Patent Publication Number: US-2015062914-A1

Title: Optical semiconductor lighting apparatus

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 14/056,663, filed on Oct. 17, 2013, which is a continuation of U.S. patent application Ser. No. 13/596,582, filed on Aug. 28, 2012, and now issued as U.S. Pat. No. 8,585,250, and claims priority from and the benefit of Korean Patent Application No. 10-2012-0075103, filed on Jul. 10, 2012, and Korean Patent Application No. 10-2012-0076852, filed on Jul. 13, 2012, each of which is hereby incorporated by reference in their entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an optical semiconductor lighting apparatus. 
     2. Description of the Related Art 
     Compared with incandescent light and fluorescent light, optical semiconductors, such as LEDs or LDs, consume low power, have a long lifespan, and have high durability and high brightness. Due to these advantages, optical semiconductors have recently attracted much attention as one of components for lighting. 
     Typically, in the lighting apparatuses using such optical semiconductors, heat is inevitably generated from the optical semiconductors. Therefore, it is necessary to install heat sinks at heat generation sites so as to discharge the generated heat to the outside. 
     As the optical semiconductors have recently become popular and have been mass-produced, unit costs of the optical semiconductors have also been lowered. Therefore, the lighting apparatuses using the optical semiconductors have tended to be used for high power industrial lighting, such as factory lighting, streetlight, or security light. 
     In the lighting apparatuses using the optical semiconductors, which are used for the high power industrial lighting, generation of heat increases in proportion to the size and power of the lighting apparatuses. As a result, it is necessary to increase the capacity and volume of the heat sink so as to demonstrate excellent heat dissipation performance. 
     Generally, heat sinks mounted on the lighting apparatuses using the optical semiconductors are manufactured by die casting or the like, such that the heat sinks are integrally or detachably connected to a housing. However, the heat sinks manufactured in such a manner increase the total weight of the product and increase the manufacturing costs and the amount of raw materials used. 
     In particular, in the case of the conventional heat sinks manufactured by die casting, heat sink fins cannot be formed to have a thickness below a predetermined reference value due to characteristics of the manufacturing method thereof. Hence, a heat dissipation area intended at a limited site is narrow, and the volume and size of the heat sink is increased if a plurality of heat sink fins are formed for securing a sufficient heat dissipation area. 
     Meanwhile, in this regard, if a heat sink is manufactured in a shape of a heat sink plate by using a sheet (thin plate), a sufficient heat dissipation area may be secured. However, due to the structural limitation that the heat sink should be arranged in a line contact manner, heat generated from optical semiconductors may not be effectively transferred and discharged to the outside. 
     Furthermore, in the lighting apparatus using the optical semiconductor, a circuit board, on which the optical semiconductors are disposed, is connected to a heat sink, and the circuit board is embedded in a housing. An optical member, such as a lens, which is installed in the housing, allows light from the optical semiconductors to be irradiated more widely or narrowly. 
     In most cases, the lighting apparatus using the optical semiconductor is disposed on a rectangular or circular circuit board for convenience of manufacturing, and a housing is also rectangular or circular. 
     However, in view of the number of the lighting apparatuses arranged per unit area in order for high power, if a large number of lighting apparatuses are arranged, the total weight and volume thereof are increased due to the limitation of the structural shape. 
     SUMMARY OF THE INVENTION 
     An aspect of the present invention is directed to provide an optical semiconductor lighting apparatus that can reduce a total weight of a product. 
     Another aspect of the present invention is directed to provide an optical semiconductor lighting apparatus that can further improve the heat dissipation efficiency by inducing natural convection. 
     Another aspect of the present invention is directed to provide an optical semiconductor lighting apparatus that is simple in the product assembly and installation and is easy in maintenance. 
     Another aspect of the present invention is directed to provide an optical semiconductor lighting apparatus that can provide products with high reliability by increasing the arrangement efficiency of semiconductor optical devices per unit area. 
     According to an embodiment of the present invention, an optical semiconductor lighting apparatus includes: a housing; a light emitting module including at least one or more semiconductor optical devices and disposed at an outer side of a bottom surface of the housing; a heat sink unit disposed radially at an inner side of the bottom surface of the housing and forming a communication space at a central portion of the inner side of the bottom surface of the housing; a first heat sinking path formed radially from the central portion of the inner side of the bottom surface of the housing; and a second heat sinking path formed along an edge of the bottom surface of the housing in a vertical direction. 
     The heat sink unit may include a plurality of heat sink elements each including a pair of heat sink elements that are perpendicular to the bottom surface of the housing and face each other. 
     The optical semiconductor lighting apparatus may further include a core fixing portion that is disposed at the central portion of the inner side of the bottom surface of the housing and fixes an inner end portion of the heat sink unit. 
     An outer end portion of the heat sink unit may communicate with the second heat sinking path formed from the outer side of the bottom surface of the housing. 
     The housing further may include a side wall extending along the edge of the bottom surface of the housing. The heat sink unit may be accommodated inside the side wall. The second heat sinking path may be formed in parallel to the side wall. 
     The housing may further include a cover that is connected to an upper edge of the side wall and has a communication hole at a central portion thereof. 
     The housing may further include: a cover mutually communicating with the first and second heat sinking paths and having a communication hole at a central portion thereof; and a plurality of upper vent slot penetrating on circumferences of a plurality of virtual concentric circles formed along a direction in which the cover is formed. 
     The housing may further include a cover that is disposed at an upper side of the heat sink unit, is connected to the housing, and has a communication hole connected to the communication space. 
     The cover may further include a plurality of upper vent slots penetrating circumferences of a plurality of virtual concentric circles formed along a direction in which the cover is formed. 
     The housing may further include a ventilation fan disposed in the communication space. 
     The housing may further include a plurality of lower vent slots penetrating the bottom surface of the housing along an edge of the light emitting module, and the lower vent slots may mutually communicate with the second heat sinking path. 
     According to another embodiment of the present invention, an optical semiconductor lighting apparatus includes: a housing in which at least one or more semiconductor optical devices are disposed at an outer side of a bottom surface thereof; a plurality of bottom sheets disposed radially at an inner side of the bottom surface of the housing; and a heat sink sheet extending along both edges of the bottom sheet and facing each other. 
     The optical semiconductor lighting apparatus may further include: an extension sheet extending from an inner end portion of the bottom sheet toward a central portion of the inner side of the bottom surface of the housing; and a fixing sheet extending along both edges of the extension sheet and facing each other, wherein the fixing sheet is connected to the heat sink sheet. 
     The optical semiconductor lighting apparatus may further include a core fixing portion that is disposed at the central portion of the inner side of the bottom surface of the housing and fixes an upper edge of the fixing sheet. 
     The bottom sheet may be formed in a tapered shape, such that the bottom sheet is gradually widened toward the edge of the inner side of the bottom surface of the housing. 
     The housing may further include a plurality of fixing protrusions that protrude from the inner side of the bottom surface of the housing and are disposed along both edges of the bottom sheet. 
     The housing may further include a communication space formed between the plurality of bottom sheets and the inner end portion of the heat sink sheet from the central portion of the bottom surface of the housing, and the communication space may communicate with the first heat sinking path. 
     The housing may further include a ventilation fan disposed in the communication space. 
     The term “semiconductor optical device” used in claims and the detailed description refers to a light emitting diode (LED) chip or the like that includes or uses an optical semiconductor. 
     The semiconductor optical devices may include package level devices with various types of optical semiconductors, including the LED chip. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view illustrating an overall configuration of an optical semiconductor lighting apparatus according to an embodiment of the present invention. 
         FIG. 2  is a cross-sectional view taken along line A-A′ of  FIG. 1 . 
         FIG. 3  is a partial conceptual diagram viewed from a viewpoint B of  FIG. 1 . 
         FIG. 4  is a partial conceptual diagram viewed from a viewpoint C of  FIG. 1 . 
         FIGS. 5 to 6  are diagrams illustrating an overall configuration of a unit heat sink element constituting a heat sink unit that is an essential part of the optical semiconductor lighting apparatus according to the embodiment of the present invention. 
         FIG. 7  is a perspective view illustrating an overall configuration of an optical semiconductor lighting apparatus according to an embodiment of the present invention. 
         FIG. 8  is a cross-sectional view taken along line E-E′ of  FIG. 7 . 
         FIG. 9  is a perspective view illustrating an overall configuration of an optical semiconductor lighting apparatus according to another embodiment of the present invention. 
         FIG. 10  is a cross-sectional view taken along line F-F′ of  FIG. 9 . 
         FIG. 11  is a partial conceptual diagram viewed from a viewpoint G of  FIG. 9 . 
         FIG. 12  is a partial conceptual diagram viewed from a viewpoint I of  FIG. 9 . 
         FIGS. 13 to 14  are diagrams illustrating an overall configuration of a unit heat sink element constituting a heat sink unit that is an essential part of the optical semiconductor lighting apparatus according to another embodiment of the present invention. 
         FIGS. 15 to 18  are conceptual diagrams illustrating actual application examples of optical semiconductor lighting apparatuses according to various embodiments of the present invention. 
         FIG. 19  is a cross-sectional view taken along line K-K′ of  FIG. 17 . 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 
       FIG. 1  is a perspective view illustrating an overall configuration of an optical semiconductor lighting apparatus according to an embodiment of the present invention.  FIG. 2  is a cross-sectional view taken along line A-A′ of  FIG. 1 .  FIG. 3  is a partial conceptual diagram viewed from a viewpoint B of  FIG. 1 .  FIG. 4  is a partial conceptual diagram viewed from a viewpoint C of  FIG. 1 .  FIGS. 5 to 6  are diagrams illustrating an overall configuration of a unit heat sink element constituting a heat sink unit that is an essential part of an optical semiconductor lighting apparatus according to an embodiment of the present invention. 
     As illustrated, the optical semiconductor lighting apparatus according to the embodiment of the present invention is configured such that a heat sink unit  300  is mounted on a housing  100  where a light emitting module  200  is disposed, and first and second heat sinking paths H1 and H2 are formed inside the housing  100 . 
     For reference, reference numeral  600  in  FIG. 2  denotes a waterproof connector. In  FIG. 2 , an outer side of a bottom surface  110  refers to a side facing a lower side of the drawing from the bottom surface  110 , and an inner side of the bottom surface  110  refers to a side facing an upper side of the drawing from the bottom surface  110 . The outer side and the inner side of the bottom surface  110  are equally applied throughout the drawings. 
     The housing  100  provides a space for mounting the light emitting module  200  and the heat sink unit  300 , and the light emitting module  200  includes at least one or more semiconductor optical devices  201  and is disposed at the outer side of the bottom surface  110  of the housing  100 . The light emitting module  200  serves as a light source. 
     The heat sink unit  300  is disposed radially at the inner side of the bottom surface  110  of the housing  100 , and forms a communication space  101  at an inner central portion of the bottom surface  110  of the housing  100 . The heat sink unit  300  discharges heat generated from the light emitting module  200  to the outside of the housing  100 . 
     The first heat sinking path H1 is formed radially from the inner central portion of the bottom surface  110  of the housing  100 . To be specific, the first heat sinking path H1 may be formed radially along the direction in which the respective heat sink units  300  are formed. 
     The second heat sinking path H2 is formed along the edge of the bottom surface  110  of the housing  100  in a vertical direction. To be specific, the second heat sinking path H2 may be formed to communicate in the vertical direction of the housing  100  along the edge of the light emitting module  200 . 
     Therefore, as illustrated, natural convection is actively induced by forming a plurality of paths through which heat generated from the light emitting module  200  is discharged by the first and second heat sinking paths H1 and H2, thereby further increasing the heat dissipation efficiency. 
     It is apparent that the following various embodiments as well as the above-described embodiment can also be applied to the present invention. 
     As described above, the housing  100  provides the space for mounting the light emitting module  200  and the heat sink unit  300 , and further includes a side wall  120  (see  FIG. 2 ) extending along the edge of the bottom surface  110  of the housing  100 . The side wall  120  surrounds the outside of the heat sink unit  300 , and the second heat sinking path H2 is formed in parallel to the side wall  120 . 
     The housing  100  further includes a plurality of lower vent slots  130  penetrating the bottom surface  110  of the housing  100  along the edge of the light emitting module  200 , and the lower vent slots  130  mutually communicate with the second heat sinking path H2. 
     The housing  100  may further include a cover  500  that is connected to an upper edge of the side wall  120  and has communication holes  501  at the central portion thereof. 
     The cover  500  mutually communicates with the first and second heat sinking paths H1 and H2 and has the communication holes  501  at the central portion thereof. A plurality of upper vent slots  510  penetrating the circumferences of a plurality of concentric circles formed along the direction in which the cover  500  is formed. 
     To be specific, the communication holes  501  are connected to the communication spaces  101  through the first heat sink path H1, and the second heat sinking path H2 is connected through the outermost upper vent slot  510 . 
     Referring to  FIG. 3 , the lower vent slots  130  mutually communicate through the upper vent slots  510 . This can be understood more clearly with the detailed description of the heat sink unit  300 , which will be described later. 
     As illustrated in  FIGS. 1 and 4 , the optical semiconductor lighting apparatus according to the embodiment of the present invention may further include a core fixing portion  400  that is disposed at the inner central portion of the bottom surface  110  of the housing  100  to fix an inner end portion of the heat sink unit  300 . 
     In addition, although not specifically illustrated, a ventilation fan may be further mounted in the communication space  101  to forcibly convect heat generated from the light emitting module  200  and discharge the heat to the outside of the housing  100 , thereby obtaining a rapid heat dissipation effect. 
     Meanwhile, as described above, the light emitting module  300  is mounted on the bottom surface  110  of the housing  100  so as to obtain excellent heat dissipation performance. The light emitting module  300  includes a plurality of unit heat sink elements  301  (see  FIGS. 5  and  6 ) each including a pair of heat sink sheets  320  that are perpendicular to the bottom surface  110  of the housing  100  and face each other. 
     The outer end portion of the heat sink unit  300  communicates with the second heat sinking path H2 formed from the outer side of the bottom surface  110  of the housing  100 . 
     More specifically, the heat sink unit  300  is disposed radially at the inner side of the bottom surface  110  of the housing  100 , and includes a plurality of bottom sheets  310  contacting a side opposite to a side where the semiconductor optical device  201  is disposed, that is, the inner side of the bottom surface  110  of the housing  100 . 
     The heat sink unit  300  includes heat sink sheets  320  that extend along both edges of the bottom sheet  310  and face each other. 
     Therefore, the first heat sinking path H1 is formed radially between the adjacent heat sink sheets  320 . The second heat sinking path H2 is formed as follows. 
     That is, the second heat sinking path H2 is formed perpendicular to the first heat sinking path H1 vertically from the lower vent slots  130  in correspondence to the plurality of lower vent slots  130  penetrating the inner edge of the bottom surface  110  of the housing  100 . 
     The outer end portion of the bottom sheet  310  is cut and removed, and a cut-out portion  315  is formed between the bottom sheet  310  and the heat sink sheet  320 . Therefore, the cut-out portion  315  communicates with the lower vent slot  130 . The second heat sinking path H2 may be formed through the upper vent slot  510  of the cover  500 . 
     In this case, the heat sink unit  300  may include an extension sheet  311  extending from the inner end portion of the bottom sheet  310  toward the inner central portion of the bottom surface  110  of the housing  100 , and a fixing sheet  312  extending along both edges of the extension sheet  311  and facing the extension sheet  311 . 
     The extension sheet  311  provides a space for forming the fixing sheet  312 . The fixing sheet  312  serves as a reinforcement structure for distributing and supporting a fixing/supporting force generated by the core fixing portion  400  fixing the upper edge of the fixing sheet  312 . 
     As illustrated and described above, the core fixing portion  400  is disposed at the inner central portion of the bottom surface  110  of the housing  100 . 
     Therefore, the communication space  101  is formed in the upper space of the core fixing portion  400 , that is, the space between the plurality of bottom sheets  310  and the inner end portion of the heat sink sheet  320  from the inner central portion of the bottom surface  110  of the housing  100 , and the communication space  101  mutually communicates with the first heat sinking path H1. 
     In addition, as illustrated in  FIG. 5 , the housing  100  may further include a plurality of fixing protrusions  160  protruding from the inner side of the bottom surface  110  and disposed along both edges of the bottom sheet  310 , so as to provide a space for mounting the bottom sheet  310  constituting the unit heat sink element  301  and tightly fix and support the lower side of the heat sink sheet  320 . 
     Furthermore, as illustrated in  FIG. 6 , the bottom sheet  310  is formed in a tapered shape, such that the bottom sheet  310  is gradually widened toward the inner edge of the bottom surface  110 , so as to effectively discharge heat from the central portion of the bottom surface  110  to the outside of the housing  100 . 
     Therefore, in the heat sink unit  300 , the bottom sheet  310  and the heat sink sheet  320  constituting the unit heat sink element  301  are formed to have a U-shaped cross-section as a whole, and the bottom sheet  310  is disposed to contact the inner side of the bottom surface  110  of the housing  100 . As a result, compared with the conventional heat sink fin structure, the heat transfer area is increased to further improve the heat dissipation effect. 
     In the conventional lighting apparatus, since the heat sink is manufactured by die casting, the volume and size thereof are increased. However, according to the embodiment of the present invention, the total weight of the product can be reduced by radially arranging the unit heat sink elements  301  including the bottom sheet  310  and the heat sink sheet  320  formed in a thin plate type. 
     Meanwhile, as illustrated in  FIGS. 7 to 19 , the structures of a light engine concept can also be applied to the present invention. 
     In  FIGS. 7 to 10 , the same reference numerals as used in  FIGS. 1 to 6  are assigned to members having the same structures and functions as those of  FIGS. 1 to 6 . 
       FIG. 7  is a perspective view illustrating an overall configuration of an optical semiconductor lighting apparatus according to an embodiment of the present invention.  FIG. 8  is a cross-sectional view taken along line E-E′. 
       FIG. 9  is a perspective view illustrating an overall configuration of an optical semiconductor lighting apparatus according to another embodiment of the present invention.  FIG. 10  is a cross-sectional view taken along line F-F′ of  FIG. 9 .  FIG. 11  is a partial conceptual diagram viewed from a viewpoint G of  FIG. 9 .  FIG. 12  is a partial conceptual diagram viewed from a viewpoint I of  FIG. 9 .  FIGS. 13 to 14  are diagrams illustrating an overall configuration of a unit heat sink element constituting a heat sink unit that is an essential part of the optical semiconductor lighting apparatus according to another embodiment of the present invention. 
       FIGS. 15 to 18  are conceptual diagrams illustrating actual application examples of optical semiconductor lighting apparatuses according to various embodiments of the present invention.  FIG. 19  is a cross-sectional view taken along line K-K′ of  FIG. 17 . 
     In  FIG. 8 , reference numeral  600  denotes a waterproof connector. 
     In  FIG. 9 , the other side of the bottom surface  110  of the housing  100  refers to a side that gradually widens compared with one side thereof. One side of the bottom surface  110  of the housing  100  refers to a right lower end, and the other side thereof refers to a left upper end. 
     In  FIG. 10 , one side of the bottom surface  110  of the housing  100  refers to a right side, and the other side thereof refers to a left side. 
     In  FIG. 11 , one side of the bottom surface  110  of the housing  100  refers to a left upper side, and the other side thereof refers to a right lower side. 
     In  FIG. 12 , one side of the bottom surface  110  of the housing  100  refers to a right lower side, and the other side thereof refers to a left upper side. 
     In  FIG. 13 , one side of the bottom surface  110  of the housing  100  refers to a left lower side, and the other side thereof refers to a right upper side. 
     In  FIG. 14 , one side of the bottom surface  110  of the housing  100  refers to a left side, and the other side thereof refers to a right side. 
     In  FIG. 19 , reference numeral  600  denotes a waterproof connector. In  FIGS. 7 ,  8 ,  9 ,  10  and  19 , the outer side of the bottom surface  110  refers to a side facing a lower side of the drawing from the bottom surface  110 , and the inner side of the bottom surface  110  refers to a side facing an upper side of the drawing from the bottom surface  110 . The outer side and the inner side of the bottom surface  110  are equally applied throughout the drawings. 
     As illustrated, an engine body  800  is connected to an outer side of a bottom surface of the base casing  700 , and a heat sink unit  300  is connected to an inner side of the bottom surface of the base casing  700 . 
     The base casing  700  is a cylindrical member to provide a space for accommodating the heat sink unit  300 , which will be described later, and also provide an area for mounting the engine body  800 , which will be described later. 
     The engine body  800  is connected to the outer side of the bottom surface of the base casing  700  and is formed to have a top surface gradually widened from one side to the other side. 
     Although not specifically illustrated, it should be understood that the engine body  800  refers to a structure that includes a light emitting module (not illustrated) with semiconductor optical devices, and an optical member corresponding to the light emitting module. The engine body  800  is a structural concept extended up to a combination of a light emitting module and a power unit electrically connected thereto, which is defined in “Zhaga Consortium”, the consortium for standardization of LED light engines. 
     The heat sink unit  300  includes a plurality of unit heat sink elements  301  (see  FIGS. 13 and 14 ) each including a pair of heat sink sheets  320  disposed at the inner side of the bottom surface of the base casing  700  in a fan shape and facing each other. 
     In this case, the number of the unit heat sink elements  301  may be appropriately increased or decreased according to the size of the housing  800 , which is mounted on the outer side of the bottom surface of the base casing  700 , or the light output amount of the light emitting module, which is mounted inside the engine body  800 . 
     The heat sink unit  300  includes a bottom sheet  310  (see  FIG. 9 ) contacting the base casing  700  so as to secure a sufficient heat transfer area, and a heat sink sheet  320  extends from both edges of the bottom sheet  310 . 
     In addition, a plurality of engine body  800  are disposed radially from the central portion of the outer side of the bottom surface of the base casing  700 . More specifically, in order to obtain excellent heat dissipation performance, the heat sink unit  300  may be disposed corresponding to a position where the engine body  800  is connected. 
     It is apparent that the following various embodiments as well as the above-described embodiment can also be applied to the present invention. 
     As described above, the base casing  700  provides a mounting space and area for the engine body  800  and the heat sink unit  300 . As illustrated in  FIG. 8 , the base casing further includes a ring-shaped core fixing portion  400  for fixing the inner edges of the unit heat sink elements  301  at an upper side. 
     In addition, in order to protect the heat sink unit  300  and the components mounted inside the base casing  700  from external physical and/or chemical impacts, the base casing  700  may further include a ring-shaped cover  500  which is disposed at the upper side of the unit heat sink elements  301  and fixed to the edge of the base casing  700 . Also, a plurality of upper vent slots  510  penetrate the cover  500 . 
     In addition, the cover  500  is disposed at an upper side of the heat sink sheet  320  and connected to an upper edge of the base casing  700 , such that heat generated from the light emitting module  200  is effectively discharged while inducing natural convection through the space where the heat sink unit  300  is formed. 
     Therefore, it is possible to cope with various installation and construction environments widely and actively by appropriately increasing or decreasing the number of the engine bodies  800  and the number of the unit heat sink elements  301  constituting the heat sink unit  300 , regardless of the arrangement area in the inner and outer sides of the bottom surface of the base casing  700 . 
     Meanwhile, in addition to the above-described structure, various structures illustrated in  FIGS. 9 to 19  can also be applied to the present invention. 
     First, the heat sink unit  300  is included in the housing  100  where the light emitting module  200  is mounted. 
     The housing  100  forms the bottom surface  110  that is gradually widened from one side to the other side. To be specific, the housing  100  is formed in a fan shape to provide the space and area for mounting the light emitting module  200 , the optical member, and the heat sink unit  300 , which will be described later. 
     The light emitting module  200  includes at least one or more semiconductor optical devices  201  and is disposed at the outer side of the bottom surface  110  of the housing  100 . The light emitting module  200  serves as a light source. 
     The optical member is connected to the outer side of the bottom surface  110  of the housing  100  and faces the light emitting module  2000 . The optical member can adjust the light distribution area of light irradiated from the light emitting module  200 . 
     In order to discharge generate from the light emitting module  200  to the outside of the housing  100 , the heat sink unit  300  includes the plurality of unit heat sink elements  301  each including a pair of heat sink sheets  320  that are radially disposed in a fan shape at the inner side of the bottom surface  110  of the housing  100  and face each other. 
     Therefore, due to the structural characteristics of the bottom surface  110  of the housing  100 , the above-described structure and the optical semiconductor lighting apparatus according to the embodiment of the present invention can adjust the light output amount by mounting a plurality of base casings  700  (see  FIGS. 15 to 19 ), which will be described later. 
     As described above, the housing  100  provides the space and area for mounting the respective components of the present invention. The housing  100  further includes a side wall  120  extending along both sides of the bottom surface  110  and the edge of the other side of the housing  100 , and the heat sink unit  300  is accommodated in the inner space where the side wall  120  is formed. 
     As described above, the optical member faces the light emitting module  200 , and includes an optical cover  210  made of a transparent or translucent material. The optical cover  210  faces the light emitting module  200  and projects light irradiated from the light emitting module  200 . 
     The optical member includes a lens  220  provided at the optical cover  210 . The lens  220  corresponds to the semiconductor optical devices  201 , and reduces or expands the area and range on which light is irradiated from the respective semiconductor optical devices  201 . 
     Meanwhile, as illustrated in  FIG. 10 , the housing  100  may further include a connection rib  150  and a frame rib  170  so as to mount the optical member. 
     The connection rib  150  protrudes along the edge of the outer side of the bottom surface  110 , and the frame rib  170  is connected to the connection rib  150 . The edge of the optical member is fixed between the connection rib  150  and the frame rib  170 . 
     The housing  100  may further include a first protrusion  152 , which is stepped along the edge of the outer side of the connection rib  150 , and a second protrusion  172 , which is stepped along the edge of the outer side of the frame rib  170  and corresponds to the first protrusion  152 . 
     The first protrusion  152  and the second protrusion  172  are provided for securely and tightly connecting the connection rib  150  and the frame rib  170 . The first protrusion  152  and the second protrusion  172  are provided for securely fixing the optical member, that is, the edge of the optical cover  210 . 
     In this case, a sealing member  180  may be connected to the optical member, that is, the edge of the optical cover  210 , so as to maintain waterproofing and airproofing. 
     In addition, the housing  100  may further include the cover  500  disposed at the upper side of the heat sink sheet  320  and connected to the upper edge of the housing  100 , such that heat generated from the light emitting module  200  is effectively discharged while inducing natural convection through the space where the heat sink unit  300  is formed. 
     Furthermore, the cover  500  protects the heat sink unit  300  and the components mounted inside the base casing  700  from external physical and/or chemical impacts. 
     The cover  500  may further include at least one or more upper vent slots  510  penetrating along a direction from one side to the other side of the housing  100 . 
     In this case, the housing  100  may further include at least one or more lower vent slots  130  (see  FIGS. 10 to 12 ) penetrating the edge of the other side of the bottom surface  110  thereof. 
     Meanwhile, as described above, the heat sink unit  300  is provided to obtain heat dissipation performance. The heat sink unit  300  includes a bottom sheet  310  contacting the inner side of the bottom surface  110  of the housing  100  so as to form the heat sink sheets  320  constituting the unit heat sink element  301 . 
     The heat sink sheets  320  extend from both edges of the bottom sheet  310 . 
     In this case, in the space formed between the heat sink sheets  320 , the first heat sinking path H1 (see  FIGS. 10 ,  13  and  14 ) are formed in a fan shape from one side to the other side of the bottom surface  110  of the housing  100 . 
     In addition, the second heat sinking path H2 (see  FIGS. 10 and 13 ) is formed from the lower vent slot  130  to the upper vent slot  510  disposed at the outermost of the cover  500 . 
     Therefore, as illustrated, natural convection is actively induced by forming a plurality of paths through which heat generated from the light emitting module  200  is discharged by the first and second heat sinking paths H1 and H2, thereby further increasing the heat dissipation efficiency. 
     In addition, the heat sink unit  300  may further include an extension sheet  311  and a fixing sheet  312 , which can be used when the heat sink unit  300  is fixedly arranged at the base casing  700  to be described later. 
     That is, the extension sheet  311  extends from the inner end portion of the bottom sheet  310  toward one side of the bottom surface  110  of the housing  100 , and the fixing sheet  312  extends along both edges of the extension sheet  311  and faces the extension sheet  311 . 
     In this case, the fixing sheet  312  is connected to the heat sink sheet  320 . In order for assembly, it is preferable that the height of the fixing sheet  312  protruding from the bottom surface  110  is lower than that of the heat sink sheet  320 . 
     Due to the structural characteristic of the bottom sheet  310  disposed radially on the bottom surface  110 , it is preferable that the bottom sheet  310  is formed in a tapered shape such that the bottom sheet  310  is gradually widened from one side to the other side of the bottom surface  110 , so as to secure a sufficient contact area. 
     In addition, as illustrated in  FIG. 13 , the housing  100  may further include a plurality of fixing protrusions  160  protruding on the opposite side and disposed along both edges of the bottom sheet  310 , so as to provide a mounting space of the bottom sheet  310  constituting the unit heat sink element  301  and tightly fixing and supporting the lower side of the heat sink sheet  320 . 
     Therefore, in the heat sink unit  300 , the bottom sheet  310  and the heat sink sheet  320  constituting the unit heat sink element  301  are formed to have a U-shaped cross-section as a whole, and the bottom sheet  310  is disposed to contact the inner side of the bottom surface  110  of the housing  100 . As a result, compared with the conventional heat sink fin structure, the heat transfer area is increased to further improve the heat dissipation effect. 
     In the conventional lighting apparatus, since the heat sink is manufactured by die casting, the volume and size thereof are increased. However, according to the embodiment of the present invention, the total weight of the product can be reduced by radially arranging the unit heat sink elements  301  including the bottom sheet  310  and the heat sink sheet  320  formed in a thin plate form. 
     Meanwhile, as illustrated in  FIGS. 15 to 19 , the optical power can be adjusted by arranging a plurality of housings  100  as the concept of the light engine, and the weight of the product can be reduced by increasing the arrangement efficiency of the semiconductor optical devices  201  per unit area. Moreover, the housing  100  can be arranged in the base casing  700  so as to provide high power products. 
     The heat sink sheets  320  of the heat sink unit  300  disposed in the adjacent housings  100  are disposed radially with respect to the central portion of the base casing  700 . 
     To be specific, as illustrated in  FIGS. 15 to 18 , the plurality of housings  100  may be arranged radially with respect to the central portion of the base casing  700 . 
     In this case, the arrangement efficiency of the housings  100  per unit area can be maximized when the other sides of the housings  100  are arranged to face the outer side of the base casing  700 . 
     Although it is illustrated in the drawings that the base casing  700  has the bottom surface with a circular disk shape to form a cylindrical shape, the present invention is not necessarily limited thereto. Various applications and design modifications can also be made. For example, the base casing  700  may have a polygonal pillar shape with a polygonal bottom surface. 
     In addition, as illustrated in  FIG. 19 , the base casing  700  may include a core fixing portion  400  for pressing and fixing the upper edge of the fixing sheet  312 . By arranging the core fixing portion  400  at the central portion of the base casing  700 , the tightly connected state of the respective housings  100  can be maintained. 
     Therefore, as illustrated in  FIGS. 15 to 18 , when the housings  100  are arranged radially with respect to the central portion of the base casing  700 , the first heat sinking path H1 is also formed radially. Therefore, heat generated from the light emitting module  200  can be effectively discharged through natural convention, together with the second heat sinking path H2. 
     In addition, although not specifically illustrated, a ventilation fan may be further mounted on the base casing  700  to forcibly convect heat generated from the light emitting module  200  and discharge the heat to the outside of the housing  100 , thereby achieving a rapid heat dissipation effect. 
     As described above, the basic technical spirit of the present invention is to provide an optical semiconductor lighting apparatus that can reduce the total weight of the product, can further improve the heat dissipation efficiency by inducing natural convection, is simple in the product assembly and installation and is easy in maintenance, and can provide products with high reliability by increasing the arrangement efficiency of semiconductor optical devices per unit area. 
     According to the present invention, the following effects can be obtained. 
     First, the heat sink unit is disposed radially in the housing where the light emitting module is mounted. The first heat sinking path is formed along the direction in which the heat sink is formed, and the second heat sinking path is formed in the vertical direction of the housing along the edge of the light emitting module. By actively inducing the natural convection through the first and second heat sinking paths, the heat dissipation efficiency can be significantly increased and the heat generation problem can be solved. 
     The heat sink sheets extend from both edges of the bottom sheet radially disposed in the housing including the semiconductor optical device, and have a U-shape facing each other. Therefore, the total weight of the product can be reduced, and the manufacturing cost of the product and the amount of raw materials used can be significantly reduced. 
     That is, by making the unit heat sink element in a sheet form, it is possible to solve the problem of the conventional heat sink manufactured by die casing that it is difficult to make the heat sink in the sheet form. Therefore, the weight of the product can be reduced, and the bottom sheet can solve the difficulty in securing the heat transferring area due to the line contact of the conventional sheet-type heat sink. 
     The unit heat sink element including the bottom sheet and the heat sink sheet is fit into the housing, and the cover where the upper vent slot is formed is connected to the housing. Since it is easy to assemble the product, failure sites can be checked immediately, and the maintenance and management are simple. Therefore, products with high reliability can be provided to consumers. 
     By providing the apparatus as the concept of the light engine including the engine body, the arrangement efficiency of the semiconductor optical devices per unit area can be increased, and products with high reliability can be provided. 
     That is, by arranging the engine bodies as the concept of the light engine radially in the base casing defining a separate accommodation space, high power lighting can be implemented. Furthermore, the output power can be appropriately varied according to the installation and construction environment. 
     While the embodiments of the present invention have been described with reference to the specific embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.