JPS61105193A - Color signal processing device - Google Patents

Abstract

PURPOSE:To replace some components of a chrominance signal processing unit with a low priced X'tol required only for reference oscillation, simplifying its complicated circuit, and unifying it into MOS-IC, providing circuit structure suitable for integration by performing the operation so that a low-range chrominance signal is frequency- converted to a specified carrier frequency by a low-range conversion carrier frequency and oscillation output of a reference oscillator. CONSTITUTION:When recording, frequency and phase of a second voltage controlled oscillator 42 is controlled so that a first low-range conversion carrier frequency creased by a first volage controlled oscillator 41 and signal generator 43 is synchronized with a burst of a low-range converted carrier chrominancee signal for a certain phase. When regenerating, the low-range conversion chrominance signal in a decorder 29 which is input from a terminal 1 by a switch 28 is supplied, and is demodulated to two digital data R-Y and B-Y. The R-Y data is passed to a digital comb line filter 31 to create R-Y' data. By supplying an output signal of the voltage controlled oscillator 42 and the low-range conversion carrier frequency created by the signal generator 43 base on that signal to the decorder 29, the low-level conversion color signal is correctly converted to two color difference digital data R-Y and B-Y.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention records a carrier color signal by converting it to a low frequency, and when reproducing the color signal, the frequency is converted to the carrier color signal of the original carrier frequency to reproduce the color. The present invention relates to a signal processing device.

Conventional configuration and its problems In a conventional color VTR, for example, when recording a color video signal of the NTSC system using the VH8 system, the carrier color signal with a carrier frequency of fsa (= 3.ss M■2) is lowered. A low frequency conversion color signal having a frequency conversion frequency fC (=629Kliz) and an FM modulated luminance signal are mixed and recorded on a magnetic tape. Furthermore, when reproducing the signal recorded on this magnetic tape, the low-frequency converted color signal in the reproduced signal is frequency-converted into a carrier color signal of frequency fsc, and the resultant signal is added to the FM demodulated luminance signal and output. That's what I do.

A conventional example of a color signal processing device that performs frequency conversion during recording and reproduction of color signals as described above will be described with reference to FIG.

During recording, a carrier color signal of carrier frequency fsc is input from terminal 1. The carrier color signal is supplied to a frequency converter 2, and is multiplied by a carrier having a frequency of fsc+fc to obtain a carrier frequency of 2fsc+faO color signal and a carrier frequency of fCQ.
A signal that is the sum of color signals is obtained. From the obtained sum signal, only the carrier frequency fcO color signal is extracted by a low pass filter (LPF) 3 and is supplied to a terminal 4 as a low frequency converted color signal. During playback, a low frequency converted color signal with carrier frequency fc is input from terminal 1, and frequency converter 2 converts the frequency to fBC+f.
multiplied by the carrier of c, and the carrier frequency becomes J'SG +
A signal is obtained that is the sum of the color signal of 2 fc and the color signal of carrier frequency fscO. The sum signal is a comb filter (CO
MB) In 5, the signal from one horizontal period or two horizontal periods ago is subtracted, unnecessary frequency components are removed, and the signal is
Only the carrier frequency fsc signal is extracted by a pass filter (BPF) 6 and is supplied to a terminal 7 as a reproduced carrier color signal.

The carrier having the frequency fsc+fc supplied to the frequency converter 2 undergoes frequency conversion so that the phase or frequency of the low frequency converted color signal and the carrier color signal are kept constant regardless of the jitter of the color signal input from the terminal 1. In the conventional example shown in FIG. 1, the control is performed as follows.

First, during recording, the phase comparator (Per9. Low pass filter (LPF)10. Switch 11° Voltage Controlled Oscillator (VCOI) 12. A phase locked loop (hereinafter referred to as PLL) composed of a frequency divider (1/rl) 13 calculates the frequency fF of the horizontal synchronizing signal input from the terminal 8.
A signal with a frequency nfH obtained by multiplying 1 by n (n is a positive integer) is sent from the voltage controlled oscillator 12 to the signal generation circuit (PS/P engineering) 1.
4. The signal generation circuit 14 generates a low-frequency converted carrier wave that is subjected to phase shift or phase inversion processing every horizontal period so that crosstalk between adjacent tracks can be removed by the comb filter 5 during playback. Something,
For example, when recording and reproducing a VH5H5 TSC color video signal, the voltage controlled oscillator 12 to fH 16
Create a 4-phase clock that is supplied with a signal with a frequency of 0 times and divided by 1/4, and output it by sequentially switching it every horizontal period. Frequency converter 1 converts the low frequency converted carrier wave by 90°.
5 is supplied to one of the inputs. The terminal 16 is a terminal to which the track discrimination signal PG is input, and the signal generating circuit 14 determines the direction in which the phase is shifted using the signal PG, and performs the shift at the timing of the horizontal synchronization signal from the terminal 8. A voltage controlled oscillator (VXO) 17 operates as a voltage controlled oscillator with little frequency fluctuation that operates at The phase of the carrier color signal burst is compared with the phase comparator (PCZ) 2o, and the result is output to the low pass tie (LPF) 21 and the switch 22.
The voltage is fed back as a control voltage for the voltage controlled oscillator 16 via the voltage controlled oscillator 16. The feedback loop described above also constitutes a PLL, and the voltage controlled oscillator 16 generates a signal with a frequency fsc that is synchronized in frequency and phase with the burst of the carrier color signal, and sends this signal to the other input of the frequency converter 1.5. supplying. The frequency converter 15 multiplies the low frequency conversion carrier wave of the IM wave number fc created from the signal which is an integral multiple of the horizontal synchronization signal described above by the signal of the frequency fsa from the voltage controlled oscillator 16, and among the results, the bandpass filter is (BPF) 23 extracts carriers of frequencies f, c+fc and converts them into frequency converter 2.
is supplied to. Therefore, the low-frequency conversion carrier wave of the low-frequency conversion color signal supplied to the terminal 4 is controlled to always have a constant phase with respect to the horizontal synchronization signal at an integral multiple of the horizontal synchronization frequency.

During reproduction, the voltage controlled oscillator 17 is connected to a constant voltage source (REF) 24 via a switch 22, and operates as a fixed oscillator that oscillates at a constant reference frequency isc. The carrier color signal is frequency-converted and supplied to the terminal 7 for reproduction, and its burst is supplied to the phase comparator 2Q via the switch 18 and the burst gate 19, and the burst is supplied to the voltage controlled oscillator 1.
The phase is compared with the signal of frequency f5C from 7 in the phase comparator 20, and low-pass filter 21. The comparison result is given to the voltage controlled oscillator 12 via the adder 25 and the switch 11. From the signal supplied from the voltage controlled oscillator 12,
A low frequency conversion color signal is created in the signal creation circuit 14, multiplied by the signal from the voltage controlled oscillator 12 in the frequency converter 16, and a carrier of frequency fsc + fo is extracted in the bandpass filter 23 and sent to the frequency converter 2. The supply is the same as when recording. Side lock detector (SIDE LOC)
KDI! :T) 26, low pass filter (LPF)
27. Adder 25 prevents side lock of voltage controlled oscillator 12 during reproduction. Since a burst is an intermittent wave every horizontal period, the frequency-converted burst during reproduction has a stable point at a frequency of fBo±+nfH (m is an integer) with respect to the frequency fso of the signal generated by the voltage controlled oscillator 17. The low frequency converted carrier wave created by the signal creation circuit 14 is fa'xllfm.

When the frequency of the low frequency conversion carrier wave is other than fc, the side lock detector 26 detects it by counting the frequency of the voltage controlled oscillator 12 in the time represented by the period of the horizontal synchronization signal from the terminal 8, and corrects it. A voltage is generated, and the voltage is passed through a low-pass filter 27 to an adder 25.
Supply (at 7).

The adder 25 adds the correction voltage from the low-pass filter 27 to the soft phase ratio result from the low-pass filter 21. During playback of the operation described above, regardless of the jitter of the low frequency conversion color signal input from terminal 1, the carrier color signal synchronized with the signal of the reference frequency isa generated by the voltage controlled oscillator 1γ, which is a fixed oscillator, has a frequency. The converted carrier color signal is supplied to terminal 7.

In recent years, the conventional analog signal processing has been replaced with digital processing, and the integration of processing circuits has been increased.
A configuration as shown in the block diagram of another conventional example in FIG. 2 is conceivable.

In another conventional example shown in FIG. 2, a carrier color signal inputted from a terminal 1 is frequency-converted by a frequency converter 2, and a low-pass converted color signal of frequency fc is extracted by a low-pass filter.
This is the same as in the conventional example shown in FIG. During playback, the low frequency conversion color signal input from terminal 1 is digitally demodulated by the switch 28 into two color difference signal digital data R-Y and B-Y by the decoder (D, EC0DE) 29.
Digital comb fill (CO
MB) 30.31, each is added to the data of one horizontal period before to obtain two color difference signal digital data (R-Y)', (B-Y)' without unnecessary frequency components. Obtained color difference signal digital data (RY)', (B-Y)
' is, for example, a frequency four times the carrier frequency fsc (R-
Y )'+ (B-Y)', -(RY)'+-(
B-Y)' are sent out by an encoder (ENCODE) 32, D/person converted, passed through a bandpass filter 34, and supplied to a terminal 7 as a frequency-converted carrier color signal for reproduction. .

Frequency fsa+fc supplied to frequency converter 2 during recording
The method for creating a carrier is as follows: First, phase comparator 9° low-pass filter 10. Switch 11. A PLL consisting of a voltage-controlled oscillator 121 and a frequency divider 13 multiplies the horizontal synchronizing signal manually input from the terminal 8 by n to create a signal with a frequency of nfH and supplies it to the signal creation circuit 14, which then outputs the signal at the terminal 8. A low frequency carrier wave of frequency fc is created based on the horizontal synchronizing signal input from 8 and the track discrimination signal PG input from terminal 76, and is supplied to one input of frequency converter 16. this is,
This is similar to the conventional example shown at the beginning of FIG. Next, the low frequency converted color signal is supplied to the decoder 29 by the switch 28, and the two color difference signal digital data are converted based on the signal generated by the voltage controlled oscillator 12 and the low frequency converted carrier wave from the signal generation circuit. It is demodulated into RY and BY. The carrier color signal of the color video signal is a quadrature two-phase balanced modulation wave of color difference signals RY and B-Y, and as shown in FIG.
In the case of the NTSC system, the carrier chrominance signal burst SC has a vector (vector) tV with a phase difference of 90° and has a vector in the opposite direction to B-Y. When the carrier color signal of the NTSC system is low-pass converted, its vector is also a quadrature two-phase balanced modulation wave, and the R-Y axis of the carrier color signal is reversed by 180 degrees, but the burst vector C is the carrier color. Like the signal, it has a vector l-/y in the opposite direction of B-Y. Therefore, for example, if the frequency nfH is selected as the low frequency conversion frequency 4IC and the decoder 29 samples the clock with the frequency of 4fa, in a certain phase state of the clock, B-Y, R-
It becomes repeated data of Y, -(B-Y), -(R-Y), and the repeated data is further subjected to a process of haiku inversion 9 based on the phase of the low-frequency conversion carrier wave from the signal generation circuit 14. By doing this, it is possible to demodulate into two color difference signal data. Second
In the other embodiment shown in the figure, the sampling method of the decoder 29 uses a human/Di converter, and R-Y and B-Y are two color difference signal digital data. Here, if the low-frequency converted color signal advances by δθ with respect to the sampling clock for demodulation, the low-frequency converted color signal also advances by δθ as shown in Figure 4, and the burst also advances by δθ as shown in Figure 4. Phase error information of lc'1 sin δθ is obtained in the signal dental data RY. The R-Y data, which is the phase error information, passes through the digital comb-shaped filter 31 and becomes data (R-Y)', and the burst part information is held as phase error data in the sample hold circuit (S/H) 35. be done. X
The OR gate 37 inverts the data from the sample and hold circuit 36 in response to the recording/reproduction switching signal R/P input from the terminal 36. For example, during recording, the OR gate 37 receives a signal of voltage level "H" from the terminal 36 and inputs the data. perform an inversion,
During reproduction, it receives a signal of voltage level "L" and passes the data as is. The phase error data inverted by the XOR gate 37 during recording is converted to a D/person converter (D/person) 38. Voltage controlled oscillator (VXO) via switch 22
39. Voltage controlled oscillator 39 is inverted and D/
Its frequency is controlled by the phase error data that has been converted into a phase shifter, and it oscillates at a frequency that is four times the color subcarrier frequency fsa.The oscillation output is divided into 1/4 by a frequency divider circuit ("fa") 40, and the frequency is equal to the frequency fsa. A signal is created and supplied to the other input of the frequency converter 16.The frequency converter 16 multiplies the supplied frequency fBG and the signal of fc, and the bandpass filter 23 converts the frequency fsa + fa, Extracting the signal and supplying it to the frequency converter 2 is the same as in the conventional example shown at the beginning of FIG.

Through the operations described above, during recording, the low frequency converted color signal that has been low frequency converted for recording is demodulated using the demodulation axis created from the horizontal synchronization signal. Then, after inverting the phase error data between the low frequency conversion color signal and the demodulation axis using the XOR gate 37, I)
7, and the frequency fsC of the signal supplied to one input of the frequency converter 16 is controlled by the voltage. As a result, the carrier wave of the low frequency conversion color signal for recording supplied to the terminal 4 becomes one that is synchronized with the low frequency conversion carrier wave created by the signal creation circuit 14 at a constant phase. However, the phase error data is (R-Y) after passing through the digital comb filter 31.
'Created from a burst of data. This is because we wanted to use the circuit for both recording and playback, so when recording when crosstalk removal is not necessary, the digital comb filter 31 is used.
RY data before passing through may be used. Also,
The voltage controlled oscillator 39 is four times the carrier frequency fSC and later divided by the frequency divider 4Q to the frequency fsc, but this is used as the clock for the encoder 32 at the time of reproduction at a frequency of 4f8.
This is because G is required.

The method of demodulating the low frequency converted color signal input from terminal 1 during playback is to first convert the demodulated color difference signal digital data (R-Y
)' burst part is held as phase error data in the sample and hold circuit 35 in the same way as during recording, and the XOR gate 37 allows the data to pass through as is, contrary to the case during recording.
/ A converter 22° adder 25. Phase error data converted into an analog value is supplied to a voltage controlled oscillator 12 via a switch 11 . Voltage controlled oscillator 12 and signal generation circuit 14. The decoder 29 demodulates the low frequency converted color signal into two color difference signal digital data R-Y and B-Y, just as it did during recording, but this time the input low frequency converted color signal is accurate. It is controlled so that it is demodulated. Adder 26
．． A side lock detector 26 and a low pass filter 27 are similar to those in the conventional example shown in FIG. 1, and prevent side locks during reproduction.

The terminals 8.16 may also be considered to be similar to the prior art example shown at the beginning of FIG. From the above-described operation, the low frequency converted color signal is demodulated during reproduction. The voltage controlled oscillator 39 has switch 2.
A low voltage source 24 is connected through the reference carrier frequency 4.
It oscillates at twice 41so, and the oscillation output is sent to the encoder 32.
is supplied to.

In other words, in the other conventional example shown in FIG. 2, a low-pass conversion color signal is demodulated into two color difference signals, and the demodulated color difference signal data is converted into a signal with four times the reference carrier frequency fsc to obtain a predetermined signal. A reproduced carrier color signal having a carrier frequency fsc is obtained.

Two conventional examples of color signal processing devices have been described above, and the voltage controlled oscillator 17 or 39 is composed of an oscillator using a crystal (hereinafter referred to as X'tal) with a narrow frequency variation range. Since it works as a voltage controlled oscillator, it has a certain frequency variable range, and during playback, as a fixed oscillator, characteristics of X'tlLl with little frequency fluctuation are required, and it is difficult to obtain the desired characteristics. It has the disadvantage that it is expensive, and for the same reason, the electronic circuits associated with X'taL are also very complicated. In addition, in recent years, circuits have been digitized and converted to MO3IC, resulting in lower consumption circuits.

There is a movement toward higher integration, but conventionally, the
The electronic circuit associated with tal is composed of bipolar transistors and has the disadvantage that it is difficult to convert it into MO3IC.

Purpose of the Invention The purpose of the present invention is to replace the expensive X'tal with the desired characteristics, which was a drawback in the conventional example, with an inexpensive X'tal that only performs reference oscillation, and to further simplify the complicated circuit. It is an object of the present invention to provide a color signal processing device having a circuit configuration suitable for conversion, further conversion to Mo5xC, and integration.

Structure of the Invention The color signal processing device of the present invention includes a first phase comparator that compares the phases of two signals having a horizontal synchronization frequency, and a second phase comparator that compares the phases of two carrier waves having a low frequency conversion frequency. It includes at least an inverting circuit that inverts the polarity of the comparison result between the reference oscillator and the second phase comparator that transmits an integral multiple of the low-frequency conversion color signal, and when recording, one voltage-controlled oscillator and the first phase comparator are used. An oscillation output with a frequency that is an integral multiple of the horizontal synchronization frequency is obtained as the output of the voltage controlled oscillator, a first low-frequency conversion carrier wave is created by the oscillation output, and the second phase comparator converts the frequency to a low frequency for recording. The burst of the low-frequency conversion color signal and the low-frequency conversion carrier wave are phase-compared, the frequency and phase of the other voltage-controlled oscillator are controlled based on the comparison result, and a second low-frequency conversion carrier wave is created from the oscillation output. The oscillation output of the reference oscillator and the second low-frequency conversion carrier wave are used to perform low-frequency conversion of the carrier color signal, and during playback, one of the voltage-controlled oscillators is operated, and the oscillation output is used to perform low-frequency conversion of the carrier color signal. A carrier wave is created, the burst of the low-frequency converted color signal before frequency conversion by the second phase comparator and the low-frequency converted carrier wave are phase-compared, and the comparison result is reversed in polarity by an inverting circuit to convert the voltage to the above-mentioned voltage. The control oscillator is configured to control the frequency and phase, and operates to frequency convert the low frequency conversion color signal to a predetermined carrier frequency using the low frequency conversion carrier wave and the oscillation output of the reference oscillator, and performs frequency conversion during recording and playback. It performs the following actions.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 5 is a block diagram of a color signal processing device according to an embodiment of the present invention, and its operation will be explained below.

During recording, the carrier color signal input from terminal 1 is multiplied by a carrier of frequency fsa + fc in frequency converter 2, and the low-pass filter 3 extracts a low-pass converted color signal and supplies it to terminal 4. The figure shows the conventional example shown in FIG.

During reproduction, the switch 28 supplies the low frequency conversion color signal input from terminal 1 to the decoder 29, and after digital demodulation,
Digital comb filters 30, 31. Encoder 32.
A predetermined carrier frequency f, to terminal 7 via bandpass filtering. Obtaining the carrier color signal is similar to the other conventional example shown in FIG.

Frequency fsa+fc supplied to frequency converter 2 during recording
The method for creating a carrier is as follows: First, phase comparator 9° low-pass filter 1o first voltage controlled oscillator (VCOI) 41
A frequency divider 13 generates a signal having a frequency nfw which is n times the frequency of the horizontal synchronizing signal inputted from the terminal 8. The signal of the frequency nfII is passed through the switch 45 to the signal generating circuit (P
S/P engineering) 43 to create a first low frequency conversion carrier wave. The decoder 29 demodulates the low frequency converted color signal into two color difference signal digital data using the frequency nfg signal and the first low frequency converted carrier wave, as in the other conventional example shown in FIG. The data (R-Y)' that has passed through the digital comb filter 31 is held in a sample hold circuit where the data of the burst portion is held, and then inverted at the XOR gate 37 in response to the recording/reproduction switching signal R/P from the terminal 36. The D/A converter 38 performs D/A conversion as in the other conventional example shown in FIG. 2, but in the other conventional example shown in FIG. In this embodiment, the frequency and phase of the frequency fc supplied to the frequency converter 15 are controlled. That is, a signal at a reference carrier frequency obtained by dividing a signal at a frequency of 4 fsc from a fixed reference oscillator (XCO) 46 to 1/4 by a frequency divider 4o is supplied to one input of the frequency converter 15, The D/M-converted voltage for controlling the frequency and phase is supplied via the adder 26 to a second voltage control generator (VCO2) 42 having almost the same performance as the first voltage control generator 41, A signal generation circuit (PS/
PI) 44 creates a second low frequency converted wave based on the horizontal synchronizing signal from terminal 8 and the track discrimination signal PG from terminal 16, and supplies it to the other input of the frequency converter. The multiplication result in the frequency converter 15 passes through a bandpass filter 23 as in the other conventional example shown in FIG. 2, and then is supplied to the frequency converter 2 as a carrier of frequency fsc+fc. By the operation described above, the first voltage controlled oscillator 41 is activated during recording.
The frequency and phase of the second voltage controlled oscillator 42 are controlled so that the burst of the carrier color signal that has been low-pass converted to the first low-pass conversion carrier wave created by the signal creation circuit 43 is synchronized with a constant phase. be done. Side lock detector 26. Low pass filter 27. The adder 25 is for preventing side lock of the second voltage controlled oscillator 42, and has the same configuration as the other conventional example shown in FIG. 2, but is also operated during recording, which is different from the conventional example.

During playback, the switch 28 supplies the low frequency conversion color signal input from the terminal 1 to the decoder 29, demodulates it into two digital data R-Y and B-Y, and sends the R-Y data to the digital comb filter 31. RY)' data to be passed through the sample and hold circuit 35. XOR'7')37
．． The output signal of the voltage controlled oscillator 42 is supplied to the voltage controlled oscillator 42 through the D/A converter 38° adder 25 and is supplied to the signal generating circuit 43 via the switch 45.

By supplying the supplied output signal of the voltage controlled oscillator 42 and the area conversion carrier wave created by the signal creation circuit 43 based on the output signal to the decoder 29, the low frequency conversion color signal is accurately converted into two color difference signal digital signals. The conversion into data RY and BY is the same as the operation explained in the other conventional example in FIG. The color difference signal digital data R-Y and B-Y demodulated by the above operation pass through the digital comb filter 30°31.RY)', (B-Y)
' It becomes data and is supplied to the encoder 32. The encoder 32 requires a clock with a frequency of 4 fsa, which is four times the reference color subcarrier frequency fsc, and this clock is supplied directly from the reference oscillator 46.

The above explanation has been about recording and reproducing NTSC color video signals, but when recording and reproducing PAL color video signals, the PAL carrier color signals are shown in the vector diagrams (?L) and (b) in Figure 6. Burst SC is like -
The vector has the same magnitude in the (BY) direction and the R-Y direction, and the states (!L) and (b) are repeated every horizontal period. The low-pass converted color signal is also the seventh
As shown in Figures (C) and (d), the burst pect/shiC
has the same magnitude in the R-Y and -(B-Y) directions (because the -Y axis repeats inversion, for example, digital comb-shaped fill 31. -Y,
The B-Y data and the current data are added, and by adding a comb filter that adds the data of one horizontal period ago and the current data before or after the sample and hold circuit 35, the burst 0 (7) is added. The RY data is canceled and can be handled in the same way as an NTSC color video signal.

Further, in the color signal processing device according to the embodiment of the present invention, there is no independent phase comparator for comparing the phases of two carrier waves of the low frequency conversion frequency, but the decoder 29 digitally demodulates the low frequency conversion color signal. In this case, the burst portion of the R-Y data among the two color difference signal data is considered to be a phase error of the low frequency converted color signal that is supplied as a demodulation axis to the decoder 29 with respect to the low frequency converted color signal. The burst portion of (RY)' data after passing through the shape filter 31 is passed through a sample and hold circuit 36, an XOR circuit 3B, and a D/M converter 38, and is used as a phase comparison result. However, since this had a demodulation circuit that once demodulated to a color difference signal in order to frequency-convert the low frequency converted color signal to a carrier color signal during reproduction, it was only used as a phase comparator, and was created by the signal creation circuit 43. It can be used as a phase comparator if it can compare the low frequency converted carrier wave and the low frequency converted color signal. Also, when the frequency converter 2 is used as a frequency converting method during reproduction as in the conventional color signal processing device shown in FIG.
The signal generating circuit 43 in one embodiment of the present invention shown in FIG.
It is replaced with a low-pass conversion carrier wave that is synchronized with a constant phase to the burst of the low-pass conversion color signal during playback, like the low-pass conversion carrier wave created in , and is further supplied to the other input of the frequency converter 16 at the frequency j'. The present invention can be applied if the sc signal is a signal from a reference oscillator that oscillates at a predetermined carrier frequency.

Effects of the Invention As is clear from the above description, the color signal processing device of the present invention includes a first phase comparator that compares the phases of two signals at the horizontal synchronization frequency, and a first phase comparator that compares the phases of two carrier waves at the low frequency conversion frequency. The second phase comparator is equipped with two voltage controlled oscillators that oscillate at a frequency that is an integral multiple of the low frequency conversion color signal, and an inversion circuit that inverts the polarity of the comparison result of the second phase comparator. An oscillation output having a frequency that is an integral multiple of the horizontal synchronization frequency is obtained from the output of the voltage control oscillator by the controlled oscillator and the first phase comparator, a first low-frequency conversion carrier wave is created by the oscillation output, and a first low-frequency conversion carrier wave is created by the oscillation output; A phase comparator compares the phase of the burst of zone-converted color signals that have been low-pass converted for recording with the low-pass converted carrier wave, controls the frequency and phase of the other voltage-controlled oscillator based on the comparison result, and uses the oscillation output to control the frequency and phase of the other voltage-controlled oscillator. A second low frequency conversion carrier wave is created and the carrier color signal is low frequency converted using the oscillation output of the reference oscillator and the second low frequency conversion carrier wave, and one of the voltage controlled oscillators is operated during reproduction. create a low frequency converted carrier wave from the oscillation output, compare the phase of the low frequency converted carrier wave with the burst of the low frequency converted color signal before frequency conversion by the second phase comparator, and invert the comparison result. The circuit is configured to reverse the polarity and control the frequency and phase of the voltage controlled oscillator, and operates to convert the frequency of the low frequency conversion color signal to a predetermined carrier frequency using the low frequency conversion carrier wave and the oscillation output of the reference oscillator. In order to do this, the oscillator using x'tax, which performs two operations as a reference oscillator and a voltage-controlled oscillator, which had a drawback in the past, is replaced with one reference oscillator and one voltage-controlled oscillator, and the conventional X' Compared to the complex electronic circuitry associated with tal, the reference oscillator is
It can be configured with one S inverter, and the circuit is simple and can be easily converted into MO3IC by simply adding one voltage-controlled oscillator that was previously used, so the circuit can be simplified and MO8I
It has the effect of realizing a circuit configuration suitable for integration by converting it to C, and since the X'tal used is used only for the reference oscillator, there is no need to have a frequency variable range, and it can be realized with an inexpensive X'tal. There is also this effect.

Further, in the color signal processing device of the present invention, one of the two voltage-controlled oscillators is used in a pair with the first phase comparator, and operates only when the frequency of the horizontal synchronization signal is multiplied by an integer during recording;
If the other voltage controlled oscillator is used as a pair with the second phase comparator and operated during both recording and playback, current consumption during playback can be reduced. In order to switch the analog voltage after passing through a low-pass filter during recording and reproduction, such as the switch 11 in FIG. 2, a high-performance analog switch was required. Switch 45 in FIG.
The signal generating circuit 43 connected to the output of the switch is replaced by a switch that switches between recording and reproducing signals from two voltage-controlled oscillators as shown in FIG. can be used, which has the effect of digitizing the circuit and simplifying the connections between each block.

[Brief explanation of the drawing]

FIG. 1 is a block diagram explaining a conventional example of a color signal processing device, FIG. 2 is a block diagram explaining another conventional example of a color signal processing device, and FIG. 3 is a block diagram explaining a conventional example of a color signal processing device. )/shi diagram, Figure 4 is a vector diagram of a low-pass converted color signal obtained by low-pass converting the carrier color signal of an NTSC color video signal,
FIG. 6 is a block diagram of a color signal processing device according to an embodiment of the present invention, FIG. 6 is a vector diagram of a carrier color signal of a PAL color video signal, and FIG. 7 is a low-frequency conversion diagram of a PAL color video signal. FIG. 1.4,7,8,16.36... terminal, 2゜1
5...Frequency converter, 3,10.27...
...Low pass filter, 9...Phase comparator, 1
3, 40 peaks...divider, 25...adder, 2
6...Side lock detector, 2B, 45...
...Riitch, 29...Decoder, 30.3
1...Digital/'<L-shaped tile, 32...Song En, Korg, 23.34...Song Hunt Pass Fill,
35... Sample Honild circuit, 37...
...XOR game), 38...D/person converter, 4
1.42... Voltage controlled oscillator, 43, 44...
...Signal creation circuit, 46...Reference oscillator. Name of agent: Patent attorney Toshio Nakao (1st person)
Figure 2 Figure 3 Figure 14 Figure Scale - Y Collection 5 Figure 6 Figure 7 (02.d. Scale - Construction Procedures Amendment 11i1i December 1960 4.E! 1982 Patent Application No. 216417 2. Name of the invention Color signal processing device 3. Relationship with the person making correction Patent application Address 1006 Oaza Kadoma, Kadoma City, Osaka Name (582) Representative of Matsushita Electric Industrial Co., Ltd.
Toshihiko Yamashita 4 Agent 571 Address 1006 Oaza Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. 5 Subject of amendment 6 Contents of amendment (1) [(PCl )J to ``(P
Cl)”. (2) r (VCOI)J on page 6, line 7 of the same
(V'CO1) Correct to J. (3) "Operates with rX'tel" on page 6, line 9 of the same page, "operates with rX' tel
It is composed of an oscillation circuit using a (4) r(PCZ)J on page 6, line 13 of the same page is replaced by r(PO
2)”. (5) Correct "voltage controlled oscillator 16" in line 15 of page 6 to "voltage controlled oscillator 17". (6) "Voltage controlled oscillator 16" on page 6, line 17 will be corrected to "voltage controlled oscillator 17". ) Correct "voltage controlled oscillator 15" in the third line of page 7 to "voltage controlled oscillator 17". (8) Change “terminal 76” on page 10, line 2o to “terminal 1”.
Corrected to 6. (9) "The voltage controlled oscillator 17 or 39 is a crystal crystal with a narrow frequency variation range (hereinafter referred to as X'
It is composed of an oscillator using an oscillator (called tal).
"X' tzl used for the voltage controlled oscillator 17 is
” will be corrected. (10) Change the “reference oscillator” on page 17, line 13 to “2”.
"One voltage controlled oscillator". (11) In the 20th line of page 17, "the above-mentioned low-pass conversion carrier wave" is corrected to "the above-mentioned first low-pass conversion carrier wave". (12) Change “(VCOI)” on page 19, line 16 of the same page to r
(VcOl) Corrected to J. (13) Correct "sample hold circuit" in lines 4 and 5 of page 20 to "sample hold circuit 35." (14) "Signal wo" on page 20, line 16 will be corrected to "Signal ga". (16) In the 5th line of page 21, "Create a low-frequency converted carrier wave and use the frequency converter" to "Create a low-frequency converted carrier wave, and the created low-frequency converted carrier wave is used for the 5 frequency converter 15." I will correct it. □ (16) Correct "Frequency converter 15" in line 6 of page 21 to "And frequency converter 15." (17) On page 24, lines 13 and 14, "Since it has a demodulation circuit, use it as a single phase comparator" is corrected to "use the demodulation circuit as a phase comparator."

Claims (2)

[Claims] (1) The first step to compare the phases of two signals of horizontal synchronization frequency.
a second phase comparator that compares the phases of two carrier waves of the low-pass conversion frequency, two voltage-controlled oscillators that oscillate at a frequency that is an integral multiple of the low-pass conversion color signal, and a reference color subcarrier. It includes at least an inversion circuit that inverts the polarity of the comparison result of the reference oscillator that oscillates at an integral multiple of the frequency and the second phase comparator, and when recording, one voltage-controlled oscillator and the first
An oscillation output having a frequency that is an integral multiple of the horizontal synchronization frequency is obtained from the output of the voltage controlled oscillator by the phase comparator, a first low-frequency conversion carrier wave is created by the oscillation output, and the first low-frequency conversion carrier wave is recorded by the second phase comparator. The burst of the low-pass converted color signal that has been low-pass converted for the purpose of the invention and the first low-pass converted carrier wave are phase-compared, the frequency and phase of the other voltage-controlled oscillator are controlled based on the comparison result, and the oscillation output is used to control the frequency and phase of the other voltage-controlled oscillator. A second low frequency conversion carrier wave is created and the carrier color signal is low frequency converted using the oscillation output of the reference oscillator and the second low frequency conversion carrier wave, and one of the voltage controlled oscillators is operated during reproduction. create a low frequency converted carrier wave from the oscillation output, compare the phase of the low frequency converted carrier wave with the burst of the low frequency converted color signal before frequency conversion by the second phase comparator, and invert the comparison result. A circuit is configured to control the frequency and phase of the voltage controlled oscillator with the polarity reversed from that during recording, and frequency converts the low frequency conversion color signal to a predetermined carrier frequency using the low frequency conversion carrier wave and the oscillation output of the reference oscillator. A color signal processing device characterized in that it operates as follows. (2) One of the two voltage controlled oscillators is used as a pair with the first phase comparator, and operates only when the frequency of the horizontal synchronization signal is multiplied by an integer during recording, and the other voltage controlled oscillator operates as a pair with the first phase comparator. 2. The color signal processing device according to claim 1, wherein the color signal processing device is used in pair with a comparator and is operated during both recording and reproduction.