KR20080079017A - An array substrate of in-plane switching mode liquid crystal display device and the method for fabricating thereof - Google Patents

Abstract

An array substrate for an in-plane switching mode liquid crystal display device and a method for manufacturing the same are provided to control a voltage according to each signal wire by designing a pixel as in-line arrangement. An array substrate for an in-plane switching mode liquid crystal display device includes a substrate, a gate wire(120), a data wire(130), a thin film transistor, a first common wire(150), a second common wire(151), a plurality of common electrodes(170), a plurality of common electrodes(180), and a pixel electrode(160). The gate wire and the data wire intersect each other on the substrate. The thin film transistor is provided at an intersection between the gate wire and the data wire. The plurality of first common electrodes are diverged from the first common wire. The plurality of second common electrodes are diverged from the second common wire. The pixel electrode contacts with the thin film transistor.

Description

An array substrate of in-plane switching mode liquid crystal display device and the method for fabricating

1 is a plan view showing a unit pixel of a conventional array substrate for a transverse electric field type liquid crystal display device.

FIG. 2 is a schematic plan view magnifying the portion A of FIG. 1; FIG.

3 is a plan view illustrating unit pixels of an array substrate for a transverse electric field type liquid crystal display device according to a first exemplary embodiment of the present invention.

4A is a circuit diagram showing a black state, and FIG. 4B is a circuit diagram showing a white or gray state.

5A to 5D are cross-sectional views illustrating the process sequence by cutting along the line VV of FIG. 3.

6 is a plan view illustrating unit pixels of an array substrate for a transverse electric field type liquid crystal display device according to a second exemplary embodiment of the present invention.

7A-7C are respective circuit diagrams showing black, white and gray states.

8A to 8D are sectional views taken along the line VII-VII of FIG. 6 and shown by the process sequence.

* Explanation of symbols for the main parts of the drawings *

100: substrate 120: gate wiring

125 gate electrode 130 data wiring

132: source electrode 134: drain electrode

140: active layer 150: first common wiring

151: second common wiring 160: pixel electrode

170: first common electrode 180: second common electrode

CH2: Drain contact hole P: Pixel area

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to realizing high quality by improving contrast ratio in a transverse electric field type liquid crystal display device driven normally black.

In particular, the present invention relates to a transverse electric field type liquid crystal display device in which the first and second electrodes for driving the liquid crystal of the liquid crystal display device are formed on the same plane.

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 liquid crystal may be artificially applied to control the direction of the molecular arrangement.

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.

Hereinafter, a conventional transverse electric field type liquid crystal display device will be described with reference to the accompanying drawings.

1 is a plan view illustrating a unit pixel of a conventional array substrate for a transverse electric field type liquid crystal display device.

As shown in the drawing, the gate wiring 20 made of a conductive metal and the gate electrode 25 extending from the gate wiring 20 are formed in the first direction on the substrate 10.

The data line 30 made of a conductive metal in the second direction perpendicular to the gate line 20, the source electrode 32 extending from the data line 30, and the drain electrode 34 spaced apart from the data line 30. ) Is configured.

In this case, an area defined by the vertical intersection of the gate line 20 and the data line 30 is called a pixel area P. The gate electrode 25 formed at the intersection of the gate line 20 and the data line 30 is defined as the pixel area P. FIG. ) And a thin film transistor (T) including an active layer 40 made of pure amorphous silicon and an ohmic contact layer (not shown) made of impurity amorphous silicon layer between the source and drain electrodes 32 and 34 where a portion thereof overlaps. ) Is configured.

The pixel electrode 60, which is in contact with the drain electrode 34 through the drain contact hole CH1, is configured in the pixel region P, and the pixel electrode 60 is an extension part that contacts the drain electrode 34. 60a and a plurality of vertical portions 60b vertically branching from the extension portion 60a to the pixel region P, and the pixel electrode 60 may be configured to have a refractive portion to improve a viewing angle. Can be.

The common electrode 70 vertically branched into the pixel region P is formed on the common wiring 50 spaced in parallel with the gate wiring 20, and the common electrode 70 is a pixel electrode 60. And are staggered apart from each other in parallel.

The array substrate for a transverse electric field type liquid crystal display device having the above-described configuration is opposed to the color filter substrate, and the liquid crystal display device is fabricated through a liquid crystal in a space between the substrates.

FIG. 2 is a schematic plan view illustrating an enlarged portion A of FIG. 1 and will be described in detail with reference to the drawing.

As shown, upper and lower alignment layers (not shown) are formed on opposite sides of the array element of the array substrate 10 and the color filter element (not shown) of the color filter substrate 5, respectively, for initial alignment of the liquid crystal. Then proceed with the rubbing process. In this case, the common electrode 70 and the pixel electrode vertical part 60b that are staggered in parallel to each other in the pixel area (P of FIG. 1) may have a shape having at least one refractive part for the purpose of improving the viewing angle. .

However, when the rubbing process is carried out in the vertical direction 96 on the array element having such a pixel design, all the liquid crystals 95 do not arrange exactly 90 degrees and have an average direction (arrow direction) and irregularly. You can see the arrangement.

Formula (1) is a formula which shows the arrangement | positioning at the time of the rubbing process to an up-down direction.

--- (1)

--- (One)

이 되어 S는 0이 되고, 결정처럼 규칙적으로 배열하면

을 만족하여 S는 1이 된다.In equation (1) above, > Means the mean over time and space, and when liquid crystal molecules are arranged in disorder like liquid,

And S becomes 0, and if we arrange it regularly like

Is satisfied, and S becomes 1.

In this case, in the case of the liquid crystal, the value of S is generally known as 0.4 to 0.7. Therefore, since the arrangement of the liquid crystals is uneven in a state in which no power is applied to the liquid crystal display of the above-described configuration, the black luminance is lowered when the black is implemented due to fine light leakage, thereby causing a problem of decreasing the contrast ratio.

In response to this, in the conventional transverse electric field type liquid crystal display, various attempts have been actively made to improve such a contrast ratio, but there is no sharp alternative to this.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and an object of the present invention is to implement a high picture quality by improving a contrast ratio by changing a design of a pixel so as to uniformly adjust an arrangement of liquid crystals.

An array substrate for a transverse electric field type liquid crystal display device according to a first embodiment of the present invention for achieving the above object is a substrate, the gate wiring and data wiring perpendicularly intersecting on the substrate, A first common wiring and a second common wiring configured to be spaced apart in parallel in the interval between the thin film transistor configured at the intersection point and the gate wiring at the front end facing the gate wiring;

A plurality of first common electrodes vertically branched from the first common wiring to the pixel region, a plurality of second common electrodes vertically branched from the second common wiring and spaced in parallel with the first common electrode; And a pixel electrode in contact with the thin film transistor and configured to vertically intersect the first and second common electrodes.

In the black implementation, the pixel electrode connected to the thin film transistor serves as a floating electrode, and the liquid crystals are uniformly horizontally aligned with a difference value of each voltage applied to the first and second common electrodes.

In this case, while applying a gate voltage of -5V to the gate wiring to operate the pixel electrode connected thereto as a floating electrode, a common voltage of 0V is applied to the first common electrode and 5V is applied to the second common electrode. It is characterized by.

In the implementation of white or gray, a constant common voltage is applied to the first and second common electrodes, respectively, and a pixel voltage applied to the pixel electrode is controlled by adjusting a gate voltage applied to the gate wiring, The liquid crystal may be arranged by the voltage difference generated between the first and second common electrodes to form white or gray.

In this case, a common voltage of 0 V is applied to the first common electrode, a common voltage of 5 V is applied to the second common electrode, and the gate voltage is applied within a range of 1 V to 30 V, wherein the pixel voltage is 0. It is characterized in that applied in the range of ~ 10V.

The first and second common electrodes are separately driven, and a direct current voltage is applied, respectively, and the pixel electrode includes an extension part contacting the thin film transistor and a plurality of horizontal branches branched from the extension part and spaced in parallel with the gate line. And a vertical portion connecting the plurality of horizontal portions to one.

The first and second common electrodes may be made of the same material as the gate line, and the first and second common electrodes and the pixel electrode may vertically cross each other to form a checkerboard shape.

According to a first aspect of the present invention, there is provided a method of manufacturing an array substrate for a transverse electric field type liquid crystal display device, the method including preparing a substrate, a gate wiring on one surface of the substrate, and a first parallel to the substrate. Forming a common wiring and a second common wiring, a plurality of first common electrodes vertically extending from the first common wiring, and a plurality of second common electrodes vertically extending from the second common wiring to the first common electrode; Steps;

Forming a data line defining a pixel area perpendicularly intersecting the gate line and the first and second common lines, forming a thin film transistor at an intersection point of the gate line and the data line, and And forming a pixel electrode intersecting the first and second common electrodes.

In this case, the pixel electrode includes an extension part contacting the thin film transistor, a plurality of horizontal parts branched from the extension part and spaced apart in parallel with the gate line, and a vertical part connecting the plurality of horizontal parts to one.

An array substrate for a transverse electric field type liquid crystal display device according to a second embodiment of the present invention for achieving the above object comprises a substrate, first and second gate wirings spaced in parallel on the substrate, and common wiring; A data line defining a pixel area perpendicularly intersecting the first and second gate lines and the common line, and a first thin film transistor and a second thin film transistor formed at intersections of the first and second gate lines and the data line, respectively. A thin film transistor;

A plurality of common electrodes vertically branched from the common wiring to the pixel region, a plurality of first pixel electrodes connected to the first thin film transistor and alternately spaced apart from and parallel to the plurality of common electrodes, and the second And a plurality of second pixel electrodes connected to the thin film transistor and configured to vertically intersect the common electrode and the first pixel electrode.

In the black implementation, the second pixel electrode connected to the second thin film transistor serves as a floating electrode, and the liquid crystal is arranged horizontally by a voltage difference between the pixel voltage of the first pixel electrode and the common electrode.

In this case, a gate voltage of −5 V is applied to the second gate wiring so that the second thin film transistor connected thereto serves as a floating electrode. The pixel voltage of 1 V is applied to the first pixel electrode, and the common electrode is applied to the second gate wiring. It is characterized by applying a common voltage of 0V.

In the implementation of the white or gray state, a common voltage having a constant value is applied to the common electrode, and the respective pixel voltages applied to the first pixel electrode and the second pixel electrode are adjusted to adjust the first and second pixel electrodes. The liquid crystal is driven by the voltage difference between the common electrodes.

In the white implementation, a 7V pixel voltage is applied to the first and second pixel electrodes, respectively, and 0V is applied to the common electrode, and when a gray level is implemented, a 3V pixel voltage is applied to the first pixel electrode. The liquid crystal is driven by applying a pixel voltage of 1V to the second pixel electrode and applying 0V to the common electrode.

The common electrode and the first pixel electrode and the second pixel electrode may be configured to vertically cross to form a checkerboard shape.

According to a second aspect of the present invention, there is provided a method of manufacturing an array substrate for a transverse electric field type liquid crystal display device, the method comprising: preparing a substrate, first and spaced parallel to one direction on the substrate; Forming a second gate wiring, a common wiring, and a plurality of common electrodes vertically extending from the common wiring; and defining data of a pixel region by perpendicularly crossing the first and second gate wirings and the common wiring; Forming a wiring;

Forming a first thin film transistor and a second thin film transistor at intersections of the first and second gate lines and the data line, respectively, connected to the first thin film transistor and spaced apart from the common electrode in parallel. And forming a transparent first pixel electrode and a second pixel electrode connected to the second thin film transistor and vertically intersecting with the common electrode.

In this case, the second pixel electrode includes a plurality of horizontal parts vertically intersecting the common electrode, and a vertical part connecting the plurality of horizontal parts to one, and the second thin film through a connection line extending from one end of the horizontal part. The second pixel electrode is formed of the same material as the data line.

Hereinafter, a transverse electric field type liquid crystal display device according to the present invention will be described with reference to the accompanying drawings.

--- First Embodiment ---

The first embodiment of the present invention is designed to separately drive the first and second common electrodes spaced apart from each other in parallel with each other, and the pixel electrode is configured to vertically intersect the first and second common electrodes. And the second common electrode and the pixel electrode form a checkerboard shape. This configuration has an advantage that the voltage of each electrode can be controlled organically to improve the contrast ratio in the black state and the white or gray state.

3 is a plan view illustrating unit pixels of an array substrate for a transverse electric field type liquid crystal display device according to a first exemplary embodiment of the present invention.

As shown in the drawing, the gate wiring 120 made of a conductive metal and the gate electrode 125 extending from the gate wiring 120 are configured in the first direction on the substrate 100.

The data line 130 perpendicularly intersects the gate line 120, the source electrode 132 extending from the data line 130, and the drain electrode 134 spaced apart from the gate line 120. An area defined by the vertical intersection of the gate line 120 and the data line 130 is referred to as a pixel area P. A gate electrode 125 and a portion of the gate electrode 125 overlap with the intersection point. The source and drain electrodes 132 and 134 and the active layer 140 and the ohmic contact layer (not shown) interposed therebetween are laminated.

In this case, the active layer 140 is made of pure amorphous silicon, and the ohmic contact layer (not shown) is made of impurity amorphous silicon, respectively, and the gate electrode 125, the source and drain electrodes 132 and 134, and the active layer ( 140) and an ohmic contact layer (not shown) to form a thin film transistor (T) which is a switching element.

In addition, an extension portion 160a contacting the drain electrode 134 through a drain contact hole CH2 exposing a portion of the drain electrode 134 and the gate wiring 120 in the extension portion 160a. ) And a pixel electrode 160 including a plurality of horizontal portions 160b spaced apart in parallel with each other and a vertical portion 160c connecting the plurality of horizontal portions 160b to one.

In addition, the first and second common wirings 150 and 151 spaced apart in parallel in the interval between the gate wiring 120 and the gate wiring 120 of the previous stage are configured, and the first and second common wirings are formed. A plurality of first and second common electrodes 170 and 180 branched vertically at 150 are respectively configured.

In this case, the first common electrode 170 and the second common electrode 180 cross each other in parallel in the pixel region P, and vertically intersect the pixel electrode horizontal portion 160b with a passivation layer (not shown) therebetween. In this configuration, the first and second common electrodes 170 and 180 and the pixel electrode horizontal part 160b are designed to form a checker board. In addition, the first common electrode 170 and the second common electrode 180 are separately driven, and have a constant DC voltage from the first and second common voltage generators (not shown) configured at one side spaced apart from the substrate 100. Is authorized.

Hereinafter, a driving method of an array substrate for a transverse electric field type liquid crystal display device having the above-described configuration will be described with reference to the accompanying drawings.

4A is a circuit diagram showing a black state, and FIG. 4B is a circuit diagram showing a white or gray state.

First, as shown in a cross-sectional view of a black state, FIG. 4A illustrates that when the black state is implemented, -5 V is applied to the gate wiring 120, and the pixel electrode 160 connected thereto serves as a floating electrode. Do it.

Then, when 0 V is applied to the first common electrode 170 and 5 V is applied to the second common electrode 180, the voltage difference between the first and second common electrodes 170 and 180 is interposed between the two electrodes. As described above in Equation (1), the horizontal arrangement degree of the obtained liquid crystals can be satisfied so that the contrast ratio can be improved. In this case, the arrows not described indicate the rubbing direction of the liquid crystal.

4B is a cross-sectional view showing a white or gray state, in which 0V is applied to the first common electrode 170 and 5V is applied to the second common electrode 180 to represent a white or gray state, respectively. In this state, the gate voltage of the thin film transistor is varied in the range of 1 to 30V. In this case, the gate voltage may be improved by adjusting the arrangement of the liquid crystals in a range of 0 to 10V according to the signal of the data voltage to improve the contrast ratio in the white or gray state.

In summary, in order to implement black, the pixel electrodes 160 are maintained in a floating state so that the liquid crystals are uniformly arranged horizontally through a transverse electric field generated between the first and second common electrodes 170 and 180, and white. Alternatively, in order to achieve gray, the intensity of the electric field generated between the pixel electrode 160 and the first and second common electrodes 170 and 180 is adjusted by organically adjusting the variation of the gate voltage and the voltage of the pixel electrode 160. By changing the arrangement of the liquid crystal freely through it characterized in that the contrast ratio can be improved when implementing white or gray.

Hereinafter, a method of manufacturing an array substrate for a transverse electric field type liquid crystal display device according to the present invention will be described with reference to the accompanying drawings.

5A to 5D are cross-sectional views illustrating a process sequence cut along the line VV of FIG. 3.

As shown in FIG. 5A, one selected from a group of conductive metals such as aluminum (Al), aluminum alloy (AlNd), molybdenum (Mo), tungsten (W), chromium (Cr), and the like is deposited on the substrate 100. This pattern is used to form a gate wiring (120 in FIG. 3) and a gate electrode 125 extending from the gate wiring in one direction.

At the same time, the first common wiring (150 in FIG. 3) and the second common wiring 151 spaced apart in parallel in a section between the gate wiring (120 in FIG. 3) and the gate wiring in the preceding stage, respectively, and the first common 3 and a plurality of first and second common electrodes 170 and 180 which are vertically branched from the wiring 150 and the second common wiring 151 are formed, respectively.

In this case, the first and second common electrodes 170 and 180 are engaged with each other in parallel to be spaced apart from each other in the pixel region P, and are separated and driven.

Next, a gate is selected from a group of inorganic insulating materials such as silicon nitride (SiNx) or silicon oxide (SiO ₂ ) on the entire upper surface of the substrate 100 on which the gate wiring 120 (120 of FIG. 3) and the gate electrode 125 are formed. An insulating film 145 is formed.

As shown in FIG. 5B, a pure amorphous silicon layer (not shown) and an impurity amorphous silicon layer (not shown) are stacked and patterned on the substrate 100 on which the gate insulating layer 145 is formed. An island-like active layer 140 and an ohmic contact layer 141 overlapping the 125 and a portion thereof are formed.

Next, one selected from the group of conductive metals such as molybdenum (Mo), aluminum (Al), aluminum alloy (AlNd), and copper (Cu) on the substrate 100 on which the active and ohmic contact layers 140 and 141 are formed. Or by depositing more than this to form a source and drain metal layer (not shown), patterning it, extending the data line (130 in FIG. 3) perpendicular to the gate line (120 in FIG. 3) and the data line The formed source electrode 132 and the drain electrode 134 spaced apart from each other.

The thin film transistor T includes the gate electrode 125, the active and ohmic contact layers 140 and 141, and the source and drain electrodes 132 and 134.

As shown in FIG. 5C, one selected from the group of inorganic insulating materials such as silicon nitride (SiNx) or silicon oxide (SiO ₂ ) on the entire upper surface of the substrate 100 on which the source and drain electrodes 132 and 134 are formed, Alternatively, the passivation layer 155 is formed of one selected from the group of organic insulating materials including acryl resin and benzocyclobutene (BCB).

Next, the passivation layer 155 corresponding to a part of the drain electrode 134 is patterned to form a drain contact hole CH2 exposing a part of the drain electrode 134.

As shown in FIG. 5D, a transparent conductive metal group including indium tin oxide (ITO) and indium zinc oxide (IZO) is selected on the passivation layer 155 including the drain contact hole CH2. The pixel electrode (160 in FIG. 3) is formed with one.

In this case, the pixel electrode 160 of FIG. 3 includes an extension portion 160a that contacts the drain electrode 134, and the first and second common electrodes 170 and 180 and the passivation layer (eg, the extension portion 160a). And a plurality of horizontal portions 160b configured to vertically intersect 155 therebetween, and a vertical portion (160c of FIG. 3) connecting the plurality of horizontal portions 160b to one.

As described above, when the black is implemented, the arrangement of the liquid crystals may be adjusted through the transverse electric field generated between the first and second common electrodes 170 and 180 by allowing the pixel electrode 160 of FIG. 3 to be in a floating state. In the white or gray implementation, the gate voltage is changed and the voltage of the pixel electrode 160 of FIG. 3 is organically adjusted to occur between the pixel electrode 160 of FIG. 3 and the first and second common electrodes 170 and 180. By adjusting the intensity of the electric field to change the arrangement of the liquid crystal freely can improve the contrast ratio in the white or gray state.

As described above, the array substrate for the transverse electric field type liquid crystal display device according to the first embodiment of the present invention can be manufactured through the above-described process.

Therefore, in the present invention, the contrast ratio can be improved by designing the pixel such that the first and second common electrodes and the pixel electrode have a checkerboard shape.

--- Second Embodiment ---

The second embodiment of the present invention is designed to separately drive the first and second pixel electrodes connected to the first and second thin film transistors, respectively, in parallel with the first pixel electrode and with the second pixel electrode. The common electrode may be configured to vertically intersect, and the pixel design may be performed such that the first and second pixel electrodes and the common electrode form a checkerboard shape.

Such a configuration has an advantage of being able to control the voltage applied to each electrode organically, thereby inducing the movement of the liquid crystal to improve the contrast ratio in the black state and white or gray implementation.

6 is a plan view illustrating unit pixels of an array substrate for a transverse electric field type liquid crystal display device according to a second exemplary embodiment of the present invention.

As illustrated, the first and second gate wires 220 and 221 made of a conductive metal are spaced in parallel on the substrate 200. In addition, a common wiring spaced apart in parallel with the first and second gate wirings 220 and 221 is configured.

The data line 230 intersects the first and second gate lines 220 and 221 perpendicularly.

In this case, an area defined by the vertical crossing of the first and second gate wires 220 and 221 and the data wire 230 is referred to as a pixel area P. The intersection of the first gate electrode 225a and The first source electrode 232a and the first drain electrode 234a overlapping the portion of the first gate electrode 225a and the first active layer 240a and the first ohmic contact layer (not shown) The first thin film transistor T1 is configured to include a second gate electrode 225b and the second gate electrode 225b at the intersection of the second gate wire 221 and the data wire 230. A second thin film including a second source electrode 232b and a second drain electrode 234b overlapping a portion thereof, and a second active layer 240b and a second ohmic contact layer (not shown) interposed therebetween. The transistor T2 is configured.

The pixel region P includes a first pixel electrode 260 in contact with the first drain electrode 234a, a second pixel electrode 290 in contact with the second drain electrode 234b, and the common wiring. A common electrode 270 extending vertically at 250 is formed.

The first pixel electrode 260 may include a horizontal portion 260a in contact with the first drain electrode 234a and a plurality of vertical portions 260b vertically branched from the horizontal portion 260a to the pixel region P. And the second pixel electrode 290 includes a plurality of horizontal portions 290a vertically intersecting with the common electrode 270, and a vertical portion 290b connecting the horizontal portions 290a to one side. It is configured in the form that is connected to the second drain electrode 234b through a connection line 280 vertically and horizontally refracted extending from one side of the horizontal portion (290a).

Accordingly, the vertical portion 260b of the first pixel electrode and the horizontal portion 290a of the second pixel electrode are vertically intersected, and are formed through the first and second thin film transistors T1 and T2. It is characterized in that the drive separate.

In addition, the common electrodes 270 that are vertically branched into the pixel region P from the common wiring 250 are alternately arranged in parallel with the first pixel electrode vertical portion 260b to thereby form the common electrodes 270. ) And the first pixel electrode vertical part 260b and the second pixel electrode horizontal part 290a form a checker board shape.

The above-described configuration may separately drive the first and second pixel electrodes 260 and 290 through the first and second thin film transistors T1 and T2, and the first pixel electrode vertical part 260b and the common electrode. In a state in which 270 is alternately arranged in parallel with each other, the pixel design is such that the second pixel electrode horizontal portion 290a is vertically intersected with them to form a checkerboard shape.

This configuration has the advantage of being able to separately drive the first and second gate signals, thereby controlling the voltage of each electrode to improve the contrast ratio when implementing black, white or gray.

This will be described below in detail with reference to the accompanying drawings.

7A-7C are respective circuit diagrams showing black, white and gray states.

First, as shown in a cross-sectional view showing a black state, FIG. 7A is a state in which the second pixel electrode 290 is maintained in a floating state by applying -5V to the second gate wiring 221 to implement black. 25V is applied to the first gate line 220 to switch the first pixel electrode 260.

Next, when 1 V is applied to the first pixel electrode 260 and 0 V is applied to the common electrode 270, the positive electrode 260 may be changed due to a voltage difference between the common electrode 270 and the first pixel electrode 260. The horizontal arrangement degree of the liquid crystal interposed between the lines 270 is increased to satisfy S = 1 as described in Equation (1). Therefore, the black luminance is increased to improve the contrast ratio.

7B is a cross-sectional view showing a white state, in order to implement white, first and second thin film transistors T1 and T2 are applied to the first gate line 220 and the second gate line 221 by 25V. ), Respectively, and 0V is applied to the common electrode 270 while 7V is applied to the first and second pixel electrodes 260 and 290 so that the electric field applied between the three electrodes 260, 270 and 290 The intensity of the arrangement of the liquid crystal can be adjusted.

That is, the contrast ratio in the white state may be improved by organically determining the voltages of the three electrodes 260, 270, and 290 to induce the movement of the liquid crystal.

7C is a cross-sectional view showing a gray state, in order to implement gray, 25V is applied to the first and second gate wires 220 and 221 so that the first and second thin film transistors T1 and T2. ) And 3V are applied to the first pixel electrode 260 and 1V is applied to the second pixel electrode 290, respectively, and 0V is applied to the common electrode 270 so that the three electrodes 260, 270, and 290 are applied. By adjusting the arrangement of the liquid crystal interposed therebetween, the contrast ratio in the gray state can be improved.

7A to 7C are only examples, and it will be apparent that the values may vary depending on the characteristics or properties of the liquid crystal.

In summary, in the black state, the second pixel electrode 290 is maintained in a floating state, and the liquid crystals are uniformly horizontally arranged through a transverse electric field generated between the first pixel electrode 260 and the common electrode 270. In the white or gray state, the three electrodes 260 may be organically controlled by controlling the voltages applied to the first and second pixel electrodes 260 and 290 which are separately driven while a constant voltage is applied to the common electrode 270. By controlling the intensity of the electric field generated between the, 270, 290, it is possible to change the arrangement of the liquid crystal freely to improve the contrast ratio in the white or gray state.

Hereinafter, a method of manufacturing an array substrate for a transverse electric field type liquid crystal display device according to a second embodiment of the present invention will be described with reference to the accompanying drawings.

8A to 8D are cross-sectional views illustrating the process sequence by cutting along the line VII-VII of FIG. 6.

As shown in FIG. 8A, one selected from a group of conductive metals is deposited on the substrate 200 and patterned, thereby extending the first gate wiring 220 (in FIG. 6) and the first gate wiring in one direction. A first gate electrode 225a, a second gate wiring 220 spaced in parallel with the first gate wiring 220 and a second gate electrode 225b extending in the second gate wiring, respectively, are respectively disposed. Form.

At the same time, common wiring (250 in FIG. 6) configured to be spaced in parallel in a section between the first gate wiring (220 in FIG. 6) and the second gate wiring (221 in FIG. 6) in the front end, and in the common wiring, A plurality of vertically branched common electrodes 270 are formed.

Next, an inorganic insulating material group such as silicon nitride (SiNx) or silicon oxide (SiO ₂ ) on an upper surface of the substrate 200 on which the first gate electrode 225a and the second gate electrode (225b of FIG. 6) are formed. The gate insulating layer 245 is formed with one selected from the group consisting of two layers.

As shown in FIG. 8B, a pure amorphous silicon layer (not shown) and an impurity amorphous silicon layer (not shown) are stacked and patterned on the substrate 200 on which the gate insulating layer 245 is formed. The first active layer 240a and the first ohmic contact layer 241a overlapping the gate electrode 225a and a portion thereof, and the second active layer overlapping the second gate electrode 225b in FIG. 6 and a portion thereof. (240b of FIG. 6) and a 2nd ohmic contact layer (not shown) are formed, respectively.

Next, molybdenum (Mo), aluminum (Al), and aluminum alloy (AlNd) are formed on the substrate 200 on which the first active and ohmic contact layers 240a and 241a and the second active and ohmic contact layers (not shown) are formed. ) And one or more selected from a group of conductive metals such as copper (Cu) are deposited to form a source and drain metal layer (not shown), and then pattern the first and second gate wires (220, 221 of FIG. 6). 6 and 230, a first source electrode 232a extending from the data line and partially overlapping the first gate electrode 225a, and a first drain spaced apart from the data line (230 of FIG. 6). An electrode 234a, a second source electrode 232b extending from the data line and overlapping a portion of the second gate electrode 225b of FIG. 6, and a second drain electrode spaced apart from the second source electrode (FIG. 234b) of 6 are respectively formed.

Accordingly, a first thin film transistor T1 including the first gate electrode 225a, the first active and ohmic contact layers 240a and 240b, and the first source and drain electrodes 232a and 234a, and FIG. A second thin film including the second gate electrode 225b shown in FIG. 6, the second active layer 240b and the second ohmic contact layer (not shown), and the second source and drain electrodes 232b and 234b. Each transistor T2 is formed.

Accordingly, the first and second thin film transistors T1 and T2 may be separated and driven.

At the same time, a plurality of horizontal portions 290a vertically intersecting with the common electrode 270, and a vertical portion 290b connecting the horizontal portions 290a to one at one side, the horizontal portion 290a A second pixel electrode 290 is formed to be connected to the second drain electrode 234b through a connection line 280 that is vertically and horizontally refracted to extend from one side of the second line electrode 234b.

As shown in FIG. 8C, an inorganic insulating material group, such as silicon nitride (SiNx) or silicon oxide (SiO ₂ ), is selected on the entire upper surface of the substrate 200 on which the first source and drain electrodes 232a and 234a are formed. The passivation layer 255 is formed of one selected from the group of organic insulating materials including acryl resin and benzocyclobutene (BCB).

Next, a passivation layer 255 corresponding to a part of the first drain electrode 234a is patterned to form a drain contact hole CH3 exposing the first drain electrode 234a.

As shown in FIG. 8D, a transparent conductive metal group including indium tin oxide (ITO) and indium zinc oxide (IZO) is selected on the passivation layer 255 including the drain contact hole CH3. One first pixel electrode 260 of FIG. 6 is formed to contact the first drain electrode 234a.

The first pixel electrode 260 of FIG. 6 includes a horizontal portion 260a in contact with the first drain electrode 234a and a plurality of vertical portions vertically branched from the horizontal portion 260a to the pixel region P. 260b.

In this case, the first pixel electrode vertical part 260b is staggered in parallel with the common electrode 270 and vertically intersects the second pixel electrode horizontal part 290a with the passivation layer 255 interposed therebetween. The pixel design is performed such that the first pixel electrode vertical part 260b, the second pixel electrode horizontal part 290a, and the common electrode 270 form a checkerboard shape.

As described above, the array substrate for the transverse electric field type liquid crystal display device according to the second embodiment of the present invention can be manufactured through the above-described process.

Therefore, in the present invention, the common electrode or the pixel electrode is separately driven, and the pixel is designed in a checkerboard shape to control the intensity of the electric field according to each voltage, thereby improving the arrangement ratio of the liquid crystal, thereby improving the contrast ratio.

The present invention is configured to separately drive the common electrode or the pixel electrode, and by adjusting the arrangement of the liquid crystal interposed therebetween by controlling the voltage according to each signal wiring by designing the pixel in a checkerboard shape, It is effective to realize high quality through improvement.

Claims (20)

A substrate; Gate interconnections and data interconnections perpendicular to the substrate; A thin film transistor configured at an intersection point of the gate line and the data line; First and second common wires configured to be spaced apart in parallel in the spaced interval between the gate wires and the gate wires facing the gate wires; A plurality of first common electrodes vertically branched from the first common wiring to the pixel region, and a plurality of second common electrodes vertically branched from the second common wiring and spaced apart in parallel with the first common electrode; A pixel electrode in contact with the thin film transistor and configured to vertically intersect the first and second common electrodes Array substrate for a transverse electric field type liquid crystal display device comprising a. The method of claim 1, In the black implementation, The pixel electrode connected to the thin film transistor serves as a floating electrode, and the liquid crystal is horizontally aligned with the difference value of each voltage applied to the first and second common electrodes. Array substrate for devices. The method of claim 2, A voltage of -5V is applied to the gate wiring so that the pixel electrode connected thereto serves as a floating electrode, and a common voltage of 0V is applied to the first common electrode and 5V is applied to the second common electrode. An array substrate for a transverse electric field type liquid crystal display device. The method of claim 1, When implementing white or gray, A constant common voltage is applied to the first and second common electrodes, respectively, and a pixel voltage applied to the pixel electrode is adjusted by adjusting a gate voltage applied to the gate wiring, so that the pixel electrode and the first and second electrodes are adjusted. An array substrate for a transverse electric field type liquid crystal display device, characterized in that white or gray can be realized by arranging liquid crystals by a voltage difference generated between common electrodes. The method of claim 4, wherein A common voltage of 0V is applied to the first common electrode, a common voltage of 5V is applied to the second common electrode, and the gate voltage is applied within a range of 1V to 30V, wherein the pixel voltage is 0 to 10V. An array substrate for a transverse electric field type liquid crystal display device, which is applied within the range of. The method of claim 1, And the first and second common electrodes are separated and driven, and a direct current voltage is applied to each of the first and second common electrodes. The method of claim 1, The pixel electrode may include an extension part contacting the thin film transistor, a plurality of horizontal parts branched from the extension part and spaced in parallel with the gate line, and a vertical part connecting the plurality of horizontal parts to one. Array substrate for transverse electric field type liquid crystal display device. The method of claim 1, And the first and second common electrodes are made of the same material as the gate line. The method according to any one of claims 1 to 8, And the first and second common electrodes and the pixel electrode vertically cross each other to form a checkerboard shape. Preparing a substrate; A gate wiring on one surface of the substrate, a first common wiring and a second common wiring parallel thereto, a plurality of first common electrodes vertically extending from the first common wiring, and the first common wiring on the second common wiring; Forming a plurality of second common electrodes extending vertically between the electrodes; Forming a data line defining a pixel area perpendicularly intersecting the gate line and the first and second common lines; Forming a thin film transistor at an intersection point of the gate line and the data line; Forming a pixel electrode crossing the first and second common electrodes in the pixel region Method of manufacturing an array substrate for a transverse electric field type liquid crystal display device comprising a. The method of claim 10, The pixel electrode may include an extension part contacting the thin film transistor, a plurality of horizontal parts branched from the extension part and spaced apart in parallel with the gate line, and a vertical part connecting the plurality of horizontal parts to one. A method of manufacturing an array substrate for a transverse electric field type liquid crystal display device. A substrate; First and second gate wirings spaced apart in parallel on the substrate, and common wirings; A data line defining a pixel area perpendicularly intersecting the first and second gate lines and the common line; A first thin film transistor and a second thin film transistor respectively formed at intersections of the first and second gate lines and the data lines; A plurality of common electrodes vertically branched to the pixel area in the common wiring; A plurality of first pixel electrodes connected to the first thin film transistor and alternately spaced apart from each other in parallel with the plurality of common electrodes; A plurality of second pixel electrodes connected to the second thin film transistor and configured to vertically intersect the common electrode and the first pixel electrode; Array substrate for a transverse electric field type liquid crystal display device comprising a. The method of claim 12, In the black implementation, The second pixel electrode connected to the second thin film transistor serves as a floating electrode, and the horizontal liquid crystal display device characterized in that the liquid crystal is arranged horizontally by the voltage difference between the pixel voltage of the first pixel electrode and the common electrode. Array substrate for. The method according to claim 12 and 13, A gate voltage of −5 V is applied to the second gate wiring so that the second thin film transistor connected thereto serves as a floating electrode. The pixel voltage of 1 V is applied to the first pixel electrode, and 0 V is applied to the common electrode. An array substrate for a transverse electric field type liquid crystal display device, characterized by applying a common voltage. The method of claim 12, In the implementation of the white or gray state, A common voltage having a constant value is applied to the common electrode, and each pixel voltage applied to the first pixel electrode and the second pixel electrode is adjusted to adjust the liquid crystal to a voltage difference between the first and second pixel electrodes and the common electrode. An array substrate for a transverse electric field type liquid crystal display device, characterized in that for driving. The method of claim 15, In white implementation, Apply a 7V pixel voltage to the first and second pixel electrodes, respectively, and apply 0V to the common electrode, When implementing a specific level of gray, For driving a liquid crystal by applying a pixel voltage of 3V to the first pixel electrode and a pixel voltage of 1V to the second pixel electrode, and applying 0V to the common electrode. Array substrate. The method according to any one of claims 12 to 16, And the common electrode, the first pixel electrode, and the second pixel electrode are vertically intersected to form a checkerboard shape. Preparing a substrate; Forming first and second gate wirings spaced in parallel in one direction on the substrate, common wirings, and a plurality of common electrodes vertically extending from the common wirings; Forming a data line defining a pixel area perpendicularly intersecting the first and second gate lines and the common line; Forming a first thin film transistor and a second thin film transistor at intersections of the first and second gate lines and the data line, respectively; Forming a transparent first pixel electrode connected to the first thin film transistor and spaced apart from the common electrode in parallel, and a second pixel electrode connected to the second thin film transistor and vertically intersecting with the common electrode. Method of manufacturing an array substrate for a transverse electric field type liquid crystal display device comprising a. The method of claim 18, The second pixel electrode includes a plurality of horizontal parts vertically intersecting with the common electrode, and a vertical part connecting the plurality of horizontal parts to one, and the second thin film transistor through a connection line extending from one end of the horizontal part. A method of manufacturing an array substrate for a transverse electric field type liquid crystal display device, characterized in that the connection is formed. The method of claim 18, And the second pixel electrode is formed of the same material as that of the data line.

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