JPS58172096A - Recording and reproducing device of chroma signal - Google Patents

Abstract

PURPOSE:To improve the balance between picture quality and video recording time, to multiplex an FM sound signal between a chroma signal and an FM luminance signal, and to improve a chroma S/N ratio, by using a circuit which converts an SECAM chroma signal into a balance-modulated signal and a comb line filter. CONSTITUTION:A composite video signal impressed to an input terminal terminal 15 is separated into a luminance and a chroma signal by an LPF16 and a BPF18. After this chroma signal is controlled by an AGC circuit 19 to a constant level, the signal is converted into, for example, a PAL chroma signal by the circuit 20 which converts the FM chroma signal into the balance-modulated chroma signal. The PAL chroma signal is supplied to a dynamic emphasizing circuit 21 to emphasize its small-amplitude signal and then a recording chroma signal processing circuit 22 performs processing such as burst emphasis and frequency conversion. Further, the comb line filter 33 and a dynamic deemphasizing circuit 34 are inserted into a reproducing circuit to suppress a crosstalk signal from an adjacent track.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ID recording and reproducing device for SECAM color video signals, and in particular to a helical scan type video tape recorder using a rotating cylinder with a cylinder diameter of about 40 mm and using metal tape or vapor-deposited tape. The present invention relates to a color signal recording/reproducing circuit.

The conventional recording method for SEC and 4M color video signals is JP-A-54-57531. Japanese Patent Publication No. 54-5765
As described in ``1'', the chroma signal was converted into a low frequency signal as an FM signal, multiplexed with the FM luminance signal, and recorded on the tape. This recording method uses a cylinder with a diameter of approximately 4 OrpglL.

When adopted in a two-head helical scan type video tape recorder having a tape width of about f3 mm, the following problems arise.

(1) The balance between recording time and image quality is poor.

(It is difficult to multiplex record 21 audio signals onto a video track.

(3) It is difficult to improve the S/Ny2 of the chroma signal.

Hereinafter, conventional problems will be explained in detail using drawings.

FIG. 1 is a signal spectrum diagram recorded on a tape in the VH5 system SECAM video tape recorder described in Japanese Patent Application Laid-Open No. 54-37531.

Figure 1/2 shows the tape recording pattern. In the VH5 system, the SECAM frequency of 441 dHz is counted down to 1/4, and the center frequency is 11 MHz as shown in Figure 1.
2 FM signal and converted to FM ny:4 degree decoding 1vC
, multiplexed and recorded on tape. Since the chroma signal requires a band of approximately ±500 kHz, the exclusive band of chroma is 16 to 14 MHz. On the other hand, FM brightness signal 1
The allocation is determined by the bandwidth obtained from the tape and head systems, and in the VH5 system, the values are shown in Figure 2. The bandwidth of the reproduced luminance signal in the signal arrangement shown in Fig. 1 is (gray carrier frequency - chroma 4M cD upper limit frequency ti') Tona W), ultimately t55-14x175ME
You will only be able to get x. The bandwidth of the luminance signal is 5M
Hz or more is required, and 2.75 MHz is insufficient and has the disadvantage that an FM audio signal cannot be multiplexed between chroma signal spectrum 2 and FM luminance signal spectrum 1.

That is, when a chroma signal is recorded on a tape in the form of an FM signal, it is difficult to remove crosstalk signals from adjacent tracks using an electric circuit, and in the VH5 system, crosstalk is suppressed by the cross-azimuth effect. For this reason, the frequency a of the chroma signal is set to be high, which causes a lack of bandwidth for the luminance signal. Also, the FM chroma signal has stronger sideband energy than the AM chroma signal,
This makes it difficult to multiplex another signal between the chroma signal and the luminance signal.

Recording a chroma signal in the form of an FM signal greatly limits the tape pattern shown in FIG. 26. In other words, it is necessary to arrange the chroma signals in order to make the effects of crosstalk signals from adjacent tracks less noticeable. Chroma arrangement means that the reproduced track 3 and the adjacent tracks 4 and 5 are arranged not only in H arrangement as shown in FIG. 2, but also in the relationship of :, RY, B-1'. αH9, which can reach the same level as Chroma, is the 4th
As shown in the figure, there are only nT values, and it is not possible to balance image quality and recording time.

The object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, to allow the relationship between image quality and recording time to be selected arbitrarily1, to be able to multiplex an FM audio signal between the chroma signal and the FM luminance signal, and to further An object of the present invention is to provide a recording and reproducing device for SECAM video signals that can improve chroma S/N.

In the present invention, the SEC and 4M chroma signals are single-stage demodulated, converted into balanced modulation signals, and then subjected to burst emphasis and dynamic emphasis, and then multiplexed into an FM luminance signal together with a tracking control pilot signal and an FM audio signal, and then recorded on a tape. The width of the tape shown in Figure 4 is approximately 8 mm, and the drum diameter is approximately 40 mm.

Metal tape, tape summary 10μll11. Cassette size 95-X62r1""x14--h L Oa
The characteristics of Kwohara l -9 are shown below. αH is slow,
Only those that allow trick plays such as stills and searches are selected.

As can be seen from the m4 diagram, when recording chroma signals as FM, chroma alignment is required, and it is not possible to choose between αXS and TS, and there is a poor balance between recording time and S/N.

There are two types of necessary SIN values, one of which requires a dubbing margin and is preferably about S/N = 48 dB. That is, - the S/N of the same recording and reproduction is 48
dB, and when this reproduced signal is recorded and reproduced again, the S/N is approximately 45 dB.

This kind of usage is possible when combined with a TV camera.
This is standard usage.

Another way of thinking is to assume kl S/N = about 45 dB,
This is a case where dubbing margin is not considered. This kind of usage is standard usage in recording TV programs, etc.

Therefore, as can be seen from Figure 4, if you follow the first idea, α = 2.0, if you follow the idea of recording time 90 minutes 9m2, α2 = 10, and the recording time will be 180 minutes. Balance will also improve.

FIG. 5 is a diagram showing a tape pattern diagram when αN=2.0 or αx=to and the two video heads 1t12 shown in FIG. 3 are installed at exactly 1800,
FIG. 6 is a block diagram of a 5zcAx video signal recording and reproducing circuit suitable for the tape pattern of FIG. 5, which is an embodiment of the present invention.

There are two possible concrete plans for demodulating the FM chroma flaw signal and converting it into a balanced modulated chroma signal.

Plan W41 modulates the line-sequential signal as it is, and Plan 2 converts it into a PAL chroma signal. ia
The first option has the advantage that it is not necessary to convert line sequential signals to simultaneous signals, and the circuit becomes simpler. Although the second option requires a more complicated circuit, it is possible to
It has the advantage of being easy to record signals on one VTR.

In any case, the repetition period of the converted chroma signal is 2H (Hi-horizontal scanning period, P/IL).

Both SECAMs are 64μJF #C).

Therefore, in the guard panless cross azimuth system, the necessary conditions to be satisfied for the chroma signal frequency fte' recorded on the tape after low frequency conversion are as follows.

fLc = (-±100) fH; integer fH; horizontal synchronization frequency (15, 625KEz) If the chroma signal frequency of the main track is jtc and the chroma signal frequency of the adjacent track is ftc', then Δ= l fr, c
-ftc'l =→f's shoulder; integer including zero As an example that satisfies the above conditions, the following can be considered.

There are various ways to set Δ to −7fx. For example, the chroma signal written by a head with the first azimuth angle is set to the (478) f frequency, without phase shift, and when the second azimuth angle is The chroma signal detected by the head held is 1
The phase is 9o for each H.

To delay or advance. When the phase shift is delayed, the chroma signal frequency written on the tape when performing such a phase shifter is fLC = ((47 - 100') -
-z) fH, Δ = 7fH If the phase shift is advanced, then fcr, = ((47 - urn + -) fH, Δ = -zfH, and the required condition for the chroma signal frequency to be equal to fi. Become.

The spectrum of the chroma signal described above has a band of o, '22 to 122 mix, as shown in 2 in FIG.

Therefore, the pilot signal 39 (for example, 101JJz, 117KHz) is placed in the lower frequency band of Kuromi H.
, 147KHz, 165KHz), and an FM audio signal 40 can also be recorded between the chroma signal 2 and the FM luminance signal 1.The FM audio signal 40 has an occupied bandwidth of ±50 to Since sufficient sound quality can be ensured at ±100kHz, the center frequency is t4MHz.
.

If the occupied bandwidth is ±100 KHz, the upper limit frequency of the FM audio signal that limits the reproduction band of the luminance signal is t5AfH.
z, which can be smaller than 16KEz in FIG.

A feature of the tape pattern shown in FIG. 5 is that there is no H alignment or chroma alignment. The problem caused by the lack of chroma alignment can be solved by converting the FM chroma signal into a balanced modulation chroma signal, but the problem caused by the lack of H alignment is mainly caused by burst signal interference leaking from the adjacent track 4.5. Therefore, special measures are required for this purpose.

In FIG. 5, the mark * indicates, for example, when FM chroma polarization is converted to a balanced modulation chroma signal, R-Y1! The blank indicates the period during which the B-4 signal is omitted. Also, when the FM chroma scratch signal is converted to PAL chroma erasure, the * mark indicates the n period in which the (R-4') signal is written, and the unmarked indicates the n period in which the -(R-1') signal is written. shows.

Suppression of burst signal interference will be explained below using FIG.

The composite video signal is applied to input terminal 15 and LPF 1
6. The BPF 18 separates the signal into a luminance signal and a chroma signal. The separated chroma signal is stabilized in level by a 4CC circuit 19, and then sent to a circuit 20 for converting the FM chroma signal into a balanced modulation chroma signal, for example, P
, is converted into a 4L chroma signal. After a small amplitude signal is emphasized by a dynamic emphasis circuit 21, the PAL chroma signal is processed by a recording chroma signal processing circuit 22 such as burst emphasis and frequency conversion.
Ru.

Reference numeral 41 in FIG. 8 shows the input/output characteristics of an embodiment of the dynamic emphasis circuit 21, which is -20 to -50d.
A small m signal of about B is emphasized by about F3 dB.

Frequency %1 characteristic of dynamic emphasis circuit 21 (%
The characteristics that can be considered as input level dependence are shown in Figure 9.
There are three ways shown in FIG. 10 and FIG. 11.

Figure 1/49 is a method of emphasizing only the sideband energy of the modulated chroma signal, and is used to suppress beats caused by the pilot signal s9 multiplexed on the chroma signal 2 and the FM audio signal 40 leaking into the chroma signal. Effective. Emphasis that does not depend on the input signal level can be achieved with an FM chroma signal, but dynamic emphasis, in which the amount of emphasis increases as the input level decreases, cannot be applied with an FM chroma signal.

Therefore, when recording the pilot signal 59 and the FM audio signal 4Q in frequency multiplexing at a position adjacent to the chroma signal 2 at the frequency 11, if you want to ensure sufficient ROMA image quality,
It is essential to convert the FM chroma signal into a balanced modulation chroma signal and to apply dynamic emphasis.

The emphasis characteristic shown in Fig. 10 shows that the burst signal leaking from the l1II contact is displayed on the playback screen.
This characteristic is designed to both reduce noise and suppress interference such as the aforementioned pilot signal.

'/J411 is an emphasis characteristic mainly designed to suppress burst signals coming in from adjacent tracks, and is characterized by having no frequency characteristics at all. #
! Although the characteristics shown in FIG. 11 are most effective in suppressing burst signals, they do not sufficiently suppress interference caused by pilot signals and the like.

The degree of interference caused by the intrusion of burst signals from adjacent tracks is noticeable when the tracks are not lined up in H as shown in Figure 5.
The dynamic emphasis shown in Fig. m9, Fig. 10, and Fig. 11 is essential, and Fig. 10 and Fig. 11 are particularly desirable. However, when considering both multiple recording countermeasures such as pilot signals and countermeasures for not performing H alignment, the wJ9 diagram may be used.
FM luminance polarization 1 generated in the recording luminance signal processing circuit 17
is added and amplified by the recording amplifier 25 and then transferred to the rotary transformer 2.
The video is recorded on the video tape 8 by the video head 1112 via the video tape 6 .

In the recording amplifier 25, a signal obtained by converting the audio signal applied to the audio input terminal s6 into an FM sound signal by the recording audio processing circuit 25 and a signal from the pilot signal generation circuit 24 are also added and amplified.

Next, the operation during reproduction shown in FIG. 6 will be explained. video head 1
The signal reproduced at t12 is sent to the rotary transformer 26. Reproduction audio processing circuits 50 . Reproduction luminance signal processing circuit 51, reproduction pilot signal processing circuit 5
2. audio.

Luminance and pilot signal processing are the same as before, so we will not explain them here.

The reproduced chroma signal processing circuit s1 includes a frequency conversion circuit for returning the chroma signal converted to a low frequency band to a 4.4 chroma signal, a burst de-emphasis circuit, and the like. The output signal of circuit 51 contains a crosstalk signal from the 1111 contact track, and a comb filter 53 is used to suppress this crosstalk signal. Among crosstalk signals, those that are particularly likely to cause interference are emphasized burst signals. Jitsukō 56-5142
As stated in '6 and Japanese Patent Publication No. 54-28244, when recording and reproducing chroma signals in the form of balanced modulation, a burst signal is used as a time base reference. Therefore, it is necessary to record the burst signal as strongly as possible within the dynamic range of the tape. The recording level of the cross signal is limited by the cross-modulation characteristics caused by the non-direction of the head system, so only the burst signal is recorded at about 6 d.
B. Emphasize and record.

For this reason, if a tape pattern such as that shown in the W2B diagram is used, in which H is not aligned, burst signal crosstalk from adjacent tracks will appear in a band shape approximately in the center of the playback screen, resulting in an unsightly appearance. The crosstalk of the burst signal may be approximately -6 dBe41KVC4 with respect to the maximum level of the reproduced chroma signal, and this crosstalk signal is suppressed by 20 to 26 dB by the comb filter 55, and the output of the comb filter 53 is suppressed by 20 to 26 dB. It becomes 26 to 52 dB.

The input/output characteristics of the dynamic de-emphasis circuit 54 can be selected, for example, as shown in 42 in FIG.
It can be suppressed by about B. That is, by passing through the comb filter 55, the crosstalk signal level is -26 to -
Therefore, it is further suppressed by 6 to 8 dE in the dynamic de-emphasis circuit 34, and finally the output of the dynamic de-emphasis circuit 34 becomes τ=52 to a odB. That is, in order to effectively suppress the crosstalk signal with the dynamic de-emphasis circuit 34, it is necessary to sufficiently suppress the crosstalk with the comb filter 33 prior to this. For this reason, the dynamic de-emphasis circuit is used in the low conversion frequency band (
#! In the example in Figure 7, (47a) f 72 o, KHz
) It is desirable to perform the operation in the 44.Mffx band instead of the O"c' it. Therefore, it is desirable that the dynamic emphasis circuit 21, which is the inverse circuit of the dynamic de-emphasis circuit 34, also be placed in the 4.4 MHz band. ( The rectangular filter 55 is composed of a 2H delay line and has a frequency of 4.4 MHz as explained in Japanese Patent Application Laid-open No.
It is placed on the obi. The output signal of the dynamic de-emphasis circuit 34 is single-stage demodulated 77, SECA
The signal is converted into an FM@ signal according to the M standard and added to the luminance signal by the n1 mixer 29 to obtain a composite video signal of the output terminal 5BIfC5ECAM system. Figures 12 and 13.

FIG. 14 is a diagram showing an example of the characteristics of the dynamic de-emphasis circuit 54.
This corresponds to FIG. 9, FIG. 10, and FIG. FIG. 15 is a tape pattern diagram when αg=to in FIG. 4 and the angle θ formed by the video heads 12 and 13 in FIG. 3 is selected to be θ=(18o 625 ) degrees. If θ is chosen as shown in the above equation, the tape pattern will be 55 in Figure 15,! As shown in M, between track 3 and track 4 αH55αH
1=1oH-0, 5H=o, 51I trunk 3 totora'
;/ ri5 (1) X (D C1H56it (t
#5=tOH+15H=tsH(!: Cross alignment is not performed between tracks 4 and 3, and chroma alignment is performed between tracks 3 and 5.

Also, H alignment is performed between all tracks. 11415
When using the tape pattern shown in the figure, burst code crosstalk from adjacent tracks does not appear on the playback screen, but appears during the horizontal blanking period, so the above-mentioned problem does not occur. It is desirable to select a characteristic that makes it easy to suppress interference from pilot signals and FM audio signals.

Whether you choose the tape pattern as shown in the GS diagram or as shown in Figure 15 depends on how you choose the tape speed switch and the NT
Ease of manufacturing a dual-purpose machine with the SC method, rotating cylinder 10
The number 6 determines which of the following is important: ease of mass production.

The advantage of the tape pattern shown in Figure 5 is ■Rotating cylinder 1
0 is good for mass production (it is easier to fit heads 12 and 11 at 180°),
In this case, heads 12 and 11 are 180. In addition, the video head can be used for both NTSC, SEC, and 4M machines.

■If recording time is prioritized over image quality, it is practical to use αg to α5 in Figure 4, and αg=2.0. If the head 1t12 is arranged at 180° without H arrangement at to, then αH=α5
You can perform H arrangement with . Crosstalk from adjacent tracks becomes the most problematic when αH = 0.5, and thus when αH = 2. When considering the three modes of r3, 1.0, and 0.5, the tape pattern is shown in Figure 5 (αH=
2.0, for tO) is desirable.

On the other hand, αN=2.0. If only two modes of t'0 are considered, it is appropriate to select the tape pattern as shown in FIG.

The w416 diagram shows that the present invention can be used not only for SECAM signals but also for PAL signals.
FIG. 2 is a block diagram showing an embodiment when used in a video tape recorder that also records and reproduces signals.

Delay compensation circuit 57, 74, switch 58, 59, 75, 76, S E CAM chroma polarization signal PAL chroma polarization signal converting circuit 20 in FIG. SECAM/
PAL discrimination circuit 60. The circuit 35 for converting the PAL chroma signal back to the SECAM chroma signal is switched when the video tape recorder is used in the P, 4L or SE CAM format, respectively. Other parts are basically the same as in Figure 6. In FIG. 16, an ACC detector 62 and a variable gain amplifier 61 detect the amplitude of the burst signal at the input section of the dynamic emphasis circuit 21 so that the input level of the 4CC circuit 19 and the dynamic emphasis circuit remains constant.
Consists of. The recording chroma signal processing circuit 22 includes a carrier generator 63. Frequency converter 64. LPF65. It consists of a burst emphasis circuit 66 (see Utility Model Publication No. 56-51426. % Publication No. 54-28244). The reproduced chroma note processing circuit 31 includes an LPF67 and a variable gain amplifier 68.
．． Burst signal detector 69 Burst de-emphasis (
%・Refer to Publication No. 54-28244) 709 Frequency converter 72. It consists of a carrier generator 71BPF75. 17th
The figure is a block diagram of one embodiment of the carrier generator 63.

Figure 17 shows a circuit for setting the chroma signal frequency recorded on the tape to (47-,)lx for the reason mentioned above. 077 is the oscillation frequency of 5759 VCO, and 7961 is the phase that detects the phase difference of the horizontal synchronizing signal added. A comparator, 78 is a one-frequency divider, and 24 obtains a pilot signal emission signal. 82 is a one-frequency divider whose output has a frequency of -T-fg and a phase of 0.
', 90', 1800.2700 signals are obtained. 83 is a 9o0 shift circuit, which does not perform phase shift in the first field, and shifts 9 to 0 every 1H in the second field.
00 Phase advance or lag. 9) is a field frequency pulse application quadruplet (both PAL and SECAM are 25H).
z). 92 is a horizontal pulse application terminal (PAL, SEC
, 4M are both 15.625KHz). 84 is a waveform shaping circuit, which adjusts the rise timing of the output signal of the phase shift circuit 83 and has the function of making a phase difference of exactly 900 for each H in the second field. A carrier that shifts is obtained.

4.45MHz VCO 87, phase comparator 88, burst gate circuit 89. Burst signal application terminal 95 is phas
85 is a frequency converter; 85 is a frequency converter; 85 is a frequency converter;
6 is a BPF and its output is (4,45+ (47-
-i fH) signal is generated. FIGS. 18, 19, and 24 are diagrams showing an embodiment of the dynamic emphasis circuit 21 used in the present invention. 96 is an input terminal, 97
is an output terminal, 94 is a limiter, 95 is an adder, and 98 is a band elimination filter. The circuit in Figure 18 is W4
The emphasis characteristics shown in FIG. 11 are realized, and the circuits shown in FIGS. 819 and 24 realize the emphasis characteristics shown in FIGS. 9 and 10 by constant design. Figure 20, Figure 21, Figure 22
23, 25 (=A diagram showing an embodiment of the dynamic de-emphasis circuit 34 used in the present invention. In the figures, 100 is an input terminal, 101 is an output terminal, and 99 is a subtracter.tJ420 Figure g21 realizes the characteristics of Figure 14, and Figures 22, 23, and 425 realize the characteristics of Figure 1s12 or Figure 15, respectively.

The main points of the present invention will be summarized and described below once again.

In the present invention, the balanced variable WA1! represented by SECAM chroma signal; 2PAL/)Cl master number! Convert to number.

As a result, the chroma signal frequencies between adjacent tracks recorded on the tape are interleaved (the frequency difference is set to μ(2n-1), an integer), and a comb filter is inserted into the playback circuit. to suppress crosstalk signals from adjacent tracks.

Therefore, there is no need to take crosstalk interference from adjacent tracks into account, and therefore αH can be selected arbitrarily from the required S/N and the required recording time. In a system with a cylinder diameter of 40 mmφ tape + IIg8mlL, αH=2.0H, tuff can be selected.

On the other hand, there is dynamic emphasis as a technology to improve chroma image quality, and to use it effectively, SEC,
There is no solution for 4M chroma signals (there is a fee to use a balanced modulation chroma signal such as a PAL signal).

Furthermore, when a pilot signal or an FM audio signal is frequency-multiplexed onto a chroma signal and recorded on a video track, the pilot signal or the FM audio signal is interfered with. Dynamic emphasis and de-emphasis are extremely effective in suppressing these disturbances.

Therefore, in a video tape recorder that uses a system that does not use chroma alignment or H alignment on the tape and frequency-multiplexes the pilot signal and FM audio signal onto the chroma signal and FM luminance signal, the SECAM chroma signal is first
It is necessary to convert the L chroma polarized signal into a balanced modulated chroma signal, and then apply dynamic emphasis to this converted signal.

On the other hand, in order to make the dynamic de-emphasis in the reproducing circuit effective, it is necessary to apply the chroma signal to the dynamic de-emphasis after crosstalk components from adjacent tracks have been sufficiently suppressed using a square filter.

Therefore, the configuration of the reproducing circuit requires conversion to a comb filter dynamic de-emphasis-5ECAM chroma signal.

According to the present invention, there is no need to worry about H alignment or chroma alignment (the tape speed can be selected, so the optimum S/
You can set N and recording time. In addition, pilot signals and FM audio signals can be multiplexed without impairing chroma image quality or luminance signal band, resulting in improved tracking compatibility and significant improvement in sound quality.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the recording signal spectrum of a VH5 system SECAM video tape recorder, and Figure 2 is a diagram showing the recording signal spectrum of a VH5 system SECAM video tape recorder.
6 is a schematic diagram of a rotary cylinder showing the mounting position of the video head; FIG. 4 is a diagram showing the relationship between αH and line characteristics of the video tape recorder of the present invention; Figures 5 and 15 are pattern diagrams showing an example of a tape pattern used in the present invention, Figure 6 is a block diagram showing an embodiment of the present invention, and Figure m7 is a pattern diagram showing an example of the tape pattern used in the present invention. FIG. 8 is a characteristic diagram showing an example of the input/output characteristics of the dynamic emphasis/de-emphasis circuit used in the present invention, and FIGS. 9, 910, and 11 are examples of the characteristics of the dynamic emphasis circuit used in the present invention. Figure 12, #
Fig. 415 and Fig. 14 are characteristic diagrams showing an example of the characteristics of the dynamic de-emphasis circuit used in the present invention, and Fig. 16 shows an example in which the present invention is applied to a video tape recorder for both PAL, SEC, and 4M. Fig. 17 is a block diagram of an embodiment of the carrier generation circuit and pilot generation circuit used in the present invention, Fig. 18, s19, m.
Figure 24 is a block diagram showing an embodiment of the dynamic emphasis circuit used in the present invention, Figure 20, Figure 21, and Figure 2.
FIG. 2, FIG. 23, and FIG. 25 are circuit diagrams showing an embodiment of the dynamic de-emphasis circuit used in the present invention. 1)...SRCAM video signal input terminal, 2)...5E
A circuit that converts a CAN chroma signal into a balanced modulation chroma signal, 21...Dynamic emphasis circuit, 3...
Comb filter, 64...dynamic de-emphasis circuit. Figure 1 Figure 2 Figure 5 Figure 2 5r! i4Figure 5.9'4.4' 4♂CMIh) Leopard!
T figure 418 figure Uri ff120 figure

Claims (1)

[Claims] SEo, a means for converting a 4M system chroma signal into a balanced modulation signal, a dynamic emphasis circuit provided after the converting means, a comb-shaped filter for suppressing crosstalk from adjacent tracks, and a comb-shaped filter for suppressing crosstalk from adjacent tracks. A chroma signal recording and reproducing device characterized by having a dynamic de-emphasis circuit provided later.