Abstract:
The focusing cup of a LED package is coated exteriorly with or made of opaque material to reduce the spurious external light interference due to the reflections of the surfaces of focusing cup.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    (1) Field of the Invention  
           [0002]    This invention relates to Light Emitting Diodes (LED), particularly the package of the LED.  
           [0003]    (2) Brief description of Related Art  
           [0004]    [0004]FIGS. 1 and 2 show the prior art package for a LED. FIG. 1 shows the top view of such a LED package, and FIG. 2 shows the cross-sectional view along the section line AA′ of FIG. 1 of such a LED package. A LED chip  10  is mounted inside a cup  14  having a wall  12 . The light emitted from the LED  10  is subtended by the rays E. Due to reflections of the wall  12 , external light may reflect as rays S. Such reflected light rays may interfere with the light rays E from the LED  10 . Where the spurious reflected light rays S interfere with the emitted light rays E, a fuzzy region I may appear to change the color of the emitted light E.  
         SUMMARY OF THE INVENTION  
         [0005]    An object of this invention is to provide a LED package which does not alter the light emitted from a LED. Another object of this invention is to provide a LED package for high quality light emission.  
           [0006]    These objects are obtained by coating the exterior wall of the reflecting cup of the LED with opaque material to minimize the spurious light reflection from the exterior walls of the cup, hence the interference of spurious light. 
       
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0007]    [0007]FIG. 1 shows the top view of a prior art LED package.  
         [0008]    [0008]FIG. 2 shows a cross-section view of the LED package shown in FIG. 1.  
         [0009]    [0009]FIG. 3 shows the first embodiment of the present invention with opaque tops of the cup.  
         [0010]    [0010]FIG. 4 shows a second embodiment of the present invention with partial opaque tops of the cup.  
         [0011]    [0011]FIG. 5 shows a third embodiment of the present invention with total opaque coating of all exterior surfaces of the cup.  
         [0012]    [0012]FIG. 6 shows a fourth embodiment of the present invention with partial opaque coating of exterior surfaces of the cup.  
         [0013]    [0013]FIG. 7 shows a fifth embodiment of the present invention with opaque coating of vertical exterior walls of the cup.  
         [0014]    [0014]FIG. 8 shows a sixth embodiment of the present invention with partial opaque coating of the exterior vertical walls of the cup.  
         [0015]    [0015]FIG. 9 shows a seventh embodiment of the present invention with cup made of opaque material.  
         [0016]    [0016]FIG. 10 shows an eighth embodiment of the present invention with an inverted V-shaped interior of the cup.  
         [0017]    [0017]FIG. 11 shows a ninth embodiment of a present invention with a cylindrical interior of the cup.  
         [0018]    [0018]FIG. 12 shows a tenth embodiment of the present invention in which the LED has a top electrode. and a bottom electrode.  
         [0019]    [0019]FIG. 13(A) shows a oval-shaped cup; FIG. 13(B) shows rectangular cup; FIG. 13(C) shows a hexagonal cup. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]    [0020]FIG. 3 shows the first embodiment of the present invention. A LED  10  with two bottom electrodes is mounted over two metal leads  15  and  16 . The LED  10  is surrounded by a cup  14  with a wall  12  to confine the light emitted from the LED  10 . The top surface of the wall  12  is coated with an opaque material  21 . The light rays emitted from the LED  10  are subtended by the rays E. Any spurious light S 1  incident on the top surfaces of the cup is absorbed and not reflected, because the coating  21  is non-reflective. Thus, the light rays E emitted from the LED  10  are not interfered.  
         [0021]    [0021]FIG. 4 shows a second embodiment of the present invention. The structure is similar to that in FIG. 3, except that the top surface of the cup  12  is partially covered opaque material  22 . The partial coating makes it easier to fabricate.  
         [0022]    [0022]FIG. 5 shows a third embodiment of the present invention. Both the top surface and vertical exterior surface  23  of the cup are coated with opaque material. When the packaging dimensions is shrunk, the thickness of the cup becomes very thin. The light ray E 1  emitted from the LED  10  may penetrate through the wall of the cup  12  to cause spurious reflections and hence interference of the emitted light. By coating the vertical exterior side walls of cup  12 , this undesirable interference can be avoided.  
         [0023]    [0023]FIG. 6 shows a fourth embodiment of the present invention. The structure is similar to FIG. 5 except that the vertical exterior wall is only partially coated with opaque material  24 . The partial coating is for the convenience of fabrication and saving of coating material.  
         [0024]    [0024]FIG. 7 shows a fifth embodiment of the present invention. The structure is similar to FIG. 5, except that only the exterior vertical wall is coated with opaque material  25 . This structure is intended for easy fabrication, saving coating material and different light absorbing properties.  
         [0025]    [0025]FIG. 8 shows a sixth embodiment of the present invention. The structure is similar to FIG. 7 except that the exterior vertical wall is partially coated with opaque material  26 . The structure is intended for easy fabrication, saving coating material and different light absorbing properties.  
         [0026]    [0026]FIG. 9 shows a seventh embodiment of the present invention. The structure is similar to that in FIG. 3 except that the cup  27  is made of solid light absorbing material. With this structure, there can be no spurious reflection from all surfaces of the cup.  
         [0027]    [0027]FIG. 10 shows an eighth embodiment of the present invention. The structure is similar to that in FIG. 9, except that the interior wall  31  of the cup  14  is of inverted V-shape.  
         [0028]    [0028]FIG. 11 shows a ninth embodiment of the present invention. The structure is similar to that in FIG. 9, except that the interior wall  32  of the cup  14  is of cylindrical shape.  
         [0029]    [0029]FIG. 12 is a tenth embodiment of the present invention. The structure is similar to that in FIG. 11, except that the LED  10  has a bottom electrode and the top electrode. The bottom electrode is connected to the lead  151  and the top electrode is connected to the lead  161 .  
         [0030]    [0030]FIG. 13 shows variations of the shape of the wall  12  of the cup in FIG. 3. FIG. 13(A) has a oval shaped cup  141 ; FIG. 13(B) has a rectangular shaped cup  142 ; and FIG. 13(C) has a hexagonal shaped cup  143 .  
         [0031]    While the preferred embodiments of the invention have been described, it will be apparent to those skilled in the art that various modifications can be made in the embodiments without departing from the spirit of the present invention. Such modifications are all within the scope of this invention.