KR102210261B1 - Polarizer protection film and polarizer plate comprising the same and display device comprising the polarizer plate - Google Patents

Abstract

A polarizer protective film, a polarizing plate including the same, and a display device including the polarizing plate are provided. In the case of defining the refractive index of the polarizer protective film in the slow axis direction in the plane of the polarizer protective film as n _x and the refractive index in the fast axis direction in the plane as n _y , the range of n _x -n _y values is in the range of 0 to less than 0.01 .

Description

A polarizer protective film, a polarizing plate including the same, and a display device including a polarizing plate {POLARIZER PROTECTION FILM AND POLARIZER PLATE COMPRISING THE SAME AND DISPLAY DEVICE COMPRISING THE POLARIZER PLATE}

The present invention relates to a polarizer protective film, a polarizing plate including the same, and a display device including the polarizing plate.

On the other hand, in a liquid crystal display device or an organic light emitting device (electro luminescence), a gray scale is obtained for each pixel by optically modulating transmitted light according to an input image signal or self-emission of luminance pixels according to an image signal. A layer that modulates such transmitted light or emission luminance for each pixel is referred to as a modulation function layer. In a liquid crystal display device, the liquid crystal layer corresponds to the modulation function layer, and in the organic light emitting device, the organic EL emission layer corresponds to the modulation function layer.

Since the liquid crystal layer is not itself a light valve that completely blocks light, in the case of a liquid crystal display, polarizing plates can be placed on both sides of the liquid crystal layer in the vertical direction, that is, on the backlight side and the viewer's viewing side. have.

On the other hand, since the emission layer of the organic light emitting device does not irradiate light when no voltage is applied, a completely black display is possible, and a relatively high contrast can be provided compared to a liquid crystal display device. Therefore, in the organic light emitting device, the polarizing plate is not disposed for the purpose of shielding light emission. However, in the organic light-emitting device, external light may be reflected by an internal metal line, which causes contrast reduction, and thus a polarizing plate is disposed to prevent this.

Accordingly, a technical problem to be solved by the present invention is to provide a polarizer protective film that is thin, has excellent mechanical strength, and has excellent moisture permeability, a polarizing plate including the same, and a display device including the same.

In addition, it is an object to provide a polarizer protective film capable of preventing rainbow stains, a polarizing plate including the same, and a display device including the same.

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

In the polarizer protective film according to an embodiment of the present invention for achieving the above object, when the refractive index in the slow axis direction in the plane is n _x and the refractive index in the fast axis direction in the plane is defined as n _y , the value of n _x -n _y Is in the range of 0 to less than 0.01.

In addition, the thickness of the polarizer protective film may range from 10 μm to 45 μm.

In addition, the polarizer protective film may include a polyester-based material.

In addition, the polarizer protective film may be a polyethylene terephthalate-based, polyethylene naphthalate-based, or a copolymer including them.

In addition, the polarizer protective film may have a triple coextrusion structure including the polyethylene terephthalate-based, polyethylene naphthalate-based, or a copolymer including them.

The polarizing plate according to an embodiment of the present invention for achieving the above object includes a polarizer including a polyvinyl alcohol-based resin, and a polarizer protective film laminated on at least one surface of the polarizer, and the polarizer protective film is When the refractive index in the axial direction is defined as n _x and the refractive index in the fast axis direction in the plane is defined as n _y , the range of n _x -n _y values is in the range of 0 to less than 0.01.

In addition, the thickness of the polarizer protective film may range from 10 μm to 45 μm.

In addition, the polarizer protective film may include a polyester-based material.

In addition, the polarizer protective film may be a polyethylene terephthalate-based, polyethylene naphthalate-based, or a copolymer including them.

In addition, the polarizer protective film may have a triple coextrusion structure including a polyethylene terephthalate-based, a polyethylene naphthalate-based, or a copolymer including them.

In addition, it may further include a functional layer disposed on one surface of the polarizer protective film, the functional layer is a hard-coating layer (Hard-Coating Layer), an anti-reflection layer (Anti-Reflection Layer), an anti-glare layer (Anti-Glare Layer) And it may include at least one or more of the diffusion layer.

A display device according to an embodiment of the present invention for achieving the above object includes a display panel that displays an image according to an applied signal, and at least one polarizing plate disposed on at least one surface of the display panel, wherein the at least one The above polarizing plate includes the polarizing plate of the present invention.

In addition, the display panel further includes a backlight unit that provides light to the display panel, wherein the display panel is composed of a liquid crystal cell, the polarizing plate is an upper polarizing plate disposed above the liquid crystal cell, and a lower polarizing plate disposed below the liquid crystal cell Including, the polarizer protective film may be disposed on the viewing side of the upper polarizing plate.

In addition, a quantum dot sheet disposed between the backlight unit and the display panel and including a quantum dot material may be further included.

In addition, the display panel may be formed of an organic light emitting display panel, the polarizing plate may be disposed on a viewing side of the organic light emitting display panel, and the polarizer protective film may be disposed on a viewing side of the polarizing plate.

In addition, a quantum dot sheet disposed on the viewing side of the polarizing plate and including a quantum dot material may be further included.

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

According to the embodiments of the present invention, there are at least the following effects.

The polarizer protective film of the present invention, a polarizing plate including the same, and a display device including the same have excellent mechanical strength, excellent moisture permeability, and may prevent the occurrence of rainbow stains.

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

1 is a cross-sectional view of a polarizer protective film according to an embodiment of the present invention.
2 is a cross-sectional view of a polarizing plate according to an embodiment of the present invention.
3 is a cross-sectional view of a polarizing plate according to another embodiment of the present invention.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms different from each other, and only these embodiments make the disclosure of the present invention complete, and common knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to those who have it, and the invention is only defined by the scope of the claims.

When an element or layer is referred to as “on” another element or layer, it includes all cases where another layer or other element is interposed directly on or in the middle of another element. The same reference numerals refer to the same components throughout the specification.

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

In addition, steps constituting the manufacturing method described in the present specification are sequential or continuous, or unless otherwise specified, one step constituting one manufacturing method and the other steps are in the order described in the specification. Limited and not interpreted. Accordingly, the order of the construction steps of the manufacturing method may be changed within a range that can be easily understood by those skilled in the art, and in this case, changes apparent to those of ordinary skill in the art accompanying the same are included in the scope of the present invention.

Polarizer protective film

1 is a cross-sectional view of a polarizer protective film according to an embodiment of the present invention. Referring to FIG. 1, when the refractive index of the polarizer protective film 400 is defined as n _x in the slow axis direction and n _y as the refractive index in the fast axis direction in the plane, the range of n _x -n _y values is 0 to less than 0.01 Is the range of. Also, for example, the n _x -n _y value may be in the range of 0.001 to 0.009, or may be in the range of 0.002 to 0.007. By satisfying the n _x -n _y value, it is possible to prevent a rainbow stain from being visually recognized from the outside.

The slow axis may be defined as a direction in which the in-plane refractive index of the polarizer protective film 400 is maximized, and the fast axis may be defined as a direction perpendicular to the slow axis in the plane.

In general, when the fast axis of the polarizer protective film 400 is Θr and the absorption axis is Θp, the Θr-p value is not 90° or 0°, that is, the slow axis r of the polarizer protective film 400 ) And the absorption axis Θp of the polarizer are not perpendicular (90°) or parallel (0°), a rainbow stain is visually recognized due to the effect of phase difference birefringence. When the polarizer protective film of the present invention is positioned at the end of the viewing direction, the rainbow stain may not be visually recognized without being affected by the Θr-p value.

Meanwhile, the thickness of the polarizer protective film 400 may be in the range of 10 μm to 45 μm, for example, in the range of 20 μm to 45 μm, or in the range of 30 μm to 40 μm. By satisfying the thickness range of the polarizer protective film 400, it is possible to prevent the uneven spots from being visually recognized in the range of the n _x -n _y value. In addition, the polarizing plate can be made thinner in the above thickness range.

The polarizer protective film 400 may include a polyester-based material.

As the polyester, for example, terephthalic acid, isophthalic acid, orthophthalic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5- Naphthalenedicarboxylic acid, diphenylcarboxylic acid, diphenoxyethanedicarboxylic acid, diphenylsulfonecarboxylic acid, anthracenedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,3-cyclo Hexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, malonic acid, dimethylmalonic acid, succinic acid, 3,3-diethylsuccinic acid, glutaric acid, 2,2 -Dicarboxylic acids such as dimethylglutaric acid, adipic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, azelaic acid, dimer acid, sebacic acid, suberic acid, and dodecadicarboxylic acid, Ethylene glycol, propylene glycol, hexamethylene glycol, neopentyl glycol, 1,2-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, decamethylene glycol, 1,3-propanediol, 1,4-butanediol, 1 Diols such as ,5-pentanediol, 1,6-hexadiol, 2,2-bis(4-hydroxyphenyl)propane, and bis(4-hydroxyphenyl)sulfone, but are not limited thereto. .

A homopolymer formed by polycondensing one of the above substances, or a copolymer formed by polycondensing at least one dicarboxylic acid and two or more diols, or a polycondensation of two or more dicarboxylic acids and at least one diol. Any of a copolymer and a blend resin obtained by blending two or more of these homopolymers or copolymers may be mentioned.

In an exemplary embodiment, from the viewpoint of the crystallinity of the polyester, an aromatic polyester may be used, for example, a polyethylene terephthalate (PET) system, a polyethylene naphthalate (PEN) system, or a copolymer containing them Although can be mentioned, it is not limited only to these.

In addition, the polarizer protective film 400 may have a triple coextrusion structure including a polyethylene terephthalate-based, a polyethylene naphthalate-based, or a copolymer resin containing them.

The polyester film is obtained, for example, by a method of forming a film by melt-extruding the above-described polyester resin into a film shape and cooling and solidifying it with a casting drum.

The polarizer protective film 400 is performed by biaxial stretching, and more specifically, stretching in the MD direction and stretching in the TD direction. In addition, the stretching ratio in the MD direction and the stretching ratio in the TD direction of the polarizer protective film 400 of the present invention may be substantially equal. Thereby, the shrinkage rates in each direction can be controlled. The stretching ratio in the MD direction of the polarizer protective film 400 may be in the range of 3 to 3.5 times, and the stretching ratio in the TD direction may be in the range of 2.5 to 4 times.

On the other hand, the stretching method is not particularly limited, and a vertical and horizontal sequential biaxial stretching method, a vertical and horizontal simultaneous biaxial stretching method, or the like can be employed. In an exemplary embodiment, the simultaneous biaxial stretching method may be used, but is not limited thereto. As the stretching means, any suitable stretching machine, such as a roll stretching machine, a tenter stretching machine, or a pantograph-type or linear motor-type biaxial stretching machine, may be used, but is not limited thereto.

Polarizer

2 is a cross-sectional view of a polarizing plate according to an embodiment of the present invention. Referring to FIG. 2, the polarizing plate 1 includes a polarizer 200 including a polyvinyl alcohol-based resin, and the polarizer 200 It includes a polarizer protective film 400 laminated on at least one surface, and the polarizer protective film 400 is the polarizer protective film described above. That is, when the refractive index of the polarizer protective film 400 in the in-plane slow axis direction is defined as n _x and the refractive index in the fast axis direction in the plane is defined as n _y , the range of n _x -n _y values is in the range of 0 to less than 0.01 Or, it may be in the range of 0.001 to 0.009 or in the range of 0.002 to 0.007. In addition, the thickness of the polarizer protective film may be in the range of 10 µm to 45 µm, for example, in the range of 20 µm to 45 µm, or in the range of 30 µm to 40 µm.

As mentioned above, the polarizer protective film 400 may include a polyester-based material, and may be a polyethylene terephthalate-based, a polyethylene naphthalate-based, or a copolymer including them. In addition, the polarizer protective film 400 may have a triple coextrusion structure including the polyethylene terephthalate-based, polyethylene naphthalate-based, or a copolymer containing them. Meanwhile, since these have already been described in the polarizer protective film, overlapping descriptions will be omitted.

The polarizer 200 is a film capable of converting natural light or polarized light into arbitrary polarized light, and generally can be converted into a specific linearly polarized light. As the polarizer 200, a dichroic material such as iodine or a dichroic dye is adsorbed to a hydrophilic polymer film such as a polyvinyl alcohol-based film, a partially formalized polyvinyl alcohol-based film, and an ethylene-vinyl acetate copolymer-based partial saponification film. And polyene-based oriented films such as a dehydration treatment product of pilivinyl alcohol and a dehydrochloric acid treatment product of polyvinyl chloride, and the like, but are not limited thereto. In an exemplary embodiment, a polyvinyl alcohol-based film containing iodine may have a high degree of polarization and excellent adhesion to the polarizer protective film 400, but is not limited thereto.

An adhesive layer 300 is interposed between the polarizer 200 and the polarizer protective film 400 so that the polarizer 200 and the polarizer protective film 400 may be laminated to each other. The adhesive layer 300 may include a water-based adhesive, but is not limited thereto, and may include an ultraviolet curable adhesive.

The water-based adhesive may include one or more selected from the group consisting of polyvinyl alcohol-based resins and vinyl acetate-based resins, or may include polyvinyl alcohol-based resins having a hydroxy group, but is not limited thereto.

In addition, the UV-curable adhesive may include an acrylic compound, and may be, for example, acrylic, urethane-acrylic, or epoxy. However, it is not limited thereto.

3 is a perspective view of a polarizing plate according to another embodiment of the present invention. Referring to FIG. 3, an adhesive layer 500 may be disposed on the other surface of the polarizer 200. In addition, although not shown separately, a release film is disposed on the other surface of the adhesive layer 500 to facilitate storage and transport of the polarizing plate. In addition, the adhesive layer 500 may be used for attaching a polarizing plate to a display panel to be described later.

Further, although not shown separately, a primer layer may be disposed between the polarizer 200 and the adhesive layer 500 to protect the polarizer 200 and to improve adhesion between the polarizer and the display panel. The primer layer may be formed by a method of applying a coating liquid including a water-dispersible polymer resin, water-dispersible fine particles, and water on the polarizer 200 using a bar coating method, a gravure coating method, and the like, and drying.

Meanwhile, although not shown separately, according to another embodiment of the present invention, a polarizer protective film may be laminated on both sides of the polarizer with an adhesive layer interposed therebetween. That is, a polarizer protective film, an adhesive layer, a polarizer, an adhesive layer, and a polarizer protective film may be stacked and laminated in this order, and an adhesive layer may be disposed on the polarizer protective film positioned on the surface to be laminated with the display panel to be laminated with the display panel. have

Meanwhile, although not shown separately, the polarizing plate according to another embodiment of the present invention may further include a functional layer disposed on one surface of the polarizer protective film. The functional layer may include at least one of a hard-coating layer, an anti-reflection layer, an anti-glare layer, and a diffusion layer.

More specifically, the functional layer may be formed on one surface of the polarizer protective film, that is, on a surface opposite to the surface on which the polarizer of the polarizer protective film is disposed. When describing the functional layer for example, the hard coating layer can improve the moisture-heat durability of the polarizing plate and prevent dimensional change, the anti-reflection layer can reduce reflection by extinguishing light of light incident from the outside, and the anti-glare layer It is possible to prevent glare by inducing diffusion and reflection of light incident from the outside.

Display device

Although not shown separately, the present invention may provide a display device including the polarizing plate.

The display device may include a display panel that displays an image according to an applied signal, and one or more polarizing plates disposed on at least one surface of the display panel.

The display device may be a liquid crystal display device, and when the display device is a liquid crystal display device, it may include a backlight unit in addition to the display panel and the polarizing plate. In this case, the display panel may be formed of a liquid crystal cell. The liquid crystal cell may generally include two substrates and a liquid crystal layer interposed between the substrates. One of the substrates is usually colored A filter, a counter electrode, and an alignment layer may be formed, and a liquid crystal driving electrode, a wiring pattern, a thin film transistor device, and an alignment layer may be formed on the other substrate.

In other words, the liquid crystal display may include a liquid crystal cell, a backlight unit, a lower polarizing plate disposed between the liquid crystal cell and the backlight unit, and an upper polarizing plate disposed on a viewer side of the liquid crystal cell. In addition, at least one of the upper polarizing plate and the lower polarizing plate includes the polarizer protective film described above, and more preferably, the polarizer protective film of the present invention may be disposed as a polarizer protective film positioned on the viewing side of the upper polarizing plate. have. However, the present invention is not limited thereto, and the polarizer protective film of the present invention may be disposed as a polarizer protective film on the backlight side of the lower polarizing plate.

Meanwhile, as described in the polarizing plate, a functional layer may be further disposed on one surface of the polarizer protective film, and the functional layer may be disposed on one surface of the polarizer protective film of the upper polarizing plate. That is, the functional layer may be disposed on the outermost surface of the polarizer protective film located on the viewing side of the upper polarizing plate.

An operation mode of the liquid crystal cell may be, for example, a twisted nematic mode or an electrically controlled birefrigence mode. The electrically controlled birefrigence mode may include a vertical alignment method, an optically compensated (OCB) method, an in-plane switching (IPS) method, and the like.

In general, the backlight unit may include a light source, a light guide plate, and a reflective layer. Depending on the configuration of the backlight, it can be arbitrarily classified into a direct type, a side light type, and a planar light source type.

The lower polarizing plate may be interposed between the backlight unit and the liquid crystal cell. In this case, the polarizer of the lower polarizing plate may transmit only light vibrating in a specific direction among the light incident from the light source of the backlight unit.

In addition, the upper polarizing plate may be disposed opposite the backlight of the liquid crystal cell. In this case, it may be interposed between other components of the liquid crystal display device, or may be located on the surface of the liquid crystal display device. In addition, when two polarizing plates are positioned with the liquid crystal cell interposed therebetween, transmission axes of polarizers of each polarizing plate may be orthogonal or parallel.

Meanwhile, the display device may further include a quantum dot sheet positioned between the backlight unit and the display panel and including a quantum dot material.

The term “quantum dot material” means that a semiconductor nanoparticle has a size of several to several tens of nm, and has a characteristic of emitting light differently depending on the size of the particle due to the quantum quanfinement effect. More specifically, the quantum dot material generates strong light in a narrow wavelength band, and the light emitted by the quantum dot material is generated when electrons in an unstable (excited) state descend from a conduction band to a valence band. At this time, the quantum dot material has a property of generating light of a shorter wavelength as the particle size is smaller, and generating light of a longer wavelength as the particle size is larger. Therefore, by adjusting the size of the quantum dot material, it is possible to emit all light in the visible light region of a desired wavelength.

The quantum dot material may include any one of Si-based nanocrystals, II-VI-based compound semiconductor nanocrystals, III-V-based compound semiconductor nanocrystals, IV-VI-based compound semiconductor nanocrystals, and mixtures thereof. .

The II-VI compound semiconductor nanocrystals are CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSe, CdZnS, HgSTe, CdZnS CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HggZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeTe, and at least one selected from the group consisting of HgZnSeTe, CdHgSTe, HgZnSeS, and HgZnSeS, HgZnSeS.

The III-V-based compound semiconductor nanocrystal is at least one selected from the group consisting of GaPAs, AlNP, AlNAs, AlPAs, InNP, InNAs, InPAs, GaAlNP, GaAlNAs, GaAlPAs, GaInNP, GaInNAs, GaInPAs, InAlNP, InAlNAs, and InAlPAs. It may include.

The IV-VI compound semiconductor nanocrystal may include SbTe.

In quantum dot materials, the smaller the particle, the shorter wavelength light is generated, and the larger the particle, the longer wavelength light is emitted. For example, a size of 55 to 65 Å generates red light, a size of 40 to 50 Å generates green light, and a size of 20 to 35 Å generates blue light. As described above, the quantum dot material can improve the optical efficiency of the display device by generating strong light in a narrow wavelength band at a wavelength corresponding to each color according to the size of the particles. Meanwhile, a display device uses an organic light emitting device. It may be an organic light-emitting display device (Organic Light-Emitting Diode: OLED), and in this case, the display panel may be an organic light-emitting display panel. . The organic light emitting display panel may include respective pixels, and each of the pixels may include an OLED composed of an organic emission layer between an anode and a cathode, and a pixel circuit that independently drives the OLED. The pixel circuit may mainly include a switching thin film transistor (TFT), a capacitor, and a driving TFT. The switching thin film transistor charges the data voltage to the capacitor in response to the scan pulse, and the driving TFT can control the amount of current supplied to the OLED according to the data voltage charged to the capacitor, thereby controlling the amount of light emitted by the OLED and displaying the image. Can be displayed. Meanwhile, since the organic light emitting display panel is widely known in the art, a more detailed description will be omitted.

The polarizing plate may be disposed on the viewing side of the organic light emitting display panel, and the polarizer protective film may be disposed on the outermost side of the polarizing plate. That is, the polarizing plate may be attached to the side where the viewer observes the image displayed from the organic light emitting display panel, and the polarizer protective film may be disposed on the viewing side of the polarizing plate where the viewer observes the image. Accordingly, it is possible to prevent a decrease in contrast due to reflection of light incident from the outside.

In the case of an organic light emitting diode display, when a functional layer is disposed on the polarizer protective film, the functional layer may be disposed on the visible side of the polarizer protective film.

Meanwhile, the organic light-emitting display device may be disposed on the viewing side of the polarizing plate and further include a quantum dot sheet including a quantum dot material, thereby increasing the optical efficiency of the organic light-emitting display device. The quantum dot sheet has been described in the liquid crystal display, and redundant descriptions will be omitted.

Hereinafter, the present invention will be described through specific experimental data.

Examples 1 to 4

When the refractive index of the polarizer protective film in the in-plane slow axis direction is n _x and the refractive index in the in-plane fast axis direction is n _y , the polarizer protective film was prepared by setting n _x -n _y values as shown in Table 1 below. After applying to a polarizing plate, a liquid crystal panel was manufactured by attaching to a display panel. Table 1 below shows the n _x -n _y values and thickness of each example.

Comparative Examples 1 to 4

A polarizer protective film was prepared by setting n _x -n _y values as shown in Table 1 below, and applied to a polarizing plate and then attached to a display panel to manufacture a liquid crystal panel. Table 1 below shows the n _x -n _y values and thickness of each example.

Experimental example

The rainbow mura of the liquid crystal panels of Examples 1 to 4 and Comparative Examples 1 to 4 was observed and shown in Table 1 below. The evaluation of the rainbow mura was performed by visual evaluation, and the visual evaluation was performed by visually discriminating color and mura by varying the front and viewing angles of the liquid crystal panel to which the polarizing plate is attached to the display panel.

n _x -n _y Thickness(㎛) Rainbow mura Comparative Example 1 0.012 40 Lv. 5 Comparative Example 2 0.011 41 Lv. 4 Comparative Example 3 0.010 41 Lv. 4 Comparative Example 4 0.010 50 Lv. 5 Example 1 0.009 38 Lv. 3 Example 2 0.008 40 Lv. 3 Example 3 0.002 40 Lv. One Example 4 0.007 45 Lv. 2

In the evaluation of the rainbow village of Table 1, the visual evaluation is Lv. It is divided into 1 to 10 levels, and Lv. As the number goes to 1, it means that the occurrence of Rainbow Mura decreases. Rainbow Mura is Lv. 1 to Lv. In case of 3, it means the level of applicable panel, and Lv. 4 or more means that there is a degree of mura that the panel cannot apply. As shown in Table 1, in the case of the comparative example, the rainbow mura phenomenon occurs relatively more, whereas in the examples satisfying the range of n _x -n _y values of the present invention, the rainbow mura is less than the level applicable to the panel. You can see what is observed.

It goes without saying that all the embodiments described above are exemplary, and different embodiments may be applied in combination with each other.

1, 2: polarizer
200: polarizer
300: adhesive layer
400: polarizer protective film
500: adhesive layer

Claims (16)

delete delete delete delete delete Polarizer comprising a polyvinyl alcohol-based resin; And
Including; a polarizer protective film laminated on the viewing side of the polarizer,
The slow axis of the polarizer protective film and the absorption axis of the polarizer are not perpendicular (90°) or parallel (0°),
When the refractive index of the polarizer protective film in the in-plane slow axis direction is defined as n _x and the refractive index in the fast axis direction in the plane is defined as n _y , the range of n _x -n _y values is in the range of 0.005 to 0.009,
The polarizer protective film has a thickness of 35 μm to 45 μm, a polarizing plate. The method of claim 6,
The polarizing plate is that the slow axis of the polarizer protective film and the absorption axis of the polarizer are not perpendicular (90°). The method of claim 6,
The polarizer protective film is a polarizing plate comprising a polyester-based material. The method of claim 8,
The polarizer protective film is a polarizing plate comprising a polyethylene terephthalate-based, polyethylene naphthalate-based, or a copolymer containing them. The method of claim 8,
The polarizer protective film is a polarizing plate having a triple coextrusion structure comprising a polyethylene terephthalate-based, a polyethylene naphthalate-based, or a copolymer containing them. The method of claim 6,
Further comprising a functional layer disposed on one surface of the polarizer protective film,
The functional layer is a polarizing plate including at least one of a hard-coating layer, an anti-reflection layer, an anti-glare layer, and a diffusion layer. A display panel that displays an image according to an applied signal; And
Including; an upper polarizing plate disposed on the viewer side of the display panel,
The upper polarizing plate includes the polarizing plate of any one of claims 6 to 11. The method of claim 12,
Further comprising a backlight unit providing light to the display panel,
The display panel is composed of a liquid crystal cell,
The display device further includes a lower polarizing plate disposed under the liquid crystal cell. The method of claim 13,
A display device further comprising a quantum dot sheet positioned between the backlight unit and the display panel and including a quantum dot material. The method of claim 12,
The display device is configured of an organic light emitting display panel. The method of claim 15,
A display device further comprising a quantum dot sheet disposed on a viewer side of the upper polarizing plate and including a quantum dot material.

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