TW201028745A - Light guide plate and backlight unit using the same - Google Patents

Abstract

The object of the invention is to provide a light guide plate which can be miniaturized and a backlight unit and, more particularly, to provide a light guide plate capable of increasing the overall light guidance property, diffusivity, and planar uniformity of the film surface and a backlight unit using the same. To solve the problem, the light guide plate of this invention is equipped with a transparent substrate film and a light diffusion layer deposited on one side of the substrate film, the light diffusion layer comprising light diffusion agent and its adhesive agent. The mass ratio of the light diffusion agent to the adhesive agent is greater than 0.1 and less than 2. The absolute value (|n1-n2|) of the difference between the refraction index (n1) of the light diffusion agent and of the refraction index (n2) of the adhesive agent in the light diffusion layer is greater than 0.03. The particle diameter of the light diffusion agent in the light diffusion layer is preferably greater than 0.1 μm and less than 20 μm. The light diffusion layer may be comprised of a plurality of light diffusion parts deposited in a scattered manner on one side of the substrate film.

Description

201028745 VI. Description of the Invention: [Technical Field] The present invention relates to a light guide sheet and a backlight unit using the same, and more particularly to a light guide sheet suitable for a liquid crystal display device and a backlight using the same unit. BACKGROUND OF THE INVENTION Liquid crystal display devices (LCDs) are mostly used as flat panel displays using features such as thin, lightweight, and low power consumption, and are used as information display devices for mobile phones, mobile information terminals (PDAs), personal computers, televisions, and the like. Uses increase year by year. In recent years, the characteristics required for liquid crystal display devices vary depending on the application, such as redundancy (simultaneous latitude), easy viewing (wide viewing angle), energy saving, source, chemical, thin and light weight, etc. The requirements for thinning and high brightness are more demanding. The liquid helium display device is widely used in a backlight system in which a liquid crystal layer is irradiated from a strange surface to emit light, and a backlight unit such as a side light type or a direct type is provided on the lower surface side of the liquid crystal layer. The edge type backlight unit 21 basically includes, as shown, a linear light source 22 as a light source, and an end portion disposed along the light source U. A plate-shaped light guide plate 23 is laminated on the light guide plate 23. A plurality of optical sheets 24 on the surface side. The optical sheet 24 has specific optical functions such as refraction and diffusion, and specifically corresponds to a light diffusion sheet 25 which is disposed on the surface side of the light guide plate 23 and mainly has a light diffusing function, and is disposed on the light diffusion sheet 25. The cymbal 26 and the like having a function of refracting toward the normal direction on the surface side. The function of the backlight unit 21 will be described. First, the light incident from the light source 22 to the light guide 23 will be emitted from the surface of the light guide plate 23 through the reflection point of the light guide plate 23 or a reflection sheet (not shown). The light emitted from the light guide plate 23 is incident on the light diffusion sheet 25, diffused by the light diffusion sheet 25, and emitted from the surface of the light diffusion month 25. Thereafter, the light emitted from the light-diffusing sheet 25 is incident on the cymbal sheet 26, and is then emitted through the dam portion 26a formed on the surface of the prism sheet 26 to emit light having a peak distribution in a substantially normal direction. At this time, when both sides of the light guide plate 23 are formed on the flat mirror surface across the entire area, most of the light from the light source 22 will be reflected on the light guide plate 23: the interface with the outer father's, so the efficiency of being emitted from the light guide plate 23 Will decrease. Therefore, a plurality of fine concavities and convexities are usually formed on one surface of the light guide plate 23 as reflection points to diffuse light in the light guide plate 23 to improve the emission efficiency. Such a light guide plate has a predetermined thickness for ensuring light guiding property, and is usually formed by injection molding using a metal mold for forming a light guide plate (see, for example, JP-A-2007-21400). As described above, the light guide plate is formed by injection molding using a metal mold. Therefore, it is difficult to reduce the thickness of the light guide plate, and the manufacturing cost is high and the shape correction time is long. In addition, in order to promote the reduction in thickness, a technique of using a thin light guide sheet in place of a light guide plate has been developed (see, for example, JP-A-6-_, for example), but this technique does not have sufficient light guiding property and diffusibility. A bad situation like face-to-sentence. Patent Document 1: Japanese Laid-Open Patent Publication No. Hei. No. 2007-214001. Patent Document 2: Japanese Patent Laid-Open No. Hei 6-186558.

Backlight unit. And the finisher's purpose is to shape the light guide sheet which can be used to improve the film surface and the invention to solve the above problems, and the light guide sheet is a transparent base film. And a light diffusion layer laminated on the substrate film, and the light diffusion layer is a light guide sheet containing a light diffusion agent and an adhesive thereof. Since the light guide sheet contains a light-diffusing material and a binder thereof in the light-diffusing layer laminated on one side of the base film, the light guiding property, light diffusibility, and surface uniformity of the entire surface can be improved. The mass ratio of the above light diffusing agent to the binder is preferably 〇1 or more and 2 or less. The light diffusibility is exhibited by defining the mass ratio of the light diffusing agent to be effective. The absolute value (| nrI12 | ) of the difference between the refractive index (ηι) of the light diffusing agent in the light diffusing layer and the adhesive refractive index (h) may be 〇 〇 3 or more. The diffusion can be effectively performed by making the light diffusing agent and the binder have the above refractive index difference. The particle diameter of the light diffusing agent in the light diffusing layer is preferably 〇1 μm or more and more preferably 2 0 // m or less. When the particle diameter of the light diffusing agent is less than the above range, the light diffusing effect is insufficient. On the contrary, if it exceeds the above range, the light diffusing portion is difficult to form. The light diffusion layer is preferably provided with fine irregularities on the surface. When the light diffusion layer has fine irregularities on the surface, light is refracted and diffused on the surface of the light diffusion layer, and the light diffusibility and surface uniformity are particularly increased by 2010. The light-diffusing layer is preferably composed of a plurality of light-diffusing portions which are layered on one side of the base film. Since the light-diffusing layer is composed of a plurality of light-diffusing portions which are layered on one side of the substrate film, the light guiding property, light diffusibility and surface uniformity of the entire film surface can be further improved. It is preferable that the light diffusion portion is formed in a convex lens shape. In this way, the light diffusing portion is formed into a convex lens shape, whereby the light guiding property, the light diffusing property, and the surface uniformity of the entire surface of the crucible can be further improved, and the control of the light diffusibility can be easily performed. The average diameter (D) of the light diffusing portion is preferably 1 〇/z m or more and 3 〇〇 or less. The optical diffusing portion is formed in a convex lens shape having such a diameter, and optical functions such as diffusion of the light guiding sheet and emission toward the normal direction side can be easily and surely controlled. The height ratio (h/D) of the average height (H1) of the light diffusing portion to the average diameter may be 〇. 5 or more and 〇. 5 or less. By defining the same ratio (Hi/D) of the light diffusing portion to the above range, optical functions such as diffusion and emission toward the normal direction side are improved. The laminate ratio of the light diffusion portion is 1 〇. /. Above and below 9〇%. By defining the layering ratio as the above range, it is possible to easily control optical functions such as diffusion. The arrangement pattern of the light-diffusing portion may be formed such that the density gradually changes from one end side to the other end side. By this means, when the light source is disposed only on one end side, the diffusion rate in the vicinity of the light source is suppressed, and the diffusivity of the portion farther from the light source is increased, thereby improving the light guide to the entire surface. The arrangement pattern of the diffusion portion may be formed such that the density gradually increases from both ends to the center. By this means, when the light source is disposed at both ends of the light guide sheet, the diffusion rate in the vicinity of the light source is suppressed, and the diffusivity of the portion farther from the light source is increased, thereby improving the light guiding property and surface of the entire surface. Uniformity. The surface of the base film on which the light diffusion layer is not laminated has a corrugated shape, and the average height (h2) of the 稜鏡 shape is equal to the 稜鏡 spacing (p) (H2/P). It is preferably 0.05 or more and 〇5 or less. Since the inner surface of the base film has the above-described height ratio, the light in the direction parallel to the edge of the light source side can be pulled in the normal direction, and the light guiding property, diffusibility and surface of the entire light guiding sheet of the light guiding sheet can be made. Uniformity will increase exceptionally. The end surface of the base film may have a ridge shape in the thickness direction. According to this means, when the light guide sheet is assembled to a backlight unit having a thin type (4) as a light source, light of the light source can be efficiently introduced into the sheet body.

❿ Lifting. Base

When a reflective layer is laminated on the inner surface side of the reflective film film on the inner surface side of the base film, the uniformity of 201028745 degrees is suppressed and the quality is improved. Here, the "single-sided side system. ^ ^ " is a case where a first diffusion layer is directly laminated on one surface of the base film, and the other side layer is also coated on the single side of the base film. The case of the light diffusion layer is such that the order j is .3⁄4. The term "inner side" refers to a case where a reflective layer is directly laminated on a surface opposite to the surface on which the light of the base film is emitted, and a case where the base film is unloaded through the other layer and a reflective layer is laminated. the concept of. Here, the term "light-diffusing layer and reflective layer" means that the base film is the same as the area material, and is laminated in the order of the base film, the light (four) layer, and the reflective layer. The "convex lenticular shape" means that the ❹ shape is convex, and the planar shape is not limited to a circular shape. The "average height (Ηι)" refers to the average vertical distance from the base surface to the topmost portion of the convex lens-shaped light diffusion portion. The "average diameter (9)" means the average diameter of the base of the light-diffusing portion in the form of a convex lens. The "layering rate" refers to the ratio of the light diffusing portion per unit area in the projected shape of the surface of the light guiding sheet. The "average height (%)" refers to the average vertical distance from the base surface to the apex. Further, the "pitch spacing (p)" refers to the average inter-vertex distance of the cross-sectional shape of the crucible. As described above, with the light guide sheet of the present invention and the backlight unit using the same, the light guide plate can be made thinner, and the overall light guiding property, diffusibility, and surface uniformity of the film can be improved. [Embodiment] Hereinafter, embodiments of the present invention will be described in detail with reference to the appropriate drawings. The light guide sheet 1 of Fig. 1 includes a base film 2 and a plurality of light diffusing portions 3 provided on the inner surface side of the base film 2. The plurality of light diffusing portions 3 constitute a layer of light diffusion 201028745. The base film 2 is formed of a transparent, especially colorless, transparent synthetic resin because it must pass light. The synthetic resin used for the base film 2 is not particularly limited, and examples thereof include polyethylene terephthalate, polyethylene naphthalate, acryl resin, polycarbonate, and polyphenylene. Ethylene, polyolefin, cellulose acetate, weather resistant ethylene, active energy ray hardening resin, electron beam curing resin, and the like. Among them, polycarbonate which is excellent in transparency and high in strength is preferable. The thickness (average thickness) of the base film 2 is not particularly limited, and is, for example, defined as 50 " m or more and 800 " m or less, preferably 1 〇〇 " m or more and 6 〇〇 or less. When the thickness of the base film 2 is less than the above range, the light guiding property is lowered, and when it is exposed to heat in a backlight unit or the like, curling tends to occur, and it is difficult to use it. On the other hand, when the thickness of the base film 2 exceeds the above range, the thickness of the backlight unit becomes large and the thickness of the liquid crystal display device is required to be reduced. The light diffusing portion 3 is provided with a light diffusing agent 4 and an adhesive 5 therefor. The optical diffusing agent 4 is covered by the adhesive 5. The light incident on the light diffusing portion 3 can be uniformly diffused by the light diffusing agent 4 contained in the light diffusing portion 3. Further, the light diffusing agent 4 is transmitted through the surface of the light diffusing portion 3 to form a fine convex portion substantially uniformly and densely. By the refraction of the lens of the fine concavities and convexities formed on the surface of the light guide sheet, the light can be more well diffused. The light diffusing portion 3 has a shape of a convex lens. Since this means has a convex lens shape ', the reflection angle of the light on the inner surface of the light diffusion portion 3 can be adjusted to be more uniform and the light can be more well diffused and reflected in the normal direction. The light-diffusing portion 3 is disposed on the entire inner surface of the base film 2 so that the density gradually increases from the side to the other side of the opposite side. By this means, when the light source is disposed only on the side, the diffusion rate in the vicinity of the light source is suppressed, and the diffusivity of the portion farther from the light source is increased, whereby the light can be uniformly spread over the entire surface. The lower limit of the layering ratio of the light diffusing portion 3 is 10%, particularly preferably 15%, more preferably 20%. When the layering ratio of the light diffusing portion 3 is defined to be equal to or higher than the lower limit, the area occupied by the light diffusing portion 3 on the surface of the light guiding sheet is increased, and optical functions such as diffusion and refraction of the light guiding sheet 1 are particularly enhanced. . The upper limit of the layering ratio of the light diffusing portion 3 is 90%, particularly preferably 75%, more preferably 60 Å/Å. By defining the layering ratio of the light diffusing portion 3 to be equal to or less than the above upper limit, the arrangement of the light diffusing portions 3 on the surface of the light guiding sheet can be freely moved while ensuring the diffusibility, and the optical function can be easily controlled. The average diameter (D) of the light diffusing portion 3 is ... above the claw and 3 〇〇 _ below, and more preferably 40 e m or more and 1 〇〇 " m 丁 ^ . By defining the diameter of the light diffusing portion 3 to the above range, the diffusion of the light guiding sheet can be easily and surely controlled and improved. Further, the light diffusing portion is straight: the same can be changed depending on the position on the sheet. For example, by narrowing the diameter of the light diffusing portion 3 on the side of the side, and increasing the distance from the light source =, the uniformity of the brightness of the entire surface can be obtained. Further, the light diffusion is not limited to a circular shape, and a polygonal shape such as an elliptical shape or a hexagonal shape can be suitably used. The average height (Ηι) of the light diffusing portion 3 with respect to the height of the average diameter (9) 201028745 = (H] / D) is preferably 〇 以上 5 or more and 〇 5 or less. By setting the gate ratio of the light diffusing portion 3 to the above range, the light diffusing portion 3 having the convex lens shape can effectively function as a convex lens on the surface of the light diffusing portion 3, and diffuse the light toward the normal direction. Reflection and so on. As shown in Fig. 2, the light diffusing portion 3 is provided with fine irregularities 6 on the surface, and the fine uneven portions 6 on the surface are formed by the presence of the light diffusing agent 4 contained in the vicinity of the surface. The size and density of the concavities and convexities 6 can be adjusted in accordance with the average particle diameter and content of the optical diffusing agent to be described later. For example, the β average radius of curvature of each of the concavities and convexities 6 can be defined as one or more and 2 〇 " m. When the light guide sheet j having the fine unevenness 6 on the surface of the light diffusing portion 3 is not only the interface of the light diffusing agent 4, but also the light is diffused and diffused on the surface of the light diffusing portion 3, and thus the light diffusibility and surface are formed. Uniformity will be especially improved. The refracting and diffusing of the surface of the light diffusing portion 3 is performed when the inner surface side of the light ray passing through the light guiding sheet is emitted, and the light emitted from the inner surface side is reflected in the reflecting sheet laminated on the inner surface of the light guiding sheet 1. And it is again emitted from the surface side of the light guiding sheet 1, and thus is efficient. The light diffusing agent 4 is a particle having a property of diffusing light, and the forming material is roughly classified into an inorganic filler and an organic filler. As the specific material of the inorganic filler, cerium oxide, aluminum hydroxide, aluminum oxide, zinc hydride, cerium sulfide, magnesium ruthenate, or a mixture thereof may be used. As the specific material of the organic filler, an acrylic resin, an acrylic resin, a polyurethane, polyvinyl chloride, polystyrene, polyamine or the like can be used. Among them, an acrylic-based resin having high transparency is preferable, and polymethyl methacrylate (PMMA) is particularly preferable. It can also contain fluorescent materials. The shape of the light diffusing agent 4 is not particularly limited, and examples thereof include a spherical shape, a vertical 11 201028745 square shape, a needle shape, a rod shape, a spindle shape, a 妃 _ uf / plate type, a scaly shape, a fiber shape, and the like. It is a bead which is excellent in light diffusibility. The lower limit of the average particle diameter of the light diffusing agent 4 and the & τ 』 祖 祖 仫 为 is 1//m, particularly preferably m, more preferably 5", and the upper limit of the average particle diameter of the light diffusion is... m' More preferably, it is preferably more than 15%. The reason is that if the average particle diameter of the light diffusing agent 4 is less than the above range, the unevenness of the surface of the light diffusing portion 3 formed by the light diffusing agent* becomes small, and If the average particle diameter of the light diffusing agent 4 is outside the above range, the thickness of the light guiding sheet 1 may increase and it may become difficult to uniformly diffuse. The average particle diameter is obtained by microscopically magnifying an arbitrarily selected light diffusing agent 4 to measure the diameter of the particles, and the value is derived as a simple average. Further, when the light diffusing agent 4 is not spherical, it is The size of the light diffusing agent 4 raised by either one is equal to the size of the light diffusing agent 4 which is raised vertically. The mass ratio of the light diffusing agent 4 to the adhesive 5 is 〇丨 or more and 2 or less. Preferably, it is 0.3 or more and 〇.5 or less. The reason is that the light diffusing agent 4 If the mass ratio is less than the above, the light diffusibility is insufficient, and if the mass ratio of the light diffusing agent 4 exceeds the above range, the effect of fixing the light diffusing agent 4 is lowered. The absolute value (|nrn2l) of the difference between the refractive index (ηι) and the refractive index (^) of the binder 5 is preferably 〇.03 or more, and particularly preferably ηι > η2. The light is diffused by the diffusing agent 4 and the binder 5 having the refractive index difference described above, in addition to the interface between the substrate film 2 and the light diffusing portion 3 and the reflection of the surface of the light diffusing portion 3, an effective reflection is also produced at the interface between the light diffusing agent 4 and the adhesive 5 and 201028745 Refraction, it is possible to efficiently reflect, diffuse, etc. toward the normal side. The adhesive 5 is formed by crosslinking and curing the polymer composition containing the base polymer. The light diffusing agent 4 passes through the adhesive. 5, and fixed to the surface of the base film 2. Further, the polymer composition for forming the adhesive 5 may be appropriately blended with, for example, a micro inorganic filler, a hardener, a plasticizer, or a dispersant in addition to the base polymer. , various leveling agents, UV absorbers, antioxidants The viscous modifier, the lubricant, the light stabilizer, the refractory material, etc. The base polymer is not particularly limited, and examples thereof include an acrylic acid-based resin, an amine vinegar-based resin, and a polyester resin. The gas-based resin, the poly- sulphur-based resin, the polyamidamine, the epoxy-based resin, the ultraviolet-curable resin, etc. can be used in combination of two or more kinds of these polymers. It is preferable that the material is high in workability and can easily form the polyol of the light diffusing portion 3 by means of coating, etc. From the viewpoint of the light transmittance of the k-port, it is preferable that the adhesive 5 is used. The substrate polymer used is transparent, and colorless and transparent is preferred. ❿ The above polyols can be exemplified by the polymerization of the early components containing hydroxyl-containing unsaturated monomers. _ 聚酯 兀 、 、 、 聚酯 聚酯 聚酯 聚酯 聚酯 聚酯 聚酯 聚酯 聚酯 聚酯 聚酯 聚酯 聚酯 聚酯 聚酯 聚酯 聚酯 聚酯

It is also possible to use these monomers or a mixture of two or more. In the case of a M-containing unsaturated monomer, the formula is as follows: (a) 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, olefin 酴 = # 2-hydroxyethyl methacrylate Methyl propyl ketone 2-hydroxypropyl, allylic acid ¥ _ alcohol, isopropanol, cinnamyl alcohol, crotyl alcohol and other hydroxyl-containing unsaturated monomers drunk, etc. M it ^ such as ethyl alcohol, epoxy , propylene glycol, heptane propane, butanediol, cyclo-porine, 1,4-bis(hydroxymethyl)cyclohexane, 13 201028745 phenyl glycidol _, glycidic glycerol citrate, pracus IF Li Yi, Chemical Industry Co., Ltd. please use 2 yuan alcohol or epoxy compound and unsaturated carboxylic acid such as acrylic acid, methyl propyl enoic acid, maleic acid, fumaric acid, soybean acid, itaconic acid, etc. The hydroxyl group-containing monomer obtained by the reaction is delayed. The polyol may be produced by polymerizing one or more selected from the group consisting of the above-mentioned unsaturated monomers containing a hydroxy group. © ❹ The above polyols may be selected from the group consisting of ethyl acrylate, acrylic propyl acrylate, propylene glycol, acrylic acid, butyl acrylate, ethyl hexanoic acid, and ethyl hexanoic acid. Benzyl acrylate, methyl propyl acrylate, methyl methacrylate isopropyl methacrylate, n-butyl methacrylate, butyl methacrylate, ethyl hexyl acrylate , methacrylic acid glycidol vinegar, methyl propyl hexanoic acid, styrene, vinyl toluene, r methyl styrene, acrylic acid, methacrylic acid, acrylonitrile, 6 acid vinyl vinegar, propionic acid Vinyl vinegar, vinyl stearate, allyl acetate, diallyl adipate, diallyl itaconate, diethyl maleate, ethylene ethylene, ethylene oxide, acrylamide, N • hydroxymethyl acrylamide, N. Butoxymethyl acrylamide, propylene propylene propylene, ethylene, propylene, isoprene, etc.; The above or two or more kinds of ethylenically unsaturated monomers are produced by polymerizing a hydroxyl group-containing unsaturated monomer selected from the above (a) and (b). The polyol obtained by polymerizing the monomer component containing a hydroxyl group-containing unsaturated monomer has a number average molecular weight of 1,000 or more and 500,000 or less, preferably 5,000 or more and 100,000 or less. Further, the hydroxyl value is 5 or more and 300 or less' is preferably 1 Å or more and 2 Å or less, more preferably 2 Å or more and 150 or less. 14 201028745 Polyester polyols obtained under conditions of excess radicals can (c) such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, hydrazine, 3-butanediol, hydrazine, 4 butanediol, 1,5-pentanediol, neopentyl glycol, hexanediol, decanediol, 2,2,4-trimethyl-1,3-pentanediol, trishydroxypropane, trihexyl, glycerol , pentaerythritol, cyclohexanediol, hydrogenated bis, A, bis (by fluorenyl) cyclohexene, p-phenylene di(hydroxyethyl ether), tris(hydroxyethyl) isocyanuric acid Polyols such as esters and diterpene diols and (d), for example, maleic acid, fumaric acid, succinic acid, adipic acid, azelaic acid, sebacic acid, trimellitic acid, terephthalic acid, ortho-benzene a polybasic acid such as dicapric acid or ^iso-p-dicarboxylic acid in a polyhydric alcohol such as propylene glycol, hexanediol, polyethylene glycol or trimethyl ketone, which has a base number greater than the retardation number of the polybasic acid The reaction is carried out to manufacture. The number average molecular weight of the polyester polyol obtained under the excess of the hydroxyl group is 500 or more and 300,000 or less, preferably 20 Å or more and 1 Torr or less. Further, the hydroxyl value is 5 or more and 3 Å or less, preferably i 〇 or more and 200 or less, more preferably 2 Å or more and 15 Å or less. φ. A polyol which is a base polymer of the polymer composition, which is obtained by polymerizing a monomer component having the above-mentioned polyester polyol and the above-mentioned unsaturated group-containing unsaturated monomer, and having a mercapto group An acrylic-based polyol such as an acrylic unit is preferred. The polyester polyol or the acrylic polyol as the binder 5 of the base polymer has high transparency and weather resistance, and can suppress yellowing of the light diffusing portion 3 and the like. In particular, by using an acrylic-based polyol as the base polymer and using the light-diffusing agent 4 made of an acrylic-based resin, the unnecessary refraction, reflection, and the like at the interface of the diffusing agent 4 can be reduced, and the Directional light diffusing function of light guide 1, optical transparency, etc. Optical 15 201028745 Function. also,? Γ π m Both the polyester poly-alcohol and the acryl-based base can be used. Any number of only: Yes: = alcohol and propylene glycol-based polyol, the base value of the base is not particularly limited, and the solid component is water-based, and the cross-linking point is The coating material property such as solvent resistance, heat resistance, and surface hardness tends to decrease. The polymer composition of the filling agent 15 is composed of a minute inorganic filler, and contains a small inorganic filler in the binder, and the heat resistance of the seed or the light guide sheet 1 is improved. The inorganic substance constituting the organic filler is not particularly limited. However, the inorganic oxide is defined as a metal element mainly permeable to various oxygen-containing metal compounds which constitute a three-dimensional network with oxygen. The metal element used for the oxide of the machine is, for example, preferably selected from the group consisting of Groups 2 to 70 of the periodic table of the elements, and is selected from the group consisting of Group 3 to Group 5 of the periodic table of the elements =: especially selected from the group consisting of Si, The elements of A1, ... are better, and the metal ketone is kb colloidal dioxygen cuts as the best inorganic filler in terms of heat resistance enhancement effect and uniform dispersibility. Further, the shape of the fine inorganic filler may be any spherical shape such as a spherical shape, a needle shape, a plate shape, a scaly shape, or a crushed shape, and is not particularly limited. The lower limit of the average particle diameter of the fine inorganic filler is preferably 5 thief, and particularly preferably 10 nm. On the other hand, the upper limit of the average particle diameter of the fine inorganic filler is preferably 50 nm', and particularly preferably 25 nm. The reason why the film is based on gamma is that if the average particle diameter of the micro inorganic filler is less than the above range, the surface energy of the micro inorganic filler will become high, and the aggregation will easily occur, and the opposite is true. When the thousand-thick particle diameter exceeds the above range of 16 201028745, the influence of the short wavelength becomes cloudy, and the transparency of the light guide sheet 1 cannot be completely maintained. The lower limit of the mass ratio of the fine inorganic filler (the mass ratio of only the inorganic component to 100 parts of the base polymer of the binder 5) is preferably 5 parts in terms of solid content, more preferably 5G. Share. On the other hand, the upper limit of the above mass ratio of the fine inorganic filler is preferably $5 parts, more preferably 2 parts, and particularly preferably 100 pieces. The reason for this is that if the minute inorganic content is less than the above range, the light guide sheet core may not be sufficiently exhibited:: Conversely, if the mass ratio exceeds the above range, it may be difficult to blend into the polymer composition, and light The light transmittance of the diffusing portion 3 is lowered. The above-mentioned minute inorganic filler may be one in which an organic polymer is fixed on its surface. By fixing the fine inorganic filler with the organic polymer in this manner, the dispersibility in the binder 5 and the affinity with the binder 5 can be improved. The molecular weight, shape, composition, presence or absence of a functional group of the organic polymer are not particularly limited, and any organic polymer can be used. Further, the shape of the organic polymer can be any shape such as a linear chain, a branched chain, or a crosslinked structure. Specific resins constituting the above organic polymer, such as (meth)acrylic resin, polystyrene, polyvinyl acetate, polyethylene, polypropylene, etc., polyolefin, polyethylene, polyethylene, polyethylene terephthalate A polyacetate such as ethylene glycol dicarboxylate or a copolymer thereof, or a resin partially denatured with a functional group such as an amine group, an epoxy group, a trans group or a thiol group. In the crucible, organic polymerization of (mercapto)acrylic acid units such as W (meth)acrylic acid-based erythrazone, (meth)acrylic acid-styrene resin, and (meth)acrylic acid-polyester tree It is preferable that the material has a film forming ability as a factor of 17 201028745. On the other hand, Xiao Jia is a resin having compatibility with a substrate polymer of the above polymer composition, and is preferably the same composition as the base polymer contained in the polymer composition. Moreover, the micro inorganic filler can contain organic polymerization in the microparticles.

Things. Thereby, the core of the micro inorganic filler, that is, the inorganic material, is moderately soft: and toughness can be imparted. X The above organic polymer may be an alkoxy group, and the content thereof is preferably a fine inorganic filler to which an organic polymer is immobilized per lg & (4) _ 〇 1 or more and 5 〇 mmol g. By the alkoxy group, the affinity with the matrix resin constituting the binder 5 and the dispersibility in the binder 5 can be improved. The above alkoxy group means an RO group bonded to a metal element forming a microparticle skeleton. This R is an alkyl group which may be substituted, and the r fluorenyl groups in the granules may be the same or different. Specific examples of R include a methyl group, an ethyl group, and a n-propyl group: an isopropyl group and an n-butyl group. It is preferable to use the same metal alkoxy group as the metal constituting the minute inorganic filler, and # when the fine inorganic filler is colloidal cerium oxide, it is preferred to use cerium as the metal alkoxy group. The organic polymer in the fine inorganic filler in which the organic polymer is fixed is not particularly limited, and it is preferably 5% by mass or more and 50% by mass or less based on the fine inorganic filler. The above-mentioned organic polymer fixed to the fine inorganic filler uses a hydroxyl group, and the polymer composition for constituting the binder 5 contains a polyfunctional isocyanine selected from the group consisting of two or more functional groups reactive with a light group. At least one of the compound, the trihydroamine compound, and the amine-based plastic resin may be used. 201028745 The base of the micro-inorganic filler and the binder 5 is bonded via a cross-linking structure, and it is good for preservation stability, stain resistance, flexibility, weather resistance, storage safety, and the like. Further, the obtained film has a gloss. ❹

G The base polymer of the above binder 5 is preferably a polyol having a cycloalkyl group. By introducing the ring-burning group as the base material polymer constituting the binder 5 in this way, the water-repellent property such as the water repellency and water resistance of the adhesive 胄5 becomes high, and the guide under high temperature and high humidity conditions The flexibility, dimensional stability, etc. of the light sheet will be improved. Further, the basic properties of the coating film such as weather resistance, hardness, thickness feeling, and solvent resistance of the optical expansion (4) 3 are improved. Further, the affinity with the micro inorganic filler to which the organic polymer is fixed on the surface and the uniformity of the micro- and inorganic fillers are further improved. The cycloalkyl group is not particularly limited, and examples thereof include a cyclobutylpentyl group, a cyclohexyl group, a cyclodextene group, a cyclooctyl group, a cyclodecyl group, a cyclodecyl group, a cyclodecyl group, and a cyclodecene group. Triyl, cyclotetradecyl, cyclopentadecyl, cyclooctadecyl, cyclohexadecyl, cyclooctadecyl and the like.

2 A polyol having the above cycloalkyl group can be obtained by copolymerizing a polymerized 'unsaturated precursor having a cycloalkyl group. The polyunsaturated monosystem having a cycloalkyl group means having at least D and a monomer in the molecule. This polyunsaturated is not saturated with the polymerization of the ring-burning group. (The muffler is not particularly limited to L. For example, = propylene hexanoic acid acrylate, (methyl) propyl ketone methyl hexanoic acid vinegar, Methyl) propylbutylcyclohexanacetate, (meth)acrylic acid cyclododerconic acid, etc. The isocyanate 5 is used as a curing agent in the second polymer composition. ^ It is contained in a polymer composition. The isocyanate 3 is a hardening agent for the stronger strengthening of the bribes ^^^, skin. The shell will become a cross-linking structure, the film properties of the light diffusing part 3 will advance - step 19 201028745. This isocyanate can be used with the above The functional isocyanate compound phase is a substance which is preferably an aliphatic isocyanic acid which prevents yellowing of the film.

In particular, when a polyol is used as the base polymer, one of hexamethylene diisocyanate, isophoric acid diisocyanate, and benzodimethyl diisocyanate is used as the hardener in the polymer composition. Alternatively, two or more types may be used in combination. When these hardeners are used, the curing reaction rate of the polymer composition becomes large. Therefore, even if a cationic agent which contributes to the dispersion stability of the fine inorganic filler is used as an antistatic agent, the cationic resistance can be sufficiently complemented. The rate of hardening reaction caused by the electrostatic agent is lowered. Further, an increase in the curing reaction rate of the polymer composition contributes to uniform dispersion of the fine inorganic filler to the binder. As a result, the light guide sheet can suppress the deflection and yellowing caused by heat, ultraviolet rays, and the like. Further, an antistatic agent may be contained in the above polymer composition.形成 By forming the adhesive 5' by kneading a polymer composition having an antistatic agent, the light guide sheet 1 exhibits an antistatic effect, and attracts dust or prevents electrostatic bands which are difficult to overlap with an optical sheet or the like. Bad situation. Further, when the antistatic agent is applied to the surface, the surface is sticky and dirty, so that the drawback is obtained by kneading the antistatic agent in the polymer composition. The antistatic agent is not particularly limited, and examples thereof include a cationic antistatic agent such as an anionic compound such as a mercaptosulfate or an alkyl phosphate, and a polymer antistatic such as an alcoholic anhydride monostearate or an ethanolic acid. Non-ionic antistatic agents such as antistatic agents such as antistatic agents, quaternary ammonium salts, imidazolin, polyethylene glycol, and polyoxyethylene sorbitol, and polypropylene. Among them, it is preferable that the antistatic effect is large. 20 201028745 < A cationic antistatic agent, which exhibits an antistatic effect with a small amount of addition. Further, the polymer composition may contain an ultraviolet absorber. By forming the binder 5 from the polymer composition containing the ultraviolet absorber in this manner, the light guide sheet 1 is given an ultraviolet blocking function, and the trace amount of ultraviolet rays emitted from the light source of the backlight unit is interrupted. It can prevent the destruction of the liquid crystal layer caused by ultraviolet rays. The ultraviolet absorber is not particularly limited as long as it is a compound which absorbs ultraviolet rays and is efficiently converted into heat energy and is stable to light, and a conventional one can be used. Among them, a salicylic acid-based ultraviolet absorber, a diphenylketone-based ultraviolet absorber, and a benzotriazole which have high ultraviolet absorption function and good compatibility with the above-mentioned base polymer, and which are stably present in the base polymer. The azole-based ultraviolet ray absorbing agent and the cyano acrylate-based ultraviolet ray absorbing agent are preferred, and one or more selected from the group may be used. Further, as the ultraviolet absorber, a polymer having an ultraviolet absorbing group in a molecular chain (e.g., "U Double UV" series of a Japanese catalyst) may be preferably used. By using a polymer having a ruthenium ultraviolet absorbing group in the molecular chain, compatibility with the main polymer of the binder 5 is high, and deterioration of the ultraviolet absorbing function due to bleeding of the ultraviolet absorbing agent or the like can be prevented. Further, a polymer having an ultraviolet absorbing group in a molecular chain may be used as a base polymer of the binder 5. Further, the polymer having the violet _ outer absorbing group bonded thereto may be used as the base polymer of the binder 5, and the ultraviolet absorbing agent may be contained in the base polymer to further improve the ultraviolet absorbing function. The lower limit of the content of the ultraviolet absorber with respect to the base polymer of the binder 5 is 0.1% by mass, particularly preferably 丨% by mass, more preferably 3% by mass, and 21 201028745, the upper limit of the above content of the ultraviolet absorber is 10% by mass, It is particularly preferably 8 mass%, more preferably 5 mass%. The reason is that if the mass ratio of the ultraviolet absorber to the base polymer is less than the lower limit, the ultraviolet absorption function of the light guide sheet 1 cannot be effectively exhibited. Conversely, if the mass ratio of the ultraviolet absorber exceeds the upper limit, The base polymer may have an adverse effect, resulting in a decrease in strength, durability, and the like of the adhesive 5. It is also possible to use an ultraviolet stabilizer (including a substrate polymer having a molecular chain-bonded ultraviolet stabilizer) in combination with the ultraviolet absorber or the ultraviolet absorber. By the ultraviolet stabilizer, radicals generated by ultraviolet rays, ❹ active oxygen, and the like are deactivated, and ultraviolet stability and weather resistance can be improved. The ultraviolet stabilizer can preferably be used as a barrier to high UV stability = UV stabilizer. Further, by using a combination of an ultraviolet absorber and an ultraviolet stabilizer, the deterioration of the ultraviolet rays and the financial property are particularly enhanced. ❹, 生下', the manufacturing method of the light guiding sheet 1 will be described. The light guide sheet 1 is formed by a step of forming a light diffusing portion by mixing the light diffusing agent 4 with the polymer composition constituting the binder 5, and the light diffusing portion is made of a polymer. The layer is deposited on the surface of the base film 2, and the step of forming the light diffusing portion 3 is formed. The method of expanding the light-diffusing portion and forming the layer on the surface of the base (4) 2 is a method of laminating a composition of light Cl: by printing. The printing method is not particularly limited. Gravure printing, screen printing, ink jet printing, and laser printing The light guiding sheet U of Fig. 3 includes a base film 12 and a plurality of light diffusing portions 3 laminated on the inner surface side of the base film 22 201028745 12 . A wavy crotch portion 13 is provided on the surface side of the base film 12. Since the light diffusing portion 3 is the same as the above-described light guiding sheet, the same reference numerals will be omitted. The crotch portion 13 has a wavy ridge shape, and the surface of the light guide sheet is disposed in the dense direction of the light diffusing portion 3 (in the backlight unit, perpendicular to the light source side end of the light guide sheet 11) Direction). In terms of the height of the crucible, the height ratio (Η2/ρ) of the average height (Η2) of the crucible to the crucible spacing (ρ) is preferably 0.05 or more and 〇.5 or less, and particularly preferably 〇1 or more. 〇2 or less, the light guide sheet 11 is also refracted by the light in the crotch portion 13 on the surface of the base film 12, so that light parallel to the end side of the light source side can be emitted upward in the normal direction. The light diffusing property and surface uniformity of the entire light sheet 11 are particularly enhanced. The crotch portion 13 may be formed integrally with the base film 2 # + , 秄膘 2 or may be formed separately from the base film 2 . Since the crotch portion 13 is required to penetrate light, it is formed of a transparent, especially colorless, transparent synthetic resin. Specifically, the same synthetic resin as the above-described base film 12 is used. The edge light type backlight unit shown in FIG. 4 includes a light guide sheet η, a light source 9 disposed on the side surface of the light diffusing portion 3 where the light diffusing portion 3 is relatively thin, and a light source 9 disposed on the light guide sheet. The optical sheet 7 on the side of the surface 11 (the surface on which the crotch portion 13 is formed) and the reflection sheet 8 disposed on the inner surface side of the guide light guide sheet 11 are superposed. The light source 9 is preferably a thin LED, a fluorescent tube or the like. The light emitted by the light source 9 travels in the ^m m leading sheet 11 while being reflected to the parent interface of the surface, and is incident on the light diffusing portion 3 disposed on the inner surface. # Surface shot. The 23 201028745 light from the light source 9 is generally strong near the light source 9 and becomes weaker as it goes further from the light source 9. However, by the light guide 11 , the density of the light diffusing portion 3 is lower in the vicinity of the light source 9 and is higher as it is farther from the light source '9, so that light is near the light source 9 The light diffusing 胄3 scatters and emits a small proportion toward the surface, and the ratio of the emitted light from the light source 9 becomes higher, and as a result, the light guide sheet emits light of uniform brightness. Further, since the light diffusing agent 4 contains the light diffusing agent 4, the light is diffused to be finer by the light diffusing agent 4, and light having a uniform surface uniformity is emitted from the surface of the light guiding sheet. Further, since the surface of the light diffusing portion 3 is provided with the fine unevenness 6, the surface of the light diffusing portion 3 is also refracted and diffused. The diffused light is emitted from the inner surface of the light guide sheet 11, and is reflected by the reflection sheet 8, and is again transmitted through the light guide sheet 11 and then emitted from the surface of the main guide sheet of the guide sheet, so that the light diffusibility and the surface are uniform. Sex will be further enhanced. Further, the surface of the light guide sheet u is disposed on the crotch portion 13 of the ridge of the light diffusing portion 3 in the & $ direction (that is, the direction in which the money is made and the direction perpendicular to the end side of the light source 9 side). The light ❹ in the direction parallel to the edge of the light source side can be pulled toward the normal direction. Therefore, the surface of the light guide sheet will emit light with a high degree of uniformity. Figure 5 light guide! In the case of the base film 12, a plurality of light-diffusing portions 3 which are layered on the inner surface side of the material film 12, and the surface side of the base film 12: the densely-disposed direction of the light-diffusing portion 3 a portion and a light diffusing layer 4 disposed on the base film 12, and a plurality of recessed portions 15 which are sparsely-side-side edges, a base film 12, and a light diffusing portion 3 (provided with a light diffusing agent* Since the adhesive 5) and the crotch portion (not shown) are the same as the above-mentioned light guide sheet u, the same number is omitted. The concave portion 15 has a substantially rectangular shape in which the long sides are parallel to one end side of the light guiding sheet 14, and the bottom side 16 has a shape in which the ridge lines are in the thickness direction. The size of the recessed portion 15 is appropriately set in accordance with the size of the LED 17 to be assembled in the edge type backlight unit. The light guide sheet 14 is designed such that when the edge type backlight unit is assembled with the thin LED 17 as a light source, the recessed portion 15 interferes with the thin LEm 7. When a thin LED is used as the light source, the light source will be discontinuous, so the light intensity will become large, especially in the vicinity of the light source. However, the light emitted from the thin LED 17 by the light guide sheet 14' is diffused in a direction parallel to one end side of the base film 12 due to the shape of the bottom edge μ, so that the brightness can be improved in the vicinity of the light source. Uniformity. Further, since the light-receiving portion 7 is disposed in the recessed portion 15, the area of the light emitted from the thin LED 17 and the end surface of the light guide sheet μ is widened, and the light from the thin LED 17 can be enlarged. Since it is efficiently introduced into the light guide sheet 14, the front brightness can also be improved. The light guide sheet 18 of FIG. 6 includes a base film 2, a plurality of light diffusing portions 3 which are laminated on the inner surface of the base film 2, and a non-laminated portion of the light diffusing portion 3 laminated on the inner surface of the base film 2. The transparent layer 19 of the light diffusing portion 3 and the reflective layer 20 laminated on the inner surface of the transparent layer 19. The base film 2 and the light-diffusing portion 3 (including the light-diffusing agent 4 and the adhesive 5 thereof) are the same as those of the above-described light guide sheet 1. Therefore, the same reference numerals will be omitted. The transparent layer 19 is formed of a transparent, preferably colorless, transparent polymer for subsequently attaching the substrate film 2 and the reflective layer 20, while suppressing the passage of the substrate film 2 and the anti-(4) 2G between 2010 and 201028. The loss of light. The polymer preferably has a refractive index close to that of the synthetic resin constituting the group (4) 2, and examples thereof include an acrylic resin, an amine brew resin, a polyester resin, a fluorine resin, a polyoxo resin, and an amine. 'Imines, epoxy resin, ultraviolet curable resin, etc. can be used, or two or more types of these polymers can be used. In particular, the above polymer is preferably a polyol which is highly affixable and can be easily fixed by the base film 2 and the reflective layer 20 by means of coating or the like. The reflective layer 20 is formed of a white synthetic resin. This white synthetic resin is a synthetic resin containing white pigments and fine bubbles. The synthetic resin which can be used for the reflective layer 20 is not particularly limited, and examples thereof include polyethylene terephthalate, polyethylene naphthalate, acrylic resin, polycarbonate, and polystyrene. Ethylene's polyolefin, cellulose acetate, weather resistant ethylene, etc. Among them, polyethylene terephthalate having excellent heat resistance is preferred. The white pigment is not particularly limited, and examples thereof include titanium oxide (titanium white), zinc oxide (zinc oxide), lead carbonate (lead white), barium sulfate, and calcium carbonate (white). The average particle diameter of the white pigment is preferably 1 〇〇 nm or more and 3 〇 # m or less is more preferably 20 〇 nm or more and 20 / zm or less. The reason for this is that if the average particle diameter of the white pigment is less than the above range, the reflective layer 20 may not be sufficiently reflective, and if the average particle diameter of the white pigment exceeds the above range, the reflectance of the reflective layer 20 There are ambiguities that become uneven. By the light guide sheet 18', the inner surface of the base film 2 is laminated with the reflective layer 2〇, so that the loss of light from the light source penetrating through the base film 2 can be suppressed, and the light can be efficiently emitted from the surface side. . Usually, the inner surface of the light guide sheet 18 may be additionally provided with a reflection sheet, but in this case, the light loss 26 201028745 between the light guide sheet 18 and the reflection sheet is large. However, the transparent layer 19' composed of a synthetic resin having a refractive index close to that of the substrate film 2 is laminated between the substrate 4 and the reflective layer 2, thereby suppressing light to and from the substrate film 2 The light loss with the reflective layer 2〇 effectively emits light from the surface side and improves the front luminance 曰. Further, the light guide sheet of the present invention and the backlight unit using the same are not limited to the above-described embodiments, and for example, the inner side of the light guide sheet u and the light guide 14 may be opposite to each other, that is, the crotch portion 13 may be disposed. The surface is assembled as an inner surface to be used in a backlight unit. Further, the surface of the substrate film and/or the inner surface may be laminated with other layers (for example, a UV absorbing layer, an antistatic layer, an antireflection layer, etc., or a thin LED may be provided without the recess 15 In the light guide sheet 18, the transparent layer 19 may not be laminated, but the light diffusing portion 3 directly laminated on the inner surface of the base film 2 may be laminated. In the case of the method of laminating the reflective layer 2, a method of applying a white synthetic resin, a method of depositing silver ore, etc., or the like may be used. a full-area layer light diffusing layer on one side of the film. In this case, the thickness of the light diffusing agent relative to the binder can be varied on the substrate film from the thickness of the light diffusing layer (for example, from the end side of the substrate film to the other side) One end side gradually increases the light guiding property, diffusibility, and surface uniformity of the surface of the light guiding sheet with respect to the mass ratio of the light diffusing agent to the binder. [Examples] The present invention is based on the examples, but the present invention The heart is not explained by the record of the example. ^ 27 201028745 [Comparative The base film is formed by using a transparent polyethylene terephthalate having a thickness of 300/zm. The polymer composition for the light diffusion portion is a non-light diffusing agent and is composed of an acrylic acid-based polyol and A polymer composition composed of a solvent, a light-diffusing portion polymer composition was deposited in a lenticular shape on the inner surface of the base film by screen printing, thereby obtaining a light guide sheet of a comparative example. The light diffusing portion of the light guiding sheet has an average diameter of 60/ζπι and a layering ratio of 50%. [Examples 1 to 8] The polymer composition for the light diffusing portion is an acrylic acid group as a light diffusing agent. A polymer composition composed of a resin-made bead, an acrylic-based polyol (binder), and a solvent. The mass ratio of the acrylic-based resin beads to the acrylic-based polyol (adhesive) by screen printing The polymer composition for a light-diffusing layer, which was designated as 〇J, 0.2, 0.3, 0.4, 0.5, 1, 1.5, and 2, was laminated in a convex lens shape on the inner surface of the base film, thereby obtaining Example 1 ~8 light guide film. In addition to the above ratio [Examples 9 to 19] The surface of the base film was processed to have a 稜鏡 height ratio (ί^/Ρ) of 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 〇·6, 0.7, respectively. a wavy shape of 0.8, 0.9, and 1. The composition of the light-diffusing layer formed by the ratio of the mass ratio of the acrylic-based resin beads to the acrylic-based polyol (adhesive) is 0.2 by screen printing. The light guide sheets of Examples 9 to 19 were obtained by laminating the lenticular surfaces in a convex lens shape on the inner surface of each of the base material films. The other examples were the same as those of the above comparative examples. 28 201028745 [Evaluation of characteristics] The above examples The light guide sheets of 1 to 8 and the light guide sheets of the comparative example were assembled in the edge light type as the light unit', and the surface uniformity of the front luminance was measured. Surface uniformity The front side luminance is measured in one side of the light guide, and the ratio of the minimum brightness to the maximum 値 is calculated. The results are shown in Table 1 below. [Table 1] Surface uniformity comparison example ❷ 0.912 Example 1 (Light diffusing agent mass ratio Example 2 (light diffusing agent mass ratio Example 3 (light diffusing agent mass ratio Example 4 (light diffusing agent mass ratio example) 5 (light diffusing agent mass ratio Example 6 (light diffusing agent mass ratio 0.1) 0.2) 0.935 0.957

0.970

Example 7 (Light diffusing agent mass ratio

As shown in Table 1 above, the light guide sheets of Examples i to 8 showed higher surface uniformity than the comparative sheets which did not contain the light diffusing agent. Moreover, the light guide sheets of Examples 1 to 8 are compared, and the mass ratio of the first diffusing agent to the binder is 0.1 or more, and the surface uniformity is changed to the mass ratio of 〇3 or more. Got higher. Next, the apex u of the above-mentioned Embodiments 9 to 19, i I, sf, and the first chip group are placed on the edge light type backlight unit 70', and the surface uniformity of the front side is measured. The rise of the fruit is shown in Table 2 below. 29 201028745 Table 2] Example 9 (稜鏡 height ratio: 0.05) Example 10 (prism height ratio: 0.1) Example 11 (稜鏡 height ratio: 0.2) Example 12 (稜鏡 height ratio: 〇. 3) Example 13 (稜鏡 height ratio: 0.4) Example 14 (稜鏡 height ratio: 0.5) Example 15 (稜鏡 height ratio: 0.6) Example 16 (稜鏡 height ratio: 0.7) Example 17 (稜鏡Height ratio: 〇.8) Example 18 (prism height ratio: 〇·9) Example 19 (稜鏡 height ratio: 1. 〇)

As shown in Table 2 above, 'the embodiment shows that the mass of the embodiment is equal to the equivalent of the crotch, and has: :: 〇 〇 : surface: hook property. Further, after comparing the light guide sheets of Examples 9 to 19, the mirror ratio is 〇.〇5 or more and 〇5 becomes higher in uniformity, and the height becomes higher than the horse 0.1 or more and 0.2 or less. . (Industrial Applicability) As described above, the light guide sheet of the present invention is useful as a liquid crystal display device and is particularly suitable for use in a transmissive liquid crystal display. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic bottom view (3) and a schematic partial cross-sectional view (b) of a light guiding sheet according to an embodiment of the present invention. Figure 2 is a diagram! A schematic enlarged view of a light diffusing portion of the light guide sheet. Fig. 3 is a view showing a light guide sheet in a different form from the light guide sheet of Fig. i. 4 is a schematic perspective view showing a backlight unit having the light guide sheet of FIG. 3.

Fig. 5 is a schematic bottom plan view showing the light guide sheet of Fig. 3 and Fig. 3. Light guide sheets of different shapes Fig. 6 is a schematic cross-sectional view showing light guide sheets of Figs. 1, 3 and 5. The guide of the different form I Fig. 7 shows the conventional edge light type backlight unit. [Main component symbol description] Q 1 Light guide sheet 2 Substrate film 3 Light diffusing portion 4 Light diffusing agent 5 Adhesive • 6 Concave and convex 7 Optical sheet 8 Reflecting sheet 9 Light source 31 201028745 11 Light guide sheet 12 Substrate film 13 Crotch portion 14 Light guide sheet 15 Concave portion 16 Bottom side 17 Thin LED 18 Light guide sheet 19 Transparent layer 20 Reflecting layer 21 Backlight unit 22 Light source 23 Light guide plate 24 Optical sheet 25 Light diffusion sheet 26 Prism sheet 27a

32

Claims (1)

201028745 ' VII. Patent application scope: 1. A kind of light guide layer is provided with a transparent base film and a light diffusion layer laminated on one side of the base film, and the light diffusion layer contains a light diffusing agent and a bonding agent thereof. . 2. The light guide sheet of the first aspect of the patent application, wherein the mass ratio of the light diffusing agent to the binder is 〇1 or more and 2 or less. 3. The light guide sheet of claim 1, wherein the absolute value (| nrh I ) of the difference between the refractive index (ηι) of the first diffusing agent and the refractive index (10) of the adhesive in the light diffusing layer is 〇·〇 3 or more. 4. The light guide sheet of claim 1, wherein the average particle diameter of the light diffusing agent in the light diffusing layer is greater than or equal to O.lym and less than 20 " m. 5. For example, Shen Sing's patent scope 1 @ + t • ^ is a light guide film of Guti, in which the light diffusion layer has fine irregularities on the surface. 6 · The light guide sheet of the third paragraph of the patent application, wherein the light diffusion layer is constructed by a plurality of light diffusion portions which are laminated on the early side of the fine amine @ m 1 and the film surface. to make. The light diffusing portion 7 is formed into a convex lens shape as in the light guide sheet of claim 6 of the patent application. The light guide sheet of the sixth aspect of the patent application, wherein the light diffusion portion has an average diameter (D) of 10 #m or more and 30 〇em or less. 9. The light guide sheet of claim 6, wherein the light diffusing portion and the thousandth meanness (H/the height ratio (Hi/d) of the average diameter (9) are 〇〇5 or more and 0.5 or less. 33 201028745 10. For the light guide of the sixth patent of the patent scope, the stacking ratio of the light diffusing part is 10% or more and 9〇0/. 11 _If the patent application scope is the sixth whistle The guiding pattern of the light diffusing portion is formed such that the density gradually increases from one end % 1 to the other end side. 12. The light guide of the sixth item of the patent application scope a sheet in which the pattern of the light-diffusing portion is formed in such a manner that the density gradually increases from two to two. The light guide sheet of the first patent range of the patent, wherein the base The surface of the material film having the light diffusion layer without a layer has a wavy shape. ^ For example, the light guide of the first item of the patent range, wherein the shape is large, and the uniformity is H2) The height ratio (10) with respect to the 稜鏡 spacing (p) is 〇〇5 or more and 〇.5 or less. Among them, the base film 15. If applied The end surface of the light guide sheet of the third aspect has a double-line shape in the thickness direction. wherein the substrate film is 16. The inner side of the light guide sheet of the first aspect of the patent application has a reflective layer. A liquid crystal display device for dispersing light from a light source and guiding the light to a surface side thereof, which is characterized by having a light guide sheet of patent application 帛1 0 VIII, schema: (such as the next page) 34