| 摘要 |
PURPOSE:To execute an optimum tracking extending over the whole of one piece of track by bringing reproducing signal by a pair of magnetic heads to time division multiplex in a section for scanning the recording area of a PCM signal, and controlling independently an electrostrictive element, based on an obtained reproducing pilot signal. CONSTITUTION:Switching circuits 3, 4 are controlled by a prescribed switching signal, and the circuits 3, 4 divide a reproduced PCM signal and a video RF signal from magnetic heads 1a, 2a, respectively. Outputs of the circuits 3, 4 are supplied to a switching circuit 5 controlled by a prescribed switching signal, and by the circuit 5, the PCM signal and the video RF signal are brought to time division multiplex in a section for scanning an area where the PCM signal is recorded. From the output of the circuit 5, a reproducing pilot signal is separated, and based on its signal, an error signal for tracking is formed by a reference pilot generating circuit 12, a balanced modulating circuit 11, etc. This error signal is supplied to a switching circuit 19 controlled by the switching signal of a shape to which switching signals of the circuits 3, 4 and the switching signal of the circuit 5 are superposed. Subsequently, the error signal passing through a circuit 9 is supplied selectively to bimorph plates 21a and 21b, respectively, and each of them is controlled by an independent form.
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