Patent Publication Number: US-8523400-B2

Title: Light-emitting diode streetlight structure

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to a streetlight structure, and particularly to a light-emitting diode (LED) streetlight structure with excellent heat-dissipation and lighting performance. 
     BACKGROUND OF THE INVENTION 
     LEDs are diodes capable of emitting light when forward biased. They are light-emitting devices manufactured by semiconductor materials mostly including III-V chemical elements, such as gallium phosphide or gallium arsenide in the early days and aluminum-gallium-indium phosphide or gallium-indium nitride for high-brightness LEDs at present day. The light-emitting principle is to apply a current to the compound semiconductor. Then part of the energy will be released in the form of light via recombination of electrons and holes and thus achieving light-emitting effect. 
     Because the used materials are different, the energy levels of electrons and holes in LEDs differ. When the electrons and holes recombine, the released photons will hence have different energies, resulting in light with different wavelengths, which are light with different colors such as red, orange, yellow, green, blue, or invisible light. 
     Different from earlier light sources, LEDs are luminescent with low power consumption, long lifetime, no warm-up time, fast response, and small size. Besides, they are vibration tolerant, suitable for mass production, and easy to be manufactured extremely small or in arrays according to requirements of applications. Currently, LEDs are widely applied to indicators and displays of information, communication, and consumer electronic products, and thereby they have become indispensable important devices in daily lives. 
     As the LED technology becomes increasingly mature, its application areas are becoming wider. In the residence area, the applications include wall lamps, night lamps (the requirement in brightness for this application is not high, and thereby is the earliest application of LEDs), auxiliary lighting, garden lamps, and reading lamps. In the equipment area, the applications include emergency indicators and hospital bed lamps. In the store area, their applications include spotlights, embedded lamps, barrel lamps, and light bars. In the outdoor applications, LEDs can be used to decorate the appearance of buildings and used in solar-energy lamps. In addition, they can also applied to light shows. 
     The lighting market is long considered as the greatest and potential market of LEDs, even though no major lighting product is proposed owing to cost and performance limitations. However, it is undeniable that LED technology has been developing rapidly in recent years, making it to occupy some market in the special light market, such as the niche markets of freezer lighting, aviation lamps, or traffic lights). In the general lighting market, including barrel lamps, embedded lamps, spotlights, and landscape lighting products, some products start to replace traditional light sources such as halogen lamps or incandescent lamps. 
     At present, a heat dissipating structure is disposed below the LED module in an LED streetlight. It is because LEDs generate a huge amount of heat. If no heat dissipating structure is disposed, the lifetime of the LED module can be very possibly reduced owing to overheating. Besides, the lifetime of the power supply of the LED streetlight can be also substantially reduced caused by long-term overheating applications, and hence leading to frequent replacement of power supplies. Moreover, the lighting angle and direction of current LED streetlight are fixed, and therefore they cannot be adjusted according to the environment during installation. 
     Accordingly, the present invention provides an LED streetlight structure, which has a heat dissipating structure at the power supply and has a angle adjusting structure for the lamppost for improving heat dissipation of the power supply and changing the lighting angle and direction of the LED streetlight structure. 
     SUMMARY 
     An objective of the present invention is to provide an LED streetlight structure. According to the present invention, the housing contacting the power supply has a heat dissipating structure, which can dissipate the heat generated by the power supply and reduce the temperature thereof. Accordingly, heat dissipation of the power supply is enhanced, and hence increasing its lifetime. 
     Another objective of the present invention is to provide an LED streetlight structure having an angle adjusting structure. By means of the angle adjusting structure, the angle of a lamppost can be adjusted for changing the lighting angle and direction of the light emitted by the LED streetlight structure, and hence achieving an ideal lighting performance. 
     For achieving the objective described above, the present invention provides an LED streetlight structure comprising a light-emitting module, a power module, and a lamppost. The light-emitting module comprises at least a light-emitting apparatus and a heat-dissipating base, wherein the light-dissipating base is disposed in the heat-dissipating base. The power module is disposed on one side of the light-emitting module, and comprises a first housing, a second housing, a power supply, and a driving circuit board. The driving circuit board is disposed in the first housing; the power supply is disposed in the second housing. The driving circuit board connects to the power supply. The second housing is disposed in the first housing. The light-emitting apparatus connects to the driving circuit board. A heat-dissipating part is disposed on the surface of the second housing. The heat-dissipating part corresponds to the power supply and has a plurality of heat-dissipating fins. The lamppost is disposed on one side of the power module and corresponds to the light-emitting module. 
     The present invention also provides an LED streetlight structure comprising a light-emitting module, a power module, and a lamppost. The light-emitting module comprises at least a light-emitting apparatus and a heat-dissipating base, wherein the light-dissipating base is disposed in the heat-dissipating base. The power module is disposed on one side of the light-emitting module, and comprises a first housing, a second housing, a power supply, and a driving circuit board. The driving circuit board is disposed in the first housing; the power supply is disposed in the second housing. The driving circuit board connects to the power supply. The second housing is disposed in the first housing. The light-emitting apparatus connects to the driving circuit board. A heat-dissipating part is disposed on the surface of the second housing. The lamppost is disposed on one side of the power module and corresponds to the light-emitting module. An angle adjusting structure is disposed in the first housing of the power module. The lamppost is disposed slidably on the angle adjusting structure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a three-dimensional view of the LED streetlight structure according to a preferred embodiment of the present invention; 
         FIG. 2  shows an exploded view of the LED streetlight structure according to a preferred embodiment of the present invention; 
         FIG. 3  shows an exploded view of the light-emitting apparatus according to a preferred embodiment of the present invention; 
         FIG. 4  shows an exploded view of the power module according to another preferred embodiment of the present invention; and 
         FIG. 5  shows an exploded view of the power module and the lamppost according to another preferred embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     In order to make the structure and characteristics as well as the effectiveness of the present invention to be further understood and recognized, the detailed description of the present invention is provided as follows along with embodiments and accompanying figures. 
       FIG. 1  shows a three-dimensional view of the LED streetlight structure according to a preferred embodiment of the present invention. As shown in the figure, the present invention provides an LED streetlight structure  1 , which comprises a power module  10 , a light-emitting module  12 , and a lamppost  14 . The light-emitting module  12  is disposed on one side of the power module  10 . The lamppost is disposed on the other side of the power module  10  and corresponds to the light-emitting module  12 .  FIG. 2  shows an exploded view of the LED streetlight structure according to a preferred embodiment of the present invention. As shown in the figure, the power module  10  comprises a first housing  101 , a second housing  103 , a power supply  105 , and a driving circuit board  107 . The power supply  105  is disposed in the second housing  103 ; the driving circuit board  107  is disposed in the first housing  101 . The power supply  105  described above can be fixed in the second housing  103  using fasteners; the driving circuit board  107  can also be fixed in the first housing  101  using fasteners. When the power supply  105  and the driving circuit board  107  of the power module are damaged, it is only necessary to disassemble and replace the power supply  105  and the driving circuit board  107  without replacing the whole power module  10 . 
     The power supply  105  connects to the driving circuit board  107 , which, in turn, connects to the light-emitting module  12 . The second housing  103  having the power supply  105  is disposed in the first housing  101  having the driving circuit board  107 . In order to avoid moisture from entering the power module  10 , the power module  10  according to the present embodiment further comprises a washer  108  disposed between the first and the second housings  101 ,  103  for increasing closeness therebetween. 
     A heat-dissipating part  1032  is disposed on the outer surface of the second housing  103 . The heat-dissipating part  1032  is composed by a plurality of heat-dissipating fins  10321 . Besides, the heat-dissipating part  1032  corresponds to the power supply  105 . When the power supply  105  is used for a long time, it will generate heat. The heat-dissipating part  1032  can dissipate the heat generated by the power supply  105  effectively and lowering the temperature of the power supply  105 , and hence increasing the lifetime of the power supply  105 . A general LED streetlight does not have the heat-dissipating part disposed at the location of the power supply, and thereby overheating phenomenon occurs when the power supply is used form long time, which will shorten the lifetime of the power supply. The LED streetlight structure  1  according to the present invention has improved the problem described above. 
       FIG. 3  shows an exploded view of the light-emitting apparatus according to a preferred embodiment of the present invention. As shown in the figure, the light-emitting module  12  comprises at least a light-emitting apparatus  121  and a heat-dissipating base  123 . The light-emitting apparatus  121  is disposed on the heat-dissipating base  123 . The light-emitting apparatus  121  includes a base  1211 , a circuit board  1212 , a plurality of LEDs  1213 , a plurality of lenses  1214 , two lens frames  1215 , a frame  1216 , and a glass sheet  1217 . The heat-dissipating base  123  includes a heat-dissipating body  1231  and a heat-dissipating cover  1233 . 
     The circuit board  1212  is disposed on the base  1211  and connects with the driving circuit board  107  of the power module  10 . There is a first positioning hole  12121  at the center of the circuit board  1212 . The heat-dissipating body  1231  has a first fixing hole  12311 , which corresponds to the first positioning hole of the circuit  1212 . Then, a fixing member  11  (not shown in the figure) is used for passing through the first positioning hole  12121  of the circuit board  1212 . The fixing member  11  is fastened to the first fixing hole  12311  of the heat-dissipating body  1231 . Thereby, the circuit board  1212  is fixed on the heat-dissipating body  1231 . 
     The plurality of LEDs  1213  are disposed on the circuit board  1212  and connect electrically to a plurality of contacts (not shown in the figure). The plurality of lenses  1214  are disposed on the corresponding LEDs  1213 , respectively. The two lens frames  1214  have a plurality of bores  12151 , which are arranged according to the locations of the plurality of LEDs  123  having the plurality of lenses  1214 . Each bore  12151  corresponds to an LED  1213  among the plurality of LEDs  1213 . Each of the two lens frames  1215  has a positioning hole  12153 , respectively. The circuit board  1212  has two first holes  12123  corresponding to the two positioning holes  12153 . The heat-dissipating body  1231  has two second fixing holes  12313  corresponding to the two first holes  12123  of the circuit board  1212 . Two fixing members (not shown in the figure) pass through the two positioning holes  12143  corresponding to the two lens frames  1214  and the two first holes  12123  of the circuit board  1212 . The two fixing members are fastened to the two second fixing holes  12313  corresponding to the heat-dissipating body  1231 . Hence, the positions of the two lens frames  1215  can be fixed. 
     The frame  1216  is fixed on the heat-dissipating body  1231  and accommodates the base  1211 , the circuit board  1212 , the plurality of LEDs  1213 , the plurality of lenses  1214 , and the two lens frames  1215 . At least a sliding block  12161  is disposed on each sides of the frame  1216 . A sliding trench  12315  is disposed on each side of the heat-dissipating body  1231 . The plurality of sliding blocks  12161  on both sides of the frame  1216  slide into the corresponding sliding trenches  12315 , respectively. The frame  1216  moves to the location above the base  1211 , the circuit board  1212 , the plurality of LEDs  1213 , the plurality of lenses  1214 , and the two lens frames  1215 . A plurality of positioning holes  12163  are disposed on the periphery of the frame  1216 ; a plurality of holes  12111  are disposed on the periphery of the base  1211 . The plurality of holes  12111  correspond to the plurality of positioning holes  12163 . The heat-dissipating body  1231  has a plurality of third positioning holes  12317  corresponding to the plurality of holes  12111  of the base  1211 . The plurality of fixing members  11  are fastened to the corresponding plurality of third fixing holes  12317  of the heat-dissipating body  1231 , and hence fixing the position of the frame  1216 . 
     The frame  1216  has an opening  12165 , and the glass sheet  1217  is disposed at the opening  12165  of the frame  1216 . For avoiding the glass sheet  1217  from escaping the opening  12165  of the frame  1216 , the light-emitting apparatus  121  according to the present invention further has four pressure plates  1218  disposed at the four sides of the opening  12165  of the frame  1216 . When the glass sheet  1217  is disposed at the opening  12165  of the frame  1216 , the four pressure plates  1218  press the glass sheet  1217  and securing the frame  1216 . Thereby, the glass sheet  1217  can be fixed, avoiding it from escaping the opening  12165  of the frame  1216 . In the following, how the four pressure plates  1218  are fixed on the frame  1216  is described. Each pressure  1218  has a positioning hole  12181 . A fixing hole  12167  is disposed on each side of the opening  12165  of the frame  1216 . Then, four positioning members  11  are used for passing through the positioning hole  12181  of the pressure plate  1218  and fastened at the corresponding fixing hole  12167  of the frame  1216 . Accordingly, the four pressure plates  1218  are secured on the frame  1216 . 
     In order to prevent exterior moisture from entering the light-emitting apparatus  121 , au/usher  1219  is further disposed between the glass sheet  1217  and the opening  12165  of the frame  1216  for increasing closeness therebetween and thus preventing exterior moisture from entering the light-emitting apparatus  121 . 
     The heat-dissipating body  1231  of the heat-dissipating base  123  has a plurality of heat-dissipating fins  12319 . By taking advantage of the large areas of the plurality of heat-dissipating fins  12319  for increasing heat-dissipating areas, the heat generated by the light-emitting apparatus  121  can be dissipated, and hence the temperature of the light-emitting apparatus  12  and enhancing the lifetime and light-emitting efficiency of the light-emitting apparatus  121 . 
     The heat-dissipating cover  1233  of the heat-dissipating base  123  is disposed at on end of the heat-dissipating body  1231  and corresponds to the power module  10 . The heat-dissipating cover  1233  has a plurality of positioning holes  12331 . The heat-dissipating body  1231  also has a plurality of fourth fixing holes (not shown in the figure) at one end. The plurality of fourth fixing holes correspond to the plurality of positioning holes  12331  of the heat-dissipating cover  1233 . Then pass the plurality of fixing members  11  through the corresponding the plurality of positioning holes  12331  of the heat-dissipating cover  1233  and fasten them to the plurality of fourth fixing holes of the heat-dissipating body  1231 . The heat-dissipating cover  1233  also has a plurality of heat-dissipating holes  12333  for improving heat dissipation of the heat-dissipating base  123  effectively. 
     Refer again to  FIGS. 1 to 3 . The power module  10  is disposed on one side of the light-emitting module  12 . The connection between the power module  10  and the light-emitting module  12  is described as follows. The first housing  101  of the power module  10  has a plurality of positioning holes  1013  on the surface adjacent to the light-emitting module  12 . The heat-dissipating body  1231  of the light-emitting module has a plurality of fifth fixing holes  12314  on the surface adjacent to the power module  10 . A plurality of fixing members (not shown in the figure) pass through the corresponding plurality of positioning holes  1013  of the first housing  101  of the power module  10  and are fastened to the corresponding plurality of fifth fixing holes  12314  of the heat-dissipating body  1231  of the light-emitting module  12 . When the power module  10  or the light-emitting module is damaged, only the power module  10  or the light-emitting module has to be replaced, not necessary to replace the whole LED streetlight structure  1 . 
     The lamppost  14  is disposed on the other side of the power module  10  and corresponds to the light-emitting module  12 . The first housing  101  of the power module  10  has an assembly cavity  1017 ; the lamppost  14  is disposed in the assembly cavity  1017 . The power module  10  further includes a limiter  109 , which is sawtooth-shaped and located on the lamppost  14 , and is fixed in the assembly cavity  1017  of the first housing  101 . A positioning hole  1091  is disposed on each of the both ends of the limiter  109 , respectively. Two fixing holes  10171  are disposed in the assembly cavity  1017  and correspond to the two positioning holes  1091  of the limiter  109 . The two fixing members  11  pass through the corresponding two positioning holes  1091  of the limiter  109 , and are fastened to the corresponding two fixing holes  10171  of the assembly cavity  1017 . Thereby, the limiter  109  is secured in the assembly cavity  1017  and is located on the lamppost  14 . The limiter  109  limits the lamppost  14  in the assembly cavity  1017  of the first housing  101 . 
       FIG. 4  shows an exploded view of the power module according to another preferred embodiment of the present invention. According to the embodiment described above, the power module  10  of the power module  10  is disposed on the first housing  101 . The present embodiment further discloses that the second housing  103  can be lifted using one side of the first housing  101  as the pivot and can be disassembled from the first housing  101  for easy replacement of the power supply  105  disposed in the housing  103  in the future. The first housing  101  has at least a hook member  1015  on the side away from the light-emitting module  12 ; the second housing  103  has at least a buckle member  1033  on the side away from the light-emitting module  12 . The plurality of buckle members  1033  of the second housing  103  are hooked by the corresponding plurality of hook members  1015  of the first housing  101 . Thereby, the number of components for securing the first and second housings  101 ,  103  is reduced. 
     When repairing and maintaining the power supply  105  of the power module  105 , one only needs to lift the second housing  103  and disassemble the second housing  103  having the power supply  105  from the first housing  101  for repairing and maintaining the power supply  105  and the driving circuit board  107  in the power module  10 . While lifting the second housing  103 , the plurality of buckle members  1033  of the second housing  103  rotate in the corresponding plurality of hook members  1015  for lifting the second housing  103 . Then the plurality of buckle members  1033  of the second housing  103  is forced to escape from the plurality of hook members  1015  of the first housing  101  for easy repair of the power supply  105  disposed in the second housing  103 . After repair, assemble the second housing  103  to the first housing  101 . Thereby, no high-up-in-the-air repair is required, and hence reducing danger in repairing. 
       FIG. 5  shows an exploded view of the power module and the lamppost according to another preferred embodiment of the present invention. As shown in the figure, the difference between the present embodiment and the previous one is that the LED streetlight structure  1  according to the present embodiment can change the lighting angle and direction of the light emitting by the light-emitting module  12  by adjusting the angle of the lamppost  14 . The assembly cavity  1017  in the first housing  101  of the power module  10  according to the present embodiment has an angle adjusting structure  10173 , which is sawtooth-shaped. The lamppost  14  is disposed in the assembly cavity  1017 ; the lamppost  14  is slidably disposed on the angle adjusting structure  10173 . By adjusting the angle of the lamppost  14  via the angle adjusting structure  10173 , the lighting angle and direction of the light emitted by the light-emitting module  12  can be adjusted correspondingly. 
     The present invention provides an LED streetlight structure. The power module of the LED streetlight structure according to the present invention has the heat-dissipating part composed of the plurality of heat-dissipating fins. The heat-dissipating part dissipates the heat generated by the power supply in the power module, and hence enhancing heat dissipation of the power module and lifetime of the power supply. 
     The power module of the LED streetlight structure according to the present invention has the first and second housings. The second housing can be lifted and disassembled for easily repairing the power supply disposed in the second housing. After repair, assemble the second housing to the first housing. Thereby, no high-up-in-the-air repair is required, and hence reducing danger in repairing. 
     The power module of the LED streetlight structure according to the present invention has the angle adjusting structure. By adjusting the angle of the lamppost via the angle adjusting structure, the lighting angle and direction of the light emitted by the light-emitting module can be adjusted correspondingly, and hence achieving an ideal lighting performance. 
     Accordingly, the present invention conforms to the legal requirements owing to its novelty, nonobviousness, and utility. However, the foregoing description is only embodiments of the present invention, not used to limit the scope and range of the present invention. Those equivalent changes or modifications made according to the shape, structure, feature, or spirit described in the claims of the present invention are included in the appended claims of the present invention.