| 摘要 |
PURPOSE:To eliminate completely a chattering so that a switching position is not delayed, and to obtain a good reproducing picture by detecting a skew generated in a switching part to an auxiliary rotary head from a main rotary head, and correcting it by a variable delay line. CONSTITUTION:Reproducing output signals from main rotary heads M1, M2 and auxiliary rotary heads S1, S2 are amplified by reproducing amplifiers 26, 27 and 28, 29, respectively, and inputted to switches 21, 22. Outputs from the switches 21, 22 are inputted to envelope detecting circuits 23, 24 and also inputted to a switch 34. Subsequently, envelopes of an output the main rotary head and an output of an auxiliary rotary head are compared by a comparator 25, and this output signal is supplied as a main auxiliary head switching signal to a D input terminal of a D-FF 33 through a chattering preventing circuit 31. The output of the D-FF 33 goes to that which is synchronized with a horizontal synchronizing signal and supplied as a control signal to the switch 34, and switching to the auxiliary rotary head from the main rotary head is executed.
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