KR100778844B1 - Multi domain Liquid Crystal Display Device - Google Patents

Abstract

The present invention is a first substrate and a second substrate; A plurality of gate wirings and data wirings formed vertically and horizontally on the first substrate to define pixel regions; A pixel electrode formed in the pixel region and having a honeycomb-shaped electric field induction window formed therein to divide the pixel region into a plurality of domains; A light blocking layer formed on the second substrate; A color filter layer formed on the light blocking layer; A common electrode formed on the color filter layer; A dielectric structure formed on the common electrode and formed in each of the plurality of domain regions; And it provides a multi-domain liquid crystal display device comprising a liquid crystal layer formed between the first substrate and the second substrate.

Field Induction Window, Dielectric Structure

Description

Multi domain Liquid Crystal Display Device

1A and 1B are schematic cross-sectional views of a conventional liquid crystal display device.

2 is a plan view of a unit pixel of a multi-domain liquid crystal display according to an exemplary embodiment of the present invention.

3A, 3B, and 3C are cross-sectional views taken along lines A-A, B-B, and C-C of FIG. 2, respectively.

4 is a plan view of a unit pixel of a multi-domain liquid crystal display device according to another exemplary embodiment of the present invention.

5A, 5B, and 5C are cross-sectional views according to embodiments of the A-A, B-B, and C-C lines of FIG. 4, respectively.

6A, 6B, and 6C are cross-sectional views according to another exemplary embodiment of the A-A, B-B, and C-C lines of FIG. 4, respectively.

<Description of main parts of drawing>

160: gate wiring 180: data wiring

300: auxiliary electrode 400: pixel electrode

420: field induction window 500: dielectric structure

The present invention relates to a liquid crystal display device, and more particularly to a multi-domain liquid crystal display device having a stable texture.

In general, a liquid crystal display device is composed of a lower substrate and an upper substrate facing each other at a predetermined interval, and a liquid crystal layer formed between the two substrates.

Among the liquid crystal display devices, the vertical alignment mode liquid crystal display device uses a negative liquid crystal having a negative dielectric anisotropy. In a state where no voltage is applied, the long axis direction of the liquid crystal molecules is perpendicular to the alignment layer plane. When the voltage is applied, the liquid crystal molecules are displayed at an angle by controlling the transmittance of light using the property of being oriented obliquely by the electric field.

Meanwhile, in the vertical alignment mode, in order to realize a wide viewing angle, an auxiliary electrode, a rib, or a slit is formed on a substrate to distort the electric field applied to the liquid crystal layer, thereby directing the director of the liquid crystal molecules in a desired direction. A positioning method (for example, patterned vertical alignment (PVA) and multi-domain vertical alignment (MVA)) has been proposed, which will be described below with reference to the drawings.

1A is a plan view of a unit pixel of a conventional liquid crystal display, and FIG. 1B is a cross-sectional view of the A-A line of FIG. 1A.

Conventional liquid crystal display devices include a first substrate 1 and a second substrate 2; A plurality of gate wirings (7) and data wirings (9) formed on the first substrate (1) vertically and horizontally to define pixel regions; A pixel electrode 13 formed in the pixel region and having an electric field induction window 14 therein; A common auxiliary electrode 11 formed on the same layer as the gate wiring 7 and overlapping the circumference of the pixel electrode 13; A gate insulating film 3 formed on the gate wiring 7 and a protective film 5 formed on the data wiring 9; A light blocking layer 4 formed on the second substrate 2; A color filter layer 6 formed on the light shielding layer 4; A common electrode 8 formed on the color filter layer 6; A dielectric structure 10 formed on the common electrode 8; And a liquid crystal layer (not shown) formed between the first substrate 1 and the second substrate 2 (Domestic Application No. 10-1999-0007633).

The conventional liquid crystal display device distorts the electric field applied to the liquid crystal layer by the action of the electric field induction window 14, the common auxiliary electrode 11, and the dielectric structure 10. Therefore, the dielectric energy is positioned in the desired direction by the distorted electric field, thereby driving the liquid crystal molecules in the unit pixel in various ways to implement a multi-domain effect.

However, in the conventional liquid crystal display device, the domain is formed in a rectangular shape so that the distance between the domain edge portion and the dielectric structure is different for each position. Due to such a structure, the electric field is asymmetrically formed, which makes it difficult to obtain a stable texture.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a multi-domain liquid crystal display device having a stable texture.                         

Another object of the present invention is to provide a liquid crystal display device having no afterimage through effective field distortion and maximizing multi-domain effects such as wide viewing angle and high aperture ratio.

The present invention to achieve the above object, the first substrate and the second substrate; A plurality of gate wirings and data wirings formed vertically and horizontally on the first substrate to define pixel regions; A pixel electrode formed in the pixel region and having a honeycomb-shaped electric field induction window formed therein to divide the pixel region into a plurality of domains; A light blocking layer formed on the second substrate; A color filter layer formed on the light blocking layer; A common electrode formed on the color filter layer; A dielectric structure formed on the common electrode and formed in each of the plurality of domain regions; And it provides a multi-domain liquid crystal display device comprising a liquid crystal layer formed between the first substrate and the second substrate.

That is, the multi-domain liquid crystal display device according to the present invention divides domains by forming an electric field induction window in a honeycomb shape in the pixel electrode, and forms a dielectric structure in each domain, so that the distance from the dielectric structure to the edge of the domain is fixed. This allows stable texture implementation.

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

First embodiment

2 is a plan view of a unit pixel of a multi-domain liquid crystal display according to an exemplary embodiment of the present invention, FIG. 3A is a cross-sectional view according to an embodiment of the AA line of FIG. 2, and FIG. 3B is a line of the BB line of FIG. 2. 3C is a cross-sectional view according to an embodiment of the CC line of FIG. 2.

A first embodiment of the present invention is the first substrate 100 and the second substrate 200; A plurality of gate wirings 160 and data wirings 180 formed vertically and horizontally on the first substrate 100 to define pixel regions; A gate insulating layer 120 formed on the entire surface of the substrate including the gate wiring 160, a passivation layer 140 formed on the entire surface of the substrate including the data wiring 180, and formed in the pixel region, wherein the pixel region includes a plurality of domains. A pixel electrode 400 having a honeycomb electric field induction window 420 formed therein to be divided; A light blocking layer 220 formed on the second substrate 200; A color filter layer 240 formed on the light blocking layer 220; A common electrode 260 formed on the color filter layer 240; A circular dielectric structure 500 formed on the common electrode 260 and formed in each of the plurality of domain regions; And it relates to a multi-domain liquid crystal display device comprising a liquid crystal layer (not shown) formed between the first substrate 100 and the second substrate 200.

In this case, as the number of the honeycomb electric field induction windows 420 formed inside the pixel electrode 400 increases, display element characteristics such as response characteristics and driving voltages are improved, but at the same time, the aperture ratio is reduced, so that appropriate adjustment is possible. Is required. In addition, even if the field induction window 420 is formed in the honeycomb shape, the pixel electrode 400 is connected between each domain to form one pixel.

The pixel electrode 400 may be made of indium tin oxide (ITO) or indium zinc oxide (IZO).

The dielectric structure 500 is formed in plural to correspond to each of the domains divided by the field induction window 420, the dielectric constant is preferably equal to or smaller than the dielectric constant of the liquid crystal (not shown), preferably Is less than or equal to 3. The dielectric structure 500 is preferably made of a photosensitive material, more preferably made of acrylic resin (photoacrylate) or BCB (BenzoCycloButene).

Although not shown in the drawing, a thin film transistor including a gate electrode, a source electrode, and a drain electrode connected to the gate line 160, the data line 180, and the pixel electrode 400, respectively, is a switching element. It is formed at the intersection of the gate wiring 160 and the data wiring 180.

The liquid crystal (not shown) is preferably formed by including a chiral dopant in the VA (Vertical Alignment) liquid crystal so that molecular alignment and optical axis of the liquid crystal are continuously formed by applying an electric field.

The common electrode 260 is preferably made of ITO.

The gate insulating layer 120 and the passivation layer 140 may be formed of a material such as BCB (BenzoCycloButene), an acrylic resin, a polyamide compound, SiNx, or SiOx.

In addition, the gate wiring 160, the data wiring 180, the light blocking layer 220, the color filter layer 240, and the like may be easily implemented by those skilled in the art having ordinary skill in the art. It can be formed by changing from.

In addition, although not shown in the drawing, an alignment layer may be formed on the entire surface of at least one of the first substrate 100 and the second substrate 200.                     

The alignment layer may be formed by rubbing orientation treatment using a material such as a polyamide or polyimide compound, polyvinylalcohol (PVA), polyamic acid, or the like, or may be formed without orientation treatment. have.

In addition, the photoreaction may be formed using a photoreactive material such as PVCN (polyvinylcinnamate), PSCN (polysiloxanecinnamate), or CelCN (cellulosecinnamate) -based compound, or may be formed without orientation treatment. The light alignment treatment simultaneously determines the pretilt angle, the alignment direction, or the pretilt direction by at least one light irradiation, wherein the light irradiation uses light in the ultraviolet region. Although it is preferable to use, any of unpolarized light, unpolarized light, linearly polarized light, and partially polarized light may be used.

In addition, a retardation film may be formed on an outer surface of at least one of the first substrate 100 and the second substrate 200. The retardation film compensates for the viewing angle in the direction perpendicular to the substrate and the direction of the viewing angle change, thereby widening the region without gray inversion, and increasing the contrast ratio in the oblique direction. Although it may be formed as a negative uniaxial film or a negative biaxial film having two optical axes, a negative biaxial film is more preferable in terms of wide viewing angle.

In addition, polarizers (not shown) may be attached to both substrates 100 and 200, and the polarizers (not shown) may be integrally formed with the retardation film.

Second embodiment

4 is a plan view of a unit pixel of a multi-domain liquid crystal display according to another exemplary embodiment of the present invention. FIG. 5A is a cross-sectional view of an AA line of FIG. 4, and FIG. 5B is a cross-sectional view of the BB line of FIG. 4. FIG. 5C is a cross-sectional view according to an embodiment of the CC line of FIG. 4.

A second embodiment of the present invention is the first substrate 100 and the second substrate 200; A plurality of gate wirings 160 and data wirings 180 formed vertically and horizontally on the first substrate 100 to define pixel regions; A gate insulating layer 120 formed on the entire surface of the substrate including the gate wiring 160, a passivation layer 140 formed on the entire surface of the substrate including the data wiring 180, and formed in the pixel region, wherein the pixel region includes a plurality of domains. A pixel electrode 400 having a honeycomb electric field induction window 420 formed therein to be divided; An auxiliary electrode 300 formed on the same layer as the gate wiring 160 and formed in a region corresponding to the field induction window 420; A light blocking layer 220 formed on the second substrate 200; A color filter layer 240 formed on the light blocking layer 220; A common electrode 260 formed on the color filter layer 240; A circular dielectric structure 500 formed on the common electrode 260 and formed in each of the plurality of domain regions; And it relates to a multi-domain liquid crystal display device comprising a liquid crystal layer (not shown) formed between the first substrate 100 and the second substrate 200.

That is, in the multi-domain liquid crystal display device according to the second embodiment of the present invention, the auxiliary electrode 300 is formed on the same layer as the gate wiring 160 so as to correspond to the electric field induction window 420 formed in the pixel electrode 400. Except for forming a, it is the same as the multi-domain liquid crystal display device according to the first embodiment described above. Therefore, the same reference numerals are given, and the description of the same parts is omitted.

In this case, the auxiliary electrode 300 may be formed to overlap the pixel electrode 400 with the gate insulating layer 120 and the passivation layer 180 therebetween, or may be formed so as not to overlap. In this case, the storage electrode does not need to be formed separately. However, when the storage electrode is formed so as not to overlap, the storage electrode connected to the pixel electrode 400 is formed under the pixel electrode 400. It is preferable to form the gate wiring 160, the auxiliary electrode 300, and the storage capacitor. However, in order to increase the storage capacitance, the storage electrode may be formed as described above even when formed to overlap.

The auxiliary electrode 300 is preferably made of any one material selected from the group consisting of indium tin oxide (ITO), indium zinc oxide (IZO), Cu, Al, Mo, Cr, Ta, Ti, and an Al alloy. The gate wiring 160 may be formed of the same material at the same time, or may be formed of a different material from the gate wiring 160 using an additional mask, or may be formed of different double layers. In this case, the auxiliary electrode 300 is electrically connected to the common electrode 260 and forms an electric field with the pixel electrode 400 to efficiently drive the liquid crystal (not shown) of the domain boundary.

Third embodiment

4 is a plan view of a unit pixel of a multi-domain liquid crystal display according to an exemplary embodiment of the present invention, FIG. 6A is a cross-sectional view according to another exemplary embodiment of the AA line of FIG. 4, and FIG. 6B is a cross-sectional view of the BB line of FIG. 4. 6 is a cross-sectional view according to another exemplary embodiment of the CC line of FIG. 4.

In the multi-domain liquid crystal display device according to the third embodiment of the present invention, except that the auxiliary electrode 300 is formed on the same layer as the data line 180 rather than on the same layer as the gate line 160, They are identical and therefore given the same signs.

When the auxiliary electrode 300 is formed on the same layer as the data line 180, the pixel area is reduced by that amount in order to prevent a short with the data line 180, so that the auxiliary electrode 300 is gated in terms of aperture ratio. More preferably, the same structure as in the above-described first embodiment is formed on the same layer as the wiring 160.

The present invention is not limited to the above embodiments, but is within the range that can be modified by those skilled in the art within the scope of the technical idea of the present invention.

In the multi-domain liquid crystal display device according to the present invention having the above configuration, the distance from the dielectric structure to the edge of the domain is constant, so that the electric field is symmetrically formed in the domain, thereby achieving stable texture.

In addition, due to the field distortion of the plurality of field induction windows, auxiliary electrodes, and dielectric structures, there is no afterimage, and a wide viewing angle can be secured.

In addition, when the auxiliary electrode is formed to overlap the pixel electrode, a separate storage electrode is not required to be formed, thereby simplifying the process and improving the aperture ratio.                     

In addition, by using a VA (Vertical Alignment) liquid crystal containing a chiral dopant, it is possible to implement a stable mode such that the molecular arrangement and optical axis of the liquid crystal are continuously formed by applying an electric field.

Claims (14)

A first substrate and a second substrate; A plurality of gate wirings and data wirings formed vertically and horizontally on the first substrate to define pixel regions; A pixel electrode formed in the pixel region and having a honeycomb electric field induction window formed therein to divide the pixel region into a plurality of domains; A light blocking layer formed on the second substrate; A color filter layer formed on the light blocking layer; A common electrode formed on the color filter layer; A dielectric structure formed on the common electrode and formed in each of the plurality of domain regions; And A multi-domain liquid crystal display device comprising a liquid crystal layer formed between the first substrate and the second substrate. The method of claim 1, And an auxiliary electrode is formed on the first substrate in an area different from the pixel electrode and corresponding to an electric field induction window formed in the pixel electrode. The method of claim 2, And the auxiliary electrode is formed on the same layer as the gate wiring. The method of claim 2, And the auxiliary electrode is formed on the same layer as the data line. The method of claim 2, And the pixel electrode is formed to overlap a predetermined portion of the auxiliary electrode. The method of claim 2, The pixel electrode is formed so as not to overlap with the auxiliary electrode. The method of claim 1, And a storage electrode connected to the pixel electrode is formed under the pixel electrode. The method of claim 1, The liquid crystal is a multi-domain liquid crystal display device characterized in that the chiral dopant is included in the vertical alignment liquid crystal (VA). The method of claim 1, And a thin film transistor is formed at an intersection point of the gate wiring and the data wiring. The method of claim 2, The auxiliary electrode is made of any one material selected from the group consisting of indium tin oxide (ITO), indium zinc oxide (IZO), Cu, Al, Mo, Cr, Ta, Ti, and Al alloys Liquid crystal display device. The method of claim 1, An alignment film is formed on at least one of the first substrate and the second substrate. The method of claim 11, The alignment film is a multi-domain liquid crystal display device characterized in that the alignment treatment by a rubbing method or a photo alignment method. The method of claim 11, And the alignment layer is not aligned. The method of claim 1, And a retardation film formed on at least one of the first substrate and the second substrate.

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