Patent Publication Number: US-9416953-B2

Title: LED lighting apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is the U.S. national stage application of International Patent Application No. PCT/KR2012/003016, filed Apr. 19, 2012, which claims priority to Korean Application No. 10-2011-0037237, filed Apr. 21, 2011, the disclosures of each of which are incorporated herein by reference in their entirety. 
     TECHNICAL FIELD 
     The present disclosure relates to an LED lighting apparatus, and more particularly, to an LED lighting apparatus having an improved heat dissipation effect. 
     BACKGROUND ART 
     Generally, lighting apparatuses are being utilized as home lightings or other indoor and outdoor lightings using incandescent lamps, fluorescent lamps, or High brightness light emitting diodes (LEDs). 
     Among these, LED lighting apparatuses have low power consumption and semi-permanent life when compared to general incandescent lamps. Thus, the LED lighting apparatuses are being widely used. 
     An LED lighting apparatus according a related art includes a heat sink for effectively dissipating heat generated in an LED. However, the heat sink has a structure which does not effectively dissipate heat generated in a power supply unit (PSU). 
     As a result, a PSU&#39;s life may be reduced, or a lift of the LED lighting apparatus may be reduced by the heat generated in the PSU. 
     DISCLOSURE OF INVENTION 
     Technical Problem 
     Embodiments provide an LED lighting apparatus which can effectively dissipate heat generated in a power supply unit. 
     Solution to Problem 
     In one embodiment, a light emitting diode (LED) lighting apparatus includes: an LED; a socket part supplying a power into the LED; a heat sink body having one side on which the LED is mounted and the other side to which the socket part is coupled; and a heat sink fin disposed along a circumference of the heat sink body, the heat sink fin having one side extending downward from the heat sink body. 
     Advantageous Effects of Invention 
     The LED lighting apparatus according to the current embodiment may be modified in shape to reduce a weight and improve the heat dissipation performance. 
     Also, the LED lighting apparatus may form the air layer between the socket part and the heat sink body to simultaneously and effectively absorb the heat generated in the power supply unit and the heat generated in the LED. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is an exploded perspective view of an LED lighting apparatus according to an embodiment. 
         FIG. 2  is a perspective view of the assembled LED lighting apparatus according to an embodiment. 
         FIG. 3  is a sectional view illustrating a flow of heat generated in a power supply unit of the LED lighting apparatus according to an embodiment. 
         FIG. 4  is a partial sectional view of the LED lighting apparatus according to an embodiment. 
         FIG. 5  is a sectional view illustrating a flow of heat generated in an LED and the power supply unit of the LED lighting apparatus according to an embodiment. 
         FIGS. 6 and 7  are perspective views illustrating a modified example of a protrusion of the LED lighting apparatus according to an embodiment. 
         FIG. 8  is a comparison graph illustrating variation of a time taken to reach a light stabilization state of each of LED lighting apparatuses according to an embodiment and a related art. 
         FIG. 9  is a comparison graph illustrating a temperature of each of LED lighting apparatuses according to an embodiment and a related art. 
     
    
    
     MODE FOR THE INVENTION 
     Hereinafter, exemplary embodiments will be described in detail with reference to the accompanying drawings. 
       FIG. 1  is an exploded perspective view of an LED lighting apparatus according to an embodiment.  FIG. 2  is a perspective view of an assembled LED lighting apparatus according to an embodiment.  FIG. 3  is a sectional view illustrating a flow of heat generated in a power supply unit of the LED lighting apparatus according to an embodiment.  FIG. 4  is a partial sectional view of the LED lighting apparatus according to an embodiment.  FIG. 5  is a sectional view illustrating a flow of heat generated in an LED and the power supply unit of the LED lighting apparatus according to an embodiment.  FIGS. 6 and 7  are perspective views illustrating a modified example of a protrusion of the LED lighting apparatus according to an embodiment.  FIG. 8  is a comparison graph illustrating variation of a time taken to reach a light stabilization state of each of LED lighting apparatuses according to an embodiment and a related art.  FIG. 9  is a comparison graph illustrating a temperature of each of LED lighting apparatuses according to an embodiment and a related art. 
     Referring to  FIGS. 1 and 2 , an LED lighting apparatus according to an embodiment includes an LED  100 , a socket part  200  supplying power into the LED  100 , a heat sink body  300  having one side on which the LED  100  is mounted and the other side to which the socket part  200  is coupled, and heat sink pins  400  disposed along a circumference of the heat sink body  300  and having one side extending to surround the outside of the socket part  200 . 
     The LED  100  may include one of a red LED, a green LED, and a blue LED which can emit various colors or a combination thereof. Also, the LED  100  may be mounted on a printed circuit board (not shown). 
     The LED  100  may be mounted on one side of the heat sink body  300  that will be described in detail later. Also, a globe  120  may be further disposed on the one side on which the LED  100  is mounted to protect the LED  100 . 
     The socket part  200  may have a cylindrical shape with a predetermined space therein. The socket part  200  may have a terminal shape so that one side of the socket part  200  is fitted into a receptacle buried in an existing ceiling surface. 
     A stepped portion  240  may be disposed along a circumference of a side surface of the socket part  200 . The socket part  200  may be formed of a plastic resin to insulate parts received into the socket part  200  from each other. 
     A power supply unit  260  may be disposed within the socket part  200 . The power supply unit  260  may be connected to the LED  100  to maintain constant voltage and current of a power applied through the socket part  200  and also constant intensity of light emitted from the LED  100 . 
     Here, a predetermined hole (not shown) through which the power supply unit disposed within the socket part  200  is connected to the LED  100  may be defined in the other side of the socket part  200 . 
     The heat sink body  300  may have a cylindrical shape with an inner space. The heat sink body  300  may be formed of a metallic material having superior formability and thermal conductivity. For example, the heat sink body  300  may be formed of aluminum among the metallic materials. 
     A separate mounting space for mounting the LED  100  may be defined in one side of the heat sink body  300 . The other side of the heat sink body  300  may be opened. Also, an end of the other side of the heat sink body  300  may be seated on the stepped portion  240  disposed on the outside of the socket part  200 . 
     Referring to  FIG. 3 , a portion including a front end of the socket part  200  may be disposed inside the heat sink body  300 , and a remaining portion of the socket part  200  may be exposed to air. 
     Thus, heat H generated in the power supply unit  260  may be directly dissipated to the outside through a sidewall of the socket part  200 . As a result, the LED lighting apparatus may have a relatively low thermal resistance to improve heat dissipation performance when compared to a LED lighting apparatus according to a related art in which heat is dissipated to the outside via a socket part, an air layer, and a heat sink body. 
     When power is supplied into the LED  100 , heat is generated in the power supply unit  260  within the socket part  200 , and then the heat generated in the power supply unit  260  is dissipated to the outside via the socket part  200 . 
     That is, since a portion of the heat sink body surrounding the outside of the sock part according to the related art is removed, the structure according to the current embodiment may have a relatively low thermal resistance when compared to that of the structure according to the related art, thereby improving heat dissipation performance. 
     Also, since the heat sink body according to the current embodiment is significantly reduced in size than that according to the related art, the LED lighting apparatus according to the current embodiment may be reduced in weight and cost. 
     The heat sink pin  400  may be disposed outside the heat sink body  300 . The heat sink pins  400  may be radially disposed along the circumference of the heat sink body  300 . Also,the heat sink pins  400  may be spaced a predetermined distance from each other on the outside of the heat sink body  300 . Each of the heat sink pins  400  may have a wing shape having an upper width greater than a lower width. 
     The heat sink fin  400  may have a length greater than that of the heat sink body  300  in a length direction to surround the outside of the socket part  200 . Thus, the heat sink body  300  may have a length less than about  ½  of that of the heat sink fin  400 . The heat sink fin  400  may be formed of the same material as the heat sink body  300 . Also, the heat sink fin  400  and the heat sink body  300  may be integrally manufactured through extrusion, die casting, or forging. Alternatively, the heat sink fin  400  may be additionally jointed to the heat sink body  300  after the heat sink body  300  is manufactured. A method of jointing the heat sink fin  400  to the heat sink body  300  may include a brazing, soldering, or welding method. 
     Although the heat sink fin  400  has the wing shape, the present disclosure is not limited thereto. For example, the heat sink fin  400  may have a polygonal or oval shape. Also, the heat sink fin  400  may be varied in thickness, height, and distance to improve the heat dissipation effect. 
     As described above, since the heat sink fin  400  has the wing shape with a wide width and is sufficiently elongated in length, the heat generated from the Led  100  may be sufficiently absorbed to improve heat dissipation performance. 
     Referring again to  FIG. 1 , protrusions  280  may be further disposed on the front end of the socket part  200  to effectively dissipate the heat generated in the power supply unit  260 . The protrusions  280  may be disposed at a certain distance on the front end of the socket part  200  and have various shapes. 
     Referring to  FIG. 4 , when the socket part  200  is coupled to the heat sink body  300 , the protrusions  280  may be disposed between the front end of the socket part  200  and an inner surface of the heat sink body  300  facing the front end of the socket part  200 . Thus, an air layer  500  may be formed between the front end of the socket part  200  and the inner surface of the heat sink body  300 . The air layer  500  may be a medium which can reduce a temperature of heat and effectively absorb heat generated from the power supply unit  260 . Also, the air layer  500  may effectively absorb heat generated from the LED  100  mounted on one side of the heat sink body  300  to maximize the heat dissipation effect. 
     That is, referring to  FIG. 5 , the heat H generated in the Led  100  may be absorbed into the air layer  500  formed between the socket part  200  and the heat sink body  300  to prevent the heat H from being transferred into the socket part  200 . 
     As described above, the heat H generated in the power supply unit  260  may be absorbed also into the air layer  500  formed between the socket part  200  and the heat sink body  300  to prevent the heat H from being transferred into the heat sink body  200 . 
     The air layer  200  may isolate the two heat sources from each other to minimize an effect due to the heats H therebetween, thereby maximizing the heat dissipation performance. 
     Although the protrusions  280  are disposed on both facing sides of the front end of the socket part  200 , the present disclosure is not limited thereto. For example, the protrusions  280  may be provided with a shape as shown in  FIGS. 6 and 7 . 
     Referring to  FIG. 6 , a protrusion  280  may be provided in plurality on the front end of the socket part  200 . The plurality of protrusions  280  may be spaced from each other on a concentric circle. 
     The protrusions  280  may minimize an area on which the socket part  200  and the heat sink body  300  contact each other when the socket part  200  and the heat sink body  300  are coupled to each other. Also, the socket part  200  may be stably supported on the heat sink body  300  by the protrusions  280 . 
     Here, each of the protrusions  280  may have a polygonal pillar having a triangular or pentagonal shape. Alternatively, each of the protrusions  280  may have a circular or oval pillar shape. 
     Referring to  FIG. 7 , a protrusion  280  may have a close loop shape on the front end of the socket part  200 , e.g., a ring shape. 
     The protrusion  280  may stably form an air layer therein when the socket part  200  and the heat sink body  300  are coupled to each other to prevent heat from be introduced into the air layer from the outside of the protrusion  280 . 
     Although the protrusion  280  has the ring shape, the present disclosure is not limited thereto. For example, the protrusion  280  may have a triangular or square shape defining a close loop. Although the protrusion  280  is disposed on the front end of the socket part  200 , the present disclosure is not limited thereto. For example, the protrusion  280  may be disposed on an inner surface of the heat sink body  300  facing the front end of the socket part  200 . 
     Also, although the protrusion  280  is disposed on one of the socket part  200  and the inner surface of the heat sink body  300 , the present disclosure is not limited thereto. For example, protrusions  280  may be disposed on all of the socket part  200  and the inner surface of the heat sink body  300 . 
     Also, when the protrusions  280  are disposed on all of the socket part  200  and the inner surface of the heat sink body  300 , the two protrusions may be modified in shape so that the two protrusions are coupled to each other. 
     Referring to  FIG. 8 , when a light stabilization state of the LED lighting apparatus according to the current embodiment is measured, it may be seen that an LED lighting apparatus A according to the current embodiment is stabilized faster by about 8% than that of an LED lighting apparatus B according to the related art. 
     Also, referring to  FIG. 9 , in the heat dissipation performance of the LED lighting apparatus according to the current embodiment, it may be seen that the LED of the LED lighting apparatus A according to the current embodiment has a temperature less by about 0.5° than that of the LED of the LED lighting apparatus B according to the related art to improve heat dissipation performance for all that the heat sink body is removed in shape. 
     As described above, the LED lighting apparatus according to the current embodiment may be modified in shape to reduce a weight and improve heat dissipation performance. 
     Also, the LED lighting apparatus according to the current embodiment may form the air layer  500  between the socket part  200  and the heat sink body  300  to simultaneously and effectively absorb the heat generated in the power supply unit  260  and the heat generated in the LED  100 . 
     It will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure. Thus, it is intended that the present disclosure covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.