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US 8,947,801 B1Granted
Multi-track asymmetric read-back signal correction
AssigneeSeagate Technology LLC
InventorJason Charles Jury
Life of this patent
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Abstract
Various aspects of the present disclosure are directed toward an apparatus, such as a disc drive, including a disc having multiple tracks, a magneto-resistive transducer assembly, and multiple-track signal correction circuitry. The multiple-track signal correction circuitry compensates for asymmetry in a readback signal of read data stored in at least one of multiple tracks based on different correction coefficients for respective ones of the multiple tracks.
Claims19
An apparatus comprising:
- a first circuit configured to present a readback signal representing data stored in at least one of multiple tracks on a data-recording disc;
- and
- a multiple-track signal correction circuit connected to the first circuit and configured to compensate for asymmetry in the readback signal using different correction coefficients for respective ones of the multiple tracks to compensate for distortions relating to magnetic data patterns stored on a track of the disc that is targeted to be accessed as magnetic data patterns stored on adjacent tracks.
An apparatus comprising:
- a disc drive including
- a disc,
- a transducer assembly configured to read magnetically-stored data stored in multiple tracks of the disc by providing a readback signal from each of the multiple tracks;
- for each of an associated one of the multiple tracks
- a front-end signal processing circuit including an amplifier configured and arranged to provide gain to the readback signal and including an analog filter configured and arranged to provide a version of the readback signal in which noise, present in an output signal from the amplifier, is removed, and
- a signal estimation circuit including an analog-to-digital conversion circuit configured and arranged to convert an analog version of the readback signal to a digital signal, and including a digital filter configured and arranged to shape the digital signal and to provide estimated values of the respective readback signals based on the shaped digital signal;
- and
- a multiple-track signal correction circuit configured and arranged to compensate for asymmetry in the readback signal of the read data stored in at least one of multiple tracks, based on the estimated values and different correction coefficients for respective ones of the multiple tracks to compensate for distortions relating to magnetic data patterns stored on a track of the disc that is targeted to be accessed as magnetic data patterns stored on adjacent tracks.
5 more elements
An apparatus comprising:
- a disc drive including
- a disc,
- a transducer assembly configured to read magnetically-stored data stored in multiple tracks of the disc by providing a readback signal from each of the multiple tracks;
- for each of an associated one of the multiple tracks
- a front-end signal processing circuit including an amplifier configured and arranged to provide gain to the readback signal and including an analog filter configured and arranged to provide a version of the readback signal in which noise, present in an output signal from the amplifier, is removed, and
- a signal estimation circuit including an analog-to-digital conversion circuit configured and arranged to convert an analog version of the readback signal to a digital signal, and including a digital filter configured and arranged to shape the digital signal and to provide estimated values of the respective readback signals based on the shaped digital signal;
- and
- a multiple-track signal correction circuit configured and arranged to compensate for asymmetry in the readback signal of the read data stored in at least one of multiple tracks, based on the estimated values and different correction coefficients for respective ones of the multiple tracks, wherein the multiple-track signal correction circuit is further configured and arranged with a cancellation module configured and arranged to cancel asymmetry distortions in the readback signals, and wherein the cancellation module is configured and arranged to cancel asymmetry distortions in the readback signals and therefrom produce corrected signals for each of the readback signals by executing a summation-based process that is a function of, for each of an associated one of the multiple tracks, an expected signal, the correction coefficient and the number of the multiple tracks.
5 more elements
A method of compensating for asymmetry in readback signals in a storage device comprising:
- reading data stored in multiple tracks of a medium and providing a readback signal from each of the multiple tracks;
- and
- compensating for asymmetry in the readback signal stored in at least one of the multiple tracks based on different correction coefficients for respective ones of the multiple tracks to compensate for distortions relating to magnetic data patterns stored on a track of the medium that is targeted to be accessed as magnetic data patterns stored on adjacent tracks.
Dependencies are inferred from the claim text.