| 摘要 |
<p>A data recording and reproducing system in which a disk having a plurality of data tracks has a track following code stored thereon, enabling a recording head moved by a servo system to be centered in relation to a desired track. The code includes, on one side of the track centerline, first regions of magnetic flux in which there is a first area of magnetic flux reversal, and, on the other side of the track centerline, second regions of magnetic flux in which there is a second area of opposite flux reversal adjacent the first area. The lines of flux in each area are equal. A recording head, when centered on the track centerline, detects no difference in the number lines of flux between the first and second areas due to its self-nulling properties, though the output signal of the head, which represents the rate of change of detected flux as the head traverses the two areas, may show differences at different points in time of detection. An integrator integrates the head out??? signal, which integrated signal thus represents such difference in the number of lines of flux and is an error signal used in the servo system to move the head on center, is needed. If the head is off center, a difference in number of lines of flux will be detected, thereby producing the error signal to move the head on center.</p> |
