JPH0296493A - Signal delay processing circuit for vtr - Google Patents

Abstract

PURPOSE:To evade the gravity dislocation addition of a signal at the time of double dubbing and to prevent the deterioration of a picture quality by providing a mode discrimination delay means which provides a one-horizontal scanning time difference between the time difference between a luminance signal and a chrominance signal at a reproduced output terminal in a first mode and the same time difference in a second mode. CONSTITUTION:The luminance signal selected by a switch 8 is FM-modulated by an FM-modulator 6, and the chrominance signal selected by a switch 9 is converted into low frequencies by a frequency low range converter 7, and they are added by an adder 5. Thereafter, the signals are amplified by a recording amplifier 4, and recorded on a magnetic tape which is not shown in a figure by magnetic hands 2 and 2'. At the time of reproducing, the recording signals on the tape is alternately reproduced by reproducing heads 3 and 3', amplified by reproducing amplifiers 14 and 14., then linked by a switcher 15, the luminance signal is frequency-compensated by an equalizing circuit 16, and demodulated by an FM demodulator 18. The low-frequency-converted chrominance signal is fetched by a low pass filter 17, and restored to the original frequencies by a frequency high range converter 21.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is applicable to a VTR that performs guard panless recording using a two-color signal low-pass conversion direct recording method, which requires a comb filter in the reproduction color signal circuit. Regarding the signal processing circuit of ＼7TR.

[Conventional technology]

VTRs such as the V1-IS system, the Beta system, and the 8 mm video system employ a system in which the two-color signal is converted to a low frequency and recorded. Therefore, when performing guard panless azimuth recording, the cross 1 of the momentary contact track
The luminance signal is 70% due to azimuth loss, but the chrominance signal with a low recording frequency is attenuated to a small extent by azimuth loss. Conventionally, therefore, the crosstalk components of the nine color signals have been removed by circuitry as described in Japanese Patent Publication Nos. 58-57034. That is, during the recording and reproducing process, the phase of the crosstalk component of the color signal is inverted every time 1), and during reproduction, this is removed through a comb filter.

However, the conventional method has a problem in that the center of gravity of the color signal drops by 0.5)I in the vertical direction of the screen because it passes through the comb filter.

[Problem to be solved by the invention]

In the conventional method, there was a problem that the center of gravity of the two-color signal dropped by 0.5I (0.5 I).This deviation is not a big problem in terms of Y1, but when dubbing is repeated two or three times, the deviation adds up. Detracts from image quality.

SUMMARY OF THE INVENTION An object of the present invention is to provide an apparatus in which center-of-gravity shift is not added even when dubbing is repeated, and image quality is not impaired.

[Means to solve the problem]

The first means adopted in the present invention to achieve the above object is that during dubbing, the color signal is 0.5 T-
1st output state where I has decreased 9 Color signal is 0 during normal playback
．． 5I (means to output in the raised second output state).

The second method is to use a second output state when dubbing.

It is an output shifting means in the first output state during normal reproduction.

The third means is a means for alternately repeating the first and second output states in accordance with the number of times of dubbing.

The fourth means is to stop passing the color signal through the comb filter during dubbing.

[Effect]

Above 1. Second. In the third means, the first
Go through the first state and the second state once.

The center of gravity shift between the luminance signal and the color signal is canceled out.

With the fourth means, no center of gravity shift occurs during dubbing.

〔Example〕

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

This embodiment includes a nine-rotation cylinder 1, recording heads 2 and 2' arranged on the rotation cylinder 1, and reproduction heads 3 and 3 arranged on the rotation cylinder 1.
', a recording amplifier 4 that supplies No. 43 to the recording heads 2 and 2', and an adder 5 connected to the human power of the recording amplifier 4.
and an FMM modulator 6 and a frequency low-pass converter 7 connected to the input of the adder 5, and switches 8 and 9 connected to the input of the FMM modulator 6 and 9 connected to the input of the frequency low-pass converter 7. switch 9, a Y/C separation circuit 10 connected to the inputs of switches 8 and 9, a Y input terminal 11 connected to the other input of switch 8, and a Y/C separation circuit 10 connected to the other input of switch 9. C input terminal 12 and Y/C separation circuit l
a composite input terminal 13 connected to the input of O, a playback amplifier 14 connected to the output of the playback head 3, and a playback amplifier 14' connected to the output of the playback head 3'';
and a switcher 15 to which the outputs of the reproducing amplifiers 14 and 14' are connected.

Equalize circuit 16 to which the output of switcher 15 is connected
and a low-pass filter 17, an FMM modulator 18 to which the output of the equalization circuit 16 is connected, an LH (H is one horizontal scanning period) delay circuit 19 to which the output of the FMM modulator 18 is connected, and an FMM modulator 18 and A switch 20 to which the output of the tH delay circuit 19 is connected, and a low-pass filter 17
a frequency high-band converter 21 to which the output of the 9-frequency high-band converter 21 is connected; and an I-I delay circuit 2 to which the output of the 9-frequency high-band converter 21 is connected.
A subtracter 23 to which the outputs of the 2 and 1 frequency high frequency converter 21 and the 1H delay circuit 22 are connected, a Y/C mixing circuit 24 to which the outputs of the switch 20 and the subtracter 23 are connected, and the output of the switch 20 The connected Y output terminal 25, the C output terminal 2G connected to the output of the subtracter 23, and the composite output terminal 2 connected to the output of the Y/C mixing circuit 24.
It consists of 7.

Switches 8 and 9 are input selectors for Y/C component force input composite input. Y selected by switch 8
The (luminance) signal is FM modulated by an FMM modulator 6, the C (color) signal selected by a switch 9 is converted to a low frequency by a frequency low frequency converter 7, and both are added by an adder 5. It is amplified by a recording amplifier 4 and sent to recording heads 2 and 2.
' is recorded on a magnetic tape (not shown). Second
The figure shows the frequency allocation of the recording signal.

101 is the spectrum of the FM-modulated Y signal, and 102 is the spectrum of the C signal that has been low-band converted to a frequency lower than that of the Y signal. On the magnetic tape in Figure 3! - Indicates the rack pattern. 200 is a magnetic tape, 201 is a track recorded by the recording head 2, and 202 is a track recorded by the recording head 2''.

The magnetic tape 200 is wound around the rotating cylinder 1 by more than 180 degrees, and the magnetic tape 200 is wound around the rotating cylinder 1 by a servo circuit (not shown).
The traveling of 00 and the rotation of rotating cylinder 1 are controlled,
Video signals for one field are alternately recorded as one track on the magnetic tape 200 by the recording heads 2 and 2'.

During reproduction, the recording signals on the tape are alternately reproduced by the reproduction heads 3 and 3', amplified by the reproduction amplifiers 14 and 14', respectively, and then connected by the switcher 15. After receiving compensation, the signal is demodulated into the original signal by the FM demodulator 18. On the other hand, the low-frequency converted C signal is extracted by the low-pass filter 17 and returned to its original frequency by the 9-frequency high-frequency converter 21.

Incidentally, in order to realize high-density recording without guard bands as shown in FIG. 3, the heads 2 and 2' and 3 and 3'' are set in opposite azimuths to each other.

In this way, even if the 1-ranking shifts during playback as shown in FIG. 3, lIl! This is because the FM modulation multiplied signal crosstalk from the l-contact track is attenuated by azimuth loss.

On the other hand, the low frequency converted C signal cross 1-1 is as follows.

Because the recording wavelength is long, the attenuation due to azimuth loss is small, so it is useful for single-frequency low-frequency conversion and high-frequency conversion.

The measures shown in FIG. 4 or 5 are taken.

In both figures, the direction of the arrow represents the phase of the C signal.

Figure 4 shows the so-called PI method adopted in the Beta standard and 8mm video standard, and shows the track pattern A (C signal phase is constant) signal and the 1 to rank pattern B (C signal (the phase of which is inverted every LH) is generated alternately for each field. Track buttons A and B are alternately formed on the tape, one track at a time. Then, when converting the high frequency range during playback, the phase is restored to its original state.

A crosstalk component from an adjacent track (B if A, A if B) becomes a signal whose phase is inverted every 1H. When this is passed through the comb filter constructed as shown in Figure 1 22.23, 9
Since the signal components are strengthened where the vertical correlation of the image is strong, and the cross 1 to 3 components are weakened, crosstalk can be removed.

Figure 5 shows the so-called PS system adopted in the VH3 standard, in which track button A' (the phase of the C signal is rotated +90 degrees in steps of 11-1) and track button B'
(The phase of the C signal is rotated by 190 degrees every LH) are alternately formed on the tape. If the phase is returned during playback, the crosstalk component becomes a signal whose phase is reversed every 1H, and the I
) Similar to the I method, crosstalk can be removed using a comb filter.

Methods 1 and above are widely used in conventional devices, but there is a problem in that passing the C signal through a comb filter lowers the center of gravity of the C signal in the vertical direction of the screen. This point will be explained using FIG. The vertical axis is the vertical direction of the screen, and the horizontal axis is the level. First, consider the case of separate Y/C input. When there is a colored object on the screen, the Y signal is signaled, and the C signal is Y' in the figure.
Be like Co. When this is recorded and played back, the Y signal does not change, but the C signal passes through a comb filter, so C1
The center of gravity drops by 0.5F (as shown in '). This shift in the center of gravity does not pose much of a problem visually, but when dubbing is repeated two or three times, the shifts add up and degrade the image quality.

The purpose of the present invention is to solve this problem.

Therefore, in this embodiment, the circuit configured as shown in FIG.
), the output is delayed by 1H.

When dubbing is repeated in the dubbing mode, the C signal output changes as shown in Fig. 6 C1, ' + c, ' T c, ', but in the normal reproduction mode, each relatively increases by 1 to I, so C1, It becomes like C,,C3.

According to this embodiment, therefore, the first generation (CI).

The 21st ij generation (C,) and the 3rd concave generation (C1) up to the 33rd generation.

It is possible to suppress the shift of the center of gravity of Y/C to within ±0.5H (a level that does not cause any visual problems). In a normal tq collection system 11, it is sufficient to consider up to three generations: gathering, editing, and copying.

Next, composite input/output will be explained.

As the Y/C separation circuit 10, any of various configurations used in conventional devices may be used, but as shown in FIG. ．． Delay compensation circuit 30. If the configuration is such that a comb filter consisting of subtractors 31 and 32 is used, and the C signal is extracted by a simple bandpass filter 33.

There is no shift in the center of gravity of the C signal due to Y/C separation.

Exactly the same effect as in the case of Y/C separate input can be obtained. Furthermore, if the configuration is such that the C signal is also extracted using a comb filter as shown in Fig. 8, the C signal becomes the same as C1' in Fig. 6 at the time when Y/C decomposition is performed, so the first generation 0
2. The second law distance becomes C3, and in the third generation (not shown), the center of gravity deviation becomes 1. This has the effect of reducing cross color.Furthermore, by detecting the vertical correlation of the nine images and switching to the configuration shown in Figure 8 if there is a correlation, or to the configuration shown in Figure 7 if there is no correlation, 1
Regarding center of gravity shift, the same effect as in the case of Y70 minute input can be obtained, and cross color can be reduced. Furthermore, Y
In the case of a device that has only a low band mode that uses the signal band only up to around 3M]l/, there is no need to extract the Y signal with a comb filter (there is almost no C signal below 3Mllz), so the seventh The comb filter shown in the figure becomes unnecessary (the C signal is removed by the low-pass filter included in the FM modulator 6).

The Y/C mixer 24 may be a simple adder if it is in low band mode (because the Y signal and C signal do not overlap),
In high band mode, which also uses a band of 3 MHz or higher for the Y signal, the frequency interleaving relationship between the spectrum of the C signal and the Y signal should be established (the comb-shaped spectra are in each other's valleys). The high-frequency spectrum causes frequency fluctuations due to jitter (time axis fluctuations due to recording and playback), and if they are added as is, they will overlap with the C signal and cause interference, so before addition, a comb filter is used to adjust the frequency within the C signal region. It is necessary to remove the high frequency components of the Y signal. Figure 9 shows an example of its implementation, in which the Y signal is
Delay circuit 34. Bandpass filter 35. Delay compensation circuit 36. After passing through a comb filter consisting of subtracters 37 and 38, the signal is added to the C signal in an adder 39. In this way, although the resolution is somewhat reduced, it is possible to obtain a reproduced image with less cross color.

As the LH delay circuit, a glass delay line, a CCD (charge-coupled device), a digital memory, etc. may be used, but in any case, the circuit scale becomes considerably large. When I actually built the circuit, I found that it required a 1H delay circuit 19 for double center of gravity deviation correction and a 1H delay circuit 34 for the reproduced Y signal comb filter, and associated circuits such as level adjustment and filters were also required for each of them. It turns out that the circuit scale becomes extremely large. Therefore, in the present invention, as shown in FIG.
The 1H delay circuit 34 for the signal comb filter is integrated into one
The H delay circuit is now used. By the action of the switch 40, when the reproduced Y signal is used as it is as the Y signal output (DUBB), the output of the 1H delay circuit 19 is used to apply a comb filter.

When using the output of the 1H delay circuit 19 (NORM), the reproduced Y signal is used as it is and is applied with a comb filter.

Further, the output of the Y signal output terminal 25 may also be taken from the signal after passing through the comb filter (output of the subtraction rlr 38).

The 1H delay circuit can be a glass delay line, CCD (charge coupled device), digital memory, etc. In order to ensure the performance of the comb filter, it is necessary to set the level and delay time of the 1H delay signal accurately? A needs to be adjusted. However, when we actually evaluated the prototype, we found that when analog switches were used for switches 20 and 40, there were subtle variations in attenuation and delay time between switches 20 and 40, and between the two channels of each switch. 2. It has been found that it is difficult to make adjustments to ensure the performance of the comb filter in both normal reproduction mode and dubbing mode.

Therefore, in the present invention, as shown in FIG. 11, a digital memory 19'' is used as a 1H delay circuit, and a switch 20
．． 40 is converted into (M) signal by a digital circuit. In other words, the reproduced Y signal is converted into approximately 8-bit digital data by an A/D converter 41.

Data is delayed by 1H by digital memory 19'.

The switch 20.40 is connected to the digital selector 20',
40' and after performing these processes, D/
A converters 42 and 43 convert the signals back to analog signals. In this way, there is no variation between channels, and the performance of the comb filter can be ensured in both the normal playback mode and the dubbing mode. moreover.

Bandpass filter 35. Delay compensation circuit 36. Subtractor 3
7.) Succeeded! 38 may be constructed from a digital circuit.

Furthermore, in the 1λ case where a TBC (time base collector) is used for the purpose of reducing reproduction jitter or editing, the time axis fluctuation of the reproduced Y signal is reduced, so the comb filter for the reproduced Y signal is not necessary. An example of the configuration in that case is shown in FIG.

Digital TBC circuits 44, 45 and 45'' are used as the TBC.

The digital TBC circuit uses a digital memory that can perform writing and reading asynchronously, and writes data using a clock that is synchronized with the playback signal (with time axis fluctuation).
Time axis correction is performed by reading with a reference clock that has no time axis fluctuations. The reproduced Y signal is converted into digital data by the A/D converter 41, first the time axis is corrected by the TBC 44, the data is then delayed by 1H by the digital memory 19', and the data is delayed by the digital selector 20' in dubbing mode. data that does not play, 1H during normal playback
The delayed data is selected and converted back to an analog signal by D/A converter 42. The reproduced C signal.

First, the decoder 46 outputs color difference signals (R-Y and B-Y
) and then converted into digital data by A/D converters 47 and 47', respectively, and TB C45,
45', and the D/A converter 48.4
8', the signal is returned to an analog signal, and encoder 49 converts it back into a C signal. Since the time axes of the Y and C signals have been corrected, only the adder 39 is required as the Y/C mixing circuit. In addition.

The digital processing may be performed after multiplexing (time division multiplexing) the RY signal and the BY signal. In this way, A/D converter 47.47' and T B
C45, 45' can be configured with one circuit.

By the way, the signal output from the composite output terminal 27 is connected to a monitor during normal playback and to the next stage device during dubbing. If the Y/C separation circuit of the next stage device has the configuration shown in Figure 8, the center of gravity of the YlClC minute C signal will drop by 0.5H, and the center of gravity of the YlClC minute C signal will drop by 0. It will drop by 1H. Considering such cases.

As shown in FIG. 13, the LH delayed signal may be used as the Y signal for output from the composino 1 even in the dubbing mode.

Furthermore, as shown in FIG. 14, a separate Y/C output terminal 50 exclusively for dubbing may be provided.

In addition, as shown in FIG. 15, the control of the switch 20 is reversed so that the reproduced Y signal is set to 1. H may be delayed and the delay may not be made during the 2 normal playback mode. The vertical waveforms of Y and C in this case are shown in FIG. What initially looked like C8 becomes C8 when recorded and played back.
It will be like this (1st (seyo)).

In the dubbing mode, C5 is relatively 1.0, h is C1', and when this is recorded and reproduced, it becomes C2 (second generation). When this is set to dubbing mode, it becomes something like 62', and when it is recorded and played back, it becomes something like C1 (third generation). therefore.

Up to the third generation, the center of gravity of the C signal remains within ±0.5H, and the same effect as the embodiment shown in FIG. 1 can be obtained.

Furthermore, FIG. 17 shows an example in which a Y/C separate output terminal exclusively for dubbing is provided.

Also, if you want to keep the Y/C center of gravity shift within ±0.5 for the 3rd generation and beyond, use the odd number of times as shown in Figure 18.
LH delay during dubbing (ODD).

It is sufficient that there is no delay when dubbing (EVEN) for an even number of times (1). The opposite is also possible. This ODD/EVEN control may be directly controlled by the user of this device using an external SW, but since it is generally troublesome for the user to count the number of dubbings, the ODD/EVEN discrimination signal is It is preferable to multiplex record on the top, read this during playback, and automatically switch between ○DD and EVEN. There are various methods for recording the discrimination signal, but the one shown in FIG. 18 is one that utilizes a VITC (time code inserted into a vertical blanking period) user's control. Dubbing input terminal 51
．． A dubbing output terminal 52 is provided to multiplex an ODD/EVEN discrimination signal in addition to the Y signal and C signal.

○DD/EVEN input from the dubbing input terminal 51
The discrimination signal is multiplex recorded by the time code generator 57 during the vertical blanking period of the video signal. ○
D D / EV E N J14 (If there is no other signal input, it is assumed that it is the 0th dubbing and EVEN
It's fine if you do this. The multiplexed ODD/EVEN discrimination signal is read by the reader 58 into the time code 1, and the inverter 59 inverts ODD and EVEN (if the previous time was ODD, this time it is EV E N, and the previous time was EVEN). If so, this time it's ODD). This discrimination signal is used to control the switch 20, and is multiplexed to the dubbing output terminal 52 and sent to the ninth stage device.

According to this embodiment, no matter how many times dubbing is repeated, Y
/C center of gravity shift can be suppressed within ±0.5H.

In addition, if there is not much crosstalk of the C signal from the adjacent trunk by recording with a wide head and playing back with a slightly narrow head, as shown in Figure 19, when dubbing Alternatively, the reproduced C signal may not be passed through the comb filter, but passed through a 2H comb filter only during the final normal reproduction, and the Y signal may be delayed by 1H. That is, the switches 20 and 60 output the reproduced Y signal and C signal as they are during dubbing mode, and output the reproduced Y signal and C signal as they are during normal reproduction.
, 62.1/2 damping'rp163. Adder 64. A signal passed through a 2H comb filter composed of a subtracter 65 is output. In this way, the vertical waveforms of the Y and C signals will not change in dubbing mode, but the center of gravity of both will be lowered in normal playback mode.

There is no shift in the center of gravity of Y/C.

In this embodiment, since the reproduced C signal is not passed through the comb filter during dubbing, the cross 1 to -
The signal component is also dubbed along with the signal, but this can be removed by a comb filter during final playback. However, crosstalk (crosstalk components recorded on adjacent tracks crosstalk).

It cannot be removed because it is in phase with the signal component. therefore,
The two conditions for this embodiment are that the crosstalk is sufficiently small to the extent that it does not impair image quality.

According to this embodiment, no matter how many times dubbing is repeated, Y/
The shift in the center of gravity of C can be set to 0, and the vertical spread of the C signal can also be suppressed to ±1H.

Now, in all the embodiments described above, the 1H delay circuit provided in the Y signal system was set to 0N10FF depending on the mode.
As shown in FIG. 20, a 1H delay circuit 66 may be provided in the C signal system, and a switch 67 may be used to set it to 0N10FF. The 1H delay circuit 68 is for time adjustment. This embodiment can obtain the same effects as the embodiment shown in FIG. That is, it is only necessary to add a 1H time difference between the Y signal and the C signal depending on the mode.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to provide an apparatus in which even when dubbing is repeated, the center of gravity deviation of the luminance signal and color signal is not added together, and image quality is not impaired.

[Brief explanation of drawings]

1, 18, and 19 are general block diagrams of an embodiment of the present invention, FIG. 2 is a recording signal frequency distribution diagram, and FIGS. 3, 4, and 5 are track button diagrams. . 6 and 16 are vertical waveform diagrams of video signals, FIGS. 7 and 8 are block diagrams of the input section of the embodiment of the present invention, and FIG.
10, 11, 12, and 13. FIG. 14, FIG. 15, FIG. 17, and FIG. 20 are block diagrams of the output section of the embodiment of the present invention. 1... Rotating cylinder, 2,2''... Recording head, 3
゜3'... Playback head, 6... FM modulator, 7...
・Frequency low-band converter, 18...FM demodulator, 19
...I Fr delay circuit. 20... Switch, 21... Frequency high range converter, 2
2...1H delay circuit, 23...subtractor, 60...
Switch, 61.62...1H delay circuit, 63...
・1/2 attenuator, 64... adder. 65...Subtractor drawing purification a (no change in content) Figure I Patent attorney Masaru Ogawa \ man - I9, 1H Hennu post υ 20 each Suun 1, 23, temperature reduction' shame 24 -・Y/C Mixture - Rotation A L Compiled Diagram Tsutazu Not Diagram 6)) Completed ■3・G■O■G Compiled Diagram C1' f C,; Concave A Toro Delay 1 Layer 41 Circuit Bulk Diagram Challenging Diagram So: qv'n7qm Y Cltm, to! Collected drawings Y, C. 01'C3' Draft Time Court Sillator Procedural Amendment (Method) % Formula % Case Indication Showa 1963 Patent Application No. 10,000 Relation to the Case

Claims (1)

[Claims] 1. A VTR having a comb-shaped filter in the reproduced color signal circuit, which has at least two modes, a first mode and a second mode, and whose luminance at the reproduced output terminal in the first mode. The present invention is characterized by comprising mode-specific delay processing means for creating a difference of one horizontal scanning period between the time difference between the signal and the color signal and the time difference between the luminance signal and the color signal at the reproduction output terminal in the second mode. VTR signal delay processing circuit. 2. The mode-specific delay processing means includes a one-horizontal scanning period delay means provided in the reproduced luminance signal circuit, and the reproduced luminance signal is delayed for one horizontal scanning period in either the first mode or the second mode. 2. A signal delay processing circuit for a VTR according to claim 1, further comprising mode switching means for passing the signal through the delay means and not allowing the signal to pass in the other mode. 3. The signal delay processing circuit for a VTR according to claim 1, further comprising mode switching means for selecting the first mode during dubbing and the second mode during normal playback. 4. A VTR having a comb filter in the reproduced color signal circuit is equipped with at least a dubbing-dedicated output terminal and a normal reproduction output terminal, and the time difference between the luminance signal and chrominance signal at the dubbing-dedicated output terminal and the luminance signal at the normal reproduction output terminal. A signal delay processing circuit for a VTR, comprising a delay processing means for each output terminal to provide a 1H difference between the time difference of a color signal and a time difference of a color signal. 5. The output terminal-specific delay processing means is a one-horizontal scanning period delay means inserted into only one of the luminance signal supplied to the dubbing-only output terminal and the luminance signal supplied to the normal playback output terminal. A signal delay processing circuit for the VTR described above. 6. The signal delay processing circuit for a VTR according to claim 1, further comprising dubbing mode switching means for selecting the first mode during odd-numbered dubbing and the second mode during even-numbered dubbing. 7. The dubbing mode switching means according to claim 6, wherein the dubbing mode switching means is a means for multiplex-recording a discrimination signal indicating whether the number of dubbing is an odd number or an even number on a magnetic tape, and reproducing this to automatically switch. VTR signal delay processing circuit. 8. A signal delay processing circuit for a VTR having a comb filter in the reproduced color signal circuit, characterized in that the VTR includes means for preventing the reproduced color signal from passing through the comb filter during dubbing. 9. The comb filter is a three-line type, and includes a one-horizontal scanning period delay means provided in the reproduced luminance signal circuit and a means for preventing the reproduced luminance signal from passing through the one-horizontal scanning period delay means during dubbing. 9. A signal delay processing circuit for a VTR according to claim 8, further comprising: a signal delay processing circuit for a VTR. 10. A claim further comprising means for configuring a comb filter using the input and output of each one horizontal scanning period delay means, and for generating a composite signal by mixing the output of the comb filter and the reproduced color signal. 10. A signal delay processing circuit for a VTR according to item 2, 5 or 9. 11. A signal delay processing circuit for a VTR according to claim 2, further comprising means for generating a composite signal by mixing the output of each one horizontal scanning period delay means and the reproduced color signal. 12. Claim 2, wherein the one-horizontal scanning period delay means comprises an AD converter, a digital memory, and a DA converter.
12. A signal delay processing circuit for a VTR as described in 5, 9, 10 or 11. 13. The signal delay processing circuit for a VTR according to claim 12, comprising a digital TBC circuit.