JPS59114987A - Color video signal recorder and reproducer - Google Patents

Abstract

PURPOSE:To ensure the reproduction with high quality for a color video signal recording/reproducing device by performing the intermittent recording every 2H with a gate pulse which has a 4H cycle and 2H pulse width and its phase advanced by 90 deg. every field and substituting the carrier chrominance signal thinned in a 2H period with the carrier chrominance signal in a 2H period immediately preceding the first carrier chrominance signal. CONSTITUTION:A gate pulse which has a 4H cycle and 2H pulse width and its phase advanced about 90 deg. every scan period of track is generated 12 in a record mode. The repetitive transmission of a low band conversion carrier signal is carried out and discontinued alternately every 2H period with use of said gate pulse. Then the transmitted low band conversion carrier chrominance signals are intermittently recorded every 2H period. In a reproduction mode a pulse given from a switching pulse generating circuit 33 is used to switch a switching circuit 31 to which the input and output signals of a delay circuit 32 are supplied. Thus the reproduced low band conversion carrier signals in which the input and output signals of the circuit 32 are synthesized in terms of time division are consecutively extracted through the circuit 31.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a color video signal recording device and a recording/reproducing device, and particularly relates to a color video signal recording device and a recording/reproducing device. The present invention relates to a device for recording and reproducing a color video signal so that even a recording and reproducing device using an azimuth recording and reproducing method without guard bands between tracks can obtain a high-quality reproduced output of a color image signal.

BACKGROUND ART Conventionally, as an example of recording and reproducing SECAM system color video signals using a helical scanning system magnetic recording and reproducing device (VTR), a SECAM system color video signal, a luminance signal, and a carrier color signal which is a frequency modulated wave are used. The luminance signal is frequency modulated, the carrier chrominance signal is frequency-converted to a lower band than the frequency-modulated luminance signal band, and then these frequency-modulated luminance signals and low-frequency converted carrier chrominance signals are The multiplexed signals are recorded by alternately forming tracks on a magnetic tape using, for example, two rotating heads having different azimuth angles.
Also, the multiplexed signal reproduced from the magnetic tape is separated into a frequency-modulated luminance signal and a low-frequency converted carrier chrominance signal, the frequency-modulated luminance signal is FM demodulated, and the low-frequency converted carrier chrominance signal is frequency-converted back to the original band. The recording and reproducing device rI1. It has been known.

In such a recording/reproducing device, a reproduced signal obtained by reproducing a single track with a rotating head includes adjacent tracks.
The previously recorded low frequency conversion carrier color signal is mixed in as a crawl talk component. This is because the luminance signal that is frequency modulated and distributed has a high frequency band, so it has a large azimuth loss and is hardly reproduced as cyclotalk, whereas the low frequency converted carrier chrominance signal has a low frequency band. Therefore, the azimuth loss is relatively small and is reproduced as l crosstalk.

However, generally, the horizontal synchronizing signals are arranged in a direction perpendicular to the longitudinal direction of the track (so-called H arrangement).
Since the low frequency converted carrier color signals are recorded so that the modulation signal components are adjacent to each other, the crosstalk of the low frequency converted carrier color signals from adjacent tracks is as follows. There is a correlation between the color video signal components at one field interval, and since the modulated signal components are recorded adjacent to each other, each reproduction low level of the reproduced track and the adjacent track is The frequencies of the range conversion carrier color signals are approximately the same.
Since the frequency of the beats generated by both signals is close to zero, there is almost no effect of crosstalk.

For example, if the drum diameter, tape width, drum rotation speed, and number of horizontal scanning lines are kept the same but only the tape running speed is lowered in order to record and play over a longer period of time, the result will be as shown in Figure 1. , resulting in a tape pattern in which horizontal synchronizing signal recording positions are not aligned in adjacent tracks. Here, the first
In the figure, IB, 2B, and 3 are formed sequentially from the right side to the left side.
R...

312B, 313R track t1.313R, 3
14B..., 624B, 625H tracks t2, I
B, 2R.

Track t3.3B,..., 312R, 313B.
313B.

Among the tracks t4, etc. of 314B, 315B, .
(horizontal scanning period), and no guard band is provided. In Fig. 1, R and B are the carrier color signals frequency-modulated by the color difference signal holes -Y and B-Y, respectively (here, the horizontal synchronization interval in which the low-frequency conversion signal is recorded) is shown. The numbers indicate the order of horizontal scanning lines in one frame.

Problems to be Solved by the Invention However, when reproducing a magnetic tape with a tape pattern that is not arranged in H as shown in FIG.
Because the carrier frequencies of the low frequency conversion carrier color signals of adjacent tracks are different, the beat frequency due to crosstalk from the adjacent tracks extends to the high frequency range, which appears as noise on the playback television screen. There was a problem with it being put away.

On the other hand, if a guard band is provided between adjacent tracks in order to eliminate crosstalk from adjacent tracks, the same recording and playback time as with an azimuth recording and playback system can be secured for magnetic tapes of the same length. In order to achieve this, the track width of the head must be made smaller, and for this purpose a guard band is provided to reduce the S/S/
On the other hand, if you try to secure the same S/N as a recording/reproducing device without a guard band, the recording density of the magnetic tape will decrease and the recording/reproducing time will become shorter. I end up. Also, if you install a guard band,
There was a problem with noise bars appearing on the screen during special playback.

Therefore, in the present invention, when converting the carrier color signal to a low frequency signal and recording it, a gate pulse with a period of 4H, a pulse width of 2H, and a phase advanced by 90° for each field is used to
The problem described above can be solved by recording intermittently every 2H and replacing the carrier color signal of the 2H period thinned out using a 2H delay circuit during playback with the carrier color signal of the 2H period of the allocated 2H period. It is an object of the present invention to provide a second video signal recording device and a recording/reproducing device that solve the problems.

Means for Solving the Problems In the present invention, the period is 4 horizontal scanning periods, the pulse width is equal to 2 horizontal scanning periods, and the pulse width is approximately 90 mm per track scanning period.
A gate pulse whose phase is advanced by ° is generated, and using the gate pulse, transmission and transmission cutoff of the low-pass conversion carrier color signal are repeated alternately every two horizontal scanning periods, and every two horizontal scanning periods. Intermittently records the low-frequency conversion carrier color signal transmitted every time, and when reproducing, the low-frequency conversion carrier color signal reproduced from the magnetic recording medium or the reproduced low-frequency conversion carrier color signal is frequency-converted.
(The reproduced carrier color signal, which has been returned to the original band, is supplied to a delay circuit that delays it by two horizontal scanning periods, and a switching pulse with the same signal waveform and phase as the gate pulse is generated, and this switching pulse ( A switch circuit to which the input signal and output signal of the delay circuit are supplied is switched using a metal wire, and the input signal and the output signal of the delay circuit are synthesized in time series from the switch circuit. A low frequency conversion carrier color signal or a reproduced carrier color signal is continuously extracted, and one embodiment thereof will be described below with reference to FIG. 2 and the subsequent drawings.

Embodiment FIG. 2 shows a lock system diagram of an embodiment of the recording system of the apparatus of the present invention. In the figure, SECAM input to input terminal 1
In the color video signal, the bandpass filter 2 separates the carrier chrominance signal into F-waves, and at the same time, the low-pass filter 3 separates the luminance signal into F-waves.

The carrier color signal is supplied to an equalizer circuit 4, where it is given a reverse bell characteristic, and then brought to a predetermined constant level by an automatic chroma control circuit (ACC circuit) 5, and then sent to a frequency converter 6. supplied to The frequency converter 6 performs frequency conversion to obtain the frequency of the difference between the frequency of the oscillator 7 and the carrier color signal from the ACC circuit 5, and converts the frequency of the carrier color signal to a lower frequency range (low frequency converted carrier color signal). Output. Here, a drum pulse synchronized with the rotational phase of the rotary head 17 (to be described later) of the oscillator 7#'i and whose phase is inverted every one track scanning period is supplied to the input terminal 8, and one track scanning period consists of the first oscillation. During the next one-track scanning period, it oscillates at a second oscillation frequency that is higher (or lower) than the first oscillation frequency by, for example, seven times the horizontal scanning frequency.

Therefore, if the rotary head 17 records one field worth of video signals to one track, the frequency converter 6 outputs a low frequency converted carrier color signal of the first frequency every one field period. And this is also one product (however, the transponder is the horizontal scanning frequency, - for example, 15.6251d(z)
A low-pass conversion carrier color signal having a second frequency that differs in frequency by the same amount as the second frequency is taken out alternately and in time series. This low frequency conversion carrier color signal is supplied to the gate circuit 10 via the amplifier 9'l1i-.

The gate pulse of the gate circuit 10 is generated by the gate pulse generation circuit 12 based on both the horizontal and vertical synchronization signals from the synchronization signal separation circuit 11 that separates and extracts both the horizontal and vertical synchronization signals in the luminance signal. do. That is, the gate pulse generation circuit 12 generates four types of gate pulses with a period of 4H and a symmetrical rectangular wave with a pulse width of 2H, each having a phase difference of 90°, as shown in FIGS. 3(4) to 3(D), respectively. However, during the same one field period, the negative gate pulse is output, and each time a vertical synchronization signal is received, the negative gate pulse, which is 90 degrees ahead of the previous gate pulse, is output. Repeat every one field period. That is, the gate pulses shown in FIGS. 3(A) to 3(D) are generated from the gate pulse generating circuit 12 every one field period.
Trunk) - (0) - (D) - (A) - . . . are output cyclically in the following order. This gate pulse is applied to the gate circuit 10. Note that the phase switching of the gate pulse and the switching pulse to be described later is performed at the track scanning period, and here, the case where one field is recorded and reproduced on one track is taken as an example.

The gate circuit 10 allows the low frequency conversion carrier color signal from the amplifier 9 to pass during the high level period of the gate pulse, and blocks the passage thereof during the low level period.

Therefore, during the 2H period formed by the gate circuit 10, 1M of the low frequency conversion carrier color signal is outputted, and during the next 2H period, no signal is outputted, which is alternately repeated. The low-pass converted carrier color signal intermittently taken out every 2H from the gate circuit 10 in this way is supplied to the mixing circuit 14 after unnecessary high frequency components are removed by the low-pass filter 13. Ru.

On the other hand, the luminance signal extracted from the low-pass filter 3 is supplied to a frequency modulator 15, where it is frequency modulated (FM) so that the low-pass converted carrier color signal also occupies a high frequency band. ) to be done. F taken out from the frequency modulator 15
After the M luminance signal is filtered by a high-pass filter 16 to remove unnecessary low frequency components mixed in the low-pass conversion carrier color signal band, it is supplied to a mixing circuit 14 where it is frequency-divided with the low-pass conversion carrier color signal. Multiplexed. This multiplexed signal is recorded on a cicada tape 18 by a rotating head 17.

The rotary head 17 is mounted on a rotating body such as a rotary drum, for example, by a 180 mm
Two rotating heads are mounted at equal intervals, with gaps having different azimuth angles, and as is well known, they are wound around the rotating body over an angular range of over 180°. The above-mentioned frequency division multiplexed signal is recorded by forming tracks inclined in the longitudinal direction on the magnetic tape 18 which is being run.

FIG. 4 shows an example of a tape pattern recorded by the apparatus of the present invention. In the figure, the same parts as in FIG. 1 are given the same reference numerals. As shown in FIG. 4, track 1. -18
There is no guard band between adjacent tracks, and each horizontal synchronization signal has a width of 0.7 between adjacent tracks.
It is recorded with a difference of 5H. Figure 4, like Figure 1, only shows how the low-frequency conversion carrier color signal is recorded, and the shaded section is the area in which the low-frequency conversion carrier color signal is not recorded. shows.

Next, this tape pattern will be explained in more detail. As an example, one field period during which the gate pulse shown in FIG. 3(A) is supplied to the gate circuit 10 corresponds to track 1. shown in FIG. 3A, the relationship between the waveform of the gate pulse shown in FIG. 3(A) and the horizontal scanning line number of the recorded video signal is as shown in FIG. 1
Since the video signal for one field is recorded on the track of a book, when the first rotary head finishes recording the video signal for the first field on the track tl, the second rotary head At the same time that the video signal of the second field begins to be recorded on the track t2, the gate pulse changes to the third gate pulse shown in (B) in the figure whose phase is advanced by 90 degrees from the gate pulse shown in (B). Switch.

Here, since 1 field is 312.5H, the 3rd field is 312.5H.
The wedge 1 relationship between the waveform of the gate pulse shown in FIG. 5(B) and the horizontal scanning line number of the video signal recorded on track t2 is as shown in FIG. 5(B). The signal is recorded, but the low frequency conversion carrier color signals of the 314th and 315th H are not recorded, and the next 316th I.

The 317th H low frequency conversion carrier color signal is recorded, and the following 2H
Recording stop and recording are repeated alternately each time.

At the same time that the video signal of the third field starts to be recorded on the sitrack t3 by the first rotation-1-rad, the gate pulse is the same as the gate pulse whose phase is advanced by 90 degrees from the gate pulse shown in FIG. 3(B). Switching to the gate pulse shown in Figure (0). The relationship between the waveform of the gate pulse shown in FIG. 3 (0) and the horizontal scanning line number of the video signal recorded on track t3 is as shown in FIG. 5 (0). Since the gate pulse is at a low level during IH, the low-frequency conversion carrier color signal during that IH period is not recorded, and the next second
2H is recorded every 2H from the Hth track t3.
0.5H in the first half of the last 313th H is not recorded.

Next, the video signal of the fourth field starts to be recorded on the track t4 by the second rotary head, but at the same time as the recording starts, the phase of the gate pulse leads by 90 degrees from the gate pulse shown in FIG. 3(0). Then, the gate pulse is switched to the one shown in FIG. 3(D). The relationship between the waveform of the gate pulse shown in FIG. 3(D) and the horizontal scanning line number of the video signal recorded on track t4 is as shown in FIG.
Since the gate pulse is at a high level during the first 0 and 5 H periods of the field and the next IH period, the second half of the 313th H and the 314th H low frequency conversion carrier color signal are recorded in B1.
The next 2H (315th) 1st, 316th H) are not recorded, the low frequency conversion transport color signal of the next 2H (317th and 318th H) is recorded, and thereafter recording is stopped every 2H. The recording is repeated alternately.

Further, the video signal of the next fifth field is recorded on the track t6 by the first rotary head, and the video signal of the next sixth field is recorded on the track t6 by the second rotary head.
6 is recorded. When recording the video signal of the 5th field, the gate pulse has a phase of 9 from that shown in ) in Figure 3.
The gate pulse is switched to the gate pulse shown in (A) in the same figure which has advanced by 0°, and when the video signal of the 6th field is recorded, the gate pulse shown in (B) in the same figure is changed.
Switches to the gate pulse shown in . The relationship between the horizontal scanning line number of the video signal of the fifth field and the gate pulse waveform shown in Fig. 3 (4) used when recording that signal is as shown in Fig. 5 (E). , the gate pulse becomes low level in the first 2H of the fifth field. Furthermore, the relationship between the horizontal scanning line number of the video signal of the sixth field and the gate pulse waveform shown in FIG. 3(B) used when recording that signal is as shown in FIG. At the first 0.5H of the field, Gate Nox becomes low level. In addition, for convenience of illustration, Figure 5 (1,) to (F) are the same figures), ψ), (0), Φ), (E)
The illustration is made so that the time relationship matches only between and (F).

Thereafter, in the same manner as above, a low-pass conversion carrier color signal is generated using a gate pulse, which is a symmetrical rectangular wave with a period of 4H and a pulse width of 2H, and whose phase is advanced by 90° every field period, as shown in FIG. < Recorded intermittently every 2H. The intermittent recording is performed at a cycle of eight tracks. As a result, as shown in FIG. 4, there is a recording section in which the low frequency converted carrier color signal recorded on one track is lined up next to the low frequency converted carrier color signal of the next recorded adjacent track. teeth,
Only the last 0.25H (that is, 16 μs) of the low-frequency conversion carrier color signal recorded on one track is recorded, and furthermore, the low-frequency conversion carrier color signals are adjacent to each other between adjacent tracks. The recorded sections only occur intermittently every 3H. As a result, as will be described later, it is possible to practically eliminate the adverse effect on the reproduced image due to the low frequency conversion carrier color signal reproduced from the adjacent track as crosstalk.

Next, to explain the reproduction system of the apparatus of the present invention, FIG. 6 shows a block diagram of an embodiment of the reproduction system of the apparatus of the present invention. In the same figure, magnetic tapes having the tape pattern shown in FIG.
In FIG. 6, two rotary heads are represented by one rotary head 19 and shown as 7. ), and the candlestick number division multiplexed signal obtained by the reproduction is passed through a preamplifier 20 to a low-pass filter 21 and a high-pass filter 22.
are supplied respectively. The reproduced FM luminance signal extracted by the high-pass filter 22 is supplied to an FM post-modulator 23, where it is FM demodulated into a reproduced luminance signal, which is then supplied to a mixing circuit 24.

On the other hand, the low-pass filter 21 selects the frequency of the low-pass converted carrier color signal being reproduced and frequency-divided decoding and extracts it.

This reproduced low-pass converted carrier color signal is supplied to a limiter 25, where the AM fluctuation component is removed, and then supplied to a frequency converter 27 via an amplifier 26, where the oscillation frequency of the oscillator 28 and the frequency are converted. be done. As mentioned above, the carrier wave frequency of the low-pass conversion carrier color signal is equal to oscillation frequency for each field! The oscillator 28 is activated by a drum pulse from the input terminal 29 so as to be shifted by −fH.
oscillation frequency is controlled. As a result, the reproduced carrier color signal returned to the original SECAM carrier color signal band is intermittently taken out every 2H from the frequency converter 27.

This reproduced carrier color signal is applied to the terminal a of the switch circuit 31 through the amplifier 30, and is applied to the terminal a of the switch circuit 31 through the entire 2H delay circuit 32. This switch circuit 31 is switched and controlled by a gate pulsing/pulsing pulse taken out from the gate pulse generating circuit 12. The switching pulse generation circuit 33 is supplied with an output phase error signal of a phase comparator 35 that compares the phases of the switching pulse and an output signal of a detector 34 that detects the envelope of the reproduced low-pass conversion carrier color signal, and operates a gate. It is configured to perform phase shift detection. The switching pulse generation circuit 33 also generates a horizontal synchronization signal separated from the reproduced luminance signal by a synchronization signal separation circuit 36, and a drum pulse with a two-field period synchronized with the rotational phase of the rotary head 19 from the input terminal 37. are supplied, respectively, to generate a switching pulse with a pulse width of 2H and a period of 4H, and a switching pulse whose phase is advanced by 90'' every field period.

The switch circuit 31 is the switching pulse described above. 2, i v <yvXAMtl&f+a K*ifi i kl
It is configured to selectively output the output reproduced carrier color signal of m@630' and selectively output the output delayed reproduced carrier color signal of the low level period #'i2H delay circuit 32 of the switching pulse. Here, as is well known, the carrier color signal of the 8ECAM system consists of a first frequency modulated wave frequency modulated by the color difference signal B-Y, and a second frequency modulated wave frequency modulated by the color difference signal B-Y. and are line sequential signals synthesized alternately and in time series for each IH, so the color information of the carrier color signals at 2H intervals is similar. Therefore, the color information of the output delayed reproduced carrier color signal of the 2H delay circuit 32 and the reproduced carrier color signal 2H before the output delayed reproduced carrier color signal is similar to each other.

The switch circuit 31 is the reproduction carrier color signal or the missing 2H
Since the period is controlled by switching to selectively output the output delayed reproduced carrier color signal of the 2H delay circuit 32, the output end of the switch circuit 31 receives the 2H recorded on the track.
During the reproduction period of the low-pass converted carrier color signal, the reproduced carrier color signal is taken out from the amplifier 30, and during the reproduction of the 2H period in which no low-pass converted carrier color signal is recorded, the 2H delay circuit 3
A reproduction carrier color signal of similar color information from 2H periods before is replaced and extracted. The reproduced carrier color signal extracted from the switch circuit 31 is supplied to an equalizer circuit 38, where it is given a frequency characteristic (Shinkai Pel characteristic) complementary to that of the equalizer circuit 4 of the recording system, and then sent to the mixing circuit 24. and is multiplexed with the reproduced luminance signal. Accordingly, a reproduced color video signal conforming to the SECAM system is taken out from the mixing circuit 24 and outputted to the output terminal 39.

The equalizer circuits 4 and 38 are provided to improve the accuracy of phase shift detection by the phase comparator 35 during reproduction.

Next, crosstalk from adjacent tracks during the above-mentioned playback will be explained. As mentioned above, among the frequency modulated luminance signal and the low frequency converted carrier chrominance signal recorded on adjacent tracks, the frequency modulated luminance signal having a high frequency has a large azimuth loss, so it is hardly reproduced as crosstalk. On the other hand, the low-frequency conversion carrier color signal has a relatively small azimuth loss at low frequencies, so it is reproduced as crosstalk. When the tracking scan is performed accurately, the low frequency conversion carrier color signal of the adjacent track is hardly reproduced as crosstalk.

On the other hand, in order to suitably obtain a special playback image, if the rotary head 19 has a track width wider than the recording track width (if the rotary head 19 is a so-called Phi wide head), during normal playback, When tracking scanning is performed accurately (the head scanning position relationship at this time is
Even in the cases shown in FIGS. I and II), since adjacent tracks are scanned at the same time, low-frequency conversion carrier color signals from adjacent tracks are reproduced as crosstalk.

However, in this case, in order to record and form tracks of the same width, the surface positions of the bottom ends of the two wide heads are aligned, so the wide heads scan the track (hereinafter referred to as the "main track"). (In the case of the tape pattern in Fig. 4, as shown in 1.11, the wide head spans the entire width of the main track and a part of the adjacent track to be played next to the main track.) ). Therefore, the low frequency conversion carrier color signal reproduced as crosstalk from the adjacent track is the one recorded in the adjacent track to be reproduced next to the main track.

Therefore, if the reproduced horizontal synchronization signal and the reproduced low-frequency conversion carrier color signal shown in Figure 7) are reproduced from the main track, the low-frequency conversion carrier color signal reproduced from the adjacent track as crosstalk. These waveforms are reproduced from 0.25H period (=16 μS) before the end of the IH period of the main track reproduction signal, as shown in FIG. However, Figure 7).

As can be seen from φ), for the low frequency converted carrier color signal CR1 reproduced from the main track,
The period in which the low-frequency conversion carrier color signal CB, which is reproduced as crosstalk at every interval, is mixed is 0.25H (=16μs
), excluding the horizontal sync pulse width and a part of the back porch, it is only about 8.8 μs, and when the tape pattern shown in Fig. 1 is played back, the cross-streak period is 0.75 μs.
The time can be significantly reduced compared to H (=48 μs).

Of the approximately 88 μs crosstalk-containing section shown above, considering the non-transmission period of the carrier color signal specified by the 8ECAM method for the main track raw signal, the burst section, and the overscan of the telepigimin receiver, etc. The crosstalk-containing section that appears is about 2 μs, and appears only in a width of about 2 μs from the right edge of the screen. Moreover, this crosstalk component of approximately 2 μs is caused by the frequency interleaving effect, since the low frequency conversion carrier color signals of adjacent tracks are recorded with their FM carrier frequencies shifted by 2 fH from each other as described above. , there is almost no visual problem.

Furthermore, according to the present disaster example, the period during which the burst signal part CB of the low frequency converted carrier color signal CR1 reproduced from the main track is reproduced; as shown in FIG. 7 (5), however, Since this corresponds to a period in which the low frequency conversion carrier color signal is not recorded in the adjacent track, no crosstalk component is mixed into the burst signal portion CB, and there is no adverse effect on the playback screen.

Note that if only - of the gate pulses t shown in Figure 3) to (D) supplied to the gate circuit 10 is always used and the phase of the gate pulse is not switched for each field, The low-frequency conversion carrier color signal is intermittently recorded every 2H, and the low-frequency conversion carrier color signal recording area of adjacent recording racks.

If the intervals are 0.75H adjacent to each other, a crosstalk component will appear on the left side of the screen, which is extremely inconvenient.On the other hand, when switching to a gate pulse whose phase is delayed by 90° every field, This is undesirable because the burst portion of the reproduced low-pass conversion carrier color signal of the main track is affected by the crosstalk component.

On the other hand, when the gate pulse is switched so as to advance the phase by 90° for each field as in the present invention, the adverse effect on the screen due to crosstalk interference can be minimized as described above.

Application Examples Note that the device of the present invention is limited to the above embodiments.
For example, the input signal to the gate pulse generation circuit 120 is synchronized with the rotational phase of the rotary head 17 instead of the vertical synchronization signal. MIS drum pulses may be used, a trench gate circuit 10 may be provided in the front stage of the frequency converter 6, and the entire low-pass filter 21 consisting of a switch circuit 31 and a 2H delay circuit 32 may further convert the frequency. Vessel 27
It may also be provided in the middle of the transmission path leading to. Furthermore, in the recording system, the carrier frequencies of the low-frequency converted carrier color signals recorded on adjacent tracks are shifted by 1 fH from each other, but the carrier frequencies of the low-frequency converted carrier color signals recorded on one track of the adjacent tracks are different from each other. Even if the phase is switched by 180° for each IH, the frequency interleaving effect can be similarly obtained.

First, the present invention can be applied to recording and reproducing not only i9EtEAM color video signals but also NTSC and PAL color video signals.

With this grant, as proposed by the present applicant in Japanese Patent Publication No. 56-9073 and Japanese Patent Publication No. 55-32273, the phase of the low frequency conversion carrier color signal is changed to 90" for each IH on one of the adjacent recording tracks. On the other hand, in the case of the N'TSC method, the phase of the low-frequency conversion carrier color signal is recorded by moving it in the opposite direction to the adjacent track by 90- for each 1I (N'TSC method). In addition, in the case of the PAL system, recording is performed without a phase shift, so there is no need to take countermeasures against loss talk.Therefore, #j1 applied to color video signals of the present invention'J&:NT'sc system and PAL system, the recording system and The phase shifting means is not required in both the reproduction system, and a simple and inexpensive circuit configuration can be achieved.

Effects As described above, according to the present invention, a low frequency conversion carrier color signal is intermittently recorded every 2H using a gate pulse, and the phase of the gate pulse is changed by 90' every one track scanning period. Since the recording interval of each 2H of the low-frequency conversion carrier color signal recorded on two adjacent tracks is recorded in steps of . It is possible to almost prevent bad shadows on the screen due to the low-frequency conversion carrier color signal reproduced as crosstalk from 1 rack, and moreover, in a tape pattern that is not aligned with H, it is recorded on the later of the two adjacent tracks. Since the low frequency conversion carrier color signal portion immediately after the horizontal synchronization signal of the track is adjacent to the low frequency conversion carrier color signal portion immediately before the horizontal synchronization signal of the previously recorded track, the previously recorded track Even when using a wide head that simultaneously scans the full width of a track and a portion of a later recorded track, the negative effects of crosstalk can be minimized without any negative impact on the burst signal portion, and the Since the recorded low-pass conversion carrier color signals are recorded in a frequency relationship that is interleaved with each other, there is almost no visual problem with the adverse effects on the screen caused by the crosstalk components that are reproduced and mixed in only the above-mentioned small section. Furthermore, since there is no need to provide a siggard band due to the azimuth recording and playback method, there is no need to narrow the width of the recording track, and therefore the required 8/N of the playback signal can be secured. The input/output signals (reproduction carrier color signal or reproduction low-frequency conversion carrier color signal) are alternately switched and outputted every fi2H by a switching pulse having the same waveform and the same phase switching as the gate pulse. Therefore, it has the advantage that the carrier color signal can be continuously extracted by replacing it with the carrier color signal 2H before without missing the carrier color signal.

[Brief explanation of drawings]

FIG. 1 is a diagram schematically showing the recording positional relationship of the conveyance color signal in an example when recording a SECAM system color video signal, FIG. 2 is a block system diagram showing an embodiment of the recording system of the present invention, and FIG. Figures (A) to φ) respectively show gate pulse waveforms, and Figure 4 schematically shows an example of the recording positional relationship of SECAM color system color video signals and color signals recorded in the apparatus of the present invention. Figures 5 (4) to (F) are diagrams showing the relationship between the gate pulse waveform and the horizontal scanning line number of the video signal when recording one track, respectively, and Figure 6 shows the reproduction system of the present invention. Block system diagram showing one embodiment, FIG. 7 (4
) and (B) are the reproduction times of the low frequency converted carrier color signal and horizontal synchronizing signal waveforms reproduced from the main track and the low frequency converted carrier color signal and horizontal synchronizing signal waveforms reproduced from the adjacent track in the apparatus of the present invention, respectively. FIG. 3 is a diagram showing an example of a relationship. 1-...Color image signal input terminal, 2...Band filter, 3,13.21...Low-pass filter, 6,27...
・Constant number converter, 8, 29.37...Drum pulse input terminal, 10...Gate circuit, 11.36...Synchronization signal separation circuit, 12...Gate pulse generation circuit, 16
゜22...High-pass filter, 18...Magnetic tape, 3
1... Switch circuit, 32... 2H delay circuit, 33
... switching pulse generation circuit, 34 ... detector, 35 ... phase comparator, 39 ... reproduced color video signal output terminal. Figure 5

Claims (3)

[Claims] (1) A carrier color signal separated from a standard color video signal is frequency-converted to a low frequency band, and the low-frequency converted carrier color signal is transferred onto a magnetic recording medium by sequentially using a plurality of rotating heads with different azimuth angles. In a device that records on formed tracks, the period is 4 horizontal scanning periods, the pulse width is equal to 2 horizontal scanning periods, and the pulse width is approximately 9 times per track scanning period.
A gate pulse whose phase is advanced by 0° is generated, and using the gate pulse, the transmission and transmission cutoff of the low-pass conversion carrier color signal are repeated alternately every two horizontal scanning periods, A color video signal recording device characterized by intermittently recording the transmitted low frequency conversion carrier color (number i) every other time. (2) The color video signal recording device according to claim 1, wherein the low frequency conversion carrier color signals recorded on two adjacent tracks are recorded in a frequency relationship that is frequency interleaved. . (3) The carrier color signal separated from the standard color video signal is frequency-converted to a low frequency band, and the low-frequency converted carrier color signal is formed on a magnetic recording medium by sequentially using multiple rotating heads with different azimuth angles. In a recording and reproducing device that records on and reproduces a track recorded on a track, a gate whose period is equal to 4 horizontal scanning periods, whose pulse width is equal to 2 horizontal scanning periods, and whose phase is advanced by approximately 90° for each track scanning period. A pulse is generated, and the gate pulse is used to alternately transmit and cut off the transmission of the low frequency conversion carrier color signal every two horizontal scanning periods, and the transmitted low frequency signal is transmitted every two horizontal scanning periods. A converted carrier color signal is intermittently recorded, and when reproduced, the low frequency converted carrier color signal reproduced from the magnetic recording medium or the reproduced low frequency transformed carrier color signal is frequency-converted and returned to the original band. In addition to supplying the reproduced carrier color signal to a delay circuit that delays the signal by two horizontal scanning periods, a switching pulse having the same signal waveform and phase as the gate pulse is generated, and the switching pulse is used to control the input and output signals of the delay circuit. and the input signal and the output signal of the delay circuit are sequentially synthesized by the switching circuit and the input signal and the output signal of the delay circuit, respectively, to continuously generate a reproduced low-pass conversion carrier color signal or a reproduced carrier color signal. A color video signal recording and reproducing device characterized in that the color video signal can be extracted in a specific manner.