KR100670054B1 - Wide viewing angle liquid crystal display device and substrate used therein - Google Patents

Abstract

A color filter is formed on the first substrate, a protective film is formed on the color filter, and a black matrix is formed on the protective film. The common electrode is formed on the black matrix. Here, the black matrix serves as a protrusion to form irregularities in the common electrode. The pixel electrode which has an opening pattern is formed in the 2nd board | substrate which opposes a 1st board | substrate. The liquid crystal material is injected and vertically aligned between the first substrate and the second substrate. In this case, a wide viewing angle can be secured by forming an opening pattern and a projection without adding a process at all compared to a conventional vertically aligned liquid crystal display device, and the common electrode voltage is increased because the common electrode of the upper panel is not patterned. The problem is solved.

LCD, Projection, Opening, Black Matrix, Color Filter, Common Electrode

Description

Wide viewing angle liquid crystal display device and substrate used therefor {LIQUID CRYSTAL DISPLAYS AND PANELS FOR THE SAME}

1 is a cross-sectional view of a color filter substrate for a liquid crystal display device according to a first embodiment of the present invention;

2 is a cross-sectional view of a liquid crystal display device according to a second embodiment of the present invention;

3 is a layout view of a liquid crystal display according to a third exemplary embodiment of the present invention.

4 is a cross-sectional view taken along line IV-IV 'of FIG. 3.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device and a thin film transistor substrate used therein, and more particularly, to a vertically aligned liquid crystal display device forming an opening pattern and a projection in a pixel electrode, and a thin film transistor substrate used therein.

In general, a liquid crystal display device injects a liquid crystal material between an upper substrate on which a common electrode, a color filter, and the like are formed, and a lower substrate on which a thin film transistor and a pixel electrode are formed. By applying a different potential to form an electric field to change the arrangement of the liquid crystal molecules, and through this to control the light transmittance is a device that represents the image.

However, it is an important disadvantage that the liquid crystal display device has a narrow viewing angle. In order to overcome these disadvantages, various methods for widening the viewing angle have been developed. Among them, liquid crystal molecules are oriented vertically with respect to the upper and lower substrates, and a method of forming a constant opening pattern or forming protrusions on the pixel electrode and the common electrode opposite thereto is performed. This is becoming potent.

In the conventional method of forming the opening pattern, an opening pattern is formed on the pixel electrode and the common electrode, and the viewing angle is widened by adjusting the direction in which the liquid crystal molecules lie down using a fringe field formed by the opening patterns. There is this.

However, in this case, since the common electrode made of indium tin oxide (ITO) formed on the color filter is patterned by using photolithography, a photolithography process is added.

In addition, the adhesion between the ITO deposited on the color filter by sputtering and the color filter resin is not good, so that the precision of the common electrode is inferior. In addition, there is a problem that damage occurs when the color filter is exposed during the etching of ITO, so in order to prevent it, a reliable organic insulating layer (overcoat layer) must be coated on the color filter. When the overcoat layer is formed, the common electrode may not directly contact a black matrix formed of chromium (Cr), and so the resistance may increase, resulting in a serious flicker defect.

In addition, since an opening pattern is formed in the common electrode, an increase in resistance of the common electrode is increased.

The method of forming the projections is a method of controlling the lying direction of the liquid crystal molecules by using the electric field distorted by the projections by forming projections on the pixel electrode and the common electrode formed on the upper and lower substrates, respectively.

In this manner, there is a problem in that the production cost increases because the process of forming the upper and lower substrate projections has to be added.

An object of the present invention is to simplify the manufacturing process of a wide viewing angle liquid crystal display device.

In order to solve this problem, in the present invention, a protrusion is formed of a black matrix.

Specifically, a color filter is formed on the substrate, a protective film is formed on the color filter, and a black matrix layer is formed on the protective film. The transparent electrode layer is formed on the black matrix layer.

The black matrix layer functions as a protrusion and forms a domain by combining with an opening pattern formed on the pixel electrode.

Next, a structure of a color filter substrate for a liquid crystal display according to an exemplary embodiment of the present invention will be described with reference to the drawings.

1 is a cross-sectional view of a color filter substrate for a liquid crystal display according to a first embodiment of the present invention.

The color filter 210 is formed on the bottom surface of the substrate 200 made of a transparent material such as glass, and the passivation layer 240 is formed on the color filter 210. A black matrix 230 is formed on the passivation layer 240 to form protrusions. A common electrode 220 made of a transparent conductive material such as ITO is stacked on the entire surface of the substrate 200 on the black matrix 230. In this case, the common electrode 220 has irregularities due to the black matrix 230. The passivation layer 240 prevents the color filter 210 from being damaged when the black matrix 230 is patterned. The thickness of the passivation layer 240 is about 1.3 μm, the thickness of the black matrix 230 is about 1.5 μm, and the thickness of the common electrode 220 is about 1,500 μm.

Due to the unevenness of the common electrode 220, the electric field formed between the pixel electrode (not shown) and the common electrode 220 is inclined without being formed perpendicular to the substrate 200, thereby securing a wide viewing angle. have.

2 is a cross-sectional view of a liquid crystal display according to a second exemplary embodiment of the present invention.

A gate line (not shown) extends in the horizontal direction in the lower substrate 100, and a gate insulating layer 130 is formed on the gate line. The data line 162 is formed in the vertical direction on the gate insulating layer 130, and transfers an image signal transmitted through the data line 162 to the pixel electrode 170 according to a scan signal transmitted through the gate line. Thin film transistors (not shown) and the like, which are switching elements to cut off, are formed. The protective insulating layer 180 is formed on the data line 162, and the pixel electrode 170 is formed on the protective insulating layer 180. The opening 171 is formed in the pixel electrode 170.

In the upper substrate 200, instead of the passivation layer 240 covering the color filter 210, the second common electrode 250 made of the same material as the common electrode 220 is formed on the liquid crystal display substrate according to the first embodiment. The same is true except that there is. Here, the second common electrode 250 is about 1,500 Å and the black matrix 230 is about 1.3 μm. However, the thickness of these films can vary.

In this case, the electric field applied to the liquid crystal layer is formed by the uneven common electrode 220 formed while riding over the black matrix 230 and the opening pattern 171 formed on the pixel electrode 170 of the lower substrate. Will be tilted relative to In this case, the black matrix 230 may be formed of an organic material as well as an inorganic material such as chromium and chromium oxide.

Since the common electrodes 220 and 250 are formed in duplicate, the common electrode resistance decreases. Therefore, flicker can be reduced. When the black matrix 230 is formed of chromium, the common electrode resistance is further reduced.

3 is a layout view of a liquid crystal display according to a third exemplary embodiment of the present invention, and FIG. 4 is a cross-sectional view taken along line IV-IV ′ of FIG. 3.

The gate electrode 126 and the source electrode 165 in an area formed by the two gate lines 122 formed in the horizontal direction on the lower substrate 100 and the two data lines 162 formed in the vertical direction intersect. And a pixel electrode 170 connected to the thin film transistor including the drain electrode 166 and the semiconductor layer 140. In addition, a storage electrode line 127 is formed in the lower substrate 100 in parallel with the gate line 122, and the storage electrode 128 is connected to the storage electrode line 127.

The protrusion formed by the black matrix 230 of the upper substrate 200 is divided into a horizontal portion formed in the horizontal direction at a position half-dividing the pixel electrode 170 of the lower substrate 100 and the pixel electrode 170 divided into half. It includes an oblique portion formed in the diagonal direction in the upper and lower portions of the. At this time, the upper and lower diagonal portions are perpendicular to each other. This is to evenly distribute the inclined direction of the electric field in four directions.

The opening pattern 171 formed in the pixel electrode 170 has an oblique portion of the protrusion formed of the black matrix 230 at the center thereof, and includes a diagonal opening parallel to the left side and a vertical opening parallel to the left and right sides of the pixel electrode 170. have.

The storage electrode 128 formed on the lower substrate 100 is formed along the opening pattern 171. The sustain electrode 128 has an effect of strengthening the fringe field generated by the opening pattern. The sustain electrode 128 is formed of the same material as the gate wiring in the same layer as the gate wiring. The sustain electrode 128 is formed of a double layer of a chromium layer and an aluminum-neodymium layer. However, when the gate wiring is formed in a single layer, the sustain electrode 128 is also formed in a single layer.

The protrusion formed of the black matrix 230 and the opening pattern 171 of the pixel electrode 170 overlap each other to divide the pixel electrode 170 into a plurality of domains. At this time, each domain forms a polygon in which the two longest sides are parallel to each other. This is for shortening the response time of the liquid crystal molecules. That is, the direction in which the liquid crystal molecules are arranged by the inclined electric field formed by the black matrix 230 and the opening pattern 171 may be in parallel with each other. In this case, the response time is shortened because the operation of the liquid crystal molecules is completed by only one step operation.

The shapes of the projection patterns and the opening patterns shown in the third embodiment of the present invention can be applied to the first and second embodiments of the present invention, and the shapes of these patterns can be formed in various other forms.

When the substrate for a liquid crystal display device is manufactured with the above structure, an opening pattern and protrusions can be formed to secure a wide viewing angle without any additional process as compared with a normal vertical alignment liquid crystal display device, and the common electrode of the upper panel is patterned. This eliminates the problem of increasing the common electrode voltage.

Claims (11)

Board, A color filter formed on the substrate, A first transparent electrode layer formed on the color filter, A black matrix layer formed on the first transparent electrode layer, A second transparent electrode layer formed on the black matrix layer Substrate for a liquid crystal display device comprising a. Board, A color filter formed on the substrate, A flattened protective film formed on the color filter, A black matrix layer formed on the protective film, A transparent electrode layer formed on the black matrix and having irregularities Substrate for a liquid crystal display device comprising a. First substrate, A color filter formed on the first substrate, A black matrix pattern formed on the first common electrode layer, A second substrate facing the first substrate, A gate line formed on the second substrate, A data line insulated from and intersecting the gate line; A pixel electrode formed in an area where the gate line and the data line cross each other; And a switching device configured to transfer or block an image signal transmitted through the data line to the pixel electrode according to a scan signal transmitted through the gate line. The pixel electrode has an opening pattern, and further includes a projection pattern formed on the second substrate along the opening pattern. In claim 3, And a color filter formed between the first substrate and the first common electrode layer. In claim 3, And a second common electrode layer formed on the black matrix layer. First substrate, A color filter formed on the first substrate, A protective film formed on the color filter, A black matrix pattern formed on the passivation layer, A common electrode layer formed on the black matrix pattern; A second substrate facing the first substrate, A gate line formed on the second substrate, A data line insulated from and intersecting the gate line; A pixel electrode formed in an area where the gate line and the data line cross each other; And a switching device configured to transfer or block an image signal transmitted through the data line to the pixel electrode according to a scan signal transmitted through the gate line. The pixel electrode has an opening pattern, and further includes a projection pattern formed on the second substrate along the opening pattern. delete In claim 3 or 6, The black matrix pattern and the opening pattern of the pixel electrode divide the pixel electrode into four domains. In claim 8, And the domain is a polygon in which two longest sides are parallel to each other. In claim 9, The domain is classified into a first domain and a second domain, the first domain has two longest sides in a first direction, and the second domain has a longest two sides in a second direction, and the first direction and the second domain. Liquid crystal display with an angle of between 85 ° and 95 °. In claim 10, And the first direction is a diagonal direction with respect to the side of the pixel electrode.

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