JPH0342755B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a recording and reproducing device for a carrier color signal, and in particular, it pre-emphasizes the carrier color signal and records it on a magnetic recording medium, and de-emphasizes the reproduced carrier color signal during reproduction. The present invention relates to a carrier color signal recording and reproducing apparatus for restoring the original reproduced carrier color signal with reduced noise.

BACKGROUND TECHNOLOGY In a recording and reproducing apparatus such as a VTR, a luminance signal and a carrier color signal are separated from a color video signal to be recorded and reproduced, each is subjected to predetermined signal processing, and then both signals are multiplexed and recorded. In the case of reproduction, noise has conventionally been reduced using line correlation for the carrier color signal as well as for the luminance signal. In other words, since the reproduced carrier color signal usually has line correlation, but most of the noise mixed in the reproduced carrier color signal has no line correlation, the input/output reproduced carrier color of the 1H delay circuit By mixing the signals to extract noise that has no line correlation and mixing this noise with the reproduced carrier color signal through a limiter, it is possible to extract a reduced reproduced carrier color signal in which the noise is canceled out.

However, in the conventional recording/reproducing apparatus having the above-mentioned noise reduction circuit, for a reproduced carrier color signal having no line correlation, signal components having no line correlation are also subtracted from the input reproduced carrier color signal along with the noise. Therefore, there was a problem that the spatial frequency characteristics in the vertical direction (vertical resolution) deteriorated.

Therefore, the present applicant previously proposed a recording and reproducing apparatus for carrier color signals as shown in FIG. 8 in Japanese Patent Application No. 138872/1982. In the figure, the standard television system (NTSC system or PAL system) input to input terminal 1
The color video signal is supplied to a low-pass filter 2 to separate the luminance signal, and is supplied to a bandpass filter 3 to separate the carrier color signal. The luminance signal is supplied to a recording luminance signal processing circuit 4, where it undergoes predetermined signal processing such as frequency modulation (FM). On the other hand, the carrier color signal is supplied to the pre-emphasis circuit 5, where it appears in the vertical direction on the screen for one horizontal scanning period (1H), as will be described later.
Pre-emphasis is performed for each signal component at intervals, and after being given a pre-emphasis characteristic in which the level of the high-frequency component in the vertical direction is relatively enhanced compared to the low-frequency component, the recording conveyance color signal processing circuit 6 is given pre-emphasis characteristics. Here, it is converted into a predetermined signal form suitable for magnetic recording and reproduction, such as frequency conversion to a low frequency band. The luminance signal and the carrier chrominance signal which are respectively converted into predetermined signal formats and taken out by the recording luminance signal processing circuit 4 and the recording carrier chrominance signal processing circuit 6 are supplied to the recording amplifier 7, where they are mixed and amplified, respectively. Thereafter, the data is recorded on the magnetic tape 9 by the rotary recording head 8.

On the other hand, during reproduction, the already recorded signal on the magnetic tape 9 is reproduced by the rotary reproduction head 10, and the reproduced signal is passed through the preamplifier 11 to the high-frequency filter 1.
2, supplied to the low-pass filter 13; For example, an FM luminance signal is separated by a high-pass filter 12 and demodulated into a luminance signal of the original band by a reproduced luminance signal processing circuit 14. On the other hand, the low-pass filter 13
For example, the carrier color signal that has been low-pass converted and recorded is separated from the reproduced signal, and this carrier color signal is supplied to the reproduced carrier color signal processing circuit 15, where it is returned to its original signal form. This becomes the reproduced transport color signal. The reproduced carrier color signal is supplied to the de-emphasis circuit 16, where the high-frequency component of the vertical spatial frequency has a characteristic that the level is relatively attenuated compared to the low-frequency component.
is given a characteristic that is complementary to the vertical spatial frequency versus level characteristic of . Therefore, from the de-emphasis circuit 16, the reproduced carrier color signal which has been pre-emphasized is restored to its original waveform before being pre-emphasized and is taken out and supplied to the mixing circuit 17 where it is extracted from the reproduced luminance signal processing circuit 14. Mixed with the reproduced luminance signal. As a result, mixing circuit 1
7 to an output terminal 18, a reproduced color video signal with noise components reduced in frequency is taken out.

Here, since the spatial frequency versus level characteristic in the vertical direction of the screen is de-emphasized by the de-emphasis circuit 16, the S/N ratio of the reproduced carrier color signal can be improved, and the de-emphasis circuit 16 can improve the S/N ratio. Since the spatial frequency versus level characteristic in the vertical direction is emphasized and recorded by the pre-emphasis circuit 5 provided in advance in the recording system, the S/N ratio is improved and the spatial frequency in the vertical direction is output to the output terminal 18. A reproduced color video signal with no deterioration in level characteristics is extracted.

Next, the pre-emphasis circuit 5 will be explained. FIG. 9 shows a block diagram of an example of the pre-emphasis circuit 5. In the figure, a carrier color signal inputted to an input terminal 20 and separated from, for example, an NTSC color video signal is supplied to subtraction circuits 21 and 22, respectively. The output carrier color signal of the subtraction circuit 21 is supplied to a 1H delay circuit 23, where it is delayed by one horizontal scanning period, and then the coefficient circuit 24 outputs a coefficient.
The signal is multiplied by K ₁ (for example, 0.76) and supplied to the phase adjuster 25 . The phase adjuster 25 is a 1H delay circuit 23
This circuit is unnecessary if a delay time of 1H can be obtained accurately. However, the delay time actually obtained by the 1H delay circuit 23 is not exactly 1H, and in this case, the delay time obtained by the subtraction circuit 23 without performing phase adjustment.
If the output signal of the coefficient circuit 24 is supplied to the input carrier color signal and a subtraction operation is performed on the input carrier color signal, the coefficient _K1 is equivalently reduced, so that the required pre-emphasis characteristic cannot be obtained.

Therefore, by adjusting the phase of the output signal of the coefficient circuit 24 using the phase adjuster 25 so that it becomes the same as the phase of the carrier color signal delayed by 1H, the desired pre-emphasis characteristic can be obtained.

The subtraction circuit 21 performs a subtraction operation of subtracting the output signal of the phase adjuster 25 from the carrier color signal from the input terminal 20. Here, as is well known, the color subcarrier frequency of the carrier color signal in the NTSC system is 227.5 times the horizontal scanning frequency, and due to the fraction of 0.5, the color subcarrier has a phase of 0.5 period at the beginning and end of 1H. In other words, they differ by 180°. Therefore, the carrier color signal extracted with an accurate 1H delay from the phase adjuster 25 has a phase relationship with the input carrier color signal from the input terminal 20 if there is a line correlation, and the subtraction circuit 21 From here, a carrier color signal that is substantially added to the carrier color signal 1H before is extracted. The output carrier color signal of this subtraction circuit 21 is 1H
The signal is supplied to the delay circuit 23, while it is supplied to the coefficient circuit 26, where it is multiplied by a coefficient K ₂ (for example, 0.14) and then supplied to the subtraction circuit 22 through the phase adjuster 27.

The subtraction circuit 22 performs a subtraction operation of subtracting the output carrier color signal of the phase adjuster 27 from the input carrier color signal, and outputs the obtained signal to the output terminal 28 as a pre-emphasized carrier color signal. Here, the phase adjuster 27 is provided to accurately adjust the phase of the two-input carrier color signal in the subtraction circuit 22.
The output signal of the output terminal 28 is a carrier color signal to which a pre-emphasis characteristic is added, in which the level of the high-frequency component of the spatial frequency in the vertical direction of the screen of the input carrier color signal is relatively enhanced compared to the low-frequency component. , is output as an output signal (pre-emphasized carrier color signal) of the pre-emphasis circuit 5.

Problems to be Solved by the Invention Here, the input terminal 20 is supplied with the carrier color signal shown in FIG. When a carrier color signal having the waveform shown in FIG. 10A is supplied to the input terminal 20, a carrier color signal having the same waveform as the waveform shown in FIG. However, even in the case of a carrier color signal input having a strong H correlation, the frequency characteristics of the 1H delay circuit 23 are narrower than the frequency band of the input carrier color signal, and it is difficult to provide a predetermined 1H delay characteristic. If this is not possible, distortion such as smear will occur in the output of the 1H delay circuit 23, and a carrier color signal with a signal waveform with degraded transient characteristics will appear at the output end of the subtraction circuit 21, as shown in FIG. 10B.
Furthermore, there is a problem in that a carrier color signal with distortions such as overshoot and ringing is taken out from the subtraction circuit 22 to the output terminal 28 as shown in FIG. 10C. In particular, this distortion is caused by the coefficient circuit 2 in order to improve the signal-to-noise ratio (S/N ratio).
The larger the coefficient of 4 is, the larger it becomes, and S/
This contradicts the improvement of the N ratio. Especially Figure 10A
Distortion in the color burst signal indicated by CB in ~C is caused by a carrier color signal processing circuit (for example, an APC circuit,
The problem was that it interfered with the operation of the ACC circuit (ACC circuit) and degraded the quality of the reproduced image.

Further, if the input carrier color signal of the pre-emphasis circuit 5 is schematically illustrated for one field, it is as shown in FIG. 11A, for example. Here, Fig. 11A
For convenience of illustration, 29 indicates the carrier color signal with the same saturation level, and the color burst signal during the period in which only the color burst signal is transmitted within the vertical blanking period is indicated by 29 in the figure A. As is well known, in periods other than the erasing period, the carrier color signal is a color burst signal and the carrier color signal of the video period (for convenience of explanation, this will be referred to as the "modulated color signal"), which are alternately synthesized in a time-series manner. Although it is a signal, the same figure A
For convenience of illustration, only the waveform of the modulated color signal is shown continuously as shown at 30 in periods other than the vertical blanking period, and the color burst signal waveform is not shown. In reality, the modulated color signal is transmitted intermittently, but when observed on an oscilloscope with a small time axis, it appears to be continuous, as shown at 30 in FIG. 11A.

When the carrier color signal as shown in FIG. 11A is passed through the pre-emphasis circuit 5, the color burst signal 29 of several H periods at the beginning of the field has a carrier color signal non-transmission period immediately before it and has no line correlation. Then, as shown in FIG. B, the amplitude becomes larger than that of the subsequent color burst signal, for example, near the center of the screen. This amplitude increase is suppressed together with the modulated color signal by the ACC circuit in the recording/carrying color signal processing circuit 6, as shown in FIG. 11C, and then transmitted.
6, the color burst signal and the modulated color signal of several H periods at the beginning of the field of the reproduced conveyed color signal lose the complementarity of emphasis, and the amplitude becomes smaller than that at the time of recording, as shown in FIG. 11D. As a result, there was a problem in that the color at the top of the screen became lighter.

Accordingly, the present invention provides a carrier color signal recording and reproducing apparatus which solves the above-mentioned problems by substantially stopping the operation of the pre-emphasis circuit and de-emphasis circuit during the transmission period of the color burst signal. The purpose is to

Means and Effects for Solving the Problems According to the present invention, a carrier color signal is supplied to the recording system, and the high frequency component of the vertical spatial frequency is compared to the low frequency component during the period excluding the color burst signal input period. A pre-emphasis circuit is provided which outputs the color burst signal with a relatively enhanced level, and substantially stops the operation of the color burst signal. During the period when the signal is supplied, excluding the input period of the color burst signal, the high-frequency component of the vertical spatial frequency is attenuated relative to the low-frequency component, and is complementary to the characteristic of the pre-emphasis circuit. In addition to imparting characteristics to the color burst signal, a de-emphasis circuit is provided which can substantially stop the operation of the color burst signal, and pre-emphasis and de-emphasis are not performed on the color burst signal. Each embodiment will be described with reference to FIGS. 1 to 7.

Embodiment FIG. 1 is a block diagram of a first embodiment of the pre-emphasis circuit provided in the recording system of the apparatus of the present invention, and FIG. 3 is a block diagram of the first embodiment of the de-emphasis circuit provided in the reproduction system of the apparatus of the present invention. Show the diagram. The apparatus of the present invention has a configuration similar to that shown in FIG. 8, but the configurations of the pre-emphasis circuit 5 and the de-emphasis circuit 16 are different from those of the recording/reproducing apparatus proposed by the applicant. In FIG. 1, the same components as those in FIG. 9 are designated by the same reference numerals, and their explanations will be omitted. In FIG. 1, a carrier color signal input to an input terminal 20 is supplied to subtraction circuits 21 and 22, respectively, and is supplied to a coefficient circuit 31. For example, when a carrier color signal as shown in FIG. 2A is input, the coefficient circuit 31 selects an overshoot signal from the carrier color signal having a waveform as shown in FIG. 2C, which is extracted from the subtraction circuit 22. It is provided to adjust the amplitude to be the same as the amplitude of a portion where distortion such as ringing or ringing does not occur (that is, a waveform portion where no distortion due to transient response is observed) and output it. Therefore, subtraction circuit 2
The amplitude of the waveform portion of the output carrier color signal of No. 2 in which no distortion due to the transient response is observed and the amplitude of the output carrier color signal of the coefficient circuit 31 at the same time are approximately at the same level.

The pre-emphasized carrier color signal taken out from the subtraction circuit 22 is sent to the terminal 32a of the switch circuit 32.
On the other hand, the carrier color signal, which is simply level-adjusted and extracted without being given any pre-emphasis characteristics by the coefficient circuit 31, is supplied to the terminal 32b of the switch circuit 32. On the other hand, the horizontal synchronizing signal separated from the luminance signal to be recorded is supplied to the burst gate pulse generating circuit 34 via the input terminal 33, where it is connected to the input terminal 20 by known means as shown in FIG. 2A. The color burst signal transmission period T ₁ in an input carrier color signal such as a color burst signal and a certain period T ₂ after the end of this transmission period T ₁ are continuously at a high level, for example, and are at a low level during the other periods. A burst gate pulse as shown in FIG. 2B is generated. This burst gate pulse is applied to the switch circuit 32 as a switching pulse, and during its high level period (T ₁ +T ₂ ), the input carrier color signal of the terminal 32b is selectively outputted, and during its low level period, the input carrier color signal of the terminal 32a shown in FIG. The input carrier color signals as shown in C are selectively output.

As a result, from the common terminal of the switch circuit 32 to the output terminal 35, high frequencies of the air conditioning frequency in the vertical direction are transmitted to the carrier color signal (modulated color signal) excluding the color burst signal input period of the input carrier color signal. A color burst signal is provided with a pre-emphasis characteristic that relatively enhances the level of the low-frequency component compared to a low-frequency component, and a color burst signal (indicated by CB in FIG. 2A) is not provided with the above-mentioned pre-emphasis characteristic. A carrier color signal as shown in FIG. 2D, consisting of a signal, is extracted. In addition, in Figure 2 D,
CB indicates a color burst signal corresponding to the color burst signal in the input carrier color signal shown in FIG. Furthermore, since the burst gate pulse shown in FIG. 2B remains at a high level for a certain period _T2 after the end of the color burst signal transmission period, it remains at the output terminal of the subtraction circuit 22 even after the end of the color burst signal transmission period. It can be seen from FIGS. 2C and 2D that distortion components can be removed.

According to this embodiment, since there is no distortion component due to pre-emphasis in the color burst signal, it is possible to solve the problems that occurred in the above-mentioned recording and reproducing apparatus for carrier color signals proposed by the present applicant.

Next, a first embodiment of the de-emphasis circuit will be described with reference to FIG. In FIG. 3, a reproduced carrier color signal restored to its original band is input to a terminal 40, and this reproduced carrier color signal is supplied to a subtraction circuit 41, an addition circuit 42, and a coefficient circuit 43, respectively.
The output signal of the subtraction circuit 41 is output from the 1H delay circuit 44,
The coefficient circuit 47 is fed back to the subtraction circuit 41 through the coefficient circuit 45 and the phase adjuster 46, respectively.
and a phase adjuster 48, and are supplied to the adder circuit 42. The phase adjuster 46, like the phase adjuster 25, is a circuit that performs phase adjustment to obtain an accurate 1H delayed output. Also, the coefficient L ₁ of the coefficient circuit 45
is, for example, 0.87, and the coefficient L ₂ of the coefficient circuit 47 is, for example,
It is 0.18.

The adder circuit 42 adds the reproduced carrier color signal from the input terminal 40 and the reproduced carrier color signal from the phase adjuster 48 and outputs the resulting signal to the terminal 49a of the switch circuit 49. This output signal is a reproduced carrier color signal (de-emphasized reproduced carrier) to which a de-emphasis characteristic is applied, in which the high-frequency component of the spatial frequency in the vertical direction of the screen of the input reproduced carrier color signal is relatively attenuated in level compared to the low-frequency component. color signal).
Further, this de-emphasis characteristic is exactly complementary to the pre-emphasis characteristic in which the level is attenuated by the level enhancement of the pre-emphasis characteristic.

On the other hand, coefficient circuit 43 is provided for the same purpose as coefficient circuit 31 and supplies its output carrier color signal to terminal 49b of switch circuit 49. Further, a reproduced horizontal synchronizing signal separated from the reproduced luminance signal enters the input terminal 50 and is supplied to the burst gate pulse generating circuit 51. The burst gate pulse generation circuit 51 has a circuit configuration similar to that of the burst gate pulse generation circuit 34, and the burst gate pulse generation circuit 51 has a high level, for example, during the color burst signal transmission period in the reproduced carrier color signal and a certain period immediately thereafter. During the other periods, a low-level burst gate pulse is generated and applied as a switching pulse to the switch circuit 49. During the high-level period, it is connected to the terminal 49b, and during the low-level period, it is connected to the terminal 49b.
Connect to 9a.

As a result, from the common terminal of the switch circuit 49 to the output terminal 52, the reproduced carrier color signal excluding the color burst signal input period of the input reproduced carrier color signal is transmitted from the adder circuit 42 to which the above-described de-emphasis characteristic is applied. The coefficient circuit 43 from which the carrier color signal is taken out and to which no de-emphasis characteristic is applied during the color burst signal transmission period
A reproduced color burst signal will be extracted.

Next, a second embodiment of the apparatus according to the present invention relating to the invention set forth in claim 2 will be described. FIG. FIG. 6 shows a block system diagram of the de-emphasis circuit of the reproduction system of the second embodiment of the apparatus of the present invention. In FIGS. 4 and 6, the same parts as in FIGS. 1 and 3 are designated by the same reference numerals, and their explanations will be omitted. In FIG. 4, a coefficient circuit 55 is a circuit corresponding to the coefficient circuit 24, and its coefficient M ₁ is selected to be, for example, about 0.76. Similarly, the coefficient circuit 56 is a circuit corresponding to the coefficient circuit 26, and its coefficient M ₂ is selected to be approximately 0.24, for example.

The carrier color signal taken out from the subtraction circuit 22 is
It is supplied to a non-linear circuit 57. The non-linear circuit 57 is, for example, an amplitude limiter that limits the amplitude of an input signal to a constant value, and is configured so that input signals having an amplitude smaller than this constant value are passed through and output as they are without amplitude limiting. ing. The carrier color signal taken out from the non-linear circuit 57 is multiplied by a coefficient M ₃ (for example, about 1.3) by a coefficient circuit 58 and then supplied to an adder circuit 60 through a switch circuit 59, where the carrier color signal from the input terminal 40 is multiplied by a coefficient M 3 (for example, about 1.3). After being added to the signal, it is output to the output terminal 61. The output signal from the output terminal 61 is output as a carrier color signal to which a non-linear pre-emphasis characteristic is applied depending on the amplitude of the carrier color signal.

Here, when a carrier color signal as shown in FIG. 5A is input to the input terminal 20, a signal as shown in FIG. 5B appears at the output terminal of the subtraction circuit 21, and the subtraction circuit 21
At the output terminal of 2, a signal as shown in figure C, which is the difference between the two signals shown in figures A and B, appears, but if the frequency characteristics of the 1H delay circuit 23 are insufficient, transients may also occur in this signal. Response distortion remains. However,
The switch circuit 59 is controlled by a burst gate pulse from the burst gate pulse generating circuit 34, and is opened only during the color burst signal transmission period and a certain period immediately thereafter, and is closed during other periods. Therefore, a signal as shown in FIG. 5D is taken out from the switch circuit 59 and supplied to the adder circuit 60. As a result, the addition circuit 60
During periods other than the color burst signal transmission period, a carrier color signal with the above-mentioned non-linear pre-emphasis characteristic is taken out, and during the color burst signal period, the color burst signal in the carrier color signal from the input terminal 20 is pre-emphasized. It is taken out as is without any damage.

Next, the second de-emphasis circuit shown in FIG.
To explain the embodiment, coefficient circuits 65, 6
6 are coefficient circuits corresponding to coefficient circuits 45 and 47 in FIG. 3, respectively, and the coefficients N ₁ and N ₂ are, for example,
It was selected as 0.87 and 0.13. The reproduced carrier color signal taken out from the subtraction circuit 42 is sent to a non-linear circuit 57.
Coefficient circuit 6 through non-linear circuit 67 having the same configuration as
8, where it is multiplied by a coefficient N ₃ (for example, 0.57) and then sent to the subtraction circuit 5 via a switch circuit 69.
5. The switch circuit 69 is opened by the gate pulse from the burst gate pulse generating circuit 51 only for a predetermined fixed period within the color burst signal transmission period of the reproduced carrier color signal and the period immediately after which the carrier color signal is not present. 68
The output signal of the coefficient circuit 68 is blocked from being transmitted to the subtraction circuit 70, and is closed during periods other than the above, and the output signal of the coefficient circuit 68 is supplied to the subtraction circuit 70. The subtraction circuit 70 performs a subtraction operation of subtracting the reproduced carrier color signal output from the switch circuit 69 from the reproduced carrier color signal from the input terminal 40 during periods other than the color burst signal transmission period and the fixed period immediately thereafter. A reproduced carrier color signal to which a non-linear de-emphasis characteristic complementary to the pre-emphasis characteristic is given is generated and outputted to the output terminal 71. Further, during the color burst signal transmission period, the subtraction circuit 70 outputs the color burst signal in the reproduced carrier color signal from the input terminal 40 as it is to the output terminal 71.

FIG. 7 shows a block system diagram of an embodiment of a circuit in which a pre-emphasis circuit and a de-emphasis circuit are each constructed using a common circuit. First, the operation during reproduction will be explained. During reproduction, the switches 76, 78, 92 and 93 are respectively switched to the contact P side. As a result, the reproduced carrier color signal that has entered the input terminal 75 is supplied to the subtraction circuit 79 through the switch 76, the subtraction circuit 79, the 1H delay circuit 80, the coefficient circuit 81, and the phase adjuster 82, where the switch It is subtracted from the reproduced carrier color signal after 1H from 76. The output signal of the subtraction circuit 79 is
1H delay circuit 80, while coefficient circuit 8
3. The signals are supplied to a subtraction circuit 85 through phase adjusters 84, where they are subtracted from the reproduced carrier color signal from the switch 76, and then further supplied to a switch circuit 88 through a non-linear circuit 86 and a coefficient circuit 87. .

On the other hand, the reproduced horizontal synchronizing signal inputted to the input terminal 89 is supplied to the burst gate pulse generation circuit 90, where it is converted into a burst gate pulse similar to that of the burst gate pulse generation circuit 51, and then sent to the switch circuit 88 as a switching pulse. is applied as . As a result, the switch circuit 88 performs the same opening/closing control as the switch circuit 69. Therefore, only the signals of transmission periods other than the color burst signal transmission period pass through the switch circuit 88 and are supplied to the subtraction circuit 91, where they are subtracted from the reproduced carrier color signal from the switch 76. Therefore, the subtraction circuit 9
1, during periods other than the color burst signal transmission period, a reproduced carrier color signal to which a non-linear de-emphasis characteristic has been added is extracted, similar to the output signal of the subtraction circuit 70 shown in FIG. It is output to terminal 94. According to this embodiment, by providing the non-linear circuit 86, it is possible to reduce the rate at which the de-emphasis circuit cannot restore the original waveform (for example, if the gain of the differential amplifier 77 is G, then 1/ There is only a deviation of G).

On the other hand, during recording, the switches 76, 78, 92 and 93 are each connected to the contact R side. As a result, the carrier color signal that has entered the input terminal 75 passes through the switch 76, the differential amplifier 77, the switch 78, the subtraction circuit 79, the 1H delay circuit 80, the coefficient circuit 81, and the phase adjuster 82, and then passes through the subtraction circuit 79. is supplied to The carrier color signal taken out from this subtraction circuit 79 is supplied to a 1H delay circuit 80, and is also supplied to a subtraction circuit 85 through a coefficient circuit 83 and a phase adjuster 84, where the carrier color signal from switch 78 is supplied. After being subtracted, the signal is supplied to the non-linear circuit 86.

The non-linear circuit 86 has the same configuration as the non-linear circuits 57 and 67, and the output carrier color signal of the subtracting circuit 85 is extracted with the amplitude of a portion larger than a constant value being limited in amplitude, and is further outputted through a coefficient circuit 87 to a switch circuit. 88. On the other hand, the horizontal synchronizing signal to be recorded is separated and input to the input terminal 89.
The signal is supplied to the burst gate pulse generation circuit 90. During recording, the burst gate pulse generation circuit 90 generates the same pulse as the burst gate pulse from the burst gate pulse generation circuit 34, and uses this as a switching pulse to control the switching circuit 88.
supply to Therefore, the switch circuit 87 operates as the coefficient circuit 87 during periods other than the color burst signal transmission period.
The output signal of the subtraction circuit 91 is passed through and supplied to the subtraction circuit 91, where it is subtracted from the carrier color signal from the switch 78.
The signal is supplied to the inverting input terminal of the differential amplifier 77 through the signal line. In this circuit, a de-emphasis circuit during reproduction is placed in the feedback loop of the differential amplifier 77, thereby obtaining a pre-emphasis characteristic that is the opposite of the de-emphasis circuit. Therefore, the signal outputted from the differential amplifier 77 to the output terminal 94 through the switch 93 becomes a non-linear pre-emphasized carrier color signal during periods other than the color burst signal transmission period, as in FIG. The period results in a non-linear non-preemphasized color burst signal. Note that the coefficient circuits 81, 83 and 8
The coefficients O ₁ , O ₂ and O ₃ of 7 are, for example, 0.87 and 0.13, respectively.
and 0.57.

In the above embodiment, the de-emphasis circuit having the configuration shown in FIG. 6 is put into the feedback loop of the differential amplifier 77 to obtain the pre-emphasis characteristic, but the pre-emphasis circuit having the configuration shown in FIG. It may also be inserted into the feedback loop of the differential amplifier 77 to obtain de-emphasis characteristics.

Note that the present invention is not limited to the above-described embodiments; for example, although the phase adjuster is provided on the output side of the coefficient circuit in all the embodiments, it may be provided on the input side of the coefficient circuit.

Furthermore, although the above embodiments have been described with respect to the case where NTSC carrier color signals are pre-emphasized and de-emphasized, the present invention can also be applied to PAL carrier color signals. However, in this case, in the carrier color signal of the PAL system, the phase of the color subcarrier of one of the two color difference signals is inverted every 1H, so the delay circuits 23 and 4
4 and 80 are each configured to have a delay time that is a natural number times 2H. Also, non-linear circuits 57, 6
7 and 86 are not limited to amplitude limiters.

Effects of the Invention As described above, according to the present invention, pre-emphasis and de-emphasis are performed on the spatial frequency in the vertical direction only for the carrier color signal in the period excluding the color burst signal transmission period.
Similar to the apparatus proposed by the applicant mentioned above, it is possible to improve the S/N ratio of the reproduced carrier color signal, and also to improve vertical spatial frequency characteristics by de-emphasis, unlike the conventional noise reduction circuit using line correlation. Even if a delay circuit is used that does not reduce the vertical resolution (vertical resolution) and has frequency characteristics that allow the carrier color signal to be transmitted without distortion, Since the above-mentioned pre-emphasis and de-emphasis are not performed, the color burst signal does not suffer from distortion due to deterioration of transient characteristics. or
It is possible to prevent deterioration of the reproduced image quality without causing any trouble to the operation of the ACC circuit, etc.), and also because the amplitude of the color burst signal is the same during the several H periods at the beginning of the field as in other periods. The operation of the ACC circuit has no effect on the complementarity of emphasis, and thus the complementarity of emphasis can be improved. Furthermore, in a recording/reproduction device equipped with only either a nonlinear pre-emphasis circuit or a non-linear de-emphasis circuit, the amplitude of the carrier color signal is not so emphasized during recording and reproduction, so that it is difficult to record or reproduce the signal from the magnetic tape recorded by the current VTR. Even if the reproduced carrier color signal is passed through a non-linear de-emphasis circuit, it can be reproduced into the original signal waveform with almost no practical problems.On the other hand, the magnetic tape recorded by the apparatus of the present invention can also be
Current VTRs can reproduce the original carrier color signal waveform with almost no practical problems, and therefore
It has features such as being compatible with VTRs.

[Brief explanation of drawings]

1 and 3 are block system diagrams showing the main parts of the recording system and reproduction system of the first embodiment of the apparatus of the present invention, respectively, and FIG. 2 is a signal waveform diagram for explaining the operation of the block system shown in FIG. 1. , FIG. 4 and FIG. 6 are block system diagrams showing the main parts of the recording system and reproducing system of the second embodiment of the apparatus of the present invention, respectively, and FIG. 5 is a signal waveform for explaining the operation of the block system shown in FIG. 4. 7 is a block system diagram of the main part of the third embodiment of the device of the present invention, and FIG.
The figure is a block system diagram showing an example of a carrier color signal recording/reproducing device previously proposed by the applicant, and FIG. 9 is a block system diagram showing an example of the main part of the recording system of the device proposed by the applicant. , FIG. 10 is a signal waveform diagram for explaining the operation of the block system shown in FIG. 9, and FIG. 11 is a signal waveform diagram for explaining the operation of the block system shown in FIGS. 8 and 9. 1... Color video signal input terminal, 2... Low-pass filter for luminance signal separation, 3... Bandpass filter for carrier color signal separation, 5... Pre-emphasis circuit, 6
...Record transport color signal processing circuit, 9...Magnetic tape, 16...De-emphasis circuit, 18...Reproduction color video signal output terminal, 20...Carrier color signal input terminal, 21, 22, 41, 70, 79, 8
5, 91...subtraction circuit, 23, 44, 80...
1H delay circuit, 24, 26, 31, 43, 45,
47, 55, 56, 58, 65, 66, 68, 8
1, 83, 87...Coefficient circuit, 25, 27, 4
6, 48, 82, 84... Phase adjuster, 28, 3
5, 61...Pre-emphasized carrier color signal output terminal, 32, 49, 59, 69, 76, 78, 8
8, 92, 93... switch circuit, 33, 89...
...Horizontal synchronization signal input terminal, 34, 51, 90...
Burst gate pulse generation circuit, 40... Reproduction carrier color signal input terminal, 42, 60... Addition circuit, 5
0...Reproduction horizontal synchronization signal input terminal, 52, 71...
...De-emphasized carrier color signal output terminal, 5
7,67,86...Nonlinear circuit, 77...Differential amplifier.

Claims (1)

[Claims] 1. A carrier color signal separated from a color video signal is converted into a predetermined signal format and recorded on a recording medium, and when reproduced, the reproduced signal reproduced from the recording medium is converted into the original signal format. In a carrier color signal recording/reproducing device for obtaining a reproduced carrier color signal, the carrier color signal is supplied to the recording system, and the spatial frequency in the vertical direction for the carrier color signal in a period excluding the color burst signal input period is The high-frequency components of the color burst signal are outputted with their level enhanced relatively compared to the low-frequency components, and the operation is substantially stopped for the color burst signal, and the color burst signal is outputted without imparting the above-mentioned level enhancement characteristics. A pre-emphasis circuit is provided, and the reproduction system is supplied with the reproduced carrier color signal restored to its original signal form, and the reproduced carrier color signal in the period excluding the color burst signal period is A characteristic that relatively attenuates the level of high frequency components compared to low frequency components, which is complementary to the characteristic of the pre-emphasis circuit, and which imparts a characteristic to the color burst signal in the reproduced carrier color signal. 1. A recording and reproducing apparatus for a carrier color signal, characterized in that a de-emphasis circuit is provided which substantially stops its operation and outputs the signal without imparting the level attenuation characteristic. 2. Converting the carrier color signal separated from the color video signal into a predetermined signal format and recording it on a recording medium, and upon reproduction, obtaining a reproduced carrier color signal in the original signal format from the reproduced signal reproduced from the recording medium. In a carrier color signal recording/reproducing device, the above-mentioned carrier color signal is supplied to the recording system, and the high-frequency components of the spatial frequency in the vertical direction are reduced for the carrier color signal in a period excluding the color burst signal input period. The level is relatively enhanced and outputted according to the amplitude of the carrier color signal compared to the color burst signal, and the operation is substantially stopped for the color burst signal to perform the non-linear level enhancement. A pre-emphasis circuit is provided that outputs the signal without imparting characteristics, and the reproduction system is supplied with the reproduced carrier color signal that has been restored to its original signal form, and the reproduced carrier color signal in the period excluding the color burst signal period is On the other hand, the high-frequency component of the vertical spatial frequency is compared with the low-frequency component, and the level is relatively attenuated according to the amplitude of the reproduced carrier color signal, and is a non-linear characteristic that is complementary to the characteristic of the pre-emphasis circuit. A de-emphasis circuit is provided which imparts a characteristic to the color burst signal in the reproduced carrier color signal, substantially stops its operation, and outputs the color burst signal without imparting the non-linear level attenuation characteristic. A recording/reproducing device for a carrier color signal, characterized in that: