KR100674241B1 - Liquid crystal display - Google Patents

Abstract

The present invention discloses a liquid crystal display device in which the screen quality and manufacturing yield are improved by enabling the repair of defective pixels. In the disclosed liquid crystal display device, a plurality of gate lines and a data line are arranged to be orthogonal to each other under an insulating film, and a thin film transistor is disposed at an intersection of the gate line and the data line, and the gate line and the data line are interposed therebetween. In a limited unit pixel, an array substrate having a structure in which pixel ITO electrodes are arranged to be connected to a thin film transistor is bonded to a color filter substrate having a color filter and a counter electrode under an intervening liquid crystal layer. A first connection pattern disposed in parallel with the gate line to partially repair the defect of the pixel ITO electrode, the first connection pattern having one end and the other end overlapping with the corresponding data lines, respectively; A front end gate parallel to the data line and having one end and the other end corresponding to each other A second connection pattern may be formed to overlap the line and the first connection pattern, respectively.

Description

Liquid crystal display

1A and 1B are diagrams for explaining a conventional problem.

2 is a diagram illustrating a unit pixel structure of a conventional liquid crystal display device.

3 is a diagram illustrating a unit pixel structure of a liquid crystal display according to an exemplary embodiment of the present invention.

4A to 4C are views for explaining a repair method of the liquid crystal display according to the present invention;

5A and 5B are views for explaining visibility of dark pixels after repair of the liquid crystal display according to the present invention;

6 and 7 illustrate a unit pixel structure of a liquid crystal display according to another exemplary embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

30: thin film transistor 31: common electrode line

32n, 32n + 1: Gate line 33: First connection pattern

34m, 34m + 1: Data line 35: Second connection pattern

A: defective area B: dark area

C: normal area 50a, 50b: dark area

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device having a pixel structure capable of split repair.

Liquid crystal display (Liquid Crystal Display) has been developed as a display device to replace the CRT (Cathode-ray tube). In particular, the thin film transistor liquid crystal display device having a thin film transistor as a switching element for each pixel realizes high quality, large size, and color screen comparable to the CRT. The TV market is also in the spotlight.

Such a thin film transistor liquid crystal display typically has a structure in which an array substrate including a thin film transistor and a pixel electrode, and a color filter substrate including a color filter and a counter electrode are bonded to each other under a liquid crystal layer.

In the liquid crystal display, on the other hand, hundreds of thousands to millions of pixels are directly directed to a single panel. Therefore, when a defect occurs in a switching element of each pixel, that is, a thin film transistor, in the manufacturing of an array substrate, and when a defect occurs in a pixel indium tin oxide (ITO) electrode, this appears as a defect on the screen and yields a product. Lowers. In particular, since defects in the pixel ITO electrodes are frequently generated due to process problems, measures to prevent the occurrence of pixel defects due to defects in the pixel ITO electrodes are necessary.

Conventionally, when pixel defects occur due to a process problem, in particular, in case of a bright pixel defect, dark pixels are made by using laser irradiation so as to have low visibility.

However, as described above, the method of making a bright pixel into a dark pixel is considered in view of visibility, and the number of the bright pixels is counted in proportion to the resolution and the pixel size to determine whether the panel is defective. As shown in FIG. 1A, when the pixel having the high resolution (Dot Per Inch) pixel is low, the visibility of the dark pixel 10a is not low, but as shown in FIG. 1B, the pixel having the low resolution pixel is shown. In this case, even after only one dark pixel 10b is produced, the dark pixel 10b is visually recognized as large. Therefore, the entire panel is inevitably treated poorly, and thus the manufacturing yield of the liquid crystal display device is reduced.

Accordingly, an object of the present invention is to provide a liquid crystal display device capable of preventing a decrease in manufacturing yield due to pixel defects, even when having a low resolution pixel. .

In order to achieve the above object, in the present invention, a plurality of gate lines and data lines are arranged orthogonal to each other under an insulating film, and a thin film transistor is disposed at an intersection of the gate lines and the data lines, and In a liquid crystal display device in which an array substrate having a structure in which pixel ITO electrodes are arranged to be connected to a thin film transistor in a unit pixel defined by a data line is bonded to a color filter substrate having a color filter and a counter electrode under an intervening liquid crystal layer. In each of the unit pixels, a first portion in which one side end and the other end end are disposed in parallel with the corresponding data lines, respectively, is disposed in parallel with the gate line to divide and repair a defect of the pixel ITO electrode. The one end and the other end correspond to the connection pattern and the data line in parallel with each other. The liquid crystal display device is characterized in that a second connection pattern is formed to overlap the front gate line and the first connection pattern, respectively.

In addition, in the present invention, a plurality of gate lines and data lines are arranged to be orthogonal to each other under an insulating film, and a thin film transistor is disposed at an intersection of the gate lines and the data lines, and is defined as a unit pixel defined by the gate lines and the data lines. A pixel ITO electrode is arranged to be connected to the thin film transistor and an array substrate having a common electrode line arranged in parallel with a gate line is disposed at the center of the unit pixel. The color filter substrate includes a color filter and a counter electrode under the liquid crystal layer. And a front gate line corresponding to each of the one end and the other end of the unit pixel in parallel with the data line to divide and repair defects of the pixel ITO electrode in the unit pixel. At least one connection pattern disposed to overlap the common electrode line It provides a liquid crystal display device characterized in that formed.

(Example)

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, the technical principle of the present invention will be briefly described. In the present invention, a floating connection pattern is formed in a unit pixel so that the unit pixel is divided into a desired area. The defective pixel is repaired by cutting using a laser and welding by using the floating connection pattern.

In this case, the actual size of the defective pixels is significantly reduced by the division repair, and thus the visibility is lowered, so that the pixel defects can be reduced, and thus, the screen quality and the manufacturing yield can be improved. .

In detail, FIG. 2 is a diagram illustrating a pixel structure of a conventional liquid crystal display, and as shown, a pair of gate lines 22n and 22n + are arranged so that unit pixels extend in one direction through an insulating film (not shown). 1) and a pair of data lines 24m and 24m + 1 arranged to extend in the other direction perpendicular thereto, and at the intersection of the gate line 22n + 1 and the data line 24m + 1. The thin film transistor 20 which is a switching element is provided, and the pixel ITO electrode 26 is arranged in contact with the thin film transistor 20 in the unit pixel.

In such a pixel structure, when a defect occurs in the pixel ITO electrode 26 due to a process, the pixel becomes a defect, and it is common to perform a dark process. If it is a low resolution liquid crystal display device, Visibility increases and manufacturing yield falls.

Accordingly, the present invention designs the unit pixel with the structure as shown in FIG. As shown in FIG. 3, the unit pixel of the liquid crystal display according to the present invention is a pair of gate lines 32n and 32n + 1 arranged perpendicularly to and interposed with an insulating film (not shown). Thin film, which is partitioned by a pair of data lines (34m, 34m + 1) arranged to extend in another direction, and at the intersection of the gate line (32n + 1) and the data line (34m + 1) The transistor 30 is provided, and the pixel ITO electrode 36 is disposed in contact with the thin film transistor 30 in the unit pixel, and the defects of the pixel ITO electrode 36 can be repaired separately. A first connection pattern 33 disposed in parallel with the gate lines 32n and 32n + 1 and partially overlapping one end and the other end with the corresponding data lines 34m and 34m + 1, respectively; One side and the other end is disposed in parallel with the data line (34m, 34m + 1) Previous gate line (32n) and the first connecting patterns 33 and the second connection pattern 35 which is disposed in each of a portion to overlap each have a structure corresponding to the additional formed.

Here, the first connection pattern 33 is formed together with the gate lines 32n and 32n + 1, and the second connection pattern 35 is formed together with the data lines 34m and 34m + 1. The first connection pattern 33 and the second connection pattern 35 are formed to be disposed at, for example, the pixel center part.
The first connection pattern 33 and the second connection pattern 35 shown in FIG. 3 perform a function of compensating capacitance together with the function of the black matrix.
In the liquid crystal display according to the present invention having such a pixel structure, as shown in FIG. 4A, a short between the front gate line 32n and the pixel ITO electrode 36 occurs due to a defect of the pixel ITO electrode 36. When generated, as shown in FIG. 4B, the pixel ITO electrode portion of the defective area A is cut through laser irradiation.
At this time, since the defective generation region A shorted with the front gate line 32n among the pixel electrodes is shorted with the front gate line 32n, the capacitance necessary for holding an image is not formed in the defective generation region A. Do not. Therefore, the voltage cannot be maintained for one frame, so that the defective state A becomes black while the liquid crystal is driven. On the other hand, the image is normally displayed on the pixel electrode connected to the gate line 32n + 1. As a result, different voltages are applied to the defective occurrence region A of the pixel electrode and the unshorted portion of the pixel electrode. That is, since different voltages are applied to one pixel electrode, different voltages are applied to the liquid crystals belonging to one pixel electrode, thereby generating a foreground line and an unwanted light leakage by the foreground line. . However, since the portion where light leakage is generated is covered by the first connection pattern 33 and the second connection pattern 35, light leakage is fundamentally blocked because no light is provided. That is, the first and second connection patterns 33 and 35 play a black matrix.
On the other hand, when the defect generation region A of the pixel electrode is removed by laser cutting, the overlapping area of the front gate line A and the pixel electrode is reduced so that the corresponding pixel electrode cannot maintain the voltage for one frame. Can be caused.
Therefore, one side end of the second connection pattern 35 and the front end gate line 32n corresponding thereto are electrically connected to each other through laser irradiation again.
Then, one end of the first connection pattern 35 and the front gate line 32n are electrically connected to each other, and the pixel electrode overlaps the first connection pattern 35 to generate capacitance. Here, the capacitance generated due to the overlap of the pixel electrode and the first connection pattern 35 compensates for the capacitance lost due to the reduction of the overlap area between the pixel electrode and the front gate line 32n by laser cutting, and thus, for one frame. You can keep the video.
As shown in FIG. 4C, the defective area is darkened. In Fig. 4C, reference numeral B denotes a dark region and C denotes a normal region, respectively.

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In this case, since only the actual defective area is darkened in the entire size of the bad pixel, the size of the dark area B becomes very small, and thus the visibility is significantly lowered. Therefore, even in a low resolution liquid crystal display device, the visibility is reduced. As a result, screen quality can be improved, and manufacturing yield can be increased.

5A and 5B are diagrams for explaining visibility of dark pixels after repair of the liquid crystal display according to the present invention. As shown in FIG. 5A and FIG. In the case of FIG. 5B in which only the defective area is darkened, visibility of the dark areas 50a and 50b is lowered.

6 and 7 illustrate a pixel structure of a liquid crystal display according to another exemplary embodiment of the present invention. Here, the same parts as in FIG. 3 are designated by the same reference numerals, and the same parts as in FIG. 3 will be omitted and only different parts will be described.

Referring to FIG. 6, in the liquid crystal display according to the present embodiment, at least one second connection pattern 35 is formed. In this case, the size of the dark treatment area can be further reduced, which further lowers the visibility.

Referring to FIG. 7, the liquid crystal display according to the present exemplary embodiment corresponds to a structure in which the common electrode line 31 is disposed between the gate lines 32n and 32n + 1, and in this embodiment, the common electrode line 31. ) May function as the above-described first connection pattern, so that only the second connection pattern 35 of the front gate line 32n and the common electrode line 31 corresponding to each of one end and the other end in the unit pixel is included. They are additionally installed in parallel with the data lines 34m and 34m + 1, respectively, overlapping portions. The division repair is performed by laser welding between one end of the second connection pattern 35 and the front gate line 32n, and the other end of the second connection pattern 35 and the common electrode line 31. In this case, at least one second connection pattern 35 may be formed as described above.

In this case, since only the one end and the other end of the second connection pattern 35 need to be laser welded, the split repair can be simplified.

As described above, according to the present invention, after forming the first and second connection patterns in the floating state in the unit pixel, only the defective area is darkened through the division repair, thereby increasing the screen quality by reducing the visibility. In addition, the production yield can be improved.

As mentioned above, although the present invention has been illustrated and described with reference to specific embodiments, the present invention is not limited thereto, and the following claims are not limited to the scope of the present invention without departing from the spirit and scope of the present invention. It can be easily understood by those skilled in the art that can be modified and modified.

Claims (9)

A plurality of gate lines and data lines are arranged orthogonally under the insulating layer, and a thin film transistor is disposed at an intersection of the gate line and the data line, and connected to the thin film transistor in a unit pixel defined by the gate line and the data line. In the liquid crystal display device in which an array substrate having a structure in which pixel ITO electrodes are arranged is bonded to a color filter substrate having a color filter and a counter electrode under an intervening liquid crystal layer, In each unit pixel, a first connection is disposed in parallel with the gate line to partially repair the defect of the pixel ITO electrode, and the one end and the other end are respectively overlapped with the corresponding data lines. And a second connection pattern formed in parallel with the data line and having one end and the other end respectively overlapping with the corresponding front gate line and the first connection pattern. The liquid crystal display of claim 1, wherein the first connection pattern is formed with a gate line and the second connection pattern is formed with a data line. The liquid crystal display device of claim 1, wherein the first connection pattern and the second connection pattern are formed in a central portion of the pixel, respectively. The liquid crystal display device of claim 1, wherein at least one second connection pattern is formed. The liquid crystal display of claim 1, wherein one side end and the front gate line of the first connection pattern are electrically connected to each other. A plurality of gate lines and data lines are arranged orthogonally under the insulating layer, and a thin film transistor is disposed at an intersection of the gate line and the data line, and connected to the thin film transistor in a unit pixel defined by the gate line and the data line. A pixel ITO electrode is disposed so that an array substrate having a structure in which a common electrode line is arranged in parallel with a gate line is bonded to a color filter substrate having a color filter and a counter electrode interposed therebetween. In the apparatus, In each of the unit pixels, one side end and the other end of the unit I are disposed in parallel with the data line so as to partially repair the defects of the pixel ITO electrode, and each of the one end and the other end overlap each other with the corresponding front gate line and the common electrode line. Liquid crystal display device characterized in that at least one connection pattern is formed. The liquid crystal display of claim 6, wherein the connection pattern is formed together with a data line. The liquid crystal display of claim 6, wherein each of one end and the other end of the connection pattern is electrically connected to each of the corresponding front gate line and common electrode line by laser irradiation. The liquid crystal display of claim 6, wherein at least one connection pattern is formed.

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