PURPOSE: To reduce the scale of a circuit and to decrease the number of lead- out terminals of the circuit when it is integrated, by performing FM modulation during recording through a VCO and a switch circuit, and FM demodulation during demodulation through a VOC, a phase detecting circuit, a loop filter, and a switch circuit.
CONSTITUTION: During recording, a sound signal inputted from an input terminal 1 is outputted from a terminal 20 after passing through an AGC circuit 2 and a preemphasis circuit 3, and then level adjustment is performed by a variable resistance 32. This level-adjusted signal is inputted from a terminal to a VCO4 through a switch circuit 28 to be FM-modulated. During reproduction, an FM wave reproduced from a magnetic tape 8 by a magnetic head 7 is inputted from a terminal 25 to a limiter circuit 9. The FM wave passed through the circuit 9 is FM-demodulated by the PLL detecting circuit consisting of a phase detecting circuit 10, a switch circuit 28, the VCO4, and a loop filter 11. Thus, the circuit scale is reduced and the number of lead-out terminals is decreased when the circuit is integrated.
WATAYA YOSHIZUMI
OWASHI HITOAKI
| JPS51130209A | 1976-11-12 | |||
| JPS52153086A | 1977-12-19 | |||
| JPS5457944A | 1979-05-10 | |||
| JPS4878863A | 1973-10-23 | |||
| JPS5787212A | 1982-05-31 | |||
| JPS5831602A | 1983-02-24 |