Predictive characterization of adjacent track erasure in recording media
AssigneeWD Media, LLC
InventorsMark A. Nichols, Harold H. Gee, Eric Roddick, Mrugesh Desai
Life of this patent
Estimating the term…
Abstract
Cross-track density capability is predicted for a large number of writes based on a plurality of erase band width measurements. Over the plurality of erase band width measurements, a number of writes in a series of writes performed as part of an aggressing track sequence is varied. A model of the magnetic track width (MTW) as function of the number of writes employed in the MTW measurements may be generated and an estimate of the erase band width for a large number of writes derived from the model as a prediction of cross-track density capability.
Claims19
A method for determining a cross-track density capability of a recording media, the method comprising:
- squeezing a victim track with a first aggressing side track writing sequence until a signal stored on the victim track reaches a threshold level of degradation, the first aggressing side track writing sequence comprising:
- iteratively displacing the side track in an across-track direction toward the victim track and performing a side track write n times with each iteration;
- determining a first erase band width associated with the first aggressing side track writing sequence;
- squeezing a victim track with a second aggressing side track writing sequence until a signal stored on the victim track reaches a threshold level of degradation, the second aggressing side track writing sequence comprising:
- iteratively displacing the side track in an across-track direction toward the victim track and performing a side track write m times with each iteration, wherein m is different than n;
- determining a second erase band width associated with the second aggressing side track writing sequence;
- and
- generating, from the first and second erase band width, a model characterizing the erase band width of the media as a function of the number of side track writes in an aggressing side track writing sequence.
An automated tester for determining a cross-track density capability of a recording media, the automated tester comprising:
- means for squeezing a victim track with a first aggressing side track writing sequence until a signal stored on the victim track reaches a threshold level of degradation, the first aggressing side track writing sequence comprising:
- iteratively displacing the side track in an across-track direction toward the victim track and performing a side track write n times with each iteration;
- means for determining a first erase band width associated with the first aggressing side track writing sequence;
- means for squeezing a victim track with a second aggressing side track writing sequence until a signal stored on the victim track reaches a threshold level of degradation, the second aggressing side track writing sequence comprising:
- iteratively displacing the side track in an across-track direction toward the victim track and performing a side track write m times with each iteration, wherein m is different than n;
- means for determining a second erase band width associated with the second aggressing side track writing sequence;
- and
- means for generating, from the first and second erase band width, a model characterizing the erase band width of the media as a function of the number of side track writes in an aggressing side track writing sequence.
An automated tester for determining a cross-track density capability of a recording media, the automated tester comprising:
- a spinstand;
- an MTW tester to squeeze a victim track with a first aggressing side track writing sequence until a signal stored on the victim track reaches a threshold level of degradation, the first aggressing side track writing sequence comprising:
- iteratively displacing the side track in an across-track direction toward the victim track and performing a side track write n times with each iteration;
- determine a first erase band width associated with the first aggressing side track writing sequence;
- squeeze a victim track with a second aggressing side track writing sequence until a signal stored on the victim track reaches a threshold level of degradation, the second aggressing side track writing sequence comprising:
- iteratively displacing the side track in an across-track direction toward the victim track and performing a side track write m times with each iteration, wherein m is different than n;
- and
- determine a second erase band width associated with the second aggressing side track writing sequence;
- and
- a MTW modeler to generate, from the first and second erase band width, a model characterizing the erase band width of the media as a function of the number of side track writes in an aggressing side track writing sequence.
Dependencies are inferred from the claim text.