Abstract:
An apparatus of inspecting a liquid crystal display device includes a magnetic sensor scanning a signal line pattern on a substrate to detect a defective position of the signal line pattern, a camera imaging the signal line pattern detected by the magnetic sensor, an inspecting jig contacting a probe pin with the signal line pattern to determine the existence of defective in the signal line pattern, a transferring tool system transferring at least one of the substrate, the magnetic sensor and the camera in a two-axis direction, and a controller controlling the magnetic sensor, the camera, the inspecting jig and the transferring tool system.

Description:
The present invention claims the benefit of the Korean Patent Application No. P2003-35341 filed in Korea on Jun. 2, 2003, which is hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a liquid crystal display device, and more particularly, an apparatus and a method for inspecting and repairing a liquid crystal display device capable of reducing a defective rate and increasing production efficiency and yield of the liquid crystal display device. 
     2. Description of the Related Art 
     Generally, liquid crystal displays (LCDs) control an electric field supplied to a liquid crystal cell to thereby control light transmittance of liquid crystal material for displaying a desired picture. The liquid crystal displays are classified into a vertical electric field type and a horizontal electric field type in accordance with a direction of the electric field driving the liquid crystal. 
     The liquid crystal display of vertical electric field type has a common electrode and a pixel electrode formed on an upper substrate and a lower substrate, respectively, such that a vertical electric field is formed in the liquid crystal cell by a voltage applied to the common electrode and the pixel electrode. The liquid crystal display of vertical electric field type has a higher aperture ratio but a narrower viewing angle. 
     The liquid crystal display of horizontal electric field type has a common electrode and a pixel electrode formed on a same substrate, such that a horizontal electric field is formed to the liquid crystal cell by a voltage applied to the common electrode and the pixel electrode. The liquid crystal display of horizontal electric field type has a wider viewing angle of about 160°. An example of the liquid crystal display of horizontal electric field type is a liquid crystal display device of in-plane switching (hereinafter referred to as “IPS”) mode. 
       FIG. 1  is a plan view showing a portion of signal lines and a thin film transistor formed on a lower substrate in a liquid crystal display device of in-plane switching (IPS) mode according to the related art, and  FIG. 2  is a sectional view of the lower substrate taken along the lines I-I′ and II-II′ in  FIG. 1 . In  FIGS. 1 and 2 , the liquid crystal display device of the IPS mode comprises a gate line  2  and a data line  4  with a gate insulating film  46  therebetween formed on a lower glass substrate  45  in such a manner to intersect each other, a thin film transistor (TFT)  6  formed at each intersection of the gate line  2  and data line  4 , a pixel electrode  14  connected to a drain electrode  12  of the TFT  6 , a common electrode  18  alternatively arranged with the pixel electrode  14  on an identical plane, a common voltage line  16  commonly connected to a plurality of common electrodes  18 , and a storage capacitor  20  to maintain a pixel voltage. The liquid crystal display device further comprises an upper substrate having a color filter (not shown), a black matrix and an upper polarizer formed thereon. In addition, liquid crystal materials are injected between the lower substrate and the upper substrate. 
     The gate electrode  8  of the TFT  6  is connected to the gate line  2 , and a scan pulse is supplied to the gate line  2 . In an edge of the gate line  2 , a gate pad  24 , which is connected to an output terminal for the scan pulse in a gate driving circuit, is linked. A source electrode of the TFT  6  is connected to the data line  4 , and a data voltage, that is supplied to the pixel electrode  14  of the liquid crystal cell, is applied to the data line  4 . In an edge of the data line  4 , a data pad  30 , which is connected to an output terminal for data voltage in a data driving circuit (not shown), is linked. 
     The TFT  6 , in response to a scan voltage of the gate line  2 , supplies the data voltage to the pixel electrode  14 . The TFT  6  comprises a gate electrode  8 , a source electrode  10 , a drain electrode  12 , an active layer  48  for forming a channel between the source electrode  10  and the drain electrode  12 , and an ohmic contact layer  50  for making an ohmic contact between the active layer  48  and source/drain electrodes  10  and  12 . 
     The pixel electrode  14  is connected to the drain electrode  12  of the TFT  6  via a first contact hole  13  passing through a passivation film  52 . The pixel electrode  14  is connected to the drain electrode  12  at its one side and includes a first horizontal part  14 A connected to the drain electrode  12  and formed in parallel with its adjacent gate line  2  and a second horizontal part  14 B formed to overlap with the common voltage line  16 , and a finger part  14 C formed in parallel with the data line between the first and the second horizontal parts  14 A and  14 B. 
     The common electrode  18  is extended in parallel with the data line  4  from the common voltage line  16  such that it is alternatively arranged with a finger part  14 C of the pixel electrode  14  on an identical plane. The common electrode  18  is separated from the pixel electrode  14  by a predetermined distance. 
     If the data voltage is supplied to the data line  4 , a common voltage is supplies to the common voltage line  16  and the common electrode  18 , and the scan voltage is supplied to the gate line  2 , then the TFT is turned-on and the data voltage is supplied to the pixel electrode  14  via the source electrode  10  and the drain electrode  12  of the TFT  6 . At this time, an electric field is supplied between the pixel electrode  14  and the common electrode  18 , the electric field being substantially drawn to a horizontal direction. The liquid crystal molecules, in response to the horizontal electric field, is rotated due to a dielectric anisotropy to thereby modulate light. 
     The storage capacitor  20  includes a dielectric layer, which has a gate insulating film  46 , the active layer  48  and the ohmic contact layer  50 , a storage electrode  22  and the common voltage line  16  facing each other with the dielectric layer therebetween, and the pixel electrode  14  connected to the storage electrode  22  via a second contact hole  21  passing through the passivation film  52 . 
     The gate pad  24  includes a lower gate pad electrode  26  formed at the edge of the gate line  2  and an upper gate pad electrode  28  connected to the lower gate pad electrode  26  via a third contact hole  27  passing through the gate insulating film  46  and the passivation film  52 . 
     The data pad  30  includes a lower data pad electrode  32  formed at the edge of the data line  4  and an upper data pad electrode  34  connected to the lower data pad electrode  32  via a fourth contact hole  33  passing through the passivation film  52 . 
     A common pad  36  includes a lower common pad electrode  38  formed at the edge of the common voltage line  16  and an upper common pad electrode  40  connected to the lower common pad electrode  38  via a fifth contact hole  39  passing through the passivation film  52 . 
       FIG. 3  is a flow chart of an inspecting process and a repairing process of the liquid crystal display device of  FIGS. 1 and 2  according to the related art. In  FIG. 3 , at steps S 1  and S 2 , the lower glass substrate  45  is taken from the cassette and is inspected on a short circuit of the gate line  8  and the common electrode  18  thereof using an inspecting jig, as shown in  FIG. 4  (to be described later). 
     At step S 3 , if the substrate  45  is determined to have a good-quality at the step S 2 , that is, the lower glass substrate  45  in which the gate line  2  and the common voltage line  16  are not shorted, the substrate  45  is transferred to a next process. On the other hand, at step S 6 , a defective substrate  45  having a short between adjacent the gate line  2  and the common voltage line  16 , as determined at the step S 2 , is returned to a photo-rework process. The photo-rework process is operated in a photo equipment of a mask process on the defective substrate  45 . The photo-rework process includes a photo-resist applying process, an arrangement process of a mask, an exposure process, a development process, and a wet etching process, and is carried out again to pattern the gate line  2 , the gate electrode  8 , the lower gate pad electrode  26 , the common voltage line  16 , the common electrode  18  and the lower common pad electrode  38 . 
     Alternatively, at step S 5 , the defective substrates  45 , as determined at the step S 2 , may be repaired through the processes of a pattern inspecting process to closely inspect the patterns of the gate line  2  and the common voltage line  16  along their patterns through the use of a microscope. In addition, at step S 7 , a laser repairing process is performed to open a short point determined at the pattern inspecting process of step S 5  using a laser beam. The substrate  45  after the pattern inspecting process of step S 5  can be returned to the photo-rework process of the step S 6 . 
       FIG. 4  is a schematic circuit view representing an inspecting jig. In  FIG. 4 , a measuring multi-meter  201  is controlled by a personal computer (PC)  202  and a plurality of switches SWs supplying voltages supplied from the measuring multi-meter  201  to probe pins  205 . In addition, the inspecting jig further includes a driving circuit board (not shown) for supplying an inspecting voltage to the gate line  2  and the common voltage line  16  via a shorting bar provided on the lower glass substrate  45  (not shown). The switches SWs are formed on a relay matrix board and are connected between output lines  203  of the measuring multi-meter  201  and input lines  206  of the probe pins  205 , to thereby switch a signal transmission between the measuring multi-meter  201  and the probe pins  205 . 
     The probe pins  205  are fixed on a probe block  204  that is capable of rising and falling. The controlling PC  202  provides a measured data supplied from the measuring multi-meter  201  to a display device (not shown). Moreover, the controlling PC  202  supplies commands required for the inspection, such as an operator&#39;s command, through the use of input devices, for example, a keyboard or a mouse, a switch controlling command for controlling the switches, and a command for rising and falling the probe block  204  supporting the probe pins  205  to the driving circuit board of the inspecting jig. 
     When the lower glass substrate  45  is loaded in the inspecting jig, a testing voltage, which is supplied from the driving circuit board, is provided to the gate line  2  and the common voltage line  16  via the shorting bar. At this time, the probe pins  205  are connected to the lower gate pad electrode  26  and the lower common pad electrode  38 . Then, the switches SWs are turned-on. If it is detected that the gate line  2  and the common voltage line  16  are not shorted, a resistance of the gate line  2  and the common voltage line  16  has a value higher than a predetermined reference value measured by the measuring multi-meter  201 . However, if it is detected that the gate line  2  and the common voltage line  16  are shorted, a resistance of the gate line  2  and the common voltage line  16  has a value lower than a predetermined reference value due to a conductive alien substance or a defect of a photolithography process. This is because a current path is not formed between the gate line  2  and the common voltage line  16  that are not shorted, while a current path is formed between the gate line  2  and the common voltage line  15  that are shorted . 
     In the liquid display device of IPS mode, a distance between the gate line  2  and the adjacent common voltage line  16  is about 3 μm as shown in  FIG. 1 . Thus, a short between the gate line  2  and the common voltage line  16  frequently occurs in this narrow width. In particular, it has been determined that about 30% of the substrates  45  after undergoing a first mask process have a short defect and are returned to the photo-rework process. Further, because it is difficult to locate the short position rapidly and accurately by the pattern inspecting process, few defective substrates  45  are transferred to the laser repair process. Accordingly, the defective substrates are returned to the photo equipment to repeat the first mask process, thereby delaying the photolithography process and reducing production efficiency. This problem worsens with fabricating substrates having a larger size. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention is directed to a method and apparatus for inspecting and repairing liquid crystal display device that substantially obviates one or more of the problems due to limitations and disadvantages of the related art 
     An object of the present invention is to provide an apparatus and a method of inspecting and repairing a liquid crystal display device those are capable of reducing a defective rate and increasing production efficiency and yield of the liquid crystal display device. 
     Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. 
     To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, the method for inspecting a liquid crystal display device includes scanning a signal line pattern on a substrate using a magnetic sensor to detect a defective position of the signal line pattern. 
     In another aspect, the method for repairing a liquid crystal display device includes scanning a signal line pattern on a substrate using a magnetic sensor to detect a defective position of the signal line pattern, generating coordinate data of the defective position, and performing a repair process on the substrate using the coordinate data. 
     In yet another aspect, the apparatus of inspecting a liquid crystal display device includes a magnetic sensor scanning a signal line pattern formed on a substrate to detect a defective position of the signal line pattern, and a sensor driving circuit driving the magnetic sensor and generate coordinate data of the defective position. 
     In another aspect, the apparatus of inspecting a liquid crystal display device includes a magnetic sensor scanning a signal line pattern on a substrate to detect a defective position of the signal line pattern, a camera imaging the signal line pattern detected by the magnetic sensor, an inspecting jig contacting a probe pin with the signal line pattern to determine the existence of defective in the signal line pattern, a transferring tool system transferring at least one of the substrate, the magnetic sensor and the camera in a two-axis direction, and a controller controlling the magnetic sensor, the camera, the inspecting jig and the transferring tool system. 
     In yet another aspect, the apparatus of repairing a liquid crystal display device includes a magnetic sensor scanning a signal line pattern formed on a substrate to detect a defective position of the signal line pattern, and a repairing means repairing the substrate on a basis of coordinate data of the defective position. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. In the drawings: 
         FIG. 1  is a plan view showing a portion of signal lines and a thin film transistor formed on a lower substrate in a liquid crystal display device of in-plane switching (IPS) mode according to the related art; 
         FIG. 2  is a sectional view of the lower substrate taken along the lines I-I′ and II-II′ in  FIG. 1 ; 
         FIG. 3  is a flow chart of an inspecting process and an repairing process according to the related art; 
         FIG. 4  is a schematic circuit view representing an inspecting jig according to the related art; 
         FIG. 5  illustrates a method for inspecting and repairing a liquid crystal display device according to an embodiment. 
         FIG. 6  is a block diagram of an apparatus for inspecting and repairing of a liquid crystal display device according to an embodiment; 
         FIG. 7  illustrates a configuration of the line camera of  FIG. 6 ; 
         FIG. 8  illustrates an operation of the magnetic sensor of  FIG. 6 ; 
         FIGS. 9 and 10  are diagrams representing a short detecting method of a signal line using the magnetic sensor shown in  FIG. 6 ; 
         FIG. 11  is a diagram representing an open detecting method of the signal line using the magnetic sensor shown in  FIG. 6 ; and 
         FIG. 12  is a diagram representing a method of detecting an interlayer short of the signal lines. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Reference will now be made in detail to the preferred embodiments, examples of which are illustrated in the accompanying drawings. 
       FIG. 5  illustrates a method for inspecting and repairing a liquid crystal display device according to an embodiment. In  FIG. 5 , at step S 71 , a substrate may be taken out from a cassette after the substrate has undergone a fabricating process for manufacturing a liquid crystal display device in the IPS mode. For instance, a gate line, a gate electrode, a lower gate pad electrode, a common voltage line, a common electrode and a common pad electrode may have been formed on the substrate before it is taken out from the cassette. 
     At step  72 , the substrate may be placed on a stage and inspected using a jig. In particular, the jig may be used to detect a short/open point in a signal line formed on the substrate. If no existence of a short/open point in the signal line is detected at step S 72 , the substrate may be transferred to a next process at step S 73 . 
     However, if a short/open point is detected at step S 72 , the substrate may be further inspected using a magnetic sensor at step S 74 . In particular, the magnetic sensor may find that the jig mistakenly detected a short/open point at step S 72 , then the substrate is transferred to a next process at step S 73 . However, the magnetic sensor may confirm the existence of the short/open point between adjacent gate line and common voltage line, then the substrate may be considered as a defective substrate. 
     Alternatively, the substrate taken out from the cassette may bypass the inspection by the jig at step S 72  and may be inspected directly with the magnetic sensor at step S 74 , as shown in the dashed line, thereby reducing inspection time. 
     At step S 75 , a line camera and/or an area camera may be moved by an automatic program or by an inspecting operator to a short/open point detected by the magnetic sensor. For example, the inspecting operator may further confirm the existence of the short/open point by visual inspection from the image(s) taken by the cameras. 
     At step S 76 , a coordinate/position of the short/open point may be generated by the camera and the magnetic sensor. At step S 77 , such a coordinate of the short/open point may be transmitted to a laser repair equipment which repairs the short/open point based on the detected coordinate. 
       FIG. 6  is a block diagram of an apparatus for inspecting and repairing of a liquid crystal display device according to an embodiment. In  FIG. 6 , an apparatus for inspecting a liquid crystal display device may include an X-Y stage  67  for supporting a substrate  75  thereon. The apparatus may include an inspecting jig  66  for detecting an existence of a short point in a signal line formed on the substrate  75 . In particular, the inspecting jig  66  may include probe pins (not shown) for contacting pad regions of the substrate  75 . A current may be applied to the pad regions through the probe pins to thereby detect a resistance of the signal line. In particular, the detected current or resistance data may be compared to a predetermined reference data to determine whether there is a short point in the signal line. 
     In addition, the X-Y stage  67  may move the substrate  75  along an X-axis and a Y-axis as the apparatus detects for an existence and coordinate data of a short point or an open point in the signal line. In particular, the apparatus may include a line photographing part  60  and an area photographing part  63  for collecting different sight information regarding the substrate  75  to determine the coordinate data of the short/open point. The line photographing part  60  may include a line camera  61  and a corresponding image processor  62 . Further, the area photographing part  63  may include an area camera  64  and a corresponding image processor  65 . 
     Moreover, the apparatus may include a magnetic sensor processor  68  for accurately detecting a short point or an open point in a signal line by an induction field. The magnetic sensor processor  68  may include a magnetic sensor  69  and a sensor driver  70 . The apparatus may further include a display device  72  for displaying a coordinate data of the detected short/open point and a memory  73  for storing the coordinate data. 
     A controller  71  may be included to control the operation of the apparatus and may be connected to a repairing equipment  74  for repairing the detected short/open point in the signal line. For instance, the controller  71  may drive the X-Y stage  67  to allow the magnetic sensor  69  to be scanned the substrate  75  along the X-axis direction and the Y-axis direction. The controller  71  may determine a short point and an open point of the signal line from the sensor driver  70  and control the line photographing part  60  and the area photographing part  63  depending upon the coordinate data. Alternatively, the magnetic sensor  69 , the line camera  61 , and the area camera  64  may be movable along the X-axis and the Y-axis for scanning the substrate  75 , while the substrate  75  is held still without having the X-Y stage  67 . 
     Furthermore, the controller  71  may provide the coordinate data to the display device  72  or transmit the coordinate data to the repairing equipment  74  under the controls of a predetermined program or an inspecting operator. The controller  71  may transmit the coordinate data and information on the short/open point from the line photographing part  60  and the sensor processor  68  to the repairing equipment  74  by a standard communication system, such as RS-232. The repairing equipment  74  may perform a repairing process by irradiating a laser beam to the short/open point on a basis of the data supplied from the controller  71 . 
       FIG. 7  illustrates a configuration of the line camera of  FIG. 6 . In  FIG. 7 , the line photographing part  60  shown in  FIG. 6  may photograph the signal line along a longitudinal direction. The line camera  61  may have a plurality of charge-coupled devices (CCDs)  61   a  disposed in a row for scanning a signal line  80  of the substrate  75  shown in  FIG. 6  at a horizontal shifting interval (STR) along the X-axis. The line camera  61  may convert light incident from the substrate  75  to an electrical signal. The image processor  62  may receive such an electrical signal, amplify the signal, convert the signal to a digital signal, and analyze the digital signal to thereby determine the coordinate data of the short/open point based on the horizontal shifting interval (STR) and a vertical shifting distance of the line camera  61 . The coordinate data and an image data photographed from the line camera  61  may then be provided to the controller  71  shown in  FIG. 6  such that such data may be stored, displayed or used for a repair in accordance with a predetermined program or an inspecting operator. 
     In addition, the area camera  64  may include a microscope (not shown) having optical lens of high magnification and CCDs to collect a magnification of a desired area. The area camera  64  may convert an enlarged photographed image to an electrical signal and supply such signal to the image processor  65 . The image processor  65  may amplify the image signal, convert the image signal to a digital signal, supply the digital data to the controller  71 . The controller  71  may store the enlarged image data in the memory  73  and may provide the enlarged image data, under the controls of a predetermined program or an inspecting operator, to the display device  72 , to thereby allow the inspecting operator to view the enlarged image. 
       FIG. 8  illustrates an operation of the magnetic sensor of  FIG. 6 . In  FIG. 8 , the magnetic sensor  69  shown in  FIG. 6  may include a known magnetic sensor, such as one of a magneto-resistance (MR) sensor, a giant magneto-resistance (GMR) sensor, a fluxgate sensor and an inductive sensor. For instance, a MR sensor is a magnetic sensor detecting a variation of an electric field and an existence of a magnetic body by a change of a voltage using a magneto-resist effect device (a MR device). Generally, the MR device is formed of an indium tin (InSn) thin film of monocrystalline having a high electron mobility. If a current i flows through the signal line  80 , an electric field perpendicular to the current is generated, thereby inducing a magnetic field M. The magnetic field M would then change a resistance of the MR device. Accordingly, the short/open point of the signal line  80  may be detected by detecting a change in resistance of the MR device with the voltage. A permanent magnet of the rare-earth system may be additionally adhered to the MR device to improve a sensing perception. 
     The sensor driver  70  may supply a driving current to the MR device of the magnetic sensor  69 . In addition, the sensor driver  70  may amplify the voltage supplied from the MR device, compare it to a predetermined reference voltage, and supply a digital signal representing whether there is a short/open in the signal line to the controller  71 . Moreover, the sensor driver  70  may produce a coordinate data indicating a position of a short point or an open point on a basis of a relative movement amount of the substrate  75  to the magnetic sensor  69  or a relative movement amount of the magnetic sensor  69  to the substrate  75 . 
     In  FIGS. 9 to 12 , the reference numeral ‘V’ represent a voltage detected by the magnetic sensor  69  and the reference numeral ‘d’ represents a length of the substrate. In addition, the signal line is schematically represented as a portion of the gate line  2  and the common voltage line  16  formed on the substrate  45  shown in  FIG. 2 . 
       FIGS. 9 and 10  are diagrams representing a short detecting method of a signal line using the magnetic sensor shown in  FIG. 6 . In  FIG. 9 , a high potential voltage Vh may be applied to one side of the gate line  2  and a low potential voltage V 1  may be applied to an opposite side of the common voltage line  16 . In addition, the high potential voltage Vh may be selected as a high gate voltage Vgh of a scan pulse and the low potential voltage V 1  may be selected as a common voltage Vcom. 
     The magnetic sensor  69  may scan the gate line  2  and the common voltage line  16  by a non-contacting method along a width direction (shown as the dashed line along the Y-axis) across the gate line  2  and the common voltage line  16 . If there is no short, no current would flow from one side to another, since no current passage is formed between the gate line  2  and the common voltage line  16 . However, if there exists a shorted point  102  between the gate line  2  and the common voltage line  16  caused by a defective patterning or a foreign conductive material, then a current i would flow between the gate line  2  and the common voltage line  16 , thereby causing a change in voltage V detected by the magnetic sensor  69 . 
     In particular, a magnetic field induced by the current i at the short point  102  may induce the MR device of the magnetic sensor  69 . Thus, a resistance of the MR device in the magnetic sensor  69  becomes lower by the induction magnetic field and the resistance thereof may be detected as a higher voltage. In addition, where a gate line  2  and the common voltage line  16  are not shorted, since the induction magnetic field is induced to the MR device of the magnetic sensor  69 , the magnetic sensor  69  has a higher resistance. Thus, when the magnetic sensor  69  scans the gate line  2  and common voltage line  16  that are not shorted, a voltage of the magnetic sensor  69  is detected as a lower value. 
     Further, the controller  71  may move the line camera  61  to the short point detected by the magnetic sensor  69  and then shift the line camera  62  along a longitudinal direction of the gate line  2  and the common voltage line  16 , that is, along the X-axis. If the short point  102  is detected by the line camera  61 , then the image processor  62  supplies the coordinate data indicating the position of the short point  102  to the controller  71  on a basis of the movement amount of X-axis direction and Y-axis direction. 
     In  FIG. 10 , a high potential voltage Vh may be applied to one side of the gate line  2  and a low potential voltage V 1  may be applied to the same side of the common voltage line  16 . As the magnetic sensor  69  scans the gate line  2  and the common voltage line  16  by a non-contacting method along a width direction  111   y  crossing the gate line  2  and the common voltage line  16 , the magnetic sensor  69  may detect a higher voltage in Vy at the short point  112 . Then, the magnetic sensor  69  may be moved to scan the substrate along a longitudinal direction  111   x  to detect a coordinate of the short point  112 . In particular, as the magnetic sensor  69  scans along the X-axis, since a current would flow through the gate line  2  and the common line  16  up to the short point  112 , a change in voltage Vx may be detected by the magnetic sensor  69 , thereby determining a coordinate of the short point  112  without other inspecting means. 
       FIG. 11  is a diagram representing an open detecting method of the signal line using the magnetic sensor shown in  FIG. 6 . In  FIG. 11 , the gate line  2  and the common voltage line  16  are shorted by shorting lines  123   a  and  123   b  or the other separate conductive means at their both sides. In addition, a high potential voltage Vh may be applied to one side of both the gate line  2  and the common voltage line  16 , while a low potential voltage V 1  may be applied to an opposite side of both the gate line  2  and the common voltage line  16 . 
     The magnetic sensor  69  may scan the gate line  2  and the common voltage line  16  by a non-contacting method along a width direction  121  along the Y-axis. If there is no open point, a current i would flow from one side to another. Thus, a rise in the voltage V would be detected by the magnetic sensor  69  at each of non-defective gate line  2  and common voltage line  16 . However, if there is an open point  122  in the common voltage line  16 , no current would flow in the common voltage line  16 . Thus, a lower voltage would be detected by the magnetic sensor  69  at the open common voltage line  16 . 
     Further, the controller  71  may move the line camera  61  to an open line detected by the magnetic sensor  69  and then shift the line camera  62  along a longitudinal direction of the gate line  2  and the common voltage line  16 , that is, along the X-axis. If the line camera  61  detects the open point  122 , then the image processor  62  may supply the coordinate data indicating the position of the open point  122  to the controller  71  on a basis of the movement amount of x-axis direction and y-axis direction. 
       FIG. 12  is a diagram representing a method of detecting an interlayer short of the signal lines. In  FIG. 12 , one side of the gate line  2  and the common voltage line  16  may be shorted by shorting lines  133   a  or the other separate conductive means, while keeping another side of the gate line  2  and the common voltage line  16  in an electrically insulated state. In addition, one side of the data line  4  may be shorted by shorting lines  133   b  or the other separate conductive means, while keeping another side of the data line  4  in an electrically insulated state. A high potential voltage Vh may be applied to one sides of the gate line  2  and the common voltage line  16 , and a low potential voltage V 1  may be applied to the one side of the data line  4 . 
     The magnetic sensor  69  may scan the gate line  2  and the common voltage line  16  by a non-contacting method along a width direction  121  along the Y-axis. If there is no open point, a current i would flow from one side to another. Thus, a rise in the voltage V would be detected by the magnetic sensor  69  at each of non-defective gate line  2  and common voltage line  16 . However, if there is an open point  122  in the common voltage line  16 , no current would flow in the common voltage line  16 . Thus, a lower voltage would be detected by the magnetic sensor  69  at the open common voltage line  16 . 
     The magnetic sensor  69  may scan the gate line  2  and the common voltage line  16  by a non-contacting method along a direction in which the gate line  2  and the data line  4  intersect, such as a scan direction  131   y  in the Y-axis. In such a scanning, a current (i) would flow between the gate line  2  and the common voltage line  16  in which an interlayer short point  132  exists. However, a current (i) would not flow between the gate line  2  and the common voltage line  16  in which an interlayer short point  132  does not exist. An existence of the current (i) results in a resistance change in the MR device and thus the resistance change is detected as a voltage (V). 
     After the interlayer short point  132  is detected in y-axis direction, the magnetic sensor  69  may scan the data line  4  by a non-contacting method along a scan direction  131   x  in the X-axis. In such a scanning, a current (i) would flow through the data line  4  in which an interlayer short point  132  exists, while a current (i) would not flow through the data line  4  in which the interlayer short point  132  does not exist. An existence of the current (i) causes a resistance change of the MR device, and then the resistance change is detected as a voltage (V). Accordingly, if the magnetic sensor  69  scans along the X-axis and Y-axis, then the interlayer short point is accurately detected. 
     The above-described apparatus and method for inspecting and repairing the liquid crystal display device of the embodiments detect a short point and an open point of the liquid crystal display device. Therefore, most of the defective substrates may be restored by the repair process and the number of substrates returned to the photo-rework process is minimized, to thereby reduce the load of the photo-rework process. In advance, the inspecting and repairing apparatus and the method enable the improvement of the detection accuracy using the line camera and the area camera, and the rapid repair process on a basis of data detected by the line camera an the magnetic sensor. As a result, it is possible to reduce a defect ratio of the liquid crystal display device and to increase a production efficiency and a productive of the liquid crystal display device. 
     It will be apparent to those skilled in the art that various modifications and variations can be made in the apparatus and the method for inspecting and repairing the liquid crystal display device of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.