KR200207713Y1 - Video/audio multiplex optical modules - Google Patents

Abstract

The present invention relates to a CCTV multiple connection device irrespective of the number of cameras, in a device for connecting to a plurality of cameras and monitors and speakers installed in a long distance, the multiplexing of CCTV to transmit a video signal and an audio signal using an optical cable It relates to a transmission device. Prior art uses coaxial cable to transmit one-to-one or separates audio signals, which is expensive and mostly unidirectional. In order to secure this disadvantage, optical fiber has much less transmission loss than coaxial cable, it is very small in volume without the induction of electromagnetic field, and it transmits to optical fiber in terms of low cost and broadband because it transmits dozens of strands in one cable. Transceiver system technology. Popular technology using RF technology to dozens of channels at high frequency and low cost to convert electrical signals into optical signals to simplify circuits, and to transmit and receive signals in both directions to control cameras, video transmission technology and data transmission It is about improving technology. And transmits dozens of strands in one cable, the transmission through the optical fiber is characterized by strong noise and no influence on electromagnetic waves.

Description

Video / Audio Multiplex Optical Modules

The present invention relates to a CCTV multi-connection device, especially when installing a large number of surveillance cameras in a large space such as underground parking lot, department store, factory security, and production surveillance management in a general building, using two optical fibers regardless of the quantity. The present invention relates to a multi-transmission device capable of easily transmitting camera video and audio. The conventional CCTV connection device is expensive as the number of CCTV when the camera and the monitor is connected by one coaxial cable and the camera and the speaker are connected by another coaxial cable. Since coaxial cable is required, there was a problem that it takes a lot of money to build the system, and the installation of the system is complicated because the coaxial cable is used as much as the number of CCTV installed. Currently, surveillance cameras are installed in various places to prevent theft or crime prevention in places where many people gather, such as banks, department stores, or underground parking lots. to be.

Therefore, the present invention for solving the above problems is to separate the video signal and the audio signal output from a plurality of cameras into different frequencies and the video signal and audio signal signal converted to different frequencies by separating each channel Develop a way to demodulate and feed to a monitor. And when connecting a large number of cameras to remote monitors, there is a need for a technology that converts electrical signals into optical signals and reverse conversion so that they can be connected by optical cables in a way that reduces line and construction costs. In particular, since the interference and noise is a big problem at high frequencies, technology to solve this problem is a key item of the invention. When multiple cameras are installed in a large space such as an underground parking lot or a department store of a general building, the present invention relates to a CCTV multiple connection device for connecting each camera and a monitor. In order to control the camera, a technique is needed to transmit signals in both directions.

1 is a block diagram of a CCTV multi-connector of the present invention.

2 is a conceptual diagram of a demodulated NTSC signal and demodulation according to the present invention;

3 is a block diagram of a TX RX bidirectional transmission and reception method of the present invention.

4 is a block diagram of a bidirectional transmission and reception system of wavelength division multiplexing (WDM).

5 is a block diagram of a multi-screen system using an optocoupler.

6 is a block diagram of a system for outputting two signals using an optocoupler.

One Multiplexing modulation means 2 : Bandpass Filter 3 Mixer 4 : Low frequency amplifier 5 Optical converter 6 Wavelength Divider 7 Demodulator

1 to 6, an embodiment of the present invention will be described as follows. [FIG. 1] shows different frequencies of video and audio signals respectively inputted from cameras connected to a plurality of cameras. Low noise amplifier (4) through a plurality of signal modulators (MT1 ~ MTn) and a BPF (2) to modulate the band and pass through a specific frequency, and through the Combinder (3) to remove the noise through filtering to mix the signals It includes an all-optical converter 5 for converting an electrical signal into an optical signal through. After transmitting a signal using an optical fiber, the optical / electric converter 5 divides an NTSC signal having a predetermined band among NTSC signals of different frequency bands inputted from the multiplexing modulation means 1 through an optical cable into a specific frequency. The divider 6 is formed. In FIG. 1, demultiplexing demodulation means 7 composed of a plurality of signal demodulation units DMT1 to DMTn having a frequency demodulation function corresponding to frequency modulation of the signal modulators MT1 to MTn. In the demodulator, the video signal is divided into 4 parts through a splitter, and the video signal is amplified by the video amplifier and output to the monitor. The audio signal is amplified by the audio signal and output through the speaker.

FIG. 2 is a detailed description of FIG. 1, which includes a signal synthesizer 50 for synthesizing an NTSC signal by synthesizing a video signal and an audio signal input from each camera, and a modulation frequency for generating a modulation frequency of the NTSC signal. The oscillator 52 generates a predetermined frequency and frequency modulator 51 for FDMA modulation of the NTSC signal output through the signal synthesizer 50 according to the frequency output from the modulated frequency oscillator 52, and the frequency modulator. The NTSC signal output from the 51 is filtered by the first filter 53 to remove noise, and to modulate the frequency signal corresponding to each channel with the isolator 54 which prevents the reverse flow of the output signal, and converts the electric signal into an optical signal. Is transmitted through the pre / photo converter 55 to convert to. The receiver includes an optical / electric converter 56 for converting an optical signal into an electrical signal, a high frequency amplifier 57 for amplifying the received NTSC signal, a frequency oscillator 59 for demodulating the NTSC signal, and an NTSC signal in each frequency band. And a third filter 61 which is output to the monitor through a frequency demodulator 58 for demodulating a second signal and a second filter 60 for separating an image signal from the demodulated NTSC signal, and separates an audio signal from the demodulated NTSC signal. The device that outputs to the speaker through.

3 is a diagram of a connection state between optical transmission apparatuses, a transmitter TX for multiplexing multiple signals, converting an electrical signal into an optical signal, and transmitting the optical signal; There is a transmission and reception module composed of a receiving unit (RX) is used as a practical optical transmission system, connected to the transmission and reception module 102 through the optical jumper code 104 transmitted from the transmission unit of the transmission and reception module 101, the transmission and reception module 102 In again, the optical signal is connected to the optical cable line 103. The optical transmission and reception terminals 101 and 102 transmit and receive video, audio, and data using two optical fibers, respectively, and display the demodulated video signal on a monitor through a splitter on a plurality of screens. Listen to the voice selectively among the screens of the screen, and the remaining divided screen is converted to a text message and displayed on the screen. The data transmission is for controlling the object (camera).

As shown in FIG. 4, the WDM1 and the WDM2 are installed in both wavelength division multiplexing (WDM) systems to transmit a video having a wavelength lambda ₁ 201 to the WDM2, and a control signal having a wavelength λ 2 (202) to the WDM1. Transmitting and receiving system for transmitting a video of λ 과 and a control signal of λ ₂ in one transmission to the optical cable 203 of one wire in two directions.

5 shows that the signal transmitted through the camera 301 is distributed by the optical signal using the optical coupler 303 through the optical transmission device 302, thereby distributing the optical signal through the signal demodulation 304. System can be seen through each monitor (305) in different places.

FIG. 6 is a system in which λ and λ2 signals, which are input by modulating (403) signals from two or more different surveillance cameras (401, 402), are transmitted by one line at a time difference using an optical coupler (404). In addition, surveillance cameras and sensors are installed in one place, and when the sensors operate, the cameras operate to obtain more accurate information.

As described above, the present invention provides means for multiplexing and converting video and audio signals output from multiple surveillance cameras at different frequencies, and converting electrical signals into optical signals and converting optical signals into electrical signals. Means for demodulating video and audio signals converted to different frequencies and supplying them to the monitor and transmitting them through optical cables when connecting multiple surveillance cameras and remote monitors. When installing a large number of surveillance cameras in a large space such as a parking lot or a department store, the optical cable connecting each camera to the monitor and the speaker has less transmission loss than the coaxial cable, and is very small in volume without the induction of electromagnetic fields. , Because it uses quartz, it is resource-rich and broadband I used to.

Claims (5)

In the optical communication transceiver, an NTSC signal is generated by synthesizing an input unit input from a plurality of cameras and a surveillance camera with a sensor, a camera controller for controlling the surveillance camera with a sensor, and video and audio signals generated from the camera. Data processing unit for signal synthesizer and camera control, frequency oscillator for modulating NTSC signal and data, modulator for modulating for each channel according to frequency output from frequency oscillator, filtering signal output from the frequency modulator Optical transmission device consisting of a filter unit for removing, a multiplexing unit for transmitting the noise-removed signal to a single optical cable, an all-optical conversion unit for converting the multiplexed electrical signal into an optical signal, an optical cable for transmitting the optical signal, Optical / electric converter for converting the received optical signal into an electrical signal, amplifying the received data and NTSC signal A high frequency amplifier, a frequency oscillator for reproducing data and NTSC signals, a demodulator for demodulating NTSC signals into respective frequency bands, a controller for demodulating data, and a second filter for separating image signals from the demodulated NTSC signals. An optical communication transmitting and receiving device for outputting through a speaker via a display unit for outputting to the monitor through a third filter for separating the audio signal from the demodulated NTSC signal. The control unit of the optical transmission / reception apparatus of claim 1 modulates and transmits an NTSC signal obtained by synthesizing video / audio signals generated by a plurality of cameras in a wavelength division multiplexing scheme capable of bidirectional transmission. _The NTSC signal of ₁ person is transmitted to the WDM2 using an optical cable and demodulated to reproduce video and audio signals. An optical communication transmission / reception apparatus that converts an all-in-one signal into a _two- person signal and transmits it using an optical cable, and converts and / or demodulates an optical signal to control a camera as a target. The display unit of claim 1, wherein the image signal is filtered by the second filter unit from the demodulated NTSC signal, and the filtered image signal is displayed on the monitor through a divider, and the displayed multiple screens are displayed. An optical communication transceiver for selectively listening to the voice and displaying the subtitles on the screen by a converter for converting each voice signal of the divided screen into text data. The camera controller of claim 1, wherein the sensor unit detects a changing environment through a sensor attached to the camera, and transmits the detected change state to the camera controller to drive the camera, and selectively among a plurality of cameras depending on whether the camera is driven. Monitorable optical transceiver. In the optical communication transmission and reception method of claim _1, the NTSC signal input from one camera is transmitted at a wavelength of λ ₁ to distribute and use an optical coupler to monitor or listen to each communication device at different places. Optical communication transmitter and receiver that can transmit NTSC signals from two or more different cameras to wavelengths such as λ ₁ , λ _2, etc. and transmit them using an optical switch and an optical coupler.