JP2555189B2 - PAL system color signal processing circuit - Google Patents

Description

The present invention relates to a PAL system color signal processing circuit, and more particularly to a PAL system color signal processing circuit suitable for use in a VTR reproducing system and the like.

[Conventional technology]

In VTRs that record and reproduce PAL system video signals, depending on the recording format on the magnetic tape, colors may disappear on the playback screen during special playback such as search, slow, and still, or in the middle or at the top of the playback screen. The hue may be disturbed.

This is because, as described in JP-A-65-96589, the recording position shift amount of the horizontal synchronizing signal in the track length direction between adjacent tracks on the magnetic tape is α _H (1H on the magnetic tape). Ratio of (1 horizontal period) to recording length), α _H = integer or (However, n is an integer) This occurs when the recording format is set. In the PAL system, the burst signal phase is +135
The phase continuity of the carrier color signal (hereinafter simply referred to as the color signal) in the video signal is maintained by switching alternately every °, -135 ° and 1H, but special reproduction is performed with the above recording format. When the track jumping is performed, the phase of the burst signal continues to + 135 °, -135 °, or -135 °, -135 °, and the phase continuity (hereinafter,
It is discontinuous due to the loss of line sequentiality). In this discontinuous portion of the phase, the color discrimination circuit of the television receiver malfunctions, or it takes a long time to pull in, so that the reproduction screen loses its color or has an abnormal hue.

In order to prevent such disappearance of color and abnormality of hue, it is necessary to correct the color signal so as to maintain the line sequentiality. For that purpose, first, a point where the line sequentiality of the color signal becomes discontinuous is detected. There is a need to. Hereinafter, an example of the detecting means will be described.

FIG. 7 is a block diagram showing the detection means by the method of detecting the burst signal. 28 is a burst gate, 29 is a phase detection circuit, 30 is an LPF (low pass filter), 31 is a comparison circuit, and 32 is a waveform shaping circuit. Reference numeral 33 is a switching switch, 34 is an FF (flip-flop circuit), and 35 is an inverting circuit. Further, FIG. 8 is a diagram showing signals of respective parts in FIG. 7, and the signals corresponding to FIG. 7 are denoted by the same reference numerals.

7 and 8, the color signal of the input PAL system video signal is supplied to the burst gate 28, and the burst signal A is separated and supplied to the phase detection circuit 29.
Further, the + 90 ° phase subcarrier corresponding to the RY axis of this color signal has a −90 ° phase subcarrier whose phase is inverted by the inverting circuit 35, and 1H (however, by the switching switch 33). 1H
Are alternately selected every 1 horizontal period), + 90 °,-
A subcarrier B whose phase changes from 90 ° is formed. The auxiliary carrier liquid B is supplied to the phase detection circuit 29.

The switching switch 33 is controlled by a control signal generated from the FF 34 which is also triggered by a horizontal synchronizing signal which is phase-synchronized with the color signal. Here, when the phase of the burst signal A is + 135 °, the subcarrier B It is assumed that the switching timing of the switching switch 33 has been initialized so that the phase of-is 90 degrees.

In the phase detection circuit 29, the burst signal A is detected by the subcarrier B. Since the phase change order of the subcarrier B is initialized as described above, a negative pulse C is output every time the burst signal A is supplied from the phase detection circuit 29 together with the input of the color signal. This pulse C is LPF30
It is supplied to the comparison circuit 31 via and is compared in level with the positive reference voltage Eref. At this time, since the pulse C is negative and has a lower level than the reference voltage Eref, the comparison circuit 31 does not output a signal.

Now, if a track jump occurs due to special reproduction at time t ₁ in FIG. 8, the line sequence of the color signals becomes discontinuous at this time, and the phase of the burst signal A shifts by 1H. Become. For this reason, if the line sequentiality becomes discontinuous after the phase of the burst signal A reaches + 135 °, the phase of the burst signal A again becomes + 135 ° and +1.
The phase of 35 ° continues twice, and then it repeats at -135 ° and + 135 °.

Therefore, the phase detection circuit 29 outputs the positive pulse C because the phase relationship of the burst signal A with respect to the subcarrier B is reversed from the time t ₁ . The pulse C is supplied to the comparison circuit 31 via the LPE 30 and compared with the reference voltage Eref in level. At this time, the pulse C has a higher level than the reference voltage Eref, and a pulse is output from the comparison circuit 31 every time the pulse C is supplied. Due to the track jump, the pulse is output from the comparison circuit 31 until time t ₂ when the line sequentiality of the color signal becomes discontinuous again. This pulse is supplied to the waveform shaping circuit 32, and the control signal D that is "H" (high level) during the period in which the comparison circuit 31 outputs the pulse is obtained.

In this way, the output of the pulse from the comparison circuit 31 detects that the phase relationship of the burst signal with respect to the subcarrier B is reversed due to the discontinuity of the line sequentiality of the color signal. The control signal D whose level of the reverse rotation period changes will be obtained.

Therefore, by the reproduced color signal, a color signal in which the RY component is inverted with respect to this color signal is formed as a correction color signal, and the reproduced color signal is normally selected by the switching switch. , When the level of the control signal is inverted, by selecting the correction color signal,
The line sequentiality of the color signal becomes continuous.

In the above-mentioned Japanese Patent Laid-Open No. 56-96589, the corrected color signal is formed by delaying the reproduced color signal by 1H using a 1H delay means.

[Problems to be Solved by the Invention]

By the way, in the above-mentioned conventional technique, the 1H delay means is used to form the corrected color signal. As 1H delay means,
At present, there are a glass delay line and a CCD delay line, and the glass delay line is large and costly. At present, the CCD delay line has high power consumption and high cost. If a color signal delayed by 1H is used as the correction color signal, a 1H shift occurs between the luminance signal and the color signal even if the discontinuity of the line sequentiality of the color signal is lost, and Color misregistration occurs in the vertical direction and the image quality deteriorates.

Further, as shown in FIGS. 7 and 8, when the control signal for selecting and switching the color signal and the correction color signal is formed, the signal processing is performed using the subcarrier of about 4.43 MHz. Therefore, there is a problem in that the signal to be handled is likely to have a phase shift, which lowers the performance of the control signal generation circuit.

An object of the present invention is to solve such a problem, to generate a correction color signal without the need of 1H delay means, and to generate a control signal for switching between an input color signal and a correction color signal with high accuracy. It is to provide a PAL system color signal processing circuit capable of performing.

[Means for solving the problem]

To achieve the above object, the present invention provides a demodulation circuit for demodulating an input color signal on the RY axis and an RY from the demodulation circuit.
A coefficient circuit that multiplies the baseband signal by −2, a modulation circuit that modulates the RY baseband signal from the coefficient circuit on the RY axis, and the RY component from the modulation circuit is added to the input color signal. An RY inversion circuit including an adder circuit, and detection means for detecting that the burst signal obtained by detection of the input color signal is supplied and the line sequentiality of the input color signal is discontinuous. Generating means for generating a control signal whose level is inverted each time the detecting means detects the line-sequential discontinuity;
The switch means is controlled by the control signal to switch and select the input color signal and the output signal of the adding circuit in the RY inverting circuit.

[Action]

In the RY inverting circuit, even the RY component of the input color signal is demodulated to the baseband and is multiplied by -2 and modulated on the RY axis. R
-The amplitude is doubled by being inverted with respect to the Y component,
By adding this to the input color signal, it becomes a color signal having an RY component that is inverted with respect to the input color signal.

In this way, it is possible to obtain a color signal in which the RY component is inverted with respect to the input color signal without using the 1H delay means.

The line sequentiality of the color signals becomes discontinuous, and the input color signal and the color signal from the RY inversion circuit are switched by the switch means. However, since these color signals have the above relation, Line discontinuity is lost, and the 1H delay means is not used in the RY inversion circuit, and the input color signal and the color signal output from the RY inversion circuit at the same time. Have the same information content, there is no time lag between the color signal and the luminance signal obtained from the switching means even if the switching means is switched.

Further, the burst signal used in the detecting means is obtained by detecting the input color signal, and it is possible to prevent the performance deterioration of the control signal generating means due to the phase shift as in the prior art.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a PAL color signal processing circuit according to the present invention, in which 1 is an input terminal, 2 is an LPF,
3 is an ACC (Automatic Chroma Level Control) circuit, 4 is a frequency conversion circuit, 5 is an APC (Automatic Phase Control) circuit, 6 is a phase adjustment circuit, 7 is a demodulation circuit, 8 is an LPF, 9 is a modulation circuit,
10 is an adding circuit, 11 is an RY inverting circuit, 12 is a switching switch, 1
3 is a burst gate, 14 is an inverting circuit, 15 is a switching switch, 16
Is a comparison circuit, 17 is a T-FF (T-type flip-flop circuit),
18 is an input terminal, 19 is a PLL (Phase Locked Loop) circuit, 20 is a frequency dividing circuit, 21 is an ExOR (exclusive OR) circuit, and 22 is an output terminal.

In FIG. 1, a reproduction video signal from a magnetic tape (not shown) is input to the input terminal 1. In this reproduced video signal, the luminance signal of the PAL system video signal is FM-modulated and arranged on the high frequency side, and the color signal is arranged on the low frequency side as a low frequency conversion color signal and is supplied to the LPF2. The low frequency conversion color signal is separated. This low frequency conversion color signal is ACC
The amplitude of the burst signal is adjusted by the circuit 3 so as to be constant, and then the burst signal is supplied to the frequency conversion circuit 4, and the APC circuit 5
The frequency is converted into a PAL color signal by the subcarrier SC ₁ from. This color signal A is supplied to the q side of the switching switch 12 and R-
It is supplied to the Y inversion circuit 11 and also to the APC circuit 5. The APC circuit 5 generates subcarriers SC ₁ and SC _{2 that} are synchronized with the burst signal of the color signal A. Here, the frequency of the sub-carrier SC ₁ is the sum or difference of the sub-carrier frequency of the low frequency conversion color signal and the sub-carrier frequency of the color signal A, and the frequency of the sub-carrier SC ₂ is the sub-carrier frequency of the color signal A. be equivalent to.

The RY inversion circuit 11 is a color signal A ′ in which the RY component is phase-inverted with respect to the color signal A output from the frequency conversion circuit 4.
Normally, the switching switch 12 is closed on the q side to select the color signal A. However, when the line sequence of the color signal A is discontinuous, it is closed on the P side and the RY inversion is performed. The color signal A'from the circuit 11 is selected. As a result, the line sequentiality of the color signal A is corrected and a continuous line sequential color signal is obtained at the output terminal 22.

The RY inverting circuit 11 is composed of a demodulating circuit 7, an LPF 8, a modulating circuit 9 and an adding circuit 10. The operation will be described below with reference to FIG.

The fact that the R-Y component of the color signal A'is inverted with respect to the color signal A means that in the vector phase diagram of the B-Y axis and R-Y axis shown in FIG. Is a vector $ _{1 of} the phase shown in FIG. 2, the subcarrier of the color signal A ′ is a belt carrier $ ₅ having a phase symmetrical with respect to the vector $ ₁ with respect to the B-Y axis.
_{If 5} , then the subcarrier of the color signal A'is the vector $ ₁ . The RY inversion circuit 11 is a vector $ ₁
Or from sub-carrier of the color signal A $ ₅ Vector $ ₅ or $ ₁ and generates a color signal A '.

Therefore, first, the color signal A output from the frequency conversion circuit 4 is supplied to the demodulation circuit 7, and the subcarrier SC ₂ whose phase is adjusted by the phase adjustment circuit 6 so as to be in phase synchronization with the RY component of the color signal A _2. Thus, the RY component B of the color signal A is demodulated. Here, the subcarrier of the color signal A is the vector $ in FIG.
_{If it is 1} , the demodulated RY component B is the component S ₂ on the RY axis of the vector $ ₁ . The R-Y component B is removed unnecessary harmonic components in LPF 8, is -2 times Yotsute to means such as a coefficient unit (not shown), the sub-carriers SC from the phase adjustment circuit 6 in the modulation circuit 9 as the component S ₃ Modulated by ₂ . The output signal of the modulation circuit 9 has the same information content as the R-Y component of the color signal A, and the vector $ ₄ whose phase is inverted by twice the magnitude of the component vector of the vector $ _{1 in} the R-Y axis direction. It is represented by. Therefore, by adding the output signal of the modulation circuit 9 and the color signal A in the addition circuit 10, the vector $
The color signal A'of the subcarrier represented by the sum vector of ₁ and $ ₄ , that is, the vector $ ₅ is obtained.

The same applies when the subcarrier of the color signal A is the belt carrier $ ₅ , and the color signal A ′ of the subcarrier represented by the vector $ ₁ is obtained from this color signal A.

Next, the means for generating the control signal I for switching the switching switch 12 will be described with reference to FIG. However, FIG. 3 is a waveform diagram showing the signals of the respective parts of FIG. 1, and the signals corresponding to those of FIG. Further, t ₁ and t ₂ in FIG. 3 represent the time points when the line sequentiality of the color signal becomes discontinuous.

The baseband RY component B output from the LPF 8 of the RY inverting circuit 11 is also supplied to the burst gate 13, and the baseband burst signal D is extracted by the gate pulse C. Here, the burst signal of the color signal A is
Since it switches between + 135 ° and -135 ° for each 1H, RY component B
Inverts the polarity every 1H including the burst signal. But,
At 2H before and after the line-sequential discontinuities t ₁ and t ₂ , the RY component B including the burst signal has the same polarity. This also applies to the burst signal D extracted by the burst gate 13.

The burst signal D is directly supplied to the X side of the switching switch 15 and is inverted by the inverting circuit 14 to be switched.
Supplied on the Y side of 15. The switching switch 15 is controlled by the control signal F from the ExOR circuit 21, and normally, the burst signal D and the burst signal E from the inverting circuit 14 are alternately selected every 1H and a burst signal G having a constant polarity is output. To do. The burst signal G is compared with the reference voltage in the comparison circuit 16, and the pulse H is generated when the voltage of the burst signal G is higher than the reference voltage. The T-FF 17 is triggered by this pulse H, and a control signal I whose level is inverted each time the pulse H is supplied is obtained.

On the other hand, the horizontal synchronizing signal HS of frequency f _H separated from the reproduction signal input to the input terminal 1 is input from the input terminal 18. The horizontal synchronizing signal HS is waveform-shaped by the PLL circuit 19 and then supplied to the frequency dividing circuit 20 to form a pulse having a duty ratio of 50% at a frequency of f _H / 2. This pulse and the control signal I generated by T-FF17 are supplied to ExOR21 to form the control signal F of the switching switch 15. When the control signal I is "L", the output pulse of the divide-by-2 circuit 20 becomes the control signal F as it is, and the control signal I is "H" (high level).
At this time, the output signal of the divide-by-2 circuit 20 is inverted to become the control signal F. From the position of the horizontal synchronizing signal in the reproduction signal, the output pulse of the divide-by-2 circuit 20, and hence the control signal F level inversion point (rising and falling points) is immediately before the burst signals D and E.

Here, the switching switch 15 selects the burst signal D on the X side when the control signal F is "L", and the control signal F is "H".
At this time, the burst signal E on the Y side is selected.

Now, when the control signal I is "L" and the switch 15 selects the burst signal D when the burst signal D is "L", the switch 15 selects the burst signal E when the burst signal D is "H". Assuming that ExOR is 21 and the control signal F is output, the switch 12 selects the color signal A on the q side, and the switching switch 15 alternately selects the negative pulses of the burst signals D and E. Therefore, all the burst signals G output from the switching switch 15 are negative, the pulse H is not generated from the comparison circuit 16, the control signal I is held at "L", and the switching switch 12 is colored. Continue to select signal A.

After that, when a line-sequential discontinuity of the color signal A occurs at time t ₁ , the polarities of the two burst signals D before and after that become equal. That is, as shown in FIG. 3, assuming that the time point t ₁ is between the time point when the burst signal D is positive and the time point after the next 1H, two burst signal D that are positive are continued. .
The switching switch 15 selects the negative burst signal E at the time of the earlier positive burst signal D of these, and next selects the later positive burst signal D. Then the burst signal G becomes positive and the pulse H from the comparison circuit 16
Occurs. Therefore, the T-FF 17 is triggered so that the control signal I becomes "H", and the switching switch 12 selects the color signal A'on the p side.

On the other hand, when the control signal I becomes "H", the level of the control signal F is inverted, the switching timing of the switching switch 15 is shifted by 1H, and the negative burst signals D and E are alternately selected. As a result, the control signal G becomes negative again, and the comparison circuit
No pulse is generated from 16. For this reason, the switching switch 12 continues to select the color signal A '.

Thereafter, the line-sequential of discontinuity again color signal A at time t ₂ is generated, becomes the burster signal G is positive in the same, the control signal I is inverted to "L" in the comparison circuit 16 the pulse H occurs To do. As a result, the switch 12 switches to the q side to select the color signal A. Further, the control signal F is inverted by the control signal I being inverted to "L", and the switching switch is turned on.
The burst signal G from 15 becomes negative.

As described above, the switching switch 12 is switched every time the line-sequentiality of the color signal A becomes discontinuous, so that the color signal obtained at the output terminal 22 is kept line-sequential. Also, R
Since the baseband burst signal obtained by the -Y inversion circuit 11 is used for detecting line-sequential discontinuity, there is no need to provide a special burst signal detection circuit, and the circuit configuration is simplified accordingly.

The initial level of the control signal I can be either "L" or "H", and the initial level of the control signal F can be either "L" or "H". 12 is only initially set so as to select either one of the color signals A and A ', and there is no particular problem.

FIG. 4 is a block diagram showing another embodiment of the PAL system color signal processing circuit according to the present invention, in which 23 and 24 are DC voltage sources,
Reference numeral 25 is a switching switch, and 26 is a multiplication circuit. The parts corresponding to those in FIG.

In the figure, the baseband burst signal D output from the burst gate 13 is supplied to the multiplication circuit 26 and is switched to 1H by the switching switch 25 controlled by the control signal F.
DC voltage E from DC voltage sources 23 and 24 alternately supplied for each
It is multiplied by ₁ and E ₂ .

Here, if E ₁ > E ₂ , then normally in a multiplication circuit,
The switching switch 25 is controlled by the control signal F so that the positive burst signal D is multiplied by the DC voltage E _2, and the negative burst signal D is multiplied by the DC voltage E ₁ . In this case, the level of the output pulse G'of the multiplication circuit 26 becomes maximum when the burst signal D is positive, but the reference voltage of a level higher than this maximum level is set in the comparison circuit 16, and therefore, The comparison circuit 16 does not generate the pulse H.

On the other hand, when the line sequentiality of the color signal A becomes discontinuous,
The positive and negative order of the burst signal D is shifted by 1H,
The multiplication of the positive burst signal D and the DC voltage E ₁ is performed. As a result, the multiplication circuit 26 generates a pulse G'having a level equal to or higher than the reference voltage set in the comparison circuit 16, and the comparison circuit 16 generates a pulse H to trigger T-FF17. Accordingly, the levels of the control signals I and F are inverted, the switching switch 12 is switched, the switching timing of the switching switch 25 is shifted by 1H, and the level lower than the reference voltage of the comparison circuit 16 is output from the multiplication circuit 26. Pulse G '
Will be output.

As described above, this embodiment can also obtain the same effect as that of the embodiment shown in FIG.

FIG. 5 is a block diagram showing still another embodiment of the PAL system color signal processing circuit according to the present invention, in which 27 is an opening / closing switch, and parts corresponding to those in FIG. The description is omitted.

Further, FIG. 6 is a waveform diagram showing the signals of the respective parts in FIG. 5, and the signals corresponding to those in FIG. 5 are designated by the same reference numerals.

In FIG. 5 and FIG. 6, the burst signal D of the base band, which is output from the burst gate 13 and whose polarity is inverted every 1H, is supplied to the opening / closing switch 27. The open / close switch 27 is controlled by a control signal F having a duty ratio of 50% in a 2H cycle from the ExOR 21, and is closed when the control signal F is "H". As a result, the open / close switch 27 extracts every other burst signal D and supplies it to the comparison circuit 16 as a pulse G ″.

A reference voltage of a positive level, which is lower than the amplitude of the positive burst signal D, is set in the comparison circuit 16. Therefore, since the level of the output pulse G ″ of the open / close switch 27 is lower than the reference voltage set in the comparing circuit 16 when the open / close switch 27 is extracting every other negative polarity burst signal D, No pulse H is generated from the comparison circuit 16.

However, when the line signals of the color signals are discontinuous and two burst signals D of the same polarity continue, the burst signal D of the positive polarity is generated.
Then, the open / close switch 27 is closed, and the pulse G ″ at this time becomes positive and becomes a higher level than the reference voltage set in the comparison path 16. Therefore, the comparison circuit 16 outputs the pulse H. Then, the T-FF 17 is triggered, the level of the control signal I is inverted and the switching switch 12 is switched, the level of the control signal F is inverted, and the open / close switch 27 again extracts the negative burst signal D.

As described above, in this embodiment, the same effect as that of the embodiment shown in FIG. 1 can be obtained, but the input pulse G ″ of the comparison circuit 16 is further changed by the open / close switch 27 to generate every other burst signal D. Since it is obtained by extracting, the circuit configuration is simplified as compared with the embodiments shown in FIGS. 1 and 4.

In addition, in FIG.
Since every other burst signal D is extracted to detect the discontinuity of the line sequentiality of the color signals, the detection of this discontinuity may be delayed by 1H from the time when the discontinuity is actually generated. That is, when two burst signals of positive polarity continue due to the discontinuity of line sequentiality, the opening / closing switch 27 extracts the positive burst signal D of the latter one, and the burst signal D of the line sequentiality is immediately extracted. Continuity is detected, but as shown in FIG. 6, when the line sequentiality becomes discontinuous at times t ₁ and t ₂ , if two burst signals D of negative polarity continue, these two The positive polarity burst signal D next to the negative polarity burst signal D is extracted by the open / close switch 27 to detect the line-sequential discontinuity, and this detection is delayed by 1H.

For this reason, the switching timing of the switching switch 12 is 1H.
However, the line sequentiality of the color signal becomes discontinuous for 1H, causing color fading, etc., but during the 1H period where this color fading occurs, the lower side of the noise bar that appears on the screen during search playback or still playback It is located in the area where the achromatism is not recognized, so there is no problem.

[Effects of the Invention] As described above, according to the present invention, a color signal in which the RY component is inverted with respect to the input color signal can be generated without using the 1H delay means. The RY inverting circuit for generating a signal can be configured as a small size, low cost and low power consumption and is suitable for integration, and the input color signal and the color from the RY inverting circuit can be obtained. By switching the signals, the discontinuity of the line sequentiality of the color signals is eliminated, and moreover,
This switching does not cause color shift on the screen.

Further, the control signal generating means for switching and controlling the input color signal and the color signal from the RY inversion circuit also has improved performance to generate the control signal with high accuracy, and the circuit configuration thereof is also simplified. .

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a PAL system color signal processing circuit according to the present invention, FIG. 2 is an operation explanatory diagram of an RY inversion circuit in FIG. 1, and FIG. FIG. 4 is a waveform diagram showing signals, FIG. 4 is a block diagram showing another embodiment of the PAL system color signal processing circuit according to the present invention, and FIG. 6 is a diagram showing signals of respective parts of FIG. FIG. 7 is a block diagram showing an example of a conventional PAL color signal processing circuit,
FIG. 8 is a diagram showing signals of the respective parts of FIG. 7 ... Demodulation circuit, 9 ... Modulation circuit 10 ... Addition circuit, 11 ... RY inversion circuit 12 ... Switching switch, 13 ... Burst gate 14 ... Inversion circuit, 15 ... Switching switch 16 ... … Comparison circuit 17 …… T-type flip-flop circuit 18 …… Horizontal synchronizing signal input terminal 20 …… Dividing circuit by two, 21 …… Exclusive OR circuit 22 …… Output terminal, 23,24 …… DC voltage source 25… … Switching switch, 26 …… Multiplier circuit 27 …… Opening / closing switch

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP 61-144188 (JP, A) JP 60-206288 (JP, A) JP 58-225791 (JP, A) JP 56- 96589 (JP, A)

Claims (5)

(57) [Claims] 1. A demodulation circuit for demodulating an RY component of a carrier color signal of an input PAL video signal, a coefficient unit for multiplying an RY baseband signal from the demodulation circuit by −2, and the coefficient. And a R-Y baseband signal output from the modulator for modulating the same sub-carrier as the sub-carrier supplied to the demodulation circuit to generate an R-Y component, and the R-Y from the modulation circuit. The RY inverting means including an adding circuit for adding the Y component and the input carrier color signal, and a burst signal obtained by detection of the input carrier color signal are supplied to supply the carrier color signal. Detecting means for detecting that the line-sequentiality is discontinuous; generating means for generating a control signal whose level is inverted by the detection of the line-sequential discontinuity by the detecting means; Therefore, the carrier color signal which is controlled and input by the And a switch means for selecting switching the output signal of the adder circuit in the circuit, PAL system chrominance signal processing circuit for discontinuous line sequential of the carrier chrominance signal is characterized by being configured so as to be corrected. 2. The PAL system color signal processing circuit according to claim 1, wherein a burst signal of the RY baseband signal obtained by the RY inverting circuit is supplied to the detecting means. 3. The switch according to claim 1 or 2, wherein the detecting means alternately selects the burst signal supplied and the burst signal whose level is inverted, and an output signal of the switch and a reference signal. And a comparison circuit for generating a pulse for inverting the level of the control signal with the level change of the output signal of the switching switch due to the discontinuity of the line sequentiality of the carrier color signal, and the switching circuit. And a switching control means for setting the switching phase of the switch according to the level of the control signal.
L system color signal processing circuit. 4. The switching switch according to claim 1, wherein the detection means alternately selects the first and second DC voltages of different levels for each horizontal period, and the switching switch outputs the switching switch. A multiplication circuit that multiplies a DC voltage and the supplied burst signal, and a comparison circuit that compares the output signal of the multiplication circuit with a reference voltage to cause a discontinuity in the line sequentiality of the carrier color signal. A comparison circuit for generating a pulse for inverting the level of the control signal as the level of the output signal changes; and a switching control means for setting the switching phase of the switching switch according to the level of the control signal. PAL system color signal processing circuit. 5. The carrier according to claim 1, wherein the detection means compares the level of an open / close switch that extracts every other burst signal supplied, and an output signal of the open / close switch with a reference voltage. A comparator circuit for generating a pulse for inverting the level of the control signal with the level change of the output signal of the open / close switch due to the discontinuity of the line sequentiality of the color signal, and the phase of the open / close switch as the control signal A PAL system color signal processing circuit, which comprises an opening / closing control unit that is set according to the level.