JP2003198737A - Video intercom system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To newly extend a master unit provided with a monitor without needing any cable wiring work. <P>SOLUTION: The video intercom system comprises a camera attached entrance slave unit 1 and a living room master unit 2 with a monitor. When a monitor attached extension master unit 4 is newly extended to the system without making a cable wiring work, a living room master unit wireless transmission/reception adaptor 3 is connected to the monitor attached living room master unit, and an extension master unit wireless transmission/reception adaptor 5 making wireless communication with the master unit wireless transmission/reception adaptor is connected to the extension master unit with a monitor so as to realize wireless communication between the monitor attached living room master unit and the extension master unit provided with the monitor. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a TV intercom system, and more particularly to a TV intercom system capable of newly installing an additional master unit with a monitor without performing cable wiring work.

[0002]

2. Description of the Related Art Conventionally, as this type of TV intercom system, one having a structure as shown in FIG. 2 has been known. In the figure, the conventional TV door phone system is
The camera-equipped entrance cordless handset 6 is provided with a monitor-equipped in-room master unit 7 and a monitor-added master unit 8 provided in the living room. The camera-equipped front cordless handset 6 has a cordless handset connection cable L10. Is connected to the monitor-installed room master unit 7, and the monitor-mounted room master unit 7 is connected to the monitor-installed master unit 8 via the expanded master-unit connection cable L20.

The entrance cordless handset 6 with a camera has a camera section 61.
A video FM modulation circuit 62, a slave unit audio circuit 63, a slave unit multiplex / separation circuit 64, a slave unit call detection circuit 65, a call button 66, and a slave unit speech section 67. Here, the slave unit multiplexing / separating circuit 64 is the video FM modulating circuit 6
2. The slave unit voice circuit 63 and the slave unit call detection circuit 65 are connected to each other. The camera unit 61 is connected to the video FM modulation circuit 62, the slave unit communication unit 67 is connected to the slave unit audio circuit 63, and the slave unit call detection circuit 65 is connected. A call button 66 is connected to each.

The monitor-equipped room master unit 7 includes a master unit call detection circuit 71, a master unit control circuit 72, first and second master unit multiplexing / separating circuits 73a and 73b, and an additional master unit control signal transmission circuit. 74, parent device monitor circuit 75, and parent device audio circuit 76
A base unit call notification unit 77, a base unit monitor 78, and a base unit communication unit 79. Here, the base unit control circuit 72
Is connected to the base unit call detection circuit 71, the extension base unit control signal transmission circuit 74, the base unit monitor circuit 75, the base unit voice circuit 76, and the base unit call notification unit 77. Of the master unit multiplex / separation circuit 73a of the second master unit multiplexing / separation circuit 73b.
However, a master unit monitor 78 is connected to the master unit monitor circuit 75, and a master unit speech section 79 is connected to the master unit voice circuit 76. Further, the master device monitor circuit 75 and the master device audio circuit 76.
Are the first and second master device multiplexing / separating circuits 73a,
73b, and a slave unit multiplexing / separating circuit 64 is connected to the first master unit multiplexing / separating circuit 73a via a slave unit connecting cable L10.

The extension master unit 8 with monitor includes an extension master unit control circuit 81, a data signal receiving circuit 82, an extension master unit monitor circuit 83, an extension master unit multiplexing / separating circuit 84, and an extension master unit monitor 85. An additional parent device voice circuit 86, an additional parent device call notification unit 87, and an additional parent device call unit 88 are provided. Here, the extension master unit control circuit 81 is configured to control the data signal receiving circuit 8
2, the additional parent device monitor circuit 83, the additional parent device voice circuit 86, and the additional parent device call notification unit 87 are connected to the data signal receiving circuit 82, the additional parent device monitor circuit 83, and the additional parent device voice circuit 86. A machine multiplexing / separating circuit 84, an extension master machine monitor 85 are connected to the extension master machine monitor circuit 83, and an extension master machine speech section 88 is connected to the extension master machine voice circuit 86.

Next, the operation of the TV intercom system having such a configuration will be described.

First, when a visitor presses the call button 66 of the camera-equipped entrance slave unit 6, a slave unit calling circuit 65 outputs a master unit calling signal, and this master unit calling signal is transmitted to the slave unit multiplex / separation circuit. 64, slave unit connection cable L10, first master unit multiplex / separation circuit 73a (hereinafter, slave unit multiplex / separation circuit 6
4, the path of the child device connection cable L10 and the first parent device multiplexing / separating circuit 73a is referred to as a "first transmission path". ) And the master unit call detection circuit 71, and the master unit control circuit 72
Transmitted to.

When such a base unit call signal is detected by the base unit control circuit 72, the base unit control circuit 72 controls the base unit call notification section 77 to emit a ringing sound and monitor the base unit. The circuit 75, the master unit voice circuit 76, the master unit monitor 78, and the master unit speech section 79 are activated. At the same time, the extension master unit calling signal is output from the parent unit control circuit 72, and the extension parent unit calling signal is transmitted to the extension master unit control signal sending circuit 74, the second parent unit multiplexing / separating circuit 73b,
Expansion master unit connection cable L20, expansion master unit multiplexing / separation circuit 84 (hereinafter, second master unit multiplexing / separation circuit 73b, expansion master unit connecting cable L20, and expansion master unit multiplexing / separation circuit 8)
The route of No. 4 is called the "second transmission route". ) And the data signal receiving circuit 82, and is transmitted to the extension master unit control circuit 81.

When the extension master unit call signal is detected by the extension master unit control circuit 81, the extension master unit control circuit 81 is detected.
Control, the ringing tone is emitted from the extension call notification unit 87, the extension monitor circuit 83, the extension master unit monitor 85,
The extension master unit voice circuit 86 and the extension master unit speech section 88 are activated.

On the other hand, the image of the visitor picked up by the camera section 61 is FM-modulated by the image FM modulation circuit 62,
As an FM video signal, to the parent device monitor circuit 75 via the first transmission path, or to the extension parent device monitor circuit 83 via the first transmission path, the parent device monitor circuit 75 and the second transmission path. Is transmitted. The FM video signal is demodulated in the master device monitor circuit 75 or the extension master device monitor circuit 83, whereby the image of the visitor is displayed in the master device monitor 7.
8 or an additional master device monitor 83 is displayed.

Further, the voice signal output from the handset unit speech section 67 is transmitted to the base unit voice circuit 76 via the handset unit voice circuit 63 and the first transmission path, or to the first transmission path,
It is transmitted to the extension master unit voice circuit 86 via the master unit voice circuit 76 and the second transmission path.

[0012] Here, the resident is the extension master unit 8 with a monitor.
When the handset of the main unit monitor circuit 75, the main unit voice circuit 76, the main unit monitor 78, and the main unit communication unit 79 are deactivated, the main unit 7 with monitor has a handset, and an additional monitor The circuit 83, the extension parent device monitor 85, the extension parent device voice circuit 86, and the extension parent device speech section 88 are deactivated. Therefore, when the resident picks up the handset of the extension master unit 8 with a monitor and makes a call response, the front door unit 6 with a camera
A call path is formed between the monitor and the extension master unit 8 with a monitor. On the contrary, when the handset of the monitor-equipped master unit 7 is picked up and the call is answered, between the camera-equipped slave unit 6 and the monitor-equipped master unit 7. A call path is formed in the room, which enables calls between residents and visitors. When the resident finishes the call and lowers the handset, the master unit monitor circuit 75, the master unit voice circuit 76, the master unit monitor 78 and the master unit communication unit 79 or the extension monitor circuit 83, the extension parent unit monitor 85, the extension unit are added. The base unit voice circuit 86 and the extension base unit call unit 88 are deactivated, and the state returns to the standby state.

[0013]

However, in such a conventional TV intercom system, it is necessary to provide a dedicated wiring by the extension master unit connection cable between the room master unit with monitor and the extension master unit with monitor. However, when newly installing an additional main unit with a monitor, there is a difficulty in that the additional master unit connection cable must be newly installed.

The present invention has been made in order to solve such a problem, and an object of the present invention is to provide a TV intercom system in which an additional master unit with a monitor can be easily added without newly performing wiring work. I am trying.

[0015]

In order to achieve such an object, a TV intercom system of the present invention is a TV intercom system consisting of a front door subunit with a camera and an in-room master unit with a monitor, and cable wiring. When adding an additional base unit with a monitor without performing any work, connect the base unit wireless transmitter / receiver adapter to the base unit with a monitor,
The wireless communication between the master unit with monitor and the extension master unit with monitor is realized by connecting the extension master unit wireless transmitter / receiver adapter that wirelessly communicates with the master unit wireless transmitter / receiver adapter to the monitor-added master unit. There is.

In addition, in the TV doorphone system of the present invention, the entrance slave unit with a camera has a video FM modulation circuit, and the room master unit with a monitor and the extension master unit with a monitor have a video FM signal transmitted from the video FM modulation circuit. It is characterized in that it has a master device monitor circuit for demodulating the modulated signal and displaying the image on a monitor, and an additional master device monitor circuit.

Further, the master unit wireless transmission / reception adapter in the TV doorphone system of the present invention is capable of FM-transmitting voice / data signals from the entrance slave unit with camera and the master unit in the room with monitor.
It has a downlink voice / data signal FM modulation circuit that modulates and generates a downlink voice / data FM modulation signal. The extension master radio transmission / reception adapter receives the downlink voice / data FM modulation signal from the downlink voice / data signal FM modulation circuit. It is characterized by having a downlink voice / data signal FM demodulation circuit for FM demodulation.

The additional master radio transmission / reception adapter in the TV doorphone system of the present invention is an upstream voice / data signal for FM-modulating a voice / data signal from the additional master with monitor to generate an upstream voice / data FM modulated signal. FM
It has a modulation circuit, and the master unit wireless transmission / reception adapter uses the upstream voice / data signal FM modulation circuit to transmit the upstream voice / data FM.
It is characterized by having an upstream voice / data signal FM demodulation circuit for FM demodulating a modulated signal.

Further, the base station wireless transmission / reception adapter in the TV doorphone system of the present invention maintains the band difference in order to prevent the video FM modulation signal from the camera-equipped front station from interfering with the downlink audio / data FM modulation signal. In addition, the extension master radio transmission / reception adapter has a frequency conversion unit for performing frequency conversion to a high frequency band, and the extension master radio transmission / reception adapter frequency-converts the video FM modulated signal from the parent radio transmission / reception adapter to the frequency before conversion while maintaining the band difference. It is characterized by having a converter.

According to the TV intercom system of the present invention, the master wireless transmission / reception adapter is connected to the monitor living room master and the additional master wireless transmission / reception adapter for wireless communication with the master wireless transmission / reception adapter is connected to the monitor added master. By connecting, wireless communication between the room master unit with monitor and the extension master unit with monitor is possible, so it is possible to easily add the extension master unit with monitor without performing cable wiring work. .

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the TV door intercom system of the present invention will be described in detail below with reference to the drawings.

Referring to FIG. 1, a television door phone system according to the present invention includes a camera-equipped front cordless handset 1 provided at a front door.
Connected to the monitor-installed room master unit 2 and the monitor-added master unit 4 installed in the living room, the room master radio transmission / reception adapter 3 connected to the monitor-mounted room master unit 2, and the monitor-added master unit 4. And an additional main unit wireless transmission / reception adapter 5, and the camera-equipped slave unit 1 is connected to the monitor-equipped master unit 2 via a slave unit connection cable L1.

The entrance cordless handset 1 with a camera has a camera section 11
1, a video FM modulation circuit 12, a slave unit audio circuit 13, a slave unit multiplexing / separating circuit 14, a slave unit call detection circuit 15, a call button 16, and a slave unit speech section 17. Here, the slave unit multiplexing / separating circuit 14 is the video FM modulating circuit 1
2. The slave unit voice circuit 13 and the slave unit call detection circuit 15 are connected to each other, and the video FM modulation circuit 12 includes the camera unit 11, the slave unit voice circuit 13 includes the slave unit call unit 17, and the slave unit call detection circuit 15. A call button 16 is connected to each.

The monitor-equipped master unit 2 for the living room includes a master unit call detection circuit 21, a master unit control circuit 22, first and second master unit multiplexing / separating circuits 23a and 23b, and an additional master unit control signal transmission circuit. 24, parent device monitor circuit 25, parent device audio circuit 26
A base unit call notification unit 27, a base unit monitor 28, and a base unit communication unit 29. Here, the master unit control circuit 22
Is connected to the base unit call detection circuit 21, the extension base unit control signal transmission circuit 24, the base unit monitor circuit 25, the base unit voice circuit 26 and the base unit call notification unit 27. The first master unit multiplex / separation circuit 23a is connected to the second master unit multiplex / separation circuit 23 in the additional master unit control signal transmission circuit 24.
b, a master unit monitor 28 is connected to the master unit monitor circuit 25, and a master unit speech section 29 is connected to the master unit voice circuit 26. Further, the master unit monitor circuit 25 and the master unit audio circuit 2
6 is connected to the first and second master device multiplexing / separating circuits 23a and 23b, respectively, of the master device audio circuit 26, and the slave device is connected to the first master device multiplexing / separating circuit 23a via the slave device connection cable L1. The multiplexing / demultiplexing circuit 14 is connected.

The room master radio transmission / reception adapter 3 includes a master radio multiplex / separation circuit 31, a master frequency converter 32, a downstream voice / data signal FM modulation circuit 33, and an upstream voice / data signal FM demodulation circuit 34. And a mixer 35, a master transmitter / receiver circuit 36, and a living room master antenna 37.
Here, the master frequency converter 32 and the downlink voice / data signal FM modulation circuit 33 are connected to the master wireless multiplex / separation circuit 31 and the mixer 35, respectively, and the master wireless multiplex / demultiplexer 31 is connected.
A second master device multiplexing / separating circuit 23b is connected to the separating circuit 31. Further, the upstream voice / data signal FM demodulation circuit 34 is connected to the parent device wireless multiplexing / demultiplexing circuit 31 and the parent device transmission / reception circuit 36, and the parent device transmission / reception circuit 36 is connected to the mixer 35 and the living room parent device antenna 37. ing.

The extension master unit with monitor 4 includes an extension master unit control circuit 41, a data signal receiving circuit 42, an extension master unit monitor circuit 43, an extension master unit multiplexing / separating circuit 44, and an extension master unit monitor 45. An additional parent device voice circuit 46, an additional parent device call notification unit 47, and an additional parent device call unit 48 are provided. Here, the additional parent device control circuit 41 is configured to control the data signal receiving circuit 4
2, the additional parent device monitor circuit 43, the additional parent device voice circuit 46, and the additional parent device call notification unit 47 are connected to the data signal receiving circuit 42, the additional parent device monitor circuit 43, and the additional parent device voice circuit 46. An additional master device monitor circuit 45 is connected to the additional master device monitor circuit 43, and an additional master device communication circuit 48 is connected to the additional master device voice circuit 46.

The additional parent wireless transmission / reception adapter 5 includes an additional parent transmitting / receiving circuit 51, a separator 52, an upstream voice / data signal FM modulator 53, a downstream voice / data signal FM demodulator 54, and an additional parent. The frequency converter 55, the extension master wireless multiplexing / demultiplexing circuit 56, and the extension master antenna 57 are provided. Here, the upstream voice / data signal FM modulation circuit 53 is connected to the extension master device transmitting / receiving circuit 51 and the extension master device wireless multiplexing / separating circuit 56, and the extension master device transmitting / receiving circuit 5 is connected.
A separator 52 and an extension base unit antenna 57 are connected to 1. Further, the extension master unit frequency converter 55 and the downlink voice / data signal FM demodulation circuit 54 are connected to the separator 52 and the extension master unit wireless multiplex / separation circuit 56, respectively. The extension master unit multiplexing / separating circuit 44 is connected.

Next, the operation of the TV intercom system having such a configuration will be described.

First, when a visitor pushes down the call button 16 of the camera-equipped entrance slave unit 1, a master unit calling signal is output from the slave unit calling circuit 15, and this master unit calling signal is transmitted to the slave unit multiplexing / separating circuit. 14, slave unit connection cable L1, first master unit multiplexing / separating circuit 23a (hereinafter, slave unit multiplexing / separating circuit 14,
The path of the child device connection cable L1 and the first parent device multiplexing / separating circuit 23a is referred to as a "first transmission path". ) And the master unit call detection circuit 21 to the master unit control circuit 22.

The call signal is sent to the master unit control circuit 2
2 is detected by the master unit control circuit 2, a ringing tone is emitted from the master unit call notification unit 27, and the master unit monitor circuit 25, the master unit voice circuit 26, the master unit monitor 28, and the master unit 28. The machine talk unit 29 is activated.

At the same time, the extension master unit calling signal is output from the parent unit control circuit 22, and the extension parent unit calling signal is transmitted to the extension parent unit control signal sending circuit 24 and the second parent unit multiplexing / separating circuit 23b. And via the base unit wireless multiplex / separation circuit 31 (hereinafter, the paths of the second master unit multiplex / separation circuit 23b and the main unit wireless multiplex / separation circuit 31 are referred to as “second transmission paths”).
Say. ) The downlink voice / data signal is transmitted to the FM modulation circuit 33. The extension master unit calling signal is FM-modulated in the downlink voice / data signal FM modulation circuit 33 and transmitted as the downlink voice / data FM modulation signal to the master unit transmitting / receiving circuit 36 via the mixer 35, and the room master unit Antenna 37
Is transmitted as a radio signal from and is received by the extension master unit antenna 57.

The radio signal received by the extension master unit antenna 57 is transmitted to the downlink voice / data signal FM demodulation circuit 54 via the extension master unit transmitting / receiving circuit 51 and the separator 52, and this downlink voice / data signal is transmitted. The FM demodulation circuit 54 performs FM demodulation and separates the extension base unit calling signal. The separated extension base unit calling signal is the extension base unit wireless multiplex /
Separation circuit 56, additional master device multiplexing / separating circuit 44 (hereinafter, the paths of the additional master device wireless multiplexing / separating circuit 56 and the additional master device multiplexing / separating circuit 44 are referred to as “third transmission paths”) and data signal reception. It is transmitted to the extension master unit control circuit 41 via the circuit 42.

When the extension master unit call signal is detected by the extension master unit control circuit 41, the extension master unit control circuit 41 is detected.
Under the control of, the extension master unit call notification unit 47 emits a ringing sound, and the extension master unit monitor circuit 43, the extension master unit monitor 45, the extension master unit voice circuit 46, and the extension master unit communication unit 48 are in the active state. To be

Here, the resident is the extension master unit 4 with a monitor.
Taking the handset of, as in the conventional TV intercom system, the master monitor circuit 25, the master audio circuit 26,
The base unit monitor 28 and the base unit call unit 29 are deactivated,
A call path is formed between the camera-equipped front cordless handset 1 and the monitor-added master unit 4, and conversely, when taking the handset of the monitor-equipped living-room master unit 2, the extension monitor circuit 43, the extension master unit monitor 45, The additional parent device voice circuit 46 and the additional parent device call section 48 are deactivated, and a call path is formed between the entrance slave device 1 with camera and the living room master device 2 with monitor. This allows
Calls between residents and visitors are possible.

Next, the transmission of video signals and audio / data signals transmitted from the camera-equipped front cordless handset 1 and the monitor-equipped room master unit 2 will be described.

First, the image of the visitor captured by the camera unit 11 is, for example, 12 MH in the image FM modulation circuit 12.
An audio signal that is FM-modulated at a frequency of about z, is transmitted as an FM video signal to the parent device monitor circuit 25 via the first transmission path, and is output from the child device talk section 17 is
It is transmitted to the master unit voice circuit 26 via the slave unit voice circuit 13 and the first transmission path. Then, these FM video signals and audio signals are sent to the second master device multiplexing / separating circuit 23.
It is multiplexed in b and transmitted to the master unit wireless multiplexing / demultiplexing circuit 31.

The FM video signal and audio signal transmitted to the room master radio transmission / reception adapter 3 are separated by the master radio multiplexing / separating circuit 31, and the former FM video signal is sent to the master frequency converter 32 and the latter. The voice signal is
The data signals are transmitted to the FM modulation circuit 33. Then, the former FM video signal is frequency-converted to, for example, about 82 MHz in the master frequency converter 32, and the video F
The latter audio signal is FM-modulated at a frequency of, for example, about 70 MHz in the downstream voice / data signal FM modulation circuit 33 as the M modulation signal, and is transmitted to the mixer 35 as the downstream voice / data FM modulation signal. It Then, it is mixed in the mixer 35, transmitted to the master unit transmitting / receiving circuit 36, transmitted as a radio signal from the living room master unit antenna 37, and received by the additional living room master unit antenna 57.

Here, in the radio transmitter / receiver adapter 3 for the master unit of the room, the FM frequency-modulated signal from the entrance cordless handset 1 with camera is frequency-converted by the master unit frequency converter 32 into a high frequency band while maintaining a band difference of about 12 MHz. Of the downstream voice
This is to prevent interference with the data FM modulated signal.

Thus, the radio signal received by the extension master unit antenna 57 is transmitted to the downlink separator 52 via the extension master unit transmitting / receiving circuit 51, and in this separator 52, the video FM modulation signal and the downlink audio / signal are transmitted. The data FM modulated signal is separated. Then, the former video FM modulated signal is again frequency-converted to a frequency of about 12 MHz in the extension master device frequency conversion section 55, and is sent to the extension master device monitor circuit 43 as a video FM signal via the third transmission path. Is transmitted.

The latter downlink voice / data FM modulated signal is FM demodulated in the downlink voice / data signal FM demodulation circuit 54 in the same manner as the above-mentioned extension master unit calling signal, and is demodulated by the third signal.
Is transmitted to the additional parent device voice circuit 46 via the transmission path of

It should be noted that the voice from the extension master unit 4 with a monitor
The data signal is a downlink voice / data signal FM modulation circuit 33.
By using the upstream voice / data signal FM modulation circuit 53 corresponding to the above and the upstream voice / data signal FM demodulation circuit 34 corresponding to the downstream voice / data signal FM demodulation circuit 54. -It can be transmitted to the handset 1 with a camera via a route opposite to that of the data signal. That is, the voice signal output from the extension master unit call section 48 passes through the extension master unit voice circuit 46 and the third transmission path, and the upstream voice / data signal FM modulation circuit 53.
To the upstream voice / data signal FM modulation circuit 5
3 is FM-modulated and is transmitted as an uplink voice / data FM-modulated signal from the additional parent device antenna 57 via the additional parent device transmitting / receiving circuit 51 as a radio signal. Then, the wireless signal received by the room main unit antenna 37 is transmitted via the main unit transmission / reception circuit 36 to the upstream voice / data FM demodulation circuit 34.
Demodulated in the second transmission path, the master unit voice circuit 2
6, the data is transmitted to the handset call section 17 via the first transmission path and the handset voice circuit 13.

As described above, the resident calls the base unit call notification unit 2
7 or by confirming the ringing sound emitted from the extension base unit call notification unit 47 and picking up the handset of either the monitor-equipped base unit base unit 2 or the monitor-attached extension base unit 4, the camera-equipped front door When the handset is lowered after the call is established with the device 1 and the call ends, the master device monitor circuit 2
5, parent device voice circuit 26, parent device monitor 28 and parent device communication section 29 or extension monitor circuit 43, extension parent device monitor 45,
The extension master unit voice circuit 46 and the extension master unit communication unit 48 are deactivated, and the standby state is restored.

[0043]

As is apparent from the above description, according to the TV intercom system of the present invention, the master wireless transmitter / receiver adapter is connected to the monitor-equipped master unit and the master wireless transmitter / receiver adapter is connected to the monitor-added master unit. Wireless communication between the extension master unit with monitor and the extension master unit with monitor can be performed by connecting the extension master unit wireless transmission / reception adapter to wireless communication with the master unit without cable wiring work. It is possible to add an extension base unit.

[Brief description of drawings]

FIG. 1 is a block diagram of a TV intercom system according to the present invention.

FIG. 2 is a block diagram of a conventional TV door phone system.

[Explanation of symbols]

1 ... Door unit with camera 12 ... Image FM modulation circuit 2 ... In-room master unit with monitor 25 ... Parent device monitor circuit 3 ... Master wireless transceiver adapter 32 ... Frequency converter (base unit frequency converter) 33 ... Downstream voice / data signal FM modulation circuit 34. Upstream voice / data signal FM demodulation circuit 4 ... Expansion base unit with monitor 43 ... Expansion parent device monitor circuit 5 ... Expansion base unit wireless transmission / reception adapter 53 ... Upstream voice / data signal FM modulation circuit 54 ... Downstream voice / data signal FM demodulation circuit 53 ... Frequency conversion unit (expansion main unit frequency conversion unit)

Claims (5)

[Claims] 1. A TV intercom system comprising an entrance cordless handset with a camera (1) and an in-room master unit (2) with a monitor, wherein an extension master unit with a monitor (4) is newly installed without performing cable wiring work. Upon expansion, a master wireless transmission / reception adapter (3) is connected to the living room master with monitor, and an expansion master wireless transmission / reception adapter (5) that wirelessly communicates with the master wireless transmission / reception adapter is connected to the expansion master with monitor. A television door phone system, wherein wireless communication is realized between the monitor-attached room master unit and the monitor-added master unit by being connected. 2. The front door device with a camera has a video FM modulation circuit (12), and the room master unit with a monitor and the extension master device with a monitor have a video FM modulation transmitted from the video FM modulation circuit. The TV door phone system according to claim 1, further comprising a master device monitor circuit (25) for demodulating a signal and outputting the image on a monitor, and an additional master device monitor circuit (43). 3. The wireless transmission / reception adapter for the master unit is used for voice communication from the entrance slave unit with the camera and the master unit in the living room with the monitor.
Downlink voice / data signal FM modulation circuit for FM-modulating a data signal to generate a downlink voice / data FM modulation signal (33)
The additional master wireless transmission / reception adapter has a downlink voice / data signal FM for FM demodulating the downlink voice / data FM modulation signal from the downlink voice / data signal FM modulation circuit.
The television door phone system according to claim 2, further comprising a demodulation circuit (54). 4. The upstream master station wireless transmission / reception adapter FM-modulates a voice / data signal from the additional master station with a monitor to generate an upstream voice / data FM modulated signal.
An uplink voice / data signal FM demodulation circuit having a data signal FM modulation circuit (53), wherein the master wireless transmission / reception adapter FM demodulates the uplink voice / data FM modulation signal from the uplink voice / data signal FM modulation circuit. The TV door phone system according to claim 2, further comprising (34). 5. The master unit wireless transmission / reception adapter maintains a band difference in a high frequency band while preventing a video FM modulation signal from the camera-equipped front cordless handset from interfering with the downlink voice / data FM modulation signal. The additional master radio transmission / reception adapter has a frequency conversion unit (32) for frequency conversion,
The frequency conversion unit (55) for frequency-converting a video FM modulated signal from the master wireless transmission / reception adapter to a frequency before conversion while maintaining a band difference.
The TV door phone system according to claim 4.