KR102040300B1 - Optical film, polarizing plate comprising the same and optical display apparatus comprising the same - Google Patents

Abstract

Resin layer; And a protective layer formed on the resin layer, wherein the light incidence surface of the optical film includes one or more optical patterns, and the optical pattern has a first surface formed on a lower surface thereof and the first surface. An embossed optical pattern composed of one or more inclined surfaces connected to each other, wherein the optical pattern has a value of 60% to 95% of Equation 1, and an optical film having a bottom angle α of 83 ° to 87 °, a polarizing plate including the same, and the same. A liquid crystal display device is provided.

Description

OPTICAL FILM, POLARIZING PLATE COMPRISING THE SAME AND OPTICAL DISPLAY APPARATUS COMPRISING THE SAME}

The present invention relates to an optical film, a polarizing plate including the same, and an optical display device including the same. More particularly, the present invention relates to an optical film, a polarizing plate including the same, and an optical display device including the same, capable of improving front brightness.

The liquid crystal display device operates by emitting light from the backlight unit through the liquid crystal panel. The liquid crystal display includes a liquid crystal panel, a viewer side polarizer formed on one surface of the liquid crystal panel, and a light source side polarizer formed on the other surface of the liquid crystal panel and formed between the backlight unit and the liquid crystal panel.

The light source side polarizing plate emits light from the backlight unit toward the liquid crystal panel. In general, the polarizing plate is composed of a polarizer, a protective film formed on at least one surface of the polarizer. In order to increase light efficiency and increase front brightness, a diffuser plate, a prism sheet, and the like are further formed between the light source side polarizer and the backlight unit, or the shape of the light exit surface of the light guide plate is changed. However, the diffusion plate, the prism sheet, and the like can thicken the liquid crystal display device, and the change of the shape of the light guide plate is complicated in the manufacturing process. Therefore, there is a need for an optical film that can increase the front luminance without using a diffusion plate, a prism sheet, or the like.

Background art of the present invention is disclosed in Japanese Patent Laid-Open No. 2006-251659.

The present invention provides an optical film capable of improving front luminance, a polarizing plate including the same, and an optical display device including the same.

The present invention provides an optical film, a polarizing plate including the same, and an optical display device including the same, which may improve front brightness and increase light efficiency.

The optical film of the present invention is a resin layer; And a protective layer formed on the resin layer, wherein the light incidence surface of the resin layer includes one or more optical patterns, and the optical pattern has a first surface formed on a lower surface and is connected to the first surface. It is an embossed optical pattern composed of the above inclined surface, the optical pattern has a value of the following formula 1 is 60% to 95%, the base angle α may be 83 ° to 87 °:

<Equation 1>

d / (w + d) x 100

In Formula 1, d is the maximum width of the first surface of the optical pattern (unit: μm)

w is the maximum distance in micrometers between the optical pattern and the immediately adjacent optical pattern.

The polarizing plate of the present invention may include the optical film of the present invention.

The optical display device of the present invention may include the optical film of the present invention or the polarizing plate of the present invention.

The present invention provides an optical film capable of improving front brightness, a polarizing plate including the same, and an optical display device including the same.

The present invention provides an optical film, a polarizing plate including the same, and an optical display device including the same, which may improve front brightness and increase light efficiency.

1 is a cross-sectional view of an optical film according to an embodiment of the present invention.
2 is a cross-sectional view of an optical film according to another embodiment of the present invention.
3 is a cross-sectional view of an optical film according to another embodiment of the present invention.
4 is a cross-sectional view of an optical film according to another embodiment of the present invention.
5 is a cross-sectional view of an optical film according to another embodiment of the present invention.
6 is a cross-sectional view of a polarizer according to an embodiment of the present invention.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. The drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification.

In the present specification, "upper" and "lower" are defined based on the drawings, and according to a viewpoint, "upper" may be changed to "lower" and "lower" to "upper", and "on" or What is referred to as “on” may include not only the above but also intervening other structures in the middle. On the other hand, what is referred to as "directly on", "directly on" or "directly formed" or "formed directly in contact" means not intervening with other structures.

As used herein, the terms "horizontal direction" and "vertical direction" mean long and short directions of a rectangular LCD screen, respectively. As used herein, the term “front” and “side” refers to (0 °, 0 °) in terms of (φ, θ) by a spherical coordinate system based on a horizontal direction.

As used herein, the term "bottom part" means the lowest part of an embossed optical pattern. Preferably, the lower part means the lowermost part of the optical pattern when the optical pattern is viewed from the light incidence plane of the optical pattern.

As used herein, "aspect ratio" means the ratio of the maximum height (maximum height / maximum width) to the maximum width of the optical pattern.

As used herein, "period" means the distance between neighboring optical patterns, for example, the sum of the maximum width of one optical pattern and the width of one flat portion.

As used herein, “plane retardation (Re)” is a value at a wavelength of 550 nm and is represented by the following formula A:

<Formula A>

Re = (nx-ny) x d

(In Formula A, nx and ny are refractive indices in the slow axis direction and the fast axis direction of the protective layer or base layer, respectively, at a wavelength of 550 nm, and d is the thickness (unit: nm) of the protective layer or base layer).

As used herein, "(meth) acryl" refers to acrylic and / or methacryl.

Hereinafter, an optical film according to an embodiment of the present invention will be described with reference to FIG. 1. 1 is a cross-sectional view of an optical film according to an embodiment of the present invention.

Referring to FIG. 1, the optical film 10 includes a protective layer 200 and a resin layer 100A.

Resin Layer (100A)

The resin layer 100A is formed on the light incidence surface of the protective layer 200, so that the front luminance of the light transmitted in the order of the resin layer 100A and the protective layer 200 can be increased.

The resin layer 100A is composed of a light incident surface and a light exit surface.

The light incident surface of the resin layer 100A includes a pattern portion having a flat portion 105 between one or more optical patterns 101 and an immediately adjacent optical pattern 101. The optical pattern 101 may be an embossed optical pattern, and may be an optical pattern including one or more inclined surfaces 103 and 104 having a first surface 102 formed at a lower portion and connected to the first surface 102. In the optical pattern 101, Equation 1 may be 60% to 95% and a base angle α may be 83 ° to 87 °. Formula 1 is explained in full detail below. As a result, light incident vertically with respect to the first surface 102 of the light incident on the resin layer 100A may pass through the protective layer 200 vertically through the resin layer 100A, thereby improving front brightness. . On the other hand, the light incident on the side of the resin layer 100A that is not perpendicular to the first surface 102 is incident on the optical pattern 101 and then reflected on the inclined surfaces 103 and 104 and then again. Front brightness can be improved by making it exit to the front (vertical). As described above, the optical film includes both light incident to the side as well as light incident vertically through the first surface 102 by the optical pattern 101 including the first surface 102 and the inclined surfaces 103 and 104. It is possible to improve the front luminance with respect to the. A conventional inverted prism optical pattern having a triangular cross section composed of an inclined surface without the same plane as the first surface may scratch the light guide plate and reduce the front luminance improvement effect.

The light exit surface of the resin layer 100A faces the light entrance surface of the resin layer 100A and is formed directly with the protective layer 200 to transmit light passing through the resin layer 100A to the protective layer 200. Let's do it.

Hereinafter, the pattern portion of the resin layer 100A will be described in more detail.

The pattern portion has a flat portion 105 between one or more optical patterns 101 and the immediately neighboring optical pattern 101. The optical patterns 101 are spaced apart from each other by the separation distance e. The optical pattern 101 may be an optical pattern formed of one or more inclined surfaces 103 and 104 having a first surface 102 formed at a lower portion and connected to the first surface 102. The 'distance distance' is defined as the shortest distance between the optical pattern 101 and the immediately neighboring optical pattern 101.

1 is an embossed optical pattern, the first surface 102 is one plane and the inclined surfaces 103 and 104 are planar, the cross section is trapezoidal shape (e.g., the top of the prism having a triangular cross section, cut-prism type). However, an intaglio pattern (eg, a cut-lenticular lens pattern in which a top surface of a lenticular lens pattern is cut or a top surface of a microlens pattern is cut) is formed with a first surface formed at a lower part, a first surface being flat, and an inclined surface curved. Cut-micro lens pattern) may be included in the scope of the present invention. In addition, FIG. 1 illustrates a case where the first surface is a flat surface, but the first surface may be included in the scope of the present invention even when a curved surface or a fine unevenness is formed. Preferably, the optical pattern may be a trapezoidal pattern in cross section.

The optical pattern 101 may have a value of Equation 1 of 60% to 95% and a base angle α of 83 ° to 87 °:

<Equation 1>

d / (w + d) x 100

In Formula 1, d is the maximum width of the first surface of the optical pattern (unit: μm)

w is the maximum distance in micrometers between the optical pattern and the immediately adjacent optical pattern.

In the range of the value and the base angle of Equation 1, the front luminance can be finally improved by adjusting the light passing vertically with respect to the lower part of the optical pattern and the light transmitted to the side to be reflected on the inclined plane and emitted vertically. . Preferably the value of formula 1 may be 70% to 90%, more preferably 75% to 85%. The base angle α may be between 84 ° and 87 °. In the above range, there is a front brightness improvement effect, there may be a viewing angle improvement effect. The "base angle α" is defined as an angle of less than 90 ° of the angle formed by the inclined surface directly connected to the maximum width of the optical pattern and the maximum width of the optical pattern.

The optical pattern 101 may have an aspect ratio of 0.5 to 2, preferably 0.8 to 1.5. In the above range, the front condensing efficiency may be increased.

The optical pattern 101 is the maximum distance w between the lower part of the optical pattern and the lower part of the immediately adjacent optical pattern: the maximum width d of the lower part of the optical pattern 101: the maximum height of the optical pattern 101 The ratio of (h) may be from 1: 2 to 5: 2 to 5. In the above range, there may be a front brightness improvement effect.

In the optical pattern 101, the ratio h / w of the maximum height h of the optical pattern to the maximum distance w between the lower part of the optical pattern and the lower part of the immediately adjacent optical pattern is 2 to 6.5, For example, 2 to 5, preferably 3 to 5. In the above range, there may be a light loss minimizing effect.

The optical pattern 101 may have a maximum distance w between the lower end of the optical pattern and the lower end of the immediately adjacent optical pattern of 3 μm to 30 μm, preferably 5 μm to 15 μm. In the above range, there may be an effect that the light loss is minimized. The optical pattern may have a maximum height h of 10 μm to 60 μm, preferably 20 μm to 55 μm. In the above range, there may be an effect that the light collection efficiency is increased. The optical pattern 101 may have a maximum width d of the lowermost portion of 30 μm to 150 μm, preferably 50 μm to 150 μm. In this range, there may be an effect of reducing light loss. The optical pattern 101 may have a separation distance e of 0 μm to 10 μm, preferably 0 μm to 5 μm, and more preferably 0 μm to 3 μm. In the above range, there may be an effect of increasing the light efficiency. As the separation distance e is narrower, the light efficiency may increase because the ratio of the length d increases.

In the optical pattern 101, the sum w + d of the maximum distance w between the lower part of the optical pattern and the lower part of the immediately adjacent optical pattern and the maximum width d of the lower part is 30 μm to 180 μm, for example For example, the thickness may be 40 μm to 180 μm. In this range, there may be an effect of minimizing light loss and increasing front brightness.

In the optical pattern 101, the maximum width d of the lower part of the lower part may be 2 to 5 times, preferably 3 to 5 times the maximum distance w between the lower parts of the optical pattern, The effect of the front luminance increase can be obtained. This is because only the light incident on the lower part of the optical pattern 101 is fully reflected by the inclined surface of the optical pattern, thereby contributing to the increase in front luminance.

Although not shown in FIG. 1, the optical pattern 101 may be formed in an extended form of a stripe type. The optical patterns 101 may be arranged in the same direction with respect to the direction in which light is emitted from the light source in the liquid crystal display. Through this, the optical pattern may be excellent in light condensing and front brightness improvement effect.

FIG. 1 illustrates a case in which the maximum separation distance, the maximum height, the maximum width of the lower part, and the minimum separation distance are the same in the optical pattern and the neighboring optical pattern, respectively. However, one or more of the maximum separation distance, the maximum height, the maximum width of the lower part, and the minimum separation distance may also be included in the scope of the present invention.

The overall thickness of the resin layer 100A may be equal to or greater than the maximum thickness of the optical pattern 101. In consideration of the manufacturing process of the optical pattern 101, the total thickness of the resin layer 100A may be 100% or more, for example, more than 100% and 120% or less of the maximum thickness of the optical pattern. The overall thickness of the resin layer 100 may be 50 μm or more, for example, 50 μm to 200 μm. Within this range, it can be used for an optical display device.

The resin layer 100A has a lower refractive index than the protective layer 200. Therefore, the light passing through the light exit surface of the resin layer 100A can be transmitted without affecting the front luminance improvement when passing through the protective layer 200. The refractive index difference between the protective layer 200 and the resin layer 100A may be 0.01 to 0.1, preferably 0.01 to 0.05. In the above range, it may not affect the front brightness improvement of the resin layer. Specifically, the refractive index of the resin layer 100A may be 1.45 to 1.60, for example, 1.50 to 1.55. In the above range, there may be an effect of increasing the light efficiency. The resin layer 100 may be formed of an optically transparent resin capable of providing the refractive index range or a resin layer composition containing the resin. For example, the resin layer may be formed of an ultraviolet curable composition or a thermosetting composition including one or more resins of (meth) acrylic, polycarbonate, silicone, and epoxy resins, but is not limited thereto.

Protective layer (200)

The protective layer 200 is formed on the light exit surface of the resin layer 100A to emit light incident from the resin layer 100A. Light transmitted through the protective layer 200 by the resin layer 100A may have improved front luminance. The resin layer 100A is formed directly on the protective layer 200. The "directly formed" means that the adhesive layer, the adhesive layer, and the adhesive layer are not interposed between the resin layer 100A and the protective layer 200.

The protective layer 200 may include at least one of a protective film or a protective coating layer that is optically transparent by transmitting light while supporting the resin layer 100A.

When the protective layer 200 is a protective film type, it may include a protective film formed of an optically transparent resin. The protective film may be formed by melting and extruding the resin. If necessary, additional stretching processes may be added. The resin may include a cellulose ester resin including triacetyl cellulose, a cyclic polyolefin resin including a cyclic olefin polymer (COP), a polycarbonate resin, a polyethylene terephthalate (PET), and the like. Polyacrylate resin containing polyester resin, polyether sulfone resin, polysulfone resin, polyamide resin, polyimide resin, acyclic-polyolefin resin, polymethyl methacrylate resin, etc. which are mentioned, It may include one or more of polyvinyl alcohol-based resin, polyvinyl chloride-based resin, polyvinylidene chloride-based resin.

The protective film may be a non-stretched film. The protective film may be a retardation film or an isotropic optical film having a predetermined range of phase difference by stretching the resin in a predetermined method. In one embodiment, the protective film may have a Re of 8,000 nm or more, specifically 10,000 nm or more, more specifically more than 10,000 nm, more specifically 10,100 nm to 15,000 nm. Within this range, rainbow stains can be prevented from being recognized. In another embodiment, the protective film may be an isotropic optical film having a Re of 60 nm or less, specifically 0 nm to 60 nm and more specifically 40 nm to 60 nm. It is possible to improve the image quality by compensating the viewing angle in the above range. The term "isotropic optical film" means a film in which nx, ny, and nz are substantially the same, and the term "substantially the same" includes both cases where the error is not only the same but also includes some errors. Preferably, the protective film may have Re of 8,000 nm or more.

In one embodiment, the protective film may include a base film and a primer layer formed on at least one side of the base film. The ratio of the refractive index of the primer layer (the refractive index of the primer layer / the refractive index of the substrate film) to the refractive index of the base film is 1.0 or less, specifically 0.6 to 1.0, more specifically 0.69 to 0.95, more specifically 0.7 to 0.9, and more Specifically, it may be 0.72 to 0.88. Within this range, the transmittance of the first base layer can be increased. The base film may have a refractive index of 1.3 to 1.7, specifically 1.4 to 1.6. In the above range, it can be used as the base film of the first base layer, it is easy to control the refractive index with the primer layer, it is possible to increase the transmittance of the first base layer. The base film may include a film formed of the above-mentioned resin. The primer layer may have a refractive index of 1.0 to 1.6, specifically 1.1 to 1.6, more specifically 1.1 to 1.5. In the above range, it has a proper refractive index compared to the base film can increase the transmittance of the base layer. The primer layer may have a thickness of 1 nm to 200 nm, specifically 60 nm to 200 nm. In the above range, it can be used in the optical film, to have a proper refractive index compared to the base film to increase the transmittance of the base layer, it can be avoided brittle phenomenon. The primer layer may be a non-urethane-based primer layer containing no urethane group. Specifically, the primer layer may be formed of a composition for a primer layer containing a resin or monomer, such as polyester, acrylic. The refractive index can be provided by controlling the mixing ratio (eg molar ratio) of these monomers. The composition for primer layers may further contain 1 or more types of additives, such as a UV absorber, an antistatic agent, an antifoamer, surfactant.

When the protective layer is a protective coating layer type, good adhesion to the resin layer, transparency, mechanical strength, thermal stability, moisture barrier properties, durability can be improved. In one embodiment, the protective coating layer may be formed of an active energy ray curable resin composition comprising an active energy ray curable compound and a polymerization initiator.

The active energy ray curable compound may include at least one of a cationically polymerizable curable compound, a radically polymerizable curable compound, a urethane resin, and a silicone resin. The cationically polymerizable curable compound may be an epoxy compound having at least one epoxy group in a molecule, or an oxetane compound having at least one oxetane ring in a molecule. The radically polymerizable curable compound may be a (meth) acrylic compound having at least one (meth) acryloyloxy group in a molecule.

The epoxy compound may be at least one of a hydrogenated epoxy compound, a chain aliphatic epoxy compound, a cyclic aliphatic epoxy compound, and an aromatic epoxy compound.

The radically polymerizable curable compound may implement a protective coating layer having excellent hardness and mechanical strength and high durability. The radically polymerizable curable compound can be obtained by reacting two or more kinds of (meth) acrylate monomers and functional group-containing compounds having at least one (meth) acryloyloxy group in a molecule, and at least two (meth) acryloyl jade in the molecule. The (meth) acrylate oligomer which has timing can be mentioned. As a (meth) acrylate monomer, the monofunctional (meth) acrylate monomer which has one (meth) acryloyloxy group in a molecule | numerator, two (meth) in a molecule | numerator The bifunctional (meth) acrylate monomer which has a) acryloyloxy group, and the polyfunctional (meth) acrylate monomer which has three or more (meth) acryloyloxy groups in a molecule | numerator can be used. The (meth) acrylate oligomer may be a urethane (meth) acrylate oligomer, a polyester (meth) acrylate oligomer, an epoxy (meth) acrylate oligomer, or the like.

The polymerization initiator can cure the active energy ray curable compound. The polymerization initiator may comprise one or more of a photocationic initiator, a photosensitizer. Photocationic initiators can be used those commonly known to those skilled in the art. Specifically, the photocationic initiator may use an onium salt containing a cation and an anion. Specifically, the cation is diphenyl iodonium, 4-methoxydiphenyl iodonium, bis (4-methylphenyl) iodonium, bis (4-tert-butylphenyl) iodonium, bis (dodecylphenyl) iodonium, (4 Triarylsulfonium, such as diaryl iodonium, triphenylsulfonium, and diphenyl-4-thiophenoxyphenylsulfonium, such as -methylphenyl) [(4- (2-methylpropyl) phenyl) iodonium; 4- (diphenylsulfonio) phenyl] sulfide etc. are mentioned. Specifically, the anion is phosphate (PF ₆ ^-) hexafluoropropane, borates (BF ₄ ^-) tetrafluoroborate, antimonate hexafluorophosphate (SbF ₆ ^-), are Senate hexafluorophosphate (AsF ₆ ^-), hexamethylene Chloro antimonate (SbCl ₆ ⁻ ) and the like. A photosensitizer can be used conventionally known to those skilled in the art. Specifically, the photosensitizer may be used at least one of thioxanthone, phosphorus, triazine, acetophenone, benzophenone, benzoin, oxime.

The active energy ray curable resin composition may further include conventional additives such as silicone-based leveling agents, ultraviolet absorbers, antistatic agents, and the like.

The protective layer 200 may have a thickness of 5 μm to 200 μm, specifically, 30 μm to 120 μm, and a protective film type of 35 μm to 100 μm, and a protective coating layer type of 5 μm to 50 μm. Can be. It can be used in the light emitting display device within the above range.

A surface treatment layer such as a primer layer, a hard coating layer, an anti-fingerprint layer, an antireflection layer, an antiglare layer, a low reflection layer, and an ultra low reflection layer may be further formed on at least one surface of the protective layer 200. The primer layer can improve adhesion between the polarizer and the protective layer. The hard coating layer, anti-fingerprint layer, anti-reflection layer, etc. may provide additional functions, such as a protective layer, a polarizing film.

The optical film 10 may have a thickness of 50 μm to 200 μm, for example, 60 μm to 150 μm. In the above range, there may be an effect of ensuring the fairness and surface hardness.

Optical films can be prepared by conventional methods known to those skilled in the art. For example, the optical film may be formed by coating the resin layer composition on the protective layer, applying the optical pattern and the flat portion, and curing the composition, but is not limited thereto. Alternatively, the optical film may be formed by a UV imprinting method so that the optical layer and the flat portion of the composition for the resin layer is formed on the protective layer.

Hereinafter, an optical film according to another embodiment of the present invention will be described with reference to FIG. 2. 2 is a cross-sectional view of an optical film according to another embodiment of the present invention.

Referring to FIG. 2, the optical film 20 is substantially the same as the optical film 10 except that the optical pattern 101 includes a resin layer 100B having a pattern portion continuously formed without being spaced apart from each other. Do. In this case, there may be an effect of increasing the light efficiency more than the optical film (10). As the w length is narrower, the light efficiency increases because the ratio of the d length increases.

Hereinafter, an optical film according to another embodiment of the present invention will be described with reference to FIG. 3. 3 is a cross-sectional view of an optical film according to another embodiment of the present invention.

Referring to FIG. 3, the optical film 30 includes the resin layer 100C filled with the filling unit 110 including a reflective material in an area between the optical pattern 101 and the immediately neighboring optical pattern 101. It is substantially the same as the optical film 10 except for that.

Filler 110 includes a reflective material. Therefore, the light reaching the filling portion can be reflected to further increase the light efficiency. Front brightness can be further improved by improving light efficiency.

The reflective material is a material that reflects light with a reflectance of 95% to 100% and does not have diffuse reflection, and may include metals such as aluminum, chromium, and nickel.

The filling unit 110 may fill at least a portion of the region between the optical pattern 101 and the immediately adjacent optical pattern 101. 3 illustrates a case in which the reflective material completely fills a region between the optical pattern 101 and the immediately neighboring optical pattern 101.

Filling unit 110 may be formed by a conventional method. For example, after forming a resin layer including a pattern portion having an optical pattern formed on one surface of the protective layer 200, the resin layer may be formed by depositing a reflective material by a vacuum deposition method between the optical pattern and an immediately adjacent optical pattern.

Hereinafter, an optical film according to another embodiment of the present invention will be described with reference to FIG. 4. 4 is a cross-sectional view of an optical film according to another embodiment of the present invention.

Referring to FIG. 4, the optical film 40 includes the resin layer 100D filled with the filling unit 110 including a reflective material in an area between the optical pattern 101 and the immediately neighboring optical pattern 101. It is substantially the same as the optical film 20 except for that.

Hereinafter, an optical film according to another embodiment of the present invention will be described with reference to FIG. 5. 5 is a cross-sectional view of an optical film according to another embodiment of the present invention.

Referring to FIG. 5, except that the optical film 50 includes the optical pattern 101 and the resin layer 100E having the reflective material coating layer 120 formed on each inclined surface of the immediately adjacent optical pattern 101. Is substantially the same as the optical film (10). At least a portion of the inclined surface of the optical pattern 101 may be coated with a reflective material, thereby producing a RECYCLE effect of the light by the inclined surface.

The polarizing plate of the present invention may include an optical film according to embodiments of the present invention. Through this, the polarizing plate of the present invention can improve the front brightness and increase the light efficiency when used in the optical display device.

A polarizing plate according to an embodiment of the present invention will be described with reference to FIG. 6. 6 is a cross-sectional view of a polarizer according to an embodiment of the present invention.

Referring to FIG. 6, the polarizing plate 60 may include a polarizing film 300 and an optical film 10. By forming the optical film 10 on the light incident surface of the polarizing film 300, the front brightness can be improved and the light efficiency can be increased.

The polarizing film 300 may polarize and transmit light incident from the optical film 10. The polarizing film 300 is formed on the light exit surface of the optical film 10, that is, the protective layer 200.

The polarizing film 300 may include a polarizer. Specifically, the polarizer may include a polyvinyl alcohol polarizer manufactured by uniaxially stretching the polyvinyl alcohol film, or a polyene polarizer manufactured by dehydrating the polyvinyl alcohol film. The polarizer may have a thickness of 5 μm to 40 μm. Within this range, it can be used for an optical display device.

The polarizing film 300 may include a polarizer and a protective layer formed on at least one surface of the polarizer. The protective layer may protect the polarizer to increase the reliability of the polarizer and increase the mechanical strength of the polarizer. The protective layer is substantially the same as described in the protective layer of the optical film. Preferably, the protective layer will be a polyester-based protective film (e.g. polyethylene terephthalate film) having a Re of at least 8,000 nm, specifically 10,000 nm or more, more specifically more than 10,000 nm, more specifically 10,100 nm to 15,000 nm. Can be.

Although not shown in FIG. 6, at least one of an adhesive layer, an adhesive layer, and an adhesive layer may be formed between the polarizing film 300 and the optical film 10 to adhere the polarizing film 300 and the optical film 10 to each other. . The adhesive layer may include one or more of an aqueous adhesive and a photocurable adhesive.

In addition, although not shown in FIG. 6, a laminate of the protective layer and the adhesive layer (or the adhesive layer or the adhesive layer) may be formed between the polarizing film 300 and the optical film 10 to increase the mechanical strength of the polarizing plate.

In addition, although not shown in FIG. 6, one or more of an adhesive layer, an adhesive layer, and an adhesive layer may be formed on the polarizing film 300 to adhere the polarizing plate to a liquid crystal panel. The adhesive layer may include a (meth) acrylic adhesive resin, a silicone adhesive resin, or the like as an adhesive resin.

The liquid crystal display device of the present invention may include the optical film of the present invention or the polarizing plate of the present invention. In one embodiment, the polarizing plate of the present invention may include a light source side polarizing plate with respect to the liquid crystal panel. The "light source side polarizing plate" means a polarizing plate positioned between the liquid crystal panel and the backlight unit. A viewer side polarizer may be formed on the liquid crystal panel to face the light source side polarizer. The viewer-side polarizing plate is a conventional polarizing plate known to those skilled in the art, and may use a polarizing plate including a polarizer and a protective layer formed on at least one surface of the polarizer. The polarizer and the protective layer are as described above.

In the LCD, the backlight unit, the light source side polarizer, the liquid crystal panel, and the viewer side polarizer may be sequentially stacked, and the light source side polarizer may include the polarizer of the present invention. The liquid crystal panel may employ a VA (vertical alignment) mode, an IPS mode, a patterned vertical alignment (PVA) mode, or a super-patterned vertical alignment (S-PVA) mode, but is not limited thereto.

Hereinafter, the configuration and operation of the present invention through the preferred embodiment of the present invention will be described in more detail. However, the following examples are provided to help the understanding of the present invention, and the scope of the present invention is not limited to the following examples.

Example  One

UV imprinting method (UV light quantity: 500mJ) with UV curable resin (SSC-5760, Shina T & C) on one side of the protective film polyethylene terephthalate (PET) film (Toyobo, thickness: 80㎛, Re = 14,000nm at wavelength 550nm) / cm ² ) to prepare an optical film including a resin layer (refractive index: 1.50) formed with a pattern portion having the specifications shown in Table 1 below.

The polyvinyl alcohol film was stretched three times at 60 ° C., adsorbed with iodine, and stretched 2.5 times in an aqueous boric acid solution at 40 ° C. to prepare a polarizer.

The prepared optical film protective layer was adhered to one surface of the polarizer with an adhesive for polarizing plate. The cycloolefin polymer film (ZEON, ZB12-052125) was adhere | attached on the other surface of the said polarizer with the adhesive agent for polarizing plates (Adeka, KRX-4031), and the polarizing plate was produced.

Example  2

In Example 1, to form a pattern having a specification of Table 1 to produce an optical film. A polarizing plate was manufactured in the same manner as in Example 1 using the prepared optical film.

Example  3

UV imprinting method (UV light quantity: 500mJ) with UV curable resin (SSC-5760, Shina T & C) on one side of the protective film polyethylene terephthalate (PET) film (Toyobo, thickness: 80㎛, Re = 14,000nm at wavelength 550nm) / cm ² irradiation) to form a pattern portion having the specifications shown in Table 1 below.

Aluminum was deposited by a vacuum deposition method with a reflective material between the optical pattern and the neighboring optical pattern to prepare an optical film having a filling part filled with the reflective material between the optical pattern and the neighboring optical pattern.

A polarizing plate was manufactured in the same manner as in Example 1 using the prepared optical film.

Example  4

In Example 3, to form a pattern having a specification of Table 1 below to prepare an optical film. A polarizing plate was manufactured in the same manner as in Example 1 using the prepared optical film.

Comparative example  One

The polyvinyl alcohol film was stretched three times at 60 ° C., adsorbed with iodine, and stretched 2.5 times in an aqueous boric acid solution at 40 ° C. to prepare a polarizer.

On one surface of the polarizer, a protective film polyethylene terephthalate (PET) film (Toyobo, thickness: 80 μm, Re = 14,000 nm at a wavelength of 550 nm) was bonded with an adhesive for a polarizing plate. The cycloolefin polymer film (ZEON, ZB12-052125) was adhere | attached on the other surface of the said polarizer with the adhesive agent for polarizing plates (Adeka, KRX-4031), and the polarizing plate was produced.

Comparative example  2

In Example 1, to form a pattern having a specification of Table 1 to produce an optical film. A polarizing plate was manufactured in the same manner as in Example 1 using the prepared optical film.

Production Example  One: Poet  Preparation of Polarizer

The polyvinyl alcohol film was stretched three times at 60 ° C., adsorbed with iodine, and stretched 2.5 times in an aqueous boric acid solution at 40 ° C. to prepare a polarizer.

A polyethylene terephthalate (PET) film (Toyobo, thickness: 80 μm, Re = 14,000 nm at a wavelength of 550 nm) was adhered to one side of the polarizer with an adhesive for polarizing plate, and a cycloolefin polymer film (ZEON, ZB12) was formed on the other side of the polarizer. -052125) was bonded with an adhesive for polarizing plate (Adeka, KRX-4031) to prepare a polarizing plate.

Production Example  2: Manufacturing Module for Liquid Crystal Display

The polarizing plate prepared in Example 1 and the comparative example of the visual recognition side polarizing plate, the glass plate (liquid crystal panel) of Example 1 were sequentially assembled with the light source side polarizing plate, thereby manufacturing a module for a liquid crystal display device. The resin layer of the polarizing plates of an Example and a comparative example was made to face a light source, and the cycloolefin polymer film was made to adhere to a glass plate (liquid crystal panel). The viewing side polarizing plate of Preparation Example 1 allowed the cycloolefin polymer film to adhere to the glass plate (liquid crystal panel), and the polyethylene terephthalate (PET) film to be disposed on the light exit surface of the polarizer.

A light source, a light guide plate, and the above-described module for a liquid crystal display were assembled to produce a liquid crystal display (a Samsung TV (40 inches, the same configuration as the UN40J6868F) except for the configuration of the liquid crystal display module of Examples and Comparative Examples).

Front luminance values were measured in the white mode at the front of the spherical coordinate system (0 °, 0 °) using EZCONTRAST X88RC (EZXL-176R-F422A4, ELDIM). The relative luminance at the front side was calculated as {(front luminance value of Example) / (front luminance value of Comparative Example 1)} × 100.

Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 Example 4 Optical pattern
shape - triangle Trapezoid Trapezoid Trapezoid Trapezoid α
(°) - 85 85 85 85 85 w
(Μm) - 10 10 10 10 10 d
(Μm) - 0 30 50 30 50 h
(Μm) - 50 50 50 50 50 e
(Μm) - 1.3 1.3 1.3 1.3 1.3 Optical pattern
Width
(Μm) - 10 40 60 40 60 Value of expression 1
(%) - 0 75 83.3 75 83.3 Reflective material
Inclusion - Not included Not included Not included include include face
Relative brightness
(%) 100 84  110 108  112  109

As shown in Table 1, the front relative luminance of the optical film and the polarizing plate according to the present embodiment was remarkably improved. On the other hand, in Comparative Example 2, the length of d was 0 μm and did not have a value of Equation 1 of the present application, so that the front light loss was maximized, so that the front relative luminance greatly decreased.

Simple modifications and variations of the present invention can be easily made by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.

Claims (19)

Polarizing film; And a polarizing plate comprising an optical film formed on the light incident surface of the polarizing film,
The optical film is a resin layer; And a protective layer formed on the resin layer,
At least one optical pattern is formed on the light incident surface of the optical film spaced apart,
The optical pattern is an embossed optical pattern formed of one or more inclined surfaces connected to the first surface and the first surface is formed on the lower surface,
The embossed optical pattern has a value of Equation 1 below 60% to 95% and a base angle α of 83 ° to 87 °:
<Equation 1>
d / (w + d) x 100
(Equation 1, d is the maximum width of the first surface of the embossed optical pattern (unit: μm)
w is the maximum distance between the embossed optical pattern and the immediately adjacent embossed optical pattern in μm,
There is no filling between the embossed optical pattern and the immediately adjacent embossed optical pattern, or
And a filling part filling at least a portion between the embossed optical pattern and the immediately adjacent embossed optical pattern and including a reflective material.
The polarizing plate according to claim 1, wherein the resin layer is formed on a light incident surface of the protective layer.
The polarizing plate according to claim 1, wherein the resin layer is formed directly with the protective layer.
delete The polarizing plate of claim 1, wherein the embossed optical pattern has a trapezoidal cross section.
The maximum width (d) of the lower part of the embossed optical pattern according to claim 1, wherein the maximum width (d) between the lower part of the embossed optical pattern and the lower part of the embossed optical pattern immediately adjacent: The polarizing plate whose ratio of the maximum height h of the optical pattern of is 1: 2-5: 2-5.
The ratio of the maximum height h of the embossed optical pattern to the maximum distance w between the lower part of the embossed optical pattern and the immediately lower part of the embossed optical pattern, wherein h / h. w) is a polarizing plate of 2 to 6.5.
The polarizing plate according to claim 1, wherein the resin layer has a lower refractive index than the protective layer.
The polarizing plate according to claim 1, wherein the embossed optical pattern has an aspect ratio of 0.5 to 2.
delete The polarizing plate of claim 1, wherein the reflective material has a reflectance of 95% to 100%.
The polarizing plate of claim 1, wherein the reflective material comprises a metal.
The polarizer of claim 1, wherein the filler comprises the filler, and the filler is completely filled with the reflective material.
The polarizing plate of claim 1, wherein an inclined surface of the embossed optical pattern is coated with the reflective material.
delete delete The polarizing plate of claim 1, wherein the optical film is formed on a light incident surface of the polarizing film by at least one of an adhesive layer, an adhesive layer, and an adhesive layer.
The polarizing plate according to claim 1, wherein a laminate of the protective layer and the adhesive layer is further formed between the polarizing film and the optical film.
A liquid crystal display device comprising the polarizing plate of any one of claims 1 to 3, 5 to 9, 11 to 14, 17, and 18.

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