KR101090495B1 - Diffusion film for led light - Google Patents

Abstract

PURPOSE: A diffusion film for an LED is provided to increase the light focusing efficiency of the light incident and emitting surfaces of a film to minimize loss of light, thereby increasing frontal brightness. CONSTITUTION: A base layer(10), a first diffusion layer(20), and a second diffusion layer(30) are successively laminated. The first diffusion layer includes light diffusion particles(21,22) and a binder resin wherein the mean droplet diameter of the light diffusion particles is between 0.1 and 5 micro meter. The difference between the refractive index of the light diffusion particles and the refractive index of the binder resin is smaller than 0.2. The second diffusion layer includes light diffusion particles(31) and a binder resin wherein the mean droplet diameter of the light diffusion particles is between 10 and 30 micro meter. The difference between the refractive index of the light diffusion particles and the refractive index of the binder resin is between 0.1 and 0.2. The light diffusion particle refractive index of the first diffusion layer is between 1.3 and 2.7.

Description

Light Diffusion Film for Light Emitting Diodes {DIFFUSION FILM FOR LED LIGHT}

The present invention relates to a light diffusion film for a light emitting diode, and more particularly, a structure in which a base layer, a first diffusion layer, and a second diffusion layer are sequentially stacked, and the first diffusion layer for improving shielding power and the second for improving luminance. The present invention relates to a light diffusion film for a light emitting diode in which a diffusion layer is laminated to improve shielding power and brightness simultaneously.

BACKGROUND ART Liquid crystal displays (LCDs) are being used as information display devices such as mobile phones, portable information terminals (PDAs), computers, televisions, and the like by utilizing characteristics such as thinning, light weight, and low power consumption. Recently, the use of light emitting diodes (LEDs) in various electronic products such as TVs, notebooks, mobile phones, etc. is increasing. The light emitting diode light source has been spotlighted because its color is clear and its power consumption is relatively small.

As a core component of the liquid crystal display (LCD), a backlight unit may be used. The backlight unit is used as a dimming device to evenly transmit light to the entire TFT-LCD panel and displays an image with transmitted light. . Since it is non-luminous, it cannot be used without a light source, and the backlight unit is a device that functions as a light source on the LCD and uniformly irradiates the information display surface. The backlight unit directly arranges the light source on one side of the panel to directly illuminate the front surface of the panel, and arranges a line light source on one side or a plurality of side surfaces of the panel to reflect and diffuse light rays on a light guide plate and a reflective sheet. It is divided in a manner.

Recent trends include an edge type method in which a light emitting diode light source for a TV is disposed on at least one side of a liquid crystal display in order to reduce the weight and weight of a backlight unit, and a reflecting film is disposed at a lower part thereof, and then a light guide plate and a light diffusion film are placed thereon. The unit of the structure which laminated | stacked the prism is used. In this case, when the thickness of the backlight unit is reduced, the pattern of the light guide plate is visually recognized on the screen when the screen is pressed, and the shielding function of the light diffusion film requires a higher level than the conventional one.

In order to solve this problem, attempts have been made to change the pattern of high haze and light guide plate by adding more particles to the light diffusing film than conventional methods. However, these attempts are limited due to the productivity and workability of the users, and the shielding power is improved, but the brightness is lowered.

Recently, various methods have been proposed to improve the brightness of such a light diffusing film. For example, Korean Patent No. 10-834406 discloses a light diffusing film for a liquid crystal display backlight unit including light diffusing particles formed by mixing two or more kinds of organic particles having different refractive indices and a light diffusing film fixed to a support. Is disclosed. Korean Patent No. 10-587905 discloses a liquid crystal display comprising a binder resin, a light diffusing layer composed of organic particles alone or organic particles and inorganic particles, and having a difference in refractive index between the binder resin, organic particles, and inorganic particles. Disclosed is a light diffusing film for a backlight unit. In addition, Korean Patent No. 10-801024 proposes an optical film having increased brightness by coating a light diffusing layer in a multilayered manner as a content of a multilayer optical film.

However, the conventional techniques as described above have a problem that does not satisfy uniformity, condensing efficiency and shielding power at the same time.

Disclosure of Invention An object of the present invention is to provide a light diffusion film for a light emitting diode having improved shielding power and brightness by stacking a first diffusion layer and a second diffusion layer with a light diffusion film for a light emitting diode including a base layer, a first diffusion layer, and a second diffusion layer. will be.

Another object of the present invention is to provide a light diffusion film for a light emitting diode further provided with an anti-blocking layer on the opposite side of the substrate layer on which the first diffusion layer and the second diffusion layer is laminated.

In order to achieve the above object, the present invention provides a structure in which a base layer, a first diffusion layer, and a second diffusion layer are sequentially stacked, and the first diffusion layer includes light diffusion particles and a binder resin having an average particle diameter of 0.1 to 5 μm. The difference between the refractive index of the diffusing particles and the refractive index of the binder resin is 0.2 or less, and the second diffusion layer comprises light diffusing particles and a binder resin having an average particle diameter of 10 to 30㎛, the refractive index difference of the light diffusing particles and the binder resin It provides a light diffusion film for a light emitting diode, characterized in that 0.1 to 0.2.

The refractive index of the light diffusion particles of the first diffusion layer is preferably 1.3 to 2.7.

At this time, the light diffusion particles of the first diffusion layer may include any one or more of organic particles or inorganic particles, the inorganic particles are silicon oxide, titanium oxide, barium sulfate, calcium carbonate, zirconium oxide, aluminum oxide, synthetic silica and It may contain at least one selected from the group consisting of glass beads.

In addition, the organic particles may contain at least one selected from the group consisting of acrylic resin, styrene resin and silicone resin.

It is preferable that the refractive index of the light-diffusion particle of the said 2nd diffusion layer is 1.3-1.7.

In this case, the light diffusion particles of the second diffusion layer includes any one or more of inorganic particles or organic particles, and the inorganic particles are at least one member of the group consisting of silicon oxide, barium sulfate, calcium carbonate, aluminum oxide, synthetic silica and glass beads It can be selected and contained above.

In addition, the organic particles may contain at least one selected from the group consisting of acrylic resins, styrene resins and silicone resins.

The first diffusion layer and the second diffusion layer include a curing agent and an organic solvent.

The present invention has a structure in which a base layer, a first diffusion layer and a second diffusion layer are sequentially stacked, wherein the first diffusion layer includes light diffusion particles and a binder resin, and the second diffusion layer includes light diffusion particles and a binder resin. By constructing a multi-layer diffusion layer on one side and by varying the refractive index and size of the particles of each diffusion layer, it is possible to provide a light diffusion film for a light emitting diode with improved shielding power and brightness by increasing the uniformity and condensing efficiency of the surface structure of the diffusion layer.

In addition, the present invention provides a light-diffusion film that can improve the front brightness by minimizing the loss of light by improving the light condensing efficiency on the incident surface and the exit surface of the film and by controlling the surface structure of the entrance surface and the exit surface in the light source It is possible to provide a light diffusion film for a light emitting diode with increased utilization of emitted light.

In addition, the present invention has an improved luminance value even by using the same light source by increasing the utilization of light emitted from the light source, it is possible to provide a light diffusion film for a light emitting diode that can reduce the power consumption to reduce energy consumption. .

1 is a cross-sectional view of a light diffusion film for a light emitting diode according to the present invention.
2 is a cross-sectional view of the anti-blocking layer laminated on the light diffusion film for a light emitting diode according to the present invention.

Hereinafter, the present invention will be described in more detail.

The present invention provides a structure in which a base layer, a first diffusion layer and a second diffusion layer are sequentially stacked, wherein the first diffusion layer includes light diffusion particles and a binder resin having a particle diameter of 0.1 to 5 μm, and the refractive index of the light diffusion particles and the binder The refractive index difference of the resin is 0.2 or less, the second diffusion layer comprises light diffusing particles and a binder resin having a particle diameter of 10 to 30㎛, the refractive index difference of the light diffusing particles and the binder resin is 0.1 to 0.2, characterized in that It provides a light diffusion film for a light emitting diode.

1 is a cross-sectional view of a light diffusion film for a light emitting diode according to the present invention. The light diffusing film according to FIG. 1 of the present invention includes a base layer 10, a first diffusion layer 20 in which light diffusion particles 21 and 22 are fixed to a binder resin on one surface of the base layer 10, and the first diffusion layer 20. A second diffusion layer laminated on the diffusion layer 20 and having the light diffusion particles 31 of the second diffusion layer having a different average particle diameter and refractive index from the light diffusion particles 21 and 22 of the first diffusion layer fixed to the binder resin ( 30).

In the light-diffusion film of the present invention, the base layer should be excellent in adhesion with the binder resin, and the transmittance of light incident from the rear surface should be 90% or more. It is preferable that the thickness of the base layer is 50 to 250 μm, and when the thickness is less than 50 μm, the mechanical properties and the heat resistance of the film are insufficient, and when the thickness is more than 250 μm, the product becomes thick and the price increases. It has a structure contrary to the trend of thinning. In this case, as the base layer of the present invention, polyacrylate, polyimide, polycarbonate, polyester, polypropylene, polyethylene or epoxy is used, and polyester is mainly used.

In the light diffusion film of the present invention, the light diffusion particles 21 and 22 of the first diffusion layer are fixed to the binder resin on one surface of the base layer 10 and laminated to the first diffusion layer 20.

A high haze layer is formed by mixing the organic and inorganic particles of the first diffusion layer to provide a high shielding function. In this case, the average particle diameter of the light diffusion particles is 0.1 to minimize the recycling and loss of light in the diffusion layer. It is limited to 5㎛, form a difference between the refractive index of the light diffusing particles and the refractive index of the binder resin to 0.2 or less serves to collect the light to the second diffusion layer.

The light diffusion particles 21 and 22 of the first diffusion layer may be dispersed in a single layer or multiple layers in the binder resin, and preferably, inorganic particles 22 are essentially used. The light diffusing particles are spherical transparent particles, and any one or more of organic particles or inorganic particles having a refractive index of 1.3 to 2.7 may be used. In this case, when the refractive index is less than 1.3, the light condensing efficiency of the particles is low, so it is difficult to expect a lens effect due to the particles. When the refractive index is more than 2.7, scattering and reflection occur a lot on the particle surface, and light emitted in the vertical direction is deteriorated. There is a problem that leads to a decrease in luminance.

As the organic particles, organic polymer particles such as acrylic resin particles (refractive index = 1.49), styrene resin particles (refractive index = 1.59), and silicone resin particles (refractive index = 1.43) may be used, and silicon oxide (refractive index = 1.46) and oxidation may be used. Titanium (refractive index = 2.3), barium sulfate (refractive index = 1.64), calcium carbonate (refractive index = 1.63), zirconium oxide (refractive index = 2.05), aluminum oxide (refractive index = 1.63), synthetic silica (refractive index = 1.47) and glass beads ( Inorganic particles such as refractive index = 1.51) may be used, and these light-diffusing particles may be used alone or in combination of two or more thereof.

It is preferable that the average particle diameter of the light-diffusion particles 21.22 of the first diffusion layer is 0.1 to 5 µm. If the average particle size is less than 0.1㎛, inorganic particles are difficult to disperse, and if it exceeds 5㎛, the particle distribution becomes uneven, resulting in uneven surface uniformity, concealability, and brightness. Can be.

At least one resin selected from acrylic resins, melamine resins, ester resins, and urethane resins is used as the binder resin for fixing the first diffusion layer light-diffusing particles 21 and 22 in a single layer. The refractive indexes of the light diffusing particles 21 and 22 of the first diffusion layer 20 should be larger than that of the binder resin, and preferably, the difference in refractive index should be 0.2 or less. When the difference in refractive index between the light diffusing particles and the binder resin of the first diffusion layer exceeds 0.2, a lot of light refraction and scattering occurs on the surface of the particle, resulting in a loss of light rising to the second diffusion layer, the refractive index of the binder resin is light diffusion particles If the refractive index is larger than the refractive index, a large amount of reflection occurs on the surface of the particles, thereby decreasing luminance.

In the production of the light diffusion film of the present invention, the method of laminating the first diffusion layer on the substrate layer 10 is not particularly limited, but usually, the binder resin of the first diffusion layer is dissolved in a suitable solvent to provide light of the first diffusion layer. The diffusion particles 21 and 22 are mixed and then laminated in such a manner that the coating liquid is applied to the base layer 10. The coating method may also be used without particular limitation, but preferably, methods such as knife coating, gravure coating, reverse roll coating and the like may be used. In addition, it is possible to obtain a surface shape by pressing the coating layer using a mold having a shape.

In the light diffusion film of the present invention, a second diffusion layer is laminated on the first diffusion layer 20, and the refractive index and the average particle diameter of the light diffusion particles 31 of the second diffusion layer are the light diffusion particles 21 and 22 of the first diffusion layer. The second diffusion layer light-diffusion particles are different from the refractive index and the average particle diameter of the c) and are laminated to the second diffusion layer 30 by being fixed to the binder resin.

As the second diffusion layer light diffusing particles 31, any one or more of organic particles or inorganic particles having a refractive index of 1.3 to 1.7 can be used as spherical transparent particles.

In this case, when the refractive index is less than 1.3, the light condensing efficiency of the particles is low, so it is difficult to expect the lens effect caused by the particles. A problem occurs that the luminance is lowered.

The organic particles may be organic polymer particles such as acrylic resin particles (refractive index = 1.49), styrene resin particles (refractive index = 1.59), and silicone resin particles (refractive index = 1.43), and the inorganic particles may be silicon oxide (refractive index). = 1.46), inorganic particles such as barium sulfate (refractive index = 1.64), calcium carbonate (refractive index = 1.63), aluminum oxide (refractive index = 1.63), synthetic silica (refractive index = 1.47), and glass beads (refractive index = 1.51) can be used. In addition, these light-diffusion particles can be used individually or in mixture of 2 or more types.

It is preferable that the average particle diameter of the light-diffusion particle 31 of a said 2nd diffused layer is 10-30 micrometers. At this time, when the average diameter of the particles is less than 10㎛, it is difficult to expect the light condensing effect by the particles, and when it exceeds 30㎛, there is a fear that the light-diffusing particles are separated and the thickness becomes thick, so it is easy to mount on the product There is a problem that is not. In addition, when particles having particle sizes of different sizes are mixed, the uniformity and regularity of the particle surface smoothness are lowered, which causes a problem of lowering the luminance .

As the binder resin for fixing the light diffusion particles 31 of the second diffusion layer in a single layer, at least one resin selected from acrylic resin, melamine resin, ester resin, and urethane resin is used. The refractive index of the light diffusing particles 31 of the second diffusion layer 30 is greater than the refractive index of the binder resin, the difference should be 0.1 or more. If the difference between the refractive index of the light diffusing particles and the binder resin of the second diffusion layer is less than 0.1, the loss of light from the first diffusion layer occurs, the brightness is lowered, but if more than 0.1, the difference in the light collection efficiency and internal refractive index due to the lens effect of the particles As a result, the light condensing function can be improved to further improve luminance.

On the other hand, the second diffusion layer 30 can be applied on the first diffusion layer by the same method as the coating method of the first diffusion layer 20.

In forming the first diffusion layer and the second diffusion layer of the present invention, isocyanate-based, melamine formaldehyde, urea-formaldehyde, polyisocyanate, polyaziridine, zirconium composite, epoxy-based compound, zinc oxide, etc. may be used as a curing agent. Methyl ethiketone can be used as a solvent.

2 is a cross-sectional view of the anti-blocking layer further laminated on the light diffusion film of the present invention. In FIG. 2, an anti-blocking layer 40 may be further stacked on a surface opposite to a surface on which the first diffusion layer and the second diffusion layer are stacked on the base layer 10.

In addition, the light diffusion film according to the present invention having the anti-blocking layer may be further provided with at least one configuration selected from the group consisting of a light source unit, a light guide plate, and a reflective sheet to be used as a backlight unit for a light emitting diode.

Hereinafter, the present invention will be described in detail with reference to examples.

The following examples are merely illustrative of the present invention, but the scope of the present invention is not limited to the following examples.

Example 1

A first diffusion layer coating liquid having the following composition was applied to one surface of a polyester film (XU42, Toray Advanced Materials Co., Ltd., 100 μm thick) using a bar coater, and dried at 100 ° C. for 2 minutes to form a first diffusion layer. Thereafter, the second diffusion layer was mixed with a second diffusion layer coating liquid having the following composition on the first diffusion layer and applied using a bar coater, and dried at 100 ° C. for 2 minutes to form a coating layer as a single layer to manufacture a light diffusion film for a light emitting diode. It was.

First diffusion layer  Composition of Coating Liquid

Binder Resin (Refractive Index 1.49 Acrylic Resin): 25.0 wt%

Curing agent (isocyanate): 2.5 wt%

-Light Diffusion Particle 1 (refractive index 1.59, styrene resin particles having an average particle diameter of 5 μm): 20% by weight

-Light Diffusion Particles 2 (refractive index 1.64, barium sulfate particles with an average particle diameter of 0.1 to 2 μm): 5% by weight

Methyl ethyl ketone: 47.5 wt%

2nd diffusion layer  Composition of Coating Liquid

Binder Resin (Refractive Index 1.49 Acrylic Resin): 15.0 wt%

Curing agent (isocyanate): 1.5 wt%

-Light diffusing particles (refractive index 1.59, styrene resin particles with an average particle diameter of 10 ㎛): 17.5% by weight

Methyl ethyl ketone: 66 wt%

<Example 2>

A light diffusing film was manufactured in the same manner as in Example 1 except that the average particle diameter of the styrene resin particles of the second diffusion layer was 20 μm.

&Lt; Example 3 >

A light diffusing film was manufactured in the same manner as in Example 1 except that the average particle diameter of the styrene resin particles of the second diffusion layer was 30 μm.

Comparative Example 1

On one surface of the polyester film (XU42, Toray Advanced Materials Co., Ltd., 100 μm in thickness), a coating liquid having the following composition was applied to prepare a light diffusion film.

Composition of Coating Liquid

Binder Resin (Refractive Index 1.49 Acrylic Resin): 25.0 wt%

Curing agent (isocyanate): 2.5 wt%

-Light Diffusion Particles (Refractive Index 1.49 Average Particle Size 10㎛ Acrylic Resin Particles): 25% by weight

Methyl ethyl ketone: 47.5% by weight.

Comparative Example 2

A light-diffusion film was manufactured in the same manner as in Example 1 except that the light-diffusing particles 1 of the first diffusion layer were 20% by weight of zirconium oxide particles having a refractive index of 2.02 and an average particle diameter of 5 μm.

Comparative Example 3

A light diffusing film was manufactured in the same manner as in Example 1 except that the light diffusing particles 1 of the first diffusion layer were used as refractive index 1.46 silicone resin particles and the light diffusing particles 2 were silicon oxide particles having a refractive index of 1.43.

<Comparative Example 4>

A light diffusing film was manufactured in the same manner as in Example 1 except that the average particle diameter of the light diffusing particles 1 of the first diffusion layer was 10 μm.

Comparative Example 5

A light diffusing film was manufactured in the same manner as in Example 1 except that the average particle diameter of the light diffusing particles of the second diffusion layer was 5 μm.

Comparative Example 6

A light diffusing film was manufactured in the same manner as in Example 1 except that the light diffusing particles of the second diffusion layer were zirconium oxide having a refractive index of 2.05.

Experimental Example

1.Rise change rate (%)

With respect to the light diffusing films prepared in Examples 1 to 3 and Comparative Examples 1 to 6, using the BM-7A equipment of TOPCON Co., Ltd., measured by the average value of the vertical luminance 9Point on the backlight unit assembly based on Comparative Example 1 It is shown in Table 1 measured by the rate of change in brightness increase (%).

2. Evaluation of shielding force

1) Measurement of shielding force

The measurement shielding force was quantified by defining the front luminance on the backlight unit assembly at 100 intervals using the Topcon BM-7A measuring device as shown in Equation 1 below.

Equation 1 is a formula made to quantify the shielding force, it is measured at equal intervals to compare the luminance deviation of the dark portion and the wrist indicates that the shielding force is excellent the smaller the luminance deviation. The measured shielding force was determined to be 'excellent' if less than 10%, 'normal' if 10-15%, and 'under' if more than 15%.

2) Visual shield evaluation

Visual inspection is judged as 'excellent' when viewed from the front when the film is placed on the backlight, 'under' when seen from the front, 'normal' when seen from the front, and 'normal' when seen from the side, and 'excellent' from the front and side It was.

The physical properties were measured and described in Table 1, and if there is at least one level in luminance or shielding, the final evaluation is 'under' level, and if the shielding level is higher than normal in luminance, the final evaluation is 'normal' level. If the level of excellence in shielding is good, the final assessment is marked as 'excellent'.

In Example 1 to 3 and Comparative Examples 1 to 6, the brightness increase rate of change (%), visual shielding force, and measurement shielding force of the light diffusion films prepared in Table 1 were evaluated.

Luminance Rise Change Rate (%) Shielding force Visual shielding force Measured shielding force Example 1 + 2% Great Great Example 2 + 2% Great Great Example 3 + 1% Great Great Comparative Example 1      -(standard) Under Under Comparative Example 2 -5% Great Great Comparative Example 3 -4% Great Great Comparative Example 4 -4% Great usually Comparative Example 5 -3% Great Great Comparative Example 6 -5% Great Great The change rate of luminance increase is measured by the average value of 9 points of vertical luminance and is based on Comparative Example 1.
Measured shielding force = (average of luminance maximum-average of luminance minimum) ÷ total average luminance × 100

As shown in Table 1, it was confirmed that the light diffusing films of Examples 1 to 3 have a relatively high luminance as compared to the light diffusing films of Comparative Examples 1 to 6.

Examples 1 to 3 was confirmed that the luminance is equal to or more than the comparative example 1 consisting of a conventional light diffusing film and at the same time improve the shielding.

In Comparative Example 2, when the difference between the refractive index of the light diffusing particles of the first diffusion layer and the refractive index of the binder resin is greater than 0.2, the larger the refractive index of the particle is than the refractive index of the binder resin, the more light refraction and scattering occur at the particle surface. The brightness was lower than that of Example 1 due to the loss and the diffusion efficiency.

In addition, in Comparative Example 3, the binder resin refractive index of the first diffusion layer is larger than the light diffusion particle refractive index of the first diffusion layer, so that the reflection occurs a lot on the surface of the particle and the luminance is lowered.

In addition, the shielding power and luminance of Example 1, in which the light-diffusion particle average particle diameter of the first diffusion layer was 5 µm, were superior to those of Comparative Example 4, in which the average particle diameter of the first diffusion layer was 10 µm.

In addition, in Comparative Example 5, when the average particle diameter of the light diffusing particles of the second diffusion layer was 5 μm, the light condensing efficiency was lowered on the surface, and as a result, the luminance was lowered compared to Example 1.

In Comparative Example 6, when the difference in refractive index of the light diffusing particles of the second diffusion layer is greater than 0.2, the surface particles of the second diffusion layer increase the diffusion of light rather than condensing, compared to Example 1, thereby increasing the luminance of Example 1 It was confirmed that lower.

As described above, the present invention has a structure in which a base layer, a first diffusion layer, and a second diffusion layer are sequentially stacked, and the first diffusion layer includes light diffusion particles and a binder resin, and the second diffusion layer includes light diffusion particles and a binder resin. Including a multi-layer diffusion layer on one surface of the transparent base film and by varying the refractive index and size of the particles of each diffusion layer to increase the uniformity and condensing efficiency of the surface structure of the diffuser layer to improve the shielding power and brightness at the same time Provided.

The present invention provides a light diffusing film that can improve the front brightness by minimizing the loss of light by improving the light condensing efficiency on the incident surface and the exit surface of the film, and the surface structure of the incident surface and the exit surface is emitted from the light source It contributed to the increased utilization of light.

In addition, the present invention increases the utilization of light emitted from the light source, thereby providing an improved luminance value even when using the same light source, which is useful for reducing energy consumption.

Although the present invention has been described in detail only with respect to the embodiments described, it will be apparent to those skilled in the art that various modifications and variations are possible within the technical spirit of the present invention, and such modifications and variations belong to the appended claims.

10: base material layer
21, 22: light diffusing particles of the first diffusion layer
31: light diffusing particles of the second diffusion layer
20: first diffusion layer
30: second diffusion layer
40: anti-blocking layer

Claims (9)

A base layer; A first diffusion layer; And a second diffusion layer, in which the first diffusion layer includes light diffusing particles having a mean particle size of 0.1 to 5 μm and a binder resin, wherein the difference between the refractive indices of the light diffusing particles and the binder resin is 0.2 or less. The second diffusion layer includes light diffusing particles having an average particle diameter of 10 to 30 μm and a binder resin, wherein the difference between the refractive indices of the light diffusing particles and the refractive index of the binder resin is 0.1 to 0.2. film. The light diffusing film for light emitting diodes according to claim 1, wherein the light diffusing particle refractive index of the first diffusion layer is 1.3 to 2.7. The light diffusing film for light emitting diodes according to claim 1, wherein the light diffusing particles of the first diffusion layer include at least one of organic particles and inorganic particles. The light emitting diode of claim 3, wherein the inorganic particles are at least one selected from the group consisting of silicon oxide, titanium oxide, barium sulfate, calcium carbonate, zirconium oxide, aluminum oxide, synthetic silica, and glass beads. Light diffusion film. 4. The light diffusing film for light emitting diodes according to claim 3, wherein the organic particles are at least one selected from the group consisting of acrylic resins, styrene resins and silicone resins. The light diffusing film for light emitting diodes according to claim 1, wherein the light diffusing particle refractive index of the second diffusion layer is 1.3 to 1.7. The light diffusing film for light emitting diodes according to claim 1, wherein the light diffusing particles of the second diffusion layer include at least one of inorganic particles and organic particles. The light diffusing film for light emitting diodes according to claim 7, wherein the inorganic particles are at least one selected from the group consisting of silicon oxide, barium sulfate, calcium carbonate, aluminum oxide, synthetic silica, and glass beads. 8. The light diffusing film for light emitting diodes according to claim 7, wherein the organic particles are at least one selected from the group consisting of acrylic resins, styrene resins and silicone resins.

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