KR101768149B1 - Optical member and display apparatus having the same - Google Patents

Abstract

The present invention relates to an optical member and a display device having the optical member, wherein the optical member has a first surface, a second surface opposed to the first surface, and a material layer formed between the first surface and the second surface , The material layer has a transmission region through which light is transmitted and a plurality of scattering regions where light is scattered, the plurality of scattering regions being spaced apart from each other in the plane direction, and including a plurality of scattering particles therein.
Therefore, the present invention can improve the light extraction efficiency and improve the color shift phenomenon while minimizing the reduction of the front luminance of the display device.

Description

TECHNICAL FIELD [0001] The present invention relates to an optical member and a display device having the optical member.

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to an optical member and a display device having the optical member, and more particularly, to an optical member and a display device having the optical member capable of improving light extraction efficiency and color shift.

Recently, a flat panel display has been attracting attention as a display device. Such flat panel display devices include a liquid crystal display (LCD), a plasma display panel (PDP), and an organic light emitting display device.

Among them, the organic light emitting display has a wide viewing angle and a fast response speed, so that a high-quality display can be realized. Particularly, an organic light emitting display device having a microcavity structure has an advantage that the output efficiency can be increased by utilizing the resonance effect of light between the upper and lower electrodes, and the color purity of light can be improved. The organic light emitting display includes a substrate, a first electrode having a light-transmitting property formed on the substrate, an organic layer formed on the first electrode, and a second electrode formed on the organic layer and having a high reflectance. Usually, the substrate uses a glass substrate or a plastic substrate. And the organic material layer includes a hole injection layer, a hole transport layer, a light generation layer, a hole blocking layer, and an electron transport layer. That is, a plurality of organic material layers are laminated between the first electrode and the second electrode, thereby manufacturing an organic light emitting display having a multilayer structure.

On the other hand, the organic light emitting display has a problem that the light extraction efficiency is lowered due to the light traveling in the lateral direction rather than the front due to the internal reflection, and color shift is generated according to the viewing angle due to the device structure have.

In order to solve these problems, that is, to reduce luminance due to total reflection and prevent color shift due to the structure, a technique of providing a diffusion layer using particles of a specific size in an organic light emitting display has been proposed.

However, when a diffusion layer using particles of a specific size is used, there is a disadvantage that the total reflection is reduced and the color shift is suppressed, but the front luminance of the display device is lowered.

Korean Patent Publication No. 10-2009-0019752

The present invention provides an optical member capable of improving light extraction efficiency and a display device having the optical member.

The present invention provides an optical member capable of improving color shift and a display device having the optical member.

An optical member according to an embodiment of the present invention has a first surface, a second surface opposite to the first surface, and a material layer formed between the first surface and the second surface, And a plurality of scattering regions through which light is scattered, wherein the plurality of scattering regions are spaced from each other in the plane direction and include a plurality of scattering particles therein.

The scattering region is formed in a direction transverse to the first surface and the second surface, and is exposed on at least one of the first surface and the second surface.

The scattering region includes a base agent, and the scattering particles are dispersed in the base agent.

The content of the scattering particles in the scattering region is in the range of 10 to 70% by weight based on the total weight of the scattering region.

And the transmission region includes a first layer formed between the plurality of scattering regions and a second layer formed below the scattering region.

And the scattering region is formed in a convex shape toward the second surface.

Wherein the scattering region is spaced apart from the second face and exposed to the first face, wherein the scattering region comprises only the scattering particles.

The distance (C) between the scattering regions and the width (d) of the scattering region are in the range of 1: 0.1 to 1: 1.

(A) from the end of the one scattering region to the end of another scattering region adjacent to the other scattering region to the height (b) of the scattering region has a range of 1: 0.5 to 1: 5.

The height (b) of the scattering region is equal to or greater than the width (d) of the scattering region.

And the sum of the volumes of the transmitting regions is larger than the sum of the volumes of the scattering regions.

And the refractive index of the transmissive region is equal to or smaller than the refractive index of the base member.

The difference in refractive index between the scattering particles and the base is in the range of 0.01 to 0.7.

A display device according to an embodiment of the present invention includes a light emitting layer in which light is generated, a circularly polarized light layer formed on the light emitting layer, and a transmissive region through which light is transmitted, And a material layer including a plurality of scattering particles arranged in the horizontal direction and having a plurality of scattering particles therein.

Wherein the circularly polarizing layer comprises a phase difference film (QWP) and a polarizing film formed on the phase difference film (QWP).

The scattering region is formed in a direction transverse to the material layer and is in contact with the planar light layer at least on one side.

The transmissive region is formed between the plurality of scattering regions, and at least one surface thereof is in contact with the planar light layer.

Wherein the scattering region includes a base material, the scattering particles are dispersed in the base material, the transmission region includes a polymer resin, and the refractive index of the polymer resin is equal to or smaller than the refractive index of the base material. .

The distance (C) between the scattering regions and the width (d) of the scattering region is in the range of 1: 0.1 to 1: 1.

(A) from the end of the one scattering region to the end of another scattering region adjacent to the other scattering region to the height (b) of the scattering region is in the range of 1: 0.5 to 1: 5.

The height (b) of the scattering region is equal to or greater than the width (d) of the scattering region.

According to embodiments of the present invention, there is provided a liquid crystal display device including a plurality of scattering regions in which light is transmitted and a plurality of scattering regions in which light is scattered, wherein a plurality of scattering regions are spaced apart from each other in the plane direction, Layer is used as an optical member. That is, this optical member is formed on the light emitting layer.

Thus, according to the embodiments of the present invention, total reflection is suppressed and light extraction efficiency is improved while suppressing reduction in the front luminance of the display device. Further, according to the embodiments of the present invention, it is possible to improve the color shift in which the color change rapidly occurs according to the viewing angle while suppressing the reduction of the front luminance of the display device.

Further, the embodiments of the present invention can easily manufacture the optical member as a separate member from the display device, and can easily place the optical member at various positions of the display device according to the desired performance, thereby improving the optical performance of the display device.

1 is a cross-sectional view schematically showing a display device according to an embodiment of the present invention;
2 is a cross-sectional view and a plan view showing an optical member according to an embodiment of the present invention;
3 is a cross-sectional view conceptually showing a light emission path in a display device according to an embodiment of the present invention
4 is a perspective view schematically showing an optical member according to a modification of the present invention;
5 is a cross-sectional view showing an optical member according to another modification of the present invention
6 is a graph showing the optical characteristics of the test example of the present invention
FIG. 7 is a graph showing the relationship between a color coordinate

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but is capable of other various forms of implementation, and that these embodiments are provided so that this disclosure will be thorough and complete, It is provided to let you know completely. In the drawings, thicknesses are exaggerated or enlarged to clearly illustrate the layers and regions, and the same reference numerals denote the same elements in the drawings.

FIG. 1 is a cross-sectional view schematically showing a display device according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view and a plan view showing an optical member according to an embodiment of the present invention.

1, a display device according to an embodiment of the present invention receives an electrical signal and optically displays an image. The display device includes a light emitting layer 10 in which light is emitted, a circularly polarized light layer And a circular polarization layer 30 disposed between the light emitting layer 10 and the circularly polarizing layer 30. The light is scattered through the transmission region 22 through which light is transmitted and has a plurality of scattering particles disposed therein, And a material layer (20) comprising a plurality of scattering regions (21).

The light emitting layer 10 is made of an organic material and includes an organic light emitting layer (OLED) capable of self-emission. The light emitting layer 10 includes an organic layer 11 for generating light, a first electrode 12 formed on one side of the organic layer 11 and a second electrode 13 formed on the other side of the organic layer 11 . The first electrode 12 serves as a positive electrode and is formed of a transparent conductive oxide through which light can be transmitted. The first electrode 12 is formed of indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO) ₂ O < ₃ >. The second electrode 13 may be any one of LiF / Al, Ca / Al, Ca / Ag, Ag, Au, and Cu. have. The first electrode 12 which is a transparent electrode through which light is transmitted is positioned between the organic layer 11 and the pattern layer 20 and the second electrode 13 through which light is reflected is formed on the other side of the organic layer 11 do.

The organic layer 11 may include at least one of a hole injection layer (HIL), a hole transport layer (HTL), a light emitting layer (EML), a hole blocking layer (HBL) A transport layer (ETL), and the like. At this time, a hole injecting layer (HIL), a hole transporting layer (HTL), a light generating layer (EML), a hole blocking layer (HBL) and an electron transporting layer (ETL). At least one of the hole injecting layer (HIL), the hole transporting layer (HTL), the hole blocking layer (HBL) and the electron transporting layer (ETL) may not be formed depending on the structure and characteristics of the light emitting layer 10 to be manufactured, In addition, another layer may be formed.

In this case, the first electrode 12 for the positive electrode is formed of a translucent material, the second electrode 13 for the negative electrode is formed of a material having a high reflectivity, and the light generated in the organic layer 11 is emitted to the positive electrode (Bottom Emission type) which is emitted in the direction of the light emitting layer (12). However, the present invention is not limited to this, and it may be a top emission type in which light generated in the organic layer 11 is emitted in a direction in which the cathode electrode (the second electrode 13) is located. Here, the light emitting layer 10 of the upper emission type is formed by forming the first electrode 12 for the positive electrode using a material having a high reflectivity, such as Ni, and forming the metal material to have a small thickness, The second electrode 13 is formed. In the case of such a top emission type, the pattern layer and the circular polarization layer may be laminated in the lower direction of the second electrode 13 (the lower direction of the second electrode in Fig. 1). In another example, the light generated in the organic layer 11 may be a double emission type (Transparent Emission type) in which light is emitted to both sides of the positive electrode (the first electrode 12) and the negative electrode (the second electrode 13). In the double-sided emission type, the light emitting layer 10 is formed such that both the first electrode 12 and the second electrode 13 have a light transmitting property, and the upper part of the first electrode 12 and the lower part of the second electrode 13 A pattern layer and a polarizing film may be laminated on each.

The circularly polarizing layer 30 is a layer that prevents external light from being reflected again in the display panel and blocks reflection of external light to improve luminance and color purity. The circular polarization layer 30 may include a phase difference film (QWP) 31 and a polarizing film (Pol) A retardation film (QWP) 31 is positioned between the material layer 20 and the polarizing film 32. The retardation film 31 serves to phase-shift the one-direction circularly polarized light among the external incident light to change it to circularly polarized light in a direction corresponding to the absorption axis of the polarizing film 32. The retardation film 31 used is similar to or the same as that used in a conventional display device, so a detailed description thereof will be omitted.

The polarizing film 32 is formed on the retardation film 31. The polarizing film 32 absorbs polarized light in a specific direction, for example, Y-axis polarized light among light incident from outside (hereinafter referred to as external incident light) As shown in Fig. At this time, external incident light that is not absorbed by the polarizing film 32 but is transmitted is scattered by the material layer 20, and is then incident on the light emitting layer 10. The polarizing film 32 may be formed using a material in which polyvinyl alcohol (PVA) and an iodine dye are mixed. For example, a material in which PVA and an iodine dye are mixed may be formed into a film, and then the film may be attached to the retardation film 31. Here, the polarizing film 32 is not limited to the polarizing film formed of the above-described materials, and various polarizing films used in a conventional display device can be applied.

The material layer 20 is an optical member which is disposed between the light emitting layer 10 and the circularly polarizing layer 30 and used for improving the optical performance of the display device.

1 and 2, an optical member according to an embodiment of the present invention includes a first surface 23, a second surface 24 facing the first surface 23, and a first surface 23, An optical component having a layer of material (20) formed between a surface (24), the layer of material (20) having a transmissive region (22) through which light is transmitted and a plurality of scattering regions (21) The plurality of scattering regions 21 are spaced apart from each other in the plane direction and include a plurality of scattering particles 211 therein.

The optical member is a thin sheet or plate shaped member having a first side 23 and a second side 24 facing each other and a side connecting them, which includes a material layer 20 including regions having different characteristics, Respectively.

The material layer 20 is formed to have a predetermined thickness and has a transmission region 22 through which light is transmitted and a plurality of scattering regions 21 through which light is scattered. That is, the transmission region 22 and the scattering region 21 coexist in the same layer, and these regions are distinguished from each other. For example, the transmissive region 22 and the scattering region 21 can be alternately and repeatedly formed in the plane direction of the material layer 20, and the scattering regions 21 in the material layer 20 can be formed at predetermined intervals They may be disposed apart from each other. The scattering region 21 and the transmission region 22 may be arranged regularly or irregularly. Although the scattering region 21 is shown as a cylindrical shape in the drawing, the shape of the scattering region 21 is a region having a predetermined width and height, and its shape and size are not particularly limited.

The scattering region 21 includes a plurality of scattering particles 211 therein and scatters incident light. The scattering region 21 is formed in a direction transverse to the first surface 23 and the second surface 24, And may be exposed on at least one of the first side 23 and the second side 24. [ That is, the scattering region 21 extends in the thickness direction of the material layer 20 and has a suitably adjusted width. The scattering region 21 may be exposed on either the first side 23 and the second side 24 or on both the first side 23 and the second side 24. When the scattering region 21 is exposed on the first surface 23 and the second surface 24, the scattering region 21 can be formed by penetrating the material layer 20 in its thickness direction. At this time, when the optical member is used in a display device, as shown in Fig. 1, the scattering region 21 can contact with another layer of the display device. For example, the scattering region 21 may be in contact with the planar light layer 30 at least on one side.

The scattering region 21 includes the base material 212 and the scattering particles 211 are dispersed in the base material 212.

The base material 212 may be a material that maintains the shape of the scattering region 21 and may be manufactured using a polymer resin such as a thermosetting composition or a photocurable composition. Further, the base material 212 may be manufactured using an adhesive. When an adhesive is used, the bonding force with the layers stacked on the upper and lower portions can be improved. The thermosetting composition may include a thermosetting resin and a curing agent. As the thermosetting resin, at least one of an acrylic resin, a silicone resin and an epoxy resin may be used. As the curing agent, an isocyanate compound, an amine compound, an organic acid anhydride compound, An amide compound, a dialdehyde compound, an adiridine compound, a metal chelate compound, a metal alkoxide compound or a metal salt. The photo-curable composition may comprise a photo-curable compound and a photo-initiator, the photo-curable compound may be a polymer or an oligomer, a monomer, and the photo-curable compound may be a combination of two or more of polymers, oligomers and monomers It is possible. Here, examples of the polymer or oligomer include an acrylic compound, a silicone compound, an epoxy compound, etc. These may be used alone or in combination of two or more.

The scattering particles 211 use particles different in refractive index from the base 212. That is, the scattering particles 211 can be made of a material having a refractive index higher than that of the base material 212, or a material having a refractive index lower than that of the base material 212. The refractive index of the scattering particles 211 may be in the range of 1.5 to 2.7, and the refractive index difference with the base material 212 may be in the range of 0.01 to 0.7. At this time, if the refractive index difference is smaller than 0.01, scattering particles are difficult to recognize due to incident light, and when the difference in refractive index exceeds 0.7, the haze is severely changed.

The scattering particles 211 may be made of at least one of ZrO ₂ , TiO ₂ , Al ₂ O ₃ , MgO, and SiO ₂ , and the shape of the particles may be spherical or various polygonal shapes. The size of the scattering particles 211 may range from 0.1 to 2 mu m. Here, the size means the average diameter of the particles. If the scattering particles 211 having the above-mentioned range size are used, scattering particles having a size similar to that of the visible light region are used. Therefore, the scattering particles can be scattered forward by maximizing the Mie scattering effect, And the color shift phenomenon in which the color is distorted according to the viewing angle of the display device can be reduced. The filling rate of the scattering particles 211, that is, the content of the scattering particles 211 with respect to the total weight of the scattering region 21 may be in the range of 10 to 70% by weight. When the content is less than 10% by weight, the effect of improving the color shift is insignificant. When the content is more than 70% by weight, the luminance is lowered.

The transmissive region 22 is an area through which light is incident, and means the entire region except the scattering region 21 in the material layer 20. That is, the transmissive region 22 forms most of the areas of the first surface 23 and the second surface 24 and may form a surface on which the other layers of the display device can be contacted. For example, the transmissive region 22 is formed between a plurality of scattering regions, and at least one surface of the transmissive region 22 can be in contact with the circularly polarizing layer 22. In addition, the ratio of the transmissive region 22 to the entire material layer 20 may be higher than that of the scattering region 21. For example, the sum of the volumes of the transmitting regions 22 may be greater than the sum of the volumes of the scattering regions 21. This makes it possible to increase the ratio of light transmitted through the optical member. The transmissive region 22 may include a first layer 221 formed between the plurality of scattering regions 21 and a second layer 222 formed below the scattering region 21. have. Of course, the second layer 222 may not be formed, in which case the lower surface of the first layer 221 is exposed. Here, the second layer 222 can improve the adhesion with other layers of the display device contacting the lower portion, and facilitates the manufacturing process of the optical member.

In addition, the transmissive region 22 may comprise a polymeric resin, and the polymeric resin may comprise the same or different material as the base material 212. That is, the polymer resin may be selected from among the materials of the base material 212 described above, and may be manufactured by selecting the same material as the base material 212 in the same material layer 20, . The refractive index of the transmissive region 22 may be equal to or less than the refractive index of the base material 212.

Since the optical member described above can be manufactured using various manufacturing methods known in the art, a detailed description of the manufacturing process will be omitted.

Generally, when a film in which scattering particles are dispersed is attached to an upper portion of a display device, the total reflection is eliminated and the color shift is somewhat improved. However, the light is scattered at an angle that does not cause total internal reflection, There is a problem that the screen (black visibility) which should be seen in black when the user turns off is bright. On the other hand, in the embodiment of the present invention, since the optical member in which the scattering region in which the scattering particles are dispersed and the transmission region located between the scattering regions are formed on the same layer is provided and positioned on the lower portion of the retardation film, The color shift can be efficiently improved and the black visibility can be remarkably improved.

In the following, the geometry of the optical member and the geometrical relationship between the elements will be described in more detail with reference to Fig.

The spacing C between the scattering regions 21 in the optical member and the width d of the scattering region 21 may range from 1: 0.1 to 1: 1. As the ratio of the space between the scattering regions 21 is larger, the ratio of the transmission region 22 to the scattering region 21 increases, so that light emitted without scattering increases and the center luminance increases. At this time, when the distance C between the scattering regions 21 and the width d of the scattering region 21 is less than 1: 0.1, the size of the scattering region 21 becomes very small, It is very difficult to accurately and stably manufacture the transmissive region 22, and the mass productivity is lowered. If the distance C between the scattering regions 21 and the width d of the scattering region 21 is excessively larger than 1: 1, the size of the scattering region 21 is excessively increased, The light is reduced and the center luminance is lowered.

Further, the width (a) from the end of one scattering region to the end of another scattering region adjacent to the height (b) of the scattering region may be in the range of 1: 0.5 to 1: 5. That is, the aspect ratio (a: b) of one optical area may be in the range described above. The height b of the scattering region 21 may be equal to or larger than the width d of the scattering region 21. The larger the height b of the scattering region 21 in the aspect ratio is, the greater the scattering of light emitted at a large angle increases and the degree of improvement of the color shift according to the viewing angle increases. At this time, when the aspect ratio is smaller than 1: 0.5, the height b of the scattering region 21 becomes too low, so that the scattering of the light emitted at a large angle is reduced and the improvement of the color shift according to the viewing angle becomes insignificant. In addition, when the aspect ratio is excessively larger than 1: 5, the height b of the scattering region 21 becomes excessively high and it is difficult to stably form the scattering region 21 and the transmission region 22, .

The height b of the scattering region 21 in the optical member may be 100 占 퐉 or less and the height e of the second layer 222 of the transmission region 22 may be 0.1 to 5 占 퐉. Here, if the height b of the scattering region 21 is too high, it is difficult to form the scattering region 21 stably. Also, if the height e of the second layer 222 is too low, less than 0.1 mu m, difficulties may arise in the manufacturing process. If the height e of the second layer is too large, As shown in FIG.

Hereinafter, the light emission path will be described in detail with reference to FIG. 3 is a cross-sectional view conceptually showing a light emission path in a display device according to an embodiment of the present invention.

In the display device of the embodiment of the present invention, an optical member provided with the scattering region 21 and the transmission region 21 in the same layer is disposed between the light emitting layer 10 and the retardation film 31. From this, the light emitted from the light emitting layer 10 is transmitted and scattered, thereby improving the light extraction efficiency and improving the color shift phenomenon while minimizing the front luminance reduction.

The light generated from the light emitting layer 10 passes through the transmission region 22 and the scattering region 21 and the light passing through the scattering region 21 is scattered by colliding with the dispersed scattering particles 211. That is, the straight-line light out of the light incident on the optical member is directly emitted to the outside through the transmission region 22, and the light incident obliquely is scattered by the scattering particles 211 located in the scattering region 21, And it is deflected toward the front while being dispersed by the light. As described above, since the direct light passes as it is, and the inclined light is scattered by the scattering particles 211 and directed toward the front side, the light extraction efficiency is improved while minimizing the front luminance reduction, Can be improved.

Hereinafter, various modifications of the optical member of the present invention will be described with reference to the drawings. FIG. 4 is a perspective view schematically showing an optical member according to one modification of the present invention, and FIG. 5 is a sectional view showing an optical member according to another modification of the present invention. The description of the same parts as those of the above embodiment will be omitted.

Referring to FIG. 4, an optical member according to one modification alters the shape of the scattering region 21 formed in the material layer 20. That is, the scattering region 21 is spaced from the second surface 24, exposed to the first surface 23, and the portion located within the material layer 20 forms a curved surface. The curved surface of the scattering region 21 may be formed in a convex shape toward the second surface 24. Of course, the scattering region 21 includes a base member 212 forming a curved surface and scattering particles 211 dispersed therein.

In this structure, since the individual unit pattern is formed, the degree of freedom of the position where the pattern is arranged is high, so that the appearance problem such as moiré can be solved easily.

Referring to FIG. 5, an optical member according to another modification alters the structure of the scattering region 21 formed in the material layer 20. In the above-described embodiments, the scattering region 21 includes the base agent and scattering particles, but this modification includes scattering particles only. That is, the scattering region is spaced from the second side 24 and exposed toward the first side 23, and the scattering region 21 includes only the scattering particles 211. For example, the material layer 20 includes a transmissive sheet 22 serving as a transmissive region through which light is transmitted, and the transmissive sheet 22 is formed with a concave groove 213 recessed inwardly from the first surface. A plurality of scattering particles 211 are filled in the space of the concave groove 213 to form the scattering region 21. At this time, the height h of the scattering region 21 may be 0.8 to 1.2 times the average diameter of the scattering particles 211. The scattering particles 211 located in the concave groove 213 can be formed into a substantially single layer.

In this structure, since air acts as a base agent, the difference in refractive index between the scattering particles and the air is maximized, and the scattering effect can be further improved.

The structure and shape of the scattering region and the transmission region can be variously changed in addition to the above-described variations.

Test Example  And Conventional example

Hereinafter, specific test examples and conventional examples of the present invention will be described.

The optical member of the test example was manufactured by patterning a sheet of a polymer resin to form a concave portion and filling the concave portion with a base material in which scattering particles were dispersed. First, a polymer resin having a refractive index of about 1.5 was applied onto the base material, and a concave portion was formed in the polymer resin using the mold having the concave-convex portion and cured. That is, a transmissive region is formed of a polymer resin, and a scattering region is formed in the concave portion. In this case, the width c of the transmission region is 3 占 퐉, the width d of the concave portion is 2.5 占 퐉, the height b of the concave portion is 3.2 占 퐉, the height of the polymer resin on the lower side of the concave portion, ) Was formed to be 2 탆.

Thereafter, the polymer resin and spherical alumina (Al 2 O 3) scattering particles having a refractive index of 1.77 were mixed at a weight ratio of 50:50. Thereafter, the mixture was filled in the concave portion of the cured polymer resin using a squeezing method, and then UV-cured to complete the optical member. That is, a sheet-like optical member having a transmission region formed of a polymer resin and a scattering region in which scattering particles are dispersed was produced. At this time, the width d of the concave portion 2.5 占 퐉 is the width of the scattering region, and the height (b) 3.2 占 퐉 of the concave portion is the height of the scattering region.

In the conventional example, a sheet in which an optical member is not used or scattered particles are dispersed as a whole is used as an optical member. That is, Conventional Example 1 does not use an optical member, and Conventional Example 2 uses a sheet in which scattering particles are dispersed with an optical member. In the optical member of Conventional Example 2, spherical alumina (Al2O3) scattering particles and ethyl acetate were mixed at a ratio of 66: 0.9: 33.1 to a polymer resin having a refractive index of approximately 1.5. Thereafter, the mixture was stirred at room temperature for about 1 hour to prepare a particle dispersion. Thereafter, the dispersion of particles was coated to a thickness of about 200 탆 using a blotting coater, dried to remove the solvent in a 100 캜 seed oven for 10 minutes, and maintained in a 40 캜 seed oven for 24 hours, .

Each optical member manufactured as described above was placed in a display device, and optical performance was observed. A circular polarizing film commercialized as a circularly polarizing layer is utilized as a light source and a commercially available organic light emitting display panel (OLED panel) is used. An optical member of each of the above examples is installed thereon and an EZ contrast ) Luminance and color coordinates according to the viewing angle were measured using an apparatus (Eldim Co., France), and pixel images were measured using a K-9500 (Keens, Japan).

That is, a circularly polarized light layer was laminated on the upper part of the light source (OLED panel) (the surface on which the light was emitted to the outside) in order to observe the optical performance of the case where no separate optical member was provided (Conventional Example 1). The luminance and chromaticity coordinates were measured by viewing angle using EZ contrast equipment. In order to evaluate the optical performance of Conventional Example 2, the optical member of Conventional Example 2 was laminated on the circularly polarizing layer after laminating the light source and the circularly polarizing layer in the same manner as described above, and the luminance according to the viewing angle And color coordinates were measured. In order to evaluate the optical performance of the test example, the light source and the circularly polarizing layer were laminated in the same manner as described above, and the optical member of the test example was disposed therebetween, and the brightness and the color coordinate according to the viewing angle were measured using the EZ contrast equipment.

FIG. 7 shows the chromaticity coordinate graph according to the viewing angles of the test example of the present invention.

The characteristic table of FIG. 6 shows the luminance and chromaticity coordinate results for the above examples, and the luminance refers to an average value of luminance values measured at nine points among the areas above the optical member disposed on the display device. The color coordinates (u ', v') are transformed into CIE 1976 UCS (u ', v') values based on the measured CIE 1931 (x, y) ).

expression)

u = 4x / -2x + 12y + 3

v = 6y / -2x + 12y + 3

u '= u

v '= 3v / 2

As shown in Fig. 6 and Fig. 7, it can be seen that the luminance of the test example is increased as compared with the conventional examples 1 and 2. Fig. That is, the test example shows that the luminance is increased by about 105.8% as compared with the conventional example 2 using the scattering particles. It can also be seen that the color shift phenomenon is improved in the test example as compared with the conventional example 1. That is, in the case of the display device not using the optical member of Conventional Example 1, the color shift phenomenon appears to be severe as the viewing angle increases. In particular, it can be seen that the color change rapidly occurs at an angle of 60 degrees or more. On the other hand, when the optical member of the embodiment of the present invention is applied to the lower portion of the retardation film of the display device, the color change is gentle even when the viewing angle is increased, and the color shift phenomenon is improved.

Although the organic light emitting display device has been described above, the present invention is not limited thereto. The present invention can be applied to various light emitting devices or display devices that improve the light extraction efficiency and improve the color shift phenomenon.

Although the technical idea of the present invention has been specifically described according to the above embodiments, it should be noted that the above embodiments are for explanation purposes only and not for the purpose of limitation. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention.

10: light emitting layer 20: material layer
30: circular polarization layer 22: transmission region
21: scattering region 211: scattering particle

Claims (21)

An optical member having a first side, a second side opposite to the first side, and a material layer formed between the first side and the second side,
Wherein the material layer has a transmission region through which visible light is transmitted and a plurality of scattering regions through which visible light is scattered,
The plurality of scattering regions are spaced apart from each other in the plane direction, and reduce the color shift of the visible light region therein Comprising a plurality of scattering particles,
The height of the scattering region is 100 占 퐉 or less,
Wherein the plurality of scattering particles each have a size of 0.1 to 2 탆 and induce forward scattering of visible light. The method according to claim 1,
Wherein the scattering region is formed in a direction transverse to the first surface and the second surface, and is exposed on at least one of the first surface and the second surface. The method according to claim 1,
Wherein the scattering region includes a base material, and the scattering particles are dispersed in the base material. The method according to claim 1,
Wherein the content of the scattering particles with respect to the total weight of the scattering region is in the range of 10 to 70 wt%. The method according to claim 1,
Wherein the transmission region includes a first layer formed between the plurality of scattering regions and a second layer formed below the scattering region. The method of claim 5,
And the scattering region is formed in a convex shape toward the second surface. The method according to claim 1,
Wherein the scattering region is spaced apart from the second face and exposed to the first face, wherein the scattering region comprises only the scattering particles. The method according to claim 1,
Wherein an interval (C) between the scattering regions and a width (d) of the scattering region is in a range of 1: 0.1 to 1: 1. The method according to claim 1,
(A) from the end of the one scattering region to the end of the other scattering region adjacent thereto to the height (b) of the scattering region is in the range of 1: 0.5 to 1: 5. The method according to claim 1,
Wherein the height (b) of the scattering region is equal to or greater than the width (d) of the scattering region. The method according to claim 1,
Wherein the total sum of the volumes of the transmitting regions is larger than the sum of the volumes of the scattering regions. The method of claim 3,
And the refractive index of the transmissive region is equal to or smaller than the refractive index of the base member. The method of claim 3,
Wherein the refractive index difference between the scattering particles and the base agent is in the range of 0.01 to 0.7. A light emitting layer in which light is generated;
A circular polarization layer formed on the light emitting layer; And
And a plurality of scattering particles disposed between the light emitting layer and the circularly polarizing layer and scattering visible light and reducing a color shift of a visible light region in a transmission region through which visible light transmits, A material layer comprising a scattering region;
/ RTI >
The height of the scattering region is 100 占 퐉 or less,
Wherein the plurality of scattered particles are each formed in a size of 0.1 to 2 탆 to induce forward scattering of visible light. 15. The method of claim 14,
Wherein the circularly polarizing layer comprises a retardation film (QWP) and a polarizing film formed on the retardation film (QWP). 15. The method of claim 14,
Wherein the scattering region is formed in a direction transverse to the material layer and is in contact with the circularly polarized light layer at least on one side. 18. The method of claim 16,
Wherein the transmission region is formed between the plurality of scattering regions, and at least one surface thereof is in contact with the circularly polarized light layer. 15. The method of claim 14,
Wherein the scattering region comprises a base agent, the scattering particles are dispersed in the base agent,
Wherein the transmissive region includes a polymer resin, and the refractive index of the polymer resin is equal to or smaller than a refractive index of the base material. 15. The method of claim 14,
Wherein a distance (C) between the scattering regions and a width (d) of the scattering region is in a range of 1: 0.1 to 1: 1. 15. The method of claim 14,
(A) from the end of one of the one scattering region to the end of another scattering region adjacent thereto to the height (b) of the scattering region is in a range of 1: 0.5 to 1: 5. 15. The method of claim 14,
Wherein a height (b) of the scattering region is equal to or greater than a width (d) of the scattering region.

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