Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N7/00—Television systems
  • H04N7/18—Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast
  • H04N7/181—Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast for receiving images from a plurality of remote sources
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N7/00—Television systems
  • H04N7/18—Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
  • H04N1/00095—Systems or arrangements for the transmission of the picture signal
  • H04N1/001—Systems or arrangements for the transmission of the picture signal specially adapted for transmission via digital wireline networks
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
  • H04N1/00095—Systems or arrangements for the transmission of the picture signal
  • H04N1/00114—Systems or arrangements for the transmission of the picture signal with transmission of additional information signals

Definitions

• the present invention relates to a CCTV(Closed Circuit Television) system and its embodying method using a single coaxial cable, and more particularly, to a system and a method for transmitting video signal and data signal in a CCTV, which can save installation costs by transmitting video signal and data signal through a single coaxial cable and minimize distortion of video.
• Background Art
• the method is that data signal is inserted and transmitted together with video signal within the vertical flyback period of time containing vertical synchronization.
• video signal is transmitted without any process as it is, and at this time, data signal is overlapped and transmitted within the vertical flyback period of time of the video signal to prevent data signal from being shown on a screen.
• a receiving part detects data signal through time gap and amplitude of data signal on the basis of vertical sync signal.
• vertical sync signal of video signal is distorted or instabilized due to unexpected obstacles occurring by a line condition or external factors during the transmission, it causes instability in detection of data signal or impossibility of detection in the worst case.
• video signal and data signal are converted into different frequencies respectively and mixed.
• the mixed signal is separated into two signals using frequency difference between video signal and data signal in a receiving part and demodulated respectively to return to original signal.
• data signal is not influenced by sync signal of video signal.
• FIG. 2 illustrates a distribution view of frequency according to the second method.
• the present invention provides a system transmitting video signal without any process as it is, converting data signal into different frequency band, which is not influenced by video signal, and having an ground potential corrector mounted on a video receiving terminal to prevent occurrence of power frequency noise due to ground potential.
• the ground potential corrector is a two-way ground potential corrector for correcting ground potential of two-way data since transmission directions of video signal and data signal are different from each other.
• the system includes a camera part 100, a control receiving part 200 having a mixer, a separator, a modulator/demodulator and a control receiver, a control transmitting part 300 having a two-way ground potential corrector, a separator, a mixer, a converter/modulator, and a control transmitter, and a monitor 400.
• the control receiving part 200 mixes data signals such as video signal, microphone signal, alarm signal and so on and transmits mixed signal to the control transmitting part 300 through a single coaxial cable.
• the control transmitting part 300 corrects ground potential in two directions using the two-way ground potential corrector. Output from the two-way ground potential corrector is divided into video signal and data signal.
• Video signal is transmitted to the monitor and data signal is output to an alarm speaker through the modulator/demodulator. Additionally, data signals, such as control signal, alarm signal, microphone signal, etc., of the control transmitter are modulated and mixed in the mixer and transmitted to the control receiver through the two-way ground potential corrector.
• the present invention can be changed, converted, replaced and substituted within a range of the business model, technical method and system and is not restricted in the above.
• FIG. 1 illustrates a view showing a conventional method of transmitting data signal within vertical flyback period of time of video signal
• FIG. 2 illustrates a view showing a conventional method of modulating and transmitting video signal
• FIG. 3 illustrates a schematic view of the present invention
• FIG. 4 illustrates a distribution view of frequency of video signal and data signal according to the present invention
• FIG. 5 illustrates an enlarged schematic view of the present invention. Best Mode for Carrying Out the Invention
• a system according to the present invention largely includes a camera part
• the camera part 100 includes a camera 110 for obtaining video of a monitored area or specific video, a lens 120 for adjusting distance, an illuminator 130 for adjusting luminosity and a rotary stand 140 for adjusting a location of the camera.
• the control receiving part 200 includes a separator 260 for separating data signal, which is transmitted through the single coaxial cable from the control transmitting part 300, from video signal, a modulator/demodulator 250 for demodulating separated data signal, a control receiver 240 for transmitting demodulated data to the rotary stand 140, the lens 120 and the illuminator 130, and a mixer 270 for mixing video signal of the camera 110 and data signal for an alarm 220 and a microphone 210 modulated through the modulator/demodulator 250.
• a separator 260 for separating data signal, which is transmitted through the single coaxial cable from the control transmitting part 300, from video signal
• a modulator/demodulator 250 for demodulating separated data signal
• a control receiver 240 for transmitting demodulated data to the rotary stand 140, the lens 120 and the illuminator 130
• a mixer 270 for mixing video signal of the camera 110 and data signal for an alarm 220 and a microphone 210 modulated through the modulator/demodulator 250.
• Video signal of the camera 110 is input into the mixer 270, and data signal for the lens 120, the illuminator 130 and the rotary stand 140 of the camera is received from the control receiver 240 through a plurality of control lines.
• the control receiver 240 receives data signal transmitted from a control transmitter 340 of the control transmitting 300 and controls peripheral devices of the camera, such as a zoom lens, the illuminator, the rotary stand and so on.
• Data signal for the microphone 210 and the alarm 220 is converted through the modulator/demodulator 250, mixed with video signal through the mixer 270, and transmitted to a two-way ground potential corrector 380 of the control transmitting part 300 through the single coaxial cable.
• FIG. 4 illustrates a distribution view of frequency of video signal and data signal according to the present invention.
• video signal is not modulated at all. Instead of the modulation of video signal, frequency, which does not influence on video signal, is selected and modulates data signal. Video signal and the modulated data signal are mixed and transmitted through the single coaxial cable.
• the control transmitting part 300 includes the control transmitter 340 for generating data controlling the lens 120, the illuminator 130 and the rotary stand 140, a modulator/demodulator 350 for modulating or demodulating data signal, a mixer 360 for transmitting data signal modulated in the modulator/demodulator to the control receiving part 200 through the single coaxial cable, a separator 370 for separating signal transmitted from the two-way ground potential corrector 380 into video signal and data signal, and the two-way ground potential corrector 380 for preventing distortion of video signal and data signal.
• the two-way ground potential corrector 380 corrects ground potential of video Signal and data signal transmitted in two directions through the single coaxial cable.
• the separator 370 separates video signal from data signal. Video signal is transmitted to the monitor 400, and data signal is output to an alarm 33 and a speaker 320 after demodulated through the modulator/demodulator 350.
• the two-way ground potential corrector 380 prevents distortion of video signal and data signal due to the ground potential.
• the control transmitter 340 is to control the lens 120, the illuminator 130 and the rotary stand 140 of the camera part.
• the modulator/demodulator 350 modulates data signal and transmits to the mixer 360.
• the mixed signal is transmitted to the separator 260 of the control receiving part 200 through the two-way ground potential corrector 380.
• FIG. 5 illustrates an enlarged schematic view of the present invention using a plurality of cameras.
• one control transmitter 340 is connected to plural modulators/demodulators and controls each of them.
• the present invention can provide clear and stable quality of video and stably send and receive even in a long distance. Moreover, the present invention can considerably reduce installation expenses since multiplexing and transmitting video signal and data signal. Furthermore, the present invention can prevent deterioration of the system even though the system is used for a long time since a circuit is simple.

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Publications (1)

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ID=19672633

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Citations (2)

Family Cites Families (5)

• 2000
  • 2000-06-19 KR KR1020000033739A patent/KR100334256B1/ko not_active IP Right Cessation
• 2001
  • 2001-06-16 AU AU2001274638A patent/AU2001274638A1/en not_active Abandoned
  • 2001-06-16 WO PCT/KR2001/001034 patent/WO2001099428A1/en active Application Filing

Patent Citations (2)

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