| 摘要 |
PURPOSE:To count up pilot signals precisely independently of the traveling speed of a tape, to display the traveling distance of the tape and to detect also its traveling direction by adding or subtracting the counted value on the basis of the output of an ATF pilot signal. CONSTITUTION:When reproducing is executed at a normal speed in the positive direction, the supply of pilot signals from BPFs 18-21 to a CPU 22 is successive ly changed in the order of f1 f2 f3 f4 in each scanning period. In this case, the CPU 22 adds the counted value every change of the pilot signals. In case of reproducing at a speed of several times in the reverse direction, the CPU 22 does not count up the initial and final reproducing pilot signals in each scanning period and subtracts the counted value at every change of pilot signals except the initial and final ones. Thus, the pilot signals can be properly counted up in both the forward and reverse directions, so that a precise counted value can be obtained.
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