Victor Company of Japan, Limited

Kazuyuki Suenaga

Toyotaka Machida

Hitoshi Aoike

Toshimasa Kumazaki

An FM demodulating circuit demodulates a frequency-modulated signal of a predetermined channel of frequency-modulated signals of respectively different channels, where the frequency-modulated signals are obtained by frequency-modulating carriers of respectively different frequencies by information signals of respectively different channels and transmitting the frequency-modulated signals in a mutually multiplexed state. The FM demodulating circuit has a demodulated output characteristic such that a frequency at which a differential value describing the slope of a demodulated output characteristic curve becomes maximum, is substantially equal to a center frequency of the frequency-modulated signal of the above predetermined channel, and a frequency at which the differential value becomes minimum is equal to a center frequency of a frequency-modulated signal of a channel other than the above predetermined channel.

FM demodulating circuit having an insensitive frequency point

In a video recording system the chroma components of a color television signal are applied to a multiplexer where they are interleaved in frequency with each other so that the energy concentration of each chroma component occurs at frequencies interleaved with the frequencies at which the energy concentration of the other chroma component occurs. The interleaved chroma components and the luminance component are supplied respectively to frequency modulators each producing an output having energies distributed over the full range of the passband of the system. The outputs of the modulators are fed to first and second transducers for recording the luminance and chroma components on adjacent tracks of a recording medium.

Video recording by frequency modulation of luminance and multiplexed

An FM signal demodulating circuit comprises a peak differential type amplifier having two input terminals, a resonance circuit network connected between the two input terminals of the peak differential type amplifier, and a capacitor between the resonance circuit network and the ground. The resonance circuit network comprises a plurality of parallel resonance circuits which are connected in series and have respectively different parallel resonance frequencies. The demodulating circuit has a demodulating characteristic curve for demodulating FM signals having different carrier frequencies.

FM Demodulator for a plurality of carrier frequencies

The hue of a color image is controlled by a detector which monitors the luminance signal level to produce a gain control signal when it exceeds a predetermined level to effect reduction in the relative proportion of the red content in a whitish area in the color image without sacrifice to adversely affect the faithful reproduction of flesh tones. The detector may be arranged to monitor the output level of red primary color so as to effect control in the amount of the red color output so that redish cast in the color image is effectively suppressed without sacrifice in the reproduction of flesh tones.

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Noda, Japan

Kazuyuki Suenaga