Magnetic bit-patterned disk and disk drive
AssigneeKabushiki Kaisha Toshiba
InventorHiroshi Mutoh
Life of this patent
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Abstract
According to one embodiment, a disk drive having a magnetic disk of the bit pattern media type is provided. The disk drive has a reproduction module configured to reproduce a signal from a measurement area provided on the magnetic disk and holding groups of phase-shift measuring bits, a measurement module configured to measure a phase shift that a write clock signal has with respect to data recording bits held in a data record area provided on the magnetic disk, when the signal reproduced by the reproduction module is indefinite, and a recording module configured to record data that corresponds to the data recording bits, by using the write clock signal adjusted by the phase shift.
Claims10
A disk drive comprising:
- a magnetic disk of the bit pattern media type, comprising a data record area including data recording bits and a measurement area including phase-shift measuring bits, wherein each phase-shift measuring bit is offset by an amount from a reference position, wherein an interval between a plurality of reference positions including said reference position is substantially equal to that between the data recording bits;
- a reproduction module configured to reproduce a signal from the measurement area on the magnetic disk configured to store groups of the phase-shift measuring bits;
- and
- a measurement module configured to measure a phase shift of a write clock signal with respect to the data recording bits, based on at least one of the phase-shift measuring bits corresponding to the reproduced signal that is determined to be instable because a magnetization direction corresponding to a level of the reproduced signal cannot be determined.
A magnetic disk comprising:
- independent magnetic dots;
- a data record area comprising groups of data recording bits, each group corresponding to one or more magnetic dots;
- and
- a measurement area comprising groups of phase-shift measuring bits, each group corresponding to one or more magnetic dots and configured to measure the phase shift of a write clock signal with respect to the data recording bits, based on at least one of the phase-shift measuring bits corresponding to a reproduced signal that is determined to be instable because a magnetization direction corresponding to a level of the reproduced signal cannot be determined, wherein each phase-shift measuring bit is offset by an amount from a reference position, and wherein an interval between a plurality of reference positions including said reference position is substantially equal to that between the data recording bits.
Dependencies are inferred from the claim text.