JPS5949081A - Television interphone system - Google Patents

Abstract

PURPOSE:To decrease the number of modulation and demodulation circuits and also the frequency occupying area, by transmitting a call signal to select an optical interphone slave device from an interphone master set for calling out it after being superimposed on a video signal transmitted from a television camera of the interphone master set. CONSTITUTION:The call signal outputted from a control circuit 6 is super-imposed on the video signal at an output period of a vertical blanking pulse of the video signal, inputted to a signal separation circuit 15 from a demodulation circuit D4 of the interphone slave set 2 for the superimposed video signal, and the superimposed signal is separated into the video signal and the call signal, the video signal is displayed on a screen of a monitor television 8, the call signal is inputted to a control circuit 11, and when the address is coincident with an address of the own station, a calling bell 16 goes out. The control circuit 11 of the interphone slave set 2 is provided with an operating panel 17 to transmits a direction control signal or the like to the television camera 3 of the interphone master set 1, a control signal is modulated into a high frequency signal of carrier frequency f4 at a modulation circuit M4 and transmitted via a signal line 7.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a television intercom system used in housing complexes such as condominiums.

Fig. 1 is a diagram showing the schematic structure of a conventional TV intercom system, in which an intercom base unit (1) with a TV camera is installed near the entrance of a housing complex (A) such as a condominium.
An intercom handset (2) with a TV monitor is installed in each room. Fig. 2 shows the structure of the interphone main unit (1), which includes a communication device consisting of a microphone (4) and a speaker (5) for a visitor to talk to people in the room, and a desired intercom handset (1) for the visitor to use. 2) and a control circuit (6) for a person in the room to control the direction of the television camera (3). The audio signal from the microphone (4) is sent to the modulation circuit (
M1), the signal is modulated into a high-frequency signal with a carrier frequency f1, and is transmitted to a signal line (7) made of a coaxial cable. In addition, the video signal from the television camera (3) is transmitted to the modulation circuit (M2).
) is modulated into a high frequency signal of carrier frequency f2 and transmitted to the signal line (7). Furthermore, the calling signal of the intercom handset (2) output from the control circuit (6) is modulated into a high frequency signal of carrier frequency f3 by the modulation circuit (M3) and transmitted to the signal line (7). On the other hand, the high frequency signal of carrier frequency f4 sent from the intercom cordless handset (2) is demodulated by the demodulation circuit (D1) and sent to the control circuit (6).
The signal is input to the camera to control the direction of the television camera (3). In addition, the carrier frequency f5no high frequency signal sent from the intercom handset (2) is sent to the demodulation circuit (D2).
The signal is demodulated and output from the speaker (5) as an audio signal. Next, Figure 3 shows the configuration of the intercom handset (2) installed in the room of each house, and the monitor TV (8) for displaying the video transmitted from the interphone main unit (1), and the indoor intercom handset (2). A communication device consisting of a microphone (9) and a speaker (10) for a person to talk to a visitor, as well as a device that receives a call signal from an interphone base unit (1) and sends a direction control signal to a television camera (3). Each high frequency signal of carrier frequency f1, f2, f3 transmitted from the control circuit (1) for
(D4) and (D5), respectively, to the speaker (10), monitor television (8), and control circuit (11).
) respectively. On the other hand, the control circuit (1
The control signal output from 1) and the audio signal output from the microphone (9) are modulated into high frequency signals with carrier frequencies f4 and f5 by modulation circuits (M4) and (M5), respectively, and are transmitted to the signal line (7). It is something that In this way, in the conventional TV intercom system, video signals from the interphone base unit (1), audio signals for calls, and calling signals to the interphone slave unit (2) are transmitted through one signal line (7). modulation circuits (M1) to (2) for frequency division multiplexing.
M5) and demodulation circuits (D1) to (D5) are required in large numbers, and the frequency occupied area also becomes large.

The present invention has been made to solve these problems of the conventional example, and transmits a calling signal from the interphone base unit's television camera to select and call an arbitrary interphone slave unit from the interphone base unit. It is an object of the present invention to provide a television intercom system in which the number of modulation circuits and demodulation circuits can be reduced by superimposing the video signal on a video signal to be transmitted, and the frequency occupied area can also be reduced.

The configuration of the present invention will be described below with reference to illustrated embodiments. Fourth
The figure is a block diagram showing the configuration of an embodiment of the present invention.

The interphone base unit (1) is a signal line made of a coaxial cable (
7), and this signal line (7) is connected to the branch (1
2) and multiple intercom handsets (2)
It is connected to the. The microphone (4) of the intercom main unit (1)
) and the video signal output from the television camera (3) are modulated into high frequency signals with carrier frequencies f1 and f2 by modulation circuits (M1) and (M2), respectively, and then sent to the signal line (7). is transmitted, and the intercom handset (2
) are respectively demodulated by demodulation circuits (D3) and (D4) and supplied to the speaker (10) and monitor television (8). On the other hand, the control circuit (11) of the intercom handset (2)
) The control signal output from the microphone (9) and the audio signal output from the microphone (9) are modulated into high frequency signals with carrier frequencies f4 and f5 by modulation circuits (M4) and (M5), respectively, and are transmitted through the signal line (7). The signals are demodulated by the demodulation circuits (D1) and (D2) of the interphone base unit (1), respectively, and supplied to the control circuit (6) and the speaker (5). The control circuit (6) of the intercom base unit (1) is provided with a call operation panel (13) for selecting a desired intercom slave unit (2), and each intercom slave unit (2) is individually assigned. The control circuit (6
). A synchronizing signal is supplied from the television camera (3) to the control circuit (6), and the ringing signal is outputted from the control circuit (6) within the period of the vertical blanking pulse of the television camera (3). It's getting old.

5(a) to 5(c) show operational waveform diagrams of the embodiment of FIG. 4. FIG. 5(a) shows the video signal input from the television camera (3) to the mixing circuit (14),
In addition, FIG. 5(b) shows the control circuit (6) to the mixing circuit (14).
) shows a call signal input to the Furthermore, Figure 5 (
c) shows the superimposed video signal output from the mixing circuit (14), and as shown in the figure, since it is superimposed on the video signal during the output period T0 output from the control circuit (6), the calling signal is The actual image is not disturbed by P0. However, the superimposed video signal as shown in FIG.
) is input to the signal separation circuit (15), and the signal shown in FIG.
) and a calling signal as shown in FIG. 5(b). Of these, the video signal is displayed on the screen of the monitor television (8), and the calling signal is input to the control circuit (11), and when the address represented by this calling signal matches the address of the own station, the calling signal is output. (16) is set to sound. The control circuit (11) of the intercom handset (2) or the intercom handset (
An operation panel (17) is provided for sending control signals for direction control to the television camera (3) in 1), and the control signals from this operation panel (17) are sent in the same way as in the conventional example. It is modulated into a high frequency signal of carrier frequency f4 by a modulation circuit (M4) and transmitted via a signal line (7). As shown in the waveform diagram of FIG. 6, the control circuit (11) of the intercom handset (2) sends the calling signal P0 multiple times within the period of the vertical blanking pulse of the video signal. If the same ringing signal is received several times in a row and the address represented by the ringing signal matches the address of the own station, the ringing bell (16) can be made to ring. This can prevent calls from being made by mistake.

The present invention is configured as described above, in which intercom handsets each having a monitor television and a communication means are installed at a plurality of locations, each of which is connected to each intercom handset via a signal line, and a television camera and a communication means are connected to each other. A calling signal for transmitting a calling signal representing the address of the interphone handset by superimposing it on the video signal during the generation period of the vertical blanking pulse of the video signal of the television camera transmitted via the signal line. means for separating and detecting the above-mentioned calling signal from the video signal on the interphone base unit by providing a sending means in the interphone base unit; and a calling notification unit that operates when the calling signal matches an address assigned to the own station. Because it is equipped with a TV camera, there is no need to separately provide a frequency range or a line to transmit the calling signal from the interphone base unit with the TV camera to the interphone slave unit with the monitor TV. This has the advantage that the modulation/demodulation circuit for the video signal can be used in combination with the modulation/demodulation circuit for the video signal, and furthermore, since the calling signal is superimposed during the generation period of the vertical blanking pulse of the video signal output from the television camera. Another advantage is that it does not affect the image displayed on the TV monitor.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of the conventional example, Fig. 2 is a block diagram showing the structure of the above intercom base unit, Fig. 3 is a block diagram showing the structure of the above intercom slave unit, and Fig. 4 is a block diagram showing the structure of the above intercom base unit. The block diagram of the embodiment, FIGS. 5(a), 5(b), 6(c) and 6 are explanatory diagrams of the same operation. (1) is the interphone base unit, (2) is the interphone slave unit, (
3) is a TV camera, (4) is a microphone, (5) is a speaker, (6) is a control circuit, (7) is a signal line, (8) is a monitor TV, (9) is a microphone, (10) is a speaker , (1
1) is the control circuit, (13) is the call operation panel, (14) is the mixing circuit, (15) is the signal separation circuit, and (16) is the call bell.■

Claims (1)

[Claims] (1) Interphone handsets each having a monitor TV and a means of communication are installed at multiple locations, and an interphone base unit is connected to each intercom handset via a signal line, and has a television camera and means of communication, and the signal line The interphone main unit is provided with a calling signal sending means for sending a calling signal representing the address of the interphone handset by superimposing it on the video signal during the generation period of the vertical blanking pulse of the video signal of the television camera transmitted through the interphone base unit. A television interphone system comprising means for separating and detecting the above-mentioned calling signal from a video signal in an interphone handset, and a calling notification means that is activated when the calling signal matches an address assigned to the own station. .