JPS60127822A - Transmission system and transmission/reception system of information signal - Google Patents

Abstract

PURPOSE:To improve the S/N further by changing an emphasis amount time- wise in response to the state of a video signal. CONSTITUTION:An information signal S1 applied to a terminal 1 is fed to a signal processing circuit 2 and also to an emphasis decision circuit 3. The emphasis suitable for the signal S1 is applied sequentially by the circuit 2 through the control of the circuit 3, an information signal S'1 whose emphasis is changed timewise is obtained from the circuit 2 and the signal is fed to a synthesis circuit 4. Furthermore, the control signal of the circuit 3 is coded by a coding circuit 5 and becomes a control signal ID, superimposed on the signal S'1 at the circuit 4 and the result is recorded onto a magnetic tape 7 via a magnetic head 6 or transmitted from an antenna 8. When the signal is reproduced from a tape 7 by the magnetic head 9, the signal S'1 an emphasis decoding circuit 12, the signal S'1 is de-emphasised by the control of the circuit 12 based on the signal ID and the original signal S1 is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an information signal transmission system and transmission/reception system suitable for application to, for example, recording and reproducing video signals on a magnetic tape.

Background technology and its problems For example, when recording and reproducing video signals on magnetic tape, in order to improve the noise and maintain high image quality, pre-emphasis is applied on the recording side to emphasize high frequencies, and this is applied on the reproducing side. De-emphasis with the opposite characteristic is applied.

Conventionally, in this type of emphasis, the amount of emphasis is fixed at a constant value, but if the amount of emphasis can be changed over time according to the video signal condition and the optimal emphasis can be applied, even greater effects can be obtained. It is considered that the

This also applies to, for example, the recording and reproduction of audio signals or the transmission and reception of broadcasting.

Purpose of the Invention In view of the above, the present invention applies emphasis appropriate to the state of the information signal to further improve the S/N ratio.

SUMMARY OF THE INVENTION In order to achieve the above object, the first invention information signal transmission method changes the amount of emphasis of the information signal all the time, encodes a control signal for this emphasis on a part of the information signal, and then superimposes it. It is characterized by transmitting. In addition, the second invention information signal transmission/reception method temporally changes the amount of emphasis on the information signal, encodes a control signal for this emphasis on a part of the information signal, superimposes it, and transmits it, and transmits the transmitted information signal. This method is characterized by applying temporally different emphasis to the control signals received and obtained.

Therefore, according to the first and second inventions, it is possible to apply emphasis appropriate to the state of the information signal, and it is possible to further improve the S/N ratio.

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

1 and 2 illustrate the principle of the embodiment described below. FIG. 1 shows a transmission system, and an information signal s1 to be transmitted is supplied to an input terminal (1). This information signal SX
is supplied to the signal processing circuit (2) and also to the emphasis determining circuit (3). And this decision circuit (
In the control multi-signal processing circuit (2) of [3], appropriate emphasis is sequentially applied to the information signal S□. That is, an information signal sI' whose emphasis amount is temporally changed is obtained from this signal processing circuit (2), and this is sent to the synthesizer (4).
). Further, the emphasis control signal supplied to the signal processing circuit (2) is encoded by the encoding circuit (5), and the encoded control signal ID is sent to the synthesizer (4).
) and is superimposed on a part of the information signal B, /. The information signal sX' on which the control signal ID is superimposed is recorded on a magnetic tape (7) using, for example, a magnetic head (6), and is transmitted using, for example, a transmitting antenna (8).

In addition, Fig. 2 shows a receiving system, for example, a magnetic tape (7).
The information signal SI' on which the control signal ID is superimposed, which is reproduced by the magnetic head (9) K and received using, for example, the receiving antenna αQ, is supplied to the signal processing circuit αη, and is also supplied to the emphasis decoding circuit (2). ). Based on the control signal ID, the decoding circuit 0 is controlled so that the multi-signal processing circuit α◇ sequentially applies emphasis to the information signal SX', which has a characteristic opposite to that in the transmission system. Therefore, the original information signal SX is obtained at the output terminal α→ derived from this signal processing circuit αη.

By the way, in the transmission system, the coded control signal I
For example, the following can be considered as the superimposition position of D with respect to the information signal Sx.

(2) If the information signal S is a video signal, it is superimposed on the vertical blanking period. In this case, it can be easily applied without any modification to the information signal SX, and is suitable for combination with a relatively slow emphasis.

The shortest period for changing the emphasis amount is one vertical period (
1v).

(2) When the information signal S1 is a video signal, the signal of each horizontal period is time-axis compressed and superimposed on the vacant time area of each horizontal period. In this case, it is suitable for transmitting and receiving the luminance signal Y and the color signal C as time-series signals after time-base compression, for example. In this case, independent emphasis can be applied to the luminance signal Y and the color signal C.

■If the information signal S is an audio signal that does not have a synchronization signal, it is compressed on the time axis at predetermined time intervals and superimposed on the vacant time area.

(2) If the information signal SX is an audio signal without a synchronization signal, if a video signal is present at the same time, it is superimposed on this video signal.

Further, as an emphasis method, the following can be considered, for example.

■Detect the level of the information signal S□ and apply emphasis based on the level of the information signal S□. For example, in the case of a video signal, the lowest level and the highest level are detected, and the transmitting system processes the signal so that the lowest level is the pedestal level and the highest level is the white peak level, and the receiving system processes the signal with the opposite characteristics. do.

For example, when a video signal is as shown in FIG. 3A, the signal is processed in the transmission system as shown in FIG. 3B. For this video signal, a DC control signal whose lowest level is a bedscale level and a gain control signal whose maximum level is a white peak level are encoded to form a control signal ID.

For example, in the case of an audio signal, the peak level is detected, the signal processing is performed in the transmitting system so that the peak level becomes the maximum level, and the signal processing with the opposite characteristics is performed in the receiving system.

At this time, the gain control signal whose peak level is the maximum level is encoded and used as the control signal ID.

In the case of method (2), it is preferable to expand the levels gradually and to compress them rapidly. For example, it is preferable to perform gentle control in units of several fields◇ ■Detect the APL (average image level) of the information signal S1 and apply emphasis based on this. That is, the transmitting system performs signal processing to change γ (linearity) according to the APL, and the receiving system performs signal processing with the opposite characteristic. For example, in the transmission system, γ is changed so that both information with a small APL and information with a large APL are as close to 50% as possible, and the information existing portion is expanded. In this method, a control signal that changes the value of γ is coded and used as a control signal ID. This method (2) is effective, for example, when the video signal exists from the 4th digital level to the white peak level and the method (2) cannot be used.

For example, if the video signal is as shown in Figure 4A,
γ=2 is selected, and the signal is processed in the transmission system as shown in FIG. For example, when the video signal is as shown by CK in the figure, r=0.2 is selected and the signal is processed in the transmission system as shown in the figure.

■The above methods ■ and ■ assume a constant frequency spectrum for the information signal S, but due to the nature of the signal,
If the spectrum has characteristics, emphasis is applied based on these characteristics. For example, the transmitting system performs signal processing that detects the low and high frequency levels and expands them separately according to each level, and the receiving system performs signal processing with the opposite characteristics.

In this method, a signal that controls the amount of expansion is coded and used as a control signal ID.

For example, if the spectrum of the information signal Sx is as shown in FIG.
The signal is processed as shown in .

FIGS. 6 and 7 show an embodiment of the present invention. This example is an example where the information signal S1 is a video signal, the control signal ID is superimposed on the vertical blanking period of the video signal, and the amount of emphasis is changed in units of one vertical period (1v), as in (2) above.

In FIG. 6 (recording system), a video signal Sv as shown in FIG. 8A, for example, is supplied to the input terminal (l→).

This video signal Sv is passed through the second amplifier circuit α0'f and then supplied to the signal processing circuit 00. This signal processing circuit ◇
Q is a DC level control circuit α for carrying out the emphasis method described above, a dyne control circuit Q barrel, a γ control circuit for carrying out the emphasis method described above, and a video signal Sv.
Emphasis processing is performed in which the amount of de-emphasis is changed in units of 1 V by methods (1) and (2).

In other words, Cranno circuit α! Video signal Sv via 19
are minimum level detection circuit (a) and maximum level detection circuit Q
The minimum level V, and the maximum level vH, which are supplied to and detected respectively, are supplied to a DC level and key determination circuit (2) that constitutes a control circuit. Then, control signals corresponding to the levels vL and vH are supplied to the decision circuit (c), the J DC level control circuit (171), and the gain control circuit α, respectively.Then, the video signal Sv is supplied to the DC level control circuit α The DC level is controlled 1 so that the minimum level vL of the video signal Sv becomes the 4-destal level, and the gain is controlled in units of 1V in the gain control circuit 0 so that the maximum level vH of the video signal Sv becomes a white peak level. Ru.

Also, the video signal Sv passed through the clamp circuit α→ is A
The average level vA detected by the PL detection circuit (c) is supplied to the γ determination circuit (c). and,
For this decision circuit), the average level vA for the γ control circuit Q and
A control signal according to the voltage is supplied, and the value of γ is controlled, for example, to N (normal), L (low), and H (high) in units of 1 V (see FIG. 9).

The video signal Sv' obtained by the signal processing circuit QQ and subjected to the emphasis processing according to methods (1) and (2) is supplied to a synthesizer.

The video signal Sμ via the clamp circuit (a) is supplied to the synchronization separation circuit), and the horizontal and vertical synchronization signals PH and Pv obtained thereby are supplied to the control circuit (a), respectively.

Further, the control signals from (c) and (c) to the decision circuit are supplied to the coding circuit (product) and encoded. The coded control signal 1D is then supplied to a combiner. In this synthesizer (c), the control signal ID is superimposed on the vertical blanking period of the video signal Sv'. The video signal Sv' on which this control signal ID is superimposed is F
After being modulated by the M modulator (to), it is supplied to the magnetic head (to) and recorded on the magnetic tape 0η.

In the example of FIG. 6, if we focus on the operation of the γ control circuit α, the decision circuit (c) supplies a control signal as shown in FIG. 8B, and γ is changed sequentially over time. . Therefore, the video signal sv is processed as shown in FIG. 8C. In this FIG. 8C, ID is a superimposed control signal.

In addition, in Fig. 7 (reproduction system), the video signal sv' reproduced from the magnetic tape 0 by the magnetic head 0 is demodulated by the FM demodulator), and then passed through the clamp circuit (b) for signal processing. Supplied to circuit (2). This signal processing circuit (to) is connected to the γ control circuit (2) and the gain control circuit 0.
The level control circuit performs emphasis processing opposite to that of the signal processing circuit aQ in FIG. 6.

That is, the video signal Sv' passed through the clamp circuit o4 is supplied to the control signal detection circuit 0;
The control signal ID is detected at. This control signal ID is decoded by a code decoder U that constitutes a control circuit, and then a DC level and dyne determination circuit θ → and γ determination circuit
supplied to

Then, based on the decoded control signal, a control signal is supplied to the decision circuit (9), the DC level control circuit 0→, and the dyne control circuit 0. The DC level control circuit (c) and the gain control circuit 0 in FIG. 6 are the DC level control circuit αη and the gain control circuit QF! It is made to operate in the opposite way to I.

Further, based on the decoded control signal, a control signal is supplied to the decision circuit (1) and the gamma control circuit (g).

The .gamma. control circuit (to) operates in the opposite way to the .gamma. control circuit (to) in FIG.

In FIG. 7, focusing on the operation of the γ control circuit (g), a control signal as shown in FIG. 8 is supplied from the determining circuit θ, and γ is changed sequentially over time. Therefore, the video signal Sv' shown in FIG. 8C is processed as shown in FIG. 8A.

The video signal Sv' passed through the clamp circuit 04 is supplied to the synchronization separation circuit (2), and the horizontal and vertical synchronization signals PM and Pv obtained therefrom are supplied to the control circuit 00.

In the end, in the signal processing circuit 09, emphasis processing opposite to that of the signal processing circuit αQ in FIG. 6 is performed, and the original video signal Sv is obtained from this signal processing circuit cLQ.
This is supplied to the output terminal).

As described above, according to the examples of FIG. 6 and FIG. 7, since the amount of emphasis is temporally changed depending on the state of the video signal Sv during recording and reproduction, it is possible to further improve SA. High quality images can be obtained.

Next, FIGS. 10 and 11 show another embodiment of the present invention. In this example, as shown in (■) above, the information signal S1 is a video signal, the signal of each horizontal period of the video signal is time-axis compressed, the control signal ID is superimposed on the empty time region, and the emphasis amount is 1 horizontal period. This is an example in which it can be changed in units of period (1H). In FIGS. 10 and 11, parts corresponding to those in FIGS. 6 and 7 are given the same reference numerals, and detailed explanation thereof will be omitted.

In FIG. 10 (recording system), a video signal Sv as shown, for example, in FIG. 12 AK is supplied to the input terminal α◆. This video signal Sv is supplied to a time axis compression circuit (46) after being passed through a clamp circuit αυ. Further, the video signal Sv passed through the clamp circuit (G) is supplied to the control circuit 0η, and the operation of the compression circuit (4G) is controlled by this control circuit 07.
). Then, from the compression circuit (A), the signal portion of each horizontal period is compressed in the time axis to produce a video signal SVT.
(shown in FIG. 12B) is obtained, and the signal processing circuit (16
supplied to.

The signal processing circuit (16 is a DC level control circuit α that executes the emphasis method of
In addition to the low-frequency and high-frequency level control circuits that implement the emphasis methods of 1 and 2, emphasis processing is performed on the video signal svT in which the amount of emphasis by the methods of 1 and 2 is changed in units of 1H.

That is, the video signal Sv passed through the flange circuit α→ is supplied to the low-pass filter and the bypass filter υ, and the low-frequency component SL and high-frequency component SH detected by each are sent to the control circuit (consisting of 22 circuits). is supplied to the low-frequency and high-frequency level determination circuit ■.Then, this determination circuit
A control signal corresponding to the level of the low frequency component SL and the level of the high frequency component SH is supplied to the high frequency level control circuit (491). The levels of the low frequency component SL and the high frequency component SH of the video signal "VT" are respectively multiplied by a predetermined value.

Incidentally, the portions related to the DC level control circuit a and the dyne control circuit 0→ operate in the same manner as in the example of FIG.

The video signal B/, which has been subjected to emphasis processing according to methods (1) and (2), obtained by these signal processing circuits (16 in total) is supplied to a synthesizer (2).

Further, the control signals from the decision circuit (c) and Zeng are supplied to the encoding circuit (to) and encoded. The coded control signal ID is then supplied to a combiner (4). And this synthesizer CI! At e, the video signal sv′r
The control signal ID is added to the time domain of each horizontal period vacated by the compression of
are superimposed. Then, ``Video signal Sv'rl'i on which this control signal ID is superimposed: FM modulator C? After being modulated by ω, it is supplied to the magnetic head (30) and the magnetic tape 6B is
recorded in

In this example in Fig. 10, the low-frequency and high-frequency level control circuits (
Focusing on the operation 4.2, control signals for controlling the levels of the low-frequency component SL and the high-frequency component SH are supplied from the decision circuit line to the magnifications shown in FIG. 12 C and D, respectively. The level of can be changed sequentially over time.

Therefore, the video signal SvT is processed as shown in FIG. 12E. In this FIG. 12E, it is the superimposed control signal.

In Fig. 11 (reproduction system), the video signal SV!r reproduced by the magnetic tape 6υ and the magnetic head (3z) is demodulated by the FM demodulator (c), and then the video signal SV!r is demodulated by the FM demodulator (c), and then
) to the signal processing circuit (35'). This signal processing circuit (35') is supplied to the low-frequency and high-frequency level control circuit (
On the other hand, the dyne control circuit 0 to the DCC level control circuit performs emphasis processing that is opposite to that of the signal processing circuit (16') in FIG.

That is, the video signal sv passed through the flange circuit C341
4 is supplied to the control signal detection circuit (39), and the control signal ID is detected by this detection circuit 0.This detection signal ID is supplied to the code decoder (4υ) which constitutes the control circuit (40').
After being decoded by the DC level and gain determining circuit (
4 and a low frequency/high frequency level determination circuit.

Then, based on the decoded control signal, a decision circuit -
A low frequency/high frequency level control circuit (incorporated foundation) is supplied with a K control signal. The low-frequency/high-frequency level control circuit I41 is configured to operate in the opposite manner to the low-frequency/high-frequency level control circuit shown in FIG.

Visit PC level control circuit 2 and dyne control circuit 02!1
The related parts are constructed in the same way as the example in FIG.

In the end, the signal processing circuit (35') performs emphasis processing that is opposite to that of the signal processing circuit (16') in FIG. is obtained.

This video signal svT is supplied to a time base expansion circuit. Further, this video signal svT is supplied to a control circuit 6η, and the operation of the expansion circuit branch is controlled by this control circuit 6η. The decompression circuit (4e) operates in the opposite manner to the compression circuit (4e) in FIG. 10, and the original video signal sv (shown in FIG.
K is supplied.

In this way, also in the example of FIG. 10 and the example of FIG. 11, the amount of emphasis is temporally changed depending on the state of the video signal sv during recording and reproduction.

As shown in FIG. 13A, for example, in recording and reproducing a video signal, the luminance signal Y and the color signals R-Y, B-Y are compressed in the time axis and converted into time-series signals. Y
En7 assist can be applied to the color signals R-Y and B-Y separately. For example, if we consider that the gain control circuit α1 has an emphasis, a control signal for controlling the level to the magnification shown in FIG. 13B is supplied from the decision circuit (c) to the control circuit α, and this video signal is The processing can be performed as shown in FIG. 13C.

Next, FIGS. 14 and 15 also show other embodiments of the present invention. In this example, the information signal Sx is an audio signal, and the audio signal is compressed on the time axis at predetermined intervals, and the control signal ID is superimposed on the vacant time area, as shown in (2) above.

In FIG. 14 (recording system), an audio signal SA as shown in FIG. 16A, for example, is supplied to an input terminal. This audio signal SA is supplied to the time base compression circuit. The audio signal sA is also supplied to the control circuit -, and the operation of the compression circuit 6 is controlled by the control circuit -. Then, from the compression circuit axis, the audio signal that has been time-axis compressed at every predetermined period is also transmitted (as shown in Figure 16B).
is obtained.

This audio signal SAT is supplied to the signal processing circuits (16).
Emphasis processing is performed on the audio signal SAT by the methods (2) and (2).

That is, the audio signal SA from the terminal - is supplied to the level detection circuit D, and the signal detected thereby is sent to the control circuit (
2y) is supplied to the gain determining circuit that constitutes the circuit. Then, a control signal corresponding to the detection level is supplied to the decision circuit te2 and the multi-signal processing circuit (16 gain control circuits) to change the dyne. Also, the audio signal sA from the terminal - is processed by the Ronosos filter 6 ( The low frequency component SL and high frequency component SH that are supplied to the bypass filter f) η and detected by each are supplied to a low frequency/high frequency level determination circuit. Processing circuit (16 low frequency and high frequency level control circuits, low frequency component SL and high frequency component S.

A control signal corresponding to the level of is supplied, and the level of each component is multiplied by a predetermined value.

This signal processing circuit (16) is used to obtain an audio signal sA4 (
(shown in FIG. 16C) is supplied with a combiner.

Further, the control signals from the decision circuit 11 and Zeng are supplied to the encoding circuit (to) and encoded. The coded control signal ID is then supplied to a combiner. Then, in this synthesizer, the control signal ID is superimposed on the time area of the audio signal S that is vacant due to compression (16th
(See Figure C).

The audio signal SAT on which the control signal ID is superimposed is supplied to the magnetic head shaft together with, for example, a high frequency audio signal (not shown) and recorded on the magnetic tape ring.

In addition, in Fig. 15 (reproduction system), the audio signal "'AT" on which the control signal ID is superimposed and reproduced by the magnetic tape ring and the magnetic head branch is the low-frequency/high-frequency level control circuit and the gain control circuit. The signal is supplied to a different signal processing circuit (35), and an emphasis process opposite to that of the signal processing circuit (16) in FIG. 14 is performed.

That is, the audio signal SA4 is supplied to the control signal detection circuit 0■, where the control signal ID is detected.

This control signal ID is decoded by a code decoder (4υ) constituting a control circuit (40), and then supplied to a low frequency/high frequency level determining circuit and a dyne determining circuit (2).

Then, based on the control signal, the decision circuit and
A control signal is supplied to the ``-ffilJ control circuit and the gain control circuit, so that the signal processing circuit (the 16 low-frequency and high-frequency level control circuits and the dyne control circuit) shown in FIG. 14 operates in the opposite manner. Therefore, in this signal processing circuit (35), emphasis processing that is opposite to that in the signal processing circuit (16) in FIG. 14 is performed, and from this, an audio signal "AT" (shown in FIG. 16B) is obtained.

This audio signal SAT is supplied to a time axis expansion circuit. Further, this audio signal SAT is supplied to a control circuit, and the operation of the expansion circuit is controlled by this control circuit. Then, the decompression circuit operates in the opposite way to the compression circuit (to) in Fig. 14, and the original audio signal SA (as shown by AK in Fig. 16) is obtained and supplied to the output terminal (to). be done.

In this way, in the example of FIG. 14 and the example of FIG. 15, 1,
Recording and reproduction are performed with the amount of emphasis changed over time according to the state of the signal SA.

Next, FIGS. 17 and 18 also show other embodiments of the present invention. In this example, the control signal ID that temporally controls the emphasis amount of the audio signal as shown in (■) above is
This is an example of superimposing on a video signal that exists simultaneously with an audio signal. In these FIGS. 17 and 18, the 14th
The same reference numerals are given to the parts corresponding to those in the figure and FIG. 15, and detailed explanation thereof will be omitted.

In FIG. 17 (recording system), the video signal Sv is supplied to the input terminal (c), and this is supplied to the time axis compression circuit (7o).Then, from this compression circuit (a), for example, each horizontal period is Video signal Sv whose signal portion is time-base compressed
, is obtained and supplied to the synthesizer (c).

In addition, the audio signal SA is supplied to the terminal (goods),
This is supplied to the signal processing circuit (16) and the control circuit (2
Emphasis processing in which the amount of emphasis is temporally changed is performed by the second control, as in FIG. 12. The encoded audio signal SX obtained by the signal processing circuit (22) is supplied to the magnetic head shaft together with, for example, a high frequency/?earth signal (not shown) and is recorded on the magnetic tape.

The coded control signal ID obtained by the control circuit (22) is supplied to a synthesizer (71).Then, in this synthesizer (c), the video signal Sv' is compressed into an empty time region. A control signal ID is superimposed.

The video signal SvT on which this control signal ID is superimposed is FM
After being modulated by the modulator V→, for example, a rotating magnetic head (7G
and fQ and recorded on the magnetic chip fIe.

In Fig. 1E18 (reproduction system), the video signal SvT reproduced by the rotating magnetic head (c) on the magnetic tape ring and the f-stop is demodulated by the FM demodulator f0 and then supplied to the time axis expansion circuit. Ru. This expansion circuit (to) operates in the opposite manner to the compression circuit (2) in FIG. 17, and the original video signal Sv is obtained and supplied to the output terminal 6υ.

In addition, the audio signal SA' reproduced by the magnetic head fC4 and the magnetic head 4 is supplied to the signal processing circuit (35).The video signal SvT from the demodulator (c) is supplied to the control signal detection circuit 0. The control signal ID is detected here.Then, this control signal ID is supplied to the control circuit (40
supplied to. The signal processing circuit (35 control circuits) operates in the opposite way to the signal processing circuit (16) in FIG. 17, and reverse emphasis processing is performed on the audio signal SA'. , from this signal processing circuit (35), the original audio signal SA is obtained and supplied to the output terminal Q4.

In this way, in the example of FIG. 17 and the example of FIG. 18 as well, the amount of emphasis is temporally changed according to the state of the audio signal SA and is recorded and reproduced.

Also in the other embodiments (Figs. 10 to 18) described above,
Since the emphasis amount is temporally changed and recorded and reproduced according to the state of the video signal Sv or the audio signal SA, the same effects as in the above embodiment can be obtained.

Although the above-mentioned embodiment has been described as an example of a recording/reproducing device, the present invention can be similarly applied to, for example, a transmitting/receiving device for broadcasting. In addition, as an emphasis method,
However, other methods may also be used.

Effects of the Invention According to the present invention described above, an optimum emphasis is applied by changing the amount of emphasis over time according to the state of the information signal, so that SA can be further improved.

[Brief explanation of drawings]

1 and 2 are configuration diagrams showing the principle of the present invention, FIGS. 3 to 5 are diagrams for explaining the invention, and FIGS. 6 and 7 are configuration diagrams each showing one embodiment. Figures 8 and 9 are illustrative diagrams, Figures 10, 11, and 14, respectively.
15'', 17, and 18 are configuration diagrams showing other embodiments, and FIGS. 12, 13, and 16 are diagrams for explanation thereof. (2) α3 is a signal processing circuit, (3) is an emphasis determination circuit, (4) is a synthesizer, (5) is a coding circuit, and (2) is an emphasis decoding circuit.

Claims (1)

[Scope of Claims] 1. An information signal transmission method in which the amount of emphasis of an information signal is changed over time, and a control signal for this emphasis is encoded and superimposed on a part of the information signal before being transmitted. 2. In order to temporally change the amount of emphasis on the information signal, the control signal for this emphasis is encoded and superimposed on a part of the information signal, and then transmitted, and the transmitted information signal is received. An information signal transmission/reception method that applies temporally different emphasis to the control signal. 3. The information signal transmission system according to claim 1, wherein the information signal is a video signal or an audio signal. 4. The information signal transmission and reception system as set forth in claim 2, wherein the information signal is a video signal or an audio signal.