JP2655728B2 - Apartment intercom - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an intercom for a dwelling house, and relates to a unit between a door provided in a common entrance or a caretaker room and a dwelling unit provided in each dwelling unit. It is suitable for use for making a telephone call.

[Prior Art] Conventional Example 1 FIG. 4 shows a schematic configuration of a conventional intercom with a television. When the visitor operates the call switch 24 provided on the entrance G, the resistance R ₁ is connected in parallel with the impedance Z ₁ , a call signal is transmitted to the dwelling unit J, and the ringing sound from the calling speaker 3 of the dwelling unit J. Sounds. When the resident responds by pressing the answer switch 4 to this ringing tone, the power line l ₁
Power is supplied to the television camera 21 provided at the entrance vessel G via, the video signal is transmitted to the dwelling unit J via a coaxial cable l _0, the video is displayed on the monitor television 1. The audio signals from the handset 2 of the dwelling unit J is transmitted to the front door unit G through the signal line l ₂ for call, voice resident is output from the speaker 22 via the audio transformers 29 of the entrance unit G You. On the other hand, the audio signal of the visitor input by the microphone 23 of the entrance unit G is the coupling capacitor 27 and audio amplifier 26, via the bridge circuit 28 and the audio transformers 29, dwelling unit J via the signal line l ₂ for call , And a voice signal of the visitor is output from the handset 2 of the dwelling unit J. As a result, a call is made between the visitor and the resident, and the resident can check the appearance of the visitor. Note that to enable notification to the entrance unit G is connected with much lamp 25 through the resistor R _2, the home of the abnormality through the emergency communication lines l ₄ in the front door side.

In this conventional example, in order to connect the dwelling unit J and the entrance unit G, a coaxial cable l ₀ for the transmission video signal, the power supply line l _1,
Call and call signal line l ₂ , ground line l ₃ and emergency call line
We are using a 4-core cable of l _4. Therefore, the wiring of the transmission line is complicated, and if, for example, only a 2-core or 4-core cable for intercom communication is installed at the time of installation, the wiring must be redone when an additional TV camera is installed. There was a problem.

Conventional Example 2 FIGS. 5 (a) and 5 (b) show a schematic configuration of another conventional example. This system is configured by combining a dwelling unit J having a monitor TV 1 installed in a dwelling unit and an entrance unit G having a television camera 21 installed at the entrance, both of which are dedicated to coaxial cable or the like. Are connected by a transmission line l. Power is supplied from the dwelling unit J side to the entrance unit G side, and video, audio and control signals are multiplex-transmitted to communicate necessary information.

More specifically, the dwelling unit J includes a power supply superimposing circuit 8 for supplying power to the entrance G, and an FM of a call signal transmitted in response to operation of the call switch 24 of the entrance G.
A ringing detection circuit 19 for demodulating the modulated wave, a ringing tone generating circuit 20 for amplifying the demodulated ringing sound and sounding the ringing sound from the ringing speaker 3, an audio modulation circuit 17 for FM modulating the audio signal, and a transmission from the entrance G. An audio demodulation circuit 13 for demodulating the FM-modulated signal and extracting an audio signal, a handset 2 having a microphone and a speaker for communication, audio amplifiers 14 and 15 constituting a communication line including the handset 2, and a sidetone prevention circuit 16, A video signal output circuit 11 for extracting a video signal transmitted from the entrance G and outputting the video signal to the monitor television 1 and a band pass filter 18 for outputting an FM modulation signal output from the audio modulation circuit 17.
And a FM demodulation signal sent from the entrance G through a band pass filter 12 and an audio demodulation circuit 13
To the video signal output circuit 11 via the video filter 10 and the balanced input / output circuit 9 for transmitting the supply voltage of the power supply superimposing circuit 8 to the front door G. Have. The voice modulation circuit 17 FM-modulates the transmission voice signal from the handset 2 and sends it out to the transmission line l through the balanced input / output circuit 9. It is configured to demodulate the FM modulation signal and output the sound of the entrance device G from the handset 2. The video signal transmitted from the entrance apparatus G is amplified by the video signal output circuit 11 through the video filter 10 from the balanced input / output circuit 9 and then output to the monitor television 1. The power supply superposition circuit 8 is provided with a short circuit protection circuit 6 and an open circuit detection circuit 7 for the transmission line. When the response switch 4 is operated, the control circuit 5 operates to activate the power supply superimposing circuit 8 and supply power to the entrance apparatus G.

On the other hand, the entrance apparatus G includes an audio demodulation circuit 38 for demodulating the FM modulation signal sent from the dwelling unit J to extract an audio signal, an audio modulation circuit 40 for modulating an audio signal from the microphone 23, and a call switch 24. A call signal generation circuit 43 that generates a call signal in response to an operation, an operation state determination circuit 42 that determines an operation state and enables generation of a call signal if not in a call state,
An FM modulation signal output from the audio modulation circuit 40 via the band-pass filter 41, an FM modulation signal output from the ringing signal generation circuit 43, and a video filter from the television camera 21.
A balanced input / output circuit that inputs a video signal output through 30 and a video signal output circuit 31, sends out a multiplex transmission signal to a transmission line l, and outputs an FM modulation signal to a voice demodulation circuit 38 via a band pass filter 37. 32, transmission line 1 and entrance G
A depolarizing circuit 33 for depolarizing the connection with the power supply and a power supply for the entrance apparatus G via the balanced input / output circuit 32 from the modulated signal transmitted from the dwelling unit J via the transmission line l. And a power supply separation circuit 34. The power supply voltage separated by the power supply separation circuit 34 is used as a camera power supply and a circuit power supply via a power supply switch circuit 35 and a shunt regulator 36. The audio modulation circuit 40 FM-modulates the audio signal input from the microphone 23 and amplified by the audio amplifier 26 and sends it to the dwelling unit J through the balanced input / output circuit 32. The FM modulation signal from 32 is demodulated, amplified by the audio amplifier 39, and the sound is output from the speaker 22.

In this intercom system, dwelling unit J and entrance unit G
Are connected by a pair of transmission lines 1 made of a coaxial cable or the like, and a video, audio, and other control signals necessary for information communication are multiplex-transmitted between the two via the transmission lines l. ing.

FIG. 6 shows a frequency division state of a signal transmitted via the transmission line 1 in the present system. As shown in the figure, the FM modulated wave of the audio signal sent from the dwelling unit J to the entrance unit G is transmitted at the first carrier frequency, and the FM modulated wave of the audio signal sent from the entrance unit G to the dwelling unit J is the It is transmitted at two carrier frequencies and the FM modulated wave of the calling signal is transmitted at the third carrier frequency. These are set to a frequency higher than the video signal frequency band of the TV camera transmitted at baseband to prevent interference. Have been. Note that a power supply voltage is superimposed as a DC component, and these are multiplex-transmitted via a dedicated transmission line l.

By the way, when such a system is used in an apartment house or the like having a large number of dwelling units, in order to make a call between a common entrance (or a management room) and one of a plurality of dwelling units,
It is necessary to switch a plurality of voice lines by some means. For example, a method is conceivable in which control is performed so that only the household unit during a call can transmit the frequency allocated for transmitting the audio signal. In this method, since each dwelling unit is always connected to the common entrance, it is necessary to use a dedicated branch or distributor in order to match the impedance of the transmission line. On the other hand, it is also possible to use a method in which only the selected dwelling unit is connected to the entrance unit and the other dwelling unit is separated from the entrance unit. In this system (see Japanese Patent Application No. 01-88678), a transmission line switch may be provided in place of the transmission line impedance matching branch or distributor. In this switch, a transmission line connected to the entrance unit and a transmission line connected to each of the plurality of dwelling units are connected, and any one of the dwelling units is switched to the entrance unit.

[Problems to be Solved by the Invention] However, when the above-described star-wiring switch is provided between the entrance and a plurality of dwelling units, since the installation locations of the dwelling units are dispersed, the switching unit is switched. There is a problem in that the wiring from the housing to each dwelling unit becomes longer, and the total wiring length becomes longer. Further, since a large number of transmission lines are concentrated on one switch, wiring is complicated, and there is a problem that wiring mistakes are likely to occur during construction.

The present invention has been made in view of such a point,
It is an object of the present invention to reduce the total length of a multi-unit dwelling intercom in which one of a plurality of dwelling units is selectively switched to an entrance unit, and to simplify wiring.

[Means for Solving the Problems] In the intercom for collective housing according to the present invention, in order to solve the above problems, as shown in FIG. 1 to FIG. _In an interphone that multiplexes and transmits at least an audio signal and a video signal among ₁ , J ₂ , J ₃ ,... Using a pair of transmission lines l, an input terminal 51 and a feed terminal 52
And a plurality of branching devices having at least one branching terminal 53
B ₁ , B ₂ , B ₃ , ... are cascade-connected such that the feed terminal is connected to the input terminal of another branch unit, and the input terminal of the cascade-connected first-stage branch unit is a transmission line connecting to the entrance apparatus. And the feed terminals of the cascade-connected last-stage branch unit are connected to the terminating means, and the branch terminals of the plurality of branch units are connected to the transmission lines connected to different dwelling units, respectively. The input terminal is connected to the terminal, and the input terminal of any one of the branching devices is switched to the branch terminal in response to a selection signal given from outside during a call, and is branched in response to the release signal given from outside when the call ends. controller C ₁ to switch connected to the terminal sends an input terminal of the vessel, C _2, C _3, ... and providing the selection signal or release signal provided to the controller to be multiplexed transmitted through the transmission line l It is a feature.

The terminating means connected to the feed terminal of the cascade-connected last-stage branch unit may be a dwelling unit or a terminating resistor.

[Operation] In the present invention, as described above, the plurality of branching devices B ₁ , B ₂ , B ₃ ,... Having the input terminal 51, the sending terminal 52, and at least one branch terminal 53 are connected to the sending terminal. Is connected in cascade so that is connected to the input terminal of another branch unit, and the input terminal of the first-stage branch unit connected in cascade is connected to the transmission line leading to the entrance,
During standby, the input terminal of the branching device is connected to the feed terminal as shown in FIG. 2, so that a trunk line from the entrance to all the branching devices to the terminating means can be constructed.
When a call is made, the input terminal of one of the branching devices is switched to the branch terminal as shown in FIG. 3, so that any one of the dwelling units is paired with the entrance device via the transmission line l. Since it is connected to 1 and the other dwelling units are disconnected,
There is no possibility that the communication quality is deteriorated due to impedance mismatch or the like. Also, at the end of the call, by switching and connecting the input terminal of the branching device to the sending terminal, as shown in FIG. 2, it is possible to reconfigure the trunk line from the entrance to the terminating means through all the branching devices. The branching devices B ₁ , B ₂ , B ₃ , ...
The controller C _1, C _2, C ₃ for controlling the switching operation, ... are preferably each splitter _{B 1, B 2, B 3} , is installed ... vicinity of multiplexing through the transmission line The switching operation of the branching units B ₁ , B ₂ , B ₃ ,... Is controlled in accordance with a selection signal or a cancellation signal externally given by transmission.

Embodiment FIG. 1 is a block diagram of one embodiment of the present invention. First, the entrance apparatus G includes a door phone D with a camera and a dwelling unit selection unit S. The configuration of the doorphone D with a camera is the same as that of the conventional door intercom with a television shown in FIG.
The video signal and the audio signal are multiplexed and put on the transmission line l. In order to reduce power consumption, the camera intercom D is not supplied with power during standby (during non-communication), and is supplied with power from the repeater R via the transmission line 1 only during operation. Is configured. The dwelling unit selection unit S is a device for selecting one of a plurality of dwelling units J ₁ , J ₂ , J ₃ ,... From the side of the entrance unit G, and includes a ten key T for selection. The selection signal of the dwelling unit at the entrance G is based on the DTMF (Double
(Modulated Tone Frequency) signal. This selection signal may be superimposed on the audio signal from the entrance G, or may be transmitted on a carrier different from the audio signal of the entrance G. In this case, a fourth carrier frequency may be added to the multiplex transmission signal shown in FIG. 6, and the fourth carrier frequency may be modulated to transmit a selection signal or a release signal.

The dwelling units J ₁ , J ₂ , J ₃ ,... Have the same configuration as the dwelling unit J in the conventional example shown in FIG. In the arrangement shown in FIG. 1, but dwelling unit J ₂ are provided two, in which one of the switch K is connected to the branching unit B _2. Each dwelling unit J ₁ , J ₂ , J ₃ ,... Supplies a low DC voltage to the transmission line l in the standby state, and supplies a high DC voltage to the transmission line l in the operating state. It is configured.

The relay R relays the selection signal generated by the dwelling unit selection unit S in the entrance G to the controllers C ₁ , C ₂ , C ₃ ,... Via the signal line 1 by multiplex transmission. Based on this selection signal, the controllers C ₁ , C ₂ , C ₃ ,... Control the switching operation of the branching units B ₁ , B ₂ , B ₃ ,. The relay R relays the signal on the transmission line l connected to the entrance G to the input terminal 51 of the _first branch B1. The branching device B ₁ has an input terminal 51, a feed terminal 52,
It has a branch terminal 53. The input terminal 51 is selectively switched and connected to either the feed terminal 52 or the branch terminal 53. The other branching devices B ₂ , B ₃ ,... Have the same configuration. First feed terminal of the splitter B ₁ represents is connected to the second input terminal of the branching device B _2, the feed terminal of the second branching device B ₂ is connected to an input terminal of the third branching device B ₃ I have. The feed terminal of the _third branch B3 is connected to the input terminal of the fourth branch (not shown) or to the termination means. Termination means may be a characteristic impedance equivalent termination impedance of the transmission line l, it may be another dwelling unit J _4.

Hereinafter, the switching operation of the branching devices B ₁ , B ₂ , B ₃ will be described with reference to FIGS. 2 and 3. First, during standby, as shown in FIG. ₂ , the input terminal 51 of each of the branching devices B ₁ , B ₂ , B ₃ is connected to a feed terminal.
52, so that the door unit J ₄ (or the terminal means) from the entrance device G via the repeater R, the branch devices B ₁ , B ₂ , B ₃
The trunk line leading to is constructed. Next, at the time of a call, the entrance G
, A selection signal is transmitted to the controllers C ₁ , C ₂ , and C ₃ via the repeater R. Now, assuming that a selection signal for selecting the dwelling unit J ₂ is given to the controllers C ₁ , C ₂ , and C ₃ , only the branching unit B ₂ becomes the third unit.
As shown in the figure, a switching operation is performed so as to connect the input terminal 51 to the branch terminal 53. Thus, the repeater R from the entrance device G, via the splitter B _1, B _2, transmission line leading to the dwelling unit device J ₂ is constructed.

Repeater R includes a voltage determining circuit for monitoring the voltage of the transmission line connected to the first splitter B _1, detects the voltage level of the DC component of the transmission line, in accordance with the detection result, An operation state and a non-operation state of the dwelling unit are determined. Splitter B ₂ performs a switching operation, after dwelling unit J ₂ is connected, the dwelling unit calling signal from the entrance vessel G or repeaters R is transmitted to the dwelling unit J ₂ to the repeater R. As described in the conventional example, a carrier wave of a special frequency may be transmitted as the paging signal, or the transmission signal may be transmitted by lowering the transmission line voltage to a certain value or by short-circuiting the transmission line. You may do it. _On the side of the dwelling unit J2, the call signal is received and the operation is started, and the circuit for power supply is operated to raise the voltage level of the DC component of the transmission line l. As described above, the dwelling unit supplies a low DC voltage to the transmission line l even in the standby state, but in the operating state, the DC voltage of the transmission line l is set higher than in the standby state. . In the repeater R, the level of the DC voltage is monitored by a voltage discriminating circuit to detect the start of operation of the dwelling unit. When the start of operation of the dwelling unit is detected, the power supply superimposing circuit of the repeater R operates to supply power to the camera-equipped door phone D of the entrance G. Therefore, when power is supplied to the camera-equipped door phone D, the dwelling unit is always connected normally and starts operating normally. For this reason, a state where the FM modulated wave from the dwelling unit is not supplied to the audio demodulation circuit of the FM system in the door phone with camera D does not occur, and abnormal noise does not occur.

Here, while the first dwelling unit is being selected and called at the entrance unit G, calling another dwelling unit may cause inconvenience. In other words, if the second dwelling unit is called while the first dwelling unit is being called, there is a possibility that a plurality of dwelling units will answer at the same time. It is preferable to prohibit calling of the container. Therefore, in this embodiment, after selecting and calling the first dwelling unit, a method of not accepting selection of another dwelling unit until the end of the call is adopted. Specifically, repeater R
The relay R does not relay the selection signal from the dwelling unit selection unit S to the controllers C ₁ , C ₂ , and C ₃ until the end of the call is detected by the voltage determination circuit.

At the end of the call, the level of the DC voltage of the transmission line 1 decreases because the DC voltage of the transmission line 1 is set to the standby state voltage on the dwelling unit side. Therefore, the repeater R monitors the level of the DC voltage of the transmission line 1 and detects the fall of the voltage, thereby canceling the selection of the dwelling unit. Specifically, a release signal is sent from the repeater R to the controllers C ₁ , C ₂ , and C ₃ , and all the branching units B ₁ , B ₂ , and B ₃ are brought into the standby connection state shown in FIG. It is to reset. However, in the present embodiment, since the audio demodulation circuit of the FM system is used in the intercom D with the camera, the power supply superimposing circuit in the repeater R is required before the release signal is sent to the controllers C ₁ , C ₂ and C _3. Is stopped, the power supply of the doorphone D with the camera in the entrance G is cut off first,
The generation of abnormal noise is prevented.

Incidentally, the splitter B ₂ or a free line to the transmission line leading to the dwelling unit device J ₂ from when the voltage of the transmission line l leading to dwelling unit J ₂ by disconnection is not normal, splitter B ₂ a dwelling unit J ₂ in after switch connection to the side of the voltage of the transmission line leading to the relay R from the first splitter B ₁ represents not a specified voltage. Therefore, the relay R, after the branching device B ₂ was switching operation by the selection signal,
If the voltage of the transmission line 1 does not reach the specified voltage even after a certain time (for example, one second) has elapsed, a release signal is forcibly generated, and all the branching devices B ₁ , B ₂ , B ₃ are switched to the second. Return to the state shown in the figure.
Further, in this case, since the rise of the voltage of the transmission line connected to dwelling unit J ₂ is not detected, the power superposition circuit of the repeater R does not start the power supply operation to the camera-equipped intercom D. That is, in the present embodiment, the power supply of the camera-equipped door phone D in the entrance apparatus G is not turned on unless the dwelling unit is properly connected and does not start operating normally.

The above operation has been described for the case where dwelling unit device J ₂ is selected, it goes without saying that the same operation also when dwelling unit device J ₁ and J ₃ is selected. Further, the number of branching devices and dwelling units is not limited to the embodiment, and may be any number.

The operating power of the branching devices B ₁ , B ₂ , B ₃ and the controllers C ₁ , C ₂ , C ₃ includes the entrance device G, the repeater R, the switching device K, the dwelling devices J ₁ , J ₂ , J ₃ It may be supplied from any of. Further, a dedicated power supply line may be provided for supplying operation power, or a power supply superimposed on the transmission line may be used. In addition, a relay circuit having a normally open contact, a normally closed contact, and a common contact is used as a changeover switch of a branching device, a normally open contact is connected to a branch terminal, a normally open contact is connected to a feed terminal, and a common terminal is input. If used by connecting to the terminal, simply turning off the power supply to the relay circuit will return the common contact to the normally closed contact, making it easy to return to the standby state where the input terminal is connected to the feed terminal. it can.

In the above embodiment, as shown in FIG. 1, the controller C _1, C
_2, the transmission line for transmitting a selection signal or release signal to C ₃ l
Although it is illustrated as wiring another signal line, this is a functional illustration of the signal flow for convenience of explanation, and in the present invention, this selection signal or cancellation signal is The function of the signal line for transmission is realized by multiplex transmission on the signal line l, which facilitates wiring in the present invention.

Although in the embodiment has a relay R is provided between the entrance unit G and the first splitter B _1, the entrance device G function of the relay R
, The repeater R may be omitted.

[Effects of the Invention] In the present invention, as described above, a branch device having an input terminal, a feed terminal, and a branch terminal is cascade-connected such that the feed terminal is connected to the input terminal of another branch device. The input terminal of each turnout is connected to the feed terminal during standby, and the input terminal of one of the turnouts is connected to the branch terminal during a call, so that the entrance connected to the input terminal of the first-stage turnout. A transmission line from the unit to a dwelling unit connected to a branch terminal of an arbitrary branching unit can be configured.At this time, since other dwelling units are disconnected from the transmission line, good transmission quality can be obtained. In addition, since each branching device can be connected by a feed line, the total length of the line is shortened. Further, since the selection signal or the release signal is transmitted by multiplex transmission through the transmission line, the wiring is also facilitated. There is.

[Brief description of the drawings]

FIG. 1 is a block diagram of one embodiment of the present invention, FIGS. 2 and 3 are block diagrams for explaining the operation of the embodiment, FIG. 4 is a schematic configuration diagram of a conventional example, and FIGS. (B) is a block diagram of a dwelling unit and a door in another conventional example, and FIG. 6 is an explanatory diagram showing an example of frequency division on a transmission line used in the same. B ₁ , B ₂ , and B ₃ are switchers, C ₁ , C ₂ , and C ₃ are controllers, G is a front door,
J ₁ , J ₂ , J ₃ , and J ₄ are dwelling units, and 1 is a transmission line.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masahiko Amano 1048 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Works Co., Ltd. (JP, U)

Claims (1)

(57) [Claims] An interphone for multiplexing transmission of at least an audio signal and a video signal between a door and a dwelling unit using a pair of transmission lines.
A plurality of branch devices having one branch terminal are cascade-connected such that a feed terminal is connected to an input terminal of another branch device, and a transmission line connecting an input terminal of the cascade-connected first-stage branch device to an entrance device. And the feed terminals of the cascade-connected last-stage branch unit are connected to the terminating means, and the branch terminals of the plurality of branch units are connected to the transmission lines connected to different dwelling units, respectively. The input terminal is connected to the feed terminal, and the input terminal of any one of the branching devices is switched to the branch terminal in response to a selection signal provided externally during a call, and the terminal is branched in response to the release signal provided externally at the end of the call. An intercom for a multi-family housing, comprising a controller for switching and connecting an input terminal of the container to a feed terminal, wherein a selection signal or a release signal given to the controller is multiplex-transmitted via the transmission line.