Abstract:
A light board is made with a receptacle substrate for accommodating cassette light units. The convenience of assembly and disassembly of the light units from the receptacle substrate makes the product easily to be maintained for changing different color light units, changing different displaying patterns, removing or replacing a failure light unit.

Description:
RELATED APPLICATIONS 
   The present application is based on, and claims priority from, Taiwan Application Serial Number 095105301, filed Feb. 17, 2006, the disclosure of which is hereby incorporated by reference herein in its entirety. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to a matrix display of light emitted diodes. 
   2. Description of the Related Art 
     FIG. 1  is a prior art that illustrates a traditional light board. Conventional light board is made up with a printed circuit board (PCB)  10  on which a plurality of light-emitting diodes (LED)  11  are positioned. Only one LED  11  is shown in  FIG. 1 . Each of the diodes has bottom metals  11   a  and  11   b . Corresponding metal circuits  10   a  and  10   b  is provided on the board  10  to electrically couple with the electrodes  11   a  and  11   b  of the light-emitting diode  11  respectively to form a traditional light-emitting diode display board. The shortcomings of the prior art are as follows: (1) inflexibility in color change, i.e., it is impossible or inconvenient to change different light color diodes at any moment; (2) inconvenience in maintaining and replacing a failure diode. 
   SUMMARY OF THE INVENTION 
   The primary object of the present invention is to prepare a light board that is convenient for assembly and disassembly of the light units from the light board. A second object of the present invention is to provide a light board that can be easily maintained and allows for easy changing of different color light units, or different displaying patterns. A third object of the present invention is to provide a light board that allows easy and rapid replacement of a failure light unit from the light board. 
   In a light board using a cassette light unit, the cassette light unit has a pedestal with a top metal and a bottom metal, and a transparent unit is made at the top of a light chip for modifying the light beam emitted from the light chip. The light board has a first metal coupling with the top metal of the cassette unit when the cassette light unit is inserted in position. A second metal electrically coupling with the bottom metal of the cassette light unit when the cassette light unit is inserted in position. A slit between the first metal and the second metal is for the anchor of the light unit. An insulation material is positioned between the first metal and the second metal for electrical isolation there between. 
   The cassette light unit comprises: a light-emitting diode chip. The light-emitting diode chip has a first electrode and a second electrode. The top metal of a pedestal electrically couples with the first electrode of the light-emitting diode chip. The bottom metal of a pedestal electrically couples with the second electrode of the light-emitting diode chip. The top metal of the pedestal has an open area to accommodate the light-emitting diode chip to be mounted onto the bottom metal. An insulation material is positioned between the top metal and the bottom metal for electrical insulation there between. A transparent head is positioned above the light-emitting diode chip for modifying the light beam emitted from the light chip. 
   The present invention discloses a light board having openings on a plurality of coplanar first metals for the insertion of the light units. It is convenient to change different color light units, and it is easy and rapid to remove or replace a failure light unit from the light board. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a traditional light board; 
       FIG. 2A  is a top view of a cassette light unit used in the present invention; 
       FIG. 2B  is a side view of  FIG. 2A ; 
       FIG. 3  is a top view of a first embodiment of the present invention with a single light unit; 
       FIG. 4A  is a top view of a light board of the present invention before insertion of a light unit; 
       FIG. 4B  is a side view of  FIG. 4A ; 
       FIG. 5  is a top view of a light board of the present invention with multiple light unit slots; 
       FIG. 6  is a top view of a second embodiment of the present invention with a matrix light unit slots. 
       FIG. 7  is a plane view of a matrix display according to the present invention 
       FIG. 8  is a first frame used in the present invention. 
       FIG. 9  is a second frame used in the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 2A  is a top view of a light unit  50  used in this invention. It shows a cassette light unit  50  that encapsulates a light-emitting diode chip  20 . The light unit  50  has pedestal with a top metal  21  and a bottom metal  22 . The first electrode or surface electrode of the light-emitting diode chip  20  is electrically coupled with the top metal  21  through a bonding wire  24 . The top metal  21  has an open area at its center for mounting light-emitting diode chip  20  on the top surface of bottom metal  22 . The second electrode or bottom electrode of the light-emitting diode chip  20  is electrically coupled with the bottom metal  22 . A transparent glue  23  is coated above the light-emitting diode chip  20  for modifying the emitted light and to ensure the reliability of the product. Double wire bonding can be used to couple the two electrodes respectively to the top metal  21  and the bottom metal  22  if the LED  20  has two surface electrodes. 
     FIG. 2B  is a side view of the light unit  50  of  FIG. 2A . It shows a cassette light unit  50  comprises: a light-emitting diode chip  20  mounted on the top surface of the bottom metal  22  through an open area of the top metal  21 . The top metal  21  is electrically coupled with the first electrode or surface electrode of the light-emitting diode chip  20  through a metal wire  24 . The bottom metal  22  is electrically coupled with the second electrode or bottom electrode of the light-emitting diode chip  20 . A transparent glue  23  is made above the light-emitting chip  20  to modify the emitted light. An insulation material  25  is positioned in between the top metal  21  and the bottom metal  22  for electricity insulation there between. 
     FIG. 3  is a top view of a first embodiment of the present invention with a single light unit  50 . A light board with a single cassette light unit  50  of the present invention is shown. A receptacle substrate of the light board has a first metal  31  and a second metal  32 . The first metal  31  has a pair of elastic cantilevers  311  which hold the periphery of the top metal  21  of the pedestal of the cassette light unit  50  steadily, so as to anchor the cassette light unit  50  in position. Each elastic cantilever  311  is electrically coupled with the top metal  21  of the cassette light unit  50 . The open area between the parallel elastic cantilevers  311  allows for light emission of the cassette light unit  50 . An insulation material  33  is disposed between the first metal  31  and the second metal  32 . 
     FIG. 4A  is a top view of a light board of the present invention before insertion of a light unit  50 . The first metal  31  has a parallel elastic cantilevers  311 . A light unit  50  is inserted in between the first metal  31  and the second metal  32 . The dotted lines denote an inserted light unit  50 . The transparent glue  23  is protruded out above the first metal  31  for handling. The transparent glue  23  can be made thin for reliability only. 
     FIG. 4B  is a side view of  FIG. 4A . A cassette light unit  50  is shown ready to be inserted into a slot of the receptacle substrate. It shows that the receptacle substrate has a first metal  31  and a second metal  32 , and an insulating material  33  disposed in between the first metal  31  and the second metal  32 . The first metal  31  has a pair of parallel elastic cantilever  311  for touching and anchoring the inserted cassette light unit  50 . Each elastic cantilever  311  is electrically coupled with the top metal  21  of the cassette light unit  50  and the second metal  32  is electrically coupled with the bottom metal  22  of the cassette light unit  50  when the cassette light unit  50  is inserted in position. Due to the small size of the cassette light unit  50 , the protruded transparent head  23  can be made bigger as a grip for handling for assembly and disassembly of the light unit  50 . The transparent glue  23  can be alternatively made very thin for light emission modification or for reliability only. 
     FIG. 5  is a top view of a light board of the present invention with multiple light unit slots arranged in a row, i.e., in a line-type. An elongated light board receptacle substrate  602  is shown to include a first metal  31 , a second metal  32 , and insulation layer  33  inserted between the first metal  31  and the second metal  32 . Parallel cantilevers  311  are elastically bent downward, toward the second metal  32 . The open area between each pair of parallel cantilevers  311  is for accommodation of one light unit  50 . 
     FIG. 6  is a top view of a second embodiment of the present invention with matrix light unit slots. A matrix light board is illustrated as having, e.g., 4*3 receptacle slots, each slot is ready to receive a cassette light unit  50  (not shown in this figure). 
   The transparent glue  23  can be in the shape of a lamp bulb, so as to modify the emitted light. The transparent bead  23  can be alternatively made into different products, such as, animals, plants, people, mountain or river sceneries, knives or forks and buildings etc. The product shall emit the light from the embedded light chip when the light unit is inserted into the receptacle in position, and become a lighting sculpture product. 
     FIG. 7  is a plane view of a matrix display according to the present invention. 
   A matrix display  99  made of 4*3 light units is shown as an example. Four coplanar parallel first metals ( 315 ˜ 318 ) are interweaved with three coplanar parallel second metals ( 325 ˜ 327 ); each of the first metals ( 315 ˜ 318 ) has three sockets with parallel cantilevers  311  and an opening  34 , the opening  34  is for the insertion of a light unit  50  as shown in  FIG. 2 . Insulation slits  41  are set for the insulation between the first metals  315 ˜ 318 . Through each opening  34 , a corresponding one of second metals  325 ˜ 327  is exposed. Insulation material  33  is disposed between the first metals  315 ˜ 318  and the second metals  325 ˜ 327  for electric insulation. Insulation slits  42  are set for the insulation between the parallel second metals. Insulation slits  41 ,  42  are, e.g., air gaps, however, it can be made by other well-known insulation materials. 
   Once a light unit is inserted in position, the top metal  21  of the pedestal electrically couples to the corresponding first metal  315 ˜ 318 , the bottom metal  22  of the pedestal electrically couples to the corresponding second metal  325 ˜ 327 . The first metals  315 ˜ 318  and the second metals  325 ˜ 327  are each connected to a control circuit (not shown) so as to control the on/off of each of the light units to form a matrix display. 
     FIG. 8  is a frame used in the present invention 
   A frame to anchor the matrix display  99  is disclosed. A horizontal bar  52  has three metal contacts  525 ˜ 527 . When the horizontal bar  52  is attached to the display  99  from rear, the first ends of the three metal contacts couple electrically to the corresponding second metals  325 ˜ 327 . The second ends of the three metal contacts  525 ˜ 527  couple to a first power terminal (not shown in the figure). Similarly, a vertical frame bar  51  has four metal contacts  515 ˜ 518 . When the vertical bar  51  flips to attach to the display  99 , the four metal contacts couple electrically to the corresponding first metals  315 ˜ 318 . The second ends of the four metal contacts  515 ˜ 518  couple to a second power terminal (not shown in the figure). 
     FIG. 9  is a second frame used in the present invention 
   The frame is a second design for the matrix display of this invention.  FIG. 9  is a frame that is an integral structure of the prior design shown in  FIG. 8 . A U shaped frame  62  has one side opening for the sliding in/out of a matrix display  99 . The opening side can be either in the left side, right side, topside, or bottom side for the sliding in/out of the display  99 . A right side opening is shown as an example in  FIG. 9 . The U shaped frame  62  has a groove  621  made in its three sides designed for the insertion and retention of the matrix display  99 . There are three metal contacts  525 ˜ 527  in the horizontal section of the frame  62  each of which electrically couples to a corresponding one of the three vertical metals  325 ˜ 327 . There are four metal contacts  515 ˜ 518  in the vertical section of the frame  62  each of which electrically couples to a corresponding one of the four horizontal metals  315 ˜ 318 . The metal contacts  525 ˜ 527  and  515 ˜ 518  electrically couple to a power supply (not shown) for the controlling on/off of each light unit in the matrix display  99 . 
   While the preferred embodiments has been described by way of example, it will be apparent to those skilled in the art that various modification may be made in the embodiments without departing from the spirit of the present invention. Such modifications are all within the scope of the present invention, as defined by the appended claims.