Color video signal recording and reproducing system

Claim 2

A color video signal recording and reproducing system comprising first filter means for separating a luminance signal from a color video signal, means for frequency modulating said luminance signal, second filter means for separating a carrier chroma signal from said color video signal prior to the modulation of said luminance signal, first non-modulating frequency converter means for converting the unmodulated frequency band of said carrier chroma signal to a frequency band which is lower than frequencies occupied by the frequency modulated luminance signal, means for superimposing the luminance signal output of said frequency modulator means and the chroma signal output of said non-modulating frequency converter means one on the other, means for recording and reproducing the superimposed signal on a magnetic medium, third filter means for separating a frequency modulated luminance signal from a signal reproduced by said recording and reproducing means, means for demodulating said luminance signal, fourth filter means for separating the frequency converted carrier chroma signal from said signal reproduced from said medium, second frequency converter means for restoring the frequency band of said filtered carrier chroma signal to the original frequency band, means comprising a color burst keyer for keying a color burst signal from the output signal of said second frequency converter means, oscillator means for producing a reference subcarrier signal, means for comparing the phase of said color burst signal with the phase of the output signal of said oscillator means and producing an error signal corresponding to the phase difference between both signals, and means including a voltage control oscillator having a center frequency of oscillation which is controlled by said error signal for supplying an output to said frequency converter means whereby it constitutes a feedback loop together with said color burst keyer and said phase comparator means.

Claim 3

A color video signal recording and reproducing system as defined in claim 1 comprising means for controlling the center frequency of oscillation of said voltage control oscillator means responsive to a horizontal synchronizing signal separated from said reproduced signal.

Claim 4

A color video signal recording and reproducing system as defined in claim 1 comprising means for separating a horizontal synchronizing signal from said reproduced signal, frequency discriminator means for discriminating the frequency of the horizontal synchronizing signal separated by said separator means, and means for controlling the center frequency of oscillation of said voltage control oscillator means responsive to the output voltage of said frequency discriminator means together with said error signal, said center frequency of oscillation having A frequency variation which is proportional to the frequency variation of the subcarrier of the reproduced carrier chroma signal.

Claim 5

A color video signal recording and reproducing system comprising first filter means for separating a luminance signal from a color video signal, means for frequency modulating said luminance signal, second filter means for separating a carrier chroma signal from said color video signal, first non-modulating frequency converter means for converting the frequency band of said carrier chroma signal to a frequency band which is lower than frequencies occupied by the frequency modulated luminance signal, means for superimposing the output of said frequency modulator means and the output of said non-modulating frequency converter means one on the other, means for recording and reproducing the superimposed output signal on a magnetic medium, third filter means for separating a frequency modulated luminance signal from a signal reproduced from said magnetic medium, means for demodulating said luminance signal, fourth filter means for separating the frequency converted carrier chroma signal from said signal reproduced from said magnetic medium, second frequency converter means for restoring the frequency band of said filtered carrier chroma signal to the original frequency band, means comprising a color burst keyer for keying a color burst signal responsive to the output signal of said second frequency converter means, oscillator means for producing a reference subcarrier signal, means for comparing the phase of said color burst signal with the phase of the output signal of said oscillator means and producing an error signal corresponding to the phase difference between both signals, voltage control oscillator means having a center frequency of oscillation which is controlled responsive to said error signal, means for separating a horizontal synchronizing signal from said reproduced signal, multiplier means for multiplying the frequency of the basic wave component of said horizontal synchronizing signal to a frequency near the subcarrier frequency of the converted carrier chroma signal, and third frequency converter means for frequency converting the output signal of said multiplier means responsive to the output of said voltage control oscillator means and for providing an output signal which is supplied to said second frequency converter means, thereby constituting a feedback loop together with said color burst keyer and said phase comparator means.

Claim 6

A color video signal recording and reproducing system comprising first filter means for separating a luminance signal from a color video signal, means for frequency modulating said luminance signal, second filter means for separating a carrier chroma signal from said color video signal, first non-modulating frequency converter means for converting the frequency band of said carrier chroma signal to a frequency band which is lower than frequencies occupied by the frequency modulated luminance signal, means for superimposing the output of said frequency modulator means and the output of said non-modulating frequency converter means one on the other, means for recording and reproducing the superimposed output signal on a magnetic medium, third filter means for separating a frequency modulated luminance signal from a signal reproduced from said magnetic medium, means for demodulating said luminance signal, fourth filter means for separating the frequency converted carrier chroma signal from said signal reproduced from said magnetic medium, second frequency converter means for restoring the frequency band of said filtered carrier chroma signal to the original frequency band, means comprising a color burst keyer for keying a color burst signal responsive to the output signal of said second frequency converter means, oscillator means for producing a reference subcarrier signal, means for comparing the phase of said color burst signal with the phase of the output signal of said oscillator means and producing an error signal corresponding to the phase difference between both signals, voltage control oscillator means having a center frequency of oscillation which is controlled responsive to said error signal, means for separating a horizontal synchronizing signal from said reproduced signal, multiplier means for multiplying the frequency of the basic wave component of said horizontal synchronizing signal to a frequency near the subcarrier frequency of the converted carrier chroma signal, and third frequency converter means for frequency converting the output signal of said multiplier means responsive to the output of said voltage control oscillator means and for providing an output signal which is supplied to said second frequency converter means, thereby constituting a feedback loop together with said color burst keyer and said phase comparator means.

Claim 7

A color video signal recording and reproducing system as defined in claim 1 in which said color video signal is an NTSC color video signal.