KR100218527B1 - Liquid crystal display device and its manufacturing method of in-plane switching mode - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device of a planar driving type. The present invention consists of a liquid crystal material in which a wiring is formed and a second substrate not in contact with the first substrate, and a liquid crystal material interposed therebetween. Common electrodes are vertically formed on the first substrate to receive a common voltage, gate lines are formed laterally, and vertical pixel electrodes are formed between the common electrodes.

A data line is formed on the common electrode along a common electrode through a gate insulating layer. One terminal is connected to the gate line, the other terminal is connected to the data line, and the other terminal is connected to the pixel electrode. Respectively. Through this structure, the present invention increases the aperture ratio while expanding the viewing angle.

Description

Flat panel driving type liquid crystal display device and manufacturing method thereof

FIGS. 1a and 1b are plan views showing a conventional substrate for a liquid crystal display of a planar driving type.

FIGS. 2A and 2B are plan views illustrating a substrate for a liquid crystal display of a planar driving type according to a first embodiment of the present invention. FIG.

FIG. 3 is a cross-sectional view taken along line A-A in FIG.

4A to 4E are plan views illustrating a method of manufacturing a substrate for a liquid crystal display according to a first embodiment of the present invention.

FIG. 5 is a plan view showing a substrate for a liquid crystal display of a planar driving type according to a second embodiment of the present invention; FIG.

6 is a cross-sectional view taken along line B-B in FIG. 5;

FIG. 7 is a view showing a substrate for a liquid crystal display of a planar driving type according to a third embodiment of the present invention; FIG.

8 is a cross-sectional view taken along line C-C of FIG. 8;

9A to 9B are plan views showing a method of manufacturing a substrate for a liquid crystal display according to a third embodiment of the present invention.

FIG. 10 and FIG. 11 are diagrams for explaining the operation of the liquid crystal display device according to the embodiment of the present invention. FIG.

FIG. 12 and FIG. 13 are graphs showing transmissivity in a display device according to an embodiment of the present invention. FIG.

DESCRIPTION OF THE REFERENCE NUMERALS

100: substrate 110: gate line

120: common electrode line 121: common electrode

122: sustain electrode 130: data line

140: pixel electrode 150: gate insulating layer

160: semiconductor layers 171 and 172: contact layer

180: source electrode 190: drain electrode

200: first substrate 300: second substrate

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display (LCD), and more particularly, to a liquid crystal display of an in-plane switching mode (IPS mode).

2. Description of the Related Art A liquid crystal display (LCD) is one of the most popular flat panel displays in recent years, and is a display device using an electro-optical effect of a liquid crystal material. The driving method thereof includes a simple matrix type and an active matrix (Active matrix type).

The active matrix type liquid crystal display device controls the operation of each pixel by adding a switching element having a non-linear characteristic to each pixel arranged in a matrix form. A three-terminal type thin film transistor (TFT) is generally used as a switching element, and a thin film diode (TFD) such as a metal insulator metal (MIM) having a two-terminal type may be used.

In particular, a thin film transistor liquid crystal display device, which has been actively studied at present, includes a substrate on which a pixel electrode is formed, another substrate on which a common electrode is formed, It is made of material. In order to drive the liquid crystal molecules in such a liquid crystal display device, it is general to apply a voltage to the pixel electrode and the common electrode. In this case, a twisted-nematic (TN) method in which liquid crystal molecules are arranged at 90 ° from one substrate to another is mainly used.

However, such a liquid crystal display device, in particular, a liquid crystal display device using a twisted nematic liquid crystal material, depends on the angle of view of contrast. In particular, the angle dependency of the contrast is very high up and down.

In addition, since the pixel electrode and the common electrode must be formed on different substrates and the two substrates must be short-circuited in order to apply the voltage to the common electrode, the number of processes is increased.

As a method for solving these problems, a liquid crystal display device using a planar driving method has been proposed.

In a planar driving method, a liquid crystal display device is driven by forming both a pixel electrode and a common electrode on one substrate. Unlike a general method using a potential difference between two substrates, a liquid crystal molecule reaction It is the cause. A representative example thereof is European Patent Application No. 93307154.0.

Hereinafter, a conventional planar driving type liquid crystal display device will be described in detail with reference to the accompanying drawings.

FIGS. 1A and 1B show a conventional planar driving type liquid crystal display device, which is described in ASIA D ISPLAY '95 pp. 707-710, entitled " Development of Super-TFT-LCDs with In-Plane Switching Display Mode " (M Ohta et al.).

First, the structure shown in FIG.

A gate line 1 is formed laterally and a data line 11 orthogonal to the gate line 1 is vertically formed. The opposing electrode line 2 parallel to the gate line 1 is formed of the same material as the gate line 1 and the branches 3 and 4 of the opposing electrode line 2 extend toward the gate line 1 Is composed of a vertical part 3 and a horizontal part 4 located in the vicinity of the gate line 1 and parallel to the gate line 1 and the opposite electrode line 2. A thin film transistor TFT is formed near the intersection of the gate line 1 and the data line 11. The gate electrode of the thin film transistor TFT is part of the gate line 1 and the source electrode thereof is connected to the data line 11 ).

On the other hand, the drain electrode 12 of the thin film transistor (TFT) is formed of the same material as the data line 11 and extends to become the pixel electrode 16. The pixel electrode 16 is in the form of a rectangular ring having two portions perpendicular to the data line 11 and two portions perpendicular to the data line 11 and one portion parallel to the data line 11 is adjacent to the data line 11 And two portions perpendicular to the data line 11 are overlapped with the counter electrode line 2 and the branch 4 parallel to the counter electrode line 2, respectively. The branch 3 of the common electrode line 2 is vertically crossed at the center of the rectangular pixel electrode 16.

The structure shown in FIG. 1B will now be described. The structure of the branch of the common electrode line and the structure of the pixel electrode is opposite to that of the first embodiment. This will be described in detail.

A gate line 1 is formed laterally and a data line 11 orthogonal to the gate line 1 is vertically formed. The counter electrode line 2, which is parallel to the gate line 1, is formed of the same material as the gate line 1. The branch 6 of the counter electrode line 2 is formed as a portion orthogonal to the two portions parallel to the data line 11 and has a rectangular annular shape together with the counter electrode line 2, Quot; portion " is adjacent to the data line 11. A thin film transistor TFT is formed near the intersection of the gate line 1 and the data line 11. The gate electrode of the thin film transistor TFT is part of the gate line 1 and the source electrode thereof is connected to the data line 11 ). On the other hand, the drain electrode of the thin film transistor (TFT) is formed of the same material as the data line 11 and extends to become the pixel electrodes 13 and 14. The pixel electrodes 13 and 14 are composed of a vertical portion 13 parallel to the data line 11 and two vertical portions 14 perpendicular to the data line 11. The two horizontal portions 14 correspond to the opposite electrode lines 2 and the counter electrode lines 14, (2). ≪ / RTI > The vertical portion 13 of the pixel electrode 13 crosses the rectangular annular center formed by the common electrode line 2 and the branch 6 of the common electrode line 2.

In such a liquid crystal display device, the potential difference between the common electrode line 2 and the branch lines 3,4 and 6 and the pixel electrodes 16 and 13 and 14, in particular, the common electrode line branch 3 (6) The direction of the liquid crystal molecules is changed by using one pixel electrode 16 (13), and the display operation is performed by using the change of the light and the transmittance.

As a result of measuring the viewing angle characteristics using such a liquid crystal display device, it is reported in this paper that it is superior to a conventional liquid crystal display device.

However, the paper also has several points to consider in such a planar driving type liquid crystal display device.

First, in order to properly control the liquid crystal molecules, an electric field generated from the data line 11 must be efficiently shielded.

The pixel electrode 16 is adjacent to the data line 11 and the branch 6 of the counter electrode line 2 is adjacent to the data line 11 in the case of FIG. And shield the electric field from the electric field. Since the pixel electrode 16 (13, 14) has a floating potential while the signal is not applied, the pixel electrode 16 is easily influenced by the potential of the other portion. On the other hand, the opposing electrode line 2 and the branches 3, 4 and 6 are more influential in shielding the electric field from the data line 11 in consideration of the fact that the electric potential is constantly supplied from the external power source and thus are not affected well .

Second, the aperture ratio should be considered. In Figure 1a, the aperture ratio is determined by the area of the annular shape of the display area, that is, the pixel electrode 16. In Figure 1b, the common electrode line 2 and the ring- Area. Since the pixel electrode 11 and the data line 16 are made of the same material in the structure of Fig. 1 (a), a certain distance is required between the pixel electrode 11 and the data line 16 in order to prevent a short circuit between the pixel electrode 11 and the data line 16. However, in 1 scheme (b), since the insulating layer exists between the pixel electrodes 13 and 14 and the counter electrode line branch 6, the distance between the data line 11 and the counter electrode lines 2 and 6 may be close to each other . Therefore, in the case of the structure of Fig. 1b, the beam display area can be widened in the case of the structure of Fig. 1a, so that the structure of Fig. 1b can easily obtain a larger aperture ratio than the structure of Fig.

However, the conventional technology using such a planar driving method has the effect of widening the viewing angle compared to the conventional one, but since the electric field from the data line is not sufficiently shielded, the movement of the liquid crystal molecules is easily affected by the electric field from the data line .

In addition, since a single channel thin film transistor is used, there is a problem in that the on current is low, and it is difficult to make the parasitic capacitance constant depending on the pixel.

In addition, a large number of wirings are formed, and the aperture ratio is small.

SUMMARY OF THE INVENTION The present invention has been made in an effort to solve the above problems, and it is an object of the present invention to provide an organic EL display device capable of effectively shielding an electric field from a data line and increasing an aperture ratio, securing a constant parasitic capacitance, To be able to.

A substrate for a liquid crystal display according to the present invention for solving such problems is as follows.

A plurality of common electrodes to which a common voltage is applied are vertically formed on a transparent insulating substrate, and gate lines are formed separately from the common electrode in the horizontal direction. A common electrode and a gate line are covered with a gate insulating layer, and pixel electrodes are vertically formed therebetween. On the gate insulating layer on the common electrode, data lines, which are made of the same material as the pixel electrodes, are formed along the common electrode and connected to the pixel electrodes.

On the other hand, a three-terminal switching element may be formed on the gate insulating layer. One terminal of the switching element is connected to the gate line, the other terminal is connected to the data line, and the other terminal is connected to the pixel electrode. Connect electrically.

At this time, it is preferable that the width of the data line does not exceed the width of the common electrode, and the opening portion may be formed at the center of the common electrode overlapping with the data line.

In addition, a sustain electrode may be formed along the pixel electrode under the gate insulating layer under the pixel electrode, and the sustain electrode is connected to the gate line. At this time, the sustain electrode may be made of a transparent conductive material.

The common electrode may be made of a transparent conductive material, and the gate line may be made of chromium.

Another substrate for a liquid crystal display according to the present invention for achieving the above object is as follows.

A plurality of common electrodes to which a common voltage is applied are vertically formed on a transparent insulating substrate, and gate lines are formed separately from the common electrode in the horizontal direction. A gate insulating layer is formed on the common electrode and the gate line. Data lines are formed on the gate insulating layer along the common electrode. Pixel electrodes are vertically formed between the common electrodes and the data lines.

On the other hand, a transistor is formed in which one terminal is connected to the gate line, the other terminal is connected to the data line, and the other terminal is connected to the pixel electrode.

Here, it is preferable that the width of the data line does not exceed the width of the common electrode, and an opening may be formed at the center of the common electrode overlapping the data line.

A sustain electrode overlapped with the pixel electrode may be formed under the gate insulating layer, and the sustain electrode is connected to the gate line. At this time, the sustain electrode may be made of a transparent conductive material, the common electrode may also be made of a transparent conductive material, and the gate line may be made of chromium.

Another substrate for a liquid crystal display device to solve such a problem includes the following means.

A plurality of common electrode lines are horizontally formed on a transparent insulating tube, and common electrode lines as branches are formed vertically above and below the common electrode lines. A plurality of sustain electrodes are vertically formed between the common electrodes and a plurality of gate lines electrically connected to the sustain electrodes are formed laterally between the common electrode lines and the common electrode lines below the common electrode lines and the common electrodes . A common electrode line, a common electrode, a sustain electrode, and a gate line are covered with a gate insulating layer, and a plurality of pixel electrodes are formed vertically along the sustain electrode on the gate insulating layer. . On the gate insulating layer, a data line made of the same material as the pixel electrode is formed along the common electrode. On the other hand, in the substrate for a liquid crystal display apparatus, the channel transistor is formed. The first terminal of the channel transistor is connected to the gate line, the second terminal is connected to the data line, and the third terminal is connected to the pixel electrode And the fourth terminal is connected to the pixel electrode opposite to the third terminal with respect to the gate line.

Here, the sustain electrode and / or the common electrode may be made of a transparent conductive material, and the gate line or the pixel electrode and the data line may be made of chromium.

A liquid crystal display device for solving such problems includes a first substrate and a second substrate. The structure of the first substrate is as follows. A common electrode having a common voltage applied to a transparent insulating tube is vertically formed, and a gate line is formed laterally. A common electrode and a gate line are covered with a gate insulating layer, and a pixel electrode is formed vertically above the gate insulating layer between the common electrodes, and a data line is formed along the common electrode. On the other hand, one terminal of the transistor for switching the pixel electrode is connected to the gate line, the other terminal is connected to the data line, and the other terminal is connected to the pixel electrode. On the other hand, the second substrate faces the first substrate, has a structure in which an alignment film is formed on a transparent insulating substrate, and the alignment film is rubbed in a direction of 30 to 60 degrees with respect to the direction of the pixel electrode, have.

In this case, the first substrate may further include an alignment layer formed on the entire surface of the first substrate. Preferably, the alignment layer of the first substrate is rubbed in the same direction as the alignment layer of the second substrate.

The first polarizer may further include a first polarizer attached to the first substrate and a second polarizer attached to the second substrate. In this case, the polarization axis of the first polarizer may coincide with the rubbing direction of the orientation film of the first substrate, The polarization axis of the second polarizer may coincide with the rubbing direction of the orientation film of the second substrate, and in both cases, the polarization axes of the first polarizer and the second polarizer are preferably orthogonal to each other.

A method of manufacturing such a liquid crystal display device is as follows.

A sustain electrode is formed on a transparent insulating substrate so as to be separated from a plurality of common electrodes and a common electrode vertically, and a gate line is formed so as to be isolated from the common electrode and cross the sustain electrode. A gate insulating layer is formed, a semiconductor layer is formed on the intersection of the sustain electrode and the gate line, and a pixel electrode is formed vertically along the sustain electrode. Finally, a pixel electrode is formed vertically along the common electrode. Finally, a data line is formed vertically along the common electrode, and electrodes are formed at the center and both sides of the semiconductor layer, and the electrode formed at the center on the semiconductor layer is connected to the data line.

Here, the sustain electrode and the pixel electrode may be formed of ITO, and may further include a step of forming an extrinsic semiconductor layer together with the semiconductor layer and a step of forming a protective film.

Other methods for manufacturing such a liquid crystal display device are as follows.

A sustain electrode is formed on a transparent insulating substrate so as to be separated from a plurality of common electrodes and a common electrode vertically, and a gate line is formed so as to be isolated from the common electrode and cross the sustain electrode. After forming the gate insulating layer, a semiconductor layer is formed on the intersection of the sustain electrode and the gate line. A pixel electrode connected to the semiconductor layer vertically along the sustain electrode and a data line connected to the center of the semiconductor layer vertically along the common electrode are formed.

Here, the pixel electrode can be formed of chromium.

Other methods for manufacturing such a liquid crystal display device are as follows.

A sustain electrode is formed on a transparent insulating substrate so as to be separated from a plurality of common electrodes and a common electrode vertically, and a gate line is formed so as to be isolated from the common electrode and cross the sustain electrode. Next, a gate insulating layer is formed, and a semiconductor layer is formed on the intersection of the sustain electrode and the gate line. Then, data lines are formed vertically along the common electrode, and electrodes are formed at the center and both sides of the semiconductor layer, and electrodes formed at the center on the semiconductor layer are connected to the data lines. Finally, a pixel electrode is formed vertically along the sustain electrode, and the pixel electrode is connected to both electrodes of the semiconductor layer.

Here, the sustain electrode and the pixel electrode may be formed of ITO.

As described above, in the liquid crystal display device and the method of manufacturing the same according to the present invention, the aperture ratio can be increased by using a transparent insulating material as the pixel electrode, or the on current can be increased by using the channel transistor, thereby significantly improving the filling rate of the transistor. In addition, the polarizing axis of the polarizer attached to the substrate on which no wiring is formed is formed in parallel with the rubbing direction of the substrate, whereby an improved transmittance can be obtained.

Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings, which may be readily implemented by those skilled in the art to which the present invention pertains.

2A and 2B are layouts of a substrate of a liquid crystal display device according to a first embodiment of the present invention, and FIG. 3 is a cross-sectional view taken along line A-A in FIG.

First, the planar structure of the engine for a liquid crystal display according to the first embodiment will be described with reference to Figs. 2a and 2b.

A common electrode line 120 made of a transparent conductive material such as indium tin oxide (ITO) is formed horizontally on a transparent glass substrate 100. A common electrode 121 serving as a branch of the common electrode line 120 is formed around the common line 120 And is formed vertically downward. The common electrode 121, which is the lower branch of the upper common electrode line 120, and the common electrode 121, which is the upper branch of the lower common electrode line 120, are spaced apart from each other.

A sustain electrode 122 made of a transparent conductive material such as ITO is formed vertically from the vicinity of the upper common electrode line 120 to the vicinity of the lower common electrode line 120 and between the common electrode lines 120 ) In order to prevent short circuit.

In FIG. 2, the sustain electrodes 122 are formed to be long and long, but they may be formed short or not.

The gate line 110, which is formed in a space between the upper and lower common electrodes 121 and is spaced apart from the common electrode 121 by a predetermined distance, is connected to the sustain electrode 122 so as to intersect with each other.

A gate insulating layer (reference numeral 150 in FIG. 3) is covered over the common electrode line 120, the common electrode 121, the sustain electrode 122, and the gate line 110 described above.

A pixel electrode 140 is formed on the gate insulating layer at a position corresponding to the pixel electrode 122 and two pixel electrodes 140 are separated from each other with the gate line 110 as a boundary.

In addition, the data line 130 is formed on the gate insulating layer so as to be longer than the common electrode 121, and is narrower than the common electrode 121. In order to reduce the disturbance of the signal flowing along the data line 130 by the signal from the common electrode 121 at this time, as shown in FIG. 2B, the data line 130 of the common electrode 121 The opening (a) may be formed at the center of the portion. The data line 130 intersects the gate line 110 through a gate insulating layer and is connected to the branch gate line 110 separated from the data line 130 at the intersection of the data line 130 and the gate line 110 And forms a source electrode of the thin film transistor TFT at an intersection with the sustain electrode 122. [

Since the data line 130 is formed on the common electrode 121, most of the electric field generated from the data line 130 is directed toward the common electrode 121 and has little influence on the left and right. Especially when the width of the common electrode 121 is larger.

The structure of the thin film transistor will now be described in detail with reference to FIG.

In this embodiment, the thin film transistor has a two-channel structure, and the gate electrode 110 of the thin film transistor is part of the gate line 110. On the gate electrode 110, a gate insulating layer 150 made of a material such as silicon nitride is formed. On the gate insulating layer 150, a semiconductor layer 160 made of an amorphous material is formed, and contact layers 171 and 172 made of a material such as n + amorphous silicon are formed thereon. However, since the channel structure is adopted here, the contact layers 171 and 172 are separately located at three portions, that is, the center and the both ends, on the semiconductor layer 160. A source electrode 180 and a drain electrode 190 are formed on the contact layers 171 and 172 and a source electrode 180 formed on the contact layer 171 at the center is a branch of the data line 130 And the drain electrode 190 formed on the contact layer 172 at both ends are connected to the pixel electrode 140.

By using such a channel thin film transistor, a high ON current can be obtained, and the filling rate of the thin film transistor is greatly improved.

The liquid crystal display according to the embodiment of the present invention has a symmetrical structure with respect to the gate line 110 and the common electrode line 120 and the gate line 110 and the data line 130 The structure intersects the central portion of the pixel. Therefore, even if the pixels are vertically misaligned, the overlapping area of the gate line 110 and the data line 130 or the drain electrode 190 is the same, so that the parasitic capacitance is always constant and the display quality is stabilized.

In addition, the common electrode line 120, the common electrode 121, the pixel electrode 140, the sustain electrode 122, and the like are formed so as to overlap with ITO, and this channel transistor is adopted. Because of this streak, the aperture ratio is higher than the structure shown in Figs. 1a and 1b.

A method of manufacturing a liquid crystal display device having such a structure will be described in detail with reference to Fig. 4 (a).

First, as shown in FIG. 4A, a transparent conductive material such as ITO is stacked and etched to form a common electrode line 120 and a common electrode 121 and a sustain electrode 122, which are branches thereof. The common electrode line 120 is formed horizontally and the common electrode 121 is formed symmetrically to the upper and lower sides of the common electrode line 120 such that the sustain electrode 122 is connected to the common electrode line 120 and the common electrode 122, The common electrodes 122 are formed to be vertically long.

Next, as shown in FIG. 4B, a conductive material such as chromium is stacked and patterned to form a gate line 110 laterally between the lower common electrodes 121. At this time, the gate line 110 is connected to the sustain electrode 122 formed vertically.

Next, as shown in FIG. 4C, silicon nitride, amorphous silicon and n + amorphous silicon are sequentially stacked and the two layers are etched to form contact layers (171 and 172 in FIG. 3) and semiconductor layers (160 in FIG. 3) .

Then, as shown in FIG. 4D, a transparent conductive material such as an IPO is patterned to form a pixel electrode 140 overlapping with the sustain electrode 122. At this time, the pixel electrode 140 is not overlapped with the contact layer and the semiconductor layer formed previously.

Next, as shown in FIG. 4E, a conductive material such as chromium is stacked and patterned to form a data line 130. At this time, the data line 130 is vertically formed so as to overlap with the common electrode 121, but narrower than the common electrode 121. At the intersection of the data line 130 and the gate line 110, the branch of the data line 130 is left and right so as to become the source electrode (180 in FIG. 3) of the thin film transistor TFT, A drain electrode (190 in FIG. 3) connected to the pixel 140 is formed together. Then, the contact layer (171, 172 in FIG. 3) is etched by using this as a mask.

Finally, when a protective film is formed on the front surface, a substrate for a liquid crystal display according to the present embodiment is completed.

Next, a second embodiment will be described.

FIG. 5 is a layout view of a substrate of a liquid crystal display device according to a second embodiment of the present invention, and FIG. 6 is a cross-sectional view taken along line B-B in FIG.

5, in the substrate for a liquid crystal display according to the present embodiment, the pixel electrode 140 is formed of the same material as the data line 130, the source electrode, and the drain electrode 140, .

This is more clearly shown in the cross-sectional view of the thin film transistor according to this embodiment shown in FIG.

Referring to FIG. 6, it can be seen that the pixel electrode layer is not formed separately from the structure of FIG. 3 but is formed of the same material and the same layer as the source and drain electrodes 180 and 190.

Then, a method of manufacturing such a structure and a liquid crystal display device will be described in detail.

4A to 4C, the common electrode line 120 and the common electrode 121 and the storage electrode 122, the gate line 110, and the sustain electrode 122, which are branches of the common electrode line 120, And a contact layer (171, 172 in FIG. 6) and a semiconductor layer (160 in FIG. 6) are formed.

5, the pixel electrode 140 and the data line 130, the source electrode (180 in FIG. 6) and the drain electrode (190 in FIG. 6) of the thin film transistor (TFT) Are simultaneously formed. Then, the contact layer (171, 172 in FIG. 6) is etched by using this as a mask.

Next, as shown in FIG. 4B, a transparent conductive material such as ITO is patterned to form a pixel electrode 140 overlapping with the sustain electrode 122 and connected to the drain electrode (190 in FIG. 9) of the thin film transistor TFT . At this time, it is preferable that the pixel electrode 140 is not overlapped with the contact layer and the semiconductor layer formed previously.

Finally, when a protective film is formed on the front surface, a substrate for a liquid crystal display according to the present embodiment is completed.

For the sake of convenience, the substrate on which the wiring is formed is referred to as a first substrate and the substrate is referred to as a second substrate.

Since all wirings are formed on the first substrate, the wirings are not formed on the second substrate.

Next, an alignment film (not shown) is coated on the two substrates, rubbing is performed on the pixel electrodes or the common electrode of the first substrate in the direction of 45 DEG, and then a pure nematic liquid crystal material having a positive dielectric anisotropy is inserted, Cells are fabricated. A polarizing plate is attached to each of the two substrates so that the next polarization axes are orthogonal to each other. At this time, the polarizing axis of one polarizing plate is set to be parallel to the rubbing direction.

The movement of the liquid crystal molecules in the liquid crystal display device thus constructed will now be described with reference to FIGS. 10 and 11.

FIG. 10 shows liquid crystal molecules in the case where no electric field is formed between the pixel electrode 121 and the common electrode 140.

As shown in FIG. 10, when no electric field is generated, the liquid crystal molecules form an angle of 45 ° with respect to the initial position, that is, the longitudinal direction of the pixel electrode 121.

However, when an electric field is generated between the pixel electrode 121 and the common electrode 140, the directions of the liquid crystal molecules change. That is, as shown in FIG. 11, the molecules located in the middle of the two substrates are arranged along the direction of the electric field because they are almost not affected by the orientation force and are only affected by the electric field. However, the liquid crystal molecules in the vicinity of the surface of the two substrates are stronger in orientation than the magnitude of the force due to the applied electric field, so that the orientation remains unchanged. Eventually, from the surface of the plate to the center between the two substrates, the liquid crystal molecules gradually arrange the direction parallel to the direction of the electric field.

The results of experiments of the position and transmittance of the liquid crystal molecules of such a liquid crystal display device through simulations are shown in FIGS. 12 and 13. 12 shows a case where the polarization axis of the polarizing plate attached to the lower substrate on which the wirings are formed is parallel to the rubbing direction of the substrate, and FIG. 13 shows the case where the polarization axis is vertical.

12 and 13, the horizontal axis shows the first substrate along the distance, and the unit is μm, and the vertical axis shows the distance between two substrates, and the unit is also μm.

The data line 130 is formed on the lower substrate in the order of the data line 130 and the lower common electrode 121, the pixel electrode 140, the common electrode 121 and the pixel electrode 140 And the pixel electrode 140 were applied with a voltage of 7.00 V and a voltage of 0 V was applied to the common electrode 121, respectively.

The position of the resulting liquid crystal molecules is represented by a circle or an ellipse, the equipotential line is represented by a solid line, and the transmittance is represented by a dotted line. The transmittance shows a slightly different distribution in FIGS. 12 and 13. The maximum transmittance is 0.840 in the case of FIG. 12 where the polarizing axis of the polarizing plate attached to the lower substrate is parallel to the rubbing direction of the substrate, And the transmittance of the 13th degree is better.

As described above, the liquid crystal display device of the planar driving type according to the present invention has an effect of increasing the aperture ratio by efficiently effecting the electric field from the data line while securing a wide viewing angle which is an advantage of the conventional planar driving method.

Claims (39)

A plurality of common electrodes vertically formed on the substrate to which a common voltage is applied; a gate line which is separated from the common electrode and is formed laterally on the substrate; a gate electrode which covers the common electrode and the gate line A pixel electrode formed vertically between the common electrodes, and a gate insulating layer formed on the gate insulating layer so as to overlap with the common electrode and connected to the pixel electrode, Wherein the substrate is a substrate. The liquid crystal display device according to claim 1, further comprising a three-terminal switching element having one terminal connected to the gate line, the other terminal connected to the data line and the other terminal connected to the pixel electrode, And connected to the data line through a device. The liquid crystal display device substrate according to claim 1 or 2, wherein the width of the data line is not larger than the width of the common electrode. The substrate for a liquid crystal display apparatus according to claim 3, wherein an opening is formed in a central portion of the common electrode overlapping with the data line. The substrate for a liquid crystal display according to claim 1 or 2, further comprising a sustain electrode formed below the gate insulating layer so as to overlap with the pixel electrode and connected to the gate line. The substrate for a liquid crystal display according to claim 5, wherein the sustain electrode is made of a transparent conductive material. 3. The substrate for a liquid crystal display according to claim 1 or 2, wherein the common electrode is made of a transparent conductive material. 3. The substrate for a liquid crystal display according to claim 1 or 2, wherein the gate line is made of chromium. A plurality of common electrodes vertically formed on the substrate to which a common voltage is applied; a gate line which is separated from the common electrode and is formed laterally on the substrate; a gate electrode which covers the common electrode and the gate line A gate electrode, a gate insulating layer, a pixel electrode vertically formed between the common electrodes, and a data line formed of the same material as the data line and overlapped with the common electrode on the gate insulating layer, And a second substrate. The liquid crystal display device according to claim 9, further comprising a three-terminal switching element having one terminal connected to the gate line, the other terminal connected to the data line and the other terminal connected to the pixel electrode, And the data line is connected to the data line. 11. The substrate for a liquid crystal display apparatus according to claim 9 or 10, wherein a width of the data line does not exceed a width of the common electrode. 12. The substrate for a liquid crystal display apparatus according to claim 11, wherein an opening is formed in a central portion of the common electrode overlapping with the data line. 11. The substrate for a liquid crystal display according to claim 9 or 10, further comprising a sustain electrode formed below the gate insulating layer so as to overlap with the pixel electrode and connected to the gate line. 14. The substrate for a liquid crystal display according to claim 13, wherein the sustain electrode is made of a transparent conductive material. 11. The substrate for a liquid crystal display according to claim 9 or 10, wherein the common electrode is made of a transparent conductive material. 11. The substrate for a liquid crystal display device according to claim 9 or 10, wherein the gate line is made of chromium. A plurality of common electrode lines formed horizontally on the substrate, a plurality of common electrodes formed vertically above and below the common electrode lines as a branch of the common electrode lines, A common electrode line, a common electrode line, a common electrode line, and a common electrode line, which are separated from the common electrode and are formed laterally between the common electrode lines and are electrically connected to the common electrode line, A plurality of pixel electrodes formed vertically along the sustain electrodes on the gate insulating layer and not formed at the intersections of the gate lines and the sustain electrodes, The gate electrode is overlapped with the common electrode for gate insulation, A first terminal connected to the gate line, a second terminal connected to the data line, and a third terminal connected to the pixel electrode on one side with respect to the gate line, And the fourth terminal is connected to the pixel electrode opposite to the third terminal with respect to the gate line. 18. The substrate for a liquid crystal display according to claim 17, wherein the sustain electrode is made of a transparent conductive material. 19. The substrate for a liquid crystal display according to claim 17 or 18, wherein the common electrode is made of a transparent conductive material. 18. The substrate for a liquid crystal display according to claim 17, wherein the gate line is made of chromium. The liquid crystal display according to claim 17, wherein the pixel electrode and the data line are made of chromium. 18. The substrate for a liquid crystal display apparatus according to claim 17, wherein an opening is formed in a central portion of the common electrode overlapping with the data line. A gate insulating layer covering the common electrode and the gate line, a gate insulating layer covering the common electrode and the common electrode, a gate insulating layer covering the common electrode and the gate line, A first substrate including a pixel electrode vertically formed on the gate insulating layer, a first substrate formed on the gate insulating layer and overlapped with the common electrode, and including a data line connected to the pixel electrode, a transparent insulating substrate, And a second substrate formed on the substrate and having an alignment film which is horizontally aligned and rubbed in a direction of 30 ° to 60 ° with respect to the direction of the pixel electrode, the second substrate facing the first substrate. The liquid crystal display of claim 23, further comprising a transistor having one terminal connected to the gate line and the other terminal connected to the data line and the other terminal connected to the pixel electrode, A liquid crystal display device connected to a line. The liquid crystal display device of claim 23 or 24, wherein the first substrate further comprises an alignment layer formed on a front surface of the first substrate. The liquid crystal display device according to claim 25, wherein the orientation film of the first substrate is rubbed in the same direction as the orientation film of the second substrate. 27. The liquid crystal display of claim 26, further comprising a first polarizer attached to the first substrate and a second polarizer attached to the second substrate. 28. The liquid crystal display of claim 27, wherein a polarization axis of the first polarizer coincides with a rubbing direction of an orientation film of the first substrate. 28. The liquid crystal display of claim 27, wherein a polarization axis of the second polarizer coincides with a rubbing direction of an orientation film of the second substrate. The liquid crystal display of claim 28 or 29, wherein the polarization axes of the first polarizer and the second polarizer are orthogonal to each other. Forming a plurality of common electrodes vertically on a transparent insulating substrate and a sustain electrode separated from the common electrode, forming gate lines laterally isolated from the common electrode and intersecting the sustain electrodes, Forming a semiconductor layer on the intersection of the sustain electrode and the gate line, vertically forming a pixel electrode along the sustain electrode, forming a data line vertically along the common electrode, And forming an electrode at the center and both sides of the semiconductor layer, wherein an electrode formed at the center of the semiconductor layer is connected to the data line. 32. The method of manufacturing a substrate for a liquid crystal display device according to claim 31, wherein the sustain electrode and the pixel electrode are formed of ITO. A manufacturing method of a substrate for a liquid crystal display device according to claim 31, wherein an extrinsic semiconductor layer is formed together when the semiconductor layer is formed on the intersection of the sustain electrode and the gate line. 32. The method of manufacturing a substrate for a liquid crystal display device according to claim 31, further comprising forming a protective film. Forming a plurality of common electrodes vertically on a transparent insulating substrate and a sustain electrode separated from the common electrode, forming gate lines laterally isolated from the common electrode and crossing the sustain electrodes, Forming a sustain electrode on the semiconductor layer, forming a semiconductor layer on the intersection of the sustain electrode and the gate line, and forming a pixel electrode vertically connected to the semiconductor layer, And forming a data line to be connected to the center of the layer. The method of manufacturing a substrate for a liquid crystal display device according to claim 35, wherein the pixel electrode is formed of chromium. Forming a plurality of common electrodes vertically on a transparent insulating substrate and a sustain electrode to be separated from the common electrode, forming gate lines laterally isolated from the common electrode and crossing the sustain electrodes, Forming a semiconductor layer on the intersection of the sustain electrode and the gate line, forming a data line vertically along the common electrode, and forming an electrode at the center and both sides of the semiconductor layer, And forming a pixel electrode vertically along the sustain electrode, wherein the pixel electrode is connected to the electrodes on both sides of the semiconductor layer. The liquid crystal display according to claim 1, A method for manufacturing a substrate for an apparatus. 37. The method for manufacturing a substrate for a liquid crystal display device according to claim 37, wherein the sustain electrode and the pixel electrode are formed of ITO. 39. The method of manufacturing a substrate for a liquid crystal display device according to claim 38, further comprising forming a protective film.