JP2007201769A - Announcement broadcast system and transmission apparatus for same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an announcement broadcast system capable of carrying out an announcement broadcast even when a transmission line is broken and to provide a transmission apparatus for the system. <P>SOLUTION: The announcement broadcast system 1 configured by interconnecting a center apparatus 10 for transmitting an announcement broadcast signal and receivers 20 for receiving the announcement broadcast signal via the transmission line 42, includes: a disaster prevention wireless master station 50 for wirelessly transmitting an announcement broadcast signal; a disaster prevention wireless slave station 60 for receiving the announcement broadcast signal wirelessly transmitted from the disaster prevention wireless master station 50; and a transmission apparatus 70 for transmitting the announcement broadcast signal received by the disaster prevention wireless slave station 60 via the transmission line 42. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a notification broadcasting system for performing notification broadcasting and a transmitter used in the notification broadcasting system.

  Notification broadcasting systems for performing various types of notification broadcasting from a center to a plurality of dwelling units are widespread. This notification broadcasting system is generally configured by connecting a center device arranged on the center side and a receiver installed in each dwelling unit via a transmission line such as CATV. Then, when performing general broadcasting such as holding local events, or disaster broadcasting in the event of a fire or earthquake, the center device transmits a notification broadcast signal via a transmission line, and the receiver receives the notification broadcast signal. Then, the announcement broadcast is output by voice through a speaker (see, for example, Patent Document 1).

  In addition, disaster prevention radio systems are widely used as other systems for disaster broadcasting. The disaster prevention radio system includes a radio transmitter provided in a city hall, a radio receiver provided for each area in the jurisdiction area of the city hall, and a trumpet speaker provided in the vicinity of the radio reception facility. Configured. When a fire or earthquake occurs, a notification broadcast is wirelessly transmitted by a wireless transmitter, which is received by a wireless reception facility, and the notification broadcast is broadcast in the range of several hundred meters to several kilometers by a trumpet speaker.

Japanese Patent Laid-Open No. 9-8753

  However, in the above-described conventional notification broadcasting system, since notification broadcasting is performed via a transmission line such as CATV, when this transmission line is divided due to a fire or an earthquake, notification broadcasting can be performed. There is a problem that it cannot be done.

  On the other hand, in the above conventional disaster prevention radio system, there is no problem of line division because of wireless communication, but since the announcement broadcast was played on the trumpet speaker, the announcement broadcast may be extremely difficult to hear. In particular, there was a problem that it was difficult to give notifications to elderly people who were deaf or deaf.

  In order to solve such a problem, it is also considered that a receiver of each dwelling unit is provided with a wireless reception function, and the notification broadcast transmitted wirelessly is received by this receiver and the announcement broadcast is sent to the dwelling unit. It is done. However, in this case, since the entire long distance from the center side to each dwelling unit depends on radio transmission, problems such as radio waves not reaching the dwelling unit in the mountainous area may occur. In addition, due to the directivity of the antenna of the receiver and the like, it is difficult to reliably receive the announcement broadcast wirelessly in all the dwelling units. In addition, providing a line reception function in all the dwelling unit receivers complicates the configuration of the receiver and increases its manufacturing cost, which increases the burden on the user side and makes it difficult to disseminate it in practice. It is.

  The present invention has been made in view of the above, and an object of the present invention is to provide a notification broadcasting system and a transmitter therefor that can reliably perform notification broadcasting even when a transmission line is divided. .

  In order to solve the above-described problems and achieve the object, the present invention as claimed in claim 1 is configured such that a transmission unit that transmits a notification broadcast signal and a reception unit that receives the notification broadcast signal are transmitted via a transmission line. In the notification broadcasting system configured to be connected to each other, a wireless transmission unit that wirelessly transmits a notification broadcast signal, a wireless reception unit that receives a notification broadcast signal wirelessly transmitted by the wireless transmission unit, and a wireless reception unit Transmission means for transmitting the notification broadcast signal received through the transmission line.

  According to a second aspect of the present invention, in the first aspect of the present invention, the transmission means for transmitting the notification broadcast signal and the reception means for receiving the notification broadcast signal are connected via a transmission line. A transmitter provided in a notification broadcasting system configured as described above, comprising: a transmission unit that transmits a notification broadcast signal received by a predetermined wireless reception unit via the transmission line. .

  The invention according to claim 3 is the invention according to claim 2, further comprising transmission line abnormality determining means for determining presence / absence of abnormality of the transmission line, wherein the transmission means is determining the transmission line abnormality. When the means determines that an abnormality has occurred in the transmission line, the notification broadcast signal is transmitted.

  According to a fourth aspect of the present invention, in the present invention according to the third aspect, the carrier signal cutoff detection means for detecting the cutoff of the carrier signal in the transmission line, and the notification broadcast signal in the predetermined radio reception means. Notification broadcast determination means for determining whether or not the transmission signal is received, wherein the transmission line abnormality detection means is a case in which the interruption of the carrier signal is detected by the carrier signal interruption detection means, and the notification When it is determined by the broadcast determination means that notification broadcasting is being performed, it is determined that an abnormality has occurred in the transmission line.

  According to the present invention, the notification broadcast signal transmitted / received wirelessly can be transmitted via the transmission line, so that the notification broadcast can be broadcast to each dwelling unit using a part of the wired line of the notification broadcast system. Therefore, it is possible to output the notification broadcast using the receiver of each dwelling unit compared to the case where the notification broadcast is performed by the trumpet speaker as in the case of the conventional disaster prevention wireless system. Can be surely notified to the person. Therefore, evacuation guidance and the like during a disaster can be performed quickly and reliably. Furthermore, since it is only necessary for the wireless transmission to reach the wireless receiving means instead of each dwelling unit, it is relatively easy to construct a reception environment even in a mountainous area such as installing the wireless receiving means on the mountaintop. In addition, it is not necessary to provide a wireless reception function in the receiver, and a receiver for a normal announcement broadcasting system can be used as it is, so that the system configuration on the user side can be simplified.

  According to this invention, when it is determined that an abnormality has occurred in the transmission line, the notification broadcast signal is sent out, so that it is possible to prevent a situation in which the notification broadcast signal is duplicated when the transmission line is normal. .

  According to this invention, it is determined that an abnormality has occurred in the transmission line when the interruption of the carrier signal is detected and it is determined that the notification broadcast is being performed. Based on these multiple conditions, it is possible to reliably determine the abnormality of the transmission line.

  Embodiments of a notification broadcasting system and a receiver therefor according to the present invention will be described below in detail with reference to the accompanying drawings. [I] First, the basic concept of the embodiment will be described, then [II] the specific contents of the embodiment will be described, and [III] Finally, modifications to the embodiment will be described. However, the present invention is not limited by this embodiment.

[I] Basic Concept of Embodiment First, a basic concept common to the embodiments will be described. The present invention generally relates to a notification broadcasting system configured by connecting a transmission means for transmitting a notification broadcast signal and a reception means for receiving the notification broadcast signal via a transmission line. Here, in the notification broadcasting system, wireless transmission means for wirelessly transmitting the notification broadcast signal, wireless reception means for receiving the notification broadcast signal wirelessly transmitted by the wireless transmission means, and reception by the wireless reception means. Transmitting means for transmitting the notification broadcast signal via the transmission line. In other words, when the transmission line is divided for some reason, the announcement broadcast is wirelessly transmitted from an arbitrary place such as the city hall, and this is received within the announcement broadcast system, and is transmitted to the transmission line downstream from the division point. Superimpose. Therefore, since each dwelling unit can receive a notification broadcast using a notification broadcasting system, it is possible to solve problems such as difficulty in listening when using a trumpet speaker and directivity when receiving wirelessly in a dwelling unit. . Furthermore, in each embodiment, various measures are taken for the control contents and the like so that the radio transmission / reception of the notification broadcast can be reliably performed. In addition, based on the contents of the announcement broadcast, the announcement broadcast that is not normally urgently broadcast (for example, event announcement, etc., hereinafter referred to as the normal announcement broadcast) and the announcement broadcast that is broadcast in the event of a disaster (hereinafter referred to as the following) Disaster notification broadcast). The present invention basically allows any notification broadcast to be superimposed and transmitted using radio when the transmission line is divided, regardless of the contents thereof. However, in the following description, these normal notification broadcasts and disaster notification broadcasts are simply referred to as notification broadcasts, and only the disaster notification broadcasts are wirelessly transmitted when the transmission line is divided.

[II] Specific Contents of Embodiment Specific contents of the embodiment will be sequentially described in detail below with reference to the accompanying drawings.

(Basic configuration of announcement broadcasting system)
First, the basic configuration of the notification broadcasting system according to this embodiment will be described. FIG. 1 is a block diagram showing a configuration of a notification broadcasting system according to the present embodiment. As shown in FIG. 1, the notification broadcasting system 1 includes a center device 10 disposed on the center side, a receiver 20 disposed in each dwelling unit, and a transmission for transmitting a signal transmitted from the center device 10 to the receiver 20. A system 40 includes a disaster prevention radio master station 50 that wirelessly transmits a disaster notification broadcast, a disaster prevention radio slave station 60 that receives the disaster notification broadcast, and a transmitter 70 that transmits the disaster notification broadcast to a transmission line 42 described later. Has been. In addition, except the structure which mentions specially, the center apparatus 10, the receiver 20, and the transmission system 40 can be comprised similarly to the conventional notification broadcasting system.

(Basic configuration of notification broadcasting system 1-center device 10)
Among these, the center apparatus 10 transmits an announcement broadcast signal, and corresponds to the transmission means in the claims. The center device 10 includes an operation unit 11, a display unit 12, a microphone 13, a BGM source 14, a memory 15, a calendar circuit 16, a transmission unit 17, and a control unit 18.

  The operation unit 11 is an operation unit for performing various operations on the center device 10 and includes, for example, various switches (not shown). The display unit 12 is a display unit for displaying necessary information toward the operator, and includes, for example, a monitor and a display lamp (not shown). The microphone 13 is a voice input means for inputting voice for announcement broadcasting. The BGM source 14 is sound source means that becomes a sound source of background music for announcement broadcasting. The memory 15 is a storage unit that stores information necessary for various controls of the center device 10. The calendar circuit 16 is date information output means for outputting date information. The transmission unit 17 is a transmission unit that transmits the notification broadcast signal to the head end 41 including a predetermined carrier (corresponding to the carrier signal in the claims) in the notification broadcast frequency band. The control unit 18 is a control unit that controls each unit of the center device 10 and includes, for example, a CPU (Central Processing Unit) (not shown) and a program that is interpreted and executed on the CPU.

(Basic configuration of notification broadcasting system 1-transmission system 40)
The transmission system 40 includes a head end 41, a transmission line 42 extending from the head end 41 to the receiver 20 of each dwelling unit, and an amplifier 43, a distribution amplifier 44, a distributor 46, The mixer 47 and the protector 48 are provided. The head end 41 is amplification transmission means that receives a signal transmitted from the transmission unit 17 of the center apparatus 10, level-amplifies the signal, and sends the signal to the transmission line 42. The transmission line 42 is a transmission line that transmits a notification broadcast signal. For example, a CATV transmission line 42 that transmits a CATV signal is used. The amplifier 43 is an amplifying unit that amplifies a signal flowing through the transmission line 42. The distribution amplifier 44 is distribution amplification means for amplifying a signal and distributing the amplified signal to each dwelling unit. The distributor 46 is distribution means for distributing the signal amplified by the distribution amplifier 44 toward each dwelling unit. The mixer 47 is a mixing unit that mixes the notification broadcast signal transmitted from the transmitter 70 with the transmission line 42. The protector 48 is a DC component limiting unit that is provided in each dwelling unit and controls a DC component that rides on the transmission line 42 and reaches the receiver 20.

(Basic configuration of notification broadcasting system 1-receiver 20)
Next, the receiver 20 of FIG. 1 will be described. The receiver 20 receives an announcement broadcast signal and corresponds to the receiving means and the receiver in the claims. The receiver 20 includes a demodulation unit 21, an audio switching unit 22, an audio recording unit 23, a volume control unit 24, an amplifier 25, a speaker 26, an operation unit 27, a display unit 28, a memory 29, and a control unit 30. It is configured.

  The demodulator 21 is a demodulator that demodulates the notification broadcast signal transmitted from the center device 10, and outputs audio information to the audio switching unit 22 and outputs control information to the controller. The audio switching unit 22 outputs the audio information output from the demodulation unit 21 to the audio recording unit 23 or outputs the audio information output from the demodulation unit 21 or the audio recording unit 23 to the volume adjustment unit 24. Means. The volume adjusting unit 24 adjusts the volume of the audio information output from the audio switching unit 22 and outputs it to the amplifier 25. The audio information is amplified by the amplifier 25 and then output from the speaker 26. The operation unit 27 is an operation unit for performing various operations on the receiver 20, and includes, for example, various switches (not shown). The display unit 28 is a display unit for displaying necessary information to the user, and includes, for example, a monitor and a display lamp (not shown). The memory 29 is a storage unit that stores information necessary for various controls of the receiver 20. The control unit 30 is a control unit that controls each unit of the receiver 20, and includes, for example, a CPU (Central Processing Unit) (not shown) and a program that is interpreted and executed on the CPU.

(Basic configuration of notification broadcasting system 1-disaster prevention radio master station 50)
Next, the disaster prevention radio master station 50 will be described. The disaster prevention wireless master station 50 wirelessly transmits a disaster notification broadcast and corresponds to the wireless transmission means in the claims. As this disaster prevention radio | wireless master station 50, except the structure to mention specially, the thing similar to the radio | wireless master station installed in the local government etc. in the conventional disaster prevention radio | wireless system can be used. For example, the disaster prevention radio master station 50 is configured to include the microphone 13 and the BGM source 14 that are the same as those of the center device 10, and an operator performs voice input and the like to generate a notification broadcast signal. And the disaster prevention radio | wireless master station 50 mounts this notification broadcast signal on a predetermined | prescribed carrier, FM modulates, and carries out radio transmission with the predetermined frequency for disaster prevention radio | wireless.

(Basic configuration of notification broadcasting system 11-Disaster prevention radio slave station 60)
Next, the disaster prevention radio slave station 60 of FIG. 1 will be described. The disaster prevention radio slave station 60 receives the notification broadcast signal wirelessly transmitted by the disaster prevention radio master station 50, and corresponds to the radio reception means in the claims. The disaster prevention radio slave station 60 is arranged, for example, in a predetermined disaster prevention radio broadcast area that covers a plurality of dwelling units. In addition, as the disaster prevention radio | wireless slave station 60, the thing similar to the radio | wireless slave station which receives the signal transmitted from radio | wireless master stations, such as a local government, in the conventional disaster prevention radio | wireless system can be used except the structure which mentions specially.

  FIG. 2 is a block diagram showing the configuration of the disaster prevention radio slave station 60 and the transmitter 70. As shown in FIG. 2, the disaster prevention radio slave station 60 includes an antenna 61, a reception unit 62, a notification broadcast determination unit 63, and a transmission unit 64. The receiving unit 62 receives the notification broadcast signal wirelessly transmitted from the disaster prevention radio master station 50 via the antenna 61. The notification broadcast determination unit 63 determines whether or not the notification broadcast signal is received in the disaster prevention radio slave station 60, and corresponds to the notification broadcast determination means in the claims. The notification broadcast determination unit 63 determines, for example, whether or not the disaster notification broadcast is being performed by comparing the reception level in the reception unit 62 with a predetermined value, and determines that the disaster notification broadcast is being performed. If so, a notification broadcast detection signal is output to the transmitter 70. The transmission unit 64 is a transmission unit that transmits the notification broadcast signal received by the reception unit 62 to the transmitter 70.

(Basic configuration of notification broadcasting system 1-transmitter 70)
Next, the transmitter 70 of FIG. 1 will be described. This transmitter 70 transmits the notification broadcast signal received by the disaster prevention radio slave station 60 via the transmission line 42, and corresponds to the transmission means in the claims. For example, the transmitter 70 is disposed in the vicinity of the disaster prevention radio slave station 60. In particular, the transmitter 70 is disposed in a disaster prevention radio broadcast area that covers a plurality of dwelling units, and is disposed on the downstream side of a position where the transmission line 42 is expected to be divided. As shown in FIG. 2, the transmitter 70 is configured by connecting a receiving unit 71, a carrier cutoff detection circuit 72, an AND circuit 73, a changeover switch 74, and a transmitting unit 75 as shown in the figure.

  The receiving unit 71 is a receiving unit that receives the notification broadcast signal transmitted from the transmitting unit 64 of the disaster prevention radio slave station 60. The carrier cutoff detection circuit 72 detects the cutoff of the carrier flowing through the transmission line 42, and corresponds to the carrier signal cutoff detection means in the claims. The carrier cutoff detection circuit 72 detects a predetermined carrier signal by a known method, and continuously outputs the carrier cutoff signal when the carrier signal is not detected. The AND circuit 73 outputs an AND output of the carrier cutoff signal from the carrier cutoff detection circuit 72 and the notification broadcast detection signal from the notification broadcast determination unit 63 of the disaster prevention radio slave station 60 to the changeover switch 74. The changeover switch 74 operates based on the AND output from the AND circuit 73 and switches the presence / absence of connection of the transmission unit 75 to the transmission line 42. The transmitter 75 transmits the notification broadcast signal received by the disaster prevention radio slave station 60 by superimposing it on the transmission line 42.

(Operation of Notification Broadcast System 1)
Next, the operation of the notification broadcasting system 1 configured as described above will be described. First, the operation when the transmission line 42 is not cut off (normal time) will be described. The operator on the center side stores arbitrary audio information in the memory 15 using the microphone 13 and the BGM source 14 of the center apparatus 10 of FIG. This voice information is called from the memory 15 when it is determined that the predetermined date / time has arrived based on the date / time information from the calendar circuit 16 or at any timing designated using the operation unit 11 of the operator. . Further, the operator uses the operation unit 11 to specify the receiver 20 that is the reception destination. Here, each receiver 20 is given a unique address in advance, and the address of the receiver 20 designated as the reception destination is acquired from the memory 15. Then, the audio information and the control information including the address of the receiver 20 as the reception destination are modulated on a carrier having a predetermined frequency to generate a notification broadcast signal, and the notification broadcast signal is transmitted to the transmission unit 17. Is transmitted to the head end 41 via The head end 41 that has received this transmission transmits these pieces of information via the transmission line 42. The signal transmitted in this way is amplified or distributed by the amplifier 43, the distribution amplifier 44, or the distributor 46, and then reaches the protector 48 of each dwelling unit. The notification broadcast signal that has passed through the protector 48 is input to the receiver 20.

  In the receiver 20 of FIG. 1, the input notification broadcast signal is demodulated by the demodulator 21, control information is input to the controller 18, and audio information is adjusted in volume via the audio switcher 22. Are output to the unit 24 and the audio recording unit 23. The control unit 18 determines whether or not the address included in the control information matches its own address stored in advance in the memory 29, and if so, the audio information is output so that the audio information is output. A control signal is output to the switching unit 22. The voice switching unit 22 that has received this control signal outputs the demodulated voice information to the volume adjusting unit 24. The audio information is output from the speaker 26 through volume adjustment by the volume adjustment unit 24 and amplification by the amplifier 25. At the same time, the audio information is recorded by the audio recording unit 23, and when the predetermined reproduction timing comes or when the user gives a reproduction instruction via the operation unit 27, the audio switching unit 22 is operated. Via the speaker 26 and output from the speaker 26.

  In the state where the notification broadcast is normally performed through the transmission line 42 as described above, when there is no wireless transmission from the disaster prevention radio master station 50, the notification broadcast determination unit 63 of the disaster prevention radio slave station 60 of FIG. Since the reception level at the receiving unit 62 does not exceed the predetermined value, it is determined that the disaster notification broadcast is not performed, and the notification broadcast detection signal is not output. Accordingly, in the transmitter 70, since the AND condition of the AND circuit 73 is not satisfied, the changeover switch 74 is not yet changed over, and the changeover switch 74 is maintained on the solid line side in the figure.

  In the state where the transmission line 42 is not blocked, when there is a radio transmission from the disaster prevention radio master station 50, the radio broadcast notification broadcast signal is sent to the receiving unit 62 of the disaster prevention radio slave station 60 of FIG. Receive. Here, the notification broadcast determination unit 63 determines that the disaster notification broadcast is being performed when the reception level in the reception unit 62 is equal to or higher than a predetermined value, and outputs a notification broadcast detection signal to the transmitter 70. However, since the notification broadcast is also performed through the transmission line 42 as described above, the carrier cutoff detection circuit 72 does not yet output the carrier cutoff signal. Therefore, since the AND condition of the AND circuit 73 is not satisfied, the changeover switch 74 is not yet changed over, and the changeover switch 74 is maintained on the illustrated solid line side. As described above, when the notification broadcast is normally performed via the transmission line 42, the notification broadcast signal is transmitted by the transmitter 70 regardless of the presence or absence of the wireless transmission from the disaster prevention radio master station 50. Therefore, it is possible to prevent the notification broadcast signal from being transmitted repeatedly on the transmission line 42.

  Next, the operation when the transmission line 42 is interrupted will be described. When the transmission line 42 is divided due to a disaster or the like, and there is a wireless transmission from the disaster prevention radio master station 50, the reception unit 62 of the disaster prevention radio slave station 60 in FIG. To do. Here, the notification broadcast determination unit 63 determines that the disaster notification broadcast is being performed when the reception level in the reception unit 62 is equal to or higher than a predetermined value, and outputs a notification broadcast detection signal to the transmitter 70. . Further, the carrier cutoff detection circuit 72 outputs a carrier cutoff signal because the carrier line cannot be detected because the transmission line 42 is divided. Therefore, the AND condition of the AND circuit 73 is satisfied, and the changeover switch 74 is switched to the dotted line side by the output from the AND circuit 73. Therefore, the notification broadcast signal received by the reception unit 71 is superimposed and transmitted to the transmission line 42 via the transmission unit 75. This notification broadcast signal is received by the receiver 20 of each dwelling unit through the protector 48 of FIG. 1 as usual, and the disaster notification broadcast is output from the receiver 20.

(Effect of this embodiment)
As described above, according to the present embodiment, when the notification broadcast is normally performed via the transmission line 42, the notification by the transmitter 70 is performed regardless of the presence or absence of the wireless transmission from the disaster prevention wireless master station 50. Since broadcast signals are not transmitted, it is possible to prevent duplicate broadcast signals from being transmitted on the transmission line 42. On the other hand, when the transmission line 42 is divided due to a disaster or the like, a disaster notification is made using a part of the wired line of the notification broadcasting system 1 by transmitting a wireless transmission from the disaster prevention radio master station 50 to the transmission line 42. Broadcast to each unit. In this case, unlike the announcement broadcast by the trumpet speaker, the disaster announcement broadcast can be output using the receiver 20 of each dwelling unit. Therefore, the disaster announcement broadcast can be output very clearly, and the announcement can be surely made even for the elderly and the deaf. Can be done. Furthermore, since it is only necessary for wireless transmission to reach the disaster prevention radio slave station 60 instead of each dwelling unit, it is relatively easy to construct a reception environment even in mountainous areas, such as installing the disaster prevention radio slave station 60 on the mountaintop.

[Modifications to Embodiment]
Although the embodiments of the present invention have been described above, the specific configuration and means of the present invention can be arbitrarily modified and improved within the scope of the technical idea of each invention described in the claims. it can. Hereinafter, such a modification will be described.

(About problems to be solved and effects of the invention)
First, the problems to be solved by the invention and the effects of the invention are not limited to the above-described contents, and the present invention solves the problems not described above or has the effects not described above. There are also cases where only some of the described problems are solved or only some of the described effects are achieved. For example, even when notification broadcasting cannot be made 100% when the transmission line 42 is divided, the subject of the present invention is achieved as long as the possibility of notification broadcasting can be improved slightly.

(About the overall structure of the announcement broadcasting system)
The overall configuration of the notification broadcasting system can be arbitrarily changed unless otherwise specified. For example, the disaster prevention radio broadcasting station 60 and the receiver 70 have been described as being provided in the disaster prevention radio broadcasting area. However, the disaster prevention radio slave station 60 and the receiver 70 are located at an arbitrary position unrelated to the classification by the disaster prevention radio broadcasting area. May be provided.

(About the configuration of the disaster prevention radio slave station 60 and the transmitter 70)
In the above embodiment, the presence / absence of the notification broadcast is determined. However, this determination function is omitted, and when the carrier block is detected regardless of the presence / absence of the notification broadcast, the reception unit 62 receives the notification broadcast. All signals may be transmitted to the transmission line 42 via the transmitter 70. Alternatively, the signal may be transmitted via the transmitter 70 only when an arbitrary condition is satisfied in addition to the notification broadcast and the carrier block. For example, a unique address is assigned to each disaster prevention radio slave station 60 and transmitter 70 in advance, and the control signal transmitted from the disaster prevention radio master station 50 is decoded by the disaster prevention radio slave station 60 and transmitter 70, and this decoded control is performed. The signal may be transmitted only when its own address is included in the signal. In this case, the relay form of signals from the plurality of disaster prevention radio slave stations 60 and transmitters 70 can be further subdivided and controlled on the disaster prevention radio master station 50 side.

  The present invention can be applied to a broadcasting system that performs various types of notification broadcasting such as emergency broadcasting, and ensures the continuity of notification broadcasting when the transmission line connecting the center device and the receiver of each dwelling unit is divided. Useful.

It is a block diagram which shows the structure of the notification broadcasting system which concerns on embodiment of this invention. It is a block diagram which shows the structure of the disaster prevention radio | wireless slave station of FIG. 1, and a transmitter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Notification broadcast system 10 Center apparatus 11, 27 Operation part 12, 28 Display part 13 Microphone 14 BGM source 15 Memory 16 Calendar circuit 17 Transmission part 18, 30 Control part 20 Receiver 21 Demodulation part 22 Voice switching part 23 Voice recording part 24 Volume adjustment unit 25, 43 Amplifier 26 Speaker 29 Memory 40 Transmission system 41 Head end 42 Transmission line 44 Distribution amplifier 46 Distribution unit 47 Mixer 48 Security device 60 Disaster prevention radio slave station 61 Antenna 62, 71 Reception unit 63 Notification broadcast determination unit 64 75 Transmitter 70 Transmitter 72 Carrier cutoff detection circuit 73 AND circuit 74 Changeover switch

Claims (4)

In a notification broadcasting system configured by connecting a transmission means for transmitting a notification broadcast signal and a reception means for receiving the notification broadcast signal via a transmission line,
Wireless transmission means for wirelessly transmitting a notification broadcast signal;
Wireless receiving means for receiving the notification broadcast signal wirelessly transmitted by the wireless transmitting means;
A transmission means for transmitting the notification broadcast signal received by the wireless reception means via the transmission line;
An announcement broadcasting system characterized by comprising: A transmitter provided in a notification broadcast system configured by connecting a transmission means for transmitting a notification broadcast signal and a reception means for receiving the notification broadcast signal via a transmission line,
Transmitting means for sending out the notification broadcast signal received by the predetermined wireless receiving means via the transmission line;
A transmitter for an announcement broadcasting system characterized by comprising: A transmission line abnormality determining means for determining presence or absence of abnormality of the transmission line,
The transmission means, when it is determined that an abnormality has occurred in the transmission line in the transmission line abnormality determination means, to send the notification broadcast signal;
The transmitter for an announcement broadcast system according to claim 2. A carrier signal cutoff detection means for detecting the cutoff of the carrier signal in the transmission line;
Notification broadcast determination means for determining presence or absence of reception of a notification broadcast signal in the predetermined wireless reception means,
The transmission line abnormality detection means determines that the carrier signal interruption detection means detects the interruption of the carrier signal, and the notification broadcast determination means determines that notification broadcast is being performed. It is determined that an abnormality has occurred in the transmission line,
The transmitter for an announcement broadcast system according to claim 3.

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