JP2654773B2 - Television signal recording and playback system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a small-sized and inexpensive recording apparatus having a relatively narrow band,
The present invention relates to a method of recording and reproducing an NTSC or PAL signal as a composite signal as it is, and to a high-resolution monitor television recording that does not require much smoothness of movement.

[Conventional technology]

Generally, a small and inexpensive VT is used to record surveillance TV signals.
R, for example, VHS format-VTR or VHS format-VTR is transformed into intermittent recording, for example, a 24-hour recording on a 2-hour tape, a so-called time-lapse VTR, etc. It is composed of a luminance channel that separates the C signal, flattens the luminance signal (Y) up to about 2 MHz, and considerably reduces the response (10 dB or more) at 3 MHz, and a chromaticity channel that can pass the carrier chromaticity signal through about ± 500 kHz. ing.

Recently, the luminance band has been broadened by adopting high-band and S-VHS. However, the Y / C separation circuit is still required compared to the case where the NTSC signal is recorded as a composite signal. A decrease in resolution based on the cutoff characteristics of the Y circuit and the C circuit is basically unavoidable.

[Problem to be solved]

As described above, even with a TV signal with a resolution of 4.2 to 4.5 MHz, the resolution is generally reduced to about half by VTR recording. Even if an image is captured and recorded on a VTR, the criminal's face cannot often be identified due to lack of resolution.

The object of the present invention is to provide a recording / reproducing method that obtains a resolution of 4.5 MHz or more by processing and deforming the signal itself even when using the VHS method-VTR, thereby doubling the resolution of monitoring recording and the like. Is to do.

[Means for solving the problem]

In order to achieve the above object, the present invention divides a television signal to be transmitted into n channels into 1 / n subsamples for an arbitrary natural number n, and divides each of the divided frames in frame order. To be transmitted.

That is, the television signal recording / reproducing method of the present invention was configured to include the following means.

The television signal to be recorded is set to the upper limit frequency 2
Source sampling means for sampling at twice or more frequencies.

Sub-sampling means for sub-sampling each of a plurality of continuous samples of the output sample sequence of the source sampling means into a plurality of sub-samples and dividing the sample into a plurality of channel signals.

A means for rearranging a plurality of outputs of the sub-sampling means on a time axis, and recording the plurality of outputs on a recording device for each channel in a time-division manner for each scanning cycle of the television scanning method.

Means for sampling a reproduction signal from the recording device.

Means for controlling the sampling phase by PLL phase information obtained by sampling a color burst separated from the reproduction signal and then performing signal processing.

Inverting means for rearranging the resampling output in the same order as the source sampling output from the time-division format recorded in the recording device.

The sample sequence rearranged by the inverse conversion means is stored in a memory in a time-division unit with respect to the scanning cycle of the television scanning method, and the reading of the memory is performed by consecutive color subcarriers included in the read signal. Means to read.

Generally, surveillance records are recorded by dropping frames like a time-lapse VTR, and do not require recording of complete moving images. In such a case, one frame of the input signal to be recorded is divided into two frames, the bandwidth is reduced to one half, and the bandwidth is reduced to one half. By repeatedly sending out a wideband frame twice, there is no problem even if only 15 frames of information can be recorded per second.

In addition, in a method of transmitting a sub-sampled signal in an analog manner, as is well known to those skilled in the art, it is required that the re-sampling phase at the receiving end be exactly the same as the sub-sampling phase at the transmitting end. However, the present invention provides a simple and effective new method especially in this regard.

[Action]

According to the present invention, the NTSC television signal is
Without Y / C separation, the entire band can be recorded and reproduced using only the luminance channel such as VHS-VTR, so in applications that do not require much smoothness of motion, such as surveillance recording, etc. An inexpensive recording device is provided, and its practical effect is extremely large.

In addition, since so-called high-definition television signals having 1000 or more scanning lines can be recorded and reproduced in a frame-dropping manner, so-called "background pictures" mainly composed of still images and hi-fi music are provided at extremely low cost. It will also be.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 4 is an explanatory diagram of signal sampling according to the present invention, showing a case of 2-to-1 sub-sampling as an example. A television signal waveform to be recorded, indicated by a solid line, is sampled on the time axis at one cycle Ts of the Nyquist sampling frequency, and is subsampled and divided into two channels A and B every other sampling. If the resulting spectrum remains Nyquist sampling as shown in FIG. 5, the original TV signal component shown by the solid line in FIG. 5, ie, the baseband component, and the dotted lines above and below the sampling frequencies fs and fs. A side band component indicated by.
Needless to say, a similar high-order spectrum, that is, a repeat spectrum appears at a frequency that is an integral multiple of fs, but is omitted in FIG. As shown in Figure 4
In the signal spectrum of one channel, which is separated into two channels of A and B by sub-sampling, since the sampling is further performed at fs / 2, the frequency of fs / 2 becomes a new sampling frequency. The side band indicated by occurs, and fs and upper and lower side bands are second harmonics.

The important point here is that the subsampling phase differs by 180 degrees between both A and B channels, as is clear from Fig. 4, so the side band of fs / 2 also has a 180 degree phase difference between both A and B channels. It is different. Therefore, if the signals of both the A and B channels are transmitted using a general analog transmission path, and the signals resampled at the same phase as the preprocessing sampling (source sampling) are rearranged again into one sample sequence, , The upper and lower sidebands of fs / 2 cancel each other, and reproduces exactly the same signal as at the time of source sampling, including the baseband component, the upper and lower sidebands of fs, and the repetition spectrum at integer multiples of fs. You can do it.

It is self-evident that this is true not only for the two channels A and B, but also for any n channels, and the present invention makes it possible to use each of the n channels at a very low cost recently for home television reception. It uses a digital frame memory used for a video recorder and a home VTR to delay the required amount and transmit the frames in sequence. For this reason, the signal waveform in the recording device has the same shape as a general television waveform except that a folded signal is superimposed, which leads to a feature that a transmission line already existing in the world or a home VTR can be used as it is.

However, most home VTRs that have already become widespread, as described above, separate the NTSC signal into a luminance signal component and a chrominance signal component, record them according to their characteristics, and record them separately before output. The luminance and chromaticity signals are combined and sent out as before, but the luminance signal band of many devices is almost flat as shown by the solid line in FIG. 6, up to about 2 MHz, and gradually attenuates above that. And enters a cutoff band at about 3.2 to 3.3 MHz.

Therefore, the frequency at 50% amplitude of the upper limit of the pass band is about 2.
It is around 5MHz, so that the lower side band of fs / 2 at this frequency has a positional relationship to fold with respect to the base band.
Choose fs.

Then the sub-sampling frequency is about 5.3MHz, fs
Is around 10.7MHz. Since this fs almost coincides with the triple frequency of the NTSC color subcarrier, conversely, by selecting fs exactly three times the color subcarrier and performing coherent sampling, the color burst is used for sampling phase control and the whole is extremely It can be inexpensive.

This is the most remarkable point in the present invention.

The frequency components actually recorded and reproduced are the baseband component shown by the solid line in FIG. 6 and the VTR of the lower side wave of fs / 2.
Although only the part shown by the dotted line in the luminance channel band, the component shown by the dotted line is that the baseband component is attenuated at fs / 4 or more, while the component at fs / 4 or more is folded at the frequency fs / 4. This is a folded signal, and the frequency spreads in a lower direction.

Next, FIG. 1 and FIG.
A specific description will be given based on the embodiment of the signal processing system shown in FIG.

FIG. 1 is a block diagram of a pre-signal processing system for pre-processing a signal to be recorded prior to recording. The PAL method is also the same in principle. An example of sub-sampling will be described.

Input signal is sampled by sampling circuit 1
After being source-sampled at fs and sub-sampled by the A and B switches 2 driven at the frequency of fs / 2, the B signal is delayed by one frame in a frame memory (such as a digital frame memory) 3 and A, b switches to be switched are assembled into four frame sequential signals, and an ID pulse (identification pulse indicating whether the frame is an A sample sequence frame or a B sample sequence frame) indicating the contents of the assembly is further added to an ID addition circuit 5
And is supplied to the VTR input.

Next, the above description will be supplemented with reference to FIGS.

In FIG. 1-1, F1 indicates one frame having an input signal, and F2 indicates a subsequent frame.

The signal of the A sub-sample sequence in the F1 period passes through the a side of the switch 4 and is output as the VTR recording signal FA. F1 period B
The signal Fa of the sub-sample sequence is written to the frame memory 3 and read out one frame later to produce the one-frame delayed signal Fb of the B sub-sample sequence. Fb is output as a VTR recording signal FB through the b side of the switch 4.

The next frame recorded on the VTR is the frame following F2, and F1
Period information is recorded on the VTR as FA and FB.
You can see that all the information for the two periods has been lost, and that so-called piece dropping has occurred.

On the other hand, part of the input signal is synchronized and separated by the simultaneous separation circuit 6, and the composite synchronization signal (MS) and the burst gate pulse (B
F). 7 in the figure is a variable frequency oscillator (6 × fscVCO) having a frequency six times the color subcarrier frequency.
The oscillation output obtained by dividing the oscillation output by 2 by the first divide-by-2 circuit 8 is supplied to the sampling circuit 1, and the oscillation output obtained by dividing the oscillation output by the second divide-by-2 circuit 9 is the sub-sampling A. ,
Drive B switch 2. A part of the output of the second divide-by-2 circuit 9 is divided by 3 by the divide-by-3 circuit 10, and the 0th of the divide-by-3
Gate pulses corresponding to the first and second phases are supplied to the gate circuit 11 in the next stage. The gate circuit 11 is also supplied with a clock of fs / 2 and a burst gate pulse (BF). In this circuit, the clock of fs / 2 is gated by the triple time gate pulse from the divide-by-3 circuit 10. And then
A triple time pulse gated by the burst gate pulse is generated and sent to the # 0 circuit 12, # 1 circuit 13, and # 2 circuit 14. #
The circuits 0, # 1, and # 2 are one type of memory. A register is appropriate for a digital circuit, and a sample holder is appropriate for an analog circuit. The inputs of these three memories are sub-sampled signals, and a three-beat pulse from the gate circuit 11, which also emits a pulse during the burst period,
0, # 1 and # 2 circuits have three subsampled bursts
Each sample value in beat units is accumulated. Among the accumulated three-beat sample values of the burst, # 1 and # 2 are arithmetically averaged by an arithmetic averaging circuit 15 and subtracted by the value of # 0 by a subtraction circuit 16 to obtain a variable frequency oscillator (6 XfscVCO)
7 is a PLL control signal for controlling the frequency of the PLL.

As a result, the sample phase of # 0 always becomes stable when the instantaneous value of the sub-sampled burst sine wave coincides with the zero cross point where the value changes from positive to negative.

In other words, the source sample phase is controlled so that the instantaneous value of the subsampled burst sine wave coincides with a zero crossing point where the instantaneous value changes from positive to negative.

 This will be described with reference to FIGS. 7 and 8.

That is, FIG. 7 shows the source sampling of the burst portion and the A and B subsamples at the time of the preprocessing before recording. The solid line is the sine wave of the input burst signal, and the dotted line is the sine wave of the burst subsampled to the B channel. , And the B sample sequence is sequentially associated with # 0, # 1, and # 2.

FIG. 8 is a vector diagram illustrating the explanation of the sampling pulse phase control. In each of # 0, # 1, and # 2, A0 is a direct current component (the pedestal level of the television signal) with respect to the burst phase error φ. ), # 0 = A0 + sin (φ + π), # 1 = A0 + sin (φ−π /
3) Since # 2 = A0 + sin (φ + π / 3), subtracting # 0 from the arithmetic mean of # 1 and # 2 gives (# 1 + # 2) / 2− # 0 = (A0 + sin ( φ−π / 3) + A0 + sin (φ + π / 3)) / 2− (A0 + sin (φ + π)) = A0 + 0.5 · sin (φ) −A0 + sin (φ) = 1.5 · sin (φ) If the value is small, Sin (φ) ≒ φ holds, and a signal proportional to the phase error can be extracted regardless of A ₀ .
It can be used effectively as a PLL error signal (the PLL signal converges to the point where the error is minimized). It should be noted, however, that the burst sine wave differs in phase by π every 1H, so that the output of the 3 divider circuit 10 also shows the burst sine wave between the adjacent scanning lines based on the horizontal synchronization signal. The same is repeated with a phase shifted by half a cycle. In this respect, since the same operation as the PLL circuit of the general color receiver is performed, it is easily understood that the operation as the PLL phase control is also exactly the same as that of the general color receiver.

The state of the power-on condition of the divide-by-3 circuit 10 or the like is unknown, but it is only necessary that the phase of fs / 2 matches the sample phase in the pre-recording pre-processing and the post-reproduction post-processing. Therefore, even if the initial value of the divide-by-3 circuit 10 is deviated, the PLL loop described above must be subsampled in both the pre-recording pre-processing PLL and the post-reproduction post-processing PLL. This is the zero cross point of the burst sine wave from negative to positive.

The description returns to FIG. First, the switching / ID signal generation circuit 17 promises A as the source sample appearing next to the frame pulse detected from the composite synchronization signal (MS) and B as the next, and the composite synchronization signal and the second divide-by-2 signal. A, B from the output of circuit 9
Judge from where to start switch 2,
The A and B switch pulses are supplied to the A and B switches 2. Second
Is an ID signal, and a signal indicating the contents of a frame is converted into a zero signal (0-IRE unit of a television signal) for the a signal and a 1 signal for the b signal using, for example, the 1H period of the 20H of vertical blanking.
(80 to 100-IRE unit of TV signal) by superimposing the pulse, it becomes a synchronization signal of a, b frame cycle,
It is used for control to assemble the a and b frames after reproduction into one complete frame signal.

The reproduction signal from the VTR is subjected to the process shown in the block diagram of the post-reproduction signal processing system shown in FIG. 2, that is, the inverse conversion of the pre-signal processing system, to restore the original wideband signal. That is, the reproduced signal is resampled by the sampling circuit 18, and the signal delayed by one frame in the frame memory 19 and the signal without delay are combined into one by the A and B switches 20 driven at the frequency of fs / 2. Further, the frame is repeated twice by a frame repeat circuit 21 which repeatedly sends out a set frame during two frames in a frame sequence, and externally removes an unnecessary ID signal and sends it out to an output.

Next, the above description will be supplemented by FIGS. 2-1 and 2.

In FIG. 2A, the VTR reproduction signal FA is written as it is to the frame memory 19 as Fa, and is read out one frame later and sent to the A side of the switch 20 by a one-frame delay signal Fb (except for the one-frame delay signal Fb). Is equal to FA).

At the same time, the VTR playback signal FB is
Are supplied, and if these are combined into one by the switch 20, a restored wideband signal F1 is obtained.

However, in FIG. 2-1 it can be seen that the restored wideband signal lacks F0, F2, etc., and the frames are not continuous. The frame repeat circuit 21 compensates for this.

For clock generation and sample phase control, the same sampling circuit for pre-signal processing is used to make the re-sampling phase for post-processing the same. Therefore, the components denoted by the same reference numerals as those described above have the same configuration and operation as those of the prior signal processing system of FIG. 1, and the description of this portion is omitted to avoid repeating the same description.

What differs from the prior signal processing system is the ID detection by the ID detection circuit 22 and the control based on the detected result.

First, the frame-sequential ID pulse superimposed on the 20H is a frame to be stored in the frame memory 19 because it indicates the signal a when it is zero, and the frame repeat circuit 21 is a frame to repeatedly send out the previously sent frame. is there. When the signal is 1, the signal is a b signal.
Switching to 0 indicates that the original sampling sequence should be restored, and the frame repeater 21 sends out the output of the A and B switches 20 as it is, and at the same time prepares to send out the same signal in the next frame. To accumulate.

Another point is that in order to match the initial conditions of the A and B switches 20 with those of the pre-recording preprocessing, the A / B discriminating circuit 23 outputs the output fs / 2 of the second divide-by-2 circuit 9 at the frame start. The initial condition of the A, B switch control signal is set based on the agreement with the preprocessing system side that initially detects the polarity of the A signal.

Although omitted in FIG. 1 and FIG. 2, in order to apply the digital frame memory, A /
It goes without saying that a D / A converter is necessary for the D converter and output, but let's configure the other parts digitally,
It doesn't matter if it is analog. The important points are 1) source sampling, 2) division into two channels by half sub-sampling, and 3) recording of the divided two channels in frame order.

4) In order to make the resampled phase after reproduction exactly the same as the sample phase of the preprocessing, a PLL phase control signal is obtained from the sample output in both the preprocessing and the postprocessing.

That is the thing. As can be seen from this description, except for 3), it is easy to understand that 1), 2), and 4) can be configured in an analog manner, and in particular, according to the present invention, there is a feature that can also be configured in an analog form according to 4) Is done.

According to the signal processing described with reference to FIGS. 1 and 2, components of 0.75 times (approximately 2.7 MHz) or less of the frequency of the color subcarrier are transmitted as baseband components, and frequency components higher than that are transmitted as color subcarrier frequencies. It is folded at 0.75 times the high frequency component of the video signal in the direction of lower frequency, which is superimposed and transmitted as a folded signal by sub-sampling, so the 3.58 MHz carrier color signal is converted to about 1.8 MHz. Transmitted as a composite signal,
The transmission is performed as a single unit, so that there is no resolution degradation due to the separation and synthesis of Y and C, and the full band transmission determined by the television system is performed.

Next, an embodiment of a frame repeat circuit will be described with reference to FIG. 3, focusing on a method of reading color subcarriers in a continuous manner.

The sample sequence rearranged in the same order as the source samples by the A and B switches 20 in FIG. 2 and the result of ID detection are given as write data and a write command to the frame memory 24 in FIG. Of the frame memory 24 in accordance with the address generated by the write address generation circuit 25.
Is written to. Of course, the reading of the frame memory 24 cannot be stopped because the purpose is frame repeat. Therefore, it is a two-port memory in which writing and reading are performed simultaneously. The address switch 26 switches between a write address and a read address.

If the ID detection result is 1, no write command is issued, so
Repeated signals can be obtained only by continuing reading, but in practice there is a problem with the color frame, and the read address requires the following processing.

That is, according to the frequency interleave theory of the NTSC system,
The color subcarrier frequency is 45/2 of the horizontal scanning frequency
The number of subcarriers included in one horizontal scanning period is 227.5 cycles because it is selected to be five times, but one frame is 525 times the number of subcarriers and is still a fraction of 0.5 cycle of 119,437.5 cycles. For this reason, in general, in order to repeatedly send out a television signal for one frame, it is necessary to separate the luminance signal and the chromaticity signal once, to reverse the polarity of the chromaticity signal for each frame, and to add it to the luminance signal again. In a television system, there is no need to do so, and in the present invention, as shown in FIG. 3, the read address carry circuit 27 outputs a read address carry which is output by a flip-flop (FF) 28 after one frame is read. The problem is easily solved by counting to 1, returning the result to the read address generation circuit 27, and changing the read length.

This is because the number of subcarriers included in one read frame is an integer, and a certain frame is 119,47.5 so that the average number of repeated subcarriers is 119,437.5 cycles.
38. It is sufficient to repeat the two states of 119 and 437 in the next frame. The output of the flip-flop 28 in FIG. 3 serves to switch the read length of the read address circuit 27 (counter).

As a result, the subcarriers are continuous, but conversely, the luminance signal together with the synchronizing signal repeats a case where it advances and lags compared to the immediately preceding frame by 140 ns for each frame, so strictly speaking, it is a jitter, but fortunately The well-known AFC is used for the horizontal deflection circuit of monitors and receivers that are generally used.If the sudden phase change of 140 ns for each frame is also within the vertical blanking, 140n within the vertical blanking
AFC errors due to s phase changes are absorbed and nothing appears on the screen.

This signal has a problem under the Radio Law when it is broadcast by radio waves, but it has no problems if it is only displayed on a monitor in a closed circuit, and high-level and complex signals such as Y / C separation and chromaticity signal polarity inversion are available. It is extremely inexpensive due to its unnecessary use, and the feature of high resolution is very apparent.

In this manner, the read output of the frame memory 24 is converted into an analog signal by the D / A converter 29, and further, the sampling noise is removed by the low-pass filter (LPF) 30.
The repeat signal, that is, the wideband television signal is restored.

In the above, the case of the NTSC television signal has been described in detail as an example, but the same applies to the case of the PAL system. The strong and different point is that
The color subcarrier frequency is 4.43MHz, 8 times higher than NTSC
Since it is about 50 kHz higher, the luminance signal pass band of the VTR is 3.3 M
Hz is required. PAL signal has 1 color subcarrier
Since the phase is offset by / 4 cycle and there is also an offset in the frame direction, the phase differs by 180 degrees every 1H in the NTSC system. On the other hand, only the phase changes in the combination of the 8H period and the 8 frame period, and further, the frame repeat cycle is a four frame cycle of three 177,345 frames and one 177,344 frame so that the average number of cycles is 177,345.75. , The operation of the present invention works exactly the same.

In the above embodiment, the case where the color burst included in the color television signal itself is used to control the sampling phase and the sub-sampling phase has been described. However, the present invention is not limited to this. It is easily conceivable to configure by adding a signal.

For example, when the luminance signal band and the television signal band to be recorded cannot be selected on the basis of the color subcarrier frequency as in the embodiment and a different sampling / subsampling frequency is selected, a burst signal different from the original color burst is used. It is conceivable to add a new one, and from another viewpoint, depending on the group delay characteristics of the transmission line, a wider spectrum than gated sine waves and concentrated energy near the frequency of the sine waves , A square sine wave pulse or even a single pulse can be used.

In short, it is important to match the sampling phase of the pre-processing with the sampling phase of the post-processing. In the present invention, the point is to obtain the sampling phase control information from the result of the sub-sampling.

Next, when recording a high-definition television signal of 1125 systems on a VHS-VTR, using an 8-channel sub-sampling circuit, a band eight times the VHS-VTR band, that is, 2.6 MHz × 8 = 2
This is sufficient because a bandwidth of about 1 MHz is obtained. However, the difference in horizontal frequency is that two scanning lines of a high-definition television should correspond to one scanning line of the 525 system, and the signal waveform should be changed to the waveform of the 525 system for recording. As a result, all the effective scanning lines of the high-definition television are not recorded, and the upper and lower portions of the screen are slightly cut off, which is sufficient for practical use.

In the embodiment, the case of frame sequential has been described. However, the method is not limited to a frame as long as it is a repetitive element having a constant cycle, and a method of using line sequential using a line scan cycle and field sequential using a field cycle is also available. Needless to say, any periodicity of the television system can be used.

〔effect〕

As described above, based on the embodiments, as described in detail, the present invention is a small, inexpensive, commercially available, general-purpose television application in which the definition is more important even if the smoothness of the movement is somewhat absent, such as monitoring records. High-definition recording can be achieved simply by performing simple signal processing on VTRs using digital frame memories that are now widely used in home video equipment, so resolution improvement and problem solving in the security surveillance field, which had been particularly unsatisfactory in the past. The solution can be provided at very low cost.

[Brief description of the drawings]

FIG. 1 is a block diagram of a pre-signal processing system of the present invention, FIG. 2 is a block diagram of a post-signal processing system of the present invention, FIG. 3 is a block diagram showing one embodiment of a frame repeat circuit of the present invention, FIG. 4 is an explanatory diagram of signal sampling according to the present invention, FIG. 5 is an explanatory diagram of subsampling, FIG. 6 is an explanatory diagram of VTR response and selection of sampling frequency, and FIG. Explanatory drawing, eighth
The figure illustrates the sampling pulse phase control. FIG. 1-1 is a waveform chart showing the pre-signal processing method of the present invention, and FIG. 2-1 is a waveform chart showing the post-signal processing method of the present invention. 1 ... sampling circuit, 2 ... A, B switch, 3 ...
Frame memory, 4 a, b switch, 5 ID adding circuit, 6 synchronization separation circuit, 7 variable frequency oscillator (6 × fscVCO), 8 first frequency dividing circuit, 9 ... second
Divide-by-2 circuit, 10 divide-by-3 circuit, 11… gate circuit,
12: # 0 circuit, 13: # 1 circuit, 14: # 2 circuit, 15
... arithmetic averaging circuit, 16 ... subtraction circuit, 17 ... switching, ID signal generation circuit, 18 ... sampling circuit, 19 ... frame memory, 20 ... A, B switch, 21 ... frame repeat circuit, 22: IC detection circuit, 23: A, B discrimination circuit: 24: Frame memory, 25: Write address generation circuit, 26: Address switcher, 27: Read address generation circuit, 28: Flip-flop , 30 ... Low-pass filter (LPF).

Claims (1)

(57) [Claims] In a television signal recording / reproducing system for recording / reproducing a television signal to / from a recording device narrower than a required transmission band determined by the television system, a television signal to be recorded is twice or more the upper limit frequency thereof. Source sampling means for sampling at the above-mentioned frequency; and for each of a plurality of continuous samples of the output sample sequence of the source sampling means,
Sub-sampling means, and sub-sampling means for dividing the signals into a plurality of channels, and the outputs of the plurality of channels of the sub-sampling means are rearranged in a time-division manner on a time axis to form a television scanning system. Means for sending out frames in sequence and recording on a recording apparatus; means for sampling a reproduction signal from the recording apparatus; and a result obtained by sampling a color burst for the source sampling phase and the reproduction signal sampling phase. Means for obtaining and controlling PLL phase information from a signal; inverse conversion means for rearranging the sampling output in the same order as the output of the source sampling from the time division form recorded in the recording device; and the inverse conversion means. The sample sequence sorted by
Means for storing in a memory of a time division unit related to the scanning cycle of the television scanning method, and reading the memory so that color subcarriers included in the read signal are continuous. TV signal recording and playback system.