JPS62128289A - Multiplex broadcasting system in catv - Google Patents

Abstract

PURPOSE:To change over and select a sound according to the desire of a present viewer by multiplexing data of an FM broadcasting channel corresponding to a sound area of a TV broadcasting channel in a center side, and tuning the FM broadcasting channel to the TV broadcasting channel selected in a receiver side by the use thereof. CONSTITUTION:In the center side, a data multiplexing encoder 18 is disposed, the data of a data signal generator 15 is inputted to an FM data modulator 16, added to the output of a video and first sound source 1 by an adder 17 after an FM modulation, and as a result, said data is multiplexed on the signal area of the TV broadcasting channel, In a terminal side, the signal from a trunk line is separated into a TV frequency band and an FM frequency band by a wave separator 46, a changeover switch 28 selects the first sound or the second sound by manual operation of the viewer and a PLL circuit feeds PLL data according to the selection. The tuned signal passes through an IF amplifier 31, and an FM detector 32, is stereo-demodulated in an MPX circuit 33 and a multiplex broadcasting service can be obtained.

Description

[Detailed description of the invention] [Industrial application field]

The present invention transmits the first audio (main audio) and the second audio (auxiliary audio) on a channel different from the video broadcasting channel, and also transmits the above two audios on different channels.
This invention relates to a multiplex broadcasting system for CATV that performs multiplex broadcasting by broadcasting.

[Prior art and problems]

Conventionally, in this type of multiplex broadcasting system tuned to 0ATV, in addition to the selection operation of the TV broadcast channel, for FM broadcast, the audio corresponding to the above broadcast channel is
Broadcast Chi 1? It was troublesome to take it out from the channel by selecting it. This is because there is no data sent from the center side to check the correlation between TV broadcast channels and FM broadcast channels, and of course the problem is that the receiving side lacks a means to recognize the channel selection. There is. The present invention has been made based on the above circumstances, and
FM broadcast channel corresponding to the audio area of the channel
This is a multiplex broadcasting system for C△TV, which multiplexes data about the I channel, decodes it on the receiving side, and automatically selects the FM broadcast channel specified by this data. (Means to Solve the Problem) For this purpose, the present invention provides a method for broadcasting B voice on FM channel n, which is a video broadcast channel.
The ATV center side transmits multiple voices on different channels, and the own voice signal area of the TV broadcast channel is multiplexed with the data of the FM broadcast channel that is multiplexing the above-mentioned voices. Demodulate the channel data of the multiplexed broadcast within the band from the audio signal area of the TV broadcast channel, and send the channel data of one of the above audio to the FM receiver depending on the selection. It is characterized by being tuned to a designated FM broadcast channel. [Example] Hereinafter, an example of the present invention will be specifically described with reference to the drawings. In FIG. 1, reference numeral 18 is a data multiplex encoder on the center side, and reference numeral 13 is the first chip 1! This is a channel data switch that sets data for the first audio FM stereo broadcast channel, which will be described later. Reference numeral 14 is a second channel data switch,
This is to set the data of the FM stereo broadcast channel 17 of the second audio. Further, reference numeral 15 indicates the above-mentioned No. 1.
a data signal generator that sets each channel data according to the second channel data switch 13.14;
G is an FM data modulator that performs FM modulation on this data, and inputs the data to the adder 17 together with the output of the video/first audio source 1, and as a result, the data is multiplexed on the audio signal. Together with this output, the output of the video/first audio source 1 is input to the TV/IF modulator 2, and then input to the channel up converter 4 via the IF scramble encoder 3, where it is converted to each channel frequency. be done. On the other hand, the FM stereo audio of the first @voice passes through the first stereo encoder 5, the first FM audio modulator 6, and the first @voice FM stereo audio.
The signal is supplied to a multiplier amplifier 7. Similarly, the FM stereo sound of the second sound is supplied from the second sound source 9 to the second stereo encoder 10, passes through the ffi2 FM sound modulator 11, and is input to the second multiplier amplifier 12. Next, these images and monaural audio system. The FM stereo audio system of the first audio and the FM stereo audio system of the second audio pass through the first mixing 298 and are sent out together with the signals of other channels. On the terminal side in FIG. 2, a signal frequency-converted and descrambled in the CATV terminal 19 is supplied to the TV set 20. On the other hand, the CATV terminal group 19
The output signal is input to the stereo receiver 34, mixed with the output signal of the local oscillator 22 by the mixer 21, converted into a video IF signal and an audio IF signal, and then sent to the video detector 2.
3. The signal passes through an audio detector 24 and a bandpass filter 25 and is input to a data detector 26, where the data is detected. Reference numeral 27 denotes an FM tuner controller, which selects the first audio or the second audio by switching the changeover switch 2B, and sends PLL data according to the changeover of the changeover switch 28 to the PLL circuit 29. Then, the voltage υ controlled oscillator in the FM tuner front end 30 is controlled and tuned. The reference numeral 31 is an IF amplifier, 32 is an FM@ waver, 33 is an MPX circuit, and the signal after stereo demodulation is sent from an audio amplifier 35 to a speaker 36. The signal is supplied to speaker R37. In such a configuration, a data multiplex encoder 18 is provided on the center side, data for a first audio FM stereo broadcast channel to be described later is set by a first channel data switch 13, and data for a first audio FM stereo broadcast channel, which will be described later, is set by a first channel data switch 13. The data of the second audio FM stereo broadcast channel is set by the data signal generator 15.
The data is generated according to the set values of both the switches 13 and 14. This data is input to the FM data modulator 16, and after FM modulation, addition 2! It is added together with the output of the video/first audio source 1 at step 1117, and as a result, the above data is multiplexed into the audio area of the VhII transmission channel. This output signal and the output of the video/first audio source 1 are input to a TV-TF modulator 2, and then input to an IF scramble encoder 3 as a video IF signal and an audio IF signal. Here, the video IF signal is scrambled, and a descramble data code is multiplexed onto the audio IF signal. This signal is subjected to frequency comparator 1 in the channel up converter 4 to, for example, l-1ch. On the other hand, the FM stereo sound of the first sound is input to the first stereo encoder 5, FM modulated by the first FM sound modulator 6, and then FM-modulated by the first multiplier amplifier 7 in the FM broadcast band, e.g.
Become MHZ. Similarly, the FM stereo sound of the second sound is inputted from the second sound source 9 to the second stereo encoder 10, and is FM modulated by the second FMfr voice modulator 11.
For example, 89.4 in the FM broadcast band by the second multiplication band 12.
M1 (becomes Z. The video and monaural audio system, the FM stereo audio system of the first audio, and the FM stereo audio system of the second audio are synthesized through the first mixer 8 and On the other hand, on the terminal side, the signal from the main line is sent to T by a branching filter 4G.
It is divided into V frequency band and FM broadcast band, and the former is CΔT
The signal is input to the V terminal 19, frequency converted and descrambled, and then supplied to the TV set 20. At this time, the viewer listens to monaural audio on the TV set 20.The latter is input to the FM tuner front end 30.On the other hand, the output signal of the CATV terminal 19 is transmitted to the stereo receiver. 34, where it is mixed with the local oscillator 22 and frequency-converted into a video IF signal and an audio IF signal.
3 and an audio detector 24, a bandpass filter 25 passes only the data signal in the audio domain. Then, the T that is currently selected by the data detector 25 is
The stereo broadcast channel data added to the audio signal of the V broadcast channel is demodulated. This data is input to the 1M tuner controller 27. The changeover switch 28 allows the viewer to manually select the first audio or the second audio, and sends PLL data according to the selection to the PLL circuit 19. For example, when the TV broadcast channel is 11C11 and the viewer selects the first audio, the voltage control excavator in the FM tuner front end 30 is controlled to tune to 89MHz. Also, if the viewer selects the second audio, F
Controls the voltage controlled oscillator in the M tuner front end 30 and tunes to 89.4 MHz. Furthermore, for example, if a viewer tunes in to LCL+, which carries out the first audio broadcast at 90M I-IZ and the second audio broadcast at 90.4M HZ, the multiplexed data will be broadcast at 90M HZ and LJ. 90.4M HZ (selected by manual switching by the viewer), the 1M tuner controller 27 selects P L L
Sends PLL data to the circuit 29 and controls the voltage controlled oscillator in the FM tuner front end 30.
0MHz Hz or 90.4M l-1z 1. : You will be selecting a channel. The signal 9 tuned in this way is connected to the IF amplifier 31. After passing through the FM detector 32 and being stereo demodulated by the MPX circuit 33, the signal is supplied from the audio amplifier 35 to the Lisby power 136 and the speaker R37, thereby providing a multiplex broadcast service. In the above embodiment, the selection switch 28 selects the first voice or the second @voice, and the 1M tuner controller 27 sends PLL data to the PLL circuit 29 according to the selection to operate the FM tuner front end 30. However, as seen in the example in Figure 3, PL
L circuit 29. FM tuner front end 30.1F amplifier 31. It is equipped with the same circuit configuration as the FM detector 32 and MPX circuit 33 (PLL circuit 38. FM tuner front end 39. IF amplifier 40. FM detector 41. MPX circuit 42), and is branched into the FM broadcast band. The signal is divided into two parts, and the FM tuner front ends 30 and 39
You may also enter it in Here, the FM tuner controller 21 provides the PLL circuit 29 with the FM tuner of the first audio.
Broadcast channel P 1. , L data is sent to the PLL circuit 38, and the P of the second audio FM broadcast channel is sent to the PLL circuit 38.
Sends LL data. By doing this, the FM tuner front end 30 will be tuned to 89 MHz, which is the first stereo broadcast, and the FM tuner front end 39 will be tuned to 89.4 MHz, which is the second stereo broadcast. Ru. However,
The selection is made by the viewer's switching operation on the changeover switch 43. In this case, the output signal of the MPx circuit 42 is input to the audio amplifier 44 and then can be heard as second stereo sound through the headphones 45. In this embodiment, in addition to the benefits of the previous embodiment, the speaker 36.3? The user can listen to the first stereo audio or the second stereo audio using the headphones 45, and listen to the second stereo audio using the headphones 45 at the same time. In the above embodiment, the first and second sounds on the center side are stereo sounds, but they may be monaural. In addition, on the center side, the third voice, fourth voice,
...Audio may also be multiplexed and corresponding data signals may be prepared.

【Effect of the invention】

The present invention has been described in detail above, and on the printer side, the TV
The data of the FM broadcast channel corresponding to the a voice area of the broadcast channel is multiplexed, and this is used to select the T
Vfi transmission channel, FMtiIi transmission channel, transmission channel, audio can be switched and selected according to the current viewer's request.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the center side showing one embodiment of the present invention, FIG. 2 is a block diagram of the terminal side, and FIG. 3 is a block diagram showing a modification of the terminal side. 1... Video/first audio source, 2... TV/IF modulator, 3... IF scramble encoder, 4...
Channel up converter, 5...1st stereo Δ encoder, 6...1st FM? J voice modulator, 7...
1st multiplier amplifier, 8... 1st mixer, 9... 2nd audio source, 10... 2nd stereo encoder, 11...
...m2FMf voice modulator, 12...second multiplier amplifier,
13...1st channel data switch, 14...
2nd channel data switch, 15... Data signal generator, 1G... FM data modulator, 17... Adder, 18... Data multiplex encoder, 19-CAT
V terminal, 2O-TV set, 2i-12 mixer, 2
2... Local oscillator, 23... Video detector, 24
...Audio detector, 25...Band pass filter, 2
G... Data detector, 27... FM tuner controller, 28... Selector switch, 29... PLL circuit, 3o... FM tuner front end, 31...
・IF amplifier, 32...FM detector, 33...MP
X circuit, 34...stereo receiving device, 35...A-
Dio amplifier, 36...Speaker L131...Speaker R138...PLL circuit, 39...FM tuner front end, 40...IF amplifier, 41...
FM detector, 42... MPX circuit, 43... changeover switch, 44... A-din amplifier, 45... headphones, 46... duplexer.

Claims (1)

[Claims] FM audio on a different channel than the video broadcast channel
When broadcasting, the CATV center transmits multiple audio signals on different channels, and also transmits multiple audio signals on different channels.
The audio signal area of the V broadcast channel is multiplexed with the data of the FM broadcast channel that performs multiplex broadcasting of each of the above-mentioned sounds, and on the receiving side, the multiplexed data from the audio signal area of the TV broadcast channel is multiplexed within that band. A multiplex broadcasting system in CATV, characterized in that broadcasting channel data is demodulated, and channel data of one of the above-mentioned sounds is sent to an FM receiver according to selection, and the channel data is tuned to the FM broadcasting channel specified by the data. .