KR20090025620A

KR20090025620A - Method for communicating control signal in 2 wire communication system between wallpad and door phone

Info

Publication number: KR20090025620A
Application number: KR1020070090602A
Authority: KR
Inventors: 정제윤
Original assignee: 주식회사 경동네트웍
Priority date: 2007-09-06
Filing date: 2007-09-06
Publication date: 2009-03-11
Also published as: WO2009031745A1

Abstract

Two-wire communication between the wall pad and the door phone that enables video and audio communication by connecting two lines between the door phone installed in the front door and the wall pad installed in the room in order to check the identity and purpose of the external visitors. The present invention relates to a control signal communication method of a two-wire communication system between a wall pad and a door phone capable of transmitting and receiving a control signal to input information from a door phone as well as a video and audio signal between a wall pad and a door phone.

One embodiment of the present invention for realizing this, the video signal and the control signal between the door phone and the wall pad is carried on the carrier frequency of different bands without mutual interference, and the audio signal is transmitted using a modulation and demodulation method. It is characterized by.

In addition, according to another embodiment of the present invention, the video signal between the door phone and the wall pad is carried on a carrier frequency of a specific band, and the audio signal and the control signal are modulated and demodulated together at a frequency of a band higher than the carrier frequency of the video signal. It characterized in that the transmission.

Description

Method for communicating control signal in 2 wire communication system between wallpad and door phone}

Two-wire communication between the wall pad and the door phone that enables video and audio communication by connecting two lines between the door phone installed in the front door and the wall pad installed in the room in order to check the identity and purpose of the external visitors. The present invention relates to a communication method of a system, and more particularly, to a control of a two-wire communication system between a wall pad and a door phone that can transmit and receive a control signal to input information from a door phone as well as video and audio signals between the wall pad and a door phone. It relates to a signal communication method.

In general, a communication system using a wall pad and a door phone is a system for checking the identity and purpose of an external visitor through the video and audio communication. The wall pad is installed indoors and the door phone is installed on the porch. It is configured to supply the driving power of the door phone from the wall pad to the door phone, and it is possible to receive two-way voice transmission between the wall pad and the door phone, and the camera is installed on the door phone and the wall pad photographed by the camera of the door phone. A display device for receiving and displaying a video signal is provided. In addition, the wall pad and the door phone are mainly connected by two or four wires according to the system specification to enable such a power supply or audio and video transmission.

By the way, in the case of using 4 or more wires, the power, video and audio signals can be separated and transmitted as separate wires. Both must be sent and received.

1 is a schematic block diagram of a conventional 2-line video / audio communication system between a door phone and a wall pad.

As shown in the accompanying drawings, the wall pad 10A is a signal coupling 11 for transmitting and receiving image signals, audio signals, and power with the door phone 20A, and images received by the signal coupling 11. A display unit 12 for displaying a signal, a microphone 13 for receiving a voice signal and converting it into an electrical signal, and a high frequency modulator 14 for high frequency modulating the output signal of the microphone 13 and transmitting the signal to the signal coupling 11. ), A high frequency demodulation unit 15 for demodulating the sound image signal received by the signal coupling 11 and outputting it as an audible signal, and a power supply and door phone 20 necessary for the wall pad 10A. Consists of a power supply unit 17 for supplying the necessary power.

In addition, the door phone (20A) is a signal coupling 21 for transmitting and receiving video signals, audio signals, power and the video signal of the wall pad 10, and the visitor video signal through the signal coupling 21 Camera 22 for transmitting to wall pad 10A, microphone 23 for receiving a voice signal and converting it into an electrical signal, and high frequency modulating the output signal of the microphone 23 to signal coupling 21. The modulator 24 receives power from the high frequency demodulator 25, the speaker 26, and the wall pad 10A that demodulate the audio signal received by the signal coupling 21 and output the audible signal as an audible signal. It consists of a power supply unit 27 for supplying power required for each component of the door phone (20A).

In this structure, the wall pad 10A is connected to the door phone 20A by two wires, and the wall pad 10A is powered by the door phone 20A through the signal coupling 11 and the signal coupling 21. The video signal is transmitted without passing through the modulator / demodulator, and the audio signal is transmitted through the modulator / demodulator 14, 15, 24, and 25 in a communication process.

In this case, when the audio signal is transmitted without high frequency modulation / demodulation, the video signal and the audio signal may be mixed and noise may occur in the voice, and noise may occur in the image. Therefore, as illustrated in FIG. 2, the audio signal is modulated at a frequency higher than that of the video signal to prevent crosstalk.

However, the communication system having such a structure cannot transmit / receive separate control signals other than the video signal and the audio signal, and thus there is a problem in that the door phone cannot transmit additional information such as a password.

The present invention has been invented to solve the above problems, by transmitting and receiving the control signal using a different frequency band from the audio signal and the video signal or by communicating the control signal with the audio signal using a modulation and demodulation method, An object of the present invention is to provide a control signal communication method of a two-wire communication system between a door pad and a door phone, which is capable of transmitting and receiving a control signal in addition to a voice signal and a video signal while connecting a door phone with two wires.

In the control signal communication method of the two-wire communication system between the wall pad and the door phone according to an embodiment of the present invention for achieving the above object, the video signal and the control signal between the door phone and the wall pad are different bands without mutual interference In addition to carrying on the carrier frequency of the audio signal is characterized in that for transmitting using a modulation and demodulation method.

In the control signal communication method of the two-wire communication system between the wall pad and the door phone according to another embodiment of the present invention, the video signal between the door phone and the wall pad is carried on a carrier frequency of a specific band, and the audio signal and the control signal are And modulating and demodulating together at a frequency of a band higher than a carrier frequency of the video signal.

As described above, the present invention enables the control signal to be transmitted without increasing the number of transmission lines between the wall pad and the door phone, thereby reducing the wiring cost and using two wires connected to the doorbell and the bell in the main building. It is easy to construct in the base building, and it is possible to input and receive the control signal between the door phone and the wall pad, so it is possible to input information such as the keypad from the door phone, and the wall pad can control the camera connected to the door phone. have.

Hereinafter, the configuration and operation of the preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

3 shows a block diagram of an apparatus according to an embodiment of the present invention. Here, the components that perform the same function as the components of the apparatus shown in FIG. 1 are given the same reference numerals and detailed descriptions thereof will be omitted in order to avoid duplication of description.

In the accompanying drawings, the wall pad 10B is connected to the door phone 20B in two lines. That is, the wall pad 10B and the door phone 20B are connected to each other by the signal coupling 11 and the signal coupling 21, which are communication interfaces, by two communication lines.

Thus, the wall pad 10B supplies power to the door phone 20B through a two-wire communication line connected between the signal coupling 11 and the signal coupling 21, and furthermore, the wall pad 10B is connected to the camera of the door phone 20B. The video signal photographed at 22 is transmitted to the wall pad 10B through the two-wire communication line without passing through the modulator / demodulator, and the voice signal input to the microphone 23 of the door phone 20B is a high frequency modulator ( 24) and modulates the signal through the two-wire communication line to the wall pad 10B. The wall pad 10B side demodulates the signal through the high frequency demodulator 15 and outputs the audio frequency through the speaker 16. . Similarly, the voice signal input to the microphone 13 of the wall pad 10B is modulated by the high frequency modulator 14 and then transmitted to the door phone 20B through the two-wire communication line, and the door phone 20B. ) Demodulates through the high frequency demodulation unit 25 and outputs the audio frequency through the speaker 26.

In addition, the control signal generated by the control signal generator 18 or 28 by a keypad input or the like between the wall pad 10B and the door phone 20B does not go through a modulator like the video signal, but the signal coupling 11 and 21. The transmission signal is transmitted through the communication lines of the two wires, received by the control signal detection unit 19 or 29 of the external device, and the control signal is detected. In this case, the control signal generated by the control signal generator 18 or 28 is generated using a carrier of a high frequency band in which interference with the video signal does not occur.

4 is a diagram illustrating frequency bands of an image, audio, and control signal used in FIG. 3.

As shown, the control signal is generated and transmitted as a signal of a higher frequency band than the video signal without frequency modulation, and the audio signal is modulated and demodulated to a high frequency band that does not interfere with the video signal and the control signal to communicate. . As such, the video signal, the audio signal, and the control signal can be transmitted without mutual interference by separately transmitting the signals in different frequency bands as shown in FIG. 4.

5 shows a block diagram of an apparatus according to another embodiment of the present invention. Here, the components that perform the same functions as the components of the apparatus shown in FIGS. 1 and 3 are given the same reference numerals and detailed descriptions thereof will be omitted in order to avoid duplication of description.

In the accompanying drawings, the wall pad 10C is connected to the door phone 20C in two lines. That is, the wall pad 10C and the door phone 20C are configured such that the signal coupling 11 and the signal coupling 21, which are respective communication interfaces, are connected to each other by two communication lines.

Thus, the wall pad 10C supplies power to the door phone 20C via a two-wire communication line connected between the signal coupling 11 and the signal coupling 21, and furthermore, the camera 22 of the door phone 20C. The video signal photographed at) is transmitted to the wall pad 10C via the two-wire communication line without passing through the modulator / demodulator, and the audio signal input to the microphone 23 of the door phone 20C is a high frequency modulator 24. After modulating through), it is transmitted to the wall pad 10C through the two-line communication line, and the demodulated through the high frequency demodulator 15 on the wall pad 10C side, and then outputs the audible frequency through the speaker 16. Similarly, the voice signal input to the microphone 13 of the wall pad 10C is modulated by the high frequency modulator 14 and then transmitted to the door phone 20C through the two-wire communication line, and the door phone 20C. ) Demodulates through the high frequency demodulation unit 25 and outputs the audio frequency through the speaker 26.

In addition, the control signal generated by the control signal generator 18 or 28 by keypad input or the like between the wall pad 10C and the door phone 20C is the high frequency demodulation unit 14, 15 (24, 25) similarly to the voice signal. To communicate with each other. That is, the wall pad 10C or the door phone 20C generates a control signal generated by the control signal generator 18 or 28 in a frequency band higher than an audible frequency, modulates it with a voice signal, and transmits it to an external device. After receiving the modulated voice signal and the control signal, the external device demodulates the signal using the high frequency demodulator 15 or 25, and then outputs an audio frequency signal to the speaker 16 or 26, while a band higher than the audio frequency. The signal of is received by the control signal detector 19 or 29 through a filter (not shown) or the like to extract the control signal and perform a control action accordingly.

FIG. 6 is a diagram illustrating a division of frequency bands between a video signal and a modulation signal of an audio / control signal used in FIG. 5, and FIG. 7 is a diagram illustrating a division of frequencies before modulation of an audio signal and a control signal.

As shown in FIG. 6, the voice / control signal is generated by modulating a signal having a higher frequency band than the video signal, and generates a control signal between the voice and the control signal at a high frequency band without interference with the voice signal. . As such, the frequency between the modulation signal of the video signal and the audio / control signal and the frequency between the audio signal and the control signal are generated separately and then transmitted separately in different frequency bands, thereby transmitting without interference.

For example, the control signal generated by the control signal generator 18 or 28 may be combined with a voice signal such as a dual tone multi frequency (DTMF) signal used in a public switched telephone network (PSTN). The frequency of the control signal can be used together. However, when the real voice signal and the DTMF signal are used together, it is difficult to distinguish the DTMF signal due to the voice. That is, since the DTMF signal is present in the audible frequency band, the DTMF signal may be output to the speaker, and conversely, the specific voice signal may be recognized as the DTMF signal. Therefore, the control signal is preferably generated at a frequency higher than the voice signal frequency.

1 is a schematic configuration diagram of a two-line video / audio communication system between a door phone and a wall pad;

FIG. 2 is a diagram illustrating frequency band division of video and audio signals used in FIG. 1;

3 is a block diagram of an apparatus according to an embodiment of the present invention;

4 is a view showing frequency band division of video, audio, and control signals used in FIG. 3;

5 is a block diagram of an apparatus according to another embodiment of the present invention;

FIG. 6 is a diagram illustrating the division of a frequency band between a video signal and a modulation signal of a voice / control signal used in FIG. 5;

7 is a diagram illustrating frequency division before modulation of a voice and a control signal.

10 (10A, 10B, 10C)-Wall pad, 20 (20A, 20B, 20C)-Door phone,

11,21-signal fling, 12-indicator,

13,23-microphone, 14,24-high frequency modulator,

15,25-high frequency demodulator, 16,26-speaker,

17,27-power supply, 18,28-control signal generator,

19,29-Control signal detector.

Claims

The video signal and control signal between the door phone and the wall pad are carried on the carrier frequencies of different bands without mutual interference, and the audio signal is transmitted using a modulation / demodulation method. Control signal communication method of communication system.

The video signal between the door phone and the wall pad is carried on a carrier frequency of a specific band, and the voice signal and the control signal are modulated and demodulated together at a frequency of a band higher than the carrier frequency of the video signal. Control signal communication method of two-wire communication system between pad and door phone.