KR20130071014A - Resin composition for cover bottom of backlight unit and backlight unit including the same - Google Patents

Abstract

PURPOSE: A resin composition and a backlight unit are provided to reduce manufacturing cost, to obtain light weight and thin thickness, and to improve uniformity of emitted light. CONSTITUTION: A resin composition(100) for cover the bottom of a backlight unit comprises a base resin(110); and beads(130) in which a hollow part is formed inside thereof. The bead is at least one selected from a glass bead, acrylic bead, and amide bead. A back light unit comprises a cover bottom which includes reflective patterns and side walls protruded from the edge of the bottom side; and a light source part which is arranged inside the sidewall. The cover bottom is formed of the resin composition.

Description

Resin Composition For Cover Bottom of Backlight Unit And Backlight Unit Including The Same}

The present invention relates to the technical field of a backlight unit, and more particularly, to a backlight unit including a resin composition of a cover bottom and a cover bottom manufactured using the same.

Liquid crystal displays (LCDs) are widely used flat panel displays (FPDs), which require light because they display images using liquid crystals, which are light-receiving elements that do not emit light by themselves. Therefore, the liquid crystal display receives light from the backlight unit attached to the rear surface of the liquid crystal display panel and displays an image.

The backlight unit is classified into an edge type and a direct type according to the shape of the light source. The direct type backlight unit is configured to arrange a plurality of light sources on a rear surface of the liquid crystal display panel to supply light to the front liquid crystal display panel. The edge type backlight unit includes a light guide plate on a rear surface of the liquid crystal display panel and a light source disposed on a side surface of the light guide plate to supply a surface light source to the liquid crystal display panel. In the case of such an edge type backlight unit, a lot of researches are being conducted to smoothly supply light to the liquid crystal display panel by changing the structure of the light guide plate, such as Korean Patent Publication No. 10-2011-0021193.

1 is a schematic view of a conventional edge type backlight unit structure.

Referring to FIG. 1, the conventional edge type backlight unit includes a light guide plate 40, a reflector 50 disposed below the light guide plate 40, an LED module array 30 disposed on a side surface of the light guide plate 40, It includes an optical sheet 70 disposed on the light guide plate 40 and a metal chassis 10 for accommodating the above-described components. The light guide plate 40 converts the light irradiated from the LED module array 30 into a surface light source and supplies the light to the liquid crystal display panel, which is one of the essential components in the conventional backlight unit. However, in the backlight unit including the light guide plate 40, the light loss occurs in the light guide plate 40, the problem of increased power consumption due to the light loss, and the bending of the light guide plate 40 due to its own weight. There was a problem that occurred.

In addition, the conventional edge type backlight unit generally includes a chassis made of a metal material, that is, a metal chassis 10 to store components, and there is a problem that the weight of the backlight unit itself increases, and the bottom of the cover bottom additionally. Since the white reflective sheet to be additionally formed on the surface, there is a problem in the thinning of the product due to the problem of increased manufacturing process and the thickness of the reflective sheet.

Korean Patent Publication No. 10-2011-0021193 (published on Apr. 2011, 2011)

The present invention has been proposed to solve the above-mentioned conventional problems, a resin composition for a backlight unit cover bottom comprising a base resin, beads mixed and formed in the base resin, and having hollows formed therein, and manufactured using the same. The purpose of the present invention is to provide a backlight unit including a cover bottom, and to reduce manufacturing cost by eliminating the light guide plate and the white reflection sheet, which are conventionally used, and to improve the light reflectivity and the uniformity of the emitted light while realizing weight reduction and thinning.

The resin composition for a backlight unit cover bottom of the present invention for solving the above problems is a base resin; It comprises a bead mixed and formed in the base resin, the hollow formed inside.

In the resin composition for the backlight unit cover bottom of the present invention, the beads may be at least one of glass beads, acrylic beads, and amide beads.

In the resin composition for the cover unit cover bottom of the present invention, the content of the beads in the resin composition may be 10% by weight to 30% by weight.

In the resin composition for the cover unit cover bottom of the present invention, the diameter of the beads may be formed in the range of 0.55 to 135㎛.

The resin composition for the cover unit cover bottom of the present invention may further include an inorganic material mixed and formed in the base resin.

In the resin composition for the backlight unit cover bottom of the present invention, the inorganic material may include at least one of BaSO 4, TiO 2, and CaCO 3, and the form may have a spherical shape. In addition, the diameter of the inorganic material may be formed in the range of 0.11 to 2㎛.

In the resin composition for the cover unit cover bottom of the present invention, the base resin may be made of a thermoplastic resin, polycarbonate resin, polymethylmethacrylate resin, polypropylene resin, polyethylene ( Polyethylene) may include at least one of.

The resin composition for the backlight unit cover bottom of the present invention may further include an additive mixed in the base resin, wherein the additive is any one of a fluorescent brightener, a crosslinking agent, a heat stabilizer, an oxidation stabilizer, an ultraviolet absorber, and an antistatic agent. One or a mixture thereof.

The backlight unit of the present invention for solving the above problems, the cover bottom including a plurality of reflective patterns formed on the bottom surface and sidewalls protruding from the corner of the bottom surface; A light source unit disposed inside the sidewall; Including, but the cover bottom may include a base resin and a bead mixed and formed in the base resin and a hollow formed therein.

In the backlight unit of the present invention, the beads may be at least one of glass beads, acrylic beads, and amide beads.

In the backlight unit of the present invention, the content of the beads in the resin composition may be 10% by weight to 30% by weight.

In the backlight unit of the present invention, the diameter of the beads may be formed in the range of 0.55 to 135㎛.

In the backlight unit of the present invention, the resin composition may further include an inorganic material mixed and formed in the base resin.

In the backlight unit of the present invention, the inorganic material may include at least one of BaSO 4, TiO 2, and CaCO 3, and may have a spherical shape. In addition, the diameter of the inorganic material may be formed in the range of 0.11 to 2㎛.

In the backlight unit of the present invention, the base resin may be made of a thermoplastic resin, and may include at least one of a polycarbonate resin, a polymethylmethacrylate resin, a polypropylene resin, and a polyethylene resin. It may include any one.

In the backlight unit of the present invention, the resin composition may further include an additive formed in the base resin, wherein the additive is any one of a fluorescent brightener, a crosslinking agent, a heat stabilizer, an oxidation stabilizer, an ultraviolet absorber, and an antistatic agent. One or a mixture thereof.

In the backlight unit of the present invention, the reflection pattern may be any one of a prism shape, a lenticular shape, a concave lens shape, a convex lens shape, and a combination thereof.

In the backlight unit of the present invention, the cross-sectional shape of the reflective pattern may be any one of a triangle, a quadrangle, a semicircle, and a combination thereof.

In the backlight unit of the present invention, the reflective pattern may be integrally formed with the cover bottom.

In the backlight unit of the present invention, the cover bottom may be formed by injection molding the resin composition.

According to the present invention, by integrating the function of the white reflective sheet to the cover bottom, the manufacturing process of the backlight unit can be simplified and the thickness of the product can be reduced.

In addition, according to the present invention, since there is no need to use a conventional light guide plate, the manufacturing cost of the backlight unit may be reduced, and the process efficiency improvement effect may be achieved by omitting the light guide plate processing process.

In addition, according to the present invention, although the light guide plate and the white reflection sheet are omitted, the light reflectance and the uniformity of the light supplied to the liquid crystal display panel may be improved.

And according to the present invention, despite the reduction in manufacturing cost, the effect of providing a backlight unit that can improve the brightness of the liquid crystal display device and the weight saving effect of the backlight unit by not using a conventional light guide plate, conventional metal The weight of the additional backlight unit is reduced by forming the cover bottom with the resin composition without using the chassis.

1 is a schematic view of a conventional edge type backlight unit structure.
2 is a view schematically showing the configuration of a resin composition according to an embodiment of the present invention.
3 illustrates a structure of a backlight unit according to an exemplary embodiment of the present invention.
Figure 4 is a graph showing the reflectance of the reflective sheet and the highly reflective injection test specimen according to the prior art.
5 is a graph showing the reflectance of the cover bottom manufactured using the resin composition according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be understood, however, that the embodiments described herein and the configurations shown in the drawings are only a preferred embodiment of the present invention, and that various equivalents and modifications may be made thereto at the time of the present application. DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail to avoid obscuring the subject matter of the present invention. The following terms are terms defined in consideration of functions in the present invention, and the meaning of each term should be interpreted based on the contents throughout the present specification. The same reference numerals are used for portions having similar functions and functions throughout the drawings.

The present invention provides a resin composition for a backlight unit cover bottom which enables the cover bottom itself to perform a function of a white reflection sheet, which is conventionally used by manufacturing a cover bottom of a backlight unit with a resin composition including a bead (hereinafter referred to as a resin composition). And the backlight unit manufactured by using the same.

Figure 2 schematically shows the configuration of a resin composition according to an embodiment of the present invention.

Referring to FIG. 2, the resin composition 100 according to the present invention includes a base resin 110 and beads 130 mixed and formed in the base resin 110, and also as a pigment. The inorganic material 150 may further include an additive.

The base resin 110 is a part of the basic composition of the resin composition 100. A thermoplastic resin may be used as the base resin 110, and more specifically, polycarbonate, polymethylmethacrylate, polypropylene, polyethylene, and polyimide. At least one resin of polyurethane (Ployurethane) may be used, but is not limited thereto.

As shown in (a) and (b) of FIG. 2, a plurality of beads 130 having a structure in which a hollow 133 is formed inside and a bead layer 131 is formed on an outer circumference thereof are formed in the base resin 110. Mixed and diffused, the bead 130 serves to improve the reflection and diffusion characteristics of the light.

The reflectance of the light increases in proportion to the number of voids formed in the resin composition. When voids are formed through the foaming process, there are disadvantages of weakness in external impact, heat resistance, and flame resistance. do. However, the resin composition 100 according to the present invention improves the reflection and diffusion characteristics of light by mixing and forming the beads 130 having the hollow 133 in the base resin 110 instead of forming voids. Endurance can be improved, and heat resistance and flame retardancy can be easily realized.

For example, when the light emitted from the light source enters the bead 130, the light is reflected and transmitted by the hollow 133 of the bead 130 to be diffused, and is subsequently diffused on the surface of the reflective pattern of the backlight unit. It is emitted to the liquid crystal display panel. In this case, the reflectance and the diffusion rate of the light are increased by the bead 130, thereby improving the amount and uniformity of the emitted light supplied to the liquid crystal display panel, thereby improving the brightness of the liquid crystal display device.

The bead 130 of the present invention may be generally formed of glass, but may be made of a polyester resin, a polyacrylic resin, a polystyrene resin, a polycarbonate resin, a polyamide resin, etc. having high transparency, but is not limited thereto. It doesn't happen.

On the other hand, the hollow 133 formed inside the bead 130 may be filled with air (air), it may be made in a vacuum state. However, this is only one example, and in addition, appropriate design changes, such as filling of gas such as inert gas, will be possible if necessary.

The content of the beads 130 may be appropriately adjusted to obtain a desired light diffusing effect, and more specifically, may be adjusted within the range of 10% to 30% by weight relative to the total weight of the resin composition 100, It is not limited to this.

On the other hand, as the diameter of the bead 130 increases, the transmittance increases and the reflectance decreases. In consideration of the light diffusion effect, the reflectance and the uniformity of brightness, the diameter of the bead 130 is formed in the range of 0.55 to 135 μm. It may be, but is not limited thereto, and may be appropriately adjusted according to the degree of light diffusion effect and reflectance.

In addition to the beads 130 described above, the resin composition 100 of the present invention may further include an inorganic material 150 as a pigment for improving the reflectance. Such an inorganic material may be formed including at least one of BaSO 4, TiO 2, and CaCO 3, and the shape may be spherical, but is not limited thereto. In addition, the inorganic material may be formed in various shapes such as polygonal shape, hemispherical shape, and cylindrical shape. Can be. In addition, the diameter of the inorganic material 150 may be appropriately adjusted in consideration of the light diffusing effect and the reflectance similarly to the case of the bead 130, and more specifically, may be formed in the range of 0.11 to 2㎛, but is not limited thereto. .

In addition, the resin composition 100 of the present invention may be further mixed with additives within the range that does not inhibit the reflection effect and diffusion effect, such additives include fluorescent whitening agent, crosslinking agent, heat stabilizer, oxidation stabilizer, ultraviolet absorber, Materials such as antistatic agents or mixtures thereof may be used.

After melting the resin composition 100 of the present invention in the form of a high concentration of the master batch chip, and injection molding it can be produced a backlight unit cover bottom, the cover bottom thus manufactured is durable, heat resistance and flame retardant I can equip it. In addition, the cover bottom has an excellent light reflectance and diffusion effect, so that even if the light guide plate and the white reflection sheet are not provided, it is possible to efficiently supply light to the liquid crystal display panel and to provide a backlight unit capable of supplying uniform light. do.

3 illustrates a structure of a backlight unit according to an exemplary embodiment of the present invention.

2 and 3, the backlight unit 2 according to the exemplary embodiment of the present invention may include a cover bottom 300 and a light source unit 500, and further include an optical sheet 700. Can be formed.

The light source unit 500 serves to provide light to the liquid crystal display panel, and may be disposed inside the sidewall 350 of the cover bottom 300. The light source unit 500 of the present invention may be composed of a light source 510 for emitting light and a circuit board 530 on which the light source is mounted.

As the light source 510, one or more light emitting diodes (LEDs) emitting light may be used, and the light sources 510 are continuously arranged at a predetermined interval on the circuit board 510 to form an array. It may be, but is not limited thereto.

On the other hand, as the light source 510, not only a point light source such as a light emitting diode, but also a cold cathode fluorescent lamp (CCFL), a hot cathode fluorescent lamp (HCFL), and an external electrode fluorescent lamp (EEFL) A lamp in the form of a line light source such as a fluorescent lamp may also be used.

The cover bottom 300 includes a bottom surface 310 and a side wall 350 protruding upward from an edge of the bottom surface 310, and the side wall 350 is formed at each corner of the bottom surface 310. The structure surrounding the bottom surface 310 or the bottom surface 310 having four surfaces formed on two surfaces facing each other may be formed in a symmetrical structure, but is not limited thereto.

In particular, the cover bottom 100 of the present invention, unlike the conventional backlight unit shown in Figure 1, can be manufactured using the resin composition 100 described above in the description of Figure 2, the manufacturing method is injection Molding methods can be used. That is, as the cover bottom 100 is formed of a resin composition 100 rather than a metal material, the backlight unit 2 according to the present invention can significantly reduce weight and overall weight as compared with a conventional backlight unit.

Meanwhile, a support member 370 may be further formed at one end of the sidewall 350 except for the other end contacting the bottom surface 310. The support member 370 is formed in the shape of a protruding structure formed by extending inwardly of the cover bottom 300 at one end of the side wall 350, but is preferably formed integrally with the cover bottom 300, but is not limited thereto. It may be coupled to the side wall 350 by being formed in a separate configuration from the cover bottom 300. The support member 370 of the present invention serves to support the optical sheet 700 to be described later, and may also serve to provide a space for adding a separate reflective member.

The reflective pattern 330 is formed on the bottom surface 310. The reflective pattern 330 serves to uniformly transmit the light to the liquid crystal display panel by reflecting and diffusing the incident light. That is, the reflective pattern 510 formed on the surfaces of the reflective member 500 and the first reflective member 500 of the present invention has a function of converting incident light, which has been performed by a conventional light guide plate, into a surface light source and supplying it to a liquid crystal display panel. To perform.

The reflective pattern 330 has a structure having a plurality of patterns, and may be formed in a prism shape, a lenticular shape, a concave lens shape, a convex lens shape, or a combination thereof in order to increase the reflection and diffusion effects of light. It is not limited to this. In addition, the cross-sectional shape of the reflective pattern 330 may have a structure having various shapes such as a triangle, a square, a semicircle, and a sinusoidal wave. In addition, the size or density of each pattern may be changed according to the distance from the light source unit 300. The reflective pattern 330 of the present invention is integrally formed with the cover bottom 300, and may be simultaneously formed with the bottom surface 310 and the side wall 350 in the injection molding process, and may be formed at this time. will be.

The resin composition 100 forming the cover bottom 300 may have a structure in which the base resin 110 and the bead 130 having a hollow formed therein are mixed. In addition, the inorganic material 150 and the additive may be further mixed. Accordingly, it is possible to improve durability while improving the reflection and diffusion characteristics of the light, and has the advantage of being easy to implement heat resistance and flame resistance. In addition, by combining the function of the white reflector sheet to the cover bottom 300 to integrate, it is possible to further reduce the thickness and to improve the process efficiency by eliminating the white reflector sheet forming process.

In particular, in the case of the present invention, as the beads 130 are also diffusely formed in the reflective pattern 330, the light reflectance may be further improved, and specific reflection characteristics may be easier to implement as needed.

For example, when the light emitted from the light source unit 500 is incident on the reflection pattern 330, the reflection pattern 330 reflects the incident light by Lambertian or Gaussian. In more detail, the reflection pattern 330 allows light to be uniformly distributed by the Lambertian reflection (total reflection) and Gaussian reflection (diffuse reflection). That is, light incident on the reflective pattern 330 becomes Lambertian reflection on the surface of the reflective pattern 330 of the cover bottom 300, and at the same time, the light is evenly spread around by the Gaussian reflection. Accordingly, the light incident from the light source can be uniformly emitted without a separate light guide plate. On the other hand, when light is incident on the bead (130 of FIG. 2) formed inside the reflective pattern 330, the light is reflected and transmitted by the hollow (133 of FIG. 2) of the bead (130 of FIG. The light is second-diffused from the surface of the reflective pattern 330 and is emitted to the liquid crystal display panel. At this time, the reflectance and the diffusivity of the light are increased by the bead 130, thereby improving the amount and uniformity of the emitted light which is subsequently supplied to the liquid crystal display panel, and consequently, improving the luminance of the liquid crystal display without using the light guide plate and the white reflection sheet. You can get the effect of letting.

In addition, the detailed description of the base resin 110, the beads 130, the inorganic material 150, and the additive constituting the resin composition 100 is the same as described above in the description of FIG.

The optical sheet 700 may be disposed above the reflective pattern 330 to diffuse and collect light emitted from the reflective pattern 330. The optical sheet 700 may include at least one of a diffusion sheet, a prism sheet, and a protective sheet, and may be a sheet having a complex function of performing all of the functions of the diffusion sheet, prism sheet, and protective sheet. It may be formed. For example, the optical sheet 700 of the present invention may be formed in a form of forming a diffusion function in the lower part of the sheet, forming a prism pattern on the upper part, and forming a protective layer on the prism pattern.

Meanwhile, in the backlight unit 2 of the present invention, since the light guide plate does not exist, the support member 370 may be further formed on the cover bottom 300 to support the optical sheet 700. 700 may be disposed on an upper portion of the support member 370.

In addition, although not shown in the drawings, the backlight unit 2 of the present invention may further include a reflecting member below the support member 370 to increase the reflectance of the light, the reflecting member is a light reflecting characteristic It can be formed including this excellent Ag or Ag alloy.

Although not shown in the drawings, according to the present invention, a liquid crystal display device including the backlight unit described above may be provided.

The liquid crystal display device of the present invention may include a liquid crystal display panel and a backlight unit for supplying light to the liquid crystal display panel.

The liquid crystal display panel includes a color filter substrate and a thin film transistor substrate bonded to face the color filter substrate with the liquid crystal layer interposed therebetween.

The color filter substrate includes a color filter array including a black matrix for preventing light leakage, a color filter for realizing color, a common electrode forming a vertical electric field with the pixel electrode, and an upper alignment layer coated thereon for liquid crystal alignment on the upper substrate. Can be formed on. The thin film transistor substrate includes a thin film transistor array including a gate line and a data line formed to cross each other, a thin film transistor formed at an intersection thereof, a pixel electrode connected to the thin film transistor, and a lower alignment layer coated thereon for liquid crystal alignment. It may be formed on the lower substrate.

As described above with reference to FIG. 3, the backlight unit includes a cover bottom including a bottom surface and sidewalls protruding from an edge of the bottom surface, a light source unit disposed inside the sidewall, and a reflection pattern formed on the bottom surface. The cover bottom is made of a resin composition in which beads are mixed with the base resin. Other explanations are the same as those described above in the descriptions of FIGS. 2 and 3, and will be omitted.

In the liquid crystal display device according to the present invention, the manufacturing cost is reduced by omitting the light guide plate, and the manufacturing process efficiency is improved by omitting the light guide plate processing step. In addition, it has an overall weight reduction effect by omitting the light guide plate and an additional weight reduction effect by not forming the cover bottom with a metal. And although not including the light guide plate has the effect of providing a stable brightness. In addition, since the cover bottom is formed of the resin composition described above, it is possible to improve the light reflectance and the uniformity of the emitted light without providing a separate white reflection sheet, thereby reducing the product thickness and improving the manufacturing process efficiency. It also has additional effects.

FIG. 4 is a graph showing the intensity of light of the reflection sheet and the high reflection exiting specimen according to the prior art. More specifically, FIG. 4 (a) is a graph showing the intensity of the light of the white reflection sheet. (B) is a graph showing the intensity of light in the high-reflective ejected specimen. 5 is a graph showing the intensity of light of the cover bottom manufactured using the resin composition according to the present invention.

4 and 5, the horizontal axis represents the position (angle) of the photodetector and the vertical axis represents the intensity of the light. 4 and 5, the integrated value of each graph represents the reflectance of light.

The total reflectance of the material can be expressed as the sum of Lambertian and Gaussian reflectances. Referring to FIGS. 4 and 5, the resin composition of the present invention has an integral value (or a graph) as compared to the white reflection sheet and the high reflection injection specimen. It can be seen that the area of the graph) has a larger value, and accordingly, the resin composition of the present invention can visually confirm that the total reflectance is much superior to that of the conventional white reflection sheet and the high reflection injection specimen.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, Those skilled in the art will appreciate that many suitable modifications and variations are possible in light of the present invention. Accordingly, all such suitable modifications and variations and equivalents should be considered to be within the scope of the present invention.

2: backlight unit
100: resin composition
110: base resin
130: Bead
131: bead layer
133: hollow
150: mineral
300: cover bottom
310: bottom surface
330: reflection pattern
350: sidewall
370: support member
500: light source
510: light source
530: substrate
700: optical sheet

Claims (28)

Base resins;
Beads formed by mixing in the base resin and having a hollow formed therein;
Resin composition for a backlight unit cover bottom comprising a.
The method according to claim 1,
The beads,
A resin composition for a backlight unit cover bottom, which is at least one of glass beads, acrylic beads, and amide beads.
The method according to claim 1,
The content of the beads, the resin composition for the backlight unit cover bottom is 10% by weight to 30% by weight.
The method according to claim 1,
The diameter of the beads, the resin composition for a backlight unit cover bottom formed in the range of 0.55 to 135㎛.
The method according to claim 1,
A resin composition for a backlight unit cover bottom further comprising an inorganic substance mixed and formed in the base resin.
The method according to claim 5,
The mineral is,
A resin composition for a backlight unit cover bottom comprising at least one of BaSO 4, TiO 2, and CaCO 3.
The method according to claim 5,
The inorganic material is a resin composition for a backlight unit cover bottom consisting of a sphere.
The method of claim 7,
The resin composition for a backlight unit cover bottom is formed in the range of 0.11 to 2㎛ diameter of the inorganic material.
The method according to any one of claims 1 to 8,
The base resin is a resin composition for a backlight unit cover bottom made of a thermoplastic resin.
The method according to claim 9,
The base resin,
A resin composition for a backlight unit cover bottom comprising at least one of a polycarbonate resin, a polymethylmethacrylate resin, a polypropylene resin, and a polyethylene resin.
The method according to claim 9,
A resin composition for a backlight unit cover bottom further comprising an additive mixed in the base resin.
The method of claim 11,
Preferably,
A resin composition for a backlight unit cover bottom comprising any one or a mixture of a fluorescent brightener, a crosslinking agent, a heat stabilizer, an oxidation stabilizer, an ultraviolet absorber, and an antistatic agent.
A cover bottom including a plurality of reflection patterns formed on a bottom surface and sidewalls protruding from an edge of the bottom surface;
A light source unit disposed inside the sidewall; Including but not limited to:
The cover bottom is,
And a resin composition comprising a base resin and beads mixed and formed in the base resin and having hollows formed therein.
The method according to claim 13,
The beads,
A backlight unit which is at least one of glass beads, acrylic beads, and amide beads.
The method according to claim 13,
The content of the beads in the resin composition, 10% to 30% by weight of the backlight unit.
The method according to claim 13,
The diameter of the bead, the backlight unit formed in the range of 0.55 to 135㎛.
The method according to claim 13,
The resin composition,
The backlight unit further comprises an inorganic material mixed in the base resin.
18. The method of claim 17,
The mineral is,
A backlight unit comprising at least one of BaSO 4, TiO 2, and CaCO 3.
18. The method of claim 17,
The inorganic material is a backlight unit made of a sphere.
The method of claim 19,
The diameter of the inorganic material, the backlight unit formed in the range of 0.11 to 2㎛.
The method according to any one of claims 13 to 20,
The base resin is a backlight unit made of a thermoplastic resin.
23. The method of claim 21,
The base resin,
A backlight unit comprising at least one of a polycarbonate resin, a polymethylmethacrylate resin, a polypropylene resin, and a polyethylene resin.
23. The method of claim 21,
The resin composition,
The backlight unit further comprises an additive mixture formed in the base resin.
24. The method of claim 23,
Preferably,
A backlight unit comprising any one or a mixture of a fluorescent brightener, a crosslinking agent, a heat stabilizer, an oxidation stabilizer, an ultraviolet absorber, and an antistatic agent.
23. The method of claim 21,
The shape of the reflective pattern,
A backlight unit comprising any one of a prism shape, a lenticular shape, a concave lens shape, a convex lens shape, and a combination thereof.
23. The method of claim 21,
The cross-sectional shape of the reflective pattern,
A backlight unit consisting of any one of a triangle, a quadrangle, a semicircle, and a combination thereof.
23. The method of claim 21,
The reflection pattern
A backlight unit integrally formed with the cover bottom.
23. The method of claim 21,
The cover bottom is,
And a backlight unit formed by injection molding the resin composition.

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