Abstract:
A light-emitting diode (LED) lamp and a polygonal heat-dissipation structure thereof are provided. The LED lamp includes a polygonal heat-dissipation unit and a lighting module. The polygonal heat-dissipation unit has a polygonal hollow column and fins. The fins and the lighting module are thermally disposed on an inner surface and an outer surface of the polygonal hollow column, respectively. Thus, heat generated by the lighting module is dissipated by the fins rapidly. As the fins are thermally disposed on the inner surface of the polygon hollow column instead of being exposed, the volume of the LED lamp can be minimized, and the look of the LED lamp also can be prettified.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Technical Field 
         [0002]    The present invention relates to light-emitting diode (LED) lamps and polygonal heat-dissipation structures thereof. More particularly, the present invention relates to an LED lamp configured for illumination and a polygonal heat-dissipation structure thereof. 
         [0003]    2. Description of Related Art 
         [0004]    With such advantages as high brightness, power saving, and long service life, light-emitting diodes (LEDs) are becoming more widely used in various lighting equipment and more versatile, as LEDs nowadays function as a light source for use in street lamps, vehicle lighting, billboards, landscaping, etc. 
         [0005]    If heat generated by LEDs in operation is not efficiently dissipated, the quality of light emission by the LEDs will deteriorate, and the LEDs themselves will even be damaged and end up with a short service life. Hence, efficient heat dissipation is essential to quality light emission and a long service life as far as LEDs are concerned. 
         [0006]      FIG. 1  is a schematic view of a conventional LED lamp having a heat-dissipation device. As shown in  FIG. 1 , an LED  212  is thermally disposed on fins  120  so as for heat generated by the LED  212  to be dissipated. Generally, the fins  120  are large enough to maximize area of heat dissipation and thereby enhance heat dissipation. In addition, the fins  120  are exposed from the LED lamp to maximize area of contact between the fins  120  and air and thereby increase the efficiency of heat dissipation. 
         [0007]    However, the volume of the LED lamp is increased by the large and exposed fins  120 . If it is desired to install plural sets of fins  120  in the same LED lamp, any effort to reduce the volume of the LED lamp will prove futile. Also, the LED lamp is rendered unsightly by the fins  120  exposed therefrom, thus limiting the application of the LED lamp. 
       BRIEF SUMMARY OF THE INVENTION 
       [0008]    It is an objective of the present invention to provide a light-emitting diode (LED) lamp and a polygonal heat-dissipation structure thereof, wherein fins are disposed inside a polygonal hollow column rather than exposed from the LED lamp, thereby prettifying the look of the LED lamp. 
         [0009]    Another objective of the present invention is to provide an LED lamp and a polygonal heat-dissipation structure thereof, wherein fins are disposed on an inner surface of a polygonal hollow column, thereby making efficient use of the space inside the LED lamp and reducing the volume of the LED lamp. 
         [0010]    Yet another objective of the present invention is to provide an LED lamp and a polygonal heat-dissipation structure thereof, wherein openings are provided at two ends of a polygonal hollow column, respectively, to enable air circulation for removing heat quickly from fins provided inside the polygonal hollow column. 
         [0011]    A further objective of the present invention is to provide an LED lamp and a polygonal heat-dissipation structure thereof, wherein a reflecting element is placed in a light path of every LED, thereby allowing configuration of light emitted by the LED lamp to vary as needed by adjusting an angle of reflection of the reflecting element. 
         [0012]    To achieve the above and other objectives, the present invention provides an LED lamp including a polygonal heat-dissipation unit and a plurality of lighting modules. The polygonal heat-dissipation unit includes a polygonal hollow column and a plurality of fins, wherein the polygonal hollow column has two ends provided with a first opening and a second opening, respectively, and the polygonal hollow column further has an outer surface and an inner surface while the fins are thermally disposed on the inner surface of the polygonal hollow column. The lighting modules are disposed on the outer surface of the polygonal hollow column successively and each include: a light-emitting unit including a circuit board and a plurality of LEDs, the circuit board being thermally disposed on the outer surface of the polygonal hollow column, and the LEDs being electrically connected to and provided on the circuit board; a first reflecting element having a first reflecting surface placed in light paths of the LEDs of the light-emitting unit; and a second reflecting element having a second reflecting surface placed in a light path of light reflected off the first reflecting element. 
         [0013]    To achieve the above and other objectives, the present invention further provides a polygonal heat-dissipation structure for use with an LED lamp, wherein the polygonal heat-dissipation structure includes a polygonal hollow column and a plurality of fins. The polygonal hollow column has two ends provided with a first opening and a second opening, respectively. The polygonal hollow column further has an outer surface and an inner surface. The fins are thermally disposed on the inner surface of the polygonal hollow column. 
         [0014]    Implementation of the present invention at least brings about the following inventive effects: 
         [0015]    1. The look of an LED lamp is prettified by disposing fins inside the LED lamp; 
         [0016]    2. The volume of the LED lamp is reduced by disposing the fins on an inner surface of a polygonal hollow column; and 
         [0017]    3. The configuration of light emitted by the LED lamp can be varied by means of reflecting elements provided on the polygonal hollow column, so as to broaden application of the LED lamp. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0018]    The invention as well as a preferred mode of use, further objectives, and advantages thereof will be best understood by referring to the following detailed description of illustrative embodiments in conjunction with the accompanying drawings, wherein: 
           [0019]      FIG. 1  is a schematic view of a conventional LED lamp having a heat-dissipation device; 
           [0020]      FIG. 2  is an exploded perspective view of an embodiment of an LED lamp according to the present invention; 
           [0021]      FIG. 3  is a perspective view of the embodiment of the LED lamp shown in  FIG. 2  when assembled; 
           [0022]      FIG. 4A  is a cross-sectional view of a first reflecting element according to the present invention; 
           [0023]      FIG. 4B  is a cross-sectional view of a second reflecting element according to the present invention; 
           [0024]      FIG. 4C  is a cross-sectional view of a third reflecting element according to the present invention; 
           [0025]      FIG. 5  is a cross-sectional view taken along line A-A of  FIG. 3 ; 
           [0026]      FIG. 6  is an exploded perspective view of another embodiment of the LED lamp according to the present invention; 
           [0027]      FIG. 7  is a perspective view of yet another embodiment of the LED lamp according to the present invention; and 
           [0028]      FIG. 8  is a perspective view of still another embodiment of the LED lamp according to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0029]    Referring to  FIG. 2 , in an embodiment, a light-emitting diode (LED) lamp of the present invention includes a polygonal heat-dissipation unit  100  and a plurality of lighting modules  200 . 
         [0030]    Referring to  FIG. 2  and  FIG. 3 , the polygonal heat-dissipation unit  100  includes a polygonal hollow column  110  and a plurality of fins  120 . A first opening  111  and a second opening  112  are provided at two ends of the polygonal hollow column  110 , respectively. Hence, the first opening  111  and the second opening  112  communicate with each other to enable air circulation. The polygonal hollow column  110  further has an outer surface  113  and an inner surface  114 . The fins  120  are thermally disposed on the inner surface  114  of the polygonal hollow column  110 . The polygonal hollow column  110  and the fins  120  together form a one-piece unit. 
         [0031]    With the polygonal heat-dissipation unit  100  being conducive to air circulation, the fins  120  thermally disposed on the inner surface  114  of the polygonal hollow column  110  remove heat quickly by means of air so as to speed up heat dissipation. In addition, with the fins  120  being thermally disposed on the inner surface  114  of the polygonal hollow column  110 , the volume of the LED lamp can be minimized. 
         [0032]    Referring to  FIG. 2  and  FIG. 3 , the lighting modules  200  are disposed on the outer surface  113  of the polygonal hollow column  110  successively. Each of the lighting modules  200  includes a light-emitting unit  210 , a first reflecting element  220 , and a second reflecting element  230 , wherein the light-emitting unit  210 , the first reflecting element  220 , and the second reflecting element  230  are each screwed to the outer surface  113  of the polygonal hollow column  110  by at least two screws  30 . 
         [0033]    Referring to  FIG. 2  and  FIG. 3 , the light-emitting unit  210  includes a circuit board  211  and a plurality of LEDs  212 . The circuit board  211  is thermally disposed on the outer surface  113  of the polygonal hollow column  110 ; hence, heat generated by the circuit board  211  is transferred to the fins  120  thermally disposed on the inner surface  114  of the polygonal hollow column  110  via the polygonal hollow column  110  (as shown more clearly in  FIG. 5 ). 
         [0034]    With the LEDs  212  being electrically connected to and provided on the circuit board  211 , heat generated by the LEDs  212  is transferred to the fins  120  via the circuit board  211  and thereby dissipated. With air circulating inside the polygonal hollow column  110 , the heat transferred to the fins  120  is quickly removed by air. Hence, the LEDs  212  operate at appropriate temperature, and the quality of light emission is enhanced. 
         [0035]    To allow heat generated by the LEDs  212  during light emission to be quickly transferred to the inner surface  114  of the polygonal hollow column  110  via the circuit board  211 , the circuit board  211  is made of a material having high thermal conductivity, such as a copper circuit substrate, an aluminum circuit substrate, or a graphite circuit substrate. 
         [0036]    Referring to  FIG. 2  and  FIG. 3 , the first reflecting element  220  of each of the lighting modules  200  has a first reflecting surface  221 , and the first reflecting surface  221  is placed in light paths of corresponding ones of the LEDs  212  (as shown more clearly in  FIG. 5 ). The second reflecting element  230  of each of the lighting modules  200  has a second reflecting surface  231 , and the second reflecting surface  231  is placed in a light path of light reflected off a corresponding one of the first reflecting elements  220 ; in other words, in every occurrence of light emission of the LEDs  212 , the emitted light is reflected off the corresponding first reflecting surface  221  and the corresponding second reflecting surface  231  in sequence (as shown in  FIG. 5 ). Hence, by adjusting an angle of reflection of the first reflecting element  220  and the second reflecting element  230 , the outgoing direction of light from the LEDs  212  is varied, and the configuration of light emitted by the LED lamp is varied accordingly. 
         [0037]    Referring to  FIG. 4A , the first reflecting element  220  of each of the lighting modules  200  is formed by bending a plate to provide a first plate  222 , a first connecting plate  223 , and a first oblique plate  224 . The first plate  222  has at least two first through-holes  225  for penetration by the screws  30 . The first reflecting element  220  is fixed in position to the outer surface  113  of the polygonal hollow column  110  by passing the screws  30  through the first through-holes  225  (as shown in  FIG. 2 ). The first oblique plate  224  has the first reflecting surface  221 . The first reflecting surface  221  of the first oblique plate  224  is placed in light paths of corresponding ones of the LEDs  212  so as for light emitted by the corresponding ones of the LEDs  212  to be reflected by the first reflecting surface  221 . 
         [0038]    Referring to  FIG. 4B , the second reflecting element  230  of each of the lighting modules  200  is also formed by bending a plate to provide a second oblique plate  232 , a second connecting plate  233 , and a second plate  234 . The second plate  234  has at least two second through-holes  235  for penetration by the screws  30 . The second reflecting element  230  is fixed in position to the outer surface  113  of the polygonal hollow column  110  by passing the screws  30  through the second through-holes  235  (as shown in  FIG. 2 ). The second oblique plate  232  has the second reflecting surface  231 . The second reflecting surface  231  of the second oblique plate  232  is placed in a light path of light reflected from the corresponding first oblique plate  224  so as to reflect light reflected off the corresponding first reflecting surface  221  (as shown in  FIG. 5 ). 
         [0039]    Referring to  FIG. 2 , the second reflecting element  230  and the first reflecting element  220  between each two adjacent ones of the lighting modules  200  are integrally formed as a third reflecting element  240 . Referring to  FIG. 4C , the third reflecting element  240  is also formed by bending a plate to provide the second oblique plate  232 , the second connecting plate  233 , the second plate  234 , the first connecting plate  223 , and the first oblique plate  224 . The second plate  234  has at least two third through-holes  241  for penetration by the screws  30 . The third reflecting element  240  is fixed in position to the outer surface  113  of the polygonal hollow column  110  by passing the screws  30  through the third through-holes  241  (as shown in  FIG. 2 ). 
         [0040]    Referring to  FIG. 6 , the LED lamp further includes a cover plate  40 . The cover plate  40  corresponds in position to the first opening  111  of the polygonal hollow column  110  so as to render the LED lamp visually appealing. The cover plate  40  has a first aperture  41  in communication with the first opening  111 . 
         [0041]    Referring to  FIG. 6 , the LED lamp further includes a supporting plate  50 . The supporting plate  50  corresponds in position to the second opening  112  of the polygonal hollow column  110 . The supporting plate  50  has a second aperture  51  in communication with the second opening  112 . Hence, air circulates through the polygonal hollow column  110  by means of the second aperture  51  of the supporting plate  50  and the first aperture  41  of the cover plate  40 . 
         [0042]    Referring to  FIG. 6 , the LED lamp further includes a lamp stand  60  and at least a supporting element  70 . The lamp stand  60  is provided with a power terminal  61 . The lamp stand  60  is provided with a power unit  62  therein. The power unit  62  is electrically connected to the power terminal  61  and to the circuit board  211  of each of the light-emitting units  210  so as to convert alternating current (AC) to direct current (DC) for driving the LEDs  212  of each of the light-emitting units  210 . Hence, the LED lamp can be directly connected to a power terminal of a lamp stand for access to AC power. The power terminal  61  is an E27 power terminal or an E40 power terminal so as for the LED lamp to be applicable to a household electric appliance, such as a desk lamp, a wall lamp, and so on. 
         [0043]    Referring to  FIG. 6 , each of the at least a supporting element  70  has a first end portion  71  and a second end portion  72 . The first end portion  71  is coupled to the lamp stand  60 . The second end portion  72  is coupled to the supporting plate  50  of the LED lamp. The at least a supporting element  70  is positioned proximate to the second opening  112  of the polygonal hollow column  110 . The at least a supporting element  70  spaces apart the lamp stand  60  and the supporting plate  50  so as for air to pass through the second aperture  51  of the supporting plate  50  to enable air circulation. 
         [0044]    Referring to  FIG. 8 , the first end portion  71  of each of the at least a supporting element  70  is directly coupled to the lamp stand  60  while the second end portion  72  of each of the at least a supporting element  70  is coupled to the polygonal hollow column  110  itself. Likewise, the at least a supporting element  70  is positioned proximate to the second opening  112  of the polygonal hollow column  110 . 
         [0045]    Referring to  FIG. 7 , the LED lamp further includes a lampshade  80 . Two ends of the lampshade  80  are coupled to the cover plate  40  and the supporting plate  50 , respectively, such that the polygonal heat-dissipation unit  100  is enclosed by the lampshade  80  and protected from inadvertent impact and moisture. 
         [0046]    Referring to  FIG. 8 , alternatively, the lampshade  80  is coupled to the lamp stand  60 , and a plurality of slits  81  are formed at the lamp-stand-coupled end of the lampshade  80 . Thus, air passes through the slits  81  and the second opening  112  of the polygonal hollow column  110  to facilitate air circulation in the polygonal hollow column  110 . 
         [0047]    The foregoing preferred embodiments are illustrative of the characteristics of the present invention so as to enable a person skilled in the art to gain insight into the disclosure of the present invention and be capable of implementing the present invention accordingly, but are not intended to restrict the scope of the present invention. Hence, all equivalent modifications and variations made in the foregoing preferred embodiments without departing from the spirit and principle of the present invention should fall within the scope of the appended claims.