Patent Publication Number: US-2013242549-A1

Title: Test device for led light bar

Description:
BACKGROUND 
     1. Technical Field 
     The present disclosure relates to test devices and, more particularly, to a device for an light emitting diode (LED) light bar with high testing efficiency and accuracy. 
     2. Description of Related Art 
     LEDs have many advantages, such as high luminosity, low operational voltage, low power consumption, compatibility with integrated circuits, easy driving, long term reliability, and environmental friendliness have promoted their wide use as a lighting source. 
     An LED light bar has an elongated circuit board and a plurality of LEDs mounted on the circuit board along a line. The LED light bar is used to replace the conventional fluorescent tube. It needs to check locations of the LEDs on the circuit board, electrical connections between the LEDs and the circuit board and the performance each LED of the LED light bar before the LED light bar is shipped to the customer. A conventional test is to provide a power source with two first electrodes, and the two first electrodes are respectively electrically connected to two second electrodes of the LED to check the performance of the LED. The test needs to be repeatedly performed for each LED; accordingly the conventional test is time consuming and laborious, which results in a low testing efficiency. To check whether the LEDs are correctly mounted on the circuit board, a manual visual check is usually used. However, such a manual check is not accurate. Error often happens. Accordingly, the conventional check is not accurate. 
     Therefore, what is needed is a test device, which can overcome the above described shortcomings 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top view of a test device, in accordance with a first embodiment of the present disclosure. 
         FIG. 2  is a front view of an LED light bar to be tested. 
         FIG. 3  is a top view of the LED light bar to be tested of  FIG. 2 . 
         FIG. 4  shows the test device of  FIG. 1  being used to check the LED light bar of  FIG. 3 . 
         FIG. 5  is a top view of a test device, in accordance with a second embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , a test device  100 , in accordance with a first embodiment, is used for testing performances of LEDs of an LED light bar  200  of  FIG. 2 . 
     Referring to  FIGS. 2 and 3 , the LED light bar  200  includes a substrate  21 , and a plurality of LEDs  22  evenly mounted on the substrate  21  along a lengthwise direction of the substrate  21 . The substrate  21  is a circuit board, particularly a printed circuit board. Each LED  22  includes an anode  23  and a cathode  24 . The anode  23  and the cathode  24  electrically connect to an LED chip (not labeled) of the LED  22  and mounted on a top face of the substrate  21 , whereby the LED  22  is formed as a surface mounting type device. A distance between outer side surface of the anode  23  and outer side surface of the cathode  24  of each LED  22  is regarded as length L 1  of the LED  22 . A width of each LED  22  is H 1 . In the present embodiment, the length direction is perpendicular to the width direction. The LEDs  22  are mounted on the substrate  21  along a straight line. 
     Referring to  FIG. 1  again, the test device  100  includes a first plate  11 , a second plate  12  opposite to the first plate  11 , plural electrode pairs  13 , and a circuit structure  14 . 
     The first plate  11  and the second plate  12  are elongated plates. The first plate  11  includes a first inner surface  110 , the second plate  12  includes a second inner surface  120  opposite to the first inner surface  110  of the first plate  11 . Two supporting plates  15  are arranged between the first plate  11  and the second plate  12 . One of the supporting plates  15  connects to one end of the first plate  11  and one end of the second plate  12 . The other supporting plate  15  connects to another end of the first plate  11  and another end of the second plate  12 . In the present embodiment, the supporting plates  15  are integrally formed with the first plate  11  and the second plate  12  as a single piece. In other embodiments, the supporting plates  15 , the first plate  11 , and the second plate  12  can be separated formed from each other and then assembled together. The first plate  11  is cooperative with the second plate  12  for clamping the LEDs  22 . In the present embodiment, a distance H 2  between the first plate  11  and the second plate  12  is substantially equal to the width H 1  of each LED  22 . 
     The electrode pairs  13  are arranged on the first surface  110  of the first plate  11 . In the present embodiment, the first plate  11  has four electrode pairs  13  formed thereon. Each electrode pair  13  includes a first electrode  131  and a second electrode  132 . In the present embodiment, the shape and size of the first electrode  131  are substantially same as that of the second electrode  132 . When testing the electrical property of the LEDs  22 , the first electrode  131  is electrically connected to an anode  22  of the LED  22 , and the second electrode  132  is electrically connected to the corresponding cathode  23  of the LED  22 . In the present embodiment, a distance L 2  between the first electrode  131  and the corresponding second electrode  132  of each electrode pair  13  is substantially equal to the length L 1  of the LED  22 . It can be understood that the number of the electrode pairs  13  can be changed according to the number of the LEDs  22  on the substrate  21 . 
     The circuit structure  14  are arranged on the first plate  11  and electrically connected to the electrode pairs  13 . The circuit structure  14  can be electrically connected to an exterior power source (not shown) for providing electric power to the LEDs  22 . In the present embodiment, the circuit structure  14  extend to an outer edge of the first plate  11  to form a golden finger connector  16 ; the golden finger connector  16  can match with a golden finger interface (not shown) of the exterior power source. 
     Referring to  FIG. 4 , when the test device  100  is used for testing performances of the LEDs  22  of the LED light bar  200 , the test device  100  is pushed downwardly to the LED light bar  200  from a top thereof until the first plate  11  and the second plate  12  clamp the LEDs  22  therebetween; therefore, each of the first electrodes  131  is electrically connected to the anode  23  of each of the LEDs  22 , and the corresponding second electrode  132  is electrically connected to the corresponding cathode  24  of each of the LEDs  22 . The golden finger connector  16  is electrically connected to the exterior power source to provide electric power for the test device  100 . If all of the LEDs  22  of the LED light bar  200  emit light, this represents that the performances of the LEDs  22  of the LED light bar  200  are alright. If one of the LEDs  22  of the LED light bar  200  fails to emit light, it represents that the LED  22  and thus the LED light bar  200  can not perform properly. A maintenance or replacement is required. If the test device  100  cannot be pushed downwardly onto the LED light bar  200  properly since one or more the LEDs  22  engaging bottom(s) of one or both of the first and second plates  11 ,  12  to block the pushdown of test device  200 , which means that the LEDs  22  are not aligned with each other and arranged along a straight line; accordingly not all of the LEDs are mounted on their intended positions, whereby a re-soldering of the LEDs  22  of the LED light bar  200  which are shifted from their intended positions is required. 
     The test device  100  can test the LEDs  22  of the LED light bar  200  at the same time, whereby it can improve the test efficiency. Further the positional correctness of the LEDs  22  can be checked by the test device  100 , not by a manual visual inspection; thus, the accuracy of the check of the LED light bar  200  is enhanced. 
     Referring to  FIG. 5 , a test device  200 , in accordance with a second embodiment is shown. Differing from the test device  100  of the first embodiment, two elastic members  17  are arranged between and connected to two opposite ends of the first plate  11  and the second plate  12 . In the present embodiment, the elastic members  17  can be selected from springs, elastic flakes and so on. In  FIG. 5 , the elastic members  17  are helical springs. Since the first plate  11  and the second plate  12  are connected via the elastic members  17 , the distance between the first plate  11  and the second plate  12  can be adjusted, and the test device  200 . In use, the test device  200  is mounted onto the LED light bar  200  with the second plate  12  engaging a common front side of the LEDs  22 ; then, the first plate  11  is pushed toward a common rear side of the LEDs  22  until the electrode pairs  13  engage with the anodes  23  and cathodes  24  of the LEDs  22  to see whether all of the LEDs  22  can emit light thereby the check the performances of the LEDs  22 . On the other hand, when the second plate  12  is used to engage the common front side of the LEDs  22  and the front side of one of the LEDs  22  is spaced a gap from the second plate  12 , it can be determined that the LED  22  is shifted from its intended position, whereby the LED light bar  200  needs a maintenance to re-solder the misaligned LED  22 . 
     It is to be further understood that even though numerous characteristics and advantages have been set forth in the foregoing description of embodiments, together with details of the structures and functions of the embodiments, the disclosure is illustrative only; and that changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.