Patent Abstract:
The lighting apparatus includes a body including a recess which is defined by an inner wall; a reflector which is disposed within the recess of the body and faces the inner wall of the body, and includes a reflective surface reflecting light to the outside of the recess of the body; and a light source which is disposed within the recess of the body and emits light toward the reflective surface of the reflector.

Full Description:
BACKGROUND 
       [0001]    1. Field 
         [0002]    This embodiment relates to a lighting apparatus. 
         [0003]    2. Description of the Related Art 
         [0004]    A light emitting diode (hereinafter, referred to as LED) is an energy element that converts electric energy into light energy. The LED has advantages of high conversion efficiency, low power consumption and a long life span. As the advantages are widely spread, more and more attentions are now paid to a lighting apparatus using the LED. In consideration of the attention, manufacturer producing light apparatuses are now producing and providing various lighting apparatuses using the LED. 
         [0005]    The lighting apparatus using the LED are generally classified into a direct lighting apparatus and an indirect lighting apparatus. The direct lighting apparatus emits light emitted from the LED without changing the path of the light. The indirect lighting apparatus emits light emitted from the LED by changing the path of the light through reflecting means and so on. Compared to the direct lighting apparatus, the indirect lighting apparatus mitigates to some degree the intensified light emitted from the LED and protects the eyes of users. 
       SUMMARY 
       [0006]    One embodiment is a lighting apparatus. The lighting apparatus includes: a body including a recess which is defined by an inner wall; a reflector which is disposed within the recess of the body and faces the inner wall of the body, and includes a reflective surface reflecting light to the outside of the recess of the body; and a light source which is disposed within the recess of the body and emits light toward the reflective surface of the reflector. The light source includes a substrate disposed on the inner wall of the body and a light emitting device disposed on the substrate. The body includes an opening through which the light reflected by the reflective surface of the reflector passes and includes a connecting member which is coupled to the body. 
         [0007]    Another embodiment is a lighting apparatus. The lighting apparatus includes: a heat radiating body including a recess having a first shape, and an external appearance having a second shape; a reflector which is disposed in the recess of the heat radiating body and includes both a reflective surface reflecting light to the outside of the recess of the heat radiating body and a third shape; and a light source which is disposed in the recess of the heat radiating body and emits light to the reflective surface of the reflector. The second shape is different from the first shape. The third shape is different form the first shape. 
         [0008]    Further another embodiment is a lighting apparatus. The lighting apparatus includes: The lighting apparatus includes: a heat radiating body which includes a first body having a first recess, and a second body having a second recess; a first substrate which is disposed in the first recess of the heat radiating body and includes a first light emitting device disposed therein; a second substrate which is disposed in the second recess of the heat radiating body and includes a second light emitting device disposed therein; and a reflector which is disposed within the first and the second recesses of the heat radiating body, and includes a first reflective surface reflecting light emitted from the first light emitting device of the first substrate to the outside of the first recess, and a second reflective surface reflecting light emitted from the second light emitting device of the second substrate to the outside of the second recess, and is disposed within the first and the second recesses. The first and the second bodies of the heat radiating body are coupled to each other to have a first shape. The first and the second recesses of the heat radiating body are coupled to each other to have a second shape different from the first shape. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a perspective view showing a lighting apparatus according to an embodiment of the present invention. 
           [0010]      FIG. 2  is an exploded perspective view of a lighting apparatus shown in  FIG. 1 . 
           [0011]      FIG. 3  is a cross sectional view of a lighting apparatus shown in  FIG. 1 . 
           [0012]      FIG. 4  is a bottom perspective view of a lighting apparatus shown in  FIG. 1 . 
           [0013]      FIG. 5  is a view for describing a relation between a heat radiating body and an LED module in a lighting apparatus shown in  FIG. 1 . 
           [0014]      FIG. 6  shows another embodiment of a lighting apparatus shown in  FIG. 1 . 
           [0015]      FIGS. 7   a  and  7   b  are perspective view and exploded view of another embodiment of the LED module shown in  FIG. 2 . 
           [0016]      FIG. 8  is a top view of the lighting apparatus shown in  FIG. 4 . 
           [0017]      FIG. 9  shows another embodiment of the lighting apparatus shown in  FIG. 4 . 
           [0018]      FIG. 10  is a perspective view of an optic plate shown in  FIG. 2 . 
           [0019]      FIG. 11  is a perspective view of a connecting member shown in  FIG. 2 . 
           [0020]      FIG. 12  is a perspective view of a reflection cover  180  shown in  FIG. 2 . 
           [0021]      FIGS. 13   a  to  13   c  show data resulting from a first experiment. 
           [0022]      FIGS. 14   a  to  14   c  show data resulting from a second experiment. 
           [0023]      FIGS. 15   a  to  15   c  show data resulting from a third experiment. 
           [0024]      FIGS. 16   a  to  16   c  show data resulting from a fourth experiment. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0025]    Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. 
         [0026]    It will be understood that when an element is referred to as being “on” or “under” another element, it can be directly on/under the element, and one or more intervening elements may also be present 
         [0027]      FIG. 1  is a perspective view showing a lighting apparatus according to an embodiment of the present invention.  FIG. 2  is an exploded perspective view of a lighting apparatus shown in  FIG. 1 .  FIG. 3  is a cross sectional view taken along a line of A-A′ in a lighting apparatus shown in  FIG. 1 .  FIG. 4  is a bottom perspective view of a lighting apparatus shown in  FIG. 1 . 
         [0028]    A lighting apparatus  100  according to an embodiment of the present invention will be described in detail with reference to  FIGS. 1 to 4 . 
         [0029]    Referring to  FIGS. 1 to 3 , a heat radiating body  110  is formed by coupling a first heat radiating body  110   a  to a second heat radiating body  110   b . A first screw  115  is coupled to a first female screw  119  such that the first heat radiating body  110   a  is easily coupled to the second heat radiating body  110   b . When the first heat radiating body  110   a  and the second heat radiating body  110   b  are coupled to each other, a cylindrical heat radiating body  110  is formed. 
         [0030]    Referring to  FIGS. 1 to 3 , the upper and lateral sides of the cylindrical heat radiating body  110  have a plurality of heat radiating fins for radiating heat generated from a first LED module  120   a  and a second LED module  120   b . The plurality of the heat radiating fins widen a cross sectional area of the heat radiating body  110  and ameliorate the heat radiating characteristic of the heat radiating body  110 . Regarding a plurality of the heat radiating fins, a cylindrical shape is formed by connecting the outermost peripheral surfaces of a plurality of the heat radiating fins. 
         [0031]    Here, the cylindrical heat radiating body  110  does not necessarily have a plurality of the heat radiating fins. If the cylindrical heat radiating body  110  has no heat radiating fin, the cylindrical heat radiating body  110  may have a little lower heat radiating effect than that of the heat radiating body  110  shown in  FIGS. 1 to 3 . However, it should be noted that it is possible to implement the present invention without the heat radiating fins. 
         [0032]    Referring to  FIG. 4 , the first LED module  120   a , the second LED module  120   b , a first fixing plate  130   a , a second fixing plate  130   b  and a reflector  140  are housed inside the heat radiating body  110 . A space for housing the first LED module  120   a , the second LED module  120   b , the first fixing plate  130   a , the second fixing plate  130   b  and the reflector  140  has a hexahedral shape partitioned and formed by the inner walls of the heat radiating body  110 . An opening  117  of the heat radiating body  110  is formed by opening one side of the hexahedron partitioned by the inner walls of the heat radiating body  110  and has a quadrangular shape. That is to say, the heat radiating body  110  has a cylindrical shape and the housing space inside the heat radiating body  110  has a hexahedral shape. 
         [0033]    The first and the second heat radiating bodies  110   a  and  110   b  have integrally formed respectively. The first and the second heat radiating bodies  110   a  and  110   b  are manufactured with a material capable of well transferring heat. For example, Al and Cu and the like can be used as a material for the heat radiating bodies. 
         [0034]    The first LED module  120   a , i.e., a heat generator, is placed on the inner wall of the first heat radiating body  110   a . The second LED module  120   b , i.e., a heat generator, is placed on the inner wall of the second heat radiating body  110   b . The first heat radiating body  110   a  is integrally formed, thus helping the heat generated from the first LED module  120   a  to be efficiently transferred. That is, once the heat generated from the first LED module  120   a  is transferred to the first heat radiating body  110   a , the heat is transferred to the entire first heat radiating body  110   a . Here, since the first heat radiating body  110   a  is integrally formed, there is no part preventing or intercepting the heat transfer, so that a high heat radiating effect can be obtained. 
         [0035]    Similarly to the first heat radiating body  110   a , the second heat radiating body  110   b  emits efficiently the heat generated from the second LED module  120   b , i.e., a heat generator. The first and the second heat radiating bodies  110   a  and  110   b  are provided to the first and the second LED modules  120   a  and  120   b , i.e., heat generators, respectively. This means that the heat radiating means one-to-one correspond to the heat generators and radiate the heat from the heat generators, thereby increasing the heat radiating effect. That is, when the number of the heat generators is determined and the heat generators are disposed, it is a part of the desire of the inventor of the present invention to provide the heat radiating means according to the number and disposition of the heat generators. As a result, a high heat radiating effect can be obtained. A description thereof will be given below with reference to  FIGS. 5 and 6 . 
         [0036]      FIG. 5  is a view for describing a relation between a heat radiating body and LED modules  120   a  and  120   b  in a lighting apparatus shown in  FIG. 2  in accordance with an embodiment of the present invention. Here,  FIG. 5  is a top view of the lighting apparatus shown in  FIG. 4  and shows only the heat radiating body  110  and the LED modules  120   a  and  120   b.    
         [0037]    Referring to  FIG. 5 , the heat radiating body  110  and the opening  117  of the heat radiating body  110  have a circular shape and a quadrangular shape, respectively. The heat radiating body  110  includes five inner surfaces. The five inner surfaces and the opening  117  partition and form a space for housing the first and the second LED modules  120   a  and  120   b , the first and the second fixing plates  130   a  and  130   b  and the reflector  140 . 
         [0038]    The first and the second heat radiating bodies  110   a  and  110   b  constituting the heat radiating body  110  have a semi-cylindrical shape respectively. The two heat radiating bodies are coupled to each other based on a first base line  1 - 1   e  and then form a cylindrical heat radiating body  110 . However, the coupling boundary line is not necessarily the same as the first base line  1 - 1 ′. For example, the base line  1 - 1 ′ is rotatable clockwise or counterclockwise to some degree around the center of the heat radiating body  110 . 
         [0039]    Since the heat radiating body  110  has a cylindrical shape, the heat radiating body  110  can be easily installed by being inserted into a ceiling&#39;s circular hole in which an existing lighting apparatus has been placed. Moreover, the heat radiating body  110  is able to easily take the place of the existing lighting apparatus which has been already used. 
         [0040]    As shown in  FIG. 5 , the LED modules are placed on two inner walls which face each other in four inner surfaces of the heat radiating body  110  excluding the inner wall facing the opening  117 . 
         [0041]    The first LED module  120   a  is placed on the inner wall of the first heat radiating body  110   a . The first heat radiating body  100   a  further includes three inner walls other than the inner wall on which the first LED module  120   a  has been placed. Therefore, the heat generated from the first LED module  120   a , i.e., a heat generator, can be radiated through the three inner walls as well as the inner wall on which the first LED module  120   a  has been placed. 
         [0042]    The second LED module  120   b  is placed on the inner wall of the second heat radiating body  110   b . The second heat radiating body  100   b  further includes three inner walls other than the inner wall on which the second LED module  120   b  has been placed. Therefore, the heat generated from the second LED module  120   b , i.e., a heat generator, can be radiated through the three inner walls as well as the inner wall on which the second LED module  120   b  has been placed. 
         [0043]    While the first heat radiating body  110   a  is coupled to the second heat radiating body  110   b , the first and the second LED modules  120   a  and  120   b , i.e., heat generators, emit light toward the center of the cylindrical heat radiating body, and then the heat generated from the LED modules is radiated through the first and the second heat radiating bodies  110   a  and  110   b  which are respectively located on the circumference in an opposite direction to the center of the heat radiating body  110 . From the viewpoint of the entire heat radiating body  110 , the heat is hereby radiated in a direction from the center to the circumference and in every direction of the circumference, obtaining a high heat radiating effect. Moreover, since a heat radiating member such as the heat radiating fin formed on the heat radiating body is widely provided on the circumference of the cylindrical heat radiating body, the heat radiating member has high design flexibility. 
         [0044]      FIG. 6  is a view for describing a relation between a heat radiating body and an LED module in accordance with another embodiment of the present invention. 
         [0045]    Referring to  FIG. 6 , similarly to the case of  FIG. 5 , the heat radiating body  110  and the opening  117  of the heat radiating body  110  have a circular shape and a quadrangular shape, respectively. 
         [0046]    The heat radiating body  110  is divided into four heat radiating bodies  110   a ,  110   b ,  110   c  and  110   d  on the basis of a second base axis  2 - 2 ′ and a third base axis  3 - 3 ′. In other words, one cylindrical heat radiating body  110  is formed by coupling the four heat radiating bodies  110   a ,  110   b ,  110   c  and  110   d.    
         [0047]    With respect to five inner walls of the heat radiating body  110 , the four LED modules  120   a ,  120   b ,  120   c  and  120   d  are respectively placed on four inner walls excluding the inner wall facing the opening  117 . 
         [0048]    As such, the lighting apparatuses shown in  FIGS. 5 and 6  include a plurality of the heat radiating bodies of which the number is the same as the number of the LED module of a heat generator. The first and the second heat radiating bodies  110   a  and  110   b  are respectively integrally formed with the first and the second LED modules  120   a  and  120   b  of heat generators. Here, the first and the second heat radiating bodies  110   a  and  110   b  can be integrally formed by a casting process. Since the first and the second heat radiating bodies  110   a  and  110   b  formed integrally in such a manner do not have a join or a part where the two heat radiating bodies are coupled, the transfer of the heat generated from the heat generators is not prevented or intercepted. 
         [0049]    Since not only the inner wall on which the LED module is placed but an inner wall on which the LED module is not placed are included in one cylindrical heat radiating body  110  formed by coupling the first and the second heat radiating bodies  110   a  and  110   b , the heat radiating body  110  has a more excellent heat radiating effect than that of a conventional lighting apparatus having a heat radiating body formed only on the back side of the inner wall on which the LED module is placed. 
         [0050]    Additionally, as described above in connection with  FIG. 5 , the LED modules emit light toward the center of the cylindrical heat radiating body and the heat generated from the LED modules is radiated through the heat radiating bodies which are respectively located on the circumference in an opposite direction to the center of the cylindrical heat radiating body. The heat is hereby radiated in a direction from the center to the circumference and in every direction of the circumference, obtaining a high heat radiating effect. Moreover, since a heat radiating member such as the heat radiating fin formed on the heat radiating body is widely provided on the circumference of the cylindrical heat radiating body, the heat radiating member has high design flexibility. 
         [0051]    Hereinafter, components housed in the inner housing space of the cylindrical heat radiating body  110  will be described in detail with reference to  FIGS. 2 to 4 . Here, the first LED module  120   a  and the second LED module  120   b  face each other with respect to the reflector  140  and have the same shape. The first fixing plate  130   a  and the second fixing plate  130   b  face each other with respect to the reflector  140  and have the same shape. Therefore, hereinafter a detailed description of the second LED module  120   b  and the second fixing plate  130   b  are omitted. 
         [0052]    The first LED module  120   a  includes a substrate  121   a , a plurality of LEDs  123   a , a plurality of collimating lenses  125   a , a projection  127   a  and a holder  129   a.    
         [0053]    A plurality of the LEDs  123   a  and a plurality of the collimating lenses  125   a  are placed on one surface of the substrate  121   a . The other surface of the substrate  121   a  is fixed close to the inner wall of the heat radiating body  110   a.    
         [0054]    A plurality of the LEDs  123   a  are disposed separately from each other on the one surface of the substrate  121   a  in a characteristic pattern. That is, a plurality of the LEDs  123   a  are disposed in two lines. Also, the plurality of the LEDs  123   a  can be disposed in three or more lines based on a size of the substrate or a number of the LEDs. In  FIG. 2 , two LEDs are disposed in the upper line in the substrate  121   a  and three LEDs are disposed in the lower line. The characteristic of disposition of a plurality of the LEDs  123   a  will be described later with reference to  FIGS. 8 to 9 . 
         [0055]    The collimating lens  125   a  collimates in a predetermined direction the light emitted from around the LED  123   a . Such a collimating lens  125   a  is formed on the one surface of the substrate  121   a  and surrounds the LED  123   a . The collimating lens  125   a  has a compact funnel shape. Therefore, the collimating lens  125   a  has a lozenge-shaped cross section. 
         [0056]    Meanwhile, a groove for receiving the LED  123   a  is formed on one surface on which the collimating lens  125   a  comes in contact with the substrate  121   a.    
         [0057]    The collimating lenses  125   a  correspond to the LEDs  123   a . Thus, the number of the collimating lenses  125   a  is equal to the number of the LEDs  123   a . Here, it is desirable that the collimating lens  125   a  has a height greater than that of the LED  123   a.    
         [0058]    Such a collimating lens  125   a  collimates the light, which is emitted from around the LED  123   a , into the reflector  140 . The collimating lens  125   a  surrounds the LED  123   a  such that a user is not able to directly see the intensified light emitted from the LED  123   a . To this end, the outside of the collimating lens  125   a  can be made of an opaque material. 
         [0059]    The inside of the collimating lens  125   a  shown in  FIG. 2  can be filled with an optical-transmitting material having a predetermined refractive index, for example, an acryl and PMMA, etc. Also, a fluorescent material can be further included in the inside of the collimating lens  125   a.    
         [0060]    A projection  127   a  is received by a receiver  133   a  of the first fixing plate  130   a . Subsequently, the back side to the side in which the receiver  133   a  is formed has a projecting shape and is received by a locking part  141   a  of the reflector  140 . An embodiment without either the first fixing plate  130   a  or the receiver  133   a  of the first fixing plate  130   a  can be provided. In this case, the projection  127   a  can be directly received by the locking part  141   a  of the reflector  140 . Such a projection  127   a  functions as a male screw of a snap fastener. The receiver  133   a  and the locking part  141   a  function as a female screw of a snap fastener. 
         [0061]    After the projection  127   a  is in contact with and coupled to the locking part  141   a  directly or through the receiver  133   a  of the first fixing plate  130   a , the reflector  140  is fixed to the first fixing plate  130   a  or the first LED module  120   a . Therefore, the reflector  140  is prevented from moving toward the opening  117  (i.e., a light emission direction). In addition, the inner walls of the heat radiating body  110  prevents the reflector  140  from moving in a light emitting direction of the reflector  140 . The reflector  140  is also prevented from moving in a light emission direction of the LED modules  120   a  and  120   b  by either the LED modules  120   a  and  120   b  fixed to the heat radiating body  110  or the fixing plates  130   a  and  130   b  fixed to the heat radiating body  110 . 
         [0062]    Accordingly, it is not necessary to couple the reflector  140  to the first LED module  120 a or to the inner wall of the first heat radiating body  110   a  by use of a separate fixing means such as a screw and the like. Moreover, there is no requirement for a separate fixing means for fixing the reflector  140  to the inner walls of the first and the second heat radiating bodies  110   a  and  110   b . As mentioned above, since the reflector  140  has no additional part like a through-hole for allowing a separate fixing means to pass, the reflector  140  can be formed to have its minimum size for obtaining a slope-shaped reflecting area. This means that it is possible to cause the lighting apparatus according to the embodiment of the present invention to be smaller in comparison with the amount of the emitted light. 
         [0063]      FIGS. 7   a  and  7   b  are perspective view and exploded view of another embodiment of the LED module shown in  FIG. 2  in accordance with the embodiment of the present invention. 
         [0064]    The LED module  120   a  shown in  FIGS. 7   a  and  7   b  in accordance with another embodiment is obtained by adding a holder  129   a  to the LED module  120   a  shown in  FIG. 2 . 
         [0065]    The holder  129   a  has an empty cylindrical shape. The top and bottom surfaces of the holder  129   a  are opened. The holder  129   a  surrounds the collimating lens  125   a  on the substrate  121   a . The holder  129   a  performs a function of fixing the collimating lens  125   a.    
         [0066]    Referring to  FIGS. 2 and 3  again, the first fixing plate  130   a  includes a plurality of through holes  131   a , the receiver  133   a  and a plurality of second male screws  135   a . It is desirable that the first fixing plate  130   a  has a shape that is the same as or similar to that of the substrate  121   a.    
         [0067]    One collimating lens  125   a  is inserted into one through hole  131   a . It is desired that the through hole  131   a  has a shape allowing the collimating lens  125   a  to pass the through hole  131   a    
         [0068]    The receiver  133  is able to receive the projection  127   a  of the first LED module  120   a . When the receiver  133  receives the projection  127   a , the first LED module  120   a  and the first fixing plate  130   a  are fixed close to each other. When the projection  127   a  is attached to or removed from the receiver  133 , the first fixing plate  130   a  is easily attached to or removed from the first LED module  120   a.    
         [0069]    A plurality of the second male screws  135   a  penetrate the first fixing plate  130   a  and the first LED module  120   a , and then is inserted and fixed into a plurality of second female screws (not shown) formed on the inner wall of the first heat radiating body  110   a . The first fixing plate  130   a  and the first LED module  120   a  are easily attached and fixed to the inner wall of the first heat radiating body  110   a  by a plurality of the second male screws  135   a  and are also easily removed from the inner wall of the first heat radiating body  110   a.    
         [0070]    The reflector  140  changes the path of light emitted from the first and the second LED modules  120   a  and  120   b . Referring to  FIG. 4 , the reflector  140  reflects to the opening  117  the light emitted from the first and the second LEDs  123   a  and  123   b . As shown in  FIG. 2 , the reflector  140  has an overall shape of an empty hexahedron. Here, one pair of lateral sides among two pairs of lateral sides facing each other is opened. The upper side functioning to reflect the light has a ‘V’ shape. The bottom side corresponds to the opening  117 . 
         [0071]    The first and the second fixing plates  130   a  and  130   b  and the first and the second LED modules  120   a  and  120   b  are coupled to the opened lateral sides. The two opened lateral surfaces of the reflector  140  are hereby closed. Here, projecting parts are formed on the back sides of the sides on which the receivers  133   a  and  133   b  receiving the projections  127   a  and  127   b  are formed. Locking parts  141   a  and  141   b  are formed in the reflector  140  such that the projecting parts are in a contact with and are coupled to the locking parts  141   a  and  141   b . Therefore, the first and the second fixing plates  130   a  and  130   b  can be securely fixed to the reflector  140 . Here, as described above, the projection  127   a  can be directly received by the locking part  141   a  without the first fixing plate  130   a  or the receiver  133   a  of the first fixing plate  130   a.    
         [0072]    The reflector  140  has a shape corresponding to the housing space of the heat radiating body  110 . That is, the reflector  140  is formed to be exactly fitted to the housing space partitioned and formed by the inner walls of the heat radiating body  110 . Thus, when the first and the second heat radiating bodies  110   a  and  110   b  are coupled to each other, the reflector  140  is fitted exactly to the housing space and is not able to move inside the heat radiating body  110 . 
         [0073]    As described above, the reflector  140  is prevented from moving toward the opening  117  (i.e., the light emission direction) by the projections  127   a  and  127   b  of the first and the second LED modules  120   a  and  120   b . In addition, the reflector  140  has a shape fitting well into the housing space of the heat radiating body  110 . As a result, when the first and the second heat radiating bodies  110   a  and  110   b  are coupled to each other, the first and the second heat radiating bodies  110   a  and  110   b  give a pressure to the reflector  140 . Therefore, the reflector  140  is prevented from moving not only in the light emission direction but in a direction perpendicular to the light emission direction. 
         [0074]    Accordingly, the lighting apparatus according to the present invention does not require a separate fixing means such as a screw for fixing the reflector  140  to the inside of the heat radiating body  110 . Additionally, the reflector  140  can be formed to have its minimum size for obtaining a slope-shaped reflecting area. This means that it is possible to cause the lighting apparatus to be smaller in comparison with the amount of the emitted light. 
         [0075]    The projections of the first and the second LED modules  120   a  and  120   b  are fitted and coupled to the receivers of the first and the second fixing plates  130   a  and  130   b  respectively, and are fixed to the inner walls of the heat radiating bodies  110   a  and  110   b , respectively. Then, the receivers  133   a  and  133   b  are disposed to be in contact with and coupled to the locking parts  141   a  and  141   b  by disposing the reflector  140  between the receivers  133   a  and  133   b . The first and the second heat radiating bodies  110   a  and  110   b  are coupled to each other toward the reflector  140  so that the reflector  140  is fixed to the inside housing space of the heat radiating body  110 . As a result, since there is no requirement for a separate screw for fixing the reflector  140  to the heat radiating body  110  having the opening formed therein in one direction, it is easy to assemble the lighting apparatus of the present invention. 
         [0076]    Referring to  FIGS. 2 and 3  again, the “V”-shaped upper side (hereinafter, referred to as a reflective surface) reflects the light emitted from the first and the second LED modules  120   a  and  120   b  and changes the path of the light to the opening  117 . 
         [0077]    That is, the reflective surface of the reflector  140  is inclined toward the opening  117  of the heat radiating body with respect to one sides of the first and the second LED modules, for example, one side of the substrate. 
         [0078]    The reflective surface includes two surfaces inclined with respect to the one sides of the first and the second LED modules, and the two surfaces are in contact with each other at a predetermined angle. Herein, the predetermined angle may be in a range of 30 degree˜150 degree with respect to the one sides of the first and the second LED modules. The predetermined angle may be desirably in 60 degree˜120 degree with respect to the one sides of the first and the second LED modules. 
         [0079]    Light incident from the first and the second LED modules  120   a  and  120   b  formed at both sides of the reflective surface to the reflective surface of the reflector  140  is reflected by the reflective surface and moves toward the opening (i.e., the light emission direction), that is, in the down direction of  FIG. 1 . In this case, images formed on the reflective surface of the reflector  140  are distributed based on the properties of the distribution of the LEDs of the first and the second LED modules  120   a  and  120   b . For a detailed description of this matter, the characteristic of the distribution of the LEDs of the first and the second LED modules  120   a  and  120   b  will be described with reference to  FIGS. 8 and 9 . 
         [0080]      FIG. 8  is a top view of the lighting apparatus shown in  FIG. 4  in accordance with the embodiment of the present invention. When light emitted from a plurality of the LEDs  123   a  and  123   b  of the first and the second LED modules  120   a  and  120   b  is incident on the reflective surface of the reflector  140 , the distribution of the images  141   a  and  141   b  formed on the reflective surface is shown in  FIG. 8 . Here, assuming that the reflective surface of the reflector  140  shown in  FIGS. 8 and 9  is a mirror surface,  FIGS. 8 and 9  show images observed through the opening  117 . Actually, the reflective surface is not necessarily a mirror surface and requires a material capable of reflecting the incident light in the light emission direction. 
         [0081]    Referring to  FIG. 8 , when light emitted from each of a plurality of the LEDs  123   a  and  123   b  of the first and the second LED modules  120   a  and  120   b  is incident on the reflective surface of the reflector  140 , eight images located at the outermost circumference among the images  141   a  and  141   b  formed on the reflective surface form a concentric circumference  145 . The other two images are uniformly distributed within the concentric circumference  145 . The eight images located at the outermost circumference may be disposed on the circumference  145  at a regular interval. 
         [0082]      FIG. 9  shows a lighting apparatus having increased number of the LEDs in accordance with the embodiment of the present invention. 
         [0083]    In  FIG. 9 , with regard to the LEDs disposed in the first LED module  120   a  shown in  FIGS. 1 to 4 , four LEDs are arranged in the first line and three LEDs are arranged in the second line, and the same is true for the second LED module  120   b . Therefore, the first and the second LED modules  120   a  and  120   b  totally have fourteen LEDs. 
         [0084]    Like the lighting apparatus shown in  FIG. 8 , the lighting apparatus shown in  FIG. 9  has fourteen images  141   a  and  141   b  which are uniformly distributed at a regular interval. That is, all adjacent images of images which are aligned in one line have a same interval between them and all adjacent images of images which are aligned in adjacent lines also have a same interval between them. Eight images located at the outermost circumference of the fourteen images  141   a  and  141   b  form the concentric circumference  145 . 
         [0085]    As shown in  FIGS. 8 and 9 , when the lights emitted from a plurality of the LEDs  123   a  and  123   b  form images on the reflective surface of a mirror surface of the reflector  140 , the images are symmetrical to each other with respect to the central axis of the reflector. Here, the light emitted from the plurality of the LEDs is reflected and irradiated by the reflective surface of the reflector, and then is projected to a plane. In this case, the images of the outermost light sources are distributed on the plane to substantially have a circular shape. Therefore, even if the first and the second LED modules  120   a  and  120   b  are arranged to face each other, light emitted from the lighting apparatus according to the present invention is able to form a circle on an irradiated area. A detailed description of this matter will be described later with reference to  FIGS. 13   c  to  16   c.    
         [0086]    An optic sheet  150  converges or diffuses light reflected from the reflective surface of the reflector  140 . That is, the optic sheet  150  is able to converge or diffuse light in accordance with a designer&#39;s choice. 
         [0087]    As shown in  FIGS. 2 and 3 , an optic plate  160  receives the optic sheet  150  and stops the optic sheet  150  from being transformed by the heat. Besides, the optic plate  160  prevents a user from directly seeing the light emitted from the LED  123   a  through a reflection cover  180 . Such an optic plate  160  will be described in detail with reference to  FIGS. 3 and 10 . 
         [0088]      FIG. 10  is a perspective view of an optic plate  160 . 
         [0089]    Referring to  FIGS. 3 and 10 , the optic plate  160  includes a first frame  161 , a second frame seating the optic sheet  150 , and a glass plate  165  which is inserted and fixed to the second frame  163  and prevents the optic sheet  150  from being bent in the light emission direction by heat. 
         [0090]    The first frame  161  has a structure surrounding all corners of the optic sheet  150  and has a predetermined area of “D” from the outer end to the inner end thereof. 
         [0091]    The second frame  163  is extended by a predetermined length from the lower part of the inner end of the first frame  161  toward the center of the optic plate  160  such that the optic sheet  150  is seated. 
         [0092]    The first and the second frames  161  and  163  receive and fix the optic sheet  150 . Additionally, a connecting member  170  and the first and the second frames  161  and  163  prevent a user from directly seeing the light emitted from the LED  123   a  through the reflection cover  180 . 
         [0093]    The glass plate  165  is inserted and fixed to the second frame  163  and prevents the optic sheet  150  from being bent in the light emission direction by heat. 
         [0094]    Meanwhile, while the optic sheet  150  and the optic plate  160  are described as separate components in  FIGS. 2 ,  3  and  10 , the function of the optic sheet  150  may be included in the glass plate  165  of the optic plate  160 . In other words, the optic plate  160  per se is able to converge and diffuse light. 
         [0095]    The connecting member  170  is coupled to the heat radiating body  110  and to the reflection cover  180  respectively. As a result, the heat radiating body  110  is coupled to the reflection cover  180 . The connecting member  170  receives the optic plate  160  and fixes the received optic plate  160  so as to cause the optic plate  160  not to be fallen to the reflection cover  180 . The connecting member  170  as well as the optic plate  160  prevents a user from directly seeing the light emitted from the LED  123   a  through the reflection cover  180 . The connecting member  170  will be described in detail with reference to  FIGS. 3 and 11 . 
         [0096]      FIG. 11  is a perspective view of the connecting member  170 . 
         [0097]    Referring to  FIGS. 3 and 11 , the connecting member  170  includes a third frame  171  preventing the optic plate  160  received in the connecting member  170  from moving, and a fourth frame  173  seating the optic plate  160  and preventing the optic plate  160  from being fallen to the reflection cover  180 . 
         [0098]    The third frame  171  surrounds the first frame  161  of the optic plate  160 . Each corner of the third frame  171  has a hole formed therein for inserting a first coupling screw  175 . The heat radiating body  110  and the connecting member  170  can be securely coupled to each other by inserting the first coupling screw  175  into the hole formed in the corner of the third frame  171 . 
         [0099]    The fourth frame  173  is extended by a predetermined length from the lower part of the inner end of the third frame  171  toward the center of the connecting member  170  such that the first frame  161  of the optic plate  160  is seated. Also, the fourth frame  173  is extended by a predetermined length in a direction in which the connecting member  170  is coupled to the reflection cover  180 . 
         [0100]    The third and fourth frames  171  and  173  receive or fix the optic plate  160  and prevent a user from directly seeing the light emitted from the LED  123   a  through a reflection cover  180 . 
         [0101]      FIG. 12  is a perspective view of a reflection cover  180 . Referring to  FIG. 12 , the first and the second LED modules emit light and the reflector  140  reflects the light. Then, the light transmits the optic sheet  150  and the glass plate  165 . Here, the reflection cover  180  guides the light such that the light is prevented from being diffused in all directions. That is, the reflection cover  180  causes the light to travel toward the bottom thereof so that the light is converged within a predetermined orientation angle. 
         [0102]    The reflection cover  180  includes a fifth frame  181  surrounding the fourth frame  173  of the connecting member  170  such that the reflection cover  180  contacts strongly closely with the connecting member  170 , and includes a cover  183  converging in the down direction the light which has transmitted the optic sheet  150  and the glass plate  165 . 
         [0103]    The fifth frame  181  can be more securely coupled to the fourth frame  173  by means of a second coupling screw  185 . 
         [0104]    The cover  183  has an empty cylindrical shape. The top and bottom surfaces of the cover  183  are opened. The radius of the top surface thereof is less than that of the bottom surface thereof. The lateral surface thereof has a predetermined curvature. 
         [0105]    Hereinafter, the effect of the lighting apparatus according to the embodiment of the present invention will be described with various experiments. 
         [0106]      FIGS. 13   a  to  13   c  show data resulting from a first experiment. 
         [0107]    The first experiment employs, as shown in  FIG. 13   a , the reflector  140  having a specula reflectance of 96% and the collimating lens  125   a  having an efficiency of 92%. Also, both the heat radiating body  110  having a diameter of  3  inches and the substrates  121   a  and  121   b  of the first and the second LED modules  120   a  and  120   b  are used in the first experiment. Here, the substrates  121   a  and  121   b  are covered with white paint. 
         [0108]      FIG. 13   b  is a graph showing a luminous intensity of the first experiment. Referring to  FIG. 13   b , it is understood that the orientation angle of the light emitted from the lighting apparatus of the first experiment is about 23° and the light also converges in a vertical direction (i.e., 0°). 
         [0109]      FIG. 13   c  is a graph showing an illuminance of the first experiment. 
         [0110]    Referring to  FIG. 13   c , it is understood that ten dots are uniformly distributed on an irradiated area due to the properties of the distribution of ten LEDs and is understood that dots located at the outermost circumference form a circle. It can be found that the illuminance of the center of each dot reaches 600,000 LUX. 
         [0111]    As a result of the first experiment shown in  FIGS. 13   a  to  13   c , the efficiency of the lighting apparatus of the first experiment is about 82%. 
         [0112]      FIGS. 14   a  to  14   c  show data resulting from a second experiment. 
         [0113]    The second experiment adds the optic sheet  150  diffusing light to the first experiment shown in  FIGS. 13   a  and  13   b.    
         [0114]      FIG. 14   b  is a graph showing a luminous intensity of the second experiment. 
         [0115]    Referring to  FIG. 14   b , it is understood that the orientation angle of the light emitted from the lighting apparatus of the second experiment is about 30° and the light also converges in a vertical direction (i.e., 0°). 
         [0116]      FIG. 14   c  is a graph showing an illuminance of the second experiment. 
         [0117]    Referring to  FIG. 14   c , it is understood that ten dots are uniformly distributed on an irradiated area due to the properties of the distribution of ten LEDs and is understood that dots located at the outermost circumference form a circle. It can be found that the illuminance of the center of each dot reaches 500,000 LUX. Comparing the second experiment with the first experiment, since the optic sheet  150  diffusing light is added to the second experiment, it can be found that light is diffused more in the second experiment than in the first experiment. 
         [0118]    As a result of the second experiment shown in  FIGS. 14   a  to  14   c , the efficiency of the lighting apparatus of the second experiment is about 75%. It can be found that the efficiency of the second experiment is lower than that of the first experiment. 
         [0119]      FIGS. 15   a  to  15   c  show data resulting from a third experiment. 
         [0120]    The third experiment adds the optic sheet  150  converging light to the first experiment shown in  FIGS. 13   a  and  13   b.    
         [0121]      FIG. 15   b  is a graph showing a luminous intensity of the third experiment. 
         [0122]    Referring to  FIG. 15   b , it is understood that the orientation angle of the light emitted from the lighting apparatus of the third experiment is about 30° and the light also converges in a vertical direction (i.e., 0°). 
         [0123]      FIG. 15   c  is a graph showing an illuminance of the third experiment. Referring to  FIG. 15   c , it is understood that ten dots are uniformly distributed on an irradiated area due to the properties of the distribution of ten LEDs and is understood that dots located at the outermost circumference form a circle. It can be found that the illuminance of the center of each dot reaches 500,000 LUX. Since the optic sheet  150  is added to the third experiment, it can be found that light is converged more in the third experiment than in the second experiment. 
         [0124]    As a result of the third experiment shown in  FIGS. 15   a  to  15   c , the efficiency of the lighting apparatus of the third experiment is about 71%. It can be found that the efficiency of the third experiment is lower than that of the first experiment. 
         [0125]      FIGS. 16   a  to  16   c  show data resulting from a fourth experiment. 
         [0126]    The fourth experiment adds the optic plate  160  equipped with the glass plate  165  having a diffusing function to the first experiment shown in  FIGS. 13   a  and  13   b.    
         [0127]      FIG. 16   b  is a graph showing a luminous intensity of the fourth experiment. 
         [0128]    Referring to  FIG. 16   b , it is understood that the orientation angle of the light emitted from the lighting apparatus of the fourth experiment is about 30° and the light also converges in a vertical direction (i.e., 0°). 
         [0129]      FIG. 16   c  is a graph showing an illuminance of the fourth experiment. 
         [0130]    Referring to  FIG. 16   c , it is understood that ten dots are uniformly distributed on an irradiated area due to the properties of the distribution of ten LEDs and is understood that dots located at the outermost circumference form a circle. It can be found that the illuminance of the center of each dot reaches 450,000 LUX. Since the glass plate  165  having a diffusing function is added to the fourth experiment, it can be found that light is diffused more in the fourth experiment than in the first experiment. 
         [0131]    As a result of the fourth experiment shown in  FIGS. 16   a  to  16   c , the efficiency of the lighting apparatus of the fourth experiment is about 70%. It can be found that the efficiency of the fourth experiment is lower than that of the first experiment. 
         [0132]    The features, structures and effects and the like described in the embodiments are included in at least one embodiment of the present invention and are not necessarily limited to one embodiment. Furthermore, the features, structures, effects and the like provided in each embodiment can be combined or modified in other embodiments by those skilled in the art to which the embodiments belong. Therefore, contents related to the combination and modification should be construed to be included in the scope of the present invention. 
         [0133]    Although embodiments of the present invention were described above, theses are just examples and do not limit the present invention. Further, the present invention may be changed and modified in various ways, without departing from the essential features of the present invention, by those skilled in the art. For example, the components described in detail in the embodiments of the present invention may be modified. Further, differences due to the modification and application should be construed as being included in the scope and spirit of the present invention, which is described in the accompanying claims.

Technology Classification (CPC): 5