JPS60125093A - Recording and reproducing system for multiplex composite signal - Google Patents

Abstract

PURPOSE:To record and reproduce signals of plural channels without providing another track on a recording medium, and improve the utilization efficiency of the recording medium by multiplexing other signals with a multiplex signal of a luminance and a chrominance signal easily, and restoring it to the original signals easily. CONSTITUTION:Other signals to be multiplexed with the multiplex signal of the luminance signal and chrominance signal are, for example, sound signals supplied to input terminals 27 and 28, and the sound signal supplied to the input terminal 27 is processed by a processing circuit 14 for time-axis compression into a phase-modulated signal Sc positioned in the middle of the back porch of the horizontal synchronizing pulse of the luminance signal Sb and multiplexed with the luminance signal. The sound signal supplied to the input terminal 28, on the other hand, is processed by a processing circuit 26 for time-axis compression into a phase-modulated signal Sc positioned in the middle of a period corresponding to the horizontal synchronizing pulse added to the luminance signal Sb and multiplexed with a low-frequency converted chrominance carrier signal Sf. Even when said addition is carried out, the phase-modulated signals Sc and Sf do not exert any influence upon signals.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for recording and reproducing a multiplexed composite signal obtained by multiplexing a multiplexed signal of a luminance signal and a chrominance signal with at least one other signal. It is something.

(Prior Art and Problems) Conventionally, a rotating head type has been widely used as a recording device for recording and reproducing a multiplexed signal of a luminance signal and a color signal, for example, a composite color video signal. In video tape recorders (VTRs), audio signals, control signals, cue signals, etc. are generally recorded using dedicated recording tracks along the edges of the magnetic tape. It is.

By the way, in recent years, as the recording density of composite color video signals has become higher, the running speed of magnetic tape has been reduced.For example, the running speed of magnetic tape has decreased to 1 c/s.
VTRs of II+ and below have even appeared, but as the running speed of the magnetic tape decreases, the deterioration of the audio signal naturally becomes significant, which becomes a problem.

Also, looking at the magnetic tape used in VTRs, the magnetic tape in early broadcast VTRs was approximately 5 cm wide, but the magnetic tape used in home VTRs was approximately 5 cm wide. As a result, the ratio of the area of the audio signal track to the area of the video signal track is gradually increasing. In addition, in VTRs that have separate audio signal tracks as mentioned above, each track requires its own magnetic head, which increases the number of parts and the configuration. This has led to complications and cost issues.

A rotary head type VT having the general configuration as described above.
The problems in R can be effectively solved by creating a signal in which the TV video signal and the audio signal are multiplexed, and then recording and reproducing the signal.

Now, recording and transmitting a plurality of signals to be recorded and transmitted in the form of a multiplexed signal has been widely practiced for a long time. Conventionally, there have been many signal multiplexing methods such as various signal multiplexing methods using frequency division multiplexing as the basic construction principle and various signal multiplexing methods using time division multiplexing as the construction principle. This is well known, and for example, a TV video signal can be created by modulating an audio carrier wave with an audio signal that has a frequency much higher than the upper limit of the frequency band of the TV video signal to be recorded. and an audio signal, or for example,
A frequency modulated wave in which a TV video signal and an audio signal occupy different frequency bands (the frequency modulated wave by the audio signal occupies a lower frequency band)
As a result, a multiplexing method has been put into practice in which a TV multiple signal and an audio signal are frequency division multiplexed.

However, in the former method among the multiplexing methods mentioned above, the occupied frequency band of the recording signal is wide, and the recording wavelength of the audio carrier wave becomes short, resulting in deterioration of S/N due to various losses. In addition, in the latter of the multiplexing methods mentioned above, harmonic components due to distortion of the audio carrier wave may interfere with the TV video signal band, and in the method in which color signals are multiplexed in the low frequency band, In some cases, there are drawbacks such as a lack of bandwidth, and in both of the above-mentioned methods, there is a drawback in that after-recording is not possible.

In addition, in recent years, in order to realize the demand for high-density recording of information signals on recording media, the TLFA recording/re-recording/reproducing method uses two magnetic heads for recording/reproducing.
A magnetic recording medium is used in which the direction of the track width in the magnetic gap is inclined by a very small angle (±6 degrees, ±7 degrees) with respect to the direction perpendicular to the direction in which the recording trace (track) extends. By allowing the adjacent recording traces on the top to be recorded and reproduced by magnetic heads having different azimuth angles, the information of the adjacent recording traces is prevented from being reproduced due to so-called azimuth loss, and the information between the adjacent recording traces is A recording and reproducing method that utilizes the so-called tilted azimuth effect has become widely adopted, eliminating the need for the conventional non-recording area (girt band) and achieving high-density recording on magnetic recording media. However, in the above-mentioned recording and reproducing system that utilizes the tilted azimuth effect, signals in the low frequency band where the azimuth effect is not sufficient become crosstalk and are present in the reproduced signal.
For example, when magnetically recording and reproducing a signal frequency-multiplexed by a frequency ripple modulation wave caused by a luminance signal and a low-frequency converted carrier color signal obtained by frequency-converting a carrier fading signal to a lower frequency band,
A problem arises in that crosstalk due to the azimuth effect is not sufficiently removed for low-pass conversion carrier color signals.
A color video signal recording and reproducing method based on the so-called phase shift method (PS method) as described in detail in Japanese Patent Application Laid-Open No. 50-34419, for example, It is well known that a color video signal recording/reproducing method using a so-called phase shift method (PI method) has been proposed and put into practical use.

However, when the recording trace is made smaller in order to perform higher density recording, the reproducing element must follow the recording trace under tracking control by a tracking control system.

(Means for Solving the Problems) The present invention is a recording and reproducing method for a multi-composite signal, which is a multiplexed signal of a luminance signal and a chrominance signal, and at least one other signal. , the other signal to be multiplexed with the multiplexed signal of the luminance signal and the chrominance signal is multiplexed with the luminance signal and the chrominance signal (an N-phase signal having a period M times the horizontal scanning period) The leading edge and trailing edge are respectively , N/2 as individually phase modulated
A phase modulated signal with a wave number of The above-mentioned luminance signal is used as a frequency-modulated wave, and the above-mentioned luminance signal is frequency-modulated by the above-mentioned luminance signal. Recording of a multiplexed composite signal in which a multiplexed composite signal is recorded on a recording medium by frequency-division multiplexing a wave and a color signal existing in a low frequency range.

The reproduction method and other signals to be multiplexed into the first multiplexed signal of the luminance signal and the chrominance signal have a period M times the horizontal scanning period of the multiplexed signal of the luminance signal and the chrominance signal. The leading edge and the trailing edge are determined by the two retained sample value signals of the N retained sample value signals which are individually retained N sample value signals obtained by sampling with N phase sampling signals. A phase modulated signal of N/2 wave numbers, in which each of The luminance signal is made to exist within one or both of the periods corresponding to every M horizontal synchronizing signal periods in the color signal, and the period corresponding to one horizontal synchronizing signal period. As a frequency modulated wave, a multiplexed composite signal, which is constructed by frequency division multiplexing the frequency modulated wave by the luminance signal described above and a chrominance signal present in the low range, is reproduced from a recording medium, and the reproduced multiplexed composite signal is reproduced from a recording medium. The frequency modulated wave by the luminance signal obtained by separating the frequency modulated wave by the luminance signal and the chrominance signal in the signal is frequency demodulated, and one of every M horizontal synchronization signals in the luminance signal obtained by the above frequency demodulation. The back porch portion of one horizontal synchronizing signal, and the period corresponding to one horizontal synchronizing signal period of every M horizontal synchronizing signal periods in the color signal, or both of them. N restoration-preserving sample value signals are obtained based on the information on the leading edge and trailing edge of each N/2 wave number phase modulated signal, and the N restoration-preserving samples are obtained. The value signal is sampled with a sampling signal of a predetermined sampling period to obtain N restored sample value signals, and the N restored sample value signals are multiplexed into a multiplexed signal of a luminance signal and a chrominance signal. A method for recording and reproducing a multiplexed composite signal to obtain a restored signal of other signals, and a method for recording and reproducing a multiplexed composite signal to obtain a restored signal of other signals, as well as other signals to be multiplexed into a multiplexed signal of a luminance signal and a chrominance signal, are described. N retained sample value signals obtained by individually holding N sample value signals obtained by sampling with an N-phase sampling signal having a period M times the horizontal scanning period of the multiplexed signal. A phase-modulated signal of N/2 wave numbers, whose leading edge and trailing edge are individually phase-modulated based on two retained sample value signals in the luminance signal described above, is The pack porch portion of one horizontal synchronizing signal of every M horizontal synchronizing signals and the period corresponding to one horizontal synchronizing signal period of the period corresponding to every M horizontal synchronizing signal period in the color signal. At the same time, with the luminance signal as a frequency modulated wave, the frequency modulated wave by the luminance signal and the chrominance signal existing in the low range are frequency division multiplexed. A multiplexed composite signal made up of multiplexed composite signals is reproduced from a recording medium, and a frequency modulated wave by a luminance signal obtained by separating a frequency modulated wave by a luminance signal and a chrominance signal in the reproduced multiplexed composite signal is generated. The packed porch portion of one horizontal synchronizing signal of every M horizontal synchronizing signals in the luminance signal obtained by frequency demodulation and the one of every M horizontal synchronizing signal periods of the above-mentioned chrominance signal are frequency demodulated. Information on each leading edge and trailing edge of a phase modulated signal of N/2 wave numbers that is configured to exist within one or both of the periods corresponding to the horizontal synchronization signal period. N restored sample value signals are obtained based on the N restored sample value signals, and the N restored sample value signals are sampled with a sampling signal of a predetermined sampling period to obtain N restored sample value signals. From the restored sample value signals, the restored signals of other signals multiplexed with the multiplexed signal of the luminance signal and the chrominance signal are obtained, and the other signals multiplexed with the chrominance signal are obtained. The present invention provides a multiplexed composite signal recording and reproducing method in which a tracking reference signal is used during a reproducing operation to cause a reproducing element to follow a recording trace under tracking control to perform a reproducing operation.

(Example) Hereinafter, with reference to the accompanying drawings, a multiplexed composite (No. 8 recording and reproducing method) obtained by multiplexing at least one other signal to a multiplexed signal of a luminance signal and a chrominance signal of the present invention will be described. The content will be explained in detail.

The multiplexed composite signal recording and reproducing method of the present invention is characterized in that other signals to be multiplexed with the multiplexed signal of the luminance signal and chrominance signal are
By each two retained sample value signals in the N retained sample value signals that are obtained by individually retaining the N sample value signals obtained by sampling with the N-phase sampling signal having twice the period. , a phase modulated signal of N/2 wave numbers whose leading edge and trailing edge are individually phase modulated is used as one horizontal synchronization signal of every M horizontal synchronization signals in the luminance signal. so as to exist within one or both of the pack porch portion of the signal and the period corresponding to one horizontal synchronizing signal period of the periods corresponding to every M horizontal synchronizing signal periods in the color signal. At the same time, using the luminance signal as a frequency modulated wave, a multiplexed composite signal is recorded on a recording medium by frequency division multiplexing a frequency modulated wave by the luminance signal and a color signal existing in a low frequency range. A method for recording and reproducing a multiplexed composite signal such that the multiplexed composite signal as described above is recorded and a multiplexed composite signal reproduced from a recording medium on which the multiplexed composite signal as described above is recorded, and a frequency modulated wave by a luminance signal and a color Frequency demodulation is performed on the frequency modulated wave from the luminance signal side obtained separately from the signal, and the pack pouch portion of one of the horizontal synchronization signals for each 'MM horizontal synchronization signal in the luminance signal obtained by the frequency demodulation described above is and a period corresponding to one horizontal synchronizing signal period between every M horizontal open Im signals II in the color signal.
Information number of each leading edge and trailing edge on the phase modulated signal side of /2 wave numbers; Based on this, N restoration-preserving sample value signals are obtained, and the N restoration-preserving sample value signals are obtained. is sampled with a sampling signal of a predetermined sampling period to obtain N restored sample value signals.

The N restored sample value signals are multiplexed into a multiplexed signal of a luminance signal and a chrominance signal to obtain a restored signal of %N other words (Recording No. 1).

The reproduction method and the multiplexed composite signal side described above; First, use the other signal multiplexed with the color signal as a tracking reference signal during reproduction operation (at A, the reproduction element is placed under tracking control). Recording wire number: The recording and reproducing method of the multiplexed composite signal, and the audio signal multiplexed with the color signal in the recording and reproducing method of the multiplexed composite signal, so that the reproducing operation is performed in accordance with the following. This is a recording and reproducing method of a multiplexed composite signal that is also used as a tracking reference signal. First, at least one other signal is multiplexed to a multiplexed signal of a luminance signal and a chrominance signal to generate a multiplexed composite signal. A means for obtaining a signal, a means for restoring an original signal from a multiplexed composite signal obtained by multiplexing a multiplexed signal of a luminance signal and a chrominance signal with at least one other signal, etc. will be explained.

FIG. 1 shows a method in which a multiplexed signal of a luminance signal and a chrominance signal is multiplexed with at least one other signal to generate a multiplexed composite signal, or a multiplexed signal of a luminance signal and a chrominance signal is multiplexed with at least one other signal as described above. 1 is a block diagram showing an embodiment of a multiplexing and restoring device for multiple signals used for restoring multiple original signals from a multiplexed composite signal on which one other signal is multiplexed; FIG.

In the following description, a multiplexed signal of a luminance signal and a chrominance signal is a signal in which the luminance signal and chrominance signal are band-sharing multiplexed within the band of the luminance signal, such as in NTSC color video decoding. The explanation is given by taking as an example the case where the luminance signal obtained from the signal format and the low-frequency conversion carrier chrominance signal are used. The conversion signal may be, for example, a luminance signal and a primary color signal, a luminance signal and a color difference signal, a line sequential signal of a luminance signal and a color signal or a color difference signal, or any other appropriate signal generated by a color imaging device.

In FIG. 1, reference numeral 1 denotes an input terminal for a composite color video signal having a signal format in which a luminance signal and a chrominance signal are band-sharing multiplexed within the band of the luminance signal, such as a color video signal of the NTSC system. It is.

In addition, terminals such as 2-1, 2-2, . . . 2-m in FIG. It is an input terminal,
Reference numeral 2 in the figure is the overall code of the input terminal for other signals.

The explanation of the apparatus shown in FIG. 1 will be simplified.

The number M of other signals to be multiplexed with the multiplexed signal of the luminance signal and chrominance signal in order to It is assumed that the above three other signals supplied to the input terminal 2-m are all audio signals, and among the above-mentioned three audio signals, the audio signal supplied to the input terminal 2-m is as follows.
Although it is explained that it is used also as a tracking reference signal, in implementing the present invention, the number M of other signals to be multiplexed with the multiplexed signal of the luminance signal and the chrominance signal is arbitrary. Of course, the signal to be multiplexed with the luminance signal and the color signal may also be a low frequency signal other than the audio signal.

Now, in Figure 1, the dashed-dotted line frames MSGI, MSG2,
...MSG The part indicated by m is a signal processing circuit for signals to be multiplexed, and the signal processing circuits for these signals to be multiplexed MSGI, MSG2...M
SG m are all configured in the same configuration, and are the signal processing circuits MSGI, MSG2, . . . MSG m for the signals to be multiplexed.
are provided in the same number M as the number M of other signals to be multiplexed with respect to the multiplexed signal of the luminance signal and the chrominance signal.

In FIG. 1, in order to avoid complicating the drawing description, one of the signal processing circuits MSGI, MSG2, . . . MSG m ( Signal processing circuit Mscm for signals to be multiplexed)
Only the detailed configuration of the signal processing circuits MSGl, M for other signals to be multiplexed is illustrated.
SG2 is simply illustrated by a dashed-dotted line frame.

The composite color video signal ((a) in Figure 2) supplied to input terminal 1 is passed through a synchronous separation circuit SEP and a filter (branching filter).
Given to DW. The synchronization separation circuit SEP separates the synchronization signal from the composite color video signal supplied thereto, and converts the horizontal synchronization signal Ph ((b) in FIG. 2) into the first . Second pulse generator PCI.

Give to PG2.

The first pulse generator PCI described above generates M series of pulses P hl, P in which the horizontal synchronizing signal ph is frequency-divided by M.
h2-Phm ((e) to (6) in Fig. 2) and transmits it to a predetermined one in the signal processing circuits MSGI, MSG2...MSGm for the signals to be multiplexed. However, in the device shown in the first diagram, since M is 3 as described above, three series of pulses as shown in the second diagram are generated from the first pulse generator PCI.

That is, in the first pulse generator PCI, the number of other signals to be multiplexed with respect to the multiplexed signal of the luminance signal and the color signal is M, and the other signals mentioned above are multiplexed. When the period of a multiplexed signal of a luminance signal and a chrominance signal is T, it has a period M'T and can generate M-sequence pulses that are synchronized with the synchronization signal described above. There is. The first pulse generator PCI described above can be configured using, for example, a branching unit.

The second pulse generator PG2 also processes the pulses (C) to (e) of FIG. 2 that are generated by the first pulse generator PCI.
) M-sequence pulses Phl~Phm as shown in
generates sampling pulses Ph1sl to Phms4 as shown in (f) to (h) in FIG. Signal processing circuit MSG1. MSG2......Supplied to each predetermined one in MSG m.

(f) in FIG. 2 is the N-phase sampling pulse Phlsl-Phls4 corresponding to the pulse Phi of the pulse train shown in FIG. 2(c), and (g) in FIG. is the N-phase sampling pulse P b corresponding to the pulse Ph2 of the pulse train shown in FIG. 2(d).
2sl ~P h2s4, and (h
) are N-phase sampling pulses corresponding to the pulse Phm of the pulse train shown in FIG. 2(e), that is, sampling pulses Phm5l to Phm54. In the device shown in FIG. 1, the circuit layout is shown when N is 4, so the circuit layout shown in FIG. 2 is (f) to (h).
The sampling pulses shown in ) are respectively four-phase sampling pulses, but the value of N mentioned above is based on other values to be multiplexed with respect to the multiplexed signal of the luminance signal and the color signal. It should be selected appropriately depending on the number M of signals, the frequency band iJ required for other signals to be multiplexed with the multiplexed signal of the luminance signal and chrominance signal, etc. .

In the circuit arrangement shown in the first diagram, the second pulse generator PG
N-phase sampling pulse P hls generated from 2
l to Ph1s4 are signal processing circuits M for signals to be multiplexed.
N-phase sampling pulses Ph2sl to P given to SGI and generated from the second pulse generator PG2
h2s4 is a signal processing circuit MSG for signals to be multiplexed.
2, and further generated from the second pulse generator PG2, the N-phase sampling pulses Phm5l to Ph
mg4 is a signal processing circuit MSG m for signals to be multiplexed.
and used for sampling operations as described below for other signals to be multiplexed with respect to the multiplexed signal of the luminance signal and the chrominance signal, respectively.

Now, the color composite image supplied to input terminal 1.

7 signal is the luminance signal Y at the filter (branching filter) D%l.
and the carrier color signal C, and the luminance signal Y is sent to the adder circuit A.
DD, and the carrier color signal C is provided to the color signal processing circuit COL.

The color signal processing circuit COL converts the carrier color signal supplied thereto, for example, into a low-pass converted carrier color signal and supplies it to the superimposition circuit MIX. In the above-mentioned adder circuit ADD, the signals generated by the signal processing circuits MSGI and MSG2 for signals to be multiplexed that perform signal processing operations as described below are processed in the period corresponding to the period of the horizontal synchronization signal in the luminance signal Y, or in the period corresponding to the period of the horizontal synchronization signal in the luminance signal Y, or A frequency modulator uses a signal added in a period corresponding to a predetermined period near the synchronization signal, or a period corresponding to the above-mentioned rainy period (horizontal blanking period) as a signal wave. Give it to MOD.

The frequency modulator MOD performs a predetermined pre-emphasis on the signal wave applied thereto from the adder circuit ADD, then frequency modulates the carrier wave and provides a frequency modulated wave output to the superimposition circuit MIX.

The superimposition circuit MIX combines the frequency modulated wave output from the frequency modulator MOD and the color signal processing circuit COL.
A signal processing circuit M for output signals from and signals to be multiplexed.
Each signal, such as a signal extracted from the output signal of SG m by the gate circuit Gm, is superimposed and given to the output amplifier RA. In the output amplifier RA-, a multiplexed signal in which at least one other signal is multiplexed with respect to the multiplexed signal of the luminance signal and the chrominance signal is sent to the output terminal 3.
The multiplexed signal output from the is recorded on the recording medium TR and made public.

Next, the other signals supplied to the input terminals 2-1 to 2-m are the signals to be multiplexed by the signal processing circuit MSGI.

MSG2... MSG m The signal processing circuit MSG for the signals to be multiplexed is shown surrounded by a dashed-dotted line frame MSGm in FIG. m will be used as a representative example, and will be explained in detail with reference to explanatory waveform diagrams shown in FIGS. 3 to 5.

In FIG. 1, the signal St supplied to the input terminal 2-m
is one of the other signals that should be multiplexed with the multiplexed signal of the luminance signal and the chrominance signal, but in the example below, the signal St is assumed to be an audio signal that is also used as the tracking reference signal. FIG. 3(e) shows an example of the waveform of the signal St described above.

The signal St supplied to the input terminal 2 = m to the signal processing circuit MS, Gm for signals to be multiplexed is limited and amplified to the level missed for subsequent modulation in the process amplifier PCA, and is also amplified by an appropriate preamplifier. After the emphasis processing is performed, the signal is applied to a low-pass filter (LPF). In the low-pass filter LPF, +46 is applied to prevent aliasing distortion from occurring in the next stage sampling process.
The frequency band is limited to 172 or less of the signal S t tt sampling frequency.

The output signal from the low-pass filter LPF is given to sampling circuits (samplers) SGI to SG4. The signals given to the samplers SGI to SG4 are sampling pulses (sampling signals) Phm5l to Phm54 (see FIG. 3(a)) generated by the second pulse generator PG2.
～(d)),
Each of the samplers SGI to SG4 outputs a sample value signal. The signal S shown in (8) in Figure 3
The circled part at t is the sampling pulse P hm
This is the part sampled by sl~P hms4.

Each sample value (signal) output from each sampler 5GI-3G4 is processed by hold capacitors 01 to C4 individually provided for each sampler 5GI-5G4 at one sampling period (in the illustrated example when M is 3). In this case, it is held for three horizontal scanning periods (3H) in a color video signal.

Figure 3(f) to (i) show each hold capacitor 01 to C.
Each retained sample value signal V c 1 was retained by V c 1 .

Vc2. Vc3. It is a waveform example diagram of Vc4. Each of the held sample value signals Vcl to Vc4 is applied to each of the adders ADDI to ADD4 provided individually for each of the hold capacitors 01 to C4. The aforementioned adders ADDI to ADD4 each receive a predetermined DC voltage v generated by the DC voltage generation circuit DCV.
1 to v4 are given, but the DC voltage generation circuit DC
In the following explanation, the predetermined DC voltages v1 to v4 generated at V are calculated by converting the reference DC voltage Vs by 5 through a resistor network.
It is said that the voltage value is obtained by dividing the voltage into equal parts.

As mentioned above, from the DC voltage generation circuit DCV to the adder AD
The DC voltage applied to DI to ADD4 is the reference DC voltage V
Although it is not a necessary condition that s is divided into equal parts, there is a difference between the DC voltage generator DCV and the adder
The DC voltage applied to DI to ADD4 is the reference DC voltage V
If s is divided into equal parts, the phase modulation described later can be performed most efficiently, so it is preferable to set the DC voltage values ■1 to v4 as described above. .

The output side of the adder ADDI mentioned above is.

A signal Vcl' in which the held sample value signal Vcl is superimposed on the DC voltage ■l appears, and the adder AD
On the output side of D2, a held sample value signal Vc is applied to the DC voltage v2.
2 appears, and furthermore, a DC voltage v3 appears on the output side of the adder ADD3.
The signal Vc in which the retained sample value signal Vc3 is superimposed on
3' appears, and furthermore, a signal Vc4' in which the held sample value signal Vc4 is superimposed on the DC voltage v4 appears on the output side of the adder ADD4.

Each output signal of the adders ADDI to ADD4 described above is
Comparators COMPI to COMP provided individually
4 as a comparison voltage, and a sawtooth wave voltage generated by a sawtooth wave generator SAW is supplied as a reference voltage to each of the above-mentioned comparators COMPI to COMP.

The sawtooth wave voltage generated by the sawtooth wave voltage generator SAW described above has a first period corresponding to the synchronization signal period of one of the M synchronization signals described above, and a period around the first period described above. A second period corresponding to a predetermined period, or both periods, for example, a period corresponding to a period of a horizontal synchronization signal in a color video signal,
Or a waveform that exhibits a constant slope in a period corresponding to a defined period near the period of the horizontal synchronization signal (for example, the back porch portion), or in both of the above-mentioned periods (horizontal blanking period). It is said that

In the illustrated example, the sawtooth voltage generated by the sawtooth voltage generator SAW has a constant slope during the period of the synchronization signal in the multiplexed signal of the luminance signal and the chrominance signal. This shows a case in which the voltage reaches a specific voltage value, and the period indicated as 5 μS in FIG. 4(a) is a multiplexed signal of a luminance signal and a color signal. This is the period of the horizontal synchronizing signal, and the period in which 3H is displayed is the 3 horizontal scanning period.

(b) in FIG. 4 shows the sawtooth wave voltage Vgav given to the comparators COMPI to COMP4 as a reference voltage from the sawtooth wave generator SAW, that is, the horizontal synchronization of the multiplexed signal of the luminance signal and the chrominance signal. A sawtooth wave voltage Vsaw is formed to reach a specific voltage Vs with a constant slope during a signal period, and a comparison voltage Vcl' is applied from each adder ADDI to ADD4 to each comparator.

Vc2'h Vc3', Vc4' are shown in the figures, and each comparison i1cOMP1-COMP4 (71 people side) ~C0N
The output side number of P4; the correspondence relationship with the signals 81 to s4 shown in FIG. 4 (c) to (f) that appear is easily understood.

Output signal s1 of the comparators COMPI to COMP4 described above
The level state of ~S4 is determined by the comparator COMPI~COMP.
When the comparison voltages V cl' to Vc4' given to the comparison voltages Vcl' to Vc4' are lower than the sawtooth voltage Vgaw, the voltages are set to high level.
The comparison voltages Vcl' to Vc4' are the sawtooth wave voltage Vga
If it is higher than w, it is set to low level, so for example, the comparison voltages Vcl' to Vc4' given to the comparator COMPI-Co liver 4 are as shown in FIG. 4(b). As in a certain example, voltages Vl, V2 . V3. V4, each output signal 81, 82 . . . appears on the output side of each comparator COMPI to COMP4. S3. S4i*, it becomes what is shown in Figures (,?) (c) to (f).

Then, as described above, each comparator COMPI-COMP4
The respective output signals Sl, S2, 83 . S4
The time position of the leading edge of each comparator COMPI-COMP4
As the comparison voltages Vcl' to Vc4' given to Each of the output signals Sl, 82 . S3, 84 are each comparator CO
Comparison voltage V c 1 given to MP1 to COMP4
Depending on the magnitude of the voltage '~Vc4', the leading edge will move to the arrow X in the figure.
It is phase modulated like this.

Therefore, each of the output signals Sl, 82, 83 . If we shape the pulse obtained by differentiating the leading edge of S4, we get (g
) as shown in the pulse position modulated wave (PPM wave) Pa
l~Ps4 will be obtained.

The pulse position modulated wave (PP
M wave) Ps1 to Ps4 are 1 In the example shown, each pulse Pal is placed at a time position that equally divides the time width of 5 μB into 5.
~Pa4 exists, so its period is 1 μs (pulse repetition period is IMHz).

Now, the pulse position modulated waves (PPM waves) P sL to P s4 shown in (g) of Fig. 4 are shown in (e) of Fig. 3.
3 horizontal scanning periods (3H) of the signal St as shown in
The four sample values sampled at 30/4 intervals during the period (approximately 190 μs) are compressed on the time axis within a time period of 5 μS. .

As is clear from the above description, the number of other signals to be multiplexed with respect to the multiplexed signal of the luminance signal and chrominance signal is M, and the period at which the other signals are multiplexed is When the period of the synchronization signal in the digital signal is 1'', the N sample values extracted from the other signals mentioned above during the time represented by MT are equal to one of the M synchronization signals. It is located within one or both of the first period corresponding to the synchronization signal period of the object and the second period corresponding to a predetermined period near the first period. As such, the time axis is compressed.

N sample values extracted from the other signal during the time represented by MT are present within a first period corresponding to the synchronization signal period of one of the M synchronization signals; or the above-mentioned first condition.
or the first period described above. The state in which the sawtooth wave voltage Vsa%1, which is supplied from the sawtooth wave generator SAv to the comparators COMPI to COMI'4, exists within the second two periods is This can be easily realized by appropriately setting the degree of slope of the sawtooth wave voltage on the time axis.

All of the M other signals are also as described above, each within a separate specific synchronization signal period, or within a period corresponding to a defined period in the vicinity of said synchronization signal, or within said period. Of course, time-base compression can be performed assuming that the time period is within the two periods.

By the way, since the pulse position modulated wave (PPM wave) P5l-Ps4 shown in (g) of Fig. 4 is a pulse and contains many high frequency components, it is difficult to use a recording medium with a narrow recording band. In some cases, it may not be possible to record it.

Therefore, each output signal SL, 52 . Based on S3.84, a; I 1m (rising edge) and trailing edge (falling edge) are each subjected to different phase modulation and have approximately symmetrical phases. a modulated signal, which has a first period corresponding to the synchronization signal period of one of the M synchronization signals, and a first period corresponding to the synchronization signal period of one of the M synchronization signals;
The second period corresponds to a predetermined period near the period , and the second period corresponds to the second period.

In this way, in the above example, the basic repetition frequency becomes 1/2, ie, 5QUKHz, and recording on a narrow frequency band recording medium becomes easy. In addition, in the case of a rectangular wave, the peak value of its fundamental wave component is 1.4 of the peak value of the rectangular wave.
Since the frequency is doubled, there are advantages in that there is little drop in the peak value due to frequency characteristics, and that the rounding of the waveform at the leading edge and trailing edge can be easily recovered by a limiter or the like.

In the device shown in FIG. 1, each of the comparators COMPI to C
Each output signal S appearing at the output side of OI'lP4 1.
Based on S2゜83, N4, N/2 rectangular waveforms whose leading edge (rising) and trailing edge (falling) are each subjected to different phase modulation and have approximately symmetry. The phase modulated signal is divided into a first period corresponding to the synchronization signal period of one of the M synchronization signals and a second period corresponding to a predetermined period near the first period. The circuit arrangement for making the inverters INVI and INV exist in either one period or both periods is
2 and NAND circuit Nl.

N2 and a negative logic OR circuit OR are used, and according to the circuit arrangement described above, the signals (c) to (f) in FIG. 4 that appear on the output side of each comparator COMPI to COMP4 are used. Each output signal 81 as shown in
82. Based on the information on each leading edge of S3 and 84, the leading edge (rising edge) and the trailing edge (falling edge) are subjected to different phase modulations, as shown in FIG. 4 (h). two (N72) phase modulated signals Ppml, Pp
m2 can be created and output.

In addition, the phase modulated signal 1'pml, P p
rn2 is a circuit other than the above-described circuit arrangement shown in FIG. 1, for example, the phase modulated signal Ppml.

Ppm2 can also be easily formed by a circuit arrangement constructed using a plurality of bistable multivibrators.

The two phase modulated signals Ppml and Ppm2 described above are as follows:
A pulse Phm is supplied as a gate pulse from a first pulse generator PGI to a gate circuit Gm,
The signal output from the gate circuit Gm is passed through the AC coupling means AC to remove the DC component from the signal (FIG. 4).
i) are supplied to the superimposition circuit MIX as signals Ppml'' and Ppm2'.

Input terminal 2 of signal processing circuit MSGm for signals to be multiplexed
The tracking reference signal St shared by the audio signal given to -m is subjected to signal processing in the signal processing circuit MSGm for signals to be multiplexed as described above, and
In the illustrated example, as described above, the signal located in the period corresponding to the horizontal synchronization signal period of the color TV video signal in the time-axis compressed state is processed by the superimposition circuit MIX for every 3 horizontal 7 scanning periods of the color TV video signal. It is superimposed on the period corresponding to the horizontal synchronization signal period.

Audio signals that are individually input to input terminals 2-1, 2-2 of other signals and supplied to the signal processing circuits MSGI and MSG2 for signals to be multiplexed are also multiplexed with the signal processing circuit MSGI for signals to be multiplexed. Power signal signal processing circuit MSG2
In each of the signal processing circuits MSGm for the signals to be multiplexed, the luminance signal and the chrominance signal are multiplexed in a time-base compressed state by undergoing signal processing similar to that received by the audio signal St. Added as a signal located within a period corresponding to the horizontal synchronization signal period of the signal, or within a period corresponding to a period with a determined proximity of the synchronization signal described above, or within both of the above periods (horizontal blanking period). Supplied to circuit ADD.

FIG. 5(a) is a waveform example of the output signal from the adder circuit ADD, and FIG. 5(b) is the output signal from the signal processing circuit MSG 1 of the signal to be multiplexed. A waveform example diagram of Ppl and the output signal Pp2 from the signal processing circuit MSG2 of the signal to be multiplexed, and (
C) shows signals Ppml', Ppm2'' (in the figure, Ppm
This figure shows an example of the waveform (indicated as ').

The signals illustrated in FIG. 5(a) are the signals ppi and Pp2 shown in FIG. 5(b) for the back porch portion of the horizontal synchronizing signal ph, that is, the signals to be multiplexed. The luminance signal shown in (,) in FIG. 5 is an example of a luminance signal in which the output signal Ppl from the processing circuit MSGI and the output signal PP2 from the signal processing circuit MSG2, which is a signal to be multiplexed, are added. As shown in the figure, when the signals Ppl and Pp2 are added to the white side of the back porch of the horizontal synchronization signal, when the signals Ppl and Pp2 are added within the horizontal synchronization signal, the playback screen An advantage is obtained that the screen is not disturbed due to the horizontal synchronization disturbance that may occur.

It should be noted that the signal Ppm'' shown in FIG.
The signal P pm' is located in a period corresponding to the period of the horizontal synchronizing signal ph in the signal shown in FIG. As mentioned above, after the signal shown in FIG. 5(a) is converted into a signal form of a frequency modulated wave,
Since the signal P pm' is added at IX and used as a tracking control signal, the presence of the signal P pm' will not cause disturbance in the horizontal synchronization of the signal shown in FIG. 5(a).

FIG. 6 shows that the output signals sent from the output terminal 3, that is, the three types of signals shown in (b) and (C) of FIG. The output signal in the form of a signal arranged as shown in FIG.
5 is an explanatory diagram of a recording trace pattern on a rotating recording medium in the case where the signal shown in FIG. 5(e) is used as a tracking reference signal by recording on a rotating recording medium, for example; In the figure, IH represents one horizontal scanning period, TP represents one trace interval, and Ppl,
Pp2°P p m ', etc. indicate the position of each horizontal synchronizing signal period in which one type of each of the three types of signals explained with reference to FIG. 5 is multiplexed.

As mentioned above, when the tracking reference signal is recorded on the recording medium, the recording traces formed adjacent to each other on the recording medium are as shown in FIG. The horizontal synchronizing signal periods in each trace are aligned in the direction orthogonal to the extending direction of the trace, as in the record trace pattern shown in Figure 1, and the adjacent record traces are aligned in the same manner! It is necessary to form a recording on a recording medium in such a manner that different types of signals are not lined up, but it is necessary to record and form a pattern of traces as described above on a recording medium. This can be easily achieved by appropriately determining the rotation speed of the recording medium (the number of horizontal synchronization signals that appear during one rotation of the recording medium is not a multiple of the above-mentioned M). (You just need to determine the number of rotations).

Now, if the signal recorded on the recording medium having the recording trace pattern shown in FIG. 6 is output from the output terminal 3 of the multiplexing device for multiple signals as shown in FIG. , the signal P p m ' created based on the output signal from the signal processing circuit MSGm of the signal to be multiplexed has a low basic repetition frequency of about 500 KHz, and this signal is directly recorded. Although the amount of crosstalk with respect to adjacent recording traces is relatively large, about -20 dB, the output signals Ppl from the signal processing circuits MSGI and MSG2 of the signals to be multiplexed,
Pp2 etc. exist during the back porch period of the horizontal synchronization signal of the multiplexed signal of the luminance signal and chrominance signal in a state where it is a frequency modulated wave by a carrier wave with a frequency of about 4 MHz. The amount of crosstalk to adjacent records is approximately -4
Therefore, tracking control operation can be improved by comparing the amounts of the above-mentioned signals Ppm' that crosstalk from recording traces on both sides of the recording trace currently being traced during playback operation. (Although the tracking reference signals described above have the same frequency, the tracking reference signals for each one-by-one recording trace are, as is clear from the recording trace pattern in Fig. 6,
Since the signal is shifted by IH, the signals of the recording traces on both sides of the recording trace currently being traced are used as the reference signal for time or position using the signal Ppm' with a high signal level reproduced from the recording trace currently being traced. By extracting Ppm' and using it as a tracking reference signal, the tracking control operation by the automatic tracking control system can be performed satisfactorily.

Note that three types of signals are multiplexed so as to be located at predetermined portions within the horizontal blanking period of the multiplexed signal of the luminance signal and the chrominance signal, namely, the signal Ppm' and the signal P.
Among the frequency modulated wave by pl and the frequency modulated wave by signal Pp2, the signal Ppm' and the other two types of signals Ppl,
Since the frequency modulated waves by Pp2 and the occupied frequency bands are different from each other, there is no negative effect on each other.
Therefore, the tracking reference signal and the two audio signals can coexist independently as being in mutually unrelated states. However, if the recording signal level of the signal P p m ', which is directly recorded as the state of the phase modulated signal, is too high, it will interfere with the frequency modulated wave signal component of that part, and the corresponding signal in the reproduced color video signal will be damaged. The signal level of the above-mentioned signal P pm' needs to be set appropriately because it degrades the S/N of the signal portion (corresponding signal portion within the horizontal blanking period).

In addition, as will be described later, the waveform shaping of the horizontal synchronization signal is performed as necessary in the playback system, so that the presence of a multiplexed signal in the horizontal synchronization signal part has an adverse effect on the playback of the color video signal. It is desirable to take care to ensure that this does not affect the environment.

The multiplexed composite signal formed as described above, that is, the multiplexed signal in which other signals are time-base compression multiplexed onto the synchronization signal part of the multiplexed signal of the luminance signal and the chrominance signal, is recorded in an appropriate manner. The multiplexed composite signal is recorded by the medium TR (a part or all of the signal is made into a frequency modulated wave, for example, so that the signal is in a signal form convenient for recording by the recording system. In the example, two signals Ppl and Pp2, which are time-axis compressed and multiplexed in a specific part within the horizontal blanking period of the luminance signal on which other signals are to be multiplexed, are combined with the luminance signal. (The signal is in the form of a frequency modulated wave).

Next, as described above, a first period corresponds to the synchronization signal period in the multiplexed signal of the luminance signal and the chrominance signal, and a second period corresponds to a predetermined period near the first period described above. A first aspect of the present invention relates to a signal restoration device for restoring an original signal from a multiplexed composite signal in which another signal is time-base compression multiplexed within one or both of the periods.
This will be explained with reference to the figures.

A first period corresponding to the synchronizing signal period in the multiplexed composite signal recorded by the recording system TR, that is, a multiplexed signal of a luminance signal and a chrominance signal, and a predetermined period near the above-mentioned first period. When a multiplexed signal in which another signal is time-base compression multiplexed within one or both of the periods corresponding to the second period is input to the input terminal 4 of the signal restoration bag. , the multiplexed composite signal is amplified by a preamplifier PrA and then applied to an FM demodulator DEM and a low-pass filter LPFr.

The FM demodulator DIM performs FM demodulation and sends the demodulated signal to the synchronization separation circuit 5EPr and the gate circuit Grl.

Gr2 and the synchronizing signal shaping circuit SSP. Also,
In the above-mentioned low-pass filter LPFr, the low-pass signal component in the output signal of the preamplifier PrA, for example, I MHz,
A low-pass converted carrier chrominance signal existing in the following frequency bands,
Extract the signal Ppm' etc. and send it to the amplitude demodulator DE
T, color signal processing circuit C0Lr, and gate circuit Ge
l, Ge2.

The color signal processing circuit C0Lr converts the low-pass conversion carrier color signal into a standard carrier color signal so that the output signal therefrom is used for reproducing the standard composite color video signal, and gate circuit G e 1
h Q e 2 is a gate circuit that extracts and provides a predetermined tracking reference signal crosstalked from the recording traces on both sides to the tracking control circuit TSC, and the tracking control circuit TSC does not perform the above-mentioned tracking reference signal. A tracking control signal is generated based on the magnitude of the tracking reference signal crosstalked from the recording traces on both sides supplied via the gate circuits Gel and Ge2, so that the reproducing element is tracking-controlled.

The horizontal synchronization signal separated from the luminance signal by the synchronization separation circuit 5EPr is sent to an amplitude demodulator DET, first and second pulse generators PGI r and PG2 r, and a synchronization signal shaping circuit SSP.
is supplied to. The amplitude demodulator DET, which is supplied with the output signal of the low-pass filter LPFr, extracts and detects the signal Ppm'' present in a specific part of the horizontal blanking period (in the illustrated example, the horizontal synchronizing signal period). , output pulse Ppm'
is applied to the first pulse generator PG1r.

The first pulse generator PG1r, which is supplied with the horizontal synchronization signal from the synchronization separation circuit SUP r and the output pulse p p m I from the amplitude demodulator DHT, receives the pulse output from the amplitude demodulator DET. Based on the time position of P pm', M-sequence pulses P hlr and P h2 correspond to the M-series pulses Phi to Phm shown in (c) to (e) of FIG. 2, respectively. r
...Generate Phmr.

In addition, in the second pulse generator PG2r described above, the N
Phase sampling pulses Ph1sl to Phls4, P
N-phase sampling pulses P corresponding to h2sl to Ph2s4 and Phm5l to Phm54, respectively
h1glr〜Ph1s4r, Ph2slr"Ph2g4
r, Phm5lr"Phm54r is generated.

R5GI to R3 indicated by the dashed-dotted line frame in FIG.
Gm is either a first period corresponding to a synchronizing signal period in a multiplexed signal of a luminance signal and a chrominance signal, or a second period corresponding to a predetermined period near the first period. This is a signal restoration circuit used to restore signals multiplexed in a time-axis compressed state within one period or both periods, and is a signal restoration circuit that is used to restore signals that are multiplexed in a time-axis compressed state within one period or both periods. Since all of them have the same configuration, in order to avoid the complexity of describing the drawings, only - signal restoration circuits R5Gm are shown in FIG. , it is limited to clarifying its specific configuration mode.

The signal restoration circuit R5GI has a first period corresponding to a horizontal synchronizing signal period of a multiplexed signal of a luminance signal and a chrominance signal, and a second period corresponding to a predetermined period near the first period. (within either one or both periods)
This is a signal restoration circuit that restores the phase modulated signal PPI shown in FIG. A phase modulated signal Ppl is applied to the restoration circuit R5GI via a gate circuit Grl that performs a gate operation using the pulse Ph1r supplied from the first pulse generator PG1r as a gate pulse.

Further, the signal restoration circuit R5G2 has a first period corresponding to a horizontal synchronization signal of a multiplexed signal of a luminance signal and a chrominance signal, and a second period corresponding to a predetermined period J around the first period. The phase modulated signal Pp in (a) of FIG. 5 is multiplexed in a time-axis compressed state within one or both of the periods (within the horizontal blanking period).
This signal restoration circuit R5G2 is a signal restoration circuit that restores the signal R5G2 to the original signal.This signal restoration circuit R5G2 includes a first pulse generator PG1r.
A quadrature modulation signal Pp2 is applied to the gate circuit Gr2 which performs a gate operation using the pulse Ph2r supplied from the gate circuit Gr2 as a gate pulse.

Furthermore, the signal restoration circuit R5GTO has a first period corresponding to a horizontal synchronization signal of a multiplexed signal of a luminance signal and a chrominance signal, and a second period corresponding to a predetermined period near the first period. (in Figure 5), which is multiplexed in a time-axis compressed state within one or both of the periods (within the horizontal blanking period)
C) is a signal restoration circuit that restores the phase modulated signal (1%P pnl') to the original signal, and this signal restoration circuit R5G
A phase modulated signal P is supplied to m via a gate circuit 1@Grya that performs a gate operation using the pulse Phmr supplied from the first pulse generator PG1r as a gate pulse.
p m ' is given.

Next, the specific configuration and operation of the signal restoration circuits R3GI to R3Gm described above will be explained using the signal restoration circuit R3G+e whose detailed configuration is shown in FIG. 1 as a representative example. Phase modulated signal P p via gate circuit Grm
In the signal restoration circuit R5G m to which m' is supplied, the amplitude variation of the phase modulated signal P pm' is removed by one limiter, and then the output signal of the limiter Lτ is
The pulse Phmr supplied from the first pulse generator PG1r is applied as a gate pulse to a gate circuit GTw that performs a gate operation.

From the gate circuit GTw described above, the circuit shown in FIG.
The phase modulated signal Ppm' (consisting of two waves, Ppml' and Ppm2', shown in c) and (i) of Fig. 4, etc.) The above two waves correspond to N/2 wave numbers. The phase modulated signal P as shown in FIG. 7(a), which is the same as
pm' is obtained, but this phase modulated signal P pm'
As mentioned above, each pulse P pml' , P
The leading edge and the trailing edge of pm2' are each phase-modulated by different retained sample value signals.

The aforementioned phase modulated signals P pII11' , P p
The pulse generating circuit PSG to which m2' is supplied differentially shapes the phase modulated signals P pml' and P pm2-' to generate phase modulated signals as shown in (C) to (f) in FIG. Modulation signal Ppml'.

Pulses P sir'' P s4r corresponding to the leading edge and trailing edge of P pm2' are generated and given as sampling pulses to the samplers SP1 to SP4.

Samplers SPI to SP4 have sawtooth wave generation @5Aii
A sawtooth wave voltage V as shown in FIG. 7(g) generated at r
sa%l is supplied, but the sawtooth wave voltage generated by the sawtooth wave generator SA%lr described above is the horizontal synchronizing signal number of the multiplexed signal of the luminance signal and the chrominance signal; 1
and a second period corresponding to a predetermined period near the first period, or a specific voltage Vs is reached with a certain slope within either or both of the periods. It's something like this.

Note that (h) in FIG. 7 is a horizontal synchronization signal.

Therefore, each sampler SPI to SP4 outputs a sawtooth wave voltage value at the time position of each sampling pulse as each sample value, and the voltage of each sample value is individually sent to each sampler SPI to SP4. A hold capacitor C1r is provided.

It is held by C2r, C3r, and C4r.

As described above, each hold capacitor C1r to C4r
The voltage values held in the samplers SPI to SP4 are changed by changing the pulses Psi r '' Ps4 r, which are supplied as sampling pulses to the samplers SPI to SP4, back and forth on the time axis. Furthermore, upon multiplexing the signals, each of the specific DC voltages (1 to v4) given from the DC voltage setting circuit DCVr is superimposed on each of the above voltage values.

Therefore, when restoring the multiplexed composite signal, the voltages held by the aforementioned hold capacitors C, 1r-C4r are converted to the aforementioned specific DC voltages v1 to v4 that were added during signal multiplexing. In the circuit arrangement shown in the first diagram, in order to subtract each of the specific voltages v1 to v4 mentioned above from the output voltage of each hold capacitor C1r to C4r, it is necessary to subtract each of the hold capacitors C1r to C4r. The output voltage of C4r is subtracted by 5UBI~SυB
This is done by giving 4.

In FIG. 1, DCV r is a DC voltage setting circuit, and this DC voltage setting circuit DCV r divides the reference voltage Vs into 5 equal parts (N+1 equal parts) using a resistor network.
l, V2. V3. V4 is generated, and each of the above-mentioned voltages is supplied to predetermined subtracters 5UBI to 5UB4, respectively.

So, in subtraction 11s UBI, hold capacitor C1
The DC voltage v1 generated by the DC voltage setting circuit DCV r is subtracted from the terminal voltage of r, and a restoration holding sample value signal as shown in FIG. 8(f) is output to the output side of the subtractor 5UBI. The subtracter 5UB2 subtracts the DC voltage v2 generated by the DC voltage setting circuit DCVr from the terminal voltage of the hold capacitor C2r.
The subtracter 5unt outputs the restoration holding sample value signal Vc2r as shown in (g) in FIG. The DC voltage v3 generated by the DCVr is subtracted to generate a restoration holding sample value signal Vc3r as shown in FIG. 8(h) on the output side of the subtracter 5UB3, and 5UB4 subtracts the DC voltage v4 generated by the DC voltage setting circuit DCVr from the terminal voltage of the hold capacitor C4r, and restores the output side of the subtractor 5UB4 as shown in (i) of FIG. A held sample value signal Vc4r is generated.

Each restored holding sample value signal Vcl r =Vcl r as shown in (f) to (i) of FIG. 8 outputted from each subtractor 5UBI to 5UB4 as described above is These correspond to the held sample value signals Vcl to Vc4 shown in (f) to (i) of FIG. 3, respectively.

Then, each restoration holding sample value signal outputted from each of the subtracters 5uot to 5UB4 described above is transmitted to each subtractor 5UBI to S
Samplers 5G1r to S provided individually for each υB4
Given to G4 r. Each sampler SGI r mentioned above
=SG4r contains a sampling signal (sampling pulse) P hmsl r ” as shown in (b) to (e) of FIG. 8, which is generated by the second pulse generator PG2r.
Each of the samplers SGI r "SG4 r
The low-pass filter LPFo connected to the output side of the 8th W
A signal with a waveform as shown in (j) of i is output.

The signal shown in (k) of FIG.
This is the output signal of Fo, which corresponds to the original signal St supplied to the input terminal 2-m as shown in FIG. 3(e).

The output signal from the low-pass filter LPFo is sent to the output terminal 7 via the process amplifier PCA r. In the process amplifier PCA r described above, de-emphasis is applied to signals and compensation for signal loss is performed in correspondence with pre-emphasis applied during signal multiplexing.

The explanation so far has been about the configuration and operation of the signal restoration circuit R5G+a, but other signal restoration circuits R5G1.
The signal restoration circuit R5G, whose configuration and operation of R5G2 are also described above,
! The signal restoration circuit R5GI, ll is similar to the case of ll.
The output terminals 5 and 6 of 5G2 have input terminals 2-1.2-2.
Restoration signals corresponding to the input audio signals are output. Further, a shaped synchronization signal is output to the output terminal 8 in the figure.

In the example described so far, the first period corresponding to the horizontal synchronization signal in the multiplexed signal of the luminance signal and the chrominance signal,
Three audio signals are to be multiplexed in a state in which the time axis is compressed within one or both of the predetermined periods near the first period and the second period. signals (in the example, one of the three audio signals is also used as a tracking reference signal), that is, three low frequency signals are used, and the luminance signal and chrominance signal are Sequential specific periods in the multiplexed signal (a first period corresponding to the horizontal synchronization signal;
The three signals described above are constant for one or both of the predetermined periods near the first period and the second period (horizontal blanking period). This is an example of a case where a signal in a time-axis compressed state is multiplexed with a multiplexed signal of a luminance signal and a chrominance signal in a distribution manner in which the signals are allocated in the repeating order of
In the example described above, the signals obtained by time-base compression of the two sound/voice signals are frequency modulated together with the luminance signal, and the audio signal that is also used as the tracking reference signal is time-base compressed. The signal remains in a state where it is multiplexed into a period corresponding to a period of a predetermined horizontal synchronization signal of the low-frequency conversion carrier color signal.

The three signals multiplexed into a multiplexed signal of a luminance signal and a chrominance signal are obtained by extracting a signal that is in the form of a time-axis compressed signal even in the multiplexed composite signal, and converting it into a multiplexed signal. Although it is used as a standard for discrimination of the three signals mentioned above, in practice, all the signals to be multiplexed are in the form of a frequency modulated wave. Doing so has the advantage that it becomes easier to improve the S/N of all signals to be multiplexed.

However, like the device described above, the first period corresponding to the sequential synchronization signal in the multiplexed signal of the luminance signal and the chrominance signal, and the predetermined period near the above-mentioned first period. A multiplexed composite signal is formed by positioning a plurality of other signals in the form of signals that are individually time-base compression multiplexed within one or both of the corresponding second periods. In this case, one of the signals to be multiplexed into a multiplexed signal of a luminance signal and a chrominance signal is in a signal form that remains compressed in time axis even in the multiplexed composite signal (the signal form of the phase modulated signal is If you leave it as the original signal),
When restoring the original signal from the multiplexed composite signal, the signal in the above signal form can be extracted and used as a reference for discrimination of the three signals, and the signal can also be used as a tracking reference signal. This makes it possible to provide a recording and reproducing system that facilitates high-density recording and reproducing through tracking control. As mentioned above, as a signal in the form of a signal whose time axis remains compressed in the multiplexed composite signal, S
/N is a signal that can be used even if it is bad.

For example, the tracking reference signal, cue signal,
Address signals and other signals may be used.

Also, the values of M and N mentioned above can be set arbitrarily, but when setting the values of M and N, take into consideration the S/N required for the signal, the frequency band of the signal, etc. For example, if the horizontal scanning frequency is 15.
When multiplexing other signals to a color video signal that follows the standard rv method such as 75Kilz,
If M is 3 and N is 4, the frequency band of the multiplexed signal is approximately 10 KHz according to the sampling theorem, and if M is 3 and N is 6, the frequency band of the multiplexed signal is approximately 10 KHz. According to the sampling theorem, the band is approximately 15 RIIz. Furthermore, if M is 3 and N is 8, the frequency band of the multiplexed signal is approximately 20 KHz according to the sampling theorem. According to the sampling theorem, the frequency band of the multiplexed signal is approximately 15Klz, but as the number of N increases, the allowable amount of phase shift in the modulated signal becomes smaller, and the S/N becomes smaller. It continues to deteriorate.

FIG. 9 shows an example configuration of a recording device when the multiplexed composite signal recording and reproducing method of the present invention is applied to a magnetic recording and reproducing method using a phase shift method (for details, refer to Japanese Patent Application Laid-Open No. 52-48918). This is a block diagram, and FIG. 10 shows a magnetic recording and reproducing method using a phase shift method for recording and reproducing the multiplexed composite signal of the present invention.
FIG. 4 is a block diagram showing an example configuration of a reproducing device when applied to a reproducing apparatus (see Japanese Patent Publication No. 48918).

The components within the broken line frame VH8r in FIG. 9 are the components of a recording device according to the above-mentioned well-known phase shift magnetic recording and reproducing method (see Japanese Patent Laid-Open No. 52-48918 for details), and The components within the broken line frame VH8p in FIG. 10 are the components of a reproducing apparatus according to the above-mentioned well-known phase shift magnetic recording and reproducing method (see Japanese Patent Laid-Open No. 52-48918 for details). 9,
Regarding the structure of the broken line frames VH8r and VH8P in FIG. 10, the details thereof will be omitted as they are limited to the extent necessary for explaining the recording and reproducing method of the multiplexed composite signal of the present invention.

In FIG. 9, numeral 10 is an input terminal for a video signal to be recorded.
A signal in which a luminance signal and a chrominance signal are band-sharing multiplexed within the band of the luminance signal is supplied, such as the composite color video signal of the system.

11 is a synchronous AGC circuit, 12.21 is a low-pass filter,
13゜17.20 is a mixer, 14.26 is a signal processing circuit for signals to be multiplexed (a circuit having the same configuration as the circuit specifically explained with reference to MSGm in Fig. 1), and 15 is a pre-emphasis system. 16 is an FM modulator, 18 is a bandpass filter, 19 is a burst emphasis circuit, 22 is a synchronization separation circuit, 23 is a frequency multiplication circuit, and 24 is a phase shift circuit.

25 is a 3.58 MHz oscillator, 27.28 is another signal to be multiplexed with the multiplexed signal of the luminance signal and color signal (
29 is a magnetic head, and in FIG. 10, 30 is a high-pass filter, 31 is a double limiter, and 32 is a magnetic head.
is an FM demodulator, 33.35 is a low-pass filter, 34°5
2. 57, 64, 65 are gate circuits, 36, 39, 40
．． 42 is a mixer, 37 is a burst de-emphasis circuit, 38 is an IH delay circuit, 43 is a 3.58MHz voltage controlled oscillator, 44 is an APC detection circuit, 45 is a 3.58M
Hz oscillator, 46 is a phase shifter, 47 is a same wave number multiplier, 4
8 is a synchronization separation circuit, 49 is an output terminal for a composite color video signal, 50 is a clamp pulse supply terminal, 51 is a clamp circuit, and 53.58 is a signal restoration circuit (described in detail with reference to R5Gm in Fig. 1). 54.41 is an audio signal output terminal, 55 is a gate circuit, 56 is an AGC circuit, 59, 66.67 is a rectification filter circuit, and 60.61 is a pulse position setting circuit. 62 and 63 are monostable multivibrators for pulse width setting, 68 is a differential amplifier, 69 is a tracking control circuit, and 70 is an actuator. - In the circuit arrangement within the broken line frame VH5I in the recording apparatus shown in FIG. 9, the composite color video signal (for example, NTSC signal) supplied to the input terminal
is separated into a luminance signal and a carrier color signal, and the luminance signal is frequency-modulated into a frequency-modulated wave, and the carrier color signal has a phase that changes by 90 degrees every horizontal scanning period. The frequency-modulated wave by the luminance signal and the low-pass converted carrier color signal whose phase changes by 90 degrees every horizontal scanning period are frequency-division multiplexed. On the other hand, in the circuit arrangement within the broken line frame VH8p in the reproducing apparatus shown in FIG.
The signals reproduced from the magnetic recording medium by the magnetic spatula 29, that is, the frequency modulated wave by the luminance signal and the low-frequency conversion carrier color signal whose phase changes by 90 degrees every scanning period. 1 Frequency division multiplexing and multiplexing signals are separated into a frequency modulated wave by a luminance signal and a low-pass conversion carrier color signal whose phase changes by 90 degrees every horizontal scanning period, Next, the frequency modulated wave by the luminance signal is frequency-demodulated to become a luminance signal, and - a low-pass conversion carrier color signal whose phase changes by 90 degrees every horizontal scanning period is converted into a luminance signal. As is well known, the operation is to restore the original carrier color signal, mix the above-mentioned luminance signal and carrier color signal to form a composite color video signal, and send it to the output terminal 49. .

In an embodiment of the multiplexed composite signal recording and reproducing method of the present invention shown in FIGS. The audio signal supplied to the input terminal 27 is said to be the audio signal supplied to the input terminal 28, and the audio signal supplied to the input terminal 27 is processed by the "signal processing circuit M for signals to be multiplexed" as already described with reference to FIG.
The phase modulated signal is compressed in time by being subjected to signal processing in the processing circuit 14 for signals to be multiplexed, which has a configuration similar to that of SGm J, and is positioned during the back porch period of the horizontal synchronizing pulse in the luminance signal. The audio signal that is converted into a signal and multiplexed into a luminance signal and supplied to the input terminal 28 is processed using a configuration similar to that of the "signal processing circuit MSGIIIJ for signals to be multiplexed" already described with reference to FIG. The signal to be multiplexed is processed in the signal processing circuit 26 to be multiplexed, thereby compressing the time axis and converting it into a phase modulated signal located during the period corresponding to the horizontal synchronizing pulse added to the luminance signal. The gamut-transformed carrier color signal is multiplexed.

FIG. 11 is a waveform diagram of the signals at each part in FIGS. 9 and 10, where (a,) in FIG. 11 is the composite color video signal Sa supplied to the input terminal 1o, and (b) in FIG. ) is the luminance signal sb, (c) in Fig. 11 is the phase modulated signal Sd to be added and multiplexed to the luminance signal, and (d) in Fig. 11 is the luminance shown in (b) in Fig. 11. A signal Sd in which the phase modulated signal shown in FIG. 11(C) is additionally multiplexed on the back porch of the horizontal synchronizing pulse of the signal sb.
, (e) in FIG. 11 is the frequency modulated wave Se by the signal Sd shown in (d) in FIG. 11, and (f) in FIG.
is the low-band converted carrier color signal Sf, and (g) in FIG. 11 is the phase modulated signal Sg to be added to the low-band converted carrier color signal Sf.
It is.

Signals S of each part shown in (a) to (g) in Fig. 11
As can be easily understood by looking at a = Sg, the luminance signal s is a state in which the composite color video signal ((a) in FIG. 11) is separated and the color burst signal cb is removed.
Adding the phase modulated signal Sc ((C) in FIG. 11) to the back porch portion of b ((B) in FIG. 11),
Horizontal synchronization in the low frequency conversion carrier color signal Sf ((a) in FIG. 11) which is separated from the composite color video signal ((a) in FIG. 11) and has the horizontal synchronization pulse ph removed. Even if phase modulated signals Sg are added to the corresponding periods of pulses, those phase modulated signals Sc
, Sf have no adverse effect on the signal.

Further, if the phase modulated signal Sc added to the back porch of the horizontal synchronization signal of the brightness signal sb is added to the brightness signal in such a manner that it protrudes toward the white side of the video signal, the above-mentioned The presence of the added phase modulated signal Sc
It is ensured that there is no adverse effect on horizontal synchronization operation, synchronous AGO operation, etc.

In the embodiments shown in FIGS. 9 and 10, the multiplexed signal of a luminance signal and a chrominance signal is a multiplexed signal of a luminance signal and a low frequency conversion carrier chrominance signal. , even if the chrominance signal to be multiplexed with the luminance signal is of another signal type, the phase modulated signal added to each of these signals may adversely affect each signal, or The period during which the phase modulated signal is added needs to be set to an appropriate portion within the horizontal blanking period so as not to adversely affect the circuit operation.

In the recording apparatus, the recording signal supplied from the mixer 17 to the magnetic head 29 consists of a frequency modulated wave Se shown in FIG. 11(e) and a low frequency modulated wave Se shown in FIG. 11(f). A multiplexed composite signal of the range-converted carrier color signal Sf and the phase modulated signal Sg shown in (g) in FIG. This is a multiplexed composite signal that has been multiplexed using a multiplexing method, and is recorded on the magnetic recording medium 71 by the magnetic head 29.

In the reproducing apparatus shown in FIG. 10, the reproduced signal reproduced from the magnetic recording medium 71 is the above-mentioned multiplexed composite signal, and the multiplexed composite signal is transmitted to the high-pass filter 3.
11(e) is extracted by the low-pass filter 35, and the signal Sf shown in FIG. 11(f) and the signal Se shown in FIG. 11(g) are extracted by the low-pass filter 35. The indicated signal Sg is extracted.

The signal Se extracted by the low-pass wave generator 3o is frequency demodulated by the frequency demodulator 32 to produce a signal Sd, that is, a phase modulated signal S is present in the backpaw of the horizontal synchronizing pulse ph of the luminance signal Sb. A brightness signal sb is extracted from this signal Sd by a gate circuit 34 and supplied to a mixer 40.

Further, the signal sb is set in the clamp circuit 51 so that the tip of its vertical synchronizing pulse Pv is pushed up to the pedestal level as shown in FIG. 12(C). That is, since the phase modulated signal existing during the three horizontal scanning periods of the vertical synchronizing pulse Pv of the signal sb is lower than the pedestal level, as shown in FIG. 12(a), This is because if the multiplexed signal is restored in this state, there is a drawback that buzz will occur in the reproduced audio. Figure 12 (b)
is a clamp pulse applied to the terminal 5o of the clamp circuit 51 described above.

The output signal from the clamp circuit 51 described above is the gate 1
- The phase modulated signal Sc present in the signal is extracted by the gate circuit 52 and given to the signal restoration circuit 53. The signal restoration circuit 53 described above, the signal restoration circuit 58 described later, etc. each have the same configuration as the signal restoration circuit R5Gm already described with reference to FIG.

The signal restored by the signal restoration circuit 53 is the audio signal supplied to the input terminal 27 of the recording device, and is sent to the output terminal 54.

On the other hand, the low-pass converted carrier color signal S extracted by the low-pass filter 35 from the multiplexed composite signal reproduced by the magnetic head 29
f and the phase modulated signal Sg, the low-pass conversion carrier color signal S
f is supplied to the mixer 36 via the gate circuit 55, and the phase modulated signal Sg is supplied to the AGC circuit.

The low-pass converted carrier color signal Sf is subjected to well-known signal processing using a phase shift method in the circuits after the mixer 36, and the carrier color signal is given to the mixer 40. A composite color video signal Sa is output.

The phase modulated signal Sg supplied to the AGC circuit 56 is then extracted by the gate circuit 57 and sent to the signal restoration circuit R5G.
(2) is applied to the rectifying/filtering circuit 59 and gate circuits 64 and 65.

The signal restoration circuit R5Gm restores the original signal from the phase modulated signal Sg and sends it to the output terminal 41. Further, the rectifying filter circuit 59 generates a trigger pulse from the above-mentioned phase modulated signal Sg, thereby triggering the monostable multivibrator 60, 61 for pulse position setting.

Monostable multivibrator 6 for pulse position setting described above
The output of 0.61 triggers the monostable multivibrator 62,63 for setting the pulse width. Gate pulses having a predetermined timing and pulse width are sent from the monostable multivibrators 62 and 63 for pulseless width setting to the gate circuit 64.
, 65.

In the monostable multivibrator 60, 61 for setting the pulse position and the monostable multivibrator 62, 63 for setting the pulse width, the gate circuit 64 is arranged horizontally with respect to the point of generation of the phase modulated signal Sg. Each unit is configured so that the gate can be opened at a time earlier by a scanning period, and gate circuit 65 can be opened at a time later by one horizontal scanning period with respect to the time point at which the phase modulated signal Sg is generated. The pulse 11 of the stable multivibrator can now be adjusted.

That is, since the phase modulated signal Sg is recorded every three horizontal scanning periods when it is used as a tracking reference signal, the magnetic head 29 extracts the phase modulated signal Sg from the recording trace it is tracing. At the time of reproduction, the tracking reference signals in the recording traces on both sides used for tracking control are the phase modulated signal S from the recording traces that the magnetic head 29 is tracing.
This is because the signal Ppm' exists one horizontal scanning period before and after the time when g is reproduced, and this point is also shown in the arrangement of the signal Ppm' in the record trace pattern shown in FIG. .

The gate circuits 64 and 65 provide the rectifying and filtering circuits 66 and 67 with phase modulated signals Sg picked up as crosstalk from the recording traces on both sides of the recording trace currently being traced by the magnetic head 29. The output signals from the 11 flow filtering circuits 66 and 67 are converted into a difference signal by a differential amplifier circuit 68, and the difference signal is converted into a tracking control signal by a tracking control circuit 69 and supplied to the actuator 7o, and the magnetic head 29
Tracking is controlled so that it always follows the record trace correctly.

The description of the multiplexed composite signal and the reproduction method of the present invention are independent of whether the recording medium is in the form of a tape, disk, cylinder, or sheet, and regardless of the principle of recording and reproduction. Needless to say, it can be implemented.

(Effects) As is clear from the above detailed explanation, the multiplexed composite signal recording and reproducing method of the present invention multiplexes at least one other signal onto a multiplexed signal of a luminance signal and a chrominance signal. A multiplexed composite signal recording and reproducing method in which other signals to be multiplexed to a multiplexed signal of a luminance signal and a chrominance signal are multiplied by M times the horizontal scanning period of the multiplexed signal of the luminance signal and the chrominance signal. By using two retained sample value signals in each of the N retained sample value signals, each of which is formed by individually retaining N sample value signals obtained by sampling with an N-phase sampling signal having a period of A phase modulated signal of N/2 wave numbers, in which the leading edge and the trailing edge are each individually phase modulated,
In the back porch portion of one horizontal synchronizing signal of every M horizontal synchronizing signals in the luminance signal described above, and in one horizontal synchronizing signal period of the period corresponding to every M horizontal synchronizing signal periods in the above-mentioned color signal. The corresponding period is made to exist within one or both of the periods, and the above-mentioned luminance signal is used as a frequency-modulated wave, and the frequency-modulated wave by the above-mentioned luminance signal and the chrominance signal existing in the low frequency range are A recording and reproducing method of a multiplexed composite signal in which a multiplexed composite signal formed by frequency division multiplexing is recorded on a recording medium, and a multiplexed signal of a luminance signal and a chrominance signal should be multiplexed. N sample value signals obtained by sampling other signals using an N-phase sampling signal having a period M times the horizontal scanning period of a multiplexed signal of a luminance signal and a chrominance signal are individually Phase modulation of N/2 wave numbers such that the leading edge and the trailing edge are individually phase modulated by two each of the N retained sample value signals held. The back porch portion of one horizontal sync signal of every M horizontal sync signals in the luminance signal described above and one horizontal sync signal in a period corresponding to every M horizontal sync signal period in the chrominance signal described above. The luminance signal is made to exist within one or both of the periods corresponding to the signal period, and the above-mentioned luminance signal is used as a frequency-modulated wave to exist in a lower frequency range than the frequency-modulated wave by the above-mentioned luminance signal. A luminance signal obtained by reproducing a multiplexed composite signal formed by frequency division multiplexing a chrominance signal from a recording medium and separating the chrominance signal from the frequency modulated wave by the luminance signal in the reproduced multiplexed composite signal. The back porch portion of one horizontal synchronizing signal of every M horizontal synchronizing signals in the luminance signal obtained by the above-mentioned frequency demodulation, and the back porch part of every M horizontal synchronizing signal of the above-mentioned chrominance signal. Each leading edge of a phase modulated signal of N/2 wave numbers which is configured to exist within one or both of the period corresponding to one horizontal synchronization signal period of the synchronization signal period; N restored sample value signals are obtained based on the information with the trailing edge, and the N restored sample value signals are sampled with a sampling signal of a predetermined sampling period to obtain N restored sample values. Recording of a multiplexed composite signal in which a restored IK0 of another signal multiplexed into a multiplexed signal of a luminance signal and a chrominance signal is obtained from the N restored sample value signals.

The reproduction method and other signals to be multiplexed into the multiplexed signal of the luminance signal and chrominance signal are determined by N, which has a period M times the horizontal scanning period of the multiplexed signal of the luminance signal and chrominance signal.
The leading edge and the trailing edge are separated by two retained sample value signals in the N retained sample value signals obtained by individually retaining the N sample value signals obtained by sampling with the phase sampling signal. are phase-modulated signals of N/2 wave numbers, each of which is phase-modulated individually.
Which of the back porch portion of one horizontal synchronizing signal of each horizontal synchronizing signal and the period corresponding to one horizontal synchronizing signal period of the period corresponding to every M horizontal synchronizing signal period in the above-mentioned color signal. At the same time, the above-described luminance signal is used as a frequency-modulated wave, and the frequency-modulated wave by the above-described luminance signal and the chrominance signal existing in the low range are frequency-division multiplexed. The constituent multiplexed composite signal is reproduced from a recording medium, and the frequency modulated wave due to the luminance signal obtained by separating the frequency modulated wave due to the luminance signal and the color signal in the reproduced multiplexed composite signal is The back porch portion of one horizontal synchronizing signal of every M horizontal synchronizing signals in the luminance signal obtained by the frequency demodulation described above, and one horizontal part of every M horizontal synchronizing signal period of the aforementioned color signal. Based on the information of the front and trailing edges of the phase modulated signal of N/2 wave numbers, which are arranged to exist within one or both of the period corresponding to the synchronization signal period. to obtain N restored sample value signals, sample the N restored sample value signals with a sampling signal of a predetermined sampling period to obtain N restored sample value signals, and obtain the N restored sample value signals.
The restored signal of the other signal multiplexed with the multiplexed signal of the luminance signal and the negative signal is obtained from the restored sample value signal, and the other signal multiplexed with the color signal is obtained. Used as a tracking reference signal during playback operation,
The recording and reproducing method of multiplexed composite signals, in which the reproducing element follows the recording trace under tracking control and the reproducing operation is performed, is beautiful, so the sequential synchronization of the multiplexed signal of luminance signal and chrominance signal is effective. Within one or both of the first period corresponding to the signal portion and the second period corresponding to a predetermined period near the first period, By placing a plurality of other signals in the form of axial compression multiplexed signals, it is possible to easily multiplex other signals into the multiplexed signal of the luminance signal and the chrominance signal, or It is possible to easily restore the signal to the original one, and it becomes possible to record and reproduce signals on multiple titanium channels without providing other tracks on the recording medium, improving the efficiency of use of the recording medium. Since a dedicated recording/reproducing element is not required, it becomes easy to downsize and reduce the cost of the device.

Furthermore, the circuit configuration b1 used for signal multiplexing and restoration does not require any special time constant circuits or analog circuits, so it is easy to integrate into an integrated circuit. This is because the circuit is often used both when multiplexing the i-signal and when restoring the signal. The configuration can be simplified.

In addition, a phase-modulated signal of N/2 wave numbers, which is phase-modulated separately for the leading edge, the trailing edge, and the force 3, is generated by each two held sample value signals among the N held sample value signals. ,
a first period corresponding to a synchronization signal of one of every M synchronization signals in a multiplexed signal of a luminance signal and a chrominance signal;
Multiplexing of a luminance signal and a chrominance signal is a means for forming the signal within one or both of the predetermined period near the first period and the second period corresponding to the second period. The slope portion is formed within one or both of the first period corresponding to the synchronization signal in the sync signal and the second period corresponding to a predetermined period near the first period. By comparing the voltages of one sawtooth wave signal with a held sample value signal in which a predetermined DC voltage is superimposed on each signal, the phase reference and phase of a rectangular wave signal that is approximately symmetrical in an unmodulated state are determined. The first period corresponding to the synchronizing signal period of one of the M synchronizing signals in the multiplexed signal of the luminance signal and the chrominance signal, and the first period corresponding to the synchronizing signal period of one of the M synchronizing signals, and '1
In a phase modulated signal of N/2 wave numbers formed within one or both of the predetermined period and the second period corresponding to the period near the period,
a first period corresponding to a synchronization signal in a multiplexed signal of a luminance signal and a chrominance signal as a means for obtaining N restoration-preserving sample value signals based on information of each leading edge and trailing edge; N/2 sawtooth wave signals having a slope part in one or both of the predetermined period near the first period and the second period corresponding to the predetermined period near the first period. Each pulse corresponding to the leading edge and each pulse corresponding to the trailing edge of the phase-modulated signal are sampled almost simultaneously and compared in phase, so that the N sampled values obtained can be held individually. In addition, by using a circuit arrangement configured to obtain a restored held sample value signal by subtracting a predetermined DC voltage value from each of the N held sample values, a device with a simple circuit configuration can be obtained. This makes it possible to easily realize multiplexing and restoration of multiple signals with good linearity.

Furthermore, when the multiplexed composite signal recording and reproducing method of the present invention is applied to a rotary head type VTR, the signal quality is not affected no matter how slow the running speed of the magnetic tape is. Wow, because it is less affected by uneven running speed.
There is also less flutter.

Furthermore, even after signal multiplexing, the occupied frequency band of the signal does not expand, making after-recording easy.
It is also easy to use by adding it to a conventional recording system.

Furthermore, if one of the signals to be multiplexed into a multiplexed signal of a luminance signal and a chrominance signal is in the form of a signal whose time axis remains compressed even in the multiplexed signal, it is possible to extract the original signal from the multiplexed signal. When restoring, it is possible to extract a signal in the above signal form and use it as a reference for discrimination between the three signals, and by using the signal as a tracking reference signal, it can be used as a reference signal for tracking control. A recording and reproducing system that facilitates high-density recording and reproducing can be provided.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a multiplexing and restoring device for multiple signals;
2 to 8, 11, and 12 are explanatory waveform diagrams, FIG. 9 is a recording device to which the multiplexed composite signal recording and reproducing method of the present invention is applied, and FIG. 10 is the present invention. This is a playback device to which the multiplexed composite signal recording and playback method of the invention is applied. 1.2.2-1.2-2.2-m, 4-input terminal, 3.
5-8...Output terminal, MSGI-NSGm...Signal processing circuit for signals to be multiplexed, R5GI-R5G■...
・Signal restoration port, path, SEP, 5IEPr-synchronization separation circuit, PGI, PG2. PGlr, PG2r...Pulse generator, SAv...Sawtooth wave generator, SGI~SG4,
5G1r=SG4r, SP1~SP4・=Sampler, C
1~C4, C1r~C4r... hold capacitor,
DCv...DC voltage generation circuit, DCVr...DC voltage setting circuit, ADDI~ADD4...Adder, 5UB
I-5UB4... Subtraction amount, PSG... Pulse generation circuit, 11... Synchronous AGC circuit, 12.21... Low pass filter, 13. 17, 20... Mixing amount, 14. 2
6... Signal processing circuit for signals to be multiplexed, 15...
Pre-emphasis circuit, 16...FM variable, 1B.
...Band pass filter, 19...Burst emphasis circuit, 22...Synchronization separation circuit, 23...Frequency multiplier circuit, 24...Phase shift circuit, 25...3.58MHz
oscillator, 27.28... input terminal for other signals to be multiplexed with the multiplexed signal of the luminance signal and color signal, 29.
...Magnetic head, 30...High pass filter, 31...
・Double limiter, 32...FM demodulation book, 33,3
5...Low pass filtering amount, 34,52°57.64,6
5... Gate circuit, 36, 39, 40, 42... Mixer, 37... Burst de-emphasis circuit, 38
...1■Delay circuit, 43 is 3.58MHz ・"Voltage controlled oscillator, 44-APC detection circuit, 45...3.5
8 MHz oscillator, 46... Phase shifter, 47... Frequency multiplier, 48... Synchronization separation circuit, 49... Composite color video signal output terminal, 50... Clamp pulse supply terminal, 51... Clamp circuit, 53.58...
Signal restoration circuit, 54.41... audio signal output terminal,
55... Gate circuit, 56... AGC circuit, 59,
66.67... Rectifier filter circuit, 60.61... Monostable multivibrator for pulse phase setting, 62,63
... Monostable multivibrator for pulse width setting, 6
8...Differential amplifier, 69...Tracking control circuit, 70...Actuator, Patent applicant: Japan Victor Co., Ltd. Agent, Patent attorney: Takao Imma ~ VH5F Bian 9, Tori 101A

Claims (1)

[Claims] 1. A method for recording and reproducing a multiplexed composite signal in which at least one other signal is multiplexed on a multiplexed signal of a luminance signal and a chrominance signal, which N obtained by sampling other signals to be multiplexed into the multiplexed signal using an N-phase sampling signal having a period M times the horizontal scanning period of the multiplexed signal of the luminance signal and the chrominance signal. N sample value signals each having a leading edge portion and a trailing edge portion individually phase modulated by two each of the N sample value signals held individually. /2 wavenumber phase modulated signals are used as the back porch portion of one horizontal synchronization signal of every M horizontal synchronization signals in the brightness signal and the horizontal synchronization signal of every M of the above color signals. The luminance signal is made to exist within one or both of the periods corresponding to the signal period and the period corresponding to one horizontal synchronization signal period, and the luminance signal is set as a frequency modulated wave. Recording and reproduction method 2 of a multiplexed composite signal in which a multiplexed composite signal formed by frequency-division multiplexing a frequency modulated wave and a color signal present in the low range is recorded on a recording medium, Luminance signal and color A method for recording and reproducing a multiplexed composite signal in which at least one other signal is multiplexed on a signal multiplexed with a luminance signal and a chrominance signal, the other signal being multiplexed on the multiplexed signal of a luminance signal and a chrominance signal. , individually holding N sample value signals obtained by sampling with N-phase sampling signals having a period M times the horizontal scanning period of the multiplexed signal of the luminance signal and the chrominance signal. A phase modulated signal of N/2 wave numbers whose leading edge and trailing edge are individually phase modulated by each two held sample value signals in the N held sample value signals, In the back porch portion of one horizontal synchronizing signal of every M horizontal synchronizing signals in the luminance signal described above, and in one horizontal synchronizing signal period of the period corresponding to every M horizontal synchronizing signal periods in the above-mentioned color signal. The above-mentioned luminance signal is made to exist within one or both of the corresponding periods, and the above-mentioned luminance signal is used as a frequency-modulated wave, and the frequency-modulated wave by the above-mentioned luminance signal and the color signal existing in the low range are A multiplexed composite signal formed by frequency division multiplexing is reproduced from a recording medium, and a luminance signal modulated by the luminance signal obtained by separating the frequency modulated wave by the luminance signal and the chrominance signal in the reproduced multiplexed composite signal. Frequency demodulation of the frequency modulated wave, and the back porch portion of one horizontal synchronization signal of every M horizontal synchronization signals in the luminance signal obtained by the frequency demodulation described above, and the horizontal synchronization signal every M in the color signal described above. Each leading edge and trailing edge of a phase modulated signal of N/2 wave numbers that is configured to exist within one or both of the periods corresponding to one horizontal synchronization signal period of the period. N restored sample value signals are obtained based on the information with the part, and the N restored sample value signals are sampled with a sampling signal of a predetermined sampling period to obtain N restored sample value signals. , the phase modulated signal is restored after adjusting the signal to the digital level so as to obtain the restored signal of the other signal multiplexed into the multiplexed signal of the luminance signal and the chrominance signal from the N restored sample value signals. A method 4 for recording and reproducing a multiplexed composite signal according to claim 2, wherein the multiplexed composite signal is obtained by multiplexing a multiplexed signal of a luminance signal and a chrominance signal with at least one other signal. A recording and reproducing method in which another signal to be multiplexed with a multiplexed signal of a luminance signal and a chrominance signal has a period M times the horizontal scanning period of the multiplexed signal of a luminance signal and a chrominance signal. The front edge and the rear edge of A phase modulated signal of N/2 wave numbers, each of which is phase modulated individually, is used as a back porch portion of each of M horizontal synchronization signals in the luminance signal. and a period corresponding to one horizontal synchronizing signal period of the periods corresponding to every M horizontal synchronizing signal periods in the color signal, and the above-mentioned Using the luminance signal as a frequency-modulated wave, a multiplexed composite signal constituted by frequency-division multiplexing the frequency-modulated wave by the luminance signal and a chrominance signal existing in a low frequency range is reproduced from a recording medium, and the reproduction thereof is performed. The frequency-modulated wave by the luminance signal obtained by separating the frequency-modulated wave by the luminance signal and the chrominance signal in the multiplexed composite signal obtained by Either or both of the back porch portion of one horizontal synchronizing signal of the horizontal synchronizing signal and the period corresponding to one horizontal synchronizing signal period of every M horizontal synchronizing signal periods in the color signal. Obtain N restoration-preserving sample value signals based on the information of the respective leading edges and trailing edges of the phase modulated signals of N/2 wave numbers that are made to exist within the period, and N restored sample value signals are sampled with a sampling signal of a predetermined sampling period to obtain N restored sample value signals, and a luminance signal and a chrominance signal are multiplexed from the N restored sample value signals. In addition to obtaining a restored signal of another signal multiplexed with the color signal, the other signal multiplexed with the color signal is used as a tracking reference signal during reproduction operation to control the reproduction element for tracking control. Recording of a multiplexed composite signal so that the playback operation follows the recording trace;
Reproduction method 5: a multiplexed composite signal recording and reproduction method according to claim 4, in which the audio signal multiplexed with the color signal is also used as the tracking reference signal.