JPH06303642A - Delay device and crosstalk elimination device for reproduced chrominance carrier signal for vtr or the like using the same - Google Patents

Abstract

PURPOSE:To obtain a signal obtained by delaying a chrominance carrier signal delayed by 2H and at an original frequency band before the delay by using a single 1H delay element and a single double balanced modulator. CONSTITUTION:The device is provided with an adder 52 adding an input signal to be delayed including a chrominance carrier signal and an output signal from a band pass filter 53, a 1H delay element 54 delaying an output signal of the adder, and a double balanced modulator 55 applying double balanced modulation to the output signal of the 1H delay element to obtain an output signal for a frequency band not duplicated on the frequency band of the input signal to be delayed, and the band pass filter 53 extracts a signal at a frequency band equivalent to the frequency band of a lower side band of the output signal obtained when the chrominance carrier signal is subject to double balanced modulation from the output signal of the double balanced modulator. The extracted signal is inputted to the 1H delay element 54 via the adder 52 and the delayed signal is inputted to the double balanced modulator 55. A signal obtained from the delayed chrominance carrier signal by 2H is obtained from the double balanced modulator 55.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a delay device and a crosstalk removing device for a reproduced carrier color signal such as a PAL system VTR (video tape recorder) using the delay device.

[0002]

2. Description of the Related Art Generally, a VTR for home use records a video signal without a guard band. When the signal recorded in this way is reproduced, crosstalk from adjacent tracks occurs in the reproduced low frequency conversion color signal. In the PAL / VHS system VTR, the phase of the carrier color signal of one track is set to 9
A video signal that has undergone PS processing, in which it is switched at intervals of 1 ° (1 horizontal period) by 0 °, is recorded, and the crosstalk described above of the reproduced color signal is removed by utilizing the correlation of every 2H of the PAL system color signal. is doing.

A device shown in FIG. 6 is known as such a color signal crosstalk removing device. In FIG. 6, reference numeral 1 is an input terminal to which a reproduced low frequency conversion color signal is input. The reproduced low frequency conversion color signal is subjected to color signal processing for guard bandless recording, for example, the PS processing. The reproduced low-pass conversion color signal input to the input terminal 1 is input to the balanced modulator 2 which is a frequency converter to be frequency-converted into a balanced modulation signal, and the PS processing and the like are also restored. The balanced modulation signal output from the balanced modulator 2 is input to the band pass filter (BPF) 3, and only the signal in the vicinity of 4.43 MHz, which is the lower sideband of the balanced modulation signal, is extracted and becomes the carrier color signal. This carrier color signal contains crosstalk. The subtractor 5 subtracts the carrier color signal containing the crosstalk and the 2H delayed carrier color signal obtained by passing the carrier color signal through the 2H delay element 4. By this subtraction, the correlation between every 2H in the PAL system carrier color signal and the crosstalk from the adjacent track of the reproduced low-frequency conversion color signal are opposite to the signal 2H before, so that the crosstalk The removed carrier color signal is obtained at the output terminal 6.

Further, regarding the luminance signal of the VTR for home use, image improvement such as dropout compensation and line correlation noise reduction utilizing the correlation for each horizontal period is performed. The dropout compensation circuit is a circuit for substituting the signal 1H before the line correlation of an image when a dropout occurs in a reproduction signal. As a signal,
Although it is easy to perform the reproduction FM signal system, since it has a drawback of generating switching noise, it is currently the mainstream to use the luminance signal after demodulation. FIG. 7 shows an example of the dropout compensation circuit. In FIG. 7, reference numeral 7 is an input terminal to which a reproduction luminance signal is input.
The reproduced luminance signal normally passes through the switch circuit 8 and is output from the output terminal 10. The reproduced luminance signal that has passed through the switch circuit 8 is also input to the 1H delay element 9, and a 1H delayed reproduced luminance signal is obtained. The 1H delayed reproduction luminance signal is input to the other input terminal of the switch circuit 8. When the dropout detector 12 detects the presence of dropout in the FM signal input from the input terminal 11, the switch circuit 8 selects and outputs the 1H delayed reproduction luminance signal. This output provides dropout compensation. Since this dropout compensating circuit is a closed circuit, even a continuous dropout of 1H or more is compensated by a signal 1H before.

Since the line correlation noise reduction circuit has a strong line correlation between the reproduction luminance signal and the 1H delayed reproduction luminance signal, it is utilized that a noise component having no line correlation is obtained in the differential output of both. There is. FIG. 8 shows an example of the line correlation noise reduction circuit. In FIG. 8, reference numeral 13 is an input terminal to which a reproduction luminance signal is input. The reproduced luminance signal is input to the differential amplifier 15 and the 1H delay element 14, and the 1H delayed reproduced luminance signal is obtained here. This 1H delayed reproduction luminance signal is input to the differential amplifier 15 as described above, and a differential output between 1H is obtained. This difference output is a noise component,
This noise component is input to the limiter 16 and only minute high-frequency noise is taken out, and is mixed with the reproduction luminance signal by the next mixer 17, and a luminance signal with reduced noise is obtained at the output terminal 18.

Also, the luminance signal of the video camera or VT
In the contour correction circuit for the luminance signal reproduced from R, two delay lines each having a delay time of 0.1 to 0.5 μs are connected in series for horizontal contour correction, and two delay lines of about 1H for vertical contour correction. There is a delay line connected in series.

Now, the dropout compensation circuit described above,
Luminance image quality improvement circuits, such as line correlation noise reduction circuits, which both use 1H delay elements, are usually constructed in the same circuit system, and one 1H delay element is usually shared by each circuit. Therefore, most of the current P
The AL system VTR is equipped with at least one 2H delay element for color signals and one 1H delay element for luminance signals. By the way, the 2H delay element is relatively large, which is not only one of the obstacles for downsizing the VTR, but also the cost is relatively high. Conventionally, it is also known to obtain a signal delayed by 2H by using a single 1H delay element without using such a 2H delay element (see Japanese Patent Laid-Open No. 4-37284). This is a comb filter that frequency-converts the signal once delayed by the 1H delay element and passes it again through the 1H delay element to delay it.

FIG. 9 mainly shows the part related to the delay device of the comb filter, and the output of the high pass filter 20 and the 1H delay line 22 whose frequency is converted to the low frequency by the frequency converter 21. 23 for adding the output of
And a high-pass filter 24 for extracting a 1H-delayed signal from the output of the 1H-delay line 22 and a frequency converter 25 for converting the output of the 1H-delay line 22 into a high-frequency and sending it to a low-pass filter 26. have. Input terminal 1
The video signal input from 9 is 1H delay line 2 at the original frequency.
After passing 2, the frequency is converted to the low frequency range and again passed through the 1H delay line 22, and then converted to the original frequency. Therefore, the video signal that has passed through the 1H delay line 22 twice is output from the low-pass filter 26.
Signals that have passed through once and signals that do not pass through 2 are also obtained.

[0009]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the crosstalk removing device for the reproduced carrier color signal in, for example, in order to delay the carrier color signal by 2H or in the contour correction circuit of the luminance signal of the video camera or the luminance signal reproduced from the VTR, the luminance signal is delayed by the delay line. If the technique known in the above publication is used to delay the delay time by a factor of 2, the delay element having a relatively short delay time, for example, 1H.
Can be processed by the delay element. However, another frequency converter (corresponding to reference numeral 25 in FIG. 9) for returning the frequency band of the signal delayed by twice the delay time of this delay element is required. The present invention eliminates the above drawbacks and eliminates the need for a separate frequency converter for restoring the frequency band of a signal delayed by twice the delay time of a delay element, a VTR using the same, and the like. It is an object of the present invention to provide a reproduction carrier color signal crosstalk removing device.

[0010]

In order to solve the above-mentioned problems, a delay device according to the invention of claim 1 is an adder for adding an input signal to be delayed and an output signal from a band-pass filter which will be described later, Double-balanced modulation for obtaining a delay element to which the output signal of the adder is input and double-balanced modulation of the output signal of the delay element to obtain an output signal in a frequency band that does not overlap with the frequency band of the input signal to be delayed. Equipped with a vessel, this 2
From the output signal of the double balanced modulator, a signal in a frequency band corresponding to the frequency band of one sideband of the output signal obtained when the input signal to be delayed is double balanced modulated by the double balanced modulator is output. Extracted by bandpass filter,
Thus, the double balanced modulator is characterized in that the signal to be delayed is obtained as a signal delayed by twice the delay time of the delay element.

A delay device according to a second aspect of the present invention is the delay device according to the first aspect, wherein the signal input to the double balanced modulator is the signal to be delayed, and the signal to be delayed is the two signals. First band limiting means is provided for band limiting only to a signal having a frequency band corresponding to the frequency bands of the two types of signals, which is the one sideband of the output signal obtained when the double balanced modulation is performed by the double balanced modulator. , Instead of the bandpass filter,
It is characterized in that a second band limiting means for blocking passage of a signal in a frequency band corresponding to the frequency band of the input signal to be delayed is provided.

The delay device according to the third aspect of the present invention includes an adder for adding an input signal to be delayed including a carrier color signal and a luminance signal and an output signal from a band pass filter described later, and an adder for the adder. 1H delay element for delaying the output signal by one horizontal period of the TV signal, and double balanced modulation of the output signal of the 1H delay element to obtain an output signal in a frequency band that does not overlap with the frequency band of the input signal to be delayed 2 A double-balanced modulator, and a frequency band of one sideband of an output signal obtained when the carrier color signal is double-balanced modulated by the double-balanced modulator from the output signal of the double-balanced modulator. A signal in a corresponding frequency band is extracted by the band-pass filter so that the carrier color signal is obtained as a signal delayed by 2H from the double balanced modulator, and the signal of 1H is obtained. It is characterized in that the output signal of the extending element is provided with means for extracting a frequency band of a signal corresponding to the frequency band of the luminance signal.

A delay device according to a fourth aspect of the present invention is the delay device according to the third aspect, wherein the signal input to the double balanced modulator is the carrier color signal and the carrier color signal is the second carrier color signal.
First band limiting means is provided for band limiting only to a signal having a frequency band corresponding to the frequency bands of the two types of signals, which is the one sideband of the output signal obtained when the double balanced modulation is performed by the double balanced modulator. Instead of the band pass filter, second band limiting means for blocking passage of a signal in a frequency band corresponding to the frequency band of the carrier color signal is provided.

In order to solve the above-mentioned problems, a crosstalk eliminating apparatus for reproducing carrier color signals such as a VTR according to the present invention is provided.
The delay device according to claim 3 or 4,
A subtractor that subtracts the output signal of the double balanced modulator and the input signal, and another band pass that limits the pass band so that the frequency band of the signal obtained from this subtractor is the frequency band of the carrier color signal. It is characterized by having a filter.

[0015]

According to the delay device of the present invention having the above-mentioned structure, the input signal to be delayed and the output signal from the band pass filter are added by the adder, and the output signal of the adder is delayed by the delay signal. Delayed by the element. The output signal of the delay element is double balanced modulated by the double balanced modulator. A signal in a frequency band corresponding to the frequency band of one sideband of the output signal obtained when the input signal to be delayed is double-balanced-modulated by the double-balanced modulator from the output signal of the double-balanced modulator. Are extracted by the band pass filter. The extracted signal is input to the delay element via the adder, and the delayed signal is input to the delay element 2
Since the signal is double-balanced-modulated by the double-balanced modulator, the double-balanced modulator outputs the signal to be delayed as a signal delayed by twice the delay time of the delay element and the original frequency before the delay. It is obtained as a signal in the frequency band corresponding to the band.

In the delay device of the present invention, the signal input to the double balanced modulator is the input signal to be delayed and the input signal to be delayed by the first band limiting means. The band is limited only to the signals in the frequency bands corresponding to the frequency bands of the two types of signals, the one sideband of the output signal obtained when the double balanced modulator performs the double balanced modulation. Also, the second band limiting means blocks passage of a signal in a frequency band corresponding to the frequency band of the input signal to be delayed. Due to the blocking of this passage, the extracted signal is input to the delay element via the adder, and the delayed signal is double-balanced-modulated by the double-balanced modulator. Is obtained as a signal in which the input signal to be delayed is delayed by twice the delay time of the delay element and in a frequency band corresponding to the original frequency band before delay.

According to a third aspect of the present invention, in the delay device, an input signal including a carrier color signal and a luminance signal to be delayed and an output signal from the band pass filter are added by an adder.
The output signal of the adder is delayed by one horizontal period of the TV signal by the 1H delay element. The 1H delayed signal is double balanced modulated by the double balanced modulator, and the carrier color signal is doubled by the double balanced modulator from the output signal of the double balanced modulator by the band pass filter. A signal in the frequency band corresponding to the frequency band of the one sideband of the output signal obtained by the balanced modulation is extracted. The extracted signal is input to the 1H delay element via the adder, and the delayed signal is double-balanced-modulated by the double-balanced modulator, so that the carrier is output from the double-balanced modulator. The color signal is obtained as a signal delayed by 2H and in a frequency band corresponding to the original frequency band before delay. Further, a luminance signal delayed by 1H from the output signal of the 1H delay element is obtained by the extracting means.

In the delay device according to the present invention, the signal input to the double balanced modulator is the carrier color signal and the carrier color signal double balanced by the first band limiting means. The band is limited only to the signals in the frequency bands corresponding to the frequency bands of the two types of signals, that is, the one sideband of the output signal obtained when the double balanced modulation is performed by the modulator. Further, the second band limiting means blocks passage of a signal in a frequency band corresponding to the frequency band of the carrier color signal. By blocking this passage, the extracted signal is input to the 1H delay element via the adder, and the delayed signal is input to the 2H delay element.
Since it is double-balanced-modulated by the double-balanced modulator, the double-balanced modulator outputs the carrier color signal as a signal delayed by 2H and in a frequency band corresponding to the original frequency band before the delay. can get. Further, a luminance signal delayed by 1H from the output signal of the 1H delay element is obtained by the extracting means.

The VT of the present invention constructed as described above
A crosstalk removing device for a reproduction carrier color signal such as R is obtained by the delay device according to claim 3 or 4.
The output signal of the double-balanced modulator and the input signal to be delayed are subtracted by a subtractor, and the frequency band of the signal obtained from this subtractor becomes the frequency band of the carrier color signal by the other bandpass filter. Since the pass band is limited so that the crosstalk is removed, the carrier color signal can be obtained.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.
Will be described. FIG. 1 is a block diagram of a carrier color signal crosstalk removing apparatus, and the same reference numerals as those in FIG. 6 denote the same elements, and thus detailed description thereof will be omitted. FIG. 2 shows the output signal spectrum waveform of each block in FIG. In FIG. 1, reference numeral 50 is an input terminal to which a reproduction carrier color signal is input, and 51 is an input terminal to which a reproduction luminance signal is input. Reference numeral 52 denotes an adder which combines a reproduction carrier color signal input from the input terminal 50, a reproduction luminance signal input from the input terminal 51, and a signal output from a band pass filter (BPF) 53 described later. to add. 54
Is a 1H delay element, which delays the signal output from the adder 52 by 1H. Reference numeral 55 is a double balanced modulator, which double-balance-modulates the carrier wave from the carrier wave oscillator 56 by the signal output from the 1H delay element 54.

The band pass filter 53 uses the signal output from the double balanced modulator 55 to generate the carrier wave oscillator 56 in the double balanced modulator 55 according to a signal in a frequency band corresponding to the frequency band of the carrier color signal. Only the signal in the frequency band of the lower sideband obtained when the carrier from is double-balanced modulated is passed. The subtractor 5 subtracts the reproduced carrier color signal input from the input terminal 50 and the signal output from the double balanced modulator 55. Reference numeral 57 denotes a band pass filter, which passes only the signal in the frequency band corresponding to the frequency band of the carrier color signal from the signal output from the subtractor 5. The output terminal 6 outputs the crosstalk-free color signal output from the bandpass filter 57. Reference numeral 58 denotes a low pass filter (LPF) which passes only the signal in the frequency band corresponding to the frequency band of the reproduction luminance signal from the signal output from the 1H delay element 54. Reference numeral 59 is an output terminal for a signal output from the low pass filter 58.

Next, the operation of the apparatus shown in FIG. 1 will be described with reference to FIG. In FIG. 2, the head portion of the spectrum waveform is drawn in a circular arc shape as the current signal, the head portion as a horn is sharpened as 1H past signal, and the head portion is horizontal. Indicates that the signal is 2H past, and the black circles indicate the direction of the signal waveform. A reproduction carrier color signal is input from the input terminal 50. The spectrum waveform of this input signal is as shown in FIG. 2A, and the center frequency of the reproduced carrier color signal is 4.43 MHz. This reproduced carrier color signal is called a non-delayed carrier color signal. At the same time when the non-delayed carrier color signal is input to the input terminal 50, the input terminal 5
A reproduction luminance signal is input to 1. This reproduction luminance signal has a frequency band of approximately 0 to 3 MHz, like the frequency band of the reproduction luminance signal in a normal VTR, and its spectrum waveform is as shown in FIG. 2 (b). This reproduced luminance signal is called a non-delayed luminance signal.

The non-delayed carrier color signal, the non-delayed luminance signal, and the output signal to be described later from the bandpass filter 53 are
It is input to the adder 52 and added. The spectrum waveform of the added signal is as shown in FIG.
The signal near 0 to 3 MHz in (c) is the non-delayed luminance signal, the signal near 4.43 MHz is the non-carrier color signal, and (n-4.
The signal around 43) MHz corresponds to the output signal from the band pass filter 53, which will be described later. The non-delayed carrier chrominance signal, non-delayed luminance signal, and signal near (n-4.43) MHz output from the adder 52 are 1H.
It is input to the delay element 54, delayed by 1H, and output.
The spectrum waveform of this output signal is as shown in FIG. The signal in the vicinity of 0 to 3 MHz in FIG. 2D is a 1H past signal at the same time when the non-delayed luminance signal is input to the 1H delay element 54, and this is referred to as a 1H delayed luminance signal. The signal in the vicinity of 4.43 MHz is a signal 1H past at the same time when the non-delayed carrier color signal was input to the 1H delay element 54, and this is called a 1H delayed carrier color signal.
In addition, the signal near (n-4.43) MHz is (n-4.43) MHz in Fig. 2 (c).
43) It is a 1H delay signal of the signal around MHz.

The signal output from the 1H delay element 54 is input to the double balanced modulator 55, and the carrier wave output from the carrier wave oscillator 56 is double balanced modulated. The spectrum waveform of this output signal is as shown in Fig. 2 (e). The 1H delayed carrier chrominance signal near 4.43MHz obtained by double-balanced modulation of an nMHz carrier is the difference (n-4.43) MHz near and the sum. (N + 4.
Signals around 43) MHz and around (n-4.43) MHz are differences
Near {n- (n-4.43)} MHz = 4.43MHz and sum {n + (n-4.4
3)} MHz = (2n-4.43) MHz or 1H delayed luminance signal around 0 to 3MHz is the difference (n-0) MHz to (n-3) MHz, that is, (n-3) From MHz to near nMHz and (n + 0) MHz ((n
+3) MHz, that is, move from nMHz to around (n + 3) MHz. The signal output from the double balanced modulator 55 is band-limited by the band-pass filter 53 to (n-4.43) MHz.
Only nearby signals are taken out. The signal near (n-4.43) MHz is a signal obtained by frequency-converting the 1H delayed carrier color signal to near (n-4.43) MHz, as is clear from the above description.

The signal output from the band pass filter 53 is input to the adder 52 at the same time as the non-delayed carrier color signal is input. Therefore, the signal near (n-4.43) MHz in FIG. 2 (c) showing the spectrum waveform of the output signal of the adder 52 is the signal obtained by frequency-converting the 1H delayed carrier color signal, and FIG. In (n-
The signal in the vicinity of 4.43 MHz is a signal in which the 1H delayed carrier color signal is frequency-converted and further delayed by 1H. 2 this signal
This is called an H delay modulation signal. The 2H delay modulation signal is frequency-converted by the double balance modulator 55 into a signal in the vicinity of 4.43 MHz in FIG. A signal in the vicinity of 4.43 MHz in FIG. 2E, that is, a frequency band corresponding to the frequency band of the carrier color signal is a signal equivalent to the signal delayed by 2H with respect to the non-delay carrier color signal. This signal is called a 2H delayed carrier color signal.

The double balanced modulator 5 shown in FIG. 2 (e).
The signal from 5 is input to the subtractor 5, and is subtracted from the non-delayed carrier color signal from the input terminal 50 input at the same time.
The spectrum waveform of the output signal of the subtractor 5 is shown in FIG.
The signal near 4.43 MHz is a color signal obtained by subtracting the non-delayed carrier color signal and the 2H delayed carrier color signal, that is, the color signal with crosstalk removed. The signal output from the subtractor 5 is extracted by the band-pass filter 57 as a signal in the frequency band of the carrier color signal, that is, only the color signal from which crosstalk has been removed, and this is output to the output terminal 6. The signal output from the 1H delay element 54 is also input to the low-pass filter 58, and the signal in the frequency band corresponding to the frequency band of the luminance signal, that is, only the 1H delayed luminance signal is extracted, and is output to the output terminal 59. To be done.

FIG. 3 is a block diagram of a carrier color signal crosstalk removing apparatus according to another embodiment. Since the same reference numerals as those in FIG. 1 are the same, detailed description thereof will be omitted. FIG. 4 shows the output signal spectrum waveform of the block, which is different from the embodiment of FIG. 1 in the case of the embodiment of FIG. In the embodiment of FIG. 3, the signal input to the double balanced modulator 55 is limited in advance by the band pass filter 60, and as shown in FIG. 4 (d1), a signal corresponding to the frequency band of the carrier color signal, and This signal is a signal having a frequency corresponding to the frequency of the lower sideband obtained when double balanced modulation is performed by the double balanced modulator 55. With the above processing, band-pass filter 53 in the embodiment of FIG. 1 can be used in place of band-pass filter 53 such as a trap 61 that blocks passage of only signals in the frequency band corresponding to the frequency band of the carrier color signal.

In FIG. 1, the pass band of the band pass filter 53 is shown below when the double balanced modulator 55 modulates a signal of a frequency band corresponding to the frequency band of the reproduction carrier color signal and the reproduction luminance signal. If the frequency band corresponds to the frequency band of the sideband, the reproduction luminance signal delayed by 2H can be obtained from the output of the double balanced modulator 55 in the same manner as the reproduction carrier color signal. Further, in FIG. 3, a signal whose pass band of the band pass filter 60 corresponds to the frequency band of the carrier chrominance signal, and this signal is double balanced modulator 55.
A signal having a frequency corresponding to the frequency of the lower sideband obtained by the double-balanced modulation by the signal, and a signal corresponding to the frequency band of the luminance signal, and when the signal is double-balanced modulated by the double-balanced modulator 55. The signal of the frequency band corresponding to the frequency of the lower sideband obtained in the above, and the trap 61 passes only the signal of the frequency band corresponding to the frequency band of the carrier color signal and the frequency band corresponding to the frequency band of the luminance signal. , The reproduced luminance signal delayed by 2H can be obtained from the output of the double balanced modulator 55 in the same manner as the reproduced carrier color signal.

In FIG. 1 or 3, the frequency of the carrier wave output from the carrier wave oscillator 56 is n, which is a frequency band signal corresponding to the frequency band of the carrier color signal in the double balanced modulator 55. After double-balanced modulation, the signals band-limited by the bandpass filter 53 or the trap 61 and input to the adder 52 correspond to the respective frequency bands of the reproduction carrier color signal and the reproduction luminance signal which are also input to the adder 52. Set a frequency that does not overlap with the frequency band to be used.

In the above description, the reproduction carrier color signal is input to the input terminal 50. Instead of the reproduction carrier color signal, the reproduction carrier color signal is obtained by performing balanced modulation of the reproduced low frequency conversion color signal in the high frequency band. When a reproduction balanced modulation signal including a color signal is input, the frequency of the carrier wave output from the carrier wave oscillator 56, nMHz, is transmitted by the double balanced modulator 5
In FIG. 5, the signal that is double-balanced-modulated by the signal in the frequency band corresponding to the frequency band of the carrier color signal and then band-limited by the band-pass filter 53 or the trap 61 and input to the adder 52 is also input to the adder 52. If the frequencies are set so as not to overlap with the frequency bands corresponding to the frequency bands of the input reproduction balanced modulation signal and the reproduction luminance signal, the same effect as in the case of inputting the reproduction carrier color signal can be obtained.

In FIG. 1, the band pass filter 5
Although the pass band of 3 is the lower side band of the output signal of the double balanced modulator 55, it is not limited to this and may be the frequency band of the upper side band. Further, in FIG. 3, a signal corresponding to the frequency band of the carrier color signal in the pass band of the band pass filter 60, and the frequency of the lower side band obtained when the signal is double balanced modulated by the double balanced modulator 55. However, the signal is not limited to the lower sideband and may be the upper sideband.

In FIG. 1 or FIG. 3, the bandpass filter 57 is provided in the subsequent stage of the subtracter 5 as a means for obtaining only the color signal from which the crosstalk has been removed at the output terminal 6, but it is not necessarily provided in this latter stage. If there is no need to provide it and, for example, a reproduction carrier color signal is input to the input terminal 50, the bandpass signal is provided between the double balanced modulator 55 and the subtractor 5 as shown in FIG. The same effect can be obtained by providing the band pass filter 62 similar to the filter 57. If a reproduction balanced modulation signal is input to the input terminal 1, a bandpass filter 63 similar to the bandpass filter 62 is input to the input terminal in addition to the bandpass filter 62 as shown in FIG. 5B. 50 and the subtracter 5, the band pass filter 63 may be provided between the input terminal 50 and the subtractor 5 and the band pass filter 57 may be provided between the subtracter 5 and the subtractor 5 as shown in FIG. 5 and output terminal 6
The same effect can be obtained even if it is provided between and.

When the reproduction balanced modulation signal is input to the input terminal 50 with the configuration shown in FIG. 5B or 5C, the bandpass filter 63 and the subtractor 5 are connected to each other. A reproduced carrier color signal that has not been subjected to crosstalk removal processing can be taken out, and this signal can also be used as an APC circuit signal of a color signal used in a VTR or the like as is well known. In addition, in FIG. 1 or FIG.
If a signal in a frequency band corresponding to the frequency band of the carrier color signal is extracted from the output of the 1H delay element 54, this is a 1H delayed carrier color signal. In addition, in FIG. 1 or FIG.
When the signal leakage of the double balanced modulator 55 is large and this becomes a problem, it is desirable to increase the number of similar double balanced modulators to two and separate the band limitation. Further, in FIG. 1 or FIG. 3, when there is an influence of delay and amplitude change by each band limiting means and modulator, in the subtraction in the subtractor 5, the amplitudes of the non-delayed carrier color signal and the 2H delayed carrier color signal, It is desirable to provide adjusting means for matching the phases.

In the embodiment of FIG. 1 or FIG. 3 described above, the delay device of the present invention is used for the crosstalk removing device of the reproduced carrier chrominance signal of VTR or the like. The invention is not limited to the crosstalk removing device, and can be used for delaying horizontal contour correction or vertical contour correction of the contour correction circuit described in the above-mentioned conventional example.

[0035]

As described above, in the present invention, the signal to be delayed is delayed by twice the delay time of the delay element by using the single delay element and the single double balanced modulator. It is possible to obtain a delay device obtained as a signal and a signal in a frequency band corresponding to the original frequency band before delay, and a crosstalk removing device for a reproduction carrier color signal such as a VTR using the delay device.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a spectrum waveform diagram of an output signal of each block in FIG.

FIG. 3 is a block diagram showing another embodiment of the present invention.

FIG. 4 is a spectrum waveform diagram of output signals of some blocks in FIG.

FIG. 5 is a block diagram of a main part showing still another embodiment of the present invention.

FIG. 6 is a block diagram showing a conventional example.

FIG. 7 is a block diagram showing a conventional example.

FIG. 8 is a block diagram showing a conventional example.

FIG. 9 is a block diagram showing a conventional example.

[Explanation of symbols]

 5 subtractor 6 output terminal 50,51 input terminal 52 adder 53 band pass filter 54 1H delay element 55 double balanced modulator 56 carrier oscillator 57 band pass filter 58 low pass filter 59 output terminal 60 band pass filter 61 trap 62 Bandpass filter 63 Bandpass filter

Claims (5)

[Claims] 1. An adder for adding an input signal to be delayed and an output signal from a band-pass filter which will be described later, a delay element to which the output signal of the adder is input, and an output signal of the delay element is duplicated. A double balanced modulator for performing balanced modulation to obtain an output signal in a frequency band that does not overlap with the frequency band of the input signal to be delayed, and outputs the input signal to be delayed from the output signal of the double balanced modulator. A signal in a frequency band corresponding to the frequency band of one sideband of the output signal obtained when the double-balanced modulator is double-balanced-modulated is extracted by the band-pass filter. In the delay device, the signal to be delayed is obtained as a signal delayed by twice the delay time of the delay element. 2. The delay device according to claim 1, wherein the signal input to the double balanced modulator is the signal to be delayed, and the signal to be delayed is double balanced by the double balanced modulator. A single sideband of the output signal obtained when modulated, and a first band limiting means for band limiting only to a signal in a frequency band corresponding to the frequency bands of the two types of signals, instead of the band pass filter, A delay device comprising: second band limiting means for blocking passage of a signal in a frequency band corresponding to the frequency band of the input signal to be delayed. 3. An adder for adding an input signal to be delayed including a carrier color signal and a luminance signal and an output signal from a band-pass filter which will be described later, and an output signal of the adder for a TV.
A 1H delay element that delays one horizontal period of a signal, and a double balanced modulator that double-balance-modulates the output signal of the 1H delay element to obtain an output signal in a frequency band that does not overlap with the frequency band of the input signal to be delayed. And a frequency band corresponding to the frequency band of one sideband of the output signal obtained when the carrier color signal is double-balanced modulated by the double-balanced modulator from the output signal of the double-balanced modulator. Of the carrier color signal from the double balanced modulator.
A delay device comprising means for extracting the signal in a frequency band corresponding to the frequency band of the luminance signal from the output signal of the 1H delay element so as to be obtained as an H-delayed signal. 4. The delay device according to claim 3, wherein the signal input to the double balanced modulator is double-balanced modulated by the carrier color signal and the carrier color signal by the double balanced modulator. With the one sideband of the output signal obtained when
A first band limiting means for band limiting only to a signal in a frequency band corresponding to the frequency band of the seed signal, and in place of the band pass filter, passing of a signal in a frequency band corresponding to the frequency band of the carrier color signal And a second band limiting means for preventing the delay. 5. A subtracter that uses the delay device according to claim 3 or 4, and subtracts an output signal of the double balanced modulator from the input signal, and a frequency band of a signal obtained from the subtractor. And another band pass filter for limiting the pass band so that the frequency band is the frequency band of the carrier chrominance signal.