KR102113237B1 - Optical film and liquid crystal display - Google Patents

Abstract

The present application relates to an optical film and a liquid crystal display comprising the same. In the present application, it is possible to provide a liquid crystal display capable of improving luminance uniformity and contrast ratio of emitted light by selectively adjusting reflection of light that causes color washout by applying an optical film having a specific structure.

Description

Optical film and liquid crystal display

The present invention relates to an optical film and a liquid crystal display.

A liquid crystal display (LCD) is a display device using anisotropy of liquid crystal. A liquid crystal display generally has a structure having a liquid crystal panel including a liquid crystal layer having a liquid crystal material and a polarizing plate disposed on both sides thereof, and changing the orientation of the liquid crystal layer to implement a black and white state and display an image.

Since the liquid crystal panel generally adjusts polarization with respect to light incident perpendicularly to the panel, a problem arises in that the brightness of the light changes or the color changes with respect to light in the inclined direction.

In order to solve this problem, for example, as in the case of Patent Document 1, a method of disposing a so-called optical compensation film or the like on the viewing side of the liquid crystal panel is known.

On the other hand, the liquid crystal display has a variety of modes depending on the orientation of the liquid crystal in the liquid crystal panel, typically, TN (Twisted Nematic), VA (Vertical Alignment) or IPS (In plane switching) mode.

Among the above modes, the VA mode generally has an excellent contrast ratio and excellent color reproducibility, but a color washout occurs in which gamma value changes when observing the display at an inclined angle compared to observing the display in the front direction. .

In addition, in the case of the TN mode, the price is low and the response speed is excellent, but as in the VA mode, a phenomenon in which the gamma value changes when observing the display at an angle of inclination compared to the case of observing the display in the front direction.

Korean Patent Publication No. 2009-0080133

The present application provides an optical film and a liquid crystal display comprising the optical film. The present application solves the color washout phenomenon occurring in a liquid crystal display, particularly a liquid crystal display in a vertically aligned (VA) mode or a twisted nematic (TN) mode through a specific optical film, and improves the contrast ratio. The purpose.

This application relates to optical films. 1 exemplarily shows the optical film of the present application. The optical film of the present application may include a first region 10 and a second region 20 having different refractive indices divided by an interface composed of a plurality of inclined surfaces s1, s2, s3, s4, ..., sn. have.

In one example, the interface may be surfaces of the first region and the second region. In this case, surfaces of the first region and the second region serving as the interface may be in contact with each other.

One technical feature of the present application is to control the relationship between the refractive index (n ₁ ) of the first region, the refractive index (n ₂ ) of the second region, and the angle α formed by two adjacent inclined surfaces at the interface. Can be done with As shown in FIG. 2, the light of an angle Θ _{1 at} which discoloration does not occur can be spread to an angle θ ₂ at which discoloration occurs using total reflection through such an optical film, thereby slowing the decolorization phenomenon. When referring to the refractive index in this specification, unless otherwise specified, it means the refractive index for the 550 nm wavelength.

Hereinafter, the optical film of the present application will be specifically described.

The optical film of the present application includes a first region and a second region divided by an interface composed of a plurality of inclined surfaces, and the first region has a higher refractive index than the second region, and can satisfy the following Equation 1. .

[Equation 1]

In Equation 1, n ₁ is a refractive index of the first region, n ₂ is a refractive index of the second region, and α is an angle formed by two adjacent inclined surfaces.

When the optical film satisfies the above Equation 1, the light entering the optical film in a direction other than the vertical direction among the light incident on the optical film due to the difference between the refractive indices of the first region and the second region and the angle formed by the inclined surface should be vertical. By not going, the contrast ratio can be improved.

The optical film of the present application includes a first region and a second region having different refractive indices divided by an interface composed of a plurality of inclined surfaces, and the first region has a larger refractive index than the second region, and the following Equation 2 Can be satisfied.

[Equation 2]

In Equation 2, n ₁ is a refractive index of the first region, and α is an angle formed by two adjacent inclined surfaces.

When the optical film satisfies Equation 2, the light entering the optical film in a direction other than the vertical direction among the light incident on the optical film due to the difference between the refractive indices of the first region and the second region and the angle formed by the inclined surface should be vertical. By not going, the contrast ratio can be improved.

The optical film of the present application includes a first region and a second region having different refractive indices divided by an interface composed of a plurality of inclined surfaces, and the first region has a larger refractive index than the second region, and the following Equation 3 Can be satisfied.

[Equation 3]

In Equation 3, n ₁ is a refractive index of the first region, n ₂ is a refractive index of the second region, and α is an angle formed by two adjacent inclined surfaces.

When the optical film satisfies Equation 3, the light entering the optical film in a direction other than the vertical direction among the light incident on the optical film due to the difference between the refractive indices of the first region and the second region and the angle formed by the inclined surface should be vertical. By not going, the contrast ratio can be improved.

The optical film of the present application includes a first region and a second region having different refractive indices divided by an interface formed of a plurality of inclined surfaces, and the first region has a larger refractive index than the second region, and the following Equation 4 Can be satisfied.

[Equation 4]

In Equation 4, n ₁ is the refractive index of the first region, n ₂ is the refractive index of the second region, and α is the angle formed by two adjacent inclined surfaces.

When the optical film satisfies Equation 4, the light incident on the optical film in a direction other than the vertical direction among the light incident on the optical film due to the difference between the refractive indices of the first region and the second region and the angle formed by the inclined surface should be vertical. You can improve the contrast ratio by not going

The optical film of the present application includes a first region and a second region having different refractive indices divided by an interface composed of a plurality of inclined surfaces, and the first region has a larger refractive index than the second region, and at the interface The angle formed by the two adjacent inclined surfaces may range from 35 degrees to 70 degrees. The optical film may satisfy Equation 5 below. The optical film that satisfies this is caused by the difference between the refractive indices of the first region and the second region and the angle formed by the inclined surface, so that the light incident in the other direction except the vertical direction does not go in the vertical direction. Contrast ratio can be improved

[Equation 5]

In Equation 5, n ₁ is the refractive index of the first region, and n ₂ is the refractive index of the second region.

The optical film of the present application includes a first region and a second region having different refractive indices divided by an interface composed of a plurality of inclined surfaces, and the first region has a larger refractive index than the second region, and at the interface The angle formed by the two adjacent inclined surfaces may be in the range of 70 degrees to 110 degrees. The optical film may satisfy Equation 6 below. The optical film that satisfies this is caused by the difference between the refractive indices of the first region and the second region and the angle formed by the inclined surface. Can improve

[Equation 6]

In Equation 6, n ₁ is a refractive index of the first region, n ₂ is a refractive index of the second region, and α is an angle formed by two adjacent inclined surfaces.

In one example, the optical film of the present application may satisfy any one of the formulas 1 to 6 above. In another example, the optical film of the present application may satisfy at least two or more of the formulas 1 to 6. Specifically, the optical film of the present application may satisfy all of Equations 1 to 4 above. Such an optical film may be more advantageous in reducing the color fading phenomenon and improving the contrast ratio.

In one example, the refractive index of the first region may be in a range of about 1.50 to 1.67, and a transparent material having a refractive index in this range may use a known material without particular limitation. For example, materials used in the production of so-called prism sheets in the industry can be used. In addition, ultraviolet (UV) or thermosetting resins such as acrylate-based materials may be exemplified as known materials. For example, the above-described optical film may be manufactured by forming the layer formed on the surface with the UV curable resin or the like, and then applying the above-described pressure-sensitive adhesive or adhesive on the surface.

In one example, the refractive index of the second region may be in the range of about 1.39 to 1.49. Transparent materials having a refractive index in this range are known in various ways. As a part of the optical film forming the second region, for example, a material having a refractive index within the above range may be exemplified among known optical adhesives or adhesives, for example, acrylic adhesives, but is not limited thereto. It does not work.

In one example, angles α formed by two adjacent inclined surfaces at the boundary surface may be the same or different from each other. The standard deviation of the angle α may be in the range of 0 degrees to 5 degrees. In other examples, the standard deviation may be about 5 degrees or less, about 4 or less, about 3 or less, about 2 or less, or about 1 or less.

In one example, the interface may be the surfaces of the first and second regions themselves. Therefore, each of the first region and the second region may have a surface corresponding to the boundary surface. In the first region and the second region, the surfaces may be in contact with each other.

In one example, an area formed by two adjacent inclined surfaces at the boundary surface may be referred to as a convex portion of the first area or the second area. The convex portions of the first region and the second region may have the same shape.

In one example, the height of the convex portion of the first region or the second region (H in FIG. 1) may be appropriately selected in consideration of the purpose of the present application. For example, the height of the convex portion may be in the range of 20 to 300 μm. In this case, since the light at an angle at which discoloration does not occur can be spread to an angle at which discoloration occurs using total reflection, discoloration can be reduced. In another example, the height may be 20 μm or more, 30 μm or more, or 40 μm or more. In addition, the height may be 300 μm or less, 200 μm or less, 100 μm or less, 90 μm or less, 80 μm or less, 70 μm or less, 60 μm or less, or 50 μm or less in other examples.

In one example, the convex portions of the first region or the second region may be disposed spaced apart from each other or adjacent to each other. When the convex portions are spaced apart from each other, the region between the convex portions may be flat. The height of the flat area may be lower or higher than the height of the convex portion.

In one example, the pitch of the convex portion of the first region or the second region (P in FIG. 1) may be appropriately selected in consideration of the purpose of the present application. For example, the pitch of the convex portion may be 10 to 50 μm. In this case, since the light at an angle at which discoloration does not occur can be spread to an angle at which discoloration occurs using total reflection, discoloration can be reduced. The pitch of the convex portion may be the shortest distance from the point where one convex portion starts to the point where another convex portion starts. Specifically, the pitch of the convex portion may mean the shortest distance between the apex of one convex portion and the apex of another convex portion. In another example, the period may be about 15 μm or more, 20 μm or more, 25 μm or more, 30 μm or more, 35 μm or more, or 40 μm or more. In addition, the period may be 50 μm or less in another example.

In one example, the number of convex portions of the first region or the second region may be appropriately selected in consideration of the purpose of the present application. The convex portion may be 400 pieces / mm ² to 10000 pieces / mm ² per unit area based on the surface direction of the optical film. In another example, the ratio may be 400 / mm ² or more, 450 / mm ² or more, or 500 / mm ² or more. In addition, the rate of 10000 In other instances / mm ² or less, 9,000 / mm ² or less, to 8000 / mm ² or less, 7,000 / mm ² or less, 6,000 / mm ² or less, to 5000 / mm ² or less, 4000 / mm ² or less, 3000 / mm ² or less, 2000 / mm ² or less, 1000 / mm ² or less, 900 / mm ² or less, 800 / mm ² or less, 700 / mm ² or less, or 600 It may be less than / mm ² . In this case, the purpose of the present application can be achieved more effectively.

In one example, the boundary surface may have a structure in which a plurality of linear prisms are arranged in one direction. In the present specification, the linear prism may mean a shape in which a column having a triangular cross section extends in a linear direction.

In one example, the first area and the second area may be flat on opposite sides of the interface. In one example, the base layer may be present on one or more of the flat surfaces of the first region and the second region. A plastic film may be used as the base layer. The plastic film includes TAC (triacetyl cellulose); COP (cyclo olefin copolymer) such as norbornene derivatives; PMMA (poly (methyl methacrylate); PC (polycarbonate); PE (polyethylene); PP (polypropylene); PVA (polyvinyl alcohol); DAC (diacetyl cellulose); Pac (Polyacrylate); PES (poly ether sulfone); PEEK (polyetheretherketon) ); PPS (polyphenylsulfone), PEI (polyetherimide); PEN (polyethylenemaphthatlate); PET (polyethyleneterephtalate); PI (polyimide); PSF (polysulfone); PAR (polyarylate) or amorphous fluorine resin.

3 and 4 exemplarily show the optical film according to the first embodiment. Figure 3 is the front of the optical film and Figure 4 shows the optical film on the side. 3 and 4, the optical film may sequentially include the base layer 30, the second region 20 and the first region 10.

The contents described in the items of the optical film may be applied in the same manner unless otherwise specified with respect to the optical film according to the first embodiment of the present application.

According to the second embodiment of the present application, the optical film may have a structure in which the first optical film according to the first embodiment and the optical film according to the first embodiment are stacked. Specifically, the optical film is a first region and a second region divided by a first optical film including a first region and a second region divided by a boundary surface consisting of a plurality of inclined surfaces and a plurality of inclined surfaces A second optical film including a region may be included, and the first region may have a higher refractive index than the second region. .

In the optical film according to the second embodiment of the present application, the contents described in the items of the optical film may be equally applied unless there is a special reference to the first optical film and the second optical film.

Specifically, each of the first boundary surface and the second boundary surface may have a structure in which a plurality of linear prisms are arranged in one direction.

In the optical film of the second embodiment, the first area and the second area included in the first optical film and the second optical film, respectively, may have opposite surfaces of the interface. In the optical film of the second embodiment, a substrate layer may be present on at least one of the flat surfaces of the first region and the second region.

5 and 6 exemplarily show the optical film according to the second embodiment. 5 is a front view of the optical film and FIG. 6 is a side view of the optical film. 5 and 6, the optical film includes a base layer 30, a second region 20, a first region 10, a base layer 30, a second region 20, and a first region ( 10) may be sequentially included.

The optical film of the present application applies a layer of a material of any one of the first region and the second region on a flat substrate layer, transfers a boundary surface composed of a plurality of inclined surfaces to the layer, and then the first region and the first It can be produced by applying the other of the two areas. The transfer of the boundary surface composed of a plurality of inclined surfaces may be performed by roll-to-roll processing. As the mold used for the roll-to-roll processing, a bite B as shown in FIG. 7 may be used. When it is desired to arrange the convexities in multiple dimensions, a plurality of rule-to-roll processing may be performed in different horizontal directions.

The present application relates to a liquid crystal display comprising the optical film. The liquid crystal display may include a liquid crystal panel and the optical film of the present application disposed on the viewer-side surface of the liquid crystal panel.

As shown in FIG. 8, the optical film 1 may be disposed on the viewing side surface 2A of the liquid crystal panel 2. As used herein, the term “viewing-side surface” of a liquid crystal panel means a surface closer to an observer observing the image when the display displays the image among the upper and lower surfaces of the liquid crystal panel. In addition, the term “back side 2B” surface of the liquid crystal panel means a surface opposite to the viewing side surface among the upper and lower surfaces.

The fact that the optical film is disposed on the viewing side surface of the liquid crystal panel in the present application means that other constituent members exist between the optical film and the viewing side surface as well as when the optical film is disposed in contact with the viewing side surface. Cases may also be included. For example, as described later, a second polarizing plate may be disposed between the optical film and the viewing side surface of the liquid crystal panel.

The optical film may be disposed on the outermost side of the liquid crystal display. In the present application, that the optical film is disposed on the outermost side of the liquid crystal display may mean that any one surface of the optical film is exposed to the outside and is disposed to contact the air.

The first region of the optical film may be disposed adjacent to the liquid crystal panel compared to the second region. The optical film may be disposed such that light emitted from the liquid crystal panel passes through the first region and the second region sequentially and is discharged. When light enters from a medium having a large refractive index to a medium having a small refractive index, when the incident angle is greater than or equal to a critical angle, total light is reflected. The present application can increase the reflectance of light that is 10 to 20 degrees of the inner angle of the light source by using the total reflection principle and the inclination angle, and lower the reflectance of other light. Since the reflected light can be emitted in different directions, the luminance can be uniformly matched.

In one example, the optical film may increase light having an internal angle of 10 to 20 degrees in the liquid crystal panel to an angle at which decolorization occurs. In one example, among the light incident on the optical film from the liquid crystal panel, light having an incidence angle within the range of 10 degrees to 20 degrees may be emitted at an exit angle of 30 degrees to 70 degrees through the optical film.

In the present application, the method for arranging the optical film as described above on the viewing side surface of the liquid crystal panel is not particularly limited. For example, in the process of assembling the liquid crystal display, the optical film may be simply placed on the viewing side surface, or a method of attaching the optical film to the surface of the liquid crystal panel using an appropriate double-sided adhesive or adhesive may be applied. Can be.

In one example, the liquid crystal panel may be a VA (Vertical Alignment) mode liquid crystal panel. In another example, the liquid crystal panel may be a twisted nematic (TN) mode liquid crystal panel. The optical film peculiar to the present application is disposed on the viewer-side surface of the liquid crystal panel, thereby ensuring uniformity of emitted light at front and viewing angles in various types of liquid crystal panels, and eliminating color washout that may occur in a white state. It can, and such an effect can be appropriately expressed in a liquid crystal display of VA mode or TN mode.

The specific configuration of the liquid crystal panel applied in the present application is not particularly limited, and any known general liquid crystal panel configuration may be applied.

For example, the liquid crystal panel may be a transmissive, reflective or transflective liquid crystal panel. The driving method of the liquid crystal panel is not particularly limited in the present application, for example, an active matrix method using a passive matrix method, an active electrode such as a thin film transistor (TFD) electrode or a thin film diode (TFD) electrode, and a plasma address method. Known driving methods, such as, can be applied

The liquid crystal panel usually includes a liquid crystal layer containing a liquid crystal material interposed between two transparent substrates. The transparent substrate of the liquid crystal panel may have a property of aligning the liquid crystal material constituting the liquid crystal layer in a specific alignment direction. For example, the substrate itself has a property of aligning liquid crystals, or the substrate itself has no alignment ability, but a transparent substrate or the like having an alignment film having properties of aligning a liquid crystal material may be used. As the electrode of the liquid crystal panel, a known electrode such as ITO (Indium Tin Oxide) may be applied. Such an electrode can be usually provided on the surface of a transparent substrate in contact with the liquid crystal layer, or when a transparent substrate having an alignment film is used, it can also be provided between the substrate and the alignment film.

As the liquid crystal material included in the liquid crystal layer, a material having various negative or positive dielectric anisotropy generally used in the construction of the liquid crystal panel may be used. As such a material, various low molecular liquid crystal materials, high molecular liquid crystal materials, and mixtures thereof may be exemplified, but are not limited thereto. In addition, the liquid crystal layer of the liquid crystal panel may include a dye or a chiral agent or a non-liquid crystal material in a range that does not impair the liquid crystal properties of the liquid crystal material.

In addition, a semi-transflective liquid crystal panel may be configured by replacing one substrate on the liquid crystal panel, for example, a substrate on the back side, with a substrate having a reflective function region and a transparent function region. The region having a reflective function (hereinafter, referred to as a reflective layer) included in the transflective electrode used in the liquid crystal panel is not particularly limited, but is one of metals such as aluminum, silver, gold, chromium, platinum, or one of them. Examples include alloys containing the above, oxides such as magnesium oxide, multilayer films of dielectrics, liquid crystals showing selective reflection, or combinations thereof. These reflective layers may be flat or curved. In addition, the reflective layer may have a surface shape such as an uneven shape and have diffuse reflection property, a combination of electrodes on the transparent substrate on the back side of the liquid crystal panel, or a combination of these.

The liquid crystal panel may include other constituent members in addition to the constituent members. For example, by providing a color filter, it is possible to manufacture a color liquid crystal display device capable of providing a multicolor or pure color display with high color purity.

The liquid crystal display may further include a backlight unit, a first polarizing plate, and a second polarizing plate. In the liquid crystal display, the backlight unit, the first polarizing plate, the liquid crystal panel, the second polarizing plate, and the optical film may be sequentially disposed. The absorption axis of the first polarizing plate and the second polarizing plate may be orthogonal to each other.

The first polarizing plate or the second polarizing plate is to polarize the incident light, a polarizer commonly known to those skilled in the art, for example, a polyvinyl alcohol-based polarizer in which a polyvinyl alcohol-based film is uniaxially stretched, or a polyvinyl alcohol-based film And a dehydrated polyene polarizer. The first polarizer or the second polarizer may further include a protective film.

The first polarizing plate or the second polarizing plate may be attached to the liquid crystal panel by an adhesive layer or an adhesive layer. The adhesive layer or adhesive layer may be formed of an adhesive resin, and optionally a composition comprising a crosslinking agent, a silane coupling agent, a photoradical initiator, or a photocationic initiator. The adhesive layer or the adhesive layer may further enhance the light diffusion effect by further including a light diffusion agent. The light diffusing agent may include conventional light diffusing agents known to those skilled in the art.

The backlight unit may include a light source. The backlight unit may further include a light guide plate guiding light emitted from the light source, a reflective sheet positioned under the light guide plate, and a diffusion sheet positioned above the light guide plate. The light source generates light and may be disposed on a side surface of the light guide plate (edge type). As the light source, various light sources such as a line light source lamp or a surface light source lamp, CCFL or LED may be used. A light source cover may be disposed outside the light source. The light guide plate may guide light generated from the light source to the diffusion sheet. The light guide plate may be omitted when a direct light source is employed, and in this case, a diffusion plate may be further included. The reflective sheet may serve to reflect light generated from the light source and supply it in the direction of the diffusion sheet. The diffusion sheet may diffuse and scatter light incident through the light guide plate and supply it to the liquid crystal panel.

The liquid crystal display may include a member constituting another known liquid crystal display in addition to the liquid crystal panel and the optical film. As such a member, for example, a polarizing plate, a backlight module, or a reflecting plate may be exemplified, but is not limited thereto.

In the present application, it is possible to provide a liquid crystal display capable of improving luminance uniformity and contrast ratio of emitted light by selectively adjusting reflection of light that causes discoloration by applying an optical film having a specific structure.

1 to 6 exemplarily show the optical film of the present application.
7 exemplarily shows a roll-to-roll mold.
8 exemplarily shows a liquid crystal display of the present application.

Hereinafter, the present application will be described in detail through examples, but the scope of the present application is not limited by the following examples.

Method for evaluating optical properties simulation

A structure in which an optical film having the structure shown in FIG. 1 is disposed on a surface on the viewer side of the liquid crystal panel was set for optical property simulation evaluation. The optical film has a structure in which a plurality of linear prisms are arranged in one direction, and the first region is disposed adjacent to the liquid crystal panel compared to the second region. The structure in which the optical film is not disposed is set as Comparative Example 1. In the table below, n ₁ is a refractive index of the first region, n ₂ is a refractive index of the second region, and α is an angle formed by two adjacent inclined surfaces.

For simulation, the ASAP program of Breault Research Organization was used, and the light distribution obtained by measuring the liquid crystal panel using EZContrast equipment of ELDIM was used as a light source. The liquid crystal panel is T215HVN01.1 manufactured by AUO. The light source was measured in gray units, and the units were 0 (black), 64, 128, 192, and 255 (white). In the simulation structure, light from the liquid crystal panel was used as a light source, and polarization was determined as a polarization direction of the polarizing plate attached to the outermost portion of the liquid crystal panel. In addition, in the structure in which the optical film is in close contact with the liquid crystal panel, the light distribution from the panel is measured by luminance in each gray unit, and when the value is white (255), it is corrected to show 100% for each viewing angle.

For the simulation structure, White (luminance ratio), CR (contrast ratio) and Gary (difference ratio) were simulated, and the results are shown in Tables 1 to 8 below. The result values indicate White (luminance ratio), CR (contrast ratio), and Gray (difference ratio) based on the liquid crystal panel without the optical film. The luminance ratio means the ratio (%) of the white luminance of the simulation structure to the white luminance of Comparative Example 1, and the contrast ratio is the white luminance of the simulation structure for the value obtained by dividing the white luminance of Comparative Example 1 by the black luminance. It is the ratio (%) of the value divided by. The difference ratio means the ratio (%) of the difference between viewing angles of the simulation structure to the difference between viewing angles of Comparative Example 1. White luminance means the vertical luminance value in gray unit 255, black luminance means the vertical luminance value in gray unit 0, the difference for each viewing angle is set to 128 in gray units, and for each viewing angle (0 degrees, 15 degrees, 30 degrees). , 45 degrees, 60 degrees) When the measured luminance value is expressed as normalized luminance, it means the value obtained by subtracting the largest value from the smallest value. The lower the gray value, the better the decolorization phenomenon, and the CR value represents the contrast ratio, and the higher the higher the optical characteristic. In this simulation evaluation, when the Gary value was 80 or less, it was evaluated that there was an effect of improving the decoloring phenomenon visually, and when the CR value was 80 or more, it was evaluated that the optical property was excellent.

Evaluation result of optical characteristic simulation 1. (Equation 1)

Table 1 below shows simulation evaluation results of No. 1-4 satisfying Equation 1 and No. 5-8 not satisfying Equation 1 in the present application.

No. Alpha (α) n2 n1 Equation 1 White CR Gray One 55 1.48 1.5 -0.46684 96.68 96.79 73.62 2 50 1.53 1.55 -0.42167 96.85 96.44 73.67 3 45 1.52 1.55 -0.3013 96.75 91.91 66.56 4 60 1.48 1.5 -0.52858 96.92 97.46 81.96 5 90 1.48 1.57 -0.67605 96.01 89.08 88.24 6 70 1.48 1.5 -0.64891 96.63 97.90 101.99 7 65 1.495 1.5 -0.70006 96.71 99.18 97.09 8 35 1.4 1.5 0.092604 87.42 44.72 30.49

Result of evaluation of simulation of optical properties 2. (Equation 2)

Table 2 below shows simulation evaluation results of No. 1-5 satisfying Equation 2 and No. 6-9 not satisfying Equation 2 in the present application.

No Alpha (α) n2 n1 Equation 2 White CR Gray One 40 1.46 1.5 0.51303 95.82 83.94 73.83 2 45 1.46 1.5 0.574025 96.43 87.49 57.44 3 50 1.46 1.5 0.633927 96.42 89.66 58.28 4 50 1.528 1.568 0.662665 96.89 89.98 62.44 5 60 1.48 1.52 0.76 96.63 92.95 79.88 6 65 1.5 1.55 0.832814 96.32 91.14 101.03 7 70 1.54 1.55 0.889043 96.71 98.75 100.29 8 75 1.46 1.5 0.913142 96.65 95.39 103.16 9 80 1.52 1.62 1.041316 95.87 83.11 92.44

Result of evaluation of simulation of optical properties 3. (Equation 3)

Table 3 below shows simulation evaluation results of No. 1-5 satisfying Equation 3 and No. 6-9 not satisfying Equation 3 in the present application.

No Alpha (α) n2 n1 Equation 3 White CR Gray One 40 1.46 1.5 0.45337 95.82 83.94 73.83 2 45 1.46 1.5 0.521026 96.43 87.49 57.44 3 50 1.528 1.568 0.614897 96.89 89.98 62.44 4 55 1.46 1.5 0.649014 96.43 91.06 64.61 5 60 1.48 1.52 0.719818 96.63 92.95 79.88 6 30 1.5 1.55 0.299188 93.82 66.25 82.33 7 30 1.52 1.55 0.341388 96.47 82.27 93.01 8 70 1.495 1.5 0.856005 96.70 98.99 98.57 9 85 1.52 1.62 1.020428 96.12 85.57 88.11

Result of evaluation of optical characteristics simulation 4. (Equation 4)

Table 4 below shows simulation evaluation results of No. 1-4 satisfying Equation 4 and No. 5-8 not satisfying Equation 4.

No Alpha (α) n2 n1 Equation 4 White CR Gray One 40 1.46 1.5 0.69723 95.82 83.94 73.83 2 50 1.528 1.548 0.783473 96.64 96.01 74.47 3 57 1.48 1.52 0.894173 98.12 93.69 71.36 4 60 1.48 1.52 0.925623 96.63 92.95 79.88 5 40 1.495 1.5 0.585158 96.81 98.66 98.93 6 35 1.495 1.5 0.524159 96.83 98.65 98.06 7 35 1.52 1.55 0.628956 96.41 86.61 89.34 8 65 1.5 1.55 1.005914 96.32 91.14 101.03

Result of optical property simulation evaluation 5. (Equation 5)

Table 5 below shows simulation evaluation results of No. 1-5 satisfying Equation 5 and No. 6-8 not satisfying Equation 5 in the present application.

No Alpha (α) n2 n1 Equation 5 White CR Gray One 50 1.48 1.5 0.02 96.65 96.17 79.37 2 45 1.52 1.55 0.03 96.75 91.91 66.56 3 55 1.52 1.55 0.03 96.84 94.52 69.60 4 60 1.46 1.5 0.04 96.46 92.16 75.83 5 55 1.5 1.55 0.05 96.47 87.63 68.22 6 50 1.528 1.533 0.005 96.75 98.86 96.95 7 60 1.495 1.5 0.005 96.55 98.64 95.35 8 90 1.48 1.6 0.12 95.72 82.93 84.12

Result of evaluation of simulation of optical properties 6. (Equation 6)

Table 6 below shows simulation evaluation results of No. 1-4 satisfying Equation 6 and No. 5-8 not satisfying Equation 6.

No. Alpha (α) n2 n1 Equation 6 White CR Gray One 45 1.5 1.55 9.4 96.26 82.38 51.04 2 45 1.52 1.55 11.4 96.75 91.91 66.56 3 50 1.528 1.553 13.5 96.64 94.86 65.89 4 60 1.48 1.52 15.2 96.63 92.95 79.88 5 55 1.49 1.5 16.6 96.76 98.62 89.64 6 70 1.48 1.5 20.4 96.63 97.90 101.99 7 65 1.48 1.5 18.8 96.60 97.47 95.07 8 70 1.495 1.5 21.9 96.70 98.99 98.57

Evaluation results of optical properties simulation 7. (Equations 1 to 4)

Table 6 is a simulation of No.1-34 of Table 7 that satisfies all of Equations 1 to 4 of the present application, and No.1-50 of Table 8-9 that does not satisfy at least one of Equations 1 to 4 The evaluation results are shown.

10: first region, 20: second region, 30: substrate layer,
1: Optical film 2: Liquid crystal panel 2A: Viewing side 2B: Back side
P: cycle, H: height, A: exit axis

Claims (24)

An optical film comprising a first region and a second region having different refractive indices divided by an interface composed of a plurality of inclined surfaces, wherein the first region has a higher refractive index than the second region and satisfies Equation 1 below:
[Equation 1]

In Equation 1, n ₁ is a refractive index of the first region, n ₂ is a refractive index of the second region, and α is an angle formed by two adjacent inclined surfaces. An optical film comprising a first region and a second region having different refractive indices divided by an interface formed of a plurality of inclined surfaces, wherein the first region has a higher refractive index than the second region and satisfies Equation 2 below:
[Equation 2]

In Equation 2, n ₁ is a refractive index of the first region, and α is an angle formed by two adjacent inclined surfaces. An optical film having a first region and a second region having different refractive indices divided by a boundary surface composed of a plurality of inclined surfaces, wherein the first region has a higher refractive index than the second region and satisfies Equation 3:
[Equation 3]

In Equation 3, n ₁ is a refractive index of the first region, n ₂ is a refractive index of the second region, and α is an angle formed by two adjacent inclined surfaces. An optical film comprising a first region and a second region having different refractive indices divided by an interface formed of a plurality of inclined surfaces, wherein the first region has a higher refractive index than the second region and satisfies Equation 4 below:
[Equation 4]

In Equation 4, n ₁ is the refractive index of the first region, n ₂ is the refractive index of the second region, and α is the angle formed by two adjacent inclined surfaces. A first region and a second region having different refractive indices divided by a boundary surface composed of a plurality of inclined surfaces include a first region having a larger refractive index than the second region, and satisfying the following Equations 1 to 4 Optical film made:
[Equation 1]

[Equation 2]

[Equation 3]

[Equation 4]

In Equations 1 to 4, n ₁ is a refractive index of the first region, n ₂ is a refractive index of the second region, and α is an angle formed by two adjacent inclined surfaces. delete A first region and a second region having different refractive indices divided by a boundary surface composed of a plurality of inclined surfaces, the first region has a larger refractive index than the second region, and an angle formed by two adjacent boundary surfaces is An optical film within a range of 70 degrees to 110 degrees and satisfying the following Equation 6:
[Equation 6]

In Equation 6, n ₁ is a refractive index of the first region, n ₂ is a refractive index of the second region, and α is an angle formed by two adjacent inclined surfaces. The optical film according to any one of claims 1 to 5 and 7, wherein the boundary surface has a structure in which a plurality of linear prisms are arranged in one direction. The optical film according to any one of claims 1 to 5 and 7, wherein the first area and the second area are flat on opposite sides of the interface. 10. The optical film of claim 9, wherein a substrate layer is present on at least one of the flat surfaces of the first and second regions. The first optical film according to any one of claims 1 to 5 and 7, and
An optical film having a structure in which the second optical film according to any one of claims 1 to 5 and 7 is laminated. A liquid crystal display comprising a liquid crystal panel and the optical film according to any one of claims 1 to 5 and 7 disposed on a viewing side surface of the liquid crystal panel. The liquid crystal display of claim 12, wherein the liquid crystal panel is a VA mode liquid crystal panel. The liquid crystal display of claim 12, wherein the liquid crystal panel is a TN mode liquid crystal panel. The liquid crystal display of claim 12, wherein the first region of the optical film is disposed adjacent to the liquid crystal panel compared to the second region. The liquid crystal display of claim 12, wherein light having an incidence angle within a range of 10 to 20 degrees among light incident on the optical film from the liquid crystal panel is emitted at an emission angle of 30 to 70 degrees through the optical film. A liquid crystal display comprising a liquid crystal panel and an optical film disposed on a viewer-side surface of the liquid crystal panel, wherein the optical film includes first and second regions having different refractive indices divided by an interface composed of a plurality of inclined surfaces. In addition, the first region has a larger refractive index than the second region, and the angle formed by two adjacent interface surfaces is within a range of 35 degrees to 70 degrees, and a liquid crystal display satisfying Equation 5 below:
[Equation 5]

In Equation 5, n ₁ is the refractive index of the first region, and n ₂ is the refractive index of the second region. The liquid crystal display of claim 17, wherein the boundary surface has a structure in which a plurality of linear prisms are arranged in one direction. 18. The liquid crystal display of claim 17, wherein the first area and the second area have flat surfaces opposite to each other. 20. The liquid crystal display of claim 19, wherein a base layer is present on at least one of the flat surfaces of the first and second regions. The liquid crystal display of claim 17, wherein the liquid crystal panel is a VA mode liquid crystal panel. The liquid crystal display of claim 17, wherein the liquid crystal panel is a TN mode liquid crystal panel. 18. The liquid crystal display of claim 17, wherein the first region of the optical film is disposed adjacent to the liquid crystal panel compared to the second region. 18. The liquid crystal display of claim 17, wherein light having an incident angle within a range of 10 to 20 degrees from light incident on the optical film from the liquid crystal panel is emitted at an exit angle of 30 to 70 degrees through the optical film.

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