JPS61178504U - - Google Patents

Description

[Brief explanation of drawings]

FIG. 1 is a block diagram of one embodiment of the FM signal demodulator of this invention, FIG. 2 is a detailed block diagram of a part of FIG. 1, and FIGS. Output voltage characteristic diagram, noise removal pulse characteristic diagram,
Figure 4 is a block diagram of a conventional FM signal demodulator.
5A to 5D are timing charts for explaining the operation of FIG. 4. 2, 3...Rotating reproduction head, 9...FM demodulator, 1
5... Phase detection circuit, 15a, 15b... Phase comparator, 15c, 15d... Loop filter, 15e... Differential amplifier, 15f... Loop switching switch, 15
g... Voltage controlled oscillator, 16... Noise removal pulse generation circuit, 17... Addition circuit.

Claims (1)

[Scope of utility model registration request] FM signal demodulation, in which a plurality of rotating playback heads are sequentially switched and controlled to playback traces of a recording medium, and a playback signal of the FM signal recorded on the recording medium by each head is input to an FM demodulator to demodulate the FM signal. The device includes an oscillator that is loop-controlled to the frequency of the reproduced signal input to the demodulator, and outputs a phase difference detection signal having a level proportional to the phase difference between the oscillation signal of the oscillator and the reproduced signal when switching heads. a phase difference detection circuit having phase difference detection means, and forms a noise removal pulse having an opposite phase and the same amplitude as a joint noise pulse in the demodulated signal of the demodulator based on the phase difference detection signal, and An FM signal demodulation device comprising: a noise removal pulse generation circuit that outputs a noise removal pulse when the noise pulse is output from the demodulator; and an addition circuit that adds the demodulated signal and the noise removal pulse.