JP2000115100A - Notice broadcasting system and its terminal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable other subscribers to receive a music broadcast even in a notice broadcast. SOLUTION: The main channel and subchannel of a TV sound multiplex system are used. Music information (b) is always distributed from a CATV center 100 over the subchannel. A notice broadcast and a specific address (a) are sent from the terminal device 200 of a notifier to subscribers through the CATV center 100 when needed. The terminal device 300 of a subscriber receives notice information by changing the channel when the address is coincident and changes the channel again at the end of the notice information to receive the music broadcast. A terminal device 300 of a subscriber whose address is not coincident, receives the music broadcast continuously over the subchannel. Consequently, even when a specific terminal device receives the notice broadcast, the reception of the music information by other terminal devices is never interrupted. Further, the existent sound multiplex system is used, so an inexpensive notice broadcasting system can be structured which effectively uses frequencies.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cable broadcasting system for transmitting notification information and music information to offices or homes using a cable. In particular, the present invention relates to a notification broadcast system in which a notifier specifies a subscriber's terminal device using a CATV transmission path and transmits information, and a terminal device thereof. INDUSTRIAL APPLICABILITY The present invention is applicable to a notification broadcasting system that transmits notification information to a specified terminal device without interrupting music information to another terminal device.

[0002]

2. Description of the Related Art Conventionally, there is a cable broadcasting system in which a plurality of terminal devices are provided in a predetermined area to provide announcement information and music information. Particularly in recent years, CATV transmission lines have been used for this (FIG. 7). The system comprises, for example, a CATV center, a plurality of notifiers A and B and a plurality of subscribers A, B and C. The communication method is a one-way communication. In the case of music information, a CATV center unidirectionally sends information to a plurality of subscriber terminal devices. In the case of announcement information, the announcer uses a subscriber terminal designated via the CATV center. Provided to the device. The circuit form is a so-called multi-drop type.

[0003] The transmission system is a broadband system using one channel. For example, music information, announcement information, and terminal control information are provided in a time-division manner by a predetermined carrier (hereinafter, referred to as a carrier). Here, the notification information is, for example, a broadcast from the notifier A, and is transmitted via a CATV center via a dedicated line or a telephone line. The terminal control information is, for example, an address specifying a terminal device or control data indicating the end of notification information.

[0004] Information sent from the CATV center is shown in FIG.
Shown in In this system, music information such as background music (hereinafter referred to as BGM) is usually distributed (a). Then, at the time of notification broadcasting, first, address data of the designated terminal device is transmitted (b), and subsequently, notification information is transmitted (c). Also, at the end of the notification information,
The end data is transmitted (d). Then, after sending the end data, the music information is distributed again (e). As described above, the CATV center provides music information and notification information in a time-sharing manner.

On the other hand, the terminal devices of subscribers A and B
GM is received (f, g). When the address is sent from the CATV center, the address is decoded (h,
i). For example, the terminal device of the subscriber A whose address coincides continuously receives the notification information and provides the notification information from the speaker (j). Conversely, the terminal device of the subscriber B whose address does not match, for example, turns off the speaker device and does not provide the notification information (k). At the end of the notification information, end data is received (l, m). This allows, for example, subscriber A to continue and subscriber B to, for example, switch its speaker device to O.
N, and provided music information again (o, p). As described above, the conventional system uses one channel of the CATV transmission line, selectively provides the notification information, and provides the music information to all the terminal devices. In addition, the notification information and the music information are provided in a time-sharing manner as described above.

There is another system in which the carrier of terminal control information and the carrier of music information / notification information are separated. In this case, the address data on the terminal control information dedicated carrier is always monitored, and when the addresses match,
This is a system that receives the notification information on the other carrier and does not receive it when there is a mismatch. Even with this system,
Since the announcement information and the music information are on the same carrier, the providing method has been a time division method.

[0007]

However, since the former system provides music information and notification information on the same channel as described above, the providing system is a time division system. Therefore, as shown in a blank area of k in FIG. 8, when a specific subscriber has received the notification information, the remaining subscribers cannot receive the music information. Further, since this terminal device simply reproduces the signal transmitted from the CATV transmission line as it is, there is also a disadvantage that the noise generated when switching between the music information and the notification information is reproduced as it is.

[0008] In the latter case, a carrier dedicated to control information is further required, which complicates the system or the circuit configuration, and raises the cost. Also, if a new carrier dedicated to control information is provided,
The terminal device used for the conventional system becomes unusable,
There was also a problem with compatibility with conventional systems.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a first object of the present invention is to provide notification information, terminal control information, and music information by a voice multiplexing method, thereby providing a specific subscription. In addition to transmitting notification information to a subscriber, music information is not interrupted for other subscribers. The second object is to provide a notification information and terminal control information using a main carrier and music information using a subcarrier by using a method similar to the conventional audio multiplexing method in television broadcasting. , Without interruption of music information to all subscribers. A third object is to provide announcement information and terminal control information using a main carrier of an audio multiplex system in a conventionally used television broadcast, thereby providing a mixed system in which conventional terminal devices are mixed. Is to make it possible. Another object of the present invention is to reduce noise at the time of switching by switching between the notification information and the music information in each terminal device.

[0010]

In order to solve the above-mentioned problems, a notification broadcasting system according to the first aspect of the present invention provides a CATV system.
A notification broadcasting system for distributing notification information and music information to a plurality of terminal devices each having an address using a transmission path, wherein a second channel for transmitting the notification information and terminal control information and a second channel for providing music information are provided. With channels. The second channel is always supplied with music information, and the first channel is supplied with terminal control information including the address of the designated terminal device and notification information as needed.

The terminal device whose address matches the terminal control information of the first channel switches the music information of the second channel to the notification information of the first channel in the terminal device,
Provide notification information to subscribers. When the notification information ends, the channel is switched to the second channel again, and the music information is continuously provided. The terminal device whose address does not match continuously provides the music information of the second channel.

Since the notification information and the music information are provided by using the two independent channels as described above, even if the notification information is provided to one terminal device, the music information of another terminal device is blocked. There is no. Therefore, the notification broadcasting system is highly convenient.

[0013] According to the notification broadcasting system of the second aspect, the first channel and the second channel include:
Already, the main carrier and the subcarrier of the audio multiplex transmission system used for television broadcasting have been used. Since the existing audio multiplex transmission system is used, an inexpensive broadcast notification system is provided.

According to a third aspect of the present invention, the terminal device is applied to the announcement broadcasting system according to the first aspect, wherein a first channel and a second channel are multiplexed from a plurality of frequency-multiplexed transmission signals. Detection means for extracting the multiplexed audio signal, audio multiplex demodulation means for further extracting the first channel announcement information and music information of the second channel from the audio multiplex signal extracted by the detection means, and detection means. An address identification means for extracting an address included in the terminal control information of the first channel from the obtained audio multiplex signal and identifying the address, and an information output means for outputting notification information or music information according to the result of the address identification means And

The transmission signal transmitted from the CATV center includes an audio multiplex signal in which the notification information and terminal control information of the first channel and the music information of the second channel are multiplexed. Modulates the high-frequency carrier and outputs the modulated signal to a predetermined frequency band. The detection means of the terminal device in the announcement broadcasting system of the present invention,
An audio multiplex signal is demodulated from a plurality of frequency-multiplexed transmission signals. Here, the detection means has a concept of tuning and demodulation (detection). This audio multiplex signal is
It is sent to the next-stage audio multiplex demodulation means and address identification means.

The audio multiplex demodulation means receives the notification information of the first channel from the audio multiplex signal input from the detection means,
Separate from the music information of the channel.

The address identification means reads an address from the terminal control information of the first channel of the input audio multiplex signal. If the addresses do not match, the command is sent to the information output means. The information output means follows the command,
Subsequently, the music information of the second channel is provided. If the addresses match, a switching command is output to the information output means. The information output means switches the second channel to the first channel and provides the notification information accordingly. Further, when receiving the end data of the notification information, a switching instruction is again issued to the information output means, and the information output means switches the first channel and the second channel based on the instruction and provides the music information again.

As described above, the two independent channels are received, and the notification information and the music information are provided based on the address designation of the CATV. It does not affect the reception of music information. Accordingly, the terminal device of the highly convenient notification broadcast system can provide the notification information and the music information to the subscriber independently of the other terminal devices.

Further, according to the terminal device in the notification broadcasting system of the fourth aspect, the first channel and the second channel are transmitted.
As a multiplexing method using a channel, an audio multiplexing method that is already used in the revision broadcast is used. That is, the main carrier and the subcarrier are used. In this method, in transmitting a signal, a subcarrier is frequency-modulated with a music information signal to generate a second channel signal, and a signal including announcement information and terminal control information is multiplexed as a first channel signal. . Then, the main carrier is frequency-modulated with the multiplexed voice multiplexed signal and output as a signal of one transmission band on the wideband transmission path. In demodulating an audio multiplex signal from a broadband transmission path, a signal on the wideband transmission path is frequency-converted and passed through a predetermined bandpass filter to obtain an intermediate frequency band signal. This intermediate frequency band signal is frequency-demodulated to obtain an audio multiplex signal. Then, the audio multiplexed signal is passed through a band-pass filter that separates the first channel and the second channel, and a signal including the notification information and the terminal control information of the first channel and a signal of the second channel including the music information are added to the signal. And demodulates a signal including music information by performing FM detection on the signal of the second channel. These two pieces of information are sent to the next-stage information output means. Normally, the information output device provides music information of the second channel. in this way,
By applying the audio multiplex transmission method used in the existing television broadcasting to the terminal device in this announcement broadcasting system, the announcement information is output to specific terminals, and the music information is continuously output to other terminals. It is possible to do. Since the existing audio multiplexing system can be used, the terminal device becomes an inexpensive broadcast notification system.

The terminal device according to claim 5 is
It has a display device controlled by terminal control information sent from the CATV center. For example, the display device is an LED lamp or a liquid crystal display device for notifying an emergency broadcast. When the terminal control information for controlling the display device is transmitted from the CATV center on the first channel, the terminal device displays, for example, a blinking LED lamp or a character on the liquid crystal display device based on the terminal control information. Thereby, the subscriber's attention can be further raised. Since not only audio transmission but also visual transmission is performed,
It is a terminal device in a notification broadcasting system that transmits notification information more reliably.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. Note that the present invention is not limited to the following examples. (First Embodiment) FIG. 1 shows a schematic configuration diagram of a notification broadcasting system of the present invention. The notification broadcast system of the present invention is a CATV
Center 100, terminal devices 300 of a plurality of subscribers A, B, C,..., Terminal devices 200 of a plurality of notifiers A, B, C, and CATV cable 5 connecting them.
0, a telephone line 40. The notifier is, for example, a public agency such as a government office, and the terminal device 200 is, for example, a telephone. And the CATV cable 50 is
The ATV center 100 connects the subscriber's terminal device 300, and the telephone line 40 connects the CATV center and the announcer's terminal device 200. As a result, the music information b is constantly supplied from the CATV center to the terminal device 300 of each subscriber, and the notification information a is transmitted to the designated subscriber from the notifier via the CATV center.

FIG. 2 shows a block diagram of a transmission circuit used in the CATV center. The figure is a block diagram of a transmission circuit of a standard television two-audio multiplex system called an FM-FM system.
In this embodiment, the first channel is associated with the main channel of the audio multiplex system, and the second channel is associated with the sub audio.

The transmitting circuit used in the present invention includes an FM modulator 110 for loading music information on a subcarrier and an FM modulator 11
A mixer 120 for mixing the signal modulated by 0 with the terminal control information and the announcement information from the announcer, an FM modulator 130 for placing the output of the mixer 120 on the main carrier, the frequency of the designated main carrier Circuit 140 for stabilizing the frequency bandpass filter 150 for passing only the carrier frequency thereof and preventing noise output
Composed of

The BGM, which is music information supplied from the CATV center, is loaded on the subcarrier by the FM modulator 110 and on the main carrier by the FM modulator 130, multiplexed in frequency, and always transmitted on the CATV cable. I have.

On the other hand, the notification information is, for example, the telephone line 4 shown in FIG.
Entered using 0. In addition, terminal control information is also input prior to the notification information. The terminal control information is, for example, the address of the subscriber to be notified. This address is sent from a notifier to a push-tone telephone by DTMF (Dual Tone Frequency Modulation). The DTMF method is based on a combination of frequencies of a high frequency range and a low frequency range divided into four stages, from 0 to 9, A,
This is a system representing B, C, D, *, and #. First, address data is designated by this combination of digital data, and thereafter, notification information is input.

The input DTMF address data is mixed in the CATV center with music information obtained by modulating the above-mentioned subcarriers in the mixer 120 together with the notification information. The audio multiplexed signal transmitted from the mixer 120, that is, the multiplexed signal of music information, terminal control information, and announcement information is frequency-modulated on the main carrier by the FM modulator 130, and is passed through the band-pass filter 150 to the CATV cable Transmitted. The transmission method is a broadband method.

FIG. 3 shows information transmitted from the transmission circuit of the CATV center according to this method. The figure is a time chart. In this system, usually, music information such as BGM carried by a subcarrier is always distributed by subaudio (a). Then, when there is an announcement broadcast, for example, when the subscriber A is followed by the subscriber B, the following is performed. First, address data of the terminal device 300 of the subscriber A is transmitted (b), and subsequently, notification information is transmitted (c).
When the notification information ends, the end data is sent (d). After a while (e), similarly, the address data of the terminal device of the subscriber B is transmitted (f), followed by notification information (g), and finally, end data is transmitted (h). As described above, the CATV center provides the notification information and the terminal device control information in a time-division manner in the main voice, and always provides the
Provides music information.

On the other hand, data received by the terminal devices 300 of the subscribers A and B are as follows. First, both usually receive BGM (i, l). When the address is transmitted from the CATV center, the terminal devices 3 of the subscribers A and B
00 decodes the address. When the address of the terminal device of the subscriber A matches, the channel of the main audio and the sub audio is switched, and the notification information is received and provided from the speaker (j). Conversely, the terminal device of subscriber B whose address does not match continues to receive the sub-voice. (L). At the end of the notification information, the terminal device 300 of the subscriber A receives the end data and switches to the sub-voice (k). This allows
Even while the subscriber A is receiving the notification information, the subscriber B can receive the music information without being affected by the notification information.

Also, when the address of the subscriber B is transmitted from the CATV center (f), the subscriber B receives the notification information by the same process. Even while the notification information of the subscriber B is being received (m), the subscriber A can receive the music information without being affected by it (k).

As described above, in the announcement broadcasting system, the music information and the announcement information are provided using the independent channels of the two-audio multiplex system. Then, the subscriber's terminal receives the address designation and receives the notification information by switching the channel, so that the music information of other subscribers is not interrupted as in the related art. Therefore,
It becomes a more convenient announcement broadcasting system. Also, in this announcement broadcasting system, the main channel of the audio multiplex system is used for the first channel and the sub-channel is used for the second channel. Therefore, an inexpensive broadcast notification system that effectively uses the network frequency is provided.

(Second Embodiment) FIG. 4 shows a terminal device applied to the announcement broadcasting system of the present invention. The terminal device is a CA
A tuning device 305 for selecting a predetermined frequency band from a transmission signal propagated through a TV cable by frequency multiplexing, an FM detection unit 310 for detecting the above-mentioned audio multiplexed signal from the selected frequency band, and a notification from the audio multiplexed signal. An audio multiplex demodulator 320 for separating a main audio including information and a sub audio including music information,
Similarly, a data demodulator 330 for extracting control information, which is digital data, from the main audio of the audio multiplex signal, and a CPU 3 for decoding the data extracted from the data demodulator 330
50, a switch device 340 for switching between main sound and sub sound according to the decoding result of the CPU device 350,
Attenuator 36 that attenuates according to a command from U device 350
0 and a speaker device 370 which is the last output stage. In the present terminal device, the tuning device 305, FM
The detection unit 310 is a detection unit, the voice multiplex demodulator 320 is a voice multiplex demodulation unit, the data demodulator 330 and the CPU device 3.
Reference numeral 50 denotes an address identification unit, and a switch device 340, an attenuator 360, and a speaker device 370 are information output units.

As described in the first embodiment, on the CATV cable, music information, notification information, and terminal device control data, which are frequency-multiplexed around the main carrier f _MAINC, are carried by frequency multiplexing. Then, they are first input to the channel selection device 305 of the terminal device 300.

In the channel selection device 305, the signal on the transmission path is
Using a PLL circuit (Phase Locked Loop Circuit) and a predetermined high-frequency signal generated by a VCO (Voltage Controlled Oscillator), the signal is converted into a low frequency band, passed through a band-pass filter, and converted into an intermediate frequency band signal. I do. Thereafter, the audio multiplexed signal is detected by frequency demodulating the signal in the intermediate frequency band. Next, the audio multiplexed signal is input to the audio multiplex demodulator 320 to separate the terminal control information. Further, the audio multiplex signal is separated by the audio multiplex demodulator 320 into notification information of the first channel and music information of the second channel, and the signal of the second channel is frequency-demodulated by the subcarrier to be converted into baseband music information. Separated. At this time, the music information is the sub-voice and the announcement information is the main voice. These two sounds are transmitted to the switch device 340 at the next stage.

On the other hand, in the audio multiplexed signal (frequency: f _SUBC + f _BGM and f _{A / C} ) sent to the data demodulator 330, for example, the sub audio is removed from the frequency difference. Next, DTMF terminal control information is extracted from the main voice. The terminal control information is, for example, a subscriber address, area designation data indicating a subscriber area, an emergency broadcast or general broadcast designation broadcast code, and an announcement broadcast end data.
The terminal control information is demodulated into a data signal by the data demodulator 330 and transmitted to the CPU 350 at the next stage.

The CPU device 350 reads the input terminal control information and performs the following processing. First, the CPU device 3
50 checks whether the address which is the identification number of the terminal device matches. If they match, the switch device 34
A command for switching from the sub sound to the main sound is sent to 0. As a result, at the subscriber home whose address matches, the BGM is switched to the announcement broadcast. If the notification is an emergency communication, for example, the attenuation by the attenuator 360 is alleviated to increase the output from the speaker 370 to call attention. If the input data is the notification broadcast end data, a switch command from the main sound to the sub sound is transmitted to the switch device 340. Thereby, at the subscriber's house, the notification broadcast is switched to BGM again.

Conversely, if the addresses of the input terminal control information do not match, no switch command is sent to the switch device 340. Therefore, the BG continues from the sub audio
M is supplied.

As described above, the terminal device according to the present invention is CA
The notification information and the music information provided in the main sound and the sub sound are respectively extracted from the TV center by frequency multiplexing, and the music information is usually provided by the sub sound, and the notification information is provided only when the address matches. Therefore, other terminal devices are not affected even when the notification information is received. Therefore, even if a plurality of terminals are constructed on the same system, the terminal devices are independent from each other. Therefore, a more convenient terminal device is provided. Further, the terminal device of the present invention switches between the sub sound and the main sound when the addresses match, but the switching sometimes involves noise. In such a case, for example, the attenuator 360 at the preceding stage of the speaker 370 is operated.
Thereby, switching noise can be removed.
Therefore, a high quality terminal device is obtained.

(Modifications) Although one embodiment of the present invention has been described above, various other modifications are possible. For example, in the first embodiment, the music information is supplied independently on the sub-channel, and the notification information and the terminal control information are supplied independently on the main channel. However, as shown in FIG. It may be added. Normally, music information is supplied to the automatic switch device 160 from the sub-channel, and when terminal control information and notification information of the main audio are input, the automatic switch device 160 is preferentially switched to it. That is, BGM is inserted into the part e in FIG. 6, and the notification information, the terminal control information, and the music information are supplied in a time-division manner in the main channel as in the conventional system. As a result, a conventional terminal device supporting time division information can be used, and a mixed system with the conventional terminal device can be realized.
Therefore, an excellent announcement broadcasting system that effectively uses the conventional terminal device is provided.

Further, in the first embodiment, the announcement broadcast is provided by using the main sound, but the text broadcast is used instead of the announcement broadcast.
A notification broadcasting system for displaying on a commercially available TV device may be used.

Further, in the second embodiment, the switching control of the main sound and the sub sound or the output control of the speaker device is performed in response to the terminal control signal. However, the present invention is not limited to this.
During an emergency broadcast, a newly provided LED or the like may be operated to blink. Further, a simpler display device may be provided in the terminal device, and characters may be displayed on the terminal device.

Although various other modified examples are conceivable, specific information can be provided by using a conventional audio multiplex system and providing notification information and terminal control information using a main audio and music information using a sub audio. For the subscriber, any type of notification broadcast system and terminal device that provide the music information without interruption to interrupt the notification information to other subscribers is possible.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a notification broadcasting system according to a first embodiment.

FIG. 2 is a block diagram of a transmission circuit of the notification broadcasting system according to the first embodiment.

FIG. 3 is a time chart of the notification broadcasting system according to the first embodiment.

FIG. 4 is a block circuit diagram of a terminal device in a notification broadcasting system according to a second embodiment;

FIG. 5 is a block circuit diagram of a terminal device in a notification broadcasting system according to a modification.

FIG. 6 is a time chart of a notification broadcasting system according to a modification.

FIG. 7 is a configuration diagram of a conventional notification broadcasting system.

FIG. 8 is a time chart of a conventional notification broadcasting system.

[Explanation of symbols]

 Reference Signs List 100 CATV center 110 FM modulator 120 mixer 130 FM modulator 140 PLL circuit 200 terminal device 300 terminal device 305 tuning device 310 FM detector 320 voice multiplex demodulator 330 control data demodulator 340 switch device 350 CPU device 360 attenuator 370 Speaker device

Claims (5)

[Claims] 1. A notification broadcasting system for distributing notification information and music information to a plurality of terminal devices each having an address using a CATV transmission line, wherein a first channel for transmitting the notification information and terminal control information and music information are provided. And a terminal device that does not match the address included in the terminal control information of the first channel, the terminal device continuously providing music information through the second channel. The terminal device that provides the music information and matches the address switches the music information of the second channel to the notification information of the first channel in the terminal device, and switches to the music information of the second channel again when the notification information ends. An announcement broadcasting system characterized by the above. 2. The broadcast system according to claim 1, wherein the first channel and the second channel are a main channel and a sub-channel of an audio multiplex transmission system. 3. A terminal device applied to the broadcast system according to claim 1, wherein a first channel and a second channel are multiplexed from a plurality of transmission signals transmitted by multiplexing frequencies. Detection means for extracting the extracted audio multiplexed signal, audio multiplex demodulation means for extracting the notification information of the first channel and music information of the second channel from the audio multiplex signal extracted by the detection means, Address identification means for extracting the address included in the terminal control information of the first channel from the obtained audio multiplex signal and identifying the address; and information output means for outputting notification information or music information according to the result of the address identification means. If the address does not match by the address identification means, the music information of the second channel is continuously provided to match the address. If the terminal device in the announcement broadcasting system and switches back to the second channel of the music information at the time of announcement information ends with providing announcement information of the first channel. 4. The terminal device according to claim 3, wherein the first channel and the second channel are a main channel and a sub-channel of an audio multiplex transmission system in which frequencies are multiplexed. . 5. The terminal device in the notification broadcasting system according to claim 3, wherein said terminal control device has a display device controlled by said terminal control information.