| 摘要 |
<p>PURPOSE:To securely read out tape positioning information on a magnetic tape with a speed change at one step by making a velocity component of a magnetic head constant in the direction of a track, irrespective of any traveling speed of a tape-like recording medium. CONSTITUTION:An arithmetic sum in period or the square root of square sum in period of the detection outputs of two reel revolution detectors (FG) 14 and 15 at a tape speed for reproducing is evaluated to be held in a storage circuit 19, and at the time of high speed traveling, the tape speed at that time is obtained from the arithmetic sum in period or the square root of square sum in period of the value held in the storage circuit 19 and the detection outputs of the reel FGs at that time. Consequently, even under the transient state of changing the magnetic tape traveling speed from low speed to high speed, the velocity component of the magnetic head in the direction of the track is kept constant, thus reading always and securely the tape positioning information on the magnetic tape. By this method, even when the magnetic tape traveling speed is changed by one step, the tape positioning information can securely be read out under this transient state.</p> |
