KR20160055679A - Curved liquid crystal display - Google Patents

Abstract

Provided is a curved liquid crystal display (LCD) device with improved light transmittance. The curved LCD device according to an embodiment comprises: a first curved substrate; a second curved substrate; a first curved liquid crystal alignment layer disposed between the first and the second curved substrates; a second curved liquid crystal alignment layer disposed between the first curved liquid crystal alignment layer and the second curved substrate; and a liquid crystal layer disposed between the first and the second curved liquid crystal alignment layers and including negative dielectric constant anisotropic liquid crystal molecules. The liquid crystal layer includes a first liquid crystal molecule aligned on the surface of the first curved liquid crystal alignment layer, and a second liquid crystal molecule aligned on the surface of the second curved liquid crystal alignment layer. The first liquid crystal molecule is perpendicularly aligned in an initial state in which an electric field is not applied in comparison with the second liquid crystal molecule, and the second liquid crystal molecule is slantingly aligned in the initial state in which the electric field is not applied in comparison with the first liquid crystal molecule.

Description

[0001] CURVED LIQUID CRYSTAL DISPLAY [0002]

The invention relates to a curved liquid crystal display device.

2. Description of the Related Art A liquid crystal display device is one of the most widely used flat panel display devices and includes two substrates having a field generating electrode such as a pixel electrode and a common electrode and a liquid crystal layer interposed therebetween.

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

A liquid crystal display device is used as a display device of a television receiver, and the size of the screen increases. As the size of the liquid crystal display device increases, the visual difference may increase depending on whether the viewer views the center of the screen or both sides of the screen.

In order to compensate for the visual difference, the liquid crystal display device may be formed into a concave or convex curved shape. The curved-surface liquid crystal display device may be a portrait type having a length longer than a horizontal length and being bent in a vertical direction on the basis of a viewer, a landscape type having a vertical length shorter than the horizontal length, Lt; / RTI >

SUMMARY OF THE INVENTION An object of the present invention is to provide a curved surface liquid crystal display device with improved light transmittance.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide an apparatus and method for controlling the same.

A curved liquid crystal display according to an embodiment of the present invention 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 a second curved liquid crystal alignment layer disposed between the first curved liquid crystal alignment layer and the second curved substrate, and a second curved liquid crystal alignment layer disposed between the first curved liquid crystal alignment layer and the second curved substrate and having a negative dielectric anisotropy, Wherein the liquid crystal layer comprises a first liquid crystal molecule oriented on a surface of the first curved liquid crystal alignment layer and a second liquid crystal molecule oriented on a surface of the second curved liquid crystal alignment layer, The first liquid crystal molecules are vertically aligned relative to the second liquid crystal molecules and the second liquid crystal molecules are tilted relative to the first liquid crystal molecules.

The curved surface liquid crystal display device according to an embodiment includes a first curved substrate, a second curved substrate, a liquid crystal layer 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 disposed between the liquid crystal layer and the second curved substrate with a higher content of a polymerization initiator than the first curved liquid crystal alignment layer And a second curved liquid crystal alignment layer.

The second curved liquid crystal alignment layer has a higher average content of reactive mesogen polymers per unit area than the first curved liquid crystal alignment layer.

The second curved liquid crystal alignment layer includes a second-2 curved liquid crystal alignment layer having a lower content of an imide group (-CONHCO-) than the second-first curved liquid crystal alignment layer and the second-1 curved liquid crystal alignment layer Lt; / RTI >

The second -2 curved liquid crystal alignment layer may have a higher content of polymers of the reactive mesogens than the second 2-1 curved liquid crystal alignment layer.

Wherein the curved liquid crystal display comprises a patternless electrode disposed between the first curved substrate and the first curved liquid crystal alignment layer and having no slit pattern and a second patterned liquid crystal alignment layer between the second curved liquid crystal alignment layer and the second curved substrate, And a pattern electrode having a slit pattern disposed therebetween.

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

The curved liquid crystal display device according to the embodiments of the present invention can improve the light transmittance.

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

1 is a schematic exploded perspective view of a curved-surface liquid crystal display device according to an embodiment.
2 is a schematic enlarged view of region II of Fig.
3 is a schematic cross-sectional view taken along line III-III 'of FIG.
FIGS. 4 to 9 are cross-sectional views schematically showing a method of manufacturing a curved-surface liquid crystal display device according to an embodiment.
FIG. 10 is a graph showing a measured angle of the front-side mirror with respect to the flat panel liquid crystal display device of FIG.
11 is a light transmittance distribution image of a curved liquid crystal display device according to an embodiment.
12 is a light transmittance distribution image of a curved-surface liquid crystal display device according to the first comparative example.
13 is a light transmittance distribution image of a curved liquid crystal display device according to a second comparative example.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the invention, and the manner of achieving them, will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings.

It will be understood by those of ordinary skill in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. And the invention is only defined by the scope of the claims.

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

The dimensions and relative sizes of layers and regions in the figures may be exaggerated for clarity of illustration.

It is to be understood that when an element or layer is referred to as being "on" or " on "of another element or layer, All included.

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

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

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

1 and 2, a curved-surface liquid crystal display 500C according to an embodiment includes a first curved substrate 100C, a second curved substrate 200C facing away from the first curved substrate 100C, 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 include a display area DAC and a non-display area NDAC, respectively. The display area DAC is an area where an image is viewed, and the non-display area NDAC is an area where an image is not visible. 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 a negative dielectric constant 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 the first direction and a plurality of data lines DLC extending in the second direction perpendicular to the first direction are formed in the display area DAC of the second curved substrate 200C . The pixel electrode 291C may be disposed for 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 spaced from each other. For example, each of the sub-pixel electrodes 291-1C and 291-2C may have a rectangular shape as a whole. Each of the sub-pixel electrodes 291-1C and 291-2C may be a pattern electrode having a slit pattern. Specifically, the slit pattern may be composed of a cut-out portion DC disposed between the stem portion SC and the branch portion BC extending from the stem portion SC. The stem portion SC may be formed in the shape of a cross and the branch portion BC may extend radially in the direction of about 45 from the stem portion SC of the plus shape.

The gate line GLC may include gate electrodes 224-1C and 224-2C protruding in the second direction from the gate line GLC 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 and be formed in a "U" shape. The drain electrodes 2751-C and 275-2C may be spaced apart from the source electrodes 273-1C and 273-2C.

The pixel electrode 291C can receive the data voltage through the thin film transistor which is the switching element. The gate electrodes 224-1C and 224-2C which are the control terminals of the thin film transistor can be electrically connected to the gate line GLC and the source electrodes 273-1C and 273-2C, The drain electrodes 275-1C and 275-2C which are output terminals may be electrically connected to the data line DLC through the pixel electrodes 285-1C, 285-2C, 285-3C, and 285-4C, 291C. ≪ / RTI >

The pixel electrode 291C can 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 can control the alignment direction of the first liquid crystal molecules LC1 and the second liquid crystal molecules LC2 by distorting the electric field.

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), an ohmic contact layer (Not shown), a source electrode (not shown), source electrodes 273-1C and 273-2C, drain electrodes 275-1C and 275-2C, a passivation film .

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 the drain electrodes 275-1C and 275-2C may be spaced apart from each other by a semiconductor layer (not shown).

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

The non-display area NDAC may be a light shielding area surrounding the display area DAC as a peripheral part of the display area DAC. A driving unit (not shown) for providing a gate driving signal, a data driving signal, and the like 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 and be electrically connected to a driver (not shown).

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

A color filter layer (not shown) may be formed in an area corresponding to each pixel PXC in the display area DAC and a red color filter R, a green color filter G, and a blue color filter B . The color filter layer (not shown) may be included in either the first curved substrate 100C or 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 be stacked. The overcoat layer (not shown) may be a planarization layer covering a color filter layer (not shown). In this case, the common electrode 110C may be disposed on the overcoat layer (not shown).

For example, when the second curved substrate 200C includes a color filter layer (not shown), the second curved substrate 200C includes a color filter (not shown) for forming a color filter on a transparent insulating substrate on which the TFT is formed And may have a color filter on array (COA) structure. For example, the color filter layer (not shown) may include a passivation film (not shown) covering the source electrodes 273-1C and 273-2C and the drain electrodes 275-1C and 275-2C and an organic film (not shown) As shown in FIG.

A light shielding pattern layer (not shown) may be disposed at the boundary of each of the color filters R, G, and B. The light shielding 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 shielding pattern layer (not shown) may be a black matrix.

During the manufacture of the curved liquid crystal display 500C, due to the stress applied to the first and second flat substrates in the process of bending the flat panel liquid crystal display device, a gap between the first and second curved substrates 100C and 200C Misalignment may occur. For example, in the process of bending the flat panel liquid crystal display, the first curved substrate 100C may be shifted left or right with respect to the second curved substrate 200C. In this case, the arrangement state between the first curved substrate 100C and the second curved substrate 200C may be different from the 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 degrade 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 orientations of the directors of liquid crystal molecules, the first curved liquid crystal alignment layer AL1C ) And the boundaries of the domains of the second curved liquid crystal alignment layer (AL2C) are aligned in such a manner that the first liquid crystal molecules oriented in an oblique direction on the surface of the first curved liquid crystal alignment layer (AL1C) And may cause interference or collision in the alignment direction between the second liquid crystal molecules that are obliquely oriented on the surface of the second curved liquid crystal alignment layer (AL2C), so that the liquid crystal molecules between the first and second liquid crystal molecules The textures can be formed in a substantially vertical orientation. The texture may be visible in the display area DAC of the curved-surface liquid crystal display device 500C with a smudge or dark portion, and the curved-surface liquid crystal display 500C may have a decreased light transmittance.

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

3, the first liquid crystal molecules LC1 are liquid crystal molecules aligned on the surface of the first curved liquid crystal alignment layer AL1C and the second liquid crystal molecules LC2-1 and LC2-2 are aligned on the second liquid crystal alignment layer AL1C. And liquid crystal molecules aligned on the surface of the curved liquid crystal alignment layer (AL2C). The first liquid crystal molecules LC1 are vertically oriented relative to the second liquid crystal molecules LC2-1 and LC2-2 and the second liquid crystal molecules LC2-1 and LC2-2 are aligned vertically relative to the first liquid crystal molecules LC2-1 and LC2-2. 0.0 > LC1. ≪ / RTI > In other words, the first liquid crystal molecules LC1 are larger in square angles than the second liquid crystal molecules LC2-1 and LC2-2, and the second liquid crystal molecules LC2-1 and LC2-2 are larger in the first Is smaller than that of the liquid crystal molecules LC1.

The angle of incidence of the liquid crystals at the apex of the curved substrates 100C and 200C as an angle between the curved substrates 100C and 200C and the directors of the liquid crystal molecules LC1, LC2-1 and LC2-2, The pretilt angles of the molecules LC1, LC2-1, LC2-2 are substantially equal to the pretilt angles of the liquid crystal molecules LC1, LC2-1, LC2-2 on the flat substrate. For example, the curvature radius R of the curved-surface liquid crystal display 500C may be 2000 mm or more and 5000 mm or less. At this time, the liquid crystal molecules LC1 , LC2-1, LC2-2 are substantially equal to the square of the liquid crystal molecules LC1, LC2-1, LC2-2 in the flat substrate. A vertex is an arbitrary point on a curve, which means that the slope of the tangent at that point is substantially zero.

The pretilt angle of the liquid crystal molecules LC1, LC2-1, LC2-2 can be adjusted by adjusting the concentration of reactive mesogens, the concentration of the polymerization initiator, the voltage and the light irradiation amount, and the polymer of the reactive mesogens The liquid crystal molecules LC1, LC2-1, and LC2-2 can be oriented in an oblique direction, and the higher the concentration of the polymerization initiator, the more the polymers of the reactive mesogens can be formed.

The first liquid crystal molecules LC1 aligned on the surface of the first curved liquid crystal aligning layer AL1C and the second liquid crystal molecules LC2-1 and LC2-2 oriented on the surfaces of the second curved liquid crystal alignment layer AL2C ) Is due to the difference in the content of polymers of reactive mesogens.

The first curved liquid crystal alignment layer (AL1C) has a lower content of polymers of reactive mesogens relative to the second curved liquid crystal alignment layer (AL2C). In other words, the second curved liquid crystal alignment layer (AL2C) has a higher content of polymers of reactive mesogens than the first curved liquid crystal alignment layer (AL1C).

The reactive mesogen is a compound having a mesogen structure for expressing liquid crystallinity and a polymerizable terminal group for polymerizing, and can be represented, for example, by the following formula (1).

P1-SP1-MG-SP2-P2 (Formula 1)

In the above formula (1), P1 and P2 are polymerizable terminal groups, and examples thereof include a (meth) acrylate group, a vinyl group, a vinyloxy group, an epoxy group epoxy group, etc., and SP1 is a spacer group connecting P1 and MG, and may be, for example, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, etc. SP2 May be, for example, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and the like, and MG is a mesogen structure, for example, For example, it may be cyclohexyl, biphenyl, terphenly, naphthalene, and the like.

On the other hand, the polymerization initiator serves to initiate the polymerization of the reactive mesogens, and the higher the concentration of the polymerization initiator, the more the polymers of the reactive mesogens can be formed. The content of the polymerization initiator may be higher in the second curved liquid crystal alignment layer (AL2C) than in the first curved liquid crystal alignment layer (AL1C). That is, 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). Therefore, the second curved liquid crystal alignment layer (AL2C) may have a higher content of polymers of reactive mesogens than the first curved liquid crystal orientation layer (AL1C).

Accordingly, the second liquid crystal molecules LC2-1 and LC2-2 oriented on the surface of the second curved liquid crystal aligning layer AL2C are aligned with the first liquid crystal molecules aligned on the surface of the first curved liquid crystal alignment layer AL1C And the first liquid crystal molecules LC1 oriented on the surface of the first curved liquid crystal alignment layer AL1C can be oriented obliquely relative to the surface LC2 of the second curved liquid crystal alignment layer AL2C, Can be vertically oriented relative to the second liquid crystal molecules (LC2-1, LC2-2).

The curved-surface liquid crystal display 500C has a structure in which the first liquid crystal molecules LC1 and the second liquid crystal molecules LC2-1 and LC2-2 are different in the angle of incidence of the first liquid crystal molecules LC1 and LC2-2, It is possible to improve the generation of stains or dark portions caused by collision of the alignment directions of the liquid crystal molecules LC2-1 and LC2-2.

The first curved liquid crystal aligning layer AL1C may be formed by, for example, repeating units having an imide group (-CONHCO-) in the repeating unit of the main chain, a hydrocarbon derivative in which an alkyl group is substituted on the side chain and an alkyl group is substituted on the side chain, And a polyimide in which at least one of a hydrocarbon derivative having a terminal end substituted with an aromatic hydrocarbon and a vertical orienting agent is introduced, may be a vertically aligned liquid crystal alignment layer.

The second curved liquid crystal alignment layer AL2C may be a multilayer structure including, for example, a 2-1 curved liquid crystal alignment layer (AL2-1C) and a 2-2 curved liquid crystal alignment layer (AL2-2C) Unlike the first curved liquid crystal alignment layer (AL1C), it may contain a polymerization initiator. For example, the 2-1-round curved liquid crystal alignment layer (AL2-1C) includes a polyimide containing an imide group (-CONHCO-) in the repeating unit of the main chain and having the vertical aligner and the polymerization initiator introduced into the side chain , And the second 2-2 curved liquid crystal alignment layer (AL2-2C) may be a vertically aligned liquid crystal alignment layer which is partially reactive with the reactive mesogens disposed partially on the surface of the 2-1 curved liquid crystal alignment layer (AL2-1C) mesogens. < / RTI > The polymers of the reactive mesogens may be spaced apart from each other on the surface of the second-first-curved liquid crystal alignment layer (AL2-1C) at predetermined intervals.

For example, the polymerization initiator may be selected from the group consisting of acetophenone, benzoin, benzophenone, diethoxyacetophenone, phenyletone, thioxanthone, 2-hydroxy- Benzyl dimethyl ketone, methyl o-benzoyl benzoate, 4-phenylbenzophenone, 2-hydroxybenzoic acid, , (4-benzoylbenzyl) trimethylammonium chloride, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, diphenyl (2,4,6 - (trimethylbenzoyl) -phosphine oxide, 2-hydroxymethylpropionone nitrile, 2,2 '- {azobis (2-methyl- N- [1,1'-bis (hydroxymethyl) -2- Ethyl) propionamide], acrylic acid [(2-methoxy-2-phenyl-2-benzoyl) -ethyl] ester, phenyl 2-acryloyloxy- -Propyl ketone, 4-isopropylphenyl-2-acrylo Oxy-2-propyl ketone, 4-chlorophenyl 2-acryloyloxy-2-propyl ketone, 4-dodecylphenyl 2-acryloyloxy- 2-propyl ketone, 4-acryloyloxyphenyl 2-hydroxy-2-propyl ketone, 4-methacryloyloxyphenyl 2-hydroxy- Hydroxy-2-propyl ketone, 4- (2-acryloyloxydiethoxy) -phenyl 2-hydroxy-2-propyl ketone, 4- Hydroxy-2-propyl ketone, 4-N, N'-bis- (2-acryloyloxyethyl) -amino Acryloyloxyphenyl 2-acryloyloxy-2-propyl ketone, 4-methacryloyloxyphenyl 2-methacryloyloxy-2-propyl ketone, , 4- (2-acryloyloxyethoxy) -phenyl 2-acryloyloxy-2-propyl 2-acryloyloxy-2-propyl ketone, dibenzyl ketone, benzoin alkyl ether, benzoin methyl ether, benzoin methyl ether, Benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, dialkyl acetophenone, hydroxyl alkylketone, phenyl glyoxylate, Benzyl dimethyl ketal, acyl phosphine, alpha-aminoketone, and the like. However, the present invention is not limited thereto.

3, 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 is arranged in the first region R1 and the second region R2, The first curved liquid crystal alignment layer AL1C may form at least two domains in which the alignment directions of the liquid crystal molecules LC2-1 and LC2-2 are different from each other, The first liquid crystal molecules LC1 may form one domain substantially the same in the alignment direction of the first liquid crystal molecules LC1. The first region R1 and the second region R2 are formed around an imaginary straight line C-C 'passing the apex of the first curved substrate 100C and the apex of the second curved substrate 200C The left region and the right region, respectively.

In the first region R1 and the second region R2, the second-1 liquid crystal molecule LC2-1 may be oriented in the first oblique direction, and the second-2 liquid crystal molecules LC2-2 may be oriented in the first oblique direction, 2 direction, and the second curved liquid crystal alignment layer AL2C may be oriented in a direction in which the alignment direction of the second-first liquid crystal molecule LC2-1 is different from the alignment direction of the second-second liquid crystal molecule LC2-2 At least two domains can be formed. The first oblique direction may be approximately -? Direction with respect to the virtual straight line C-C ', and the second oblique direction may be approximately +? Direction with respect to the imaginary straight line C-C' . α is a positive real number.

In the first region R1, the first liquid crystal molecules LC1 can form one domain oriented in the third oblique direction, and in the second region R2, the first liquid crystal molecules LC1 can form one domain, One domain oriented in the fourth oblique direction can be formed. For example, the third oblique direction may be approximately -? Direction with respect to the imaginary straight line C-C ', and the fourth oblique direction may be approximately + beta ° with respect to the imaginary straight line C-C' Direction. β is a positive real number.

The curved-surface liquid crystal display 500C has a second curved liquid crystal alignment (first curved liquid crystal alignment layer) among the first curved liquid crystal alignment layer AL1C and the second curved liquid crystal alignment layer AL2C in the first region R1 and the second region R2, The first liquid crystal molecules LC1 and the second liquid crystal molecules LC2-1 and LC2-2 are aligned in the direction of alignment of the first liquid crystal molecules LC2-1 and LC2-2 by selectively forming a plurality of domains having different orientations of liquid crystal molecules selectively only in the layer AL2C. It is possible to improve the occurrence of stains or dark portions caused by the above-mentioned problems.

Hereinafter, a method of manufacturing the curved-surface liquid crystal display 500C according to one embodiment will be described with reference to FIGS. 4 to 9 are cross-sectional views schematically showing a method of manufacturing the curved-surface liquid crystal display 500C according to one embodiment.

Referring to FIG. 4, the first flat substrate 100 is disposed opposite to the second flat substrate 200 while maintaining a predetermined cell gap. For example, the second flat panel substrate 200 may be a thin film transistor substrate, and the first flat panel substrate 100 may be a color filter substrate as an opposite substrate of the second flat panel substrate 200.

The common electrode 110 may be disposed on the first flat panel substrate 100 and the first flat panel liquid crystal alignment layer AL1 may be disposed on the common electrode 110. The common electrode 110 may be formed of any one of indium tin oxide, indium zinc oxide, indium oxide, zinc oxide, tin oxide, gallium oxide, titanium oxide, aluminum, silver, platinum, chromium, molybdenum, tantalum, niobium, zinc, Or a laminated film thereof. The common electrode 110 may be a patternless electrode having no slit pattern as described above.

The first flat panel liquid crystal alignment layer (AL1) may be formed, for example, by applying and drying a first vertically oriented polyimide having a vertical orientation unit introduced into its side chain onto the common electrode (110). At this time, the first vertically oriented polyimide may include an imide group (-CONHCO-) in the repeating unit of the main chain, and may have only a vertical alignment unit in the side chain. Since the vertical aligner 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 formula (2). However, it is not limited to this. In formula (2), a, b and c are each a natural number.

(화학식 2)

(2)

The pixel electrode 291 may be disposed on the second flat panel substrate 200 and the second-1 flat panel liquid crystal alignment layer AL2-1 may be disposed on the pixel electrode 291. [

The pixel electrode 291 may be formed of any one of indium tin oxide, indium zinc oxide, indium oxide, zinc oxide, tin oxide, gallium oxide, titanium oxide, aluminum, silver, platinum, chromium, molybdenum, tantalum, niobium, zinc, Or a laminated film thereof. As described above, the pixel electrode 291 may be a pattern electrode having a slit pattern, and a part of the second flat substrate 200 may be exposed through the slit pattern of the pixel electrode 291.

The 2-1 flat panel liquid crystal alignment layer (AL2-1) can be obtained by, for example, a step of forming a composite liquid crystal aligning agent containing a second vertically oriented polyimide and a reactive mesogen (RM) having a vertical orienting unit and a polymerization initiator in the side chain And may be formed on the pixel electrode 291 through a process of coating and drying. The second vertical alignment type polyimide includes a polymerization initiator unlike the first vertical alignment type polyimide. Since the vertical aligner and the polymerization initiator have been described above, a detailed description thereof will be omitted.

For example, the (2-1) flat panel liquid crystal alignment layer (AL2-1) may include a polymer compound represented by the following formula (3). However, it is not limited to this. In Formula 3, a, b, and c are each a natural number.

(화학식 3)

(Formula 3)

The polymerization initiator can easily decompose into radicals by absorbing UV to promote the photopolymerization reaction of the reactive mesogen. For example, the polymerization initiator may decompose into radicals by absorbing long wavelength UV of about 300 nm to 400 nm to promote the photopolymerization reaction of the reactive mesogen (RM).

Referring to FIG. 5, the liquid crystal layer 300 is disposed between the first flat substrate 100 and the second flat substrate 200 arranged opposite to each other. The liquid crystal layer 300 may be formed by injecting or dropping a liquid crystal composition containing liquid crystal molecules LC1 and LC2 between the first and second flat panel substrates 100 and 200 .

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 and second flat panel substrates 100 and 200 in an initial state in which no electric field is applied to the flat panel liquid crystal display device 500. [ In other words, the respective vertical aligners of the first flat panel liquid crystal alignment layer (AL1) and the second-1 flat panel liquid crystal alignment layer (AL2-1) are arranged in the initial state in which no electric field is applied to the flat panel liquid crystal display device The molecules LC1 and LC2 can be substantially vertically aligned with respect to the first flat substrate 100 and the second flat substrate 200. [ The liquid crystal molecules LC1 and LC2 are oriented substantially perpendicular to the first and second flat substrate 100 and 200 so that the liquid crystal molecules LC1 and LC2 are aligned with the first and second flat substrates 100 and 200, To < RTI ID = 0.0 > 90 < / RTI >

After the liquid crystal layer 300 is formed, a heat treatment (H) for applying heat at the lower portion of the first flat display substrate 100 is performed.

Referring to FIG. 6, the reactive mesogen RM contained in the second-1 plate liquid crystal alignment layer AL2-1 can be eluted into the liquid crystal layer 300 through heat treatment (H in FIG. 5). The second-1 flat panel liquid crystal alignment layer (AL2-1) of FIG. 6 has a lower content of reactive mesogen (RM) than the second-1 flat panel liquid crystal alignment layer (AL2-1) of FIG. In addition, the liquid crystal layer 300 of FIG. 6 differs from the liquid crystal layer 300 of FIG. 5 in that it contains a reactive mesogen (RM).

The liquid crystal molecules LC1-1, LC1-2, LC2-1, LC2-1, LC2-1, LC2-1, LC2-2, LC2-1, LC2-2 and LC2-2 are formed in a direction perpendicular to the electric field formed between the common electrode 110 and the pixel electrode 291, when an electric field is applied to the flat panel liquid crystal display device 500. [ 2) can be tilted. The first liquid crystal molecule LC1-1 and the second liquid crystal molecule LC2-1 can be oriented in the first oblique direction and the first liquid crystal molecule LC1-2 and the second liquid crystal molecule LC2-1 can be aligned in the first oblique direction, The liquid crystal molecules LC2-2 can be oriented in the second oblique direction. When the UV light is irradiated to the flat panel liquid crystal display 500, the polymerization initiator contained in the second-first-layer liquid crystal aligning layer AL2-1 initiates a photopolymerization reaction of the reactive mesogens RM And a 2-2 flat panel liquid crystal alignment layer (AL2-2) can be formed.

Referring to FIG. 7, the reactive mesogens (RM) selectively move to the side of the second-1 nd flat liquid crystal alignment layer (AL2-1) containing the polymerization initiator, The second-2 < nd > flat panel liquid crystal alignment layer (AL2-2) can be formed. As the 2-2 flat panel liquid crystal alignment layer (AL2-2) is formed, the content of reactive mesogens (RM) in the liquid crystal layer 300 gradually decreases. It can be understood that the reduced reactive mesogens (RM) are used to form the 2-2-plane liquid crystal alignment layer (AL2-2).

(2-2) The flat panel liquid crystal alignment layer (AL2-2) may include polymers of reactive mesogens partially disposed on the surface of the (2-1) plane liquid crystal alignment layer (AL2-1). The polymers of the reactive mesogens may be spaced apart from each other on the surface of the second-1 < RTI ID = 0.0 > 1 < / RTI >

The more the polymers of reactive mesogens are formed, the more liquid molecules can be tilted. The 2-2 flat panel liquid crystal alignment layer (AL2-2) can fix or stabilize the alignment directions of the 2-1 liquid crystal molecules (LC2-1) and the 2-2 liquid crystal molecules (LC2-2). Thus, the 2-1 liquid crystal molecules LC2-1 and the 2-2 liquid crystal molecules LC2-2 oriented on the surface of the 2-2th flat panel liquid crystal alignment layer (AL2-2) are placed on the flat liquid crystal display device 500 ) Is released, the oblique orientation can be maintained as it is.

In contrast, when the electric field applied to the flat panel liquid crystal display device 500 is released, the first liquid crystal molecules LC1 are aligned in the same manner as in the initial state in which no electric field is applied to the flat panel liquid crystal display device 500, ) And the second flat substrate 200, respectively. That is, the first liquid crystal molecules LC1 can be vertically aligned relative to the second-1 liquid crystal molecules LC2-1 and the second-2 liquid crystal molecules LC2-2, The liquid crystal molecules LC2-1 and the second -2 liquid crystal molecules LC2-2 can be tilted relative to the first liquid crystal molecules LC1.

8 and 9, fluorescence UV is irradiated to the flat panel liquid crystal display device 500 without applying an electric field to the flat panel liquid crystal display device 500 to remove residual reactive mesogens RM Can be removed. Thereafter, a curved surface liquid crystal display device (500C in Fig. 3) can be manufactured through the bending step (B) of bending both ends of the flat panel liquid crystal display device 500. [

FIG. 10 is a graph showing the measurement of the square of the angle of view with respect to the flat panel liquid crystal display device (500 of FIG. 9). 9) and the second flat panel liquid crystal alignment layer (AL2-1 in Fig. 9) of the liquid crystal molecules (LC1 in Fig. 9) aligned on the surface of the first flat panel liquid crystal alignment layer (AL1 in Fig. 9) (LC2-1, LC2-2 in Fig. 9) oriented on the surface of the first liquid crystal molecules AL2-2, AL2-2. The pretilt angle is an angle between the director of the first and second flat substrate 100, 200 and the liquid crystal molecules LC1, LC2-1, LC2-2. For example, when the pretilt angle is 90 DEG, the liquid crystal molecules LC1, LC2-1, LC2-2 can be substantially vertically aligned with respect to the first and second flat substrates 100, 200 The liquid crystal molecules LC1, LC2-1, and LC2-2 may be horizontally aligned with respect to the first and second flat substrates 100 and 200 when the pre-scan angle is 0 °.

Number of samples (S / S) = 6 (P1) of the liquid crystal molecules aligned on the surface of the first flat panel liquid crystal alignment layer, (P2) of the liquid crystal molecules oriented on the surface of the second flat panel liquid crystal alignment layer, Max (Max) 89.52 DEG 88.88 DEG Minimum value (Min) 88.69 DEG 87.82 DEG Average value (Avg) 89.10 ° 88.31 DEG Standard deviation (Std) 0.313 0.439

10 and Table 1, the pretilt angles P1 of the liquid crystal molecules (LC1 in Fig. 9) oriented on the surface of the first flat panel liquid crystal alignment layer (AL1 in Fig. 9) 9) of the second liquid crystal molecules (LC2-1, LC2-2 in Fig. 9) oriented on the surfaces of the first liquid crystal molecules AL2-1, AL2-2,

9) and the second flat panel liquid crystal alignment layer (AL2-1, AL2 in Fig. 9) of the first liquid crystal molecules (LC1 in Fig. 9) oriented on the surface of the first flat panel liquid crystal alignment layer (AL1 in Fig. 9) 9) of the second liquid crystal molecules (LC2-1, LC2-2 in Fig. 9) oriented on the surface of the first curved substrate (100C in Fig. 3) and the second curved substrate (200C in Fig. 3) can be prevented.

3, the square angles of the liquid crystal molecules LC1, LC2-1 and LC2-2 at apexes of the curved substrates 100C and 200C are equal to each other at the apex of the flat substrates 100 and 200 Of the liquid crystal molecules LC1, LC2-1, LC2-2 of the liquid crystal molecules LC1, LC2-1, LC2-2. The square of the angle of the liquid crystal molecules LC1 aligned on the surface of the first curved liquid crystal alignment layer AL1C is equal to the angle of the liquid crystal molecules LC2-1, LC2-1, LC2-2 aligned on the surface of the second curved liquid crystal alignment layer AL2C, 2). The virtual straight line C-C 'is a virtual straight line passing the apexes of the curved substrates 100C and 200C.

For example, the radius of curvature R of the curved-surface liquid crystal display 500C may be, for example, 2000 mm or more to 5000 mm or less. At this time, the curvature radius R of the curved substrate 100C, , The square of the angle of the liquid crystal molecules LC1 aligned on the surface of the first curved liquid crystal alignment layer AL1C is equal to the angle of the liquid crystal molecules LC2-1 and LC2-2 aligned on the surface of the second curved liquid crystal alignment layer AL2C ) Can be increased.

11 is a light transmission distribution image of a curved liquid crystal display 500C according to one embodiment. 12 is a light transmission distribution image of a curved-surface liquid crystal display device according to a first comparative example.

4, the first flat liquid crystal alignment layer AL1 is formed on the common electrode 110 using the first vertical alignment type polyimide, and the second vertical alignment layer After forming the second-1 < RTI ID = 0.0 > 1 < / RTI > flat panel liquid crystal alignment layer (AL2-1) on the pixel electrode 291 using a complex liquid crystal aligning agent comprising an oriented polyimide and a reactive mesogen 9, a liquid crystal composition containing liquid crystal molecules LC was injected to form a liquid crystal layer 300, which was then subjected to a heat treatment (H), a UV irradiation, and a bending process (B) .

In the curved-surface liquid crystal display device according to the first comparative example, the first flat panel liquid crystal alignment layer AL1 and the 2-1th flat panel liquid crystal alignment layer (AL2-1) are all formed of a composite liquid crystal alignment agent The liquid crystal layer 300 is formed by injecting a liquid crystal composition containing liquid crystal molecules LC according to the manufacturing process shown in FIGS. 5 to 9, and then heat treatment (H), UV Irradiation and bending process (B).

11 and 12, the curved-surface liquid crystal display device according to the first comparative example, unlike the curved-surface liquid crystal display device 500C in FIG. 3, differs from the curved-surface liquid crystal display device according to the first comparative example in that the texture generated by the collision of the first liquid- (texture) was visually recognized as an arm (indicated by a dotted line).

13 is a light transmission distribution photograph of a curved liquid crystal display device according to a second comparative example. In the curved-surface liquid crystal display device according to the second comparative example, in the process step of Fig. 4, both of the first flat panel liquid crystal alignment layer AL1 and the 2-1th flat panel liquid crystal alignment layer (AL2-1) (RM) and liquid crystal molecules (LC) are injected to form a liquid crystal layer (300). Then, the liquid crystal layer (300) is irradiated with UV Irradiation and bending process (B).

Referring to FIG. 13, in the curved-surface liquid crystal display device according to the second comparative example, the texture generated due to the collision between the orientation directions of the first liquid crystal molecules and the second liquid crystal molecules was visually recognized as a dark portion (indicated by a dotted line).

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It is to be understood that the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

100C: first curved substrate 100: first flat substrate
200C: second curved substrate 200: second flat substrate
300, and 300C: liquid crystal layer liquid crystal molecules: LC
First Curved Liquid Crystal Alignment Layer: AL1C First Flat Panel Liquid Crystal Alignment Layer: AL1
Second Curved Liquid Crystal Alignment Layer: AL2C Second Flat Panel Liquid Crystal Alignment Layer: AL2
2-1 Curved Liquid Crystal Alignment Layer: AL2-1C 2-2 Curved Liquid Crystal Alignment Layer: AL2-2C
2-1 Flat panel liquid crystal alignment layer: AL2-1 Part 2-2 Flat panel liquid crystal alignment layer: AL2-2
Reactive mesogens: RM

Claims (11)

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
And a liquid crystal layer disposed between the first curved liquid crystal alignment layer and the second curved liquid crystal alignment layer and including liquid crystal molecules having a negative dielectric constant anisotropy,
Wherein the liquid crystal layer comprises a first liquid crystal molecule oriented on a surface of the first curved liquid crystal alignment layer and a second liquid crystal molecule oriented on a surface of the second curved liquid crystal alignment layer, Wherein the second liquid crystal molecules are aligned in an oblique direction relative to the first liquid crystal molecules in an initial state in which no electric field is applied. The method according to claim 1,
Wherein the second curved liquid crystal alignment layer has a higher content of reactive mesogen polymers per unit area than the first curved liquid crystal alignment layer. The method 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;
Further comprising: The method according to claim 1,
Wherein the content of the polymerization initiator in the first curved liquid crystal alignment layer is lower than that in the second curved liquid crystal alignment layer. The method according to claim 1,
The second curved liquid crystal alignment layer includes a second-2 curved liquid crystal alignment layer having a lower content of an imide group (-CONHCO-) than the second-first curved liquid crystal alignment layer and the second-1 curved liquid crystal alignment layer The liquid crystal display device comprising: The method according to claim 1,
Wherein the second curved liquid crystal alignment layer comprises a second-1 curved liquid crystal alignment layer and a second-2 curved liquid crystal alignment layer having a higher content of polymers of reactive mesogens than the second-1 curved liquid crystal alignment layer The liquid crystal display device comprising: A first curved substrate;
A second curved substrate;
A liquid crystal layer including liquid crystal molecules having a negative dielectric constant 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 content of polymerization initiator than the first curved liquid crystal alignment layer and disposed between the liquid crystal layer and the second curved substrate;
And a liquid crystal display panel. 8. The method of claim 7,
Wherein the liquid crystal molecules having negative dielectric anisotropy include first liquid crystal molecules oriented on the surface of the first curved liquid crystal alignment layer and second liquid crystal molecules oriented on the surface of the second curved liquid crystal alignment layer and in an initial state in which no electric field is applied Wherein the first liquid crystal molecules are vertically aligned with respect to the second liquid crystal molecules and the second liquid crystal molecules are tilted relative to the first liquid crystal molecules. 8. The method of claim 7,
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;
Further comprising: 8. The method of claim 7,
The second curved liquid crystal alignment layer includes a second-2 curved liquid crystal alignment layer having a lower content of an imide group (-CONHCO-) than the second-first curved liquid crystal alignment layer and the second-1 curved liquid crystal alignment layer The liquid crystal display device comprising: 8. The method of claim 7,
Wherein the second curved liquid crystal alignment layer comprises a second-1 curved liquid crystal alignment layer and a second-2 curved liquid crystal alignment layer having a higher content of polymers of reactive mesogens than the second-1 curved liquid crystal alignment layer The liquid crystal display device comprising:

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