JP2000165851A - Video door-phone system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure an excellent image during a call in an image output state and to apply lighting/put out lights control to a gate light by transmitting detec tion information such as lightness of a house entrance or the like into a house. SOLUTION: A call signal outputted through the operation of a call button 10 of a slave set 1 in an image output state and detection information of lighting/put out lights of a display light 20 driven on the basis of information such as lightness at a house entrance detected by an environment sensor 19 are superimposed in different timing only for a blanking period of a video signal outputted from a camera 12 as a positive voltage higher than a white peak of the video signal and transmitted to a demodulation circuit 32 of a master set 2. The demodulation circuit detects the demodulated output of the call signal during a call in the image output state and of the detection information on the basis of the positive voltage. Thus, an image of a visitor during a call in the image output state is displayed by a monitor unit 36 as an excellent image and a gate light 3 is lighting/put out lights controlled based on the detection information.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television door phone system, and more particularly to a door light device which secures a good image during a call at the time of displaying an image and transmits detection information such as the brightness of the entrance of the dwelling unit to the dwelling unit. The present invention relates to a TV door phone device capable of controlling turning on / off of a TV door phone.

[0002]

2. Description of the Related Art Conventionally, as this type of video door intercom, a video door intercom having a configuration shown in a block diagram of FIG. 2 has been proposed. The TV intercom apparatus shown in FIG. 1 includes a call button 60, a child device first call detection circuit 61, a camera 62, a modulation circuit 63, a child device CPU 64, and a telephone call circuit 6.
5. Handset speaker 66, handset microphone 67, environment sensor 6
8, indicator light 69 composed of white LED, etc., power supply circuit 7
0, a slave unit 51 provided with a multiplexing circuit 71 and installed at the entrance of a dwelling unit (hereinafter, referred to as a dwelling unit entrance), a base unit first call detection circuit 80, an image output call detection circuit 81, a demodulation circuit 82, and a base unit C
Master unit provided with PU83, loudspeaker amplifier 84, loudspeaker 85, monitor unit 86, communication circuit 87, handset 88 including master unit microphone 88a and receiver 88b, slave unit power supply circuit 89, and multiplex circuit 90 and installed in the dwelling unit 5
The slave unit 51 and the master unit 52 are connected by a transmission line L51 including a signal transmission line and a power supply line.

[0003] In the TV intercom apparatus configured as described above, a visitor calls a resident in a dwelling unit.
When the call button 60 of the slave unit 51 installed at the entrance to the dwelling unit is operated (hereinafter, this operation is referred to as an initial call operation), the slave unit first call detection circuit 61 detects this initial call operation, and sets the multiplex circuit 71. The DC voltage level of the transmission line L51 is dropped via the transmission line L51. Master unit 52 installed in the called dwelling unit
The base unit first call detection circuit 80 outputs to the base unit CPU 83 a first call detection signal S101 that detects a first call operation due to a voltage drop of the DC voltage level of the transmission line L51. Master C
The PU 83 detects an initial call operation by the visitor from the input first call detection signal S101, activates the monitor unit 86 and the slave unit power supply circuit 89, respectively, and makes an initial ring sound signal for sounding the loudspeaker 85. S102 is output to the loudspeaker amplifier 84. The first ringing signal S102 is amplified via the loudspeaker amplifier 84 and emitted from the loudspeaker 85 as a ringing sound. This allows
The resident is notified of the first call operation by the visitor. Also, the power from the activated slave power supply circuit 89 is
The power is supplied from the power supply circuit 70 to each circuit (each unit) in the slave unit 51 as appropriate via the multiplexing circuit 90, the transmission line L51, and the multiplexing circuit 71 of the slave unit 51.

The camera 62 of the slave unit 51 activated by the power supply from the slave unit power supply circuit 89 of the master unit 52 outputs a video signal S111 obtained by capturing an image of a visitor to the modulation circuit 63 and simultaneously outputs a vertical synchronizing signal. S121 is output to the slave unit CPU 64. The video signal S111 is transmitted to the demodulation circuit 82 via the multiplexing circuit 71, the transmission line L51, and the multiplexing circuit 90 of the master unit 52 as a video modulation signal S112 modulated (FM modulated) by the modulation circuit 63. At 82 (FM
The demodulated video demodulated signal S113 is input to the monitor unit 86. The monitor unit 86 outputs an image of the visitor at the time of the first call operation captured by the camera 62 of the slave unit 51 from the input video demodulation signal S113.

[0005] Next, before the image of the visitor is displayed on the monitor unit 86 of the base unit 52 and before the resident picks up the handset 88, the visitor sets the child unit 5
When the first call button 60 is operated again (hereinafter, this operation is referred to as an image output call operation), the slave unit CPU 64 outputs the vertical synchronization signal S121 output from the camera 62 and the image output from the call button 60. And a control signal S123 for turning off the carrier output from the modulation circuit 63 only during a blanking period of the video signal output from the camera 62, and modulates the control signal S123 together with the output call signal S122. Output to the circuit 63. As a result, the image output call signal S122 input to the modulation circuit 63 is converted into the image output call signal S132 with the carrier output intermittent as the multiplexing circuit 7.
1, transmitted through the transmission line L51 and the multiplexing circuit 90 of the master unit 52 to the image output call detection circuit 81,
The image output call detection signal S133 detected at the time of image output call 1
Is input to the master unit CPU 83. The base unit CPU 83 detects the call-out operation at the time of image display by the visitor from the input call-out detection signal S133 at the time of image display, and performs the image-call operation for sounding the loudspeaker 85 in the same pattern as the above-described first-time call operation. The sound signal S103 is output to the loudspeaker amplifier 84. The image calling ringing signal S103 is amplified through the loudspeaker amplifier 84 and emitted from the loudspeaker 85 as a ringing sound.
Thereby, the resident is notified of the calling operation at the time of image output by the visitor.

[0006] During the above-described calling at the time of image output, the video signal S141 output from the camera 62 of the slave unit 51 is output from the carrier output via the modulation circuit 63 unless the call button 60 is intermittently operated by the visitor. Is stored and modulated (FM modulation) as a video modulated signal S142, which is subjected to signal processing (video demodulated signal S143) via the same path as the video modulated signal S112 transmitted at the time of the first call operation, and transmitted to the monitor unit 86 of the master unit. Is done. The monitor unit 86 converts the input video demodulated signal S143 into the camera 6 of the slave unit 51.
The image of the visitor who is calling at the time of image output captured in 2 is output.

Next, the environment sensor 68 of the slave unit 51 activated by the power supply from the slave unit power supply circuit 89 of the master unit 52.
Is the surrounding environment of the dwelling unit where the slave unit 51 is installed (hereinafter, referred to as
(Referred to as the dwelling entrance). Here, when the above-mentioned first call operation by the visitor is performed, for example, at night when the sun goes down, and the environment sensor 68 detects that the brightness of the front door of the dwelling unit is lower than a certain level, the child unit CPU 6
By the control of 4, the indicator lamp 69 is turned on. This allows
The image of the visitor after the first calling operation, which is captured by the camera 62 of the child device 51, is sequentially output on the monitor unit 86 of the parent device 52 as a good image in which the illuminance is secured.

[0008] Further, when the resident in the dwelling unit picks up the handset 88 of the base unit 52 for answering the call during the first call operation by the visitor and the call at the time of image display, the call path (not described in detail). ) Is formed and the call is established.

[0009]

However, since the conventional video doorphone apparatus is configured as described above, the video signal output from the camera of the slave unit during the calling at the time of image output is blanking of the video signal. Outside the period, the carrier output via the modulation circuit is turned off. This allows
The demodulated output from the demodulation circuit of the master unit operated on the DC potential to the monitor unit is also “0”. This is because the demodulated output from the demodulation circuit is masked with a pulse larger than the level (base level) of the video signal synchronization signal, and the monitor unit uses this pulse as a synchronization (vertical synchronization, horizontal synchronization) signal. Because of the error, the vertical synchronization disturbance causes the vertical movement of the entire screen, and the horizontal synchronization disturbance causes the left and right movement of the upper part of the screen, which makes it difficult to secure a good image during calling during image output. There were difficulties.

[0010] Further, by turning off the carrier output from the modulation circuit of the slave unit, the image output call signal by the visitor's image output call operation is transmitted to the master unit. Cannot be transmitted to the master unit. As a result, there is a problem in that the resident in the dwelling unit cannot check whether the indicator light of the slave unit is on or off. The present invention has been made in order to solve the above-mentioned difficulties, and a calling signal output by operating a calling button (calling operation) of a slave unit at the time of displaying an image is not a signal in which a carrier is intermittently output.
During the blanking period of the video signal output from the camera of the slave unit during the calling at the image output, the positive voltage higher than the white peak of the video signal is superimposed and transmitted to the master unit, and during the calling at the image calling, By setting the demodulation output from the demodulation circuit to a positive voltage, the screen of the monitor unit (whole screen, upper part of the screen) is eliminated and a good image is secured, and the entrance of the dwelling unit detected by the environment sensor of the slave unit The detection information of the turning on / off of the indicator light driven based on the information of the brightness is used as a positive voltage which is a calling signal at the time of image output during a blanking period of a video signal output from the camera. It is an object of the present invention to provide a television intercom apparatus that superimposes the video data at a different timing from the video data and transmits the video data to the parent device.

[0011]

In order to achieve the above object, a television intercom apparatus according to the present invention lowers the DC voltage of a transmission line by an initial call detection circuit of a slave unit when a call button of the slave unit is operated. This is detected by the base unit initial call detection circuit of the base unit, the base unit CPU receives the detection signal from the base unit first call detection circuit, recognizes that the call button has been operated, and generates a first ringing sound signal. A ringing tone sounds from the loudspeaker, power is supplied to the slave unit by the slave unit power supply circuit, a video signal obtained by imaging the visitor with the camera is modulated by the modulation circuit, and is demodulated by the demodulation circuit of the master unit. The video signal is output on the monitor unit and the handset is picked up to enable communication between the slave speaker of the slave unit and the microphone of the slave unit and the handset of the master unit. A video door phone device which detects a call at image output from a call signal at image output when the output button is operated again, inputs a vertical synchronization signal from the camera to the slave unit CPU, and sounds a ringing tone from a loudspeaker. The slave unit receives the calling signal at the time of image output and the vertical synchronizing signal.
A DC voltage superimposing circuit that superimposes a positive voltage higher than the white peak of the video signal on the video signal only during a blanking period of the video signal is provided. A demodulated video signal is inputted, and a picture output call detection circuit for separating / detecting a picture output call signal and inputting the signal to the master CPU is provided. The slave detects the surrounding environment and detects the signal. Information is transmitted from the slave unit CPU to the parent device via the DC voltage superimposing circuit, modulation circuit, demodulation circuit, and image display call detection circuit at a timing different from the image calling signal within the blanking period by the vertical synchronization signal of the camera. C
It has an environmental sensor for transmitting to the PU.

According to such a TV door phone apparatus,
Illumination of an indicator lamp driven based on a call signal output by operating a call button (call operation) of a slave unit at the time of image display, and information such as brightness of a dwelling entrance detected by an environment sensor. The / off detection information is superimposed at different timings as positive voltages higher than the white peak of the video signal only during the blanking period of the video signal output from the camera, and transmitted to the demodulation circuit of the master unit. Further, the demodulation circuit of the master unit detects a demodulated output of a call signal and detection information during a call at the time of image output from a positive voltage. As a result, the image captured by the camera during the calling at the time of image output is output as a good image without causing the screen (the entire screen, the upper part of the screen) to be blurred by the monitor unit of the master unit, and is detected. The gate light can be turned on / off based on the information.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a preferred embodiment of a television intercom apparatus according to the present invention. FIG. 1 is a block diagram showing a configuration of an embodiment of a TV door phone apparatus according to the present invention, which is a call operation function by a visitor, an image taking function for taking an image of a visitor, and detecting and securing the brightness of a front door of a dwelling unit. The handset 1 installed at the entrance to the dwelling unit, which has a function of detecting and holding the illuminance, and the function of calling with the resident in the called dwelling unit, a call notification function at the time of a call operation by the visitor, and an image taken by the handset 1 A main unit 2 which is provided in the dwelling unit and has an image reproduction function for displaying an image and a call function with a calling visitor, and a gate light 3 which is turned on / off under the control of the main unit 2 and is set up at the entrance of the dwelling unit. And the child device 1 and the parent device 2
The master unit 2 and the gate light 3 are connected by a control line L2 connected to a power supply of 100 V AC, which is connected by a transmission line L1 consisting of a signal transmission line and a power supply line.

The handset 1 includes a call button 10 operated by a visitor to call a resident in the dwelling unit, and a handset that detects an operation of the call button 10 at the time of first call (first call operation) by the visitor. A first call detection circuit 11, a camera 12 which captures an image of a visitor and sequentially outputs a video signal in each frame, and simultaneously outputs a vertical synchronization signal to a slave CPU 15 which will be described later;
DC voltage superimposing circuit 13 for superimposing a positive voltage higher than the white peak of the video signal only during the blanking period of the video signal output from the CPU, and modulating the video signal and the video positive voltage superimposed signal via the DC voltage superimposing circuit 13 (FM modulation) a modulation circuit 14, detection of an operation of a call button 10 by a visitor at the time of display (call operation at display) or detection information from an environment sensor 19 to be described later, and a vertical signal output from the camera 12. A slave unit CPU 15 that controls the DC voltage superimposing circuit 13 at different timings by a synchronization signal, a slave unit speaker 17 used by a visitor to establish a call with a resident in the dwelling unit, and a slave unit microphone 18 are connected to each other. , An environment sensor 19 for detecting the brightness of the entrance of the dwelling unit, and a white LE which is turned on / off under the control of the slave unit CPU 15. A power supply circuit 21 for appropriately supplying power via a transmission path L1 from a slave power supply circuit 39 of the master unit 2 to each circuit (each unit) in the slave unit 1, which will be described later. A multiplexing circuit 22 for multiplexing various signals transmitted and received between the above-described circuits (each unit) in the slave unit 1 and the transmission line L1 is provided.

The base unit 2 includes a base unit first call detection circuit 30 and a screen display call detection circuit 31 for detecting the above-mentioned first call operation and image display call operation by the visitor, respectively. A demodulation circuit 32 for demodulating (FM demodulating) the video modulation signal and the video positive voltage superimposed modulation signal via L1, respectively;
Base unit first call detection circuit 30 and image output call detection circuit 3
The monitor unit 36, which will be described later, uses a detection signal (such as a first call detection signal, a picture-time call detection signal, etc.) output from
A main unit CPU 33 that outputs a ringing signal (first ringing signal, ringing signal at the time of image output) for activating the slave unit power supply circuit 39 and ringing the loudspeaker 35;
The loudspeaker amplifier 34 amplifies the ringing tone signal output from the base unit CPU 33, the loudspeaker 35 that emits the ringing tone signal as a ringing tone via the loudspeaker amplifier 34, and the camera 12 of the slave unit 1, A monitor unit 36 for displaying an image of the visitor after the first call operation is connected to a handset 38 including a base unit microphone 38a and a receiver 38b used by a resident in the dwelling unit to establish a call with the visitor. A communication circuit 37 for forming a communication path;
And a slave power supply circuit 3 that is activated by the control of the slave unit 3 and supplies power for starting the operation of each circuit (each unit) of the slave unit 1
9 and master unit C for driving (lighting / extinguishing) the gate light 3
The relay switch 40 which is turned on / off under the control of the PU 33, each circuit (each part) in the master unit 2 and the transmission line L1
And a multiplexing circuit 41 for multiplexing various signals transmitted and received between them.

A multiplexing circuit 22 of the handset 1 connected to the transmission line L1 via the line connection terminal T1 has an output side of the first call detection circuit 11 of the handset, a modulation circuit 14, and a DC voltage superimposing circuit 13 connected thereto. A video output side of the camera 12 and a communication circuit 16 to which a slave speaker 17 and a slave microphone 18 are connected.
And the input side of the power supply circuit 21 are connected to each other. The first input terminal P1 of the slave unit CPU 15 has:
The connection point between the other end of the call button 10 whose one end is connected to the reference potential point and the input side of the slave unit first call detection circuit 11 is the second connection point.
The input terminal P2 has a vertical synchronization output side of the camera 12, the third input terminal P3 has an environment sensor 19, the first output terminal P4 has a control input side of the DC voltage superposition circuit 13, and the second output terminal P4 has a second input terminal P2.
The indicator lamps 20 are respectively connected to the output terminals P5.

In the multiplexing circuit 41 of the base unit 2 connected to the transmission line L1 via the line connection terminal T2, the input side and the output side of the base unit first call detection circuit 30 are connected to the image output call detection circuit 31.
Of the demodulation circuit 32 connected to the input side of the monitor unit 36 and the video input side of the monitor unit 36, respectively.
And the output side of the slave unit power supply circuit 39 are connected to each other. In addition, master unit CPU3
3 has a first input terminal P11 connected to the base unit first call detection circuit 30.
The second input terminal P12 has an output side of the image output call detection circuit 31, the first output terminal P13 has an input side of a loudspeaker amplifier 34 whose output side is connected to a loudspeaker 35, and a second input terminal P12. The control terminal of the monitor unit 36 is connected to the output terminal P14, and the slave unit power supply circuit 3 is connected to the third output terminal P15.
The switching control side of the relay switch 40 is connected to the control input side of No. 9 and the fourth output terminal P16. Further, a gate light 3 and a power supply of 100 V AC are connected to the make contact and the switching contact of the relay switch 40 via line connection terminals T3 and T4 and a control line L2, respectively.

The operation of the thus configured television door phone apparatus will be described below. When the visitor operates the call button 10 of the handset 1 installed at the entrance of the dwelling unit to call a resident in the dwelling unit (first call operation), the first handset detection circuit 11 detects the first call operation. The DC voltage level between the line connection terminal T1 to which the transmission line L1 is connected via the multiplexing circuit 22 and the line connection terminal T2 of the master unit 2 is lowered. The base unit first call detection circuit 30 of the base unit 2 installed in the called dwelling unit outputs to the base unit CPU 33 the first call detection signal S1 that detects the first call operation due to the voltage drop of the DC voltage level of the transmission line L1. I do. Base unit CPU 33 detects the first call operation by the visitor from the first call detection signal S1 input via first input terminal P11, and controls from second and third output terminals P14 and P15 (details in detail). ) Activates the monitor unit 36 and the slave unit power supply circuit 39, respectively, and outputs the first ringing signal S2 for sounding the loudspeaker 35 from the first output terminal P13 to the loudspeaker amplifier 34. The first ringing tone signal S2 is amplified via the loudspeaker amplifier 34 and emitted from the loudspeaker 35 as a ringing tone. Thereby, the resident is notified of the first call operation by the visitor. The power from the slave unit power supply circuit 39 activated is supplied to the multiplex circuit 41, the line connection terminal T2, and the transmission line L.
1. Via the line connection terminal T1 of the slave unit 1 and the multiplexing circuit 22, the power is supplied from the power supply circuit 21 to each circuit (each unit) in the slave unit 1 as appropriate.

The camera 12 of the slave unit 1 activated by the power supply from the slave unit power supply circuit 39 of the master unit 2 converts the video signal S11 obtained by capturing the image of the visitor into a modulation circuit via the DC voltage superimposing circuit 13. 14 and at the same time the vertical synchronization signal S21
Is output to the slave unit CPU 15. The video signal S11 is a video modulation signal S12 modulated (FM modulated) by the modulation circuit 14.
Multiplexing circuit 22, line connection terminal T1, transmission line L
1, transmitted to the demodulation circuit 32 via the line connection terminal T2 of the master unit 2 and the multiplexing circuit 41, and demodulated by the demodulation circuit 32 (FM
Monitor unit 3 as the demodulated video demodulated signal S13.
6 is input. The monitor unit 36 outputs an image of the visitor at the time of the first call operation captured by the camera 12 of the child device 1 from the input video demodulation signal S13.

Further, based on the ringing sound emitted from the loudspeaker 35 of the base unit 2 and the image of the visitor displayed on the monitor unit 36, the first call operation by the visitor was confirmed by both voice and image. When the resident picks up the handset 38 for answering the call, the call circuit 37 is transmitted from the call circuit 37 via the multiplex circuit 41, the line connection terminal T2, the transmission line L1, the line connection terminal T1 of the slave unit 1, and the multiplex circuit 22.
A communication path between them is formed. As a result, voice (voice signal) is transmitted and received between the handset 38 of the parent device 2 used by the resident and the child device speaker 17 and the child device microphone 18 of the child device 1 used by the visitor via the formed communication path. Becomes possible and the call is established.

Next, an image of the visitor is being displayed on the monitor unit 36 of the base unit 2 and the resident is
If the visitor operates the call button 10 of the child device 1 again (call operation at the time of image output) before the call response picking up the 8,
The slave unit CPU 15 receives the vertical synchronization signal S21 from the camera 12 via the second input terminal P2 and the first input terminal P2.
An image output call signal S22 from the call button 10 is input via the button 1 to detect a display image call operation by the visitor. The slave unit CPU 15 controls the camera 12 during calling during image output.
A control signal S23 for superimposing a positive voltage higher than the white peak of the video signal as a calling signal component at the time of image output (a signal at the time of image output) only during the blanking period of the image signal output from the first device. Output from the output terminal P4 to the DC voltage superposition circuit 13. As a result, the video signal S31, which is an image of the visitor calling at the time of image output, captured by the camera 12,
Is modulated as a video positive voltage superimposed signal S32 in which a positive voltage higher than a white peak of the video signal is superimposed only during a blanking period of the video signal by the control signal S23 from the slave unit CPU 15 via the DC voltage superimposing circuit 13. The signal is transmitted to the circuit 14. This video positive voltage superimposed signal S32 is
As a video positive voltage superimposed modulation signal S 33 modulated (FM modulation) at 4, a demodulation circuit 32 via a multiplexing circuit 22, a line connection terminal T 1, a transmission line L 1, a line connection terminal T 2 of the base unit 2, and a multiplexing circuit 41. , And inputted as a video positive voltage superimposed demodulated signal S34 demodulated (FM demodulated) by the demodulation circuit 32 to the image output call detection circuit 31 and the monitor unit 36, respectively.

The image output call detection circuit 31 separates and detects a positive voltage S35, which is a call signal component (image output call signal) at the time of image output, from the input video positive voltage superimposed demodulated signal S34, and outputs the signal. Output to the machine CPU 33. The main unit CPU 33 detects a call-out operation at the time of image output by the visitor from the positive voltage S35 input via the second input terminal P12, and outputs the first output terminal P13.
Then, the image output ringing signal S3 for sounding the loudspeaker 35 is output to the loudspeaker amplifier 34 in the same pattern as in the above-described first call operation. The image calling ringing signal S3 is amplified through the loudspeaker amplifier 34 and emitted from the loudspeaker 35 as a ringing sound. Thereby, the resident is notified of the calling operation at the time of image output by the visitor. Further, the monitor unit 36 outputs an image of the visitor who is calling at the time of image output, which is imaged by the camera 12 of the child device 1 from the input video positive voltage superimposed demodulated signal S34.

Further, based on the ringing sound emitted from the loudspeaker 35 of the base unit 2 and the image of the visitor displayed on the monitor unit 36, the call operation at the time of image output by the visitor can be performed with both voice and image. When the confirmed resident picks up the handset 38 for answering the call, a call is established in the same manner as the call response at the time of the first call operation by the visitor (not described in detail).

Next, the environment sensor 19 activated by the power supply from the slave unit power supply circuit 39 of the master unit 2 detects the brightness of the entrance of the dwelling unit where the slave unit 1 is installed. Here, when the above-mentioned first call operation by the visitor is performed, for example, at night when the sun goes down, and the environment sensor 19 detects that the brightness of the entrance of the dwelling unit is lower than a certain level, the environment sensor 19 Then, the illuminance detection signal S41 containing this detection information is output to the slave unit CPU 15. The slave unit CPU 15 detects the low illuminance state at the entrance of the dwelling unit from the illuminance detection signal S41 input via the third input terminal P3, and outputs the second output terminal P5
Outputs a control signal S42 for turning on the indicator lamp 20, and outputs the vertical synchronizing signal S
According to 21, the positive voltage higher than the white peak of the video signal output from the camera 12 during the blanking period of the video signal output from the camera 12 during the calling at the time of image output is set to the low illuminance state at the entrance of the dwelling unit and the lighting of the indicator lamp 20. From a first output terminal P4, a control signal S24 for superimposing as a detection information component containing information at a timing different from the above-described call signal component at the time of image output (image output call signal) from the first output terminal P4. 13 is output. As a result, the video signal S51, which is an image of the visitor who is calling at the time of image output and whose illuminance is ensured by the lighting of the indicator lamp 20 captured by the camera 12, is converted into a DC voltage superposition circuit by the control signal S24 from the slave unit CPU 15. The signal 13 is transmitted to the modulating circuit 14 as a video positive voltage superimposed signal S52 on which a positive voltage higher than the white peak of the video signal is superimposed through a blanking period of the video signal. The video positive voltage superimposed signal S52 is converted (FM modulated) by the modulation circuit 14 into a video positive voltage superimposed modulation signal S53 via the same path as the above-described video positive voltage superimposed modulation signal S33.
2 and is input to the image output call detection circuit 31 and the monitor unit 36 as a video positive voltage superimposed demodulation signal S54 demodulated (FM demodulated) by the demodulation circuit 32, respectively.

From the input image positive voltage superimposed demodulation signal S54, the image output call detection circuit 31 detects a positive voltage which is a detection information component containing information on the low illuminance state of the entrance of the dwelling unit and the lighting of the indicator lamp 20. S55 is separated and detected, and the main unit CPU 33
Output to The main unit CPU 33 detects the low illuminance state of the entrance of the dwelling unit and the lighting of the indicator lamp 20 from the positive voltage S55 input via the second input terminal P12, and outputs the fourth output terminal P
The relay switch 40 is turned on by the control from 16.
Also, when the relay switch 40 is turned on, the connection between the line connection terminals T3 and T4 connected to the control line L2 is made, and the gate light 3 is turned on. Further, the monitor unit 36 outputs the image of the visitor in the low illuminance state of the entrance to the dwelling unit and the visitor at the time of turning on the indicator light 20 captured by the camera 12 of the slave unit 1 from the input video positive voltage superimposed demodulation signal S54. The image of the visitor captured by the camera 12 of the child device 1 after the gate light 3 is turned on is sequentially output by the monitor unit 36 of the parent device 2 as a good image in which the illuminance is secured.

[0026]

As is apparent from the above description, according to the television door phone apparatus of the present invention, the call signal output by the operation of the call button (call operation) of the slave unit at the time of displaying an image and the environment sensor are output. The detection information of the on / off state of the indicator light driven based on the information such as the brightness of the entrance of the dwelling unit detected by the camera is not used for the intermittent signal of the carrier but for the blanking of the video signal output from the camera. Only during the period, as a positive voltage higher than the white peak of the video signal is superimposed at different timings and transmitted to the demodulation circuit of the base unit, so that the calling signal during the calling from the demodulation circuit of the base unit at the time of image output and the entrance of the dwelling unit Since the detection information such as the brightness is detected from the positive voltage, the vertical synchronization of the monitor unit caused by the ringing signal at the time of image output causes the upper and lower parts of the entire screen to be distorted. In addition, the left and right shakes at the top of the screen due to the disturbance of horizontal synchronization are eliminated, and a good image can be secured even during image calling, and the resident in the dwelling unit has the brightness of the entrance of the dwelling unit and lighting of the indicator light / Light off can be confirmed, and a visitor who performs a calling operation at night can be more accurately determined, and the crime prevention property is improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of a TV door phone apparatus according to the present invention.

FIG. 2 is a block diagram showing a configuration of a conventional TV door phone device.

[Explanation of symbols]

 1... Slave unit 2... Master unit 10... Call button 11... Slave unit first call detection circuit 12... Camera 13. Voltage superimposing circuit 14 Modulation circuit 15 Slave CPU 17 Slave speaker 18 Slave microphone 19 Environmental sensor 30 ··· Main unit first call detection circuit 31 ···· Image display call detection circuit 32 ··· Demodulation circuit 33 ··· Main unit CPU 35 ··· Loudspeaker 36 ··· · Monitor unit 38 ······· Handset 39 ····· Subordinate unit power supply circuit L1 ···

Claims (1)

[Claims] When a call button (10) of a handset (1) is operated, a DC voltage of a transmission path (L1) is reduced by a handset first call detection circuit (11), and the DC voltage of a master unit (2) is reduced. The main unit first call detection circuit (30) detects the main unit CPU (33)
Receives a detection signal from the base unit first call detection circuit, recognizes that the call button has been operated, generates a first ringing signal, causes the loudspeaker (35) to sound a ringing sound, and supplies power to the slave unit power supply circuit. (39) supplies power to the slave unit, modulates a video signal obtained by capturing an image of a visitor with a camera (12) by a modulation circuit (14), and modulates the demodulation circuit (3) of the master unit.
2) demodulating the video signal, outputting the demodulated video signal with a monitor unit (36), picking up a handset (38), and setting the handset speaker (17), the handset microphone (18) and the handset microphone (18). A call can be made between the handsets of the master unit, and when the call button is operated again at the time of image display before picking up the handset, a call at image output is detected from a call signal at image output, and a call from the camera is output. A television intercom apparatus for inputting a vertical synchronization signal to a slave unit CPU (15) and sounding a ringing tone from the loudspeaker, wherein the slave unit receives the image output calling signal and the vertical synchronization signal. A DC voltage superimposing circuit for superimposing a positive voltage higher than a white peak of the video signal on the video signal only during a blanking period of the video signal by the slave CPU;
The master unit, the positive signal is superimposed, the modulation signal is modulated by the modulation circuit and the video signal demodulated by the demodulation circuit is input,
An image output call detection circuit (31) for separating / detecting the image output call signal and inputting the signal to the master CPU, wherein the slave unit detects the surrounding environment and transmits the detected information to the main unit CPU. The DC voltage superimposition circuit, the modulation circuit, the demodulation circuit, and the image output call detection circuit at a timing different from the image output call signal within the blanking period by the vertical synchronization signal of the camera from the slave unit CPU. A television intercom apparatus, comprising: an environment sensor (19) for transmitting the data to the master CPU via the CPU.