Patent Publication Number: US-2010118550-A1

Title: Rotary-clasp type LED package

Description:
BACKGROUND OF INVENTION 
     1. Field of Invention 
     This invention relates to a light emitting diode (LED) package and more particularly to a LED package having a LED lens capable of clasping a LED assembly thereof. 
     2. Related Prior Art 
     LED packages are known in the art. Such packages are generally as designed to assemble a LED lens and a LED assembly together securely. 
     Taiwan Patent No. M313317 is an exemplary of patent directed to LED package of the type to which this invention is directed. As disclosed in that patent, the LED package adopts an adhesive, such as epoxy, to combine a LED lens and a LED assembly together; however, the LED package is relatively time-consuming and costly to manufacture because of the high-temperature baking procedure. 
     Another LED package is described in Taiwan Patent No. M338431 and includes a lens, a holder and a LED assembly. The lens is mounted onto a mounting base of the LED assembly with the help of the holder. Specifically, the holder is formed with two hooks for engagement with two diagonal corners of the mounting base of the LED assembly. Further, the holder is formed with two positioning bolts to be received in two corresponding positioning holes of the mounting base of the LED assembly. There is need to preciously place the holder in right position in order to insert its two positioning bolts into the two positioning holes of the mounting base of the LED assembly for further assembly. The positioning construction is needed in this type of LED package. It is because once the mounting base of the LED assembly is not the kind having positioning holes, then that kind of holder becomes useless. Additionally, none of the parts of the LED package can be easily detached from one another for replacement once the lens, the holder and the LED assembly are bonded together. 
     SUMMARY OF INVENTION 
     Broadly stated, the present invention is directed to a LED package which is easy and fast to be assembled. The LED package generally includes a LED assembly and a LED lens. The LED lens is provided to be quickly attached on a mounting base of the LED assembly. Specifically, the mounting base of the LED assembly is formed with a plurality of ledges at corners. The LED lens includes a lens and a holder through which the lens is secured on the mounting base of the LED assembly. The holder includes a frame and a plurality of arms extending from bottoms of the frame. The lens is mounted on top of the frame of the holder. The holder is capable of clasping a mounting base of the LED assembly by the arms when the holder is placed upon the LED assembly and rotated with respect to the LED assembly by an angle. When the LED lens and the LED assembly are tightly joined together, the ledges of the mounting base are clasped in the arms of the holder. 
     Preferably, each of the arms of the holder has a fixed section and a forearm extending from a front side of the fixed section. The forearm is elastic. The forearm and the frame co-define a breach therebetween. Moreover, a free end of the forearm of one arm and a rear end of the fixed section of another arm co-define a gap in communication with the breach. The ledges of the mounting base of the LED assembly are to be confined in the breach. 
     Preferably, the holder and the lens of the LED lens are one piece formed construction so that the LED package is relatively cost-effective. 
     The present invention and the advantages thereof will become more apparent upon consideration of the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The invention is illustrated by the accompanying drawings in which corresponding parts are identified by the same numerals and in which: 
         FIG. 1  is a perspective view of a LED package in accordance with a first embodiment of the present invention; 
         FIG. 2  is an exploded downward perspective view of the LED package of  FIG. 1 ; 
         FIG. 3  is an exploded upward perspective view of the LED package of  FIG. 1 ; 
         FIG. 4  is a cross-sectional view, partially broken away to show details of construction, of the LED package of  FIG. 1 ; 
         FIG. 5  is a perspective view, partially broken away to show details of construction, of the LED package of  FIG. 1 , showing that the holder of the LED lens is placed upon the LED assembly before relative rotation; 
         FIG. 6  is a view similar to  FIG. 5 , illustrating the holder of the LED lens is rotated with respective to the LED assembly; 
         FIG. 7  is an exploded view of a LED package in accordance with a second embodiment of the invention; and 
         FIG. 8  is an exploded view of a LED package in accordance with a third embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Referring now to  FIGS. 1-6 , the LED package  100  according to a first embodiment of the present invention comprises a LED assembly  1  and LED lens  2  attached to the LED assembly  1 . 
     As shown in  FIGS. 2 and 3 , the LED assembly  1  includes a mounting base  11  and a LED die  10  mounted on a central part of the mounting base  11 . The mounting base  11  is substantially square-shaped and is formed with a plurality of ledges  12  at corners thereof. Each of the ledges  12  defines a positioning hole  120  therein. The ledges  12  are flush with other top areas of the mounting base  11 . Under each of the ledges  12  is a notch  13  defined in a lower corner of the mounting base  11 . Additionally, a pair of leads  14  extends from opposite sides of the mounting base  11  and is electrically connected to the LED dies  10 . 
     As best shown in  FIG. 3 , the LED lens  2  is adapted for quick attachment to the LED assembly  1  and includes a holder  20   a  and a lens  20 . The holder  20   a  includes a frame  200 , a confining portion  201 , two protruding rails  22  and two arms  21 . The frame  200  is hollow and the confining portion  201  is disposed on an inner peripheral wall of the hollow frame  200 . The two arms  21  extend from bottoms of the frame  200 . The lens  20  is mounted on the frame  200  of the holder  20   a  and includes a lens body  202  and a fixing portion  203  extending from a periphery of the lens body  202 . In this embodiment, the fixing portion  203  of the lens  20  is a fixing ring mounted around the lens body  202 . The confining portion  201  is constructed corresponding to the fixing portion  200  of the lens  20 . 
       FIG. 4  illustrates that the lens  20  is secured on the mounting base  11  of the LED assembly  1  as a result of the fixing portion  20  of the lens  20  being restrained by the confining portion  201  of the holder  20   a . That is, the confining portion  201  of the holder  20   a  presses the fixing portion  203  of the lens  20  against the mounting base  11  of the LED assembly  1  so as to have the lens  20  be secured in position on the LED assembly  1 . In this embodiment, the confining portion  201  of the holder  20   a  is an annular plate defining a window  204  in the center thereof. The lens body  202  of the lens  20  is partly received in the window  204  and is exposed outside the frame  200  of the holder  20  via the window  204 . Additionally, the lens body  202  of the lens  20  is constructed and based on an optical system. For instance, the lens body  202  may be domed-shaped as described in this embodiment, and may be concave and not exposed outside the frame  200  of the holder  20   a . In any case, the lens body  202  of the lens  20  is exposed in the window  204 , without being blocked by the frame  200  of the holder  20   a.    
     In order to have the LED lens  2  be able to be fast mounted on the mounting base  11  of the LED assembly  1 , the holder  20   a  are configured to clasp the mounting base  11  of the LED assembly  1  by the arms  21  when the holder  20   a  is placed upon the LED assembly  1  and rotated with respect to the LED assembly  1  by an -angle. Specifically, as shown in  FIGS. 3 and 5 , the two arms  21  are corresponding to each other and each includes a fixed section  23 ,a forearm  24  and a positioning bulge  25 . The fixed section  23  of the arm  21  extends from a bottom of the frame  200 . The forearm  24  extends from a front side  230  of the fixed section  23 . Since the LED lens  2  is made of an elastic material, the forearm  24  of the arm  21  is elastic. Moreover, a breach  27  is defined between the forearm  24  and the frame  200 . As best shown in  FIG. 3 , a free end of the forearm  24  of one arm  2  land a rear end  231  of the fixed section  23  of the other arm  21  co-define a gap  26  in communication with the breach  27 . The positioning bulge  25  of the arm  21  extends from a top of the free end of the forearm  24  toward a bottom of the frame  200  and is formed with a slope  250  at a side facing the gap  26 . 
     As shown in  FIG. 5 , each of the protruding rails  22  of the holder  20   a  extends from the rear side  231  of the fixed section  23  of the respective arm  21  along a peripheral of the frame  200  toward the gap  26 . The gaps  26  of the arms  21  are specifically sized in accordance with the width of the mounting base  11  of the LED assembly  1  in order to fit the mounting base  11 . When the holder  20   a  is placed upon the mounting base  11  of the LED assembly  1 , diagonal two of the ledges  12  of the mounting base  11  are bound by inner walls of the protruding rails  22  of the holder  20   a  in such a way that the mounting base  11  of the LED assembly  1  is free from coming off. 
     Referring to  FIG. 6 , when the holder  20   a  of the LED lens  2  is rotated with respective to the mounting base  11  of the LED assembly  1 , the diagonal two ledges  12  move along the inner walls of the protruding rails  22  of the holder  20   a  to have the other two diagonal ledges  12  be snapped into the breaches  27  of the arms  21  respectively. It is because while the other two diagonal ledges  12  pass along the slopes  250  of the positioning bulges  25  for entering into the breaches  27 , the positioning bulges  25  together with the elastic forearm  24  is pressed downward a bit by the moving ledges  12 , but are then rebounded after the ledges  12  move off the bulges  25  and enter into the breaches  27 . At this time, the other two diagonal ledges  12  of the mounting base  11  are clasped in the arms  21  of the holder  20   a . As shown in  FIG. 6 , the positioning bulge  25  of the arm  21  stops the ledge  12  from withdrawal from the breach  27 . In this embodiment, four ledges  12  are included in the mounting base  1  of the LED assembly  1 . It should be noted that only two or three ledges may also be used as long as the cooperated parts, such as arms  21  and protruding rails  22  of the holder  20   a  are provided correspondingly. 
     From the foregoing description, the present invention provides a convenient, efficient, and cost effective solution to the LED package industry. The lens  20  can be easily, fast mounted on the mounting base  11  of the LED assembly  1  without need of accurate alignment procedure or time-consuming baking procedure as mentioned in the prior art. Once a LED package is assembled and is found deficient due to a failure lens  2  or LED assembly  1 , the deficient LED package can be immediately disassembled and have the failure part be replaced. Additionally, for some other LED mounting bases having no positioning holes therein, the holder  20   a  can also be applied. 
       FIG. 7  provides an explosive perspective view of a LED package  300  in a second embodiment. As with LED package  100  of  FIGS. 1-6 , the LED package  300  of the second embodiment includes a LED assembly land a LED lens  2  attached on the LED assembly  1 . The LED lens  2  has a holder  20   b  and a lens  20  mounted on the holder  20   b . Substantially all of the precepts discussed in the first embodiment apply to the second embodiment. The major difference is that the confining portion  201   a  of the second embodiment includes three hooks rather than an annular plate  201  as illustrated in the first embodiment. The three hooks, namely the confining portion  201   a,  are provided to catch the fixing portion  203  of the lens  20  in order to secure the lens  20  on top of the frame  200  of the holder  20   b.    
     With reference to  FIG. 8 , a LED package  500  in accordance with a third embodiment of the invention is illustrated. The third embodiment is similar to the LED package  300  of the second embodiment, except that the lens  20  and the holder  20   b  are one piece formed by molding, which is relatively cost-efficient. 
     It will be appreciated that although the embodiments of the invention have been shown and described, modifications may be made. It is intended in the claims to cover such modifications which come within the spirit and scope of the invention.