Hard disk drive fly height adjust method and apparatus during error recovery
AssigneeMaxtor Corporation
InventorsRajita Shrestha, Christine Green, Jerry Moline
Life of this patent
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Abstract
Data recovery, following a read error in a hard disk drive, is provided which includes an adjustment of fly height. In one embodiment, some re-reads are performed by both adjusting the fly height and the off-track positioning of the read head. In one embodiment, two or more fly heights are normally used during read/write operations such as in a zoned manner, and adjustments to fly heights are performed with respect to the fly height for the zone where the error occurred.
Claims8
An apparatus for use in a hard disk drive, having at least a first read head, which includes data written in a plurality of tracks having an average inter-track distance, comprising:
- first circuitry which detects a read error at a first disk location while using a first normal fly height and outputs a first signal in response;
- second circuitry which attempts at least a first re-read of data at said first disk location while positioning said read head so as to be both off-track by a first off-track amount less than said average inter-track distance and at a second fly height different from said first fly height and attempts an additional re-read of data at said first disk location while re-positioning said read head to be off-track by a second off-track amount different from said first off-track amount and at a fly height different from said first normal fly height.
A method for use in a hard disk drive, having at least a first read head, which includes data written in a plurality of tracks having an average inter-track distance, comprising:
- detecting a read error at a first disk location while using a first normal fly height and outputting a first signal in response;
- performing at least a first re-read of data at said first disk location while positioning said read head so as to be both off-track by a first off-track amount less than said average inter-track distance and at a second fly height different from said first fly height;
- and
- performing an additional re-read of data at said first disk location while re-positioning said read head to be off-track by a second off-track amount different from said first off-track amount and at a fly height different from said first normal fly height.
Dependencies are inferred from the claim text.