KR20040061981A - An array substrate for In-Plane switching mode LCD - Google Patents

Abstract

PURPOSE: An array substrate for an IPS(In-Plane Switching) mode LCD device is provided to configure data lines in zigzag type with the same shape as pixel electrodes and common electrodes, and to configure projections in bent parts of the pixel electrodes and the common electrodes, thereby widening a driving area of a liquid crystal by corresponding to a bending edge portion. CONSTITUTION: Gate lines and common lines are spaced in parallel on a substrate, and are formed in one direction. Data lines(100) vertically cross the gate lines, and define pixel areas. A TFT is configured in a crossed section of the gate lines and the data lines(100). Pixel electrodes(104) are contacted with the TFT, and are zigzag-shaped in the pixel areas. Common electrodes(102) are contacted with the common lines, are spaced from the pixel electrodes(104) in parallel, and are in zigzag shape. Projections(106) are configured outside bent parts of the common electrodes(102) and the pixel electrodes(104).

Description

An array substrate for in-plane switching mode LCD

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to an array substrate for a transverse electric field type liquid crystal display device having fast response characteristics and high aperture ratio.

In general, the driving principle of the liquid crystal display device uses the optical anisotropy and polarization of the liquid crystal. Since the liquid crystal is thin and long in structure, the liquid crystal has directivity in the arrangement of molecules, and the direction of the molecular arrangement can be controlled by artificially applying an electric field to the liquid crystal.

Accordingly, if the molecular arrangement direction of the liquid crystal is arbitrarily adjusted, the molecular arrangement of the liquid crystal is changed, and light is refracted in the molecular arrangement direction of the liquid crystal due to optical anisotropy to express image information.

Currently, an active matrix liquid crystal display device (AM-LCD: abbreviated as an active matrix LCD, abbreviated as a liquid crystal display device) in which a thin film transistor and pixel electrodes connected to the thin film transistor are arranged in a matrix manner has the best resolution and video performance. It is attracting attention.

The liquid crystal display includes a color filter substrate (upper substrate) on which a common electrode is formed, an array substrate (lower substrate) on which a pixel electrode is formed, and a liquid crystal filled between upper and lower substrates. The liquid crystal is driven by an electric field applied up and down by the pixel electrode, so that the characteristics such as transmittance and aperture ratio are excellent.

However, the liquid crystal drive by the electric field applied up-down has a disadvantage that the viewing angle characteristics are not excellent. Therefore, new techniques have been proposed to overcome the above disadvantages. The liquid crystal display device to be described below has an advantage of excellent viewing angle characteristics by a liquid crystal driving method using a transverse electric field.

Hereinafter, a general transverse electric field type liquid crystal display device will be described in detail with reference to FIG. 1.

1 is a cross-sectional view showing a cross section of a general transverse electric field type liquid crystal display device.

As shown, the upper substrate 10, which is a color filter substrate, and the lower substrate 20, which is an array substrate, are spaced apart from each other and face each other. A liquid crystal layer 12 is interposed between the upper and lower substrates 10, 20. It is.

The common electrode 38 and the pixel electrode 36 are formed on the same plane on the lower substrate 20.

The liquid crystal layer 12 is operated by the horizontal electric field 21 of the common electrode 38 and the pixel electrode 36.

2A and 2B are cross-sectional views showing operations in off and on states of a general transverse electric field type liquid crystal display device, respectively.

In FIG. 2A, since the horizontal electric field is not applied in the off state, the liquid crystal layer 12 does not move.

In FIG. 2B, an arrangement state of liquid crystals in an on state where a voltage is applied is shown, and the orientation change of the liquid crystal 12a at a position corresponding to the common electrode 38 and the pixel electrode 36 is changed. However, the liquid crystal 12b positioned between the common electrode 38 and the pixel electrode 36 is formed by the horizontal electric field 21 formed by applying a voltage between the common electrode 38 and the pixel electrode 36. It is arranged in the same direction as (12). That is, in the transverse electric field type liquid crystal display device, since the liquid crystal moves by the horizontal electric field, the viewing angle is widened.

However, a color shift phenomenon or a gray level inversion phenomenon occurs depending on the viewing angle, and thus a method of designing electrodes in a zigzag shape has been proposed to solve this problem.

Hereinafter, an array substrate structure having a zigzag shape will be described with reference to FIG. 3.

FIG. 3 is a plan view illustrating one pixel of an array substrate for a transverse electric field type liquid crystal display device constructed by a zigzag method according to the related art.

As shown in the drawing, the gate wiring 12 and the common wiring 16 are formed on one side of the substrate 9 in parallel to each other by a predetermined interval, and intersect the gate wiring 12 and the common wiring 16. In particular, the data line 24 defining the pixel region P is formed from the gate line 12.

The thin film transistor T including the active layer 20, the gate electrode 14, the source electrode 26, and the drain electrode 28 is formed at the intersection point of the data line 24 and the gate line 12. .

Pixel electrodes 30a and b connected to the drain electrode 28 are formed in the pixel region P, and common electrodes 17 spaced in parallel with the pixel electrodes 30a and b and connected to the common wiring 16 are provided. ) Is configured.

The pixel electrodes 30a and b may include a horizontal portion 30a formed on the common wiring 16 and a plurality of zigzag vertical portions extending vertically from the horizontal portion 30a to the pixel region P. FIG. It consists of 30b.

The common electrode 17 extends vertically from the common line 16 and includes a plurality of zigzag vertical portions spaced in parallel with the vertical portion 30b of the pixel electrode.

As shown in the drawing, the common electrode 17 and the pixel electrode 30 are formed in a zigzag-shaped bending structure, and rubbing is performed in one direction to direct the electric field K applied to the injected liquid crystal. To change.

The shape of the electrode allows the alignment characteristics of the liquid crystals 63 to be symmetrical to each other.

Therefore, all of the liquid crystals 63 positioned in one pixel can be oriented in various directions without being oriented in the corresponding one direction, so that the alignment direction of the liquid crystals oriented in one pixel can be varied. ) Can be induced.

As described above, due to the symmetrical multi-domain structure, the refractive indices in the liquid crystal alignment direction may be canceled out to minimize the color shift phenomenon and to widen the region without gray scale inversion.

However, such a structure has an electric field because the direction of the electric field generated at the bending edge portion C of the common electrode 17 and the pixel electrodes 30a and b is perpendicular to the initial alignment direction of the liquid crystal determined by the rubbing direction. Regardless of the intensity of the liquid crystal, the liquid crystal does not rotate and remains black, and the direction of the electric field formed at the outer portion of the electrode located at the edge D in the pixel also does not normally twist the liquid crystal.

Therefore, the abnormal alignment of the liquid crystals in the in-pixel banding edge portion C and the edge portion D causes light leakage, resulting in discrepancy (defective quality with black streaks).

In addition, in order to improve the aperture ratio, when the gap between the pixel electrode and the common electrode is widened, the transmittance is not increased with distance of the electrode but is saturated at about 13 μm. In addition, the response speed is also very slow problem.

SUMMARY OF THE INVENTION The present invention has been proposed for the purpose of solving the above-described problem, and comprises a data line in a zigzag shape in the same shape as the pixel electrode and the common electrode, and a bent portion of the pixel electrode and the common electrode (the aforementioned bending edge portion). ) To make projections.

The protrusion increases the strength of the electric field distributed in the bending edge portion.

Therefore, the driving region of the liquid crystal can be widened in correspondence with the bending edge portion, and the separation region of the pixel electrode and the common electrode can be wider than the conventional one, so that the pixel electrode and the common electrode need to be excessively formed in one pixel region. There is no advantage that can secure a high opening rate.

In addition, the response speed of the liquid crystal corresponding to the protruding portion is increased.

1 is a cross-sectional view schematically showing a part of a general transverse electric field type liquid crystal display device;

2A and 2B are cross-sectional views illustrating operations of off and on states of a general transverse electric field type liquid crystal display device, respectively.

3 is a plan view schematically showing one pixel of a conventional array substrate for a transverse electric field type liquid crystal display device;

4 is a plan view schematically illustrating the configuration of a common electrode and a pixel electrode according to a first embodiment of the present invention;

FIG. 5 is a plan view magnifying D of FIG. 4;

6 is a plan view schematically illustrating a configuration of a common electrode and a pixel electrode according to a second exemplary embodiment of the present invention.

7 is a plan view schematically illustrating a configuration of a common electrode and a pixel electrode according to a third exemplary embodiment of the present invention.

<Brief description of the main parts of the drawing>

100: data wiring 102: common electrode

104: pixel electrode 106: projection

An array substrate for a transverse electric field type liquid crystal display device according to the present invention for achieving the above object is a substrate; A gate wiring and a common wiring spaced apart in parallel on the substrate and formed in one direction; A data line defining a pixel area crossing the gate line perpendicularly; A thin film transistor configured at an intersection point of the gate line and the data line; A zigzag pixel electrode formed in a pixel region in contact with the thin film transistor; A zigzag common electrode configured to be staggered while being in parallel with the pixel electrode while being in contact with the common wiring; And protrusions formed on the outer side of each of the bent portions of the common electrode and the pixel electrode.

The pixel electrode and the common electrode are configured to have at least one bent state.

The data wiring is further configured in a zigzag shape.

The pixel electrode and the common electrode are configured to be parallel to each other within a distance of 11 to 20㎛.

The length of the protrusions is designed differently according to the distance between the pixel electrode and the common electrode.

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

Example

4 is a plan view schematically illustrating an electrode configuration of one pixel of the array substrate for a transverse electric field type liquid crystal display device according to the first example of the present invention.

The first example of the present invention is characterized in that the data line, the common electrode and the pixel electrode are bent once at an angle of about 10 to 20 degrees with respect to a single pixel.

As shown, the projections 106 are formed on the opposite side of the bent edge portion J of the pixel electrode 104 and the common electrode 102 spaced at a distance of about 11 [mu] m. It can be configured by patterning the material constituting the electrode.

At this time, the distribution of the electric field is strongly generated between the protrusion 106 and the electrode adjacent thereto. A description with reference to FIG. 5 is as follows.

5 is an enlarged plan view of FIG. 4D.

As shown, when the projection 106 is formed corresponding to the bending edge portion J of the electrodes 102 and 104, and a signal is input to the pixel electrode 104 and the common electrode 102, the common electrode 102 and An electric field E is generated between the pixel electrode 104 and the pixel electrode 104.

In this case, the region in which the protrusion 106 is formed generates a strong distribution of the electric field between the two electrodes 102.104 by the protrusion 106, so that the operating region of the liquid crystal in the bending edge portion J may be enlarged. The response speed of the liquid crystal is also fast due to the strong electric field distribution.

At this time, since the region in which the protrusion 106 is formed is an area in which the liquid crystal does not move, the aperture ratio erosion by the protrusion does not occur.

6 is a plan view schematically illustrating an electrode configuration of one pixel of an array substrate for a transverse electric field type liquid crystal display device according to a second example of the present invention.

The second example of the present invention is characterized in that the data line 200 and the pixel electrode 202 are configured in a zigzag shape to induce a plurality of symmetrical regions (multi-domains).

As shown in the drawing, the pixel electrode 204 and the common electrode 202 which are spaced apart at a distance of about 11 탆 from one pixel and formed in a zigzag shape in the vertical direction are formed.

In this case, the pixel electrode 204 and the common electrode 202 have a plurality of bending edge portions, and the protrusions 206 and 208 are formed at portions corresponding to opposite sides of the bent directions, respectively, in terms of facing each other.

In the above-described configuration, since the pixel electrode 204 and the common electrode 202 are configured in a single pixel area, the lengths of the protrusions 206 and 208 are short.

However, when the separation distance between the pixel electrode 204 and the common electrode 202 is increased for the aperture ratio, the length of the protrusion is formed long.

A description with reference to FIG. 7 is as follows.

FIG. 7 is a plan view schematically illustrating an electrode configuration of one pixel of an array substrate for a transverse electric field type liquid crystal display device according to a third example of the present invention.

As shown in the drawing, the common electrode 302 and the pixel electrode 304 are alternately arranged in parallel in the pixel region P with a separation distance of about 15 to 20 μm, and the common electrode 302 and the pixel electrode 304 are arranged. And data wiring 300 is configured in a zigzag shape.

In this configuration, since the gap between the common electrode 302 and the pixel electrode 304 is large, the number of electrodes formed between both data lines 300 is also reduced. As a result, the aperture ratio can be secured.

In this case, as the distance between the two electrodes 302 and 304 is increased, the length of the protrusion 308 formed at the bending edges of the common electrode 302 and the pixel electrode 304 is increased.

As described above, the transverse electric field type liquid crystal display device according to the present invention can be manufactured with the configuration according to the first to third embodiments.

A common feature in the above-described embodiment is that the protrusion pattern is formed by patterning the electrode with a material for patterning the electrode, and the length of the protrusion may be designed differently according to the separation distance between the common electrode and the pixel electrode.

The protrusions are necessarily formed on the outside of the bent portion of the common electrode and the pixel electrode.

In addition, although briefly described, each of the components may include a gate wiring arranged perpendicularly to the data wiring, a common wiring spaced apart from the gate wiring, and electrically connected to the common electrode, and the gate wiring and the data wiring. The intersection includes a thin film transistor.

Accordingly, in the transverse electric field type liquid crystal display device according to the present invention, the data wiring or / and the pixel electrode and the common electrode are configured in a zigzag shape, whereby the light leakage region generated between the common electrode and the data wiring can be removed unlike the conventional art. At the same time, by forming an organic pattern protruding from the bending edge portions of the pixel electrode and the common electrode, the liquid crystal in the bending edge portion can enlarge the driving region, thereby improving the aperture ratio and thereby obtaining a high luminance characteristic. .

In addition, by configuring the pixel and the common electrode in a zigzag shape, there is an effect that wide viewing angle characteristics due to color compensation can be obtained.

Claims (6)

A substrate; A gate wiring and a common wiring spaced apart in parallel on the substrate and formed in one direction; A data line defining a pixel area crossing the gate line perpendicularly; A thin film transistor configured at an intersection point of the gate line and the data line; A zigzag pixel electrode formed in a pixel region in contact with the thin film transistor; A zigzag common electrode configured to be staggered while being in parallel with the pixel electrode while being in contact with the common wiring; Outside of each bent portion of the common electrode and the pixel electrode Protrusions on the sides Array substrate for a transverse electric field type liquid crystal display device comprising a. The method of claim 1, And the pixel electrode and the common electrode are bent at least once. The method of claim 1, And the data lines are arranged in a zigzag shape. The method of claim 1, And the pixel electrode and the common electrode are arranged in parallel with each other within a distance of 11 to 20 μm. The method of claim 4, wherein An array substrate for a transverse electric field type liquid crystal display device, wherein the length of the protrusion is designed differently according to the distance between the pixel electrode and the common electrode. The method of claim 1, And the projections are alternately arranged at each of the bent portions.