KR102287403B1 - Curved liquid crystal display - Google Patents

Abstract

A first curved substrate, a second curved substrate, a liquid crystal layer including liquid crystal molecules having negative dielectric anisotropy and disposed between the first curved substrate and the second curved substrate, and between the liquid crystal layer and the first curved substrate a first curved liquid crystal alignment layer disposed on and one surface facing the first curved liquid crystal alignment layer and protrusions protruding from the one surface, the average number of projections per unit area is higher than that of the first curved liquid crystal alignment layer, and the A curved liquid crystal display including a second curved liquid crystal alignment layer disposed between the liquid crystal layer and the second curved substrate is provided.

Description

Curved liquid crystal display {CURVED LIQUID CRYSTAL DISPLAY}

The present invention relates to a curved liquid crystal display.

A liquid crystal display device is one of the most widely used flat panel display devices at present, and includes two substrates on which field generating electrodes such as a pixel electrode and a common electrode are formed, and a liquid crystal layer interposed therebetween.

A liquid crystal display displays an image by applying a voltage to an electric field generating electrode to generate an electric field in a liquid crystal layer, thereby determining alignment directions of liquid crystals in the liquid crystal layer, and controlling the polarization of incident light.

As the liquid crystal display device is used as a display device of a television receiver, the size of the screen is increasing. As the size of the liquid crystal display increases as described above, the visual difference may increase depending on the case where the viewer sees the central part of the screen and the case where the viewer sees the left and right ends of the screen.

In order to compensate for the visual difference, the liquid crystal display may be bent into a concave shape or a convex shape to form a curved shape. The curved liquid crystal display device may be a portrait type that has a vertical length longer than a horizontal length and is curved in the vertical direction, a vertical length is shorter than a horizontal length, and is a landscape type that is curved in the horizontal direction, based on the viewer. may be

One problem to be solved by the present invention is to provide a curved liquid crystal display having improved light transmittance.

The problems of the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

A curved liquid crystal display according to an embodiment includes a first curved substrate, a second curved substrate, and a liquid crystal layer including liquid crystal molecules having negative dielectric anisotropy and disposed between the first curved substrate and the second curved substrate; a first curved liquid crystal alignment layer disposed between the liquid crystal layer and the first curved substrate, a surface facing the first curved liquid crystal alignment layer, and protrusions protruding from the one surface, the first curved liquid crystal alignment layer The average number of protrusions per unit area is larger than that of , and a second curved liquid crystal alignment layer disposed between the liquid crystal layer and the second curved substrate is included.

A curved liquid crystal display according to an embodiment includes a first curved substrate, a second curved substrate, and a liquid crystal layer including liquid crystal molecules having negative dielectric anisotropy and disposed between the first curved substrate and the second curved substrate; The first curved liquid crystal alignment layer and the first curved liquid crystal alignment layer disposed between the liquid crystal layer and the first curved substrate have a larger average surface roughness than the first curved liquid crystal alignment layer disposed between the liquid crystal layer and the second curved substrate Two curved liquid crystal alignment layers are included.

The second curved liquid crystal alignment layer has a higher content of mesogen than the first curved liquid crystal alignment layer.

A curved liquid crystal display according to an embodiment includes a first curved substrate, a second curved substrate, a first curved liquid crystal alignment layer disposed between the first curved substrate and the second curved substrate, and the first curved liquid crystal alignment A second curved liquid crystal alignment layer disposed between the layer and the second curved substrate, and negative dielectric anisotropy first liquid crystal molecules aligned on a surface of the first curved liquid crystal alignment layer and a surface of the second curved liquid crystal alignment layer and a second liquid crystal molecule of negative dielectric anisotropy with a smaller pretilt angle than that of the first liquid crystal molecule in an initial state in which no electric field is applied, and the first curved liquid crystal alignment layer and the second curved liquid crystal alignment and a liquid crystal layer disposed between the layers.

For example, the difference between the average value (mθ _{1 ) of the pre-tilt angle (θ 1} ) of the first liquid crystal molecule and the average value (mθ ₂ ) of the pre- _{tilt angle (θ 2 ) of the second liquid crystal molecule (mθ 1} - mθ ₂ ) may be 0.6 ° or more and 0.9 ° or less.

The curved liquid crystal display according to an embodiment may further include a patternless electrode having no slit pattern and a pattern electrode facing the patternless electrode and having a slit pattern.

The details of other embodiments are included in the detailed description and drawings.

Embodiments of the present invention may provide a curved liquid crystal display having improved light transmittance.

The effect according to the invention is not limited by the contents exemplified above, and more various effects are included in the present specification.

1 is a schematic exploded perspective view of a curved liquid crystal display according to an exemplary embodiment.
FIG. 2 is a schematic enlarged view of region II of FIG. 1 .
FIG. 3 is a schematic cross-sectional view taken along line III-III' of FIG. 1 .
4 is a photograph of the surface of the first curved liquid crystal alignment layer of FIG. 3 .
FIG. 5 is a surface photograph of the second curved liquid crystal alignment layer of FIG. 3 .
6 is an analysis graph of an average value of surface roughness of the first curved liquid crystal alignment layer of FIG. 3 .
7 is an analysis graph of an average value of surface roughness of the second curved liquid crystal alignment layer of FIG. 3 .
8 to 13 are cross-sectional views schematically illustrating a method of manufacturing a curved liquid crystal display according to an exemplary embodiment.
14 is a photo of a light transmittance distribution of a curved liquid crystal display according to an exemplary embodiment.
15 is a photograph of light transmittance distribution of the curved liquid crystal display according to Comparative Example 1;
16 is a photograph of the surface of the first curved liquid crystal alignment layer of the curved liquid crystal display according to the first comparative example.
17 is a surface photograph of a second curved liquid crystal alignment layer of the curved liquid crystal display according to Comparative Example 1;
18 is a photograph of a light transmittance distribution of a curved liquid crystal display according to Comparative Example 2;
19 is a result of measuring a voltage retention ratio (VHR) using a curved liquid crystal display according to an exemplary embodiment.
20 is a result of measuring the voltage retention ratio (VHR) using the curved liquid crystal display according to Comparative Example 3;

Advantages and features of the invention and methods for achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings.

However, the invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, and only the embodiments allow the disclosure of the invention to be complete, and the invention is provided to those of ordinary skill in the art to which the invention pertains. It is provided to fully indicate the scope of the invention, and the invention is only defined by the scope of the claims.

Like reference numerals refer to like elements throughout. In order to distinguish the curved liquid crystal display from the flat liquid crystal display, C is added after the reference numerals of the curved liquid crystal display and components constituting the same.

Sizes and relative sizes of layers and regions in the drawings may be exaggerated for clarity of description.

Reference to an element or layer “on” or “on” another element or layer includes not only directly on the other element or layer, but also with intervening other layers or other elements. include all

Although the first, second, etc. are used to describe various elements, these elements are not limited by these terms, of course. These terms are only used to distinguish one component from another. Accordingly, it goes without saying that the first component mentioned below may be the second component within the spirit of the present invention.

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

1 is a schematic exploded perspective view of a curved liquid crystal display 500C according to an embodiment of the present invention. FIG. 2 is a schematic enlarged view of region II of FIG. 1 .

1 and 2 , a curved liquid crystal display 500C according to an exemplary embodiment includes a first curved substrate 100C, a second curved substrate 200C facing the first curved substrate 100C and spaced apart from each other, and and a liquid crystal layer 300C disposed between the first curved substrate 100C and the second curved substrate 200C.

The first and second curved substrates 100C and 200C each include a display area DAC and a non-display area NDAC. The display area DAC is an area in which an image is viewed, and the non-display area NDAC is an area in which an image is not viewed. The display area DAC is surrounded by the non-display area NDAC.

The common electrode 110C may be disposed between the first curved substrate 100C and the second curved substrate 200C, and may be a patternless electrode having no slit pattern. The pixel electrode 291C may be disposed between the second curved substrate 200C and the common electrode 110C and may be a pattern electrode having a slit pattern.

The liquid crystal layer 300C may be disposed between the common electrode 110C and the pixel electrode 291C. The liquid crystal layer 300C may include liquid crystal molecules LC having negative dielectric anisotropy. The first curved liquid crystal alignment layer AL1C may be disposed between the common electrode 110C and the liquid crystal layer 300C. The second curved liquid crystal alignment layer AL2C may be disposed between the pixel electrode 291C and the liquid crystal layer 300C.

The second curved substrate 200C may be a thin film transistor substrate. A plurality of gate lines GLC extending in a first direction and a plurality of data lines DLC extending in a second direction perpendicular to the first direction may be formed in the display area DAC of the second curved substrate 200C. can A pixel electrode 291C may be disposed in each pixel PXC defined by the gate line GLC and the data line DLC.

The pixel electrode 291C may include sub-pixel electrodes 291-1C and 291-2C that are spaced apart from each other. For example, each of the subpixel electrodes 291-1C and 291-2C may have an overall rectangular shape. Each of the subpixel electrodes 291-1C and 291-2C may be a pattern electrode having a slit pattern. Specifically, the slit pattern may include a cutout DC disposed between the stem portion SC and the branch portion BC extending therefrom. The stem part SC may be formed in a cross (+) shape, and the branch part BC may extend radially in an approximately 45° direction from the cross (+) shape stem part SC.

The gate line GLC may include gate electrodes 224 - 1C and 224 - 2C protruding from the gate line GLC in the second direction toward the pixel electrode 291C. The plurality of data lines DLC may include source electrodes 273 - 1C and 273 - 2C and drain electrodes 275 - 1C and 275 - 2C. The source electrodes 273 - 1C and 273 - 2C may protrude from the data line DLC to form a “U” shape. The drain electrodes 275 - 1C and 275 - 2C may be spaced apart from the source electrodes 273 - 1C and 273 - 2C.

The pixel electrode 291C may receive a data voltage through a thin film transistor that is a switching element. The gate electrodes 224-1C and 224-2C, which are control terminals of the thin film transistor, may be electrically connected to the gate line GLC, and the source electrodes 273-1C and 273-2C, which are input terminals, are contact holes. It may be electrically connected to the data line DLC through 285-1C, 285-2C, 285-3C, and 285-4C, and the drain electrodes 275-1C and 275-2C, which are output terminals, are connected to the pixel electrode ( 291C).

The pixel electrode 291C may generate an electric field together with the common electrode 110C to control the alignment direction of the liquid crystal molecules LC of the liquid crystal layer 300C disposed therebetween. The pixel electrode 291C may distort the electric field to control alignment directions of the first liquid crystal molecules LC1 and the second liquid crystal molecules LC2-1 and LC2-2.

The thin film transistor substrate includes a base substrate (not shown) made of glass or polymer, gate electrodes 224-1C and 224-2C, a gate insulating film (not shown), a semiconductor layer (not shown), and an ohmic contact layer (not shown). time), the source electrodes 273-1C and 273-2C, the drain electrodes 275-1C and 275-2C, a passivation layer (not shown), an organic layer (not shown), etc. may include a stacked structure. .

The channel of the thin film transistor may be formed of a semiconductor layer (not shown). A semiconductor layer (not shown) may be disposed to overlap the gate electrodes 224-1C and 224-2C. Each of the source electrodes 273 - 1C and 273 - 2C and each of the drain electrodes 275 - 1C and 275 - 2C may be spaced apart from each other with respect to a semiconductor layer (not shown).

The storage electrode line SLC may include a stem line 231C substantially parallel to the plurality of gate lines GLC and a plurality of branch lines 235C extending therefrom. The storage electrode line SLC may be omitted or may be variously modified in shape and arrangement.

The non-display area NDAC is a peripheral portion of the display area DAC and may be a light blocking area surrounding the display area DAC. A driver (not shown) providing a gate driving signal and a data driving signal to each pixel PXC of the display area DAC may be disposed in the non-display area NDAC of the second curved substrate 200C. The gate line GLC and the data line DLC may extend from the display area DAC to the non-display area NDAC to be electrically connected to a driver (not shown).

The first curved substrate 100C may be a substrate opposite to the second curved substrate 200C. The common electrode 110C may be disposed on the second curved substrate 200C.

A color filter layer (not shown) may be formed in an area corresponding to each pixel PXC in the display area DAC, and includes a red color filter (R), a green color filter (G), and a blue color filter (B). may include The color filter layer (not shown) may be included in any one of the first curved substrate 100C and the second curved substrate 200C. For example, when the first curved substrate 100C includes a color filter layer (not shown), the first curved substrate 100C includes a base substrate (not shown) made of glass or polymer, a color filter layer (not shown), An overcoat layer (not shown) may have a stacked structure. The overcoat layer (not shown) may be a planarization layer covering the color filter layer (not shown). In this case, the common electrode 110C may be disposed on an overcoat layer (not shown).

For example, when the second curved substrate 200C includes a color filter layer (not shown), the second curved substrate 200C forms a color filter on a transparent insulating substrate on which a thin film transistor is formed. It may have a color filter on array (COA) structure. For example, the color filter layer (not shown) includes a passivation layer (not shown) and an organic layer (not shown) covering the source electrodes 273-1C and 273-2C and the drain electrodes 275-1C and 275-2C. can be placed between

A light blocking pattern layer (not shown) may be disposed at a boundary between each of the color filters R, G, and B. The light blocking pattern layer (not shown) may be included in any one of the first curved substrate 100C and the second curved substrate 200C. For example, the light blocking pattern layer (not shown) may be a black matrix.

During the manufacturing of the curved liquid crystal display 500C, due to the stress applied to the first and second flat substrates, respectively, in the process of bending the flat liquid crystal display, there is a gap between the first and second curved substrates 100C and 200C. A misalignment may occur. For example, in the process of bending the flat panel liquid crystal display, the first curved substrate 100C may be shifted to the left or right with respect to the second curved substrate 200C. In this case, an arrangement state between the first curved substrate 100C and the second curved substrate 200C may be different from a previously designed arrangement state between the first flat substrate and the second flat substrate. The alignment error between the first curved substrate 100C and the second curved substrate 200C may deteriorate the display quality of the curved liquid crystal display 500C.

For example, when the first curved liquid crystal alignment layer AL1C and the second curved liquid crystal alignment layer AL2C each include a plurality of domains having different orientation directions of directors of liquid crystal molecules, the first curved liquid crystal alignment layer AL1C ) of the domains and the boundary of the domains of the second curved liquid crystal alignment layer AL2C, the alignment error of the first liquid crystal molecules and the first liquid crystal molecules obliquely aligned on the surface of the first curved liquid crystal alignment layer AL1C Interference or collision in the alignment direction between second liquid crystal molecules that are aligned in different directions and are inclinedly aligned on the surface of the second curved liquid crystal alignment layer AL2C may cause interference or collision between the first and second liquid crystal molecules. of liquid crystal molecules may be substantially vertically aligned to form a texture. The texture may be recognized as a spot or dark portion in the display area DAC of the curved liquid crystal display 500C, and light transmittance of the curved liquid crystal display 500C may decrease.

Hereinafter, a curved liquid crystal display 500C according to an exemplary embodiment will be described in more detail with reference to FIG. 3 . FIG. 3 is a schematic cross-sectional view taken along line III-III' of FIG. 1 . FIG. 3 schematically illustrates alignment forms of liquid crystal molecules LC1, LC2-1, and LC2-2 in an initial state in which no electric field is applied to the curved liquid crystal display 500C.

Referring to FIG. 3 , the first liquid crystal molecules LC1 may be aligned on the surface of the first curved liquid crystal alignment layer AL1C. The second liquid crystal molecules LC2-1 and LC2-2 may be aligned on the surface of the second curved liquid crystal alignment layer AL2C. The first liquid crystal molecules LC1 may have a first pretilt angle θ ₁ and may be relatively vertically aligned compared to the second liquid crystal molecules LC2-1 and LC2-2. The second liquid crystal molecules LC2-1 and LC2-2 may have a second pretilt angle θ ₂ and may be oriented relatively obliquely compared to the first liquid crystal molecules LC1 . In an initial state in which no electric field is applied to the curved liquid crystal display 500C, the first pretilt angle θ ₁ is greater than the second pretilt angle θ _{2 .}

For example, the curved liquid crystal display device 500C according to an embodiment may have a radius of curvature R of 2000 mm or more and 5000 mm or less, and in an initial state in which no electric field is applied, a first pretilt angle θ ₁ ) of the average value (mθ ₁₎ and the second pretilt angle (θ ₂₎ the average value (mθ ₂₎ of the car (mθ ₁ - mθ ₂₎ may be less than 1.0. Specifically, the curved surface when the radius of curvature (R) is 2000 mm or less or more to 5000 mm of the liquid crystal display apparatus (500C), the first pretilt angle (θ ₁₎ an average value (mθ ₁₎ and the second pretilt angle (θ ₂₎ of the The difference (mθ ₁ - mθ ₂ ) of the average value (mθ ₂ ) may be 0.6° or more and less than 0.9°. When the radius of curvature R of the curved liquid crystal display 500C is 2000 mm or more and 5000 mm or less, the _{average value (mθ 1 ) of the first pre-tilt angle (θ 1} ) and the average value (mθ) of the second pre-tilt angle (θ ₂ ) ₂ ) collision between the alignment directions of the first liquid crystal molecules LC1 and the second liquid crystal molecules LC2-1 and LC2-2 within a range where the difference (mθ ₁ - mθ _{2 ) is 0.6° or more and less than 0.9°} The occurrence of dark areas or stains due to this may be improved.

In one example, in an initial state in which no electric field is applied to the curved liquid crystal display 500C, the second curved liquid crystal alignment layer AL2C may include second liquid crystal molecules in the first region R1 and the second region R2, respectively. While at least two or more domains having different alignment directions of LC2-1 and LC2-2 may be formed, the first curved liquid crystal alignment layer AL1C has a first region R1 and a second region R2. Each of the first liquid crystal molecules LC1 may form one domain having substantially the same alignment direction.

The first region R1 and the second region R2 are centered on an imaginary straight line C-C′ passing through the peak of the first curved substrate 100C and the vertex of the second curved substrate 200C. means the left area and the right area, respectively. A vertex is any point on the curve where the slope of the tangent at that point is substantially zero.

Referring to FIG. 3 , in the second curved liquid crystal alignment layer AL2C, in the first region R1 , the 2-1 th liquid crystal molecules LC2-1 may be aligned in a first oblique direction, and the 2-2 The liquid crystal molecules LC2 - 2 may be aligned in the second oblique direction. The second curved liquid crystal alignment layer AL2C may include at least one in which the alignment direction of the second-first liquid crystal molecules LC2-1 and the alignment direction of the second-second liquid crystal molecules LC2-2 are different from each other in the first region R1. Two or more domains may be formed. The first inclination direction may be approximately −α° with respect to the imaginary straight line C-C′, and the second inclination direction may be approximately +α° with respect to the imaginary straight line C-C′. . α is a positive real number.

In the second curved liquid crystal alignment layer AL2C, in the second region R2 , the 2-1 th liquid crystal molecules LC2-1 may be aligned in the first oblique direction, and the 2-2 th liquid crystal molecules LC2-2 ) may be oriented in the second oblique direction. The second curved liquid crystal alignment layer AL2C may include at least one in which the alignment direction of the second-first liquid crystal molecules LC2-1 and the alignment direction of the second-second liquid crystal molecules LC2-2 are different from each other in the second region R2. Two or more domains may be formed.

Alternatively, the first curved liquid crystal alignment layer AL1C may form one domain in which the first liquid crystal molecules LC1 are aligned in the third oblique direction in the first region R1 and the second region In (R2), one domain in which the first liquid crystal molecules LC1 are aligned in the fourth oblique direction may be formed. For example, the third inclination direction may be approximately −β° with respect to the imaginary straight line C-C′, and the fourth inclination direction may be approximately +β° with respect to the imaginary straight line C-C′. can be direction. β is a positive real number.

As such, in each of the first region R1 and the second region R2, selectively only the second curved liquid crystal alignment layer AL2C among the first curved liquid crystal alignment layer AL1C and the second curved liquid crystal alignment layer AL2C By forming a plurality of domains having different alignment directions of liquid crystal molecules, spots or dark areas generated due to collision of alignment directions of the first liquid crystal molecules LC1 and the second liquid crystal molecules LC2-1 and LC2-2 are formed. generation can be improved.

Hereinafter, the surfaces of the first curved liquid crystal alignment layer AL1C and the second curved liquid crystal alignment layer AL2C will be described in detail with reference to FIGS. 4 to 7 . FIG. 4 is a photograph of the surface of the first curved liquid crystal alignment layer AL1C of FIG. 3 . FIG. 5 is a surface photograph of the second curved liquid crystal alignment layer AL2C of FIG. 3 .

4 and 5 , in the second curved liquid crystal alignment layer AL2C, the average number of protrusions protruding from one surface is greater than that of the first curved liquid crystal alignment layer AL1C. That is, the protrusions are more densely arranged in the second curved liquid crystal alignment layer AL2C than in the first curved liquid crystal alignment layer AL1C. The one surface is a surface facing the first curved liquid crystal alignment layer AL1C. The protrusions protrude from the one surface. At least two of the protrusions may be disposed in an island pattern spaced apart from each other by a predetermined distance. The protrusions are attached to the first liquid crystal molecules LC1 by fixing or stabilizing the director in a state in which the second liquid crystal molecules LC2-1 and LC2-2 are relatively obliquely aligned compared to the first liquid crystal molecules LC1. A relatively small pretilt angle may be provided to the second liquid crystal molecules LC2-1 and LC2-2.

6 is an analysis graph of an average value of surface roughness of the first curved liquid crystal alignment layer AL1C of FIG. 3 . 7 is an analysis graph of an average value of surface roughness of the second curved liquid crystal alignment layer AL2C of FIG. 3 .

6 and 7 , the average surface roughness of the second curved liquid crystal alignment layer AL2C is relatively higher than that of the first curved liquid crystal alignment layer AL1C. Specifically, the first curved liquid crystal alignment layer (AL1C) has an average surface roughness average value of 10.12 nm (A) and 12.15 nm (B), whereas the second curved liquid crystal alignment layer (AL2C) has an average surface roughness average value. The average values were measured to be 12.58 nm (C) and 12.38 nm (D). The average surface roughness was measured several times at different locations, and there were variations depending on the location, but the second curved liquid crystal alignment layer (AL2C) had a relatively large average surface roughness compared to the first curved liquid crystal alignment layer (AL1C). From the measurement result of the average surface roughness value, it can be expected that the first curved liquid crystal alignment layer AL1C and the second curved liquid crystal alignment layer AL2C may each have an average surface roughness value of less than about 15 nm.

In the first curved liquid crystal alignment layer AL1C, the average number of protrusions having a size of 25 nm or more and 35 nm or less may be greater than the average number of protrusions having a size of 45 nm or more and 55 nm or less. For example, in the first curved liquid crystal alignment layer (AL1C), the average number of protrusions having a size of 25 nm or more to 35 nm or less per unit area may be greater than the average number of protrusions having a size of 45 nm or more to 55 nm per unit area. . Also, in the first curved liquid crystal alignment layer AL1C, the average number of protrusions having a size of 25 nm or more to 35 nm or less per total area may be greater than the average number of protrusions having a size of 45 nm or more to 55 nm or less per total area.

The first curved liquid crystal alignment layer AL1C may have a lower mesogen content than the second curved liquid crystal alignment layer AL2C. In addition, the content of the polymerization initiator may be lower in the first curved liquid crystal alignment layer AL1C than in the second curved liquid crystal alignment layer AL2C.

For example, the first curved liquid crystal alignment layer (AL1C) includes an imide group (-CONHCO-) in the repeating unit of the main chain, an alkyl group in the side chain, a hydrocarbon derivative substituted with an alkyl group at the end, and a cycloalkyl group at the end It may be a vertically aligned liquid crystal alignment layer including a polyimide into which at least one vertical alignment group is introduced among hydrocarbon derivatives and hydrocarbon derivatives whose ends are substituted with aromatic hydrocarbons. The first curved liquid crystal alignment layer (AL1C) is different from the second curved liquid crystal alignment layer (AL2C) in that the polymerization initiator is not introduced into the side chain of the polyimide.

Meanwhile, the second curved liquid crystal alignment layer AL2C may have a multilayer structure including a 2-1 curved liquid crystal alignment layer AL2-1C and a 2-2 curved liquid crystal alignment layer AL2-2C. The 2-2 curved liquid crystal alignment layer AL2-2C may be protrusions protruding from the surface of the 2-1 curved liquid crystal alignment layer AL2-1C, and at least two of the protrusions are spaced apart from each other by a predetermined distance. It can be arranged in an island pattern.

For example, the 2-1 curved liquid crystal alignment layer (AL2-1C) includes an imide group (-CONHCO-) in the repeating unit of the main chain, and a polyimide in which the vertical alignment group and the polymerization initiator are introduced in the side chain. It may be a vertically aligned liquid crystal alignment layer. The second-second curved liquid crystal alignment layer AL2-2C may be a polymer of reactive mesogens.

The 2-1 curved liquid crystal alignment layer (AL2-1C) may have a higher content of imide groups than the 2-2 curved liquid crystal alignment layer (AL2-2C), and the 2-2 curved liquid crystal alignment layer (AL2-2C) ) may have a higher mesogen content than the 2-1 curved liquid crystal alignment layer AL2-1C.

For example, the polymerization initiator may be acetophenone, benzoin, benzophenone, diethoxy acetophenone, phenyletone, thioxanthone, 2-hydroxy-2-methyl-1-phenylpropane-1 -one, benzyl dimethyl tar, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy)-2-propyl ketone, 1-hydroxycyclohexylphenylketone, o-benzoyl methyl benzoate, 4-phenyl benzo Phenone, 4-benzoyl-4'-methyl-diphenyl sulfide, (4-benzoyl benzyl)trimethyl ammonium chloride, bis(2,4,6-trimethylbenzoyl)-phenyl phosphine oxide, diphenyl (2,4, 6-Trimethylbenzoyl)-phosphine oxide, 2-hydroxy methyl propionnitrile, 2,2'-{azobis(2-methyl-N-[1,1'-bis(hydroxymethyl)-2-hydro oxyethyl) propionamide], acrylic acid [(2-methoxy-2-phenyl-2-benzoyl)-ethyl] ester, phenyl 2-acryroyloxy-2-propyl ketone, phenyl 2-methacryroyloxy- 2-propyl ketone, 4-isopropylphenyl 2-acryroyloxy-2-propyl ketone, 4-chlorophenyl 2-acryroyloxy-2-propyl ketone, 4-dodecylphenyl 2-acryroyloxy- 2-propyl ketone, 4-methoxyphenyl 2-acryroyloxy-2-propyl ketone, 4-acryroyloxyphenyl 2-hydroxy-2-propyl ketone, 4-methacryroyloxyphenyl 2-hydr Roxy-2-propyl ketone, 4-(2-acryroyloxyethoxy)-phenyl 2-hydroxy-2-propyl ketone, 4-(2-acryroyloxydiethoxy)-phenyl 2-hydroxy- 2-Propyl ketone, 4-(2-acryroyloxyethoxy)-benzoin, 4-(2-acryroyloxyethylthio)-phenyl 2-hydroxy-2-propyl ketone, 4-N,N '-Bis-(2-acryroyloxyethyl)-aminophenyl 2-hydroxy-2-propyl ketone, 4-acryroyloxyphenyl 2-acryroyloxy-2-propyl ketone, 4-methacrylo Iloxyphenyl 2-methacryroyloxy-2-propyl ketone, 4-(2-acryroyloxyethoxy)-phenyl 2-acryroyloxy-2-propyl ketone, 4-(2-acryroylox) Cydiethoxy) -phenyl 2-acryroyloxy-2-propyl ketone, dibenzyl ketone (dibenzyl ke tone), benzoin alkyl ether, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, dialkyl acetophenone, hydride It may be one or more of hydroxyl alkylketone, phenyl glyoxylate, benzyl dimethyl ketal, acyl phosphine, and alpha-aminoketone. However, the present invention is not limited thereto.

Although not shown, in the 2-1 liquid crystal alignment layer (AL2-1C), the content of the polymerization initiator introduced into the first polyimide alignment layer (not shown) and the side chain is higher than that of the first polyimide alignment layer. It may have a multilayer structure including an alignment layer (not shown).

For example, the first polyimide alignment layer (not shown) may be a vertically aligned liquid crystal alignment layer including a polyimide in which the vertical alignment group is introduced into a side chain, and the second polyimide alignment layer (not shown) is a side chain It may be a vertically aligned liquid crystal alignment layer including a polyimide in which both the vertical alignment group and the polymerization initiator are introduced. The first polyimide alignment layer (not shown) is different from the second polyimide alignment layer (not shown) in that the polymerization initiator is not introduced into the side chain of the polyimide.

Meanwhile, at least one of the first curved liquid crystal alignment layer AL1C and the second curved liquid crystal alignment layer AL2C may include an ion scavenger. The ion scavenger may contain a cation scavenger or an anion scavenger.

Liquid crystal molecules are easily degraded by DC voltage and have dielectric anisotropy in which the dielectric constant of the liquid crystal layer varies depending on the alignment direction of the liquid crystal molecules, so an AC voltage is generally used to drive the liquid crystal display. The image signal voltage input to the source electrode of the thin film transistor is accumulated in the liquid crystal layer and the storage capacitor when the gate pulse voltage is applied. This accumulated voltage must be maintained until the next frame, but is discharged by a certain amount by a parasitic capacitor generated by the overlapping of the gate electrode and the source electrode.

The DC voltage is off-set by the discharged voltage (kickback voltage, level shift voltage) and applied to the liquid crystal layer. When a DC voltage is applied to the liquid crystal layer, impurities in the liquid crystal layer are ionized, and the ionic impurities generated thereby are laminated on the liquid crystal alignment layer. Ion impurities lower a voltage holding ratio (VHR) and cause an afterimage.

The ion trapping agent may trap ion impurities in the liquid crystal layer 300C to improve voltage retention of the curved liquid crystal display 500C. The ion scavenger is not particularly limited, but for example, alkyl amine, aryl amine, heterocyclic amine, aniline, p-toluidine, p-Anisidine, pyrrole, pyrazole, imidazole, indole, pyridine, pyridazine, pyrimidine, quinoline (quinoline), thiazole, piperidine, pyrrolidine, furan, thiophene, aldehyde, ketone, carboxylic acid acid), an acid chloride, an ester, or an amide, and may be one or more of a carbonyl compound.

Although not particularly limited, in one example, the second curved liquid crystal alignment layer (AL2C) may have a higher content of the ion scavenger than the first curved liquid crystal alignment layer (AL1C). In some cases, the ion scavenger may not be included in the first curved liquid crystal alignment layer AL1C.

Hereinafter, a method of manufacturing the curved liquid crystal display 500C according to an exemplary embodiment will be described with reference to FIGS. 8 to 13 . 8 to 13 are cross-sectional views schematically illustrating a method of manufacturing a curved liquid crystal display 500C according to an exemplary embodiment.

Referring to FIG. 8 , the first flat substrate 100 is disposed to face the second flat substrate 200 while maintaining a predetermined cell gap. For example, the second flat substrate 200 may be a thin film transistor substrate, and the first flat substrate 100 may be a color filter substrate as a substrate opposite to the second flat substrate 200 .

The common electrode 110 may be disposed on the first flat substrate 100 , and the first flat panel liquid crystal alignment layer AL1 may be disposed on the common electrode 110 . The common electrode 110 includes indium tin oxide, indium zinc oxide, indium oxide, zinc oxide, tin oxide, gallium oxide, titanium oxide, aluminum, silver, platinum, chromium, molybdenum, tantalum, niobium, zinc, magnesium, and alloys thereof. or a laminated film thereof. The common electrode 110 may be a patternless electrode that does not have a slit pattern as described above.

The first flat liquid crystal alignment layer AL1 may be formed, for example, by coating and drying the first vertically aligned polyimide in which the vertical alignment group is introduced into the side chain on the common electrode 110 . In this case, the first vertically aligned polyimide may include an imide group (-CONHCO-) in the repeating unit of the main chain, and may have only the vertically aligned polyimide in the side chain. However, in some cases, the first vertically aligned polyimide may include an ion trapping agent introduced into the side chain. Since the vertical alignment group has been described above, a detailed description thereof will be omitted.

For example, the first vertically oriented polyimide may include a polymer compound represented by the following Chemical Formula (1). However, the present invention is not limited thereto. In the following formula (1), a, b, and c are each a natural number.

< Formula (1) >

The pixel electrode 291 may be disposed on the second flat substrate 200 , and the 2-1 flat liquid crystal alignment layer AL2 may be disposed on the pixel electrode 291 . The pixel electrode 291 includes indium tin oxide, indium zinc oxide, indium oxide, zinc oxide, tin oxide, gallium oxide, titanium oxide, aluminum, silver, platinum, chromium, molybdenum, tantalum, niobium, zinc, magnesium, and alloys thereof. or a laminated film thereof. As described above, the pixel electrode 291 may be a pattern electrode having a slit pattern, and a portion of the second flat substrate 200 may be exposed through the slit pattern of the pixel electrode 291 .

The 2-1 flat liquid crystal alignment layer AL2-1 may be formed by, for example, applying and drying a second vertically aligned polyimide having a vertical alignment group and a polymerization initiator in a side chain on the pixel electrode 291 and drying. can be formed. Unlike the first vertically aligned polyimide, the second vertically aligned polyimide includes a polymerization initiator. In some cases, the second vertically oriented polyimide may include an ion scavenger. Since the vertical alignment group and the polymerization initiator have been described above, a detailed description thereof will be omitted.

The 2-1 flat liquid crystal alignment layer (AL2-1) is a second polyimide alignment layer having a higher content of the polymerization initiator than the first polyimide alignment layer (not shown) and the first polyimide alignment layer (not shown). (not shown) may have a multi-layered structure including The first polyimide alignment layer (not shown) may be disposed between the pixel electrode 291 and the second polyimide alignment layer (not shown).

For example, the first polyimide alignment layer (not shown) may include a polymer compound represented by the following Chemical Formula (2). However, the present invention is not limited thereto. The second polyimide alignment layer (not shown) may include a polymer compound represented by the following Chemical Formula (3). However, the present invention is not limited thereto. In the following formulas (2) and (3), a, b, and c are each a natural number.

< Formula (2) >

< Formula (3) >

The polymerization initiator absorbs UV light and is easily decomposed into radicals to promote photopolymerization of reactive mesogen. For example, the polymerization initiator may absorb long-wavelength UV of about 300 nm to 400 nm and decompose into radicals to promote photopolymerization of reactive mesogen (RM).

Referring to FIG. 9 , the liquid crystal layer 300 is disposed between the first flat substrate 100 and the second flat substrate 200 that are disposed to face each other. The liquid crystal layer 300 is formed by injecting or dropping a liquid crystal composition including both liquid crystal molecules LC1 and LC2 and reactive mesogen RM between the first flat substrate 100 and the second flat substrate 200 . It can be formed through the process of

Each of the liquid crystal molecules LC1 and LC2 has negative dielectric anisotropy. The liquid crystal molecules LC1 and LC2 may be substantially vertically aligned with respect to the first flat panel substrate 100 and the second flat panel substrate 200 in an initial state in which no electric field is applied to the flat panel liquid crystal display 500 . In other words, each of the vertical aligners of the first flat panel liquid crystal alignment layer AL1 and the 2-1 flat liquid crystal alignment layer AL2-1 is an initial state in which no electric field is applied to the flat panel liquid crystal display 500 . The liquid crystal molecules LC1 and LC2 may be substantially vertically aligned with respect to the first and second planar substrates 100 and 200 . In this case, the substantially vertical alignment means that the liquid crystal molecules LC1 and LC2 are aligned within the range of 88° or more to less than 90° with respect to the first flat substrate 100 and the second flat substrate 200 . do. In an initial state in which no electric field is applied to the flat panel liquid crystal display 500 , the reactive liquid crystal monomer RM may be evenly dispersed in the liquid crystal layer 300 .

Referring to FIG. 10 , when an electric field is applied to the flat panel liquid crystal display 500 , the liquid crystal molecules LC1-1, LC1-2, LC2-1, LC2-2) may be oriented obliquely. The 1-1 liquid crystal molecules LC1-1 and the 2-1 liquid crystal molecules LC2-1 may be aligned in a first oblique direction, and the 1-2 liquid crystal molecules LC1-2 and 2-2 The liquid crystal molecules LC2 - 2 may be aligned in the second oblique direction. Thereafter, when the flat panel liquid crystal display 500 is irradiated with ultraviolet (UV) light, the polymerization initiator contained in the 2-1 flat liquid crystal alignment layer (AL2-1) initiates a photopolymerization reaction of the reactive mesogen (RM), thereby 2-2 A flat liquid crystal alignment layer (AL2-2) may be formed.

Referring to FIG. 11 , the reactive mesogen RM moves toward the 2-1 flat liquid crystal alignment layer AL2-1 to form a 2-2 flat liquid crystal alignment layer AL2-2. The 2-2 flat liquid crystal alignment layer AL2-2 may be a polymer of reactive liquid crystal monomers (RM). The 2-2 flat liquid crystal alignment layer AL2-2 may be formed on the 2-1 flat liquid crystal alignment layer AL2-1. As the 2-2 flat liquid crystal alignment layer AL2-2 is formed, the content of the reactive mesogen RM in the liquid crystal layer 300 is gradually reduced. It may be understood that the reduced reactive mesogen RM is used to form the 2-2 planar liquid crystal alignment layer AL2-2.

The 2-2 flat liquid crystal alignment layer AL2-2 may fix or stabilize the alignment directions of the 2-1 liquid crystal molecules LC2-1 and the 2-2 liquid crystal molecules LC2-2. Accordingly, the 2-1 liquid crystal molecules LC2-1 and the 2-2 liquid crystal molecules LC2-2 aligned on the surface of the 2-2 flat liquid crystal alignment layer AL2-2 are formed in the flat liquid crystal display 500 Even when the electric field applied to ) is released, the second pretilt angle θ ₂ may be maintained by memorizing the director. On the contrary, when the electric field applied to the flat liquid crystal display 500 is released, the first liquid crystal molecules LC1 are substantially vertically aligned as in an initial state in which no electric field is applied to the flat liquid crystal display 500 . _{In this case, the first pre-tilt angle θ 1} of the first liquid crystal molecules LC1 is the second _{pre-tilt angle θ 2} of the 2-1 and 2-2 liquid crystal molecules LC2-1 and LC2-2. larger than

12 and 13 , in a state where no electric field is applied to the flat panel liquid crystal display 500 , the remaining reactive mesogen (RM) may be removed by irradiating fluorescent UV to the flat panel liquid crystal display 500 . . Thereafter, a curved liquid crystal display device (500C of FIG. 3 ) may be manufactured through a bending process (B) of bending both ends of the flat panel liquid crystal display device 500 .

14 is a photo of a light transmission distribution of a curved liquid crystal display 500C according to an exemplary embodiment. 15 is a photo of light transmission distribution of the curved liquid crystal display according to Comparative Example 1;

In the curved liquid crystal display 500C, in the manufacturing process shown in FIG. 8 , a first flat liquid crystal alignment layer AL1 is formed on the common electrode 110 using a first vertically aligned polyimide, and a second vertical alignment layer AL1 is formed on the common electrode 110 . After forming the 2-1 flat liquid crystal alignment layer AL2-1 on the pixel electrode 291 using an alignment-type polyimide, according to the manufacturing process shown in FIGS. 9 to 13, reactive mesogen (RM) ) and liquid crystal molecules (LC) were injected to fabricate a flat liquid crystal display 500, and then, an electric field was applied and a bending process was performed.

In the curved liquid crystal display device according to the first comparative example, in the manufacturing process illustrated in FIG. 8 , both the first flat liquid crystal alignment layer AL1 and the 2-1 flat liquid crystal alignment layer AL2-1 are second vertically aligned After forming using a polyimide-type polyimide, a liquid crystal composition including both reactive mesogen (RM) and liquid crystal molecules (LC) is injected according to the manufacturing process shown in FIGS. 9 to 13 to inject a flat liquid crystal display 500 ) was fabricated, and then the electric field was applied and the bending process (B) was performed.

Referring to FIGS. 14 and 15 , unlike the curved liquid crystal display 500C, the curved liquid crystal display according to Comparative Example 1 has a texture generated due to the collision of the alignment directions between the first liquid crystal molecules and the second liquid crystal molecules. was recognized as a dark part (indicated by a dotted line).

16 is a photograph of the surface of the first curved liquid crystal alignment layer of the curved liquid crystal display according to the first comparative example, and FIG. 17 is a photograph of the surface of the second curved liquid crystal alignment layer of the curved liquid crystal display according to the first comparative example. 16 and 17 , it can be seen that the number of protrusions per unit area of the first curved liquid crystal alignment layer and the second curved liquid crystal alignment layer is substantially the same. On the other hand, referring to FIGS. 4 and 5 , in the case of the embodiment of the curved liquid crystal display 500C, the average number of protrusions per unit area of the second curved liquid crystal alignment layer AL2C is the first curved liquid crystal alignment layer AL1C. It can be seen that the number of projections per unit area is relatively large compared to the average number of protrusions per unit area.

18 is a photo of a light transmission distribution of a curved liquid crystal display according to Comparative Example 2; In the curved liquid crystal display device according to the second comparative example, in the process step of FIG. 8 , both the first flat liquid crystal alignment layer (AL1) and the 2-1 flat liquid crystal alignment layer (AL2-1) are first vertically aligned polyi After forming using the mid, a liquid crystal composition containing both reactive mesogen (RM) and liquid crystal molecules (LC) is injected according to the manufacturing process shown in FIGS. 9 to 13 to prepare a flat liquid crystal display 500 . After fabrication, it was fabricated through an electric field application and bending process (B).

Referring to FIG. 18 , in the curved liquid crystal display according to Comparative Example 2, the texture generated due to the collision of the alignment directions of the first liquid crystal molecules and the second liquid crystal molecules was recognized as a dark portion (indicated by a dotted line).

19 is a result of measuring the voltage retention ratio (VHR) using the curved liquid crystal display 500C according to an exemplary embodiment. 20 is a result of measuring the voltage retention ratio (VHR) using the curved liquid crystal display according to Comparative Example 3; 19 and 20, A is the voltage retention ratio before UV exposure, B is the voltage retention ratio after UV exposure, and C is the voltage retention ratio after fluorescence UV.

Referring to FIGS. 19 and 20 , it can be confirmed that the voltage retention rate (VHR) of the curved liquid crystal display 500C containing the ion scavenger is improved compared to the curved liquid crystal display of Comparative Example 3 that does not contain the ion scavenger. there is.

In the manufacturing process illustrated in FIG. 8 , in the curved liquid crystal display 500C according to an exemplary embodiment, a first flat liquid crystal alignment layer AL1 is formed on the common electrode 110 using a first vertically aligned polyimide. and forming a 2-1 flat liquid crystal alignment layer (AL2-1) on the pixel electrode 291 using a second vertically aligned polyimide in which pyridine is introduced into the side chain as an ion trapping agent, According to the manufacturing process shown in FIGS. 9 to 13, a liquid crystal composition including both reactive mesogen (RM) and liquid crystal molecules (LC) is injected to fabricate a flat liquid crystal display 500, and then an electric field is applied and bent produced through the process.

In the curved liquid crystal display device according to Comparative Example 3, in the process step of FIG. 8 , both the first flat liquid crystal alignment layer (AL1) and the 2-1 flat liquid crystal alignment layer (AL2-1) are first vertically aligned polyi It was formed using a mid. At this time, in the first vertically aligned polyimide, no ion trapping agent was introduced into the side chain. Thereafter, according to the manufacturing process shown in FIGS. 9 to 13 , a liquid crystal composition including both reactive mesogen (RM) and liquid crystal molecules (LC) is injected to manufacture a flat liquid crystal display device 500 , and then an electric field It was fabricated through the application and bending process (B).

The results of measuring the voltage retention of the curved liquid crystal display 500C according to the embodiment and the curved liquid crystal display according to Comparative Example 3 are summarized in Tables 1 and 2 below.

unit: % Example Before exposure (A) After exposure (B) After fluorescence UV (C) minimum 98.9 99.0 97.4 maximum 99.2 99.1 97.8 medium 99.0 99.1 97.6 Standard Deviation 0.11 0.04 0.14 Number of samples (S/S) 8 8 8

unit: % 3rd comparative example Before exposure (A) After exposure (B) After fluorescence UV (C) minimum 92.4 94.4 88.2 maximum 93.5 95.1 88.8 medium 92.9 94.9 88.5 Standard Deviation 0.39 0.22 0.25 Number of samples (S/S) 8 8 8

The embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments and may be manufactured in various different forms, and those of ordinary skill in the art to which the present invention pertains. It will be understood by those skilled in the art that the present invention may be embodied in other specific forms without changing the technical spirit or essential features of the present invention. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

100C: first curved substrate 100: first flat substrate
200C: second curved substrate 200: second flat substrate
300, 300C: liquid crystal layer liquid crystal molecules: LC
First curved liquid crystal alignment layer: AL1C First flat liquid crystal alignment layer: AL1
Second curved liquid crystal alignment layer: AL2C
2-1 curved liquid crystal alignment layer: AL2-1C 2-2 curved liquid crystal alignment layer: AL2-2C
2-1 flat liquid crystal alignment layer: AL2-1 2-2 flat liquid crystal alignment layer: AL2-2
Reactive mesogen: RM

Claims (20)

a first curved substrate;
a second curved substrate;
a liquid crystal layer comprising liquid crystal molecules having negative dielectric anisotropy and disposed between the first curved substrate and the second curved substrate;
a first curved liquid crystal alignment layer disposed between the liquid crystal layer and the first curved substrate; and
one surface facing the first curved liquid crystal alignment layer and protrusions protruding from the one surface, the average number of projections per unit area is higher than that of the first curved liquid crystal alignment layer, and between the liquid crystal layer and the second curved substrate a second curved liquid crystal alignment layer disposed on the
The protrusions are arranged in an irregular island pattern. According to claim 1,
In the second curved liquid crystal alignment layer, an average number of protrusions having a size of 25 nm or more to 35 nm or less is larger than an average number of protrusions having a size of 45 nm or more to 55 nm or less in the second curved liquid crystal alignment layer. According to claim 1,
a patternless electrode disposed between the first curved substrate and the first curved liquid crystal alignment layer and having no slit pattern; and
a pattern electrode disposed between the second curved liquid crystal alignment layer and the second curved substrate and having a slit pattern;
A curved liquid crystal display further comprising a. According to claim 1,
The liquid crystal molecules having the negative dielectric anisotropy include a first liquid crystal molecule and a second liquid crystal molecule having a smaller pretilt angle than the first liquid crystal molecule. 5. The method of claim 4,
The difference between the first diameter of the liquid crystal molecules square (θ ₁₎ an average value (mθ ₁₎ and the average value (mθ ₂₎ of the pretilt angle (θ ₂₎ of the second liquid crystal molecules in the (mθ ₁ - mθ ₂₎ is more than 0.6 ° to 0.9 ° or less of a curved liquid crystal display. 6. The method of claim 5,
A curved liquid crystal display having a radius of curvature (R) of 2000 mm or more and 5000 mm or less. According to claim 1,
The second curved liquid crystal alignment layer has a larger average surface roughness than the first curved liquid crystal alignment layer. According to claim 1,
The second curved liquid crystal alignment layer has a higher content of mesogen than the first curved liquid crystal alignment layer. According to claim 1,
The second curved liquid crystal alignment layer has a multilayer structure including a 2-1 curved liquid crystal alignment layer and a 2-2 curved liquid crystal alignment layer,
The 2-1 curved liquid crystal alignment layer has a higher content of imide groups (-CONHCO-) than the 2-2 curved liquid crystal alignment layer,
The 2-2 curved liquid crystal alignment layer has a higher mesogen content than the 2-1 curved liquid crystal alignment layer. 10. The method of claim 9,
wherein the 2-1 curved liquid crystal alignment layer includes a first polyimide alignment layer and a second polyimide alignment layer having a higher content of the polymerization initiator introduced into the side chain than the first polyimide alignment layer. a first curved substrate;
a second curved substrate;
a liquid crystal layer comprising liquid crystal molecules having negative dielectric anisotropy and disposed between the first curved substrate and the second curved substrate;
a first curved liquid crystal alignment layer disposed between the liquid crystal layer and the first curved substrate; and
a second curved liquid crystal alignment layer having a higher average surface roughness than the first curved liquid crystal alignment layer and disposed between the liquid crystal layer and the second curved substrate;
including,
The first curved liquid crystal alignment layer includes protrusions protruding from one surface facing the second curved liquid crystal alignment layer, and the second curved liquid crystal alignment layer includes projections protruding from one surface facing the first curved liquid crystal alignment layer. including those,
The protrusions are arranged in an irregular island pattern. 12. The method of claim 11,
a patternless electrode disposed between the first curved substrate and the first curved liquid crystal alignment layer and having no slit pattern; and
a pattern electrode disposed between the second curved liquid crystal alignment layer and the second curved substrate and having a slit pattern;
A curved liquid crystal display further comprising a. 12. The method of claim 11,
The second curved liquid crystal alignment layer has a higher mesogen content than the first curved liquid crystal alignment layer. 12. The method of claim 11,
The liquid crystal molecules having the negative dielectric anisotropy include a first liquid crystal molecule and a second liquid crystal molecule having a smaller pretilt angle than the first liquid crystal molecule. 15. The method of claim 14,
The difference (mθ1 - mθ2) between the average value (mθ1) of the pre-tilt angle (θ1) of the first liquid crystal molecules and the average value (mθ2) of the pre-tilt angle (θ2) of the second liquid crystal molecules is 0.6° to 0.9°. display device. a first curved substrate;
a second curved substrate;
a first curved liquid crystal alignment layer disposed between the first curved substrate and the second curved substrate;
a second curved liquid crystal alignment layer disposed between the first curved liquid crystal alignment layer and the second curved substrate; and
The first liquid crystal molecules of negative dielectric anisotropy aligned on the surface of the first curved liquid crystal alignment layer and the first liquid crystal molecules of the second curved liquid crystal alignment layer are aligned on the surface of the curved liquid crystal alignment layer and are smaller than the first liquid crystal molecules in the initial state without applying an electric field. a liquid crystal layer comprising second liquid crystal molecules having negative dielectric anisotropy with a small pretilt angle and disposed between the first curved liquid crystal alignment layer and the second curved liquid crystal alignment layer;
including,
The first curved liquid crystal alignment layer includes protrusions protruding from one surface facing the second curved liquid crystal alignment layer, and the second curved liquid crystal alignment layer includes projections protruding from one surface facing the first curved liquid crystal alignment layer. including those,
The protrusions are arranged in an irregular island pattern. 17. The method of claim 16,
The difference between the first diameter of the liquid crystal molecules square (θ ₁₎ an average value (mθ ₁₎ and the average value (mθ ₂₎ of the pretilt angle (θ ₂₎ of the second liquid crystal molecules in the (mθ ₁ - mθ ₂₎ is more than 0.6 ° to 0.9 ° or less of a curved liquid crystal display. 17. The method of claim 16,
a patternless electrode disposed between the first curved substrate and the first curved liquid crystal alignment layer and having no slit pattern; and
a pattern electrode disposed between the second curved liquid crystal alignment layer and the second curved substrate and having a slit pattern;
A curved liquid crystal display further comprising a. 17. The method of claim 16,
The second curved liquid crystal alignment layer has a multilayer structure including a 2-1 curved liquid crystal alignment layer and a 2-2 curved liquid crystal alignment layer, and the 2-1 curved liquid crystal alignment layer is the 2-2 curved liquid crystal alignment layer. A curved liquid crystal display with a high content of imide groups (-CONHCO-) compared to the layer. 17. The method of claim 16,
The second curved liquid crystal alignment layer has a multilayer structure including a 2-1 curved liquid crystal alignment layer and a 2-2 curved liquid crystal alignment layer, and the 2-2 curved liquid crystal alignment layer is the 2-1 curved liquid crystal alignment layer. A curved liquid crystal display with a higher mesogen content than the layer.

Images