| 摘要 |
PURPOSE:To suppress the generation of noise as much as possible by driving a switcing element in accordance with whether the noise exists in a sound signal or not. CONSTITUTION:In case of eliminating noise from an FM-modulated sound signal, a sample pulse having a hold period and a sample period is generated from a switching pulse of a rotary head 11, and inputted to a driving circuit 19. A sound signal containing a noise is applied to a switching element 23 through an operational amplifier 25 and a time correcting circuit 24, and also the sound signal is applied to a switching element 18. The element 18 is turned off only for a period in which a noise is contained, and a sample holding circuit 20 holds a signal of immediately before the element 18 is turned off. Also, the element 23 leads out an output of the circuit 20 in a period in whcih a noise is contained, and leads out an output of the circuit 24 in a period in which no noise is contained. |
