JP3083672B2 - 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 synchronizing a carrier of an audio signal AM modulation signal provided in a camera-equipped entrance device with a horizontal synchronizing signal and operating a call button by operating the phase of the carrier. The present invention relates to a television intercom device that can confirm the operation of the call button in the indoor master unit by inverting the call button in the indoor master unit.

[0002]

BACKGROUND Conventionally from the television interphone apparatus as shown in FIG. 2, is composed of a camera with the entrance door station EQ ₃ and the indoor base unit EQ _4, the terminal T ₃ of the camera with the entrance door station EQ ₃ and the indoor base unit The terminal T _{4 of the} EQ ₄ is connected by the cable CBL ₂ . The camera 1 is a camera with the entrance door station EQ _3, the composite video signal modulation circuit 2, the multiplexing circuit 3, a horizontal synchronizing signal generating circuit 4, a microphone 6, a speaker 7, the microphone amplifier 8a, speaker amplifier 8b, the video signal carrier generating circuit 21, call button F
The output side of the camera 1 to which the horizontal synchronizing signal generation circuit 4 is connected is provided with a ringing signal organization circuit 23 to which K ₂ is connected, and a video signal carrier intermittent switch 22 which is turned on and off under the control of the ringing signal organization circuit 23. It is connected to the video signal side of the multiplexing circuit 3 via the video signal modulation circuit 2. Also,
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. .

Further, the output side of the video signal carrier generation circuit 21 is connected to the video signal carrier input side of the video signal modulation circuit 2 via the video signal carrier intermittent switch 22.
Multiplexing circuit 11 to the indoor base unit EQ _4, composite video signal demodulation circuit 12, TV monitor 13, a microphone 14, a speaker 1
5, a microphone amplifier 14a, a speaker amplifier 15a, a ringing signal detecting circuit 24, and a ringing tone generating circuit 25. The video signal side of the multiplexing circuit 11 is a composite video signal demodulating circuit 12
Is connected to the television monitor 13 via the. Also,
The output side of the microphone 14 is connected to the downstream audio signal side of the multiplexing circuit 11 via the microphone amplifier 14a, and the upstream audio signal side of the multiplexing circuit 11 is connected to the speaker 15 via the speaker amplifier 15a. .

Further, a ringing signal detecting terminal 12b of the composite video signal demodulating circuit 12 is connected to an input side of a ringing sound generating circuit 25 via a ringing signal detecting circuit 24,
5 is connected to the input side of the speaker amplifier 15a. In television interphone apparatus configured in this Yo, by operating the call button FK ₂ cameras with the entrance door station EQ _3, and the call signal knitting circuit 23 is operating, the video signal carrier intermittent switch 22 repeats intermittent operation. When the video signal carrier intermittent switch 22 repeats the intermittent operation, the video signal carrier generated by the video signal carrier generation circuit 21 is intermittent, so that the video signal carrier supplied to the composite video signal modulation circuit 2 is intermittent. When the video signal carrier is intermittent, in the indoor master unit EQ ₄ , the composite video signal demodulation circuit 12 operates via the video signal side of the multiplexing circuit 11, and the video signal carrier of the composite video signal demodulation circuit 12 is turned into a vertical blanking period. Is turned off at a certain timing for an instant. This, instantaneous interruption of the video signal carrier is sent from the calling signal detection terminal 12b as a call signal detection signal to the calling signal detection circuit 24. The ringing signal detection circuit 24 operates the ringing tone generation circuit 25 according to the input ringing signal detection signal.
The speaker 15 sounds via 5a.

When the speaker 15 sounds and responds with a circuit (not shown) of the indoor master unit EQ ₄ , the camera-equipped entrance slave unit E 4
Up audio signal to be output to the microphone amplifier 8a from the microphone 6 of the Q ₃ are multiplexing circuit 3 is amplified by the microphone amplifier 8a
Via sent to the terminal T _3. Up audio signal sent to the terminal T _3, via the cable CBL ₂ and the terminal T _4, are received by the multiplexing circuit 11 of the indoor base unit EQ _4. The upstream audio signal received by the multiplexing circuit 11 is output to the speaker 15 via the speaker amplifier 15a. Downlink voice signal by the same route microphone 14 of the indoor base unit EQ _4, a microphone amplifier 14a and the camera-equipped entrance door station EQ ₃ speaker amplifier 8b, it is transmitted and received between the speaker 7.

[0006]

In such a television intercom apparatus, there is a drawback in that a paging signal organization circuit 23, a video signal carrier intermittent switch 22, a paging signal detection circuit 24, and the like must be provided. In particular, since the ringing signal organization circuit 23 and the ringing signal detection circuit 24 are composed of complicated circuits including a timing circuit, there is a problem that the number of parts is large and the inspection in the manufacturing process becomes complicated.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned difficulties, and there is provided a television intercom apparatus which has a small number of parts, does not require a complicated circuit including a timing circuit, and is easy to inspect in a manufacturing process. It will not be provided.

[0008]

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 entrance terminal has a carrier generation circuit for generating a carrier wave synchronized with the horizontal synchronization signal, and modulates an audio signal with the carrier wave to generate an A signal.
An audio signal AM modulation circuit that outputs an M modulation signal, and a phase inversion circuit that inverts the phase of a carrier wave according to the operation of a call button are provided. The indoor master unit separates a horizontal synchronization signal from a received composite video signal. A horizontal synchronizing signal separating circuit, a phase comparing circuit for comparing the phase of the horizontal synchronizing signal separated by the horizontal synchronizing signal separating circuit with the phase of the carrier of the received AM modulation signal, and both phases are fixed by comparing the phase comparing circuit. A ringing tone generation circuit that operates when it changes.

[0009]

In this television intercom apparatus, a carrier wave synchronized with the horizontal synchronizing signal is generated by the carrier generation circuit provided in the camera-equipped entrance device. The carrier is applied to an audio signal AM modulation circuit, and the audio signal is modulated to output an AM modulated signal. Next, the phase of the carrier wave of the phase inversion circuit is inverted according to the operation of the call button.

A horizontal synchronizing signal separating circuit provided in the indoor master unit separates a horizontal synchronizing signal included in the composite video signal, and a phase comparing circuit detects the phase of the horizontal synchronizing signal and the received AM.
Compare the phase of the carrier of the modulated signal. When both phases change by a certain amount by comparison of the phase comparison circuit, the ringing tone generation circuit is operated.

[0011]

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 the drawings. 1 and 2, circuits having the same functions are given the same reference numerals and the same names, and thus description thereof is omitted.

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
And Q _1, received a indoor base unit EQ ₂ in which a television monitor 13 for monitoring the composite video signal demodulation circuit 12 and demodulated video signal for demodulating the composite video signal, the camera-equipped entrance door station horizontal A carrier generation circuit 5 for generating a carrier synchronized with the synchronization signal;
An audio signal AM modulation circuit 10 for outputting a modulated signal, in response to the operation of the call button FK ₁ and a phase inverting circuit 9 for inverting the phase of the carrier, a horizontal synchronizing signal from the composite video signal received in the room master unit Horizontal synchronization signal separation circuit 1 that separates
6, a phase comparison circuit 17 for comparing the phase of the horizontal synchronization signal separated by the horizontal synchronization signal separation circuit with the phase of the carrier wave of the received AM modulation signal, and when both phases change by a fixed amount by comparison of the phase comparison circuit A ringing tone generating circuit 18 that operates.

[0013] In addition, the terminal T ₁ and the terminal T ₂ of the indoor master unit EQ ₂ of the camera with the entrance door station EQ ₁ are connected by a cable CBL _1. The camera 1 is a camera with the entrance door station EQ _1, the composite video signal modulation circuit 2, the multiplexing circuit 3, a horizontal synchronizing signal generating circuit 4, the carrier generation circuit 5, a microphone 6, a speaker 7, the microphone amplifier 8a, speaker amplifier 8b, phase inverter call button FK ₁ is connected 9 and the audio signal AM modulation circuit 10
The camera 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 audio signal A via the microphone amplifier 8a.
The input side of the M modulation circuit 10 is connected to the input side, and the output side 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 speaker 7 via the speaker amplifier 8b.

The output side of the horizontal synchronizing signal generation circuit 4 is connected to the camera 1 and the carrier generation circuit 5, and the output side of the carrier generation circuit 5 is connected to the terminal 9a of the phase inversion circuit 9. Further, the terminal 9b of the phase inversion circuit 9
It is connected to the carrier input side of the M modulation circuit 10. Multiplexing circuit 11 to the indoor base unit EQ _2, composite video signal demodulation circuit 12, TV monitor 13, a microphone 14, a speaker 15,
A microphone amplifier 14a, a speaker amplifier 15a, a horizontal synchronizing signal separating circuit 16, a phase comparing circuit 17, a ringing tone generating circuit 18 and an audio signal AM demodulating circuit 19 are provided, and the video signal side of the multiplexing circuit 11 is a composite video signal demodulating circuit. 12 and a TV monitor 13. The output side of the microphone 14 is connected to the downstream audio signal side of the multiplexing circuit 11 via the microphone amplifier 14a. Further, the upstream audio signal side of the multiplexing circuit 11 is connected to the input side of the audio signal AM demodulation circuit 19 and the output side is connected to the speaker amplifier 15.
It is connected to the speaker 15 via a. The carrier output side of the audio signal AM demodulation circuit 19 is connected to the phase comparison circuit 1.
7, the terminal 1b of the phase comparison circuit 17
7a is connected to the output side of the horizontal synchronizing signal separating circuit 16 to which the horizontal synchronizing signal output terminal 12a of the composite video signal demodulating circuit 12 is connected. Further, the output side of the phase comparison circuit 17 is connected to the speaker amplifier 15a via the ringing tone generation circuit 18.
Connected to the input side of

In the television intercom apparatus configured as described above, the carrier generation circuit 5 of the camera-equipped entrance device EQ ₁ generates a carrier synchronized with the horizontal synchronization signal output from the horizontal synchronization signal generation circuit 4. The carrier is applied to the terminal 9a of the phase inversion circuit 9. The phase inverting circuit 9 sends the input carrier to the carrier input side of the AM signal modulator 10 without inverting the phase of the carrier.

When the call button FK ₁ is operated in this state, the audio signal AM modulation circuit 10 is output from the terminal 9 b of the phase inversion circuit 9.
The phase of the carrier wave transmitted to the carrier wave input side is inverted. In the indoor master unit EQ ₂ , the phase of the horizontal synchronizing signal sent from the horizontal synchronizing signal output terminal 12 a of the composite video signal demodulating circuit 12 to the horizontal synchronizing signal separating circuit 16 is sent to the terminal 17 b of the phase comparing circuit 17. Although the phases of the carrier waves are in the normal rotation state, when the phases of the carrier waves are inverted, the two phases become inconsistent, so that the ringing tone generating circuit operates and the speaker 15 sounds.

[0017]

As is apparent from the above description, according to the television intercom apparatus of the present invention, the entrance unit with camera has a carrier generation circuit for generating a carrier synchronized with the horizontal synchronization signal, and an audio signal using the carrier. And an audio signal AM modulation circuit that modulates and outputs an AM modulation signal, and a phase inversion circuit that inverts the phase of the carrier wave according to the operation of the call button,
The indoor master unit has a horizontal synchronization signal separation circuit that separates the horizontal synchronization signal from the received composite video signal, and compares the phase of the horizontal synchronization signal separated by the horizontal synchronization signal separation circuit with the phase of the carrier wave of the received AM modulated signal. And a ringing tone generation circuit that operates when both phases change by a certain amount by comparing the phase comparison circuit, so that the number of parts is small, a complicated circuit including a timing circuit is not required, and manufacturing is possible. Inspection in the process becomes easy.

[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]

5 ... carrier generation circuit 9 ... phase inversion circuit 10 ... audio signal AM modulation circuit 16 ... horizontal synchronization signal separation circuit 17 ... and phase comparison circuit 18 ...... ringing tone generating circuit EQ ₁ ······ the entrance door station EQ ₂ ······ indoor parent-equipped camera

Claims (1)

(57) [Claims] A camera for imaging a visitor and outputting a composite video signal synchronized with a horizontal synchronizing signal; an entrance device with a camera provided with a composite video signal modulation circuit for modulating the composite video signal; An indoor master unit provided with a composite video signal demodulation circuit for demodulating a video signal and a television monitor for monitoring the demodulated video signal, wherein the camera-equipped entrance device generates a carrier wave synchronized with the horizontal synchronization signal. A carrier signal generation circuit, a sound signal AM modulation circuit for modulating a sound signal with the carrier wave and outputting an AM modulation signal, and a phase inversion circuit for inverting the phase of the carrier wave in response to an operation of a call button; The device has a horizontal synchronization signal separation circuit for separating a horizontal synchronization signal from the received composite video signal, and the phase of the horizontal synchronization signal separated by the horizontal synchronization signal separation circuit and the received A phase comparator for comparing the phase of the carrier wave of the M modulated signals, television interphone device characterized by comprising a ringing tone generation circuit which operates when both phases by comparison of the phase comparator circuit is changed a predetermined amount.