KR101173852B1 - Liquid Crystal Device and Method for producing thereof - Google Patents

Abstract

The present invention relates to a liquid crystal display device and a manufacturing method thereof.

Description

Liquid crystal display device and method for producing liquid crystal display device

The present invention relates to a liquid crystal display device and a manufacturing method thereof.

The liquid crystal display mode can be largely divided into a method using vertical alignment and a method using horizontal alignment. Vertical alignment uses MVA (Munti Domain Vertical Alignment) mode and PVA (Patterned Vertical Aligment) mode, and liquid crystal display devices using horizontal alignment use TN (Twisted Nematic) mode, IPS (In-Plane Switching) mode, and There is a FFS (Fringe-Field Switching) mode.

In the case of a liquid crystal display device using horizontal alignment, a method of rubbing a substrate coated with an alignment layer using a rubbing machine has been mainly used in order to horizontally align the liquid crystal to the substrate in a predetermined direction. Determining photo-alignment has been researched and developed and its use is gradually increasing. However, there is a problem of light leakage in the dark state due to scratches generated by the physical impact applied to the surface of the alignment layer during the rubbing process and afterimages due to the fine particles remaining after the rubbing process. This residual problem occurs in the liquid crystal display device using the optical alignment,

Particularly, in the case of photo-alignment, there is a problem of poor stability of alignment and poor response time characteristics due to low surface mooring force. In order to realize the dark state, the horizontal alignment liquid crystal display device has to coincide one of the alignment direction of the liquid crystal and the transmission axis of the polarizing plate between the vertically crossed polarizing plates to realize the dark state. Unlike a vertically aligned liquid crystal display device having a value of 0, an effective phase delay value exists so that one of the alignment direction of the liquid crystal and the transmission axis of the polarizer must be exactly matched, and the direction order of the liquid crystal is completely 1 even if it is exactly matched. Since this is not a good dark state compared to the vertically aligned liquid crystal display device is disadvantageous for the high quality implementation.

Accordingly, the present invention provides a liquid crystal display device that can improve the response time characteristics by solving the after-image problem occurring in the horizontal alignment liquid crystal display device, improving the voltage retention rate, improving the contrast ratio through the improvement of the dark state, and enhancing the surface anchoring force. Its purpose is to provide its manufacturing method.

In one aspect, to achieve the above object, a first substrate and a second substrate; Located between the first substrate and the second substrate and oriented horizontally on the first substrate and the second substrate, a liquid crystal molecule and a photocurable liquid crystal monomer are mixed, the liquid crystal in a position where the photocurable liquid crystal monomer is cured The liquid crystal display device may include a liquid crystal layer having high order of molecules and high order of liquid crystal molecules at positions other than the molecules.

In another aspect, the first substrate and the second substrate; A first alignment layer formed on the first substrate and having a higher degree of order than when the alignment material and the photocurable liquid crystal monomer are mixed to include only the alignment material; A second alignment layer formed on the second substrate and having a higher degree of order than when the alignment material and the photocurable liquid crystal monomer are mixed to include only the alignment material; A liquid crystal display device may include a liquid crystal layer positioned between the first alignment layer and the second alignment layer.

In another aspect, the step of mixing the liquid crystal molecules and the photocurable liquid crystal monomer between the first substrate and the second substrate facing each other; Maintaining a liquid crystal molecule and a photocurable liquid crystal monomer mixed between the first substrate and the second substrate at a low temperature; And curing the photocurable liquid crystal monomer by irradiating light onto the liquid crystal molecules and the photocurable liquid crystal monomer mixed between the first substrate and the second substrate maintained at the low temperature state. Can be provided.

In another aspect, the method comprising: forming a first alignment layer on the first substrate, the first alignment film is a mixture of the alignment material and the photocurable liquid crystal monomer; Forming a second alignment layer on which the alignment material and the photocurable liquid crystal monomer are mixed on the second substrate facing the first substrate; Maintaining the first alignment layer and the second alignment layer formed on the first substrate and the second substrate, respectively, at a low temperature; And curing the photocurable liquid crystal monomer by irradiating light to the first alignment layer and the second alignment layer respectively formed on the first substrate and the second substrate maintained at the low temperature. Can provide.

Accordingly, the present invention has the effect of improving the response time characteristics by solving the after-image problem occurring in the horizontal alignment liquid crystal display device, improving the voltage retention rate, improving the contrast ratio through the improvement of the dark state, and enhancing the surface mooring force.

1 is a perspective view of a liquid crystal display according to an exemplary embodiment.
FIG. 2 is a diagram illustrating an arrangement state of the liquid crystal layer of FIG. 1.
3 is a diagram illustrating an arrangement state of liquid crystal directors and liquid crystal molecules.
4 is a graph illustrating an order diagram of liquid crystal molecules according to temperature.
5 is a flowchart of a manufacturing method of a liquid crystal display according to another exemplary embodiment.
6A through 6D are diagrams illustrating respective steps of a method of manufacturing a liquid crystal display according to another exemplary embodiment of FIG. 5.
FIG. 7A is a plan view showing the liquid crystal array in the substrate before the low temperature curing step by light of the photocurable liquid crystal monomer, and FIG. 7B is a plan view showing the liquid crystal array in the substrate after the low temperature curing process by light of the photocurable liquid crystal monomer.
8 shows POM images of Comparative Example 1 and Example 1. FIG.
FIG. 9A is a result of measuring brightness of a POM image using I-solution, and FIG. 9B is a result of measuring brightness of a liquid crystal cell using an optical measuring device LCD1000S ((Otsuka Electonics Korea)).

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible even though they are shown in different drawings. In describing the embodiments of the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

In describing the components of the embodiment of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the constituent elements from other constituent elements, and the terms do not limit the nature, order or order of the constituent elements. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected to or connected to the other component, It should be understood that an element may be "connected," "coupled," or "connected."

Molecules have different arrangement characteristics depending on the temperature. Generally, it exists in a solid state having a perfect order at low temperature, but at a temperature above the melting point, it exists in a lower order liquid state. In some materials, a liquid crystal phase having an order and liquidity similar to that of a solid may exist. A liquid crystal display is used for a display using a material in which a molecule is in a liquid crystal state at normal temperature.

1 is a cross-sectional view of a liquid crystal display device according to an embodiment.

Referring to FIG. 1, the liquid crystal display device 100 according to an exemplary embodiment is disposed between an opposing first substrate 110 and a second substrate 120, and between the first substrate 110 and the second substrate 120. The liquid crystal layer 130 is included.

The first substrate 110 is a thin film transistor array substrate including a thin film transistor array (not shown) which is a driving circuit. The thin film transistor array is a switch element for switching the signals supplied to the liquid crystal cells and the liquid crystal cells arranged in a matrix form, respectively. In the thin film transistor array, a thin film transistor including a gate electrode, a gate insulating film, a semiconductor layer, a source and a drain electrode is formed on one surface of the second substrate 120 in the non-pixel region NP.

The second substrate 120 is a color substrate including a color filter (not shown) for receiving light to form a total natural color. The color filter included in the second substrate 120 may be formed by various methods, such as an ink-jet printing method or an etching process, but may be formed by various methods without being limited thereto.

The second substrate 120, which is a color substrate, and the first substrate 110, which is a thin film transistor array substrate, may each include a first polarizing plate and a second polarizing plate which are not shown in opposite directions of the liquid crystal layer 130. The first polarizing plate and the second polarizing plate function to make light incident upon vibrating in various directions (ie, polarized light) vibrating only in one direction. The first polarizing plate and the second polarizing plate may be attached to each of the first substrate 110 and the second substrate 120 by an adhesive, but are not limited thereto. The light transmission axes of the first and second polarizing plates are arranged to be perpendicular to each other.

The first substrate 110 and the second substrate 120 each include a first alignment layer 160 and a second alignment layer 170 in the direction of the liquid crystal layer 130. In this case, an insulating film 165 may be formed between the first substrate 110 and the first alignment layer 160.

The second substrate 120 may form a dielectric layer (not shown) on the second alignment layer 170.

The first substrate 110 includes two electrodes, that is, the common electrode 180 and the pixel electrode 190. A horizontal electric field L is formed between the common electrode 180 and the pixel electrode 190, and the liquid crystal molecules of the liquid crystal layer 130 are arranged side by side in the horizontal electric field L. FIG. In addition, a pixel electrode 190 electrically connected to the drain electrode of the thin film transistor array is formed corresponding to the pixel region P. FIG. The common electrode 180 is formed at one side of the pixel electrode 190 in the pixel region P to be spaced apart from each other to form a transverse electric field.

In this case, the pixel electrode 190 and the common electrode 180 are formed of a transparent metal layer selected from a group of transparent conductive metals such as indium tin oxide (ITO) or indium zinc oxide (IZO), and are well represented in the drawing. Although not provided, a plurality of pixel electrodes 190 and a common electrode 180 are provided, and the plurality of pixel electrodes 190 and the common electrode 180 are alternately arranged in parallel with each other.

In addition, although the plurality of common electrodes 180 and the pixel electrodes 190 are formed on the same layer, the two electrodes 180 and 190 may be formed on different layers as a variation. In addition, the plurality of pixel electrodes 190 may be formed on the same layer as the source and drain electrodes of the thin film transistor, and the common electrode 180 may be formed of the same material as the gate wiring.

The first substrate 110 may have an active matrix layer (not shown) in addition to the common electrode 180 and the pixel electrode 190 formed on the same surface. The active matrix layer may include a gate bus line and a data bus line. The area defined by the gate bus line and the data bus line may form one pixel. In addition, the common electrode 180 and the pixel electrode 190 may be formed of the same metal as the gate bus line or the data bus line.

As described above, the liquid crystal display device in which the common electrode 180 and the pixel electrode 190 are formed on the first substrate 110, that is, the horizontal electric field type liquid crystal display device 100 has a horizontal electric field between the two electrodes 180 and 190. By generating L) so that the liquid crystal molecules are arranged in parallel with the horizontal electric field L parallel to the two substrates 110 and 120, the viewing angle of the liquid crystal display device can be widened.

The liquid crystal layer 130 is mixed with the liquid crystal molecules 132 and the photoreactive or photocurable liquid crystal monomer 134 (hereinafter referred to as “photocurable liquid crystal monomer”), but is not limited to being mixed in any uniform arrangement or particular manner.

The liquid crystal molecules 132 may be liquid crystals having an initial dielectric anisotropy in order to increase the response speed. For example, the liquid crystal molecules 132 may be selected from one or more of the group consisting of MJ951160, MJ00435, and the like, but is not limited thereto and may be any liquid crystal having a positive dielectric anisotropy.

The liquid crystal molecules 132 are entirely disposed between the first substrate 110 and the second substrate 120 that face each other in parallel. The liquid crystal molecules 132 are horizontally aligned between the first substrate 110 and the second substrate 120. As shown in FIG. 1, the liquid crystal molecules 132 of the liquid crystal layer 130 are horizontally arranged between the two substrates 110 and 120. Meanwhile, as described above, a horizontal electric field L is formed between the common electrode 180 and the pixel electrode 190, and the liquid crystal molecules 132 of the liquid crystal layer 130 are arranged side by side in the horizontal electric field L. FIG. do.

The photocurable liquid crystal monomer 134 may be selected from one or more selected from the group consisting of RM257 (Formula 1) and EHA (Formula 2), but is not limited thereto.

The photocurable liquid crystal monomer 134 is a liquid crystal material including a terminal group capable of polymerization by the ultraviolet reaction of the photoinitiator. It mainly refers to a monomer molecule that exhibits a liquid crystal phase including a mesogen group capable of exhibiting liquid crystal and a terminal group capable of photopolymerization, and which can be photopolymerized by a photoinitiator reacting with ultraviolet rays. The photoinitiator may be selected from one or more selected from the group consisting of trimethylopropane, triacrylate, and the like, but is not limited thereto.

The thickness or density of the photocurable liquid crystal monomer 134 mixed with the liquid crystal molecules 132 and polymerized may be determined in consideration of the type of the liquid crystal molecules 132, the intensity of the applied voltage, a desired response speed, and the like. For example, when the desired response speed is relatively high, the photocurable liquid crystal monomer 134 may be mixed with the liquid crystal molecules 132 so that the polymerized thickness or density may be relatively large.

The photocurable liquid crystal monomer 134 is mixed with the liquid crystal molecules 132 adjacent to or adjacent to the first substrate 110 and the second substrate 120 between the first substrate 110 and the second substrate 120. It is polymerized. The photocurable liquid crystal monomer 134 mixed with the liquid crystal molecules 132 and polymerized is the same as that of the liquid crystal molecules 132 mainly adjacent to or separated from the first substrate 110 and the second substrate 120, respectively. They are arranged in substantially the same direction.

Referring to FIG. 2, the liquid crystal molecules 132 having a better order are arranged in a more constant direction, and when the photocurable liquid crystal monomer 134 is cured by irradiating ultraviolet rays in this state, such a state is maintained even at room temperature. It is retained to some extent and can even solve some unintended liquid crystal arrays due to substrate defects.

 In this process, the liquid crystal array on the substrate has a higher order, and the problem caused by the defect of the substrate is solved to some extent, so that a higher quality dark state can be realized, which results in a high contrast ratio and the surface mooring force of the substrate. As the response time characteristic is enhanced and the photocurable liquid crystal monomer is cured by light, the afterimage problem can be solved by reducing residual DC by trapping residual ions in the liquid crystal.

When the liquid crystal molecules 132 are irradiated with ultraviolet rays in a low temperature state mixed with the photocurable liquid crystal monomer 134 and the photocurable liquid crystal monomer 134 is cured, some degree of orderness may be maintained even at room temperature, and even as a defect of the substrate. It describes the principle and manufacturing process that can solve some unintended liquid crystal arrangement to some extent.

Referring to FIG. 3, the molecules are in a solid state having perfect order at a low temperature, that is, below a temperature of Tm (Melting temperature), and then present in a liquid crystal state having only a direction order at a temperature above Tm. Done. When the temperature increases and reaches a temperature above Tc (Clearing point), it becomes a liquid without order.

Referring to FIG. 3, in the liquid crystal state, the liquid crystal molecules 310 have a property of being arranged in a specific direction, and the direction becomes the director 320 of the liquid crystal. When the angle between the liquid crystal director 320 and the actual liquid crystal molecules 310 is referred to, the order diagram S of the liquid crystal molecules 310 is as follows.

[Equation 1]

Molecular order is equal to 1 when the molecules are perfectly arranged like solids, but is equal to a value between 0.9 and 0.3 when only the positional order is present. Referring to Figure 4 it can be seen that the order of the molecules in the liquid crystal state increases with decreasing temperature.

Transmittance (T / T ₀₎ of a typical liquid crystal display device can be expressed as follows:

&Quot; (2) "

T / T ₀ = sin ² 2Φsin ² (πdΔn / λ)

Where T ₀ is the transmittance to the reference light, Φ is the angle between the optical axis of the liquid crystal molecules and the transmission axis of the polarizer, Δn is the refractive index anisotropy, d is the thickness of the liquid crystal layer, and λ is the wavelength of the incident light. it means.

In order to implement a more perfect dark state, the angle formed between the optical axis of the liquid crystal molecules 310 and the transmission axis of the polarizer should be zero. However, in reality, the liquid crystal molecules 310 are not perfectly aligned with the liquid crystal director 320 at room temperature, so that the optical axes of the polarizer and the liquid crystal molecules may be slightly different, and thus the dark state may not be perfectly implemented. Do not. In addition, when there is a defect in the alignment layer for orienting the liquid crystal, light leakage may occur and the dark state may be further deteriorated.

The liquid crystal display according to an embodiment irradiates ultraviolet (Ultraviolet, UV) to a mixture of the photocurable liquid crystal monomer and the liquid crystal in a state where the liquid crystal has a more perfect order in a low temperature state to determine the liquid crystal order at the time of ultraviolet irradiation In this case, both substrates 110 and 120 have better liquid crystal alignment order than before curing.

A method of manufacturing a liquid crystal display according to another exemplary embodiment will be described in detail with reference to FIGS. 5 and 6A to 6D.

Referring to FIG. 5, in another embodiment, a method 500 of manufacturing a liquid crystal display device includes a mixing step (S510) of mixing a photocurable liquid crystal monomer and a liquid crystal molecule between two substrates and a low temperature for maintaining a liquid crystal cell at a low temperature state. The holding step (S520), the light irradiation step (S530) for irradiating light in a low temperature state, the photocurable liquid crystal monomer is moved to the substrates in accordance with the light irradiation and a curing step (S540). After curing, the liquid crystals on both substrates maintain the liquid crystal order at the time of ultraviolet irradiation, so that both substrates have a better liquid crystal alignment order than before curing.

6A through 6D are diagrams illustrating respective steps of a method of manufacturing a liquid crystal display according to another exemplary embodiment of FIG. 5. In FIG. 6D, reference numbers are given together, but in FIG. 6A to FIG. 6C, the reference numbers are not shown together for simplicity of the drawings. 6A through 6C are the same as those in FIG. 6D.

5 and 6A, the photocurable liquid crystal monomer is formed between the first alignment layer 160 formed on the first substrate 110 and the first alignment layer 170 formed on the second substrate 120 in the mixing step S510. 134 and the liquid crystal molecules 132 are mixed. In other words, in the mixing step S510, the liquid crystal layer in which the liquid crystal molecules 132 and the photocurable liquid crystal monomer 134 are mixed may be injected into the cell.

The amount of the photocurable liquid crystal monomer 134 mixed with the liquid crystal molecules 132 may be determined in consideration of the type of the liquid crystal molecules 132, the strength of an applied voltage, a desired response speed, and the like. For example, when the desired response speed is relatively high, the photocurable liquid crystal monomer 134 may be mixed with the liquid crystal molecules 132 so that the polymerized amount may be relatively high. For example, the photocurable liquid crystal monomer may be mixed in an amount of 0.01 to 20 wt%. If the composition ratio of the photocurable liquid crystal monomer is less than 0.01wt%, it has little practical meaning to increase the order of the liquid crystal. If it exceeds 20wt%, the thickness of the layer mixed with the liquid crystal molecules 132 and polymerized becomes too thick. The thickness of the liquid crystal layer to be driven may be too thin.

In the mixing step (S510), the liquid crystal molecules 132 may be liquid crystals having the above-described initial dielectric anisotropy, and may be selected from one or more selected from the group consisting of MJ951160, MJ00435, and the like. In addition, the photocurable liquid crystal monomer 134 may be selected from one or more selected from the group consisting of RM257 (Formula 1), EHA (Formula 2) and the like.

In the liquid crystal layer 130, the liquid crystal molecules 132 and the photocurable liquid crystal monomer 134 may be uniformly mixed. The mixing ratio may be selected through various implementations in order to obtain a constant response speed and a constant contrast ratio. However, if the concentration of the photocurable liquid crystal monomer 134 is too high, the mixture is polymerized in a rich state in the liquid crystal layer, rather, May interfere with or cause light leakage.

In this state, the liquid crystal molecules 132 are aligned in a predetermined direction by the first alignment layer 160 and the second alignment layer 170, but as described above with reference to FIGS. 3 and 4. Is not perfect otherwise, the direction of the array is not completely constant.

On the other hand, the mixture of the liquid crystal molecules 132 and the photocurable liquid crystal monomer 134 may further include a photo initiator to promote curing of the photocurable liquid crystal monomer 134 in the curing step (S540). In this case, the photoinitiator may be mixed with 0.1 to 20 wt% of the photocurable monomer composition. The photoinitiator may be selected from one or more selected from the group consisting of trimethylopropane, triacrylate, and the like, but is not limited thereto.

5 and 6B, in the low temperature maintaining step (S520), the photocurable layer is formed between the first alignment layer 160 formed on the first substrate 110 and the first alignment layer 170 formed on the second substrate 120. The liquid crystal cell in which the liquid crystal monomer 134 and the liquid crystal molecules 132 are mixed is kept at a low temperature. When the liquid crystal cell is placed at a low temperature, the liquid crystal has a more perfect order as described with reference to FIGS. 3 and 4. In this case, the temperature at which the liquid crystal cell is kept at a low temperature may be determined between Tm (Melting temperature) and Tc (Clearing point) in consideration of the type of the liquid crystal molecules 132, the intensity of the applied voltage, a desired response speed, and the like. For example, the temperature for keeping the liquid crystal cell at a low temperature may be -50 ° to 50 °, but is not limited thereto.

5 and 6C, in the light irradiation step S530, since the liquid crystal cell is kept at a low temperature in step S520, ultraviolet rays (Ultraviolet, UV) are irradiated in a state where the order of the liquid crystal is improved. In this case, the intensity or time of ultraviolet rays to be irradiated may be appropriately determined according to the type and composition ratio of the liquid crystal molecules 132 and the photocurable liquid crystal monomer 134, the moving speed of the photocurable liquid crystal monomer 134, and the like.

In this case, when the amount of ultraviolet (UV) radiation is too high, the shape of the polymer network may not be evenly formed on the surface of the substrate, and a large polymer network may be generated due to agglomeration, causing light leakage. The UV irradiation time is usually within 180 minutes, the irradiation amount may be carried out at about 50 ~ 300J, but the manufacturing method is not limited thereto.

In this case, the light to be irradiated has been described as ultraviolet rays, but may be light of a kind depending on the type of the photocurable liquid crystal monomer 134.

5 and 6D, the photocurable liquid crystal monomer 134 moves to both substrates 110 and 120 in accordance with light irradiation in the curing step S540 to cure. In the curing step (S540) of irradiating ultraviolet (UV) light to cure the photocurable liquid crystal monomer, the photocurable liquid crystal monomer 134 moves to both substrates 110 and 120 having a large amount of encapsulating energy.

After curing, the liquid crystal in both substrates 110 and 120 maintains the liquid crystal order at the time of ultraviolet irradiation, so that both substrates 110 and 120 have better liquid crystal alignment order than before curing.

The manufacturing method of the liquid crystal display device according to another exemplary embodiment has been described in detail with reference to FIGS. 5 and 6A to 6D. Hereinafter, the liquid crystal display device according to another exemplary embodiment (hereinafter referred to as Embodiment 1) and a general liquid crystal display device ( Hereinafter, the results of experiments by comparing the comparative examples will be described.

In Example 1, an FFS mode liquid crystal display (liquid cell) having a width of 4 μm and an electrode distance of 6 μm, respectively, was selected. On the other hand, the cell gap (d) was 4 μm. In the rubbing, the liquid crystal direction in the horizontal direction formed a liquid crystal direction of 83 degrees with respect to the horizontal component of the fringe field.

Liquid crystal cells with an initial positive dielectric anisotropy (Δn = 0.1016, Δε = 9.9) were mixed with a photocurable liquid crystal monomer (reactive mesogen) in a ratio of 99.9: 0.1 to inject a liquid crystal cell. Ultraviolet light was irradiated to a liquid crystal cell into which a mixture of liquid crystal molecules and a photocurable liquid crystal monomer was injected (30 mW / cm 2, 365 nm, 30 min) at a low temperature (about -20 °).

In Comparative Example, the same conditions as in Example 1 were mixed, but the photocurable liquid crystal monomer was mixed with the liquid crystal molecules, and pure liquid crystal molecules which did not irradiate ultraviolet rays at low temperature were injected into the liquid crystal cell.

POM (polarizing microscope) and i to check the order of liquid crystal molecules and to measure the brightness of the POM (polarizing microscope) image of light leakage in the dark state after preparing Example 1 and Comparative Example -solution (IMT i-solution Inc.), optical observation equipment was observed and measured.

7A is an order diagram of liquid crystal molecules of Comparative Example, and FIG. 7B is an order diagram of liquid crystal molecules of Example 1. FIG.

As shown in FIG. 7A, the comparative example in which only pure liquid crystal molecules are injected shows that even after the alignment process for arranging the liquid crystals, the liquid crystal molecules are not perfectly aligned in a uniform direction, and even because of defects in the substrate. It may be arranged in a completely different direction than the one, which can cause problems such as unexpected light leakage.

As shown in FIG. 7B, the liquid crystal cell in which the photocurable liquid crystal monomer 134 and the liquid crystal molecules 132 are mixed is irradiated with ultraviolet rays to the liquid crystal cell at low temperature to cure the photocurable liquid crystal monomer on both substrates. 1 indicates that the liquid crystal layer 130 has a superior order in a low temperature state and is arranged in a more constant direction. When the photocurable liquid crystal monomer is cured by irradiating ultraviolet rays in this state, such a state is maintained to a certain degree even at room temperature. Even unintended liquid crystal arrays due to substrate defects can be solved to some extent.

8 shows POM images of Comparative Example 1 and Example 1. FIG. When the highlighted area (dotted rectangle area) of FIG. 8A is enlarged, as shown in FIG. 8B, light leakage around the spacer is smaller in Example 1 than in Comparative Example 1. As shown in FIG. On the other hand, Figure 8 (c) is a dark POM image of the crossed polarizers of Example 1.

FIG. 9A is a result of measuring brightness of a POM image using I-solution, and FIG. 9B is a result of measuring brightness of a liquid crystal cell using an optical measuring device LCD1000S ((Otsuka Electonics Korea)).

As shown in FIG. 9A, the brightness of the entire region and the dark portion without the image spacer using I-solution shows that the dark state of Example 1 is superior to that of the comparative example. On the other hand, as shown in Fig. 9b, the brightness measurement results of the liquid crystal cell using the optical measuring device LCD1000S ((Otsuka Electonics Korea)) were the same as the measurement results using the I-solution. The enhanced surface anchoring energy shows that the photocurable liquid crystal monomer is polymerized at low temperature, thereby improving the liquid crystal order and reducing the light leakage caused by the spacer, thereby improving the overall dark state.

In this process, the liquid crystal array on the substrate has a higher order, and the problem caused by the defect of the substrate is solved to some extent, so that a higher quality dark state can be realized, which results in a high contrast ratio and the surface mooring force of the substrate. As the response time characteristic is enhanced and the photocurable liquid crystal monomer is cured by light, the afterimage problem can be solved by reducing residual DC by trapping residual ions in the liquid crystal.

Accordingly, the present invention can solve the afterimage problem in realizing a moving image by trapping residual ions generated in the liquid crystal alignment process in the process of curing the photocurable monomer composition on the alignment layer to reduce the residual DC.

In addition, when the photocurable monomer composition is cured on the alignment layer, the surface anchoring force of the alignment layer is enhanced to improve the response time characteristics of the liquid crystal display device, and when the process is performed by controlling the ambient temperature, the order of the liquid crystal after curing is improved. It is possible to maintain the liquid crystal display device having a better image quality characteristics to compensate for the problems caused by surface defects and improve the dark state.

Embodiments have been described above with reference to the drawings, but the present invention is not limited thereto.

In the above embodiments, the FFS (Fringe-Field Switching) mode liquid crystal display device is described as an example among the horizontal alignment liquid crystal display devices, but the present invention is not limited thereto. For example, various liquid crystals such as In-Plane Switching (IPS), Twisted Nematic (TN), Multi Domain Vertical Alignment (MVA), Patterned Vertical Alignment (PVA), Optically Compensated Splay (OCS), Opticaly Compensated Bend (OCB) The same may be applied to the display device modes.

In the above embodiments, the photocurable liquid crystal monomer is mixed with the liquid crystal, but the present invention is not limited thereto. For example, a certain amount of photocurable liquid crystal monomer may be mixed with the alignment film. In this case, each of the first alignment layer and the second alignment layer applied to each of the first substrate and the second substrate is coated with an alignment material and a photocurable liquid crystal monomer in an appropriate ratio. After the liquid crystal is injected therebetween, it is placed in a low temperature state and irradiated with light in an improved order to polymerize and cure the photocurable liquid crystal monomer of each of the first alignment layer and the second alignment layer. In this case, the same effects as those described above can be obtained.

In this case, the manufacturing method of the liquid crystal display device may include forming a first alignment film on which the alignment material and the photocurable liquid crystal monomer are mixed on the first substrate, and a second alignment film on which the alignment material and the photocurable liquid crystal monomer are mixed with the first substrate. Forming a second substrate, maintaining the first alignment layer and the second alignment layer formed on the first substrate and the second substrate at a low temperature; and forming the first substrate and the second substrate formed at the low temperature. And irradiating light onto the first alignment layer and the second alignment layer to cure the photocurable liquid crystal monomer. At this time, the process of each step may be the same or substantially the same as the above-described embodiments. For example, the photocurable liquid crystal monomer may be mixed in an amount of 0.01 to 20 wt%.

The terms "comprise", "comprise" or "having" described above mean that a corresponding component may be included, unless otherwise stated, and thus, excludes other components. It should be construed that it may further include other components. All terms, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. Commonly used terms, such as predefined terms, should be interpreted to be consistent with the contextual meanings of the related art, and are not to be construed as ideal or overly formal, unless expressly defined to the contrary.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

Claims (14)

delete delete delete delete delete delete delete A first step of applying a material obtained by mixing a photocurable liquid crystal monomer with at least one of a liquid crystal molecule and an alignment material between the first substrate and the second substrate;
A second step of increasing the order of the liquid crystal molecules by leaving the first substrate and the second substrate to which the mixed material is applied at -50 ° C to 50 ° C for a predetermined time; And
And a third step of curing the photocurable liquid crystal monomer by irradiating light at -50 ° C to 50 ° C. The method of claim 8,
The first step is a step of injecting the mixed material between the first substrate and the second substrate after mixing the photocurable liquid crystal monomer with the liquid crystal molecules. The method of claim 8,
In the first step, after the photocurable liquid crystal monomer is mixed with the alignment material, a thin film is formed on at least one of the first substrate and the second substrate using the mixed material. A method of manufacturing a liquid crystal display device. The method of claim 8,
The weight of the photocurable liquid crystal monomer mixed in the mixed material is a manufacturing method of the liquid crystal display device, characterized in that 0.01 to 20wt%. The method of claim 8,
The method of manufacturing a liquid crystal display device, characterized in that further mixing the photoinitiator in the first step. 13. The method of claim 12,
Wherein the photoinitiator is mixed in an amount of 0.1 to 20 wt% based on the photocurable liquid crystal monomer. delete

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