| 摘要 |
<p>HEAD TO TRACK ALIGNMENT IN A ROTATING HEAD MAGNETIC TAPE UNIT The position of a length of magnetic recording tape, adjacent a rotating head device is servo controlled to accurately position a transverse tape data track in alignment with the head path. The tape includes a longitudinal servo track. A portion of the servo track is read by the rotating head as it sweeps transversely across the tape. The servo track is formed as a constant frequency pattern having periodic sync marks which define the center of a data track. The rotating head signal constitutes a clock which is used to drive an up/down counter as the head sweeps across the servo track. The counter's counting state changes as the head sweeps the servo track, such that the residual count, which remains after the head leaves the servo track, is a measure of the magnitude and direction of head-to-track alignment.</p> |
