| 摘要 |
PURPOSE:To always maximize a dynamic range by obtaining tracking delay variables by two serial delay circuits, and varying phase offset due to variable speed reproduction on the basis of one delay variable. CONSTITUTION:At a normal reproducing time, a capstan motor 2 is controlled at its speed by a speed control circuit 4 on the basis of an FG signal outputted from a frequency generator 5 to rotate smoothly at a fixed speed. At a reverse reproducing time, the capstan motor 2 is reversed by a forward/backward rotation command circuit 10, the time constant of a pre-tracking mono-stable multivibrator 27 is simultaneously switched and a tape 1 is carried in the reverse direction at the same speed as the normal speed. At that time, the delay variable of the pre-tracking mono-stable multivibrator 27 is switched and the tracking variable is set up to the shown point (b). In addition, a delay variable 2tau2 to be adjusted by a tracking mono-stable multivibrator 8 can be set up independently of the multivibrator 27 and can be varied in a wide range.
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