| US 7,532,430 B2 | ||
| Magnetic recording medium and magnetic recording/reproducing apparatus | ||
| Makoto Asakura, Tokyo (Japan); and Hideo Sado, Tokyo (Japan) | ||
| Assigned to Kabushiki Kaisha Toshiba, Tokyo (Japan) | ||
| Filed on May 18, 2007, as Appl. No. 11/750,864. | ||
| Application 11/750864 is a division of application No. 11/329599, filed on Jan. 11, 2006, granted, now 7,262,932. | ||
| Claims priority of application No. 2005-005552 (JP), filed on Jan. 12, 2005. | ||
| Prior Publication US 2007/0217058 A1, Sep. 20, 2007 | ||
| This patent is subject to a terminal disclaimer. | ||
| Int. Cl. G11B 5/596 (2006.01) | ||
| U.S. Cl. 360—77.08 | 3 Claims |

| 1. A magnetic recording/reproducing apparatus comprising:
a reproducing unit that performs a reproducing process on a magnetic recording medium that includes a servo area where servo
data used for detecting a position of a magnetic head on the magnetic recording medium is recorded, and a writable data area,
arranged side by side with the servo area in the track direction, on which user data is written by the magnetic head, the
servo area including a preamble area where a preamble recording pattern that represents data used for providing a clock synchronization
of the servo data is formed by a plurality of magnetic sections, and a burst area where data used for detecting a relative
position of the magnetic head with respect to a track center position of the servo data is recorded and on which a single
burst recording pattern which is a layout pattern that tilts to the preamble recording pattern with a predetermined tilt angle
is formed by a plurality of magnetic sections,
the reproducing unit including
a phase detection unit that detects a phase difference of a burst reproduced signal of the burst area from a reproduced signal
of the preamble area, based upon sample values at respective points in the preamble area, which are sampled by using a synchronous
clock determined by a reproduced signal processing of the preamble area and a plurality of predetermined coefficients, as
phase difference information corresponding to a plurality of phase differences; and
a position detection unit that detects position deviation information indicating a relative distance of the magnetic head
from the track center position based upon the phase difference information; and
a speed detection unit that detects a shifting speed in a radial direction of the magnetic head of the magnetic recording
medium,
wherein the phase detection unit detects the phase difference information relating to the burst reproducing signal based upon
the sample value at each of the points sampled from the burst reproduced signal at a synchronous clock determined by the reproduced
signal processing in the preamble area and a plurality of predetermined coefficients, for respective divided gate intervals
into which a burst gate interval corresponding to a reproducing process interval for the burst area is divided,
the position detection unit detects deviation information of the magnetic head center from the track center position for each
of the divided gate intervals, based upon the phase difference information for each of the divided gates, and detects the
position deviation information in the burst gate interval based upon the deviation information for each of the divided gate
intervals, and
the speed detection unit detects the shifting speed based upon the deviation information for each of the divided gates and
a delay time for rising of the divided gate.
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