KR20210121781A - Film for compensating viewing angle, polarizing plate comprising the same and display device comprising the same - Google Patents

Abstract

A viewing angle compensation film according to an exemplary embodiment of the present application includes: a first light control layer including a first protrusion pattern layer and a first planarization layer; and a second light control layer including a second protrusion pattern layer and a second planarization layer. The first protrusion pattern layer includes a symmetrical protrusion pattern. The second protrusion pattern layer includes an asymmetrical protrusion pattern.

Description

Viewing angle compensation film, polarizing plate including same, and display device including the same

The present application relates to a viewing angle compensation film, a polarizing plate including the same, and a display device including the same.

Liquid crystal display devices are widely used from mobile phones and portable small electronic devices to large electronic devices such as personal computers and televisions, and their use is one of the flat panel displays that are gradually expanding.

As the use of the display device expands, the place where the display device is placed and the location thereof are diversified. However, the flat panel display has a problem in that a clear image cannot be obtained when viewed from a direction other than the front of the display. In particular, in the case of a vehicle display, since the position of the display and the driver's gaze are not parallel, there is a problem in that a clear image cannot be obtained from the driver's field of view.

Accordingly, in order to solve such a problem, the development of a display device capable of improving a viewing angle and a contrast ratio is required.

Republic of Korea Patent Publication No. 10-1210985

An object of the present application is to provide a viewing angle compensation film, a polarizing plate including the same, and a display device including the same.

An exemplary embodiment of the present application is,

a first light control layer including a first protrusion pattern layer and a first planarization layer; and

A second light control layer comprising a second protrusion pattern layer and a second planarization layer,

The first protrusion pattern layer includes a symmetrical protrusion pattern,

The second protrusion pattern layer provides a viewing angle compensation film comprising an asymmetrical protrusion pattern.

In addition, another exemplary embodiment of the present application provides a polarizing plate including the viewing angle compensation film.

In addition, another embodiment of the present application is,

liquid crystal cell;

a first polarizing plate provided on the viewing side of the liquid crystal cell;

a second polarizing plate provided on the opposite side of the viewing side of the liquid crystal cell; and

And a backlight unit provided on the opposite side of the surface facing the liquid crystal cell of the second polarizing plate,

It provides a display device that the first polarizing plate or the second polarizing plate is the polarizing plate.

The viewing angle compensation film according to an exemplary embodiment of the present application includes a first light control layer including a symmetrical protrusion pattern and a second light control layer including an asymmetrical protrusion pattern at the same time. However, there is a feature that can also improve the brightness near the center.

Accordingly, the viewing angle compensation film according to an exemplary embodiment of the present application may be applied to various display devices. In particular, when the viewing angle compensation film is applied to a vehicle display device, a clear image can be obtained in the driver's field of view.

1 and 2 are views schematically showing a viewing angle compensation film according to an exemplary embodiment of the present application, respectively.
3 is a diagram schematically illustrating a first light control layer according to an exemplary embodiment of the present application.
4 is a diagram schematically illustrating a second light control layer according to an exemplary embodiment of the present application.
5 to 9 are views illustrating simulation results of brightness distribution of a backlight unit to which the viewing angle compensation films of Example 1 and Comparative Examples 1 to 4 are applied, respectively.

Hereinafter, preferred embodiments of the present application will be described. However, the embodiments of the present application may be modified in various other forms, and the scope of the present application is not limited to the embodiments described below. In addition, the embodiments of the present application are provided to explain the present invention in more detail to those with ordinary knowledge in the art.

In the present application, the term “viewing side” refers to a surface or direction in which the polarizer is disposed to face the viewer when the polarizer is mounted on a display device such as a liquid crystal display. Conversely, the term "opposite to the viewing side" means a plane or direction disposed so that the polarizing plate faces the opposite side of the viewer, that is, the backlight unit when it is mounted on a display device such as a liquid crystal display device.

In the present application, "extension" means to lengthen while maintaining the inclination of a straight line or plane.

In the present application, the term “flat surface” means that the centerline average roughness (Ra) is less than 0.1 μm.

A display for automobiles must not only express clear picture quality (C/R) from the front as well as the driver's viewing angle, but also secure the brightness in the near-center field of view. A viewing angle compensation film using a symmetrical or asymmetrical micro-shape has been studied to obtain clear image quality at the driver's viewing angle. Accordingly, in the present application, a viewing angle compensation film capable of improving not only the brightness at the viewing angle but also the brightness near the center was studied, and the present invention was completed.

A viewing angle compensation film according to an exemplary embodiment of the present application includes: a first light control layer including a first protrusion pattern layer and a first planarization layer; and a second light control layer including a second protrusion pattern layer and a second planarization layer, wherein the first protrusion pattern layer includes a symmetrical protrusion pattern, and the second protrusion pattern layer has asymmetrical protrusions. Includes patterns.

In the exemplary embodiment of the present application, a difference in refractive index between the first protrusion pattern layer and the first planarization layer may be 0.02 to 0.2, or 0.05 to 0.1. In this case, the refractive index of the higher refractive index of the first protrusion pattern layer and the first planarization layer may be about 1.45 to 1.7, and the refractive index of the lower refractive index may be 1.3 to 1.55. The refractive index is measured at a wavelength of 590 nm. When the refractive index difference between the first protrusion pattern layer and the first planarization layer is less than 0.02, the optical path control effect is lowered and sufficient light collecting performance cannot be obtained. will do

In an exemplary embodiment of the present application, the first protrusion pattern layer includes a first surface including a flat surface; and a second surface facing the first surface and including a plurality of protrusions, wherein each of the protrusions constituting the first protrusion pattern layer includes a first inclined surface and a second inclined surface, and the first inclined surface or the second inclined surface extending the first inclined surface and the angle between the first surface forms (θ ₁₎ and the second angle (θ ₂₎ if one extends the second inclined surface or the second inclined surface and the first surface forming a have the same angle to each other. In this case, θ ₁ and θ ₂ may be 60° to 75°, or 60° to 70°.

_{In an exemplary embodiment of the present application, the angle (θ A} ) formed by the first inclined surface or the surface extending the first inclined surface and the second inclined surface or the extending surface of the second inclined surface may be 30 ° to 60 °, It may be 40° to 60°. _{When the angle θ A} between the first inclined surface or the surface extending the first inclined surface and the second inclined surface or the surface extending the second inclined surface meets the above range, the light incident on the viewing angle compensation film is condensed By adjusting the angle of refraction to achieve this, the viewing angle of the display device can be adjusted, and the effect of improving the contrast ratio can be obtained.

In the exemplary embodiment of the present application, the first protrusion pattern layer includes a symmetrical protrusion pattern. The height of the symmetrical protrusion pattern may be in a range of 4 μm to 190 μm, and may be in a range of 10 μm to 100 μm. In addition, a pitch of the symmetrical protrusion pattern may be 5 μm to 100 μm, or 5 μm to 50 μm. When the height and pitch of the symmetrical protrusion pattern satisfy the above ranges, the viewing angle of the display device can be adjusted by adjusting the refraction angle so that the light incident on the viewing angle compensation film forms a condensing shape, and a contrast ratio improvement effect can be obtained. .

In the exemplary embodiment of the present application, the difference in refractive index between the second protrusion pattern layer and the second planarization layer may be 0.08 to 0.2, or 0.1 to 0.17. In this case, the refractive index of the higher refractive index of the second protrusion pattern layer and the second planarization layer may be about 1.45 to 1.7, and the refractive index of the lower refractive index may be 1.3 to 1.55. The refractive index is measured at a wavelength of 590 nm. When the refractive index difference between the second protrusion pattern layer and the second planarization layer is less than 0.08, the optical path control effect is lowered and sufficient light collecting performance cannot be obtained. will do

In an exemplary embodiment of the present application, the second protrusion pattern layer includes a third surface including a flat surface; and a fourth surface facing the third surface and including a plurality of protrusions, wherein each of the protrusions constituting the second protrusion pattern layer includes a third inclined surface and a fourth inclined surface, and the third inclined surface or the third inclined surface The angle (θ ₃ ) between the extended surface of the third inclined surface and the third surface and the fourth inclined surface or the angle (θ ₄ ) formed between the extended surface and the third surface are different from each other. In this case, the θ ₃ may be 80° to 90°, or 85° to 90°. In addition, the θ ₄ may be 30° to 60°, or 40° to 60°.

_{In an exemplary embodiment of the present application, the angle (θ B} ) formed by the third inclined surface or the surface extending the third inclined surface and the fourth inclined surface or the extending surface of the fourth inclined surface may be 30 ° to 60 °, It may be 40° to 60°. _{When the angle θ B} between the third inclined surface or the surface extending the third inclined surface and the fourth inclined surface or the surface extending the fourth inclined surface meets the above range, the light incident on the viewing angle compensation film is condensed By adjusting the angle of refraction to achieve this, the viewing angle of the display device can be adjusted, and the effect of improving the contrast ratio can be obtained.

In the exemplary embodiment of the present application, the second protrusion pattern layer includes an asymmetrical protrusion pattern. The height of the asymmetrical protrusion pattern may be in a range of 1 μm to 180 μm, and may be in a range of 10 μm to 100 μm. In addition, a pitch of the asymmetrical protrusion pattern may be 5 μm to 100 μm, or 5 μm to 50 μm. When the height and pitch of the asymmetrical protrusion pattern satisfy the above ranges, the viewing angle of the display device can be adjusted by adjusting the refraction angle so that the light incident on the viewing angle compensation film forms a condensed form, and a contrast ratio improvement effect can be obtained. .

In the exemplary embodiment of the present application, the first protrusion pattern layer including the symmetrical protrusion pattern and the second protrusion pattern layer including the asymmetrical protrusion pattern may be provided in a shape perpendicular to each other. The orthogonal shape means that the grain direction of the protrusion shape of the symmetrical protrusion pattern and the asymmetrical protrusion pattern is perpendicular to each other. In the symmetrical protrusion pattern of the first protrusion pattern layer, the grain direction of the symmetrical protrusion pattern is perpendicular to the periodic direction and horizontal to the first surface. In addition, in the protrusion pattern of the asymmetric shape of the second protrusion pattern layer, the grain direction of the protrusion pattern of the asymmetric shape is perpendicular to the periodic direction and means a direction horizontal to the third surface. In the viewing angle compensation film including the first light control layer and the second light control layer, the angle between the grain direction of the symmetrical protrusion pattern and the grain direction of the asymmetrical protrusion pattern is the smaller of the two grain directions. means, and the range of this value may be 80 degrees to 90 degrees.

In an exemplary embodiment of the present application, at least one surface of the first light control layer and the second light control layer may further include at least one of a base layer and an adhesive layer.

As the base layer and the adhesive layer, those known in the art may be used, and are not particularly limited. For example, the base layer is polyester, polyacrylic, polyvinyl chloride, polycarbonate, polymethyl methacrylate, polystyrene, polyester sulfone, polybutadiene, triacetate cellulose film (TAC), cycloolefin polymer (COP), polyethylene It may be terephthalate (PET) or an acrylic film, but is not limited thereto. The acrylic film may include a (meth)acrylate-based resin, and the film including the (meth)acrylate-based resin is formed by extrusion molding a molding material containing the (meth)acrylate-based resin as a main component. can be obtained

In addition, the adhesive layer may be an optical clear adhesive (OCA) film.

In the exemplary embodiment of the present application, a plurality of protrusions included in the second surface of the first protrusion pattern layer may be continuously disposed. When the plurality of protrusions are continuously provided, the pattern layer may be formed such that the first inclined surface of one protrusion and the second inclined surface of the other protrusion contact each other. According to another exemplary embodiment, the plurality of protrusions may be provided non-continuously. In the exemplary embodiment of the present application, at least one cross-section perpendicular to the first surface of the protrusion may have a triangular, quadrangular, or pentagonal shape.

When at least one cross section perpendicular to the first surface of the protrusion has a triangular shape, one end of the first inclined surface is in contact with the end of the second inclined surface, and the other end is formed to contact the first surface, An end of the second inclined surface that is not in contact with the end of the first inclined surface may be formed to contact the first surface.

When at least one cross-section perpendicular to the first surface of the protrusion has a rectangular shape, one end of the first inclined surface and one end of the second inclined surface are in contact with the first surface, and the other end and the second end of the first inclined surface are in contact with the first surface. 2 It includes an additional inclined surface formed to abut against the other end of the inclined surface, or one end of the first inclined surface is in contact with the first surface, and the other end is formed so that the other end is in contact with the end of the second inclined surface, the first inclined surface and an end of the second inclined surface that does not abut the end and an additional inclined surface formed to abut the first surface.

When at least one cross section perpendicular to the first surface of the protrusion has a pentagonal shape, a plurality of protrusions are continuously formed, the protrusions include a first inclined surface and a second inclined surface, and the first inclined surface of one protrusion The end of the second inclined surface of the protrusion adjacent to the end of the abuts against each other, but is formed so as not to be in contact with the first surface.

In addition, in the exemplary embodiment of the present application, the content of the first protrusion pattern layer may be applied, except that the second protrusion pattern layer includes a protrusion pattern having an asymmetric shape.

In the exemplary embodiment of the present application, the first planarization layer is provided on the second surface side of the first protrusion pattern layer. In another exemplary embodiment, the first planarization layer is provided to be in contact with the second surface of the first protrusion pattern layer.

In the exemplary embodiment of the present application, the second planarization layer is provided on the fourth surface side of the second protrusion pattern layer. In another exemplary embodiment, the second planarization layer is provided to be in contact with a fourth surface of the second protrusion pattern layer.

In the exemplary embodiment of the present application, the material of the first protrusion pattern layer and the second protrusion pattern layer may each independently be an ultraviolet curable resin, but is not limited thereto. As an example of the ultraviolet curable resin, epoxy (meth) acrylate, urethane (meth) acrylate, phenylphenol ethoxylated (meth) acrylate, trimethylol propane ethoxylated (meth) acrylate, phenoxy Benzyl (meth) acrylate, phenylphenoxyethyl (meth) acrylate, ethoxylated thiodiphenyl di (meth) acrylate, phenylthioethyl (meth) acrylate monomers or oligomers thereof, or fluorene derivative unsaturated It may include a resin, but is not limited thereto.

In the exemplary embodiment of the present application, the materials of the first planarization layer and the second planarization layer may be each independently formed using an ultraviolet curable resin or an acrylate-based adhesive. Each of the first planarization layer and the second planarization layer may each independently have a thickness of about 1 μm to about 200 μm.

The viewing angle compensation film according to an exemplary embodiment of the present application may further include one or more optical layers. The optical layer may be an anti-glare layer (AG), a hard coating layer (HC), a low refractive index layer (LR), an anti-glare & low-reflection (AGLR), an anti-reflection layer (AR), and the like, but is not limited thereto.

The hard coating layer, the anti-glare layer (AG), the low refractive index layer (LR), the AGLR (Anti-Glare & Low-Reflection) and the anti-reflection layer (AR) may be formed of a material of a general-purpose primer layer, the hard coating layer, Each of the anti-glare layer (AG), the low refractive index layer (LR), the anti-glare & low-reflection (AGLR) layer, or the anti-reflection layer (AR) may have a thickness of 1 μm to 100 μm.

A refraction angle of light passing through the pattern layer of the viewing angle compensation film may be 1° to 20°. According to another exemplary embodiment, it may be 3° to 15°.

A viewing angle compensation film according to an exemplary embodiment of the present application is schematically shown in FIGS. 1 and 2, respectively. 1 and 2, the viewing angle compensation film according to an exemplary embodiment of the present application includes a first light control layer 10; and a second light control layer 20 .

The first light control layer according to an exemplary embodiment of the present application is schematically shown in FIG. 3 below. 3 , the first light control layer according to an exemplary embodiment of the present application includes a first protrusion pattern layer 30 and a first planarization layer 40 . In this case, the first protrusion pattern layer 30 may include a first surface 70 including a flat surface; and a second surface 80 facing the first surface and including a plurality of protrusions, wherein each of the protrusions constituting the first protrusion pattern layer 30 includes a first inclined surface 90 and a second inclined surface ( _{100), and the angle θ 1} between the first inclined surface 90 or the surface extending the first inclined surface 90 and the first surface 70 and the second inclined surface 100 or the second inclined surface _{The angle (θ 2} ) formed between the extended surface ( 100 ) and the first surface ( 70 ) has the same angle.

A second light control layer according to an exemplary embodiment of the present application is schematically shown in FIG. 4 below. 4 , the second light control layer according to an exemplary embodiment of the present application includes a second protrusion pattern layer 50 and a second planarization layer 60 . In this case, the second protrusion pattern layer 50 may include a third surface 110 including a flat surface; and a fourth surface 120 facing the third surface 110 and including a plurality of protrusions, wherein each of the protrusions constituting the second protrusion pattern layer 50 includes a third inclined surface 130 and a third protrusion. It includes 4 inclined surfaces 140 , and the third inclined surface 130 or an angle (θ ₃ ) formed between the third inclined surface 130 or the extended surface of the third inclined surface 130 and the fourth inclined surface 140 or _{The angle (θ 4} ) formed by the extended surface of the fourth inclined surface 140 and the third surface 130 has different angles from each other.

In addition, another exemplary embodiment of the present application provides a polarizing plate including the viewing angle compensation film.

In an exemplary embodiment of the present application, the polarizing plate includes a polarizer, the polarizer is not particularly limited, and a polarizer well known in the art, for example, polyvinyl alcohol (PVA) containing iodine or a dichroic dye ) may be used.

A polarizer exhibits a characteristic of extracting only light vibrating in one direction from incident light while vibrating in multiple directions. These properties can be achieved by stretching polyvinyl alcohol (PVA), which has absorbed iodine, with a strong tension. For example, more specifically, a step of swelling the PVA film by immersing it in an aqueous solution to swell, dyeing the swollen PVA film with a dichroic material that imparts polarization, stretching the dyed PVA film ) to form a polarizer through a stretching step of arranging the dichroic dye material side by side in the stretching direction, and a complementary color step of correcting the color of the PVA film that has undergone the stretching step. However, the polarizing plate of the present application is not limited thereto.

In addition, the polarizing plate may be provided with a general-purpose polarizer protective film commonly used on one or both sides of the polarizer.

In an exemplary embodiment of the present application, the viewing angle compensation film may be provided on the outermost side of the polarizing plate.

In addition, the polarizing plate including the viewing angle compensation film according to an exemplary embodiment of the present application may be applied to a display device.

A display device according to an exemplary embodiment of the present application includes a liquid crystal cell; a first polarizing plate provided on the viewing side of the liquid crystal cell; a second polarizing plate provided on the opposite side of the viewing side of the liquid crystal cell; and a backlight unit provided on the opposite side of the surface of the second polarizing plate facing the liquid crystal cell, wherein the first polarizing plate or the second polarizing plate may be the polarizing plate of the present invention described above.

The backlight unit includes a light source irradiating light from the rear surface of the liquid crystal panel, and the type of the light source is not particularly limited, and a general LCD light source such as CCFL, HCFL, or LED may be used.

In one embodiment of the present invention, the display device for screen display may be a vehicle display device.

According to an exemplary embodiment of the present application, as the main viewing angle (maximum brightness angle) of the display device is changed and the light concentration is increased, the contrast ratio (C/R, Contrast Ratio) at a position not parallel to the display device is increased. can be improved.

Hereinafter, the embodiments described in the present specification are illustrated through examples. However, it is not intended that the scope of the above embodiments be limited by the following examples.

<Example>

<Example 1> Symmetric and asymmetric application simultaneously

As shown in FIG. 1 below, the simulation was performed by configuring the viewing angle compensation film stacked in the order of the first light control layer 10/second light control layer 20 . Simulation was performed using ZEMAX's OpticStudio.

1) first light control layer

_{① First protrusion pattern layer: The angle θ A} between the first inclined surface and the second inclined surface _{is 50°, the angle θ 1} between the first inclined surface and the first surface is 65°, and the second inclined surface is the first The angle (θ ₂ ) formed with the plane is 65° (refractive index at a wavelength of 590 nm: 1.48)

The height of the protrusions of the pattern layer was 28 μm, the pitch of the protrusions was 15 μm, and the aspect ratio of the protrusions was 1.87.

② First planarization layer: provided on the first protrusion pattern layer (refractive index at a wavelength of 590 nm: 1.55)

2) second light control layer

_{① second protrusion pattern layer: an angle θ B} between the third inclined surface and the fourth inclined surface _{is 42°, an angle θ 3} between the third inclined surface and the third surface is 88°, and the fourth inclined surface is a third The angle (θ ₄ ) formed with the plane is 50° (refractive index at a wavelength of 590 nm: 1.48)

The height of the protrusions of the pattern layer was 28 μm, the pitch of the protrusions was 15 μm, and the aspect ratio of the protrusions was 1.87.

② Second planarization layer: provided on the second protrusion pattern layer (refractive index at a wavelength of 590 nm: 1.61)

<Comparative Example 1> Ref.

As a reference, a simulation was performed by configuring a display device to which the viewing angle compensation film of Example 1 was not applied.

<Comparative Example 2> Apply only symmetrical structure (inclination angle of 75 degrees)

In Example 1, the second light control layer was not applied, and only the first light control layer of the following configuration was applied.

1) first light control layer

_{① First protrusion pattern layer: The angle θ A} between the first inclined surface and the second inclined surface _{is 30°, the angle θ 1} between the first inclined surface and the first surface is 75°, and the second inclined surface is the first The angle (θ ₂ ) formed with the plane is 75° (refractive index at a wavelength of 590 nm: 1.43)

The height of the protrusions of the pattern layer was 28 μm, the pitch of the protrusions was 15 μm, and the aspect ratio of the protrusions was 1.87.

② First planarization layer: provided on the first protrusion pattern layer (refractive index at a wavelength of 590 nm: 1.61)

<Comparative Example 3> Apply only symmetrical structure (inclination angle 65 degrees)

In Example 1, the second light control layer was not applied, and only the first light control layer of the following configuration was applied.

1) first light control layer

_{① First protrusion pattern layer: The angle θ A} between the first inclined surface and the second inclined surface _{is 50°, the angle θ 1} between the first inclined surface and the first surface is 65°, and the second inclined surface is the first The angle (θ ₂ ) formed with the plane is 65° (refractive index at a wavelength of 590 nm: 1.48)

The height of the protrusions of the pattern layer was 28 μm, the pitch of the protrusions was 15 μm, and the aspect ratio of the protrusions was 1.87.

② First planarization layer: provided on the first protrusion pattern layer (refractive index at a wavelength of 590 nm: 1.55)

<Comparative Example 4> Apply only asymmetric structure

In Example 1, the first light control layer was not applied, and only the second light control layer of the following configuration was applied.

1) second light control layer

_{① second protrusion pattern layer: an angle θ B} between the third inclined surface and the fourth inclined surface _{is 42°, an angle θ 3} between the third inclined surface and the third surface is 88°, and the fourth inclined surface is a third The angle (θ ₄ ) formed with the plane is 50° (refractive index at a wavelength of 590 nm: 1.48)

The height of the protrusions of the pattern layer was 28 μm, the pitch of the protrusions was 15 μm, and the aspect ratio of the protrusions was 1.87.

② Second planarization layer: provided on the second protrusion pattern layer (refractive index at a wavelength of 590 nm: 1.61)

<Experimental Example 1>

Simulation was performed by configuring a display device including the viewing angle compensation film of the Examples and Comparative Examples.

The viewing angle compensation film of the embodiment or comparative example is disposed on the opposite side (opposite side to the viewing side) of the polarizer side of the lower polarizer on the opposite side to the liquid crystal cell side, the flattening layer is facing the polarizer side (viewing side), and the protrusion pattern layer is on the backlight It was placed to face the corresponding light source.

The brightness distribution of the display device was calculated, and the results are shown in Table 1, respectively.

Liquid crystal displays (LCDs) are used in various devices such as TVs, monitors, mobile phones, and tablet PCs. The liquid crystal display is a numerical value indicating performance, and the performance is expressed using a numerical value called CR (contrast ratio) indicating the ratio of white front brightness (On state) and black front brightness (Off state), and the CR is The higher the rating, the better the device.

However, for the sake of technological development and human convenience, liquid crystal displays have begun to be applied to fields that have not been previously applied, and liquid crystal displays for automobiles such as automobile dashboards and navigation systems are being introduced. In the case of such a liquid crystal display for automobiles, the screen is mostly viewed from the side rather than from the front as in the case of a conventional liquid crystal display (TV, mobile phone, etc.). Accordingly, in the present application, in addition to the front CR indicating the performance of the liquid crystal display, a numerical value called Area A CR that quantifies the performance at the viewing angle has been introduced.

In the case of a liquid crystal display, CR at a specific viewing angle tends to increase in proportion to brightness. Therefore, in the present application, Area A brightness (Intensity), which is a numerical value proportional to Area A CR, was calculated and compared.

Area A means an area where Theta/Phi has four vertices of 42°/23°, 42°/157°, 41°/192°, and 41°/348°, respectively, in the polar coordinate system. In this case, Theta denotes an angle between the normal of the display surface and the field of view, and Phi denotes an angle between the left and right horizontal lines of the display and the field of view.

Area A+ means the viewing angle area near the center, and Theta/Phi has four vertices of 13°/39°, 13°/141°, 11°/202°, and 11°/338°, respectively, in the polar coordinate system.

Both Area A and Area A+ correspond to the viewing angle evaluation standard for automotive displays.

[Table 1]

As described above, in Comparative Example 2, there is a problem in that the brightness decrease rate in Area A+ is large, and in Comparative Examples 3 and 4, there is a problem in that the brightness increase rate in Area A is small. However, according to Example 1, which is an exemplary embodiment of the present application, it can be confirmed that the effect of increasing the CR in Area A and minimizing the brightness decrease rate in Area A+ can be obtained. In particular, when looking at the results of Comparative Example 2 corresponding to the conventional structure, the brightness at 42°/157°, where the brightness is the lowest in Area A, increases to 129%, but 13°/141° with the lowest brightness in Area A+. It can be seen that the brightness is reduced to 75%. In the case of Example 1 according to an exemplary embodiment of the present application, the brightness at 42°/157° is increased to 130%, and the brightness at 13°/141° is 87%, compared to Comparative Example 2 near the center It can be seen that the decrease in brightness is small.

As described above, the viewing angle compensation film according to an exemplary embodiment of the present application includes a first light control layer including a symmetrical protrusion pattern and a second light control layer including an asymmetrical protrusion pattern at the same time, Not only the brightness at the viewing angle but also the brightness near the center can be improved.

Accordingly, the viewing angle compensation film according to an exemplary embodiment of the present application may be applied to various display devices. In particular, when the viewing angle compensation film is applied to a vehicle display device, a clear image can be obtained in the driver's field of view.

10: first light control layer
20: second light control layer
30: first protrusion pattern layer
40: first planarization layer
50: second protrusion pattern layer
60: second planarization layer
70: the first surface of the first protrusion pattern layer
80: second surface of the first protrusion pattern layer
90: first inclined surface
100: second slope
110: the third surface of the second protrusion pattern layer
120: the fourth surface of the second protrusion pattern layer
130: third slope
140: fourth slope

Claims (12)

a first light control layer including a first protrusion pattern layer and a first planarization layer; and
A second light control layer comprising a second protrusion pattern layer and a second planarization layer,
The first protrusion pattern layer includes a symmetrical protrusion pattern,
The second protrusion pattern layer is a viewing angle compensation film comprising an asymmetrical protrusion pattern. The viewing angle compensation film according to claim 1, wherein a difference in refractive index between the first protrusion pattern layer and the first planarization layer is 0.02 to 0.2. The method according to claim 1, wherein the first protrusion pattern layer is a first surface including a flat surface; and a second surface facing the first surface and including a plurality of protrusions,
Each of the protrusions constituting the first protrusion pattern layer includes a first inclined surface and a second inclined surface,
The first one surface extending the inclined surface or the first inclined surface and the first surface is an angle (θ ₁₎ and said second side extending a second inclined surface or the second inclined plane and the angle between the first surface forms (θ ₂₎ are equal to each other A viewing angle compensation film that has an angle. The method according to claim 3, The θ ₁ and θ _{2 The} viewing angle compensation film of 60 ° to 75 °. The viewing angle compensation film of claim 1, wherein a difference in refractive index between the second protrusion pattern layer and the second planarization layer is 0.08 to 0.2. The method according to claim 1, wherein the second protrusion pattern layer is a third surface including a flat surface; and a fourth surface facing the third surface and including a plurality of protrusions,
Each of the protrusions constituting the second protrusion pattern layer includes a third inclined surface and a fourth inclined surface,
The third inclined surface or angle surfaces which extend the three slopes and the third surface forms (θ ₃₎ and the second angle (θ ₄₎ surfaces extending the fourth inclined surface or the fourth inclined surface and the third surface are forming are different from each other A viewing angle compensation film that has an angle. The viewing angle compensation film of claim 6, wherein θ ₃ is 80° to 90°, and θ ₄ is 30° to 60°. The viewing angle compensation film according to claim 1, further comprising at least one of a base layer and an adhesive layer on at least one surface of the first light control layer and the second light control layer. A polarizing plate comprising the viewing angle compensation film of any one of claims 1 to 8. The polarizing plate according to claim 9, wherein the viewing angle compensation film is provided on the outermost side of the polarizing plate. liquid crystal cell;
a first polarizing plate provided on the viewing side of the liquid crystal cell;
a second polarizing plate provided on the opposite side of the viewing side of the liquid crystal cell; and
And a backlight unit provided on the opposite side of the surface facing the liquid crystal cell of the second polarizing plate,
The display device of claim 9, wherein the first polarizing plate or the second polarizing plate is the polarizing plate. The display device of claim 11 , wherein the display device is a vehicle display device.

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