JP2930815B2 - High-definition audio receiving and reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-definition audio receiving / reproducing apparatus compatible with various audio broadcasting modes in a high-definition broadcasting system.

[0002]

2. Description of the Related Art In recent years, with the development of satellite broadcasting and EDTV broadcasting, a television receiver has a large screen and high image quality. Furthermore, the practical use of high-definition broadcasting, which is the next-generation media, is almost at hand. The development of a new acoustic system that complements such a large-screen, high-quality television receiver is also becoming an important issue.

On the other hand, in the current satellite broadcasting, a PCM system capable of obtaining high sound quality has been put to practical use as an audio system. Also in the next generation of high-definition broadcasting, a PCM system is adopted as an audio system, and a new audio system has been proposed which is suitable for a large screen and high image quality of a television receiver.

[0004] The audio system of the high-definition broadcasting system includes A
It is possible to use 4 channels in the mode and 2 channels in the B mode.
A (Broadcasting Technology Council) has proposed this. For example, there are 2-channel stereo, monaural 1, 2-system broadcast, stereo 2-system broadcast, 3-1 stereo broadcast, and the like. In particular, two-channel stereo and 3-1 stereo broadcasting using four channels are new broadcasting systems not present in current broadcasting, and are a major feature of the next high-definition broadcasting. Further, in the 3-1 stereo broadcast, for example, “Television Society Journal” Vol. 4
2 No. 6 (1988) As described in the paper entitled "Stereo Audio System for Hi-Vision" on p. A system with a sense of realism has been developed and proposed.

However, as a conventional Hi-Vision audio reproducing apparatus, a 3-1 stereo system is considered, and audio signals for four channels from an audio decoder are directly connected to an audio output apparatus, and each of the four audio signals is transmitted to four audio channels. -Simply connect to the mosquito and output it.

[0006]

In the above prior art,
No consideration is given to compatibility with various audio broadcasting modes in future high-definition broadcasting. For example, one stereo broadcast is selected and played to the left and right speakers in the stereo two-system broadcast mode, or one channel audio is monaural in all the speakers in the bilingual multiplex broadcast.
There is a problem that operations such as reproduction with a camera cannot be performed.

[0007] In addition, stereo two-system broadcast mode and 3-1
In 4-channel broadcasting such as stereo broadcasting mode,
You may need more than four mosquitoes. However, when this is reproduced by a home-use receiver, it may be inevitably reproduced by two speakers on the left and right, and no consideration has been given to this. For this reason, in the stereo two-system broadcasting mode, the sub stereo cannot be reproduced, and in the 3-1 stereo broadcasting mode, only the left and right two channels can be reproduced.
There is a problem that the stereo reproduction is degraded in quality.

SUMMARY OF THE INVENTION An object of the present invention is to provide a high-definition audio receiving / reproducing apparatus which can solve such a problem and can output high-quality audio signals of 4 and 2 channels in correspondence with various high-definition broadcasting modes. To provide.

[0009]

In order to achieve the above-mentioned object, the present invention provides a plurality of audio broadcast modes, and includes first to fourth channels transmitted as 4-channel digital data. In a high-definition audio receiving / reproducing apparatus for receiving, demodulating and reproducing an audio signal, first to fourth audio output terminals as output terminals of a 4-channel audio signal;
Audio output means having fifth and sixth audio output terminals as output terminals for channel audio signals, detecting the received audio broadcast mode, and detecting a mode corresponding to the audio broadcast mode A mode detection means for generating a signal, and the demodulated audio signals of the first, third and fourth channels are added at a predetermined addition ratio to form a first added audio signal, and the demodulated second audio signal is formed. Signal conversion means for adding the audio signals of the second, third and fourth channels at a predetermined addition ratio to form a second addition audio signal, and addition ratio adjustment for adjusting the addition ratio of the signal conversion device Means, a silent state generating means for generating a silent signal, and controlled in accordance with the mode detection signal;
, The first to fourth audio signals demodulated to the output terminals
Signal switching means for selecting and outputting either the second added audio signal or the silence signal.

[0010]

The first to fourth output terminals are output terminals for four channels, and the fifth and sixth output terminals are output terminals for two channels. Therefore, these first to fourth output terminals can be connected to the front left, front right, front center, and rear speakers of a four-channel audio system or the like, and the fifth to sixth output terminals can be connected.
Can be connected to a two-channel audio terminal of a television receiver or the like or a two-channel audio terminal of a VTR.

The signal switching means appropriately selects the audio signals of the first to fourth channels, the first and second added audio signals, and the silence signal in accordance with the audio broadcasting mode, and outputs the signals to the first to fourth output terminals. And to the fifth and sixth output terminals. Thereby, a 4-channel audio signal corresponding to the audio broadcasting mode is output from the first to fourth output terminals, and a 2-channel audio signal corresponding to the audio broadcasting mode is output from the fifth and sixth output terminals. As a result, optimum high-quality sound reproduction can be performed by the above-described devices connected to the respective terminals.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a high-definition audio receiving / reproducing apparatus according to the present invention.
Is an audio decoder, 4 is an audio reproduction block, 5 is an audio control block, 6 is an addition ratio adjustment circuit, 7 and 8 are mixers, 9 is a signal selection control circuit, 10 is a broadcast mode detection circuit, and 11 is a control signal generation. Circuit, 12 is a mute control circuit, 13-1
8 is an amplifier, 19 is a two-channel system HDTV receiver, 20 is a left speaker, 21 is a right speaker, 2
2 is an audio system, 23 is a left speaker, 24 is a right speaker, 25 is a center speaker, 26 is a rear speaker, and 27 is a sound reproduction mode selector.

In FIG. 1, a Hi-Vision signal input from an input terminal 1 is supplied to a Hi-Vision audio separation circuit 2, and a digital audio data signal which is time-division multiplexed to a video signal is extracted. This digital audio data signal is supplied to an audio decoder 3 and subjected to processing such as detection of an audio synchronizing signal, bit / word deinterleaving, error correction / interpolation, PCM demodulation, and the like. Is output and the audio playback block 4
Supplied to However, the audio signals of these channels may be analog signals. In this case, a D / A (digital / analog) converter is provided at the output of the audio decoder 3. Hereinafter, the digital audio signals of the respective channels are sequentially converted from the first channel to ch1, ch2, ch.
3 and ch4 signals.

The audio reproduction block 4 comprises mixers 7, 8, a mute control circuit 12, a signal selection control circuit 9, and the like. In the audio reproduction block 4, all of the ch1 to ch4 signals are supplied to the signal selection control circuit 9, and the ch1, ch3, and ch4 signals are supplied to the mixer 7 so that the addition ratio adjustment circuit 6 of the audio control block 5 The signals are added at a ratio according to the output control signal S1, and
The 2, ch3 and ch4 signals are also supplied to the mixer 8 and added at a ratio according to the control signal S1. The output signals of the mixers 7 and 8 are supplied to the signal selection control circuit 9 as ch1 'and ch2' signals, respectively. The signal selection control circuit 9 is controlled by a control signal S2 from the audio control block 5.

On the other hand, the audio control block 5 includes an addition ratio adjustment circuit 6, a broadcast mode detection circuit 10, and a control signal generation circuit 1.
1. It is composed of a sound reproduction mode selector 27 and the like. As described above, the addition ratio adjusting circuit 6 includes the mixer 7,
8, a control signal S1 for setting the addition ratio of the ch3 and ch4 signals to the ch1 and ch2 signals is generated. Broadcast mode
As will be described later, for example, the two-channel T
Various broadcast modes, such as V audio, bilingual broadcast, and 3-1 stereo broadcast, are detected from the coded data CD output from the audio decoder 3. The sound reproduction mode selector 27 is used for TV / additional sound and TV sound (main / sub / main +
Sub), main / sub stereo, multiplexed monaural audio, 4-channel to 2-channel conversion, and through-mode switching.
In response to the mode detection signal MD output from the broadcast mode detection circuit 10, a selector mode signal SM corresponding to the state of the audio reproduction mode selector 27 is generated. The control signal generation circuit 11 generates a control signal S2 corresponding to the mode detection signal MD from the broadcast mode detection circuit 10 and the selector mode signal SM from the audio reproduction mode selector 27, and supplies them to the audio reproduction block 4.

Therefore, in the audio reproduction block 4,
The control signal S2 from the control signal generation circuit 11 is supplied to the signal selection control circuit 9 and the mute control circuit 12.
The signal selection control circuit 9 uses the control signal S2 to control the input audio source, ch1 to c corresponding to various broadcast modes.
h4, ch1 ', ch2', etc., and select the most appropriate audio signal, and select the selected audio signal L1, R1, C, S, L2,
Output as R2. After being amplified by the amplifiers 13, 14,..., 18, these selected audio signals are output from the audio output terminals 53, 54,. When the control signal S2 indicates that it should be muted,
The mute control circuit 12 detects this and controls the signal selection control circuit 9 so that the signal selection control circuit 9 does not select and output any input signal. This will mute.

When the input signal of the signal selection control circuit 9 is a digital signal, a D / A converter is provided at the output of the signal selection control circuit 9 for each selected audio signal.
These selected audio signals can be output as analog audio signals.

The above 6 output from the audio reproduction block 4
Of the two selected audio signals, two-channel selected audio signals L2 and R2 output from audio output terminals 53 and 54 are 2
The channel system is for the high-definition television receiver 19, and is supplied to its left speaker 20 and right speaker 21, respectively. The remaining four channels of the selected audio signal outputs L1, R1, C and S are the left speaker 23, the right speaker 24, the center speaker 25, and the rear speaker 26.
The selected audio signal L1 is to the left speaker 23, the selected audio signal R1 is to the right speaker 24, and the selected audio signal C is to the center speaker. The selected audio signal S is supplied to the rear speaker 26.

Next, the functions and operations which characterize the high-definition audio receiving / reproducing apparatus of the present invention will be described with reference to FIGS. FIG. 2 is a diagram showing the form of each audio broadcasting mode in the high-definition broadcasting system, audio channel sources corresponding to each audio output, and a selection method by the signal selection control circuit 9.

As shown in FIG. 2, the audio modes in the high-definition broadcasting system include a two-channel mode using two-channel audio signals and a four-channel mode using four-channel audio signals. . The two-channel mode includes a TV audio broadcast and an additional audio broadcast. The TV audio broadcast includes a main / sub audio bilingual multiplex broadcast, a monaural broadcast, and a two-channel stereo broadcast. There is only stereo broadcast. In the 4-channel mode, in addition to 3-1 stereo broadcasting, multiplex stereo broadcasting of main and sub stereos and main audio, sub 1, sub 2, sub 3
A four-multiplex audio broadcast of audio is also conceivable. Furthermore, there is a through mode which is not related to the broadcasting mode.

1 to 4 in the column of "audio output" in FIG. 2 correspond to ch1 to ch output from the audio decoder 3 in FIG.
Four signals are abbreviated. Also, 1 + 3 '+ 4', 2
Although + 3 '+ 4' are described later, ch1, ch added at the addition ratio determined by the control signal S1 by the mixer 7 of FIG.
The added signal of the ch3 and ch4 signals, and the ch2 and ch added by the mixer 8 of FIG. 1 at the addition ratio determined by the control signal S1.
3 shows the addition signal of the ch4 signal. M indicates that the selected audio signal is muted.

Further, as a sound output form of the receiver, a four-output form for outputting four kinds of sounds and a two-output form for outputting two kinds of sounds are possible. FIG. 2 shows these two audio output modes collectively, and the selected audio signal
When the signal is output for the channel system, the signal source name for the selected audio signals L1, R1, C, S of the signal selection control circuit 9 is shown. When the selected audio signal is output for a two-channel system, the selected audio signals are indicated as L2 and R2. Here, the two-channel selected audio signals L2 and R2 are mainly used for a TV receiver with a built-in two-speaker or a VTR for two-channel audio recording. Hereinafter, these audio output modes will be described.

As a control method of audio channel selection,
As shown in the rightmost column of FIG. 2, there are ten types A to J. The method of selecting a source channel for each broadcast mode is as follows.

(1) In the case of a two-channel stereo broadcast, L1, R
Allocated to one channel, C and S channels are muted. Only the TV sound is always assigned to the L2 and R2 channels. (2) In the case of bilingual or monaural 4 multiplex broadcasting, L
Reproduction of only one channel of main / sub sound, or main + sub sound, main / sub 1 in all of 1, R1, C, S channels
Simultaneous reproduction of all three sounds can be selected. In addition, it is possible to select the reproduction of only one channel of the main / sub sound of the TV sound, or the simultaneous reproduction of all the main / sub sound and the main / sub sound 1 to 3 for both the L2 and R2 channels. (3) In the case of multiplex stereo broadcasting, the main stereo (ch
1, ch2) or sub-stereo (ch3, ch4). These signals are assigned to the L1 and R1 channels and the L2 and R2 channels, and the C and S channels are muted. (4) In the case of 3-1 stereo broadcast, 4-channel audio is allocated to L1, R1, C, and S channels. Also,
As described above, switching to the 4-channel / 2-channel conversion signal is possible. Furthermore, since the L2 and R2 channels are used for a 2-channel dedicated TV receiver, VTR recording, and the like, the above-mentioned 4-channel / 2-channel conversion signal is always assigned in 3-1 stereo broadcasting. (5) In the through mode, regardless of the broadcast mode, four-channel audio is always provided for the L1, R1, C, and S channels, and L1, R2 channels are provided for the L2, R2 channels.
Allocate the same sound as one channel.

FIG. 3 is a block diagram showing a specific example of the audio reproduction block 4 in FIG.
Reference numerals 29 and 30 denote input terminals for digital audio data from the decoder 3 in FIG. 1, reference numerals 31 and 32 denote switch circuits,
34 is a digital filter, 35 to 38 are terminals, 39,
40 is a switch circuit, 41 to 44 are D / A converters, 45
48 to LPF (low-pass filter), 49 to 52 are amplifiers, 53 to 58 are output terminals, 59 to 64 are switch circuits, 65 and 66 are mute circuits, and 82 and 92 to 97 are input terminals. Parts corresponding to 1 are denoted by the same reference numerals.

Referring to FIG.
Ch1 from the audio decoder 3 of FIG.
Digital audio data D1 including the ch2 signal and digital audio data D2 also including the ch3 and ch4 signals are input from the input terminal 30, respectively. These digital audio data D1 and D2 may be serial data or parallel data, but here are serial data. FIG. 6 shows an example of the data format in this case. Further, the audio control block 5 receives, from the input terminal 82, code data CD indicating the broadcast mode from the audio decoder 3, and outputs a control signal S 2 corresponding to this input terminal 92 of the audio reproduction block 4.
, And the control signal S1 generated by the addition ratio adjusting circuit 6 (FIG. 1) to the input terminal 28 of the audio reproduction block 4. The control signal S2 includes switch switching control signals SW1, SW2, SW3, SW4, and SW5 and a mute on / off control signal MT. The switch switching control signals SW1, SW2, SW3, SW4, and SW5 are input terminals 92, 93, From 95, 96, and 97, the mute on / off control signal MT is input to the audio reproduction block 4 from the input terminal 94.

Digital audio data D1, D input
Reference numeral 2 denotes terminals a and b of the switch circuit 31 that is switched by the switch switching control signal SW1 and a switch circuit 3 that is switched by the same switch switching control signal SW1.
2 terminals b and a, respectively. Switch circuit 3
As will be described later, the states of the switch circuits 31 and 32 are different depending on the switch control signal SW1, and the switch circuits 31 and 32 may both be closed to the terminal a side or the terminal b side. Side, the switch circuit 32 closes to the terminal a, and conversely, the switch circuit 31 closes to the terminal a and the switch circuit 32 closes to the terminal b.

The digital audio data output from the switch circuit 31 is supplied to a digital filter 33, where the digital audio data is filtered to remove aliasing components and the like, and is divided into digital audio data of different channels.
5 and 36 are supplied to the terminals a and b of the switch circuit 39. Similarly, the digital audio data output from the switch circuit 32 is also supplied to the digital filter 34, where the digital audio data is filtered to remove aliasing components and is divided into digital audio data of different channels. Output and switch circuit 40
Are supplied to the terminals a and b.

The switch circuits 39 and 40 have two switching circuits, and have two common terminals c1 and c2 common to the input terminals a and b on the output side, respectively. As will be described later, the states of the switch circuits 39 and 40 differ according to the switch switching control signal SW2, and the common terminals c1 and c2 may select different terminals a and b, respectively. a or b may be selected.

The common terminals c1 and c2 of the switch circuit 39
The digital audio data output from is supplied to D / A converters 41 and 42, respectively, and converted into analog audio signals. LPFs 45 and 46 remove noise outside the audio band, and are amplified by amplifiers 49 and 50. After that, the audio signals are supplied to mixers 7 and 8 as audio signals L and R, respectively, and are also supplied to terminals a of switch circuits 63 and 64. These audio signals L and R are further supplied to terminals a of switch circuits 59 and 60. Similarly, digital audio data output from the common terminals c1 and c2 of the switch circuit 40 are supplied to D / A converters 43 and 44, respectively, and converted into analog audio signals. Are amplified by the amplifiers 51 and 52, and the audio signals C and S output from the amplifiers 51 and 52 are removed.
Are supplied to the mixers 7 and 8 and the audio signal C
Is connected to the terminal b of the switch circuit 61 and the mute circuit 65,
The audio signal S is supplied to the terminal b of the switch circuit 62 and the mute circuit 66, respectively.

In the mixer 7, the three-channel analog audio signals L, C, and S from the amplifiers 49, 51, and 52 are added at a predetermined addition ratio determined by the control signal S 1 from the audio control block 5. Similarly, amplifiers 50 and 5
3, 52 analog audio signals R from
C and S are added at a predetermined addition ratio determined by the control signal S1. The audio signal L 'output from the mixer 7 is supplied to terminals b of the switch circuits 59 and 63, respectively, and the audio signal R' output from the mixer 8 is supplied to the switch circuits 60 and 6.
The signals are supplied to four terminals b. Switch circuits 59 and 60
Are supplied to the terminals a of the switch circuits 61 and 62, respectively.

Here, the switch circuits 63 and 64 are switch-controlled by a switch switch control signal SW3 from an input terminal 95, and the switch circuits 61 and 62 are connected to an input terminal 9
The switch circuits 59 and 60 are controlled to be switched by the switch switching control signal SW5 from the input terminal 97, respectively, by the switch switching control signal SW4 from the switch 6. The mute circuits 65 and 66 are on / off controlled by a mute on / off control signal MT from an input terminal 94. Here, turning on the mute circuits 65 and 66 means that mute is applied. The switch circuits 59 and 60, the switch circuits 61 and 62, and the switch circuits 63 and 64 are respectively
When one selects the terminal a, the other also selects the terminal a, and when one selects the terminal b, the other also selects the terminal b.

The output audio signals from the switch circuits 63 and 64 are the selected audio signals L1 and R1 output from the output terminals 55 and 56 described above, and hereinafter, the output audio signals from the switch circuits 61 and 62. Are output terminals 53 and 54
And the selected audio signals C and S output from the output terminals 57 and 58, respectively.

FIG. 4 shows each switch circuit 3 in FIG. 3 in the control systems A to J corresponding to each broadcast mode shown in FIG.
1,32,39,40,63,64,59,60,6
FIG. 3 is a diagram showing states of the mute circuits 65 and 66 and mute circuits 65 and 66. In the drawing, "-" indicates that the state of the switch circuit to which this is attached has no relation to the operation of this embodiment. For example, regarding the control method B, since the mute circuits 65 and 66 are in a mute state and the switch circuits 61 and 62 are closed to the terminal a side, the amplifier 5
The audio signals C and S output from the audio reproduction devices 1 and 52 are not output from any output terminal of the audio reproduction block 4. Therefore, the states of the switch circuits 32 and 40 have no relation to the operation in the control system B.

In order to realize the control methods A to J shown in FIG. 2, each of the switch circuits and the mute circuits 65,
The state of 66 is set by the control signal S2 as shown in FIG.

For example, in the case of the through mode shown in FIG. 2, the control method is A, and according to FIG.
1, 32, 63, 64, 59, 60, 61 and 62 are all closed to the terminal a side, and the common terminal c1 of the switch circuits 39 and 40 selects the terminal a and the common terminal c2 selects the terminal b. In addition, the mute circuits 65 and 66 are in a mute-off state, and pass the audio signal as it is without being muted.

In this state, the digital audio data D1 shown in FIG. 6 is supplied to the digital filter 33 through the switch circuit 31, and is divided into a ch1 signal and a ch2 signal. The signals are output to the terminals 36, respectively. The ch1 signal is the switch circuit 3
9, a D / A converter 41, an LPF 45, and an amplifier 49 to become an audio signal L. This audio signal L is output as a selected audio signal L1 from an output terminal 55 through a switch circuit 63, and a switch circuit 59. , 61 and output from the output terminal 53 as the selected audio signal L2.
The ch2 signal is supplied to the switch circuit 39 and the D / A converter 4
2, an LPF 46 and an amplifier 50 to become an audio signal R. This audio signal R is output as a selected audio signal R1 from an output terminal 56 through a switch circuit 64, and is also output as an output terminal through switch circuits 60 and 62. From 54, it is output as the selected audio signal R2.

In the case of the digital audio data D2 shown in FIG.
2, a ch3 signal is output to a terminal 37 by a digital filter 34, and a ch4 signal is output to a terminal 38. The ch3 signal is supplied to the switch circuit 40 and the D / A converter 4
3, the audio signal C passes through the LPF 47 and the amplifier 51, and the audio signal C passes through the mute circuit 65 and is output from the output terminal 57 as the selected audio signal C. Also, c
The h4 signal is output from the switch circuit 40, D / A converter 44, LP
The sound signal S passes through the F48 and the amplifier 52 and becomes a selected sound signal S from the output terminal 58 through the mute circuit 66.

Therefore, as shown in FIG. 2, in the through mode, the selected audio signals L1 and L2 are the ch1 signal, the selected audio signals R1 and R2 are the ch2 signal, and the selected audio signal C is the ch3 signal. , The selected audio signal S is a ch4 signal.

In the case of the TV 2-channel stereo broadcast mode, the control method is B. This is the selected audio signal L
1 and L2 are ch1 signals and selected audio signals R1 and R2 are ch
Two signals, which mute the selected audio signals C and S. In the control method B, the same control is performed when bilingual reproduction of main and sub-audios, selection of TV audio in the additional audio broadcast mode, and selection of the main stereo of multiplex stereo. In order to realize this, according to FIG.
6 are turned on to mute the selected audio signals C and S, and switch circuits 31, 32, 39 and 4 are turned on.
The states of 0, 59 to 64 are the same as in the control method A. However, the state of the switch circuits 32 and 40 is determined by the control method B
Does not matter.

When the sub stereo of the multiplex stereo broadcast is selected, the control method is C. This is the selected audio signal L
1, L2 are ch3 signals, and selected audio signals R1, R2 are ch
There are four signals for muting the selected voice signals C and S. In order to realize this, the same as the control method B except that the switch circuit 31 is closed to the terminal b side in FIG. 4, and the digital audio data D2 shown in FIG. ch
Divide into four signals.

Next, the case of monaural sound reproduction will be described. First, in the case of reproducing the main audio of the TV audio, the control method is D. As shown in FIG. 2, the selected audio signals L1, R1, C, S, L2, and R2 are all ch1 signals. In the control method D, the same control is performed at the time of TV monaural audio reproduction and main audio reproduction of 4-channel multiplex broadcasting. In order to realize this, as shown in FIG. 4, the switch circuit 31 is selected on the terminal a side, and the switch circuit 32 is selected on the terminal b side. According to this, the switch circuits 31, 3
2 selects the same digital audio data D1 shown in FIG. Common terminals c1, c2 of switch circuits 39, 40
Has selected the terminal a side, so that the digital filter 3
The ch2 signal output from the terminals 3 and 34 to the terminals 36 and 38 is cut off by the switch circuits 39 and 40 and the amplifiers 49 to 52
The audio signals L, R, C, and S output from are all ch1 signals. Then, since the switch circuits 59 to 64 are closed to the terminal a side, and the mute circuits 65 and 66 are both turned off and muting is not applied, the selected audio signals L1, R1, C, S, L2 obtained at the output terminals 53 to 58. R2 all become ch1 signals.

As another monaural sound reproduction mode,
As shown in FIG. 2, the selected audio signals L1, R1, C, S,
TV audio sub-audio reproduction in which all L2 and R2 are only ch2 signals, 4-channel multiplex sub-audio reproduction (control method E),
Similarly, there are four-channel multiplexed sub-two-sound reproduction using only the ch3 signal (control method F) and four-channel multiplexed two-sound reproduction using only the ch4 signal (control method G). These can also be realized by determining the states of the switch circuits and the mute circuits 65 and 66 as shown in FIG.

In the case of selecting the 3-1 stereo mode in the 3-1 stereo broadcast mode, the control method is H. This is, as shown in FIG. 2, the selected audio signals L1, R1, C,
S is a ch1, ch2, ch3, and ch4 signal, respectively, and a signal obtained by adding the selected audio signal L2 to the ch1, ch3, and ch4 signals at a predetermined ratio by the mixer 7, that is, the ch1 ′ signal and the selected audio signal R2 are set to ch2 and ch3. , Ch4 signals by the mixer 8 at a predetermined ratio,
2 ′ signal. About this addition ratio,
It will be described later.

To realize this, the switch circuit 3
1, 32, 39, 40, 61 to 64 and mute circuit 6
The states 5 and 66 are the same as those in the case of the control method A, except that the switch circuits 59 and 60 select the terminal b. In this state, the audio signals L, R, C, and S output from the amplifiers 49, 50, 51, and 52 are ch1, ch2, ch3, and ch4, respectively, as in the control method A.
And the selected audio signals L1, R1, C, and S obtained at the output terminals 55, 56, 57, and 58 are ch1 and ch, respectively.
2, ch3 and ch4 signals. However, the added sound signal L 'from the mixer 7 is output from the output terminal 53 through the switch circuits 59 and 61, and the added sound signal R' from the mixer 8 is output through the switch circuits 60 and 62. Output from terminal 54. Therefore, the selected audio signal L2
Is an added audio signal L ', that is, an added signal ch1' having a predetermined ratio of the ch1, ch3, and ch4 signals.
2 is an added sound signal R ', that is, an added signal ch2' having a predetermined ratio of the ch2, ch3, and ch4 signals.

In the case of selecting the 4-channel / 2-channel conversion mode in the 3-1 stereo broadcast mode, the control method is I. This is because, as shown in FIG. 2, the selected audio signals L1 and L2 are used as the ch1 'signals by the mixer 7,
The selected audio signals R1 and R2 are converted into channels by the mixer 8 described above.
The 2 'signal is used to mute the selected audio signals C and S. To realize this, as shown in FIG. 4, the switch circuits 31, 32, 39, 40, 59, 6
0, 61, and 62 are the same as those in the case of the control system H, except that the switch circuits 63 and 64 select the terminal b side, and the mute circuits 65 and 66 are turned on to select the selected audio signals C and S. Try to mute.

According to this, the added audio signal L ′ output from the mixer 7, that is, the ch1 ′ signal is
3, the added audio signal R ′ output from the mixer 8, that is, the ch2 ′ signal output from the mixer 8 is output from the output terminal 56 through the switch circuit 64, and the selected audio signals C and S are output. Is different from the control method H only in that mute is performed. Therefore, as described above, the selected audio signals L1 and L2 become the ch1 'signal, the selected audio signals R1 and R2 become the ch2' signal, and the selected audio signals C and
S cannot be obtained.

In the case of the additional audio selection in the additional audio broadcast mode, the control method is J. The selected audio signals L1 and R1 are ch3 and ch4 signals, respectively, the selected audio signals C and S are muted, and the selected audio signals L2 and R2 are
Always output only the TV sound, so ch1 and c
h2 signal.

To realize this, as shown in FIG. 4, both the switch circuits 31 and 32 are closed to the terminal b side,
The common terminals c1 and c2 of the switch circuits 39 and 40 select the terminal a and the terminal b, respectively. Further, the switch circuits 63 and 64 are closed to the terminal a side,
The switch circuits 61 and 62 are closed to the terminal b side, and the mute circuits 65 and 66 are turned on to mute the selected audio signals C and S. By turning on these mute circuits 65 and 66, the states of the switch circuits 59 and 60 become irrelevant.

In this state, since the switch circuit 31 selects the digital audio data D2 and the switch circuit 32 selects the digital audio data D1, the digital filter 33 sends the ch3 signal and the ch4 signal to the terminals 35 and 36, respectively.
A signal is output and the digital filter 34 outputs
The ch1 signal and the ch2 signal are output to 7 and 38, respectively.
Then, the ch3 signal and the ch4 signal pass through the switch circuit 39, and are respectively D / A converters 41 and 42, LPFs 45 and 4,
6, output from the output terminals 55 and 56 via the amplifiers 49 and 50 and the switch circuits 63 and 64 as selected audio signals L1 and R1. The ch1 signal and the ch2 signal pass through the switch circuit 40, and are respectively D / A converters 43 and 44, L
PF47, 48, amplifiers 51, 52, switch circuit 6
Via the output terminals 1 and 62, the selected audio signals are output from the output terminals 53 and 54 as selected audio signals L2 and R2. In this case, since the mute circuits 65 and 66 are turned on, the selected audio signals C and S are selected.
Is muted and is not output.

As described above, since the output terminals 53 and 54 for outputting the selected audio signals L2 and R2 are output terminals dedicated to two channels of TV audio, they are automatically detected in the 3-1 stereo broadcast mode. The 4-channel / 2-channel conversion addition signal, that is, the above-mentioned ch1 'and ch2' signals, and in the additional audio broadcast mode, even if the additional audio mode is selected, ch1 and ch1 which are TV audio signals are always used. ch2
Only signals will be output.

FIG. 5 is a block diagram showing a specific example of the voice control block 5 in FIGS. 1 and 3, and reference numeral 71 denotes a TV.
/ Additional audio changeover switch circuit, 83 is a 3-1 stereo broadcast mode detection circuit, 84 is an additional audio broadcast mode detection circuit, 85 is a 2-channel TV audio broadcast mode detection circuit,
86 is a 4-channel multiplex stereo broadcast mode detection circuit;
87 is a 4-channel multiplex audio broadcast mode detection circuit;
Is a 4-channel-2 channel conversion switch circuit,
Reference numeral 89 denotes a main / sub / main + sub audio switch circuit, 90 denotes a main / sub stereo switch circuit, 91 denotes a monaural audio switch circuit, and 120 denotes a through-mode switch circuit. Are given the same reference numerals.

In FIG. 5, a broadcast mode detection circuit 10 includes a 3-1 stereo broadcast mode detection circuit 83, an additional audio broadcast mode detection circuit 84, a two-channel TV audio broadcast mode detection circuit 85, and four-channel multiplexing. It comprises a stereo broadcast mode detection circuit 86 and a four-channel multiplex audio broadcast mode detection circuit 87. One of these detection circuits 83 to 87 detects the broadcast mode based on the code data CD from the input terminal 82 and performs the broadcast mode. Outputs a detection signal.

Here, the 3-1 stereo broadcast mode detection circuit 83 detects the 4-channel stereo broadcast mode in FIG. 2 based on the code data CD, and the additional audio broadcast mode detection circuit 84 performs the 2-channel additional audio broadcast mode. , 2
The channel TV audio broadcast mode detection circuit 85 is a 2-channel TV audio broadcast mode, the 4-channel multiplex stereo broadcast mode detection circuit 86 is a 4-channel multiplex stereo broadcast mode, and the 4-channel multiplex audio broadcast mode detection circuit 87. Respectively detect the four-channel monaural multiplex audio broadcast mode.

The audio reproduction mode selector 27 is a TV
/ Additional audio changeover switch circuit 71, 4 channel-2 channel conversion changeover switch circuit 88, main / sub / main + sub sound changeover switch circuit 89, main / sub stereo changeover switch circuit 90, monaural sound changeover switch circuit 91 and through It comprises a mode changeover switch circuit 120, a 4-channel to 2-channel conversion changeover switch circuit 88, a TV / additional sound changeover switch circuit 71, a main / sub / main + sub sound changeover switch circuit 89, and a main / substereo changeover switch circuit. 9
The 0 and monaural audio changeover switch circuits 91 are a 3-1 stereo broadcast mode detection circuit 83, an additional audio broadcast mode detection circuit 84, and a two-channel TV audio broadcast mode detection circuit 85 of the broadcast mode detection circuit 10, respectively. Upon receiving a broadcast mode detection signal from the 4-channel multiplex stereo broadcast mode detection circuit 86 and the 4-channel multiplex audio broadcast mode detection circuit 87, the control code corresponding to the user's instruction operation is output. In the through mode, the through mode switch circuit 120 outputs a control code for the through mode.

The control signal generation circuit 11 is provided with the changeover switch circuits 71, 88 to 91, 1 of the audio reproduction mode selector 27.
20 and a broadcast mode detection signal output from the 2-channel TV audio broadcast mode detection circuit 85 of the broadcast mode detection circuit 10 and switch switching control signals SW1 and SW2 corresponding thereto. , SW3
It outputs SW4, SW5 and a mute on / off control signal MT.

Next, the operation of this specific example in each broadcast mode will be described. In 2-channel TV audio broadcasting mode:
In this case, the code data CD from the input terminal 82 indicates a multiplexed audio, a two-channel TV audio broadcast mode of a monaural or stereo mode, and the two-channel TV audio broadcast in the broadcast mode detection circuit 10. Mo
And a broadcast mode signal indicating one of these modes is generated. This broadcast mode detection signal is transmitted to the main / sub / main +
The signal is supplied to either the sub sound changeover switch circuit 89 or the control signal generation circuit 11. Upon receiving the broadcast mode detection signal, the main / sub / main + sub audio switching switch circuit 89 sets the state according to the user's instruction operation, and supplies a control code determined by this state to the control signal generation circuit 11.

Here, in the multiplex audio mode, a multiplex audio broadcast mode detection signal indicating the multiplex audio mode is supplied to the main / sub / main + sub audio switch circuit 89, and this main / sub / main A state according to the user's instruction operation is set in the + sub-audio switch circuit 89. And this Lord /
The sub / main + sub audio switch circuit 89 generates a control code determined by the state and supplies it to the control signal generation circuit 11.
Switch switching control signals SW1, SW2, S corresponding to this
W3, SW4, SW5 and mute on / off control signal M
By generating T, the control method D, E or B shown in FIG. 2 can be executed.

That is, when the main / sub / main + sub audio switch circuit 89 is in the state indicating the main audio selection, the state of each switch circuit and mute circuit in FIG. 3 is set as in the control system D shown in FIG. Then, as shown in FIG. 2, the selected audio signals L1, R1, C, S, L2, and R2 are all ch1 audio signals. When the main / sub / main + sub audio switch circuit 89 is in a state indicating the sub audio selection, FIG.
The state of each switch circuit and mute circuit is set as in the control method E shown in FIG. 4, and as shown in FIG. 2, all the selected audio signals L1, R1, C, S, L2, and R2 are set to ch2.
It is an audio signal. Further, when the main / sub / main + sub audio switch circuit 89 is in a state indicating (main + sub) audio selection, each switch circuit and mute circuit in FIG. Then, as shown in FIG. 2, the selected audio signals L1 and L2 are ch1 signals, the selected audio signals R1 and R2 are ch2 signals, and the selected audio signals C and S are muted.

In addition, a monaural or stereo broadcast mode
In the case of the mode, a control code corresponding to each mode is supplied from the 2-channel TV audio broadcast mode detection circuit 85 to the control signal generation circuit 11, and the switch switching control signals SW1, SW2, SW3, SW4, SW5, By generating a mute on / off control signal MT, regardless of the state of the main / sub / main + sub audio switch circuit 89, FIG.
The control method D or B shown in FIG. Therefore, in the monaural broadcast mode, each switch circuit and the mute circuit in FIG. 3 are set to the state as in the control system D shown in FIG. 4, and the selected audio signals L1, R1, C, S,
Let L2 and R2 be ch1 audio signals. In the stereo broadcast mode, the switch circuits and the mute circuit in FIG. 3 are set in the state as in the control system B shown in FIG. 4, the selected audio signals L1 and L2 are set to the ch1 signal, and the selected audio signals R1 and R1 are set. R2 is used as the ch2 signal to select the audio signal C,
Mute S.

In the case of the two-channel additional audio broadcast mode:
In this case, the code data CD from the input terminal 82 is 2
The additional audio broadcast mode detection circuit 84 in the broadcast mode detection circuit 10 represents the channel additional audio broadcast mode.
To generate a broadcast mode detection signal indicating the two-channel additional audio broadcast mode. This broadcast mode detection signal is supplied to a TV / additional audio changeover switch circuit 71 in the audio reproduction mode selector 27, and the TV / additional audio changeover switch circuit 71 is set to a state according to a user's instruction operation. And a TV / additional audio changeover switch circuit 7
1 generates a control code according to the state and supplies it to the control signal generation circuit 11. Therefore, the control signal generation circuit 11 switches the switch control signals SW1, S corresponding to the control code.
W2, SW3, SW4, SW5 and a mute on / off control signal MT are generated to appropriately set the states of the switch circuit and the mute circuit in FIG.

Here, when the TV sound is selected, the same control as in each of the two-channel TV sound broadcasting modes is performed as shown in FIG.

When the TV / additional audio changeover switch circuit 71 is in a state indicating the selection of additional audio, each switch circuit and mute circuit in FIG. 3 are set in the state as in the control system J shown in FIG. 4, and are shown in FIG. As shown in FIG.
1 and R1 are ch3 and ch4 signals, respectively, and the selected audio signals L2 and R2 are ch1 and ch2 signals, respectively, to mute the selected audio signals C and S.

In the case of the 4-channel stereo broadcast mode:
In this case, the code data CD supplied from the input terminal 82 represents the 3-1 stereo broadcast mode of the 4-channel stereo broadcast mode.
The 3-1 stereo broadcast mode detection circuit 83 detects the 3-1 stereo broadcast mode, and outputs a broadcast mode detection signal indicating the detected mode. When this broadcast mode detection signal is received, the state of the 4-channel to 2-channel conversion switch circuit 88 in the audio reproduction mode selector 27 is set according to the user's instruction operation, and the control code determined by the state is controlled. The signal is supplied to the signal generation circuit 11. The control signal generation circuit 11 generates switch switching control signals SW1, SW2, SW3, SW4, SW5 and a mute on / off control signal MT according to the control code, and can execute the control method H or I shown in FIG. To

That is, when the four-channel / two-channel conversion changeover switch circuit 88 is in a state indicating the 3-1 stereo selection, each switch circuit and the mute circuit in FIG. 3 are set to the state as in the control system H shown in FIG. And FIG.
As shown in FIG. 3, the selected audio signals L1, R1, C, and S are ch1, ch2, ch3, and ch4 signals, respectively, and the selected audio signals L2, R2 are ch1 that is the added audio signal from the mixers 7, 8 in FIG. ', Ch2' signal.

When the four-channel / two-channel conversion changeover switch circuit 88 is in a state indicating the selection of the four-channel / two-channel conversion, each switch circuit and the mute circuit in FIG. 3 are set to the state as in the control system I in FIG. Then, as shown in FIG. 2, the selected audio signals L1 and L2 are
The selected audio signals C1 and Sch are muted as the 1 'signal and the selected audio signals R1 and R2 as the ch2' signal.

In the case of the 4-channel multiplex stereo broadcast mode: In this case, the code data CD from the input terminal 82 indicates the 4-channel multiplex stereo broadcast mode.
The 4-channel multiplex stereo broadcast mode detection circuit 86 in the broadcast mode detection circuit 10 detects this and supplies a broadcast mode detection signal indicating the 4-channel multiplex sub-stereo broadcast mode to the main / sub-stereo switch circuit 90. I do. The main / sub stereo switch 90 is connected to the broadcast mode.
When receiving the state detection signal, the state is set to a state corresponding to the user's instruction operation, and a control code corresponding to this state is supplied to the control signal generation circuit 11. The control signal generation circuit 11 generates switch switching control signals SW1, SW2, S corresponding to the control code.
W3, SW4, SW5 and mute on / off control signal M
T is generated so that the control method B or C shown in FIG. 2 can be executed.

That is, the main / sub stereo switch circuit 9
When 0 indicates the main stereo selection, each switch circuit and the mute circuit in FIG. 3 are set in the state as in the control system B shown in FIG. 4, and the selected audio signals L1 and L2 are set as shown in FIG. ch1 signal and the selected audio signal R
1 and R2 are used as ch2 signals to mute the selected audio signals C and S.

When the main / sub-stereo selector switch circuit 90 is in a state indicating sub-stereo selection, each switch circuit and mute circuit in FIG.
As shown in FIG. 2, the selected audio signals L1 and L2 are set as ch3 signals, and the selected audio signals R1 and R2 are set as shown in FIG.
Is used as a ch4 signal to mute the selected audio signals C and S.

In the case of the 4-channel monaural multiplex audio broadcast mode: the code data CD from the input terminal 82 indicates any of the 4 channels, and the broadcast mode detection circuit 10
The four-channel multiplex audio broadcast mode detection circuit 87 detects a broadcast mode detection signal indicating the four-channel multiplex audio broadcast mode. Upon receiving the broadcast mode detection signal, the monaural audio changeover switch circuit 91 is set to a state corresponding to the user's instruction operation, and supplies a control code determined in this state to the control signal generation circuit 11. The control signal generation circuit 11 generates switch switching control signals SW1, SW2, SW3, SW4, SW5 and a mute on / off control signal MT according to the control code, and controls the control system D, E, F or G shown in FIG. To be able to run.

That is, the monaural audio changeover switch circuit 91
Is in the state indicating the channel 1, each switch circuit and the mute circuit in FIG. 3 are set in the state as in the control system D shown in FIG. 4, and as shown in FIG. 2, the selected audio signals L1, L2, C, S, R1, and R2 are all ch1 signals. When the monaural audio changeover switch circuit 91 is in the state indicating channel 2, the state of each switch circuit and mute circuit in FIG. 3 is set as in the control system E shown in FIG. 4, and as shown in FIG. L1, L
2, C, S, R1, and R2 are all ch2 signals. When the monaural sound changeover switch circuit 91 is in the state indicating channel 3, the state of each switch circuit and mute circuit in FIG. 3 is set as in the control system F shown in FIG.
As shown in FIG. 2, the selected audio signals L1, L2, C, S,
Let R1 and R2 be all ch3 signals. When the monaural audio changeover switch circuit 91 is in the state indicating channel 4, the state of each switch circuit and the mute circuit in FIG. 3 is set as in the control system G shown in FIG. 4, and as shown in FIG. L1, L2, C, S, R1, and R2 are all ch4 signals. In this way, the audio of any channel can be reproduced by the two-channel system high-definition television receiver 19 and the audio system 22 (FIG. 1).

In the case of a through mode (output as it is) irrelevant to the broadcast mode: in this case, the through mode changeover switch circuit 120 is set to a state indicating the through mode by a user's instruction operation. A control code indicating the through mode determined by this state is generated, and the control signal generation circuit 11
Supplied to The control signal generation circuit 11 takes in the control code in preference to the control codes from the other changeover switch circuits 88, 71, 89, 90, 91 and the broadcast mode detection signal from the broadcast mode detection circuit 10, and incorporates the control code into this control code. Corresponding switch switching control signals SW1, SW2, SW3, SW
4, SW5 and a mute on / off control signal MT are generated so that the control method A shown in FIG. 2 can be executed.

That is, the control signal generation circuit 11 generates the switch switching control signals SW1, SW2, SW3, SW4
SW5 and the mute on / off control signal MT
, The state of each switch circuit and mute circuit is set as in the control system A shown in FIG. 4, and the selected audio signals L1, L2, C, and S are respectively set to ch1, ch2, c as shown in FIG.
h3 and ch4 signals, and the selected audio signals L2 and R2 are ch1 and ch2 signals, respectively.

FIGS. 7A and 7B are circuit diagrams showing specific examples of the mixers 7 and 8 of FIG. 3 used in the 4-channel / 2-channel conversion mode, respectively. )
, 67 is an input terminal, 68 to 70 are coefficient multipliers,
72 and 73 are input terminals, 74 is an adder, and 75 is an output terminal. In FIG. 7B, reference numeral 76 denotes an input terminal,
77 to 79 are coefficient multipliers; 72 and 73 are input terminals;
Is an adder, and 81 is an output terminal. Reference numeral 28 denotes an input terminal of the control signal S1 shown in FIG.

In FIG. 7A, an audio signal L output from an amplifier 49 (FIG. 3) is input to an input terminal 67, multiplied by a coefficient α in a coefficient multiplier 68, and supplied to an adder 74. You. Also, audio signals C and S output from the amplifiers 51 and 52 (FIG. 3) are input to the input terminals 72 and 73, respectively.
Is input and multiplied by a coefficient β1 and a coefficient β2 by coefficient multipliers 69 and 70, and then supplied to an adder 74. Adder 74
The output signals of these coefficient multipliers 68, 69, 70 are added, and the output signal is supplied from an output terminal 75 to a terminal b of the switch circuits 59, 63 in FIG. The coefficients β1, β of the coefficient multipliers 69, 70
Numeral 2 corresponds to the control signal S1 from the input terminal 28.

The same applies to the mixer 8 shown in FIG.
That is, the audio signal R output from the amplifier 50 (FIG. 3) is input to the input terminal 76, multiplied by the coefficient α in the coefficient multiplier 77, and supplied to the adder 80. Also, the input terminal 7
The audio signals C and S output from the amplifiers 51 and 52 (FIG. 3) are input to the multipliers 2 and 73, respectively.
After being multiplied by a coefficient β1 and a coefficient β2 by 9, it is supplied to an adder 80. In the adder 80, these coefficient multipliers 77, 7
The output signals 8, 79 are added, and the output signal is supplied from the output terminal 81 to the terminal b of the switch circuits 60, 64 in FIG. Here, the coefficients β1 and β2 of the coefficient multipliers 78 and 79 are in accordance with the control signal S1 from the input terminal.

The value of the coefficient α of the coefficient multipliers 68 and 77 is normally set to 1, and the coefficient β of the coefficient multipliers 69 and 78 is
The values of ₁ and β ₂ of the coefficient multipliers 70 and 79 are respectively determined by the control signal S1 supplied from the addition ratio adjusting circuit 6 (FIG. 1).
Although it can be varied in the range of values from 0 to 1, it is usually set to a value of 0.7.

FIG. 8 is a circuit diagram showing a specific example of the mute circuits 65 and 66 of FIG. 3. Reference numeral 94 denotes an input terminal of a mute on / off control signal MT, and 98 denotes an audio signal C or S.
, 99 is a switch circuit, and 101 is an output terminal of the selected audio signal C or S.

In the figure, the switch circuit 99 is turned on / off by a mute on / off control signal MT input to the input terminal 94 from the mute control circuit 12 of FIG. Then, each is closed to the terminal a side. Therefore, when the mute is on, the audio signal C input from the amplifier 51 of FIG. 3 to the input terminal 98 or the audio signal C input from the amplifier 52 of FIG.
Is interrupted (muted) by the switch circuit 99, and the output terminal 101 cannot obtain the selected audio signal C or S. When the mute is off, the audio signal C or S input to the input terminal 98 is output.
Passes through the switch circuit 99, and the selected audio signal C or S is obtained at the output terminal 101. The output terminal 101
Corresponds to the output terminal 57 or 58 in FIG.

As described above, in this embodiment, 6
Optimal audio signals corresponding to the respective broadcast modes can be obtained at the three output terminals 53 to 58. That is, the output terminal 5
3, 54 are dedicated output terminals for 2-channel TV sound,
The output terminals 55 to 58 are used for additional audio, for four-channel stereo broadcasting, and the like, and can reproduce a high-quality sound signal with no uncomfortable feeling even in four-channel broadcasting. The two-channel output terminals 53 and 54 can be used as audio recording terminals for a VTR or the like in accordance with both the two-channel and four-channel broadcast modes, and can also be used as TV audio monitors. Can be.

FIG. 9 is a block diagram showing another specific example of the audio reproduction block 4 in FIG.
Is a demultiplexer, 104 is an input terminal, and 105 is a selector. The parts corresponding to those in FIG.

In this specific example, the switching operation of the audio channel switch and the addition operation of the audio signal are all intensively performed by the analog audio processing unit after the D / A conversion. Next, the configuration and operation of this specific example will be described.

Referring to FIG. 9, digital audio data D as shown in FIG.
1 and D2 are filtered by digital filters 33 and 34, respectively, and then supplied to demultiplexers 102 and 103 to be divided into ch1 and ch2 signals and ch3 and ch4 signals. These signals are D / A converters 41 to 4 respectively.
4. The signals are processed by the LPFs 45 to 48 and the amplifiers 49 to 52, and are supplied to the terminals I ₁ , I ₂ , I ₃ and I ₄ of the selector 105 as analog audio signals L, R, C and S.

The audio signals L, C, and S from the amplifiers 49, 51, and 52 are supplied to the mixer 7, where they are added at a ratio corresponding to the control signal S1 from the addition ratio adjustment circuit 6, and the added audio signal L 'is added. Is generated. Similarly, amplifiers 50, 51,
The audio signals R, C, S from 52 are supplied to the mixer 8,
Addition is performed at a ratio corresponding to the control signal S1 from the addition ratio adjustment circuit 6 to generate an added audio signal R ′. These added audio signals L ′ and R ′ are supplied to terminals I ₅ and I ₆ of the selector 105. In the mixers 7 and 8, L,
The C and S signals are added to the R, C and S signals.

[0085] The selector 105 as an input terminal, to the other terminal I ₁ ~I _6, has a terminal I _7, the terminal I ₇
Indicates that the input level for mute is zero potential. Also,
As output terminals, there are terminals O ₁ , O ₂ , O ₃ , O ₄ , O ₅ , and O ₆ , and as shown in FIG. 1, output terminals 53, 54, 55, 56, 57, 58. The selector 105 is switch-controlled by a control signal S1 input from the control signal generation circuit 11 of FIG. 1 to the input terminal 104, and the terminals O ₁ , O ₂ , O ₃ , O ₄ , O in response to the control signal S2. ₅ and O ₆ are connected to _one of terminals I _{1 to} I ₇ , respectively. Thereby, these output terminals 5
3, 54, 55, 56, 57, 58 have audio signals L, R,
C, S, L ', R' are selected audio signals L2, R2, L1,
It will be obtained as any of R1, C and S.

FIG. 11 is a diagram showing a control method for each broadcast mode and a signal selecting operation in the selector 105.
Here, the relationship between the broadcast mode and the control methods A to J is as shown in FIG. 2, and the output terminals O _{1 to} O ₆ and the input terminals I
₁ connection relationship between ~I ₇ is selected for each broadcast mode audio signals L
1, R1, C, S, L2, and R2 are to be the signals shown in FIG. Therefore, also in the specific example shown in FIG. 9, the same audio signal as in the specific example shown in FIG. 3 is obtained at the output terminals 53 to 58 in each broadcast mode.

FIG. 10 shows the sound reproduction block 4 in FIG.
FIG. 10 is a block diagram showing still another specific example of FIG.
Numerals 110 to 110 indicate D / A converters, 118 and 119 indicate digital mixers, and 121 indicates a data selector. The parts corresponding to those in FIG.

This specific example has basically the same configuration as the specific example shown in FIG. 9, except that a mixer and a selector are arranged in front of the D / A converter, and a digital audio signal Is different from the specific example shown in FIG. 9 in that the selected audio signal is obtained in digital form by selecting.

The digital audio data D1 and D2 as shown in FIG. 6 input from the input terminals 29 and 30 are filtered by digital filters 33 and 34, respectively.
Supplied to the demultiplexers 102 and 103 and c
The signal is divided into an h1 signal and a ch2 signal, and a ch3 signal and a ch4 signal. Then, the ch1, ch3, and ch4 signals are supplied to the digital mixer 118, and are digitally added at a ratio determined by the control signal S1 from the addition ratio adjusting circuit 6, thereby forming a digitally added audio signal DL '.
The ch2, ch3, and ch4 signals are supplied to a digital mixer 119, and are digitally added at a ratio determined by the control signal S1 from the addition ratio adjustment circuit 6, to form a digitally added audio signal DR '.

The digitally added audio signals DL ', D
R ′ is represented by the following equation. DL ′ = α ch1 + β ₁ ch3 + β ₂ ch4 DR ′ = α ch2 + β ₁ ch3 + β ₂ ch4 where α, β ₁ , and β ₂ are addition coefficients determined by the control signal S1 from the addition ratio adjustment circuit 6. Is a value in the range.

The ch1, ch2, ch3, and ch4 signals output from the demultiplexers 102 and 103 are respectively demultiplexed.
Terminals I ₁ , I ₂ , I as input terminals of the selector 121
_3, is supplied to the I _4, also, a digital mixer 118,
19, the digital added audio signals DL ', D
R 'is a terminal I as an input terminal of the data selector 121.
₅ and I ₆ . Note that the data selector 121
Terminal I ₇ for muting to the zero potential and the input signal also has. Further, the data selector 121 has terminals O _{1 to} O ₆ as output terminals, and receives a control signal S 2 from the input terminal 104 to output a terminal I ₁ according to the broadcast mode, as shown in FIG. connection relationship between ~I ₇ and the terminal O ₁ ~ O ₆ is set. Therefore, terminals O _{1 to} O ₆ are connected to ch1 and ch1, respectively.
Any of the ch2, ch3, and ch4 signals, the digitally added audio signals DL 'and DR', and the zero potential signal are obtained.

The signals obtained at the terminals O _{1 to} O ₆ of the data selector 121 are converted into analog audio signals by D / A converters 105 to 110, respectively, and processed by LPFs 111 to 116 and amplifiers 13 to 18. Output terminals 53, 54, 5
5, 56, 57, 58 select audio signals L2, R2, L
1, R1, C, and S are output.

As described above, in this embodiment, in audio broadcasting using four channels of high-definition broadcasting, 4
Since a dedicated TV 2-channel audio terminal is provided separately from the channel audio output terminal, not only a 2-channel stereo broadcast and a bilingual broadcast, but also a new broadcast mode can be realized with a speaker with a built-in television receiver.
It is possible to switch and select each channel audio signal from an optimal audio decoder for each broadcast mode corresponding to -1 stereo, multiple stereo, multiple monaural broadcasting, and the like. Further, by connecting the above-mentioned two-channel output terminal to the two-channel audio input terminal of the current VTR,
It is also possible to record one stereo 4-channel broadcast without feeling uncomfortable. Therefore, in both the two-channel and four-channel systems, it is possible to reproduce from the high-quality music broadcasting with a sense of realism to the multiplex audio information program while making the most of the high-definition various audio broadcasting.

[0094]

As described above, according to the present invention,
In both the two-channel and four-channel systems, high-quality audio signals can be optimally selected and reproduced according to the various audio modes of the four channels of high-definition broadcasting, and recording on a VTR or the like is also possible. It becomes possible by connecting an output terminal dedicated to two channels. Further, since unnecessary output terminals are muted, unnecessary noise does not occur.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a high-definition audio receiving and reproducing apparatus according to the present invention.

FIG. 2 is a diagram showing output audio channels for each broadcast mode in the embodiment shown in FIG.

FIG. 3 is a block diagram showing a specific example of an audio reproduction block in FIG. 1;

FIG. 4 is a diagram illustrating a state of each switch circuit for each control method in the specific example illustrated in FIG. 3;

FIG. 5 is a block diagram showing a specific example of an audio reproduction mode selector and a broadcast mode detection circuit in FIG. 1;

FIG. 6 is a diagram showing a format of input digital audio data in FIG. 3;

FIG. 7 is a configuration diagram showing a specific example of the mixer in FIGS. 1 and 3;

FIG. 8 is a configuration diagram showing a specific example of the mute circuit in FIG. 3;

FIG. 9 is a block diagram showing another specific example of the audio reproduction block in FIG. 1;

FIG. 10 is a block diagram showing still another specific example of the audio reproduction block in FIG. 1;

FIG. 11 is a diagram showing the operation of the selector in FIGS. 9 and 10;

[Explanation of symbols]

 Reference Signs List 3 audio decoder 4 audio reproduction block 5 audio control block 6 addition ratio adjustment circuit 7, 8 mixer 9 signal selection control circuit 10 broadcast mode detection circuit 11 control signal generation circuit 12 mute control circuit 27 audio reproduction mode Selector selector 31, 32, 39, 40, 59 to 64 switch circuit 65, 66 mute circuit 105 selector 118, 119 digital mixer 121 data selector

──────────────────────────────────────────────────続 き Continuation of the front page (72) Kazuhiro Kaizaki 4-6 Kanda Surugadai, Chiyoda-ku, Tokyo Hitachi, Ltd. (56) References JP-A-3-85831 (JP, A) JP-A Sho57 -4609 (JP, A) JP-A-5-95334 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H04H 5/00 301 H04N 5/60 H04S 1/00

Claims (4)

(57) [Claims] 1. A high-definition audio receiving and reproducing apparatus having a plurality of audio broadcasting modes, receiving, demodulating, and reproducing audio signals of first to fourth channels transmitted as 4-channel digital data. A sound output means having first to fourth sound output terminals as output terminals of a four-channel sound signal, and fifth and sixth sound output terminals as output terminals of a two-channel sound signal; A mode detection means for detecting the audio broadcast mode and generating a mode detection signal corresponding to the audio broadcast mode; and demodulated audio signals of the first, third and fourth channels. Are added at a predetermined addition ratio to form a first added audio signal, and the demodulated second, third, and fourth channel audio signals are added at a predetermined addition ratio to form a second added audio signal. Signal conversion means for performing the Means for adjusting the addition ratio by means, means for generating a silent state for generating a silent signal, and when the audio broadcast mode is a predetermined four-channel broadcast mode, the audio output means To select and supply any one of the audio signals of the first to fourth channels, the first and second added audio signals, and the silence signal to the first to fourth output terminals. And the fifth and sixth output terminals of the audio output means.
And a second signal switching means for outputting the first and second added audio signals based on the video detection signal. 2. A high-definition audio receiving / reproducing apparatus having a plurality of audio broadcasting modes, receiving, demodulating, and reproducing audio signals of first to fourth channels transmitted as digital data of four channels. In the above, audio output means having first to fourth audio output terminals as output terminals of four-channel audio signals, and fifth and sixth audio output terminals as output terminals of two-channel audio signals, A mode detection means for detecting the audio broadcast mode and generating a mode detection signal corresponding to the audio broadcast mode; a silent state generating means for generating a silent signal; When the mode is an additional audio broadcast mode in which the audio signals of the third and fourth channels include an additional audio signal independent of the TV audio signal, the first and the second audio output means may be used.
The second audio output terminal selects and outputs the demodulated TV audio signal of the first and second channels or the demodulated additional audio signal of the third and fourth channels, and outputs the selected audio signal. To the third and fourth output terminals,
The first signal switching means for outputting the silent signal; and the fifth and sixth output terminals of the audio output means,
And a second signal switching means for selecting and outputting the demodulated TV audio signals of the first and second channels based on the video detection signal. 3. A high-definition audio receiving / reproducing apparatus having a plurality of audio broadcasting modes, receiving, demodulating and reproducing audio signals of first to fourth channels transmitted as digital data of four channels. A sound output means having first to fourth sound output terminals as output terminals of a four-channel sound signal, and fifth and sixth sound output terminals as output terminals of a two-channel sound signal; A mode detection means for detecting the audio broadcast mode and generating a mode detection signal corresponding to the audio broadcast mode; a silent state generating means for generating a silent signal; When the audio signal of the mode or the third and fourth channels is other than the additional audio broadcast mode including the additional audio signal independent of the TV audio signal, each of the first to fourth audio output means is used. Output terminal First signal switching means for selecting and outputting any one of the demodulated audio signals of the first to fourth channels and the silence signal in response to a mode detection signal; and the audio output means. Second signal switching means for selecting and outputting the same audio signal as the audio signal output to the first and second output terminals to the fifth and sixth output terminals, and corresponding to the mode detection signal. Voice control means for generating a control signal.
A high-definition audio reception / reproduction device for performing switching control of the signal switching means. 4. A high-definition audio receiving / reproducing apparatus having a plurality of audio broadcasting modes and receiving, demodulating and reproducing audio signals of the first to fourth channels transmitted as 4-channel digital data. An audio output means having first to fourth audio output terminals as output terminals of a four-channel audio signal, and fifth and sixth audio output terminals as output terminals of a two-channel audio signal; First signal switching means for selecting and outputting the demodulated audio signals of the first to fourth channels to first to fourth output terminals of the output means; and fifth and sixth signal output means of the audio output means. And a second signal switching means for selecting and outputting the demodulated first and second channel audio signals at the output terminal, and always providing the first and second channel audio signals regardless of the audio broadcasting mode. Audio signal by signal switching means A high-definition audio reception / playback device, which performs a selection operation of: