| 摘要 |
PURPOSE:To eliminate the need for cavity resonators for resonance circuits by adding the electrostatic capacity between a disc and the electrode of a reproducing stylus to the oscillation output of an oscillation circuit to provide an FM-modulated wave signal and subjecting this oscillation output to FM demodulation. CONSTITUTION:When an electric power source + B is supplied to a cavity resonator constituting an oscillation circuit 10, the circuit 10 transmits the oscillation output of a frequency fo. The FM-modulated output changing in correspondence to the change in electrostatic capacity Cv, that is, the change in recording information, is transmitted from the circuit 10. This FM-modulated output is removed of noise components in a limiter circuit 11, after which it is dropped to the frequency band suited for a post treatment in a frequency dividing circuit 12. The frequency-divided output of the circuit 12 divided down in this way is demodulated in an FM demodulating circuit 13. and only the change component by the electrostatic capacity Cv, that is, a recording information reproduction signal is transmitted to an output terminal 14. |
