| 摘要 |
<p>Data head offset detecting circuitry (3,4,5,6) in a magnetic disk drive unit comprises a first offset detector (3) that detects an offset beta , of a data head (2) from its intended position on a track of a data surface (1), based on servo information stored on the data surface and read therefrom by the data head. The circuitry also comprises a second offset detector (4) that detects an offset gamma , of a servo head (34) from its intended position on a corresponding track of a servo surface (1), based on servo information on the servo surface read by the servo head, and an offset calculator (5) for calculating a real offset alpha , representative of the offset between the servo head and the data head concerned, by subtracting the offset gamma from the offset beta . Such circuitry can permit an offset used subsequently for correcting "off-track" of the data heads (deviation of a head from its intended on-track position) to be detected accurately even when the heads are vibrating at the time the offset is being measured. <IMAGE></p> |
