JP4483705B2 - Intercom system for housing complex - Google Patents

Description

  The present invention provides an alternative communication channel between any one of a common unit device installed at a common entrance of an apartment house, a telephone device installed in a management room, and a dwelling unit installed in each dwelling unit. The intercom system for collective housing that enables communication by establishing a communication system, in particular, in addition to individual calls in which the common unit device and the communication device and one dwelling unit make a one-to-one call, to the plurality of dwelling units simultaneously by the calling device The present invention relates to an intercom system for collective housing that can perform broadcasting.

  Conventionally, a communication path is alternatively set between any one of a common unit installed at a common entrance of a housing complex and a communication device installed in a management room and a dwelling unit installed in each dwelling unit. In addition to individual calls in which the common unit device and the call device and one dwelling unit call one-on-one, the collective housing can be broadcast to a plurality of dwelling units by the call device. An intercom system is provided (see, for example, Patent Document 1).

  FIG. 9 is a system configuration diagram showing a conventional example described in Patent Document 1. In FIG. A communication device (management room intercom) 100 installed in a management room of an apartment house includes a microphone 101a, a speaker 101b, a transmission amplifier 101c that amplifies the output (sending signal) of the microphone 101a, and an input (receiving signal) to the speaker 101b. A communication circuit 101 including a two-line four-line conversion circuit 101e that performs two-line four-line conversion between the two-line communication line La and the input lines and output lines of the two amplifiers 101c and 101b. I have.

  On the other hand, the dwelling unit 110 installed in each dwelling unit includes a microphone 111a, a speaker 111b, a transmission amplifier 111c that amplifies the output (transmission signal) of the microphone 111a, and a reception amplifier that amplifies the input (reception signal) to the speaker 111b. 111d, a call circuit 111 including a 2-line 4-line conversion circuit 111e for converting 2-line 4-line conversion between the 2-line call line La and the input lines and output lines of the two amplifiers 111c, 111b, and the call circuit 111 A connection switch 112 that switches between a state connected to the line La and a state not connected, and closes the connection switch 112 when a call start instruction is received from the communication device 100 by a control signal transmitted through a control line (not shown). Thus, a communication path is established with the call device 100, and an individual call becomes possible. Further, in the case where the communication device 100 performs simultaneous broadcasting for a plurality of dwelling units 110, in each dwelling unit 110 that has received an instruction to start simultaneous broadcasting from the calling device 100 by a control signal transmitted via a control line, Speakers of a plurality of dwelling units 110 for which a broadcast channel is established from the call device 100 via the call line La by closing the connection switch 112 and establishing communication paths with the call device 100. 111b is transmitted.

Furthermore, in the above conventional example, the main device 120 is provided on the call line La between the call device 100 and the dwelling unit 110 in order to broadcast simultaneously using the call line La for individual calls. The main device 120 includes an amplifier 121 that amplifies an audio signal at the time of broadcast, a matching transformer 122 for matching the impedance in the frequency band of the audio signal of the communication line La to which a plurality of dwelling units 110 are connected, and a matching A first changeover switch 123 that switches between a state in which a series circuit of the transformer 122 and the amplifier 121 is connected to the communication line La on the dwelling unit 110 side and a state in which the connection is not made, and an audio signal is the amplifier 121, the matching transformer 122, And a second changeover switch 124 that selectively switches between a route passing through 123 and a route not passing through 123. That is, when the first switch 123 is opened and the second switch 124 is closed in the main device 120 during an individual call, an audio signal is transmitted through a path that does not pass through the amplifier 121, the matching transformer 122, and the first switch 123. When the first changeover switch 123 is closed and the second changeover switch 124 is opened during the broadcast, the audio signal is transmitted through the path passing through the amplifier 121, the matching transformer 122, and the first changeover switch 123. The telephone line La can be shared for broadcasting.
Japanese Patent Publication No. 8-28780

  However, in the above-described conventional example, since the broadcast audio signal is transmitted through the matching transformer 122 in the main device 120 with the impedance matched to the impedance of the communication line La or the reception impedance of the dwelling unit 110, As the number of dwelling units 110 increases, the attenuation of the audio signal increases, and there is a problem that the amplification degree of the amplifier 121 of the main device 120 must be increased to compensate for the attenuation.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an intercom system for an apartment house that can share the same signal line for individual calls and broadcasts while suppressing attenuation of audio signals during broadcasts. It is to provide.

  In order to achieve the above object, the first aspect of the present invention is a common unit device that is installed at a common entrance of an apartment house and can input and output voice, and an audio input and output unit that is installed in a management room of the apartment house. When the communication device is installed in each dwelling unit of the apartment house, the common device and the communication device are connected via the transmission line and are selected by operating the selection means of the common device or the communication device. A plurality of dwelling units that establish a communication path with the common unit device or the communication device, and the transmission line is a trunk line connected to the common unit device and the communication device and a separate line connected to each dwelling unit. The trunk line and the separate line for the dwelling unit are composed of a control line that transmits at least a control signal that is generated in response to the operation of the selection means and instructs the start of an individual call, and a signal line that transmits a voice signal. Is a common equipment A communication means for making a call with each call device via a signal line, and a communication path by connecting the call means to the signal line of the dwelling unit line when receiving a control signal transmitted via the control line. Control means for establishing the communication device, the call device comprises a call means for making a call with a dwelling unit via a signal line, a selection means for selecting a dwelling unit as a call partner, and a plurality of dwelling units A broadcast start instruction means for instructing the start of the target broadcast, and a control signal for instructing the start of an individual call to the dwelling unit selected by the selection means are transmitted via the control line and the broadcast start instruction is given. Control means for transmitting a control signal for instructing the start of simultaneous broadcasting to a plurality of target dwelling units via a control line when the start of simultaneous broadcasting is instructed by the means, and input in the dwelling unit Match the impedance of the output An individual call path with impedance, a broadcast path with an impedance lower than the input and output impedances of the dwelling unit, and an individual call path for transmitting audio signals and a simultaneous broadcast during broadcast A path switching means for transmitting an audio signal through a communication path is provided on a signal line included in a telephone or trunk line.

  According to a second aspect of the present invention, in the first aspect of the invention, the shared section device frequency-modulates and outputs a video signal obtained by capturing an image of a visitor in a frequency band different from the frequency band of the audio signal, and for individual calls. A trunk line device comprising: a route; a broadcast channel; a route switching unit; and a multiplexing unit that frequency-multiplexes a video signal output from the common unit to an audio signal transmitted through the signal line. It is characterized by that.

  The invention of claim 3 is characterized in that, in the invention of claim 1, an individual call route, a broadcast route, and route switching means are provided on a signal line included in the trunk line.

  According to a fourth aspect of the present invention, in the first aspect of the present invention, the call device is provided with an individual call route, a simultaneous broadcast route, and route switching means, and a plurality of systems of trunk lines are selectively used for the shared device and the call device. The main line device is connected to the main line, and the main line device has an individual call route provided for each main line, a simultaneous broadcast route provided for all other main lines except one main line, and an individual call for each main line. And a route switching means for switching between a broadcast route and a broadcast route.

  In the invention of claim 5, in the invention of claim 4, the shared section device frequency-modulates the video signal obtained by imaging the visitor in a frequency band different from the frequency band of the audio signal, and transmits the modulated video signal to the trunk apparatus. The main line device is a video signal amplifying means for amplifying the frequency-modulated video signal sent from the shared section device, and a video signal for selectively switching and connecting the output terminals of the video signal amplifying means to a plurality of main lines. Output switching means, multiplexing means for frequency-multiplexing the video signal amplified by the video signal amplifying means to the audio signal transmitted through the signal line, and for individual calls connected to the output terminal of the video signal amplifying means Characterized in that it comprises a route, a broadcast route provided for every other trunk line except one main line, and a route switching means for switching the individual call route and the broadcast route for each main line. To do.

  The invention of claim 6 is the invention of claim 3, further comprising a trunk line device for selectively connecting a plurality of trunk lines to the shared device and the call device, and the trunk line device is an individual call path provided for each trunk line. And a broadcast channel provided for each trunk line, and a route switching means for switching the individual call route and the broadcast channel for each trunk line.

  The invention according to claim 7 is the invention according to claim 6, wherein the shared unit device modulates a video signal obtained by imaging a visitor in a frequency band different from the frequency band of the audio signal, and transmits the modulated video signal to the trunk line device. The main line device is a video signal amplifying means for amplifying the frequency-modulated video signal sent from the shared section device, and a video signal for selectively switching and connecting the output terminals of the video signal amplifying means to a plurality of main lines. Output switching means, multiplexing means for frequency-multiplexing the video signal amplified by the video signal amplifying means to the audio signal transmitted through the signal line, and for individual calls connected to the output terminal of the video signal amplifying means It comprises a route, a broadcast channel provided for each main line, and a route switching means for switching between the individual call route and the broadcast channel for each main line.

  The invention of claim 8 is characterized in that, in the invention of claim 5 or 7, the trunk line device comprises means for separating the output end of the video signal amplification means from any trunk line during simultaneous broadcasting.

  The invention of claim 9 is the invention according to any one of claims 4 to 8, further comprising a trunk distribution device that distributes one trunk line to a plurality of trunk lines, and the trunk distribution device is provided for each trunk line of the plurality of systems. And an individual call route, a broadcast channel provided for each main line, and a route switching means for switching the individual call route and the broadcast route for each main line.

  According to the first aspect of the present invention, since the audio signal is transmitted through the individual call path switched by the path switching unit at the time of the individual call, a call having a high resistance against inductive noise can be performed. The audio signal is transmitted through the broadcast channel switched by, and the broadcast channel has an impedance lower than the input and output impedances of the dwell unit. Even when the number increases, the attenuation of the audio signal can be suppressed, and the signal line can be shared between the individual call and the broadcast.

  According to the invention of claim 2, since the audio signal and the video signal are multiplexed by the multiplexing means of the trunk line apparatus and transmitted through the common signal line, the signal line is shared not only for individual calls and simultaneous broadcasting but also for the video. Thus, further wiring saving can be achieved. In addition, it is possible to use an inexpensive call device that does not include the individual call route, the broadcast route, and route switching means.

  According to the invention of claim 3, as in the invention of claim 1, even when the number of dwelling units subject to simultaneous broadcasting increases, attenuation of the audio signal can be suppressed, and individual calls and simultaneous broadcasting can be achieved. The signal line can be shared.

  According to the invention of claim 4, in the trunk line device, the route switching means switches between the individual call route and the simultaneous broadcast route, and the broadcast device has the broadcast for one trunk line of the plurality of trunk lines. It is possible to reduce the number of broadcast routes provided in the trunk line device by using the use route.

  According to the invention of claim 5, the circuit configuration can be simplified by sharing the video signal amplifying means by a plurality of main lines.

  According to the sixth aspect of the present invention, it is possible to suppress the attenuation of the audio signal even when the broadcast is performed through a plurality of systems of trunk lines, and the signal line can be shared between the individual call and the broadcast. Moreover, it is possible to use an inexpensive call device that does not include an individual call route, a broadcast route, and route switching means.

  According to the seventh aspect of the present invention, the circuit configuration can be simplified by sharing the video signal amplifying means with a plurality of main lines.

  According to the invention of claim 8, since the output end of the video signal amplifying means is disconnected from any main line during the broadcast in the trunk device, the broadcast audio is affected by the impedance of the output with respect to the audio signal band of the video signal amplifying means. It is possible to prevent the signal from being attenuated.

  According to the invention of claim 9, in the case where the number of trunk lines and the number of dwelling units are significantly increased by further distributing a plurality of trunk lines distributed by the trunk apparatus to a plurality of trunk lines by the trunk distribution apparatus. However, it is possible to suppress the attenuation of the audio signal during the broadcast, and it is possible to share the signal line between the individual call and the broadcast.

  As described in the related art, the control line among the transmission lines transmits a control signal for the common unit device (lobby interphone) 1 and the communication device (management room interphone) 3 to select the other unit 2. Therefore, the circuit connected to the control line in the lobby intercom 1, the management room intercom 3, and the dwelling unit 2 must always be operated. That is, since the control signal including the address for the lobby intercom 1 and the management room intercom 3 to select the dwelling unit 2 is transmitted to all the dwelling units 2, the control signal for receiving the control signal in all the dwelling units 2 is used. The CPU that interprets the receiving circuit and the control signal and performs necessary processing always operates. On the other hand, since the processing for the audio signal and the video signal may be performed after the dwelling unit 2 is selected, the audio signal and the video signal can be handled collectively, and the audio signal and the video signal are in the frequency band. Are different (the video signal has a sufficiently high frequency relative to the audio signal), and can be multiplexed by a frequency multiplexing technique.

Therefore, in the embodiment described below, multiplexing means for multiplexing the FM video signal transmitted from the lobby intercom 1 via the video line Lb into the audio signal transmitted from the management room intercom 3 via the call line La. Is provided in the trunk line device 4, and an example in which the number of lines used for the transmission line is reduced as compared with the conventional configuration after the trunk line device 4 will be described. The control signal is used not only for calling the dwelling unit 2 from the lobby intercom 1 and the management room intercom 3 but also for the purpose of instructing the start of simultaneous broadcasting by the management room intercom 3. A baseband signal may be used for this type of control signal. Since the baseband signal has a wide frequency band and is difficult to separate from an audio signal and a video signal, this also controls the audio signal and the video signal. It is necessary from the point of transmission quality to transmit signals separately.
(Embodiment 1)
A system configuration diagram of this embodiment is shown in FIG. In the present embodiment, a common unit device (lobby intercom) 1 installed at a common entrance of an apartment house, a communication device (management room intercom) 3 installed in a management room, and a plurality of units respectively disposed in each dwelling unit The dwelling unit 2 is provided, and the lobby intercom 1, the management room intercom 3, and the dwelling unit 2 are connected via a transmission line. The transmission line includes a trunk line L1 connected to the trunk line device 4, and a dwelling unit separate line L2 branched from the trunk line L1 and connected to each dwelling unit 2. As this transmission line, a multi-pair twisted pair cable having two or more pairs in the sheath is used. In the illustrated example, the camera provided in the lobby intercom 1 between the lobby intercom 1 and the dwelling unit 2 (see FIG. A control signal for designating the dwelling unit 2 selected by the selection means (described later) of the lobby interphone 1 or the control room interphone 3 and the signal line Ld for multiplexing and transmitting the video signal and the audio signal picked up in (not shown). A pair line is used for each of control lines (not shown) for transmitting. That is, in the illustrated transmission line, two pairs of pair wires are used. Here, the video signal transmitted through the signal line Ld is frequency-modulated in the lobby intercom 1, and the frequency-modulated video signal (hereinafter referred to as “FM video signal”) and the audio signal are multiplexed in the trunk device 4. It becomes. The FM video signal multiplexed and transmitted with the audio signal via the signal line Ld is separated by a demultiplexing circuit 201 provided in each dwelling unit 2 as will be described later, and then frequency demodulated by an FM demodulator 25a. And displayed on the monitor 22.

  The lobby intercom 1 includes a microphone and a speaker for inputting / outputting sound, a camera for imaging a visitor, an FM modulation circuit for frequency-modulating a video signal output from the camera, a number key and a call button for designating a dwelling unit number If the call button is operated after the visitor operates the number key and selects the visited house number, the dwelling unit 2 corresponding to the house number is selected. Here, the lobby intercom 1 is connected to the management room intercom 3 via a telephone line La and a control line (not shown), and the dwelling unit number selected by the lobby intercom 1 is connected via a control line (not shown). Then, the management room intercom 3 sends a control signal (call command) to the dwelling unit 2 corresponding to the dwelling unit number via a control line (not shown). Also, an audio signal transmitted from the lobby intercom 1 via the communication line La via the management room intercom 3 and an FM video signal transmitted from the lobby intercom 1 via the video line Lb are multiplexed in the trunk device 4. And transmitted to each dwelling unit 2 via the signal line Ld. That is, on the side of the dwelling unit 2 from the trunk line device 4, the signal line Ld also serves as the call line La and the video line Lb.

  On the other hand, the dwelling unit 2 includes a microphone 21a and a speaker 21b for inputting and outputting audio, and the microphone 21a and the speaker 21b are connected to an audio circuit 24c via amplifiers 24a and 24b, respectively. Here, as described above, the demultiplexing circuit 201 is provided in the dwelling unit 2 in order to use the signal line Ld for both the audio signal and the video signal. The demultiplexing circuit 201 includes a low-frequency passage unit 201a inserted between the audio circuit 24c and the signal line Ld, and a high-frequency passage unit 201b inserted between the coupling transformer 25c and the signal line Ld. The low frequency passage unit 201a has a low impedance to the audio signal and a high impedance to the video signal, and the high frequency passage unit 201b has a high impedance to the audio signal and a low impedance to the video signal. Use one. In the illustrated example, an inductor is used as the low frequency passage 201a, and a capacitor is used as the high frequency passage 201b. The audio circuit 24c includes a circuit that converts the two signal lines Ld and the input lines and output lines of the two amplifiers 24a and 24b into two lines and four lines, and demultiplexes the audio signal input from the microphone 21a. And the audio signal from the signal line Ld separated by the demultiplexing circuit 201 is output to the speaker 21b side. Accordingly, voice signals can be exchanged between the lobby intercom 1 and the management room intercom 3 and the dwelling unit 2 through the signal line Ld, and a visitor uses the lobby intercom 1 and a resident uses the dwelling unit 2. Voice calls can be made between visitors and residents, and voice calls can be made between managers and residents by the manager using the control room intercom 3 and the residents using the dwelling unit 2. It becomes.

  In the dwelling unit 2, a liquid crystal display or a CRT is used for the monitor 22. The FM video signal input to the dwelling unit 2 through the signal line Ld is input to the amplifier 25b via the coupling transformer 25c for balance-unbalance conversion after being separated by the demultiplexing circuit 201, and amplified by the amplifier 25b. After that, frequency demodulation is performed in the FM demodulator 25a. The video signal output from the FM demodulator 25 a is input to the monitor 22, thereby displaying the video on the screen of the monitor 22. That is, since the visitor's image imaged with the camera of the lobby intercom 1 is displayed on the monitor 22 of the dwelling unit 2, the resident in the dwelling unit can confirm the visitor.

  The dwelling unit 2 is provided with a CPU (not shown) for controlling an internal circuit, and a control signal transmission / reception circuit (not shown) serving as an interface with a control line (not shown) is connected to the CPU. The control signal transmission / reception circuit has a function of sending a control signal output from the CPU to a control line (not shown) and delivering the control signal received from the control line (not shown) to the CPU.

  Here, for the control line (not shown), the trunk line L1 and the dwelling unit separate line L2 are directly connected in the branching device 7. Therefore, the control signal sent from the management room intercom 3 is transmitted to all the dwelling units 2 connected to the control line (not shown). Here, an address (for example, a dwelling unit number) is individually set in the CPU of the dwelling unit 2. For example, by selecting an address in the lobby intercom 1, a control signal (call command) specifying the address is managed. It can be transmitted from the room intercom 3 to all the dwelling units 2 via a control line (not shown). If the address included in the control signal is its own address, the CPU of the dwelling unit 2 has a relay contact 29 of the dwelling unit relay inserted between the trunk line L1 and the audio circuit 24c in the signal line Ld of the dwelling unit separate line L2. Is established to establish a communication path with the lobby intercom 1, and the FM demodulator 25 a and the monitor 22 are activated to display a visitor image captured by the camera of the lobby intercom 1 with the monitor 22 of the dwelling unit 2. And a ringing tone is emitted from the speaker 21b through the voice circuit 24c.

  The trunk line device 4 passes through the video amplifier 41 that amplifies the FM video signal transmitted from the lobby intercom 1 via the video line Lb, the FM video signal amplified by the video amplifier 41 and the management room intercom 3. A multiplexing circuit 40 that multiplexes a voice signal transmitted from the lobby intercom 1 via the telephone line La or a voice signal transmitted from the management room intercom 3 via the telephone line La is provided. The multiplexing circuit 40 includes a low-frequency passage unit 40a inserted between the call line La and the signal line Ld, and a high-frequency passage unit 40b inserted between the video amplifier 41 and the signal line Ld. In the illustrated example, an inductor is used as the low-frequency passage 40a, and a capacitor is used as the high-frequency passage 40b. However, a DC cut capacitor is inserted between the low-frequency passage portion 40a and the signal line Ld.

  The management room intercom 3 includes a microphone 31a for inputting / outputting sound and a speaker 31b, and the microphone 31a and the speaker 31b are connected to an audio circuit 34c via amplifiers 34a and 34b, respectively. The voice circuit 34c includes a circuit that converts the two-line call line La and the input lines and output lines of the two amplifiers 34a and 34b into two-line and four-line, and converts the voice signal input from the microphone 31a to the call line La. It has a function of sending out and outputting an audio signal from the call line La to the speaker 31b side. Further, between the amplifier 34a connected to the microphone 31a and the audio circuit 34c, a state where the output end of the amplifier 34a is connected to the audio circuit 34c and a state where the output end of the low impedance driving circuit 32 for broadcasting is connected are selected. A first changeover switch 33 is provided for switching between the voice circuit 34c and the call line La, and a state in which the call line La is connected to the voice circuit 34c and an output terminal of the broadcast low impedance drive circuit 32. A second changeover switch 35 that selectively switches between connection states is provided. That is, the first changeover switch 33 and the second changeover switch 35 correspond to path switching means, and are connected from the amplifier 34a to the communication line La via the first changeover switch 33, the voice circuit 34c, and the second changeover switch 35. The route to reach the call line La from the amplifier 34a to the call line La via the first changeover switch 33, the broadcast low impedance drive circuit 32, and the second changeover switch 35 becomes the broadcast route. Here, the output impedance of the audio circuit 34c (the output impedance of the individual call path) is set to a value substantially equal to the input impedance of the dwelling unit 2, but the output impedance of the broadcast path is a low-impedance driving circuit for broadcasting. The impedance is converted by 32 to an impedance lower than the input impedance of the dwelling unit 2. Although not shown in the figure, the management room intercom 3 is provided with a changeover switch for switching between a state where the telephone line La connected to the lobby intercom 1 is connected to a state where the telephone line La is connected to the main line device 4 and a state where it is not connected. Only when an individual call is made between the lobby intercom 1 and one of the dwelling units 2, the switch line is turned on and the call line La connected to the lobby intercom 1 is connected to the main line device 4. It is connected to the telephone line La.

  Similarly to the dwelling unit 2, the management room intercom 3 is also provided with a CPU (not shown) for controlling the internal circuit, and the CPU has a control signal transmission / reception circuit (not shown) serving as an interface with a control line (not shown). ) Is connected. The control signal transmission / reception circuit has a function of sending a control signal output from the CPU to a control line (not shown) and delivering the control signal received from the control line (not shown) to the CPU.

  Next, the operation of this embodiment will be described. First, the case where an individual call is made between the lobby intercom 1 and one dwelling unit 2 selected by the lobby intercom 1 will be described. A control signal (call command) is transmitted from the management room intercom 3 to the dwelling unit 2 selected by the lobby intercom 1 via a control line (not shown), and the address included in the control signal matches. 2, the CPU closes the relay contact 29 of the dwelling unit relay in response to the call command and causes the speaker 21 b to send out the ringing sound through the voice circuit 24 c. Further, in the dwelling unit 1 selected as the lobby intercom 1, the CPU activates the FM demodulator 25a and the monitor 22, and the FM demodulator 25a performs frequency demodulation on the FM video signal transmitted via the signal line Ld. A video of a visitor captured by one camera is displayed on the monitor 22. When the resident operates a response button (not shown) of the dwelling unit 2 in response to a call from the lobby intercom 1, the CPU activates the voice circuit 24c.

  On the other hand, in the management room intercom 3, after sending the call command, the CPU turns on a changeover switch (not shown) to connect the communication line La connected to the lobby intercom 1 to the communication line La connected to the trunk line device 4. As a result, a communication path is established between the lobby intercom 1 and the selected dwelling unit 2 so that an individual call is possible, and a visitor imaged by the camera of the lobby intercom 1 only in the selected dwelling unit 2 Can be displayed on the monitor 22.

  Next, a case where an individual call is made between the management room intercom 3 and one dwelling unit 2 selected by the management room intercom 3 will be described. A control signal (call command) is transmitted from the control room intercom 3 to the dwelling unit 2 selected by the control room intercom 3 via a control line (not shown), and the addresses included in the control signal match. In the machine 2, the CPU closes the relay contact 29 of the dwelling machine relay in response to the call command and sends a ringing tone from the speaker 21b through the voice circuit 24c. When the resident operates a response button (not shown) of the dwelling unit 2 in response to a call from the management room intercom 3, the CPU activates the voice circuit 24c. In the management room intercom 3, the CPU turns off a changeover switch (not shown) to disconnect the call line La connected to the lobby intercom 1 from the call line La connected to the trunk line device 4, and further to the first changeover switch 33 and the first switch The two changeover switches 35 are respectively switched to the sound circuit 34c side. As a result, a communication path via the individual call path is established between the management room intercom 3 and the selected dwelling unit 2, and individual calls are possible. Here, since the output impedance of the audio circuit 34c is set to a value approximately equal to the input impedance of the dwelling unit 2 by the broadcasting low impedance driving circuit 32, between the management room intercom 3 and one dwelling unit 2 is set. Individual calls with high resistance to induced noise can be made.

  Finally, a case where simultaneous broadcasting is performed to the plurality of dwelling units 2 from the management room intercom 3 installed in the management room of the apartment house will be described.

  When the manager operates a broadcast start button (not shown) provided on the management room interphone 3, the CPU of the management room interphone 3 controls the control lines (not shown) for the plurality of dwelling units 2 to be broadcast. Control signal (simultaneous broadcast start command) is transmitted through the relay station 29, and the CPUs of all the dwelling units 2 that are the targets of the simultaneous broadcasting close the relay contact 29 of the dwelling unit relay in response to the broadcast start command. And the audio circuit 24c is activated. Further, the CPU of the management room intercom 3 turns off the changeover switch (not shown) to disconnect the call line La connected to the lobby intercom 1 from the call line La connected to the trunk line device 4, and the first changeover switch 33 and The second changeover switch 35 is switched to the broadcast low impedance drive circuit 32 side. As a result, a communication path is established between the management room interphone 3 and the plurality of dwelling units 2 via the simultaneous broadcast path, and simultaneous broadcasting from the management room intercom 3 to the plurality of dwelling units 2 becomes possible. Here, the load impedance viewed from the broadcasting low impedance driving circuit 32 decreases as the number of dwelling units 2 to be broadcasted increases. Since the output impedance is converted to an impedance lower than the input impedance of the dwelling unit 2, compared with the case where impedance matching is performed by the matching transformer 122 as in the conventional example shown in FIG. Even when the number of dwelling units 2 is increased, the attenuation of the audio signal can be suppressed.

(Embodiment 2)
The present embodiment is characterized in that the trunk line device 3 is provided with an individual call route, a broadcast route, and route switching means. Accordingly, since the basic configuration of the present embodiment is common to that of the first embodiment, the same components are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 2, the main line device 4 includes a low impedance driving circuit for broadcasting 42 for converting the output impedance to an impedance lower than the input impedance of the dwelling unit 2, and a low impedance driving circuit for broadcasting the call line La. The first changeover switch 43 that selectively switches between the state connected to the input terminal 42 and the state not connected to the input terminal 42 and the state where the output terminal of the broadcast low impedance drive circuit 42 is connected to the low-frequency passage unit 40a are not connected. A second changeover switch 44 that selectively switches between states is provided. That is, the first changeover switch 43 and the second changeover switch 44 correspond to path switching means, and the first changeover switch 43 does not go through the broadcast low impedance drive circuit 42 but goes through the second changeover switch 44. The route to the low frequency passage unit 40a is a route for individual calls, and the route from the first changeover switch 43 to the low frequency passage unit 40a via the broadcast low impedance drive circuit 42 and the second changeover switch 44 is broadcast simultaneously. Route. In the present embodiment, the management room interphone 3 is not provided with a route for individual calls, a route for simultaneous broadcasting, and route switching means.

  In the present embodiment, the trunk line device 4 is also provided with a CPU (not shown) for controlling an internal circuit similarly to the dwelling unit 2, and the CPU transmits and receives control signals as an interface with the control line (not shown). A circuit (not shown) is connected. The control signal transmission / reception circuit has a function of sending a control signal output from the CPU to a control line (not shown) and delivering the control signal received from the control line (not shown) to the CPU.

  Next, the operation of this embodiment will be described. First, the case where an individual call is made between the lobby intercom 1 and one dwelling unit 2 selected by the lobby intercom 1 will be described. A control signal (call command) is transmitted from the management room intercom 3 to the dwelling unit 2 selected by the lobby intercom 1 via a control line (not shown), and the address included in the control signal matches. 2, the CPU closes the relay contact 29 of the dwelling unit relay in response to the call command and causes the speaker 21 b to send out the ringing sound through the voice circuit 24 c. Further, in the dwelling unit 1 selected as the lobby intercom 1, the CPU activates the FM demodulator 25a and the monitor 22, and the FM demodulator 25a performs frequency demodulation on the FM video signal transmitted via the signal line Ld. A video of a visitor captured by one camera is displayed on the monitor 22. When the resident operates a response button (not shown) of the dwelling unit 2 in response to a call from the lobby intercom 1, the CPU activates the voice circuit 24c.

  On the other hand, in the trunk line device 4, the CPU that has detected that the call command has been transmitted switches the first and second change-over switches 43, 44 from the first change-over switch 43 via the broadcast low-impedance drive circuit 42. Instead, an individual call path that reaches the low-frequency passage section 40a via the second changeover switch 44 is formed. As a result, a communication path is established between the lobby intercom 1 and the selected dwelling unit 2 via the individual call path, enabling individual calls, and the lobby intercom 1 only in the selected dwelling unit 2. Visitors captured by the camera can be displayed on the monitor 22. Note that the case of making an individual call between the control room intercom 3 and one dwelling unit 2 selected by the management room intercom 3 is almost the same as the case of the individual call between the lobby intercom 1 and the dwelling unit 2. Since there is, explanation is omitted.

  Next, the case where simultaneous broadcasting is performed from the management room intercom 3 to the plurality of dwelling units 2 will be described.

  When the manager operates a broadcast start button (not shown) provided on the management room interphone 3, the CPU of the management room interphone 3 controls the plurality of dwelling units 2 and the trunk line device 4 to be broadcast. A control signal (broadcast start command) is transmitted via a line (not shown), and in response to the broadcast start command, the CPUs of all the dwelling units 2 that are the targets of the broadcast are relays of dwelling unit relays. The contact 29 is closed and the audio circuit 24c is activated. Further, the CPU of the management room intercom 3 turns off a changeover switch (not shown) to disconnect the call line La connected to the lobby interphone 1 from the call line La connected to the trunk line device 4.

  On the other hand, in the trunk line device 4, the CPU switches the first and second change-over switches 43, 44 in response to the simultaneous broadcast start command, and the broadcast low-impedance drive circuit 42 and the second change-over are switched from the first change-over switch 43. A broadcast channel is formed via the switch 44 to reach the low frequency passage 40a. As a result, a communication path is established between the management room interphone 3 and the plurality of dwelling units 2 via the simultaneous broadcast path, and simultaneous broadcasting from the management room intercom 3 to the plurality of dwelling units 2 becomes possible. Here, the load impedance viewed from the low-impedance driving circuit for broadcasting 42 decreases as the number of dwelling units 2 to be broadcasted increases, but the output impedance of the broadcast channel is low-impedance driving for broadcasting. Since the impedance is converted to an impedance lower than the input impedance of the dwelling unit 2 by the circuit 42, compared with the case where impedance matching is performed by the matching transformer 122 as in the conventional example shown in FIG. Even when the number of dwelling units 2 increases, the attenuation of the audio signal can be suppressed.

  As described above, in the present embodiment, the individual call route, the broadcast channel, and the route switching unit are provided in the trunk line device 3, so that the individual call route, the broadcast channel, and the route switching unit are not provided and are inexpensive. The management room intercom 3 can be used.

  In the present embodiment, the main line device 4 is provided with a CPU and a control signal transmission / reception unit, and the first and second changeover switches according to a control signal transmitted from the management room intercom 3 via a control line (not shown). For example, the DC voltage is superimposed on the signal line Ld from the dwelling unit 2 selected during the individual call, and the DC voltage superimposed on the signal line Ld is detected in the trunk line device 4. The first and second changeover switches 43 and 44 may be switched.

(Embodiment 3)
In the present embodiment, the trunk line device 4 selectively connects a plurality of trunk lines to the lobby intercom 1 and the management room intercom 3, the individual call path provided for each trunk line, and other than one trunk line. It is characterized in that it comprises a broadcast channel provided for every main line, and a route switching means for switching the individual call route and the broadcast channel for each main line. However, since the basic configuration of the present embodiment is the same as that of the first embodiment, common components are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 3, the trunk line device 4 is connected to a plurality of (three in the illustrated example) trunk lines L1a, L1b, L1c, and transmits FM video signals transmitted from the lobby intercom 1 via the video line Lb. The paths are divided into three paths, and video amplifiers 41a, 41b, 41c and a high-frequency passage section 40b are provided for each of the distributed paths, and each system is provided to these three video amplifiers 41a, 41b, 41c and the high-frequency passage section 40b. Signal lines Ld included in the trunk lines L1a, L1b, and L1c are connected to each other. Further, the transmission path of the audio signal transmitted from the management room intercom 3 through the communication line La is branched into three paths, and the branched paths are the third changeover switches 45a, 45b, 45c and the low-frequency passage unit. Each signal line Ld is connected to each system via 40a. Further, the trunk line device 4 converts the output impedance to an impedance lower than the input impedance of the dwelling unit 2 and is provided in two low-frequency driving circuits 42a and 42b for broadcasting respectively provided on two paths branched from the transmission path of the audio signal. Broadcast to the signal lines Ld of all other systems (for example, L1a, L1b) except for the low frequency passage portions 40a, 40a and one of the three systems of trunk lines L1a, L1b, L1c (for example, L1c) Fourth switching switches 46a and 46b that selectively switch between a state in which the low impedance driving circuits 42a and 42b and the low-frequency passage units 40a and 40a are connected and a state in which they are not connected. That is, in the present embodiment, the third change-over switches 45a, 45b, 45c, the fourth change-over switches 46a, 46b, and the first and second change-over switches 33, 35 correspond to path switching means, The path passing through the changeover switch 45a or 45b or 45c and the low-frequency passage section 40a becomes the individual call path, and the path passing through the low-impedance driving circuit 42a or 42b for broadcasting, the low-frequency passage section 40a, and the fourth changeover switch 46a or 46b. Will be a broadcast channel.

  The dwelling unit 2 in the present embodiment has the same configuration as that of the first embodiment, and is connected to the dwelling unit separate line L2 branched from the trunk line L1a, L1b, L1c of any system by the branching unit 7. The management room intercom 3 has the same configuration as that of the first embodiment, and includes an individual call route, a simultaneous broadcast route, and route switching means.

  Next, the operation of this embodiment will be described. First, the case where an individual call is made between the lobby intercom 1 and one dwelling unit 2 selected by the lobby intercom 1 will be described. A control signal (call command) is transmitted from the management room intercom 3 to the dwelling unit 2 selected by the lobby intercom 1 via a control line (not shown), and the address included in the control signal matches. 2, the CPU closes the relay contact 29 of the dwelling unit relay in response to the call command and causes the speaker 21 b to send out the ringing sound through the voice circuit 24 c. Further, in the dwelling unit 2 selected as the lobby intercom 1, the CPU activates the FM demodulator 25a and the monitor 22, and the FM demodulator 25a demodulates the frequency of the FM video signal transmitted via the signal line Ld. A video of a visitor captured by one camera is displayed on the monitor 22. When the resident operates the response button of the dwelling unit 2 in response to the call from the lobby intercom 1, the CPU activates the voice circuit 24c.

  On the other hand, in the management room intercom 3, after sending the call command, the CPU turns on a changeover switch (not shown) to connect the communication line La connected to the lobby intercom 1 to the communication line La connected to the trunk line device 4.

  In the trunk line device 4, the dwelling unit 2 selected by closing one of the third change-over switches 45a, 45b, 45c is connected to the dwelling unit 2 by the CPU that has detected that the call command has been transmitted. The telephone line La is connected only to the trunk line L1a, L1b, or L1c, and all the fourth changeover switches 46a and 46b are opened. As a result, communication between the lobby intercom 1 and the selected dwelling unit 2 via the individual call route (route passing through the third changeover switch 45a or 45b or 45c and the low-frequency passage unit 40a) in the trunk line device 4 In addition to the establishment of the route, individual calls are possible, and the visitor captured by the camera of the lobby intercom 1 can be displayed on the monitor 22 only in the selected dwelling unit 2.

  Next, a case where an individual call is made between the management room intercom 3 and one dwelling unit 2 selected by the management room intercom 3 will be described. A control signal (call command) is transmitted from the control room intercom 3 to the dwelling unit 2 selected by the control room intercom 3 via a control line (not shown), and the addresses included in the control signal match. In the machine 2, the CPU closes the relay contact 29 of the dwelling machine relay in response to the call command and sends a ringing tone from the speaker 21b through the voice circuit 24c. When the resident operates the response button of the dwelling unit 2 in response to the call from the management room intercom 3, the CPU activates the voice circuit 24c. In the management room intercom 3, the CPU turns off a changeover switch (not shown) to disconnect the call line La connected to the lobby intercom 1 from the call line La connected to the trunk line device 4, and further to the first changeover switch 33 and the first switch Each of the two changeover switches 35 is switched to the audio circuit 34c side to form a path that does not pass through the broadcast low impedance drive circuit 32.

  In the trunk line device 4, the dwelling unit 2 selected by closing one of the third change-over switches 45a, 45b, 45c is connected to the dwelling unit 2 by the CPU that has detected that the call command has been transmitted. The telephone line La is connected only to the trunk line L1a, L1b, or L1c, and all the fourth changeover switches 46a and 46b are opened. As a result, via the individual call path (the path passing through the third changeover switch 45a or 45b or 45c and the low-frequency passage unit 40a) in the trunk line device 4 between the management room intercom 3 and the selected dwelling unit 2 A communication path is established and individual calls are possible. In addition, since the output impedance of the audio circuit 34c is set to a value substantially equal to the input impedance of the dwelling unit 2 between the lobby intercom 1 or the management room intercom 3 and one dwelling unit 2, the resistance against induction noise is set. High individual communication can be performed.

  Finally, a case where simultaneous broadcasting is performed from the management room intercom 3 to the plurality of dwelling units 2 will be described.

  When the manager operates a broadcast start button provided on the management room intercom 3, the CPU of the management room intercom 3 controls lines (not shown) for the plurality of dwelling units 2 and the trunk line device 4 to be broadcast. ) To transmit a control signal (broadcast start command), and in response to the broadcast start command, the CPUs of all the dwelling units 2 that are the targets of the broadcast close the relay contact 29 of the dwelling unit relay. At the same time, the audio circuit 24c is activated. Further, the CPU of the management room intercom 3 turns off a changeover switch (not shown) to disconnect the call line La connected to the lobby intercom 1 from the call line La connected to the main line device 4 and is connected to the main line L1c. Only when the dwelling unit 2 is included in the broadcast target, the first changeover switch 33 and the second changeover switch 35 are respectively switched to the broadcast low impedance drive circuit 32 side.

  On the other hand, in the trunk line device 4, in response to the broadcast start command, the CPU opens all the third changeover switches 45a, 45b, and 45c, and the dwelling unit 2 connected to the trunk line L1a is included in the broadcast target. If so, the fourth changeover switch 46a is closed, and if the dwelling unit 2 connected to the trunk line L1b is included in the broadcast target, the fourth changeover switch 46b is closed. As a result, there is a communication path between the management room intercom 3 and the plurality of dwelling units 2 via the simultaneous broadcast path (the path passing through the fourth changeover switches 46a and 46b and the low-frequency passage section 40a) in the trunk line device 4. Once established, simultaneous broadcasting from the management room intercom 3 to the plurality of dwelling units 2 becomes possible.

  Thus, for one of the three trunk lines L1a, L1b, and L1c, the dwelling unit 2 included in the broadcast target by the broadcast low impedance drive circuit 32 provided in the management room intercom 3 is used. For the other two systems of trunk lines L1a and L1b, the load impedance of the dwelling unit 2 included in the broadcast target is set by the broadcast low-impedance drive circuits 42a and 42b provided in the trunk line device 4. It is driven and each dwelling unit 2 can listen to the simultaneous broadcast.

  As described above, according to the present embodiment, for the trunk line L1c of one system among the trunk lines L1a, L1b, and L1c, by using the simultaneous broadcast route of the management room intercom 3, There is an advantage that it is possible to reduce the route for simultaneous broadcasting and the fourth switch to be provided.

(Embodiment 4)
The present embodiment is characterized in the configuration of the trunk line device 4 as shown in FIG. 4, and the other configurations are the same as those in the third embodiment. Therefore, the same configurations are denoted by the same reference numerals and description thereof is omitted. To do.

  The main line device 4 in the present embodiment is different from that of the third embodiment in that the output end of one video amplifier 41 is selectively switched to a plurality of lines (three lines in the illustrated example) of the main lines L1a, L1b, and L1c. A video signal changeover switch 47 to be connected is provided, and an audio signal for individual call is multiplexed with an FM video signal input to the video signal changeover switch 47 via the low-frequency passage unit 40a. That is, in the third embodiment, the FM video signal transmitted from the lobby intercom 1 via the video line Lb is always distributed and transmitted to all the trunk lines L1a, L1b, L1c. The FM video signal is transmitted only to one of the trunk lines L1a, L1b, or L1c to which the dwelling unit 2 selected from the intercom 1 is connected.

  Next, the operation of this embodiment will be described. First, the case where an individual call is made between the lobby intercom 1 and one dwelling unit 2 selected by the lobby intercom 1 will be described. A control signal (call command) is transmitted from the management room intercom 3 to the dwelling unit 2 selected by the lobby intercom 1 via a control line (not shown), and the address included in the control signal matches. 2, the CPU closes the relay contact 29 of the dwelling unit relay in response to the call command and causes the speaker 21 b to send out the ringing sound through the voice circuit 24 c. The CPU of the trunk line device 4 that has detected the calling command controls the video signal switch 47 to switch to the trunk line L1a, L1b, or L1c to which the selected dwelling unit 2 is connected. As a result, in the dwelling unit 2 selected as the lobby intercom 1, the CPU activates the FM demodulator 25a and the monitor 22, and the FM demodulator 25a performs frequency demodulation on the FM video signal transmitted via the signal line Ld. Visitors' images captured by the camera of the lobby intercom 1 can be displayed on the monitor 22. When the resident operates the response button of the dwelling unit 2 in response to the call from the lobby intercom 1, the CPU activates the voice circuit 24c.

  On the other hand, in the management room intercom 3, after sending the call command, the CPU turns on a changeover switch (not shown) to connect the communication line La connected to the lobby intercom 1 to the communication line La connected to the trunk line device 4.

  The CPU of the trunk line device 4 controls the video signal changeover switch 47 as described above to switch to the trunk line L1a, L1b, or L1c to which the selected dwelling unit 2 is connected, and the fourth changeover switches 46a, 46b. Open all. As a result, a communication path is established between the lobby intercom 1 and the selected dwelling unit 2 via an individual call path (a path passing through the low-frequency passage unit 40a and the video signal changeover switch 47) in the trunk line device 4. Individual calls can be made, and visitors captured by the camera of the lobby intercom 1 can be displayed on the monitor 22 only in the selected dwelling unit 2. Note that the case of making an individual call between the control room intercom 3 and one dwelling unit 2 selected by the management room intercom 3 is almost the same as the case of the individual call between the lobby intercom 1 and the dwelling unit 2. Since there is, explanation is omitted.

  Next, the case where simultaneous broadcasting is performed from the management room intercom 3 to the plurality of dwelling units 2 will be described.

  When the manager operates a broadcast start button provided on the management room intercom 3, the CPU of the management room intercom 3 controls lines (not shown) for the plurality of dwelling units 2 and the trunk line device 4 to be broadcast. ) To transmit a control signal (broadcast start command), and in response to the broadcast start command, the CPUs of all the dwelling units 2 that are the targets of the broadcast close the relay contact 29 of the dwelling unit relay. At the same time, the audio circuit 24c is activated. Further, the CPU of the management room intercom 3 turns off a changeover switch (not shown) to disconnect the call line La connected to the lobby intercom 1 from the call line La connected to the main line device 4 and is connected to the main line L1c. Only when the dwelling unit 2 is included in the broadcast target, the first changeover switch 33 and the second changeover switch 35 are respectively switched to the broadcast low impedance drive circuit 32 side.

  On the other hand, in the trunk line device 4, in response to the broadcast start command, if the dwell unit 2 connected to the trunk line L1a is included in the broadcast target, the fourth changeover switch 46a is closed, and If the dwelling unit 2 connected to the trunk line L1b is included in the broadcast target, the fourth changeover switch 46b is closed. As a result, there is a communication path between the management room intercom 3 and the plurality of dwelling units 2 via the simultaneous broadcast path (the path passing through the fourth changeover switches 46a and 46b and the low-frequency passage section 40a) in the trunk line device 4. Once established, simultaneous broadcasting from the management room intercom 3 to the plurality of dwelling units 2 becomes possible.

  Thus, as in the third embodiment, one of the three trunk lines L1a, L1b, and L1c is subject to simultaneous broadcasting by the broadcasting low impedance drive circuit 32 provided in the management room intercom 3. The load impedance of the dwelling unit 2 included in the unit is driven, and the other two systems of trunk lines L1a and L1b are included in the broadcast target by the broadcast low impedance drive circuits 42a and 42b provided in the trunk unit 4 The load impedance of the machine 2 is driven, and the broadcast can be listened to by each dwelling machine 2.

  In addition, in this embodiment, when distributing FM video signals to the three systems of trunk lines L1a, L1b, and L1c, one video amplifier 41 is shared by all the trunk lines L1a, L1b, and L1c. Thus, there is an advantage that the circuit configuration can be simplified.

(Embodiment 5)
The present embodiment is characterized in that an individual call route, a broadcast route, and route switching means are provided only in the trunk line device 3 as compared with the third embodiment. Accordingly, the basic configuration of the present embodiment is the same as that of the third embodiment, and thus the same components are denoted by the same reference numerals and description thereof is omitted.

  In the trunk line device 4 in the present embodiment, as shown in FIG. 5, for all the trunk lines L1a, L1b, L1c, the low-impedance driving circuits for broadcasting 42a, 42b, 42c, the low-frequency passage units 40a, 40a, 40a and the fourth switching are performed. The switches 46a, 46b, 46c are provided, the state in which the call line La is connected to the third changeover switches 45a, 45b, 45c, that is, the state in which the individual call path is formed, and the call line La A fifth changeover switch 48 is provided to selectively switch between the state connected to the impedance drive circuits 42a, 42b and 42c, that is, the state where a simultaneous broadcast path is formed. In other words, in the present embodiment, the fourth change-over switches 46a, 46b, 46c and the fifth change-over switch 48 correspond to path switching means.

  The dwelling unit 2 in the present embodiment has the same configuration as that of the first to fourth embodiments, and is connected to the dwelling unit separate line L2 branched from the trunk line L1a, L1b, L1c of any system by the branching unit 7. The management room intercom 3 has the same configuration as that of the second embodiment, and does not include an individual call route, a simultaneous broadcast route, and route switching means.

  Next, the operation of this embodiment will be described. First, the case where an individual call is made between the lobby intercom 1 and one dwelling unit 2 selected by the lobby intercom 1 will be described. A control signal (call command) is transmitted from the management room intercom 3 to the dwelling unit 2 selected by the lobby intercom 1 via a control line (not shown), and the address included in the control signal matches. 2, the CPU closes the relay contact 29 of the dwelling unit relay in response to the call command and causes the speaker 21 b to send out the ringing sound through the voice circuit 24 c. Further, in the dwelling unit 2 selected as the lobby intercom 1, the CPU activates the FM demodulator 25a and the monitor 22, and the FM demodulator 25a demodulates the frequency of the FM video signal transmitted via the signal line Ld. A video of a visitor captured by one camera is displayed on the monitor 22. When the resident operates the response button of the dwelling unit 2 in response to the call from the lobby intercom 1, the CPU activates the voice circuit 24c.

  On the other hand, in the management room intercom 3, after sending the call command, the CPU turns on a changeover switch (not shown) to connect the communication line La connected to the lobby intercom 1 to the communication line La connected to the trunk line device 4.

  In the trunk line device 4, the CPU that has detected that the call command has been transmitted switches the fifth changeover switch 48 to the third changeover switches 45 a, 45 b, 45 c, and the third changeover switch 45 a, The telephone line La is connected only to the trunk line L1a, L1b, or L1c to which the dwelling unit 2 selected by closing any one of 45b and 45c is connected. As a result, the individual call path (the fifth changeover switch 48, the third changeover switch 45a or 45b or 45c, and the low-frequency passage unit 40a in the trunk line device 4 is connected between the lobby intercom 1 and the selected dwelling unit 2. A communication path via the route) is established, and an individual call becomes possible, and a visitor captured by the camera of the lobby intercom 1 can be displayed on the monitor 22 only in the selected dwelling unit 2. . Note that the case of making an individual call between the control room intercom 3 and one dwelling unit 2 selected by the management room intercom 3 is almost the same as the case of the individual call between the lobby intercom 1 and the dwelling unit 2. Since there is, explanation is omitted.

  Next, the case where simultaneous broadcasting is performed from the management room intercom 3 to the plurality of dwelling units 2 will be described.

  When the manager operates a broadcast start button provided on the management room intercom 3, the CPU of the management room intercom 3 controls lines (not shown) for the plurality of dwelling units 2 and the trunk line device 4 to be broadcast. ) To transmit a control signal (broadcast start command), and in response to the broadcast start command, the CPUs of all the dwelling units 2 that are the targets of the broadcast close the relay contact 29 of the dwelling unit relay. At the same time, the switch (not shown) is turned off to disconnect the call line La connected to the lobby intercom 1 from the call line La connected to the trunk line device 4 and to activate the voice circuit 24c.

  On the other hand, in the trunk line device 4, in response to the broadcast start command, the CPU switches the fifth changeover switch 48 to the side of the low-impedance drive circuits 42a, 42b, 42c for broadcast and is included in the broadcast target. Only the fourth change-over switches 46a, 46b, 46c corresponding to the trunk lines L1a, L1b, L1c to which the existing dwelling unit 2 is connected are closed. As a result, between the management room intercom 3 and the plurality of dwelling units 2, the simultaneous broadcast path (the fifth changeover switch 48, the fourth changeover switches 46a, 46b, 46c, and the low frequency passage unit 40a in the trunk line device 4 are provided. The communication path via the route) is established, and simultaneous broadcasting from the management room intercom 3 to the plurality of dwelling units 2 becomes possible.

  In the present embodiment, as shown in FIG. 6, as in the fourth embodiment, a video signal changeover switch 47 may be provided so that one video amplifier 41 is shared by all the trunk lines L1a, L1b, L1c. .

  Further, as shown in FIG. 7, the video signal changeover switch 47 is provided with an open terminal (a terminal not connected to any of the trunk lines L1a, L1b, L1c), and the video signal changeover switch 47 is opened during simultaneous broadcasting. If the output terminal of the video amplifier 41 is disconnected from any of the trunk lines L1a, L1b, and L1c during simultaneous broadcasting by switching to 47a, the broadcast audio signal is affected by the impedance of the output with respect to the audio signal band of the video amplifier 41. There is an advantage that attenuation can be prevented.

(Embodiment 6)
In the present embodiment, a function of distributing a single trunk line to a plurality of trunk lines, an individual call path and a broadcast path provided for each trunk line, an individual call path and a broadcast path for each trunk line It is characterized in that it has a main line distribution device 5 provided with a path switching means for switching between. However, since the basic configuration of the present embodiment is the same as that of the fifth embodiment, the same components are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 8, by connecting the main line distribution device 5 to the main line distributed by the main line device 4, it can be distributed to a plurality of main lines. This trunk distribution device 5 is provided with a capacitor for blocking low frequency signals on the input side and output side, and a video amplifier 51 for amplifying an FM video signal inputted from one system trunk line (L1b in the illustrated example); The changeover switch 52 that selectively switches and connects the output terminal of the video amplifier 41 to the trunk lines L1ba, L1bb, L1bc or the open terminal 52a of a plurality of systems (three systems in the illustrated example), and one end at the input terminal of the video amplifier 41 Are connected to the low-frequency passage unit 53, the low-frequency passage unit 54 is connected to the output end of the video amplifier 41, and the output impedance is converted into a plurality of impedances lower than the input impedance of the dwelling unit 2 (see FIG. The three low-impedance driving circuits for broadcasting 55a, 55b, and 55c and the low-impedance driving circuits for broadcasting 55a, 55b, and 55 are shown. A plurality of (three in the illustrated example) low-frequency passages 56 connected to the output terminals of the first and second broadcast low-impedance drive circuits 55a, 55b, and 55c are connected to the output terminals of the low-frequency passage parts 56, respectively. Connection switches 57a, 57b, and 57c selectively connected to the signal lines Ld of the trunk lines L1a, L1b, and L1c of the system, the other end of the low frequency passage unit 53 and the other end of the low frequency passage unit 54 and a low impedance for simultaneous broadcasting A path changeover switch 58 that selectively switches to the input ends of the drive circuits 55a, 55b, and 55c is provided. That is, in the trunk distribution device 5, the FM video signal and the voice signal input from the trunk line L1b are separated, and a path (individual call path) that passes only the low-frequency passage unit 54 as a transmission path of the separated voice signal. The broadcast low-impedance driving circuit 55a, 55b or 55c, the low-frequency passing section 56, and the path through the connection switch 57a, 57b or 57c (broadcast path) can be alternatively selected.

  In the present embodiment, the trunk distribution device 5 is also provided with a CPU (not shown) for controlling the internal circuit similarly to the trunk device 4, and the CPU has a control signal serving as an interface with a control line (not shown). A transmission / reception circuit (not shown) is connected. The control signal transmission / reception circuit has a function of sending a control signal output from the CPU to a control line (not shown) and delivering the control signal received from the control line (not shown) to the CPU.

  Next, the operation of this embodiment will be described. However, since the operations of the lobby intercom 1, the dwelling unit 2, the management room intercom 3, and the main line device 4 other than the main line distribution device 5 are substantially the same as those in the fifth embodiment, the description will be omitted as appropriate, and the operation of the main line distribution device 5 will be mainly described. Explained.

  First, the case where an individual call is made between the lobby intercom 1 and one dwelling unit 2 selected by the lobby intercom 1 will be described. A control signal (call command) is transmitted from the management room intercom 3 to the dwelling unit 2 selected by the lobby intercom 1 via a control line (not shown), and the address included in the control signal matches. 2, the CPU closes the relay contact 29 of the dwelling unit relay in response to the call command and causes the speaker 21 b to send out the ringing sound through the voice circuit 24 c. Further, in the dwelling unit 2 selected as the lobby intercom 1, the CPU activates the FM demodulator 25a and the monitor 22, and the FM demodulator 25a demodulates the frequency of the FM video signal transmitted via the signal line Ld. A video of a visitor captured by one camera is displayed on the monitor 22. When the resident operates the response button of the dwelling unit 2 in response to the call from the lobby intercom 1, the CPU activates the voice circuit 24c.

  On the other hand, in the management room intercom 3, after sending the call command, the CPU turns on a changeover switch (not shown) to connect the communication line La connected to the lobby intercom 1 to the communication line La connected to the trunk line device 4.

  In the trunk line device 4, the CPU that has detected that the call command has been transmitted switches the path changeover switch 48 to the video signal changeover switch 47 side, and the dwelling unit 2 that has selected the video signal changeover switch 47 is connected. Switch to the main line (for example, L1b). Further, in the trunk distribution device 5, the CPU that detects that the call command has been transmitted switches the path switch 58 to the low-frequency passage unit 54 side, and the dwelling unit 2 with the switch 52 selected is connected. Switch to the existing trunk line (for example, L1ba). As a result, the individual call path (the fifth changeover switch 48, the third changeover switch 45a or 45b or 45c, and the low-frequency passage unit 40a in the trunk line device 4 is connected between the lobby intercom 1 and the selected dwelling unit 2. And a communication path via the individual call path (the path passing through the low-frequency passage unit 53, the path changeover switch 58, and the low-frequency passage unit 54) in the trunk line distribution device 5 is established, and the individual call becomes possible. At the same time, it is possible to display on the monitor 22 the visitors imaged by the camera of the lobby intercom 1 only in the selected dwelling unit 2. Note that the case of making an individual call between the control room intercom 3 and one dwelling unit 2 selected by the management room intercom 3 is almost the same as the case of the individual call between the lobby intercom 1 and the dwelling unit 2. Since there is, explanation is omitted.

  Next, the case where simultaneous broadcasting is performed from the management room intercom 3 to the plurality of dwelling units 2 will be described.

  When the manager operates a broadcast start button provided on the management room intercom 3, the CPU of the management room intercom 3 controls lines (not shown) for the plurality of dwelling units 2 and the trunk line device 4 to be broadcast. ) To transmit a control signal (broadcast start command), and in response to the broadcast start command, the CPUs of all the dwelling units 2 that are the targets of the broadcast close the relay contact 29 of the dwelling unit relay. At the same time, the switch (not shown) is turned off to disconnect the call line La connected to the lobby intercom 1 from the call line La connected to the trunk line device 4 and to activate the voice circuit 24c.

  On the other hand, in the trunk line device 4, in response to the broadcast start command, the CPU switches the fifth changeover switch 48 to the side of the low-impedance drive circuits 42a, 42b, 42c for broadcast and is included in the broadcast target. Only the fourth change-over switches 46a, 46b, 46c corresponding to the trunk lines L1a, L1b, L1c to which the existing dwelling unit 2 is connected are closed. In the trunk distribution device 5, the CPU switches the path switch 58 to the side of the low-impedance driving circuit 55a, 55b, 55c for broadcast in response to the broadcast start command and is included in the broadcast target. Only the connection switches 57a, 57b, 57c corresponding to the trunk lines L1ba, L1bb, L1bc to which the dwelling unit 2 is connected are closed. As a result, between the management room intercom 3 and the plurality of dwelling units 2, the simultaneous broadcast path (the fifth changeover switch 48, the fourth changeover switches 46a, 46b, 46c, and the low frequency passage unit 40a in the trunk line device 4 are provided. Route), as well as a route for simultaneous broadcasting in the trunk distribution device 5 (low-frequency passage unit 53, route changeover switch 58, low-impedance driving circuit for broadcasts 55a, 55b, 55c, low-frequency passage unit 56, and connection switches 57a, 57b) , 57c) is established, and broadcast from the management room intercom 3 to the plurality of dwelling units 2 becomes possible. Here, the load impedance viewed from the broadcasting low impedance driving circuits 55a, 55b, and 55c decreases as the number of dwelling units 2 to be broadcast simultaneously increases, but the broadcasting low impedance driving circuits 55a and 55b. , 55c converts the output impedance of the broadcast channel to an impedance lower than the input impedance of the dwelling unit 2, so that attenuation of the audio signal is suppressed even when the main line distribution device 5 distributes the main line into multiple systems. be able to.

  In the present embodiment, the main line distribution device 5 is provided with a CPU and a control signal transmission / reception unit, and a changeover switch 52 and a connection switch 57a are provided according to control signals transmitted from the management room intercom 3 via a control line (not shown). , 57b, 57c and the path changeover switch 58 are switched. For example, a DC voltage is superimposed on the signal line Ld from the dwelling unit 2 selected at the time of the individual call, and is superimposed on the signal line Ld in the trunk distribution device 5. A configuration may be adopted in which the switches are switched by detecting a DC voltage.

1 is a system configuration diagram showing Embodiment 1 of the present invention. It is a system block diagram which shows Embodiment 2 of this invention. It is a system block diagram which shows Embodiment 3 of this invention. It is a system configuration figure showing Embodiment 4 of the present invention. It is a system configuration figure showing Embodiment 5 of the present invention. It is a system block diagram which shows the other structure same as the above. It is a system block diagram which shows other structure same as the above. It is a system block diagram which shows Embodiment 6 of this invention. It is a system configuration | structure figure which shows a prior art example.

Explanation of symbols

1 Lobby intercom (common equipment)
2 dwelling unit 3 management room intercom (communication device)
4 Main Line Device 31a Microphone 32 Low Impedance Drive Circuit for Broadcast 33 First Switch 34a Amplifier 35 Second Switch L1 Trunk Line La Call Line Ld Signal Line

Claims (9)

A common unit installed at the common entrance of the apartment building and capable of voice input / output, a communication device installed in the management room of the apartment complex and capable of voice input / output, and a common unit installed in each unit of the apartment The communication device and the communication device are connected via a transmission line and, when selected by operating a selection unit included in the common device or the communication device, establishes a communication path with the common device or the communication device. With multiple dwelling units,
The transmission line includes a common line device and a trunk line connected to the communication device, and a separate line connected to each dwelling unit, and the trunk line and the separate dwelling line are generated by at least the operation of the selection means and are used for individual calls. It consists of a control line that transmits a control signal instructing start and a signal line that transmits an audio signal.
The dwelling unit has a communication means for making a call through the signal line between the common device and the communication apparatus, and a control signal transmitted via the control line. Control means for establishing a communication path by connecting to a line,
The call device instructs a call means for making a call with a dwelling unit via a signal line, a selection means for selecting a dwelling unit as a call partner, and a start of simultaneous broadcasting for a plurality of dwelling units. The broadcast start instructing means transmits a control signal instructing the start of the individual call to the dwelling unit selected by the selection means through the control line, and the broadcast start instructing means instructs the start of the broadcast. Control means for transmitting a control signal for instructing start of simultaneous broadcasting to a plurality of target dwelling units via a control line,
Individual call path with impedance matched with input and output impedance in dwelling unit, broadcast path with lower impedance than input and output impedance in dwelling unit, and individual call path during individual call An intercom system for collective housing, characterized in that a path switching means for transmitting an audio signal and transmitting an audio signal through a broadcast channel during broadcast is provided on a signal line included in a telephone or main line. The shared unit device frequency-modulates and outputs a video signal obtained by imaging a visitor in a frequency band different from the frequency band of the audio signal,
A trunk line comprising an individual call route, a broadcast route, route switching means, and multiplexing means for frequency-multiplexing a video signal output from a shared device to an audio signal transmitted via a signal line The intercom system for an apartment house according to claim 1, further comprising a device.   2. The intercom system for an apartment house according to claim 1, wherein an individual call route, a broadcast route, and route switching means are provided on a signal line included in the trunk line. The call device is provided with a route for individual calls, a route for simultaneous broadcasting, and route switching means,
A trunk line device that selectively connects a plurality of trunk lines to a common unit and a call device is provided, and the trunk line device is provided for each trunk line other than one trunk line and an individual call route provided for each trunk line. 2. The collective housing intercom system according to claim 1, further comprising: a simultaneous broadcast route provided; and a route switching unit that switches between an individual call route and a simultaneous broadcast route for each trunk line. The shared unit device modulates the video signal obtained by imaging the visitor in a frequency band different from the frequency band of the audio signal, and transmits it to the trunk line device.
The main line device is a video signal amplifying means for amplifying the frequency-modulated video signal sent from the shared section device, and a video signal for selectively switching and connecting the output terminals of the video signal amplifying means to a plurality of main lines. Output switching means, multiplexing means for frequency-multiplexing the video signal amplified by the video signal amplifying means to the audio signal transmitted through the signal line, and for individual calls connected to the output terminal of the video signal amplifying means Characterized in that it comprises a route, a broadcast route provided for every other trunk line except one main line, and a route switching means for switching the individual call route and the broadcast route for each main line. The intercom system for collective housing according to claim 4.   A trunk line device is provided that selectively connects a plurality of trunk lines to a shared device and a call device.The trunk line device includes an individual call path provided for each trunk line, and a broadcast path provided for each trunk line. 4. The collective housing intercom system according to claim 3, further comprising route switching means for switching between an individual call route and a simultaneous broadcast route for each main line. The shared unit device modulates the video signal obtained by imaging the visitor in a frequency band different from the frequency band of the audio signal, and transmits it to the trunk line device.
The main line device is a video signal amplifying means for amplifying the frequency-modulated video signal sent from the shared section device, and a video signal for selectively switching and connecting the output terminals of the video signal amplifying means to a plurality of main lines. Output switching means, multiplexing means for frequency-multiplexing the video signal amplified by the video signal amplifying means to the audio signal transmitted through the signal line, and for individual calls connected to the output terminal of the video signal amplifying means 7. The collective housing according to claim 6, comprising a route, a broadcast channel provided for each main line, and a route switching means for switching the individual call route and the broadcast route for each main line. Intercom system.   8. The intercom system for an apartment house according to claim 5 or 7, wherein the trunk line device comprises means for separating the output end of the video signal amplification means from any trunk line during simultaneous broadcasting.   A trunk distribution device that distributes a single trunk line to a plurality of trunk lines; the trunk distribution device includes: an individual call route provided for each trunk line of the plurality of routes; a simultaneous broadcast route provided for each trunk line; 9. The collective housing intercom system according to any one of claims 4 to 8, further comprising route switching means for switching an individual call route and a simultaneous broadcast route for each main line.

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