JPH02202194A - Additional signal multiplexer and multiplexed signal receiver - Google Patents

Abstract

PURPOSE:To transmit an additional signal regardless of a moving picture or a still picture by transmitting an in-frame average signal as the high area component of a chromaticity signal, reducing the band of the high area component to half and transmitting the additional signal by using the reduced band. CONSTITUTION:A center chromaticity signal CC supplied to an input terminal 51 is separated to a center chromaticity low area component CCL of 0-0.3MHz and a center chromaticity high area component CCH of 0.3-1.5MHz by an LPF 52 and an adder circuit 53. For the center chromaticity high area component CCH, an in-frame average is obtained by an in-frame average circuit 54 composed of a field delay circuit 55, adder circuit 56 and 1/2 coefficient circuit 57. The output of the in-frame average is transmitted as the center chromaticity high area component CCH. Thus, the additional signal can be multiplexed regardless of cases that the picture is the moving picture or still picture.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Field of Industrial Application) The present invention maintains compatibility with existing color television broadcasting systems such as the NTSC system, while also being compatible with the original color television signals of this system. The present invention relates to an additional signal multiplexing device for multiplexing another signal onto an original color television signal and transmitting the same, and a multiplexing signal receiving device for receiving the multiplexed signal sent by such an additional signal multiplexing device.

(Prior Art) The NTSC system, which is one of the color television broadcasting systems, can be said to be an excellent system that is compatible with black and white television broadcasting and has sufficient performance as a color television broadcasting system. This can be seen from the results of implementation in Japan, the United States, and other countries.

Incidentally, over its long history, the image quality of the NTSC system has been significantly improved since its initial implementation as a result of constant efforts by both the transmitting and receiving sides.

However, in the NTSC system, there is a desire for further improvement in image quality due to the recent spread of large screen displays.

IDTV is a method for improving the image quality of the NTSC system.
(Improved Deflnitlon T
There is a method called e1evls1on). This method aims to improve image quality by making full use of the transmitted NTSC color television signal (hereinafter referred to as NTSC signal) on the receiving side. This IDTV could not be implemented under conventional analog technology, but has become possible due to recent advances in digital technology. This IDTV
According to , image quality can be significantly improved compared to conventional analog systems.

However, since this IDTV is based on the NTSC system, the upper limit of the image quality that can be improved is limited by the NTSC standard. Here, the upper limit items for the system include (1) screen aspect ratio (2) horizontal resolution of 330 Tv lines.

The aspect ratio of (1) is currently 4:3, but it is known that users prefer ratios such as 523 or 6:3 (Broadcasting System published by Japan Broadcasting Publishing Association (Editor) (See page 80 of 2 Japan Broadcasting Corporation)).

In addition, the high-definition television broadcasting system (H1ghDef'
1nltlon Te1ev1slon), 16
:9 aspect ratio may be adopted (CCI
RReport 801-2).

Regarding the horizontal resolution (2), in the NTSC system, 4
．． Since it is specified as 2 MIIz, the limit is 330 Tv. On the other hand, the vertical resolution is the number of effective scanning lines (480
450 TV lines is possible, considering the margins such as overscan. Therefore, at this stage,
In terms of horizontal and vertical balance, it is desirable to improve horizontal resolution.

As an example of a system that improves the above two items and maintains compatibility with current television receivers, for example, Josep
h L, LoClcero'A Co5pat1b
le Hlgh-Def'1n1t1on telev
lslon System (SLSC)withCh
roslnance and aspect R
atio ImprovementsSMPTE J
ournal, May 1985 (Reference 1)
There is.

This 5LSC method will be described below.

FIG. 8 shows a spectrum diagram of the 5LSC method.

In FIG. 8, the 0-4.2 MHz signal is a signal to maintain compatibility with current television receivers. 4.9-10. The -IMHz signal is an additional signal used to expand the aspect ratio and the resolution of one luminance and one chromaticity.

In this way, in this 5LSC system, the signal for -1 station is transmitted using the band for two channels, and one channel basically transmits something similar to the current television broadcast signal, while the other channels send additional signals to improve image quality.

According to such a configuration, channels received by current television receivers do not include additional signals, so
It is considered that there is high compatibility with respect to interference.

However, since each station occupies two channels, it is not efficient. Particularly in situations where channel allocation is near the limit, such as in Japan, implementation is expected to be difficult. Also,
When considering intra-station and inter-station transmission, current television broadcasting equipment does not have a band of 10 MHz, so it is necessary to invest in all new equipment.

From the above, it is desirable to achieve transmission within the band of one channel. Moreover, if additional signals can be multiplexed around the baseband of 4.2 MHz, compatibility with current television broadcast equipment such as video tape recorders and transmitters can be achieved.

As one method of multiplexing additional signals to the baseband near 4.2 MHz, T. Fuklnuki et al.

'Extended Deflnlslon TV F
ully Cospatable with Exlst
ing Sta+1d'ard8 1EEE Tr,
onCosmunieatlon Vol, C0M-
32 NO, 8, August 1984 (Reference 2).

In the NTSC system, in the case of still images, this method uses luminance detail components (approximately 4 to
6M! lz signal (hereinafter referred to as luminance high-frequency signal) Yo
This is to multiplex the data. Here, the unused area is the first area in the vertical-time direction spectrum diagram of FIG. The area of the third quadrant is used. In addition, in the figure, C
is the chromaticity signal.

This method is applicable only to still images and not to moving images. This is because in the case of a video, the spectrum spreads in the time axis direction, and the original NTSC signal and the additional signal (brightness high frequency signal Yo) overlap, making it impossible to separate the two signals on the receiving side. .

Since the luminance high-frequency signal Y1 (is effective for still images), even if the above method can transmit the additional signal only for still images, the purpose of improving the resolution of still images can be achieved. .

However, when transmitting a signal for enlarging the aspect ratio as an additional signal, the additional signal must be sent not only for still images but also for moving images. therefore,
The above-mentioned additional signal multiplexing method, which can transmit additional signals only in the case of still images, cannot be used to transmit additional signals for expanding the aspect ratio.

(Problems to be Solved by the Invention) As mentioned above, when multiplexing additional signals to the current NTSC signal, the conventional method has a problem in that the additional signals can only be multiplexed during still images. .

Therefore, the present invention makes it possible to multiplex an additional signal onto the original color television signal, regardless of whether the image resulting from the original color television signal is a moving image or a still image. An object of the present invention is to provide an additional signal multiplexing device and a multiplexed signal receiving device in which the image quality of an original color television signal does not deteriorate.

[Structure of the Invention] (Means for Solving the Problem) In order to achieve the above object, the present invention transmits the low frequency component of each field as the low frequency component of the chromaticity signal on the transmitting side. By transmitting the intra-frame average signal as a high-frequency component, the band of the chromaticity signal in the time axis direction is reduced, and this reduced area is used to multiplex the additional signal.

Furthermore, on the receiving side, the chromaticity signal is reproduced by using the high-frequency components of the chromaticity signal in field repetition.

(Function) According to the above configuration, it is possible to reduce the high frequency component band of the chromaticity signal by half, and this reduction area becomes a no-signal area even in the case of a moving image. Additional signals can be multiplexed regardless of the situation, and the image quality can be prevented from deteriorating even in the case of moving images.

Furthermore, since the smoothness of the motion is sufficiently compensated for by the low-frequency components, the motion does not become unnatural.

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

FIG. 1 is a circuit diagram showing the configuration of a main part of an embodiment of an additional signal multiplexing device according to the present invention. Further, FIG. 2 is a circuit diagram showing the overall configuration of one embodiment. Note that FIG. 1 corresponds to the multiplex pre-processing circuit 33 in FIG. 2.

Here, before explaining FIG. 1, the overall configuration of one embodiment will be explained using FIG. 2.

In FIG. 2, reference numeral 11 denotes a source image generation circuit that generates a source image television signal as primary color signals R, G, and B. These primary color signals R and G.

B is a non-interlaced signal with 525 scanning lines, and its aspect ratio is set to, for example, 5:3.

Primary color signals R and G output from the source image generation circuit 11
, B are the luminance signal Y and the chromaticity signal 1 . It is converted to Q.

The luminance signal Y is processed by the screen division circuit 13 to have an aspect ratio of 5.
:3 screen (hereinafter referred to as wide aspect screen) with an aspect ratio of 4:3 located in the center part of the screen (hereinafter referred to as wide aspect screen).
CY (hereinafter referred to as the center brightness signal) corresponding to the center screen) (hereinafter referred to as the center brightness signal); and a signal (hereinafter referred to as the side brightness signal) corresponding to the screen obtained by excluding the center screen from the wide aspect screen (hereinafter referred to as the side screen). signal)
It is divided into SY. Chromaticity signal 1. Q is similarly divided by the screen division circuit 14 into a signal CC corresponding to the center screen (hereinafter referred to as center chromaticity signal) and a signal SC corresponding to the side screen (hereinafter referred to as side chromaticity signal).

Center luminance signal CY output from screen division circuit 13
is time-expanded by a factor of 5/4 by the time expansion circuit 15.

On the other hand, the side luminance signal SY is filtered through a low-pass filter (hereinafter referred to as
0 to 875K by LPF) 16 and adder circuit 17
H2 side brightness low frequency component SYL and 875KHz~5
It is separated into a side luminance high frequency component SY of MHz.

The side luminance low frequency component SYL is reduced to 1 by the time compression circuit 18.
After being compressed in time by /4 times, it is multiplexed by the horizontal overscan multiplexing circuit 19 onto the horizontal overscan portion of the center luminance signal SY output from the time expansion circuit 15. The center luminance signal CY, on which the side luminance low frequency components SY have been multiplexed, has its diagonal high frequency components removed by the multiplex blurring processing circuit 20. Although details will be described later, the side luminance high frequency component SYH is multiplexed into this deletion area.

The side brightness high-frequency component SYH is time-expanded by four times in a time expansion circuit 21, and then compressed in a band compression circuit 22 to a band that can be multiplexed into the multiplex area set by the multiplex blurring processing circuit 20. This compressed output is modulated by a modulation circuit 23, and then its amplitude is nonlinearly compressed by a nonlinear compression circuit 24.

The side brightness high-frequency component YH output from the nonlinear compression circuit 24 is sent to the multiplex pre-processing circuit 20 by the addition circuit 25.
The center luminance signal CY output from the center luminance signal CY is multiplexed using the multiplexing area.

This multiple output is converted into a signal having an interlaced scanning structure by an inclace conversion circuit 26.

Center chromaticity signal CC output from the screen division circuit 14
is time-expanded by a factor of 5/4 by the time expansion circuit 27. In addition, the side chromaticity signal SC is connected to the LPF 28 and the adder circuit 2.
9, the signal is separated into a side chromaticity low-frequency component SCL and a side chromaticity high-frequency component 5C)l.

Here, the bands of the side chromaticity low band component SCL and the side chromaticity high band component SCH will be explained using FIG. 3(a). FIG. 3(a) shows the spectrum of the side chromaticity signal SC output from the screen division circuit 14. Chromaticity signal with aspect ratio 5:3 1. Q is the chromaticity signal l of the current NTSC system.

In order to have the same horizontal resolution as Q, the band of chromaticity signal I must be 1.9 MHz (-1,5x (5/-4)
(5/3) MHz) is required, and the band of the chromaticity signal Q is 630 to 7 (=500x (5/4)x (
5/3) Km) is required. Of these, 0 to 120K
Hz is the side chromaticity low frequency component SCL, 1.20K1
1z to 1.9M11z is the side chromaticity high-frequency component SC0.

Side chromaticity low frequency component 501- output from LPF28
is time-compressed by a factor of 1/4 by the time compression circuit 30, and then multiplexed by the horizontal overscan multiplexing circuit 31 onto the horizontal overscan portion of the center chromaticity signal CC output from the time expansion circuit 27. Side chromaticity low range component S
The reason why CL is multiplexed in the horizontal overscan area is that this low chromaticity component C has large energy, so if it is multiplexed in the area that appears in the display area of the display, interference by the side chromaticity low frequency component SCL will be noticeable. This is because

The center chromaticity signal CC, in which the side chromaticity low frequency components SC are multiplexed in the horizontal overscan section, is converted into horizontal band 1.0 by the precombing circuit 32. 5Ml1z, vertical band 52
Bandwidth limited to 5/4 ep. This band-limited center chromaticity signal CC is processed by a multiplex pre-processing circuit 33.
As shown in FIG. 4, the band of the high frequency component in the time axis direction is reduced by half.

side chromaticity high-frequency component SC output from the adder circuit 29;
The spectrum is as shown in FIG. 3(b). This side chromaticity high-frequency component SC, is first time-expanded four times by the time expansion circuit 34, and is
) is converted into a signal with the spectrum shown in This time-expanded side chromaticity high-frequency component SC, is averaged within the frame by the intra-frame averaging circuit 35, that is, the first chromaticity high-frequency component SC.
The average of the field and the second field is taken, and the band in the time axis direction is limited to ±15 Hz. This average output is used by the multiplication circuit 36 to modulate the carrier signal output from the carrier generation circuit 37. The frequency of this carrier signal is set to (1/13)f”3c,
Moreover, the phase is set to be inverted for each field. That is, the carrier signal is set so that the phase thereof is inverted for each scanning line, and the phase is the same in the first scanning line and the 263rd scanning line. The side chromaticity high-frequency component SCH output from the multiplication circuit 36 is supplied to a band pass filter (hereinafter referred to as BPF) 38, and a component having a band shown in FIG. 3(d) is extracted. The three-dimensional spectrum of this component is as shown in FIG.

Side chromaticity high frequency component 5CI (
is added to the side center signal CC output from the multiplex pre-processing circuit 33 by the adder circuit 39, and the chromaticity signal 1 is
．． It is considered to be Q. The chromaticity signals 1 and Q are converted into signals having an interlace scanning structure by an ink-lace conversion circuit 40. The vertical-time domain spectrum of this conversion output is shown in Figure 6 (a
). Here, O indicates the center signal CC and the side chromaticity low frequency component SCL, and x indicates the side chromaticity high frequency component SC. The side chromaticity high-frequency component SC, . is modulated by the multiplier circuit 36 using a field inversion carrier signal having a frequency of (1/13) fsc, so it is located at a position of 30 Hz on the time axis.

FIG. 6(a) output from the interlace conversion circuit 40
The chromaticity signals I and Q having the spectrum are modulated in the NTSC encoder 41 using a carrier signal of frequency fsc and converted into signals having the spectrum shown in FIG. 6(b). As a result, the center chromaticity signal CC and the side chromaticity low frequency component SCL indicated by ○ are the chromaticity signal 1. of the current NTSC signal. The side chromaticity high-frequency component se, located at the same position as Q and indicated by X, is the chromaticity signal 1. of the current NTSC system with respect to the horizontal-vertical plane. It will be located at a position symmetrical to Q.

The modulated chromaticity signals I and Q are multiplexed with the luminance signal Y output from the interlace conversion circuit 26, and guided to the output terminal 42 as an NTSC signal for transmission.

In addition, as mentioned above, the center chromaticity signal CC indicated by o
The spectrum of the side chromaticity low-range component SC1, , is as shown in FIG.

Now, the configuration of the multiplex blurring processing circuit 33, which constitutes the main part of one embodiment, will be explained using FIG.

In FIG. 1, an input terminal 51 is supplied with a center chromaticity signal CC output from the precombing circuit 32 in FIG. As mentioned above, this center chromaticity signal CC has side chromaticity low-frequency components SCL in the horizontal overscan section.
are multiplexed, and the horizontal band is 1 as shown in Figure 4.
．． 5 MHz, vertical band limited to 525/4 cph.

The center chromaticity signal CC supplied to the input terminal 51 is L
The PF 52 and the adder circuit 53 separate the signal into a center chromaticity low frequency component CCL of 0 to 0.3 MIIz and a center chromaticity high frequency component CC of 0.3 to 1.5 MHz.

Center chromaticity high frequency component CCL is field delay circuit 55
, an adding circuit 56, and an intra-frame averaging circuit 54 comprising a 1/2 coefficient circuit 57. This intra-frame average output is transmitted to the receiving side as the center chromaticity high frequency component CCH. This is due to the following reasons. That is, as the center chromaticity high frequency component CCH,
Due to visual characteristics, the first . Center chromaticity high-frequency component C of one of the second fields
It is sufficient to transmit the CH. However, when considering the image quality of a moving image, it is possible to improve the image quality more by sending the average output within a frame. Furthermore, by taking the intra-frame average, the receiving side can reproduce the image without performing any special processing. Therefore, in the circuit shown in FIG. 1, the intra-frame average output is sent as the center chromaticity high-frequency component CCH.

On the other hand, the center chromaticity low frequency component CCL is delayed by one field by the field delay circuit 58, and is time aligned with the center chromaticity high frequency component CCH.

This delayed output is sent to the intra-frame averaging circuit 5 in the adder circuit 59.
It is added to the center chromaticity high-frequency component CC output from 4, and is led to the output terminal 60 as a center chromaticity signal CC for transmission.

3 of the center chromaticity signal CC output from the output terminal 60
The dimensional spectrum is as shown in FIG. 4 mentioned above. That is, in this center chromaticity signal CC, the band in the time axis direction of the center chromaticity high-frequency component CC is reduced by half by intra-frame averaging processing, and is limited to ±15 Hz. By reducing this area, the side chromaticity high-frequency components SC, can be multiplexed into the center chromaticity signal CC, regardless of whether the image is a still image or a moving image.

One embodiment of the additional signal multiplexing device has been described above, but next,
A multiplex signal receiving device that receives multiplexed signals sent by such an additional signal multiplexing device will be described.

FIG. 7 is a circuit diagram showing the configuration of an embodiment of the receiving device.

In this FIG. 7, 71 is the NTS of the multiplex configuration mentioned above.
This is an input terminal to which the C signal is supplied. This NTSC signal is a baseband signal.

The NTSC signal supplied to the input terminal 71 is converted into a luminance signal Y and a chromaticity signal ■ by a Y/C separation circuit 72.

It is separated into Q.

The luminance signal Y is separated by the three-dimensional filter 73 into a center luminance signal CY and a side luminance signal SY. The center luminance signal CY is time-compressed by a factor of 415 by the time compression circuit 74 and returned to its original time length. The side luminance signal SY is nonlinearly expanded by a nonlinear expansion circuit 75 and then demodulated by a demodulation circuit 76. This demodulated output is sent to the time compression circuit 77.
The time is compressed by 1/4 and returned to the original time length.

The output signals of the time compression circuits 74 and 77 are sent to the screen combining circuit 78.
are combined into a luminance signal Y with an aspect ratio of 5:3.

On the other hand, the chromaticity signal output from the Y/C separation circuit 72! ,
Q is demodulated by the color demodulation circuit 79 using a carrier signal of frequency [sc] output from the carrier generation circuit 80. As a result, the spectra of the chromaticity signals 1 and Q are converted from the spectrum shown in FIG. 6(b) to the spectrum shown in FIG. 6(a).

The output of the color demodulation circuit 79 is a center chromaticity signal C multiplexed with side chromaticity low frequency components SCL by a three-dimensional filter 81.
C and a side chromaticity high-frequency component 5CH-. The center signal on which the side chromaticity low frequency component SCL is multiplexed is separated into the center chromaticity signal CC and the side chromaticity low frequency component SCL by the horizontal overscan sampling circuit 82. The center chromaticity signal CC is time-compressed by a factor of 415 by the time compression circuit 83 and returned to its original time length. The side chromaticity low frequency component SCL is also multiplied by 4 by the time expansion circuit 84 and returned to the original time length.

The side chromaticity high-frequency component SC outputted from the three-dimensional filter 81 is demodulated by the multiplication circuit 85 using the field inverted carrier signal outputted from the carrier generation circuit 86 and having a frequency of (1/13) fsc. After high-order components are removed from this demodulated output by the LPF 87, the time is compressed by a factor of 1/4 by the time compression circuit 88 and returned to the original time length.

The spectrum of this compressed output is as shown in FIG. 3(b).

Side chromaticity high frequency component C output from time compression circuit 88
CH and the side chromaticity low-frequency component SCL outputted from the time expansion circuit 84 are added by an addition circuit 89. As a result, a side chromaticity signal SC having the spectrum shown in FIG. 3(a) is obtained. This side chromaticity signal SC is combined by the screen combining circuit 91 with the center chromaticity signal CC output from the time compression circuit 83. As a result, a wide aspect chromaticity signal with an aspect ratio of 5:3 1. It becomes Q.

The luminance signal Y and the chromaticity signal 1. output from the two screen combination circuits 78 and 90. Q is converted into primary color signals R, G, and B by a matrix circuit 91 and guided to an output terminal 92. A wide aspect screen is displayed by the primary color signals R, G, and H guided to the output terminal 92.

As described above, in this embodiment, on the transmitting side, the center chromaticity signal CC is divided into the center chromaticity low frequency component CCL and the center chromaticity high frequency component CCH, and the center chromaticity low frequency component CC is divided into the center chromaticity low frequency component CCH.
As L, the center chromaticity low range component CCL of that field is sent for each field, and the center chromaticity high range component CCL is sent for each field.
C, by sending an intra-frame average signal, the time axis band of the center chromaticity high frequency component CCH is reduced by half, and this reduced band is used to multiplex the side chromaticity high frequency component SC■. It was designed to do so.

On the other hand, on the receiving side, the center chromaticity low frequency component CCL of each field is used as the center chromaticity low frequency component CCH,
The intra-frame average signal is used as the center chromaticity high-frequency component CCH by field repetition.

According to the above configuration, it is possible to reduce the band of the center chromaticity high frequency component CC by half, and since this reduction area becomes a no-signal area even in the case of a moving image, regardless of whether it is a moving image or a still image. , side chromaticity high-frequency component SC■ can be sent,
Moreover, it is possible to prevent image quality from deteriorating even when a moving image is displayed.

That is, in general, in the case of a moving image, the center chromaticity signal CC and the side chromaticity low frequency component SCL shown by O in FIG.
spectrum and the side chromaticity high-frequency component Set+ indicated by
As shown in FIG. 3(C), the spectra of 1 and 2 each spread in the time axis direction. In this case, the movement is intense 1. , the spectrum spread from the position showing Q and X becomes horizontal -
overlap in the vertical plane. In such a state, it becomes impossible to separate the center chromaticity signal CC and the side chromaticity high-frequency components SC. As a result, in such a case, the center chromaticity signal CC and the side chromaticity high-frequency component S
It becomes impossible to accurately reproduce CH.

However, in this embodiment, as is clear from the spectrum diagrams in FIGS. 4 and 5, the horizontal band of 0.3 to 1.5 MILz of the center chromaticity signal CC has a band in the time axis direction. Since it is limited to ±1511z, the spectra do not overlap, and both the center chromaticity signal CC and the side chromaticity high-frequency component SCH can be accurately reproduced.

In addition, in this embodiment, center chromaticity region components CC,
, the center chromaticity low-frequency component CC+- of that field is transmitted for each field, so the chromaticity signal of the NTSC system is obtained.

The smoothness of the Q movement is sufficiently compensated, and the horizontal direction is 0.3~
No unnatural motion 6 occurs due to the band in the time axis direction of the 1.5 MHz region being limited to ±15 Hz.

Although one embodiment of the present invention has been described above, the present invention is of course applicable to cases other than the case where side chromaticity high frequency components SCH in a wide aspect method are multiplexed as additional signals.

[Effects of the Invention] As described above, the present invention reduces the bandwidth of the high frequency component by half by transmitting the intra-frame average signal as the high frequency component of the chromaticity signal, and uses this reduced bandwidth. Since it is possible to transmit additional signals by using the
It is possible to prevent image quality from deteriorating during video recording.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing the configuration of essential parts of an embodiment of the additional signal multiplexing device of the present invention, FIG. 2 is a circuit diagram showing the overall configuration, and FIG. 3 explains the operation of FIG. 2. Figure 4 is a spectrum diagram for explaining the operation of Figures 1 and 2, Figures 5 and 6 are spectrum diagrams for explaining the operation of Figure 2, and Figure 7 is a spectrum diagram for explaining the operation of Figure 2. The figure is a circuit diagram showing the configuration of an embodiment of the multiplexed signal receiving apparatus of the present invention, and FIGS. 8 and 9 are spectrum diagrams for explaining the conventional additional signal multiplexing system. 51... Input terminal, 52... LPF, 53, 56° 59... Addition circuit, 54... Intra-frame average circuit,
55.58...Field delay circuit, 57...1/
2 coefficient circuit, 60...output terminal. Applicant's agent Patent attorney Takehiko Suzue Figure 3

Claims (2)

[Claims] (1) In an additional signal multiplexing device that multiplexes and transmits an additional signal on an NTSC color television signal, the low frequency component is composed of the low frequency component of the first field as the chromaticity signal of the color television signal. , the high frequency component consists of a first signal consisting of the average signal of the high frequency components of the first and second fields, the low frequency component consists of the low frequency component of the second field, and the high frequency component is obtained from the above average signal. a band reduction means for reducing the band of the chromaticity signal in the time axis direction by outputting a second signal of
a modulation means for modulating using a carrier signal having the same phase in the scanning line and the 263rd scanning line; and a modulation means for modulating the additional signal modulated by the modulation means using the band reduced by the band reduction means to the color television. an additional signal multiplexing device comprising multiplexing means for multiplexing signals; (2) In a multiplex signal receiving device that receives a multiplexed signal in which an additional signal is multiplexed on an NTSC color television signal, the chromaticity signal of the color television signal is composed of a first signal and a second signal, The first signal includes the low frequency component of the first field and the first,
an average signal of high-frequency components of a second field; the second signal consists of a low-frequency component of the second field and the average signal; the phase of the additional signal is inverted for each scanning line; And the first
It is modulated using a carrier signal that has the same phase in the scanning line and the 263rd scanning line, and this modulated additional signal is multiplexed in the reduced area by using the high frequency component of the chromaticity signal as the average signal. a separating means for receiving a signal as the multiplexed signal, and separating a component of the multiplexed signal consisting of the chromaticity signal and the additional signal into the chromaticity signal and the additional signal; It is characterized by comprising: chromaticity signal processing means for converting the first and second signals of the chromaticity signal into first and second field chromaticity signals, respectively, and demodulating means for demodulating the additional signal. A multiplex signal receiving device.