KR20100072780A - High luminance multifunctional plate combined by diffusion plate, method of manufacturing thereof and liquid crystal display equipped with them - Google Patents

Abstract

PURPOSE: A high luminance multifunctional plate combined by diffusion plate, a manufacturing method thereof, and a liquid crystal display having the same are provided to enhance the light concentration efficiency of incident light which enters in an ineffective angle and implement high brightness. CONSTITUTION: A diffusing plate(40) is located on the top and lower parts of a diffusing plate integrated high brightness complex plate(1). A lamp bright line is removed of the diffusing plate using the internal diffusing agent(20). The brightness uniformity is realized. A polarization layer(50) is located on the top of the diffusing plate integrated high brightness complex plate. The polarization layer uses the polarizing effects of the birefringence suede(30).

Description

Diffusion plate integrated high brightness composite plate, manufacturing method thereof, and liquid crystal display device having the same

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diffuser plate integrated high brightness composite plate, a manufacturing method thereof, and a liquid crystal display device having the same, wherein a polarizing layer comprising birefringent island-in-the-sea yarns is disposed on an ordinary diffuser plate in which a light diffusing agent is dispersed. The birefringent interface between the isotropic substrate and the birefringent island-in-the-sea yarn and the birefringent interface between the sea component and the island component constituting the birefringent island-in-the-sea yarn, as well as incident light incident at an effective angle, High brightness composite plate with integrated diffuser plate to improve the light collecting efficiency and improve the high brightness, assemblability and reliability while reducing the number of optical films mounted on the backlight unit, its manufacturing method and liquid crystal display device having the same It is about.

Liquid crystal display (hereinafter referred to as "LCD") is a low power consumption, low heat generation and high definition image output device that can be manufactured in an ultra-thin, and has recently been spotlighted as an image display device in various fields of the industry, especially the LCD-TV market The proportion has continued to grow from 7% in 2004 to 22% in 2007. Unlike other flat panel display systems, the liquid crystal itself is a non-luminescent material, and since polarized light is used, a light source is required and a device for enhancing the light efficiency is required. This is called a backlight unit (hereinafter referred to as "BLU"). I am in charge.

Particularly, in the case of a TV requiring high luminance, a BLU of a back light type of a type in which a large number of lamps are stored on the back is used.

Looking at the internal structure of the BLU for LCD TV in general, the reflection sheet; lamp; Diffuser plate; Diffusion sheet; Prism sheet; Protective sheet; And a liquid crystal panel, wherein the reflective sheet reflects the light from the lamp upwards to reach as much light as possible to the diffuser plate, and the diffuser plate removes the lamp luminance by the diffusion effect of the internal diffuser and uniformity of luminance. Perform the castle function. In addition, the diffusion sheet located on the diffusion plate uniformly diffuses and primary condensing light, and then increases the secondary luminance by condensing the prism sheet stacked on the diffusion sheet. In the backlight method, the maximum image brightness is designed with the minimum power consumption.

Among the BLUs, the diffusion sheet used for the purpose of improving luminance usually serves to condense light by the lens shape caused by the projections of the organic particles.

On the other hand, the prism sheet is formed in a linear prism lens structure having a triangular cross section on the base sheet layer, so that the light incident at a specific range of effective angles is focused while some of the light is recycled by recursive reflection. The light is re-incident to the angle of the range and condensed again to increase the luminance.

As described above, a combination of optical components of a general BLU consists of a diffusion sheet, a prism sheet, and a protective sheet on a diffusion plate, and two diffusion sheets are provided on the premise that a large amount of incident light must be provided to realize high brightness. The method of laminating, laminating the diffusion sheet and prism sheet, and then laminating the diffusion sheet and prism sheet and laminating the protective film or laminating the pattern extrusion sheet, prism sheet and protective sheet on the pattern diffusion plate It has been tried.

However, in such a case, the unit price of the BLU is increased by using the multilayer optical sheet, and the problems of assemblability and reliability are pointed out as well as the process cost increase due to the process of assembling the multiple sheets of the optical film.

In recent years, various composite sheets having integrated functions have emerged in accordance with market trends for lowering manufacturing costs as well as trends in LCD enlargement and thinning.

Accordingly, the present inventors have endeavored to obtain an integrated high-brightness optical component that meets the needs of conventional LCDs and thinner films, and thus provide a composite plate in which a polarizing layer made of refractive index islands is integrated on a diffuser plate containing a light diffusing agent. In addition, by replacing the optical component consisting of two to three optical sheets on the diffusion plate in the conventional backlight unit with one composite plate of the present invention, it is possible to reduce the number of optical sheets having a multi-layer structure while improving luminance as well as assembly and reliability. By confirming that it can improve, this invention was completed.

Disclosure of Invention An object of the present invention is to provide a diffuser plate-integrated high brightness composite plate in which a polarizing layer made of a birefringent island-in-the-sea yarn is integrated on a diffuser plate in which a light diffusing agent is dispersed in a transparent substrate, and a manufacturing method thereof.

Another object of the present invention is to provide a backlight unit for an LCD TV employing the diffusion plate integrated high brightness composite plate and a liquid crystal display device having the same.

In order to achieve the above object, the present invention provides a diffuser plate-integrated high-brightness composite plate in which a polarizing layer made of birefringent island-in-the-sea yarns is integrated on a diffuser plate in which a light diffusing agent is dispersed in a transparent substrate.

The thickness of the polarizing layer made of the birefringent island-in-the-sea yarn is 10 to 500 µm, and the diameter of the birefringent island-in-the-sea yarn is 0.3 to 50 denier.

In the present invention, the polarizing layer formed of the birefringent island-in-the-sea yarn is a birefringent island-in-the-sea yarn or a birefringent island-in-the-sea yarn which is partially dispersed and woven.

The diffusion plate-integrated high brightness composite plate of the present invention has a refractive index of n'x in the stretching direction (x-axis direction) of the island component of the polarizing layer composed of the birefringent island-in-the-sea yarns, the y-direction and z being a direction perpendicular to the stretching direction. When the refractive indices in the directions are n'y and n'z, respectively, and the refractive indices in the x-axis direction, the y direction, and the z direction of the sea component are nx, ny, and nz, respectively, the larger the difference in refractive index between n'x and nx is, The smaller the difference between the refractive indices of 'y, ny' and the difference between the refractive indices of n'z and nz, the higher the brightness. At this time, the transparent substrate in the polarizing layer has the same refractive index as any one of the sea component or island component of the island-in-the-sea yarn.

More preferably, in the polarizing layer made of the birefringent island-in-the-sea yarn, the refractive index between the sea component and the island component satisfies the following formula.

┃n'x-nx┃> 0.1 (1)

┃n'y-ny┃ <0.05 (2)

┃n'z-nz┃ <0.05 (3)

(In the above, n'x is the refractive index in the stretching direction (x-axis direction) of the island component, n'y and n'z are the refractive indices in the y and z directions, which are perpendicular to the stretching direction, and nx and ny And nz are refractive indices in the x-axis direction, y-direction, and z-direction of the sea component.)

In the present invention, the birefringent island-in-the-sea yarn has an area ratio of the sea component and the island component of 2: 8 to 8: 2 on the basis of the cross section, and any one of the sea component or island component in the birefringent island-in-the-sea yarn is isotropic and the other Is characterized by being anisotropic. More preferably, the sea component of the island-in-the-sea yarn is isotropic, and the island component is anisotropic.

The island-in-the-sea yarn used in the present invention may use a material that is optically birefringent and has excellent light transmittance. Preferably, the sea component and the island component are made of the same material. In this case, the material of the sea component and island component is preferably polyethylene naphthalate (PEN), copolyethylene naphthalate (co-PEN), polyethylene terephthalate (PET), polycarbonate (PC), polycarbonate (PC) alloy , Polystyrene (PS), heat-resistant polystyrene (PS), polymethyl methacrylate (PMMA), polybutylene terephthalate (PBT), polypropylene (PP), polyethylene (PE), acrylonitrile butadiene styrene (ABS), Polyurethane (PU), polyimide (PI), polyvinyl chloride (PVC), styrene acrylonitrile mixture (SAN), ethylene vinyl acetate (EVA), polyamide (PA), polyacetal (POM), phenol, It is made of one or more materials selected from the group consisting of epoxy (EP), urea (UF), melamine (MF), unsaturated polyester (UP), silicone (SI), elastomer and cycloolefin polymer.

In the diffuser plate integrated high brightness composite plate of the present invention, the light diffusing agent should be uniformly dispersed in the diffuser plate, and the preferred content is 0.01 to 10% by weight.

According to the diffuser plate integrated high brightness composite plate of the present invention, any one lens pattern selected from lenticular, prism or pyramid may be formed on the upper surface of the diffuser plate integrated high brightness composite plate.

The present invention is a first embodiment of the manufacturing method of the diffuser plate integrated high brightness composite plate, when melting the mixed resin mixed with the light diffusing agent in the transparent base resin, when the molten mixed resin is extruded through a die, After the polarizing layer made of birefringent island-in-the-sea yarn is designed to be positioned on the mixed resin, the polarizing layer made of birefringent island-in-the-sea yarn is added and laminated through a roller, thereby providing a manufacturing method of cooling, sheet forming and stretching.

In addition, the present invention is a second embodiment of the method for manufacturing a diffuser plate integrated high-brightness composite plate, manufacturing a diffuser plate in which a light diffusing agent is dispersed in a transparent substrate, and a polarizing layer made of birefringent islands , Covering the base fabric, and provides a manufacturing method consisting of pressing on both sides using a heating plate under heating and pressing conditions in which the base fabric is melted.

The thickness of the diffuser plate integrated high brightness composite plate manufactured from the manufacturing method of the first embodiment or the second embodiment of the present invention is 1 to 5 mm, and the thickness of the polarizing layer made of birefringent island-in-the-sea yarns satisfies 10 to 500 m.

The polarizing layer made of the birefringent island-in-the-sea yarn of the present invention may be provided in the form of a fiber composed of the birefringent island-in-the-sea yarn or a birefringent island-in-the-sea yarn partially dispersed.

In the manufacturing method of the second embodiment of the present invention, the transparent base material and the base fabric used preferably have the same refractive index, and the refractive index is 1.4 to 2.0.

Furthermore, the present invention provides a backlight unit for an LCD TV, comprising: a lamp; A diffuser plate-integrated high-brightness composite plate in which a polarizing layer made of a birefringent island-in-the-sea yarn is integrated into a diffuser plate in which a light diffusing agent is dispersed in a transparent substrate; And a liquid crystal panel; and sequentially provide a backlight unit for an LCD TV, and a liquid crystal display device having the same.

According to the present invention, by providing a diffusion plate-integrated high brightness composite plate in which a polarizing layer made of birefringent island-in-the-sea yarns is integrated on a diffuser plate in which a light diffusing agent is dispersed on a transparent substrate, the number of optical sheets having a multilayer structure formed on a conventional diffuser plate High brightness while reducing

In addition, the diffusion plate-integrated high brightness composite plate of the present invention improves the assemblability by integrating the optical component consisting of two to three sheets of the optical sheet on the conventional diffusion plate into one composite plate of the present invention, and improves the assembly of the conventional multilayer structure sheet. When assembling, it is possible to improve the reliability by eliminating the problem between the sheets at the source.

In addition, the present invention can provide a liquid crystal display device having a high brightness composite plate integrated with a diffuser plate in the backlight unit for LCD TV, simplifying the assembly process of the optical component, reducing the process cost and slimming.

Hereinafter, the present invention will be described in detail.

The present invention provides a diffuser plate-integrated high brightness composite plate in which a polarizing layer made of birefringent island-in-the-sea yarns is integrated on a diffuser plate in which a light diffusing agent is dispersed in a transparent substrate.

As shown in FIG . 1 , the diffusion plate-integrated high-brightness composite plate 1 of the present invention has a birefringent island-in-the-sea yarn 30 on an upper part of the diffusion plate 40 in which the light diffusing agent 20 is dispersed in the transparent substrate 10. The polarizing layer 50 made of a structure is integrated.

That is, on the structure of the diffuser plate integrated high brightness composite plate 1 of the present invention, the diffuser plate 40 located at the lower part realizes the luminance uniformity by removing the diffuse effect by the internal diffuser 20 and the lamp bright line. The polarization layer 50 located on the plate-integrated high brightness composite plate 1 performs a function as a polarization layer that raises the brightness by using the polarization effect of the birefringent island-in-the-sea yarn 30.

Hereinafter, the polarizing layer 50 made of the birefringent island-in-the-sea yarn 30 will be described based on the structure of the diffusion plate integrated high brightness composite plate 1.

In the diffuser plate integrated high brightness composite plate 1 of the present invention, a birefringent island-in-the-sea yarn is disposed on the diffuser plate, thereby forming a birefringent interface between the isotropic substrate and the birefringent island-in-the-sea yarn, and a birefringent island-in-the-sea yarn. By the birefringent interface between the sea component and the island component described above, the condensing efficiency of not only incident light incident at an effective angle but also incident light incident at an invalid angle can be improved and brightness can be drastically improved.

Accordingly, the diffusion plate integrated high brightness composite plate 1 of the present invention can realize high brightness equal to or higher than without stacking an optical sheet in multiple layers on a diffusion plate in a conventional backlight unit [ Table 1 ].

2 illustrates the principle of high brightness of the diffuser plate integrated high brightness composite plate according to the present invention, in which the refractive index of the island component of the polarizing layer 50 made of the birefringent island-in-the-sea yarn 30 (n-axis direction) is n. 'x, the refractive indices in the y and z directions, which are perpendicular to the stretching direction, are n'y and n'z, respectively, and the refractive indices in the x-axis, y and z directions of the sea component are nx, ny and When nz, the difference between the x-axis refractive index of the island component and the x-axis refractive index of the sea component is large, and the refractive indexes in the y-direction and z-direction of the island component which are perpendicular to the stretching direction (n'y and n'z) ) Is equal to the refractive indices of the y- and z-directions of the sea component (n'y = ny and n'z = nz), and the luminance increase is optimized. At this time, the transparent substrate in the polarizing layer has the same refractive index as any one of the sea component or island component of the island-in-the-sea yarn.

That is, when the refractive index is satisfied, the unpolarized light emitted from the light source reaches only the polarization (P polarization) portion perpendicular to the stretching direction through the composite plate 1 to reach the panel, and the polarization of the remaining stretching direction ( S polarized light) is reflected downward, and in this process, the polarized light is changed upward while being reflected back from the diffuser plate 40 or the reflective sheet under the BLU. Therefore, the P-polarized part passes through the composite plate 1, and the remaining S-polarized light is recycled (Recycling) on the same principle, thereby increasing the luminance.

Thus, the island-in-the-sea yarn 30 of the present invention uses a material that is optically birefringent and excellent in light transmittance, and preferably uses a material having the same sea component and island component.

In addition, in the island-in-the-sea yarn 30 of the present invention, either the sea component or the island component should be isotropic and the other should be anisotropic. That is, since the optical properties of the sea component or island component in the island-in-the-sea yarn 30 are different, and a birefringent interface is formed in the island-in-the-sea yarn, the brightness enhancement efficiency is remarkably increased in comparison with the other case.

More specifically, in the birefringent island-in-the-sea yarn 30 of the present invention, the sea component has isotropy, and the island component has anisotropy, so that unpolarized light emitted from the light source constitutes the inside of the island-in-the-sea yarn. Due to the birefringence generated at the interface between minutes, P polarized light passes through the composite plate, and S polarized light is continuously recycled along the path of increasing luminance while recycling.

More specifically, in the birefringent island-in-the-sea yarn 30 of the present invention, since the sea component has isotropy and the island component has anisotropy, the unpolarized light emitted from the light source is isotropic transparent substrate 10 and birefringent islands. The brightness is not only improved by the birefringent interface due to the refractive index of the polarizing layer 50 made of the yarn 30, but also P-polarized light is generated by the birefringence generated at the interface between the sea component and the island component constituting the inside of the island-in-the-sea yarn. Passes through the composite plate 1, and the S-polarized light is continuously recycled along the path of increasing luminance while recycling.

In this case, the present invention can be used to produce a composite fiber by twisting dozens of islands and islands, as a seaweed component and the material of the island component used in the present invention, preferably polyethylene naphthalate (PEN), copolyethylene naphthalate (co-PEN), polyethylene terephthalate (PET), polycarbonate (PC), polycarbonate (PC) alloy, polystyrene (PS), heat-resistant polystyrene (PS), polymethyl methacrylate (PMMA), polybutylene Terephthalate (PBT), polypropylene (PP), polyethylene (PE), acrylonitrile butadiene styrene (ABS), polyurethane (PU), polyimide (PI), polyvinyl chloride (PVC), styrene acrylonitrile Mixed (SAN), ethylene vinyl acetate (EVA), polyamide (PA), polyacetal (POM), phenol, epoxy (EP), urea (UF), melamine (MF), unsaturated polyester (UP), silicone ( SI), an elastomer and a cycloolefin polymer 1 uses at least one selected from the.

That is, the birefringent island-in-the-sea yarn 30 of the present invention uses the same material of sea component and island component, but can be used as long as it is a combination of resins having different optical properties. For example, the sea component of the island-in-the-sea yarn may use isotropic co-PEN, and the island component may use PEN having birefringence, but is not limited thereto.

In this case, the refractive index of the isotropic sea component is 1.4 to 2.0, and in some cases may match the refractive index of the transparent substrate on the diffuser plate integrated high brightness composite plate.

The shape of the cross-section of the birefringent island-in-the-sea yarn 30 of the present invention is not particularly limited to a circle, an ellipse, a polygon, or the like, and may have various cross-sectional shapes. In addition, the cross section of the island component among the islands and islands is also not limited to the shape shape, it is also possible to have a heteromorphic cross section, such as circular, oval, polygon, etc., the shape, size, number and arrangement of the island component is efficiently adjusted according to the purpose Can be used. However, the birefringent island-in-the-sea yarn 30 of the present invention should satisfy the area ratio of the sea component and the island component of 2: 8 to 8: 2 based on the cross section.

The thickness of the birefringent island-in-the-sea yarn 30 of the present invention is 0.3 to 50 denier, and the thickness of the polarizing layer 50 made of the birefringent island-in-the-sea yarn 30 is preferably 10 to 500 µm. In this case, if the thickness of the polarizing layer is less than 10 μm, the brightness enhancement effect due to birefringent islands-in-the-sea yarn is insufficient, and if the thickness of the polarization layer exceeds 500 μm, the brightness enhancement effect does not increase any more and becomes saturation. It is not preferable because it acts as a cost increase factor.

Hereinafter, the diffusion plate 40 in which the light diffusing agent 20 is dispersed in the transparent substrate 10 on the structure of the diffusion plate integrated high brightness composite plate 1 will be particularly limited as long as it is a material used as a conventional BLU optical component. Can be used without.

More specifically, the transparent substrate used in the diffusion plate of the present invention may be used without particular limitation, so long as it is a transparent resin that can be used for optical, preferred examples are polymethyl methacrylate (PMMA), polystyrene (PS), Polyethylene terephthalate (PET), random copolymer resin of styrene and methyl methacrylate (MS resin) or polycarbonate (PC) can be selected and used.

The light diffusing agent 20 used in the diffusion plate 40 of the present invention can be used without particular limitation as long as it is a material commonly used in the art. Specifically, one selected from the group consisting of silica, talc, calcium oxide, titanium dioxide, zinc oxide, barium sulfate, silicon dioxide, calcium carbonate, magnesium carbonate, aluminum hydroxide, clay, calcium phosphate and glass beads At least one inorganic particle or at least one organic particle selected from the group consisting of acrylic resin, polystyrene, polyurethane, epoxy, polyvinyl chloride, polyacrylonitrile, polyamide, and polymethyl methacrylate, and the inorganic particle and organic Mixed forms of the particles are also possible.

The size of the light diffusing agent 20 used in the present invention is not limited, but preferably an average particle diameter of 0.1 to 50 μm is used.

In addition, the content of the light diffusing agent 20 for increasing the light diffusing effect is preferably contained 0.01 to 10% by weight relative to the transparent base resin in order to conceal the lamp bright line and obtain a uniform brightness distribution. At this time, when the content of the light diffusing agent 20 exceeds 10% by weight, there is a problem that the light transmittance is lowered. In particular, the diffusing agent 20 of the present invention should be uniformly dispersed in the entire region of the composite plate of the present invention except for the polarization layer 50 made of birefringent island-in-the-sea yarns.

Further, the diffuser plate integrated high brightness composite plate 1 of the present invention is lenticular to the upper surface of the diffuser plate integrated high brightness composite plate, that is, the polarization layer 50 made of the birefringent island-in-the-sea yarn 30, One lens pattern selected from a prism or a pyramid may be formed.

The present invention provides a method for producing a diffuser plate integrated high brightness composite plate.

A first preferred embodiment of the production method of the present invention is an extrusion process, wherein a mixed resin in which a light diffusing agent is mixed with a transparent base resin is melted, and the molten mixed resin 60 is die 61. When extruded through), the polarizing layer 62 made of a birefringent island-in-the-sea yarn is positioned on the mixed resin, and then laminated through rollers 63, 64, and 65, and then cooled, sheet-formed and stretched. Carried out in a process [ FIG. 3 ].

In addition, the second embodiment of the present invention for the method for producing a diffuser plate integrated high brightness composite plate is carried out by a hot pressing method. Specifically, after manufacturing a diffusion plate 40 in which a light diffusing agent is dispersed in a transparent substrate, the polarizing layer 50 made of birefringent island-in-the-sea yarn is placed on the diffusion plate, the substrate fabric 52 is covered, and then the substrate It consists of pressing on both sides using the heating plate 53 in the heating and pressing conditions in which the fabric 52 is melted [ FIG. 4 ].

In the method of manufacturing a composite plate according to the hot press method of the present invention, when heat and pressure are applied by a hot press, as the base material 52 is melted and impregnated in the fiber, the fiber and the diffusion plate are laminated. At this time, the base material 52 is made of the same material as the transparent substrate, preferably having the same refractive index as the transparent substrate, the refractive index is 1.4 to 2.0.

The thickness of the diffuser plate integrated high brightness composite plate manufactured from the manufacturing method of the first embodiment or the second embodiment of the present invention is 1 to 5 mm, and the thickness of the polarizing layer made of birefringent island-in-the-sea yarns is made to satisfy 10 to 500 μm. do.

At this time, when the thickness of the diffuser plate integrated high brightness composite plate is less than 1mm, bending reliability problems occur due to the thinness, and when it exceeds 5mm, the manufacturing cost of the composite plate rises and a problem in slimming the backlight unit occurs.

In addition, if the thickness of the polarizing layer for implementing a high brightness in the diffuser plate integrated high brightness composite plate of the present invention is less than 10㎛, the polarization effect is lowered is not preferred, while if produced in a thickness exceeding 500㎛, the polarization effect is There is a problem that only the polarizer layer manufacturing cost rises no longer.

In the manufacturing method of the present invention, the polarizing layer made of birefringent island-in-the-sea yarn is provided in the form of a fiber made of birefringent island-in-the-sea yarn or a part of the birefringent island-in-the-sea yarn dispersed and woven.

Furthermore, the present invention provides a backlight unit for an LCD TV, comprising: a lamp; A diffuser plate-integrated high-brightness composite plate in which a polarizing layer made of a birefringent island-in-the-sea yarn is integrated into a diffuser plate in which a light diffusing agent is dispersed in a transparent substrate; And liquid crystal panels; Provided are a sequentially stacked backlight unit for an LCD TV, and a liquid crystal display device having the same.

As shown in FIG. 5 , which shows a backlight unit having a diffuser plate integrated high brightness composite plate of the present invention as compared with a conventional backlight unit, the liquid crystal display of the present invention is equipped with a diffuser plate integrated high brightness composite plate, thereby providing a Since the optical component consisting of two or three optical sheets on the diffusion plate can be replaced, the manufacturing cost of the liquid crystal display device can be reduced.

In addition, since only one composite plate is assembled in the backlight unit when assembling two or three diffusion plates and sheets, the assembly time of sheets can be shortened three to four times, and a single plate of a composite plate integrated with a diffusion plate is also provided. By replacing with, it is possible to improve the assembly of the backlight unit. Further, when the multilayer assembly of the conventional optical sheet, the problem between the sheets between the source can be solved at the source to improve the reliability.

Accordingly, the present invention provides a liquid crystal display device having a high brightness composite plate integrated with a diffuser plate in a backlight unit for an LCD TV to reduce the process cost by simplifying the assembly process of the optical component while implementing high brightness.

Hereinafter, the present invention will be described in detail by Examples and Experimental Examples.

The following Examples and Experimental Examples are only illustrative of the present invention, and the scope of the present invention is not limited to the following Examples and Experimental Examples.

&Lt; Example 1 >

Unstretched with anisotropic PEN (nx = 1.88, ny = 1.57, nz = 1.57) as a drawing part inside the filler of isotropic Co-PEN (nx = 1.57, ny = 1.57, nz = 1.57) After the island-in-the-sea yarn was spun under the condition of a spinning temperature of 305 ° C. and a spinning speed of 1500 M / min, a stretched island-in-the-sea yarn of 50d / 24F was obtained by three times stretching.

Isotropic Co-PEN is used as a warp, using four fibers (50d / 24F × 4) of the island-in-the-sea yarn manufactured above as a warp yarn.

The fabric was woven into the fabric using the weft yarn. After dry mixing silica particles as a light diffusing agent to polycarbonate (PC) resin, the mixture is melt extruded by feeding into a twin screw extruder, and the fabric made of the island-in-the-sea yarn is laminated on a resin extruded through a T-die. After cooling, a composite plate in the form of a sheet having a thickness of 3 mm was prepared.

<Example 2>

Using a polycarbonate (PC) resin as a transparent substrate, a diffusion plate using silica as a light diffusing agent was prepared, and anisotropic PEN (nx) was formed inside the filler of isotropic Co-PEN (nx = 1.57, ny = 1.57, nz = 1.57). = 1.88, ny = 1.57, and nz = 1.57) to form a 50d / 24F island-in-the-sea yarn with 37 islands, and the fibers made of the island-in-the-sea yarns in one longitudinal direction on the front surface of the diffuser plate. Aligned and placed. Thereafter, the base fabric of the Co-PEN material was placed on the front of the island-in-the-sea yarn to prepare an optical sheet sample.

The sample was placed between heating plates maintained at 170 ° C., and then pressed for 3 minutes to prepare a composite plate having a thickness of 3 mm.

<Example 3>

A composite plate was manufactured in the same manner as in Example 1, except that the island-in-the-sea yarn in which the number of island components was arranged in 217 was used.

Experimental Example 1 Luminance Measurement

In order to measure the luminance of the composite plate prepared in Example 2, after assembling the panel on the 32 "direct type backlight unit equipped with the composite plate on a lamp, the BM-7 measuring instrument of Topcon Corporation was used. The luminance of the two points was measured and the average value was shown.

On the other hand, as a conventional backlight unit, a lamp, a diffusion plate, a diffusion sheet, a prism sheet was carried out in the same manner to compare the results shown in Table 1 below.

From the above results, the backlight unit employing the diffuser plate-integrated composite plate of the present invention replaced the optical component consisting of two or three optical sheets on the conventional diffuser plate, and confirmed the same or higher brightness while using one sheet. Thus, the diffuser plate integrated composite plate of the present invention may implement a high brightness while reducing the number of optical sheets having a multilayer structure formed on the diffuser plate in the conventional backlight unit, thereby reducing the manufacturing cost of the backlight unit.

As described above, the present invention

First, by integrating a polarizing layer made of birefringent island-in-the-sea yarn on top of a diffuser plate in which a light diffusing agent is dispersed in a transparent substrate, a diffuser plate integrated high-brightness composite which realizes high brightness while reducing the number of optical sheets having a multilayer structure formed on a conventional diffuser plate. Plates were provided.

Secondly, by adopting the diffusion plate integrated high brightness composite plate of the present invention, since only one composite plate is assembled than when conventional diffusion plates and sheets 2-3 sheets are assembled, sheet assembly time can be shortened 3 to 4 times. In addition, by replacing the single diffusion plate integrated composite plate structure of the present invention, the assemblability and reliability of the backlight unit is improved, it is possible to fundamentally solve the problem of sheet-to-sheet in the conventional multi-layer assembly.

Third, the present invention is to provide a liquid crystal display device with a thin plate of a diffuser plate integrated high brightness composite plate in the backlight unit for LCD TV, simplifying the assembly process of the optical component, reducing the process cost.

While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims.

1 is a schematic diagram showing a cross-section of the diffusion plate integrated high brightness composite plate of the present invention,

Figure 2 illustrates the principle of the diffusion plate integrated high brightness composite plate of the present invention,

Figure 3 shows the main process of the diffusion plate integrated high brightness composite plate of the present invention by extrusion method,

Figure 4 shows the manufacturing process of the diffusion plate integrated high brightness composite plate of the present invention by the hot press method,

5 shows a comparison of a backlight unit having a diffuser plate integrated high brightness composite plate according to the present invention with a conventional backlight unit.

Claims (18)

On the diffuser plate where the light diffusing agent is dispersed in the transparent substrate, A diffuser plate integrated high brightness composite plate in which a polarizing layer made of birefringent island-in-the-sea yarns is integrated. The diffusion plate-integrated high brightness composite plate according to claim 1, wherein a thickness of the polarizing layer made of the birefringent island-in-the-sea yarns is 10 to 500 µm. The diffuser plate integrated high brightness composite plate according to claim 1, wherein the birefringent island-in-the-sea yarn is 0.3 to 50 denier. The diffuser plate-integrated high brightness composite plate according to claim 1, wherein the polarizing layer is a birefringent island-in-the-sea yarn or a birefringent island-in-the-sea yarn is a partially dispersed woven fiber. 2. The diffuser plate integrated high brightness composite plate according to claim 1, wherein the refractive index between the sea component and the island component satisfies the following formula in the polarizing layer composed of the birefringent island-in-the-sea yarns. ┃n'x-nx┃> 0.1 (1) ┃n'y-ny┃ <0.05 (2) ┃n'z-nz┃ <0.05 (3) (In the above, n'x is the refractive index in the stretching direction (x-axis direction) of the island component, n'y and n'z are the refractive indices in the y and z directions, which are perpendicular to the stretching direction, and nx and ny And nz are refractive indices in the x-axis direction, y-direction, and z-direction of the sea component.) The diffuser plate-integrated high brightness composite plate according to claim 1, wherein the birefringent island-in-the-sea yarns are isotropic in the sea component or the island component, and the other is anisotropic. The diffuser plate-integrated high brightness composite plate according to claim 1, wherein the transparent substrate in the polarizing layer has the same refractive index as any one of the sea component or island component of the birefringent island-in-the-sea yarn. The sea component of the island-in-the-sea yarn of claim 6 is polyethylene naphthalate (PEN), copolyethylene naphthalate (co-PEN), polyethylene terephthalate (PET), polycarbonate (PC), polycarbonate (PC) alloy, polystyrene (PS), heat-resistant polystyrene (PS), polymethyl methacrylate (PMMA), polybutylene terephthalate (PBT), polypropylene (PP), polyethylene (PE), acrylonitrile butadiene styrene (ABS), polyurethane (PU), polyimide (PI), polyvinyl chloride (PVC), styrene acrylonitrile mixture (SAN), ethylene vinyl acetate (EVA), polyamide (PA), polyacetal (POM), phenol, epoxy (EP), urea (UF), melamine (MF), unsaturated polyester (UP), silicone (SI), elastomer and cycloolefin polymer, characterized in that the diffusion is made of at least one material selected from the group consisting of Plate integrated high brightness composite plate. According to claim 6, wherein the island component of the island-in-the-sea yarn is polyethylene naphthalate (PEN), copolyethylene naphthalate (co-PEN), polyethylene terephthalate (PET), polycarbonate (PC), polycarbonate (PC) alloy, polystyrene (PS), heat-resistant polystyrene (PS), polymethyl methacrylate (PMMA), polybutylene terephthalate (PBT), polypropylene (PP), polyethylene (PE), acrylonitrile butadiene styrene (ABS), polyurethane (PU), polyimide (PI), polyvinyl chloride (PVC), styrene acrylonitrile mixture (SAN), ethylene vinyl acetate (EVA), polyamide (PA), polyacetal (POM), phenol, epoxy ( EP), urea (UF), melamine (MF), unsaturated polyester (UP), silicone (SI), elastomer and cycloolefin polymer, characterized in that the diffusion plate made of at least one material selected from the group consisting of. Integrated high brightness composite plate. The diffuser plate integrated high brightness composite plate according to claim 1, wherein the diffuser plate integrated high brightness composite plate further includes one lens pattern selected from lenticular, prism, or pyramid. The diffuser plate integrated high brightness composite plate according to claim 1, wherein 0.01 to 10 wt% of a light diffusing agent is uniformly dispersed in the diffusion plate. Melting the mixed resin mixed with the light diffusing agent in the transparent base resin, and when the molten mixed resin is extruded, the polarizing layer made of birefringent island-in-the-sea yarn is placed on the mixed resin, and then cooled, sheet-formed and A method for producing a diffuser plate integrated high brightness composite plate according to claim 1, characterized by performing a drawing process. Manufacturing a diffusion plate in which a light diffusing agent is dispersed in a transparent substrate, Raising a polarizing layer of birefringent island-in-the-sea yarn on the entire surface of the diffuser plate, covering the base fabric, and then crimping on both sides using a heating plate under heating and pressing conditions in which the base fabric is melted, the birefringent island-in-the-sea yarn is formed on the top of the diffuser plate A method for producing a diffuser plate integrated high brightness composite plate according to claim 1, wherein the polarizing layer is integrated. The method for manufacturing the diffuser plate integrated high brightness composite plate according to claim 12 or 13, wherein the high brightness composite plate has a thickness in a range of 1 to 5 mm. The method for manufacturing the diffusion plate-integrated high brightness composite plate according to claim 12 or 13, wherein the polarizing layer made of the birefringent island-in-the-sea yarns has a thickness of 10 to 500 µm. The method according to claim 12 or 13, wherein the polarizing layer is a birefringent island-in-the-sea yarn or a birefringent island-in-the-sea yarn that is partially dispersed and woven fiber. The method of manufacturing a diffuser plate integrated high brightness composite plate according to claim 13, wherein the transparent substrate or the base fabric has a refractive index of 1.4 to 2.0. lamp; A diffuser plate integrated high brightness composite plate having a polarizing layer made of birefringent island-in-the-sea yarns integrated into a diffuser plate in which a light diffusing agent is dispersed in the transparent substrate of claim 1; And A liquid crystal display device comprising: a backlight unit for an LCD TV which is sequentially stacked.

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