Patent ID: 7440221

Claim:
A disk drive comprising: a recording medium including data tracks that are concentrically or spirally formed, each of said data tracks being formed with part of each data track being overwritten by an adjacent data track on an inner circumferential side or by an adjacent data track on an outer circumferential side; a head assembly including a write head for writing information to the recording medium, and a read head for reading out information from the recording medium; and a control device to control a position of the head assembly relative to the recording medium; wherein: position-error detection signals whose phases differ from each other are repeatedly written to a data track area of the recording medium in a track direction with written positions of the position-error detection signals being deviated from each other by a track pitch in a track width direction; and said control device controls a position of the head assembly on the basis of the position-error detection signals read out by the read head.