Patent Publication Number: US-2012044680-A1

Title: Illuminating device with light emitting diodes

Description:
RELATED APPLICATIONS 
     This application claims priority to Taiwan Application Serial Number 099127765, filed Aug. 19, 2010, which is herein incorporated by reference. 
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to an illuminating device, more particularly to an illuminating device with light emitting diodes. 
     2. Description of Related Art 
     In daily life, illuminating apparatuses are necessarily important tools for people. Light bulbs or lamps of illuminating apparatuses are used as main light sources nowadays. Because these Light bulbs or lamps would consume more electric power when working, such as fluorescent lamps, incandescent bulbs, halogen lamps, or halogen bulbs, light sources mentioned above are replaced with modules made of light emitting diodes gradually in the present day for energy saving and carbon reduction. 
     However, light emitting diode modules would also generate thermal energy when lightening, so that generated thermal energy would be constantly accumulated for a long illuminating time. Finally, light emitting diode modules would have some problems about deterioration and illumination decay due to the accumulated thermal energy. 
     Generally speaking, a light emitting diode module is disposed in a light emitting diode housing (so-called MR16) so as to be protected by the light emitting diode housing. However, the light emitting diode housing cannot dissipate the thermal energy generated from the light emitting diode module efficiently. Therefore, the heat dissipation efficiency of the light emitting diode housing is insufficient. As such, the thermal energy would be constantly accumulated on the light emitting diode module to cause some chip deterioration problems. In addition, when the heat dissipation efficiency of the light emitting diode housing is insufficient, circuits formed on a substrate may be affected, such as short circuits or burned circuits because of the inadequate heat dissipation rate. 
     For these reasons, how to develop an illuminating device capable of solving the mentioned problems and disadvantages becomes a goal for the related industries to achieve. 
     SUMMARY 
     One object of the present invention is to provide an illuminating device with light emitting diodes capable of enhancing heat dissipation efficiency by increasing a heat dissipation area of the light emitting diodes. 
     Another object of the present invention is to provide an illuminating device with light emitting diodes capable of enhancing heat exchange rate rapidly by increasing air convection passages. 
     An illuminating device of the present invention includes a rear housing, a front housing, and an illuminating module. The rear housing includes a first cavity therein. The front housing is disposed in the first cavity and includes a second cavity and a plurality of through holes therein, wherein the through holes communicate with the second cavity. The illuminating module is sandwiched between the rear housing and the front housing. The illuminating module includes a substrate and light emitting diodes. The substrate includes a first surface and a second surface opposite to the first surface, wherein the first surface is in contact with the rear housing directly, and the second surface is in contact with the front housing directly. The light emitting diodes are arranged on the second surface of the substrate in an array arrangement and extending toward the second cavity via the through holes one-to-one. 
     In an embodiment of the present invention, the substrate is a printed circuit board or a metal board. 
     In another embodiment of the present invention, the illuminating device further includes a power-connecting portion, wherein the power-connecting portion is disposed, on a surface of the rear housing opposite to the front housing. 
     In an embodiment of the present invention, the rear housing includes first air holes, and the first air holes communicate with the first cavity of the rear housing and outside air. 
     In an embodiment of the present invention, the front housing further includes second air holes, and the second air holes communicate with the second cavity of the front housing and the first cavity of the rear housing. 
     In a variation of the embodiment of the present invention, the second air holes are disposed on a sidewall of the front housing. In another variation of the embodiment of the present invention, the front housing includes an opening, wherein an edge of the opening includes a ring-shaped flange extending outward, and the second air holes are disposed on the ring-shaped flange. 
     In an embodiment of the present invention, an interior wall of a sidewall of the front housing surrounding the second cavity includes a reflecting layer. 
     In another embodiment of the present invention, a surface of the rear housing in contact with the first surface of the substrate includes a first insulating layer, and a surface of the front housing in contact with the second surface of the substrate includes a second insulating layer. 
     In another embodiment of the present invention, a surface of the rear housing or the front housing includes a heat dissipation layer. 
     The illuminating device with light emitting diodes of the present invention increases an area in contact with the light emitting diodes to highly reduce working temperature of the light emitting diodes, thereby decreasing the failure probability of the light emitting diodes. Furthermore, the illuminating device with the light emitting diodes of the present invention improves the condition of air convection so as to enhance the heat exchange rate. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a perspective exploded view in a direction of an illuminating device with light emitting diodes of an embodiment of the present invention. 
         FIG. 1B  is a perspective exploded view in another direction of the illuminating device with light emitting diodes of the embodiment of the present invention. 
         FIG. 2  is a perspective view of a combination of the illuminating device with light emitting diodes of the embodiment of the present invention. 
         FIG. 3  is a front schematic view of the illuminating device with light emitting diodes of the embodiment of the present invention. 
         FIG. 4  is a cross-sectional view taken along line  4 - 4  of  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are schematically shown in order to simplify the drawings. 
     An illuminating device with light emitting diodes is provided in the present disclosure. The illuminating device includes a rear housing, a front housing, and an illuminating module. The front housing includes through holes. The illuminating module is sandwiched between the rear housing and the front housing. The illuminating device includes light emitting diodes extending through the through holes in a one-to-one relationship. 
     As such, due to the illuminating module sandwiched between the front housing and the rear housing, the thermal energy generated from the working illuminating module can be transmitted away from the illuminating module by the front housing and the rear housing. Thus, the present disclosure increases the heat dissipation area Of the illuminating module to highly reduce the working temperature of the light emitting diodes, thereby decreasing the failure probability of the light emitting diodes caused by high temperature. 
       FIG. 1A  is a perspective exploded view in a direction of an illuminating device with light emitting diodes of an embodiment of the present invention.  FIG. 1B  is a perspective exploded view in another direction of the illuminating device with light emitting diodes of the embodiment of the present invention.  FIG. 2  is a perspective view of a combination of the illuminating device with light emitting diodes of the embodiment of the present invention. 
     As shown in  FIG. 1A ,  FIG. 1B , and  FIG. 2 , in an embodiment of the present invention, an illuminating device  100  includes a rear housing  200 , a front housing  300 , an illuminating module  400 , and a power-connecting portion  500 . 
     The rear housing  200  has a cup or a bowl appearance. An opening first cavity  210  is defined by a sidewall surrounding the rear housing  200 . A bottom surface of the rear housing  200  corresponding to the first cavity  210  includes a protruding portion  220 . The protruding portion  220  extends into the first cavity  210 . A surface of the protruding portion  220  disposed in the first cavity  210  is an assembling surface  230  for the illuminating module  400  disposed thereon. In addition, a first concave  240  (shown in  FIG. 1  B) is formed on a side of the protruding portion  220  facing away from the front housing  300  for the power-connecting portion  500  disposed therein. 
     As shown in  FIG. 1A , the front housing  300  with a cup or a bowl appearance is fixed in the first cavity  210 . A second cavity  320  is defined by a sidewall surrounding the front housing  300 . An interior wall of a sidewall of the front housing  300  surrounding the second cavity  320  includes a reflecting layer  330 . The reflecting layer  330  can provide better illuminating efficiency. These through holes  310  are formed in an array arrangement on a bottom part of the front housing  300  corresponding to the second cavity  320 . A second concave  380  (shown in  FIG. 1  B) is formed on a surface of the bottom part of the front housing  300  facing the rear housing  200  and facing away from the second cavity  320 . The second concave  380  communicates with every through hole  310 . 
     The power-connecting portion  500  is disposed on a surface of the rear housing  200  facing away from the front housing  300 . The power-connecting portion  500  includes a bottom portion  510  and a power supply unit  520 . The bottom portion  510  is disposed in the first concave  240  of the rear housing  200 , and the bottom portion  510  includes a third concave  530  therein. The power supply unit  520 , such as a voltage-transferring device, is disposed in the third concave  530 . The power supply unit  520  would be electrically connected with the illuminating module  400  through the rear housing  200  and an external power supply by conducting wires  521  (shown in  FIG. 4 ). However, the power supply unit  520  is not necessarily disposed in the third concave  530 . 
     The illuminating module  400  further includes a substrate  420  and light emitting diodes  410 . The substrate  420  includes a first surface  421  and a second surface  422  opposite to the first surface  421 . The first surface  421  of the substrate  420  is in contact with the assembling surface  230  of the rear housing  200  directly. The second surface  422  of the substrate  420  is disposed into the second concave  380  and is in contact with a bottom surface of the second concave  380  of the front housing  300  directly. Simultaneously, these light emitting diodes  410  are correspondingly arranged on the second surface  422  of the substrate  420  in the array arrangement mentioned above, so that the light emitting diodes  410  can extend into the second cavity  320  through the through holes  310  in a one-to-one relationship. 
     In the above mentioned, the substrate  420  may be a printed circuit board or a metal board, wherein the printed circuit board means a board body with insulating properties including circuits capable of communicating signals thereon. The light emitting diodes  410  are packaged first, and then is soldered on the printed circuit board. 
     Alternatively, the metal board is made of cut metal board bodies. Any two adjacent metal board bodies includes a gap therebetween for separating the physically contact between the two adjacent board bodies, and the light emitting diodes  410  are packaged on the gap between the two adjacent metal board bodies directly. The metal conductive board is used as a conductive medium between the light emitting diodes  410  because of the conductive properties of the metal conductive board, thereby the light emitting diodes  410  would achieve series or parallel electrical connection generated therebetween by desirable shapes of the metal conductive board after cutting directly. 
     The assembling surface  230  of the rear housing  200  further includes many first bolt holes  250 . A bottom surface of the front housing  300  facing the rear housing  200  further includes many second bolt holes  340 . A surface of the bottom portion  510  facing the rear housing  200  includes corresponding fixing holes  540 . Each of the first bolt holes  250 , the second bolt holes  340 , and the fixing holes  540  is disposed correspondingly. As such, when assembling the illuminating device  100 , bolts  600  penetrate through the first bolt holes  250 , the second bolt holes  340 , and the fixing holes  540  in sequence, thereby a bottom of the front housing  300  may be fixed on the assembling surface  230  of the rear housing  200 . Moreover, the substrate  420  of the illuminating module  400  is sandwiched between the front housing  300  and the rear housing  200 , and the bottom portion  510  would be fixed in the first concave  240  of the rear housing  200 , so that the power supply unit  520  is fixed in the third concave  530  (as shown in  FIG. 2 ). 
     As shown in  FIG. 3  and  FIG. 4 ,  FIG. 3  is a front schematic view of an illuminating device with light emitting diodes of the embodiment of the present invention, and  FIG. 4  is a cross-sectional view taken along line  4 - 4  of  FIG. 3 . 
     In an embodiment of the present invention, radians of sidewalls of the front housing  300  and the rear housing  200  are different, thereby when the front housing  300  is disposed in the first cavity  210  of the rear housing  200 , a gap of the first cavity  210  would be formed between sidewalls of the front housing  300  and the rear housing  200 . Air holes  260  are formed on the sidewall of the rear housing  200 , so that the first cavity  210  would communicate with outside air. For example, the first air holes  260  can surround the sidewall of the rear housing  200  with intervals, as show in  FIG. 1A  or  FIG. 2 . 
     The front housing  300  further includes second air holes  360 ,  370 , so that the second cavity  320  and the first cavity  210  would communicate with outside air by the air holes  360 ,  370 , as show in  FIG. 4 . As such, not only the heat generated from the illuminating device  100  would be conducted by the front housing  300  and the rear housing  200 , but also the thermal energy generated from the working light emitting diodes  410  would be dissipated by the convection from the first cavity  210  to the second cavity  320  or outside. Additionally, cold air outside of the illuminating device  100  also can flow into the second cavity  320  and the, first cavity  210  for rapidly enhancing the heat exchange efficiency of the illuminating device  100 . 
     For example, in an embodiment of the second air holes, the second air holes  360  may surround the sidewall of the front housing  300  (shown in  FIG. 3 ) with intervals and are arranged correspondingly to the first air holes one-to-one, thereby communicating with outside air rapidly. Alternately, in another embodiment of the second air holes, an edge of an opening of the front housing  300  corresponding to the second cavity  320  includes a ring-shaped flange  350  extending to outside. The ring-shaped flange  350  is connected with an edge of an opening of the rear housing  200  for covering the first cavity  210 . The second air holes  370  are arranged on the ring-shaped flange  350  with intervals, therefore the second air holes  370  would communicate with the first air holes  260  by the gap formed between the front housing  300  and the rear housing  200 . Furthermore, as shown in  FIG. 4 , the present invention may include different second air holes  360 ,  370  disposed on the front housing  300  capable of better enhancing the heat exchange efficiency of the illuminating device  100 . 
     In another embodiment of the present invention, the front housing  300  and the rear housing  200  may be made of metal or plastic. The metal is provided with high thermal conductivity, such as silver, copper, gold, nickel, aluminum, tin, chromium, and alloy composed of above mentioned. 
     However, when the front housing  300  and the rear housing  200  are made of metal, a first insulating layer  232  may be formed on the surface of the rear housing  200  by electrically insulating treatment, and a second insulating layer  312  may be formed on the surface of the front housing  300  by an electrically insulating treatment. Practically, in an economical way, at least the assembling surface  230  of the rear housing  200  for being in contact with the first surface  421  of the substrate  420  includes the first insulating layer  232 , and at least the surface of the second concave  380  of the front housing  300  for being in contact with the second surface  422  includes the second insulating layer  312 . The first and the second insulating layers  232 ,  312  can be the same or different products. These products with insulating layers may be insulating paint, anodic treatment layers or dissipation adhesives, etc. 
     Besides, no matter the front housing  300  and the rear housing  200  are made of metal or plastic, the surface of the front housing  300  or the rear housing  200  may include a heat dissipation layer  234 , wherein the heat dissipation layer  234  may be a carbon deposit layer, a diamond deposit layer, or other deposit layer with high thermal conductivity. 
     To sum up, the illuminating device  100  with light emitting diodes  410  of the present invention increases the area in contact with the light emitting diodes  410  to highly reduce the working temperature of the light emitting diodes  410 , thereby decreasing the failure probability of the light emitting diodes  410  due to the insufficient heat dissipation efficiency. Furthermore, the illuminating device  100  with light emitting diodes  410  of the present invention improves convective condition of the air so as to enhance the heat exchange rate. 
     The reader&#39;s attention is directed to all papers and documents which are filed concurrently with his specification and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference. 
     All the features disclosed in this specification (including any accompanying claims, abstract, and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.