Abstract:
A voltage test device used in liquid crystal display (LCD) panels, including test solder pads and test lines, is proposed. The test solder pads are connected to an LCD panel through the test lines. Each of the test lines includes a switch test line and a signal-inputting test line. The voltage test device further includes a first connector. The switch test line includes a first portion of the switch test line and a second portion of the switch test line. The first portion of the switch test line is connected to the second portion of the switch test line through the first connector. The first connector is used for preventing the electric current in excess of a predetermined threshold from flowing inside the LCD panel. Meanwhile, a voltage testing system used in LCD panels is proposed.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a liquid crystal display (LCD) devices, and more particularly, to a test device used in liquid crystal display (LCD) panels and an associated system. 
         [0003]    2. Description of the Prior Art 
         [0004]    Two principal methods of discharge—air discharge and contact discharge—are applied to thin film transistor-liquid crystal display (TFT-LCD) panels on which reliability testing is conducted. Referring to  FIG. 1 , electro-static discharge (ESD) testing at a voltage range of 0 to 4 KV is conducted on test points  1  to  8 . 
         [0005]    In an actual application, test points  3  to  8  can pass the ESD testing successfully while test points  1  and  2  cannot. When the amount of voltage is excessive during the ESD testing is conducted on test points  1  and  2 , horizontal or vertical bright lines will occur easily. Analysis reveals that switching circuits under a driver chip  11  of the LCD panel (referring to  FIG. 1B ) is damaged, which leads to irregular transmissions of signals. 
         [0006]    Referring to  FIG. 1B ,  FIG. 1B  shows an internal structure diagram in  FIG. 1A . A test solder pad  12  is disposed near test points  1  and  2  (referring to  FIG. 1A ). When the ESD testing is conducted on test points  1  and  2 , electric current flows inside the LCD panel through a test line  13  connected to the test solder pad  12 . The electric current flowing inside the LCD panel causes damage to the circuits inside the LCD panel, which is the primary reason why the switching circuits are damaged. 
         [0007]    In sum, an excessive amount of electric current occurring during the voltage testing is conducted on LCD panels usually causes damage to the circuits inside the LCD panels in the conventional technology. This problem needs to be solved by LCD manufacturers. 
       SUMMARY OF THE INVENTION 
       [0008]    An object of the present invention is to provide a voltage test device for testing an LCD panel for solving the problem occurring in the conventional technology; that it, an excessive amount of electric current occurring during the voltage testing is conducted on the LCD panel usually causes damage to the switching circuits inside the LCD panel. 
         [0009]    According to the present invention, a voltage test device used in liquid crystal display (LCD) panels, comprising test solder pads connected to an LCD panel through the test lines, and test lines comprising a switch test line and a signal-inputting test line, 
         [0010]    the voltage test device further comprises a first connector, the switch test line comprises a first portion and a second portion connected to the first portion through the first connector, and the first connector is used for preventing the electric current in excess of a predetermined threshold from flowing inside the LCD panel; 
         [0011]    the signal-inputting test line comprises a first portion and a second portion; 
         [0012]    the voltage test device comprises a second connector, and the first portion of the signal-inputting test line is connected to the second portion of the signal-inputting test line through the second connector; 
         [0013]    when the amount of electric current flowing through the switch test line exceeds a predetermined threshold, the connection between the first portion of the switch test line and the second portion of the switch test line is cut due to a burnout of the first connector, so that the amount of electric current flowing inside the LCD panel is restricted; 
         [0014]    when the amount of electric current flowing through the signal-inputting test line exceeds a predetermined threshold, the connection between the first portion of the signal-inputting test line and the second portion of the signal-inputting test line is cut due to a burnout of the second connector. 
         [0015]    In one aspect of the present invention, the second connector comprises a second fastening component and a second conductor connected to the signal-inputting test line through the second fastening component. The second conductor has a higher resistance than the signal-inputting test line. 
         [0016]    In one aspect of the present invention, the first connector comprises at least two branch connectors connected in parallel with each other and disposed between the first portion of the switch test line and the second portion of the switch test line. 
         [0017]    In one aspect of the present invention, a third connector and a first transistor is disposed on the switch test line; 
         [0018]    a second transistor is disposed on the signal-inputting test line, and the voltage test device further comprises a fourth connector; 
         [0019]    wherein a source of the first transistor is connected to the test solder pad corresponding to the switch test line through the third connector, and a drain of the first transistor is connected to a gate of the second transistor through the fourth connector; 
         [0020]    a source of the second transistor is connected to the test solder pad corresponding to the signal-inputting test line, and a drain of the second transistor is connected to a source of a switch inside the LCD panel. 
         [0021]    In one aspect of the present invention, the first connector, the third connector, and the fourth connector all comprise a fastening component and a conductor; 
         [0022]    the conductor in each of the connectors is connected to a test line corresponding to each of the connectors through the fastening component in each of the connectors; 
         [0023]    wherein the conductor in each of the connectors has a higher resistance than its corresponding test line. 
         [0024]    Another object of the present invention is to provide a voltage test device for testing an LCD panel to solve the problem occurring in the conventional technology; that it, an excessive amount of electric current occurring during the voltage testing is conducted on the LCD panels usually causes damage to the switching circuits inside the LCD panels. 
         [0025]    According to the present invention, a voltage test device for testing an LCD panel, comprising test solder pads connected to an LCD panel through the test lines, and test lines comprising a switch test line and a signal-inputting test line, 
         [0026]    the voltage test device further comprises a first connector, the switch test line comprises a first portion and a second portion, and the first portion of the switch test line is connected to the second portion of the switch test line through the first connector; 
         [0027]    the first connector is used for preventing the electric current in excess of a predetermined threshold from flowing inside the LCD panel. 
         [0028]    In one aspect of the present invention, when the amount of electric current flowing through the switch test line exceeds a predetermined threshold, the connection between the first portion of the switch test line and the second portion of the switch test line is cut due to a burnout of the first connector, so that the amount of electric current flowing inside the LCD panel is restricted. 
         [0029]    In one aspect of the present invention, the signal-inputting test line comprises a first portion and a second portion; 
         [0030]    the voltage test device comprises a second connector, and the first portion of the signal-inputting test line is connected to the second portion of the signal-inputting test line through the second connector. 
         [0031]    In one aspect of the present invention, when the amount of electric current flowing through the signal-inputting test line exceeds a predetermined threshold, the connection between the first portion of the signal-inputting test line and the second portion of the signal-inputting test line is cut due to a burnout of the second connector. 
         [0032]    In one aspect of the present invention, the second connector comprises a second fastening component and a second conductor connected to the signal-inputting test line through the second fastening component; 
         [0033]    wherein the second conductor has a higher resistance than the signal-inputting test line. 
         [0034]    In one aspect of the present invention, the first connector comprises at least two branch connectors connected in parallel with each other and disposed between the first portion of the switch test line and the second portion of the switch test line. 
         [0035]    In one aspect of the present invention, a third connector and a first transistor is disposed on the switch test line; 
         [0036]    a second transistor is disposed on the signal-inputting test line, and the voltage test device further comprises a fourth connector; 
         [0037]    wherein a source of the first transistor is connected to the test solder pad corresponding to the switch test line through the third connector, and a drain of the first transistor is connected to a gate of the second transistor through the fourth connector; 
         [0038]    a source of the second transistor is connected to the test solder pad corresponding to the signal-inputting test line, and a drain of the second transistor is connected to a source of a switch inside the LCD panel. 
         [0039]    In one aspect of the present invention, the first connector, the third connector, and the fourth connector all comprise a fastening component and a conductor; 
         [0040]    the conductor in each of the connectors is connected to a test line corresponding to each of the connectors through the fastening component in each of the connectors; 
         [0041]    wherein the conductor in each of the connectors has a higher resistance than its corresponding test line. 
         [0042]    Another object of the present invention is to provide a voltage test system for testing an LCD panel for solving the problem occurring in the conventional technology; that it, an excessive amount of electric current occurring during the voltage testing is conducted on the LCD panel usually causes damage to the switching circuits inside the LCD panel. 
         [0043]    According to the present, a voltage test system for testing an LCD panel comprises a voltage test device. The device comprises test solder pads connected to an LCD panel through the test lines, and test lines comprising a switch test line and a signal-inputting test line, 
         [0044]    the voltage test device further comprises a first connector, the switch test line comprises a first portion and a second portion, and the first portion of the switch test line is connected to the second portion of the switch test line through the first connector; 
         [0045]    the first connector is used for preventing the electric current in excess of a predetermined threshold from flowing inside the LCD panel. 
         [0046]    In one aspect of the present invention, when the amount of electric current flowing through the switch test line exceeds a predetermined threshold, the connection between the first portion of the switch test line and the second portion of the switch test line is cut due to a burnout of the first connector, so that the amount of electric current flowing inside the LCD panel is restricted. 
         [0047]    In one aspect of the present invention, the signal-inputting test line comprises a first portion and a second portion; 
         [0048]    the voltage test device comprises a second connector, and the first portion of the signal-inputting test line is connected to the second portion of the signal-inputting test line through the second connector. 
         [0049]    In one aspect of the present invention, when the amount of electric current flowing through the signal-inputting test line exceeds a predetermined threshold, the connection between the first portion of the signal-inputting test line and the second portion of the signal-inputting test line is cut due to a burnout of the second connector. 
         [0050]    In one aspect of the present invention, the second connector comprises a second fastening component and a second conductor connected to the signal-inputting test line through the second fastening component; 
         [0051]    wherein the second conductor has a higher resistance than the signal-inputting test line. 
         [0052]    In one aspect of the present invention, the first connector comprises at least two branch connectors connected in parallel with each other and disposed between the first portion of the switch test line and the second portion of the switch test line. 
         [0053]    In one aspect of the present invention, a third connector and a first transistor is disposed on the switch test line; 
         [0054]    a second transistor is disposed on the signal-inputting test line, and the voltage test device further comprises a fourth connector; 
         [0055]    wherein a source of the first transistor is connected to the test solder pad corresponding to the switch test line through the third connector, and a drain of the first transistor is connected to a gate of the second transistor through the fourth connector; 
         [0056]    a source of the second transistor is connected to the test solder pad corresponding to the signal-inputting test line, and a drain of the second transistor is connected to a source of a switch inside the LCD panel. 
         [0057]    In contrast to the prior art, the voltage test device for testing an LCD panel provided by the present invention comprises test solder pads and test lines. The test solder pads are connected to an LCD panels through the test lines. The test lines comprise a switch test line and a signal-inputting test line. The voltage test device further comprises a first connector. The switch test line comprises a first portion of the switch test line and a second portion of the switch test line. The first portion of the switch test line is connected to the second portion of the switch test line through the first connector. The first connector is used for restricting the amount of electric current flowing inside the LCD panel on the basis of the current strength, preventing the circuits inside the LCD panel from being damaged by an excessive amount of electric current. In other words, the circuits inside the LCD panel is protected from being damaged during the voltage testing is conducted on the LCD panel, which effectively increasing testing efficiency. 
         [0058]    These and other features, aspects and advantages of the present disclosure will become understood with reference to the following description, appended claims and accompanying figures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0059]      FIGS. 1A-1B  depicts a voltage test for an LCD panel by using conventional technology. 
           [0060]      FIG. 2  shows a structure diagram of a voltage test device for testing an LCD panel according to a first preferred embodiment of the present invention. 
           [0061]      FIG. 3  shows a structure diagram of a voltage test device for testing an LCD panel according to a second preferred embodiment of the present invention. 
           [0062]      FIG. 4  shows a structure diagram of a voltage test device for testing an LCD panel according to a third preferred embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0063]    As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. Further, the terms and phrases used herein are not intended to be limiting but rather to provide an understandable description of the invention. 
         [0064]      FIG. 2  shows a structure diagram of a voltage test device for testing an LCD panel according to a first preferred embodiment of the present invention. 
         [0065]    According to the first embodiment, the voltage test device comprises a switch test line  21  and a signal-inputting test line  22 . The first test solder pad  23  corresponds to the switch test line  21 , and the second test solder pad  24  corresponds to the signal-inputting test line  22 . The voltage test device further comprises a first connector  25  and a second connector  26 . 
         [0066]    The switch test line  21  comprises a first portion  211  and a second portion  212 . The first portion  211  is connected to the second portion  212  through the first connector  25 . 
         [0067]    According to the first embodiment as shown in  FIG. 2 , the signal-inputting test line  22  comprises a first portion of the signal-inputting test line  221  and a second portion of the signal-inputting test line  222 . The first portion of the signal-inputting test line  221  is connected to the second portion of the signal-inputting test line  222  through the second connector  26 . 
         [0068]    Continuing to refer to  FIG. 2 , the first connector  25  comprises a first fastening component  251  and a first conductor  252 . The first conductor  252  is connected to the switch test line  21  through the first fastening component  251 . The first fastening component  251  and the first conductor  252  both have a higher resistance than the switch test line  21 . 
         [0069]    Continuing to refer to  FIG. 2 , the second connector  26  comprises a second fastening component  261  and a second conductor  262 . The second conductor  262  is connected to signal-inputting test line  22  through the second fastening component  261 . The second fastening component  261  and the second conductor  262  both have a higher resistance than the signal-inputting test line  22 . 
         [0070]    Preferably, the first and second conductors  252  and  262  are made of indium tin oxide (ITO); otherwise, the conductors  252  and  262  are made from conductive materials having a higher resistance (e.g., metallic materials) as long as the first conductor  252  has a higher resistance than the switch test line  21 , and the second conductor  262  has a higher resistance than the signal-inputting test line  22 . The first and second fastening components  251  and  261  may be made of metallic materials having a higher resistance. 
         [0071]    The operating principle of the first preferred embodiment as shown in  FIG. 2  is as follows: 
         [0072]    Voltage testing starts to be conducted on an LCD panel  27 . Firstly, high voltage is applied on the first test solder pad  23  for turning on a switch (not shown) inside the LCD panel  27 . Subsequently, a test signal applied on the first test solder pad  23  is input inside the LCD panel  27  through the switch test line  21 , and a test signal applied on the second test solder pad  24  is input inside the LCD panel  27  through the signal-inputting test line  22 . 
         [0073]    The amount of electric current flowing through the switch test line  21  and the signal-inputting test line  22  may exceed a predetermined threshold, e.g.,  10 A. When such a situation occurs, heat generated by the excessive amount of electric current causes the first conductor  252  and the second conductor  262  to be burnt out because the first conductor  252  has a higher resistance than the switch test line  21  and the second conductor  262  has a higher resistance than the signal-inputting test line  22 . Accordingly, a disconnection of the switch test line  21  to the signal-inputting test line  22  prevents the excessive amount of electric current from flowing inside the LCD panel  27 . In other words, the circuits inside the LCD panel  27  are protected. 
         [0074]    Obviously, the circuits inside the LCD panel  27  can be prevented from being damaged by an excessive amount of electric current during the voltage testing is conducted on the LCD panel  27  according to the first embodiment as shown in  FIG. 2 . 
         [0075]      FIG. 3  shows a structure diagram of the voltage test device for testing an LCD panel according to a second preferred embodiment of the present invention. 
         [0076]    Differing from the first preferred embodiment, a first connector  35  comprises at least two branch connectors in the second preferred embodiment. Three branch connectors shown in  FIG. 3  are a top connector  351 , a medial connector  352 , and a bottom connector  353  from top to bottom. The three connectors  351 ,  352 , and  353  are connected in parallel and are disposed between the first portion  211  of the switch test line  21  and the second portion  212  of the switch test line  21 . Since the three connectors  351 ,  352 , and  353  are connected in parallel, the width of the first connector  35  is far smaller than that of the switch test line  21 . In this way, the first connector  35  has a lower resistance than the switch test line  21  even though the first connector  35  and the switch test line  21  both are made of the same materials. 
         [0077]    In an actual application, it is possible that two branch connectors (for example, the top connector  351  connected to the medial connector  352 ) or a plurality of branch connectors are connected in parallel as long as the width of the first connector  35  is smaller than that of the switch test line  21 . 
         [0078]    Referring to  FIG. 3 , the top connector  351 , the medial connector  352 , and the bottom connector  353  all comprise a fastening component and a conductor (not shown). Take the top connector  351  for example. The top connector  351  comprises a top fastening component  3511  and a top conductor  3512 . The top conductor  3512  is connected to the switch test line  21  through the top fastening component  3511 . The top fastening component  3511  and the top conductor  3512  both have a higher resistance than the switch test line  21 . 
         [0079]    Preferably, the conductor in each of the top connector  351 , the medial connector  352 , and the bottom connector  353  is made of ITO; otherwise the conductor is made from conductive materials having a higher resistance (such as metallic materials) as long as the conductor in each of the connectors  351 ,  352 , and  353  has a higher resistance than the switch test line  21 . The fastening component in each of the connectors  351 ,  352 , and  353  is made of metallic materials having a higher resistance. 
         [0080]    The operating principle of the second preferred embodiment as shown in  FIG. 3  is as follows: 
         [0081]    The voltage testing starts to be conducted on the LCD panel  27 . Firstly, high voltage is applied on the first test solder pad  23  for turning on the switch (not shown) inside the LCD panel  27 . Subsequently, a test signal applied on the first test solder pad  23  is input inside the LCD panel  27  through the switch test line  21 , and a test signal applied on the second test solder pad  24  is input inside the LCD panel  27  through the signal-inputting test line  22 . 
         [0082]    The amount of electric current flowing through the switch test line  21  may exceed a predetermined threshold, e.g.,  10 A. However, the first connector  35  on the switch test line  21  has a far higher resistance than the switch test line  21  because the three connectors  351 ,  352 , and  353  in the first connector  35  are connected in parallel. Such a design successfully prevents an excessive amount of electric current from flowing inside the LCD panel  27 . In other words, the circuits inside the LCD panel  27  are effectively protected. 
         [0083]      FIG. 4  shows a structure diagram of the voltage test device for testing an LCD panel according to a third preferred embodiment of the present invention. 
         [0084]    The difference between the first and second preferred embodiments and the third preferred embodiment is that, in the voltage test device as shown in  FIG. 4 , the switch test line  21  comprises a first transistor  41  and a third connector  43  in addition a first connector  45 ; the signal-inputting test line  22  comprises a second transistor  42 ; the voltage test device further comprises a fourth connector  44 . 
         [0085]    Referring to  FIG. 4 ,  FIG. 4  shows that the first transistor  41  and the third connector  43  are disposed on the first portion  211  of the switch test line  21 . The source of the first transistor  41  is connected to the first test solder pad  23  through the third connector  43 , and the drain of the first transistor  41  is connected to the gate of the second transistor  42  through the fourth connector  44 . 
         [0086]    The third connector  43  comprises a third fastening component  431  and a third conductor  432 , and the source of the first transistor  41  is connected to the first test solder pad  23  through the third conductor  432 . The third fastening component  431  and the third conductor  432  both have a higher resistance than the switch test line  21 . 
         [0087]    The source of the second transistor  42  is connected to the second test solder pad  24 , and the drain of the second transistor  42  is connected to the source of the switch inside the LCD panel  27 . 
         [0088]    The fourth connector  44  comprises a fourth fastening component  441  and a fourth conductor  442 . The drain of the first transistor  41  is connected to the gate of the second transistor  42  through the fourth conductor  442 . 
         [0089]    The first connector  45  comprises a first fastening component  451  and a first conductor  452 . The first fastening component  451  and the first conductor  452  both have a higher resistance than the switch test line  21 . 
         [0090]    The operating principle of the third preferred embodiment as shown in  FIG. 4  is as follows: 
         [0091]    Voltage testing starts to be conducted on the LCD panel  27 . Firstly, high voltage is applied on the first test solder pad  23  for turning on the first transistor  41 . After passing through the drain of the first transistor, the high voltage turns on the second transistor and the switch inside the LCD panel  27  at the same time. Subsequently, a test signal representing the first test solder pad  23  is input inside the LCD panel  27  through the switch test line  21 , and a test signal representing the second test solder pad  24  is input inside the LCD panel  27  through the signal-inputting test line  22 . The voltage testing conducted on the LCD panel  27  is finished. 
         [0092]    When the amount of electric current flowing through the switch test line  21  exceeds a predetermined threshold (for example,  10 A), two measures are used to restrict the amount of electric current flowing inside the LCD panel  27  according to the third preferred embodiment as shown in  FIG. 4 . The two measures are as follows: 
         [0093]    Firstly, heat generated by the excessive amount of electric current causes the first conductor  452  in the first connector  45  to be burnt out, thereby causing the switch test line  21  to be disconnected. So the excessive amount of electric current is prevented from flowing inside the LCD panel  27 . In other words, the circuits inside the LCD panel  27  are protected. 
         [0094]    Secondly, the third conductor  432  in the third connector  43  has a higher resistance than the switch test line  21 . The source of the first transistor  41  is connected to the first test solder pad  23  through the third conductor  432 . Since the suddenly generated heat causes the third conductor  432  to be burnt out, the third conductor  432  cannot serve as a conducting channel for signals output by the source of the first transistor  41  to pass through. In other words, the first transistor  41  cannot perform its function. The second transistor  42  will be turned on after high voltage provided by the first transistor  41  is applied on it. The malfunction of the first transistor  41  leads to the malfunction of the second transistor  42  as well. Thus, the excessive amount of electric current cannot flow inside the LCD panel  27 , protecting the circuits inside the LCD panel  27  effectively. 
         [0095]    The present invention further provides a voltage testing system used in LCD panels. The system comprises an LCD panel and a voltage test device for testing an LCD panel provided by the present invention. Information about the voltage test device has been fully revealed, so no further details are released hereafter. 
         [0096]    While the present invention has been described in connection with what is considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements made without departing from the scope of the broadest interpretation of the appended claims.