JP3895534B2 - Audio information provision system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a system for providing predetermined audio information to a desired area via a cable television transmission network.
[0002]
[Prior art]
Conventionally, road traffic information and the like by FM waves leaked using a leaking cable have been broadcast in some areas on tunnels and on expressways. In this case, information about the occurrence of a traffic accident and the presence or absence of traffic jams is transmitted to the driver who is driving the vehicle by FM waves. In recent years, for example, FM broadcasts have been provided to tourists who are driving a vehicle in a desired area using radio wave leakage means such as a leakage cable, etc. There is an idea of revitalizing the local economy by using the advertising effect associated with this. In such FM broadcasting, a dedicated cable is laid in a section from an FM broadcasting station that normally transmits audio information to an area that provides information, and audio information is transmitted via this cable. However, the installation of such a dedicated cable has a practical problem because it requires cost and labor.
[0003]
[Problems to be solved by the invention]
The present invention has been made in view of the problems of the prior art, and provides a system for individually providing various types of audio information to a plurality of different areas at low cost by using a cable television transmission network. Objective.
[0004]
[Means for Solving the Problems]
In order to achieve the above object, the invention of claim 1 is an audio information providing system for providing audio information via an existing cable television transmission network, and stores a plurality of types of audio signals constituting the provided information. A storage means and a plurality of audio signals stored in the storage means are transmitted using a predetermined frequency band through a cable television transmission network that is a combination of optical fibers and coaxial cables arranged in a plurality of regions. A signal transmission means and a cable for drawing branched from a cable television transmission network in a desired area for providing information, are connected to the cable television transmission network via the cable for drawing, and are transmitted by the signal transmission means. Signal modulation that extracts an audio signal of a specific frequency band from the acquired audio signal and modulates the extracted audio signal into a frequency signal that can be received by the audio receiver And an output cable that is suspended on a hanger disposed in the cable television transmission network, connected to the signal modulation means, and outputs an audio signal modulated by the signal modulation means, and a part of the output cable A radio wave leakage cable that is formed and leaks the radio wave output via the output cable to the outside and enables reception by the audio receiving device.
[0005]
In this system , an audio signal is transmitted to a signal modulation means via a cable television transmission network, modulated by the signal modulation means into a frequency signal that can be received by the audio receiving device, and radio waves including the audio signal are leaked from a leaking cable. As a result, voice information can be provided (transmitted) in a desired area where the leakage cable is provided, and can be received by the voice receiver. For example, when the leakage cable is laid along the road and the sound receiving device is mounted on the car, appropriate sound information can be acquired for each region while the car is running. In order to implement this method, the signal transmission means such as a cable may be provided in the section from the nearest point on the existing cable television transmission network to the signal modulation means, and the signal modulation means from the point where the audio information is transmitted. Since it is not necessary to newly lay the entire section up to the means, it is possible to reduce the cost and labor required for laying the signal transmission cable. The signal modulating means is branched from the cable transmission network and suspended from the lead-in cable, and the output cable on which the leakage cable is formed is suspended from a hanger disposed in the cable transmission network.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a voice information providing system according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration of the voice information providing system, and FIG. 2 shows a main configuration of the system. This system 1 uses a part of an existing cable television (hereinafter abbreviated as CATV) transmission network 20 to transmit desired audio information (for example, regional information), and is a general-purpose FM radio in a predetermined region. The receiver (voice receiving device) 18 can receive the signal.
[0011]
The existing CATV transmission network 20 is a broadcasting center facility, and a cable head antenna end (hereinafter abbreviated as a head end) 2 for transmitting audio signals and image signals as optical signals. An optical fiber 3 for transmitting the transmitted optical signal to the optical node 4, an optical node 4 for photoelectrically converting the optical signal transmitted by the optical fiber 3 into an electrical signal, and an electrical signal output from the optical node 4 The trunk line coaxial cable 5 for transmission below the trunk line amplifier 6, the trunk line amplifier 6 for amplifying the electrical signal attenuated during transmission by the trunk line coaxial cable 5, and the electrical signal transmitted by the trunk line coaxial cable 5 And tap-off 8 (see FIG. 2) for branching and distributing to televisions owned by CATV subscribers. In the CATV transmission network 20, transmission of electrical signals from the main line amplifier 6 and below is performed, as necessary, as shown in FIG. 2, a branch coaxial cable 5 a branched from the main line amplifier 6 and a tap-off connected thereto. 8 may be used. As shown in FIG. 2, the branching to the drawing coaxial cable 7 may be branched from the nearest branching coaxial cable 5a using the drawing terminal 7a. Note that reference numeral 17 in FIG. 1 denotes a dummy resistor provided at the end of the CATV transmission line.
[0012]
The system 1 uses a part of such a cable transmission network 20 and transmits the audio signal amplified by the main line amplifier 6 to a signal processor amplifier (signal modulation means, hereinafter abbreviated as SP amplifier) 10. For extracting the desired audio signal from the audio signal transmitted by the coaxial cable 7 and the FM signal of the predetermined frequency band that can be received by the FM radio receiver 18. This is realized by additionally arranging the SP amplifier 10 and an output cable 9 provided with a leakage cable 9a (radio wave leakage means) for leaking radio waves in a frequency band including a modulated audio signal. The The optical fiber 3, the optical node 4, the trunk coaxial cable 5, the trunk amplifier 6, and the lead-in coaxial cable 7 implement a signal transmission means. The radio wave leaked by the leak cable 9a is received by the FM radio receiver 18 possessed by the user, and desired audio information is provided.
[0013]
The audio signal transmitted from the head end 2 is generated by using a system as shown in FIG. 3 in a CATV center, for example. In FIG. 3, the sound input from the recording microphone 11a is synthesized with various sound effects such as background music by the mixer 12 and recorded in the memory device 13 as a source in a digital manner. Reference numeral 13a denotes an operation unit of the memory device 13, which issues a source recording and sending command. The source recorded in the memory device 13 can be confirmed while being reproduced by the monitor speaker 14, and if the mixer 12 or the recording microphone 11a is used, it is possible to further synthesize sound effects and sounds as necessary. it can. In the embodiment shown in FIG. 3, the memory device 13 records sources (sources 1 to 10) for 10 stations (10 channels). Further, the memory device 13 has a built-in automatic sending function for the sources 1 to 10, and automatically sends the recorded sources 1 to 10 to the modulator 15 (MO1 to MO10) by operating the operation unit 13a. The sources 1 to 10 sent from the memory device 13 are converted into an analog system by the modulator 15, then synthesized by the mixer 16 as necessary, and transmitted to the head end 2 as an audio signal. The modulators MO1 to MO10 are arranged corresponding to the sources 1 to 10 so that the sources 1 to 10 can be transmitted to the mixer 16 at the same time. In addition, the head end 2 of the present system can also transmit audio signals for live broadcasting. At that time, the sound input from the live broadcast microphone 11b plus the sound effect of the mixer 12 is recorded as a source in the memory device 13 and is also D / A converted via the modulator 15, and if necessary. By synthesizing with the mixer 16, an audio signal is generated. Here, the source of the live broadcast may be transmitted to the modulator 15 without being recorded in the memory device 13.
[0014]
The audio signal generated as described above is converted into an optical signal by the head end 2 and transmitted to the optical node 4 nearest to the area where the audio information is provided by the optical fiber 3 (see FIG. 1). Normally, a 4-core type optical fiber 3 is used for CATV broadcasting. Among them, only 2 cores are used for signal transmission of CATV broadcasting, and the remaining 2 cores are closures as spare cores. It is closed at. Therefore, it is possible to use a frequency for an empty channel that is not used for CATV broadcasting by using this spare core. More specifically, one channel for CATV broadcasting is usually configured with a band of 6 MHz, and transmission of an audio signal of one station in the system 1 requires a band of 500 kHz + α (adjacent band). Therefore, audio signals for 10 stations (sources 1 to 10 in FIG. 3) can be transmitted by one vacant channel for CATV broadcasting. As described above, in an area where the optical fiber 3 for CATV transmission is already laid, it is not necessary to newly lay the optical fiber 3, and the construction of cables becomes easy. In an area where the optical fiber 3 is not laid, the spare core may be extended from the nearest optical fiber 3 for laying. In the CATV transmission network 20 used by the present system 1, the distance from the head end 2 to the optical node 4 tends to increase with the expansion of the viewing area. By adopting the HFC (Hybrid Fiber Coax) method that uses the coaxial cable 5 for the trunk line, the transmission efficiency is improved in the long distance section from the head end 2 to the optical node 4 by using the optical fiber 3 with low transmission loss. The relay amplifier can be omitted.
[0015]
Thus, the audio signal by the optical signal transmitted from the head end 2 is transmitted to the optical node 4 using the spare core of the optical fiber 3. The optical node 4 receives the power supply from the power supply unit 19 (see FIG. 2), photoelectrically converts the optical signal into an electrical signal, and the audio signal based on the electrical signal is connected to the trunk line via the trunk coaxial cable 5. Output to amplifier 6 and below. The coaxial cable used for the trunk line coaxial cable 5 generally has a larger transmission loss and a greater signal attenuation than the optical fiber 3, so that the trunk line amplifier 6 amplifies the signal at any time while downstream. Is transmitting. For example, as shown in FIG. 1, a plurality of main line amplifiers 6 are arranged at predetermined intervals (about 400 m) in the main line route of the CATV transmission network 20.
[0016]
In the present system 1, such a head end 2 to the main line amplifier 6 in the CATV transmission network 20 is diverted, and a pull-in coaxial cable 7 branched from the nearest main line amplifier 6 is connected to the SP amplifier 10. The audio signal output from the optical node 4 by the coaxial cable 7 is transmitted to the SP amplifier 10. Accordingly, since the cables need only be newly provided after the drawing coaxial cable 7, the cost can be reduced and the work process can be simplified. In this way, the audio signals of the sources 1 to 10 are transmitted from the head end 2 to the SP amplifier 10 via the CATV transmission network 20.
[0017]
The SP amplifier 10 extracts an audio signal of a desired source from the audio signals of the sources 1 to 10 transmitted from the optical node 4. Since each source is transmitted by a signal in a predetermined frequency band corresponding to an empty channel for CATV broadcasting as described above, an audio signal of a desired source can be extracted by extracting a signal in a specific frequency band. The SP amplifier 10 modulates the extracted audio signal into an FM wave having a predetermined frequency band that can be received by the FM radio receiver 18 and outputs the FM wave. The SP amplifier 10 is installed by suspending it on cables (hanging lines) such as a drawing coaxial cable laid outdoors for each region (channel) where audio information is provided.
[0018]
An output cable 9 is connected to the SP amplifier 10, and an audio signal modulated into an FM wave having a predetermined frequency by the SP amplifier 10 is output to the output cable 9 as described above. As shown in FIG. 4, the output cable 9 is formed by a leakage cable 9a in a predetermined fixed section. The leaky cable 9a is a cable for leaking the radio wave including the signal to the outside when transmitting the modulated FM wave. In the present system 1, such a leaky cable 9a is formed in a predetermined fixed section. Thus, voice information can be provided by FM broadcasting in the surrounding area of the section. The drawing coaxial cable 7 and the output cable 9 can be laid by hanging them on a hanger provided for the cable system transmission line. In FIG. 4, 21 indicates a power line, 22 indicates an NTT telephone line, and 23 indicates a utility pole.
[0019]
The system 1 can provide audio information by FM broadcasting to a desired area using the CATV transmission network 20 as described above. However, the area is not limited to one place, and FIG. As shown in the figure, if a branching coaxial cable 7 is branched from the nearest trunk amplifier 6 to a plurality of areas where voice information is desired to be provided, and the SP amplifier 10 or lower is arranged downstream thereof, the plurality of areas can be handled. The voice information of the station can be provided. That is, the sources 1 to 10 to be recorded in the memory device 13 shown in FIG. 3 are recorded in advance according to the contents of each region, and the audio signals of the sources 1 to 10 are transmitted from the head end 2 to the respective stations via the CATV transmission network 20. If the sound signal of the source corresponding to each region is extracted by each SP amplifier 10 and FM-modulated, and the radio wave including the modulated signal is leaked by the leakage cable 9a. It is possible to provide audio information having different contents for each region.
[0020]
As the type of audio information provided in this way, various services and information can be considered. For example, historical facts and legends that have been handed down in tourist spots such as famous places and historic sites are visited. “Electronic narrative service (see FIG. 5)” broadcast to tourists. Tourists can use this as a tourist guide by receiving this broadcast on a portable FM radio. Another example is the “FM voice sign service (see FIG. 6)” that broadcasts traffic information and the like along a section of a section where a leakage cable is laid. As shown in FIGS. 6 (a) to 6 (d), it is possible to provide special information on local products, parking lot guidance, traffic jam / It provides traffic information for construction, etc., and the driver receives this broadcast by FM radio mounted on the vehicle. In the present embodiment, these broadcasts are broadcast at the same frequency in any region (station) for each type of audio information. For example, when providing the voice information of the “electronic storyteller service” at the tourist spot shown in FIG. 5, the band centering on 77.7 MHz and the voice of the “FM voice signage service” along the road shown in FIG. In the case of providing information, a band centered on 88.8 MHz is used, and these frequency bands are common in all regions. Therefore, if the user adjusts the reception frequency of the FM radio receiver 18 according to the type of information that the user wants to know first, it is not necessary to readjust the reception frequency every time the user moves in each area.
[0021]
Further, the SP amplifier 10 is adjusted so that the frequency band of the extracted audio signal is changed from the audio signals of the respective sources transmitted from the head end 2 via the CATV transmission network 20, and is extracted by the SP amplifier 10. Source can be set arbitrarily. Further, by adjusting the SP amplifier 10, the same source can be broadcast to a plurality of areas. For example, in the embodiment shown in FIG. 1, two SP amplifiers 10 (the uppermost SP amplifier 10 and the lowermost SP amplifier 10 in FIG. 1) adjusted to extract the audio signal in the frequency band corresponding to the source 1 of the channel 1 are used. Since the SP amplifiers 10) are arranged at two locations, FM waves are leaked from the leakage cables 9a connected to the respective SP amplifiers, and the audio information of the same source 1 can be provided in the surrounding area. .
[0022]
Furthermore, in FIG. 2, a lead-in terminal 7a is provided on the upstream side of the tap-off 8, and the SP amplifier 10 is connected by a lead-in cable 7 that extends from the lead-in terminal 7a. Like the SP amplifier 10, a lead-in terminal 7 a may be provided on the downstream side of the tap-off 8 and connected to the CATV transmission network 20. At this time, as shown in FIG. 1, the drawing coaxial cable 7 may be extended from the downstream side of the plurality of tap-offs 8. That is, the SP amplifier 10 can be installed at an arbitrary location on the CATV transmission network 20. However, at this time, in order to prevent interference of radio waves leaked from the leak cable 9a, it is desirable to provide the leak cables 9a corresponding to the respective channels separated by about 500 m or more. Note that the broadcast radio wave transmitted due to leakage can be made practical enough even if a weak radio wave that does not require permission is used, although the reception range is narrow.
[0023]
As described above, according to the present embodiment, a part of the CATV transmission network 20 is diverted so that the audio signal is transmitted to the SP amplifier 10, and a predetermined audio signal is extracted by the SP amplifier 10 and received by the FM radio receiver 18. By modulating the frequency signal to a possible frequency and leaking radio waves including the audio signal from the leakage cable 9a, audio information can be provided to a desired area. Further, in this embodiment, since a part of the CATV transmission network 20 is diverted, the equipment that has to be newly provided is an output cable including a drawing coaxial cable 7, an SP amplifier 10, and a leakage cable 9a. Since 9 is sufficient, the arrangement of transmission facilities is simplified. In addition, since the CATV transmission network 20 used by the present embodiment employs an HFC (Hybrid Fiber Coax) system for transmitting audio signals, high transmission efficiency can be obtained with a simple configuration.
[0024]
In this embodiment, since information is provided using FM waves, the user can provide various broadcast services using portable and in-vehicle FM radio receivers 18 which are inexpensive popular products. You can enjoy it.
[0025]
Furthermore, in the present embodiment, in any region, broadcasting is performed using FM waves of the same frequency band for each type of audio information to be provided, so that the FM radio can be adapted to the type of information that the user wants to know first. If the reception frequency of the receiver 18 is adjusted, it is not necessary to adjust the reception frequency every time the region is moved thereafter. Further, in the case of the FM radio receiver 18 having a reception frequency memory function, if the reception frequency having a high usage frequency is stored in the FM radio receiver 18 in advance, the convenience is further enhanced.
[0026]
The present invention is not limited to the configuration of the above-described embodiment, and various modifications are possible. For example, the radio wave leaking from the leakage cable 9a may be an AM wave without being limited to an FM wave. Information may be provided using character information in addition to general voice information.
[0027]
If a channel processor amplifier is applied instead of the SP amplifier 10 used in the present embodiment, it is possible to provide a plurality of types of audio information in one broadcasting region. Furthermore, the number of sources recorded in the memory device 13 is not limited to 10 stations, and can be increased according to the area where the audio information is provided and the type of audio information provided by adding recording means in the memory device 13. .
[0028]
Furthermore, specific examples of the types of information to be provided are not limited to the above examples. For example, guidance broadcasting by voice for visually handicapped people, guidance broadcasting to an evacuation site at the time of disaster, and lifeline It is also possible to provide information on In particular, in the latter case, it is possible not only to perform guided broadcasting of appropriate contents individually for a plurality of disaster-stricken areas and evacuation sites, but also for the victims to not change the reception frequency of the FM radio receiver 18 during the evacuation. Therefore, it can be used effectively.
[0029]
【The invention's effect】
As described above, according to the first aspect of the present invention, the audio signal is transmitted to the signal modulation means via the existing cable television transmission network, and the signal modulation means modulates the audio signal to a frequency signal that can be received by the audio reception device, and leaks. By leaking radio waves including audio signals from the cable, it is possible to provide audio information to a desired area where the leakage cable is provided. In addition, an existing cable television transmission network can be used to transmit an audio signal, whereby a new signal transmission cable is laid over the entire section from the point where the audio information is transmitted to the signal modulation means. This eliminates the need to reduce the cost required for cable laying, and to provide an information providing service by audio broadcasting at a low cost. Here, since the optical fiber and the coaxial cable are used together as the cable television transmission network, the transmission efficiency can be improved by using the optical fiber with low transmission loss in the long distance section, and the relay amplifier can be omitted. it can. Moreover, since the memory | storage means which memorize | stores audio | voice information is provided, the same audio | voice information can be provided many times as needed. Further, since information corresponding to each area is extracted from a plurality of audio information by the signal modulation means arranged in a desired area, a fine service can be provided for each area. Furthermore , the signal modulation means can be provided by suspending on a cable for drawing branched from the cable transmission network, and the output cable can be provided by suspending on a hanger provided on the cable transmission network. it can.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of an information providing system according to an embodiment of the present invention.
FIG. 2 is a diagram showing a main configuration of the system.
FIG. 3 is a configuration diagram of a CATV center facility in the system.
FIG. 4 is a perspective view showing an example of laying a leaking cable in the system.
FIG. 5 is an explanatory diagram showing an example of a service using the system.
6A, 6B, 6C, and 6D are perspective views showing another example of services using the system.
[Explanation of symbols]
1 Voice information provision system 3 Optical fiber (signal transmission means)
4 Optical nodes (signal transmission means)
5 Coaxial cable for trunk line (signal transmission means)
6 Trunk amplifier (signal transmission means)
7 Pull-in coaxial cable (signal transmission means)
9a Leakage cable (Radio wave leakage means)
10 SP amplifier (signal modulation means)
18 FM radio receiver (voice receiver)
20 Cable TV transmission network

Claims (1)

An audio information providing system for providing audio information via an existing cable television transmission network,
Storage means for storing a plurality of types of audio signals constituting the information to be provided;
A signal transmission means for transmitting a plurality of audio signals stored in the storage means using a predetermined frequency band via a cable television transmission network formed by using optical fibers and coaxial cables provided in a plurality of areas together; ,
From the audio signal transmitted by the signal transmission means , suspended from a cable for drawing branched from a cable television transmission network in a desired area for providing information , connected to the cable television transmission network via the cable for drawing in A signal modulation means for extracting an audio signal of a specific frequency band and modulating the extracted audio signal into a frequency signal receivable by the audio receiving device;
An output cable that is hung on a hanger disposed in the cable television transmission network, connected to the signal modulation means, and outputs an audio signal modulated by the signal modulation means;
Voice information comprising: a radio wave leakage cable formed on a part of the output cable and leaking a radio wave output through the output cable to the outside and enabling reception by the voice receiving device. Offer system.

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