Abstract:
Disclosed is a light-emitting diode (LED) lighting apparatus. The LED lighting apparatus comprises: a light source module comprising an LED light source; a thermal base coupled to the light source module so as to receive heat generated by the light source module; and a heat-dissipating member comprising a ventilation unit coupled to an edge region of the thermal base so as to discharge heat transmitted from the thermal base and open a central area of the thermal base so as to facilitate air ventilation to the outside. The LED lighting apparatus can increase heat-dissipating efficiency by maximizing ventilation efficiency and enabling air around the heat-dissipating member to flow smoothly without stagnating.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of PCT/KR2010/006768 filed Oct. 5, 2010, which claims the benefit of Korean Patent Application No. 10-2010-0017149, filed with the Korean Intellectual Property Office on Feb. 25, 2010, the disclosure of which is incorporated herein by reference in its entirety. 
     BACKGROUND 
     1. Technical Field 
     The present invention relates to an LED lighting apparatus. 
     2. Background Art 
     An LED lighting apparatus has a large amount of heat generated due to heat generated by the LED. Generally, when the LED lighting apparatus is overheated, the LED lighting apparatus may malfunction or be damaged, and thus it is essentially required to equip the LED lighting apparatus with a heat-dissipating structure in order to prevent the overheating. 
     Accordingly, disclosed previously has been an LED lighting apparatus having heat-dissipating fins. In the LED lighting apparatus having heat-dissipating fins therein, the heat-dissipating fins are attached to a cylindrical body that surrounds a light source so as to expand the surface area. However, the heat-dissipating fin structure is limited in expanding the surface area, and the air present in between the heat-dissipating fins is stagnated with heat therein, lowering the heat-dissipating efficiency relative to the surface area. 
     To improve this problem, Korean Patent Publication 2009-0095903 has disclosed a structure that discharges a linear heat radiation member on an external circumferential surface of the body surrounding a light source. However, in this kind of structure also, the air having the heat held therein is stagnated on the exterior of the body in such a way that the problem of lowered heat-dissipating efficiency remains unsolved. Moreover, the heat generated from the light source is confined in the cylindrical body to cause a thermal bottleneck phenomenon, in which the heat confined in the cylindrical body is not transferred to the heat radiation member quickly enough. 
     Korean Patent Publication 2009-0076545 has disclosed an LED lighting apparatus in which open heat radiation passages are formed in a heat sink in order to facilitate air flow. However, this kind of structure also merely improves the air flow limitedly at an end portion of the heat sink and thus is not capable of solving the problem caused by the air having the heat held therein, and the problem of insufficient active heat radiation area for heat dissipation still remains unsolved. 
     SUMMARY 
     The present invention provides an LED lighting apparatus in which heat-dissipating efficiency is improved by activating air flow around a heat-dissipating member. 
     An aspect of the present invention features an LED lighting apparatus, which includes: a light source module comprising an LED light source; a thermal base coupled to the light source module so as to receive heat generated by the light source module; and a heat-dissipating member comprising a ventilation unit coupled to an edge region of the thermal base so as to discharge heat transferred from the thermal base and open a central area of the thermal base so as to facilitate air ventilation to the outside. 
     The LED light source can be provided in plurality, and the plurality of LED light sources can be arranged to correspond to the edge region of the thermal base. 
     The heat-dissipating member can include a heat-dissipating loop that is constituted with linear members and comprises a spiral structure repeatedly forming a heat-absorbing unit coupled to the edge region of the thermal base to receive heat and a heat-dissipating unit separated from the heat-absorbing unit to dissipate the absorbed heat. 
     The heat-dissipating loop can include a capillary tube type of heat-pipe loop, into which working fluid is injected. 
     The thermal base can be formed with a heat-transfer groove in the shape of a trench, and the heat-dissipating loop can be inserted into and arranged in the heat-transfer groove. 
     The heat-dissipating member can include a hollow-type heat-dissipating fence coupled with the edge region of the thermal base and having a plurality of penetration holes formed therein so as to enable air flow to the inside. 
     The heat-dissipating fence can be provided in plurality and coupled to the thermal base in a multi-layer structure. 
     The heat-dissipating member can include a plurality of linear members, each of which has a heat-absorbing unit coupled with the edge region of the thermal base to receive heat and a heat-dissipating unit separated from the heat-absorbing unit to dissipate the absorbed heat. 
     The thermal base can have a penetration hole formed therein so as to enable air flow. 
     With the present invention, it becomes possible to improve the heat-dissipating efficiency of the LED lighting apparatus by maximizing ventilation efficiency and enabling air around the heat-dissipating member to flow smoothly without stagnating. 
     Moreover, the heat-dissipating efficiency can be improved by preventing heat transfer from slowing down because the heat generated by LED is widely diffused. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded perspective view showing an LED lighting apparatus in accordance with an embodiment of the present invention. 
         FIG. 2  is a perspective view showing the LED lighting apparatus in accordance with an embodiment of the present invention. 
         FIG. 3  is a perspective view showing a thermal base of the LED lighting apparatus in accordance with an embodiment of the present invention. 
         FIG. 4  illustrates heat transfer passages in the thermal base of the LED lighting apparatus in accordance with an embodiment of the present invention. 
         FIG. 5  illustrates air flow in the LED lighting apparatus in accordance with an embodiment of the present invention. 
         FIG. 6  is a perspective view showing a heat pipe loop of the LED lighting apparatus in accordance with an embodiment of the present invention. 
         FIG. 7  is an exploded perspective view showing an LED lighting apparatus in accordance with another embodiment of the present invention. 
         FIG. 8  illustrates a heat-dissipating fence structure of the LED lighting apparatus in accordance with another embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. 
       FIG. 1  is an exploded perspective view showing an LED lighting apparatus in accordance with an embodiment of the present invention, and  FIG. 2  is a perspective view showing the LED lighting apparatus in accordance with an embodiment of the present invention. 
     The LED lighting apparatus in accordance with an embodiment of the present invention includes a light source module  5 , a thermal base  10  and a heat-dissipating member  20 ,  30 . 
     The light source module  5  is a portion that includes an LED light source  6 , which can emit light by use of electrical energy, to generate light required for lighting. As illustrated in  FIG. 1 , the light source module  5  in accordance with the present embodiment is constituted with the LED light source  6  and a module board  7 , in which the LED light source  7  is mounted. 
     The thermal base  10  is a portion that receives heat generated by the LED light source  6  and transfers the heat to a heat-dissipating member. For this, one side of the thermal base  10  is coupled with the LED light source  6  so as to enable heat transfer, and an edge region of the thermal base  10  is coupled with the heat-dissipating member so as to enable heat transfer. Accordingly, the heat absorbed by the thermal base  10  can be readily transferred to the heat-dissipating member. 
       FIG. 3  is a perspective view showing the thermal base of the LED lighting apparatus in accordance with an embodiment of the present invention, and  FIG. 4  illustrates heat transfer passages in the thermal base of the LED lighting apparatus in accordance with an embodiment of the present invention. 
     As illustrated in  FIG. 4 , most of the heat absorbed by the thermal base  10  is dissipated through edge regions where the heat-dissipating member is coupled. Accordingly, the heat transfer passages, in which the cross-sectional areas thereof are increased along the passages, are formed in the thermal base  10 . As the heat transfer becomes faster with the increase of the cross-sectional areas, the heat absorbed by the thermal base  10  is not stagnated but quickly transferred to the heat-dissipating member to increase the heat-dissipating efficiency. 
     In the case that the LED light source  6  is provided in plurality, the plurality of LED light sources  6  can be arranged to correspond to the edge region of the thermal base to shorten the heat transfer passages and further improve the speed of heat transfer to the heat-dissipating member. 
     As illustrated in  FIG. 1 , in the present embodiment, the light source module  5  having the plurality of circularly-arranged LED light sources  6  is mounted on one surface of the circular thermal base  10 , and the cylindrical heat-dissipating member is coupled to the edge region of the other surface of the thermal base  10 . As illustrated in  FIG. 3 , formed in the middle of the thermal base  10  is a penetration hole  14 , into which a power cable  8  for supplying electricity to the light source module  5  is inserted. 
     The heat-dissipating member  20 ,  30  is a portion that is coupled with the edge region of the thermal base to dissipate the heat transferred from the thermal base  10 . Particularly, the heat-dissipating member  20 ,  30  of the present embodiment is formed with a ventilation unit  22 ,  32  that opens a central area of the thermal base  10  and allows the air to flow freely so as to facilitate air ventilation to the outside. 
       FIG. 5  illustrates air flow in the LED lighting apparatus in accordance with an embodiment of the present invention. 
     As illustrated in  FIG. 5 , the LED lighting apparatus of the present embodiment has an inside that is sufficiently hollow to open the central area of the thermal base  10 , and the hollow space inside the thermal base  10  allows for easy ventilation with the outside through the ventilation unit. Accordingly, ventilation efficiency of the LED lighting apparatus is maximized so that the air around the heat-dissipating member is not stagnated but flows freely to improve the heat-dissipating efficiency. That is, by increasing the ventilation efficiency and facilitating continuous air flow around the heat-dissipating member, it becomes possible to prevent the air having the heat held therein from stagnating and lowering the heat-dissipating performance. 
     Moreover, the air ventilated toward the inside works to dissipate not only the heat of the heat-dissipating member but also the heat absorbed by the thermal base  10 , further enhancing the heat-dissipating efficiency. In other words, the surface of the thermal base  10  can be also utilized as an active area for heat dissipation. It is also possible that the thermal base  10  is formed with a penetration hole for ventilation, to further enhance the ventilation efficiency of the LED lighting apparatus. 
     Specifically, as illustrated in  FIGS. 1 and 2 , the heat-dissipating member in accordance with the present embodiment can include a spiral structure of heat-dissipating loop  20  that is constituted with linear members repeatedly forming a heat-absorbing unit  20   a , which is coupled to the edge region of the thermal base  10  to receive heat, and a heat-dissipating unit  20   b , which is separated from the heat-absorbing unit  20   a  to discharge the absorbed heat. In other words, the heat-dissipating loop  20  has a spiral structure that reciprocates between a region that is coupled with the thermal base  10  and a region that is apart from the thermal base  10 . Accordingly, a gap between spirals of the heat-dissipating loop  20  becomes the ventilation unit  22 , through which air is freely ventilated to the outside. In addition, by forming the heat-dissipating member in a spiral structure, the surface area required for heat dissipation can be maximized in a limited space. 
     Moreover, as illustrated in  FIG. 3 , the thermal base  10  is formed with a heat-transfer groove  12  in the shape of a trench, and as illustrated in  FIG. 2 , the heat-dissipating loop  20  can be successively inserted into and coupled with the heat-transfer groove  12 . Accordingly, by filling solder and the like in the heat-transfer groove  12  after inserting the heat-dissipating loop  20 , the heat-dissipating loop  20  can be readily coupled with the thermal base  10 . Moreover, elastic force is at work between spiral-shaped loops of the heat-dissipating loop  20  so that each loop of the heat-dissipating loop  20  inserted into the heat-transfer groove  12  can be separated from adjacent loops and maintain its inserted form by the elastic force. 
     Here, as illustrated in  FIG. 4 , each loop of the heat-dissipating loop  20  inserted in the heat-transfer groove  12  is arranged at an angle in the heat-transfer groove  12  so as to increase the density of the arranged heat-dissipating loop  200  and the area of contact with the thermal base  10 . 
     Moreover, the heat-dissipating loop  20  can include a capillary tube type of heat-pipe loop  25 , into which working fluid  26  is injected. 
       FIG. 6  is a perspective view showing the heat pipe loop of the LED lighting apparatus in accordance with an embodiment of the present invention. 
     As illustrated in  FIG. 5 , the heat-pipe loop  25  in accordance with the present embodiment has an oscillating capillary tube type of a heat pipe formed in a spiral structure therein, and the oscillating capillary tube type heat pipe has a structure in which the working fluid  26  and air bubbles  27  are injected in a predetermined ratio into the capillary tube and then the capillary tube is sealed from the outside. Accordingly, the oscillating capillary tube type heat pipe has a heat transfer cycle in which heat is mass transported in the form of latent heat by volume expansion and condensation of the air bubbles  27  and the working fluid  26 . As a result, the heat-dissipating efficiency of the heat-dissipating member can be maximized. 
     Here, the heat-pipe loop  25  can be generally formed in the shape of a board. The board-shaped heat-pipe loop  25  can be formed in a cylindrical shape by rolling the heat-pipe loop  25  in an annular shape and having both ends of the heat-pipe loop  25  by a joint  28 . The cylindrical-shape heat-pipe loop  25  can be readily inserted in the heat-transfer groove  12  and can have a higher heat-dissipating efficiency because air flow required for heat dissipation becomes freer. 
     The heat-dissipating member constituted with the linear members is not restricted to the spiral loop type but can be embodied in various permutations, for example, a parallel-arranged plurality of linear members, each of which has a heat-absorbing unit coupled with the edge region of the thermal base  10  to receive heat and a heat-dissipating unit separated from the heat-absorbing unit to dissipate the absorbed heat. 
     Moreover, the heat-dissipating member can be embodied in various other forms than the linear members. 
       FIG. 7  is an exploded perspective view showing an LED lighting apparatus in accordance with another embodiment of the present invention, and  FIG. 8  illustrates a heat-dissipating fence structure of the LED lighting apparatus in accordance with another embodiment of the present invention. 
     As illustrated in  FIG. 7 , the heat-dissipating member in accordance with the present embodiment includes a hollow-type heat-dissipating fence  30 , which is coupled with the edge region of the thermal base  10  and has a plurality of penetration holes formed therein so as to enable air flow to the inside. Accordingly, the plurality of penetration holes formed in the heat-dissipating fence  30  become the ventilation unit  32 , and the inside of the LED lighting apparatus in accordance with the present embodiment can have free air ventilation with the outside through the penetration holes. 
     The heat-dissipating fence  30  in accordance with the present embodiment is very easy to manufacture and be coupled with the thermal base  10 . Moreover, as illustrated in  FIG. 8 , the heat-dissipating efficiency can be further improved by coupling a plurality of multi-layer heat-dissipating fences  30  to the thermal base. 
     While the present invention has been described with reference to certain embodiments, the embodiments are for illustrative purposes only and shall not limit the invention. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the invention. 
     It shall be also appreciated that a very large number of embodiments other than those described herein are possible within the scope of the present invention, which shall be defined by the claims appended below.