KR100345957B1 - In Plane Switching mode Liquid crystal display device - Google Patents

Abstract

The present invention relates to a liquid crystal display device, and more particularly, to a transverse electric field type liquid crystal display device for implementing a multi domain.

In detail, the present invention forms a plurality of dielectric protrusions in the form of chevrons on the common electrode and the pixel electrode, distorting the horizontal electric field distributed between the common electrode and the pixel electrode to symmetrically align the liquid crystals. It is an object of the present invention to propose a transverse electric field type liquid crystal display (In plane LCD) having uniform luminance characteristics, high aperture ratio, and gray scale inversion in a wide area.

Description

In plane switching mode liquid crystal display device

The present invention relates to an image display device, and more particularly, to a liquid crystal display (LCD) including a thin film transistor (TFT).

In particular, the present invention relates to a liquid crystal display of an in-plane switching (hereinafter referred to as IPS mode) in which first and second electrodes for driving a liquid crystal of a liquid crystal display are formed on the same substrate.

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

Accordingly, when the molecular arrangement direction of the liquid crystal is arbitrarily adjusted, the molecular arrangement of the liquid crystal is changed, and light polarized by optical anisotropy may be arbitrarily modulated to express image information.

Such liquid crystals may be classified into positive liquid crystals having positive dielectric anisotropy and negative liquid crystals having negative dielectric anisotropy according to the electrical characteristics. The liquid crystal molecules having positive dielectric anisotropy have long axes of liquid crystal molecules in a direction in which electric fields are applied The liquid crystal molecules arranged in parallel and having negative dielectric anisotropy are arranged perpendicularly to the direction in which the electric field is applied and the long axis of the liquid crystal molecules.

Currently, active matrix LCDs (AM-LCDs) in which thin film transistors and pixel electrodes connected to the thin film transistors are arranged in a matrix manner have attracted the most attention due to their excellent resolution and video performance.

In general, the structure of a liquid crystal panel, which is a basic component of a liquid crystal display, will be described.

1 is an exploded perspective view showing a part of a general TN liquid crystal display.

As illustrated, a general color liquid crystal display device includes a color filter 7 including a black matrix 6 and a sub color filter (red, green, blue) 8 and a transparent common electrode 18 formed on the color filter. The upper substrate 5 includes a lower substrate 22 having an array wiring including an upper substrate 5, a pixel region P and a pixel electrode 17 formed on the pixel region, and a switching device T. The liquid crystal 14 is filled between the lower substrate 22 and the lower substrate 22.

The lower substrate 22 is also referred to as an array substrate, and the thin film transistor T, which is a switching element, is positioned in a matrix type, and the gate wiring 13 and the data wiring 15 passing through the plurality of thin film transistors cross each other. Is formed.

The pixel P area is an area where the gate line 13 and the data line 15 cross each other. The pixel electrode 17 formed on the pixel region P uses a transparent conductive metal having relatively high light transmittance, such as indium-tin-oxide (ITO).

In the liquid crystal display device configured as described above, the liquid crystal layer 14 disposed on the pixel electrode 17 is oriented by a signal applied from the thin film transistor T, and the liquid crystal layer is aligned according to the degree of alignment of the liquid crystal layer. The image can be represented in a manner that controls the amount of light that passes through layer 14.

The liquid crystal display described above has a structure in which a common electrode is formed on a color filter panel which is an upper panel. That is, the liquid crystal display device having a structure in which the common electrode is perpendicular to the pixel electrode drives liquid crystal by an electric field applied up and down, and has excellent characteristics such as transmittance and aperture ratio, and the common electrode of the upper panel is grounded. It serves to prevent the destruction of the liquid crystal cell due to static electricity.

2A and 2B illustrate an operation of the liquid crystal 10 when voltage is applied to the twisted nematic liquid crystal panel, and FIG. 2A is a view showing an arrangement of liquid crystals of the TN liquid crystal panel when no voltage is applied. At this time, the liquid crystal 14 has a dielectric anisotropy is positive, when viewed in plan phase, since in the orientation direction and a liquid crystal to have a twisted state to the horizontally arranged 90 ^o.

2B is a diagram illustrating an arrangement state of liquid crystal molecules when a voltage is applied to upper and lower substrates. When voltage is applied to the upper and lower substrates, the liquid crystal molecules 14 twisted to 90 ^o are in the direction of an electric field. As a result, the extreme value of the liquid crystal molecules becomes approximately 90 °.

Therefore, there is a problem in that the change in C / R (contrast ratio) and luminance according to the viewing angle becomes severe, and thus the wide viewing angle cannot be realized.

FIG. 3 is a diagram illustrating a configuration of a liquid crystal display device in an IPS mode proposed to solve the problem of the viewing angle caused by the vertical electric field. The pixel electrode 34 and the common electrode 36 are the same on the substrate 30. It is formed on a plane. That is, the liquid crystal 14 is operated by the horizontal electric field 35 of the pixel electrode 34 and the common electrode 36 on the same substrate. The color filter panel 32 is formed on the liquid crystal layer 14.

4A and 4B illustrate a change in arrangement of liquid crystal molecules during voltage on / off in IPS mode. As shown in FIG. 4A, an electric field 35 is not applied to the pixel electrode 34 or the common electrode 36. It is shown that the change of the arrangement of the liquid crystal molecules does not occur in the state.

4B is a diagram illustrating a change in liquid crystal molecular array when a voltage is applied to the pixel electrode 34 and the common electrode 36, and it can be seen that a transverse electric field 35 is formed.

5A and 5B are plan views illustrating molecular arrangements of liquid crystals according to whether an electric field is applied to the common electrode and the pixel electrode, and FIG. 5A shows a voltage difference between the common electrode 34 and the pixel electrode 36. When not applied, the alignment direction 41 of the liquid crystal molecules is arranged in the same direction as the alignment direction of the initial alignment layer (not shown).

FIG. 5B illustrates an arrangement direction 41a of the liquid crystal molecules when a voltage is applied to the pixel electrode 34 and the common electrode 36. It is understood that the liquid crystal molecules are arranged in the direction 42 in which the electric field is applied. Can be.

The advantage of the IPS mode is that the wide field of view is possible because the change of the extreme value of each liquid crystal is small when the electric field is applied. That is, when the liquid crystal display device is viewed from the front, the liquid crystal display device may be visible in the up / down / left / right directions at about 70 °.

FIG. 6 is a diagram illustrating characteristics of color coordinates according to viewing angles of the liquid crystal display of the IPS mode according to angles of 45 ^° and 135 ^° .

The IPS mode has the advantage of a wide viewing angle, but it can be seen that color shift occurs depending on the viewing angle in standard white light (0.329, 0.333). This is due to the birefringence characteristics of the liquid crystal, and published by S. Endow et al., "18.1-inch Diagonal Super-TFT-LCDs with wide viewing angle and fast response time of 20 ms" (Advanced 18.1-inch Diagonal Super-TFT-LCDs with Mega Wide Viewing Angle and Fast Response Speed of 20ms: IDW 99 ', p. 187) also point to this problem.

Meanwhile, FIG. 7 is a diagram illustrating transmittance according to a viewing angle in each grayscale by dividing the grayscales of a general liquid crystal display into eight levels. When the grayscale having 0% transmittance is expressed from the front, the left / right viewing angle is 60 ^°. It is understood that the transmittance is greater than that when expressing the fourth level of gray level in the region of about 25%.

That is, once again, the gray level of one level indicating the dark state displays the dark state from the front, but when the left / right viewing angle is about 60 ^o , gray level inversion occurs and gray inversion corresponding to about four levels (grey inversion). ) Is generated and becomes a white state rather than a dark state.

Such a phenomenon is called gradation inversion, and this phenomenon is caused by the birefringence characteristic of the liquid crystal, and thus there is a problem in implementing a high-quality liquid crystal display device due to the inversion of transmittance between the gradation levels.

As such, the cause of the unevenness of brightness in the halftone is due to the birefringence characteristic of the liquid crystal itself.

That is, the birefringence should be zero between the two polarizers in order to display the complete dark state in the liquid crystal display. However, since the liquid crystal itself is an optical system operating by birefringence, the value is opposite and the magnitude is corrected. Is to create a new system with the same birefringence.

To this end, in the present invention, a method of compensating birefringence of the liquid crystal may be performed by forming at least two domains having the same size and opposite directions in the same pixel area. Hereinafter, a method of compensating birefringence will be described with reference to FIGS. 8A and 8B.

8A and 8B illustrate differences in birefringence according to a viewing angle of a general liquid crystal display and a liquid crystal display having two domains. In the case of a two domain liquid crystal display arranged in different directions, the birefringence value of one direction is shown. Since other domains compensate, the phenomenon of gray level inversion with the viewing angle is reduced.

That is, FIG. 8A is a diagram showing a cross section of a liquid crystal display having one domain, wherein the birefringence values at positions a, b, and c are different. Therefore, in a liquid crystal display having one domain shown in FIG. 8A, a deterioration in image quality characteristics inevitably occurs due to a viewing angle.

Figure 8b is a diagram showing the cross section of the liquid crystal display device forming the two domains in the pixel region, the second liquid-crystal birefringence value of a _first of the liquid crystal molecules will take a molecular arrangement in a direction opposite to the first liquid crystal molecules The birefringence value of a ₂ of the molecule is compensated (as a result, the birefringence value is about 0), so that the deterioration of the image quality according to the viewing angle is small.

Accordingly, an electrode shape for such birefringence compensation has been proposed. Hereinafter, an IPS mode liquid crystal display device in which a common electrode and a pixel electrode are configured in a zigzag manner will be described below.

FIG. 9 is an enlarged plan view showing some pixels of an array substrate for a transverse electric field type liquid crystal display device constructed by a conventional Zigzag method.

As illustrated, the common electrode 36 and the pixel electrode 34 are formed in a zigzag-shaped bending structure, and a rubbing operation is performed in one direction 61 to apply an electric field applied to the injected liquid crystal. The direction of 63 is changed.

The shape of the electrode allows the alignment characteristics of the liquid crystal to have symmetry with each other.

Therefore, the liquid crystal positioned in one pixel can be oriented in various directions without being aligned in the corresponding one direction, thereby inducing a multi domain that can vary the alignment direction of the liquid crystal oriented in one pixel. can do.

As described above, due to the symmetrical multi-domain structure, the birefringence in the liquid crystal alignment direction is canceled with each other to minimize the color shift phenomenon and widen the region without gray scale inversion.

However, such a structure has an initial orientation of the liquid crystal in which the direction 63 of the electric field generated at the bending edge portion C of the bent portion of the common electrode 36 and the pixel electrode 34 is determined by the rubbing direction 61. Since it is perpendicular to the direction, the liquid crystal does not rotate regardless of the intensity of the electric field and remains black, and the direction of the electric field formed on the outer portion of the electrode located at the edge (D) in the pixel also does not twist the liquid crystal normally. can not do it.

Therefore, the above-described abnormal alignment of the liquid crystals at the banding edge portion C and the intra-pixel edge portion D causes light leakage, resulting in discrepancy (defective image quality with white streaks). Therefore, a method of extending the black matrix (not shown) formed on the upper substrate to the pixel region is used as a method for preventing the disclination, which is largely generated at the edge of the pixel, from being seen from the outside. It causes a problem of decreasing the aperture ratio of the.

Accordingly, an object of the present invention is to propose a transverse electric field type liquid crystal display device which realizes a multi-domain and does not reduce luminance and aperture ratio.

1 is an exploded perspective view showing a part of a general TN liquid crystal display device;

2A and 2B illustrate an operation of a TN mode liquid crystal display device.

FIG. 3 is a cross-sectional view corresponding to one pixel part of a liquid crystal display device in a general IPS mode.

4A and 4B are perspective views showing the operation of the IPS mode liquid crystal display device in the off state and the on state, respectively.

5A and 5B are plan views illustrating the operation of a liquid crystal display device in a general IPS mode.

6 is a diagram illustrating color coordinates according to a viewing angle of a general IPS mode LCD.

7 is a diagram illustrating transmittance according to a viewing angle according to each gray level of a general liquid crystal display device.

8A and 8B are diagrams illustrating a light path for a liquid crystal molecule of a single domain and a light path for liquid crystal molecules of a multidomain, respectively.

9 is a plan view showing some pixels of a conventional array substrate for a transverse electric field type liquid crystal display device having an electrode form of ZIGZAG,

10 is a plan view showing some pixels of an array substrate for a transverse electric field type liquid crystal display device according to a first embodiment of the present invention;

11A and 11C are enlarged cross-sectional views illustrating a part of a liquid crystal panel having dielectric protrusions;

12A and 12B are views illustrating alignment characteristics of liquid crystals according to the first embodiment of the present invention, respectively.

FIG. 13 is a plan view showing some pixels of an array substrate for a transverse electric field type liquid crystal display device according to a second embodiment of the present invention;

14A and 14B are views illustrating alignment characteristics of the liquid crystal according to the second embodiment of the present invention, respectively.

FIG. 15 is a plan view illustrating some pixels of an array substrate for a transverse electric field type liquid crystal display device according to a third exemplary embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

150: gate wiring 152: gate electrode

160: common wiring 162: common electrode

170: data wiring 172: source electrode

174 drain electrode 176 pixel electrode

190: Dielectric protrusions in the form of chevrons

In accordance with an aspect of the present invention, a transverse electric field type liquid crystal display device includes: first and second substrates facing each other; A first signal wire formed on the first substrate in a first direction and a second signal wire extending in a second direction while crossing the first signal wire; A thin film transistor formed at a portion where the first signal line and the second signal line cross each other and receive a signal from the first and second signal lines;

A third signal wire extending in the same direction as the first signal wire and receiving a first voltage; A plurality of first electrodes branched from the third signal line in the second direction; A plurality of second electrodes interposed between the first electrodes in the second direction and receiving a second voltage signal corresponding to the first voltage from the thin film transistor; It is formed over the plurality of first and second electrodes, the "∧" or "∨" shape is formed continuously in parallel to the first signal wiring and the third signal wiring, each successive interval is up / down a predetermined interval A plurality of dielectric protrusions configured to be spaced apart in parallel; And a liquid crystal disposed between the first and second substrates and having a different dielectric constant from the first dielectric protrusion.

In this case, the "∧" or "∨" shape, which is a part of the dielectric protrusion, is formed over the pixel electrode or the common electrode. Alternatively, the dielectric protrusion of this type may cover a large area including a plurality of pixel electrodes and the common electrode. It may be configured.

The dielectric protrusion may use a smaller or larger dielectric constant than the liquid crystal.

In this case, the dielectric protrusion is generally configured using an organic material.

Such organic materials may be exemplified by photoresist, BCB, acrylic, and the like.

The liquid crystal is a positive liquid crystal in which dielectric anisotropy is positive and the initial alignment direction is processed in a direction perpendicular to the first electrode and the second electrode.

Alternatively, the liquid crystal is a negative liquid crystal in which dielectric anisotropy is negative, and in this case, the initial alignment direction of the liquid crystal is processed in a direction perpendicular to the first electrode and the second electrode.

In the above configuration, the first wiring is a gate wiring, and the first electrode represents a common electrode.

According to another aspect of the present invention, a liquid crystal display device includes: first and second substrates facing each other; A first signal wire formed on the first substrate in a first direction and a second signal wire extending in a second direction while crossing the first signal wire; A thin film transistor formed at a portion where the first signal line and the second signal line cross each other and receive a signal from the first and second signal lines; A third signal wire extending in the same direction as the first signal wire and receiving a first voltage; A first electrode formed of a vertical pattern branched from the third signal line in the second direction and a plurality of horizontal patterns branched from the vertical pattern and parallel to the third signal line; A plurality of second electrodes alternately formed between the horizontal patterns of the first electrodes, and receiving a second voltage signal corresponding to the first voltage from the thin film transistor; It is formed on top of a plurality of two electrodes that are alternately arranged with the horizontal pattern of the first electrode, the "∧" or "∨" form is formed in parallel to the second signal wiring, each successive left / A plurality of dielectric protrusions configured to be parallel to each other at predetermined intervals; And a liquid crystal disposed between the first and second substrates and having a different dielectric constant from the first dielectric protrusion.

Hereinafter, a liquid crystal display according to the present invention will be described in detail with reference to the accompanying drawings.

First Embodiment

In the first embodiment of the present invention, in the IPS mode liquid crystal display, pixel electrodes or common electrodes are alternately arranged to form a multi-domain, and a plurality of chevron type dielectric protrusions are disposed on the electrodes. The present invention relates to a structure of a liquid crystal display device which forms multiple domains by forming and dispersing an array of electric fields.

FIG. 10 is an enlarged plan view illustrating some pixels of an IPS mode liquid crystal display according to a first exemplary embodiment of the present invention.

As shown in the drawing, the gate wiring 150 and the common wiring 160 are arranged in parallel with each other, and the data wiring 170 is positioned in the vertical direction.

A gate electrode 152 and a source electrode 172 are formed on the gate wiring 150 and the data wiring 170 at the portion where the gate wiring 150 and the data wiring 170 cross each other, and the source electrode 172 is formed. ), A drain electrode 174 is formed.

In addition, an active layer 154 is formed on the gate electrode 152 to be in contact with the source electrode 172 and the drain electrode 174 at the same time.

On the other hand, the common wiring 160 arranged in the horizontal direction is formed with a plurality of common electrodes 162 are formed in a plurality of branches in the vertical direction. The common electrode 162 is formed in a direction parallel to the data line 170.

The pixel electrodes 176 contacting the plurality of drain electrodes 174 are alternately formed with the common electrodes 162 in a direction in which the common electrodes 162 are vertically branched.

In addition, a chevron shape (chevron: "∧" or "∨" shape) is disposed continuously across the plurality of pixel electrodes 176 and the common electrode 162 up and down. A plurality of pixels are formed in the pixel region P, which are parallel to each other at predetermined intervals.

In such a configuration, each dielectric protrusion positioned at a predetermined slope between the common electrode 162 and the pixel electrode is symmetrically configured.

As the dielectric protrusion 190, a material having a dielectric constant smaller than that of the liquid crystal 189 is used. Preferably, a material having a dielectric constant of about 5 or less is used.

As described above, the electric field generated in the vicinity of the dielectric protrusion 190 having a relatively smaller dielectric constant than the liquid crystal is very thin compared to the electric field generated in the portion where only the liquid crystal is present.

In other words, since the dielectric protrusion 190 has a relatively low dielectric constant compared to the liquid crystal, the affinity with the electric field is smaller than that of the liquid crystal. Thus, the arrangement of the electric field is constant at a predetermined angle around the dielectric protrusion 190. Proceeding from the common electrode to the pixel electrode. That is, the direction of the electric field is inclined in the direction perpendicular to the direction of the dielectric projection.

Here, since the dielectric protrusions are symmetrically configured with a predetermined slope between the plurality of pixel electrodes 176 and the common electrode 162, the plurality of pixel electrodes 176 and the common electrode are influenced by the dielectric protrusions. Between 162, fringe fields are formed which are distorted in opposite directions.

Therefore, the first and second domains of the liquid crystal positioned between the electrodes are arranged in different directions according to the application of the electric field.

The reason why the liquid crystals 189 are arranged in opposite directions with respect to the pixel electrode 176 and the common electrode 162 as described above is that the degree of freedom of the liquid crystal becomes two.

That is, if the molecular alignment direction (ie, the alignment direction) of the initial liquid crystal is the same direction as the extension direction of the pixel electrode 176 and the common electrode 162, the degree of freedom of the liquid crystal becomes 2, so that the liquid crystals are arranged left / right. . At this time, the force causing the liquid crystal to be arranged left / right is due to the electric field disturbed by the dielectric protrusion 190, and two different domains are formed by this electric field.

In other words, the liquid crystal having the initial arrangement direction parallel to the pixel electrode 176 and the common electrode 162 is rearranged horizontally in the direction of the electric field when an electric field is applied. Is rotated in a small direction of the angle with the electric field.

Therefore, since the angle formed between the electric field and the initial arrangement direction of the liquid crystal 189 is different by the dielectric protrusion 190, different domains are formed.

Hereinafter, the structure of the dielectric protrusion will be described with reference to FIGS. 11A and 11B.

11A and 11B are cross-sectional views illustrating a cross section taken along a portion of FIG. 10.

As shown in FIG. 11A, the common electrode 162 and the pixel electrode 176 are formed on the same plane on the same plane through an insulating layer, and the dielectric protrusion 190 is formed of the common electrode 162 and the pixel. Formed over electrode 176.

On the contrary, as shown in FIG. 11B, the dielectric protrusion 190 may be formed on the upper substrate, but may be formed to be formed close to the lower substrate including the common electrode 162 and the pixel electrode 176.

In this case, as shown in FIG. 11C, the dielectric protrusion 190 may be configured to have a height equal to a gap G maintained between the upper and lower substrates of the liquid crystal panel, and in this case, the gap of the liquid crystal panel. It may also be substituted for a positive (not shown) used to maintain.

In such a configuration, the liquid crystal may use both a positive type liquid crystal and a negative type liquid crystal, in which case the initial alignment direction of the liquid crystal may be treated differently.

12A and 12B show the alignment directions of the positive liquid crystal and the negative liquid crystal, respectively.

FIG. 12A illustrates the alignment state of the liquid crystal 189 according to the voltage when the positive type liquid crystal is used and the initial alignment of the liquid crystal is processed in a direction parallel to the common electrode and the pixel electrode.

As shown, when a voltage is applied, a horizontal electric field distributed between the common electrode 162 of FIG. 10 and the pixel electrode 176 of FIG. 10 forms a strong fringe field distorted by the dielectric protrusion, thereby forming the positive liquid crystal. The common electrodes are rotated in the directions f and g which are symmetrical with each other.

Therefore, two-domains having symmetry with each other can be configured.

In the case where the negative liquid crystal shown in FIG. 12B is used, two domains having symmetry can be configured as in the case of FIG. 12A, and the alignment process of the liquid crystal is performed by the pixel electrode (176 of FIG. 10) and the common electrode. The processing is perpendicular to (162 in FIG. 10).

Accordingly, in the array substrate for the IPS mode liquid crystal display according to the first embodiment of the present invention, the domains compensate each other for the color inversion effect on the viewing angle. Since each domain compensates for these optical effects, it is possible to widen the region without gray scale inversion.

In addition, since this structure does not exhibit abnormal alignment of the liquid crystal as compared to the conventional IPS mode liquid crystal display device, there is no disclination, thereby improving luminance.

Second Embodiment

According to the second embodiment of the present invention, unlike the first embodiment, the common electrode and the pixel electrode are alternately formed in a direction parallel to the common wiring and the gate wiring to induce a multi-domain IPS. An array substrate for a mode liquid crystal display device is proposed.

A description with reference to FIG. 13 is as follows.

FIG. 13 is an enlarged plan view illustrating some pixels of an array substrate for an IPS mode liquid crystal display according to a second exemplary embodiment of the present invention.

As illustrated, the common electrode 162 and the pixel electrode 176 are alternately formed in a direction parallel to the common wiring 160 and the gate wiring 150.

That is, the common wiring 160 is vertically branched in parallel with each other in parallel with the data wirings 170 on both sides of the pixel region P, and extends on both sides of the vertically branched common electrode 162. And a common electrode having a plurality of horizontal components parallel to the common wiring.

In this case, the pixel electrodes 176 are alternately spaced apart from the common electrodes 162 of the plurality of horizontal components by a predetermined interval.

In such a configuration, a chevron type dielectric protrusion 190 is further formed over the common electrode 162 and the pixel electrode 176.

That is, the chevron shaped “∧” or “∨” shaped protrusions are configured to be symmetrically divided around the pixel electrode and the common electrode, respectively.

Accordingly, the dielectric protrusion 190 having a predetermined slope around each of the electrodes is symmetrically configured, and this symmetrical configuration is continuously performed on the pixel region P. FIG. Since this configuration is a structure in which the horizontal electric field is symmetrically distorted as described above, the liquid crystal molecules 189 are rotated symmetrically.

Hereinafter, operation characteristics of the liquid crystal panel having the electrode structure of the second embodiment will be described with reference to FIGS. 14A and 14B.

FIG. 14A illustrates a case in which a liquid crystal panel including a structure of a substrate according to a second embodiment of the present invention is processed in which an alignment direction of liquid crystal is parallel to the common electrode and a pixel electrode, and a positive liquid crystal is used.

As illustrated, when a voltage is applied, the electric field distributed between the common electrode 162 of FIG. 13 and the pixel electrode 176 of FIG. 13 has a strong distorted fringe field having an inclination angle due to the dielectric protrusion. As a result, the liquid crystal has a symmetry (h, i) around each electrode and is distributed.

Therefore, domains having symmetry with each other can be configured.

This case also applies to the case where a negative liquid crystal is used as shown in FIG. 14B and the alignment direction of the liquid crystal is processed perpendicular to the common electrode 162 of FIG. 13 and the pixel electrode 176 of FIG. As described above, the alignment of the liquid crystal is achieved with symmetry.

Modifications different from those of the first and second embodiments will be described in Example 3 below.

Third Embodiment

FIG. 15 is a plan view illustrating some pixels of an array substrate for a liquid crystal display according to a third exemplary embodiment of the present invention.

As shown, the third embodiment of the present invention defines the pixel P as two or more regions, unlike the dielectric protrusion 190 symmetrically configured around each electrode, and the above-described chevron-type dielectric material. Make sure the projections are located over two areas.

In other words. Dielectric protrusions in the form of "돌" and "∨" are constructed over a wider area and these shapes are continuous.

As a result, dielectric protrusions located in each region are symmetrically positioned at a predetermined angle.

Such a configuration can also obtain operating characteristics of the same liquid crystal panel as those of the first and second embodiments described above.

As described above, the present invention, as described in detail in each embodiment, the basic concept is that the conventional liquid crystal display device of the IPS mode is applied to the liquid crystal 189 to improve the poor quality of the image according to the viewing angle, such as color shift and gradation inversion depending on the viewing angle By forming multiple domains, each domain compensates for image quality.

To this end, in each embodiment of the present invention, a method of disrupting the arrangement of electric fields applied to each electrode by forming chevron-type dielectric protrusions each having a continuous shape of "∧" or "∨" on the pixel electrode or the common electrode. Use

As described above, when the direction of the electric field is distorted by changing the pixel electrode and the common electrode, at least two domains arranged in different directions are formed according to the application of the electric field, and these domains compensate for the birefringence of light according to the viewing angle. Therefore, there is an advantage of improving the deterioration of the image quality according to the viewing angle.

In addition, in the above-described first, second, and third embodiments, the case where the dielectric protrusion has a lower dielectric constant than the liquid crystal has been described. However, when the dielectric protrusion uses a material having a different dielectric constant from that of the liquid crystal 189, the formation of multiple domains is performed. There is no problem.

As described above, the liquid crystal display according to the exemplary embodiments of the present invention has the following characteristics.

First, in the liquid crystal display of the conventional IPS mode, the liquid crystal molecules are rotated in one direction in a plane, so that the color inversion according to the viewing angle exists, but the liquid crystal display according to the present invention rotates in at least two different opposite directions. As the domain is formed, there is an advantage of improving the characteristics of color inversion according to the viewing angle.

Second, there is an advantage that can improve the characteristics of grayscale inversion according to the viewing angle by the two domains that rotate in different directions.

Claims (12)

First and second substrates facing each other; A first signal wire formed on the first substrate in a first direction and a second signal wire extending in a second direction while crossing the first signal wire; A thin film transistor formed at a portion where the first signal line and the second signal line cross each other and receive a signal from the first and second signal lines; A third signal wire extending in the same direction as the first signal wire and receiving a first voltage; A plurality of first electrodes branched from the third signal line in the second direction; A plurality of second electrodes interposed between the first electrodes in the second direction and receiving a second voltage signal corresponding to the first voltage from the thin film transistor; It is formed on the plurality of first and second electrodes , "∧" or "∨" shape is formed continuously in parallel to the first signal wiring and the third signal wiring, each successive spaced up and down a predetermined interval A plurality of dielectric protrusions configured in parallel; A liquid crystal positioned between the first and second substrates and having a different dielectric constant from the first dielectric protrusion Liquid crystal display comprising a. The method of claim 1, The "∧" or "∧" shape, which is a part of the dielectric protrusion, is formed on the pixel electrode or the common electrode. The method of claim 1, The "∧" or "∧" shape, which is a part of the dielectric protrusion, is formed on a wide area including a plurality of pixel electrodes and a common electrode. The method of claim 1, And the dielectric protrusion has a lower dielectric constant than the liquid crystal. The method of claim 1, And the dielectric protrusion has a higher dielectric constant than the liquid crystal. The method of claim 1, The dielectric protrusion is an organic material. The method of claim 1, And a dielectric protrusion formed on the upper substrate. The method of claim 6, The organic material is a liquid crystal display device selected from the group consisting of photoresist, BCB, acrylic. The method of claim 1, The first wiring is a gate wiring, and the first electrode is a common electrode. The method of claim 1, And the liquid crystal is a positive liquid crystal having a positive dielectric anisotropy and an initial alignment direction is the second direction. The method of claim 1, Wherein the liquid crystal is a negative liquid crystal in which dielectric anisotropy is negative and the initial alignment direction is the first direction. First and second substrates facing each other; A first signal wire formed on the first substrate in a first direction and a second signal wire extending in a second direction while crossing the first signal wire; A thin film transistor formed at a portion where the first signal line and the second signal line cross each other and receive a signal from the first and second signal lines; A third signal wire extending in the same direction as the first signal wire and receiving a first voltage; A first electrode formed of a vertical pattern branched from the third signal line in the second direction and a plurality of horizontal patterns branched from the vertical pattern and parallel to the third signal line; A plurality of second electrodes alternately formed between the horizontal patterns of the first electrodes, and receiving a second voltage signal corresponding to the first voltage from the thin film transistor; It is formed on the plurality of two electrodes that are alternate with the horizontal pattern of the first electrode, the "∧" or "∨" shape is formed in parallel to the second signal wiring, each successive left / right A plurality of dielectric protrusions arranged in parallel at a predetermined interval; A liquid crystal positioned between the first and second substrates and having a different dielectric constant from the first dielectric protrusion Liquid crystal display comprising a.