Abstract:
A liquid crystal display array panel includes a substrate, a plurality of gate lines on the substrate, a plurality of data lines on the substrate, an active display region having a plurality of pixels defined by the plurality of gate lines and data lines, and at least two repair lines partially positioned on the active display region and separated from each other. The repair lines crossing some of the plurality of gate lines and all the data lines.

Description:
This application claims the benefit of Korean Patent Application No. 1998-47625, filed on Nov. 7, 1998, which is hereby incorporated by reference for all purposes as if fully set forth herein. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a liquid crystal display (LCD) device, and more particularly, to an array panel of the LCD device with a repair structure. 
     2. Description of the Related Art 
     In general, a liquid crystal display (LCD) device displays an image using a plurality of pixels. The LCD device having a thin film transistor (TFT) as a switching element is typically called a thin film transistor liquid crystal display (TFT-LCD) device. 
     The TFT as the switching element has a gate electrode, a source electrode and a drain electrode. The gate and source electrodes of the TFT are connected to gate and data lines, respectively. Through the gate line, a pulse voltage is applied to operate the gate electrode, and through the data line, a signal voltage is transmitted to operate the source electrode. 
     The LCD device has a plurality of pixels, each of which is operated by a corresponding switching element that is driven by the gate and data lines. 
     The plurality of pixels and the TFTs are formed in a microstructure, and it is very important to form the gate and data lines and other components of the TFTs uniformly. In a display device, therefore, even a small particle may cause a point defect such as a pixel defect and a line defect such as an open gate and/or data lines. 
     Such defects have become serious problems with the increase in the display area of the image device. To solve the problems, a redundant design or repair structure has been introduced. The redundant design or repair structure is more needed for repairing a line defect than a point defect, since a point defect can be repaired without severely damaging the product. However, even one line defect may deteriorate the value of the product. Thus, a redundant design for the line defect has been developed. 
     FIG. 1 shows a conventional repair structure for a line defect of a TFT-LCD device. An active display region  17  with a plurality of pixels is located on a substrate of a liquid crystal display (LCD) device. A plurality of gate lines  11  are arranged in a transverse direction and a plurality of data lines  13  are arranged in a longitudinal direction. A repair line  15  is located outside the active display region  17  in order to repair an open data line. When one of the data lines  13  is opened, the repair line  15  is connected to the open line at two cross points SP 1  and SP 2 . Then, the data signal flows toward a source electrode along a path in the repair line  15 . 
     FIG. 2 shows a modified conventional repair structure of FIG. 1, and FIG. 3 shows another conventional repair structure. In FIGS. 2 and 3, the same method as in FIG. 1 is used to repair the line defect. 
     However, the conventional repair structures have the following disadvantages. Since the repair line  15  is formed outside the active display region  17  in FIGS. 1,  2  and  3 , the length of the path of the repair line  15  along which the gate or data signals must flow is long. Thus, a resistance of the repair line  15  increases causing signal loss and signal delay. In addition, crosstalk at the affected area of the LCD device resulting from a parasitic capacitance generated at a crossing portion of the repair line and the gate or data line is large. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention is directed to a liquid crystal display array panel having a repair structure 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 a repair structure having a reduced or minimum length of the path in repairing opened gate or data lines. 
     Additional features and advantages of the invention will be set forth in the description with 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, a liquid crystal display array panel includes a substrate; a plurality of gate lines on the substrate; a plurality of data lines on the substrate extending transverse to the plurality of gate lines; an active display region having a plurality of pixels defined by the plurality of gate lines and data lines; at least two repair lines partially positioned on the active display region and separated from each other; and wherein the repair lines cross some of the plurality of gate lines and all the data lines. 
     The repair lines are in the form of a rectangular closed loop, each having first and second transverse lines spaced from each other, and first and second longitudinal lines for connecting the first and second transverse lines. The rectangular closed loop repair lines are spaced from and parallel to each other. At least one of the transverse lines of the repair line is positioned under one of the plurality of gate lines with a first insulating layer therebetween. The transverse line under the gate line has a protrusion in a first region under the data line other than a second region where the gate line covers. Further, a liquid crystal display array panel includes a connection bar extending over corresponding longitudinal lines of the adjacent repair lines while a second insulating layer lies between the connection bar and the repair lines. 
    
    
     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 illustrating a repair structure for an LCD device according to the prior art; 
     FIG. 2 shows a modified repair structure of FIG. 1; 
     FIG. 3 is a plan view illustrating another repair structure according to the prior art; 
     FIG. 4 is a plan view illustrating a repair structure according to an embodiment of the present invention; 
     FIG. 5 is an enlarged view of portion “(1)” of FIG. 4; 
     FIG. 6 is an enlarged view of portion “(2)” of FIG. 4; 
     FIG. 7 is a sectional view taken along line VII—VII of FIG. 6; 
     FIG. 8 is an enlarged view of portion “( 3 )” of FIG. 4; 
     FIG. 9 is a plan view illustrating a line defect of a data line according to the embodiment of the present invention; and 
     FIG. 10 is a plan view illustrating a line defect of a gate line according to the embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Reference will now be made in detail to the preferred embodiment of the present invention, example of which is illustrated in the accompanying drawings. 
     As shown in FIG. 4, an active display region  205  with a plurality of pixels is divided into three sections “A”, “B” and “C”. Three repair lines  301 ,  303  and  305  are located in sections “A”, “B” and “C” in the form of a rectangular closed loop, respectively. They are also electrically disconnected from each other. 
     The rectangular closed loop repair line  301  in section “A” has a first transverse repair line  101 , a second transverse repair line  105  spaced from and parallel to the first transverse repair line  101 , and first and second longitudinal repair lines  103  and  107  connecting the first and second transverse repair lines  101  and  105 . The first and second longitudinal repair lines  103  and  107  are located in the non-display region or outside the active display region  205  without overlapping the data lines (not shown). 
     The rectangular closed loop repair lines  303  and  305  of sections “B” and “C” are substantially the same as that of section “A”. 
     First and second connection bars  128  and  135  are preferably arranged to couple the rectangular closed loop repair lines  301  and  303 . The third and fourth connection bars  141  and  143  are also arranged to connect the rectangular closed loop repair lines  303  and  305 . The connection bars  128 ,  135 ,  141  and  143  are arranged on an insulating layer on the rectangular closed loop repair lines  301 ,  303  and  305 . 
     As shown in FIG. 5, which is an enlarged view of portion ( 1 ) in FIG. 4, the first transverse repair line  101  is located at a portion outside the active display region  205  and crosses over the data line  203  with an insulating layer (not shown) between them. 
     FIG. 6 is an enlarged view of portion ( 2 ) in FIGS.  4 . As shown in FIG. 6, the transverse repair lines  105  and  109  have protrusion portions  105   a  and  109   a  and recess portions  105   b  and  109   b , respectively, at all cross points with the data lines  203  such as the cross points “g” and “h”. The gate line is linearly shaped without any protrusions. Thus, there is no gate line over the protrusion portions  105   a  and  109   a  of the repair lines  105  and  109 . 
     FIG. 7 shows a sectional view taken along line VII—VII of FIG.  6 . On a glass substrate  401  is deposited and patterned a suitable conductive metal preferably selected from the group consisting of Mo, Al, W and W-Ta or the like in order to form the repair line  109 . Then, a first insulating layer  403  is formed on the repair line  109 . On the first insulating layer  403  is formed the gate line  201 . On the gate line  201 , a second insulating layer  405  is formed. On the second insulating layer  405 , the data lines  203  are formed which cross over the gate line  201 . The repair line  109 , the gate line  201  and the data line  203  are electrically disconnected or insulated from each other by the first and second insulating layers  403  and  405 . 
     When the gate line  201  become open, it is electrically connected to the repair line  109  through the first insulating layer  403  at a point where the repair line  109  is positioned below the opened gate line  201 . When the data line  203  is opened, it is shorted with the repair line  109  at the protrusion portion  109   a  through the second insulating layer  405 . 
     FIG. 8 shows one of the connection bars for coupling the adjacent rectangular closed loop repair lines  301 ,  303  and  305 . The connection bar  128  couples the adjacent repair lines  301  and  303  mainly when one of the repair lines  301  and  303  is opened. The connection bar  128  is arranged on an insulating layer (not shown) over each end portion of the first longitudinal repair lines of the rectangular closed loop repair lines  301  and  303 . The rectangular closed loop repair lines  301  and  303  are connected to each other at the overlapping portions “F1” and “F2” by the connection bar  128 . 
     FIG. 9 shows a method for repairing a data line with a line defect. 
     Let us assume that certain data lines  203   a  and  203   b  are opened at portions OP 1  and OP 2  in sections “A” and “B”, respectively. In order to repair the open portion OP 1  in section “A”, the data line  203   a  is connected to the first transverse repair line  101  of the closed loop repair line  301  at a cross point “K1” and to the second transverse repair line  105  of the repair line  301  at a cross point “K2”. Then the data signal can transmit through two paths P 1  and P 2 . Then, a portion RP 1  in the longer path P 2  is preferably cut. 
     In order to repair the open portion OP 2 , the data line  203   b  is connected to the first transverse repair line  109  of the closed loop repair line  303  at a cross point “K3” and to the second transverse repair line  113  of the repair line  303  at a cross point “K4”. The data signal can transmit through two paths P 3  and P 4 . Then, a small portion in the longer path P 4  is preferably cut. 
     FIG. 10 shows a method for repairing a line defect in a gate line. 
     Let us assume that certain gate lines  201   a  and  201   b  become open at portions OP 3  and OP 4  in section “A”, respectively. In order to repair the open portion OP 3  in the section “A”, the gate line  201   a  is connected to the first longitudinal repair line  103  of the closed loop repair line  301  at a cross point “K5” and to the second longitudinal repair line  107  of the repair line  301  at a cross point “K6”. In order to repair the open portion OP 4 , the gate line  201   b  is connected to the first longitudinal repair line  103  of the closed loop repair line  301  at a cross point “K7” and to the second longitudinal repair line  107  of the repair line  301  at a cross point “K8”. 
     However, paths that will interfere with the repair line should be removed. For example, one path in the rectangular closed loop repair line  301  which is connected to a good gate line and the other path in the rectangular closed loop repair line  301  which is connected to the good gate line should be electrically disconnected from each other. Thus, portions CP 1  and CP 2  on the first longitudinal repair line  103  and cutting portions CP 3  and CP 4  on the second longitudinal repair line  107  are removed or cut to allow each gate signal to flow separately along each corresponding path in the rectangular closed loop repair line  301 . 
     The repair structure according to the present invention has several advantages. For example, since the length of the repair line becomes smaller, the resistance of the repair line decreases. Thus, signal loss and signal delay due to the open in the signal lines such as data lines and gate lines can be reduced. 
     The rectangular loop repair lines shown and described in the present invention may be a closed loop as described or an open loop such as a “C” shape, for example. 
     It will be apparent to those skilled in the art that various modifications and variation can be made in the liquid crystal display array panel having a repair structure 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.