Dynamic magnetic information storage or retrieval – Automatic control of a recorder mechanism – Controlling the head
Reexamination Certificate
2006-06-27
2006-06-27
Wong, K. (Department: 2651)
Dynamic magnetic information storage or retrieval
Automatic control of a recorder mechanism
Controlling the head
C360S077080
Reexamination Certificate
active
07068461
ABSTRACT:
A disk drive is disclosed comprising a disk having a plurality of servo bursts written using perpendicular magnetic recording, wherein each servo burst is written at a servo burst frequency. A fill pattern is written between the servo bursts using perpendicular magnetic recording at a frequency substantially equal to an even harmonic of the servo burst frequency, and a phase shift occurs at the transition between the servo burst and the fill pattern. A head is actuated over the disk, and a sampling device samples a read signal emanating from the head to generate a sequence of read signal sample values. Control circuitry demodulates the servo bursts from the sequence of read signal sample values by computing a single-point Discrete Fourier Transform (DFT) at the servo burst frequency.
REFERENCES:
patent: 5311376 (1994-05-01), Joan et al.
patent: 5343340 (1994-08-01), Boutaghou et al.
patent: 5786957 (1998-07-01), Inoue et al.
patent: 6025970 (2000-02-01), Cheung
patent: 6057977 (2000-05-01), Cunningham
patent: 6754025 (2004-06-01), Shepherd et al.
patent: 6785085 (2004-08-01), Guzik et al.
patent: 2002/0057509 (2002-05-01), Nishida et al.
patent: 2003/0026016 (2003-02-01), Heydari et al.
patent: 2003/0048562 (2003-03-01), Heydari et al.
Chue Jack M.
Lee Tehri S.
Weerasooriya Siri S.
Prejean, Esq. Jonathan E.
Sheerin, Esq. Howard H.
Western Digital Technologies Inc.
Wong K.
LandOfFree
Servo writing a disk drive by overwriting a harmonic... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Servo writing a disk drive by overwriting a harmonic..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Servo writing a disk drive by overwriting a harmonic... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3694920