JPH0479488B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention enables a security guard or the like to carry a slave station in a building, for example, and send emergency situation and other information to a fixedly installed master station such as a security room. The present invention relates to a signal transmission device for transmitting signals.

[Prior art and its drawbacks] Generally, devices used for this type of purpose are:
A method of transmitting signals using telephone radio (hereinafter referred to as a transceiver) is used, and communication is performed using radio waves between a transceiver carried by a security guard and a transceiver fixedly installed in a security room. Within such structures, the propagation of radio waves is greatly attenuated due to the transmission distance, the structure of the structure, etc., making reliable signal transmission impossible.

FIG. 6 is a diagram for explaining a conventional signal transmission method using a transceiver. That is, the sixth
In the figure, 11 is a small transceiver used by security guards, etc., 12 is a transceiver fixedly installed in the security room, and inside the premises there is a partition 14.
Propagation of radio waves between the transceiver 11 and the transceiver 12 is greatly attenuated by radio wave obstructions such as the floor 15 and the floor 15, making reliable signal transmission impossible.

[Object of the Invention] The present invention has been made in view of the above points, and provides a signal that can realize reliable signal transmission between a portable slave station and a fixedly installed master station at low cost even within a premises. The purpose is to provide transmission equipment.

[Summary of the Invention] In other words, the signal transmission device according to the present invention has a transmission line for common television reception installed in buildings, apartment complexes, hospitals, schools, etc., which has broadband characteristics, and is capable of transmitting signals other than television signals. The main feature of this system is that a mobile slave station and a fixedly installed master station are basically connected through this transmission path.

In this case, the coupling means for connecting the slave station and the fixedly installed master station through the transmission path is a long band-shaped antenna (two parallel lines ) is used. Further, since the transmission line has transmission loss, an amplifier or a side circuit to reduce the transmission loss is provided between the transmission line and the coupling means.

[Embodiment of the Invention] A signal transmission device according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram for explaining a signal transmission method of a signal transmission device according to an embodiment.

In FIG. 1, numeral 21 is a master station fixedly installed in a security room or the like, and 22a to 22C are mobile slave stations carried by security guards, etc., respectively. The slave stations 22a to 22C each communicate with the master station 21 by radio waves.
to transmit signals. The master station 21 is equipped with a display section 21a that displays a symbol corresponding to an identification code, which will be described later, and a function that generates a sound signal such as a chime.
Each radio wave from 2a to 22C is received, and a symbol corresponding to the received identification code of the slave station 22a to 22C is displayed by lighting on the display section 21a, and a chime is sounded.

FIG. 2 is a block diagram showing the basic configuration of the present invention, in which the slave station 22 and the master station 21 are connected by transmission line means 31.
and is connected by a connecting means 32.

The slave station 22 includes a transmission push button switch 33, an identification code generation circuit 34, a high frequency transmission circuit 35, and a power supply 36. The identification code generation circuit 34 has 8
Generates a unique identification code consisting of bits. The high frequency transmitting circuit 35 transmits a high frequency modulated with the above identification code. Further, the power source 36 is a battery.

The master station 21 includes a high frequency amplification circuit 37, a detection demodulation circuit 38, a code decoding and display circuit 39, and a power supply 40. The high frequency amplification circuit 37 amplifies the high frequency generated by the high frequency oscillation circuit 35 of the slave station 22. The detection demodulation circuit 38 demodulates the identification code. The code decoding/displaying circuit 39 decodes the identification code, and in response to the decoding, lights up the code assigned to the slave station 22 in advance and sounds a chime.

The transmission line means 31 serves as a signal transmission line between the master station 21 and the slave station 22, and is constituted by a coaxial cable (generally, the transmission line for common television reception is often shared).

The coupling means 32 couples the master station 21 and the slave station 22 through the transmission line means 31 (for example, a coaxial cable), and is provided with an antenna on the slave station 22 and the transmission line means 31 (coaxial cable). , space propagation (coupling) by radio waves. Another method is to connect two parallel lines (Retzchel line) or surface wave lines (G line, F line, etc.) to one end of the transmission line means 31 (coaxial cable), and connect these lines (two parallel lines). Alternatively, a non-reflection terminator may be connected to the other end of the surface wave line (surface wave line), and the slave station 22 may be constructed using a loop or coil-shaped coupler as an antenna.

That is, such lines such as two parallel lines and surface wave lines are transmission lines with extremely low transmission loss, and by terminating them with a non-reflection terminator, only traveling waves are generated, and no standing waves are generated. and,
In principle, a magnetic field exists in these lines in the direction of propagation of electromagnetic waves, that is, in a direction perpendicular to the axial direction of the line, so the slave station 22 is provided with a loop or coil-shaped coupler as an antenna to couple with this magnetic field. For example, the connection between the slave station 22 and the master station 21 is ensured, and the communication becomes possible.

In addition, in parallel twin lines and surface wave lines,
Since the strength of the magnetic field decreases in inverse proportion to the fourth power of the distance from these lines, interference with other electrical equipment can be significantly reduced by considering the installation position of these lines. Furthermore, since the master station 21 and slave station 22 cannot be coupled to each other unless they go near the railway line, it is effective in protecting secrets. Furthermore, since there are no standing waves on these lines,
A major feature is that the strength of the magnetic field is uniform at any position in the axial direction of the line, allowing stable communication (signal transmission between the master station 21 and slave stations 22).

Other coupling means 32 can be constructed by connecting a leaky coaxial line to one end of the transmission line means 31 (coaxial cable), and using various antennas in the slave station 22. It is also possible to create a transmission line with one overhead line as a residential route and the ground as a return route. That is, an antenna is provided in the slave station 22, a transmission line consisting of a ground plate and a single conductor is connected to one end of the transmission line means 31 (coaxial cable), and a non-reflection terminator is connected to the other end of the transmission line. In reality, a grounding plate several tens of centimeters wide is used as the ground, and conducting wires several millimeters thick are installed as overhead wires at intervals of several centimeters in the center of this grounding plate. is good. In addition, when installing this conducting wire on a ceiling surface, for example, a thin aluminum plate or the same plate may be bonded to the ceiling surface as a grounding plate.

FIG. 3 is a block diagram showing a configuration in which a transmission line for common television reception is used as the transmission line means 31, and two parallel lines and a loop antenna are used as the coupling means 32.

In FIG. 3, numerals 41 to 43 are equipment and transmission lines for common television reception, 41 is a distributor, 42 is a branch for the television end, and 43 is a transmission line for common television reception. Further, 22 is the slave station shown in FIGS. 1 and 2, which is carried by a security guard or the like. This slave station 22 is provided with a loop antenna 44 for coupling.

Reference numeral 45 indicates two elongated parallel parallel lines of several wavelengths that serve as receiving antennas.
A non-reflection terminator 46 and an impedance matching device 47 are connected to both ends of the filter. Reference numeral 48 denotes a correction amplifier for correcting the transmission loss of the transmission line 43 for common television reception, and when receiving radio waves from the slave station 22, a position identification code unique to each receiving antenna, that is, for determining the position of the slave station 22, is provided. A position discrimination code addition circuit 49 for adding a position discrimination code is built-in. Note that this position discrimination code addition circuit 4
9 is normally provided within the correction amplifier 48, but it can also be provided independently of the correction amplifier 48.

The high frequency signal amplified by this correction amplifier 48 is sent to a transmission line 43 for common TV reception via a predetermined branching device 42 . 50 is a bypass circuit that bypasses the reverse attenuation of the distributor 41. Due to this bypass circuit 50, the signal output from the slave station 22 flows in the direction of the arrow, and is input to the master station 21 via the branch 42 to which the master station 21 is connected.

FIG. 4 is a perspective view showing the arrangement of equipment for the configuration shown in FIG. 3, in which 51 is a floor and 52 is a partition.

In other words, there is a transmission line 4 for joint TV reception on the premises.
3 is installed, and each room is equipped with a branch 42 (terminal) of this transmission line 43 for common television reception. This transmission line 43 for common television reception
is used as a transmission line means, and the frequency (signal) for signal transmission between the master station 21 and the slave stations 22 is transmitted to the distributor 41 and branch 42 installed in the middle of the transmission line 43 for joint television reception. A bypass circuit 50 is added to reduce transmission loss.

The master station 21 is connected via a cable or the like to a branch 42 located in a predetermined room such as a security room, and is fixedly installed in the same room.

On the other hand, the two parallel lines 45 are connected to the master station 21 and slave station 22.
It is used as a coupling means for connecting the two parallel lines 45, and is installed by penetrating the partition 52 on the ceiling of each room or hallway, and connecting the non-reflection terminator 46 and the impedance matching unit 47 to both ends of the two parallel lines 45. Fix it to the ceiling. Then, the impedance matching device 47 and the branching device 42 near the bypass circuit 50 are connected by a cable or the like with the correction amplifier 48 interposed therebetween.

In such a configuration, security guards etc.
2, and near the two parallel tracks 45, the master station 21
It becomes possible to transmit signals with In this case, slave station 22
The signal (radio wave) transmitted from
5. It is received by a receiving antenna consisting of a non-reflection terminator 46 and an impedance matching device 47, and is sent to the master station 21 through a transmission line 43 for common TV reception. Therefore, even in the cabin, reliable signal transmission between the mobile mobile slave station 22 and the fixedly installed master station 21 is possible without attenuating the propagation of radio waves due to obstacles such as the floor 51 or partition 52. It becomes possible.

FIG. 5 is a system configuration diagram of FIG. 4 above,
The main station 21 is fixedly installed on the first floor of the aircraft, and receiving antennas consisting of two parallel lines 45, a non-reflection terminator 46, and an impedance matching device 47 are installed on the second and third floors.

In FIG. 5, 61 is a television receiving antenna, 62 is a television receiving amplifier, and a transmission line 43 for common television reception is provided from a distributor 41 connected to the television receiving amplifier 62 to each floor. . The master station 21 is connected to a branch 42 in a maintenance room or the like on the first floor, and the receiving antenna is connected to a predetermined branch 42 on the second and third floors with a correction amplifier 48 installed therein.

If the signal transmission device of the present invention is used with the configuration shown in FIG. It is accurately transmitted to the master station 21 on the first floor via the antenna and transmission line 43 for common television reception. In this case, it is determined which receiving antenna on the 2nd or 3rd floor received the signal (radio wave) of the slave station 22, in other words, it is determined which slave station 22 on the 2nd or 3rd floor has emitted the signal. Discrimination is possible.

Although the present embodiment describes one-way transmission from the slave station to the master station, the present invention is not limited to this, and for example, transmission from the master station 21 to the slave station 22 can also be realized extremely easily. . That is,
It is sufficient to configure the slave station 22 with a receiving function and the master station 21 with a transmitting function. In the example shown in FIG. This can be easily realized by making each of the terminals 50 and 50 bidirectional, thereby enabling bidirectional communication between the master station 21 and the slave stations 22.

Furthermore, in this embodiment, the slave station 22 is provided with a circuit that generates a unique identification code, and the master station 21 is provided with a circuit that decodes the same identification code, so that the master station 21 side can identify the slave station 22 that has transmitted the signal. I configured it to do this, but
When performing two-way communication as described above, the master station 2
It is also possible to provide a circuit for generating a unique identification code in the slave station 22 and a circuit for decoding the same identification code in the slave station 22 so that the slave station 22 can identify the master station 21.

[Effects of the Invention] As described above, according to the present invention, reliable signal transmission between a mobile mobile slave station and a fixedly installed master station is possible even in a premises where there are radio wave obstructions such as partitions and floors. becomes. In addition, it is easy to install coupling means such as two parallel lines and the installation of a master station, and by using a TV shared reception transmission line as the transmission line means, there is no need to install a new transmission line. A highly expandable signal transmission device can be realized at low cost.

[Brief explanation of drawings]

FIG. 1 is a perspective view for explaining a signal transmission method of a signal transmission device according to an embodiment of the present invention, and FIG.
The figure is a block diagram showing the basic configuration of the present invention, Figure 3 is a block diagram showing the configuration when a transmission line for common television reception and two parallel lines are used, and Figure 4 is the equipment for the configuration shown in Figure 3 above. Fig. 5 is a perspective view showing the arrangement of the above system configuration diagram in Fig. 4,
The figure is a perspective view for explaining a conventional signal transmission system. 21... Master station, 22... Slave station, 41... Distributor, 42... Branch, 43... Transmission line for common TV reception, 44... Loop antenna, 45... Two parallel lines, 46... ...Reflection-free terminator, 47... Impedance matching device, 48... Correction amplifier, 50...
...Side circuit, 61...TV receiving antenna, 62
...Amplifier for television reception.

Claims (1)

[Scope of Claims] 1. A common television reception line installed in a premises and having a plurality of lines distributed by a distributor and a turnout provided on each of the lines, and this common television reception line. a master station connected to one of the above-mentioned lines of the railway line via the above-mentioned branching device; a mobile mobile slave station having an antenna and transmitting signals to the above-mentioned master station; Two parallel lines that are connected to each of the lines of the television common reception line via the branch, have a non-reflection terminator connected to the other end, and connect the master station and the slave station through the antenna of the slave station. a plurality of coupling means each consisting of a line or a surface wave line; each of the coupling means and each line of the television common reception line is provided via the brancher; a plurality of amplifiers that correct losses; an identification code generation circuit that is provided in the slave station and generates an identification code unique to the slave station; and an identification code generation circuit that is provided within each of the amplifiers or independently and that determines the position of the slave station. a plurality of position discrimination code adding circuits for adding position discrimination codes for the purpose of the present invention; and a code decoding circuit provided in the master station for decoding the identification code and the position discrimination code of the slave station. signal transmission equipment. 2. Signal transmission according to claim 1, characterized in that a bypass circuit is provided between each of the lines of the television common reception line for flowing the signal from the slave station to the master station. Device.