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, modulator means for frequency-modulating a carrier wave responsive to said luminance signal, second filter means for separating a carrier chrominance signal from said color video signal, first frequency converter means for converting the frequency band of the carrier chrominance signal to a frequency band which is lower than frequencies occupied by the luminance signal output of said modulator means and in which the frequency of the subcarrier of the chrominance signal output of said frequency converter means is substantially equal to fH/4 X (2n + 1) (where fH is the frequency of the horizontal synchronizing signal of said color video signal and n is a positive integral number), means for superimposing the luminance signal output of said modulator means and the carrier chrominance signal output of said first 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 chrominance signal from the said signal reproduced from said magnetic medium, and second frequency converter means for restoring the frequency band of the output carrier chrominance signal of said fourth filter means to the original frequency band.

Claim 3

A color video signal recording and reproducing system comprising first filter means for separating a luminance signal from a color video signal, modulator means for frequencymodulating a carrier wave responsive to said luminance signal, second filter means for separating a carrier chrominance signal from said color video signal, first frequency converter means for converting the frequency band of the carrier chrominance signal to a frequency band which is lower than frequencies occupied by the luminance signal output of said modulator means and in which the frequency of the subcarrier of the chrominance signal output of said frequency converter means is substantially equal to fH/4 X (2n + 1) (where fH is the frequency of the horizontal synchronizing signal of said color video signal and n is a positive integral number), means for superimposing the luminance signal output of said modulator means and the carrier chrominance signal output of said first 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 chrominance signal from the said signal reproduced from said magnetic medium, and second frequency converter means for restoring the frequency band of the output carrier chrominance signal of said fourth filter means to the original frequency band.

Claim 4

A color video signal recording and reproducing system comprising first filter means for separating a luminance signal from a color video signal, modulator means for frequencymodulating a carrier wave responsive to said luminance signal, second filter means for separating a carrier chrominance signal from said color video signal, first frequency converter means for converting the frequency band of the carrier chrominance signal to a frequency band which is lower than frequencies occupied by the luminance signal output of said modulator means and in which the frequency of the subcarrier of the chrominance signal output of said frequency converter means is substantially equal to fH/4 X (2n + 1) (where fH is the frequency of the horizontal synchronizing signal of said color video signal and n is a positive integral number), means for superimposing the luminance signal output of said modulator means and the carrier chrominance signal output of said first 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 chrominance signal from the said signal reproduced from said magnetic medium, and second frequency converter means for restoring the frequency band of the output carrier chrominance signal of said fourth filter means to the original frequency band.

Claim 5

The system of claim 1 wherein said first frequency converter means comprises a frequency converter, and a local oscillator which applies an output oscillation frequency for frequency conversion to said frequency converter, said output oscillation frequency of the local oscillator being a frequency which is substantially equal to fs + fH/4 X (2n + 1) (where fs is the frequency of the subcarrier of the carrier chrominance signal prior to the frequency conversion).

Claim 6

The system of claim 2 wherein said output oscillation frequency of the local oscillator is approximately 4.267919 MHz.

Claim 7

The system of claim 1 which further comprises 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 for 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 comparator means.

Claim 8

The system of claim 4 which further comprises means for separating a horizontal synchronizing signal from said reproduced signal, and frequency discriminator means for discriminating the frequency of the horizontal synchronizing signal separated by said separator means, said means for controlling the center frequency being means responsive to the output voltage of said frequency discriminator means together with said error signal for controlling the center frequency of oscillation of said voltage control oscillator means, said center frequency of oscillation having a frequency variation which is proportional to the frequency variation of the subcarrier of the reproduced carrier chrominance signal.

Claim 9

The system of claim 1 which further comprises color burst keyer means 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 frequency converted carrier chrominance 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 means and said phase comparator means.

Claim 10

A color video signal recording and reproducing system comprising first filter means for separating a luminance signal from a color video signal, second filter means for separating a carrier chrominance signal from said color video signal, first frequency converter means for converting the frequency band of the carrier chrominance signal to a lower frequency band, means responsive to the carrier chrominance signal which has been frequency converted by said first frequency converter means for obtaining a signal having a frequency which is double the carrier frequency of the frequency converted carrier chrominance signal, adding means for adding the double frequency signal to the luminance signal from said first filter means, modulator means for frequency modulating a carrier signal with the output signal of said adding means, said lower frequency band being lower than frequencies occupied by the frequency modulated signal from said modulator means, means for superimposing the frequency modulated signal and the carrier chrominance signal output of said first 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 signal from a signal reproduced by said recording and reproducing means, means for demodulating the luminance signal, said double frequency signal being in opposite phase to a wave which will be produced in the demodulated luminance signal during recording and reproducing of the superimposed signal on the magnetic medium and has a frequency which is double the carrier frequency of the frequency converted carrier chrominance signal, fourth filter means for separating the frequency converted carrier chrominance signal from said signal reproduced from said magnetic medium, and second frequency converter means for restoring the frequency band of the output carrier chrominance signal of said fourth filter means to the original frequency band.

Claim 11

A color video signal recording and reproducing system comprising first filter means for separating a luminance signal from a color video signal, second filter means for separating a carrier chrominance signal from said color video signal, first frequency converter means for converting the frequency band of the carrier chrominance signal to a lower frequency band, means responsive to the carrier chrominance signal which has been frequency converted by said first frequency converter means for obtaining a signal having a frequency which is double the carrier frequency of the frequency converted carrier chrominance signal, adding means for adding the double frequency signal to the luminance signal from said first filter means, modulator means for frequency modulating a carrier signal with the output signal of said adding means, said lower frequency band being lower than frequencies occupied by the frequency modulated signal from said modulator means, means for superimposing the frequency modulated signal and the carrier chrominance signal output of said first 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 signal from a signal reproduced by said recording and reproducing means, means for demodulating the luminance signal, said double frequency signal being in opposite phase to a wave which will be produced in the demodulated luminance signal during recording and reproducing of the superimposed signal on the magnetic medium and has a frequency which is double the carrier frequency of the frequency converted carrier chrominance signal, fourth filter means for separating the frequency converted carrier chrominance signal from said signal reproduced from said magnetic medium, and second frequency converter means for restoring the frequency band of the output carrier chrominance signal of said fourth filter means to the original frequency band.

Claim 12

The system of claim 7 which further comprises 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 13

The system of claim 8 which further comprises means for separating a horizontal synchronizing signal from said reproduced signal, and frequency discriminator means for discriminating the frequency of the horizontal synchronizing signal separated by said separator means, said means for controlling the center frequency being means responsive to the output voltage of said frequency discriminator means together with said error signal for controlling the center frequency of oscillation of said voltage control oscillator means, said center frequency of oscillation having a frequency variation which is proportional to the frequency variation of the subcarrier of the reproduced carrier chrominance signal.

Claim 14

The system of claim 7 which further comprises color burst keyer means 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 frequency converted carrier chrominance 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 means and said phase comparator means.

Claim 15

A color video signal recording and reproducing system comprising first filter means for separating a luminance signal from a color video signal, modulator means for frequency-modulating a carrier wave with said luminance signal, second filter means for separating a carrier chrominance signal from said color video signal, first frequency converter means for converting the frequency band of the carrier chrominance signal to a frequency band which is lower than frequencies occupied by the luminance signal output of said modulator means, means for superimposing the luminance signal output of said modulator means and the carrier chrominance signal output of said first 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 chrominance signal from said signal reproduced from said magnetic medium, means responsive to the frequency converted carrier chrominance signal separated by said fourth filter means for obtaining a signal having a frequency which is double the subcarrier frequency of said frequency converted carrier chrominance signal, means for adding said double frequency signal to the luminance signal demodulated by said demodulating means, said double frequency signal being in opposite phase to a wave which is produced in the demodulated luminance signal during recording and reproducing of the superimposed signal on the magnetic medium and has a frequency which is double the subcarrier frequency of the frequency converted carrier chrominance signal from said first frequency converter means, and second frequency converter means for restoring the frequency band of the output carrier chrominance signal of said fourth filter means to the original frequency band.

Claim 16

A color video signal recording and reproducing system comprising first filter means for separating a luminance signal from a color video signal, modulator means for frequency-modulating a carrier wave with said luminance signal, second filter means for separating a carrier chrominance signal from said color video signal, first frequency converter means for converting the frequency band of the carrier chrominance signal to a frequency band which is lower than frequencies occupied by the luminance signal output of said modulator means, means for superimposing the luminance signal output of said modulator means and the carrier chrominance signal output of said first 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 chrominance signal from said signal reproduced from said magnetic medium, means responsive to the frequency converted carrier chrominance signal separated by said fourth filter means for obtaining a signal having a frequency which is double the subcarrier frequency of said frequency converted carrier chrominance signal, means for adding said double frequency signal to the luminance signal demodulated by said demodulating means, said double frequency signal being in opposite phase to a wave which is produced in the demodulated luminance signal during recording and reproducing of the superimposed signal on the magnetic medium and has a frequency which is double the subcarrier frequency of the frequency converted carrier chrominance signal from said first frequency converter means, and second frequency converter means for restoring the frequency band of the output carrier chrominance signal of said fourth filter means to the original frequency band.

Claim 17

The system of claim 11 which further comprises 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 18

The system of claim 12 which further comprises means for separating a horizontal synchronizing signal from said reproduced signal, and frequency discriminator means for discriminating the frequency of the horizontal synchronizing signal separated by said separator means, said means for controlling the center frequency being means responsive to the output voltage of said frequency discriminator means together with said error signal for controlling the center frequency of oscillation of said voltage control oscillator means, said center frequency of oscillation having a frequency variation which is proportional to the frequency variation of the subcarrier of the reproduced carrier chrominance signal.