JPH10224491A - Intercom system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an intercom system in which not only an intercom hand set but also a base unit can be shared in various using styles. SOLUTION: An intercom connection extension adapter 71 is added to a base unit 11 to which hand sets 21 and 22 , are respectively connected. The intercom connection extension adapter 71 is provided with a connecting terminal T71 connected to the base unit 11 and a connecting terminal T72 connected to the other intercom connection extension adapter 71 . A switch element 711 determines whether or not each base unit 11 is to pass a signal exchanged with the intercom hand sets 2 and 22 between the connecting terminals T71 and T72 . Besides, a CPU 76 controls the siwtch element 711 so as to permit the passage of following signals when the signal received from the connecting terminal T72 contains identification information and the information is coincident with preset identification information. A setting button 76a instructs the operation of the CPU 76 and the ON/OFF of the switch element 711 .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a doorphone having a doorphone slave unit arranged at a gate or an entrance, and a master unit capable of making a call between the doorphone slave unit when a call from the doorphone slave unit is received. It is about the system.

[0002]

2. Description of the Related Art Conventionally provided intercom systems are provided with various configurations depending on the place of use. Those shown in FIG. 13 is a door phone system for residential, the main unit 1 ₁ via a first signal line L _11, L ₁₂ doorphone entrance station 2 _1, 2 ₂ are respectively connected, also the expansion through the second signal line L ₂₁ in the main unit 1 ₁ base unit 3 _1, 3
₂ has a connected configuration. Door phone handset 2 ₁ , 2 ₂
It is usually intended to be placed outdoors, and has a function of performing an operation for generating the ringing tone in at least the main unit 1 _1, and a function of performing conversation between the master unit 1 _1. Also, depending on the doorphone entrance station 2 _1, 2 _2, also having a function of displaying by imaging a visitor to the main unit 1 _1.

[0003] Here, as shown in FIG. 14, a TV camera 21 for imaging the visitor as a doorphone entrance station 2 _1, it is used which comprises a microphone 22 and a speaker 23 for calls. The video signal output from the TV camera 21 is input to the demultiplexing circuit 24 after being modulated by the video modulation circuit 21a. The demultiplexing circuit 24 connected terminal T ₂₁ is provided, the signal line L ₁₁ is connected to the connection terminal T _21.

The audio signal output from the microphone 22 is amplified by a microphone amplifier 22a,
The signal is input to the demultiplexing circuit 24 through the line conversion circuit 25. On the other hand, the audio signal output from the multiplexing / demultiplexing circuit 24 is passed through a two-wire to four-wire
And is converted into a sound by the speaker 23 and output. The two-wire to four-wire conversion circuit 25 transmits the audio signal from the microphone 22 and the audio signal to the speaker 23 on the same line, and transmits the audio signal from the microphone 22 to the speaker 23.
It is provided to suppress the wraparound.

[0005] The doorphone entrance station 2 ₁ is calling button 26a is provided consisting of a switch, the call button 26a is press operation, the control signal generated by the control signal transmission circuit 27 is connected via demultiplexer 24 It sent from the terminal T ₂₁ to the signal line L _11. The power supply of the intercom slave unit 2 ₁ is the master unit 1
Is supplied through the signal line L ₁₁ from given to the internal circuit of the doorphone entrance station 2 ₁ is stabilized in the power supply circuit 28. Incidentally, the signal line L ₁₁ is a two wire balanced cable,
Video signals, from the audio signal, used for the supply of the transmission and the power of the control signal, the video signal in signal line L _11, the audio signal,
Control signals are mixed and transmitted in a form superimposed on the power supply. Since the video signal, the audio signal, and the control signal have different frequency bands (for example, the audio signal is 300 Hz to 4 kHz, the control signal is around 100 kHz,
The video signal is 1 to 10 MHz. JP-A-5-20716
See No. 6 Publication), a signal input through the connection terminal T ₂₁ from the demultiplexing circuit 24 in the signal line L _11, by discriminating the different frequency bands, it is to separate the control signal and the video signal and the audio signal . The video signal generated by the doorphone entrance station 2 _1, audio signal, control signals are sent to the signal line L ₁₁ superimposed on the power supply.

On the other hand, as shown in FIG.
2_TwoIs the door phone handset 2₁From TV camera 21 and video
It has a configuration in which the modulation circuit 21a is omitted. Base unit 1₁Is
As shown in FIG.₁₁, L₁₂Is connected
Connection terminal T ₁₁, T₁₂And a connection terminal T₁₁, T₁₂Through
Signal line L₁₁, L₁₂The signal received from the intercom is turned off
Selected through the exchange switch 10 and selected.
The signal is demultiplexed 14₁To separate the video signal and the audio signal.
Separated. Base unit 1₁Is the door phone handset 2₁TV cameras
A monitor 11 for displaying the image captured by the monitor 21;
Eh, also door phone handset 2₁, 2_TwoCalls can be made with
Microphone 12 and speaker 13
I have. CRT or liquid crystal display is used for monitor 11
Can be.

[0007] The video signal separated by the demultiplexing circuit 14 _1, images captured is inputted to the monitor 11 after being demodulated by the video demodulation circuit 11a by the TV camera 13 is a monitor 11
Will be displayed. The audio signal separated by the demultiplexing circuit 14 ₁ is amplified by being input to the speaker amplifier 13a through the two-wire four-wire conversion circuit 15 similar to that provided in the intercom slave 2, the speaker amplifier 13a
The speaker 13 is driven by the output of. The audio signal from the microphone 12 is amplified by the microphone amplifier 12a,
It is input through the two-wire four-wire conversion circuit 15 to the demultiplexing circuit 14 _1.

Signal line L₁₁, L₁₂The control signal transmitted is
Demultiplexing circuit 14₁Control signal reception times without passing
Road 17b₁, 17b_TwoInput to the CPU 16 through
You. Door phone handset 2₁, 2_TwoControl signal from the call button 2
6a, the control signal is received.
The CPU 16 takes the door phone slave 2 that has generated the control signal.
₁, 2_TwoDemultiplexing circuit 14₁To connect to the door
The telephone handset switch 10 is switched.

A plug 1 connected to a commercial power supply is
9a is provided, the power supply circuit 19 for supplying power to the internal circuit and the doorphone entrance station 2 _1, 2 ₂ and stabilized by rectifying the commercial power supply is provided. Video signal to the output voltage of the power supply circuit 19 in the demultiplexing circuit 14 _1, the audio signal is superimposed. The output of the demultiplexer 14 ₁ is sent to the signal line L _11, L ₁₂ through the connection terminals T _11, T _12.

[0010] By the way, the main unit 1 _1, intercom handset 2
And displays an image captured by _one of the TV camera 21, or a call between the doorphone entrance station 2 _1, 2 _2, function or exchanges control signals with the doorphone entrance station 2 _1, 2 ₂ However, it is desirable that these functions can be used in multiple places indoors. Therefore, to connect the signal line L ₂₁ to the connection terminals T ₁₃ provided in the base unit 1 _1, it is considered to provide the extension master station 3 _1, 3 ₂ via the signal line L _21.

In order to provide the extension base units 3 ₁ and 3 ₂ , video signals, audio signals and control signals can be transmitted between the intercom units 2 ₁ and 2 ₂ and the extension base units 3 ₁ and 3 _2. There must be. In other words, between the demultiplexing circuit 14 ₂ connected to the demultiplexing circuit 14 ₁ and the connection terminals T ₁₃ connected to the connection terminals T _11, T _12, video signals, audio signals, control signals independently It forms a path to pass. In the drawing, it forms a two-way path with a simple configuration in which only connects the demultiplexer 14 _1, 14 _2, because the video signal is relatively large high attenuation-frequency, two-way video A power amplifier may be interposed. Control signals are only received from the signal lines L ₁₁ and L ₁₂ ,
Because there are transmitted and received from the direction of the signal line L _21, interposing the control signal reception circuit 18 between the CPU16 and the demultiplexing circuit 14 _2. Therefore, the control signals received from the connection terminals T ₁₁ and T ₁₂ are input to the CPU 16 through the control signal receiving circuits 17 a and 17 b, and are further transmitted from the CPU 16 to the control signal transmission / reception circuit 18, the demultiplexing circuit 14 ₂ , the connection terminal T
Expansion through ₁₃ base unit 3 _1, 3 ₂ than it is transmitted to.
Further, a control signal is transmitted and received between the master unit ₁₁ and the additional master units 3 ₁ and 3 ₂ through the control signal transmitting / receiving circuit 18. CP
U16 extension master station 3 _1, 3 ₂ and the operation button 16a made of switches for performing a call during a call is attached to.

Extension base unit 3₁As shown in FIG.
Monitor 31, video demodulation circuit 31a, microphone 32, microphone
Equiamp 32a, speaker 33, speaker amplifier 33
a, demultiplexing circuit 34, 2-wire to 4-wire conversion circuit 35, CP
U36, control signal transmission / reception circuit 38, and power supply circuit 39
You. Here, extension master unit 3₁Are the master unit 1 ₁
It has the same function as each element of. Demultiplexing circuit
34 is a connection terminal T₃₁Through the signal line L_{twenty one}Connected to.
In addition, a power supply circuit 39 for rectifying and stabilizing commercial power is provided.
However, this power supply circuit 39 is₁Internal circuit of
To power the main unit 1₁Door phone handset like
2₁, 2_TwoNo power is supplied to the Power supply circuit 39
Is provided with a plug 39a connected to a commercial power supply.
Extension master unit 3₁The master unit 1₁Like the parent device 1₁Call
An operation button 36a comprising a switch for performing
ing. Also, the signal line L_{twenty one}At the end of the
To prevent this, a terminating resistor 4 is connected.

[0013] extension master station 3 _1, as shown in FIG. 17, but those with a monitor 31 in response to the doorphone entrance station 2 _1, extension master stations 3 ₂ monitor 31 and the video demodulation circuit 3
1a is omitted. As described above, the main unit 1 ₁ and extension master station 3 ₁ displays the video from the intercom slave 2 ₁ to the monitor 11 and 31, and by the main unit 1 ₁ and extension master station 3 _1, 3 ₂ Doahonko to receive a call from the machine 2 _1, 2 _2, it is possible or calls among the doorphone entrance station 2 _1, 2 _2. Therefore, to monitor the image from the intercom slave 2 ₁ at a plurality of locations arranged in a different location the extension master station 3 _1, 3 ₂ and base unit 1 _1, the call from the doorphone entrance station 2 _1, 2 ₂ receiving or allows or to call among the doorphone entrance station 2 _1, 2 _2.
Further, between the base unit 1 ₁ and extension master station 3 _1, 3 _2, between the extension master stations 3 _1, 3 ₂ mutually are possible call or call becomes possible calls and calls between chamber . Here, extension master unit 3
_1, 3 ₂ are configured to listen at all times the call from the doorphone entrance station 2 _1, 2 _2. This is the expansion base unit 3 ₁ , 3
₂ at a plurality of locations is for use in the same manner as the master unit 1 _1.

The above-mentioned door phone system is used for ordinary houses.
One house, like a two-family house
Most or all of the living space of the two families is separated within
Homes that basically violate the lives of each family
Not have two independent doorphone systems
Also made calls and calls between doorphone systems possible.
Sometimes. In this case, a system as shown in FIG.
Configuration. The base unit 1 'is basically the base unit 1 described above.₁Same as
Has the same configuration, but the connection terminal T₁₃To
Extension master unit 3₁, 3_TwoIs not attached to the base unit 1 '.
Are signal lines L _{twenty two}Is to be connected via
You. The configuration of master unit 1 'is master unit 1.₁Same as but basic
Has a connection terminal T₁₁, T₁₂Door phone handset directly connected to
2₁, 2_TwoOnly receive signals from
One household in response to the absence of
Door phone handset 2 provided in₁, 2_TwoSignal from the other world
It is also possible to transfer to the parent device 1 'of the obi
You. It is also possible to make a call between the two master units 1 '.
ing.

Further, in an apartment house or the like, as shown in FIG. 19, a door phone system for each door is connected to the lobby intercom 5. In other words, each doorphone system parenthesis "comprises a and a doorphone entrance station 2 _1, 2 _2, the main unit 1" main unit 1 but are those having the same configuration as the base unit 1 _1, each apartment of the main unit 1 ″ Connect the connection terminal T ₁₃ to the branching device 6 provided on the signal line L ₂₃ , respectively, and are connected to the lobby intercom 5 via the signal line L _23. That is, one signal line L ₂₃ , each master unit 1 ″ is connected via the branch unit 6. in this case,
Terminal resistor 8 for preventing reflection similarly the video signal to the parent device 1 ₁ is connected to one end of the signal line L _23.

The lobby intercom 5 is a door phone handset 2
_It has a configuration substantially the same as that of ₁ and includes a TV camera 51, a video modulation circuit 51a, a microphone 52, a microphone amplifier 52a,
Speaker 53, speaker amplifier 53a, demultiplexing circuit 5
A four-, two-, or four-wire conversion circuit 55 is provided. An operation button 56a including a key switch is provided. The CPU 56 generates a control signal based on the operation of the operation button 56a, and transmits the control signal to the demultiplexing circuit 5 via a control signal transmitting / receiving circuit 57.
Give to 4. When a control signal is transmitted from master device 1 ″, it is given to CPU 56 via control signal transmitting / receiving circuit 57,
The CPU 56 operates the lobby intercom 5 according to the content of the control signal. The control signal from the master unit 1 ″ enables operations such as adjusting the field of view (direction, etc.) of the TV camera 51. The lobby intercom 5
A power supply circuit 59 is supplied with power from a commercial power supply via a plug 59a.

In the case of this configuration, by designating the master unit 1 ″ using the operation button 56a of the lobby intercom 5,
Only the designated master unit 1 ″ can transmit and receive signals to and from the lobby intercom 5. Therefore, it is necessary to identify each master unit 1 ″, and each master unit 1 ″ has a household number unique to each house. Is set, and a communication procedure is required such that only the parent device 1 ″ designated using the household number exchanges signals with the lobby intercom 5.

[0018]

As described above THE INVENTION An object you try solving], although the intercom system has various use forms can be used in common in any use form doorphone entrance station 2 _1, 2 _2. On the other hand, the master unit 11 ₁ ,
Although the configurations 1 ′ and 1 ″ have many points in common, there are slight differences in their functions, so that master units 11 ₁ , 1 ′ and 1 ″ having different functions are required for each use mode. There is a problem that the variety becomes large, which leads to an increase in development cost, production cost, and inventory management cost.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a door phone system that can share not only the intercom slave unit but also the master unit in various use modes. is there.

[0020]

According to the first aspect of the present invention, there is provided a doorphone connection extension adapter attached to a plurality of master units each connected to a doorphone slave unit, and the doorphone connection extension adapter is connected to the master unit. A first connection terminal and a second connection terminal for external connection, and a signal transmitted and received between each master unit and the intercom slave unit passes between the first connection terminal and the second connection terminal. A switch element for selecting a state of permitting and a state of prohibiting the transmission, and when a signal including the identification information is received from the second connection terminal, when the signal matches the identification information set in advance, the passage of the subsequent signal is performed. Control means for controlling the switch element to permit, and selection means for selecting permission / prohibition of signal passage and validity / invalidity of the control means;
A signal transmission / reception path is formed between the connection terminals. According to this configuration, it is possible to transmit and receive signals between the parent devices while using the conventionally provided parent device. By operating the switch element, signals can be transmitted between the two parent devices. Since a state where passage is permitted and a state where passage is prohibited can be selected, a system for a two-family house can be constructed. In addition, since the switch element can be operated by the identification information, when a large number of master units are connected to the lobby intercom, the identification information from the lobby intercom is received, and each master unit and the lobby are connected. It is possible to individually control a call with the intercom, and it is also possible to construct a system for an apartment house. In this way, by using the doorphone connection expansion adapter, it becomes possible to expand a normal doorphone system for a two-family house or an apartment house. As a result, there is no need to manufacture a variety of parent machines, and costs such as development costs, manufacturing costs, and inventory costs are reduced.

According to a second aspect of the present invention, in the first aspect of the present invention, the master unit has a third connection terminal for connecting the intercom slave unit and a fourth connection terminal for external connection, and There is a path for passing a signal between the connection terminal and the fourth connection terminal, and the doorphone connection expansion adapter is connected to the fourth connection terminal. The invention of claim 3 is
The invention according to claim 1, wherein the master unit includes a third connection terminal for connecting a doorphone slave unit, a fourth connection terminal for external connection, and a fifth connection terminal for connecting a doorphone connection expansion adapter. A path through which a signal passes between the third connection terminal and the fourth connection terminal, and a state in which signal passage is permitted and a state in which signal transmission is prohibited between the fourth connection terminal and the fifth connection terminal And a second switch element for selecting the above is inserted.

Claims 2 and 3 are preferred embodiments. In the configuration of claim 2, a two-family house or an apartment house is provided by applying a door phone connection expansion adapter to a conventionally provided base unit. Can be handled. In the latter configuration, a second switch element is added to the conventional parent device. In addition, in any of the configurations, the base unit has a connection terminal for external connection, so if an expansion base unit having the same function as the base unit is connected, a call with the intercom slave unit can be made at many places. .

According to a fourth aspect of the present invention, there is provided a doorphone connection expansion adapter attached to a plurality of master units each connected to a doorphone slave unit, wherein the doorphone connection expansion adapters are first and second adapters connected to the master unit. 2 and a third connection terminal for external connection, and a signal transmitted and received between each master unit and the intercom slave unit passes between the first connection terminal and the third connection terminal. A first switch element for selecting between a state permitting and a state prohibiting, and a second element for selecting a state permitting and prohibiting the passage of a signal from the third connection terminal to the second connection terminal. Control means for controlling the first switch element so as to permit passage of subsequent signals when the signal including the identification information is received from the third connection terminal and matches the identification information set in advance when the signal is received from the third connection terminal; , First and second With the permission of the passing signal in the switching element of the selecting means for selecting the valid and the invalid prohibited and the control means, fourth master unit for connecting the intercom slave
And a fifth connection terminal for external connection and a sixth connection terminal connected to the second connection terminal.
A path through which a signal passes between the fourth connection terminal and the fifth connection terminal, and a call is made when a signal indicating a call is input from one of the third connection terminal and the sixth connection terminal In this case, a signal transmission / reception path is formed between the third connection terminals of the plurality of doorphone connection expansion adapters. According to this configuration, signals can be exchanged between the master units while using the master unit provided conventionally, and when the first and second switch elements are operated, two master units are operated. Since it is possible to select a state in which the passage of the signal between the machines is permitted or a state in which the signal is prohibited, it is possible to construct a system for a two-family house. In addition, since the first and second switch elements can be operated by the identification information, when connecting to the lobby intercom using a large number of master units, the identification information from the lobby intercom is received. In addition, it is possible to individually control a call between each base unit and the lobby intercom, and it is also possible to construct a system for an apartment house. In this way, by using the doorphone connection expansion adapter, it becomes possible to expand a normal doorphone system for a two-family house or an apartment house. As a result, there is no need to manufacture a variety of parent machines, and costs such as development costs, manufacturing costs, and inventory costs are reduced. In this configuration, the path of the control signal (described in the conventional configuration) is separated into the first switch element and the second switch element, and the passage of the control signal inside the master unit uses the master unit alone. It is the same as when In other words, noise reduction and the like can be made as usual when actually manufacturing the master unit, and the design burden is reduced.

According to a fifth aspect of the present invention, there are provided two master units each having a doorphone slave unit connected thereto, and a doorphone connection expansion adapter interposed between the parent units, and the doorphone connection expansion adapter is connected to each master unit. The first and second connection terminals to be transmitted and the signals transmitted and received between each base unit and the intercom slave unit are connected to the first connection terminal.
A switch element for selecting between a state in which passage between the connection terminal and a second connection terminal is permitted and a state in which passage is prohibited;
A selection means for selecting permission or prohibition of the passage of a signal is provided. In this configuration, permission and prohibition of signal passage between two master units can be controlled only by using one doorphone connection expansion adapter, so that a normal system can be expanded to a two-family house system. Is easy.

According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the master unit has a third connection terminal for connecting the intercom slave unit and a fourth connection terminal for external connection. There is a path for passing a signal between the connection terminal and the fourth connection terminal, and the doorphone connection expansion adapter is connected to the fourth connection terminal. The invention of claim 7 is
The invention according to claim 5, wherein the master unit includes a third connection terminal for connecting a doorphone slave unit, a fourth connection terminal for external connection, and a fifth connection terminal for connecting a doorphone connection expansion adapter. A path through which a signal passes between the third connection terminal and the fourth connection terminal, and a state in which signal passage is permitted and a state in which signal transmission is prohibited between the fourth connection terminal and the fifth connection terminal And a second switch element for selecting the above is inserted.

The inventions of claims 6 and 7 are preferred embodiments. According to an eighth aspect of the present invention, in the first aspect of the present invention, the doorphone connection expansion adapter includes a ROM storing a processing procedure and data used in the processing.
Is made exchangeable. According to this configuration, since the contents of the ROM can be changed, it is possible to easily cope with a change in specifications such as a change in processing contents.

According to a ninth aspect of the present invention, in the first aspect of the present invention, the master unit has a door phone connection expansion adapter built in one body. According to this configuration, one type of master unit can be used independently, developed for two-family housing, and for multi-family housing.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) This embodiment, as shown in FIG. 1, adds the intercom connection extension adapter ₇₁ to the doorphone system and adapted for coupling between two intercom system via the intercom connection extension adapter 7 ₁ Things. The configuration of each intercom system is the same as that of a general intercom system provided conventionally, and
_1, 3 ₂ are used base unit 1 ₁ which is connectable to the connecting terminal T _13. Doorphone connection expansion adapter 7 ₁ is the extension base unit 3
_1, is 3 ₂ likewise via the signal line L ₂₁ to the base unit 1 ₁ of the connection terminals T ₁₃ connected.

The intercom connection extension adapter ₇₁ separates the control signal from the signal received from each doorphone system,
In accordance with the contents of the control signal and the setting contents of a setting button 76a to be described later, it is determined whether or not to pass the video signal and the audio signal, and the format of the control signal is converted as necessary. Intercom connection extension adapter ₇₁ is provided with two connection terminals T _71, T _72, one connection terminal T ₇₁ is connected directly to the signal line L ₂₁ of one of the doorphone system, the other connection terminal T ₇₂ and the other the signal line L ₃₁ to the connection terminals T ₇₂ doorphone intercom connection extension adapter ₇₁ which is connected to the system
Connected via Each of the respective connection terminals T _71, T ₇₂ includes a demultiplexer 74 _1, 74 _2, the demultiplexer 7
4 _1, 74 _2, or separates the control signal from the input signal through the respective connection terminals T _71, T _72, connected by multiplexing the control signal and the video signal and audio signal terminals T _71,
It has a function of or sent from T _72.

The control signal separated by the connected inputted through the terminal T _71, T ₇₂ demultiplexer 74 _1, 74 ₂ is inputted to the control signal transceiver circuit 78 _1, 78 ₂ through CPU 76. The remaining video signal and audio signal from which the control signal has been separated by one of the demultiplexing circuits 74 ₁ and 74 ₂ are transmitted via the switch element 71 to the other demultiplexing circuits 74 ₁ and 74 7.
4 ₂ is input to the demultiplexing circuit 74 ₁ of the other, 74
_{In 2} , the control signal transmission / reception circuit 78 output from the CPU 76
_The control signal supplied through ₁ and 78 ₂ and the video signal and the audio signal supplied through the switch element 71 are multiplexed and output to the outside through the connection terminals T ₇₁ and T ₇₂ .
The power supply circuit 79 is connected to a commercial power supply via a plug 79a as a power supply for the internal circuit.

The CPU 76 connects two intercom systems, such as for a two-family house, or a large number of intercom systems, such as for an apartment house, depending on the setting state of a setting button 76a having a switch group. Is selected and the lobby intercom 5 can be used. The form of the control signal is converted according to this selection. The ON / OFF of the switch element 71 is set by the setting button 76.
It is determined by combining the setting state of a and the content of the received control signal.

In the setting button 76a, in addition to the setting for two-family housing and the setting for multi-family housing, in the setting for two-family housing, the intercom slave unit is managed for each household or one of the households is out of home. It is possible to switch whether the parent unit of the other household manages the intercom slave unit, and in the setting for an apartment complex, it is possible to set a household number for identifying the parent unit for each unit.

More specifically, when used for a two-family house, as shown in FIG. 1, the intercom units 2 ₁ and 2 ₂ , the base unit ₁₁ and the expansion base units 3 ₁ and 3 are provided for each household.
₂ are appropriately combined to construct a door phone system, and the connection terminal T ₇₁ of the door phone connection expansion adapter 7 ₁ is connected to an appropriate position of the signal line L ₂₁ connecting the base unit ₁₁ and the expansion base units 3 ₁ and 3 _2. Connecting. Moreover, to connect the connection terminals T ₇₂ between the intercom connection extension adapter ₇₁ connected to the doorphone system via a signal line L _31.

When two-family housing is selected by the setting button 76a, the switch element 71
The direction from ₂ to demultiplexer 74 ₁ to allow the passage of always signals without off, it is desirable to determine the on-off according to the setting state of the setting button 76a for reverse. Similarly, toward the control signal reception circuit 78 ₂ from the control signal reception circuit 78 ₁ to allow the passage of the control signal in CPU 76, the selected state of the setting buttons 76a to whether to permit transmission of a signal in the opposite direction It is desirable to determine according to. This is to enable the calling of the other by operating the setting button 76a on one side, and by operating the setting button 76a on the other side in response to this call, two-way signal transmission is possible between both doorphone systems. become.

However, by always turning off the switch element 71 and prohibiting the passage of control signals, the two doorphone systems are used in a state of being separated from each other so as not to exchange signals. Further, the setting button 76a at one intercom connection extension adapter ₇₁ if set during absence, as described above, since the signal at its intercom connection extension adapter ₇₁ is allowed to pass through in both directions,
From the main unit 1 ₁ of one of the intercom system makes it possible to call the base unit 1 ₁ of the other doorphone system, both by operating the setting button 76a even intercom connection extension adapter ₇₁ belonging to the other doorphone system doorphone Bi-directional signal transmission between systems is possible.

By the way, for use in an apartment house, FIG.
As shown in, the branching device 6 which is inserted in the signal line L ₂₃ connecting the intercom connection extension adapter ₇₁ of the connection terminal T _72. To one end of the signal line L ₂₃ terminating resistor 8 is connected, lobby interphone 5 is connected to the other end. The intercom connection extension adapter ₇₁ of the connection terminal ₇₁ a signal line ₂₁ connected to the connection terminal T ₁₃ of the base unit 1 ₁ is connected. This connection is the same as for a two-family house.

When the multi-family housing is selected by the setting button 76a, the switch element 71 is always off.
Further, CPU 76 includes a household number in the control signal included in the signal received through the connection terminals T _72, set button 76a
Together to allow the collating the household number set to different values for each doorphone system both by match, the passage of the video signal and the audio signal from the signal line L ₂₃ turns on the switch element 71 by, extension master station 3 ₁ such as the removing household number from the control signal, is from 3 ₂ to deliver to the signal line L ₂₃ as a control signal the same form as the control signal transmitted to the base unit 1 _1.

As described above, the door housing for a general house is used.
Machine 1 for building a system ₁Do you use
Are the most versatile doorphone systems for ordinary homes.
Of course, you can build
₁Extension base unit 3₁, 3_TwoThe connection provided to connect
Connection terminal T_{twenty one}Doorphone expansion adapter 7 connected to₁
Is added, the doorphone connection expansion adapter 7₁Setting button
By the operation of 76a, two-family housing and apartment
Features can be selected, so both configurations
It can be easily handled. In other words, the parent machine
1₁, Door phone handset 2 ₁, 2_Two, Extension base unit 3₁, 3_TwoWhen
And three types of usage while using a common configuration
It is possible to respond to. Other configurations and
The operation is the same as that of a conventional home doorphone system.
You.

[0039] In Embodiment 2 This embodiment, as shown in FIG. 3, with the addition of a switching element 16b to the base unit 1 ₁ for residential. Switching element 16b is connected between the connection terminals T ₁₃ and the connection terminals T _12, the on-off the CPU16 determines in accordance with the operation of the operation button 16a. Intercom connection extension adapter ₇₁ is used as having the same configuration as in Embodiment 1, but intercom connection extension adapter 7
That connects the _first connecting terminal T ₇₁ via a signal line L ₃₂ to the connection terminal T ₁₂ of the base unit 1 ₁ is different.

When constructing a door phone system for a general house, the switch element 16b is turned off. In this case, functions similarly to the base unit 1 ₁ of the doorphone system for residential described as the prior art. On the other hand, when used for a two-family house, it is necessary to select a state in which the two intercom systems are operated separately and a state in which signals are exchanged between the two intercom systems. Therefore, as shown in FIG. 4, the connection terminal T ₇₁ of the base unit 1 ₁ of the connection terminals T ₁₂ and intercom connection extension adapter ₇₁ are connected via a signal line L _32, switch element 16b of the main unit 1 ₁ Turn on. At this time, the door phone handset changeover switch 10
It is left by selecting the connection terminal T _11. Such settings, signal path is formed doubly between the connecting terminal T ₁₁ and the connection terminal T ₁₂ in the base unit 1 _1, without a loop is formed, the connection terminal T ₁₂ is the same function as the substantially connecting terminal T _13. However, when the CPU 16 turns on the switch element 16b, the CPU 16 ignores the input of the control signal receiving circuit 17b. The construction described above, it will function equivalent to that connected the intercom connection extension adapter ₇₁ to the connection terminal T ₁₃ in the first embodiment. Further, when used for collective housing, as shown in FIG. 5, the main unit 1 ₁ of the connection terminals intercom connection extension is connected to the T ₁₂ adapter ₇₁ of the connection terminals T ₇₂ and via a branching unit 6 the signal line L ₂₃ Just connect it to.

The present embodiment, in short, to a connection terminal T ₁₂ of the connection points relative to the main unit 1 ₁ of the intercom connection extension adapter _71, so that the function of the master unit 1 ₁ is the same function as the substantially Embodiment 1 The second embodiment is different from the first embodiment only in that a switch element 16b is provided for control. Other configurations and operations are the same as those of the first embodiment. (Embodiment 3) This embodiment, as shown in FIG. 6, the configuration of the intercom connection extension adapter 7 ₃ is obtained by a structure different from that of the above embodiment. That is, three connection terminals T ₇₂ through T whereas those that intercom connection extension adapter 7 ₃ described above had two connection terminals T _71, T _{72
It has 74} . Further, the main unit 1 ₁ is used the same configuration as Embodiment 1.

[0042] In the embodiment 1, although the connection terminal T ₇₁ was also used for transmission and reception, in the present embodiment a receive-only connection terminals T _73, and using the connection terminals T ₇₄ to transmit only. Therefore, the demultiplexing circuit 74 ₃ connected to the connection terminal T ₇₃
Demultiplexer 74 ₂ is connected via a switching element 71 ₃ is connected a control signal receiving circuit 78 ₃ in. The demultiplexing circuit 74 ₄ connected to the connection terminal T ₇₄
Demultiplexer 74 ₂ is connected with the control signal transmission circuit 78 ₄ is connected via a switching element 71 ₄ to. Here, the switch element 71 ₃ is connected to the connection terminal T ₇₃
It is controlled based on the control signal received by the control signal reception circuit 78 ₃ through the switch element 71 ₄ connecting terminal T ₇₂
It is controlled based on the control signal received by the control signal reception circuit 78 ₂ through.

The doorphone connection expansion adapter 7 _{3 of} this configuration
To be used for two-family houses with via a signal line L ₂₁ to the connection terminals T ₁₃ provided in the base unit 1 ₁ is connected to the connection terminals T _73, the connection terminals T provided in the base unit 1 _{1 12} via the signal line L ₃₃ connecting the connection terminals T _74, further connects the connecting terminal T ₇₂ to intercom connection extension adapter 7 ₂ connection terminals T ₇₂ which is connected to the other door phone system. The setting button 76a is set for a two-family house.

Here, normally, the switch elements 71 ₃ , 71
Turn off ₄ and operate each intercom system separately. On the other hand, if setting for the time away by operating the setting button 76a, the control signal for the call to the intercom connection extension adapter 7 ₃ control signal reception circuit 78 ₂ through CPU76 connected to the other side door phone system is transmitted, the main unit 1 ₁ via the control signal transmission circuit 78 ₄
Can be called to indicate that the setting is made for absence. If the setting for absence is available, the door phone handset 2
Signals from _one is input to the connection terminal T ₇₃ via the main unit 1 _1, the switch element 71 ₃ is turned on by a control signal CPU76 through the control signal receiving circuit 78 ₃ has received.
Further, the control signal is a control signal receiving circuit 78 ₂ through the mating doorphone system intercom connection expansion adapter 7
₃ and the other party's doorphone connection expansion adapter 7 ₃
Control signal CPU through the control signal transceiver circuit 78 ₂
76.

Thus, the other party's doorphone connection extension
Dapta 7_ThreeSwitch element 78_FourTurns on and the door
Handset 2₁Signal from the other party's doorphone system
Machine 1 ₁It is input to. In short, the door phone handset
2₁Side door phone connection expansion adapter 7_ThreeThen switch required
Element 78_ThreeTurns on, and the other party's doorphone
Puta 7_ThreeThen switch element 78_FourTurns on. But
Tte door phone handset 2 ₁Main unit 1 of the doorphone system on the side
₁Is the connection terminal T₁₁And connection terminal T₁₃Between the video signal and
Base station of the other party's intercom system
1₁Is the connection terminal T₁₂And connection terminal T₁₃Between the video signal and
And audio signals. Where the audio signal
Is transmitted in both directions, so that calls can be made.

When used [0046] The intercom connection extension adapter 7 ₃ in this embodiment for collective housing, as shown in FIG. 7, the base unit 1 ₁ as is the case for two-family houses the connection terminals T _73, T ₇₄ connect, connected to the signal line L ₂₃ connecting terminal T ₇₂ via a branching unit 6. To one end of the signal line L ₂₃ terminating resistor 8 is connected, lobby interphone 5 is connected to the other end.

[0047] By setting the setting button 76a for the collective housing, by specifying the household number from the lobby intercom 5 specific intercom connection extension adapter 7 ₃ called, video signals and audio switching element 71 ₄ is on Signal transmission becomes possible. Here, the audio signal is bidirectionally transmitted through the switch element 78 _4. Further, when transmitting a control signal to the lobby intercom 5, switching element 71 ₃ is turned on. Furthermore, in the case of a call between base unit 1 _1, the switch element ₇₄₃ is turned on in calling, the switch element 74 ₄ is turned on at the called side.

Other configurations and operations are the same as those of the first embodiment. Embodiment 4 In the embodiments described above, the two respective in use in a family house in two of the main unit 1 ₁ had been connected intercom connection extension adapter _71, in this embodiment,
As shown in FIG. 8, using an intercom connection extension adapter ₇₁ having the same configuration as Embodiment 1, an example in which so as to connect two of the main unit 1 ₁ via one intercom connection extension adapter 7 ₁ Show. This configuration embodiment be another example of the use of the intercom connection extension adapter ₇₁ used in the 1, intercom connection extension adapter ₇₁ is in use as a two-family houses
As a single unit to simplify the system configuration. Therefore, when it is used for an apartment house, it is the same as the first embodiment. Other configurations and operations are the same as those of the first embodiment.

[0049] (Embodiment 5) In this embodiment, as shown in FIG. 9, using the base unit 1 ₁ shown in embodiment 2, when used for similarly two-family houses as in Embodiment 4, one 2 main units _{1 1} via the doorphone connection expansion adapter 7 ₁
Are connected. This configuration is a further example of the use of the main unit 1 ₁ and intercom connection extension adapter ₇₁ used in the embodiment 2, the system configuration is simplified when used as a two-family houses. In addition, use for an apartment house is the same as that of the second embodiment.

[0050] (Embodiment 6) In this embodiment, as shown in FIG. 10, used, equipped with a four connection terminals T ₇₃ through T ₇₆ as intercom connection extension adapter 7 _6, for use as a two-family houses for, in which two of the base unit 1 ₁ is connected via the intercom connection extension adapter 7 ₆ one.
The connection terminals T ₇₃ and T ₇₅ are for reception only, and the connection terminals T ₇₄ and T _74
T76 is used exclusively for transmission. Connection terminals T _73, T ₇₅ are respectively connected to the demultiplexing circuit 74 _3, 74 ₅ and through the control signal receiving circuit 78 _3, 78 _5, the connection terminals T _74, T ₇₆
It is connected to the control signal transmission circuit 78 _4, 78 _6, respectively, via the demultiplexer circuit 74 _4, 74 _6. The control signals input to the control signal receiving circuits 78 ₃ and 78 ₅
The control signal transmitting circuits 78 ₄ , 7 which are converted as necessary at 6
Output through 8 _6. Switching element 71 _5, 71 ₆ are respectively controlled by CPU76 is inserted between the demultiplexing circuit ₇₄₃ and between the demultiplexing circuit 74 ₄ and the demultiplexer 74 ₅ of demultiplexer 74 _6. Further, the CPU76 is connected set button 76a is, the internal power supply of the intercom connection extension adapter 7 ₆ is supplied by the power supply circuit 79 having a plug 79a which is connected to a commercial power source.

When used for a two-family house, the parent machine ₁₁
In normally setting the intercom slave changeover switch 10 so that the connection terminal T ₁₁ is enabled. Moreover, the intercom connection extension adapter 7 _6, usually switch elements 7
1 _5, 71 ₆ Leave off, to operate independently of each base unit 1 ₁ is connected via a intercom connection extension adapter 7 _6.

On the other hand, when the user is out of the office, the setting for the absence is selected by operating the setting button 76a. In this case, households are set up either of the main unit 1 ₁ it is possible to specify whether become absence. Now, the upper side of the base unit 1 ₁ shown in FIG. 10
Households that have set up will be away. In this case, since the control signal may be made transferred from the main unit 1 ₁ of the upper to the base unit 1 ₁ of the lower, giving a control signal to the CPU76 through the control signal receiving circuit 78 _3, the converted control signal at the CPU76 It is sent from the control signal transmitting circuit 78 _5. That is, since it is sufficient to pass signals between the connection terminals T ₇₃ and the connection terminals T _76, to turn on the switching element 71 _5. Switching element 71 ₅ is a video signal and an audio signal if the ON will pass through the intercom connection extension adapter 7 ₆ bidirectionally.

In this state, the upper master unit 1₁Connected to
Door phone handset 2₁When a control signal for calling occurs
Upper master unit 1₁Control signal passed through the doorphone connection extension
Adapter 7₆Through the lower parent unit 1₁Is input to under
Side master unit 1₁Then the connection terminal T ₁₂Control signal is input to
The connection terminal T₁₂To enable the door
Set the slave unit changeover switch 10 and
Side master unit 1₁Intercom handset 2 connected to₁from
The video signal is transmitted to the lower master unit 1₁To display the image.
In addition, a call between them can be made.

[0054] Although the operation example described above is the case of households that install master unit 1 ₁ of the upper is absent, if absent households that install master unit 1 ₁ of the lower switch element 71 signal will pass through between the ₆ and the connecting terminal T ₇₄ is turned on to the connection terminal T _75. Other configurations and operations are the same as those of the first embodiment. (Embodiment 7) In this embodiment, as can be changed, such as conversion contents of and control signals (processing content for various settings) processing procedure in the intercom connection extension adapter ₇₁ easily, procedures and converted contents the ROM76b describing the programs and data for determining the like, showing an example in which apart from the intercom connection extension adapter ₇₁ of CPU 76 (FIG. 11). The ROM 76b is mounted so as to be replaceable, and can be replaced when the specification is changed. Also, RO
When an EEPROM is used as the M76b, the ROM 76b
The specification can be changed without replacing. This configuration is applicable not only to the first embodiment but also to other embodiments.

[0055] (Embodiment Mode 8) In this embodiment, as shown in FIG. 12, the embodiment in the first configuration, intercom connection extension adapter 7 ₁ main unit 1 ₁ the function of the intercom connection extension adapter ₇₁ instead of providing the It is built in. Accordingly, the setting button 16c corresponding to the setting button 76a, the demultiplexer 14 ₃ corresponding to the demultiplexing circuit 74 _2, and the control signal transceiver circuit 18 ₃ corresponding to the control signal transmitting and receiving circuit 78 _2, the switching element 71 ₁ a switching element 16 ₃ corresponding, are added to the base unit 1 ₁ and the connection terminals T ₁₄ corresponding to the connecting terminal T _72. Demultiplexing circuit 74 ₁ is also used in demultiplexing circuit 14 _2, the control signal reception circuit 78 ₁ is also used in the control signal transmitting and receiving circuit 18.

[0056] In this configuration, because a built-in function of the intercom connection extension adapter ₇₁ to the main unit 1 _1, by connecting the connection terminals T ₁₄ between the base unit 1 ₁ of the same type for two-family house system the can be constructed, it is possible to construct a system for collective housing by connecting each base unit 1 ₁ to the signal line L ₂₃ through the branching unit 5. Other configurations and operations are the same as those of the first embodiment.

[0057]

According to the first aspect of the present invention, there is provided a doorphone connection extension adapter attached to a plurality of master units each having a doorphone slave unit connected thereto, and the doorphone connection extension adapter is connected to the master unit by a first unit. Connection terminal and second connection for external connection
And a state in which a signal transmitted / received between each base unit and the intercom slave unit is permitted or prohibited between passing through the first connection terminal and the second connection terminal. Control means for controlling the switch element so as to permit passage of subsequent signals when the signal including identification information is received from the second connection terminal and the signal matches the identification information set in advance, Selection means for selecting whether to permit or prohibit the passage of the signal and to enable or disable the control means, wherein a signal transmission / reception path is formed between the second connection terminals of the plurality of doorphone connection expansion adapters. By using the door phone connection expansion adapter while using a general master unit used alone, signals can be exchanged between the master units. By operating the switch element, the two master units can be exchanged. Signal passing Since it is possible to select a condition to be inhibited to a state in which it is soluble, it is possible to construct a system for the two-family houses. Further, since the switch element can be operated by the identification information, it is possible to construct a system for an apartment house. In other words, by using the doorphone connection expansion adapter,
There is an advantage that a normal door phone system can be extended to a two-family house or an apartment house. As a result, there is no need to manufacture many types of master units,
This has the effect of reducing costs such as manufacturing costs and inventory costs.

According to a fourth aspect of the present invention, there is provided a doorphone connection expansion adapter attached to a plurality of base units each connected to a doorphone slave unit, and the first and second doorphone connection expansion adapters are connected to the base unit. 2 and a third connection terminal for external connection, and a signal transmitted and received between each master unit and the intercom slave unit passes between the first connection terminal and the third connection terminal. A first switch element for selecting between a state permitting and a state prohibiting, and a second element for selecting a state permitting and prohibiting the passage of a signal from the third connection terminal to the second connection terminal. Control means for controlling the first switch element so as to permit passage of subsequent signals when the signal including the identification information is received from the third connection terminal and matches the identification information set in advance when the signal is received from the third connection terminal; , First and second With the permission of the passing signal in the switching element of the selecting means for selecting the valid and the invalid prohibited and the control means, fourth master unit for connecting the intercom slave
And a fifth connection terminal for external connection and a sixth connection terminal connected to the second connection terminal.
A path through which a signal passes between the fourth connection terminal and the fifth connection terminal, and a call is made when a signal indicating a call is input from one of the third connection terminal and the sixth connection terminal In this case, a signal transmission / reception path is formed between the third connection terminals of the plurality of doorphone connection expansion adapters, and has the same effect as the first aspect of the invention.

According to a fifth aspect of the present invention, there are provided two master units each connected to a door phone slave unit, and a door phone connection expansion adapter interposed between the parent units, and the door phone connection expansion adapter is connected to each master unit. The first and second connection terminals to be transmitted and the signals transmitted and received between each base unit and the intercom slave unit are connected to the first connection terminal.
A switch element for selecting between a state in which passage between the connection terminal and a second connection terminal is permitted and a state in which passage is prohibited;
Selecting means for selecting permission or prohibition of signal passage, and controlling permission and prohibition of signal passage between two master units only by using one doorphone connection expansion adapter. Therefore, there is an advantage that the system can be easily expanded from a normal system to a system for a two-family house.

According to the eighth aspect of the present invention, when the doorphone connection expansion adapter includes a ROM storing a processing procedure and data used at the time of processing, and the contents of the ROM are exchangeable, the contents of the ROM can be changed. Therefore, there is an advantage that it is possible to easily cope with a specification change such as a change in processing content. In the case where the base unit incorporates the door phone connection expansion adapter in one body as in the invention of claim 9, one type of base unit is used independently, for two-family housing and for multi-family housing. It has the advantage that it can be deployed.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a construction example for a two-family house according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a building example for an apartment house.

FIG. 3 is a block diagram showing a master unit used in a second embodiment of the present invention.

FIG. 4 is a block diagram showing a construction example for a two-family house according to the above.

FIG. 5 is a block diagram showing a construction example for an apartment house according to the above.

FIG. 6 is a block diagram showing a construction example for a two-family house according to Embodiment 3 of the present invention.

FIG. 7 is a block diagram showing a construction example for an apartment house according to the above.

FIG. 8 is a block diagram showing a construction example for a two-family house according to a fourth embodiment of the present invention.

FIG. 9 is a block diagram showing a construction example for a two-family house according to a fifth embodiment of the present invention.

FIG. 10 is a block diagram showing a construction example for a two-family house according to a sixth embodiment of the present invention.

FIG. 11 is a block diagram showing a door phone connection expansion adapter used in a seventh embodiment of the present invention.

FIG. 12 is a block diagram showing a master unit used in Embodiment 8 of the present invention.

FIG. 13 is a block diagram showing a parent device provided conventionally.

FIG. 14 is a block diagram showing an intercom slave unit.

FIG. 15 is a block diagram showing another example of the intercom slave unit.

FIG. 16 is a block diagram showing an additional master unit.

FIG. 17 is a block diagram showing another example of the extension master unit.

FIG. 18 is a block diagram showing an example of a conventional construction for a two-family house.

FIG. 19 is a block diagram showing an example of a conventional construction for an apartment house.

[Explanation of symbols]

Reference Signs List 1 ₁ master unit 2 ₁ doorphone slave unit 2 ₂ doorphone slave unit 3 ₁ extension master unit 3 ₂ extension master unit 7 ₁ doorphone connection expansion adapter 71 ₁ switch element 74 ₁ demultiplexing circuit 74 ₂ demultiplexing circuit 76 CPU 76a setting button 78 ₁ Control signal transmission circuit 78 ₂ Control signal transmission circuit _T71 connection terminal _T72 connection terminal

 ──────────────────────────────────────────────────続 き Continued from the front page (72) Inventor Yoshihiro Tanikawa 1048 Kadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Works, Ltd.

Claims (9)

[Claims] 1. A doorphone connection expansion adapter attached to a plurality of master units each connected to a doorphone slave unit, wherein the doorphone connection expansion adapter has a first connection terminal connected to the master unit and an external connection terminal. And a state in which a signal transmitted / received between each base unit and the intercom slave unit is permitted and prohibited in each of the base units from passing between the first connection terminal and the second connection terminal. And control means for controlling the switch element to permit passage of a subsequent signal when a signal including identification information is received from the second connection terminal and matches a predetermined identification information. And a selection unit for selecting whether to allow or prohibit the passage of the signal and whether to enable or disable the control unit. A signal transmission / reception path is formed between the second connection terminals of the plurality of doorphone connection expansion adapters. That A unique door phone system. 2. The base unit according to claim 3, further comprising: a third unit for connecting a door phone slave unit.
And a fourth connection terminal for external connection, and a path for passing a signal between the third connection terminal and the fourth connection terminal. The door phone system according to claim 1, wherein the door phone system is connected to a connection terminal. 3. The base unit according to claim 3, wherein the base unit is connected to a door phone slave unit.
A connection terminal, a fourth connection terminal for external connection, and a fifth connection terminal for connecting the doorphone connection expansion adapter, and a path for passing a signal between the third connection terminal and the fourth connection terminal. And a second switch element is inserted between the fourth connection terminal and the fifth connection terminal, the second switch element selecting between a state in which signal passage is permitted and a state in which signal passage is prohibited. The door phone system according to claim 1. 4. A door phone connection extension adapter attached to a plurality of master units each connected to a door phone slave unit, wherein the door phone connection expansion adapter includes first and second connection terminals connected to the master unit and A third connection terminal for external connection, and a state in which a signal transmitted / received between each base unit and the intercom slave unit is permitted to pass between the first connection terminal and the third connection terminal. The first to select the prohibited state
, A second switch element for selecting between a state in which a signal is allowed to pass from the third connection terminal to the second connection terminal and a state in which the signal is prohibited, and identification information from the third connection terminal. Control means for controlling the first switch element so as to permit the passage of a subsequent signal when the signal coincides with the preset identification information when the signal is received; and a control means for passing the signal through the first and second switch elements. The master unit includes a fourth connection terminal for connecting the intercom slave unit, a fifth connection terminal for external connection, and a second connection terminal. A sixth connection terminal connected to the third connection terminal and the sixth connection terminal, and a path for passing a signal between the fourth connection terminal and the fifth connection terminal. Signal to call from one of the Be comprised allow calls to be, intercom system, characterized in that the signal transfer path is formed between the third connection terminal of the multiple intercom connections expansion adapter. 5. A mobile phone comprising: two master units each connected to a doorphone slave unit; and a doorphone connection expansion adapter interposed between the parent units, wherein the doorphone connection expansion adapter is connected to each of the first and second master units. A second connection terminal, and a state in which a signal transmitted and received between each parent device and the intercom slave device is allowed and prohibited in a state where the signal is allowed to pass between the first connection terminal and the second connection terminal. An intercom system comprising: a switch element for selection; and selection means for selecting permission or prohibition of signal passage. 6. A third unit for connecting a door phone slave unit to the master unit.
And a fourth connection terminal for external connection, and a path for passing a signal between the third connection terminal and the fourth connection terminal. The door phone system according to claim 5, wherein the door phone system is connected to a connection terminal. 7. A third device for connecting a door phone slave unit to the master unit.
A connection terminal, a fourth connection terminal for external connection, and a fifth connection terminal for connecting the doorphone connection expansion adapter, and a path for passing a signal between the third connection terminal and the fourth connection terminal. And a second switch element is inserted between the fourth connection terminal and the fifth connection terminal, the second switch element selecting between a state in which signal passage is permitted and a state in which signal passage is prohibited. The door phone system according to claim 5. 8. The doorphone connection expansion adapter includes a ROM storing a processing procedure and data used in the processing.
2. The door phone system according to claim 1, wherein the contents of the ROM are exchangeable. 9. The door phone system according to claim 1, wherein the parent device has a door phone connection expansion adapter built in one body.