Apparatus for removing jitter in color television signal

Claim 3

An apparatus for removing jitter in a color signal according to claim 1, in which said jitter detection means comprises: a synchronizing signal separation circuit for separating a horizontal synchronizing signal from the color signal played back by said record/play-back means; a first monostable multivibrator for outputting a first pulse at the leading edge of said horizontal synchronizing signal inputted thereto; a second monostable multivibrator for producing a second pulse at the trailing edge of the first pulse; and a logic circuit which is coupled at one input with the second pulse and at the other input with the horizontal synchronizing signal through an inverter and which produces a comparing signal at the trailing edge of the horizontal synchronizing signal.

Claim 4

An apparatus for removing jitter in a color signal according to claim 1, in which said jitter detection means comprises: a synchronizing signal separation circuit for separating a horizontal synchronizing signal from the color signal played back by said record/play-back means; a first monostable multivibrator for outputting a first pulse at the leading edge of said horizontal synchronizing signal inputted therein; a second monostable multivibrator for producing a second pulse at the trailing edge of the first pulse; an analogue switch which is connected at one input with the second pulse and at the other input with the play-back color signal and which produces the play-back color signal in response to the second pulse; and a voltage comparator which is coupled at one input terminal with the output signal from said analogue switch and at the other input terminal a reference signal and both the signals are voltage-compared and produces a comparing signal on the basis of the result of the comparing.

Claim 5

An apparatus for removing jitter in a color signal according to claim 1, in which said jitter detection means comprises: a pilot signal separation circuit for separating a pilot signal from the color signal played back by said video signal record/play-back means; and a logic circuit for producing a comparing signal at the trailing edge of said pilot signal separated.

Claim 6

An apparatus for removing jitter in a color signal according to claim 1, in which said jitter correction means comprises: a phase comparator which is coupled at one input terminal with a comparing signal from said jitter detection means and at the other input terminal with a reference frequency signal outputted from said reference signal generating means and which compares the phases of both the signals; and a variable delay circuit which is coupled with the output signal from said phase comparator and delays the play-back color signal including jitter in accordance with the output voltage of said output signal.

Claim 7

An apparatus for removing jitter in a color signal according to claim 5, in which said variable delay circuit is a charge coupled device.

Claim 8

An apparatus for removing jitter in a color signal according to claim 1, in which said reference signal generating means comprises: a crystal oscillator; a 1/4 frequency divider which frequency-divides the frequency of the output signal from said crystal oscillator into 1/4 and provides a reference frequency signal to first and second frequency converters which convert the chrominance signal into low or high frequency signals when the color video signal is recorded or played back by said record/play-back means; a 1/1085 frequency divider which frequency-divides the frequency of the output signal from said oscillator into 1/1085 and provides a reference signal to said phase comparator; and a 1/525 frequency divider which frequency-divides the frequency of the output signal from said 1/1085 frequency divider into 1/525 and provides a reference signal to the servo circuit of said record/play-back means.

Claim 9

An apparatus for removing jitter in a color signal according to claim 1, in which said jitter correction means comprises: a phase comparator which is coupled at one input with a comparing signal detected by said jitter detection means and at the other input with a reference signal and compares the phases of both the signals; a first variable delay circuit which is coupled with the luminance signal demodulated by said modulating means and delays the luminance signal by a predetermined time on the basis of the output signal from said phase comparator; and a second variable delay circuit which is coupled with the chrominance signal of said play-back video signal and delays the chrominance signal by a predetermined time on the basis of the output signal of said phase comparator.

Claim 10

An apparatus for removing jitter in a color signal according to claim 8, in which said first and second variable delay lines are each comprised of a charge coupled device delay line and an oscillator for driving the charge coupled device delay line.

Claim 11

An apparatus for removing jitter in a color signal according to claim 1, in which said reference signal generating means comprises: a crystal oscillator; a 1/4 frequency divider which frequency-divides the frequency of the output signal from said crystal oscillator into 1/4, and provides a reference signal to first and second frequency converters which convert the chrominance signal into low or high frequency signals when the color video signal is recorded or played back by said record/play-back means; a 1/1085 frequency divider which frequency-divides the frequency of the output signal from said oscillator into 1/1085 and provides a reference signal to said phase comparator; and a 1/525 frequency divider which frequency-divides the frequency of the output signal from said 1/1085 frequency divider into 1/525 and provides a reference signal to the servo circuit of said record/play-back means; a first logic circuit which is coupled at one input terminal with the output signal from said oscillator; a first counting circuit which is coupled at one input terminal with the output signal of said first logic circuit; means for producing a first pulse from said first counting circuit; means for producing a second pulse in response to the first pulse; a second logic circuit which is coupled at one input terminal with the first pulse and at the other input terminal with the play-back horizontal synchronizing signal and which produces a first logical signal; a third logical circuit which is coupled with the first and second pulses to produce a second logical signal; and a second counting circuit which is coupled at one input terminal with the output signal from said second logic circuit and at the other input terminal with the output signal from said third logic circuit, and applies an output signal to the other input terminal of said first logic circuit and to the other input terminal of said first counting circuit.

Claim 12

An apparatus for removing jitter in a color signal according to claim 10, in which said first logic circuit is an OR gate.

Claim 13

An apparatus for removing jitter in a color signal according to claim 10, in which said second logic circuit is an AND gate.

Claim 14

An apparatus for removing jitter in a color signal according to claim 10, in which said third logic circuit comprises a AND gate.

Claim 15

An apparatus for removing jitter in a color signal according to claim 10, in which said first counting circuit is a 1/1085 up/down counter.

Claim 16

An apparatus for removing jitter in a color signal according to claim 10, in which said second counting circuit is a 1/N up/down counter.