JP6243574A | ||||
| JP7334948A | ||||
| JP7282749A |
Attorney, Agent or Firm:
Yu Sanada