WO2011065610A1

WO2011065610A1 - Panel for liquid crystal display device and multi domain liquid crystal display device including same

Info

Publication number: WO2011065610A1
Application number: PCT/KR2009/007081
Authority: WO
Inventors: 김재훈
Original assignee: 한양대학교 산학협력단
Priority date: 2009-11-30
Filing date: 2009-11-30
Publication date: 2011-06-03

Abstract

According to an embodiment of the present invention, alignment can be performed by adding an alignment regulator to an alignment layer that includes a horizontal alignment layer or the horizontal alignment layer and a vertical alignment layer on a substrate. Thus, the invention provides a multi domain liquid crystal display device having a fast response speed and an excellent viewing angle in the entire gradation range.

Description

[Specifications

[Name of invention]

Display panel for liquid crystal display and multi-domain liquid crystal display including the same

The present invention relates to a display panel for a liquid crystal display and a multi-domain liquid crystal display including the same.

Background Art

Among the liquid crystal display devices, the twisted nematic (TN) mode has a high light transmission efficiency compared to other liquid crystal display devices, and the manufacturing process is simple and is most widely used. However, there is a problem that the viewing angle is lowered in a specific direction.

In the liquid crystal display device of the twisted nematic (TN) mode, the method of using a retardation film and the method of applying multiple orientations using a horizontal alignment film are known as methods for improving a viewing angle. However, when using a retardation film, an additional process is required and the product cost increases. In addition, in the method of applying the multi-orientation, when the alignment using the horizontal alignment layer, the pretilt angle is not very high, there is a problem that the multi-domain can not be formed at low gradation, in the case of the multi-domain, there is a problem of the slow response speed.

[Detailed Description of the Invention]

[Technical problem]

The technical problem to be solved by the present invention is to provide a multi-domain liquid crystal display device having an excellent viewing angle in the gray scale and a fast response speed. Technical Solution

<5> A display substrate for a liquid crystal display according to an exemplary embodiment of the present invention includes a substrate, a horizontal alignment layer disposed on the substrate, a vertical alignment layer disposed on the horizontal alignment layer, and an alignment distributed in the vertical alignment layer. Contains modifiers ᅳ

<6> The orientation regulator may be a polymerized photopolymerizable monomer or oligomer.

The horizontal alignment layer may include a first region and a second region which are rubbed in different directions.

The first region and the second region may be rubbed in opposite directions.

<9> A liquid crystal display according to an embodiment of the present invention is a first substrate, on the first substrate A first horizontal alignment layer disposed on the first horizontal alignment layer, a first vertical alignment layer including an alignment regulator, a second substrate facing the first substrate, and a second substrate disposed on the second substrate And a second horizontal alignment layer disposed on the second horizontal alignment layer, the second vertical alignment layer including an alignment regulator, and a liquid crystal layer injected between the first substrate and the second substrate.

The liquid crystal layer may be a Virin nematic liquid crystal layer.

<ιι> The first horizontal alignment layer may include a first region and a first region which are rubbed in opposite directions.

And a second region, wherein the second horizontal alignment layer may include a third region and a fourth region that are rubbed in opposite directions, and a rubbing direction of the first region and the second region and the third region. And the rubbing direction of the fourth region may be perpendicular to each other.

<12> A display substrate for a liquid crystal display according to another exemplary embodiment of the present invention includes a substrate, an alignment layer on which the horizontal alignment layer and the vertical alignment layer are mixed, and an alignment regulator distributed on the alignment layer. do.

The liquid crystal display according to another exemplary embodiment of the present invention is disposed on the first substrate and the first substrate, and is disposed in the first alignment layer including a horizontal alignment layer and a vertical alignment layer, and disposed in the first alignment layer. An orientation regulator, a second substrate facing the first substrate, a second alignment layer disposed on the second substrate, the second alignment layer including a horizontal alignment layer and a vertical alignment layer, the alignment agent distributed in the second alignment layer, and And a liquid crystal layer injected between the first substrate and the second substrate.

<14> A display substrate for a liquid crystal display according to another exemplary embodiment of the present invention includes a substrate, a horizontal alignment layer disposed on the substrate, and including an alignment regulator, wherein the horizontal alignment layers are rubbed in opposite directions to each other. It includes a first area and a second area.

Advantageous Effects

According to the exemplary embodiment of the present invention, an alignment regulator may be added to the alignment layer or the horizontal alignment layer including the horizontal alignment layer and the vertical alignment layer on the substrate to align the alignment agent. As a result, it is possible to provide a multi-domain liquid crystal display having an excellent viewing angle in all gray scales. In addition, it is possible to provide a multi-domain liquid crystal display device having not only an excellent viewing angle in all gray scales but also a fast response speed.

[Brief Description of Drawings]

1 is a diagram illustrating a display panel for a liquid crystal display according to an exemplary embodiment of the present invention. It's a shave.

2 is a cross-sectional view illustrating a liquid crystal display according to an exemplary embodiment of the present invention.

3 is a cross-sectional view illustrating a display panel for a liquid crystal display according to another exemplary embodiment of the present invention.

4 is a cross-sectional view illustrating a liquid crystal display according to another exemplary embodiment of the present invention.

5 is a cross-sectional view illustrating a display panel for a liquid crystal display according to another exemplary embodiment of the present invention.

6 is a cross-sectional view illustrating a liquid crystal display according to another exemplary embodiment of the present invention.

7 and 8 conceptually illustrate a method of forming a multi-domain of a liquid crystal display according to an exemplary embodiment of the present invention.

9 is a graph showing the result of pretilt of the dual alignment layer of the liquid crystal display according to an experimental example of the present invention.

10 is a graph illustrating domain stability evaluation results of a liquid crystal display according to an experimental example of the present invention.

11 and 12 are diagrams illustrating evaluation results of display characteristics of multiple domains of a liquid crystal display according to an exemplary embodiment of the present invention.

13 and 14 are graphs showing results of transmittance for each gray level depending on a position of a liquid crystal display according to an exemplary embodiment of the present invention.

15 to 17 are graphs showing the results of a response rate of the liquid crystal display according to an exemplary embodiment of the present invention.

[Form for implementation of invention]

Advantages and features of the present invention, and a method of accomplishing the same will be apparent with reference to the embodiments described below in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the embodiments are to make the disclosure of the present invention complete, and the general knowledge in the art to which the present invention belongs. It is provided to fully convey the scope of the invention to those skilled in the art, and the present invention is defined only by the scope of the claims.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

First, a display for a liquid crystal display according to an exemplary embodiment of the present invention with reference to FIG. 1. The board is explained. 1 is a cross-sectional view illustrating a display panel for a liquid crystal display according to an exemplary embodiment of the present invention.

Referring to FIG. 1, a display panel for a liquid crystal display according to an exemplary embodiment of the present invention may include an insulating substrate 110, a horizontal alignment layer 120 and a horizontal alignment layer 120 disposed on the insulating substrate 110. And a vertical alignment layer 130 disposed thereon. The vertical alignment layer 130 includes the alignment regulator 20. Although not shown, a signal element such as a gate line, a data line, and a switching element connected to the signal line, for example, a thin film transistor (TFT) and a pixel electrode connected to the switching element, are formed on the insulating substrate 110. There may be. In addition, a color filter, a light blocking member, a common electrode, and the like may be formed on the insulating substrate 110.

<32> The horizontal alignment layer 120 and the vertical alignment layer 130 may be formed of PI, photoalignment layer, nylon (nylon),

It may include at least one of materials such as PVC, PVA.

The <33> orientation regulator 20 is formed by photopolymerizing a photopolymerizable monomer or oligomer. Photopolymerizable monomers or oligomers include Reactive Mesogen (RM) and NOA series from Nor Land. Reactive mesogen (RM) means a polymerizable mesogenic compound. "Mesogenic compound" or "mesogenic material" 'includes materials or compounds comprising one or more rod-shaped, plate- or disc-shaped mesogenic groups, ie groups having the ability to induce liquid crystalline behavior. Liquid crystal compounds with shaped or plate-shaped groups are known in the art as calamitic liquid crystals, and liquid crystal compounds with disk-shaped groups are known in the art as discotic liquid crystals, or compounds containing mesogenic groups. The substance does not necessarily have to exhibit a liquid crystalline phase by itself, and it is also possible to exhibit liquid crystalline phase behavior only in a mixture with other compounds or upon polymerization of mesogenic compounds or substances, or their mixtures.

Reactive mesogen is a substance that is accumulated by light such as ultraviolet rays and is oriented according to the alignment state of adjacent materials. Examples of reactive mesogens include compounds represented by the following formula:

<35> Ρ1-Α1- (Ζ1-Α2) η-Ρ2,

Where P1 and P2 are independently selected from acrylate, methacrylate, vinyl, vinyloxy and epoxy groups, and A1 and A2 are 1,4-phenylene and naphthalene-2,6-diyl is independently selected from the (diyl) group, Z1 is one of C00-, 0C0- and a single bond, and n is one of 0, 1 and 2.

More specifically, there may be mentioned a compound represented by one of the following formulas:

Here, PI and P2 are independently selected from acrylate, methacrylate, vinyl, vinyloxy, and epoxy groups.

After laminating the horizontal alignment layer 120 on the substrate 110, without rubbing, the vertical alignment layer 130 can be laminated thereon, or after the horizontal alignment layer 120 is laminated on the substrate 110, After rubbing in the direction, the vertical alignment layer 130 may be laminated thereon.

All alignment layers according to the exemplary embodiment of the present invention are rubbed so that the liquid crystal molecules disposed thereon have a predetermined pre-tilt. In this specification, the pretilt may have an angle and a direction. In the following description, it is defined as a polar angle (0-180) and an azimuthal angle (0-360), respectively. That is, the line inclination may be interpreted to include both azimuthal angle (0-360) and polar angle (0-180). Here, the azimuth angle means an angle at which the projection of the alignment film or the liquid crystal onto the substrate surface is tilted based on the signal line of the liquid crystal display device, for example, the gate line or the data line. The polar angle refers to the angle of inclination with respect to the line (normal line of the substrate surface) perpendicular to the horizontal plane of the substrate or the alignment regulator.

The vertical alignment layer 130 is mixed with a vertical alignment material solvent (NMP: BL: BC) and coated. The thickness of the vertical alignment 130 varies depending on the content of the vertical alignment layer material (capacity percentage: \ ^%). Lose.

After adding the alignment regulator 20 to the vertical alignment layer 130, the response speed can be increased by fixing UV pretilt direction of the liquid crystal director by applying UV to the liquid crystal layer while applying voltage to the liquid crystal layer.

In general, the minimum line inclination angle (0 ^) required to form four stable domains is obtained by the following equation.

2

e _min = π d / L where d is the cell spacing of the liquid crystal layer and L is the horizontal size of the domain.

For example, if the cell spacing is ， and the horizontal size of the domain is 100 1, the minimum pretilt angle (e _min ) required to form four stable domains is about 22 ^° .

In general, because the horizontal alignment film has a pretilt ^angle of about 4-5 ^° and the vertical alignment film has a pretilt angle of about 89-90 ^° , four stable stably in twisted nematic (TN) modes It is difficult to form a domain.

In the case of the liquid crystal display panel according to the embodiment of the present invention, since the vertical alignment layer 130 is applied after the horizontal alignment layer 120 is applied, the anchoring energy of the two alignment layers 120 and 130 By combining, a pretilt angle having a median value of pretilt angles of the horizontal alignment layer 120 and the vertical alignment layer 130 may be realized. For example, when the thickness of the vertical alignment layer 130 is increased compared to the horizontal alignment layer 120, the pretilt angle may be increased, and vice versa.

Therefore, in the case of the display panel for a liquid crystal display device according to an exemplary embodiment of the present invention, since the liquid crystal molecules are a dual alignment layer having a stacked structure of a horizontal alignment layer and a vertical alignment layer, the liquid crystal molecules may be aligned to have a desired line tilt angle.

In addition, by adding an alignment regulator to the vertical alignment layer and applying a voltage to the liquid crystal layer and irradiating UV to fix the pretilt direction of the liquid crystal director, the response speed of the liquid crystal molecules may be increased.

Next, a liquid crystal display according to an exemplary embodiment of the present invention will be described with reference to FIG. 2. 2 is a diagram illustrating a liquid crystal display according to an exemplary embodiment of the present invention.

Referring to FIG. 2, the liquid crystal display according to the present exemplary embodiment may have two tables facing each other. Commercially available (100, 200) and a liquid crystal layer (3) injected therebetween.

The lower panel 100 includes a first horizontal alignment layer 120 disposed on the first insulating substrate 110 and a first vertical alignment layer 130 disposed on the first horizontal alignment layer 120. . The alignment regulator 20 is distributed in the first vertical alignment layer 130. The first horizontal alignment layer 120 and the first vertical alignment layer 130 may include at least one of materials such as PI, photoalignment layer, nylon, PVC, and PVA.

The upper panel 200 includes a second horizontal alignment layer 220 disposed on the second insulating substrate 210 and a second vertical alignment layer 230 disposed on the second horizontal alignment layer 220. . The alignment regulator 20 is distributed in the second vertical alignment layer 230. The second horizontal alignment layer 220 and the second vertical alignment layer 230 may include at least one of materials such as PI, photoalignment layer, nylon, PVC, and PVA.

The first horizontal alignment layer 120 and the first vertical alignment layer 130 of the lower panel 100 include at least two first and second regions that are rubbed in different directions, and the upper panel ( The second horizontal alignment layer 220 and the second vertical alignment layer 230 of 200 may include at least two third and fourth regions that are rubbed in different directions.

The first and second regions of the first horizontal alignment layer 120 and the first vertical alignment layer 130 of the lower panel 100 may be rubbed in opposite directions, and the second area of the upper panel 200 may be rubbed. The third and fourth regions of the horizontal alignment layer 220 and the second vertical alignment layer 230 may be rubbed in opposite directions.

In addition, the rubbing direction of the first area and the second area of the lower display panel 100 and the upper display panel.

The rubbing directions of the third region and the fourth region of 200 may be perpendicular to each other.

After the first horizontal alignment layer 120 is laminated on the first substrate 110 of the <6i> lower panel 100, the first vertical alignment layer 130 may be laminated on the first substrate 110 without rubbing, or the first substrate 110 may be laminated thereon. After laminating the first horizontal alignment layer 120 on the substrate 110 and rubbing in a desired direction, the first vertical alignment layer 130 may be laminated thereon.

In addition, after the alignment regulator 20 is added to the vertical alignment layer 130, UV irradiation may be performed in a state where voltage is applied to the liquid crystal layer to fix the pretilt direction of the liquid crystal director.

Similarly, after the second horizontal alignment layer 220 and the second vertical alignment layer 230 of the upper panel 200 are stacked on the second substrate 210, the second horizontal alignment layer 220 is not rubbed. Or a second vertical alignment layer 230 thereon, or a second horizontal on the second substrate 210. After laminating the alignment layer 220, the surface may be rubbed in a desired direction, and then the second vertical alignment layer 230 may be laminated thereon.

In the illustrated embodiment, both the lower display panel 100 and the upper display panel 200 include a horizontal alignment layer and a vertical alignment layer, but at least one display panel of the two display panels 100 and 200 is formed of the horizontal alignment layer and the vertical alignment layer. It may also include an alignment film forming a laminated structure. In addition, although the lower display panel 100 and the upper display panel 200 both include the alignment regulator 20 in the illustrated embodiment, at least one display panel of the two display panels 100 and 200 includes the alignment control agent 20. You may.

Although not shown, a switching element connected to signal lines and signal lines, such as gate lines and data lines, on the first substrate 110 or the second substrate 210, for example, a thin film transistor (TFT), and The pixel electrode, the color filter, the light blocking member, and the common electrode connected to the switching element may be formed.

As described above, the liquid crystal display according to the exemplary embodiment of the present invention forms an alignment layer in which a vertical alignment layer including a horizontal alignment layer and an alignment regulator is stacked on a substrate, and rubs in a desired direction, and then a voltage is applied to the liquid crystal layer. By irradiating UV to fix the pretilt direction of the liquid crystal director oriented by the alignment layer to align the desired pretilt angle and to enhance the pretilt direction, it is possible to implement multiple domains even in low gradation, liquid crystal molecules The answer can be faster. Accordingly, a liquid crystal display device having excellent viewing angle in all gray scales can be obtained, and a fast response speed can be realized.

3 and 4, a display panel for a liquid crystal display and a liquid crystal display according to another exemplary embodiment of the present invention will be described. 3 is a cross-sectional view illustrating a display panel for a liquid crystal display according to an exemplary embodiment of the present invention, and FIG. 4 is a cross-sectional view of a liquid crystal display according to an exemplary embodiment of the present invention.

Referring to FIG. 3, the display panel for a liquid crystal display according to the exemplary embodiment of the present invention includes the insulating substrate 110 and the mixed alignment layer 140 disposed on the insulating substrate 110. The mixed alignment film 140 is an alignment film obtained by mixing a horizontal alignment film and a vertical alignment film. The mixed alignment layer 140 includes the alignment regulator 20. Although not shown, a signal line such as a gate line, a data line, and a switching element connected to the signal line, for example, a thin film transistor (TFT) and a pixel electrode connected to the switching element, may be formed on the insulating substrate 110. Can be. In addition, a color filter, a light blocking member, a common electrode, and the like may be formed on the insulating substrate 110. The mixed alignment layer 140 may include at least one of materials such as PI, photoalignment layer, nylon, PVC, and PVA.

The mixed alignment layer 140 is mixed with a vertical alignment material in a solvent (NMP: BL: BC) and mixed with the horizontal alignment layer. Depending on the content of the vertical alignment layer material (capacity percentage: \%), the mixed alignment layer

The pretilt angle by 140 varies.

<7i> As described above, the twisted nematic (TN) has a pretilt angle of about 4-5 ^° and the vertical alignment film has a pretilt ^angle of about 89-90 ^° . In the) mode, it is difficult to form stable four domains.

In the display panel for a liquid crystal display according to an exemplary embodiment of the present invention, since the alignment regulator 20 is added to the mixed alignment layer 140 in which the horizontal alignment layer and the vertical alignment layer are mixed, the display panel is rubbed. By combining the anchoring energy of the pretilt angle having the intermediate value of the pretilt angle of the horizontal alignment layer and the vertical alignment layer can be implemented. As described above, the pretilt angle may vary depending on the content of the vertical alignment layer material added to the solvent. Therefore, in the case of the liquid crystal display panel according to the embodiment of the present invention, since the horizontal alignment layer and the vertical alignment layer are a mixed alignment layer, the liquid crystal molecules may be aligned to have a desired pretilt angle.

In addition, the mixed alignment layer 140 to which the alignment regulator 20 is added is laminated on the substrate 110 and oriented in a desired direction, and then irradiated with UV under a state in which a voltage is applied to the liquid crystal layer. By preserving the pretilt direction of the aligned liquid crystal director, the pretilt direction can be strengthened and the response speed of the liquid crystal can be increased.

Next, a liquid crystal display according to an exemplary embodiment of the present invention will be described with reference to FIG. 4.

Referring to FIG. 4, the liquid crystal display according to the present exemplary embodiment includes two display panels 100 200 facing each other and a liquid crystal layer 3 injected therebetween.

The lower panel 100 includes a first insulating substrate 110 and a first mixed alignment layer 140 disposed on the first insulating substrate 110. An orientation regulator 20 is distributed in the first mixed alignment layer 140. The first mixed alignment layer 140 may include at least one of materials such as PI, photoalignment layer, nylon, PVC, and PVA.

The upper panel 200 includes a second insulating substrate 210 and a second mixed alignment layer 240 disposed on the second insulating substrate 210. The alignment regulator 20 is distributed in the second mixed alignment film 240. The second mixed alignment layer 240 may be formed of PI, photoalignment layer, nylon, It may include at least one of materials such as PVC, PVA.

The first mixed alignment layer 140 of the lower panel 100 may include at least two first and second regions that are rubbed in different directions, and may include a second mixed alignment layer of the upper panel 200. 240 includes at least two third and fourth regions that are rubbed in different directions.

The first region and the second region of the first mixed alignment layer 140 of the lower panel 100 may be rubbed in opposite directions, and the second mixed alignment layer 240 of the upper panel 200 may be rubbed. The third region and the fourth region may be rubbed in opposite directions.

In addition, the rubbing direction of the first region and the second region of the lower display panel 100 and the upper display panel.

In the illustrated embodiment, both the lower panel 100 and the upper panel 200 include a mixed alignment layer, but at least one of the two panels 100 and 200 may include a mixed alignment layer. In addition, although the lower display panel 100 and the upper display panel 200 both include the alignment regulator 20 in the illustrated embodiment, at least one of the two display panels 100 and 200 may include the alignment regulator 20. It may be.

Although not shown, a switching element, for example, a thin film transistor (TFT), connected to signal lines such as a gate line, a data line, and the like may be disposed on the first substrate 110 or the second substrate 210. The pixel electrode, the color filter, the light blocking member, and the common electrode connected to the device may be formed.

In the liquid crystal display according to the exemplary embodiment of the present invention, after rubbing an alignment layer in which a horizontal alignment layer and a vertical alignment layer to which an alignment regulator is added is mixed on a substrate in a desired direction, the liquid crystal display according to the embodiment of the present invention irradiates UV with a voltage applied to the liquid crystal layer By fixing the line inclination direction of the liquid crystal director oriented by the alignment film to align the desired pretilt angle, and to enhance the pretilt direction, it is possible to realize multiple domains even in low gradation, the response of the liquid crystal molecules It can also be faster. Therefore, a liquid crystal display device having excellent viewing angle in all gray scales can be obtained, and a fast response speed can be realized.

5 and 6, a display panel for a liquid crystal display and a liquid crystal display according to another exemplary embodiment of the present invention will be described. 5 is a cross-sectional view illustrating a display panel for a liquid crystal display according to an exemplary embodiment of the present invention, and FIG. 6 is a cross-sectional view of a liquid crystal display according to an exemplary embodiment of the present invention.

Referring to FIG. 5, a display panel for a liquid crystal display according to an exemplary embodiment of the present invention is The insulating substrate 110 and the alignment film 150 disposed on the insulating substrate 110 are included. The alignment layer 150 includes an orientation regulator 20. The alignment layer 150 may be a horizontal alignment layer. Although not shown, a switching element connected to the signal line such as a gate line and a data line and a signal line such as a thin film transistor (TFT) and a pixel electrode connected to the switching element are formed on the insulating substrate 110. There may be. In addition, a color filter, a light blocking member, and a common electrode may be formed on the insulating substrate 110.

The alignment layer 150 may include at least one of materials such as PI, photoalignment layer, nylon, PVC, and PVA.

In the case of a display panel for a liquid crystal display according to an exemplary embodiment of the present invention, after the alignment layer 150 to which the alignment regulator 20 is added is laminated on the substrate 110 and rubbed in a desired direction, a voltage is applied to the liquid crystal layer. By applying UV light in the applied state to fix the pretilt direction of the liquid crystal director oriented by the alignment layer, the pretilt direction is strengthened, so that multiple domains can be realized even in the entire grayscale, and the speed of response of the liquid crystal molecules can be increased. Therefore, it is possible to obtain a liquid crystal display having an excellent viewing angle at all gray levels, and to realize a fast response speed.

Next, a liquid crystal display according to an exemplary embodiment of the present invention will be described with reference to FIG. 6.

Referring to FIG. 6, the liquid crystal display according to the present exemplary embodiment includes two display panels 100 and 200 facing each other and a liquid crystal layer 3 injected therebetween.

The lower panel 100 includes a first insulating substrate 110 and a first alignment layer 150 disposed on the first substrate 110. The alignment regulator 20 is distributed in the first alignment layer 150. The first alignment layer 150 may include at least one of materials such as PI, photoalignment layer, nylon, PVC, and PVA.

The upper panel 200 includes a second insulating substrate 210 and a second alignment layer 250 disposed on the second substrate 210. The alignment regulator 20 is distributed in the second alignment layer 250. The second alignment layer 250 may include at least one of materials such as PI, photoalignment layer, nylon, PVC, and PVA.

The first alignment layer 150 of the lower panel 100 includes at least two first and second regions that are rubbed in different directions, and the second alignment layer 250 of the upper panel 200 is And at least two third and fourth regions that are rubbed in different directions. The first region and the second region of the first alignment layer 150 of the lower panel 100 may be rubbed in opposite directions, and the third region of the second alignment layer 250 of the upper panel 200 may be rubbed. And the fourth region may be rubbed in opposite directions.

In the illustrated embodiment, the lower display panel 100 and the upper display panel in the illustrated embodiment.

Although both of the display panels 200 include the alignment regulator 20, at least one display panel of the two display panels 100 and 200 may include the alignment regulator 20.

In the liquid crystal display according to the exemplary embodiment of the present invention, an alignment film to which an alignment regulator is added is laminated on a substrate and rubbed in a desired direction, and then, the liquid crystal display is oriented by the alignment film by irradiating UV with a voltage applied to the liquid crystal layer. By fixing the pretilt direction of the liquid crystal director, the pretilt direction is strengthened, so that multiple domains can be realized even in full grayscale, and the response speed of the liquid crystal molecules can be increased. Therefore, a liquid crystal display device having excellent viewing angle in all gray scales can be obtained, and a fast response speed can be realized.

Next, a method of forming a multi-domain of a liquid crystal display according to an exemplary embodiment of the present invention will be described with reference to FIGS. 7 and 8. 7 and 8 conceptually illustrate a multi-domain forming method of a liquid crystal display according to an exemplary embodiment of the present invention. FIG. 7 conceptually illustrates a rubbing direction of the alignment layer structure, and FIG. 8 conceptually illustrates an arrangement of liquid crystal directors according to rubbing of FIG. 7.

In FIG. 7, a denotes a rubbing direction of the lower panel 100, and b denotes an upper panel.

The rubbing direction of 200 is represented, and c represents the arrangement direction of the liquid crystal director.

Referring to FIG. 7, the alignment layers of the lower panel 100 are rubbed in opposite directions to each other so that the first sub regions Ra and Rb oriented in the first direction and the second sub oriented in the second direction. The regions Rc and Rd are distinguished. In this case, the alignment layer of the lower panel 100 may be any one of various alignment layers described in the above embodiments.

cioo> The second alignment layers of the upper panel 200 are rubbed in opposite directions, so that the third sub-regions Ra and Rc oriented in the third direction and the fourth sub-regions Rb and Rd oriented in the fourth direction. Separate by). In this case, the alignment layer of the upper panel 200 may be any one of various alignment layers described in the above embodiments.

cioi> Then, by bonding the lower panel 100 and the upper panel 200, as shown in FIG. 8, the four regions Ra, Rb, and the liquid crystal director 31 are oriented in different directions. Rc, Rd) can be formed. As such, by forming four domains having different orientation directions, the viewing angle may be increased. In this case, the liquid crystal display according to the exemplary embodiment of the present invention may be aligned such that the liquid crystal molecules have a desired pretilt angle by using an alignment layer including a horizontal alignment layer and a vertical alignment layer.

The lower panel 100 and the upper panel 200 are bonded together, the liquid crystal layer 3 is injected, and UV is irradiated while a voltage is applied to the liquid crystal layer, so that the lower panel 100 and the upper panel It is possible to fix the pretilt direction of the liquid crystal director pretilted by the alignment film (200). As a result, the liquid crystal molecules of the liquid crystal layer may be aligned at a desired angle, the pretilt direction of the liquid crystal layer may be strengthened, multiple domains may be realized even at low gray levels, and the response speed of the liquid crystal molecules may be increased. Therefore, a liquid crystal display device having excellent viewing angle in all gray scales can be obtained, and a fast response speed can be realized.

103. Next, the result of pretilt of the dual alignment layer of the liquid crystal display according to the experimental example of the present invention will be described with reference to FIG. FIG. 9 is a graph showing a result of pretilts of a binary alignment layer of a liquid crystal display according to an experimental example of the present invention. FIG.

Referring to FIG. 9, in the alignment layer structure or the mixed alignment layer structure including the horizontal alignment layer and the vertical alignment layer according to the embodiment of the present invention, the increase in the number of vertical alignment layers may increase the pretilt angle. Could know. Therefore, when using an alignment layer or a mixed alignment layer having a laminated structure including a horizontal alignment layer and a vertical alignment layer according to an embodiment of the present invention, by adjusting the content of the vertical alignment layer, the liquid crystal molecules can be aligned to have a desired pretilt angle. And it was found.

Next, the domain stability of the liquid crystal display according to an exemplary embodiment of the present invention will be described with reference to FIG. 10. 10 is a graph illustrating domain stability evaluation results of a liquid crystal display according to an exemplary embodiment of the present invention. In FIG. 10, the solid line illustrated in each drawing represents a domain boundary. 10 (a) shows a case where the pretilt angle is 4 ^° , FIG. 10 (b) shows a case where the pretilt angle is r, and FIG. 10 (c) shows a case where the pretilt angle is 18 ^° . Indicates.

10 (a), when the liquid crystal molecules aligned by the alignment layer have a pretilt ^angle of 4 ^° , the stability of the four domains in the sub-gradation range in which a voltage of about 1.2 V is applied to the liquid crystal layer. 10B, when the liquid crystal molecules have a pretilt angle of T, the four domains in the sub-gradation range in which a voltage of about 1.0 V is applied to the liquid crystal layer are found. It turned out that stability is falling. 10 Referring to (c) of, when the liquid crystal molecules oriented by the alignment layer has a pretilt ^angle of 18 ^° , it was confirmed that four multi-domains are stably formed even at a low voltage of 0V. In other words, if the pretilt angle is less than 18 ^° , no multi-domain is formed at low voltage. Therefore, as in the display panel for the liquid crystal display according to the present embodiment, it is understood that a stable multivalent domain can be realized by adjusting the pretilt angle by using a dual alignment film or a mixed alignment film having a stacked structure including a horizontal alignment layer and a vertical alignment layer. Could.

11 and 12, display characteristics of multiple domains of the liquid crystal display according to an exemplary embodiment of the present invention will be described. 11 and 12 are diagrams showing evaluation results of display characteristics of multiple domains of a liquid crystal display according to an experimental example of the present invention.

FIG. 11 illustrates a case in which four domains are formed in a liquid crystal display device of a twisted nematic (TN) mode using a conventional horizontal alignment layer, and FIG. 12 illustrates an embodiment of the present invention. The case where four domains are formed in a liquid crystal display device in a twisted nematic (TN) mode by including an alignment regulator in an alignment layer including a horizontal alignment layer and a vertical alignment layer is shown.

cio9> FIGS. 11 and 12 (a), (b) and (c) respectively show magnitudes of voltage applied to the liquid crystal layer.

In the case of OV, 1.2V, and 10V, the figure shows the luminance distribution, and (d) is the figure showing the contrast ratio distribution.

iio> Referring to FIGS. 11 and 12, in an alignment layer including a horizontal alignment layer and a vertical alignment layer according to an embodiment of the present invention, an alignment regulator is included in a liquid crystal display device of a twisted nematic (TN) mode. In the case of forming four domains, the luminance distribution and the contrast ratio distribution of the four domains are formed in the liquid crystal display device of the twisted nematic (TN) mode using a conventional horizontal alignment film. The symmetry of the four domains is shown. Accordingly, it can be seen that the liquid crystal display according to the exemplary embodiment of the present invention can realize a twisted nematic (TN) liquid crystal display having four domains having directional symmetry in the entire gray scale range. there was. As a result, it was found that a liquid crystal display having an excellent viewing angle in the entire gray scale range could be implemented.

cin> Next, the display characteristics of the liquid crystal display according to an experimental example of the present invention will be described with reference to FIGS. 13 and 14. 13 and 14 are experimental examples of the present invention Is a graph showing a result of transmittance for each gray level according to a position of a liquid crystal display according to the present invention.

FIG. 13 illustrates a case where a conventional horizontal alignment layer is used, and FIG. 14 illustrates a case where an alignment regulator is included in an alignment layer including a horizontal alignment layer and a vertical alignment layer according to an exemplary embodiment of the present invention.

Referring to FIG. 13, when the existing horizontal alignment layer is used, when the polar angle value of the liquid crystal display device is about −50 ^° or less, the transmittance change appears accurately depending on the gray level. In the polar angle, gray scale inversion was observed in which the transmittance value was reversed depending on the gray scale. Referring to FIG. 14, when an alignment adjusting agent is included in an alignment layer including a horizontal alignment layer and a vertical alignment layer according to an exemplary embodiment of the present invention, transmittance changes according to gray levels, without gray scale inversion, in the range of the polar angle. Was found to appear correctly.

^; ii4> As described above, it was confirmed that the viewing angle symmetry was improved in the case of the liquid crystal display device according to the embodiment of the present invention, compared to the general liquid crystal display device of the twisted nematic (TN) mode. It was confirmed that the reversal was also improved.

Next, the answering speed of the liquid crystal display device according to an experimental example of the present invention will be described with reference to FIGS. 15 to 17. 15 to 17 are graphs showing a response rate result of a liquid crystal display according to an exemplary embodiment of the present invention. FIG. 15 shows the rising time of the liquid crystal molecules, FIG. 16 shows the falling time of the liquid crystal molecules, and FIG. 17 shows the total response time of the liquid crystal molecules. 15 to 17, A relates to a liquid crystal display of a general twisted nematic (TN) mode, and B refers to a liquid crystal display of a general multi-domain twisted nematic (TN) mode. C relates to a multi-domain liquid crystal display according to an embodiment of the present invention.

15 to 17, in comparison with a liquid crystal display of a general twisted nematic (TN) mode or a general multi-domain Berlin twisted nematic (TN) mode, In the multi-domain liquid crystal display according to the exemplary embodiment of the present invention, it was found that the response speed was improved. As described above, it was found that the response speed was improved by including the alignment regulator in the double alignment layer as in the liquid crystal display according to the exemplary embodiment of the present invention.

Although the preferred embodiment of the present invention has been described in detail above, The scope of the title is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concepts of the present invention defined in the following claims are also within the scope of the present invention.

Industrial Applicability

The present invention can provide a multi-domain liquid crystal display device having not only an excellent viewing angle in all gray scales but also a fast response speed.

Claims

[Range of request]

[Claim 11

Board,

A horizontal alignment layer disposed on the substrate;

A vertical alignment layer disposed on the horizontal alignment layer, and

A display substrate for a liquid crystal display device comprising an alignment regulator distributed in the vertical alignment layer.

[Claim 2]

In paragraph 1,

The orientation control agent is a display substrate for a liquid crystal display device which is a polymerization of a photopolymerizable monomer or oligomer.

[Claim 3]

In that 12th term,

And the horizontal alignment layer includes a first region and a second region that are rubbed in different directions.

[Claim 4]

From that 13

And the first region and the second region are rubbed in opposite directions to each other.

[Claim 5]

In claim 1,

[Claim 6]

In paragraph 5,

The first region and the second region are rubbed in the opposite direction to each other Display substrate for display device.

[Claim 7]

First substrate,

A first horizontal alignment layer disposed on the first substrate,

A first vertical alignment layer disposed on the first horizontal alignment layer and including an alignment regulator;

A second substrate facing the first substrate;

A second horizontal alignment layer disposed on the second substrate,

A second male alignment layer disposed on the second horizontal alignment layer and including an alignment regulator;

And a liquid crystal layer injected between the first substrate and the second substrate.

[Claim 8]

In paragraph 7,

The alignment control agent is a liquid crystal display device that is a combination of a photopolymerizable monomer or oligomer.

[Claim 9]

In claim 8,

The liquid crystal layer is a liquid crystal display of Birlin nematic liquid crystal layer.

[Claim 10]

In claim 9,

The first horizontal alignment layer includes a first region and a second region which are rubbed in opposite directions to each other,

And the second horizontal alignment layer includes a third region and a fourth region which are rubbed in opposite directions.

[Claim 111] In paragraph 10,

The rubbing direction of the first region and the second region and the rubbing direction of the third region and the fourth region are perpendicular to each other.

[Claim 12]

In claim 7,

[Claim 13]

In claim 12,

[Claim 14]

In claim 13,

A rubbing direction of the first region and the second region and a rubbing direction of the third region and the fourth region perpendicular to each other;

[Claim 15]

In paragraph 7,

[Claim 16]

In claim 15,

[Claim 17]

Board,

An alignment film disposed on the substrate and having a horizontal alignment film and a vertical alignment film mixed with each other; and

Display substrate for liquid crystal display devices containing the orientation regulator distributed in the said oriented film.

[Claim 18]

In claim 17,

[Claim 19]

In claim 18,

The alignment layer includes a first region and a second region which are rubbed in different directions.

[Claim 20]

In claim 19,

[Claim 21]

In claim 17,

[Claim 22]

In claim 21,

[Claim 23]

First substrate ，

A first alignment layer disposed on the first substrate and including a horizontal alignment layer and a vertical alignment layer;

An orientation regulator distributed in the first alignment layer,

A second substrate facing the first substrate,

A second alignment layer disposed on the second substrate, the second alignment layer including a horizontal alignment layer and a vertical alignment layer;

An orientation regulator distributed in the second alignment layer, and

[Claim 24]

In claim 23,

The orientation regulator is a liquid crystal display device that is a polymerization of a photopolymerizable monomer or oligomer.

[Claim 25]

In claim 24,

[Claim 26]

In claim 25,

The first alignment layer includes a first region and a second region which are rubbed in opposite directions;

The second alignment layer includes a third region and a fourth region that are rubbed in opposite directions.

[Claim 27] In claim 26,

[Claim 28]

In claim 23,

The liquid crystal layer is a liquid crystal display device of the Virin nematic liquid crystal layer.

[Claim 29]

In claim 28,

The first alignment layer may include a first region and a second region that are rubbed in opposite directions.

The second alignment layer includes a third region and a fourth region which are rubbed in opposite directions to each other;

[Claim 30]

In paragraph 29,

[Claim 31]

In claim 23,

The second alignment layer includes a third region and a fourth region which are rubbed in opposite directions.

[Claim 32]

In paragraph 31,