JPS60120688A - Recording regenerator of color vided signal - Google Patents

Abstract

PURPOSE:To suppress picture quality deterioration when a color video signal is multiple-recorded on time division bases by providing separately AGC circuits for a luminance signal and for a color difference signal which intend the optimum of the input level at the front stage of a time division multiplexer. CONSTITUTION:When input signals are Y, R, G and B, switches 38 and 39 are connected as shown in the diagram. The Y signal passes through an AGC circuit 40, and a linear sequence color difference signal U/V from a converter 37 is added to a time division multiplexer 43 through an AGC circuit 41. On the other hand, when the input signal is a composite color video signal, the luminance signal from an LPF 35 is added to the AGC circuit 40 and the linear sequence color difference signal U/V from a decoder 36 is added to the AGC circuit 41. A detector 42 detects the amplitude of the luminance signal and controls the gains of the AGC circuits 40 and 41. As a result, the luminance signal Y and the linear sequence color difference signal U/V, which are the optimal amplification levels are obtained from the AGC circuits 40 and 41, and the time division multiple signal is recorded in a magnetic tape 51 through an AGC circuit 45, a processing circuit 47, and a frequency modulator 48.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a device for recording and reproducing luminance signals and chrominance signals by time division multiplexing 1°, and in particular, the present invention relates to a device for recording and reproducing luminance signals and chrominance signals by time division multiplexing 1 degree, and in particular, the present invention relates to a device for recording and reproducing luminance signals and color signals by time division multiplexing 1°, and in particular, the present invention relates to a device for recording and reproducing luminance signals and color signals by time division multiplexing. Concerning the circuit configuration of a recording/reproducing device suitable for the interconnection standards established by the committee.

[Background of the invention]

V as a conventional home color video signal recording and reproducing device
There are VTRs (video tape recorders) of the l-1s standard and the β standard. These home VTRs frequency-modulate the luminance signal, and record the color signal by frequency multiplexing it on the lower frequency side of the frequency-modulated luminance signal using low frequency conversion 1 to 1.

FIG. 1 shows an embodiment of a conventional home VTR.

In FIG. 1, 1 is an input terminal for a composite color video signal, 2 is an AGC circuit that controls the amplitude level of the color video signal, 3 is an LPF (low-pass filter) that extracts a luminance signal from the color video signal, and 4 1 is a detector that detects the amplitude level of the luminance signal and controls the AGC circuit 2; 5 is a luminance signal process circuit that performs emphasis; 6 is a frequency modulator that modulates the frequency of the luminance signal; 7
is the HP that suppresses the low-frequency components of the frequency-modulated luminance signal.
F (high-pass filter), 8 is a BPF (band-pass filter) that extracts a color signal with subcarriers from a color video signal, and 9 is an ACC circuit (automatic color signal control circuit) that controls the amplitude level of the color signal. ), 10 is a burst detection circuit that extracts a burst signal from a color signal, and 11 is an ACC circuit that detects the amplitude level of the extracted burst signal.
A detector for controlling the circuit 9, 12 a frequency converter for converting the color signal into a low frequency range, 15 an LPF for extracting the low frequency converted color signal, 14 a color signal process circuit for performing a color killer operation, etc. 15 is a mixer that frequency-multiplexes the frequency-modulated luminance signal and the low-frequency converted color signal; 16;
1 is a recording amplifier, 17 is a recording head, and 18 is a magnetic tape. As described above, in the composite color video signal from the input terminal 1, the luminance signal is frequency-modulated, and the color signal is low frequency converted and frequency-modulated to the lower frequency side of the frequency-modulated luminance signal, and is recorded on the magnetic tape. The method of converting the color signal to a low frequency and recording it in this way is generally called the power 2-under recording method.

This color amplifier recording method has two problems: (1) image quality deterioration such as beat disturbance due to interference between two signals, and (2) AM
(3)
There are problems such as the color signal is susceptible to frequency fluctuations such as zinc and PM noise, and (4) when two or more heads are used, the difference in output from the reproduction heads causes color flicker.

As a method to solve the drawbacks of this color amplifier recording method, there is a method that compresses the time axis of each luminance signal and color signal, arranges them so that they do not overlap on the time axis, and then frequency-modulates and records them. . Such a recording method is generally called a time division multiplex recording method.

FIG. 2 shows an embodiment of the circuit configuration of an apparatus for time-division multiplex recording of color video signals, and FIG. 3 shows an example of this time-division multiplex signal format. In FIG. 2, 19 is an input terminal for a composite color video signal, 20 is an AGC circuit that controls the amplitude level of the color video signal, 21 is an LPF that extracts the luminance signal Y from the color video signal, and 22
23 is a detector that detects the amplitude level of the luminance signal and controls the AGC circuit 20; 23 is a BPF that extracts a color signal from the color video signal output from the AGC circuit 20; 24-digit BPF 2;
A decoder 25 decodes the color signal extracted in step 5 into color difference signals tJ, V and converts the decoded color difference signals U, V into line-sequential color difference signals; Line sequential color difference signal U
26 is a frequency modulator that frequency-modulates the time-division multiplexed signal, 27 is a recording amplifier, 28 is a recording head, and 18 is a magnetic field. It's a tape. Here, the luminance signal Y input to the time division multiplexer 25 and the line-sequential color difference signal - bow U
/V are respectively denoted by 5a and sh in FIG. 6, and the time axis is compressed by the time division multiplexer 25 to double and double, respectively. An example of a signal obtained by time division multiplexing these signals is /r as shown in 3C. However, in FIG. 3, 29 is a reference signal indicating the zero level of the color difference signal [J/V. In this way, when the luminance signal Y and the color difference signal U/V are time-division multiplexed, frequency-modulated using one gear, and recorded, unlike the color amplifier recording method, (
1) Suppression of beat disturbance due to frequency interference (2) (31
1 signal contains AM noise and PM noise due to frequency modulation recording.
(4) Since the playback head output difference is unlikely to become an amplitude level difference after demodulation, color flicker can be suppressed, and the image quality can be improved.

However, this time division multiplexing recording method decodes a composite color video signal into a component signal and records it, and when playing back, encodes the component signal into a composite color video signal and outputs it, so it requires a decoder and an encoder, and a circuit The configuration becomes complicated.

Furthermore, passing through these decoders and encoders causes deterioration in image quality. In particular, since each dubbing process passes through a decoder and an encoder, the dubbing characteristics are significantly degraded.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks when performing time-division multiplex recording of luminance signals and color signals, and to provide a signal processing circuit that is optimal for time-division multiplex recording.

[Summary of the invention]

In order to achieve the above object, the present invention adopts a circuit configuration that complies with the interconnection standard that establishes the connection method between a home television receiver and peripheral devices such as VTI (VTI), video discs, and teletext compatible equipment. , a color video recording and reproducing apparatus is provided with input/output terminals for at least primary color signals H, G, and B.

In Japan, this interconnection standard is EIA, J standard (Japanese electronic machinery industry technology file, 'I'TC-03,
January 1981) was established in France as dCENgLEC.
There are standards.

In addition, in order to optimally comply with these interconnection standards, AGC circuits for luminance signal Y and for color difference signals are separately provided in the front stage of the time division multiplexer to optimize the input level, and these AGC circuits are Output luminance signal Y (including synchronization signal)
and the color difference signals to a converter that converts them into primary color signals R, G, B, and a luminance signal Y (including a synchronization signal).

[Embodiments of the invention]

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

FIG. 4 is a circuit block diagram showing an embodiment in which the present invention is applied to an apparatus for time-division multiplexing recording and reproducing color video signals. In the figure, O is an input terminal for a composite color video signal, 31 is an input terminal for a luminance signal Y (hereinafter, a synchronization signal is included), 62 to 64 are primary color signals R,
These are G and B input terminals, and the input terminals 31 to 34 comply with the above-mentioned interconnection standard. First, the recording system will be explained. 35 is an LPF that extracts the luminance signal Y from the composite color video signal from the input terminal 61;
6 is a decoder that converts a composite color video signal into a line-sequential color difference signal U/V; 37 is an input terminal 62~
Line-sequential color difference signal U from primary color signals R, G, and B from filter 4
/V converter, 38° 59 is a switch circuit, and when the input signal is a composite color video signal, the switch is connected in the opposite direction as shown in the figure, and the luminance signal Y from the LPF 35 is connected to the AGC circuit 40 for luminance signal. However, the line-sequential color difference signal U/V from the decoder '56 is guided to the color difference signal AGC circuit 41. On the other hand, the input signal is Y, R, G, B
, the switch is connected as shown and the AGC
The brightness signal Y from the input terminal 31 is input to the circuit 40 through the AGC
A line-sequential color difference signal U/V from the converter 37 is introduced into the circuit 41 . 42 is a detector, which detects the amplitude of the luminance signal output from the AGC circuit 40, and detects the amplitude of the luminance signal output from the AGC circuit 40, 41.
control the gain of. As a result, the composite color video signal from the input terminal 50 and the input terminals 61 to 3
If the amplitude level ratios of Y, 1(. t
J/V is obtained. 4'5 is a time division multiplexer, which time division multiplexes the luminance signal Y and the line-sequential color difference signal U/V, as shown in FIG. 3, for example. 44 is an output terminal for this time division multiplexed signal. At the time of recording, the amplitude level of the time-division multiplexed signal is optimized in A, the GC circuit 45 and the wave detector 46, and after being subjected to emphasis etc. in the process circuit 47, the frequency is changed in the frequency modulator 48. The signal is modulated and recorded on a magnetic tape 51 through a recording amplifier 49 and a recording head 50.

During this recording, the luminance signal Y and the line-sequential color difference signal U/V from the AGC circuits 40 and 41 are led to the converter 66 through the switch /+1.62 as shown in the figure, and this converter converts the luminance signal Y and the line-sequential color difference signal U/V. Sequential color difference signal U/■ is Y, 几, G
, B and guided to the respective output terminals 64-67. These output terminals 64 to 67 are compatible with the above-mentioned interconnection standard, and are connected to the luminance signal AGC circuit 40 in this way.
By separately providing circuits 41 for line-sequential color difference signals and guiding their respective outputs to a time-division multiplexer 43 and a Y, R, G, B converter 63, a color video signal that is time-division multiplexed and recorded. images can be viewed on home television equipment that supports the interconnection standard. In this case, instead of an encoder that converts to a complex composite color video signal, a converter that converts the luminance signal Y and line-sequential color difference signals U/V to Y, R, G, and B, which can be easily realized with a matrix circuit, is used. Just set it up. Furthermore, there is no dot interference or cross color caused by the encoder, and the image quality can be improved.

Next, the reproduction system will be explained. 51 is a standard head, and can generally be used also as the recording head 50. 55 is a preamplifier, 54 is a frequency demodulator, 55 is a process circuit, and the signal reproduced by the playback head 52 is sent to the preamplifier 5.
The signal is demodulated into a baseband time division multiplexed signal by a frequency demodulator 54, subjected to de-emphasis etc. by a process circuit 55, and a switch circuit 56 connected in the opposite direction to that shown in the figure.
is led to terminal 57 through. The time division multiplexed signal guided to this terminal 57 has its amplitude level optimized by the AGC circuit 5B and the detector 59, and is then guided to the time division demodulator 6D. This time division demodulator 60 demodulates the time division multiplexed signal into the original luminance signal Y and line sequential color difference signal U/■. At the time of reproduction, the switch circuits 61 and 62 are connected in the opposite direction to that shown in the figure, and the luminance signal Y demodulated by the time division demodulator 60 and the line-sequential color difference signal U/V are guided to the converter 63, and the Y , 几, G, B and output to output terminals 64-67. Thereby, even during reproduction, it is possible to obtain a reproduced image free from disturbances caused by conventional encoding into a composite color video signal.

However, dubbing and recording from other VTR or video equipment and home television equipment can be done by directing the Y, R, G, and B outputs from the interconnection standard compatible connectors of the respective equipment to the input terminals 31 to 64. It is possible. In this case, especially when dubbing from a component recording device, there is no need for encoding to convert into a composite color video signal, and image quality deterioration due to dubbing is suppressed.

As described above, by using the present invention, it is possible to suppress image quality deterioration in a device that time-division multiplexed recording and reproducing of color video signals, and also to be able to comply with interconnection standards, and to connect two video signals without switching connectors, etc. The image signal input to the signal recording and reproducing device can be viewed on a home television device.

Furthermore, the present invention shown in FIG. 4 includes a signal converter that converts a color video signal into a time division multiplexed signal at terminals 44 and 57 and demodulates the time division multiplexed signal into the original Y, R, G, H; It can be anonymously separated from the recording/reproducing unit that records and reproduces time division multiplexed signals.

By separating the system in this way, the recording/playback section can be connected to the recording/playback section and signal conversion section of other video recording/playback devices such as video discs, video files, and electronic still cameras. It is possible to aim for The connection signal in this case is a time division multiplexed signal, and the signal converter outputs the time division multiplexed signal from the terminal 44 and is connected to other equipment, and receives the time division multiplexed signal from the terminal 57. Therefore, in the case of , it is better to provide an AGC circuit 58 in front of the time division demodulator 60 for optimizing the amplitude level of the time division multiplexed signal.

Further, the recording/reproducing section receives a signal from another PA device through the terminal 44, and outputs a signal from the terminal 57. therefore,
In this case, it is better to provide the AGC circuit 45 before the frequency modulator in order to optimize the input signal level. A switch circuit 56 is provided after the AGC circuit 45.
By connecting the other input terminal of the switch circuit to the reproduction process circuit 55, it is possible to optimize the level of the input signal from the terminal 44 and output it through to the terminal 57, and to output the reproduced signal to the terminal 57. 57.

Further, in the embodiment shown in FIG. 4, an AGC circuit 58 and a detector 59 for optimizing the amplitude level of the time division multiplexed signal are provided before the time division demodulator 60, and similarly, an AGC circuit 58 and a wave detector 59 are provided before the frequency modulator/18. An AGC circuit 45 and a detector 46 are provided, and FIGS. 5 and 6 show specific configuration examples of the circuits for optimizing the amplitude level of these time division multiplexed signals. Figure 7 is Figure 5.

FIG. 7 is a diagram for explaining the circuit operation of FIG. 6;

In FIG. 5, 68 is an input terminal for time division multiplexed signals;
9 is an AGC circuit, the time division multiplexed signal whose amplitude level is controlled by the AGC circuit 69 is clamped by a flag circuit 70, and a synchronization signal is extracted from the time division multiplexed signal by a synchronization separation circuit 71.

In FIG. 7, 7a is the luminance signal Y before time-axis compression, and 7I] is the luminance signal Y when the luminance signal Y is compressed by %, and the line-sequential color difference signal U/V is compressed by A times the time-axis. 20 is the reference signal for color difference signals U and V; 7 is a time division multiplexed signal;
5, 76, and 77 are time-axis compressed U, Y, and V, respectively.
It's a signal. If this time-division multiplexed signal 7b is input to the input terminal 68 in FIG. The key pulse signal 7d whose amplitude level is approximately the normal white signal level is added to the time division multiplexed signal from the clamp circuit 70 by an adder circuit 72. In this way, the key pulse signal is added to a time division multiplexed signal 1d7e, and the peak detector 73 performs peak detection on this signal 7e to control the gain of the A G'C circuit 69. As a result, for example, when the amplitude level of the time division multiplexed signal is smaller than the amplitude level of the normalized key pulse signal 7d, the key pulse signal 7d is peak detected and the synchronization signal level is determined regardless of the time division multiplexed signal level. The AGC circuit operates to keep it constant. This is called keyed AGC. Conversely, when the key pulse signal 7d becomes smaller due to synchronization signal level compression and the amplitude level of the time division multiplexed signal becomes larger, peak detection is performed at the maximum amplitude point of the time division multiplexed signal, and the peak of the time division multiplexed signal is detected. The AGC circuit 69 is controlled to keep the value constant.

This is called peak AGC. In this way, the AGC circuit 69
By controlling the dynamic range of the circuit, linearity of the time division multiplexed signal can be ensured without reducing the dynamic range of the circuit, and the demodulation characteristics of the time division demodulator 60 and the frequency modulation characteristics of the frequency modulator 48 can be controlled. You can improve your performance.

FIG. 6 shows the embodiment shown in FIG. 5 except that a gate circuit 74 is provided and the gate circuit 74 is provided, and the components other than the gate circuit 74 operate in the same manner as in FIG. That is, the gate circuit 74 removes the color difference signal portion from the time division multiplexed signal 7e in which the key pulse signal from the adder circuit 72 is multiplexed, and removes the color difference signal portion from the synchronization signal.
A gate signal like f is formatted as 'High'
By opening the gate circuit 74 only during this period, a signal from which the color difference signals U and V have been removed is guided to the peak detector 73 as shown in 7g. As a result, the AGC circuit 69 is controlled by the level of the key pulse signal 7d generated from the synchronization signal and the time-axis compressed luminance signal, and changes in the I)C level due to the addition level of the color difference signals U and V or clamp errors, etc. This can prevent malfunctions of the AGC circuit due to

FIG. 8 shows another embodiment in which the present invention is applied to an apparatus for time-division multiplexing recording and reproducing color video signals. The embodiment in FIG. 8 is not significantly different from the embodiment in FIG. 4, except that the time division multiplexer 46 and time division demodulator 60 in FIG. be.

In FIG. 8, 78 is a switch circuit, which switches the luminance signal Y from the LPF 35 and the luminance signal from the input terminal 2 according to the input signal in the same way as the switch circuit 38 in FIG. 4 during recording. AGC circuit 40
, 41, the luminance signal Y and the line-sequential color difference signal tJ/V whose amplitude levels have been optimized are guided to a time division multiplexer/demodulator 79 and switch circuits 81 and 82. The time division multiplexer/demodulator 79 operates as a time division multiplexer during recording, and passes the time division multiplexed signals through all the switch circuits 80 connected as shown in the figure in the same manner as in the embodiment of FIG. recorded. On the other hand, the luminance signal Y and the line-sequential color difference signal U/V led to the switch circuits 81 and 82 are led to the converter 66 and output terminals 64 to 67 as in the embodiment shown in FIG.
, R, G, and B output signals to a home television device compatible with the above-mentioned interconnection standards, the composite color video signal size of the input terminal 60 or the input terminals 31 to 64 can be changed without changing the connector. component signal Y.

1 (, , G, B images can be viewed) During 0 playback, the switch circuit 78 switches to guide the playback time division multiplexed signal from the terminal 57 to the AGC circuit 40.
The time division multiplexed signal whose amplitude level has been optimized by the GC circuit is guided to the time division multiplex/demodulator 79. This time division multiplexing/demodulator 79 operates as a time division demodulator during reproduction, and demodulates the reproduced time division multiplexed signal into the original luminance signal Y and line-sequential color difference signal U/V. The demodulated luminance signal Y passes through a switch circuit 80 connected in the opposite direction to that shown in the figure, and is sent to a switch circuit 81, and the line sequential color difference signal U/V is sent to a switch circuit 82.
guided by each. At the time of reproduction, the switch circuits 81 and 82 are connected in the opposite direction to that shown in the figure, and the demodulated reproduced luminance signal Y and the line-sequential color difference signal U/V are sent to the converter 6 in the same way as in the embodiment shown in FIG.
Lead to 6, Y.

JG and B are led to output terminals 64-67.

As described above, when the embodiment of the present invention shown in FIG. 8 is used, the same effects as the embodiment shown in FIG. It is possible to achieve a reduction in size and a significant cost reduction.

FIG. 9 shows another embodiment in which the present invention is applied to a time division multiplexing recording/reproducing apparatus, and is a block diagram of a signal converting section of the time division multiplexing recording/reproducing apparatus.

The embodiment of FIG. 9 differs from the embodiment of FIG. 4 in that the AGC circuit configuration provided before the time division multiplexer 43 is shown more specifically, and that
/D converters 88, 89, 91 and D/A converter 90
, 92 , 93 are used to indicate digital time division multiplexing and demodulation.

In FIG. 9, 83 is a clamp circuit, 84 is a synchronous separation circuit, 85 is an adder circuit, 86 is a peak detector,
The luminance signal Y output from the AGC circuit 40 is subjected to keyed and peak AGC in the same manner as the AGC method for time division multiplexed signals shown in FIG. In this case, the gain of the AGC circuit for the line-sequential color difference signal U/V is controlled by the signal obtained by detecting the luminance signal Y, as in FIG.

One embodiment of FIG. 9 has a switch 78 in place of the switch 38, although not shown, as in FIG. 8, and a ])/A converter 9.
By providing a switch 80 on the output side of 0, the time division multiplexer 43 and the time division demodulator 60 can be used in common. In this case, A/D converter 91, D/A converter 96 and AGC
The circuit 69, the clamp circuit 70, the synchronous separator 71, the adder circuit 72, and the peak detector 73 can also be omitted, making it possible to significantly reduce the circuit scale and cost.

FIG. 10 is a block diagram of another embodiment in which the present invention is applied to a time-division multiplex recording/reproducing apparatus, and in which the time-division demodulator 60 is omitted from the signal conversion section. This example is the eighth example.
The difference from the embodiment shown in the figure is that the reproduced luminance signal Y and the reproduced line-sequential color difference signal U/V guided to the output terminals 96 and 97 of the time division demodulator 60 are provided before the AGC circuits 40 and 41, respectively. The switch circuits 94 and 95 are connected to the switch circuits 94 and 95.

In FIG. 10, switch circuits 94 and 95 are the switch circuits 58 of the embodiments of FIGS. 4 and 9 except during reproduction.
, 39, but during reproduction, the time-division demodulated luminance signal Y and the line-sequential color difference signal U/V are
GC circuits 40 and 41, and these AGC circuits 40
, 41 are led to a converter 65. As shown in the figure, the clamp circuit 83゜870 output is transferred to the converter 63.
It is also possible to lead to

In this way, the time-division demodulated luminance signal Y and the line-sequential color difference signal U/V are transferred to the switches 94 and 95 at the front stage of the AGC circuit.
By connecting the switch circuits 61 and 62 provided in the embodiment of FIG. 8, it is possible to eliminate the switch circuits 61 and 62 provided in the embodiment of FIG.

In addition, by passing the reproduced signal through the AGC circuit 40°41,
The playback level can be optimized.

FIG. 11 shows another embodiment using the present invention. This embodiment differs from the embodiment shown in FIG. 9 in that a time-division multiplexed signal output from a D/A converter 90 is used as a signal to be detected by a peak detector 86, and this time-division multiplexed signal is clamped by a clamp circuit 98, and a key pulse signal is added and peak detected in the same manner as in FIG.

Since the gains of the AGC circuits 40 and 41 are controlled by this detection output, these AGC circuits 40 and 41 are
It operates to keep the amplitude level of the time division multiplexed signal output from the /A converter 90 constant.

FIG. 12 shows another embodiment using the present invention.
The difference from the embodiment shown in FIG. 1 is that detectors for controlling the gains of the luminance signal AGC circuit 40 and the color difference signal AGC circuit 41 are provided separately.

In FIG. 12, as in FIG. 11, the output of the D/A converter 90 is clamped by a clamp circuit 98, and the key pulse signal is added by an adder circuit 85. The hour/minute 1-weight signal to which this key pulse signal has been added is guided through gate circuits 98, 99 to peak detectors 86, 1(]0 for controlling the respective AGC circuits 40, 41. In this case, The gate circuit 98 operates in the same manner as the gate circuit 74 shown in the embodiment of FIG. 6, and as shown in 7g of FIG. The key pulse signal is guided to the peak detector 86. On the other hand, the gate circuit 99 supplies the line-sequential color difference signal U/from which the luminance signal Y has been removed.
V and the key pulse signal to a peak detector 100. Therefore, the AGC circuit 40 operates as a keyed and peak AGC using the time-division multiplexed luminance signal Y and the key pulse signal, and the AGC circuit 41 operates as a keyed and peak AGC using the time-division multiplexed line-sequential color difference signal U/V and the key pulse signal. It operates as a peak AGC and can set the time-division multiplexed luminance signal Y and line-sequential color difference signal U/■ to their respective optimum levels.

The above is a luminance signal user GC 40 at the front stage of the time division multiplexer 46.
An example in which an AGC 41 for line-sequential color difference signals is provided is described. Further, the case where only U and V are used as color difference signals is described.

However, the present invention is not limited to the above AGC circuits 40 and 41, but includes, for example, an AGC circuit for line sequential color difference signals.
Instead of the circuit 41, it is also possible to provide separate AGC circuits for the color difference signals U and V, respectively. It is also possible to use I and Q as color difference signals.

FIG. 13 shows an embodiment of the present invention in which the AGC circuits 106 and 104 for the color difference signals U and V are provided separately.

In the embodiment of FIG. 13, the outputs of the decoder 66 and the converter 37 are not line-sequential color difference signals U/V, but simultaneously output color difference signals U and V, which are led to switch circuits 101 and 102, respectively. The switch circuits 101 and 102 are switched depending on the input signal in the same manner as the switch circuit 39 in the embodiment shown in FIG. , B
is input, the outputs of the converter 37 are guided to AGC circuits 103 and 104, respectively.

The AGC circuits 105 and 104 are gain-controlled in the same way as the AGC circuit 40, and the color difference circuits U and V, which are designed to optimize the field of view, are switch circuits 105 and 108, respectively.
You will be directed to 109. The switch circuit 105 outputs the color difference signal U,
V is switched line by line and converted into a line-sequential color difference signal Tl/V, which is time-division multiplexed with the luminance signal Y and outputted to the terminal 44ζ as in the embodiment of FIG. On the other hand, the color difference signals U and V led to the switch circuits 108 and 109 are connected to the terminal 1.
During playback from 06 and 107, the time-division demodulated color difference signals U and V are switched, and during playback, the time-division demodulated luminance signal Y and simultaneous color difference signals U and V are switched, and when other than playback, the color difference signals U and V are switched to A.
The luminance signal Y and simultaneous color difference signals U and V from the GC circuits 40 , 103 , and 104 are led to a converter 63 . As a result, the same effect as the embodiment shown in FIG. 4 can be achieved. Furthermore, since simultaneous color difference signals are input to the converter 66, the converter 63 does not need a circuit for converting line-sequential color difference signals into simultaneous color difference signals, which simplifies the circuit configuration. can be achieved. − to ζ, 11il sequential color difference signal U during playback
/V is a time axis compression ratio and can be easily converted into simultaneous color difference signals [J, V.

In the above invention, only the case where color signals are multiplexed by line-sequential color-difference signals U/V and compressed on the time axis to a fraction of a percent has been described as a time-division multiplex recording method.

However, the present invention is not limited to the time axis compression ratio of the color difference signal and the luminance signal; for example, the line sequential color difference signal may be compressed in time axis to %, and the luminance signal may be time axis compressed to % and then multiplexed. In addition, instead of a line-sequential color signal, for example, a color difference signal U,
The luminance signals may be multiplexed by simultaneously increasing the V and compressing the time axis to %.

〔Effect of the invention〕

By using the present invention, when a color video signal is time-division multiplexed and recorded and reproduced, the recorded color video content can be monitored on a home television device without switching connectors. In addition, when connecting to a home television device or dubbing to other VTRs or recording devices, an encoder that converts component signals to composite color video signals is no longer required, and image quality deterioration can be suppressed. can.

Furthermore, the present invention is compatible with interconnection standards for television receivers and peripheral devices (EIA, J standards, CI No. EL EC standards).

[Brief explanation of the drawing]

Figure 1 is a block diagram of a conventional color under recording system VTR, Figure 2 is a block diagram of a device for time division multiplex recording of luminance signals and color difference signals, and Figure 6 is an example of a time division multiplex signal format. FIG. 4 is a block diagram showing an embodiment of the time division multiplex recording/reproducing apparatus of the present invention, and FIG. 5 is a block diagram showing an embodiment of a circuit suitable for applying AGC to the time division multiplex signal. Figure 6 shows A and GC for time division multiplexed signals. A block diagram showing another embodiment of a circuit suitable for applying
FIG. 7 is a waveform diagram explaining the operation of the embodiment shown in FIGS. 5 and 6, FIG. 8 is a block diagram showing another embodiment of the time division multiplexing recording/reproducing apparatus of the present invention, and FIG. FIG. 10 is a block diagram showing another embodiment of the time division multiplexing recording and reproducing apparatus of the invention. FIG. 11 is a block diagram showing another embodiment of the time division multiplexing recording and reproducing apparatus of the invention. FIG. 12 is a block diagram showing another embodiment of the multiplex recording/reproducing apparatus of the present invention;
FIG. 13 is a block diagram showing another embodiment of the time division multiplex recording/reproducing apparatus of the present invention. - 25 time division multiplexer 60 - Composite color video signal input terminal 61 - Luminance signal or synchronization signal input terminal 62...)
Input terminal 65...G input terminal 64...B input terminal 67...Converter 38, 59...Switch circuit 4
0.41 ・AGC circuit 42・Detector 43・Time division multiplexer 45- AGC circuit 46・Detector 58 AGC circuit 59...Detector 60 Time division demodulator 61.62 Switch circuit 63・
・Converter 64... Output terminal 65 for brightness signal or synchronization signal...
R output terminal 66...G output terminal 67...B output terminal 69...AGC circuit 70.8, 98...clamp circuit 71.84 Synchronous separation circuit 72, 85, age circuit 73.86, 100... Peak detector 74... Gate circuit 78.80, 81.82... Switch circuit 79... Combined time division multiplexer and demodulator 94, 95... Switch circuit 98, 99... Gate circuit 101, 102,
105, 108, 109... switch circuit 103
, IQ4... AGC circuit 2 Figure '3 Figure 5 Figure 6 Figure 7 Figure

Claims (1)

[Claims] 1 A first AGC circuit that controls at least the amplitude level of the luminance signal and a second AGC circuit that controls the amplitude level of the color difference signal.
A GC circuit, a means for time-division multiplexing the luminance signal and the color-difference signal by compressing the time axis separately, and a means for converting the luminance signal and the color-difference signal into primary color signals, the time-division multiplexing means A color video signal, characterized in that first and second AGC circuits are provided in the preceding stage, and the outputs of the first and second AGC circuits are led to means for converting the luminance signal and color difference signal into primary color signals. Recording/playback device) i? −
0