JP2000324467A - Private branch common reception system and branch device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and inexpensively improve a private branch common reception system transmitting a broadcasting signal from a ground station to a plurality of reception terminals so that the system may transmit a broadcasting signal from an artificial satellite to the reception terminals. SOLUTION: AMP 50 for amplifying a reception signal flowing on a branch route from a branch circuit 30 to a branch terminal TBR is arranged in a serial unit which is serially disposed on the transmission line of the common reception system to branch and output the reception signal to the respective reception terminals. Besides, DC power inputted from a BS tuner or the like to the branch terminal TBR is separated by PSF 80 and a DC constant voltage for driving AMP 50 is generated by AVR so that power source is supplied to the AMP 50. When an existing system for the ground station is changed into the one capable of receiving a satellite broadcasting, serial unit at the side of the reception terminals where the level of the reception signal becomes lower than a proper level in the case of transmitting the reception signal from a BS antenna to the transmission line of the system is converted into the serial unit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shared building in a building for receiving broadcast signals such as televisions and radios and transmitting the received signals to receiving terminals of various parts in the building via transmission lines in the building. A receiving system, and in the receiving system,
The present invention relates to a branching device for branching a part of a received signal from a transmission line and outputting the branched signal to a specific receiving terminal.

[0002]

2. Description of the Related Art Conventionally, in apartment houses, condominiums and other apartment houses, broadcast signals such as television and FM radio are received by a receiver for joint reception, and the received signals are distributed to a plurality of routes as necessary. After that, a shared reception system in a building is employed in which a reception signal is transmitted to a plurality of reception terminals in the building by transmitting the signal to a transmission line (coaxial cable) wired in the building.

In such an in-building joint receiving system, in order to transmit a received signal flowing through a transmission line to a plurality of receiving terminals, a plurality of branching devices composed of directional couplers are usually connected in series to the transmission line. And using each branching device,
A part of the received signal flowing through the transmission line is branched to a specific receiving terminal.

[0004] On the other hand, in a conventional in-building reception system, a receiving device for receiving a broadcast signal receives a broadcast wave of a television or a radio transmitted from a ground station by a receiving antenna, and receives the received signal. Is amplified by an amplifier (a so-called booster) and then sent to a transmission line in a building, or a protector etc. is provided for a broadcast signal transmitted by wire through an external CATV system. There is known a configuration in which a signal is taken in via a drop-in line, amplified as a reception signal by an amplifier, and then transmitted to a transmission line in a building.

[0005] All of these receiving apparatuses are receiving apparatuses for ground stations that receive broadcast signals from ground stations. Recently, however, broadcasting satellites (BS) or communication satellites (C) have been proposed.
Since satellite broadcasting using artificial satellites such as S) has been put to practical use, it comprises a parabolic antenna or the like which receives broadcast radio waves from such artificial satellites, converts them into a predetermined transmission frequency (intermediate frequency), and outputs the converted signals. There is also known a joint reception system in which a satellite receiver is provided, and a reception signal from the satellite receiver and a reception signal from the ground station receiver are mixed and transmitted to a transmission line in a building. ing.

[0006]

By the way, when constructing such a joint receiving system for both ground stations and satellites,
If the target building is to be newly constructed, it is only necessary to install transmission lines and transmission equipment with characteristics capable of transmitting each of the above-mentioned received signals during the construction. In existing joint receiving systems that transmit signals received from equipment, the characteristics of the transmission lines and transmission equipment correspond to the signals received by the ground station. Renovation work is required. This renovation work is extremely troublesome, and has a problem of enormous costs.

That is, for example, in Japan, even if the received signal from the ground station receiving device has the highest frequency, it is the broadcast frequency of the UHF channel 62 of the television broadcast (maximum 770 MHz). In the existing joint receiving system, a transmission line and a transmission device designed to transmit a received signal having a frequency lower than this frequency with a small loss are used.

On the other hand, the reception signal (satellite reception signal) from the satellite receiver is about 1 to 2 GHz (BS broadcasting: 1335 MHz at maximum, CS broadcasting: 1 at maximum).
Since the frequency is 895 MHz or 2150 MHz (depending on the satellite), in the existing joint receiving system, there is a portion where transmission loss of the satellite reception signal becomes large due to variation in electrical characteristics of individual devices and transmission lines.

For this reason, it is necessary to improve the existing joint receiving system so that not only the broadcasting signal from the ground station but also the broadcasting signal from the artificial satellite can be reliably transmitted to all receiving terminals at an appropriate level. , Simply, satellite receivers,
In addition to newly installing a mixer etc. that mixes the received signals from each receiving device and sends it out to the transmission line, transmission equipment such as transmission lines and branching devices wired in the building correspond to satellite reception signals It must be replaced with one with the specified characteristics, and the renovation work is extremely troublesome and costly.

On the other hand, in order to easily perform such repair work, the output (satellite reception signal) from the satellite reception device is amplified so that the satellite reception signal is at or above a predetermined level at all reception terminals of the joint reception system. It is also conceivable to provide an amplifier and compensate for the loss of the satellite reception signal on the transmission path with the amplification factor of the amplifier.

However, such measures require the provision of a new expensive amplifier for joint reception (in other words, high output) and low distortion, so that it is difficult to reduce the cost of repair work. Also, in the above countermeasure, the satellite reception signal transmitted to the reception terminal arranged on the head end side (that is, the reception apparatus side) of the joint reception system among the reception terminals receiving the reception signal via the transmission line and the branching device is taken. In some cases, the signal level may be too high. In such a case, an attenuator (attenuator) with a built-in demultiplexing circuit is provided on the receiving terminal side to pass the received signal from the ground station and attenuate only the satellite received signal. I have to.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an in-building joint receiving system for transmitting a broadcast signal from a ground station to a plurality of receiving terminals has been changed to one capable of transmitting a broadcast signal from an artificial satellite. It is an object of the present invention to make it possible to perform the repair work easily and at low cost.

[0013]

Means for Solving the Problems and Effects of the Invention According to a first aspect of the present invention, there is provided a shared reception system in a building, wherein a part of a reception signal is branched from a transmission line. And a branching device used for outputting to a specific receiving terminal side. The branching device is provided on a branching path from the branching unit to the branching terminal, in addition to the branching unit including the directional coupler connected in series to the transmission line of the system via the input terminal and the output terminal. Amplifying means for amplifying a received signal, and power supply means for supplying power to the amplifying means with DC power or AC power input from outside via at least one of an input terminal, an output terminal, and a branch terminal.

For this reason, according to the branching device of the present invention, for example, the existing in-building joint receiving system for receiving a broadcast signal from a ground station and transmitting it to a plurality of receiving terminals, When modifying the system so that it can be received and transmitted, the above-mentioned satellite receiver and mixer are installed at the head end side of the system, and the signals received from the ground station and artificial satellite are transmitted from the head end side to the transmission line. In such a state, the reception signal of the appropriate signal level can be transmitted to all the reception terminals simply by replacing the reception device with the transmission device to the reception terminal in which the signal level of the satellite reception signal becomes low. Become.

That is, when the existing in-building joint reception system is changed to a system capable of transmitting satellite reception signals as described above, when a satellite receiver and a mixer are installed on the head end side of the system, The receiving terminals that cannot transmit the satellite reception signal at an appropriate level are a part of all the receiving terminals, and some of the receiving terminals differ from system to system due to variations in characteristics of transmission lines and transmission devices.

Therefore, in the present invention, a branching device having an amplifying means provided on a branching path for branching and outputting a received signal from a transmission line to each receiving terminal has been developed. The signal level of the received signal transmitted to the receiving terminal can be changed without affecting the signal level of the received signal transmitted to the other receiving terminal by replacing the transmitting device with the transmitting device for the receiving terminal whose level is lowered. They can be set at the level.

Therefore, by using the branching device of the present invention, when performing a repair work to increase the types of broadcast signals receivable by the in-building joint receiving system, the transmission line and the transmission equipment are changed to
There is no need to change to the one corresponding to the increasing characteristics (frequency) of the broadcast signal, and the repair work can be realized simply and inexpensively.

Further, the branching device of the present invention amplifies and outputs a received signal only to a specific receiving terminal side, and the amplifying means includes a signal level of the received signal transmitted to the specific receiving terminal. , The output level is large and the distortion is low and expensive, such as an amplifier that amplifies the output from the receiving device so that the signal level of the received signal is equal to or higher than the appropriate level in all the receiving terminals. There is no need to configure with an amplifier circuit.

Therefore, when the branching device of the present invention is used, when the repair work for increasing the types of broadcast signals receivable by the in-building joint receiving system is performed, the increased received signals are amplified on the head end side. Repair work can be realized at lower cost than when an amplifier is provided. Further, according to the branching device of the present invention, since the signal level of the received signal of the other receiving terminal is not affected, the signal level of the received signal to the other receiving terminal becomes too large, and the Can be prevented.

Still further, in the branching device of the present invention, the power supply means uses the DC or AC power externally input to the input terminal, the output terminal, or the branch terminal of the branching device to supply power to the amplifying means. Since the power supply is performed, the branching device is provided with a power connector for taking in power from the commercial power supply,
There is no need to incorporate batteries. For this reason, in order to use the branching device of the present invention, it is not necessary to perform wiring work for power supply and consumption management of the battery, thereby improving usability.

Here, the power supply means supplies power to the amplifying means by using power input through at least one of the input terminal, the output terminal, and the branch terminal. If the power input through the terminal is low-frequency AC power, or if the voltage level is too high even if it is DC power, the amplifier cannot be driven normally. Therefore, in such a case, the power supply means may be configured as described in claim 2.

That is, in the branching device according to the second aspect, the power supply means includes a constant voltage circuit for generating a DC constant voltage for driving the amplifying means by power input from the input terminal, the output terminal or the branch terminal. The DC constant voltage generated by the constant voltage circuit is supplied to the amplifier. For this reason, it becomes possible to always supply a DC voltage of an appropriate voltage level to the amplifying means, and it is possible to operate the amplifying means stably.

On the other hand, any one of an input terminal, an output terminal, and a branch terminal may be set as a terminal for the power supply means to take in power. For example, a common receiving system using the branch device may include an amplifier ( In a system in which alternating current (or direct current) power for driving various transmission devices such as a booster is superimposed on a transmission line, a main path in the branching device that connects an input terminal and an output terminal via a branching unit is provided. Since a current for driving the transmission device flows, the power supply means is configured to receive power from a main path connected to the input terminal or the output terminal, and to supply power to the amplification means using the power. I just need.

It is not known whether the joint receiving system in which the branching device is used is a system in which power for driving a transmission device is not superimposed on a transmission line, or whether power is superimposed on a transmission line. In some cases, the power supply means is configured to supply power to the amplifying means by the power input from the branch terminal, or the power supply means is connected to the power superimposed on the transmission line. What is necessary is just to comprise so that both the electric power inputted from a terminal side may be used selectively. If the power supply means is configured as described in claim 3, a branching device that can be used in any system regardless of the specification of the joint receiving system can be provided with a simple device configuration (in other words, at low cost). ) Can be realized.

When the power supply means is configured as described in claim 3, it is necessary to input power for driving the amplification means to the branch terminal of the branching device. If a dedicated power supply device is used for this power supply, the user who connects the receiving terminal to the branch terminal must prepare the power supply device, which causes a burden on the user. Become.

However, conventionally, there is a terminal device used as a receiving terminal which is configured to be able to output DC power for supplying power to a receiving antenna from an input terminal of a received signal. Therefore, if the power supply means is configured to receive the power supply from the terminal device connected to the branch terminal and supply the power to the amplification means, the user can use a special power supply. A desired broadcast signal can be enjoyed without preparing a device.

That is, for example, a satellite broadcast receiving tuner for receiving a broadcast signal from an artificial satellite such as a BS broadcast or a CS broadcast, or a terminal device such as a television receiver or a video tape recorder incorporating the tuner is: Normally, a DC voltage for feeding power to a receiving antenna (specifically, a converter of a parabolic antenna) can be output from the reception signal input terminal. For this reason, if the power supply means is configured to supply power to the amplification means using the DC voltage output from such a terminal device, the user can receive the signal from the terminal device such as a BS tuner at the branch terminal. It is only necessary to connect the signal input terminals, and the amplifying means in the branching device can be operated extremely easily.

Next, the amplifying means may be configured so as to amplify all the received signals flowing through the branch path in the branching device. When the joint receiving system is changed to receive another broadcast signal such as satellite broadcasting, the receiving terminal receiving the received signal via the branching device of the present invention receives the received signal transmitted by the existing system. May be too high.

Therefore, in order to prevent such a problem, the amplifying means is provided with a demultiplexing circuit for converting the reception signal flowing through the branch path into a first reception signal (for example, a first reception signal having a different frequency band). , BS and CS broadcast signals)
And a second reception signal (for example, an FM / VHF / UHF broadcast signal), and one of the two types of reception signals (first reception signal) is amplified by an amplifier circuit. The first reception signal amplified by the amplification circuit and the second reception signal from the demultiplexing circuit may be mixed by a mixing circuit and output to the branch terminal side.

That is, in this way, in the branching device, of the received signals flowing through the branch path, only the received signal in the desired frequency band can be amplified, and the other received signals can be passed as it is. For this reason, for example, when the satellite reception signal can be transmitted in addition to the reception signal from the ground station transmitted by the existing system by the repair work of the joint reception system, only the satellite reception signal is amplified. , And other received signals can be output as before.

In order to amplify the satellite reception signal and allow another reception signal to pass therethrough, the demultiplexing circuit may be configured as described in claim 6. That is, in the branching device according to the sixth aspect, the branching circuit converts the received signal flowing through the transmission line into a first received signal from a satellite receiving device that receives a broadcast signal transmitted from an artificial satellite. Since the received signal from the receiving device for the ground station that receives the broadcast signal transmitted from the ground station is separated into two systems as the second received signal, only the satellite received signal as the first received signal is amplified. The signals received from other ground stations can be passed as they are.

Further, the output level of the received signal from the branch terminal of the branching device includes the signal level of the received signal input from the input terminal via the transmission line, the passing loss of the received signal at the branching unit, and the amplifying unit. In order to make the output level of the reception signal from the branch terminal of the branching device more appropriate,
It is preferable that the amplifying means is configured to be capable of adjusting the gain of the received signal, and that the branching device be provided with an operation unit for manually setting the gain. That is, in this case, by manually operating the operation unit, the signal level of the reception signal output from the branch terminal to the reception terminal can be adjusted, so that repair work of the joint reception system can be performed more easily. Will be possible.

The present invention also relates to a branching device for branching and outputting a part of a received signal flowing through a transmission line to a specific receiving terminal in a joint receiving system, such as a branching device incorporated in a rectangular casing. Such a branching device can be applied, but in order to improve the usability, as described in claim 8, a series unit housed and used in an outlet box provided on a wall of a building It is desirable to do. In other words, the series unit is embedded in the wall surface of the building and is used in a state where only the branch terminal is exposed on the wall surface. Therefore, if the branching device of the present invention is used as a series unit, it is installed in each part in the building with good appearance. Since the receiving terminal can be connected easily, the usability can be improved.

According to a ninth aspect of the present invention, a broadcast signal transmitted from the outside is received, and the received signal is transmitted to a transmission line wired in a building and a transmission line provided on the transmission line. In the in-building joint receiving system for transmitting to a plurality of receiving terminals via a device, a branch of the present invention (one of claims 1 to 8) described above as one of transmission devices provided on a transmission line. It is characterized by having a device,
According to a tenth aspect of the present invention, in the ridge joint receiving system according to the ninth aspect, as a receiving device for receiving a broadcast signal, a satellite receiving device for receiving a broadcast signal transmitted from an artificial satellite, It is provided with two types of receivers, a ground station receiver for receiving a broadcast signal transmitted from a station, and mixes the received signals from each of the receivers and sends out to a transmission line.

In the joint receiving system according to the ninth or tenth aspect, the branching device of the present invention is used as one of transmission devices for transmitting a received signal to a plurality of receiving terminals in a building. Therefore, it is possible to extremely easily set the signal level of the received signal transmitted to each receiving terminal to an appropriate level or more, for example, in a repair work of the system.

[0036]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram illustrating a configuration of an entire in-building joint receiving system according to an embodiment to which the present invention is applied.

As shown in FIG. 1, the in-building joint receiving system of the present embodiment is basically composed of broadcast radio waves of FM radio broadcast and VHF television broadcast (frequency band: 76 MHz to 22 MHz).
2 MHz) and a VHF antenna 2 for receiving UHF television broadcasts (frequency band: 470 MHz to 770).
And a UHF antenna 4 for receiving signals from the antennas (hereinafter collectively referred to as terrestrial wave reception signals). A terrestrial station joint reception system configured to transmit a terrestrial wave reception signal to a plurality of reception terminals by transmitting the terrestrial reception signal to a plurality of reception terminals by transmitting the terrestrial reception signal to a transmission line formed of a coaxial cable wired inside.

Then, the in-building joint receiving system of the present embodiment receives the television broadcast wave from the broadcasting satellite (BS) from the joint receiving system for the ground station by the repair work.
It has been changed to a joint receiving system for both ground stations and satellites that can transmit the received signal (satellite received signal) together with the terrestrial received signal to a plurality of receiving terminals.

For this reason, the in-building joint receiving system according to the present embodiment includes, in addition to the ground station receiving device including the VHF antenna 2, the UHF antenna 4, and the amplifier 8, a television broadcast from a broadcasting satellite (BS). As a satellite receiving apparatus, a radio wave is received, and the received signal is converted by a converter into a satellite receiving signal (BS-IF) of a predetermined intermediate frequency band (1035 MHz to 1335 MHz) for cable transmission and output. A BS antenna 6 is provided.
A mixer (MIX) 10 is provided for mixing the output from the S antenna 6 (satellite reception signal) and the output from the amplifier 8 (terrestrial reception signal) and transmitting the mixed signal onto a transmission line.

The F mixed in the mixer 10
The reception signals of the M, VHF, UHF, and BS broadcasts are distributed to a plurality of paths by a distribution circuit 12 provided on the transmission line, and then various series units 14 connected in series to the transmission lines of each path. , 16, and 20 to a plurality of receiving terminals.

The series units 14, 16, and 20 branch a part of the received signal flowing on the transmission line from the head end side to the terminal side of the system in which the antennas 2, 4, and 6 are installed, and the branch is performed. It is a type of branching device that outputs a received signal to the corresponding receiving terminal side, and is a well-known device that is used by being housed in an outlet box embedded in a wall of a room in a building.

Then, these various series units 14, 1
Among the units 20, 20, the serial unit 14 has a built-in branch circuit composed of a directional coupler.
In addition to the branch circuit, the serial unit 16 at the end of the transmission line, to which the output terminal side, which is the end of the transmission path formed by the transmission line, is terminated so as to have the same impedance as the coaxial cable constituting the transmission line. This has a built-in termination resistor.

On the other hand, the serial unit 20 corresponds to the branching device of the present invention, and has a function of amplifying the reception signal branched by the branch circuit to the serial unit 16 having the built-in branch circuit. . In this embodiment, a BS receiver (BS tuner, a television receiver with a built-in BS tuner, or a B
By supplying DC power from a video tape recorder (with a built-in S tuner) 18, an internal amplifier circuit can be operated. Hereinafter, the configuration of the series unit 20 will be described.

As shown in FIG. 2, the serial unit 20 is, like other conventionally known serial units 14 and 16, etc., fixed in an outlet box (also referred to as a switch box). A metal plate 22 provided with a screw hole for mounting a resin cover from above the series unit fixed to the unit is provided, and various functional circuits such as a branch circuit are stored on the back side of the plate 22. The housing 24 is assembled.

A pair of input / output terminals Tin and Tout for connecting coaxial cables, which are transmission lines of the joint receiving system, are provided on both the left and right sides of the housing 24. And a simplified terminal diagram for providing a branch terminal TBR for outputting a received signal branched from the transmission line to the corresponding receiving terminal side, and also illustrating a function of the serial unit 20 (a function of amplifying the branched received signal). Function display member 2 consisting of a display seal or the like described schematically in
6 is affixed.

The input terminal Tin is for inputting a reception signal transmitted via a transmission line, and the output terminal Tout outputs the reception signal input from the input terminal Tin to the terminal. These are all made by processing the end of the coaxial cable to expose the center conductor (core wire) and the outer conductor (braid), and directly screw these parts to the corresponding connection parts. The coaxial cable constituting the transmission line can be fixed.

The branch terminal TBR is constituted by a so-called F-type plug. A coaxial cable having an F-type connector attached to a reception signal input terminal of a receiving terminal including the BS receiver 18 shown in FIG. It can be easily mounted via the. However, the branch terminal TBR does not necessarily need to be configured with an F-type plug, and the coaxial cable may be directly screwed and fixed similarly to the input / output terminals Tin and Tout.

On the other hand, as shown in FIG. 3, the functional circuit housed in the housing 24 of the series unit 20 includes a branch circuit 30, a low-pass filter (LPF) 40, and an amplifier circuit (AMP) as an amplifier. ) 50, lightning arrester (AR
R) 60, low-pass filter (LPF) 70, power supply separation filter (PSF) 80, and constant voltage circuit (AVR) 9
Consists of zero. Note that the PSF 80 and the AVR 90 function as power supply means of the present invention.

The branch circuit 30 of this embodiment is a so-called transformer-type branch circuit including a branch transformer T1 and a resistor R1, and each transmission path from the branch transformer T1 to the input terminal Tin side and the output terminal Tout side. On the (main path), coupling capacitors C1 and C2 for passing a received signal and cutting a low frequency signal component having a lower frequency than the DC signal or the received signal are provided in series. Note that the branch circuit 3
As 0, a strip line type branch circuit well known in the art may be used.

Next, LPF40, AMP50, ARR6
0, LPF 70 and PSF 80 are respectively connected to the branch circuit 30
Are provided in series in this order on a branch path from the terminal to the branch terminal TBR. Among them, LPF40 and LPF70
Is for passing a received signal flowing through the transmission line and blocking the passage of a signal component having a frequency higher than the received signal (in this embodiment, a frequency higher than 1335 MHz). Three coils L1, L2, L3 connected in series, and these coils L1 to L3
And capacitors (ground: the same potential as the outer electrodes of the terminals Tin, Tout, and TBR to which the outer conductor of the coaxial cable is connected).
LPF 70 is composed of two coils L4 and L5 connected in series to the branch path, and coils L4 and L5.
A capacitor C6 provided between the connection point of
It is composed of

Further, the AMP 50 disposed between the LPF 40 and the LPF 70 converts the received signal flowing through the branch path into the entire band (76 MHz to 1335 MHz in this embodiment).
This is for amplifying with a gain (amplification factor) of about 5 dB to 15 dB, and is a wideband amplifier (IC) 5 formed into an IC.
2 and a coupling capacitor C5 provided on the output side.

The ARR 60 is provided between the branch line and the ground, and absorbs a high-voltage noise component induced on the transmission line of the system by a lightning strike or the like so as to absorb the high-voltage noise component.
In addition to preventing output to the BR, the high-voltage noise component coming from the branch terminal TBR is absorbed to protect the AMP 50. The diodes D1, D2, and D3 are connected in series with each other with the ground side as the anode. And diodes D4, D5, and D6 connected in series with the branch line side as the anode, and the diodes of these diode series circuits are connected in parallel with each other.

On the other hand, the PSF 80 is a DC power input from a terminal device such as the BS receiver 18 via the branch terminal TBR (in this case, the power is 15 V DC because the BSF is for driving the BS antenna 6). Is separated from the branch path via the choke coil L6 and is output to the AVR 90 side. In the PSF 80, the LPF 70
A coupling capacitor C7 for preventing DC power from being output on the side branch path is provided.

A which receives DC power from PSF 80
The VR 90 is for generating a DC constant voltage (for example, 5 V) for operating the wide band amplifier 52 in the AMP 50 from the power, and the VR 90 is used to generate a constant voltage from the PSF 80 to the AMP 50.
A current limiting input resistor R2 and a high frequency signal choke coil L7, which are provided in series on an energizing path to the wideband amplifier 52 leading to a wideband amplifier 52, and a connection point between the input resistor R2 and the choke coil L7 and the ground. Zener diode ZD1 for generating a constant voltage and bypass capacitor C8 for absorbing a high-frequency noise component flowing through the conduction path,
C9.

As described above, in the in-building joint receiving system according to the present embodiment, a part of the received signal is branched off from the transmission line and output to the corresponding receiving terminal as one of the transmission devices (serial unit). , A serial unit 20 having an amplifying function of amplifying the received signal after branching is used. This means that when changing the existing joint reception system for ground stations to a system shared by ground stations and satellites, all transmission lines and transmission equipment are changed to satellite reception signal compatible types as in the past, or In order to transmit satellite reception signals to all receiving terminals at an appropriate level, it is possible to construct a system for both ground stations and satellites with simple and inexpensive repair work without providing an extremely high gain amplifier for amplifying satellite signals. In order to

That is, the series unit 20 is
AMP5 provided on the branch path from 0 to the branch terminal TBR
At 0, the output level of the received signal to the corresponding receiving terminal without affecting the signal level of the received signal at the other receiving terminal because it is configured to amplify the received signal after branching. Can be raised. Therefore, in the joint receiving system of the present embodiment, when performing the repair work of the existing system, the BS antenna 6 and the mixer 10 are used.
Is added, so that the terrestrial reception signal and the satellite reception signal can be transmitted to each receiving terminal side. In this state, only the serial unit that cannot output the satellite reception signal at an appropriate level is sent to the serial unit 20. The exchange enables the satellite reception signal to be supplied at an appropriate level to all the reception terminals of the joint reception system.

Therefore, according to the in-building joint receiving system of this embodiment, the joint receiving system for the ground station can be changed to the joint receiving system shared by the ground station and the satellite by simple and inexpensive repair work. As a result, it is possible to provide a system that can receive satellite broadcasts to residents of an existing building or apartment complex that employs a joint reception system for a ground station without imposing a large expense. Also, existing buildings and condominiums that have adopted a joint reception system for ground stations will be able to receive satellite broadcasts at a low cost, which will promote the spread of satellite broadcasts, and for residents, You will be able to enjoy cultural life.
In some cases, other than satellite broadcasting, radio waves from a communication satellite may be received.

As described above, one embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and various embodiments can be adopted. For example, in the above-described embodiment, the in-building joint receiving system in which the joint receiving system for the ground station is changed to a system capable of receiving BS broadcasting has been described.
If the present invention is applied to a case where an antenna is provided and an in-building joint receiving system capable of transmitting received signals of FM, VHF, UHF, BS, and CS broadcasts is constructed, the same effect as in the above embodiment can be obtained. The effect can be obtained. However, in order to be able to transmit the received signal of the CS broadcast, the broadband amplifier 52 constituting the AMP 50 incorporated in the serial unit 20 is required.
Frequency bandwidth of, for example, 76 MHz to 1895 MHz
(Or 76MHz to 2150MHz)
We need to make it even wider.

In the above embodiment, the series unit 20
Has been described as operating the AMP 50 by receiving power supply from a terminal device such as the BS receiver 18 connected to the branch terminal TBR. However, for example, the amplifier 8 and the like are arranged on a transmission line in which the series unit 20 is provided. In a system in which power for supplying power to another transmission device (for example, AC power of several tens of volts obtained by stepping down an AC voltage from a commercial power supply) is superimposed, a DC constant voltage for driving the AMP50 is generated from this AC power. You may make it.

More specifically, as shown in FIG.
By connecting a rectifier circuit 92 composed of a rectifying diode bridge or the like to a main path connecting the branch circuit 30 and the input terminal Tin (or an output terminal Tout), the AC current flowing through the main path is rectified, Input with AVR90. Then, the DC constant voltage generated by the AVR 90 is
The DC constant voltage may be applied to the branch path from the branch circuit 30 to the branch terminal TBR, separated from the branch path by the PSF 80 provided on the branch path, and supplied to the AMP 50.

In the series unit 20 shown in FIG.
The DC constant voltage generated by the VR 90 is applied to a branch path between the branch circuit 30 and the LPF 40, and is applied to the LP path.
By separating the DC voltage at the PSF 80 provided between the F40 and the AMP 50 to supply the DC constant voltage for operation to the AMP 50, the output from the AVR 90 (DC constant voltage) is used without using the PSF 80. AM directly
You may make it supply to P50.

In the series unit 20 shown in FIG.
Since it is necessary to flow an alternating current on the transmission line to which the input / output terminals Tin and Tout are connected, the branch circuit 30 includes a choke coil L10 connecting the input / output terminals Tin and Tout.
Is provided to allow an alternating current to flow between the input / output terminals Tin-Tout via the choke coil L10. In the branch circuit 30, a coupling capacitor C10 is provided on the output path of the reception signal to the branch path connected to the LPF 40, and the capacitor C10 causes the AVR 90 to transmit the signal via the branch transformer T1 and the resistor R1. Prevents current from flowing to ground.

On the other hand, in the above embodiment, the serial unit 20
Has been described as amplifying all the received signals flowing through the branch path. For example, in the serial unit 20, only the satellite received signal having a large transmission loss in the above-mentioned joint receiving system is amplified, and the terrestrial received signal is You may comprise so that it may pass as it is.

That is, as exemplified in FIG. 5, in the serial unit 20 shown in FIG. 3, instead of the LPF 40, a branching circuit for dividing the branch output from the branch circuit 30 into a satellite reception signal and a terrestrial reception signal. 100 and LPF7
Instead of 0, a mixing circuit 110 that mixes the satellite reception signal and the terrestrial reception signal and outputs the mixed signal to the branch terminal TBR is provided. One path is connected to a second path through which a terrestrial reception signal passes. Then, on the first path through which the satellite reception signal passes, the AM
P50 and ARR60 are provided.

When the serial unit 20 is configured as described above, the received signal branched by the branch circuit 30 is
Since only the satellite reception signal can be selectively amplified, the signal level of the terrestrial reception signal output from the branch terminal TBR becomes too large. It can also be prevented that the wave reception signal is saturated and normal reception cannot be performed. In addition, since the AMP 50 only needs to amplify the satellite reception signal, the bandwidth of the signal frequency that can be amplified can be narrowed as compared with the above-described embodiment.
The price of 0 can be suppressed.

The demultiplexing circuit 100 and the mixing circuit 110
Are LPFs 102 and 112 for blocking satellite reception signals and passing terrestrial reception signals, and HPFs 104 and 114 for blocking terrestrial reception signals and passing satellite reception signals, respectively.
It is composed of Next, in the above-described embodiment, the gain (amplification factor) of the AMP 50 provided in the series unit 20 has been described as being about 5 dB to 15 dB. However, as illustrated in FIG. Between the amplifier 52 and the coupling capacitor C5, the variable resistor VR shown in FIG.
By operating the slide switch SW etc. shown in
A variable attenuator (attenuator) ATT capable of adjusting the amount of attenuation of a received signal is provided, and the gain (amplification factor) of the AMP 50 can be adjusted by externally operating the amount of attenuation of the variable attenuator ATT. Good.

According to the serial unit 20 'having the AMP 50 configured as described above, the signal of the reception signal output from the branch terminal TBR (the satellite reception signal when the internal circuit is configured as shown in FIG. 5). The level can be set to a more optimal level.

In the series unit 20 ', the AMP 50
As shown in FIG. 6 (b) or (c), the "knob" of the variable resistor VR or the slide switch SW serving as an operation unit is connected to a plate so that the amplification factor (gain) of the device can be easily adjusted. A gain display member 28 made of a display seal or the like indicating the amplification factor (gain) of the AMP 50 corresponding to the rotation position or the slide position of the “knob” is attached around the hole protruding from the hole formed in the hole 22. It is good to

In the above description, the case where the branching device of the present invention is applied to a serial unit that can be housed in an outlet box has been described. However, in the present invention, each of the above functional circuits is shown in FIG. The present invention can be applied to a branching device incorporated in a housing made of a suitable metal or synthetic resin, and the same effects as in the above embodiment can be obtained.

In the branching device shown in FIG. 7, three connectors for easily attaching a coaxial cable are fixed around a housing using a connector, and each connector is connected to an input terminal Tin and an output terminal. A well-known terminal Tout and a branch terminal TBR are used. On the surface of this housing, a function display member that schematically describes, in a simple circuit diagram, the function of the branching device (the function of amplifying the branched reception signal), similarly to the serial unit 20 shown in FIG. 26 is affixed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a configuration of a shared reception system in a building according to an embodiment.

FIG. 2 is an explanatory diagram illustrating an appearance of a serial unit 20.

FIG. 3 is an electric circuit diagram illustrating a circuit configuration of the serial unit 20.

FIG. 4 is a block diagram illustrating a modification of the circuit configuration of the serial unit 20.

FIG. 5 is a block diagram showing a modification of the circuit configuration of the series unit 20.

FIG. 6 is an explanatory diagram showing a circuit configuration of an AMP 50 capable of adjusting an amplification factor and an external appearance of a serial unit 20 ′ incorporating the same.

FIG. 7 is an explanatory diagram illustrating an appearance of a branch device different from a series unit.

[Explanation of symbols]

2 VHF antenna, 4 UHF antenna, 6 BS antenna, 8 amplifier, 10 mixer, 12 distribution circuit,
14, 16, 20 ... series unit, 18 ... BS receiver,
22 plate, 24 housing, 26 function display member, T
in: input terminal, Tout: output terminal, TBR: branch terminal, 3
0: branch circuit, T1: branch transformer, 40, 70 ... LP
F (low-pass filter), 50 ... AMP (amplifier circuit),
52 broadband amplifier, 60 ARR (lightning arrester), 80 ...
PSF (power supply separation filter), 90 AVR (constant voltage circuit) 90, 100 branching circuit, 110 mixing circuit, 28
... gain display member, ATT ... variable attenuator, VR ... variable resistor, SW ... slide switch.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masahiro Otsu 80, Nogami 80, Asada-cho, Nisshin-shi, Aichi F-term (reference) in Maspro Denko Corporation 5C056 FA08 HA01 HA08 HA12 HA14 5C064 BA07 BB05 BC12 BC14

Claims (10)

[Claims] 1. An in-building joint receiving system for receiving a broadcast signal transmitted from outside and transmitting the received signal to a plurality of receiving terminals via a transmission line wired in a building. A branching device used to branch a part of the received signal from a transmission line and output the branched signal to a specific receiving terminal side, wherein the branching device is connected in series to the transmission line via an input terminal and an output terminal, and an input terminal Directional coupling, forming a main path for passing the received signal from the main path to the output terminal, and branching a part of the received signal from the main path to output to a branch terminal side connectable to the receiving terminal. Branching means comprising: a device; an amplifying means provided on a branching path from the branching means to the branching terminal, for amplifying a received signal flowing through the branching path; and at least one of the input terminal, the output terminal, and the branching terminal Through Power supply means for supplying power to the amplifying means with direct current or power of a lower frequency than the received signal, which is input from the outside, and a branching device for a shared reception system in a building. . 2. The power supply means includes a constant voltage circuit for generating a DC constant voltage for driving the amplifying means by power input from the input terminal, output terminal or branch terminal, and the constant voltage circuit generates the constant voltage circuit. 2. The branching device according to claim 1, wherein a constant DC voltage is supplied to the amplification unit. 3. The branching device according to claim 1, wherein the power supply unit supplies power to the amplification unit with power input from the branch terminal. 4. The system according to claim 3, wherein the power supply means receives power from a terminal device connected to the branch terminal and supplies power to the amplification means. Branching device. 5. The amplifying means includes: a branching circuit that separates a reception signal flowing through the branch path into two systems of a first reception signal and a second reception signal having different frequency bands; and an output from the branching circuit. Amplifying circuit for amplifying the first received signal among the two types of received signals, mixing the first received signal output from the amplifier circuit and the second received signal output from the demultiplexing circuit And a mixing circuit that outputs the signal to the branch terminal side. 6. The branching circuit converts a reception signal flowing through the branch path into a first reception signal from a satellite reception device that receives a broadcast signal transmitted from an artificial satellite,
6. The branching system according to claim 5, wherein a received signal from a ground station receiving apparatus that receives a broadcast signal transmitted from the ground station is separated into two systems as a second received signal. apparatus. 7. The amplifying means is configured to be capable of adjusting an amplification factor of the reception signal, and the branching device includes an operation unit for setting the amplification factor by a manual operation. A branching device for a shared reception system in a building according to any one of claims 1 to 6. 8. The building according to claim 1, wherein the branching device is a serial unit that is used by being housed in an outlet box provided on a wall of a building. Branch device of the joint reception system. 9. Receiving a broadcast signal transmitted from outside, and transmitting the received signal to a plurality of receiving terminals via a transmission line wired in a building and a transmission device provided on the transmission line. A shared reception system in a building, wherein the branching device according to any one of claims 1 to 8 is provided as one of the transmission devices. 10. A receiver for a satellite for receiving a broadcast signal transmitted from an artificial satellite, and a receiver for a ground station for receiving a broadcast signal transmitted from a ground station. The shared reception system in a building according to claim 9, wherein the received signals are transmitted to the plurality of receiving terminals by mixing the received signals and transmitting the mixed signals to the transmission line.