Embedded track information for patterned media
AssigneeSeagate Technology LLC
InventorMark David Bedillion
Life of this patent
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Abstract
A bit-patterned magnetic media (BPM) includes with respect to each data track a first sub-track and a second sub-track, each sub-track comprised of a plurality of bit-islands. A transducer head placed over a data track generates a readback signal. Channel response circuitry demodulates the readback signal and detects fine positioning information based on a comparison of a readback signal generated in response to the first sub-track and a readback signal generated in response to the second sub-track.
Claims11
A disc drive system comprising:
- a bit-patterned magnetic medium (BPM) having at least a first data track that includes a first sub-track and a second sub-track, wherein each of the first sub-track and the second sub-track are comprised of bit-islands;
- a transducer head capable of being selectively positioned over a desired data track, wherein the transducer head generates an amplitude-modulated readback signal in response to the bit-islands associated with the first sub-track and the second sub-track;
- and
- channel response circuitry operably connected to demodulate the readback signal generated by the transducer head, wherein the channel response circuitry detects fine positioning information based on a comparison of a readback signal generated in response to the first sub-track and a readback signal generated in response to the second sub-track of a particular data track.
A method of finely positioning a transducer head over a data track having a first sub-track and a second sub-track in a bit-patterned media in which both the first sub-track and the second sub-track are comprised of bit-islands, the method comprising:
- generating an amplitude-modulated readback signal in response to the transducer head moving over the bit-islands of the first sub-track and the second sub-track;
- distinguishing between readback signals generated with respect to the first sub-track and the second sub-track of the data track;
- calculating the relative position of the transducer head relative to the first sub-track and the second sub-track based on a comparison of the readback signal generated with respect to the first sub-track with the readback signal generated with respect to the second sub-track;
- finely positioning the transducer head over the data track based on the calculated position of the transducer head.
Dependencies are inferred from the claim text.