JPH0822059B2 - Video intercom - Google Patents

Description

Description: TECHNICAL FIELD [0001] The present invention relates to a video call device, and more particularly, to a television unit having a television monitor built in at least one of a predetermined number of indoor master devices whose models can be arbitrarily selected. Is connected, and when a call is made from the doorstep handset and the handset is picked up in response to this, the TV camera activates and the image of the visitor is displayed on the TV monitor. The present invention relates to a video communication device configured so that, when the handset is dropped, the TV camera stops operating and the image on the TV monitor disappears.

[Technical Background of the Invention] Conventionally, a video call device as shown in FIG. 6 has been known. This type of TV call device 1 includes a child device 2 having a built-in TV camera 5 and a predetermined number of TV monitor built-in master devices 4 in which the call device 6 and a TV monitor 3 are integrated. In this case, the TV monitor 3 and the communication device 6 are connected by an internal connection, and the video on the TV monitor 3 is the TV camera 5 and the TV monitor built-in master unit 4.
And are activated.

[Problems with the Background Art] However, the conventional video call device is known as a master unit with a built-in TV monitor in which the call device and the TV monitor are integrated, but the call device may be a parent-child type, a mutual type, a composite type, or the like. There are many types of indoor master units that have different circuit configurations and shapes due to differences in the telephone network, usage for home use, business use, hospital use, housing complex use, etc. A different master unit with a built-in television monitor must be prepared for each case, and the circuit configuration becomes complicated and the cost becomes high.

In addition, the conventional video call device has a plurality of main units with built-in TV monitors, and is configured to unconditionally display an image on all TV monitors when there is a call from the entrance cordless handset. Even when the user is not present and does not want the image to be displayed, the image is displayed, which is not preferable from the viewpoint of energy saving.

[Object of the Invention] The video communication device of the present invention has been made in view of the above problems. One of various indoor master units having different circuit configurations and shapes depending on the communication network and application is used. Select one to electrically connect to a TV unit with a built-in TV monitor, and it can be easily configured without any modification.In addition, when responding, the image is displayed on the TV monitor and the handset of the base unit is dropped. It is an object of the present invention to provide a video call device capable of erasing video and realizing energy saving.

[Summary of the Invention] According to the video call device of the present invention, in order to achieve this object, a call is made between a TV camera, an entrance cordless handset including a call circuit including a microphone, a speaker, and the call communication circuit of the entrance cordless handset. It has an indoor master unit connected via a line and a master unit TV unit with a built-in TV monitor connected to the TV camera of the entrance slave unit by a video transmission cable. A line level detection circuit that detects the level and generates output values at the time of response and at the end of call, and response detection that detects the response time from the output value of the line level detection circuit and supplies power to the TV camera and TV monitor for a predetermined time A circuit and an end-of-call detection circuit that detects the end-of-call time from the output value of the line level detection circuit and shuts off the power supply to the television camera and the television monitor.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention applied to an intercom will be described in detail with reference to the drawings. As shown in FIG. 1, a video call device 10 of the present invention includes a TV camera 11, an entrance slave 12, an indoor master 13 having a handset 39 and an extension master 13 ',
A television monitor 14, a master TV unit 15 having the TV monitor 14 built-in, and an extension master TV unit 16 having the TV monitor 14 built-in. A line level detection circuit 17 (Fig. 5) and a response detection circuit are provided in the main unit TV unit 15.
18 (FIG. 5), a call end detection circuit 19 (FIG. 5), and a timer circuit 34 (FIG. 5) are mounted. According to this video call device, as shown in FIG. 2, the slave unit D (the TV camera 11, the entrance slave unit 12), the master unit t (the indoor master unit 13, and the master unit TV unit).
15, a communication network is formed between the extension base unit 13 'and the extension base unit TV unit 16). FIG. 3 shows the relationship among the TV camera 11, the entrance slave device 12, the indoor master device 13, and the TV monitor 14 shown in FIG. First, the television camera 11 projects a visitor by using an image pickup tube such as a vidicon or a solid-state image pickup element such as a CCD as its image pickup element. The entrance cordless handset 12 includes a communication circuit 22 including a microphone 20, a speaker 21, and the like, and an illumination lamp that illuminates visitors.
23, a shutter 24 for protecting the image pickup device of the television camera 11 from sunlight, a sunlight shutter drive circuit 25 for driving the shutter 24, and an optical sensor 26.
The indoor base unit 13 connects the call line 22 to the call circuit 22 of the entrance cordless handset 12.
Connected through. Further, the indoor master device 13 is connected to the interlocking control circuit 36, which is composed of the line level detecting circuit 17, the response detecting circuit 18, the call end detecting circuit 19 and the like, which are built in the master TV unit 15, by the interlocking control line 33. ing. The TV monitor 14 built in the base unit TV unit 15 is a door unit 12
Is connected to the television camera 11 by a coaxial cable 28 as a video transmission cable.

The voltage of the power source E is converted by the voltage conversion circuit and supplied to the television monitor 14 via the television monitor switching circuit 31. Similarly, the power source E is also supplied to the TV camera 11 via the coaxial cable 28.
The constant current circuit 30 keeps the line current constant at a predetermined value depending on the preheat (standby) and the operation (photographing). Further, the power source E supplies power to the illumination lamp 23 via the illumination lamp switching circuit 29.

The line level detection circuit 17 (FIG. 5) detects a voltage change as a line level change of the communication line 27.
The line level detection circuit 17 (FIG. 5) is composed of a comparator IC1 which compares the reference level with the line level when the call line 27 is responding or ending the call. The response detection circuit 18 (Fig. 5) is a line level detection circuit.
The response time is detected from the output value of FIG. 17 (FIG. 5) to switch the illumination lamp switching circuit 29, the constant current circuit 30 for supplying power to the TV camera 11 via the coaxial cable 28, and the TV monitoring switching circuit 31. Turn on the lighting lamp 23,
Power is supplied to the TV camera 11 and the TV monitor 14 for a predetermined time.

The response detection circuit 18 (FIG. 5) is a transistor Tr1 as a switching element connected to the output terminal of the comparator IC1 of the line level detection circuit 17 (FIG. 5).
And a delay type flip-flop (hereinafter referred to as D flip-flop) IC connected to the output terminal of the transistor Tr1
It consists of 3 (Fig. 5). The timer circuit 34 includes a flip-flop IC4 (FIG. 5) which operates by the output of the D flip-flop IC3 (FIG. 5), a resistor R1 as a delay element which delays the output by a predetermined time, and a capacitor C1. Reference level and D flip-flop IC4 (5th
Comparator IC5 (Fig. 5) that compares the outputs of
It comprises a transistor Tr2 as a switching element which operates by the output of the comparator IC5 (Fig. 5) and inverts the output of the D flip-flop IC4 (Fig. 5).

The call end detection circuit 19 (Fig. 5) is a line level detection circuit.
When the end of call is detected from the output value of 17 (Fig. 5), the lighting lamp switching circuit 29, the constant current circuit 30, and the televi monitor switching circuit 31 are switched off, and the lighting lamp 23,
The power supply to the TV camera 11 and the TV monitor 14 is cut off.

This call end detection circuit 19 (Fig. 5) is a comparator IC1.
It consists of a D flip-flop IC2 (Fig. 5) connected to the output of (Fig. 5) and its own output connected to a D flip-flop IC4 (Fig. 5). Further, as shown in FIG. 4, the extension master unit TV unit 16 shown in FIG. 1 has a built-in TV monitor 14 and a TV monitor switching circuit 31, and the TV monitor 14 is a master unit TV unit 15 (FIG. 3).
Is connected to the TV monitor 14 of No. 1 by a cable 28 and is also connected to the master TV unit 15 (FIG. 3) by the M terminal.

Based on FIG. 5, the operation of the video call device of the present invention configured as described above will be described. The motion control circuit 36 (line level detection circuit 17,
The response detection circuit 18, the call end detection circuit 19, and the timer circuit 34) will be described in detail. Call line 27 here (Fig. 3)
The line level, that is, the line voltage of the
(Fig.) And indoor master unit 13 (Fig. 3)
It is set to V ₁ , V _{2 in the} ringing state, and V ₃ (V ₂ <V ₁ <V ₃ ) in the talking state.

First, in the waiting state with no visitors, call line 27
The line level difference between the H terminal connected to the communication line of FIG. 3 and the E terminal connected to the common line of the same line is V ₁ . In this state, the positive terminal reference level of the comparator IC1 (hereinafter referred to as IC1) of the line level detection circuit 17, that is, the reference voltage is set to V _a (V ₁ <V _a <V ₃ ).
Is at a logic level "H" (hereinafter referred to as "H"). Then, the transistor Tr1 of the response detection circuit 18 (hereinafter Tr1
Is called non-conductive, and the Q output of the D flip-flop IC3 (hereinafter referred to as IC3) connected to the collector of Tr1 is at the logic level "L" (hereinafter referred to as L). Also IC
Since the output of 1 is H, the Q output of the D flip-flop IC2 (hereinafter referred to as IC2) of the end-of-talk detection circuit 19 is L. As a result, a negative pulse is applied to the R input of the D flip-flop IC4 (hereinafter referred to as IC4) of the timer circuit 34, the Q output becomes L, and the transistor Tr3 (hereinafter referred to as Tr3) is non-conductive. On the other hand, the positive terminal voltage of the comparator IC5 (hereinafter referred to as IC5) of the timer circuit 34 is set to V _b (V ₁ <V _b <V ₃ ) determined by the balance with the timer time, and the Q output of IC4 becomes L. IC5 due to the relationship
Output becomes H, and transistor Tr2 (hereinafter referred to as Tr2)
Is non-conducting.

In this state, there is a call from the entrance cordless handset 12 (Figs. 1 and 3), and the called party responds to the call by the handset 39 (Fig. 1).
, The line voltage of the call line 27 (FIG. 3) rises from V ₁ to V ₃ , so the H terminal of the interlocking control circuit 36 and E
The voltage across the terminals also shows V ₃ . As a result, the output of IC1 becomes L, Tr1 becomes conductive, and the C input of IC3 becomes H. Therefore, the Q output of IC3 becomes H, so H is given to the S input of IC4, and IC4
Q output becomes high. Then, since Tr3 becomes conductive, the switching circuit 29 for lighting lamps connected to this (3rd
(Fig.), Constant current circuit 30 (Fig. 3), and switching circuit 31 for TV monitor (Fig. 3) are turned on to turn on the illumination lamp 23.
(Fig. 3), TV camera 11 (Fig. 3), TV monitor
Activate 14 (Fig. 3). In addition, the indoor base unit 13 (Fig. 3)
The line voltage (the voltage between the H terminal and the E terminal) indicates V ₃ when the call is transmitted between the door cordless handset 12 and the entrance cordless handset 12.

Then, when the call is finished and the handset 39 (Fig. 1) is taken down for a predetermined time while Tr3 is conducting, the line voltage (H
The voltage between the terminal and the E terminal) is reduced from V ₃ to V _1, and the output of IC ₁ becomes H. Then H is given to the C input of IC2,
Q output becomes H, and H is given to R input of IC4. Along with this, the Q output of IC4 becomes L, and Tr3 is made non-conductive, and the functions of the illumination lamp 23 (Fig. 3), the television camera 11 (Fig. 3), and the television monitor 14 (Fig. 3) are stopped. When the handset is picked up, C1 is charged with a time constant determined by the resistor R1 and the capacitor C1 as a delay element, and when the negative terminal voltage of IC5 exceeds V6, the output of IC5 becomes L and Tr2 becomes conductive. Then, H is given to the C input of IC4 and the Q output of IC4 becomes L.
To By doing so, Tr3 becomes non-conductive, and the illumination lamp 23 (Fig. 3) and the TV camera 11 (3rd
(Fig.), The function of the TV monitor 14 (Fig. 3) is stopped so that the image displayed on the TV monitor 14 (Fig. 3) disappears but the call can be continued.

In order to contribute to the understanding of the circuit operation described above, D
The truth bales of flip-flop IC4 (Table 1) are posted.

In the above embodiment, the line level detection of the response detection circuit and the call end detection circuit is performed by the voltage detection method, but the circuit can be configured by the current detection method. A comparator using an operational amplifier was used to detect the voltage, but a similar circuit could be created by combining a Zener diode that detects the line level when the call line is responding or when the call is terminated, and a transistor driven by this output. Can be configured.

[Effects of the Invention] As is apparent from the above embodiments, according to the video call device of the present invention, the call line from the entrance cordless handset incorporating the call communication circuit including the microphone and the speaker to the call communication circuit of the entrance cordless handset. When calling the indoor main unit connected via, the line level detection circuit that detects the line level of the call line and generates the output value at the time of answering and ending the call detects the line level of the call line and the response detection circuit When the response is detected from the output value of the line level detection circuit, the TV monitor and the TV camera connected to the TV monitor with a video transmission cable are supplied with power for a predetermined time to display an image, and when the call ends, the call end detection circuit The end of the call is detected from the output value of the line level detection circuit, and the power supply to the TV camera and TV monitor is cut off to erase the image. Of the various types of indoor base units with different circuit configurations and shapes depending on the application, you can select any one and electrically connect it to the TV unit containing the TV monitor without any modification. The effect is that it can be simply configured, and that an image can be displayed on the TV monitor at the time of response, and the image can be erased by lowering the handset of the indoor master unit to realize energy saving.

[Brief description of drawings]

FIG. 1 is a perspective view showing a video call device according to the present invention, FIG. 2 is a block diagram showing a call network of the video call device according to the present invention, and FIG. 3 is a door station and an indoor parent of the video call device according to the present invention. Block diagram of the main unit and the main unit TV unit, No. 4
FIG. 5 is a block diagram of an extension base unit TV unit of a video call device according to the present invention, FIG. 5 is an embodiment of an interlocking control circuit mounted on a base unit TV unit of the video call device according to the present invention, and FIG. 3 is a perspective view showing the video communication device in FIG. 10 …… TV call device 11 …… TV camera 12 …… entrance subunit 13 …… Indoor master 14 …… TV monitor 15 …… Parent TV unit 17 …… Line level detection circuit 18 …… Response detection circuit 19… … End call detection circuit 20 …… Mic 21 …… Speaker 22 …… Call circuit 27 …… Call line 28 …… Coaxial cable (video transmission cable) 34 …… Timer circuit

Claims (1)

[Claims] 1. A TV camera, an entrance cordless handset including a call circuit including a microphone, a speaker, and the like, and a plurality of parent devices connected to the call call circuit of the entrance cordless handset via a call line.
A plurality of TV units having a built-in TV monitor connected to the TV camera of the entrance slave by a video transmission cable, and the call line is a line level when answering and a line when answering, respectively. A video call device set to a level, wherein one of the plurality of TV units detects a response line level and a call end line level of the call line, and outputs at a response and a call end. A line level detection circuit that generates a value, a response detection circuit that detects the output value of the line level detection circuit at the time of response and supplies power to the television camera and the television monitor for a predetermined time, and a line level detection circuit A call termination detecting circuit for detecting an output value at the time of talking to shut off the power supply to the television camera and the television monitor. Talking device.