KR100869739B1 - Liquid Crystal Display Device - Google Patents

Abstract

The present invention relates to a liquid crystal display device that realizes a wide viewing angle by forming a plurality of domains having different alignments of liquid crystals in one pixel area. The present invention relates to a lower substrate, an upper substrate, and a pixel that is vertically and horizontally intersected on the lower substrate. A gate electrode and a data line defining an area, a pixel electrode formed in the pixel region having an electric field induction window, an auxiliary electrode formed under the pixel electrode so as to correspond to the electric field induction window, and a common electrode formed on the upper substrate An electrode, a first dielectric structure formed on the common electrode to correspond to the periphery of the pixel electrode in a direction parallel to the field induction window, and on the common electrode to correspond to the periphery of the pixel electrode in a direction perpendicular to the field induction window A second dielectric structure formed and first and second times formed on the lower substrate and the upper substrate Film, and is characterized by configured by a liquid crystal layer formed between the two substrates.

Two Domain Twisted Nematic (DTDN), field guidance window, auxiliary electrode, domain, dielectric structure

Description

Liquid Crystal Display Device

1A is a plan view of a pixel of a conventional liquid crystal display device

FIG. 1B is a structural cross sectional view along the line AA ′ of FIG. 1A

2A is a plan view of pixels of a liquid crystal display according to a first exemplary embodiment of the present invention.

FIG. 2B is a structural cross sectional view along the line B-B 'of FIG. 2A

3A is a plan view of pixels of a liquid crystal display according to a second exemplary embodiment of the present invention.

FIG. 3B is a structural cross sectional view along the line CC ′ in FIG. 3A.

4A is a plan view of pixels of a liquid crystal display according to a third exemplary embodiment of the present invention.

FIG. 4B is a structural cross sectional view along the line D-D 'in FIG. 4A

FIG. 4C is a simulation diagram showing liquid crystal alignment on the line D-D 'of FIG. 4A

5A is a plan view of pixels of a liquid crystal display according to a fourth exemplary embodiment of the present invention.

FIG. 5B is a structural cross sectional view taken along the line E-E 'of FIG. 5A

FIG. 5C is a simulation diagram showing liquid crystal alignment on the line E-E 'of FIG. 5A

6A is a plan view of pixels of a liquid crystal display according to a fifth exemplary embodiment of the present invention.

FIG. 6B is a structural cross sectional view along the line FF ′ in FIG. 6A.

7A is a plan view of pixels of a liquid crystal display according to a sixth exemplary embodiment of the present invention.

FIG. 7B is a structural cross sectional view along the line G-G 'of FIG. 7A                 

FIG. 7C is a simulation diagram showing liquid crystal alignment on the line G-G 'of FIG. 7A

8A is a plan view of pixels of a liquid crystal display according to a seventh exemplary embodiment of the present invention.

FIG. 8B is a structural cross sectional view along the line H-H 'of FIG. 8A;

9A is a plan view of pixels of a liquid crystal display according to an eighth exemplary embodiment of the present invention.

FIG. 9B is a structural cross sectional view along the line II ′ of FIG. 9A;

FIG. 9C is a simulation diagram illustrating liquid crystal alignment on the line II ′ of FIG. 9A.

* Description of symbols on the main parts of the drawings *

101: lower substrate 102: data line

103: auxiliary electrode 104: protective film

105: pixel electrode 106: electric field induction window

112: gate line 114: gate insulating film

201: upper substrate 202: light shielding layer

203: color filter layer 204: common electrode

205, 305, 405: first, second, third dielectric structures

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 that implements a wide viewing angle by forming a plurality of domains in which liquid crystals have different orientations in one pixel area.                         

In general, a liquid crystal display device includes a lower substrate, an upper substrate, and a liquid crystal layer formed between the two substrates facing each other at a predetermined interval, and the liquid crystal layer is driven by an electric field formed between the two substrates. Is displayed.

Among the liquid crystal displays, a liquid crystal display mainly used in recent years is a twisted nematic (TN) liquid crystal display, in which liquid crystals filled between two substrates are parallel to a substrate and have a constant pitch ( twisted in a spiral shape and are oriented such that the major axis of the liquid crystal is continuously changed.

However, the TN liquid crystal display device has a characteristic in that light transmittance of each gray level is changed depending on the viewing angle. In particular, light transmittance is symmetrically distributed in the left and right directions, but asymmetrically is distributed in the up and down directions, thereby causing gray inversion.

In order to solve the above problems, a method of compensating for the change in light transmittance according to the viewing angle has been proposed by dividing a domain by different liquid crystal driving in one pixel area.

As such, as a representative example of a multi-domain technique of dividing one pixel into several domains, two domain twisted nematic (TDTN) is a technique of forming two regions in which the alignment of liquid crystals is symmetrical around the center of one pixel region.

In this method, there is a complicated problem in the process of repeating the photolithography process several times. Therefore, a method of using an auxiliary electrode and an electric field induction window has been used. This method is mainly used in VA mode, but here is an example applied to TN mode.

Hereinafter, a liquid crystal display according to the related art will be described with reference to the accompanying drawings.

1A is a plan view of a pixel of a conventional liquid crystal display, and FIG. 1B is a structural cross-sectional view taken along the line AA ′ of FIG. 1A.

As shown in FIGS. 1A and 1B, a conventional liquid crystal display device is largely provided with a liquid crystal layer filled between a lower substrate 10, an upper substrate 21 opposite thereto, and both substrates 10 and 21. Poems).

A gate line 11 and a data line 12 are formed on the lower substrate 10 to cross each other in a vertical direction, and define a pixel region, and a pixel electrode 15 is formed in the pixel region.

The auxiliary electrode 13 is formed on the same layer as the data line 12 and is formed at the edge of the pixel electrode 15.

A gate insulating film (not shown) is formed between the gate line 11 and the data line 12, and a passivation layer 14 is formed between the data line 12 and the pixel electrode 15.

Although not shown, a thin film transistor including a gate electrode, a semiconductor layer, and a source / drain electrode is formed at an intersection of the gate line 11 and the data line 12.

On the upper substrate 21, a light shielding layer 22 for blocking the leakage of light to an area other than the pixel area, a color filter layer 23 for implementing color (R, G, B), and The common electrode 24 which has the electric field guide window 25 for dividing liquid crystal orientation inside is formed, respectively.

In this case, a fringe field having a different direction is formed in one pixel area by the electric field guide window 25 formed in the common electrode 24, and thus the liquid crystal alignment is changed. In this case, the auxiliary electrode 13 serves to strengthen the fringe field of the edge of the pixel electrode 15.

In addition, first and second alignment films (not shown) defining the initial alignment of the liquid crystal are formed on the front surfaces of both substrates 10 and 21. The first alignment layer formed on the lower substrate 10 and the second alignment layer formed on the upper substrate 21 are formed to be deflected by 90 ° to each other, and the liquid crystals adjacent to the first and second alignment layers are arranged along the alignment direction of the alignment layer. do.

The operation of the conventional liquid crystal display device having such a structure is as follows.

First, when no voltage is applied, the liquid crystals are arranged such that their major axes are parallel to the lower substrate 10 and the upper substrate 21, but are continuously twisted by 90 degrees. Therefore, light moves along the long axis direction of the twisted liquid crystal so that the screen shows a white state.

When a voltage is applied, the liquid crystals lying parallel to the lower substrate 10 and the upper substrate 21 stand in a direction perpendicular to the two substrates 10 and 21, so that the screen is black.

In this case, a fringe field as shown in FIG. 1B is generated by the field induction window 25 formed inside the common electrode 24, so that the liquid crystals are differently aligned with respect to the field induction window 25. To compensate for the viewing angle.

The conventional liquid crystal display as described above has the following problems.

First, in order to divide the arrangement of the liquid crystal, an auxiliary electrode formed at the edge of the pixel region generates a transverse electric field with the pixel electrode, so that an electric field direction exists to go out of the pixel region, thereby destabilizing the alignment of the liquid crystal in this region.

Secondly, the auxiliary electrode formed around the pixel electrode is generally formed of a metal through which light cannot penetrate, and should be formed at regular intervals from the wiring in order to prevent short circuits with the wiring formed on the same layer.

Therefore, the opening ratio is reduced by the portion where the auxiliary electrode overlaps with the pixel electrode, and if the auxiliary electrode is formed on the same layer as the wiring such as the data line or the gate line, the area where the pixel electrode can be formed is reduced. It causes a problem of lowering the aperture ratio.

This decrease in aperture ratio leads to a decrease in luminance, and when the extent is severe, it is necessary to adjust the brightness of the backlight, which may cause various problems such as increasing power consumption.

Third, in the case of the liquid crystal display device of the TN mode that is implemented to occur from the liquid crystal adjacent to the lower substrate when voltage is applied, the liquid crystal driving is greatly influenced by the alignment direction of the lower substrate, so that the alignment is different from that of the lower substrate. In the domain having, the liquid crystal is not oriented symmetrically with the domain having the same orientation as that of the lower substrate.

Fourth, there are two domains with different alignment of liquid crystals from side to side with a vertical center parallel to the data line of the pixel area, so that the left and right viewing angles can be compensated to some extent, but the problem of gray level inversion in the vertical direction remains. have.

Disclosure of Invention The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a liquid crystal display device that realizes a wide viewing angle by forming a plurality of domains having different alignments of liquid crystals in one pixel area.

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In addition, the liquid crystal display of the present invention for achieving the above object is a lower substrate and the upper substrate, a gate line and a data line that crosses longitudinally and horizontally on the lower substrate to define a pixel region, and within the pixel region A pixel electrode formed, a plurality of electric field induction windows formed in the pixel electrode in a direction parallel to the gate line, an auxiliary electrode formed under the pixel electrode so as to correspond to the plurality of electric field induction windows, and a common electrode formed on the upper substrate An electrode, at least one first dielectric structure parallel to the gate line on top of the common electrode, and formed at an edge of the pixel electrode, parallel to the data line on top of the common electrode, and an edge of the pixel electrode At least one second dielectric structure formed in the at least one A third dielectric structure formed between the first dielectric structures in the same direction as the gate line, first and second alignment layers formed on the lower substrate and the upper substrate, and a liquid crystal layer formed between the both substrates; And an auxiliary electrode further formed below the pixel electrode corresponding to the third dielectric structure, and an electric field induction window further formed on the pixel electrode corresponding to the third dielectric structure.

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

In the liquid crystal display device described below, the liquid crystal filled between the upper and lower substrates is a liquid crystal having a positive dielectric anisotropy arranged in accordance with an electric field generated between the upper and lower substrates.

In addition, since the arrangement of the liquid crystals varies according to the formation of the electric field, a description will be given when a voltage is applied to each of the electrodes of the upper and lower substrates in the liquid crystal display device of the present invention for classifying domains.

First, in the first and second embodiments, a liquid crystal display having a field induction window formed in a direction parallel to the data line in the center of the pixel electrode will be described.

First embodiment

FIG. 2A is a plan view of a pixel of a liquid crystal display according to a first exemplary embodiment of the present invention, and FIG. 2B is a cross-sectional view of the structure on the line BB ′ of FIG. 2A.

As shown in FIG. 2A, in the liquid crystal display according to the first exemplary embodiment, a gate line (not shown) and a data line 102 are formed on the lower substrate 101 to vertically intersect to define a pixel area. The pixel electrode 105 is formed in the pixel region. In the center of the pixel electrode 105, an electric field induction window 106 dividing the alignment of the liquid crystal when a voltage is applied is formed, and an auxiliary electrode 103 is formed under the electric field induction window 106.

In addition, a first dielectric structure 205 is formed around the pixel electrode in a direction parallel to the field induction window 106, and the alignment direction of the liquid crystal when the voltage is applied in the direction perpendicular thereto is different from that of the lower substrate. A second dielectric structure 305 is formed in the domain.

The structure of the pixel area | region and upper and lower substrate which have such a structure is demonstrated in detail.

That is, as shown in FIG. 2B, a gate line (not shown) and a data line 102 intersecting longitudinally and horizontally with each other on the lower substrate 101 to define a pixel area, and an intersection area of the gate line and the data line 102. A lower portion including a thin film transistor (not shown) formed on the substrate, an auxiliary electrode 103 formed at the center of the pixel region on the same layer as the data line 102, and the data line 102 and the auxiliary electrode 103. A passivation layer 104 formed on the entire surface of the substrate 101, a pixel electrode 105 formed in the pixel area and having an electric field induction window 106 at a portion corresponding to the auxiliary electrode 103, and the pixel electrode. A first alignment layer (not shown) and the like are formed on the entire passivation layer 104 including the 105 and formed on the lower substrate 101.

A gate insulating film (not shown) is formed between the gate line (not shown) and the data line 102, and the gate insulating film and the protective film 104 are formed of SiNx, SiOx, BenzoCycloButene (BCB), and acrylic resin (acrylic). resin, a polyamide compound, and the like.

Although not shown, a thin film transistor including a gate electrode, a semiconductor layer, and a source / drain electrode is formed at an intersection of the gate line (not shown) and the data line 102.

A light blocking layer 202 for blocking light leakage to a portion other than the pixel area on the upper substrate 201, and a color filter layer for implementing color colors R, G, and B on the light blocking layer 202. 203, the common electrode 204 formed on the front surface of the color filter layer 203, and the common electrode 204 formed on the common electrode 204 to correspond to the periphery of the pixel electrode in a direction parallel to the field induction window 106. The first dielectric structure 205 and the second dielectric formed on the common electrode 204 in a region where the orientation of the liquid crystal when the voltage is applied in the direction perpendicular to the field induction window 106 and the orientation of the lower substrate are different from each other. A second alignment layer (not shown) formed on the upper substrate 201 is provided on the entire surface of the common electrode 204 including the structure (305 of FIG. 2A) and the first and second dielectrics 205 and 305. .

Although not shown, an overcoat layer may be further formed between the color filter layer 203 and the common electrode 204.

Preferably, the dielectric constant of the first and second dielectric structures 205 and 305 is equal to or smaller than that of the liquid crystal. In addition, the first and second dielectric structures 205 and 305 are preferably made of a photosensitive material, more preferably made of acrylic resin (photoacrylate) or BCB (BenzoCycloButene).

Although not shown, the first and second alignment layers respectively defining the alignment directions of the lower substrate 101 and the upper substrate 201 may be a polyamide or polyimide compound, a polyvinylalcohol (PVA), It may be formed by rubbing orientation treatment using a material such as polyamic acid.

In addition, the first and second alignment layers may be formed by photo-alignment using a photoreactive material such as polyvinylcinnamate (PVCN), polysiloxanecinnamate (PSCN), or cellulosecinnamate (CelCN) -based compound. Such light alignment treatment simultaneously determines the pretilt angle and alignment direction by at least one light irradiation, wherein the light irradiation preferably uses light in the ultraviolet region. Any of polarized light, linearly polarized light, and partially polarized light may be used.

Although not shown, a liquid crystal layer is formed between the substrates 101 and 201. The liquid crystal layer is a twisted nematic (TN) type having a positive dielectric anisotropy. In addition, a chiral dopant may be added to the liquid crystal layer.

The operation of the liquid crystal display according to the first embodiment of the present invention having such a structure is as follows.

First, when no voltage is applied, the liquid crystals are arranged such that their major axis directions are parallel to the lower substrate 101 and the upper substrate 201, but are continuously twisted by 90 degrees. Therefore, when light moves along the long axis of the twisted liquid crystal, the screen is white.

When a voltage is applied, the liquid crystals lying in parallel with the lower substrate 101 and the upper substrate 201 stand in a direction perpendicular to the two substrates 101 and 201 sequentially from the lower substrate 101. The screen is black.

In this case, as illustrated in FIG. 2A, first and second domains in which the alignment of liquid crystals are symmetrically formed around the electric field induction window 106 are formed, and the second dielectric structure 305 is disposed on upper and lower portions of the second domain. Is formed.

As such, the reason why the second dielectric structure 305 is formed only in the second domain is because an orientation direction of the lower substrate 101 and the upper substrate 201 is toward the pixel center in the first domain and the second domain. Since the electric field induced in the electric field guide window 106 is formed in the direction toward the pixel center in each domain, the electric field formed in the second domain and the orientation direction are opposite to each other.

That is, in the TN mode, since the liquid crystal is adjacent to the lower substrate 101 when the voltage is applied, the movement of the liquid crystal is greatly limited by the alignment direction of the lower substrate 101. Accordingly, in the second domain, the second dielectric structure 305 is formed on the common electrode 204 so as to correspond to the periphery of the pixel electrode 105, so that the second dielectric structure may be formed in the upper and lower portions of the periphery of the second domain. The 305 prevents instability of the liquid crystal array by reinforcing the action of collecting the electric field inward.

In this case, the first dielectric structure 205 is a material for electric field distortion that is formed together with the electric field guide window 106 to form an electric field around the pixel.

The structures of the first and second dielectrics 205 and 305 may be formed by patterning in the same process or may be formed by separate processes.

Second embodiment

3A is a plan view of a pixel of a liquid crystal display according to a second exemplary embodiment of the present invention, and FIG. 3B is a structural cross-sectional view taken along the line CC ′ of FIG. 3A.

As shown in FIG. 3A, in the liquid crystal display according to the second exemplary embodiment of the present invention, a gate line (not shown) and a data line 102 are formed on the lower substrate 101 to vertically intersect to define a pixel area. The pixel electrode 105 is formed in the pixel region. In the center of the pixel electrode 105, an electric field induction window 106 dividing the alignment of the liquid crystal when a voltage is applied is formed, and an auxiliary electrode 103 is formed under the electric field induction window 106.

In addition, a first dielectric structure 205 is formed around the pixel electrode in a direction parallel to the field induction window 106, and a second dielectric structure 305 is formed around the pixel electrode in a direction perpendicular thereto. have.

The first and second dielectric structures 205 and 305 are not formed to face the outer side of the pixel electrode 105 when formed on the common electrode 204 to ensure texture stability. The electrode 105 is formed to overlap a predetermined portion.

The structure of the pixel area | region and upper and lower substrate which have such a structure is demonstrated in detail.

That is, as shown in FIG. 3B, a gate line (not shown) and a data line 102 and a cross region of the gate line and the data line 102 intersect each other longitudinally and horizontally to define a pixel area on the lower substrate 101. A lower portion including a thin film transistor (not shown) formed on the substrate, an auxiliary electrode 103 formed at the center of the pixel region on the same layer as the data line 102, and the data line 102 and the auxiliary electrode 103. A passivation layer 104 formed on the entire surface of the substrate 101, a pixel electrode 105 formed in the pixel area and having an electric field induction window 106 at a portion corresponding to the auxiliary electrode 103, and the pixel electrode. A first alignment layer (not shown) and the like are formed on the entire passivation layer 104 including the 105 and formed on the lower substrate 101.

A gate insulating film (not shown) is formed between the gate line (not shown) and the data line 102, and the gate insulating film and the protective film 104 are formed of SiNx, SiOx, BenzoCycloButene (BCB), and acrylic resin (acrylic). resin, a polyamide compound, and the like.                     

Although not shown, a thin film transistor including a gate electrode, a semiconductor layer, and a source / drain electrode is formed at an intersection of the gate line (not shown) and the data line 102.

A light blocking layer 202 for blocking light leakage to a portion other than the pixel area on the upper substrate 201, and a color filter layer for implementing color colors R, G, and B on the light blocking layer 202. 203, the common electrode 204 formed on the front surface of the color filter layer 203, and the common electrode 204 on the common electrode 204 to correspond to the periphery of the pixel electrode 105 in a direction parallel to the field induction window 106. The first dielectric structure 205 formed on the second dielectric structure 305 and the second dielectric structure 305 formed on the common electrode 204 so as to correspond to the periphery of the pixel electrode in a direction perpendicular to the electric field induction window 106. A second alignment layer (not shown) formed on the upper substrate 201 is provided on the entire surface of the common electrode 204 including the first and second dielectric structures.

Although not shown, an overcoat layer may be further formed between the color filter layer 203 and the common electrode 204.

Preferably, the dielectric constant of the first and second dielectric structures 205 and 305 is equal to or smaller than that of the liquid crystal. In addition, the first and second dielectric structures 205 and 305 are preferably made of a photosensitive material, more preferably made of acrylic resin (photoacrylate) or BCB (BenzoCycloButene).

As described above, the second embodiment of the present invention is the same as the first embodiment except that the second dielectric structure 305 is formed without distinction of domains, and therefore, the same reference numerals are given.

In the second embodiment of the present invention, the second dielectric structure is formed without domain distinction for the convenience of the patterning process, and performs the same operation as the first embodiment.

Meanwhile, in the first and second embodiments, the electric field induction window 106 is vertically formed at the center of the pixel electrode 105 so as to be parallel to the data line 102 so as to divide the domain. In the following description, a method of forming an electric field induction window horizontally in the pixel electrode 105 to improve the vertical viewing angle is described.

Third embodiment

FIG. 4A is a plan view of a pixel of a liquid crystal display according to a third exemplary embodiment of the present invention, FIG. 4B is a cross-sectional view of a structure on line D-D 'of FIG. 4A, and FIG. 4C is a view of the liquid crystal on line D-D' of FIG. 4A. A simulation diagram showing the orientation.

As shown in FIG. 4A, in the liquid crystal display according to the third exemplary embodiment, a gate line 112 and a data line (not shown) are formed on the lower substrate 101 so as to cross each other horizontally and define a pixel area. The pixel electrode 105 is formed in the area.

In addition, an electric field induction window 106 dividing the orientation of the liquid crystal when a voltage is applied is formed at the center of the pixel electrode 105 parallel to the gate line 112, and an auxiliary electrode under the electric field induction window 106. 103 is formed.

The first dielectric structure 205 is formed around the pixel electrode 105 in a direction parallel to the field induction window 106, and the liquid crystal when voltage is applied in a direction perpendicular to the field induction window 106. The second dielectric structure 305 is formed on the common electrode 204 in a region where the orientation of the substrate and the orientation of the lower substrate 101 are different from each other.

The structure of the pixel area | region and upper and lower substrate which have such a structure is demonstrated in detail.

That is, as shown in FIG. 4B, a gate line 112 and a data line (not shown) on the lower substrate 101 that cross each other in length and width to define a pixel area, and the pixel on the same layer as the gate line 112. An auxiliary electrode 103 formed at the center of the region, a gate insulating layer 114 formed on the entire surface of the lower substrate 101 including the gate line 112 and the auxiliary electrode 103, the gate line 112, and A thin film transistor (not shown) formed at an intersection region of the data line, a pixel electrode 105 having an electric field induction window 106 at a portion of the pixel region corresponding to the auxiliary electrode 103, and the pixel electrode. A first alignment layer (not shown) formed on the entire surface of the gate insulating layer 114 including the 105 and formed on the lower substrate 101 is provided.

In addition, a passivation layer (not shown) is formed between the data line (not shown) and the pixel electrode 105, and the gate insulating layer 114 and the passivation layer are SiNx, SiOx, BenzoCycloButene (BCB), and an acrylic resin (acrylic). resin, a polyamide compound, and the like.

Although the auxiliary electrode 103 is illustrated as being formed on the same layer as the gate line 112 in FIG. 4B, the auxiliary electrode 103 may be formed on the same layer or another layer as the data line (not shown). In consideration of the degree of integration, it is preferable to form the same layer as the gate line 112 or the data line.

Although not shown, a thin film transistor including a gate electrode, a semiconductor layer, and a source / drain electrode is formed at an intersection of the gate line 112 and the data line (not shown).

A light blocking layer 202 for blocking light leakage to a portion other than the pixel area on the upper substrate 201, and a color filter layer for implementing color colors R, G, and B on the light blocking layer 202. 203, the common electrode 204 formed on the front surface of the color filter layer 203, and the common electrode 204 on the common electrode 204 to correspond to the periphery of the pixel electrode 105 in a direction parallel to the field induction window 106. The pixel electrode 105 is a region where the first dielectric structure 205 formed in the second dielectric structure 205 and the alignment direction of the liquid crystal when the voltage is applied in a direction perpendicular to the field induction window 106 are different from the alignment direction of the lower substrate 101. The upper substrate 201 on the front surface of the common electrode 204 including the second dielectric structure 305 and the first and second dielectric structures 205 and 305 formed on the common electrode 204 to correspond to the periphery. ) Is provided with a second alignment layer (not shown).

Although not shown, an overcoat layer may be further formed between the color filter layer 203 and the common electrode 204.

Preferably, the dielectric constant of the first and second dielectric structures 205 and 305 is equal to or smaller than that of the liquid crystal. In addition, the first and second dielectric structures 205 and 305 are preferably made of a photosensitive material, more preferably made of acrylic resin (photoacrylate) or BCB (BenzoCycloButene).                     

As described above, according to the third embodiment of the present invention, the electric field induction window 106 is formed in the horizontal direction so as to be parallel to the gate line 112, and the first and the second directions are formed in the direction in which the electric field induction window 106 is formed. Except for the fact that the two dielectric structures 205 and 305 are formed, they are the same as in the first embodiment and are therefore given the same reference numerals.

The operation of the liquid crystal display according to the third embodiment of the present invention having the structure as described above is as follows.

First, when no voltage is applied, as in the first embodiment of the present invention, the liquid crystals are arranged such that their major axes are parallel to the lower substrate 101 and the upper substrate 201, but are continuously twisted by 90 °. have. Therefore, when light moves along the long axis of the twisted liquid crystal, the screen is white.

When a voltage is applied, the liquid crystals lying in parallel with the lower substrate 101 and the upper substrate 201 stand in a direction perpendicular to the two substrates 101 and 201 sequentially from the lower substrate 101. The screen is black.

In this case, as shown in FIG. 4A, first and second domains in which the alignment of the liquid crystal is symmetrically formed up and down on the electric field induction window 106 are formed, and the second dielectric structure 305 is formed in the first domain. have.

As such, the reason why the second dielectric structure 305 is formed in the first domain is that the orientation directions of the lower substrate 101 and the upper substrate 201 are directed toward the outside of the pixel in the first domain, and in the second domain. Since the electric field guided to the electric field guide window 106 is formed in the direction toward the pixel center in each domain, the electric field formed in the first domain and the orientation direction are opposite to each other.

Accordingly, in the left and right peripheral portions of the first domain, the second dielectric structure 305 is formed on the common electrode 204 in a direction perpendicular to the gate line 112 to form the second dielectric structure 305. By reinforcing the action that the electric field is collected inward through the orientation of the lower substrate 101 to prevent the instability of the liquid crystal array caused by the orientation direction.

In this case, the first dielectric structure 205 is a material for electric field distortion that is formed together with the electric field guide window 106 to form an electric field around the pixel.

In addition, the first and second dielectric structures may be formed by patterning in the same process, or may be formed in a separate process.

As described above, in the third embodiment of the present invention having the electric field guide window in the horizontal direction, since the first and second domains are formed to have the alignment of the liquid crystals which are vertically symmetrical, the liquid crystal of the general TN mode having a viewing angle of 30 ° up and down Compared to the display device, the vertical viewing angle may be compensated twice.

In addition, the liquid crystal is inclined at about 80 ° with respect to the substrate in the 6 o'clock or 12 o'clock direction with respect to the electric field induction window in the horizontal direction in terms of the left and right viewing angles. The level can be similar to that of the liquid crystal display.

4C illustrates that the first domain of FIG. 4A is formed at the left side and the second domain is formed at the right side, and the liquid crystals of the first and second domains are symmetrically aligned.

Fourth embodiment

5A is a plan view of a pixel of a liquid crystal display according to a fourth exemplary embodiment of the present invention, FIG. 5B is a cross-sectional view of a structure on the EE ′ line of FIG. 5A, and FIG. 5C is a simulation showing a liquid crystal array on the EE ′ line of FIG. 5A. It is also.

5A and 5B, on the lower substrate 101 of the liquid crystal display according to the fourth embodiment, a gate line 112 and a data line (not shown) that cross each other in a longitudinal direction and define a pixel region are formed. An auxiliary electrode 103 formed at the center of the pixel region on the same layer as the gate line 112, and a gate insulating layer formed on the entire surface of the lower substrate 101 including the gate line 112 and the auxiliary electrode 103. 114, a thin film transistor (not shown) formed at an intersection of the gate line 112 and the data line, and an electric field induction window 106 at a portion formed in the pixel area and corresponding to the auxiliary electrode 103. And a first alignment layer (not shown) formed on the entire surface of the gate insulating layer 114 including the pixel electrode 105 and formed on the lower substrate 101.

In addition, a light shielding layer 202 for blocking light leakage to a portion other than the pixel area on the upper substrate 201, and for implementing color hues (R, G, B) on the light shielding layer 202. The common electrode 204 to correspond to the color filter layer 203, the common electrode 204 formed on the front surface of the color filter layer 203, and the periphery of the pixel electrode 105 in a direction parallel to the electric field induction window 106. And a second dielectric structure 205 formed on the common electrode 204 to correspond to the periphery of the pixel electrode 105 in a direction perpendicular to the field induction window 106. 305 and a second alignment layer (not shown) formed on the upper substrate 201 on the entire surface of the common electrode 204 including the first and second dielectric structures 205 and 305.

As such, the fourth embodiment of the present invention is the same as the third embodiment except that the second dielectric structure 305 is formed without distinction of domains, and therefore, the same reference numerals are given.

In the fourth embodiment of the present invention, the second dielectric structure is formed without domain discrimination for the convenience of the patterning process, and as shown in FIG. 5C, the first and second domains are aligned so that the liquid crystals face each other. The same operation as in the third embodiment is performed.

Meanwhile, in the third and fourth embodiments, the electric field induction window 106 is formed horizontally in the center of the pixel electrode 105 to be parallel to the gate line 112 to improve the vertical viewing angle. In the fifth to eighth embodiments, a method of dividing into a plurality of domains by varying the arrangement of an electric field guide window and a dielectric structure for inducing electric field distortion in order to expand the vertical viewing angle is described below. Describe.

Fifth Embodiment

FIG. 6A is a plan view of a pixel of a liquid crystal display according to a fifth exemplary embodiment of the present invention, FIG. 6B is a cross-sectional view of the structure on the FF 'line of FIG. 6A, and FIG. 6C is a simulation showing the liquid crystal arrangement on the FF' line of FIG. 6A. It is also.

6A and 6B, in the liquid crystal display according to the fifth exemplary embodiment, a gate line 112 and a data line (not shown) are formed on the lower substrate 101 to vertically cross each other to define a pixel area. The pixel electrode 105 is formed in the pixel region.

The pixel electrode 105 has electric field induction windows 106a and 106b for dividing the alignment of the liquid crystal when a voltage is applied to the pixel electrode 105 in a direction parallel to the gate line 112. Guide windows 106a and 106b are formed at the boundary of the domain.

In addition, auxiliary electrodes 103a and 103c are formed below the field induction windows 106a and 106b. At this time, an auxiliary electrode 103b is further formed below the horizontal center of the pixel electrode 105, which is formed by forming the auxiliary electrode 103b at the center of the pixel electrode 105. This is because a process of forming a storage capacitor by forming a capacitor with the gate insulating layer 114 therebetween can be omitted.

In addition, a first dielectric structure 205 is formed on the common electrode 204 to correspond to the periphery of the pixel electrode 105 in a direction parallel to the field induction window 106, and the field induction window 106 is formed. The second dielectric structure 305 is formed on the common electrode 204 only in a region where the alignment of the liquid crystal when the voltage is applied in a direction perpendicular to the direction of the lower substrate 101 is different.

This is because the third dielectric structure 405 is further formed on the common electrode 204 corresponding to the horizontal center of the pixel electrode 105 to reinforce the unstable liquid crystal array, thereby further extending the vertical viewing angle.

As shown in FIG. 6C, it can be seen that the alignment directions are different from each other with respect to the horizontal center of the pixel.

In the fifth embodiment of the present invention, in the third embodiment, four domains are formed in the unit pixel, and the electric field induction windows 106a and 106b are formed in the horizontal center of each domain, and the lower part of the electric field induction windows 106a and 106b. The auxiliary electrodes 103a and 103c are formed in the same manner as in the third embodiment except that the third dielectric structure 405 and the auxiliary electrode 103b are formed in the horizontal center of the pixel, and therefore, the same reference numerals are given. .

Sixth embodiment

FIG. 7A is a plan view of a pixel of a liquid crystal display according to a sixth embodiment of the present invention, and FIG. 7B is a cross-sectional view of a structure on the line G-G ′ of FIG. 7A.

As shown in FIGS. 7A and 7B, the liquid crystal display according to the sixth exemplary embodiment forms an electric field induction window 106c in the horizontal center of the pixel, thereby stabilizing the liquid crystal alignment that varies on both sides of the horizontal center of the pixel.

The liquid crystal display of the sixth embodiment is the same as that of the fifth embodiment except that the field induction window 106c is further formed at the horizontal center of the pixel, and therefore, the same reference numerals are given.

Seventh embodiment

FIG. 8A is a plan view of a pixel of a liquid crystal display according to a seventh exemplary embodiment of the present invention, FIG. 8B is a cross-sectional view of a structure on the HH ′ line of FIG. 8A, and FIG. 8C is a simulation diagram of a liquid crystal array on the HH ′ line of FIG. 8A. to be.

As shown in FIGS. 8A and 8B, the liquid crystal display according to the seventh embodiment is the same as the fifth embodiment except that the second dielectric structure 305 is formed without distinction of domains for convenience of patterning. Give the same sign.

As shown in FIG. 8C, the liquid crystals are symmetrically aligned with respect to the horizontal center of the pixel.

Eighth embodiment

FIG. 9A is a plan view of a pixel of a liquid crystal display according to an eighth exemplary embodiment of the present invention, and FIG. 9B is a cross-sectional view of a structure on the line II ′ of FIG. 9A.

9A and 9B, the liquid crystal display according to the eighth embodiment is the same as the seventh embodiment except that the field induction window 106c is further formed in the horizontal center of the pixel. Therefore, the same reference numerals are given.

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

The liquid crystal display of the present invention as described above has the following effects.

First, when a pixel is divided into a plurality of domains by using an electric field induction window, a dielectric structure is formed at the edge of the domain different from the alignment direction to stabilize the texture by reinforcing the electric field distortion of the unstable liquid crystal alignment site. have.

Second, the left and right viewing angles can be implemented to be greater than or equal to 100 ° by forming an electric field induction window in a vertical direction parallel to the data line.

Third, by forming an electric field induction window in the horizontal direction parallel to the gate line to divide the domain up and down, the upper and lower viewing angle is implemented by about 60 degrees, the upper and lower viewing angle can be improved by about twice as compared to the general TN mode.

Fourth, the auxiliary electrode may be formed at the domain boundary to be used as an electrode of the storage capacitor, so that a separate storage capacitor forming process may be omitted.

Claims (9)

delete delete delete delete A lower substrate and an upper substrate; A gate line and a data line intersecting each other vertically and horizontally on the lower substrate to define a pixel area; A pixel electrode formed in said pixel region; A plurality of field induction windows formed in the pixel electrode in a direction parallel to the gate line; An auxiliary electrode formed under the pixel electrode to correspond to the plurality of electric field induction windows; A common electrode formed on the upper substrate; At least one first dielectric structure parallel to the gate line on the common electrode and formed at an edge of the pixel electrode; At least one second dielectric structure parallel to the data line on the common electrode and formed at an edge of the pixel electrode; A third dielectric structure formed between the at least one first dielectric structure in the same direction as the gate line; First and second alignment layers formed on the lower substrate and the upper substrate; And A liquid crystal layer formed between the substrates, An electric field induction window further formed in the pixel electrode corresponding to the third dielectric structure; And an auxiliary electrode further formed under the pixel electrode corresponding to the third dielectric structure. delete delete delete The method of claim 5, wherein The field induction window or the third dielectric structure may divide domains of a pixel region.

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