JPH10224776A - Video doorphone set - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an inexpensive video doorphone set with a simple configuration utilizing an existing interphone set. SOLUTION: The doorphone set is provided with a camera equipment 47, a video signal of an object is FM-modulated and the resulting modulated signal is sent to a transmission line 60 of an existing interphone set via a 1st 2-way carrier coupling circuit 43 through electrostatic coupling or electromagnetic coupling, the 1st 2-way carrier coupling circuit 43 extracts a carrier sent from a master set side via the transmission line 60 and when a carrier detection section 44 detects the carrier, a base station power supply 37 is entirely driven and when the carrier is not detected, the doorphone set is set to a standby state. A video demodulator 50 is provided and a video carrier introduced from a 2nd 2-way carrier coupling circuit 49 that is coupled electrostatically or electromagnetically with the transmission line 60 is demodulated by a video demodulation circuit 50, from which a video image output to be supplied to a monitor is introduced and a carrier switch 53 selects a carrier generated from a carrier generating circuit 51 and sent to the transmission line 60 via the 2nd 2-way carrier coupling circuit 49.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a two-way audio intercom system installed in a general home to transmit a video signal from a camera device through a two-wire transmission line of the intercom system. The present invention relates to a television intercom apparatus as described above.

[0002]

2. Description of the Related Art Voice intercoms have been widely used in ordinary houses and offices because of their low cost. Although the annual production of these vehicles reaches millions, they respond without being able to confirm who the visitors are. Therefore, there is a disadvantage that a visitor who does not want to respond will be unconditionally answered. In order to improve this, a TV door phone device incorporating a camera capable of viewing a visitor's image and having a monitor TV in an indoor base unit has begun to spread. However, due to its high price, its use has been delayed, and its annual production is only about several percent of that of intercoms.

FIG. 7 is a block diagram showing a typical configuration of a voice intercom which has been widely used, and FIG.
FIG. 1 is a block diagram showing a typical configuration of a TV door phone which has begun to spread in recent years.

FIG. 7 is a block diagram showing a configuration of a voice intercom. In the figure, a slave unit 1 installed outdoors
4 is pressed, the detection button 5 is pressed.
, And the fact that there is a call to the base unit 15 is transmitted via the two-wire transmission line 60. In response to this signal, the base unit 15 sends a signal from the power supply control circuit 12 to the transmission line 60.
Power is supplied to the slave unit 14 via the.

During standby, power is not supplied to the slave unit 14, and power is supplied by detecting that the call button S1 has been pressed. In general, the detection circuit 5 controls the supply of the power by detecting that the power supply has been short-circuited in the reverse polarity state by the base unit 15 in many cases. In the talking state, the speech control circuits 3 and 6 of both the slave unit 14 and the master unit 15 operate to enable simultaneous two-way voice communication via the two-wire transmission line 60.
Also, when a calling signal comes from the slave unit 14 to the master unit 15,
The power supply control circuit 12 detects this and activates the ringing tone generation circuit 8 so that the ringing tone is emitted from the base unit speaker 9. As described above, since the audio interphone transmits only the audio, the configuration is simple and inexpensive.

In the figure, reference numeral 1 denotes a microphone of the slave unit 14, the output of which is amplified by a microphone amplifier 2 and sent to the transmission line 60 via the above-mentioned speech control circuit 3, and 4 is the above-mentioned speech control circuit. The speaker 3 is connected to the speaker 3 and outputs a sound transmitted from the base unit 15 via the two-wire transmission line 60. Reference numeral 7 denotes a speaker amplifier of the base unit 15, and reference numeral 10 denotes a microphone of the base unit 15. The output of the microphone 10 is amplified by the microphone amplifier 11. The data is transmitted to the slave 14 via the transmission line 60. Reference numeral 13 denotes a power supply unit provided between the commercial power supply and the power supply control circuit 12.

FIG. 8 is a block diagram showing the configuration of a TV door phone. When the call button S2 in the TV intercom slave unit 35 is pressed by the visitor, the slave unit multiplex transmission unit 17
Detects this, activates the CCD camera unit 16, and outputs
The video signal from the CD camera unit 16 is transmitted to the slave unit multiplex transmission unit 1.
7 and the multiplexing transmission line 61 to the master unit multiplexing unit 25 of the master unit 36.

The video signal may be transmitted in a baseband or may be FM-modulated. Multiplex transmission unit 25
Is a circuit that performs signal processing so that a video signal and a two-way audio carrier can coexist.
Is passed through the video signal processing unit 26 and output to the image display unit 27 so that the visitor can be visually recognized.

The audio signal from the slave unit 35 is FM-modulated by an audio modulator 20 through a microphone 18 in the slave unit 35 and a microphone amplifier 19 for amplifying the audio signal.
And the multiplex transmission units 17 and 25 of the base unit 36,
The signal is demodulated by an audio demodulation unit 31 provided on the 6 side, and is output from a speaker 33 via a speaker amplifier 32.

Conversely, the audio signal from the base unit 36 is FM-modulated by the modulation unit 30 via the microphone 28 and the microphone amplifier 29, and the multiplexed transmission units 25, 1
7, is demodulated by the slave unit audio demodulation unit 21, and is supplied to the speaker 23 via the speaker amplifier 22. The necessary DC power is generated by a power supply unit 34 provided on the base unit 36 side from the commercial power supply. The DC power supply required for the slave unit 35 is supplied from the base unit power supply unit 34 with the choke coils CH3 and CH4 and the choke coils in the slave unit. The power is supplied to the power supply unit 24 provided on the slave unit 35 side through CH1 and CH2, and is made by this power supply unit. In this way, the TV door phone not only has two-way audio,
The mechanism becomes complicated to transmit unidirectional video signals,
It will be expensive.

[0011]

As described above, the conventional TV intercom system transmits not only sound but also one-way video signals in both directions, so that visitors can be confirmed with images. However, the provision of the video system makes the configuration complicated and expensive, and causes a delay in its spread.

[0012] In addition, while audio intercom devices are widely used, when a conventional TV door intercom device is newly installed in a place where the intercom device is installed, the existing audio intercom device becomes unnecessary and is often removed. For this reason, there is a problem that resources are wasted and that there is a strong sense of resistance to discarding the voice intercom device. If an existing intercom can be used as it is and a low-priced intercom camera can be attached later, a TV intercom system can be easily configured with a lean investment.

[0013]

According to the present invention, in order to solve the above-mentioned problems, in the television door phone apparatus according to the first and third aspects, an imaging means for deriving a video signal of a subject, and a video derived from the imaging means. A modulating means for modulating a signal, and a first means for transmitting a video carrier modulated by the modulating means to a transmission line of an existing intercom device by electrostatic coupling or electromagnetic coupling.
And a second carrier coupling means for extracting a video carrier transmitted via the transmission line by electrostatic coupling or electromagnetic coupling. And a video demodulation device installed near a master unit of the intercom device, comprising: a video demodulation unit for demodulating a video carrier derived from the second carrier coupling unit. Further, the modulation means is an FM modulation means.

Therefore, the camera device provided near the slave unit side of the existing intercom device derives a video signal of the subject by the imaging means. This video signal is broadband (DC to 4M
Hz), and modulation such as FM modulation is performed by a modulation means in order to coexist with a bidirectional audio signal having a band of 20 Hz to 5 kHz to be transmitted to a two-wire transmission line of an existing intercom apparatus. The modulated video carrier is coupled to the transmission line of the intercom apparatus by electrostatic coupling or electromagnetic coupling by the first carrier coupling means and transmitted to the master unit side of the intercom apparatus via the transmission line.

The video carrier transmitted to the video demodulation device provided near the master unit side of the intercom device via the transmission line is derived by the second carrier coupling means provided in the video demodulation device, and transmitted to the demodulation device. Supplied. The demodulation means demodulates the derived video carrier by FM demodulation or the like, reproduces the video signal of the subject, outputs the signal to a monitor or the like, and projects the video of the subject.

According to a second aspect of the present invention, there is provided a television intercom apparatus, comprising: an imaging unit for deriving a video signal of a subject; a modulation unit for modulating a video signal derived from the imaging unit; and a video carrier modulated by the modulation unit. Is transmitted to the transmission line of the existing intercom device by electrostatic or electromagnetic coupling, and the carrier wave transmitted from the video demodulation device installed near the master unit of the intercom device is transmitted through the transmission line. First derived by coupling or electromagnetic coupling
Bidirectional carrier coupling means, and a carrier detection means for detecting a carrier wave derived from the first bidirectional carrier coupling means,
A camera device installed in the vicinity of a slave unit of the intercom apparatus, comprising: a battery power supply unit that supplies power to each unit only when the carrier wave is detected by the carrier wave detection unit; and a carrier wave that generates the carrier wave. Generating means for extracting a video carrier transmitted via the transmission line by electrostatic coupling or electromagnetic coupling, and transmitting a carrier wave derived from the carrier generation means to the transmission line by electrostatic or electromagnetic coupling. A video demodulator installed near a master unit of the intercom apparatus, comprising: two bidirectional carrier coupling means; and a video demodulation means for demodulating a video carrier derived from the second bidirectional carrier coupling means. It is characterized by. Further, the modulation means is an FM modulation means.

Therefore, the camera device provided near the slave unit side of the existing intercom device derives a video signal of the subject by the imaging means. This video signal is broadband (DC to 4M
Hz), and modulation such as FM modulation is performed by a modulation unit in order to coexist with a bidirectional audio signal having a band of 20 Hz to 5 kHz to be transmitted to a two-wire transmission line of an existing intercom apparatus. The modulated video carrier is coupled to the transmission line of the intercom apparatus by electrostatic coupling or electromagnetic coupling by the first bidirectional carrier coupling means, and transmitted to the master unit side of the intercom apparatus via the transmission line. I do.

The video carrier transmitted to the video demodulation device provided near the master unit side of the intercom device via the transmission line is derived by the second bidirectional carrier coupling means provided in the video demodulation device. It is supplied to demodulation means. In this video demodulating means, the derived video carrier is FM
Demodulation such as demodulation is performed, and the video signal of the subject is reproduced, output to a monitor or the like, and the video of the subject is projected.

On the other hand, a carrier different from the carrier of the video carrier is output from the carrier generating means provided in the video demodulator, and the carrier is combined with the existing carrier by the second bidirectional carrier coupling means. It is coupled to the transmission line of the intercom device by electrostatic coupling or electromagnetic coupling, and is transmitted to the slave unit side of the intercom device via this transmission line.

The carrier transmitted to the slave unit side of the intercom apparatus via the transmission line is extracted through first bidirectional carrier coupling means coupled to the transmission line by electrostatic coupling or electromagnetic coupling. And detected by the carrier detection means. When the carrier detection unit detects a carrier wave transmitted from the video demodulation device, the battery power supply unit operates to supply battery power to each unit of the camera device. When a carrier wave from the video demodulation device is not detected by the carrier wave detecting means, the battery power supply means shuts off battery power to each unit other than the carrier wave detecting means.

[0021] The television intercom apparatus according to claim 4 is characterized in that:
The first or second carrier coupling means is provided in parallel with a first antenna conductor constituting a part of the transmission line and connected to the modulation means or the video demodulation means. It is characterized by comprising a second or third antenna conductor and transmitting and receiving a video carrier wave to and from the transmission line by antenna coupling.

Therefore, in the camera device provided near the slave unit of the existing intercom device, the image carrier modulated by the modulation means such as the FM modulation is transmitted to the second antenna conductor in the first bidirectional carrier coupling means. , And taken out of the first antenna conductor arranged side by side by antenna coupling, supplied to the transmission line, and transmitted to the master unit side of the intercom apparatus.

The video carrier transmitted to the master unit is supplied to the second bidirectional carrier coupling means of the video demodulator provided near the master unit, and the third carrier is coupled to the third bidirectional carrier by the antenna from the first antenna conductor. It is derived via the antenna conductor. The video carrier derived from the third antenna conductor is converted to F
Demodulation such as M demodulation is performed and derived as a video signal of the subject.

[0024] Further, the television door phone apparatus according to claim 5 is characterized in that:
In the television door phone apparatus according to claims 2 and 3, switching means for selectively operating the carrier generation means is provided.

Accordingly, when the switching means is turned on and off manually or the like, the carrier wave generating means is selectively operated in response thereto, and is provided from the master unit of the existing intercom apparatus to the slave unit of the intercom apparatus. The carrier from the carrier generator is selectively transmitted to the carrier detector. As a result, when the switching means is turned on,
Battery power is supplied from the battery power supply unit to each unit of the camera device by the output of the carrier wave detection unit, and the camera device is brought into an operating state. When the switching means is turned off,
Since the carrier wave is no longer detected by the carrier wave detection means, the battery power supply means supplies the battery power only to the carrier wave detection means and does not supply the battery power to the other parts by the output detected by the detection, and the camera device Is set to a standby state to extend the life of the battery power supply.

[0026]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 shows Embodiment 1 of the present invention.
FIG. 3 is a block diagram showing a configuration of the present invention, in which a video signal from a camera device is serially coupled to one line of a two-wire transmission line in an existing intercom device. In FIG. 1, portions corresponding to those of the conventional example are denoted by the same reference numerals, and description thereof is omitted.

The image of the visitor obtained through the lens 38 of the camera device 47 is converted into a composite image signal by the CCD 39 and the image signal processing circuit 41 controlled by the timing signal generation circuit 40. The composite video signal output from the video signal processing circuit 41 is F
FM modulation by the M modulation circuit 42 to generate a video carrier,
The signal is coupled to a two-wire transmission line 60 for an intercom device via a bidirectional carrier coupling circuit 43 and transmitted. The carrier wave is converted by the bidirectional carrier coupling circuit 43 into a camera device 47.
A specific method of coupling transmission between the transmission line and one line of the transmission line 60 will be described later.

Since the bidirectional baseband audio signals between the handset 14 and the base unit 15 of the existing intercom are transmitted on the transmission line 60, the composite video signal of these audio signals and video signals is transmitted. To coexist on the transmission line 60, the video signal is
It is necessary to perform FM modulation.

The FM modulated video carrier is transmitted by a bidirectional carrier coupling circuit 43 onto a two-wire transmission line 60 for an intercom device, propagates on the transmission line 60, and is provided in a video demodulation device 54. The bidirectional carrier coupling circuit 49 detects the video carrier from the camera device 47, demodulates it by the video FM demodulation circuit 50, and outputs the original composite video signal. The bidirectional carrier coupling circuit 49 may have the same configuration as the bidirectional carrier coupling circuit 43 provided in the camera device 47.

By connecting the composite video signal output to a television, a visitor can be easily seen. Further, it may be connected to a dedicated monitor TV. The power supply unit 52 in the video demodulation device 54 is a battery power supply that can be operated by a battery. However, the power supply unit 52 can also be configured to supply power from the base unit 15 unless it interferes with the base unit 15 of the intercom apparatus. .

On the other hand, it is technically possible to supply the power in the camera device 47 from the slave unit 14 of the intercom device. However, in order not to adversely affect the function of the interphone itself, the battery power source 37 is provided. Is preferred. The battery power source 37 needs to have a long life so that the battery need not be replaced frequently. Therefore, another carrier is selectively generated by the carrier switch 53 from the carrier generation circuit 51 in the video demodulation device 54, and the camera device is completely operated only when this carrier is detected by the camera device 47. The operation time of the camera device 47 is minimized.

Another carrier derived from the carrier generation circuit 51 is transmitted on the transmission line 60 by electrostatic coupling or electromagnetic coupling on the same principle as that of the video carrier. Then, the battery power is transmitted to the camera device 47 and detected by the carrier wave detection unit 44 in the camera device 47. Control. When the camera device 47 does not detect the carrier wave from the video demodulation device 54, only the carrier wave detection unit 44 is energized to put the camera device 47 in a standby state, and only monitors the arrival of the carrier wave from the video demodulation device 54. State to extend the life of the battery.

As described above, the carrier switch 53 is turned on.
By simply performing the / OFF operation, an outdoor image can be monitored regardless of the presence or absence of a visitor, that is, regardless of the operation of the slave unit 14 and the master unit 15 of the intercom. Will also be able to.

FIG. 2 is a diagram showing a specific configuration of the bidirectional carrier coupling circuit 43 of the camera device 47 or the bidirectional carrier coupling circuit 49 of the video demodulation device 54 in FIG. Are denoted by the same reference numerals, and description thereof is omitted. In FIG. 2, 43-1 (or 49-1)
Is the FM of the camera device 47 (or the video demodulation device 54)
A bidirectional carrier coupling circuit 43 (or 49) for supplying an output of the modulation circuit 42 (or the carrier generation circuit 51) to one line of the transmission line 60 of the intercom apparatus in series;
It is composed of a high-frequency transformer T1 provided with a primary winding 70 and a secondary winding 71 and a tertiary winding 72 electromagnetically coupled thereto.

The primary winding 70 is connected in series to one line of the two-wire transmission line 60 of the intercom apparatus via terminals A and D (or a and d), and the secondary winding 71 is connected to the terminal E
(Or e) through the FM modulation circuit 42 of the camera device 47 (or the carrier generation circuit 5 of the video demodulation device 54).
The tertiary winding 72 is connected to the output terminal
Via (or f), it is connected to the input terminal of the carrier detection unit 44 of the camera device 47 (or the video FM modulation circuit 50 of the video demodulation device 54). Terminals B and C (or b and c) are internally short-circuited and connected in series to the other line of the transmission line 60.

As described above, the bidirectional carrier coupling circuit 43-
1 (or 49-1) high-frequency transformer T1
The primary, secondary and tertiary windings 70, 71 and 72 are electromagnetically coupled, so that the output of the FM modulation circuit 42 (or the carrier generation circuit 51) is output from the terminal E (or e) to the secondary winding. The signal is supplied to the transmission line 60 of the intercom apparatus via the wire 71 and the primary winding 70 and transmitted to the other party.

The camera device 47 is transmitted via the transmission line 60.
The video signal (or carrier) transmitted from the video demodulator 54 (or the video demodulator 54)
-1 (or 43-1) via the terminals a, b, c, d (or A, B, C, D) to the primary winding 70 of the high-frequency transformer T1 and the tertiary winding 72 Via terminal f
(Or F) to the video FM demodulation circuit 50 (or the carrier detection unit 44).

(Embodiment 2) FIG. 3 shows Embodiment 2 of the present invention.
3 is a configuration diagram of a main part of FIG. In FIG. 3, FIG. 1 and FIG.
The same reference numerals are given to the portions corresponding to and the description is omitted.
FIG. 3 shows another specific configuration of the bidirectional carrier coupling circuit 43 (or 49) shown in FIG. 1. The bidirectional carrier coupling circuit 43-2 (or 49-2) shown in FIG. Bidirectional carrier coupling circuit 43-1 (or 49-
The difference from 1) is that the latter uses an electromagnetic induction by a high-frequency transformer to transmit and receive signals, whereas the former uses a high-frequency electromagnetic coupling by an antenna line. Yes, other configurations are substantially the same.

In FIG. 3, 43-2 (or 49-
2) is a bidirectional carrier coupling circuit, and the bidirectional carrier coupling circuit 43-2 (or 49-2)
0, a first antenna conductor 80 constituting a part of one of the lines, and a second antenna conductor 81 and a third antenna conductor 82 which are arranged adjacent to and opposed to each other.
The first antenna conductor 80 and the second and third antenna conductors 81 and 82 are kept in a fixed positional relationship with each other by a fixing member 84 made of a dielectric or the like.

Therefore, the first antenna conductor 80 and the second,
High frequency coupling is performed between the third antenna conductors 81 and 82 by desired electromagnetic induction. The first antenna conductor 80
Represents a transmission line 6 via terminals A and D (or a and d).
0 is connected in series to one line, and terminals B and C (or b and c) are short-circuited and connected in series to the other line of the transmission line 60.

The second antenna conductor 81 is connected to the output terminal of the FM modulation circuit 42 (or the carrier generation circuit 51) provided in the camera device 47 (or the video demodulation device 54) via the terminal E (or e). Connected to the third
The antenna conductor 82 is connected via a terminal F (or f) to an input terminal of the carrier wave detector 44 (or the video FM modulation circuit 50) provided in the camera device 47 (or the video demodulator 54).

Accordingly, the video carrier (or the carrier) from the FM modulation circuit 42 (or the carrier generation circuit 51) provided in the camera device 47 (or the video demodulator 54).
Is connected to the second antenna conductor 81 from the terminal E (or e).
And is extracted from the first antenna conductor 80 which is high-frequency-coupled to the second antenna conductor 81. And
The signal is supplied to the transmission line 60 and transmitted to the video demodulation device 54 (or the camera device 47) via the transmission line 60.

The video carrier waves (or carrier waves) transmitted from the camera device 47 (or the video demodulation device 54) via the transmission line 60 are connected to terminals a, b, c, and d.
(Or A, B, C, D) to the first antenna conductor 80 and a terminal f (or F) from a third antenna conductor 82 electromagnetically coupled to the first antenna conductor 80.
And supplied to the video FM demodulation circuit 50 (or the carrier detection unit 44).

(Embodiment 3) FIG. 4 shows Embodiment 3 of the present invention.
The same reference numerals are given to portions corresponding to FIG. 1 and the description is omitted. Embodiment 3 shown in FIG. 4 is different from Embodiment 1 shown in FIG. 1 in that the latter connects a bidirectional carrier coupling circuit in series to the transmission line, while the former connects in parallel. The other configuration is the same.

In FIG. 4, reference numeral 90 denotes a bidirectional carrier coupling circuit provided in the camera device 47, and reference numeral 91 denotes a bidirectional carrier coupling circuit provided in the video demodulation device 54. The terminals G and H of the bidirectional carrier coupling circuit 90 are connected to the input / output terminal of the slave unit 14 of the intercom apparatus to which the transmission line 60 is connected via the transmission line 45, and the terminal I is connected to the FM modulation circuit 42.
And the terminal J is connected to the input terminal of the carrier detection unit 44. The bidirectional carrier coupling circuit 91
Are connected via the transmission line 48 to the input / output terminal of the parent device 15 of the intercom apparatus to which the transmission line 60 is connected, the terminal i is connected to the output terminal of the carrier generation circuit 51, and the terminal j is connected to the input terminal. It is connected to the input terminal of the video FM demodulation circuit 50.

The above two-way carrier coupling circuits 90 and 91
May have the same configuration, and FIG. 5 shows a specific configuration thereof. 5 differs from the bidirectional carrier coupling circuit of the first embodiment shown in FIG. 2 in that a DC cut capacitor 1 is connected in series with a primary winding 100 between terminals G and H (or g and h).
03, and the terminals G and H (or g and h) are connected in parallel to the transmission line 60 of the intercom apparatus via the transmission line 45 (or 48) on the side of the slave unit 14 (or master apparatus 15) of the intercom apparatus. That is, it is a configuration.

Accordingly, the signal is supplied from the FM modulation circuit 42 (or the carrier wave generation circuit 51) of the camera device 47 (or the video demodulation device 54) to the secondary winding 101 of the high-frequency transformer T2 via the terminal I (or i). The video carrier wave (or carrier wave) is taken out to the primary winding 100 electromagnetically coupled to the secondary winding 101, and is transmitted via the DC cut capacitor 103 and the terminals G and H (or g and h) to the transmission line 45 (or the carrier). 48), is supplied in parallel to the transmission line 60, and is supplied to the video demodulation device 54 (or the camera device 4).
Transmitted to 7).

The video carrier (or carrier) transmitted from the camera device 47 (or the video demodulator 54) via the transmission line 60 is transmitted via the transmission line 48 (or 45) to the terminals g and h ( Or G, H). The video carrier (or carrier) supplied to the primary winding 100 is
00 is induced in the tertiary winding 102 electromagnetically coupled to
The signal is supplied to the video FM demodulation circuit 50 (or the carrier detection unit 44) of the video demodulation device 54 (or the camera device 47) via (or J).

In the third embodiment, the terminals G and H (or g and h) on the primary side of the bidirectional carrier coupling circuits 90 and 91 need only be connected in parallel to the transmission line 60 of the intercom apparatus. The transmission line 60 does not need to be modified.

(Embodiment 4) FIG. 6 is a circuit diagram showing a configuration of a main part of Embodiment 4 of the present invention, and shows a specific configuration of bidirectional carrier coupling circuits 90 and 91 of FIG. . 6, parts corresponding to those in FIG. 5 are given the same reference numerals, and descriptions thereof will be omitted. FIG. 6 differs from FIG. 5 in that FIG. 5 shows that the transmission line 60 and the camera device 47 or the video demodulation device 54 are electromagnetically coupled by a high-frequency transformer T2, but the circuit of FIG. Let me.

Capacitors C1 and C3 are connected between terminal G (or g) of bidirectional carrier coupling circuit 90-2 (or 91-2) and one of terminals I (or i) and J (or j). And capacitors C2 and C4 are provided between the terminal H (or h) and the other terminal of the terminal I (or i) and the terminal J (or j).

Therefore, the video carrier (or carrier) output from the FM modulation circuit 42 (or the carrier generation circuit 51) of the camera device 47 (or the video demodulation device 54) connects the capacitors C1 and C2 from the terminal I (or i). To the terminals G and H (or g and h) via the transmission line 45 (or 48).
0 and transmitted to the video demodulation device 54 (or the camera device 47).

The camera device 47 (or the video demodulation device 5)
4) The video carrier (or carrier) transmitted through the transmission line 60 from the terminal g, h (or G,
H) through the capacitors C3 and C4 to the terminal j (or J), and is supplied to the video FM demodulation circuit 50 (or the carrier detection unit 44) to demodulate (or detect) the video carrier (or the carrier). .

In the embodiment shown in FIGS. 1 and 4, the bidirectional carrier coupling circuits 43, 49 and 90, 91
Exemplifies the same configuration, but these bidirectional carrier coupling circuits are used by appropriately combining any of the circuits shown in FIGS. 2, 3, 5, and 6. be able to.

[0056]

Since the present invention has the above-described configuration, a video demodulator and a camera device are provided near the master unit and the slave unit of the existing interphone device, respectively, and the interphone is connected via a carrier coupling circuit. It is only necessary to connect the output of the video demodulation device to a monitor such as a television receiver in addition to the electromagnetic coupling or the electrostatic coupling to the existing transmission line of the device. it can. Also, since the video signal of the subject imaged by the camera device is subjected to modulation such as FM modulation, it can be directly superimposed on the transmission line of the existing intercom device for transmitting the bidirectional audio baseband signal and transmitted. Since no new transmission line is required, the installation work can be made extremely simple.

Further, a carrier different from the video carrier from the camera device is generated in the video demodulator provided on the master unit side of the existing intercom apparatus, and this carrier is transmitted through the bidirectional carrier coupling circuit and the transmission line. Since it is superimposed on the audio baseband signal and video carrier and transmitted to the camera device side,
The camera device detects the carrier, and when the carrier is detected, the battery power of the camera device is fully operated.When the carrier is not detected, the battery power can be controlled to a standby state. By controlling the battery power of the camera device from the video demodulation device side, the life of the battery power can be extended.

The carrier generated by the carrier generation circuit of the video demodulation device can be selectively transmitted to the camera device by a manual carrier switch provided on the video demodulation device. By turning on the carrier switch when the visitor comes and the machine rings, the video can be viewed only by a simple operation when there is a visitor.

Even when there is no visitor, that is, when the intercom device is not operating, if the above-mentioned carrier switch is turned ON on the master unit side, the outdoor image can be displayed as a monitor camera separated from the intercom device by a simple operation. Can be monitored. As described above, when a camera device that is generally installed outdoors is unnecessary, the base device can control the camera device to be in a standby state, so that the battery power of the camera device can be prolonged with a simple operation.

[Brief description of the drawings]

FIG. 1 is a block diagram of a first embodiment of the present invention.

FIG. 2 is a configuration diagram of an embodiment of a main part of FIG. 1;

FIG. 3 is a configuration diagram of another embodiment of a main part of FIG. 1;

FIG. 4 is a block diagram of a second embodiment of the present invention.

FIG. 5 is a configuration diagram of one embodiment of a main part of FIG. 4;

FIG. 6 is a configuration diagram of another embodiment of a main part of FIG. 4;

FIG. 7 is a block diagram showing a configuration of a conventional intercom device.

FIG. 8 is a block diagram showing a configuration of a conventional TV door phone apparatus.

[Explanation of symbols]

 14 slave unit 15 base unit 37 battery power supply 38 lens 39 CCD 40 timing generation circuit 41 video signal processing circuit 42 FM modulation circuit 43 bidirectional carrier coupling circuit 43-1 bidirectional carrier coupling circuit 43-2 bidirectional carrier coupling circuit 44 carrier Detector 45 Transmission line 47 Camera device 48 Transmission line 49 Bidirectional carrier coupling circuit 49-1 Bidirectional carrier coupling circuit 49-2 Bidirectional carrier coupling circuit 50 Video FM modulation circuit 51 Carrier generation circuit 53 Carrier switch 54 Video demodulation device 60 Transmission line 70 Primary winding 71 Secondary winding 72 Tertiary winding 80 First antenna conductor 81 Second antenna conductor 82 Third antenna conductor 90 Bidirectional carrier coupling circuit 90-1 Bidirectional carrier coupling circuit 90 -2 bidirectional carrier coupling circuit 91 bidirectional carrier coupling circuit 91-1 both Directional carrier coupling circuit 91-2 Bidirectional carrier coupling circuit 100 Primary winding 101 Secondary winding 102 Tertiary winding T1 High frequency transformer T2 High frequency transformer C1 capacitor C2 capacitor C3 capacitor C4 capacitor

Claims (5)

[Claims] An imaging device for deriving a video signal of a subject, a modulation device for modulating a video signal derived from the imaging device, and a video carrier modulated by the modulation device being electrostatically transferred to a transmission line of an existing intercom device. A camera device installed in the vicinity of the slave unit of the intercom apparatus having first carrier coupling means for transmitting by coupling or electromagnetic coupling, and electrostatically or electromagnetically coupling a video carrier transmitted through the transmission line. A video demodulation device is provided near the master unit of the intercom device, comprising: a second carrier coupling means for extracting by coupling; and a video demodulation means for demodulating a video carrier derived from the second carrier coupling means. Television doorphone device characterized by the above-mentioned. 2. An imaging means for deriving a video signal of a subject, a modulation means for modulating a video signal derived from the imaging means, and a video carrier modulated by the modulation means being electrostatically transferred to a transmission line of an existing intercom apparatus. A first method for transmitting by coupling or electromagnetic coupling, and a method for deriving, via electrostatic transmission or electromagnetic coupling, a carrier wave transmitted from a video demodulation device installed near the master unit of the intercom device via the transmission line. Carrier coupling means, carrier detection means for detecting a carrier wave derived from the first bidirectional carrier coupling means, and a battery power supply for supplying power to each section only when the carrier wave is detected by the carrier detection means A camera device installed in the vicinity of the slave unit of the intercom device having means is provided, and a carrier wave generating means for generating the carrier wave,
A second bidirectional transmission of the image carrier transmitted through the transmission line by electrostatic coupling or electromagnetic coupling, and the transmission of the carrier derived from the carrier generation means to the transmission line by electrostatic coupling or electromagnetic coupling. A video demodulation device provided near a master unit of the intercom device, comprising: a carrier coupling means; and a video demodulation means for demodulating a video carrier derived from the second bidirectional carrier coupling means. TV intercom equipment. 3. The television intercom apparatus according to claim 1, wherein said modulation means is FM modulation means. 4. The first or second carrier coupling means comprises: a first antenna conductor forming a part of the transmission line; and the modulation means or the video signal provided side by side with the first antenna conductor. 2. The television intercom apparatus according to claim 1, further comprising a second or third antenna conductor connected to the demodulation means, and transmitting and receiving the video carrier to and from the transmission line by antenna coupling. 5. A switching means for selectively operating said carrier generating means is provided.
And the television doorphone device according to 3.