KR20000009914A - Liquid crystal display device and pixel repairing method thereof - Google Patents

Abstract

PURPOSE: Liquid-crystal display and a pixel repair method is provided which corrects bad pixels indicated bright in the normally black mode. CONSTITUTION: The liquid-crystal display with the pixel electrode (800) removed from the connection part of the storage electrode (230) and the gate line (200) cuts the storage electrode (230) or the gate line (200) not overlapping the pixel electrode (800) to change the bad pixel into off bad pixel, when a high bad pixel occurs from the short circuit of the gate line (200) or storage electrode (230) and the pixel electrode (800). The liquid-crystal display with a electrode line for common voltage (500) detached from the storage electrode and the gate line (200) and with the edge of the pixel electrode (800) overlapped with the storage electrode (230), the gate line (200), and the electrode line for common voltage (500) is provided to cut the pixel electrode and the electrode line for common voltage (500) and to cut the drain electrode (620) and the pixel electrode (800) and to change the high bad pixel into the off bad pixel.

Description

Liquid crystal display and pixel defect repair method

The present invention relates to a liquid crystal display device and a method for repairing pixel defects thereof.

In general, a liquid crystal display includes a pair of transparent glass substrates on which transparent electrodes are formed, a liquid crystal material between two glass substrates, two polarizers attached to an outer surface of each glass substrate to polarize light, and a light emitting device that emits light. It consists of a back light.

In order to improve the contrast ratio, such a liquid crystal display generally adopts a normally black mode that displays a dark color in a state where no voltage is applied.

The two substrates are thin film transistor substrates in which gate lines and data lines defining pixels are formed, and thin film transistors for controlling data signals applied to the pixel electrode and the pixel electrode are formed in each unit pixel.

Next, the unit pixel structure of the liquid crystal display according to the related art will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, a gate pattern including a double gate line 20 and 22 in a horizontal direction and a gate electrode 21 formed by bending a portion of the gate line 20 is formed, and a double gate line 20 is formed. , 22 are formed in the longitudinal direction. The data line 60 formed in the vertical direction and insulated from the gate line 20, the source electrode 61 and the gate electrode 21, which are branches of the data line 60, face the source electrode 61. A data pattern made up of the drain electrode 62 extending to the gate line 22 formed above is formed. The pixel electrode 80 is formed in the pixel area defined by the intersection of the gate line 20 and the data line 60, and is connected to the drain electrode 62 through the contact hole 71.

In the conventional liquid crystal display, the gate lines 20 and 22, the storage electrode 23, and the pixel electrode 60 are completely overlapped with an insulating film interposed therebetween, thereby sufficiently securing the storage capacitance.

However, when the pixel electrode 80 and the gate lines 20 and 22 or the storage electrode 23 are short-circuited to generate a pixel defect that always displays bright colors, the pixel electrode 80 is covered with the gate electrode 20. 22) or it is difficult to disconnect the sustain electrode 23, so that it is impossible to repair the pixel defects.

The present invention provides a liquid crystal display device having pixels formed in a structure capable of repairing pixel defects that are always displayed brightly in normally black mode.

In addition, the present invention provides a pixel defect repair method capable of repairing pixel defects that are always displayed brightly in normally black mode.

1 is a layout view illustrating a structure of a unit pixel of a liquid crystal display substrate according to the related art.

2 is a layout view schematically illustrating a structure of a unit pixel of a liquid crystal display according to a first exemplary embodiment of the present invention.

3 is a layout view schematically illustrating a structure of a unit pixel of a liquid crystal display according to a second exemplary embodiment of the present invention.

4 is a layout view schematically illustrating a structure of a unit pixel of a liquid crystal display according to a third exemplary embodiment of the present invention.

In order to solve this problem, the liquid crystal display according to the exemplary embodiment of the present invention has a pixel electrode formed so as to expose a part of the sustain electrode connected to the gate line, or an electrode line for common voltage that can apply a common voltage is added. It is formed.

Here, the common voltage is a voltage applied to the common electrode opposite to the pixel electrode to drive the liquid crystal.

In the liquid crystal display according to the present invention, a method of repairing pixel coupling may be performed by disconnecting a sustain electrode that does not overlap the pixel electrode or by shorting the common voltage electrode line and the pixel electrode to apply a common voltage to the pixel electrode.

Next, a liquid crystal display according to an exemplary embodiment of the present invention and a method of repairing pixel defects thereof will be described in detail with reference to the accompanying drawings so that a person skilled in the art may easily implement the present invention. .

FIG. 2 is a layout view schematically illustrating a structure of a unit pixel of a liquid crystal display according to a first exemplary embodiment of the present invention, and FIG. 3 schematically illustrates a structure of a unit pixel of a liquid crystal display according to a second exemplary embodiment of the present invention. It is a layout shown by.

As seen in FIGS. 2 and 3. Similar to the conventional structure, a gate pattern including double gate lines 200 and 220 formed in a horizontal direction and a gate electrode 210 formed by bending a portion of the gate lines 200 is formed. A storage electrode 230 is formed to connect the dual gate lines 200 and 220 and define a pixel area. The source electrode 610 is formed around the data line 600, the source electrode 610, which is a branch of the data line 600, and is insulated from the gate line 200. ) And a data pattern formed of a drain electrode 620 extending to the gate line 220 formed thereon.

However, in the pixel area defined as the gate line 200 and the storage electrode 230 in FIG. 2, the pixel electrodes 800 connected to the drain electrode 620 through the contact hole 710 are the gate lines 200 and 220. ) And the edge portion of the storage electrode 230 overlap with each other, but the pixel electrode 800 is partially removed from the portion where the gate line 200 and the storage electrode 230 are connected to each other. In addition, in FIG. 3, the storage electrode 231 is separated from the gate line 200, and the pixel electrode 800 is formed at a portion where the gate electrode 210 and the storage electrode 230, which are part of the gate line 200, are connected. Some have been removed.

In the structure of the liquid crystal display device shown in FIGS. 2 and 3, when the gate electrode 200, 220 and the sustain electrode 230, 231 have a short circuit due to a short circuit of the pixel electrode 800, the pixel electrode 800 is disconnected. The gate lines 200 and 220 and the storage electrode 230 are disconnected by irradiating a laser to a portion A where the storage electrode 230 and the pixel electrode 800 and the gate line 220 which are removed do not overlap. Thus, the gate patterns 200, 210, 220 and the sustain electrode 230 are shorted to change the high pixel defects that are always bright to off pixel defects that are dark.

In general, in the manufacturing process of the liquid crystal display, since the tolerance for off-pixel defects is larger than that of brightly displayed high pixel defects, the effect of improving the high pixel defects in the normally black mode in the case of introducing a repair technique such as relaxation You can expect.

As a method of changing the high pixel defect into an off pixel defect, there is a method of applying a voltage applied to the common electrode to the pixel electrode where the high pixel defect occurs. That is, when the common voltage is applied, when the same voltage is applied between the pixel electrode and the common electrode facing the common voltage, a potential difference does not occur, thereby displaying a dark state. The structure that can implement this will be described in detail.

4 is a layout view schematically illustrating a structure of a unit pixel of a liquid crystal display according to a third exemplary embodiment of the present invention.

As shown in FIG. 4, unlike the first and second embodiments, a gate pattern including a single gate line 200 and a gate electrode 210 in which a portion of the gate line 200 is curved is formed in a horizontal direction. The sustain electrode 230 is connected to the gate line 200 and is formed in the vertical direction. The common voltage electrode line 500 separated from the gate patterns 200 and 210 and the storage electrode 230 is formed in the horizontal direction. In addition, the source electrode 610 around the data line 600, the source electrode 610, which is a branch of the data line 600, and the gate electrode 210, which are insulated from and intersect the gate line 200 to define a pixel area. A data pattern formed of a drain electrode 620 facing the upper portion and extending to the upper pixel area is formed. An edge of the common voltage electrode line 500, the gate patterns 200 and 210, and the storage electrode 230 overlap each other, and the pixel electrode 800 connected to the drain electrode 620 through the contact hole 710 is formed. It is formed in the pixel area.

In the liquid crystal display according to the third exemplary embodiment of the present invention, a common voltage applied to a common electrode (not shown) facing the pixel electrode 800 is applied to the common voltage electrode line 500.

When the pixel electrode 800, the gate patterns 200 and 210, and the storage electrode 230 are short-circuited and appear to be high pixel defects, the A and B portions are irradiated with a laser to expose the drain electrode 620 and the pixel electrode 800. The circuit is disconnected and the common voltage electrode line 500 and the pixel electrode 800 are shorted. Then, the common voltage applied to the electrode line 500 for the common voltage is supplied to the pixel electrode 800 to be displayed as an off pixel defect. That is, since the same voltage is applied to the pixel electrode 800 and the common electrode (not shown) facing the pixel electrode 800, a potential difference does not occur and thus a dark state is displayed due to a normally black mode, resulting in an off pixel defect.

As described above, in the liquid crystal display device and the pixel defect repair method according to the present invention, the high pixel defect displayed brightly is changed to an off pixel defect having a large allowable range for the defect in the good product judgment. Can improve the quality.

Claims (4)

A gate line formed in a horizontal direction, A storage electrode connected to the gate line, A data pattern comprising a data line insulated from and intersecting the gate line to define a pixel region, a source electrode which is a branch of the data line, and a drain electrode separated from the source electrode; An edge portion of the pixel region overlapping the sustain electrode and the gate line and including a pixel electrode connected to the drain electrode; And the pixel electrode is removed at a portion connected to the sustain electrode and the gate line. A gate line formed in a horizontal direction, a sustain electrode connected to the gate line, a data line insulated from and intersecting the gate line to define a pixel region, a source electrode which is a branch of the data line, and a drain electrode separated from the source electrode A liquid crystal including a data pattern formed in the pixel area and a pixel electrode having an edge portion overlapping the storage electrode and the gate line and connected to the drain electrode and removed from the portion connected to the storage electrode and the gate line. On the display device, When the gate line or the sustain electrode and the pixel electrode are shorted to generate a high pixel defect, disconnecting the sustain electrode or the gate line that does not overlap the pixel electrode to change the high pixel defect into an off pixel defect. Pixel defect repair method of a liquid crystal display comprising a. A gate line formed in a horizontal direction, A storage electrode connected to the gate line, A common voltage electrode line separated from the gate line and the sustain electrode and formed in a horizontal direction; A data pattern comprising a data line insulated from and intersecting the gate line to define a pixel region, a source electrode which is a branch of the data line, and a drain electrode separated from the source electrode; And a pixel electrode formed in the pixel area, an edge of which overlaps the sustain electrode, the gate line, and the common voltage electrode line and is connected to the drain electrode. A gate line formed in a horizontal direction, a sustain electrode connected to the gate line, a common voltage electrode line separated from the gate line and the sustain electrode, and formed in a horizontal direction, and a data line insulated from and intersecting the gate line; A data pattern comprising a source electrode which is a branch of a data line and a drain electrode separated from the source electrode, and an edge portion formed in the pixel area so that an edge portion thereof overlaps the common voltage electrode line, the sustain electrode, and the gate line; In the liquid crystal display device including a connected pixel electrode, Shorting the pixel electrode and the common voltage electrode line when the gate line or the sustain electrode and the pixel electrode are shorted to cause a high pixel defect. And disconnecting the drain electrode and the pixel electrode to change the pixel defect into an off pixel defect.