Compensation method to correct thermally induced off-track errors in disc drives

Abstract From the Canadian patent

A thermal test tract is provided outside the useraccessible area on the disc. A tack complete of a known frequency is then written on either side of this thermal test track, preferably half the usual track separate distance away. To develop a thermal compensation constant, the transducer is moved to the thermal test track with no compensation applied. This way any thermally, induced off-track error which would affect seeks to, user-accessible data tracks will be reflected in the, off-track from the nominal position of the thermal test track. The transducer is now moved in a series of defined increments smaller than normal track-to-track steps, or "micro-steps," away from the uncompensated …