JP2010081121A - Intercom system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intercom system having an intercom master unit that is provided in each household of a two-family house and has miniaturized size and reduced costs. <P>SOLUTION: The intercom master unit 1 installed in each household of the intercom system includes: a plurality of slave unit connection terminals T1 (T1a, T1b) to which slave units (intercom and camera slave units 3, 4) are connected; and a sub master unit connection terminal T2 to which sub master units 2a, ..., 2n are connected. One of the slave unit connection terminals T1 is used as a two-family terminal T1b to which the intercom master unit 1 of another household is connected. Also, the master unit 1 includes a signal switching circuit 18 (signal switching means) that is provided between the two-family terminal T1b and a video modulation/demodulation circuit 13 (video demodulation means), selects one of a signal from the slave unit of an own household and that from the intercom master 1 of another household, and includes slave unit switches SW1, SW2. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an intercom system used in a two-family house.

  In recent years, two-family houses in which a parent household and a child household coexist in one house have become widespread. In such a two-family house, an interphone system is provided for each household so that each household can individually respond to visitors. Was installed.

  In order to ensure privacy between two households, it is preferable to install a separate intercom system in each household so that interphone calls between households cannot be made. If there is a call, you may want to answer the other household instead, or make an intercom call between households. An intercom system for a two-family house that can be switched to a possible absence mode has been proposed (see, for example, Patent Document 1).

  In the interphone system disclosed in the above document, an interphone master unit is arranged in only one household, and the interphone master unit includes a door phone slave unit with a camera in each household and a plurality of interphone sub-phones installed in each household. Each is connected to the main unit. The interphone base unit and the interphone sub-base unit belong to the first group of one household, belong to the second group of the other household, or have one household and the other household combined. A switch for setting whether to belong to the group 3 is provided, and the call button is pushed by the doorphone slave of any household, and the call signal from the doorphone slave is sent to the sub-master via the master In this case, the master unit and the sub master unit refer to the setting of the changeover switch, and the ring tone is sounded only when the call signal from the own group's doorphone slave unit is input, and the response to the call is also sent to the own group's doorphone. It can be done only with the child. In addition, when the group is set to the third group by the change-over switch on either the master unit or the sub-master unit, the entire system is switched to the absence mode so that inter-household calls are possible. When the call button is pressed with a device, it is possible to respond with the parent device or the sub-parent device of the household at home.

  However, in the interphone system disclosed in the above document, only one household has an interphone master unit. Therefore, if a power failure occurs in one of the households or if the interphone master unit fails, the other household However, there was a problem that the intercom system could not be used.

  Therefore, as shown in the system configuration diagram of FIG. 9, between each of the households A <b> 1 and A <b> 2 of the two-family house, between the doorphone unit 3 with a camera installed outside the dwelling unit and the doorphone unit 3 installed inside the dwelling unit The interphone master unit 1 (hereinafter abbreviated as “master unit”) that receives and transmits audio signals through the signal line Ls1 and receives the video signal is input to the master unit through the signal line Ls1. An interphone sub-master device (hereinafter abbreviated as sub-master device) 2a, which is installed in the dwelling unit and connected to the master device 1 via a balanced two-wire signal line Ls2. There has also been proposed a system in which an interphone system composed of 2b, 2c,... Is provided and a telephone line between households A1, A2 is connected by a signal line Ls3 so that a telephone call between households can be made. Yes.

  As shown in FIG. 10, the base unit 1 includes a microphone 10a, a speaker 10b, and a two-wire / four-wire conversion circuit, and performs signal processing on an audio signal output from the microphone 10a, which will be described later. , 21, and the audio signal input from the demultiplexing circuits 16 a, 16 c, 21 is signal-processed to generate sound from the speaker 10 b, and between the sub-master units 2 a to 2 n and the camera sub unit 4. Control / sound modulation / demodulation circuit 11 for transmitting a control signal by the FSK method, monitor 12 for video display, and video modulation / demodulation for demodulating a video signal sent from the doorphone slave unit 3 or the camera slave unit 4 and displaying it on the monitor 12 The operation unit 14 for performing various operations (operation for responding to a call signal, operation for monitoring a video of a desired door phone slave unit 3, operation for calling a sub-master unit 2a) with the circuit 13 The call signal receiving circuit 15 that monitors the line voltage of the signal line Ls1 and receives the call signal transmitted from the intercom unit 3 and the audio signal and control signal input from the control / audio modulation / demodulation circuit 11 are frequency-multiplexed. And a demultiplexing circuit 16a for separating the audio signal from the multiplexed signal input via the signal line Ls1 and outputting it to the control / audio modulation / demodulation circuit 11, and the doorphone sub unit 3 or the camera. A demultiplexing circuit 16b that separates the video signal from the multiplexed signal input from the slave unit 4 via the signal line Ls1 and outputs the video signal to the video modulation / demodulation circuit 13, and the audio signal and control input from the control / audio modulation / demodulation circuit 11 The signal is frequency-multiplexed and output to the signal line Ls2, and the audio signal and the control signal are transmitted from the multiplexed signal input from the sub-master units 2a to 2n via the signal line Ls2. A demultiplexing circuit 16c that separates the signal and outputs it to the control / sound modulation / demodulation circuit 11, a demultiplexing circuit 16d that frequency-multiplexes the video signal separated by the demultiplexing circuit 16b again, and outputs it to the signal line Ls2, and a microcomputer. As main components, a control unit 17 that performs overall operation control, and an inter-household call circuit 20 for transmitting and receiving audio signals and video signals between households are provided.

  The parent device 1 of the parent household A1 and the parent device 1 of the child household A2 are connected via a signal line Ls3, and the inter-household call circuit 20 includes the control / voice modulation / demodulation circuit 11 or the demultiplexing circuits 16a, 16c. Are multiplexed and output to the signal line Ls3, and the audio signal and the control signal are separated from the frequency multiplexed signal input via the signal line Ls3. Alternatively, the video signal from the doorphone sub unit 3 or the camera sub unit 4 of another household is separated from the demultiplexing circuit 21 output to the demultiplexing circuits 16a and 16c and the frequency multiplexed signal input via the signal line Ls3. A demultiplexing circuit 22 that multiplexes the video signals input from the doorphone sub unit 3 or the camera sub unit 4 of the same household and outputs them to the main unit 1 of another household via the signal line Ls3; A switch 23 provided between the demultiplexing circuit 22 and the video modulation / demodulation circuit 13, for turning on / off the input of the video signal from the demultiplexing circuit 22 to the video modulation / demodulation circuit 13, the video modulation / demodulation circuit 13, and the demultiplexing circuit 22; And a switch 24 for turning on / off the input of the video signal from the video modulation / demodulation circuit 13 side (that is, the doorphone slave unit 3 or the camera slave unit 4) to the demultiplexing circuit 22.

  Here, the call response by the conventional intercom system will be described below. First, a case will be described in which a call from the door phone slave unit 3 of the parent household A1 is answered by the parent device 1 or the sub-parent device 2a of the parent household A1. The power supply voltage (DC voltage) from the base unit 1 to the doorphone slave unit 3 is relatively low in order to reduce the power consumption of the system when the doorphone slave unit 3 is not in a talking state or a monitor state described later. (This state is referred to as a standby power supply state.) In a call state or a monitor state, the state is relatively high (this state is referred to as an operation power supply state). The camera slave unit 4 is supplied with operating power from a commercial power source.

  When the call button 3a is operated in the standby power supply state, the intercom unit 3 transmits a call signal to the base unit 1 by lowering the line voltage of the signal line Ls1 to a voltage lower than that in the standby power supply state. In the base unit 1, the call signal receiving circuit 15 detects the call signal by monitoring the line voltage of the signal line Ls1, and when the call signal is received and output to the control unit 17, the control unit 17 outputs the signal line. Control for changing the power supply voltage to Ls1 from the standby power supply state to the operation power supply state, causing the speaker 10b to ring the calling signal, and causing the secondary master units 2a to 2n to ring the calling signal via the demultiplexing circuit 16c By sending a signal, a ringing signal is sounded from the master unit 1 and the sub master units 2a to 2n.

  In the intercom unit 3, when the power supply state is switched to the operation power supply state, the built-in camera is activated and the video signal of the camera is transmitted to the main unit 1 via the signal line Ls 1 and the audio signal processing unit is activated. Thus, the voice signal is exchanged, that is, switched to a state in which a call is possible. At this time, in the master unit 1, the video modulation / demodulation circuit 13 demodulates the video signal separated by the demultiplexing circuit 16 b and displays it on the monitor 12, and the demultiplexing circuit 16 d remultiplexes the video signal and sub-master units 2 a to 2 n. Are output to the monitors 25 of the sub-master units 2a to 2n, and the images captured by the camera of the door phone slave unit 3 are displayed.

  When the householder who has heard the call signal operates the response buttons 14a and 26 of the master unit 1 or the sub master units 2a to 2n, the master unit 1 or the sub master units 2a to 2n in which the response buttons 14a and 26 are operated and the door phone. A communication path is formed with the sub unit 3, and a housekeeper in the house can make a call with a visitor while viewing the images on the monitors 12 and 25.

  In the interphone system shown in FIG. 9 and FIG. 10, when one of the households is away and cannot respond to the visitor, the call from the doorphone sub unit 3 of one household is used to call the master unit 1 of the other household. Alternatively, the secondary master units 2a to 2n can respond. That is, in the master unit 1 of each household A1 and A2, the switches 23 and 24 of the inter-household call circuit 20 are switched according to the setting operation of the operation unit 14 for performing absence setting, and the switch 23 is turned on at home. Then, the switch 24 is turned off, and the video signal sent from the other household is separated by the demultiplexing circuit 22 and input to the video modulation / demodulation circuit 13 to enable a call with the doorphone sub unit 3 of the other household. Further, in the master unit 1 of each household A1, A2, when the absence is set, the switch 23 is turned off and the switch 24 is turned on, and the video signal from the doorphone slave unit 3 or the camera slave unit 4 of the same household is multiplexed by the demultiplexing circuit 22. And output to the signal line Ls3 so that a telephone call can be made between the doorphone slave unit 3 of the same household and the parent unit 1 or the sub-parent units 2a to 2n of the other households.

Here, when the call button 3a is pushed by the doorphone sub unit 3 of the household A1 in which the absence setting is set in the base unit 1, the call signal receiving circuit 15 of the household A1 receives the call signal and the control unit 17 And the control unit 17 switches the power supply state to the door phone slave unit 3 to the operation power supply state to sound the ringing sound from the speaker 10b and to transmit the control signal for sounding the ringing sound to the demultiplexing circuits 16c and 21. And the master unit 1 and the sub master unit 2a of the two households A1 and A2 are output by being multiplexed to each other and output to the master unit 1 and the sub master units 2a to 2n of the other household A2. The ringing tone is sounded from ~ 2n. Further, when the power supply state is switched to the operation power supply state, the doorphone sub unit 3 of the household A1 activates the camera and outputs the video signal of the camera to the base unit 1. The base unit 1 of the household A1 has its own unit. The video is displayed on the monitor 12, the video is displayed on the monitors of the secondary master units 2a to 2n, and the video signal is output from the inter-household call circuit 20 to the master unit 1 and the secondary master units 2a to 2n of the other household A2. Thus, the video is displayed on the master unit 1 and the sub-master units 2a to 2n of the other household A2. Then, when a householder of another household A2 hears a ringing tone and presses the response buttons 14a and 26 of the master unit 1 or the sub-master units 2a to 2n, the parent of the other household A2 whose response button 14a or 26 has been pressed is operated. A communication path is formed between the machine 1 or the sub-master 2a to 2n and the doorphone slave 3 of the household A1 via the intercom master 1 of the household A1, and the doorphone slave 3 of the absence household and the homephone of the home household A telephone call can be made between the master unit 1 or the sub-master units 2a to 2n.
Japanese Patent No. 3617271

  In the above-described conventional intercom system, individual intercom systems are installed in each of the households A1 and A2 of a two-family house, and the inter-household communication circuit 20 is provided in the master unit 1 of each of the households A1 and A2. For example, even if an abnormality occurs in the intercom system of one household, the intercom system of the other household is not affected, and like the intercom system disclosed in Patent Document 1, Since it is not necessary to perform group setting for each sub-master unit, there is an advantage that the setting work can be reduced, but transmission of video signals from the master unit 1 to the sub-master units 2a to 2n in the same household is one-way. In contrast to communication, video signal transmission between households is a two-way communication, so a dedicated inter-household call circuit 20 having demultiplexing circuits 21 and 22 is required. Ri, together with the increased cost of the main unit 1, there is a problem that hinders miniaturization of the base unit 1 increases the circuit scale.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an interphone system in which the interphone master unit provided in each household of a two-family house is reduced in size and cost. There is.

  In order to achieve the above object, according to the invention of claim 1, an interphone system is provided in a two-family house for making an extension call within a household and between households. Interphone parent installed in a house with a handset including a door phone with a camera and a calling means for making a call between the handset and a video display means for displaying a video taken by the handset Display means for displaying a picture taken by the slave unit via the interphone master unit and a call unit for making a call between the slave unit and the interphone master unit via the interphone master unit And interphone sub-master devices that are installed in the house, and each household inter-phone master device is connected to a plurality of slave device connection terminals to which the slave devices are connected, and to the interphone sub-master device. Vice And a video demodulating unit for demodulating a video signal input from the slave unit connection terminal and displaying the demodulated video signal on the video display unit. One of the plurality of slave unit connection terminals is an interphone master unit of another household. Is used as a two-household terminal to be connected, between the slave unit connection terminal and the two-household terminal and the video demodulation means, either the signal from the slave unit of the own household or the signal from the intercom master unit of another household And a signal switching means for selecting and inputting them to the video demodulation means and the call means.

  In the second aspect of the invention, in the first aspect of the invention, in the first aspect, the interphone master unit can exchange signals with the interphone master unit of another household, or between the interphone master unit of another household. In the two-household mode, when there is a call from a slave unit in another household, the communication mode switching means The signal switching means is switched so that a signal from the interphone master is input to the video demodulating means and the calling means, and in the independent household mode, when there is a call from the slave unit of the own household, the communication mode switching means, The signal switching means is switched so that a signal from the slave unit of the household is input to the video demodulation means and the call means.

  According to a third aspect of the present invention, in the first aspect of the invention, the interphone master unit includes an amplifier that amplifies the video signal input to the video demodulating means and outputs the amplified video signal to the secondary master terminal connection terminal. Open / close means for turning on / off the electrical circuit between the secondary master unit connection terminal connected to the two household terminal of another household and the video demodulation means is connected to the secondary master unit connection terminal of the interphone master unit of another household. It is characterized by having.

  In the invention of claim 4, in the invention of claim 3, in the interphone master unit, the two-household mode enabling the interphone master unit to exchange signals with the interphone master unit of another household, or between the interphone master unit of another household In the independent household mode, when there is a call from the slave unit of the household, the communication mode switching means The signal switching means is switched so that a signal from the slave unit is input to the video demodulating unit and the calling unit, and the opening / closing unit is turned off. In the two-household mode, the video of the slave unit of the household is sent to the interphone master unit of another household. The communication mode switching means of the interphone master that transmits the signal turns on the opening / closing means and receives and displays the video signal transmitted from the interphone master of another household. The communication mode switching means of the interphone base unit turns off the opening / closing means, and when there is a call from the slave unit of another household, the signal from the interphone base unit of the other household is input to the video demodulation unit and the communication unit. The signal switching means is switched.

  According to the first aspect of the present invention, one of the slave terminals is used as a two-household terminal, and the video demodulator for demodulating the video signal from the slave is used to automatically receive the video signal from the interphone master unit of another household. Since it can be displayed on the video display means of the household interphone master unit and the interphone sub-master unit, the video signal can be transmitted bidirectionally for communication between households like the conventional interphone master unit for two-family houses. There is no need to separately provide a circuit for transmitting and receiving, and it is possible to reduce the circuit scale of the interphone master unit and to reduce the size and to reduce the cost.

  According to the invention of claim 2, since the signal transmission to the interphone master unit of another household is blocked while the interphone master unit is operating in the independent household mode, the privacy between households can be maintained and the absence of the interphone Sometimes switching the interphone master unit's communication mode to the two-household mode has the advantage that it is possible to respond to calls from the camera-equipped doorphone of the own household from the interphone master unit and interphone sub-master unit of other households. .

  According to the invention of claim 3, in addition to the effect of claim 1, the video signal from the interphone master unit of another household is output by amplifying the video signal input to the video demodulation means of the other household by the amplifier. Since it is input to the two household terminals of the intercom master unit of the own household, the wiring length of the transmission path between households can be increased.

  According to the invention of claim 4, in addition to the effect of claim 3, when the interphone master unit is operating in the independent household mode, the transmission of signals to the interphone master unit of other households is cut off. Privacy can be maintained, and the communication mode of the interphone master unit can be switched to the two-household mode when you are away so that calls from the door phone with camera in your household can be answered from the interphone master unit and interphone sub-master unit of other households. There is an advantage that it becomes possible.

(Embodiment 1)
The intercom system according to the present embodiment will be described with reference to FIGS. The intercom system according to the present embodiment is used in a two-family house so that extension calls can be made in the two households A1 and A2 of the two-family house and extension calls between the households of the households A1 and A2. Yes.

  As shown in FIG. 2, each household A1 and A2 has a doorphone unit with a camera 3 installed outside a dwelling unit such as a front door, and a predetermined area including a detection area when an environmental change is detected in a predetermined detection area. The camera sub unit 4 that captures the shooting area, the microphone 10a, the speaker 10b, and the monitor 12 (video display means) have a telephone conversation with the door phone sub unit 3 using the microphone 10a and the speaker 10b. An interphone master unit (hereinafter abbreviated as “master unit”) 1 that displays images captured by the unit (door phone sub unit 3 and camera sub unit 4) on the monitor 12, a speaker, a microphone, and a monitor (video display means). And connected to the base unit 1 via the signal line Ls2, and makes a call using the speaker and the microphone with the door phone sub unit 3 through the base unit 1, and also the video captured by the sub unit. Intercom is displayed on Nita sub master unit (hereinafter, to abbreviated as auxiliary base unit.) 2a, 2b ... and 2n, respectively.

As shown in FIG. 1, the master unit 1 of each household A1 and A2 has a plurality of slave unit connection terminals T1 (T1a) to which slave units (door phone slave unit 3 and camera slave unit 4) are connected via a signal line Ls1. , T1a, T1b) and a sub master unit connection terminal T2 to which the sub master units 2a... 2n are connected via the signal line Ls2, and one sub unit connection terminal T1b of the sub unit connection terminals T1. Is connected to the parent device 1 of another household via a signal line Ls3. That is, the sub unit connection terminal T1b is used as a two-household terminal (hereinafter referred to as a two-household terminal T1b).
The base unit 1 includes a microphone 10a, a speaker 10b, and a 2-wire to 4-wire conversion circuit, and performs signal processing on an audio signal output from the microphone 10a and outputs it to demultiplexing circuits 16a and 16c described later. The audio signals input from the circuits 16a and 16c are signal-processed to generate sound from the speaker 10b, and further, control signals are transmitted by the FSK method between the sub-master units 2a to 2n, the camera slave unit 4, and the master unit 1 of another household. And a control / sound modulation / demodulation circuit 11 for transmitting the sound.

  The master unit 1 also includes a monitor 12 (video display means) made up of a liquid crystal display, for example, and a video modulation / demodulation circuit 13 (video demodulation means) for demodulating a video signal input from a demultiplexing circuit 16b described later and displaying it on the monitor 12. And an operation unit 14 for performing various operations (operation for responding to a call signal, operation for displaying an image of a desired door phone sub unit 3, operation for calling the sub-master units 2a... 2n), and a signal line Ls1. A call signal receiving circuit 15 for receiving a call signal from the doorphone slave unit 3 or the camera slave unit 4 by monitoring the line voltage of the signal, and a control unit 17 for performing overall operation control using a microcomputer as a main component. I have.

  Here, although the master unit 1 has three sets of slave unit connection terminals T1, it has only one video modulation / demodulation circuit 13 for receiving and processing video signals, so that collision between video signals is avoided. Therefore, the time-division multiplex transmission method is employed, and the doorphone slave unit 3, the camera slave unit 4, and the master unit 1 of another household are individually set in a plurality of time slots defined by the control signal transmitted from the control unit 17. Allocation, door phone slave unit 3, camera slave unit 4 and parent device 1 of another household each transmit a video signal in a time slot assigned to the own device (own device), and in video modulation / demodulation circuit 13 of parent device 1 The original video is reconstructed from the video signal received and demodulated at each time slot and displayed on the monitor 12. The details of time division multiplex transmission are well known in the art and will not be described here.

  The base unit 1 also includes a plurality of demultiplexing circuits 16 (16a, 16b, 16c, 16d). The demultiplexing circuit 16a frequency-multiplexes the audio signal and control signal input from the control / audio modulation / demodulation circuit 11 with each other. In addition to outputting to the signal lines Ls 1 and Ls 3, the audio signal is separated from the multiplexed signal input via the signal lines Ls 1 and Ls 3 and output to the control / audio modulation / demodulation circuit 11. The demultiplexing circuit 16 b separates the video signal from the multiplexed signal input via the signal lines Ls 1 and Ls 3 and outputs the video signal to the video modulation / demodulation circuit 13. The demultiplexing circuit 16c frequency-multiplexes the audio signal and control signal input from the control / audio modulation / demodulation circuit 11 and outputs them to the signal line Ls2, and also input from the sub-master units 2a to 2n via the signal line Ls2. The audio signal and the control signal are separated from the multiplexed signal and output to the control / audio modulation / demodulation circuit 11. The demultiplexing circuit 16d frequency-multiplexes the video signal separated by the demultiplexing circuit 16b again, and outputs it to the signal line Ls2.

  The master unit 1 is connected to the two-household terminal T1b to which the master unit 1 of another household is connected and the slave switch SW1 connected between the demultiplexing circuits 16a and 16b, the doorphone slave unit 3, and the camera slave unit 4. A signal switching circuit 18 including a child device switch SW2 connected between the child device connection terminal T1a and the demultiplexing circuits 16a and 16b is provided. The control unit 17 transmits / receives signals to / from the parent device 1 of another household, or the two-household mode that enables transmission / reception of signals to / from the parent device 1 of other households according to the operation of the operation unit 14. It operates as one of the independent household modes to be cut off, and the slave switches SW1 and SW2 of the signal switching circuit 18 are operated according to the set operation mode. That is, the control unit 17 and the operation unit 14 constitute a communication mode switching unit.

  Here, the handset switches SW1 and SW2 are turned on regardless of the mode in order to exchange signals with the handset of the household (the doorphone handset 3 and the camera handset 4) and the base unit 1 of another household. However, in the independent household mode, when there is a doorphone call from the doorphone sub unit 3 of the own household and an environmental change detection input by the camera sub unit 4, the sub unit switch SW1 determines whether the call is ended by the control unit 17 or for a predetermined time. It is turned off until it elapses, and the input from the master unit 1 of another household is blocked. Further, in the two-household mode, when there is a doorphone call from the doorphone slave unit 3 of another household and an environmental change detection input by the camera slave unit 4, the slave unit switch SW2 determines whether the call is ended by the control unit 17 for a predetermined time. It is turned off until it elapses, and the input from the doorphone sub unit 3 and the camera sub unit 4 of the household is cut off.

  The intercom system of the present embodiment has the above-described configuration, and the operation of this intercom system will be described based on the state transition diagrams of FIGS. First, the operation when the master unit 1 of each household A1, A2 is switched to the independent household mode according to the operation of the operation unit 14 will be described based on FIG. In the initial state, the sub switches SW1 and SW2 are both on.

  When the householder of the parent household A1 performs an operation of switching the operation mode to the independent household mode using the operation unit 14 of the parent device 1 (processing S1), the control unit 17 of the parent device 1 receives an operation input from the operation unit 14. Based on this, the operation mode is switched to the independent household mode (processing S2). Also, in the child household A2, it is assumed that the operation mode of the parent device 1 is switched to the independent household mode (processing S3). Here, since handset switch SW1 is in the on state, control signals can be exchanged with base unit 1 in other households, and handset switch SW2 is also in the on state, so door phone handset 3 and camera The input from the sub unit 4 can be detected.

  Thereafter, when there is a visitor in the child household A2, and the visitor presses the call button 3a of the doorphone slave unit 3 (processing S4), the doorphone slave unit 3 sets the line voltage of the signal line Ls1 to be lower than the standby power supply state. The call signal is transmitted to the base unit 1 by reducing the voltage to a low voltage (step S5).

  In the main unit 1 of the child household A2, the call signal receiving circuit 15 detects the call signal by monitoring the line voltage of the signal line Ls1, and when the call signal is received and outputted to the control unit 17, the control unit 17 turns off the handset switch SW1 to cut off transmission / reception of signals (video signal, audio signal, control signal) between other households (processing S6), and the control unit 17 waits for the power supply voltage to the signal line Ls1. The power supply state is shifted to the operation power supply state, and the camera is activated by the doorphone slave unit 3. At this time, the control unit 17 causes the control / sound modulation / demodulation circuit 11 to ring the calling signal from the speaker 10b and to output a control signal for ringing the calling signal to the demultiplexing circuit 16c so that the control signal is frequency-multiplexed. Thus, the ringing tone is also sounded from the secondary master units 2a to 2n. The control unit 17 outputs a control signal for assigning time slots to the doorphone sub unit 3 and the camera sub unit 4 from the control / sound modulation / demodulation circuit 11, and the demultiplexing circuit 16a multiplexes and transmits the control signal. Synchronization is established with the intercom unit 3 (processing S7). When the intercom unit 3 returns a video signal in the time slot assigned to the intercom unit 3 (processing S8), it is separated by the demultiplexing circuit 16b. The video modulation / demodulation circuit 13 demodulates the video signal to reconstruct the original video, whereby the video of the slave unit is displayed on the monitor 12.

  Further, the video signal separated by the demultiplexing circuit 16b of the master unit 1 is sent to the demultiplexing circuit 16d, multiplexed again by the demultiplexing circuit 16d, and output to the secondary master units 2a to 2n. It is possible to display the image of the slave unit on the ~ 2n monitors (processing S9). After that, when the response button is pressed on the master unit 1 or the sub master units 2a to 2n, a communication path is formed between the master unit 1 or the sub master units 2a to 2n and the doorphone slave unit 3, and the intercom call is made. Done. When the call between the parent device 1 or the sub-parent devices 2a to 2n and the doorphone child device 3 is finished (processing S10), the control unit 17 turns on the child device switch SW1, and the parent of each household A1, A2 Control signals can be transmitted and received between the machines 1 (step S11).

  In addition, the process (process S12-S18) when there is a visitor in the parent household A1 and makes a doorphone call between the doorphone cordless handset 3 and the parent device 1 of the parent household A1 is the above-described call processing in the child household A2. Since it is the same as (Processes S4 to S11), detailed description is omitted.

  As described above, in this system, when there is no call from the doorphone sub unit 3 and no change in the environment detected by the camera sub unit 4 during operation in the independent household mode, the sub unit switch SW1 is in an on state. Control signals can be exchanged between the master units 1, and if a change in environment is detected by the door phone sub unit 3 of the own household or the camera sub unit 4 during operation in the independent household mode, Since the control unit 17 turns off the handset switch SW1, it is possible to prevent the video taken by the doorphone handset 3 or the camera handset 4 of the own household from being output to the base unit 1 of another household, and privacy between households Can be secured.

  Next, the operation when the master unit 1 of each household A1, A2 is switched to the two-household mode will be described with reference to FIG. In the initial state, the sub switches SW1 and SW2 are both on.

  When the householder of the parent household A1 performs an operation of switching the operation mode to the two-household mode using the operation unit 14 of the parent device 1 (processing S21), the control unit 17 of the parent device 1 receives an operation input from the operation unit 14. Based on this, the operation mode of the own device is switched to the two-household mode (processing S22). Further, the master unit 1 of the parent household A1 outputs a control signal (switching signal) for switching the operation mode to the two-household mode from the control / sound modulation / demodulation circuit 11 to the demultiplexing circuit 16a. Multiplexed and output to the parent device 1 of the child household A2 (processing S23). In the parent device 1 of the child household A2, the demultiplexing circuit 16a separates the control signal from the multiplexed signal transmitted from the parent household A1 and outputs it to the control / sound modulation / demodulation circuit 11. 17 switches the operation mode to the two-household mode (processing S24). Here, since handset switch SW1 is in the on state, control signals can be exchanged with base unit 1 in other households, and handset switch SW2 is also in the on state, so door phone handset 3 and camera The input from the sub unit 4 can be detected.

  In this state, when there is a visitor in the parent household A1, and the visitor presses the call button 3a of the door phone sub unit 3 (processing S25), the door phone sub unit 3 changes the line voltage of the signal line Ls1 from the standby power supply state. The call signal is transmitted to the base unit 1 by lowering the voltage to a lower voltage (step S26). In the base unit 1, the call signal receiving circuit 15 detects the call signal by monitoring the line voltage of the signal line Ls1, and when the call signal is received and output to the control unit 17, the control unit 17 outputs the signal line. The power supply voltage to Ls1 is shifted from the standby power supply state to the operation power supply state, the camera is started by the doorphone slave unit 3, and the calling signal is sounded from the speaker 10b by the control / sound modulation / demodulation circuit 11. In addition, the control unit 17 outputs a control signal for ringing the secondary master units 2a to 2n to the demultiplexing circuit 16c, frequency-multiplexes by the demultiplexing circuit 16c, and transmits it to the secondary master units 2a to 2n. Ringing sounds are generated from the master units 2a to 2n. The control unit 17 outputs a control signal for calling the master unit 1 of the child household A2 from the control / voice modulation / demodulation circuit 11 to the demultiplexing circuit 16a, and the demultiplexing circuit 16a frequency-multiplexes the control signal. The data is transmitted to the parent device 1 of the child household A2 via the two household terminal T1b and the signal line Ls3 (processing S27). The demultiplexing circuit 16a of the parent device A2 in the child household separates the control signal from the multiplexed signal and outputs it to the control / sound modulation / demodulation circuit 11. When the control unit 17 receives the control signal, the signal switching circuit 18 The device connection switch SW2 is turned off, and the input from the child device (door phone child device 3 and camera child device 4) of the child household A2 is cut off (processing S28). Further, in the parent device 1 of the child household A2, the control / sound modulation / demodulation circuit 11 rings the calling signal from the speaker 10b, and outputs a control signal for ringing the sub-parent devices 2a to 2n to the demultiplexing circuit 16c, The frequency is multiplexed by the demultiplexing circuit 16c and transmitted to the secondary master units 2a to 2n, and a ringing tone is generated from the secondary master units 2a to 2n (processing S29).

  Thereafter, the control unit 17 of the parent device 1 of the parent household A1 outputs a control signal for assigning a time slot to the door phone sub unit 3 and the camera sub unit 4 from the control / sound modulation / demodulation circuit 11, and this control signal is output to the demultiplexing circuit 16a. Is multiplexed and transmitted to synchronize with the intercom unit 3 (processing S30), and when the intercom unit 3 returns a video signal in the time slot assigned to the intercom unit 3 (processing S31). The video signal separated by the demultiplexing circuit 16b is input to the video modulation / demodulation circuit 13, and the video modulation / demodulation circuit 13 demodulates the video signal to reconstruct the original video, thereby displaying the video of the slave unit on the monitor 12. Is done. The video signal separated by the demultiplexing circuit 16b of the master unit 1 is input to the demultiplexing circuit 16d, multiplexed again by the demultiplexing circuit 16d, and then sub-master unit 2a via the sub-master unit connection terminal T2. Sent to ~ 2n. Further, the video signal transmitted by the doorphone slave unit 3 is also transmitted to the parent device 1 of the child household A2 via the child device switch SW1 and the signal line Ls3 (processing S32), and the demultiplexing of the parent device 1 of the child household A2 is performed. The video signal is separated by the circuit 16b, and the video modulation / demodulation circuit 13 demodulates the video signal to reconstruct the original video, so that the video taken by the doorphone sub unit 3 of the parent household A1 becomes the parent of the child household A2. Displayed on the monitor 12 of the machine 1. The video signal separated by the demultiplexing circuit 16b of the parent device 1 of the child household A2 is input to the demultiplexing circuit 16d and multiplexed again by the demultiplexing circuit 16d, and then via the sub-master device connection terminal T2. Is sent to the sub-parent devices 2a to 2n of the child household A2 (processing S33). Thus, the image of the child device (the door phone child device 3 or the camera child device 4) can be displayed on the parent device 1 and the sub-parent devices 2a to 2n of the parent household A1, and the parent device 1 and the child of the child household A2 can be displayed. Also in the secondary master units 2a to 2n of the household A2, it is possible to display an image of the slave unit (the door phone slave unit 3 or the camera slave unit 4) of the parent household A1.

  Here, when the householder of the child household A2 hears a ringing tone and presses the response button of the sub-master unit 2a, the parent household is connected between the doorphone sub-unit 3 of the parent household A1 and the sub-master unit 2a of the child household A2. A communication path is formed via the parent device 1 of A1 and the parent device 1 of the child household A2, and a doorphone call is performed between the doorphone child device 3 and the sub-main device 2a of the child household A2 (processing S34).

  Thereafter, when a call termination operation is performed on the secondary master unit 2a of the child household A2 (processing S35), the secondary master unit 2a terminates the call and shifts to a standby state. Then, a control signal for notifying the end of the call is output (step S36). In the master unit 1 of the child household A2, the control signal output from the sub master unit 2a is input to the demultiplexing circuit 16c via the sub master unit connection terminal T2, and is frequency-separated by the demultiplexing circuit 16c. The signal is demodulated by the sound modulation / demodulation circuit 11 and input to the control unit 17. Upon completion of the extension call, the control unit 17 turns on the handset switch SW2 (processing S37), and enters a standby state in preparation for input from the handset (doorphone handset 3 and camera handset 4) of the child household A2. Transition. The control unit 17 of the parent device 1 of the child household A2 outputs a control signal for notifying the end of the call from the control / voice modulation / demodulation circuit 11, and the demultiplexing circuit 16a multiplexes the control signal so that the two-household terminal T1b is connected. To the parent device 1 of the parent household A1 (step S38). The control signal input to the two-household terminal T1b of the parent household A1 is frequency-separated by the demultiplexing circuit 16a of the parent device 1, and then demodulated by the control / voice modulation / demodulation circuit 11 and input to the control unit 17. In response to the extension call termination process, the control unit 17 shifts to the standby state and switches the power supply state to the doorphone slave unit 3 to the standby power supply state (step S39). To stop and enter standby mode.

  As described above, in this system, the master unit 1 of each household A1, A2 also uses the terminal for connecting the master unit 1 of another household as the slave unit connection terminal T1, and in the master unit 1 in the two-household mode, The video signal input from the doorphone sub unit 3 or the camera sub unit 4 of the same household is output to the sub master units 2a to 2n of the own household via the sub master unit connection terminals 2a to 2n, and the sub unit connection terminal T1. Since the video signal is output to the master unit 1 of another household, the video signal can be output to the master unit 1 and the sub master unit 2a to 2n of the other household or the sub master unit 2a to 2n of the own household. Become.

(Embodiment 2)
The intercom system according to the present embodiment will be described with reference to FIGS. In the intercom system according to the present embodiment, one sub-master connection terminal T2b of the plurality of sub-master connection terminals T2 (T2a, T2b) is connected to the two-household terminal T1b of the master unit 1 of another household. The sub-master unit 2a to 2n is connected to the sub-master unit except the sub-master unit connection terminal T2 except for the other-household connection terminal T2b. It is connected to the terminal T2a. The other household connection terminal T2b is connected to the two household terminal T1b of the parent device 1 of the other household via the signal line Ls3, and an opening / closing means is provided between the other household connection terminal T2b and the demultiplexing circuits 16c and 16d. The extension switch SW3 is provided, and the on / off of the extension switch SW3 is switched by the control unit 17. The master unit 1 also includes an amplifier 20a between the demultiplexing circuit 16b and the video modulation / demodulation circuit 13 that amplifies the video signal separated by the demultiplexing circuit 16b and inputs the amplified video signal to the video modulation / demodulation circuit 13. An amplifier 20b that further amplifies the video signal amplified by the amplifier 20a and inputs it to the demultiplexing circuit 16d is provided between 16b and the demultiplexing circuit 16d. Except for this point, the configuration is the same as that of the first embodiment, so the common components are denoted by the same reference numerals and description thereof is omitted.

  The control unit 17 transmits / receives signals to / from the parent device 1 of another household, or the two-household mode that enables transmission / reception of signals to / from the parent device 1 of other households according to the operation of the operation unit 14. It operates as one of the independent household modes to be shut off, and the slave switches SW1 and SW2 and the extension switch SW3 of the signal switching circuit 18 are operated according to the set operation mode. That is, the control unit 17 and the operation unit 14 constitute a communication mode switching unit.

  Here, in the independent household mode, the initial values of the switches SW1, SW2, and SW3 are off, on, and on for one household (for example, the parent household A1), respectively, and for the other household (for example, the child household A2). They are on, on, and off, respectively. As a result, when the control / sound modulation / demodulation circuit 11 transmits a control signal by the control unit 17 of the master unit 1 of the parent household A1, the demultiplexing circuit 16c frequency-multiplexes and outputs it to the transmission line Ls3 via the extension switch SW3. . When the multiplexed signal is input from the transmission line Ls3, the parent device 1 of the child household A2 separates the control signal by the demultiplexing circuit 16a and transmits it to the control unit 17 via the control / sound modulation / demodulation circuit 11. On the other hand, when the control / sound modulation / demodulation circuit 11 transmits a control signal by the control unit 17 of the master unit 1 of the child household A2, the demultiplexing circuit 16a performs frequency multiplexing and outputs it to the transmission line Ls3 via the slave switch SW1. To do. When the multiplexed signal is input from the transmission line Ls3, the parent device 1 of the parent household A1 separates the control signal by the demultiplexing circuit 16c and transmits it to the control unit 17 via the control / sound modulation / demodulation circuit 11. In this way, control signals can be exchanged between households, but if there is a doorphone call from the doorphone sub unit 3 of the household or an environment change detection input by the camera sub unit 4, the sub unit switch SW1 and the extension switch SW3 is turned off until the call ends by the control unit 17 or until a predetermined time elapses, and the signal input from the master unit 1 of another household is blocked.

  In addition, when transitioning to the two-household mode, assuming that the household on the side that has transitioned to the two-household mode by the operation of the householder is the primary household and the household on the side that has transitioned to the two-household mode by the control signal from the primary household is the secondary household, The switches SW1, SW2, and SW3 are set so that the main household is turned off, on, on, and the slave household is turned on, on, and off, respectively. That is, when the parent household A1 is the main household, the settings of the switches SW1, SW2, and SW3 are not changed, and when the child household A2 is the main household, the switches of the parent household A1 and the child household A2 are changed. The settings of SW1, SW2, and SW3 are switched, and the operations of the child household A2 and the parent household A1 are switched. As a result, when there is no doorphone call from the doorphone sub-unit 3 or an environment change detection input by the camera sub-unit 4, the control signal and the paging signal can be exchanged through the same path as in the independent household mode. Further, when there is a doorphone call from the doorphone slave unit 3 of another household or an environment change detection input by the camera slave unit 4, the slave unit switch SW2 is turned off by the control unit 17 until the call is finished or a predetermined time elapses. The input from the doorphone slave unit 3 and the camera slave unit 4 of the household is cut off.

  The intercom system of the present embodiment has the above-described configuration, and the operation of this intercom system will be described based on the state transition diagrams of FIGS. First, the operation when the master unit 1 of each household A1, A2 is switched to the independent household mode according to the operation of the operation unit 14 will be described based on FIG. In the initial state, the switches SW1, SW2, and SW3 of the parent household A1 are off, on, and on, respectively, and the switches SW1, SW2, and SW3 of the child household A2 are on, on, and off, respectively.

  When the householder of the parent household A1 performs an operation of switching the operation mode to the independent household mode using the operation unit 14 of the parent device 1 (processing S41), the control unit 17 of the parent device 1 receives an operation input from the operation unit 14. Based on this, the operation mode is switched to the independent household mode (processing S42). Also, in the child household A2, it is assumed that the operation mode of the parent device 1 is switched to the independent household mode (processing S43). Here, since the extension switch SW3 of the parent household A1 is in the on state and the child device switch A1 of the child household A2 is also in the on state, the control signal can be exchanged with the parent device 1 of the other household as described above. In addition, since the handset switch SW2 of both households A1 and A2 is also in the ON state, it is possible to detect input from the doorphone handset 3 and the camera handset 4 of the own household.

  Thereafter, when there is a visitor in the child household A2, and the visitor presses the call button 3a of the doorphone slave unit 3 (processing S44), the doorphone slave unit 3 sets the line voltage of the signal line Ls1 to be higher than the standby power supply state. The call signal is transmitted to the base unit 1 by lowering the voltage to a low voltage (process S45).

  In base unit 1, call signal receiving circuit 15 detects the call signal by monitoring the line voltage of signal line Ls 1, and when receiving the call signal and outputting it to control unit 17, control unit 17 causes slave unit to be detected. The switch SW1 and the extension switch SW3 are turned off to cut off transmission / reception of signals (video signal, audio signal, control signal) between other households (processing S46), and the control unit 17 waits for the supply voltage to the signal line Ls1. The power supply state is shifted to the operation power supply state, and the camera is activated by the doorphone slave unit 3. At this time, the control unit 17 causes the control / sound modulation / demodulation circuit 11 to ring the calling signal from the speaker 10b and to output a control signal for ringing the calling signal to the demultiplexing circuit 16c so that the control signal is frequency-multiplexed. Thus, the ringing tone is also sounded from the secondary master units 2a to 2n. The control unit 17 outputs a control signal for assigning time slots to the doorphone sub unit 3 and the camera sub unit 4 from the control / sound modulation / demodulation circuit 11, and the demultiplexing circuit 16a multiplexes and transmits the control signal. Synchronization is established with the intercom unit 3 (process S47), and when the intercom unit 3 returns a video signal in the time slot assigned to the self unit (process S48), it is separated by the demultiplexing circuit 16b. The video modulation / demodulation circuit 13 demodulates the video signal to reconstruct the original video, whereby the video of the slave unit is displayed on the monitor 12.

  Further, the video signal separated by the demultiplexing circuit 16b of the master unit 1 is sent to the demultiplexing circuit 16d, multiplexed again by the demultiplexing circuit 16d, and output to the secondary master units 2a to 2n. It is possible to display the image of the slave unit on the ~ 2n monitors (process S49). After that, when the response button is pressed on the master unit 1 or the sub master units 2a to 2n, a communication path is formed between the master unit 1 or the sub master units 2a to 2n and the doorphone slave unit 3, and the intercom call is made. Done. Then, when the call between the master unit 1 or the sub master units 2a to 2n and the doorphone cordless handset 3 is finished (process S50), the control unit 17 returns the cordless handset switch SW1 and the extension switch 3 to the initial state, Control signals can be transmitted and received between the master units 1 of A1 and A2 (processing S51).

  In addition, the process (process S52-S58) when there is a visitor in the parent household A1 and makes a doorphone call between the doorphone cordless handset 3 and the parent machine 1 of the parent household A1 is the above-described call processing in the child household A2. Since it is the same as (Processes S44 to S51), detailed description is omitted.

  As described above, in this system, when there is no call from the doorphone slave unit 3 and no change in the environment detected by the camera slave unit 4 during operation in the independent household mode, control signals are exchanged between the master units 1 of each household. If it is possible to detect a change in the environment by the door phone sub unit 3 of the household or the camera sub unit 4 while operating in the independent household mode, the control unit 17 of the main unit 1 controls the sub unit switch SW1 and the extension switch. Since the SW 3 is turned off, it is possible to prevent the video taken by the doorphone sub unit 3 or the camera sub unit 4 of the own household from being output to the main unit 1 of another household, and to ensure privacy between households.

  Next, the operation when the master unit 1 of each household A1, A2 is switched to the two-household mode will be described with reference to FIG. In the initial state, the sub switches SW1 and SW2 are both on. In the initial state, the switches SW1, SW2, and SW3 of the parent household A1 are off, on, and on, respectively, and the switches SW1, SW2, and SW3 of the child household A2 are on, on, and off, respectively.

  When the householder of the child household A2 performs an operation of switching the operation mode to the two-household mode using the operation unit 14 of the parent device 1 (processing S61), the control unit 17 of the parent device 1 receives an operation input from the operation unit 14 Based on this, the operation mode of the own device is switched to the two-household mode (processing S62). The master unit 1 of the child household A2 outputs a control signal (switching signal) for switching the operation mode to the two-household mode from the control / sound modulation / demodulation circuit 11 to the demultiplexing circuit 16a. Multiplexed and output to the parent device 1 of the parent household A1 via the two-household terminal T1b (processing S63). In the parent device 1 of the parent household A1, the demultiplexing circuit 16c separates the control signal from the multiplexed signal input via the other household connection terminal T2b and outputs it to the control / sound modulation / demodulation circuit 11. This control signal In response to this, the control unit 17 switches the operation mode to the two-household mode, and turns on the slave switch SW1 and turns off the extension switch SW3 (processing S64). Thereafter, in the parent device 1 of the child household A2, the control unit 17 turns off the child device switch SW1 and turns on the extension switch SW3 (processing S65). Here, since the extension switch SW3 of the parent device 1 of the child household A2 is in the ON state and the child device switch SW1 of the parent device 1 of the parent household A1 is also in the ON state, the control signal of the parent device 1 of the other household Can give and receive.

  In this state, there is a visitor in the child household A2, and when the visitor presses the call button 3a of the doorphone slave unit 3 (processing S66), the doorphone slave unit 3 changes the line voltage of the signal line Ls1 from the standby power supply state. The call signal is transmitted to the base unit 1 by lowering the voltage to a lower voltage (step S67). In the base unit 1, the call signal receiving circuit 15 detects the call signal by monitoring the line voltage of the signal line Ls1, and when the call signal is received and output to the control unit 17, the control unit 17 outputs the signal line. The power supply voltage to Ls1 is shifted from the standby power supply state to the operation power supply state, the camera is started by the doorphone slave unit 3, and the calling signal is sounded from the speaker 10b by the control / sound modulation / demodulation circuit 11. In addition, the control unit 17 outputs a control signal for ringing the secondary master units 2a to 2n to the demultiplexing circuit 16c, frequency-multiplexes by the demultiplexing circuit 16c, and transmits it to the secondary master units 2a to 2n. Ringing sounds are generated from the master units 2a to 2n. Further, the control unit 17 outputs a control signal for calling the parent device 1 of the parent household A1 from the control / voice modulation / demodulation circuit 11 to the demultiplexing circuit 16c, and the demultiplexing circuit 16c frequency-multiplexes the control signal. It is transmitted to the parent device 1 of the parent household A1 via the other household connection terminal T2b and the signal line Ls3 (processing S68). When the demultiplexing circuit 16a of the parent device 1 of the parent household A1 separates the control signal from the multiplexed signal and outputs it to the control / sound modulation / demodulation circuit 11, the control unit 17 receives this control signal. The handset connection switch SW2 is turned off, and the input from the handset (the door phone handset 3 and the camera handset 4) of the parent household A1 is cut off (processing S69). Further, in the parent device 1 of the parent household A1, the control / voice modulation / demodulation circuit 11 causes the speaker 10b to ring, and the demultiplexing circuit 16c outputs a control signal for ringing the sub-parent devices 2a to 2n, The frequency is multiplexed by the demultiplexing circuit 16c and transmitted to the secondary master units 2a to 2n, and ringing sounds are generated from the secondary master units 2a to 2n (processing S70).

  Thereafter, the control unit 17 of the master unit 1 of the child household A2 outputs a control signal for assigning a time slot to the door phone slave unit 3 and the camera slave unit 4 from the control / sound modulation / demodulation circuit 11, and this control signal is demultiplexed by the demultiplexing circuit 16a. Is multiplexed and transmitted to synchronize with the intercom unit 3 (processing S71), and when the intercom unit 3 returns a video signal in the time slot allocated to the own unit (processing S72). The video signal separated by the demultiplexing circuit 16b is input to the video modulation / demodulation circuit 13, and the video modulation / demodulation circuit 13 demodulates the video signal to reconstruct the original video, thereby displaying the video of the slave unit on the monitor 12. Is done. The video signal separated by the demultiplexing circuit 16b of the base unit 1 is amplified by the amplifier 20a and the amplifier 20b, input to the demultiplexing circuit 16d, and then multiplexed again by the demultiplexing circuit 16d. It is sent to the secondary master units 2a to 2n via the connection terminal T2a and sent to the master unit 1 of the parent household A1 via the other household connection terminal T2b (processing S73). Then, the video signal is separated by the demultiplexing circuit 16b of the parent device 1 of the parent household A1, and the video modulation / demodulation circuit 13 demodulates the video signal to reconstruct the original video, whereby the intercom 3 of the child household A2 is reconstructed. Is displayed on the monitor 12 of the parent device 1 of the parent household A1. The video signal separated by the demultiplexing circuit 16b of the parent device 1 of the parent household A1 is amplified by the amplifier 20a and the amplifier 20b, input to the demultiplexing circuit 16d, and then multiplexed again by the demultiplexing circuit 16d. Further, it is sent to the secondary master units 2a to 2n of the parent household A1 via the secondary master unit connection terminal T2 (processing S74). Thus, the image of the child device (door phone child device 3 or camera child device 4) can be displayed on the parent device 1 and the sub-parent devices 2a to 2n of the child household A2, and the parent device 1 and the child of the parent household A1. Also in the secondary master units 2a to 2n of the household A2, it is possible to display an image of the slave unit (the door phone slave unit 3 or the camera slave unit 4) of the slave household A2.

  Here, when the householder of the parent household A1 hears a ringing tone and presses the response button of the secondary parent device 2a, the child household is connected between the doorphone cordless handset 3 of the child household A2 and the secondary parent device 2a of the parent household A1. A communication path is formed via the parent device 1 of the A2 and the parent device 1 of the parent household A1, and a doorphone call is performed between the doorphone child device 3 of the child household A2 and the sub-parent device 2a of the parent household A1 ( Process S75).

  Thereafter, when a call termination operation is performed on the sub-master 2a of the parent household A1 (processing S76), the sub-master 2a terminates the call and shifts to a standby state. Then, a control signal for notifying the end of the call is output (processing S77). In the master unit 1 of the parent household A1, the control signal output from the sub master unit 2a is input to the demultiplexing circuit 16c via the sub master unit connection terminal T2a and is frequency-separated by the demultiplexing circuit 16c. The signal is demodulated by the sound modulation / demodulation circuit 11 and input to the control unit 17. Upon completion of the extension call, the control unit 17 turns on the handset switch SW2 (processing S78) and enters a standby state in preparation for input from the handset (doorphone handset 3 and camera handset 4) of the parent household A1. Transition. The control unit 17 of the master unit 1 of the parent household A1 outputs a control signal for notifying the end of the call from the control / voice modulation / demodulation circuit 11, and the demultiplexing circuit 16a multiplexes the control signal so that the two household terminal T1b is connected. To the parent device 1 of the child household A2 (step S79). The control signal input to the other household connection terminal T2b of the child household A2 is frequency-separated by the demultiplexing circuit 16c of the base unit 1, and then demodulated by the control / sound modulation / demodulation circuit 11 and input to the control unit 17. In response to the extension call termination process, the control unit 17 shifts to the standby state and switches the power supply state to the doorphone slave unit 3 to the standby power supply state (step S80). Stop the camera and enter standby mode.

  As described above, in this system, the master unit 1 of each household A1, A2 also uses the terminal for connecting the master unit 1 of another household as the slave unit connection terminal T1, and in the master unit 1 in the two-household mode, The video signal input from the doorphone sub unit 3 or the camera sub unit 4 of the same household is output to the sub master units 2a to 2n of the own household via the sub master unit connection terminals 2a to 2n, and the sub unit connection terminal T1. Since the video signal is output to the master unit 1 of another household, the video signal can be output to the master unit 1 and the sub master unit 2a to 2n of the other household or the sub master unit 2a to 2n of the own household. Become.

  The video signals from the doorphone slave unit 3 and the camera slave unit 4 of the household are separated from the multiplexed signal by the demultiplexing circuit 16B provided in the master unit 1, and amplified by the amplifier 20a and the amplifier 20b. After that, since it is multiplexed again by the demultiplexing circuit 16d and transmitted to other households, the wiring distance between the households A1 and A2 can be increased.

1 is a schematic block diagram of an intercom system according to Embodiment 1. FIG. It is a system block diagram same as the above. It is a state transition diagram explaining operation | movement in the independent household mode same as the above. It is a state transition diagram explaining operation | movement in 2 household mode same as the above. 6 is a schematic block diagram of an intercom system according to Embodiment 2. FIG. It is a system block diagram same as the above. It is a state transition diagram explaining operation | movement in the independent household mode same as the above. It is a state transition diagram explaining operation | movement in 2 household mode same as the above. It is a system block diagram of the conventional intercom system for two-family houses. It is a schematic block diagram same as the above.

Explanation of symbols

1 Interphone master unit 2a to 2n Interphone secondary master unit 3 Door phone slave unit (door phone with camera)
4 Camera unit 10a Microphone (calling means)
10b Speaker (calling means)
11 Control and voice modulation / demodulation circuit (calling means)
12 Monitor (Video display means)
13. Video modulation / demodulation circuit (video demodulation means)
18 Signal switching circuit (signal switching means)
A1 Parent household A2 Child household T1a Child device connection terminal T1b Child device connection terminal (two household terminals)
T2 Sub-master connection terminal

Claims (4)

An intercom system that is installed in a two-family house to make an extension call within and between households,
Each household has a handset including a door phone with a camera installed outside the house, a calling means for making a call between the handset and a video display means for displaying a video taken by the handset. The interphone main unit installed and installed in the home, and a call means for making a call between the interphone main unit and the interphone main unit connected to the interphone main unit and the interphone main unit are photographed by the sub unit And interphone sub-master device provided in the house with video display means for displaying the video, respectively,
Interphone master unit of each household demodulates video signals input from multiple slave unit connection terminals to which each slave unit is connected, secondary master unit connection terminal to which interphone secondary master unit is connected, and slave unit connection terminal Video demodulating means for displaying on the video display means,
One of the plurality of slave unit connection terminals is used as a two-household terminal to which an interphone master unit of another household is connected. Between the slave unit connection terminal and the second household terminal and the video demodulation means, An interphone system comprising signal switching means for selecting any one of a signal from a telephone or a signal from an interphone master unit of another household and inputting the selected signal to a video demodulation means and a call means. Either the two-household mode that enables the interphone master unit to exchange signals with the interphone master unit of other households, or the independent household mode that blocks signal transmission with the interphone master units of other households. Communication mode switching means for switching between
In the two-household mode, when there is a call from a slave unit of another household, the communication mode switching unit is configured to input the signal from the interphone master unit of the other household to the video demodulating unit and the calling unit. Switch
In the independent household mode, when there is a call from the slave unit of the household, the communication mode switching unit switches the signal switching unit so that a signal from the slave unit of the household is input to the video demodulation unit and the call unit. The intercom system according to claim 1.   The interphone master unit includes an amplifier that amplifies the video signal input to the video demodulation means and outputs the amplified signal to the secondary master unit connection terminal. 2. An opening / closing means for turning on / off an electric circuit between the sub-master connection terminal connected to the two household terminals of another household and the video demodulating means is provided. Intercom system. Either the two-household mode that enables the interphone master unit to exchange signals with the interphone master unit of other households, or the independent household mode that blocks signal transmission with the interphone master units of other households. Communication mode switching means for switching between
In the independent household mode, when there is a call from the slave unit of the household, the communication mode switching unit switches the signal switching unit so that a signal from the slave unit of the household is input to the video demodulation unit and the call unit. And turning off the opening and closing means,
In the two-household mode, the communication mode switching means of the interphone master that transmits the video signal of the slave unit of the own household to the interphone master of the other household turns on the opening / closing means, and the interphone master of the other household The communication mode switching means of the interphone master unit that receives and displays the transmitted video signal turns off the opening / closing means, and when there is a call from the slave unit of another household, the signal from the interphone master unit of the other household is 4. The intercom system according to claim 3, wherein the signal switching means is switched so as to be input to the video demodulation means and the call means.

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