KR20110076580A - Liquid crystal display device of thin film transistor - Google Patents

Abstract

PURPOSE: A thin film transistor liquid crystal display is provided to improve an opening rate by reducing a parasitic capacitance generated according to a data line. CONSTITUTION: A thin film transistor liquid crystal display device includes as follows. A substrate. A gate line(10) and a data line(13) are arranged on the substrate to be crossed for pixel area on the substrate. A switching element(TFT) is arranged on the crossing area of the gate line and the data line. A pixel elements(19) is arranged on the pixel area. A first blocking pattern and a second blocking pattern(30,31) are separately arranged in parallel to a lower side of the data line. The first blocking pattern and the second blocking pattern faces each other by having the data line in the middle, and has a wing unit for blocking the light from exposing on the surface facing each other.

Description

Liquid Crystal Display Device of Thin Film Transistor

The present invention relates to a thin film transistor liquid crystal display device.

Recently, liquid crystal display devices, which are rapidly developing, are being manufactured with smaller, lighter weight and more powerful products. Cathode ray tubes (CRTs), which are widely used in information display devices, have many advantages in terms of performance and price, but have many disadvantages in terms of miniaturization or portability.

On the other hand, liquid crystal displays have been attracting attention as an alternative means of overcoming the shortcomings of CRTs due to the advantages of miniaturization, light weight, and low power consumption, and are currently used in almost all information processing devices that require display devices. It is the situation that is attached.

Such a liquid crystal display generally applies a voltage to a specific molecular array of a liquid crystal, converts it into a different molecular array, and converts a change in optical properties into a visual change, and is a display device using modulation of light by a liquid crystal cell.

The liquid crystal display device includes a process of manufacturing a panel upper substrate and a lower substrate accompanied with a process of forming a liquid crystal cell forming a pixel unit, forming and rubbing an alignment layer for liquid crystal alignment, and bonding the upper substrate and the lower substrate together. The process is completed through various processes such as a process of injecting and encapsulating liquid crystal between the bonded upper substrate and the lower substrate.

Recently, liquid crystal displays have been developed to realize high quality screen quality while having miniaturization, thinning, and low power.

One of them is to improve pixel aperture ratio and transmittance. The pixel area of the lower substrate is defined by crossing the gate line and the data line, and the switching element and the pixel electrode are disposed in the pixel area. In order to increase the aperture ratio and transmittance, it is necessary to widen the transmission area and reduce the non-transmission area.

However, when the aperture ratio and the transmittance of the liquid crystal display are increased, there is a problem in that a delay or horizontal cross talk of a data signal occurs due to a parasitic capacitance.

An object of the present invention is to provide a thin film transistor liquid crystal display device having an improved aperture ratio while reducing parasitic capacitance generated along a data line.

Another object of the present invention is to provide a thin film transistor liquid crystal display device in which light leakage defects are improved by disposing a blocking pattern that blocks backlight light under a data line.

The thin film transistor liquid crystal display device of the present invention for solving the above problems, the substrate; Gate lines and data lines arranged to intersect the pixel regions on the substrate; A switching element disposed at an intersection of the gate line and the data line; A pixel electrode disposed in the pixel region; And a first blocking pattern and a second blocking pattern spaced apart from each other in parallel to the lower side of the data line, wherein the first blocking pattern and the second blocking pattern face each other with the data line therebetween and face each other. The surface is characterized in that the wing formed for blocking light leakage.

The present invention has the effect of improving the aperture ratio of the pixel region of the liquid crystal display device.

In addition, the present invention has an effect of improving the light leakage failure by placing a blocking pattern that can block the backlight light under the data line.

In addition, the present invention has the effect of reducing the parasitic capacitance generated in the data line region to prevent data signal delay and crosstalk failure.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following embodiments are provided as examples to sufficiently convey the spirit of the present invention to those skilled in the art. Therefore, the present invention is not limited to the embodiments described below, but may be embodied in other forms. In the drawings, the size and thickness of the device may be exaggerated for convenience. Like numbers refer to like elements throughout.

1 illustrates a pixel structure of a liquid crystal display according to the present invention.

As shown in FIG. 1, in the liquid crystal display of the present invention, a gate line 10 and a data line 13 are alternately arranged on a substrate to define a pixel area (sub-pixel).

A TFT (Thin Film Transistor), which is a switching element, is disposed in an area where the gate line 10 and the data line 13 cross each other, and a transparent conductive material (ITO) in a direction parallel to the data line 13 is disposed in the pixel area. The pixel electrode 19 made of Indium-Tin-Oxide is disposed.

In the present invention, the pixel electrodes 29 and 19 are disposed on the left and right sides along the data line 13, and the first and second blocking patterns 30 and 31 are disposed on the same layer as the gate electrode of the gate line 10 and the TFT. Is formed. The first and second blocking patterns 30 and 31 may be patterns branched from a common line (not shown) of the liquid crystal display.

The first and second blocking patterns 30 and 31 are spaced apart from each other in an area overlapping the data line 13. Wings are formed on the surfaces of the first and second blocking patterns 30 and 31 that face each other, thereby preventing light leakage by canceling light traveling along both edges of the data line 13 of the light from the backlight. Function.

That is, the wing portion formed in the first and second blocking patterns 30 and 31 diffracts and cancels the light traveling from the backlight, so that light leakage occurs between the data line 13 and the pixel electrodes 29 and 19. Remove it.

In addition, the first and second blocking patterns 30 and 31 overlapping the data line 13 by a predetermined portion are spaced apart from each other, so that the first and second blocking patterns 30 and 31 are downward in the data line 13. ) Does not exist. Therefore, parasitic capacitance generated between the data line 13 and the first and second blocking patterns 30 and 31 can be reduced. Due to the wing portion, the separation distance between the first and second blocking patterns 30 and 31 can be reduced, thereby improving the pixel aperture ratio.

FIG. 2 illustrates the blocking patterns of FIG. 1 preventing light leakage.

Referring to FIG. 2, the first blocking pattern 30 and the second blocking pattern 31 are spaced apart by a predetermined distance, and wings 30a and 31a are formed on surfaces facing each other.

The wing portions 30a and 31a have a sawtooth shape and include a plurality of mountains.

The backlight light traveling below the first blocking pattern 30 and the second blocking pattern 31 is blocked by the first blocking pattern 30 and the second blocking pattern 31. In the wing portions 30a and 31a of the first blocking pattern 30 and the second blocking pattern 31, backlight light is diffracted and canceled to block light traveling in a predetermined oblique direction. That is, the light leakage defects traveling in a direction perpendicular to the first blocking pattern 30 and the second blocking pattern 31 are removed.

Therefore, only light traveling in an upward direction is present in a space where the first blocking pattern 30 and the second blocking pattern 31 face each other. Light traveling in the upward direction is blocked by the data line, as shown in FIG.

In addition, since the first blocking pattern 30 and the second blocking pattern 31 formed in the pixel area of the present invention are separated from each other and the data lines overlap with the separated areas, parasitics generated along the data lines are generated. Capacitance can be reduced.

In addition, light leakage along both edges of the data line can be reduced.

3a and 3b is for comparing the light leakage generated in the conventional blocking pattern and the blocking pattern of the present invention.

3A illustrates that a shield pattern (SP) is not provided with a wing portion. Light traveling between the blocking patterns SP may be seen to generate light leakage in a direction perpendicular to the blocking pattern by diffraction.

That is, the light traveling between the blocking patterns SP is traveling upward and in the upward direction of the blocking patterns.

Figure 3b is a blocking pattern formed wing portion of the present invention. As shown, it can be seen that a lot of light is visible only through the space formed by the wings of the blocking patterns, almost no light in the direction perpendicular to the blocking patterns.

That is, the wing portions formed in the blocking patterns of the present invention cancel each other, the light traveling in a direction perpendicular to the blocking pattern among the light proceeding from the bottom. This is because diffraction and cancellation occur due to the sawtooth pattern of the wing portion formed in the blocking pattern.

4 is a cross-sectional view taken along line AA ′ of FIG. 1.

As shown in FIG. 4, the gate electrode 11 is formed on the transparent insulating substrate 100, and the first blocking pattern 30 and the second blocking pattern 31 are formed on the same layer as the gate electrode 11. ) Is formed. The first blocking pattern 30 and the second blocking pattern 31 may be patterns branched from a common line (not shown).

The channel layer 14 is formed on the gate electrode 11 with the gate insulating layer 12 interposed therebetween. The channel layer 14 includes an amorphous silicon film and a doped amorphous silicon film.

Source / drain electrodes 17a and 17b are formed on the channel layer 14, and a data line is interposed between the first blocking pattern 30 and the second blocking pattern 31 with a gate insulating layer 12 interposed therebetween. (13) is formed. The channel layer 14 is formed under the data line 13. This is because the source / drain electrodes 17a and 17b and the channel layer 14 are simultaneously formed using a diffraction or a halftone mask.

The passivation layer 39 is formed on the source / drain electrodes 17a and 17b, and the pixel electrode 19 is formed on the passivation layer 39. The pixel electrode 19 is connected to the drain electrode 17b through a contact hole.

The pixel electrode 29 is formed on the data line 13 and disposed in the pixel region adjacent to the pixel electrode 19.

In the present invention, since the space between the first blocking pattern 30 and the second blocking pattern 31 is spaced below the data line 13, the data line 13, the first blocking pattern 30, and the second blocking pattern are separated from each other. Parasitic capacitance between the patterns 31 can be minimized. This may prevent crosstalk failures that may occur along the data line 13.

5A and 5B illustrate the structure of a wing formed in the blocking pattern of the present invention.

5A and 5B, the wing structure of the first and second blocking patterns SP1 and SP2 according to another embodiment of the present invention is illustrated. The wings of the first and second blocking patterns SP1 and SP2 shown in FIG. 5A are formed in a concave-convex pattern of a rectangular structure along the facing surface. The wings of the first and second blocking patterns SP1 and SP2 shown in FIG. 5B are formed in a streamlined pattern along the facing surface.

That is, the first and second blocking patterns SP1 and SP, which are spaced apart from each other, propagate light traveling through the spaced space only in an upward direction and travel in a predetermined inclination direction (direction perpendicular to the blocking patterns). The light is offset to prevent light leakage.

Shown in the drawings is only an embodiment of the present invention, and in some cases, the wing shape of the blocking pattern may be formed as a polygonal pattern, an elliptical pattern, a circular pattern, or the like.

1 illustrates a pixel structure of a liquid crystal display according to the present invention.

FIG. 2 illustrates the blocking patterns of FIG. 1 preventing light leakage.

3a and 3b is for comparing the light leakage generated in the conventional blocking pattern and the blocking pattern of the present invention.

4 is a cross-sectional view taken along line AA ′ of FIG. 1.

5A and 5B illustrate the structure of a wing formed in the blocking pattern of the present invention.

 (Explanation of reference numerals for the main parts of the drawings)

10: gate line 13: data line

19: pixel electrode 30: first blocking pattern

31: second blocking pattern

Claims (4)

Board; Gate lines and data lines arranged to intersect the pixel regions on the substrate; A switching element disposed at an intersection of the gate line and the data line; A pixel electrode disposed in the pixel region; And A first blocking pattern and a second blocking pattern spaced apart from and parallel to the lower side of the data line; The first blocking pattern and the second blocking pattern face each other with the data line interposed therebetween, and the thin film transistor liquid crystal display according to claim 1, wherein a wing portion for blocking light leakage is formed. The thin film transistor liquid crystal display of claim 1, wherein the first blocking pattern and the second blocking pattern are branched from a common line. The thin film transistor liquid crystal display of claim 1, wherein the wing part is formed of any one of a sawtooth pattern, a square uneven pattern, or a streamlined pattern. The thin film transistor liquid crystal display of claim 1, wherein the first blocking pattern and the second blocking pattern are formed on the same layer as the gate line.

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