KR101244550B1 - Light Diffusion member - Google Patents

Abstract

The present invention is to provide a light diffusing member that does not occur the phenomenon that the central portion is bent toward the front direction by minimizing the difference in expansion between the surface adjacent to the light source and not the surface, in one preferred embodiment of the present invention for the substrate layer ; And a bottom layer having a thermal expansion coefficient of 5.0 × 10 ⁻⁵ or more on at least one surface of the base layer.

Absence of light diffusion, expansion.

Description

Light Diffusion member

The present invention relates to a light diffusing member for use in a liquid crystal display.

As the industrial society develops into an advanced information age, the importance of the electronic display device as a medium for displaying and transmitting various information is increasing day by day. CRT (Cathode Ray Tube), which has been widely used in the past, has limitations due to large installation space, which makes it difficult to increase the size. Therefore, such as liquid crystal display (LCD), plasma display panel (PDP), field emission display (FED) and organic EL It is being replaced by various flat panel display devices. Among such flat panel display devices, in particular, in the case of liquid crystal display devices (LCDs), due to the advantages of thin, light, and low power consumption as a technology-intensive device in which liquid crystal and semiconductor technologies are combined, its structure and manufacturing technology have been researched and developed. In addition to the areas where liquid crystal displays have been widely used, such as notebook computers, desktop computer monitors, and portable personal communication devices (PDAs and mobile phones), large-scale technology is gradually exceeding its limitations. It is being used as a new display device that can replace CRT, which is synonymous with display, as it is applied to large TV of TV.

In the liquid crystal display (LCD) device, since the liquid crystal itself cannot emit light, a separate light source is installed at the rear of the device to adjust the intensity of the passing light through the liquid crystal installed in each pixel to realize contrast. do. In more detail, the liquid crystal display device is a device for controlling the light transmittance by using the electrical properties of the liquid crystal material, the uniformity and the directionality is controlled by passing through various functional prism films or sheets by emitting light from the light source lamp on the back of the device Indirect light-emitting display device that implements an image by passing light through a color filter to realize red, blue, green (R, G, B) colors, and controlling the contrast of each pixel by an electric method As a light emitting device that provides a light source, it is an important component for determining image quality such as brightness and uniformity of a liquid crystal display device.

As the light emitting device, a backlight unit (BLU) is widely used, and in general, light emitted from a plurality of light sources, such as a cold cathode fluorescent lamp (CCFL), is sequentially spread on a diffusion plate, a diffusion sheet, and a prism. A sheet such as a sheet is passed through to reach the liquid crystal panel. Here, the diffusion sheet performs a function of obtaining a uniform light intensity over the entire screen, and at the same time concealing a device such as a light source mounted under the diffusion sheet from the front. The prism sheet, on the other hand, performs an optical path control function for causing the light beams from various directions passing through the diffusion sheet to be converted into a range of viewing angle θ suitable for the viewer to recognize the image.

At this time, the diffusion member mounted on the light source is different in degree of expansion due to the temperature difference between the surface adjacent to the light source and the surface that is not, so that the diffusion member is slightly bent. At this time, in a humid environment, the light diffusion member is bent as shown in FIG. 5. When the BLU is stored in a humid environment, when the BLU is turned on, the lamp receives a lot of heat, causing the air to expand and the sheet adjacent to the upper surface of the sheet. This prevents evaporation and affects relative expansion by moisture, which disappears over time after lighting, especially when the BLU is slim, heat dissipation is not easy and accelerates relatively. As a result, the sheets stacked on the light diffusing member are also bent together, and thus, the center portion comes into contact with the liquid crystal panel, causing stains such as egg mura, and also causing the problem of lowering concealment.

In particular, the liquid crystal display device has recently been thinned to meet the needs of the consumer. In this case, since the above problems occur more, it is necessary to develop a light diffusion member that can prevent the warpage phenomenon.

An object of the present invention is to provide a light diffusing member in which a center portion does not bend in a front direction by minimizing an expansion difference between a surface adjacent to a light source and a surface that is not.

In one preferred embodiment of the present invention for this purpose; And a bottom layer having a thermal expansion coefficient of 5.0 × 10 ⁻⁵ or more on at least one surface of the base layer.

In the above embodiment, the bottom layer may have a thickness of 1 ~ 300㎛.

In the above embodiment, one surface of the base layer on which the bottom layer is not formed may include a structural layer in which a plurality of three-dimensional structures are arranged.

In the above embodiment, the structural layer has a first section having a curvature k according to Equation 1 below when the longitudinal section of the three-dimensional structure is represented in both directions about the peak and in the coordinates of the x-axis and the y-axis having the peak as a zero point. And, it may be to include a second section having an inclination angle with the base layer on both sides of the first section.

<Formula 1>

(Wherein x and y are nonzero integers and k is rational.)

In the above embodiment, the second section may have an inclination angle of 30 degrees to 50 degrees or 130 degrees to 150 degrees based on the substrate layer.

In the above embodiment, the first section may have a curvature k of 0.05 to 0.30.

In the above embodiment, the three-dimensional structure of the structural layer may have a pitch of 100㎛ ~ 500㎛.

In the above embodiment, the three-dimensional structure of the structural layer may be a height of 25㎛ ~ 300㎛.

In the above embodiment, the length of the bottom side of the longitudinal section in contact with the substrate layer may be 1/3 to 3/5 of the pitch.

In the above embodiment, the three-dimensional structure of the structural layer may be a structure in which the longitudinal section is symmetric with respect to the vertical center line passing through the peak point.

In the above embodiment, the base resin forming the base layer and the resin forming the bottom layer may be formed by co-extrusion.

In the above embodiment, the base resin forming the base layer and the structural layer and the resin forming the bottom layer may be co-extruded while passing through the pattern roller.

In the above embodiment, the base layer is selected from polyethylene terephthalate resin, polymethyl methacrylate resin, polycarbonate resin, polypropylene resin, polyethylene resin, polystyrene resin and styrene-acrylic copolymer resin, the structural layer is an ultraviolet curable resin or It may be selected from a polymer resin including a thermosetting resin, and may be formed by coating a resin forming the bottom layer.

In the above embodiment, the base resin may be selected from a resin, a polycarbonate resin, a polystyrene resin, a methyl methacrylate resin, an olefin resin in which a polycarbonate resin and a polystyrene resin are mixed at a weight ratio of 1: 9 to 9: 1. have.

In the above embodiment, the resin forming the bottom layer may be selected from fluororesin, styrene-butadiene copolymer, wax and rubber.

In the above embodiment, the resin forming the bottom layer may be a styrene-butadiene polymer, and may include one or more selected from fluororesin particles, styrene-butadiene copolymer particles, wax particles, and rubber particles.

 In another preferred embodiment of the invention the above light diffusing member; And a prism sheet formed on one surface of the light diffusing member.

In the backlight unit assembly according to the embodiment, the distance between the light source and the light diffusing member may be 2 to 10 mm.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in more detail with reference to the accompanying drawings.

1 is a longitudinal cross-sectional view of a light diffusing member according to a preferred embodiment of the present invention, Figure 2 is a longitudinal cross-sectional view of a light diffusing member according to another preferred embodiment of the present invention, Figure 3 is a preferred embodiment of the present invention Figure 4 is a graph showing the curvature form of the structural layer first section of the light diffusing member, Figure 4 is a longitudinal cross-sectional view of the light diffusing member 100 mounted on top of the light source 50 according to an embodiment of the present invention FIG. 5 is a longitudinal cross-sectional view of a state in which a conventional light diffusing member is mounted on an upper portion of the light source 50 and warpage occurs in an environment of high temperature and high humidity.

In the drawings, the same reference numerals are used for the same components for convenience, but they do not mean the same composition and shape.

The light diffusing member of the present invention may include a bottom layer 30 on at least one surface of the substrate layer 10. The bottom layer 30 is preferably formed on the surface adjacent to the light source 50, the thermal expansion coefficient may be 5.0 × 10 ^-5 or more. As a result, the extent to which the surface of the light diffusing member 100 is in contact with the light source 50 is expanded by heat. Therefore, as shown in FIG. 5, the phenomenon in which the central portion is bent in the front direction does not occur.

The bottom layer 30 satisfying the thermal expansion coefficient may include a component having a thermal expansion coefficient of 5.0 × 10 ⁻⁵ or more, and may be formed of, for example, a resin selected from fluororesin, styrene-butadiene copolymer, wax, and rubber. Or styrene-butadiene copolymer resin may include one or more selected from fluorine resin particles, styrene-butadiene copolymer particles, wax particles, and rubber particles.

In order to form the bottom layer 30, the base layer 10 may be first formed, and then the resin forming the bottom layer 30 may be applied to the bottom layer 30. The base layer 10 or the base layer ( 10) and resin which forms the bottom layer 30 at the time of extrusion-forming the structural layer 20 mentioned later can also be manufactured by coextrusion.

The bottom layer 30 may be manufactured to have a thickness of 1 to 300 μm in consideration of the fact that the central portion is bent in the front direction even after the bending evaluation and the temperature and humidity test during repeated expansion and contraction or reliability evaluation of the diffusion plate. It may be.

The light diffusing member of the present invention may include the structural layer 20 on the other surface on which the bottom layer 30 of the base layer 10 is not formed. More specifically, in the light diffusing member of the present invention, the structural layer 20 may include a plurality of three-dimensional structures, and the light-diffusion member of the present invention does not particularly limit the three-dimensional structure, and the peak is viewed in a longitudinal section. The structure may include a first section 2 having a curvature in both the left and right directions, and a second section 1 having an inclination angle with the base layer on both sides of the first section 2.

At this time, the second section 1 is made of a straight line having a predetermined inclination angle α with respect to the base layer 10 when the three-dimensional structure is viewed in a longitudinal section, and the inclination angle α is 30 degrees to 50 degrees or It may be 130 to 150 degrees.

Meanwhile, the curvature of the first section 2 may satisfy Equation 1 when the three-dimensional structure is represented by a longitudinal section and represented by coordinates having an x-axis and a y-axis having peaks as zero points.

<Formula 1>

(Wherein x and y are nonzero integers and k is rational.)

3 is a graph showing the shape of curvature according to Equation 1 above.

In the light diffusing member of the present invention, the k value of Equation 1 which is the curvature of the first section 2 may be 0.05 to 0.30.

The light diffusing member of the present invention includes the first section 2 and the second section 1 having the curvature as described above, so that the incident light passes through the light diffusing member and the actual image R and at least one virtual image V. This may occur. That is, the virtual image (V) refers to a sidelobe generated by implementing a small peak by transmitting only about 5 to 15% of the light, and the transmitted lights appear due to overlapping phenomenon. The principle in which the real image R and the virtual image V are shown is shown in FIG. This allows the light to be subdivided more efficiently and reliably than in light diffusion through the light diffusing particles in the conventional light diffusing member (Fig. 7).

The light diffusing member of the present invention may have a total light transmittance of 90% or more and a haze of 90% or more based on a thickness of 1.5 mm.

Such a light diffusing member of the present invention is preferably Weber Fraction of 1.0 or less, because it can provide a stable image for subsequent image evaluation.

<Formula 2>

(Wherein Lumi. Is Luminescence)

The first section 2 may have a length a ₂ of the bottom side contacting the substrate layer 10 being 1/3 to 3/5 of the pitch a, that is, both sides of the first section 2. In each of the second sections 1 formed on the substrate, it is preferable that the length a ₁ of the bottom side in contact with the base layer 10 is 1/5 to 1/3 of the pitch a. When the length (a ₂ ) of the bottom side in contact with the substrate layer (10) exceeds 3/5 of the pitch (a), the first section (2) is widened so that the longitudinal section is close to the semicircular shape, and since the interface of the substantial portion is curved, The optical separation effect due to the refraction increases, and the optical separation effect of clearly dividing the virtual image by the hypotenuse of the second section 1 decreases, thereby reducing the overall optical separation effect. In addition, when the length a2 of the bottom side in contact with the base layer is less than one third of the pitch a, the optical separation effect of clearly dividing the virtual image by the hypotenuse of the second section 1 increases, and the refraction of light is increased. By the light separation effect is reduced the overall light separation effect is reduced.

At this time, the pitch a of the three-dimensional structure of the structural layer 20 is not particularly limited, but is preferably 100 µm to 500 µm, and the height b of the three-dimensional structure constituting the structural layer 20 is particularly limited. Although it may not be, it may be 25㎛ ~ 300㎛, which is to take out the maximum lamp concealment effect in consideration of the shape of the pattern and to eliminate the moire phenomenon with the pattern sheet rising on the upper surface.

The shape of the three-dimensional structure constituting the structural layer 20 is preferably a structure that is symmetrical with respect to the center line in the vertical direction passing through the peak point, but is not limited thereto.

Such light diffusing member 100 of the present invention may be manufactured by co-extrusion. That is, the molten base resin constituting the base layer 10 and the structural layer 20 may be formed by co-extrusion while passing through the pattern roller. That is, as shown in each drawing, the base layer 10 and the structural layer 20 can be simply produced with one type of resin without the distinction of layers. The thickness including the base layer and the structural layer of the extruded light diffusing member may be 0.5 to 2.0 mm. The temperature during extrusion varies depending on the base resin, but is preferably extruded at 200 to 300 ° C. In this case, the base resin may be a resin in which a polycarbonate resin and a polystyrene resin are mixed in a weight ratio of 1: 9 to 9: 1, polycarbonate resin, polystyrene resin, olefin resin, methyl methacrylate resin, and the like. In this case, the polystyrene resin may be a polystyrene resin having heat resistance, and having a glass transition temperature of 110 ° C. or higher measured by a differential scanning calorimeter or DSC. For example, the manufacturer PS Japan, a trade name G9001, or the like may be used. The olefin resin may include a cycloolefin polymer (COP) or a cycloolefin copolymer (COC).

On the other hand, the light diffusing member of the present invention may be formed by coating and curing a crude liquid containing an ultraviolet curable resin or a thermosetting resin on one surface of the substrate layer 10 to form a structural layer 20.

In this case, polyethylene terephthalate resin, polymethyl methacrylate resin, polycarbonate resin, polypropylene resin, polyethylene resin, polystyrene resin, or styrene-acrylic copolymer resin may be used as the base layer, and the curable resin may be used as the structural layer. If it is a light transmissive material, it will not specifically limit. That is, any polymer resin containing a UV curable resin or a thermosetting resin can be used without limitation, for example, unsaturated fatty acid esters, aromatic vinyl compounds, unsaturated fatty acids and derivatives thereof, unsaturated dibasic acid and derivatives thereof, Vinyl cyanide compounds such as methacrylonitrile and the like can be used. At this time, it is possible to adjust the polymer resin to be used in consideration of the refractive index with the substrate layer.

The substrate layer 10 may have a thickness of 10 μm to 1000 μm in terms of mechanical strength, thermal stability, flexibility, and preventing loss of transmitted light, and more preferably 15 μm to 400 μm.

On the other hand, the light diffusing member of the present invention may include light diffusing particles (not shown) in the base layer 10, it is preferable to use a particle diameter of 1 ~ 50㎛, 100 parts by weight of the binder resin It is good to include about 10 to 500 parts by weight. When the light diffusing particles having such a particle diameter are included in the above content, an appropriate light diffusing effect may be provided while preventing whitening and separation of the particles.

As the light diffusing particles, a plurality of organic particles or inorganic particles may be used. Representative organic particles include methyl methacrylate, acrylic acid, methacrylic acid, hydroxyethyl methacrylate, hydroxypropyl methacrylate, acrylamide, methylol acrylamide, glycidyl methacrylate, and ethyl acryl. Acrylic particles of latex, isobutyl acrylate, normal butyl acrylate, 2-ethylhexyl acrylate homopolymer or copolymer; Olefinic particles such as polyethylene, polystyrene and polypropylene; Acrylic and olefin copolymer particles; And multi-layered multicomponent particles, siloxane polymer particles, tetrafluoroethylene particles, etc. formed by forming particles of a homopolymer and then covering the layers with other types of monomers. Examples of the inorganic particles include silicon oxide and aluminum oxide. , Titanium oxide, zirconium oxide, magnesium fluoride and the like. It will be apparent to those skilled in the art that the organic and inorganic particles are merely exemplary, and are not limited to the particles of the organic or inorganic materials listed above, and may be replaced by other known materials as long as the object of the present invention can be achieved. In addition, such a material change is also within the scope of the technical idea of the present invention.

Meanwhile, in the light diffusing member of the present invention, when the structural layer 20 is formed, the surface layer 40 may be further formed on the structural layer 20, and the surface layer 40 may include particles 45. . The surface layer 40 may be formed by the same method as the method of forming the bottom layer 30, the particles 45 may include organic particles or inorganic particles as the light diffusing particles described above, the base layer It may be the same as or different from the light diffusing particles included in (10). The surface layer 40 preferably contains 0.01 to 30 parts by weight of particles with respect to 100 parts by weight of the base resin or binder resin, which is advantageous for light diffusion and concealment, and does not reduce the light utilization efficiency while taking forward luminance into consideration. will be. Although the thickness of this surface layer 40 is not specifically limited, It is preferable that it is 10-200 micrometers.

The light diffusing member of the present invention may be subjected to an antistatic treatment, for example, an antistatic agent may be included in each layer or any one layer, or the antistatic component may be coated by a method such as spraying.

On the other hand, the present invention can provide a backlight unit assembly including a prism sheet formed adjacent to one surface of the light diffusing member described above.

In the backlight unit assembly of the present invention, the distance d between the light source and the light diffusing member of the present invention may be 2 to 10 mm, and the distance between the light source and the light diffusing member in the conventional backlight unit assembly is 13 to 17 mm. Compared to the conventional case, the front panel is not easily deformed even if the light diffusing member is more exposed to heat than the conventional one due to the shortening of the distance. The occurrence of stains can be prevented.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the scope of the present invention is not limited to the following Examples.

&Lt; Example 1 >

The polycarbonate resin pellets were coextruded at 220 ° C., uniaxial screw diameter 135 mm and 60 mm, and the total thickness of the light diffusion member was 1.5 mm. The pitch was 300 μm, the height (b) 130 μm, and the inclination angle (α). 40 degrees, curvature (k) 0.21, length (a ₁ ) of the bottom side in contact with the base layer 10 of the second section ₁ , 75 μm, length of the bottom side in contact with the base layer 10 of the first section 2 (a ₂ ) A structural layer in which a unit structure having a shape as shown in FIG. 2 is linearly arranged in a row while passing through a pattern roller to be 150 μm is formed.

On the other side of the base layer, a light diffusion member was manufactured by forming a bottom layer co-extruded with styrene-butadiene copolymer resin to a thickness of 50 μm.

<Example 2>

In Example 1, a light diffusing member was manufactured in the same manner except that the bottom layer was coextruded with a polyvinylidene fluoride (PVDF) fluororesin.

<Example 3>

A light diffusion member was manufactured in the same manner as in Example 1, except that no structural layer was formed.

<Example 4>

After applying the methacrylate resin to the mold such that the unit structure having the shape as shown in FIG. 1 is linearly arranged in a line, after laminating a polyethylene terephthalate film (Lee Sung Electronics, LM170E01), the ultraviolet ray was radiated for 3 seconds at an intensity of 120 Watts. It irradiated and hardened | cured, and it mold-released from the metal mold and produced the light-diffusion member. The pitch of the structural layer is 300 μm, the height (b) is 130 μm, the inclination angle (α) is 40 degrees, the curvature (k) is 0.21, and the base length (a1) is 75 μm in contact with the base layer 10 of the second section (1). It was 150 micrometers in length (a2) of the base side which contact | connects the base material layer 10 of the 1st section 2. As shown in FIG.

On the other side of the base layer, a light diffusion member was manufactured by forming a bottom layer co-extruded with styrene-butadiene copolymer resin to a thickness of 50 μm.

&Lt; Comparative Example 1 &

In Example 1, the light diffusion member was manufactured in the same manner except that the bottom layer was not formed.

Comparative Example 2

A light diffusion plate (manufacturer: Kolon, trade name: DP421, thickness: 1.50 mm, transmittance: 57.0%, haze: 99%) was prepared.

&Lt; Comparative Example 3 &

Light diffusing sheet (manufacturer: Kolon, brand name: LD613, thickness: 188 μm, transmittance: 75.5%, haze: 96.0%) on the prism sheet (manufacturer: Kolon, brand name: LC213, thickness: 188 μm, pitch: 50 μm, height : 25 µm, inclination angle of 45 degrees) was prepared.

Evaluation of physical properties of optical members, such as the light diffusing members prepared in Examples and Comparative Examples, was carried out in the following manner, and the results are shown in Table 1 below.

(1) coefficient of thermal expansion

The coefficient of thermal expansion of the light diffusing members in Examples and Comparative Examples was measured using JIS K 6911 test method. It can be seen that as the value of the coefficient of thermal expansion increases, the coefficient of thermal expansion per unit length increases with temperature change.

(2) EggMura measurement after BLU lighting

The light diffusing member in the above Examples and Comparative Examples was mounted on a 42-inch liquid crystal display panel backlight unit (LC420WUF), and stored at 50 ° C., 80% RH, and 96 hours, and then stored for 2 hours under normal temperature and humidity conditions. After about 7hrs after the backlight unit was turned on, EggMura occurrence was divided into 5 stages according to the occurrence and the degree of occurrence.

0: No EggMura occurrence

1: weak EggMura level

2: EggMura level medium

3: EggMura level strong

4: EggMura level very strong

(3) Luminance

The light diffusing member in the above Examples and Comparative Examples was mounted on a 42-inch liquid crystal display panel backlight unit (LC420WUF) and fixed at a distance of 4.0 mm using a luminance meter (TOPCON, BM-7). Luminance was measured at 13 points and the average value was obtained.

(4) Heat resistance

The light diffusing members in the above Examples and Comparative Examples were cut into 42-inch sizes, and then fixed in the thermo-hygrostat after standing in the longitudinal direction. At this time, the lifting bending amount of the four corner portions of the light diffusion member before and after the test was placed on the surface plate and measured by a gap gauge, and the average value of the four corner bending amounts was used. The smaller the amount of warpage and the amount of warpage change before and after the test, the higher the heat resistance.

(5) Weber fraction (hidden)

The light diffusing member in the above Examples and Comparative Examples was mounted on a 42-inch liquid crystal display panel backlight unit (LC420WUF) and the distance from the light source was fixed at 4.0 mm to determine the luminance facing meter (MINOLTA, CA-2000). Nessence) was measured, the web fraction of the formula 2 was calculated, and the results are shown in Table 1.

division Coefficient of thermal expansion
(1 / ℃) EggMura Luminance
(cd / ㎡) Heat resistance (mm) Weber fraction (%) Example 1 7.2 × 10 ^-5 One 9543 0.10 0.80 Example 2 6.8 × 10 ^-5 One 9439 0.11 0.85 Example 3 7.2 × 10 ^-5 One 6848 0.11 1.72 Example 4 6.5 × 10 ^-5 One 9345 0.15 0.82 Comparative Example 1 4.8 × 10 ^-5 3 9545 0.10 0.80 Comparative Example 2 4.5 × 10 ^-5 3 6948 0.10 1.33 Comparative Example 3 4.7 × 10 ^-5 4 7541 - 1.42

1 is a longitudinal cross-sectional view of a light diffusing member according to a preferred embodiment of the present invention;

2 is a longitudinal sectional view of a light diffusing member according to another preferred embodiment of the present invention;

3 is a graph showing the shape of curvature of the first section of the structural layer of the light diffusing member according to an embodiment of the present invention;

4 is a longitudinal cross-sectional view of a light diffusion member mounted on an upper portion of a light source according to an embodiment of the present invention;

5 is a longitudinal cross-sectional view of a state in which a conventional light diffusing member is mounted on an upper portion of a light source 50 and warpage occurs in an environment of high temperature and high humidity;

6 is a view showing a principle that the actual image (R) and the virtual image (V) is generated through the light diffusing member according to an embodiment of the present invention,

7 is a view illustrating a principle in which light is diffused in a conventional light diffusing member.

* Explanation of the symbols of the main parts of the drawings

1: second section 2: first section

10: substrate layer 20: structure layer

30: bottom layer 40: surface layer

45 particle 50 light source

60: support pin 100: light diffusion member

Claims (18)

A base layer; A bottom layer having a thermal expansion coefficient of 5.0 × 10 ⁻⁵ or more on at least one surface of the base layer; And One side of the base layer is not formed the bottom layer includes a structural layer arranged a plurality of three-dimensional structure, The structural layer may include a first section having a curvature k according to Equation 1 below when the longitudinal cross-section of the three-dimensional structure is represented in both directions centered on the peak and represented by coordinates of the x-axis and the y-axis having the peak as a zero point; The light diffusing member, characterized in that it comprises a second section having an inclination angle with the base layer on both sides of one section. <Formula 1>

(Wherein x and y are nonzero integers and k is rational.) The method of claim 1, The bottom layer is a light diffusion member, characterized in that the thickness is 1 ~ 300㎛. delete delete The method of claim 1, And the second section has an inclination angle of 30 degrees to 50 degrees or 130 degrees to 150 degrees with respect to the base layer. The method of claim 1, The first section is a light diffusion member, characterized in that the curvature (k) is 0.05 ~ 0.30. The method of claim 1, The three-dimensional structure of the structural layer is a light diffusion member, characterized in that the pitch is 100㎛ ~ 500㎛. The method of claim 1, The three-dimensional structure of the structural layer is a light diffusion member, characterized in that the height is 25㎛ ~ 300㎛. The method of claim 1, The first section has a light diffusion member, characterized in that the base length of the longitudinal section in contact with the substrate layer is 1/3 to 3/5 with respect to the pitch. The method of claim 1, The three-dimensional structure of the structural layer is a light diffusing member, characterized in that the longitudinal section is a structure symmetric with respect to the vertical center line passing through the peak point. The method of claim 1, A light diffusing member, wherein the base resin for forming the base material layer and the resin for forming the bottom layer are coextruded and formed. The method of claim 1, A light diffusing member, wherein the base resin forming the base layer and the structural layer and the resin forming the bottom layer are coextruded while passing through the pattern roller. The method of claim 1, The base layer is selected from polyethylene terephthalate resin, polymethyl methacrylate resin, polycarbonate resin, polypropylene resin, polyethylene resin, polystyrene resin and styrene-acrylic copolymer resin, The structural layer is selected from a polymer resin including an ultraviolet curable resin or a thermosetting resin, A light diffusing member, wherein the resin forming the bottom layer is coated and formed. 13. The method according to claim 11 or 12, The base resin is a light diffusing member, characterized in that the polycarbonate resin and polystyrene resin is selected from a resin, polycarbonate resin, polystyrene resin, methyl methacrylate resin, olefin resin mixed in a weight ratio of 1: 9 ~ 9: 1: . 14. The method according to any one of claims 11 to 13, The resin for forming the bottom layer is a light diffusion member, characterized in that selected from fluororesin, styrene-butadiene copolymer, wax and rubber. 14. The method according to any one of claims 11 to 13, The resin for forming the bottom layer is a styrene-butadiene copolymer, wherein the resin comprises at least one selected from fluorine resin particles, styrene-butadiene copolymer particles, wax particles and rubber particles. The light diffusing member of claim 1; And And a prism sheet formed on one surface of the light diffusing member. The method of claim 17, A backlight unit assembly wherein the distance between the light source and the light diffusing member is 2 to 10 mm.

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