| 摘要 |
PURPOSE:To suppress a demodulation noise or a big transitional fluctuation of the demodulation output, by performing demodulation under the state, where the part corresonding to the time of the detection signal from the drop-out detecting circuit is substituted with the signal generated from the signal generating circuit, when the detection signal is output from the drop-out detecting circuit. CONSTITUTION:When drop-out of the FM carrier occurs due to the reproducing signal from the optical disc, drop-out detecting circuit 16 detects it and set the output to ''0''. Therefore, AND circuit 7 has the gate closed, and the output of fixed energized circuit 4 is inhibited from being supplied to LPF5. Meanwhile, signal generating circuit 10 generates a signal equivalent to the FM carrier; and when the output of circuit 16 becomes signal ''0'', the gate of AND circuit 9 is opened, and the signal of circuit 10 is supplied to LPF5. Thus, if the drop-out detection signal is output from circuit 16, the part corresponding to the time of this signal is substituted with the signal generated from circuit 10. As a result, demodulation noise and transitional great fluctuation of the demodulation output are suppressed. |
