TWI382203B - Light diffusion laminated board - Google Patents

Description

Light diffusing laminate

The present invention relates to a light diffusing laminate, and more particularly to a light diffusing laminate having a strip-shaped hollow chamber and matching the position of the strip-shaped hollow chamber to achieve high luminance and good light diffusion.

Polycarbonate resin has excellent mechanical properties, heat resistance, and high light transmittance. In recent years, it has been widely used in the use of light-diffusing panels for side-lit or direct-lit backlights or small liquid crystal televisions. . A conventional polycarbonate light-diffusing sheet, for example, Japanese Laid-Open Patent Publication No. Hei 05-257002, is a resin composition in which a calcium carbonate or a bridged polyacrylate resin is added to a polycarbonate resin. Further, for example, JP-A 03-078701 is a light-diffusing sheet for a liquid crystal display backlight module made of a polycarbonate resin composition containing calcium carbonate and titanium oxide.

In addition, when a light diffusing agent is added to a polycarbonate resin as a light diffusing plate of a transparent document reading element in an image processing apparatus, the dark granular material has a specific amount or less. High light transmittance and good light diffusibility, and there is no problem of uneven light transmission in a small field. However, when the light diffusing plate is used for a large liquid crystal television, there is a problem that luminance is uneven.

In addition, in the use of a light-diffusing sheet for a small-sized liquid crystal display or a small-sized liquid crystal television of a side-lit or direct-lit backlight module, a polycarbonate-made light-diffusing sheet made of acrylic resin competes with each other. In recent years, large-sized liquid crystal displays or liquid crystal televisions of 15 to 39 inches have gradually become the mainstream of direct type backlights due to an increase in area. The polycarbonate light diffusing plate is superior to the quality surface (resistance to scratching, etc.), and the PMMA resin has high light transmittance, good weather resistance, and is superior to the market in terms of cost competitiveness.

However, a light diffusing plate for a direct-type backlight module made of a polycarbonate resin used in a large liquid crystal display or a liquid crystal television, when the cold cathode fluorescent lamp emits light, the light diffusing plate is under the influence of radiation for a long time. The luminance of the light-emitting surface is deteriorated, and the color tone of the image seen through the actual liquid crystal display is changed from the initial state, which causes a problem in the visibility of the entire image.

Conventionally, a backlight module for a liquid crystal display device generally includes a light guide plate formed of a light transmissive material, a line light source formed of a cold cathode tube provided at a side end portion thereof, and a light reflection film covering the line light source under the light guide plate. And a light diffusing plate or a lens film that forms a light emitting surface on the light guide plate. In recent years, in order to increase the luminance and reduce the power consumption, in a color liquid crystal display device, one or two lens films having a meandering surface are often disposed particularly on the upper surface of the light diffusing plate or between the light diffusing plate and the light guiding plate. Further, in order to improve the unevenness of the amount of light emitted by the distance from the light source, a dot pattern in which the light-diffusing ink is formed to become larger as it goes away from the light source can be printed on the inside of the light guide plate. The arrangement of the light diffusing plate is such that the light is uniformly diffused and the dot pattern printed on the light guide plate is not seen as a main purpose, and the light emitted from the light guide plate is efficiently collected in the front direction of the liquid crystal panel. In the above, one or two lens films may be disposed on the upper surface of the light diffusion sheet or between the light diffusion sheet and the light guide plate.

However, conventionally, the production of such lens films has been achieved by a method such as embossing of a thermoplastic resin sheet or a transfer of a radiation-curable resin. However, conventional lens films are also limited in material selection due to limitations in their manufacturing methods. Furthermore, the lens film also has to be used in combination with the light diffusing film because it does not have a light diffusing effect, resulting in a complicated assembly step of the backlight module.

In addition, from the viewpoint of improving the luminance of the liquid crystal screen and reducing the luminance unevenness of the entire screen, in the small liquid crystal display and the small liquid crystal television, a diffusion film, a lens film, a brightness enhancement film, or the like is used in addition to the light diffusion plate. Functional film. However, recently, since liquid crystal displays and liquid crystal televisions have also progressed from small to large, it is desired to develop a light diffusing plate which can reduce the number of functional films used and improve luminance and diffusion performance.

Therefore, an object of the present invention is to provide a light-diffusing laminate which is excellent in high luminance and good in light diffusibility.

Thus, the light diffusing laminate of the present invention comprises: a first resin layer, a second resin layer on the first resin layer, a microlens layer on the second resin layer, and a plurality of strips of hollow Room. The position of the strip-shaped hollow chamber may be simultaneously covered by the first or second resin layers or only by the second resin layer.

The first resin layer has a light diffusing function, and the microlens layer has a collecting function capable of concentrating the emitted light to increase the amount of emitted light. Therefore, the light diffusing laminate of the present invention can have both a light diffusing effect and a light collecting effect. Further, the structure and position of the strip-shaped hollow chamber can be matched, thereby achieving high brightness and good light diffusing effect.

Preferably, in the present invention, a protective layer located under the first resin layer adjacent to a light source may be further disposed, and an antioxidant, an ultraviolet absorber, a fluorescent agent or the like may be added to the protective layer to enhance the light of the present invention. UV-resistant effect and thermal stability of the diffusion laminate.

Wherein the first resin layer and the second resin layer are "direct contact", and the direct contact does not pass through the third substance as a connecting medium layer (for example, an adhesive) because when the first resin layer is When a dielectric layer is present between the second resin layers, the optical properties of the light-diffusing laminate are deteriorated because of poor UV resistance or poor thermal stability of the dielectric layer. Moreover, direct contact is produced, in particular, by co-extrusion of a co-extrusion molding apparatus having a profiled die, whereby the process can be simplified.

The specific methods for producing the microlens layer of the present invention are as follows: (a) the microlens layer and the surface have a resin sheet laminate which is opposite to the desired lens shape, and after the resin sheet is peeled off, the surface of the microlens layer is formed. The shape you want.

(b) Injecting a molten resin into a mold having a shape opposite to the surface of the desired microlens layer, and then injection molding.

(c) The resin sheet is heated and then pressed in the mold and the metal sheet to form a desired shape.

(d) Between the roller having the opposite shape to the surface of the desired microlens layer and the other roller, the desired shape can be extruded through the molten resin sheet.

(e) applying a UV curable resin (or IR hardening resin) on the laminate, pressing the roller having the reverse shape of the surface of the microlens layer to form a desired shape on the uncured UV curable resin (or IR hardening resin) , UV hardening (or IR hardening).

(f) replacing the aforementioned UV curable resin with an EB (electron beam) hardening resin.

(g) A BEF (brightness enhancing film) is adhered with an adhesive.

The strip-shaped hollow chamber is a plurality of closed patterns extending parallel to each other, and the cross-section is a closed pattern formed by a line segment of a curve and/or a line segment of a straight line, such as a quadrangle, a polygon, a circle, an ellipse, and a semicircle. Etc. Among them, a polygon is preferred, and a quadrangle is preferred. The section of the strip-shaped hollow chamber may be a straight line segment or a downward recess (a depression from the microlens layer toward the first resin layer) near a first side of the microlens layer. Moreover, the strip-shaped hollow chamber may have another shape, that is, a first side adjacent to the microlens layer and a second side spaced apart from the first side and away from the microlens layer. At least one of the first and second sides is a non-linear line segment selected from a curve or a zigzag line, and the aforementioned curve may be, for example, a circular arc segment or a wavy segment.

A first straight line and a second straight line respectively perpendicularly passing through the leftmost end and the rightmost end thereof and parallel to each other are defined on each of the strip-shaped hollow chambers, and the distance between the adjacent two first straight lines is a, and each strip is hollow For the chamber, the distance between the first straight line and the second straight line is b, where 1>b/a≧0.5, and 1>b/a≧0.9 is preferred, and 1>b/a≧0.99 is optimal. The high brightness and light diffusibility of the present invention can be achieved by various designs of the above-mentioned strip-shaped hollow chambers.

The resin, the thickness and the components which can be added for each layer are as follows: (1) The thickness of the first resin layer is 0.5 to 15.0 mm, preferably 1.0 to 8.0 mm, and most preferably 1.3 to 4.0 mm. The material is mainly a resin and may additionally add an additive, and the resin is preferably selected from the group consisting of polycarbonate (PC), polystyrene (PS), polymethyl methacrylate (PMMA), and methyl methacrylate. - Styrene (MS) resin. When 100 parts by weight of the resin is taken, 0.2 to 15 parts by weight of a light diffusing agent is added, and 0.01 to 0.1 parts by weight of an antioxidant, 0.02 to 15 parts by weight of an ultraviolet absorber, and 0 to 0.1 parts by weight of fluorescent light may be added as needed. Agent.

(2) The thickness of the second resin layer is 0.5 to 15.0 mm, preferably 0.5 to 8.0 mm, most preferably 1.0 to 6.0 mm, and the resin is preferably selected from the group consisting of PMMA, MS, and acrylonitrile-styrene (AS). . 100 parts by weight of the resin is taken, and 0 to 15 parts by weight of the ultraviolet absorber may be added as needed.

(3) The thickness of the protective layer is 0.001 to 0.5 mm, preferably 0.01 to 0.3 mm, and most preferably 0.03 to 0.15 mm. The material is a resin and an additive, and the resin is 100 parts by weight and is preferably selected from the group consisting of PMMA, MS, AS, and polyethylene terephthalate (PET). Further, it is necessary to add 0 to 30 parts by weight of a light diffusing agent, 0.01 to 0.1 part by weight of an antioxidant, 0.02 to 15 parts by weight of an ultraviolet absorber, and 0 to 0.1 part by weight of a fluorescent agent.

Furthermore, the first resin layer, the second resin layer and optionally the protective layer of the present invention may be used in addition to polycarbonate: polycarbonate, polystyrene (PS), polymethyl methacrylate. In addition to ester (PMMA), methyl methacrylate-styrene (MS), acrylonitrile-styrene (AS), it is also possible to use: cyclo-olefin copolymer, polyolefin copolymer (such as poly -4-methylpentene-1), polyethylene terephthalate (PET), polyester, polyethylene, polypropylene, polyvinyl chloride, ionomer, and the like.

Wherein, the second resin layer of the present invention has transparency, so when a resin is selected, a transparent resin is required, that is, a light transmittance of a resin plate of 3.175 mm thick needs to be 85% or more. In order to achieve the effect of the present invention in the second resin layer, it is not preferable to contain more than 0.1% by weight of the light diffusing agent, and preferably no light diffusing agent.

As the light-diffusing agent, for example, inorganic fine particles such as BaSO4, TiO2, or the like, or organic fine particles such as polystyrene resin, (meth)acrylic resin, enamel resin or silicone rubber are used, and organic fine particles are preferable. The organic microparticles are preferably more bridging organic microparticles, and are preferably organic microparticles of a bridged (meth)acrylic resin or an anthracene resin. It is particularly suitable for, for example, a partially bridged methyl methacrylate-based polymer microparticle poly(butyl acrylate) core/poly(methyl methacrylate) outer shell polymer having a rubbery ethylene content The core/shell type polymer of the core and outer shell of the polymer, and the terpene oxyalkylene resin.

The average particle diameter of the light diffusing agent is 0.1 to 30 μm, preferably 0.5 to 20 μm, and particularly suitable for 1 to 10 μm. The average particle diameter of the transparent fine particles is a number average particle diameter measured by a particle counting method.

The amount of the light diffusing agent used is 0.2 to 15 parts by weight based on 100 parts by weight of the first resin layer having a light diffusing function, and is particularly preferably 0.5 to 5 parts by weight. When the amount of the light diffusing agent used is less than 0.2 parts by weight, there is a problem that the light diffusibility is insufficient, and the light source can be seen and penetrated. On the other hand, when the amount of the light diffusing agent used exceeds 15 parts by weight, the light transmittance is lowered and the luminance is deteriorated.

The amount of the light diffusing agent used is 0 to 30 parts by weight based on 100 parts by weight of the protective layer, and is particularly preferably 5 to 25 parts by weight. When the amount of the light diffusing agent used exceeds 30 parts by weight, the light transmittance is lowered and the luminance is deteriorated.

The above-mentioned ultraviolet absorber is added for the purpose of improving weather resistance and blocking harmful ultraviolet rays. The ultraviolet absorber such as 2,2'-dihydroxy-4-methoxybenzophenone benzophenone-based ultraviolet absorber, 2-(4,6-diphenyl-1,3,5-three Triazine-based UV absorber of pyrazin-2-substituted)-5-hexylhydroxyphenol, 2-(2H-benzotriazol-2-substituted)-4-methylphenol, 2-(2H-benzo Triazol-2-substituted)-4-trioctylphenol, 2-(2H-benzotriazol-2-substituted)-4,6-bis(1-methyl-1-phenylethyl) Phenol, 2-(2H-benzotriazol-2-substituted)-4,6-bis-third amyl phenol, 2-(5-chloro-2H-benzotriazol-2-substituent) 4-methyl-6-tert-butylphenol, 2-(5-chloro-2H-benzotriazol-2-substituted)-2,4-tert-butylphenol and 2,2'- Benzotriazole-based ultraviolet absorber such as methylene bis[6-(2H-benzotriazol-2-substituted)-4-(1,1,3,3-tetramethylbutyl)phenol] .

And preferably 2-(2-hydroxy-5-tolyl)benzotriazole, 2-(2-hydroxy-5-trioctylphenyl)benzotriazole, 2-(2-hydroxy-3, 5-diisopropylbenzene)phenylbenzotriazole, 2-(2-hydroxy-3-tert-butyl-5-tolyl)-5-chlorobenzotriazole, 2,2'-methylene Bis[4-(1,1,3,3 tetramethylbutyl)-6-(2H-benzotriazol-2-substituted)phenol], 2-[2-hydroxy-3-(3, 4,5,6-Tetrahydrophthalene imine methyl)-5-methylphenyl]benzotriazole. Among them, 2-(2-hydroxy-5-trioctylphenyl)benzotriazole, 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl) More preferably, the -6-(2H-benzotriazol-2-substituted)phenol is used alone or in combination of two or more.

The fluorescent agent used in the present invention is used to improve the color tone of a synthetic resin or the like to white or blue-white, such as a stilbene type, a benzimidazole type, a benzoxazole type, or a phthalimide type. , rose red, coumarin, oxazole compounds, and the like.

The types of antioxidants are, for example, phenolic antioxidants, thioether antioxidants, and phosphorus antioxidants. Representative phenolic antioxidants are: octadecyl (3,5-bis-tert-butyl-4-hydroxyphenyl)-propionate, triethylene glycol bis[3-(3-third butyl) 5--5-methyl-4-hydroxyphenyl)propionate], tetrakis[methylene-3-(3,5-bis-tert-butyl-4-hydroxyphenyl)propionate]methane, 2 -T-butyl-6-(3-tert-butyl-2-hydroxy-6-methylbenzyl)-4-methylphenyl acrylate, 2,2'-methylene-bis (4 -methyl-6-tert-butylphenol), 2,2'-thiobis(4-methyl-6-tert-butylphenol), 2,2'-thio-diethylene-double [ 3-(3,5-bis-tert-butyl-4-hydroxyphenyl)propionate], 2,2'-ethylenediamine-bis[ethyl-3-(3,5-bis-third Butyl-4-hydroxyphenyl)propionate] and the like.

Representative thioether antioxidants are: distearyl thiodipropionate, dipalmitosulfur dipropionate, pentaerythritol-tetrakis-(β-dodecyl-thiopropionate) , dioctadecyl sulfide, and the like.

Phosphorus-based antioxidants are phosphite antioxidants or phosphate antioxidants, and are typically represented by tris(nonylphenyl) phosphite, dodecyl phosphite, and cyclic neopentane tetrahydronaphthalene. Bis(octadecylphosphite), 4,4'-butylidene bis(3-methyl-6-t-butylphenyl-bistridecylphosphite), three (2,4) -T-butylphenyl)phosphite, tetrakis(2,4-t-butylphenyl)-4,4'-extended biphenyl phosphate, 9,10-dihydro-9-oxo-10 - Phosphate phenoxy-10-oxygen and the like.

The resin used in the microlens layer is not particularly limited, and for example, a resin such as PET, polyethylene naphthalate, acrylic resin, PC, PS, or polyolefin may be selected. (polyolefin), cellulose acetate, PVC, and the like.

The above and other technical contents, features and effects of the present invention will be apparent from the following detailed description of the preferred embodiments and the accompanying drawings. Before the present invention is described in detail, it is noted that in the following description, similar elements are denoted by the same reference numerals.

Referring to Figures 1, 2 and 3, the light diffusing laminate of the present invention can be produced by co-extruding a co-extruding forming device 6 having a profiled extrusion die 611, and the light diffusing laminate can be used for backlighting of a liquid crystal display. In the module, but not limited thereto, the light diffusion laminate comprises: a protective layer 3 close to the light source 7, a first resin layer 1 on the protective layer 3, and a first resin. The second resin layer 2 on the layer 1 has a microlens layer 4 on the second resin layer 2 and having a plurality of microlens portions 41, and a plurality of strip-shaped hollow chambers 5 extending in parallel with each other.

The co-extrusion forming device 6 comprises at least two extruding machines 61, and the extruding machine 61 can use a uniaxial extruding machine or a two-axis extruding machine, and the special-shaped ejecting die 611 is configured to set a desired specific shape as needed. In the case of a lip, the co-extrusion is performed by pouring the raw material resin from the inlet portion 612 via two (or three or three or more) extruders 61, and after the raw material resin is heated, it is melted and kneaded while passing through the lip. The profiled die 611 is forced out and solidified by sizing cooling. The process is to form a desired shape inside the lip, which is directly introduced into the vacuumed sizing device after being discharged from the die, thereby obtaining a resin plate of a specific configuration.

Therefore, the present invention is capable of extruding the first resin layer 1, the second resin layer 2, and optionally the protective layer 3 of the present invention by resin extrusion by a profiled extrusion die 611 having a multi-layer design. The die 611 is formed and manufactured. In addition, it is also possible to perform surface treatment through a roller (not shown), for example, as a fine structure of surface irregularities (for example, forming the microlens portion 41 of the microlens layer 4), or as a flattening of the mold layer. Processing and so on.

[Example 1]

The material of the protective layer 3 of the present embodiment is mainly a polymethyl methacrylate resin, and the first resin layer 1 is 3 parts by weight of the organic fine particle light diffusing agent mixed with the cerium resin in 100 parts by weight of the polycarbonate resin, and the second The resin layer 2 is a polymethyl methacrylate resin. The molding method is a co-extrusion forming device 6 using a three-layer hollow plate, the cylinder temperature is maintained at 200 to 250 ° C, the mold temperature is 240 to 260 ° C, and the vacuum degree of the degassing portion is 20 mmHg, and the shape of the lip having the quadrilateral parallel is used. The die 611 is pushed out, and the discharge amount of the material for molding the first resin layer 1, the second resin layer 2, and the protective layer 3 is adjusted, and the molding is performed together. Finally, the surface of the second resin layer 2 is coated with UV-curing acrylic. The resin is used to form a microlens layer 4 in the shape of a crucible, and the apex angle θ of each of the microlens portions 41 of the microlens layer 4 is 90°.

The overall thickness of the light-diffusing laminate of the present embodiment is about 3 mm, wherein the thickness of the protective layer 3, the first resin layer 1, the second resin layer 2, and the microlens layer 4 are 0.1 mm, 2.0 mm, and 0.8, respectively. Mm, 25 μm. The measurement of the apex angle θ, the height of the 微-shaped microlens layer 4 and the thickness of the laminated layers 1, 2, and 3 is an optical microscope using a Nikon model SMZ1500 115 with a magnification of 1 to 115 times (adjustable). To measure. The strip-shaped hollow chambers 5 are surrounded by the first resin layer 1 and the second resin layer 2, have a rectangular cross section and a height of 1 mm, and each include a first side 51 adjacent to the microlens layer 4. And a second side 52 spaced from the first side edge 51 away from the microlens layer 4. The positions of the first side edges 51 are not lower than the interfaces of the first and second resin layers 1 and 2.

A first straight line L1 and a second straight line L2, which are vertically parallel to each other and parallel to each other, are defined on each of the hollow chambers 5. The distance a between the adjacent two first straight lines L1 of the present embodiment is 5.1 mm, for each strip-shaped hollow chamber 5, the distance b between the first straight line L1 and the second straight line L2 is 5 mm, and b/a is 0.98.

Referring to FIG. 4, the section of the strip-shaped hollow chamber 5 may also be a polygon, for example, a hexagon, wherein the distance between the adjacent two first straight lines L1 is a, and the first straight line L1 and the second The distance of the straight line L2 is b.

Referring to FIG. 5, the second side 52 of the strip-shaped hollow chamber 5 can also be designed as a non-horizontal straight line, so that the second side 52 is inclined, so that one end is close to the microlens layer 4, and one end is far away. The microlens layer 4.

The optical properties such as total light transmittance, luminance, and light diffusivity measured by the light-diffusing laminated sheet of Example 1 are shown in Table 1, and will be described later in comparison with Comparative Examples.

[Embodiment 2]

Referring to Fig. 3, the second embodiment of the light-diffusing laminate of the present invention is different from the first embodiment in that the light diffusing agent in the first resin layer 1 of the second embodiment is used in an amount of 1 part by weight.

[Embodiment 3]

Referring to FIG. 6, the third embodiment of the light-diffusing laminated board of the present invention is different from the first embodiment in that the thickness of the protective layer 3, the first resin layer 1 and the second resin layer 2 of the third embodiment are respectively 0.05 mm. 1.5 mm and 1.3 mm, and the strip-shaped hollow chamber 5 of the third embodiment is surrounded only by the second resin layer 2 without contacting the first resin layer 1.

[Embodiment 4]

Referring to FIG. 6, the fourth embodiment of the light-diffusing laminated board of the present invention is different from the third embodiment in that the light diffusing agent in the first resin layer 1 of the fourth embodiment is used in an amount of 1 part by weight, and the protection of the fourth embodiment is used. The thickness of the layer 3, the first resin layer 1 and the second resin layer 2 are 0.1 mm, 1.5 mm, and 1.3 mm, respectively.

[Embodiment 5]

Referring to FIG. 7, the fifth embodiment of the light-diffusing laminated board of the present invention is different from the fourth embodiment in that the second side 52 of the strip-shaped hollow chamber 5 of the present embodiment is a circular arc segment curved upward.

Referring to Figures 8, 9, and 10, in addition, the second side 52 may be designed as a horizontal straight line and the first side 51 may be designed as a circular arc segment of a downward arc (Fig. 8). Alternatively, the first side 51 is a horizontal straight line, and the second side 52 is serrated (see FIGS. 9 and 10). It should be noted that the implementation is not limited by the arc curve and the sawtooth pattern of the form.

Referring to FIGS. 11 and 12, the microlens layer 4 may be formed into a plurality of dome-shaped microlens portions 41, and the microlens portions 41 may also have the same curvature of curvature (FIG. 11), or It is an arc convex with different curvatures (Fig. 12). That is, as long as the structure of the microlens layer 4 is made, a light collecting effect of concentrating the emitted light can be generated, which is within the scope of protection of the present invention.

[Comparative Example 1]

Referring to FIG. 13, the materials and processes of the layers of the first embodiment are the same as those of the first embodiment, except that the strip-shaped hollow chambers are omitted in the first comparative example, and the total thickness of the laminated sheets is about 2 mm, and the protection thereof is protected. The thickness of the layer 3, the first resin layer 1 and the second resin layer 2 are 0.1 mm, 1.9 mm and 0.1 mm, respectively.

[Comparative Example 2]

Referring to FIG. 13, the materials and processes of the layers of Comparative Example 2 are the same as those of the second embodiment, except that the strip-shaped hollow chambers are omitted in Comparative Example 2, and the total thickness of the laminated sheets is about 2 mm, and the protection thereof is protected. The thickness of the layer 3, the first resin layer 1 and the second resin layer 2 are 0.1 mm, 1.9 mm and 0.1 mm, respectively.

[Comparative Example 3]

Referring to FIG. 14, the material of each layer of Comparative Example 3 is the same as that of the third embodiment, except that the strip-shaped hollow chamber 5 of Comparative Example 3 is completely covered by the first resin layer 1 and not with the second. The resin layer 2 is in contact, and the thicknesses of the protective layer 3, the first resin layer 1 and the second resin layer 2 are 0.1 mm, 2.8 mm, and 0.1 mm, respectively.

[Comparative Example 4]

Referring to FIG. 14, the material of each layer of Comparative Example 4 is the same as that of the fourth embodiment, except that the strip-shaped hollow chamber 5 of Comparative Example 4 is completely covered by the first resin layer 1 and not with the second. The resin layer 2 is in contact, and the thicknesses of the protective layer 3, the first resin layer 1 and the second resin layer 2 are 0.1 mm, 2.0 mm, and 0.8 mm, respectively.

Table 1 is a list of measurement results of total light transmittance, front luminance, and light diffusibility of Examples 1 to 5 and Comparative Examples 1 to 4 of the present invention. Among them: (1) Total light transmittance: It was measured in accordance with JIS K-7361 using Haze meter NDH-2000 manufactured by Nippon Denshoku Industries Co., Ltd.

(2) Front luminance: The light diffusion laminate is placed on the backlight module for the direct type liquid crystal display, and the light source is lit. The luminance meter CA-made by Melody is placed at a distance of 3 cm from the light diffusion laminate. 210 measures the luminance.

(3) Light diffusivity: The light-diffusing laminated board is placed on the backlight module for the direct-type liquid crystal display, and the light source is lit, and the light source cannot be seen through the "○" mark, and the light source can be seen through. It is indicated by the "×" mark.

It can be seen from Table 1 that the first and second embodiments of the present invention have higher luminance and good light diffusibility than the first and second comparisons of the strip-shaped hollow chambers 5 which are not provided. On the other hand, in Comparative Examples 3 and 4, although the strip-shaped hollow chamber 5 is provided, the strip-shaped hollow chamber 5 is located only in the first resin layer 1, so that the light diffusion effect is poor and the luminance is not good.

In contrast, in the first and second embodiments, the strip-shaped hollow chamber 5 is disposed between the first and second resin layers 1 and 2, and the strip-shaped hollow chambers 5 of the third, fourth and fifth embodiments are only subjected to the second resin layer. 2 coated, and both can achieve high brightness and good light diffusivity. Therefore, the configuration of the microlens layer 4 of the present invention, the strip-shaped hollow chamber 5, and the position of the strip-shaped hollow chamber 5 and the first and second resin layers 1, 2 can surely achieve the object of the present invention.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent.

1. . . First resin layer

2. . . Second resin layer

3. . . The protective layer

4. . . Microlens layer

41. . . Microlens section

5. . . Strip-shaped hollow chamber

51. . . First side

52. . . Second side

6. . . Co-injection forming device

61. . . Extruder

611. . . Alien extrusion die

612. . . Entrance

7. . . light source

L1. . . First straight line

L2. . . Second straight line

a, b. . . distance

θ. . . Top angle

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view showing a first preferred embodiment of a light diffusing laminate of the present invention; Fig. 2 is a schematic view of a device for manufacturing a coextruded forming apparatus for a light diffusing laminate of the present invention; and Fig. 3 is a cross-sectional view showing the present A first preferred embodiment and a second preferred embodiment of the present invention are shown in FIG. 4, which is a cross-sectional view showing a strip-shaped hollow chamber of another form of the light-diffusing laminate; FIG. 5 is a cross-sectional view. A strip-shaped hollow chamber of a different form of the light-diffusing laminate is shown; FIG. 6 is a cross-sectional view showing a third preferred embodiment and a fourth preferred embodiment of the light-diffusing laminate of the present invention; A cross-sectional view showing a fifth preferred embodiment of the light diffusing laminate; FIG. 8 is a cross-sectional view showing a first side of the strip-shaped hollow chamber being a circular arc curve; and FIG. 9 is a cross-sectional view showing the A second side of the strip-shaped hollow chamber is a zigzag line; FIG. 10 is a cross-sectional view showing the second side being another form of zigzag line; and FIG. 11 is a cross-sectional view showing the light diffusing laminate of the present invention Another form of microlens layer; 12 is a cross-sectional view showing still another different form of microlens layer of the light diffusing laminate; FIG. 13 is a cross-sectional view of Comparative Example 1 and Comparative Example 2; and FIG. 14 is a cross-sectional view of Comparative Example 3 and Comparative Example 4.

1. . . First resin layer

2. . . Second resin layer

3. . . The protective layer

4. . . Microlens layer

41. . . Microlens section

5. . . Strip-shaped hollow chamber

51. . . First side

52. . . Second side

7. . . light source

L1. . . First straight line

L2. . . Second straight line

a, b. . . distance

θ. . . Corner

Claims (27)

A light diffusing laminate comprising: a first resin layer having a light diffusing function, a second resin layer disposed in direct contact with the first resin layer and having transparency, and a micro layer disposed on the second resin layer a lens layer, and a plurality of strip-shaped hollow chambers surrounded by the first resin layer and the second resin layer; and defining a first straight line that is vertically passed through the leftmost and rightmost ends of each of the strip-shaped hollow chambers and parallel to each other And a second straight line, the distance between the two adjacent first straight lines is a, the distance between the first straight line and the second straight line passing through the same strip-shaped hollow chamber is b, and 1>b/a≧0.50. The light-diffusing laminate according to claim 1, wherein the direct contact between the first resin layer and the second resin layer is produced by co-extrusion. The light-diffusing laminate according to the second aspect of the invention, wherein the co-extrusion means is produced by co-extruding the die by a profiled die. The light-diffusing laminate according to claim 1, wherein the microlens layer has a light collecting function. The light-diffusing laminate according to claim 1, wherein the microlens layer is a micro-lens layer or a convex micro-lens layer. The light-diffusing laminated board according to claim 1, wherein the strip-shaped hollow chambers are formed to extend in parallel with each other. The light-diffusing laminated board according to claim 1, wherein the section of the strip-shaped hollow chamber is a closed shape formed by a line segment of a curve and/or a line segment of a straight line. The light-diffusing laminate according to claim 1, wherein the strip-shaped hollow chamber has a polygonal cross section. The light-diffusing laminated board according to the invention of claim 8, wherein the strip-shaped hollow chamber has a quadrangular cross section. The light-diffusing laminate according to claim 7, wherein the strip-shaped hollow chamber has a first side adjacent to the microlens layer and being a straight line. The light diffusing laminate according to claim 1, wherein the strip-shaped hollow chamber has a first side adjacent to the microlens layer, and a second spaced apart from the first side and away from the microlens layer. At the side, at least one of the first and second sides is a non-linear line segment. The light-diffusing laminate according to claim 11, wherein the non-linear line segment is selected from a curve or a zigzag line. The light-diffusing laminate according to claim 1, wherein 1>b/a≧0.90. The light-diffusing laminate according to the first aspect of the invention, wherein the first resin layer having a light diffusing function contains a light diffusing agent. The light-diffusing laminated board according to any one of claims 1 to 14 is a light-diffusing laminated board for a backlight module of a liquid crystal display. A light diffusing laminate comprising: a first resin layer having a light diffusing function, a second resin layer disposed in direct contact with the first resin layer and having transparency, and a micro layer disposed on the second resin layer Lens layer, and a plurality of layers in the second tree a strip-shaped hollow chamber in the lipid layer and surrounded by the second resin layer; and a first straight line and a second straight line defining a leftmost end and a rightmost end which are respectively vertically passed through each of the strip-shaped hollow chambers and parallel to each other The distance between the two adjacent first straight lines is a, and the distance between the first straight line and the second straight line passing through the same strip-shaped hollow chamber is b, and 1>b/a≧0.50. The light-diffusing laminate according to claim 16, wherein the direct contact between the first resin layer and the second resin layer is produced by co-extrusion. The light-diffusing laminate according to claim 17, wherein the co-extrusion is produced by co-extruding the die by a profiled die. The light-diffusing laminate according to claim 16, wherein the microlens layer has a light collecting function. The light-diffusing laminate according to claim 16, wherein the strip-shaped hollow chambers are formed to extend parallel to each other. The light-diffusing laminated board according to claim 20, wherein the section of the strip-shaped hollow chamber is a closed shape formed by a line segment of a curve and/or a line segment of a straight line. The light-diffusing laminate according to claim 21, wherein the strip-shaped hollow chamber has a first side adjacent to the microlens layer and being a straight line. The light diffusing laminate according to claim 16, wherein the strip-shaped hollow chamber has a first side adjacent to the microlens layer, and a second spaced apart from the first side and away from the microlens layer. At the side, at least one of the first and second sides is a non-linear line segment. The light-diffusing laminate according to claim 23, wherein the non-linear segment is selected from a curve or a zigzag line. The light-diffusing laminate according to claim 16, wherein 1>b/a≧0.90. The light-diffusing laminate according to claim 16, wherein the first resin layer having a light diffusing function contains a light diffusing agent. The light-diffusing laminated board according to any one of claims 16 to 26, which is a light-diffusing laminated board for a backlight module of a liquid crystal display.