KR20150111396A - Curved liquid crystal display and manufacturing method of the same - Google Patents

Abstract

A curved display device includes a plurality of pixels and is bent in a first direction of the first direction and a second direction which intersect each other. The curved display device includes a first substrate and a second substrate which face each other and a liquid crystal layer provided between the first substrate and the second substrate.

Description

TECHNICAL FIELD [0001] The present invention relates to a curved surface display device and a method of manufacturing the same. [0002] CURVED LIQUID CRYSTAL DISPLAY AND MANUFACTURING METHOD OF THE SAME [

The present invention relates to a curved surface display device and a method of manufacturing the same.

A liquid crystal display panel is a display panel in which a liquid crystal layer is formed between two transparent substrates, and displays a desired image by driving a liquid crystal layer to adjust light transmittance for each pixel.

In the vertical alignment mode of the liquid crystal display panel, liquid crystal molecules are vertically aligned with respect to a substrate surface when an electric field is formed, thereby transmitting light to display an image. The vertical alignment mode improves the viewing angle of a liquid crystal display panel by forming liquid crystal domains capable of aligning liquid crystal molecules in different directions. Among the operation modes of the liquid crystal display panel, a horizontal electric field switching (in plane switching) mode is a mode in which liquid crystal molecules are horizontally aligned with respect to a substrate surface when an electric field is formed to transmit light to display an image.

In addition, curved surface display panels have been developed in recent years, and curved surface display panels can provide a display area of a curved surface, thereby providing a user with an improved sense of depth and immersion.

It is an object of the present invention to provide a curved display panel capable of improving display quality and a method of manufacturing the same.

A curved display device according to an aspect of the present invention includes a plurality of pixels and is bent in the first direction among first and second directions intersecting with each other. The first substrate includes a first base substrate, a pixel electrode provided on the first base substrate, and a first alignment layer provided on the pixel electrode, the first alignment layer including at least two domains optically aligned in different directions . The second substrate includes a second base substrate facing the first base substrate, a common electrode provided on the second base substrate, and a second alignment film provided on the common electrode and vertically oriented. The liquid crystal layer includes liquid crystal molecules interposed between the first and second substrates. And a difference between the second angle and the first angle is equal to or greater than 0.8 degrees and equal to or less than 1.5 degrees when the first angle is defined as the first angle with respect to the second alignment film and the second angle is defined with respect to the first alignment film.

In one embodiment of the present invention, the first angle may be greater than or equal to 88.3 degrees and less than or equal to 89.2 degrees. In one embodiment of the present invention, the second angle may be between 89.8 degrees and 90 degrees.

In one embodiment of the present invention, the first alignment layer has a first domain optically oriented in a third direction, a second domain optically oriented in a fourth direction different from the third direction, A third domain optically oriented in another fifth direction, and a fourth domain optically oriented in a sixth direction different from the second through fifth directions.

In one embodiment of the present invention, the third to sixth directions may be inclined in the first direction and the second direction when viewed in plan.

In one embodiment of the present invention, the first to fourth domains may be arranged in the form of 2x2 matrix, 1x4 matrix, or 4x1 matrix.

In one embodiment of the present invention, the first through fourth domains may be provided for each pixel. In this case, in the two adjacent pixels, the arrangement order of the first through fourth domains in one pixel is And may be different from the arrangement order of the first to fourth domains in the remaining pixels.

In one embodiment of the present invention, the four pixels constitute one unit pixel, and the first through fourth domains may correspond one-to-one to the four pixels. In this case, in two unit pixels adjacent to each other, The arrangement order of the first to fourth domains in the unit pixel may be different from the arrangement order of the first to fourth domains in the remaining unit pixels.

The curved surface display device having the above structure may include a pixel electrode formed on a first base substrate, a first alignment layer formed on the pixel electrode, and a first alignment layer including at least two domains optically aligned in different directions , Forming a common electrode on the second base substrate, forming a vertically aligned second alignment film on the common electrode, and forming a liquid crystal layer between the first and second alignment films.

In one embodiment of the present invention, the first alignment layer may be formed by forming an alignment material on the first base substrate and providing light in an oblique direction on the first base substrate. Here, the angle formed by the upper surface of the first base substrate and the light may be selected at an appropriate angle, and the amount of the light may be 20 mJ or less.

According to an embodiment of the present invention, there is provided a high-quality curved surface display device in which defects that may be caused by misalignment are reduced.

According to an embodiment of the present invention, there is provided a method of manufacturing a high-quality curved surface display device in which defects that may be caused by misalignment are reduced.

1A is a perspective view of a curved display device according to an embodiment of the present invention.
1B is a side view of the curved display device shown in FIG. 1A.
2 is a plan view of a first substrate according to an embodiment of the present invention.
3 is a cross-sectional view taken along the line I-I 'shown in Fig.
FIGS. 4A to 4C are plan views illustrating a method of aligning light so that a first alignment layer has domains having different alignment directions according to an embodiment of the present invention. FIG.
FIG. 5A is a graph showing a square of a pre-alignment angle when changing the irradiation angle of light in the first alignment film light alignment. FIG.
FIG. 5B is a graph showing the angle of the frontal line according to the material of light when the irradiation amount of light is changed in the first alignment film photo alignment.
6A to 6D are plan views illustrating the directions of optical alignment of first to fourth domains according to another embodiment of the present invention.
FIGS. 7A to 7D are plan views illustrating the directions of optical alignment of first to fourth domains according to another embodiment of the present invention. FIG.
8A to 8D are plan views illustrating the directions of optical alignment of first to fourth domains according to another embodiment of the present invention.
FIG. 9 is a plan view showing the optical alignment directions of the first to fourth domains according to another embodiment of the present invention.
10 is a plan view of a first substrate according to another embodiment of the present invention.
11 is a cross-sectional view taken along line II-II 'shown in FIG.

The present invention is capable of various modifications and various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but on the contrary, is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Like reference numerals are used for like elements in describing each drawing. In the accompanying drawings, the dimensions of the structures are shown enlarged from the actual for the sake of clarity of the present invention. The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. The singular expressions include plural expressions unless the context clearly dictates otherwise.

In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof. Also, where a section such as a layer, a film, an area, a plate, or the like is referred to as being "on" another section, it includes not only the case where it is "directly on" another part but also the case where there is another part in between. On the contrary, where a section such as a layer, a film, an area, a plate, etc. is referred to as being "under" another section, this includes not only the case where the section is "directly underneath"

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

FIG. 1A is a perspective view of a curved display device according to an embodiment of the present invention, and FIG. 1B is a side view of the curved display device shown in FIG. 1A. In one embodiment of the present invention, the curved surface display device may have a rectangular shape, and in this case, it has a pair of long sides and a pair of short sides. However, the shape of the curved surface display device is not limited thereto, and may have various shapes such as a square shape, a polygonal shape, and a circular shape, and the direction in which the curved display device is bent may be set differently. In the present embodiment, for the convenience of explanation, the long side direction of the curved surface display device will be described as the x-axis direction.

Referring to FIG. 1A, the curved surface display device DP has a shape bent in the x-axis direction. Particularly, the curved surface display device DP is configured such that the user is bent in the direction of looking at the curved surface display device DP so that the user can see the image displayed on the curved screen (i.e., the display area DA) . A display device that provides such a curved display area DA is defined as a curved display device DP. When the image is displayed using the curved surface display device DP, it is possible to improve the three-dimensional feeling, the immersion feeling, and the sense of durability felt by the user.

The curved surface display device DP includes a first substrate SUB1, a second substrate SUB2 facing the first substrate SUB1, and a second substrate SUB2 interposed between the first substrate SUB1 and the second substrate SUB2 And a liquid crystal layer (not shown).

The first and second substrates SUB1 and SUB2 have a shape bent along the x-axis direction. A part or all of the first substrate SUB1 may be continuously bent along the x axis direction so that the display area DA may be curved along the x axis direction . Also, the second substrate SUB2 may be bent together with the first substrate SUB1.

Referring to FIG. 1B, when the first and second substrates SUB1 and SUB2 are bent, a normal 10 perpendicular to the tangent line 11 contacting the first point P1 of the second substrate SUB2 And passes through the second point P2 of the first substrate SUB1. However, the line of sight 15 passing through the second point P2 in the visual line direction in which the user looks at the curved surface display device DP is different from the first point P1 in the second substrate SUB2 And passes through the third point P3.

The interval between the first point P1 and the third point P3 varies according to the curvature of the curved surface display device DP. That is, the gap between the first point P1 and the third point P3 may increase as the curvature of the curved surface display device DP increases.

As described above, a phenomenon in which a gap is generated between the first point P1 and the third point P3 is referred to as a miss-alignment between the first substrate SUB1 and the second substrate SUB2 due to curvature define. Hereinafter, a method for preventing a defect caused by the misalignment, for example, a texture defect, is shown.

FIG. 2 is a plan view of a first substrate SUB1 according to an embodiment of the present invention, and FIG. 3 is a cross-sectional view taken along a line I-I 'shown in FIG.

2 and 3, the curved surface display device includes a first substrate SUB1, a second substrate SUB2, and a liquid crystal layer interposed between the first substrate SUB1 and the second substrate SUB2 LC).

The curved surface display device includes a plurality of pixels PX provided in a plurality of pixel regions PA provided in a matrix form. In FIGS. 2, 3A and 3B, only the pixel region PA of the pixel PXij corresponding to the i-th row and the j-th column is shown for convenience of explanation. Hereinafter, i in the reference numeral is a row number in a plurality of pixels, and j means a column number. Since the pixel regions PA have the same structure, only one pixel region PA will be described as an example for convenience of explanation. Here, the pixel region PA has a rectangular shape elongated in one direction, but the present invention is not limited thereto. The shape of the pixel area PA may be variously modified, such as a V shape or a Z shape.

The first substrate SUB1 includes a first base substrate BS1, a gate line GL, a data line DL, a thin film transistor TRij, a pixel electrode PE, and a first alignment layer ALN1 .

The first base substrate BS1 is made of an insulating material and has flexibility.

The plurality of gate lines GL are provided and extended in one direction on the first base substrate BS1. The i-1th and i-th gate lines GLi-1 and GLi of the gate lines GL are started in FIGS. 2, 3A and 3B, -1, and GLi are referred to as first and second gate lines GLi-1 and GLi.

The data lines DL are provided in plurality and are insulated from the gate lines GL with a gate insulating film GI interposed therebetween on the first base substrate BS1, . The jth and j + 1th data lines DLj and DLj + 1 of the data lines DL are started in FIGS. 2 and 3, and the jth and j + 1th data lines DLj and DLj + 1) are referred to as first and second data lines DLj and DLj + 1.

The thin film transistor TRij is electrically connected to the second gate line GLi and the first data line DLj to switch a signal supply to a pixel electrode PEij to be described later. Specifically, the thin film transistor TRij includes a gate electrode GE branched from the second gate line GLi, a source electrode SE branched from the first data line DLj, and the pixel electrode PEij. And a drain electrode (DE) electrically connected to the first electrode. A semiconductor pattern SM forming a conduction channel is provided between the source electrode SE and the drain electrode DE.

An insulating layer (INS) is provided on the thin film transistor TRij. The insulating layer INS is provided corresponding to the pixel regions PA. The insulating layer INS may include a color pixel indicating color and a black matrix BM provided between the color pixels.

The color pixel may be any one of a red color pixel R, a green color pixel G and a blue color pixel B, and addition of a magenta pixel, a yellow color pixel, a cyan color pixel, Color pixels may be included.

The black matrix BM blocks light transmitted through the liquid crystal layer LC. The black matrix BM is arranged to cover the first and second gate lines GLi-1 and GLi, the first and second data lines DLj and DLj + 1, and the thin film transistor TRij. do.

The pixel electrode PEij is connected to the second gate line GLi and the first data line DLj through a thin film transistor TRij. The pixel electrode PEij is provided in the pixel region PA. The pixel electrode PEij is provided on the insulating layer INS and is connected to the drain electrode DE of the thin film transistor TRij through a contact hole CH.

The pixel electrode PEij is disposed at a predetermined distance from the other pixel electrodes adjacent to each other in the first direction D1 (i.e., the left pixel electrode PEij-1 and the right pixel electrode PEij + 1) Lt; / RTI >

In one embodiment of the present invention, the pixel electrode PEij may be provided as a through-hole. However, the shape of the pixel electrode PEij is not limited thereto, and may include, for example, a stem portion and a plurality of branch portions extending radially from the stem portion. The stem portion may be provided in a cross shape as in an embodiment of the present invention, and the plurality of branch portions may be arranged parallel to each other and spaced apart from each other within a region defined by the stem portion. In the fringes, adjacent fringes may be spaced a micrometer distance to form a plurality of fine slits.

The first alignment layer ALN1 is provided on the pixel electrode PEij and aligns the liquid crystal molecules of the liquid crystal layer LC to have at least two alignment directions along at least two different alignment directions. Here, the pretilt angle refers to the angle at which the liquid crystal molecules are inclined with respect to the upper surface of the first alignment layer ALN1, and the alignment direction refers to the inclination direction of the liquid crystal molecules. When the first alignment layer ALN1 is optically aligned, the director of the liquid crystal molecules adjacent to the first alignment layer ALN1 is substantially the same as the opto-alignment direction.

As the material for forming the first alignment layer ALN1, organic / inorganic polymer materials having photosensitivity are included. The alignment layer material may be a material that undergoes a photopolymerization reaction, a photoisomerization reaction, or a photodecomposition reaction when exposed to the light, and may be a polymeric material such as polyimide or polyamic acid. However, the material forming the first alignment layer is not limited thereto, and may be a polynorbornene phenylmaleimide copolymer, a polyvinylcinnamate, a polyazobenzene, a polyethyleneimine, a polyvinyl alcohol ), Polyamide, polyethylene, polystylene, polyphenylenephthalamide, polyester, polyurethane, polymethylmethacrylate and the like are used. . In addition, the alignment material used for the photo alignment is not limited to an organic polymer material, and for example, an inorganic polymer such as polysiloxane may also be used as a material for the alignment layer.

In one embodiment of the present invention, the first alignment layer ALN1 may include a plurality of domains having different alignment directions. FIGS. 4A through 4C are cross- Are arranged so as to have domains having different orientation directions. Hereinafter, a method of photo-alignment of the first alignment layer will be described with reference to FIGS. 4A to 4C. 4A to 4C illustrate that the first alignment layer includes first to fourth domains (DM1, DM2, DM3, and DM4) optically aligned in different directions.

Referring to FIG. 4A, the first alignment layer corresponding to the pixel area PA of each pixel PXij is divided into a first area A1 and a second area A2 along the y-axis direction, And then exposed. The first alignment layer is optically aligned in the first direction (D1) in the first region (A1), and the first alignment layer is optically aligned in the second direction (D2) in the second region (A2).

Referring to FIG. 4B, the first alignment layer corresponding to the pixel area PA is divided into a third area A3 and a fourth area A4 along the x-axis direction and is secondarily exposed in different directions. The second alignment film is photo aligned in the third direction D3 in the third region A3 and the second alignment film is photo aligned in the fourth direction D4 in the fourth region A4.

Referring to FIG. 4C, a region where the first region A1 and the third region A3 overlap each other is a first domain DM1, and the first direction D1 and the third direction D3 , The light is optically aligned in the fifth direction D5 defined by the vector sum of the first direction D1 and the third direction D3. A region where the first region A1 and the fourth region A4 overlap each other becomes a second domain DM2 and sequentially aligns in the first direction D1 and the fourth direction D4, And is optically aligned in a sixth direction D6 defined by the vector sum of the first direction D1 and the fourth direction D4. The region where the second region A2 and the third region A3 overlap with each other becomes the third domain D3 and the region in which the light is sequentially aligned in the second direction D2 and the third direction D3 The light is aligned in the seventh direction D7 defined by the vector sum of the second direction D2 and the third direction D3. The region where the second region A2 and the fourth region A4 overlap each other becomes the fourth domain D4 and the light is sequentially photo-aligned in the second direction D2 and the fourth direction D4 , The second direction D2, and the fourth direction D4, as shown in FIG.

In one embodiment of the present invention, the first to fourth domains DM1, DM2, DM3, and DM4 corresponding to one pixel PXij are divided into first to fourth domains (DM1, DM2, DM3, DM4) circulate in the clockwise direction.

In one embodiment of the present invention, when the pretilt angles of the liquid crystal molecules in the respective domains oriented in the fifth to eighth directions (D5, D6, D7 and D8) are defined as a first angle (? 1) The angle may be between 88.3 degrees and 89.2 degrees.

The first to fourth domains DM1, DM2, DM3, and DM4 may be formed using a photo alignment process. The photo alignment process may be performed by forming a first alignment layer ALN1 on the pixel electrode PEij using the alignment layer material and then applying light inclined in a specific direction to the first alignment layer ALN1 have. The light may be ultraviolet light or polarized light.

When the light is incident on the first alignment layer ALN1, the light irradiation angle may be inclined to the upper surface of the first substrate SUB1 or the first alignment layer ALN1. In one embodiment of the present invention, the irradiation angle may be variously set.

FIG. 5A is a graph showing a square of a pre-alignment angle when changing the irradiation angle of light in the first alignment film light alignment. FIG. In the graph of FIG. 5A, the value in the y-axis direction is expressed by a value obtained by subtracting the first angle from 90 degrees.

Referring to FIG. 5A, as the irradiation angle of light increases, a value obtained by subtracting the first angle from 90 degrees in the y-axis direction increases. Therefore, by using the tendency, the angle of 90 degrees in the y- The irradiation angle can be inversely calculated from the value.

In one embodiment of the present invention, the dose of light may be set to various values.

FIG. 5B is a graph showing the angle of the frontal line according to the material of light when the irradiation amount of light is changed in the first alignment film photo alignment. In the graph of FIG. 5B, the value in the y-axis direction is represented by a value obtained by subtracting the first angle from 90 degrees. In FIG. 5B, the orientation materials (denoted by Ma, Mb, Mc) shown in FIG. 5 are different from each other, but the overall tendency of y-axis direction values according to the irradiation amount are all similar. Based on this, the dose for making a pre-angle square at the first angle is about 20 mJ ≪ / RTI > Here, even when the irradiation amount exceeds about 60 mJ / cm ² , it is possible to make a pretilt angle of a desired range, but in this case, energy consumption is large.

The second substrate SUB2 is provided opposite to the first substrate SUB1. The second substrate SUB2 includes a second base substrate BS2, an overcoat layer OC, a common electrode CE, and a second alignment layer ALN1.

The second base substrate BS2 is made of an insulating material and has flexibility.

The overcoat layer OC covers the second base substrate BS2. The overcoat layer OC may be omitted.

The common electrode CE is provided on the overcoat layer OC and forms an electric field together with the pixel electrode PE. In one embodiment of the present invention, the common electrode CE may be formed as a through plate. However, the shape of the common electrode CE is not particularly limited, and may be patterned in such a manner that some regions are removed.

The second alignment film ALN2 may be a vertical alignment film provided on the common electrode CE and not optically oriented in a specific direction. Here, the second alignment layer may not have different alignment directions. The material of the second alignment layer (ALN2) includes a polymer material such as polyimide or polyamic acid. However, the material of the second alignment layer (ALN2) is not limited thereto, and may be the same as or different from the material of the first alignment layer (ALN1).

The pretilt angle of the second alignment layer may be different from the pretilt angle of the first alignment layer. In an exemplary embodiment of the present invention, the second alignment layer may be optically aligned such that the alignment layer is not subjected to a separate alignment process, As a result, when the line inclination angle of the liquid crystal molecules by the second alignment film is a second angle (? ₂ ), the second angle? ₂ may be about 89.8 degrees to about 90 degrees.

In one embodiment of the present invention, the relationship between the first angle and the second angle is expressed by the following equation.

[Equation] 0.8 占?? _2- ?? ₁ ? 1.5?

This is explained as follows.

In general, it has been described that the curved surface display device may cause misalignment depending on the curvature of the curved surface. In particular, when a misalignment occurs between a first substrate and a second substrate, a conventional liquid crystal display device provided in the form of a curved surface display device has a problem in that, when a misalignment occurs between the first substrate and the second substrate, The transmittance of the curved display device decreases because the direction is out of alignment. In view of the fact that the liquid crystal display device is a curved surface in the embodiment of the present invention, the transmittance reduction is compensated by adjusting the angle of the pretilt angle by the first orientation film and the second orientation film. Generally, since the amount of change in luminance visible to the user's eyes in the display device is about +/- 2%, it is preferable that the transmittance reduction is -2% or more and 2% or less. In one embodiment of the present invention, the first angle (? ₁ ) and the second angle (? ₂ ) have values within a predetermined range to compensate for the transmittance reduction.

Table 1 below is a simulation value showing the transmittance and the luminance variation according to the difference between the second angle and the first angle when changing the square of the first alignment film and the second alignment film through the photo alignment.

Square angle (°) Transmittance (optional unit) Change in luminance (%) A first angle (θ ₁₎ Second angle (θ ₂₎ ? _{2 -} ? ₁ No misalignment Incorrect alignment (30μm) 89.0 90.0 1.0 0.17072 0.17072 0% 89.0 89.8 0.8 0.17191 0.16988 -1.2% 89.0 89.5 0.5 0.17339 0.16651 -4.0% 89.0 89.2 0.2 0.17459 0.1625 -6.9% 89.0 89.0 0.0 0.17527 0.15955 -9.0%

Referring to Table 1, when there is misalignment, when the difference value (? _{2 -} ? ₁ ) between the second angle? ₂ and the first angle? ₁ is 0.8 or more, , And it can be seen that the user has a value at which the luminance difference can not be seen, that is, a value of -2% or more. In the curved surface display device according to the embodiment of the present invention,? _{2 -} ? ₁ may have a value equal to or greater than 0.8 degrees. Further, since? _{2 -} ? ₁ has a value smaller than or equal to 1.5 degrees, when the value is larger than 1.5 degrees, the reaction rate of the liquid crystal molecules may become slower or the contrast ratio may decrease.

Table 2 shows the presence or absence of texture defects according to the first angle and the second angle, and it was judged based on what is visible to the user's eyes.

Square angle (°) Texture defect A first angle (θ ₁₎ Second angle (θ ₂₎ ? _{2 -} ? ₁ No misalignment Incorrect alignment (30μm) 89.0 90.0 1.0 X X 89.0 89.8 0.8 X X 89.0 89.5 0.5 X O 89.0 89.2 0.2 X O 89.0 89.0 0.0 X O

Referring to Table 2, it is possible to determine the second angle (θ ₂₎ in the first angle difference (θ ₂ -θ ₁₎ of 0.8 points is Texture defect is not generated or more of (θ _1).

The liquid crystal layer LC includes liquid crystal molecules having dielectric anisotropy and refractive index anisotropy. In an embodiment of the present invention, the liquid crystal layer LC may include liquid crystal molecules having negative dielectric anisotropy. The liquid crystal molecules in the liquid crystal layer LC are arranged in accordance with an electric field formed between the pixel electrode PEij and the common electrode CE. A common voltage is applied to the common electrode CE and the pixel electrode PEij receives a data voltage from the first data line DLj. Accordingly, an electric field is formed with a magnitude corresponding to the potential difference between the common voltage and the data voltage, and the arrangement of liquid crystal molecules in the liquid crystal layer LC is changed according to the magnitude of the electric field to control the light transmittance.

The light provided to the liquid crystal layer LC may be light provided from a backlight assembly (not shown) disposed on the rear surface of the first substrate SUB1.

The liquid crystal molecules in the first to fourth domains DM1, DM2, DM3, and DM4 are different from each other in the fifth to eighth directions D5, D6, D7, D8). In an embodiment of the present invention, as shown in FIG. 4C, the alignment directions in the first to fourth domains DM1, DM2, DM3, and DM4 can be clockwise rotated. By forming a plurality of domains DM1, DM2, DM3, and DM4 having different orientation directions in the pixel region, a wide viewing angle of the curved display device can be ensured.

In addition, the curved surface display device according to an embodiment of the present invention having the above-described structure does not cause defective optical alignment due to misalignment. This is explained as follows.

In a typical display device, the first alignment film of the first substrate and the second alignment film of the second substrate are optically oriented in different directions in each pixel region, and then the two substrates are combined to correspond to the respective pixel regions, . In this case, the vector sum of the optical alignment directions of the first alignment film and the second alignment film becomes the final optical alignment direction. However, in the case of a general display device, since the first substrate and the second substrate are located on a single plane and there is no bent portion, misalignment is not large even when the first substrate and the second substrate are combined, not big.

However, as shown in FIG. 1, in the case of a curved surface display device curved along the x-axis direction, a gap is generated between the first point P1 and the third point P3, Misalignment between the first substrate SUB1 and the second substrate SUB2 may occur. When the first substrate and the second substrate are misaligned, the liquid crystal molecules are optically aligned in directions other than the intended optical alignment direction, resulting in defects such as texture generation.

In contrast, in the curved display device according to an embodiment of the present invention, the first alignment layer of the first substrate has a plurality of domains oriented in different directions, and the second alignment layer of the second substrate is not oriented in a specific direction Therefore, the final alignment direction of the liquid crystal molecules is determined depending mainly on the light alignment direction of the first alignment film. As a result, misalignment decreases when the first substrate and the first substrate are coupled. Also, even if the misalignment is reduced, defects related to the direction of photo alignment, for example, texture generation are prevented because the pre-scan angle is set so as to compensate for the misalignment. In addition, in the curved display device according to the embodiment of the present invention, the black matrix is provided on the first substrate, and misalignment when the first substrate and the first substrate, which may occur when the black matrix is on the second substrate, .

In the curved display device according to an embodiment of the present invention, each domain may be manufactured to have various optical alignment directions. 6A to 6D are plan views illustrating the directions of optical alignment of first to fourth domains according to another embodiment of the present invention. In the embodiments of the present invention, the arrangement order of the domains is not particularly limited, but the arrangement order of the first to fourth domains in FIGS. 6A to 6D will be described with reference to FIG. The same as the example.

DM2, DM3, and DM4 in the first to fourth domains DM1, DM2, DM3, and DM4 of each pixel PXij, The photo-alignment directions of the domains may be arranged in different directions, unlike the embodiment of the present invention.

Referring to FIG. 6A, the optical alignment directions of the first to fourth domains DM1, DM2, DM3, and DM4 of each pixel PXij can rotate in a counterclockwise direction.

Referring to FIG. 6B, the optical alignment directions of the first to fourth domains DM1, DM2, DM3, and DM4 of each pixel PXij may not have a circular shape. Rather, the optical alignment directions of the first to fourth domains DM1, DM2, DM3, and DM4 of each pixel PXij may converge toward the center of the pixel region in one pixel PXij. 6C, the light alignment directions of the first to fourth domains DM1, DM2, DM3, and DM4 of each pixel PXij can diverge outward from the center of the pixel region in one pixel PXij have.

6D, the light alignment directions of the first and second domains DM1 and DM2 of each pixel PXij diverge from the center of the pixel region and the light alignment direction of the first and second domains DM1 and DM2 in the third and fourth domains DM3 and DM4 The light alignment direction can converge to the center of the pixel region.

In the above-described embodiments, one pixel has the first through fourth domains of the 2x2 matrix, but the present invention is not limited thereto. For example, each pixel PXij may have first through fourth domains DM1, DM2, DM3, and DM4 in the form of a 4x1, 1x4 matrix. 7A to 7D are diagrams for explaining the operation of the first to fourth domains DM1, DM2, DM3 (DM1, DM2, DM3) in the case where the first to fourth domains DM1, DM2, DM3, DM4 are arranged in a 4x1 matrix in one pixel PXij 8A to 8D are plan views showing the light alignment directions of the first to fourth domains DM1, DM2, DM3, and DM4 in one pixel PXij, DM2, DM3, and DM4 of the first to fourth domains (DM1, DM2, DM3, and DM4).

7A to 7D and FIGS. 8A to 8D, domains may be arranged in various shapes in one pixel, and they may be arranged to have different optical alignment directions for respective domains. Further, in one embodiment of the present invention, the photo-alignment directions can be combined in various ways corresponding to each pixel. For example, a pixel region in which a photo-alignment direction of a domain in one pixel circulates clockwise or counterclockwise is referred to as a circular pixel region, and a photo-alignment direction of a domain in one pixel diverges from the center of the pixel region Or converging to the center of the pixel region is referred to as a convergent divergent pixel region, the circulating pixel region and the convergent divergent pixel region may be alternately arranged in the x-axis direction and / or the y-axis direction. In one embodiment of the present invention, a part of the circulating type pixel area and a part of the converging diverging type pixel area may be arranged in one pixel.

In one embodiment of the present invention, neighboring transition pixels may have domains arranged in different forms. For example, the ij-th pixel may have a circular pixel region, and the (ij + 1) -th pixel may have a pixel region having a 1x4 matrix-shaped domain.

In an embodiment of the present invention, each domain is shown to have the same area, but the present invention is not limited thereto, and the area of each domain may be set differently.

In the above embodiments, one pixel has a plurality of domains oriented in different directions. However, in another embodiment of the present invention, the concept of the present invention can be extended between pixels and pixels. That is, when four pixels are grouped into one unit pixel, individual pixels can function as one domain.

FIG. 9 is a diagram illustrating a curved surface display apparatus according to another embodiment of the present invention. In FIG. 9, four pixels PXi-1j, PXi-1j + 1, PXij, and PXij + 1 are arranged in a 2x2 matrix, DM1, DM2, DM3, and DM4 in the case where the first to fourth domains DM1, DM2, DM3, and DM4 are formed.

1, the i-1th pixel PXi-1j, the i-1j + 1th pixel PXi-1j + 1, the ij pixel PXij and the ij + 1th pixel PXij + 1j + 1-th pixel PXi-1j + 1, ij-th pixel PXij, and ij + 1j + 1 may form a single unit pixel UPX, The first pixel PXij + 1 may correspond to the first to fourth domains DM1, DM2, DM3, and DM4 that are optically oriented in different directions, respectively. The photo-alignment directions of the first to fourth domains DM1, DM2, DM3, and DM4 in the unit pixel UPX are arranged in the same manner as the photo-alignment directions of the first to fourth domains of the above-described embodiments .

The curved display device according to an embodiment of the present invention may have various structures. FIG. 10 is a plan view of a first substrate SUB1 according to another embodiment of the present invention, and FIG. 11 is a cross-sectional view along a cutting line II-II 'shown in FIG. In this embodiment, in order to avoid duplication of description, differences from FIG. 2 and FIG. 3 will be mainly described.

Referring to FIGS. 10 and 11, the first substrate SUB1 further includes a shielding electrode (SCE) provided between adjacent pixel electrodes. For example, a first shielding electrode SCEj is provided between the ij-th pixel electrode PEij and the ij-1-th pixel electrode PEij-1, and the ij- A second shielding electrode SCEj + 1 may be provided between the electrodes PEij + 1.

The first and second shielding electrodes SCEj and SCEj + 1 are formed along the first and second data lines DLj and DLj + 1, respectively. The first and second data lines DLj and DLj + 1) and is arranged to cover the first and second data lines DLj and DLj + 1 when viewed in a plane.

The first shielding electrode SCEj is electrically insulated from the pixel electrode PEij and the left pixel electrode PEij-1. The second shielding electrode SCEj + 1 is electrically insulated from the pixel electrode PEij and the right pixel electrode PEij + 1.

 In one embodiment of the present invention, a voltage having the same potential as the common voltage applied to the common electrode CE is applied to the first and second shielding electrodes SCEj and SCEj + 1. An electric field is not formed between the first shielding electrode SCEj and the common electrode CE and between the second shielding electrode SCEj + 1 and the common electrode CE. The liquid crystal molecules are arranged perpendicular to the surface of the second shielding electrode SCEj + 1 in the electroless state. When the liquid crystal molecules are aligned vertically, The area provided with the first and second shielding electrodes SCEj and SCEj + 1 may be formed by the liquid crystal molecules of the backlight assembly, The first and second shielding electrodes SCEj and SCEj + 1 are connected to the first and second data lines DLj and DLj + 1, respectively, as described above. As a result, A light blocking region may be formed in the second direction D2. The second substrate SUB2 corresponds to a region where the first and second shielding electrodes SCEj and SCEj + 1 are formed, and a black matrix BM) is not provided.

When the pixel electrode PEij and the first and second shielding electrodes SCEj and SCEj + 1 are formed together on the first substrate SUB1, the first and second data lines DLj and DLj + Which may cause light leakage or dark areas.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood that various modifications and changes may be made thereto without departing from the scope of the present invention.

For example, in the embodiments of the present invention, the first alignment layer includes domains oriented in different directions and the second alignment layer is vertically aligned. However, the present invention is not limited thereto. Conversely, Domains that are oriented in different directions, and the first alignment layer may be vertically oriented. Also, in the embodiments of the present invention, a pixel or a unit pixel having four domains is disclosed, but it is apparent that the present invention can have a different number of domains.

Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

ALN1: first alignment film ALN2: second alignment film
SUB1: first substrate SUB2: second substrate
DM: domain DP: surface display device
LC: liquid crystal layer PE: pixel electrode
SCE: shielding electrode CE: common electrode
BM: Black Matrix

Claims (14)

A curved surface display device comprising a plurality of pixels and curved in the first direction among first and second directions intersecting with each other,
A first substrate comprising a first base substrate, a pixel electrode provided on the first base substrate, and a first alignment layer provided on the pixel electrode, the first alignment layer including at least two domains optically oriented in different directions;
A second base substrate facing the first base substrate, a common electrode provided on the second base substrate, and a second orientation film provided on the common electrode and vertically oriented; And
And a liquid crystal layer including liquid crystal molecules interposed between the first and second substrates,
And a difference between the second angle and the first angle is equal to or more than 0.8 and equal to or less than 1.5 degrees, wherein the first angle is defined as a first angle with respect to the second alignment film, and the second angle is defined as a second angle with respect to the first alignment film. . The method according to claim 1,
Wherein the first angle is not less than 88.3 degrees and not more than 89.2 degrees. 3. The method of claim 2,
And the second angle is not less than 89.8 DEG and not more than 90 DEG. The method according to claim 1,
The first alignment layer may include a first domain optically oriented in a third direction, a second domain optically oriented in a fourth direction different from the third direction, and a second domain optically oriented in a fifth direction different from the third and fourth directions. 3 domain, and a fourth domain optically oriented in a sixth direction different from the second to fifth directions. 5. The method of claim 4,
And the third to sixth directions are inclined in the first direction and the second direction when viewed in a plan view. 5. The method of claim 4,
Wherein the first to fourth domains are arranged in a 2x2 matrix, a 1x4 matrix, or a 4x1 matrix. 5. The method of claim 4,
Wherein the first to fourth domains are provided for each pixel. 8. The method of claim 7,
Wherein the arrangement order of the first to fourth domains in one pixel is different from the arrangement order of the first to fourth domains in the remaining pixels in two adjacent pixels. 5. The method of claim 4,
Four pixels constitute one unit pixel,
Wherein the first to fourth domains correspond one-to-one to the four pixels. 10. The method of claim 9,
Wherein the arrangement order of the first to fourth domains in one unit pixel is different from the arrangement order of the first to fourth domains in the remaining unit pixels in two unit pixels adjacent to each other. A method of manufacturing a curved surface display device warped in a first one of first and second directions,
Forming a pixel electrode on the first base substrate;
Forming a first alignment layer on the pixel electrode;
Forming a first alignment layer comprising at least two domains optically oriented in different directions;
Forming a common electrode on the second base substrate;
Forming a second alignment layer vertically oriented on the common electrode; And
And forming a liquid crystal layer between the first and second alignment films,
And a difference between the second angle and the first angle is equal to or greater than 0.8 and equal to or less than 1.5 degrees, wherein the first angle is defined as a first angle with respect to the second alignment film and the second angle is defined as a second angle with respect to the first alignment film, Gt; 12. The method of claim 11,
The step of forming the first alignment layer
Forming an alignment material on the first base substrate; And
And providing light in an oblique direction on an upper surface of the first base substrate. The method of claim 12, wherein
Wherein the irradiation amount of the light is 20 mJ or less. 14. The method of claim 13,
The step of forming the first alignment layer
Forming an alignment material on the first base substrate; And
And providing light in a direction perpendicular to an upper surface of the first base substrate.

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