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US 2009/0244751 A1Published application
Track error measurement and recovery
AssigneeKabushiki Kaisha Toshiba 1-1
InventorAnton Gerasimov
Life of this patent
Estimating the term…
Abstract
A method of measuring a track value is shown. The track value is related to track mis-registration, and is compared to a track value limit to assess a condition of the track. In example embodiments, the track value is determined as a function of multiple position error signals from previous wedges in the track. During a self servo writing operation, the track value and the track value limit are used to selectively perform a recovery action. In example embodiments, the track value limit is dynamically adjusted.
Claims20
A method comprising:
- self servo writing a track on a disk surface;
- determining a PES for multiple wedges in the track;
- calculating a track value for the track as a function of multiple PES values from multiple wedges;
- comparing the calculated track value for the track with a track value limit;
- and
- performing a recovery action based on the comparison.
3 more elements
A method comprising:
- self servo writing a track on a disk surface;
- determining a PES for multiple wedges in the track;
- calculating a track value for the track as a function of multiple PES values from multiple wedges;
- comparing the calculated track value for the track with a first track value limit;
- performing a recovery action based on the comparison;
- and
- modifying the track value limit as self servo writing progresses based on track values from multiple previous tracks.
4 more elements
A hard disk drive system comprising:
- a hard disk;
- a read/write head to follow a track on the hard disk;
- computer readable instructions stored in a media and coupled to the hard disk drive system such that when executed, the instructions cause the read/write head to perform a number of operations, including:
- self servo writing a track on the hard disk;
- determining a PES for multiple wedges in the track;
- calculating a track value for the track as a function of multiple PES values from multiple wedges;
- comparing the calculated track value for the track with a track value limit;
- and
- performing a recovery action based on the comparison.
6 more elements
Dependencies are inferred from the claim text.