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AssigneeHitachi Global Storage Technologies Netherlands B.V.
InventorsTakehiko Hamaguchi, Hideaki Maeda, Kazuaki Usui, Kazuhisa Shishida, Takashi Konishi
Estimating the term…
Embodiments of the invention provide optimum servo patterns for perpendicular magnetic recording method. In one embodiment, a burst field of servo patterns is composed of burst-signal parts in each of which a constant frequency occurs successively and zero-signal parts each of which has been demagnetized to a state of zero-magnetization, and the total magnetization of the burst field is made approximately 0. The zero signal portions are formed by shutting off a write current at a time during an operation to record servo patterns on a disk initialized to a state of zero-magnetization. The total magnetization of all servo patterns is made approximately 0 by encoding an address mark field and a track code field of servo patterns by a phase shift method.
A servo information recording method for recording a burst field comprising a burst-signal part in which a constant frequency occurs successively on magnetic recording media, the method comprising:
Magnetic recording media on which a burst field comprising a burst-signal part in which a constant frequency occurs successively has been recorded, wherein the burst field has been formed using a combination of writing a burst-signal part to the magnetic recording media, magnetization of which has been initialized to a state of zero-magnetization, by passing a write current through a write head;
A magnetic disk apparatus comprising a magnetic disk, a disk drive section for driving the magnetic disk, a head for performing recording to and reproduction from the magnetic disk, and a head drive section configured to position the head over a track on the disk, wherein the magnetic disk comprises a data area which holds data composed of information magnetized mainly in a direction perpendicular to a film surface and a servo area in which servo information for demodulating a head position signal is recorded, the servo information comprising a burst-signal part in which a constant frequency occurs successively and a zero-signal part in a state of zero-magnetization.
Dependencies are inferred from the claim text.