Abstract:
A monitoring camera capable of preventing light interference from occurring in a capturing unit due to light diffusely reflected from a covering member. The monitoring camera can include an image capturing unit; a lighting unit to emit light in a capturing direction of the capturing unit and to illuminate a monitoring area; a covering member to cover the capturing unit and the lighting unit; and a light guide unit, mounted in the capturing unit, to guide the light diffusely reflected from the covering member so the light does not enter the capturing unit.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority under 35 U.S.C. §119 (a) of Korean Patent Application No. 10-2007-0087093, filed on Aug. 29, 2007, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present general inventive concept relates to a monitoring camera employed in a closed-circuit television (CCTV) system. 
         [0004]    2. Description of the Related Art 
         [0005]    Monitoring cameras are generally used in closed-circuit television (CCTV) systems. Monitoring cameras may be installed in various locations, including homes, department stores, banks, exhibition halls, factories, and other places where monitoring is required. Mounted monitoring cameras continue to capture images, and transmit the captured images to monitors installed in offices.  FIG. 1  shows a conventional monitoring camera  1 . 
         [0006]    The monitoring camera  1  of  FIG. 1  includes a main body  10 , a capturing unit  20  mounted on the main body  10 , a lighting unit  30  to generate light, and a covering member  40  having a dome shape to cover the capturing unit  20  and the lighting unit  30 . 
         [0007]    The capturing unit  20  is rotatably mounted in the main body  10  about a support shaft  21 , and a capturing direction thereof is adjusted by a user or worker. The lighting unit  30  is mounted adjacent to the capturing unit  20  in order to increase the illuminance and obtain clean images at night. 
         [0008]    As illustrated in  FIG. 1 , since the lighting unit  30  is fixed onto the main body  10 , it is difficult for the light emitting unit  30  to emit light in many directions corresponding to the capturing direction of the capturing unit  20 . Additionally, the light emitted from the lighting unit  30  is diffusely reflected from an inner surface of the covering member  40 , and enters the capturing unit  20 , thus interfering with the operation of the capturing unit  20 . 
         [0009]    In order to solve problems such as the difficulty of changing the direction of light emitted according to the capturing direction of the capturing unit  20 , a lighting unit  30 ′ may be formed integrally with a capturing unit  20 ′, as illustrated in  FIG. 2 . However, the light is diffusely reflected from the inner surface of the covering member  40  and enters the capturing unit  20 ′ even when the lighting unit  30 ′ is formed integrally with the capturing unit  20 ′, so the light from the light emitting unit  30 ′ may also interfere with the capturing unit  20 ′. 
       SUMMARY OF THE INVENTION 
       [0010]    The present general inventive concept provides a monitoring camera capable of preventing light interference from occurring in an image capturing unit due to light diffusely reflected from a covering member. 
         [0011]    Additional aspects and utilities of the present general inventive concept 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 general inventive concept. 
         [0012]    The foregoing and/or other aspects and utilities of the present general inventive concept may be achieved by providing a monitoring camera including an image capturing unit; a lighting unit to emit light in a capturing direction of the image capturing unit and to illuminate a monitoring area; a covering member to cover the image capturing unit and the lighting unit; and a light guide unit, mounted in the image capturing unit, to guide the light diffusely reflected from the covering member so the light does not enter the image capturing unit. 
         [0013]    The light guide unit may have a stepped reflective surface to guide the light diffusely reflected from the covering member in the image capturing direction. 
         [0014]    The reflective surface may be inclined at a predetermined angle. 
         [0015]    The capturing unit may include a lens module; a board on which the lens module is mounted; and a rotating member to rotatably support the board with respect to a main body of the camera. 
         [0016]    The lighting unit may include a plurality of light emitting members mounted around the lens module on the board. 
         [0017]    The light emitting members may be light emitting diodes (LEDs). 
         [0018]    The light guide unit may be mounted on the board, enclose the lens module and lighting unit, and may include a reflecting member including the reflective surface. 
         [0019]    The covering member may have a dome shape, and the reflecting member may have a dome shape with the same curvature as the covering member. 
         [0020]    A circumference of the reflecting member may be inclined at a predetermined angle in order to prevent the reflecting member from colliding with the main body. 
         [0021]    The reflecting member may include a first exposure hole and a plurality of second exposure holes to expose the lens module and the light emitting members, respectively. 
         [0022]    The first exposure hole and plurality of second exposure holes may penetrate the reflecting member. 
         [0023]    The light guide unit may include a sealing member mounted between the covering member and the reflecting member to prevent the light from entering the first exposure hole. 
         [0024]    The reflecting member may be made of non-transparent material. 
         [0025]    The foregoing and/or other aspects and utilities of the present general inventive concept may be achieved by providing a monitoring camera, including: an image capturing unit; a lighting unit to emit light in a capturing direction of the image capturing unit and to illuminate a monitoring area; and a light dissipating unit mounted on the image capturing unit and to dissipate any light including the emitted light before entering into the capturing unit. 
         [0026]    The light dissipating unit can dissipate light that reflects from a covering member that covers the image capturing unit. 
         [0027]    The image capturing unit can include a lens module; a board on which the lens module is mounted; and a rotating member to rotatably support the board with respect to a main body of the camera. 
         [0028]    The light dissipating unit can surround the lens module and lighting unit, and comprises a stepped reflecting surface to reflect light in a plurality of outwardly directions to dissipate light including the light reflected from the covering member. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0029]    The above aspects and utilities of the present general inventive concept will be more apparent by describing certain embodiments of the present general inventive concept with reference to the accompanying drawings, in which: 
           [0030]      FIGS. 1 and 2  are cross sectional views schematically illustrating a conventional monitoring camera; 
           [0031]      FIG. 3  is a cross sectional view schematically illustrating a monitoring camera according to an exemplary embodiment of the present general inventive concept; 
           [0032]      FIG. 4  is an exploded perspective view schematically illustrating the monitoring camera of  FIG. 3 ; and 
           [0033]      FIG. 5  is an enlarged view illustrating an area E of  FIG. 3 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0034]    Reference will now be made in detail to the embodiments of the present general inventive concept, 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 general inventive concept by referring to the figures. 
         [0035]    Referring  FIGS. 3 and 4 , a monitoring camera  100  according to an exemplary embodiment of the present general inventive concept includes a main body  110 , an image capturing unit  120 , a lighting unit  130 , a covering member  140  and a light guide unit  150 . 
         [0036]    The image capturing unit  120  is rotatably mounted on a base  111  of the main body  110 , to capture an image of a monitoring area where monitoring is required. The image capturing unit  120  includes a lens module  121 , a board  122  and a rotating member  123 . 
         [0037]    The lens module  121  can capture a predetermined image, that is, an image of an area which a user desires to monitor. The lens module  121  can be a charged coupled device (CCD) module to convert an optical image into an electrical signal. 
         [0038]    The lens module  121  can be mounted on the board  122 . Specifically, the board  122  can be a controlling board, which is electrically connected to the lens module  121 . The board  122  can transmit the electrical signal corresponding to the monitoring area received from the lens module  121  to a display device, for example a monitor  160 , as illustrated in  FIG. 3 . 
         [0039]    The rotating member  123  can support the board  122  so that the board  122  may rotate about the main body  110 . The rotating member  123  includes a support unit  124  to support the board  122 , and a rotating unit  125 , which is connected to both ends of the support unit  124  through a rotation axis  125   a  and mounted on the main body  110 . 
         [0040]    Accordingly, the lens module  121  mounted on the board  122  can pivot about the rotation axis  125   a  in direction R illustrated in  FIGS. 3 and 4 . In this situation, a rotation range of the capturing unit  120  may be set when the capturing unit  120  is initially mounted, or may be controlled by signal exchange between the capturing unit  120  and a separate controlling means (not illustrated). 
         [0041]    The lighting unit  130  can be supported by the capturing unit  120 , and can emit light in a capturing direction B of the capturing unit  120  to illuminate the monitoring area. As illustrated in  FIG. 4 , the lighting unit  130  can include a plurality of light emitting members spaced apart at predetermined distances on the board  122  around the lens module  121  in order to enclose the lens module  121 . 
         [0042]    At night, when there is little illumination, the lighting unit  130  may selectively emit light so that the lens module  121  can capture a clean image. To achieve this, the lighting unit  130  can emit light by exchanging signals with a separate timer (not illustrated) or an illumination detecting sensor (not illustrated) which is mounted on the board  122 , although not illustrated. 
         [0043]    The light emitting members of the lighting unit  130  can be either light emitting diodes (LEDs) or light emitting devices to provide communication, such as semiconductor lasers. In this exemplary embodiment of the present general inventive concept, LEDs can be mounted as the light emitting members on the board  122 . 
         [0044]    The technical configuration of the lens module  121  and lighting unit  130  according to the present general inventive concept may be implemented using the conventional art, so detailed description and illumination thereof are omitted herein. 
         [0045]    The covering member  140  can cover the image capturing unit  120  and lighting unit  130 . The covering member  140  can have a dome shape, and can be fixed onto the main body  110 . The covering member  140  can be made of a transparent or semitransparent material, such as acrylic material, through which light can be transmitted. 
         [0046]    The light guide unit  150  can allow light diffusely reflected from an inner surface of the covering member  140  to move in the capturing direction. To achieve this, the light guide unit  150  includes a reflecting member  151 , a first exposure hole  152  and a plurality of second exposure holes  153 . The light guide unit  150  can be mounted on the board  122  so that the light guide unit  150  faces the covering member  140 . 
         [0047]    The reflecting member  151  can be mounted on the board  122  to face the inner surface of the covering member  140 . The reflecting member  151  can have a dome shape with the same or similar curvature as the dome-shaped covering member  140 . 
         [0048]    A reflective surface  151   a  can be formed with radially stepped portions on an outer surface of the reflecting member  151  so that the reflecting member  151  can reflect the light diffusely reflected from the inner surface of the covering member  140  in the capturing direction B. In more detail, as illustrated in  FIGS. 3 and 5 , the reflective surface  151   a  can again reflect the light that has been emitted in a direction C 1  and then diffusely reflected in a direction C 2  from the inner surface of the covering member  140 , which is inclined at a predetermined curvature, in a direction C 3 , instead of reflecting the light in the capturing direction B, so that the light may be guided outwardly. Alternatively, the reflective surface  151   a  may be inclined at a predetermined angle to cause the light to move in the capturing direction B. 
         [0049]    A circumference of the reflecting member  151  may be inclined in order to prevent the reflecting member  151  from colliding with the main body  110 , namely, with the base  111  on which the rotating unit  125  is mounted, when rotating in the direction R. 
         [0050]    The first exposure hole  152  may penetrate the reflecting member  151 , so that the lens module  121  may be inserted into the first exposure hole  152 , and thus be exposed. In this situation, the lens module  121  may be mounted in the substantial center of the board  122 , so the first exposure hole  152  may also penetrate the substantial center of the reflecting member  151 . 
         [0051]    The plurality of second exposure holes  153  may penetrate the reflecting member  151 , so that the lighting unit  130  can be inserted into the second exposure holes  153 , and thus be exposed. In this situation, the plurality of second exposure holes  153  may be formed around the first exposure hole  152  in positions corresponding to positions in which the light emitting members of the lighting unit  130  are mounted. 
         [0052]    The reflecting member  151  may be made of non-transparent material through which light cannot be transmitted. Accordingly, light can permeate only through the first exposure hole  152  and second exposure holes  153  of the reflecting member  151 . 
         [0053]    A sealing member  152   a  may be mounted between the reflecting member  151  and the covering member  140 , to enclose a circumference of the first exposure hole  152 . The sealing member  152   a  may prevent the light emitted from the lighting unit  130  in direction D 1  and diffusely reflected from the inner surface of the covering member  140  in direction D 2  from entering the first exposure hole  152 , as illustrated in  FIG. 3 . 
         [0054]    The thickness of the sealing member  152   a  may be determined to be within a range in which it is possible to prevent the light emitted from the lighting unit  130  or reflected thereafter from entering the first exposure hole  152 , taking into consideration a distance between the reflecting member  151  and the covering member  140 . 
         [0055]    An operation by which the monitoring camera  100  guides light will be described with reference to  FIGS. 3 and 5 . 
         [0056]    Referring to  FIG. 3 , if the lens module  121  of the image capturing unit  120  captures the image of the monitoring area in direction B facing the monitoring area, the captured image may be transmitted to the monitor  160  installed in an office or other location. 
         [0057]    At night or other situations when there is little illumination, the lighting unit  130  can emit light in the capturing direction B by exchanging signals with a separate timer (not illustrated) or an illumination detecting sensor (not illustrated). 
         [0058]    In this situation, if the light emitted from the lighting unit  130  is unable to penetrate the covering member  140  and is diffusely reflected from the inner surface of the covering member  140 , for example, if the light emitted from the lighting unit  130  in the direction C 1  is diffusely reflected from the inner surface of the covering member  140  in the direction C 2 , as illustrated in  FIG. 5 , the light reflected in the direction C 2  may again be reflected in the direction C 3  by the reflective surface  151   a  and may then be emitted outside the covering member  140 . 
         [0059]    Additionally, even if the light emitted from the lighting unit  130  in a direction D 1  is reflected from the inner surface of the covering member  140  in a direction D 2 , as illustrated in  FIG. 3 , it is possible to prevent the light from entering the first exposure hole  152 . 
         [0060]    Although the present general inventive concept was applied to the situation in which the light emitted from the lighting unit  130  in direction C 1  or D 1  and diffusely reflected from the inner surface of the covering member  140  is guided in the capturing direction B, the light may be emitted in many directions other than the capturing direction B of the image capturing unit  120  so that the light emitted from the lighting unit  130  and diffusely reflected from the inner surface of the covering member  140  may again be reflected by the reflective surface  151   a  of the reflecting member  151  to prevent the light from entering the lens module  121 . 
         [0061]    As described above, according to the present general inventive concept, even when light emitted from the lighting unit  130  is diffusely reflected from the covering member  140  instead of being emitted externally thereof, the light may be guided in the capturing direction by the light guide unit  150 . Accordingly, the light guide unit  150  can prevent the light emitted from the lighting unit  130  from entering the capturing unit  120 , so that it is possible to prevent light interference with the capturing unit  120 . 
         [0062]    Additionally, the sealing member  152   a  is mounted between the covering member  140  and the reflecting member  151  to enclose the first exposure hole  152 , and thus light interference with the capturing unit  120  can be further prevented. 
         [0063]    Although a few embodiments of the present general inventive concept have been illustrated and described, it will 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 general inventive concept, the scope of which is defined in the appended claims and their equivalents.