JP3203087B2 - TV intercom equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television intercom apparatus, and more particularly, to an up sound signal changeover switch which is turned on and off by first and second horizontal synchronization pulses synchronized with a horizontal synchronization signal and having mutually opposite phases. The present invention relates to a television intercom apparatus capable of transmitting and receiving an upstream audio signal and a downstream audio signal in a time-division manner by providing a downstream audio signal changeover switch in an indoor main unit and a front door unit with a camera.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 2, a television intercom apparatus has a front door unit with camera EQ3 and an indoor main unit E as shown in FIG.
The terminal T3 of the camera-equipped entrance device EQ3 and the terminal T4 of the indoor parent device EQ4 are connected by a cable CBL2.

A camera, a video signal modulation circuit 2, a multiplexing circuit 3, a horizontal synchronizing signal generation circuit 4, a microphone 6, a speaker 7, a microphone amplifier 8a, a speaker amplifier 8b, and a slave unit sound The output side of the camera 1 provided with the sound canceller CL1 and the horizontal synchronizing signal generation circuit 4 is connected to the multiplexing circuit 3 via the video signal modulation circuit 2.
Video signal side. The output side of the microphone 6 is connected to the upstream audio signal side of the multiplexing circuit 3 via the microphone amplifier 8a, and the downstream audio signal side of the multiplexing circuit 3 is connected to the speaker 7 via the speaker amplifier 8b. ing.

[0004] Further, the output side of the microphone amplifier 8a and the input side of the speaker amplifier 8b are connected to a sub-unit side sound canceller CL.
1 is connected.

A multiplexing circuit 11, a video signal demodulation circuit 12, a television monitor 13, a microphone 16, a speaker 17, a microphone amplifier 18a, a speaker amplifier 18 are provided in the indoor master unit EQ4.
b and the main unit side sound canceller CL2 are provided, and the video signal side of the multiplexing circuit 11 is connected to the television monitor 13 via the video signal demodulation circuit 12. The output side of the microphone 16 is connected to the downstream audio signal side of the multiplexing circuit 11 via the microphone amplifier 18a.
Is connected to the speaker 17 via the speaker amplifier 18b.

Further, a master unit-side sound canceller CL2 is connected to the output side of the microphone amplifier 18a and the input side of the speaker amplifier 18b.

[0007] In the television intercom apparatus configured as described above, the upstream audio signal output from the microphone 6 to the microphone amplifier 8a is amplified by the microphone amplifier 8a and transmitted to the terminal T3 via the multiplexing circuit 3. The upstream audio signal transmitted to the terminal T3 is transmitted to the cable CBL2 and the terminal T4.
And received by the multiplexing circuit 11 of the indoor master unit EQ4. The upstream audio signal received by the multiplexing circuit 11 is output to the speaker 17 via the speaker amplifier 18b.
In the same route, the downstream audio signal is transmitted to the microphone 1 of the indoor master unit EQ4.
6. It is transmitted and received between the microphone amplifier 18a, the speaker amplifier 8b of the camera-equipped entrance device EQ3, and the speaker 7.

In this state, when the output side of the microphone amplifier 8a and the input side of the speaker amplifier 8b of the entrance apparatus with camera EQ3 and the output side of the microphone amplifier 18a and the input side of the speaker amplifier 18b of the indoor master unit EQ4 are sounding. , The sound canceller CL1 on the slave unit side and the sound canceller CL2 on the master unit side
Operates and stops the sounding state. The slave unit-side sound canceller CL1 and the base unit-side sound canceller CL2 are a kind of calculation circuit. For example, the output level of the microphone amplifier 8a gradually increases.
When the level exceeds a certain level, the input level of the speaker amplifier 8b is suppressed.

[0009]

In such a television intercom apparatus, the output level of the microphone amplifier 8a increases due to external noise, acoustic coupling between the speaker 7 and the microphone 6, sneaking through an internal circuit, and the like. The side ringing canceller CL1 and the base unit side ringing canceller CL2 have drawbacks in that they must be composed of complicated circuits so as not to sound over the entire frequency band. The microphone amplifiers 8a and 18a and the speaker amplifiers 8b and 18b
Has a drawback in that the gain can be set only within a range in which the child unit side sound canceller CL1 and the base unit side sound canceller CL2 are effective.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to solve such a problem. A television interphone which can surely prevent a sound without using hardware having complicated circuit configuration or software having a high development cost. It is intended to provide a device.

[0011]

In order to achieve this object, a television intercom apparatus according to the present invention comprises a camera for imaging a visitor and outputting a composite video signal synchronized with a horizontal synchronizing signal, and a composite for modulating the composite video signal. A front door unit with a camera provided with a video signal modulation circuit, an indoor master unit provided with a composite video signal demodulation circuit for demodulating a received composite video signal and a television monitor for monitoring the demodulated video signal; The front-end slave unit includes a slave-side horizontal synchronization pulse output circuit that outputs first and second slave-side horizontal synchronization pulses synchronized with the horizontal synchronization signal and having opposite phases to each other; An up audio signal switch and a down audio signal switch that are turned on and off by a slave unit-side horizontal synchronization pulse are provided. The indoor master unit synchronizes with the horizontal synchronization signal included in the received composite video signal, and Reversed phase A main unit horizontal synchronization pulse output circuit for outputting first and second main unit horizontal synchronization pulses; a down audio signal changeover switch that is turned on and off by the first and second main unit horizontal synchronization pulses; An audio signal changeover switch.

[0012]

In this television intercom apparatus, the first and second slave-unit-side horizontal synchronization pulses synchronized with the horizontal synchronization signal from the slave-unit-side horizontal synchronization pulse output circuit of the camera-equipped entrance slave unit and having mutually opposite phases are output. Output. The first audio signal and the second audio signal are turned on and off by the first and second slave horizontal synchronization pulses. Similarly, the indoor master unit synchronizes with the horizontal synchronization signal included in the received composite video signal, and outputs the first and second master unit-side horizontal synchronization pulses having opposite phases to each other from the master unit-side horizontal synchronization pulse output circuit. The first and second master-side horizontal synchronization pulses turn on and off the downstream audio signal switch and the upstream audio signal switch. The downstream audio signal changeover switch and the upstream audio signal changeover switch on the camera-equipped entrance slave unit side and the indoor master unit side operate downward so that the upstream audio signal is time-divided.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a television intercom apparatus according to the present invention will be described below with reference to FIG. In FIG. 1, circuits having the same functions as those in FIG.

In FIG. 1, the television intercom apparatus of the present invention includes a camera 1 for imaging a visitor and outputting a composite video signal synchronized with a horizontal synchronization signal, and a composite video signal modulation circuit 2 for modulating the composite video signal. Entrance cordless handset E with camera
Q1 and an indoor master unit EQ2 provided with a composite video signal demodulation circuit 12 for demodulating a received composite video signal and a television monitor 13 for monitoring the demodulated video signal.

A slave horizontal sync pulse output circuit 5 for outputting first and second slave horizontal sync pulses synchronized with the horizontal sync signal and having opposite phases to each other is provided to the camera-equipped front slave EQ1.
And a down audio signal switch SW1 and an up audio signal switch SW2 that are turned on and off by the first and second slave horizontal synchronization pulses.

The indoor master unit EQ2 outputs first and second master horizontal sync pulses synchronized with the horizontal sync signal included in the received composite video signal and having opposite phases to each other. A horizontal synchronizing pulse output circuit 15 and a downstream audio signal switching switch SW3 and an upstream audio signal switching switch SW4 that are turned on / off by the first and second master horizontal synchronization pulses are provided.

The terminal T1 of the camera-equipped entrance device EQ1 and the terminal T2 of the indoor parent device EQ2 are connected by a cable CBL1.

A camera 1, a video signal modulation circuit 2, a multiplexing circuit 3, a horizontal synchronizing signal generation circuit 4, a microphone 6, a speaker 7, a microphone amplifier 8a, a speaker amplifier 8b, and a horizontal A synchronization pulse output circuit 5, a downstream audio signal changeover switch SW1 and an upstream audio signal changeover switch SW2 are provided, and the output side of the horizontal synchronization signal generation circuit 4 is connected to the slave-unit-side horizontal synchronization pulse output circuit 5 and the camera 1; The output side of 1 is connected to the video signal side of the multiplexing circuit 3 via the video signal modulation circuit 2. The output side of the microphone 6 is connected to the contact S3 of the upstream audio signal switch SW2 via the microphone amplifier 8a, and the contact S4 is connected to the upstream audio signal side of the multiplexing circuit 3. Further, the downstream audio signal side of the multiplexing circuit 3 is connected to the contact S1 of the downstream audio signal changeover switch SW1, and the contact S2 is connected to the speaker 7 via the speaker amplifier 8b.

The respective control sides of the downstream audio signal switch SW1 and the upstream audio signal switch SW2 are connected to the first and second horizontal synchronization pulse output terminals 5a and 5b of the slave horizontal synchronization pulse output circuit 5. Have been.

A multiplexing circuit 11, a video signal demodulation circuit 12, a television monitor 13, a microphone 16, a speaker 17, a microphone amplifier 18a, a speaker amplifier 18 are provided in the indoor master unit EQ2.
b, master-side horizontal synchronization pulse output circuit 15, downstream audio signal switch SW3 and upstream audio signal switch SW4
The video signal side of the multiplexing circuit 11 is connected to a television monitor 13 via a video signal demodulation circuit 12. The output side of the microphone 16 is connected to the contact S5 of the downstream audio signal changeover switch SW3 via the microphone amplifier 18a, and the contact S6 is connected to the downstream audio signal side of the multiplexing circuit 11. Further, the upstream audio signal side of the multiplexing circuit 11 is connected to the contact S8 of the upstream audio signal changeover switch SW4, and the contact S7 is connected to the speaker 17 via the speaker amplifier 18b.

The respective control sides of the downstream audio signal changeover switch SW3 and the upward audio signal changeover switch SW4 are connected to the first and second horizontal synchronization pulse output terminals 15a and 15b of the master unit horizontal synchronization pulse output circuit 15. Have been.

Note that the downstream audio signal changeover switch SW1,
SW3 and the upstream audio signal changeover switches SW2 and SW4 are formed of solid state elements.

In the television intercom apparatus configured as described above, the first horizontal synchronization pulse output circuit 5
And the first horizontal synchronization pulse output terminal 15a of the master-side horizontal synchronization pulse output circuit 15.
When the first horizontal synchronizing pulse is sent to the downstream audio signal changeover switches SW1 and SW3 from the switch, the downstream audio signal changeover switches SW1 and SW3 are closed, and the microphone 16 and the speaker 7 are closed.
The path of the downstream audio signal is formed. At the same time, the second horizontal synchronization pulse output terminals 5b, 1b of the slave side horizontal synchronization pulse output circuit 5 and the base unit side horizontal synchronization pulse output circuit 15
5b to the upstream audio signal changeover switches SW2 and SW4
Is transmitted, the upstream audio signal change-over switches SW2 and SW4 are opened, and the path of the upstream audio signal from the microphone 6 to the speaker 17 is cut off.

In this way, in synchronization with the first and second horizontal synchronizing pulses, the downstream audio signal changeover switches SW1, SW3
The upstream audio signal change-over switches SW2 and SW4 close and open in opposite phases to each other, and operate so as to be time-divisional with respect to the downstream and upstream audio signals.

[0025]

As is apparent from the above description, according to the television intercom apparatus of the present invention, it is possible to surely prevent sound noise without using hardware having a complicated circuit configuration or software having a high development cost.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a television intercom apparatus according to the present invention.

FIG. 2 is a block diagram of a conventional television intercom apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Camera 2 ... Composite video signal modulation circuit 5 ... Slave unit side horizontal synchronizing pulse output circuit 12 ... Composite video signal demodulation circuit 13 ... ································································································································· ..Downward audio signal switch SW2, SW4 .... Uplink audio signal switch

Claims (1)

(57) [Claims] A camera (1) for imaging a visitor and outputting a composite video signal synchronized with a horizontal synchronizing signal, and a camera-equipped entrance device provided with a composite video signal modulation circuit (2) for modulating the composite video signal. (EQ1), and an indoor master unit (EQ2) provided with a composite video signal demodulation circuit (12) for demodulating the received composite video signal and a television monitor (13) for monitoring the demodulated video signal. the entrance door station with a camera, synchronized to the horizontal synchronizing signal, and the first slave unit side horizontal synchronizing pulse output circuit for outputting the second slave unit horizontal sync pulses thus in opposite to each other (5),
The first, on the second slave unit horizontal sync pulses, and a Off uplink speech signal changeover switch (SW2) and the downlink audio signal changeover switch (SW1), to the indoor base unit, said complex received First and second phases that synchronize with the horizontal synchronizing signal included in the video signal and have opposite phases to each other
The base-side horizontal synchronization pulse output circuit (15) for outputting a base-side horizontal sync pulse, the first, on the second base-side horizontal sync pulses, Off downlink voice signal changeover switch
(SW3) and an up sound signal changeover switch (SW4) .