Abstract:
A surveillance system for controlling a camera at a remote location through a monitor. Transmission and reception of an image signal and a power application between a camera and a monitor are accomplished through a single cable. A monitor, connected to the camera through the cable, applies power to the camera through the cable and transmits a camera control signal corresponding to a camera control command to the camera, to control a field of vision of a photographed image corresponding to the camera control signal. Accordingly, the camera is controllable at a location remote from the monitor and the surveillance effect is elevated.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     Not Applicable  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a surveillance system for controlling a camera at a remote location and a method thereof. More specifically, the present invention relates to a surveillance system for applying power between a monitor and a camera through a single registered jack (RJ)-45 cable, communicating data, and controlling the camera at a remote location using a remote controller, and a method thereof.  
         [0004]     2. Description of the Related Art  
         [0005]     Typically, a surveillance system includes at least one camera, a monitor displaying an image received from the camera, and a remote controller controlling the monitor. The monitor of the surveillance system receives and displays image signals of the cameras. A plurality of monitors may be assembled in one place, or a screen of a single monitor may be split for displaying multiple images.  
         [0006]     A new surveillance system has been developed, which is capable of applying a power using an image signal transmission and reception lines between the monitor and the camera so as to solve a problem that the camera is frequently installed outside where it is difficult for the camera to be applied with the power. The transmission and reception lines adopt a RJ-45 (registered jact-45) cable. The RJ-45 cable, which features eight pins, has additional lines in addition to lines for reception and transmission of image and voice signals and power application.  
         [0007]     However, if a user observing through the monitor intends to control panning (horizontal rotation), tilting (vertical rotation), and zooming (image resizing), which are referred to as P/T/Z, the conventional surveillance system has a disadvantage that additional lines for the P/T/Z control need to be connected to the camera and a P/T/Z controller is required separately.  
       SUMMARY OF THE INVENTION  
       [0008]     To address the above and/or other disadvantages of the conventional arrangement, an aspect of the present invention is to provide a surveillance system which controls a field of vision of a plurality of cameras scattered at remote locations through a monitor or a monitor remote controller by using additional lines of a conventional transmission and reception cable without having to add a P/T/Z controller and a control line, and a method thereof.  
         [0009]     To achieve the above and/or other aspects of the present invention, the surveillance system comprises a camera for controlling a field of vision of a photographed image corresponding to a camera control signal, and a monitor connected to the camera through a cable for applying power to the camera through the cable and transmitting the camera control signal corresponding to a camera control command to the camera.  
         [0010]     The surveillance system further comprises a remote controller for transmitting the camera control command to the monitor, to control at least one of panning, tilting, or zooming of the camera.  
         [0011]     The monitor comprises a light receiver for receiving the camera control command, a monitor controller for transmitting the camera control signal corresponding to the camera control command, a monitor interface for providing an interface so that the transmitted camera control signal is recognizable by the camera, and a monitor input and output (I/O) terminal for connecting with the cable so that the camera control signal processed in the monitor interface is transmitted through the cable.  
         [0012]     The monitor interface may comply with recommended standard RS-485. The monitor I/O terminal may be a registered jack RJ-45 module.  
         [0013]     The monitor further comprises a monitor signal processor for converting an image signal transmitted from the camera to a displayable signal form, and a display for displaying on a screen the image signal converted in the monitor signal processor. The monitor may further comprise a monitor power unit for receiving power from outside the monitor and applying the power to the camera through the cable. The monitor power unit may employ a switching mode power supply (SMPS).  
         [0014]     The camera may comprise a photographing unit for forming an optical image of an external object and photoelectrically converting the optical image to an electric image signal, a camera I/O terminal for receiving the camera control signal through the cable, a camera interface for providing an interface so that the received camera control signal is recognizable by the camera, and a camera controller for controlling the photographing unit corresponding to the camera control signal.  
         [0015]     The camera interface may comply with the RS-485. The camera I/O terminal may be the RJ-45 module.  
         [0016]     The camera may further comprise a camera signal processor for processing and transmitting the image signal photographed in the photographing unit to the camera interface. The processed image signal is transmitted to the monitor through the cable.  
         [0017]     The camera further comprises a camera power unit for converting the power applied through the cable to power suitable for the camera. The cable may be an RJ-45 cable.  
         [0018]     The method of controlling a camera of an surveillance system which performs transmission and reception of an image signal and a power application between a camera and a monitor through a single cable, may comprise receiving a camera control command through the monitor, transmitting a camera control signal from the monitor through the cable corresponding to the camera control command, and controlling a field of vision of a photographed image of the camera in response to the camera control signal.  
         [0019]     The camera control signal may control at least one of panning, tilting, and zooming of the camera.  
         [0020]     The transmitting of the camera control signal through the cable may comprise receiving the camera control command, generating the camera control signal corresponding to the camera control command, interfacing the camera control signal to be received by the camera through the cable, and transmitting the interfaced camera control signal through the cable.  
         [0021]     The interfacing of the camera control signal to be received through the cable may adopt a recommended standard RS-485. The transmitting of the interfaced camera control signal through the cable may use a registered jack RJ-45 module.  
         [0022]     The transmitting of the camera control signal from the monitor through the cable may further comprise converting the image signal received from the camera to a displayable signal form, and a displaying the converted image signal on a screen.  
         [0023]     The controlling of the camera may further comprise forming an optical image of an external object and photoelectrically converting the optical image to an electric image signal, receiving the camera control signal through the cable, providing an interface so that the received camera control signal is recognizable by the camera, and controlling the forming of the optical image corresponding to the camera control signal.  
         [0024]     The camera interfacing may adopt the RS-485. The receiving of the camera control signal may be accomplished through the RJ-45 module.  
         [0025]     The controlling of the camera may further comprise transmitting the photographed image signal to a camera interface, and an image signal transmission step of transmitting the processed image signal to the monitor.  
         [0026]     Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0027]     These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:  
         [0028]      FIG. 1  illustrates a surveillance system according to an embodiment of the present invention;  
         [0029]      FIG. 2  is a block diagram of a monitor shown in  FIG. 1 ;  
         [0030]      FIG. 3  is a block diagram of a camera shown in  FIG. 1 ;  
         [0031]      FIG. 4  is a flowchart of an operation of the surveillance system according to an embodiment of the present invention;  
         [0032]      FIG. 5  is a flowchart illustrating the transmitting of the camera control signal of  FIG. 4 ; and  
         [0033]      FIG. 6  is a flowchart of controlling the camera of  FIG. 4 .  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0034]     Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.  
         [0035]      FIG. 1  illustrates a surveillance system according to an embodiment of the present invention. The surveillance system includes a remote controller  100 , a monitor  200 , at least one camera  300 - 1 ,  300 - 2 ,  300 - 3  and  300 - 4 , and RJ-45 cables  400 - 1 ,  400 - 2 ,  400 - 3  and  400 - 4 , respectively.  
         [0036]     The remote controller  100  comprises a key (not numbered) corresponding to a camera control command for controlling a respective field of vision of the cameras  300 - 1  to  300 - 4  installed at remote locations, that is, for controlling panning, tilting, and zooming (P/T/Z) of the cameras  300 - 1  to  300 - 4 . The remote controller  100  transfers the camera control command in accordance with the input of the key. The camera control command contains information on the cameras  300 - 1  to  300 - 4  to be controlled.  
         [0037]     The monitor  200  is supplied with external power and transfers the power to the cameras  300 - 1  to  300 - 4  using the RJ-45 cables  400 - 1  to  400 - 4 , and receives and displays image signals photographed by the cameras  300 - 1  to  300 - 4  through the RJ-45 cables. Upon receiving the camera control command, the monitor  200  generates and transmits a camera control signal to a corresponding camera  300 - 1  to  300 - 4 .  
         [0038]     The cameras  300 - 1  to  300 - 4  are installed at locations to be monitored. The cameras  300 - 1  to  300 - 4  operate with the applied power and transmit photographed image signals to the monitor  200  through the RJ-45 cables  400 - 1  to  400 - 4 . Upon receiving the camera control command, the cameras  300 - 1  to  300 - 4  control the field of vision of the image, that is, the P/T/Z.  
         [0039]     Each of the RJ-45 cables  400 - 1  to  400 - 4  has eight pins and includes lines for receiving and transmitting the image signals, the camera control signal, and the power.  
         [0040]      FIG. 2  is block diagram of the monitor  200  of  FIG. 1 . Referring to  FIG. 2 , the monitor  200  includes a power unit  240 , a monitor circuit unit  210 , and monitor input and output (I/O) terminals  250 - 1 ,  250 - 2 ,  250 - 3  and  250 - 4 . The monitor circuit unit  210  includes a light receiver  220 , a monitor controller  230 , a monitor interface  260 , a monitor signal processor  270 , and a display  280 .  
         [0041]     The power unit  240  is supplied with the external power and applies the power to the monitor circuit unit  210 . The power unit  240  applies the power to the cameras  300 - 1  to  300 - 4  through the monitor I/O terminals  250 - 1  to  250 - 4  and the cables  400 - 1  to  400 - 4 , respectively.  
         [0042]     The light receiver  220  receives the camera control command of an infrared signal form from the remote controller  100 . The camera control command is to control the P/T/Z of one of the cameras  300 - 1  to  300 - 4 .  
         [0043]     The monitor controller  230  controls the monitor interface  260 , the monitor signal processor  270 , and the display  280 . When the monitor  200  is applied with the external power, the monitor controller  230  scans the cameras  300 - 1  to  300 - 4  being connected and records in a certain memory (not shown) a number of the connected cameras  300 - 1  to  300 - 4  and the P/T/Z control feasibility, i.e., whether a respective camera is adapted for P/T/Z control. Upon receiving the camera control command, if the camera  300 - 1  to  300 - 4  corresponding to the camera control command is controllable with respect to the P/T/Z, the monitor controller  230  generates and transmits the camera control signal to the monitor interface  260 .  
         [0044]     The monitor interface  260  provides an interface so that the monitor  200  and each camera  300 - 1  to  300 - 4  may effectively communicate with each other through a respective one of the RJ-45 cables  400 - 1  to  400 - 4 . Advantageously, the monitor interface complies with a recommended standard RS-485. The interfaced camera control signal is transmitted to a respective monitor I/O terminal  250 - 1  to  250 - 4  connected to a respective camera  300 - 1  to  300 - 4  corresponding to the camera control command.  
         [0045]     The monitor I/O terminals  250 - 1  to  250 - 4  are RJ-45 connectors and connected to a respective one of the RJ-45 cables  400 - 1  to  400 - 4 . The monitor I/O terminals  250 - 1  to  250 - 4  output the signal transmitted from the monitor  200  to the RJ-45 cables  400 - 1  to  400 - 4 , respectively, and receive the image signals from the cameras  300 - 1  to  300 - 4 , respectively.  
         [0046]     The monitor signal processor  270  processes the image signals, which are received through the monitor I/O terminals  300 - 1  to  300 - 4  and interfaced to be recognizable by the monitor  200 , to a displayable image signal. The display  280  displays the image signal received from the monitor signal processor  270 .  
         [0047]      FIG. 3  is a block diagram of one of the cameras  300 - 1  to  300 - 4  of  FIG. 1 , which for simplicity of explanation will be referred to as a camera  300 . Referring to  FIG. 3 , the camera  300  includes a camera I/O terminal  320 , a camera power unit  330 , and a camera circuit unit  310 . The camera circuit unit  310  includes a camera interface  340 , a camera controller  350 , a photographing unit  360 , and a camera signal processor  370 .  
         [0048]     The camera I/O terminal  320  receives the camera control signal from the monitor  200  through a respective one of the RJ-45 cables  400 - 1  to  400 - 4  and transmits the received signal to the camera interface  340 . In the description of operation of the camera  300 , the respective cable will be referred to simply as cable  400 . The camera I/O terminal  320  is supplied with power through the cable  400 .  
         [0049]     The power unit  330  converts the power supplied through the cable  400  to a power suitable for the camera  300  and applies the converted power to the camera circuit unit  310 . The camera circuit unit  310  operates by the applied power.  
         [0050]     The camera interface  340  provides an interface enabling the monitor  200  and the camera  300  to effectively communicate with each other through the RJ-45 cable  400 . Advantageously, the interface complies with the RS-485. The camera controller  350  controls a field of vision of the photographing unit  360 , that is, controls the P/T/Z upon receiving the camera control signal interfaced to be recognizable by the camera controller  350 .  
         [0051]     The photographing unit  360  forms and photoelectrically converts an optical image of an external object to an electric image signal. The camera signal processor  370  processes and transmits the image signal converted in the photographing unit  360  to the camera interface  340 .  
         [0052]      FIG. 4  is a flowchart of an operation of the surveillance system for controlling the camera at a remote location through the monitor according to an embodiment of the present invention. Referring to  FIG. 4 , a camera control command is transmitted from the remote controller  100  at operation S 500 . Upon receiving the camera control command, the monitor  200  transmits the camera control signal to the camera  300  through the RJ-45 cable  400  at operation S 600 . Upon receiving the camera control signal, the camera  300  controls the P/T/Z of the photographing unit  360  at operation S 700 .  
         [0053]      FIG. 5  is a flowchart of operations for transmitting the camera control signal of  FIG. 4 . Referring to  FIG. 5 , a type and a number of the cameras  300  being connected are scanned at operation S 610 . When a camera control command containing the information on the camera  300  to be controlled at operation S 630  is received, a determination is made whether the camera  300  is controllable with respect to the PIT/Z at operation S 650 . If the camera  300  to be controlled does not have a P/T/Z control function, the camera control signal is not transmitted and the control operation is terminated. If the camera  300  has the P/T/Z control function, the camera controller  350  generates the camera control signal at operation S 670 . The generated camera control signal is interfaced to be received by the camera  300  at operation S 680 , and transmitted through the RJ-45 cable  400  at operation S 690 .  
         [0054]      FIG. 6  is a flowchart of operations for controlling the camera  300  of  FIG. 4 . Referring to  FIG. 6 , the camera  300  receives the camera control signal from the RJ-45 cable  400  through the camera I/O terminal  320  at operation S 710 . The received camera control signal is interface at operation S 730  and transmitted to the camera controller  350 . The camera controller  350  controls the P/T/Z of the photographing unit  360  at operation S 760 .  
         [0055]     As explained above, the field of vision of the camera  400  is controllable at the remote location through the monitor  200 .  
         [0056]     In light of the foregoing, a plurality of the cameras scattered at the remote locations are controllable in one place by using the monitor, without having to manually move each of the cameras. If a change of the field of vision of the cameras is required during the surveillance through the monitor, the control of the field of vision is immediately feasible and thus, the surveillance effect is elevated. Since the existing lines are utilized, additional cost for installing separate lines is not required.  
         [0057]     Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.