KR20080094989A - Optical multi-layer film for multi-function using micro-patterning - Google Patents

Abstract

A multi-functional optical multi-layer film using micro-patterning is provided to obtain a light-diffusion effect without using a light diffusion layer including an additional light-diffusing agent. A multi-functional optical multi-layer film includes a base material layer(100), a prism sheet(200), and a pattern layer(300). The prism sheet is stacked on an upper surface of the base material layer. A plurality of prism parts(210) are protruded from one surface of the prism sheet. The pattern layer is stacked on a lower surface of the base material layer. The pattern layer is composed of a first binder resin(310) which is processed by using a micro-patterning method. The pattern layer includes a plurality of beads included in the inside of the first binder resin.

Description

Multifunctional optical laminated film using micro patterning {OPTICAL MULTI-LAYER FILM FOR MULTI-FUNCTION USING MICRO-PATTERNING}

1 is an exploded perspective view of a general backlight unit.

2A and 2B are schematic partial cross-sectional views of one embodiment of a multifunctional optical laminated film using micro patterning according to the present invention.

3A-3D are schematic partial cross-sectional views of another embodiment of a multifunctional optical laminated film using micro patterning according to the present invention.

4 is a schematic partial cross-sectional view of another embodiment of a multifunctional optical laminated film using micro patterning according to the present invention.

※ Explanation of code for main part of drawing

100: base material layer 200: prism sheet

210: prism portion 212, 214: bead

300: pattern layer 310: first binder resin

312 Bead 400 Light Diffusion Layer

410: second binder resin 412: light diffusing agent

The present invention relates to an optical laminated film in a backlight unit of a liquid crystal display (LCD), and more particularly, to multi-function optical using micro patterning so that light condensing and diffusion can be simultaneously implemented to compensate for a viewing angle. It relates to a laminated film.

The backlight unit emits light from the back of a liquid crystal display (LCD), and image information is made in the liquid crystal display by using white light supplied by the backlight unit.

The structure for a general backlight unit is shown in FIG. As shown in FIG. 1, the backlight unit includes a light source 4, a light guide plate 5 for guiding the light emitted from the light source 4 to a display unit (not shown), and the light guide plate 5. ) And an optical sheet (6, 7, 8) disposed between the display unit (not shown) to improve the efficiency of light emitted from the light guide plate (5), and the light generated from the light source is exposed to the outside The reflective plate 2, the light source reflecting plate 3, and the mold frame 1 are disposed on the lower portion of the light guide plate to be prevented, and the reflecting plate 2, the light source reflecting plate 3, and the light guide plate are formed on the mold frame 1. (5), the optical sheets 6, 7, 8 are sequentially stacked.

Looking at the optical sheet (6, 7, 8) in detail, the optical sheet (6, 7, 8) is formed by sequentially stacking the base layer 6, the prism sheet (7) and the protective sheet (8) As the substrate layer 6 scatters the light emitted from the light guide plate 5 and is incident to the display unit (not shown), the substrate layer 6 serves to uniform the luminance distribution of the light, and the prism sheet 7 has an upper portion. A prism having a triangular cross-sectional shape is repeatedly formed on the surface, and the light diffused by the substrate layer 6 is focused in a direction perpendicular to the plane of the display unit (not shown) to increase luminance. Accordingly, the light passing through the prism sheet 7 almost passes perpendicular to the plane of the display unit (not shown) to have a uniform luminance distribution. In addition, the protective sheet 8 is laminated on the prism sheet 7 to protect the surface of the prism sheet 7 and to uniformly distribute the light incident through the prism sheet 7. In order to diffuse the light.

However, although the optical sheets 6, 7, and 8 allow the light to be diffused by the light diffusing agent contained in the base layer 6, not only the light diffusing agent should be used but also the light diffusion efficiency is not high. The light condensed by the prism sheet 7 has a problem that the brightness is increased but the viewing angle is narrowed, and the optical sheets 6, 7, and 8 having the functions of the sheets are used independently. have.

Accordingly, an object of the present invention is to provide an optical laminated film using micro-patterning so that the light diffusion effect and the light condensing effect can be simultaneously realized in one sheet.

In addition, an object of the present invention is to provide an optical laminated film using micro patterning that can be simultaneously focused and diffused light in the prism sheet to improve the brightness by the addition of the light diffusing agent and to compensate for the viewing angle.

The above object of the present invention,

A pattern layer comprising a substrate layer, a prism sheet laminated on an upper surface of the substrate layer and having a plurality of prism portions protruded on one surface thereof, and a first binder resin laminated on a lower surface of the substrate layer and having one surface micro patterned; It is achieved by providing a multifunctional optical laminated film using micro patterning, characterized in that it comprises.

According to a preferred feature of the present invention, the pattern layer further includes a plurality of beads contained in the first binder resin.

According to a further preferred feature of the present invention, a plurality of beads are contained in the prism sheet.

According to a further preferred feature of the invention, the prism portion of the prism sheet is coated on the surface with a plurality of beads.

According to a further preferred feature of the present invention, the first binder resin is made of any one of a UV curable urethane acrylic binder, a UV curable epoxy binder or a UV curable binder including silicone.

According to a further preferred feature of the present invention, further comprising a light diffusing layer laminated between the base layer and the prism sheet, and having a second binder resin and a plurality of light diffusing agents contained in the second binder resin. do.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, this is only to describe in detail enough to be able to easily carry out the invention by those skilled in the art, which does not mean that the technical spirit and scope of the present invention is limited.

First, in describing the preferred embodiment of the present invention, the same reference numerals will be used for the components having the same technical features.

2A and 2B are schematic partial cross-sectional views of one embodiment of a multifunctional optical laminated film using micro patterning according to the present invention. As shown in FIGS. 2A and 2B, the multifunctional optical laminated film using micro patterning includes a substrate layer 100, a prism sheet 200, and a pattern layer 300.

The base layer 100 is a transparent film through which light can be transmitted. In general, polyethersulphone (PES), polyacrylate (PAR), polyetherimide (PEI), polyethylene naphthalate ( polyethyelenen napthalate (PEN), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyallylate, polyimide, polycarbonate (PC), cellulose triacetate (TAC) ), And may include at least one of cellulose acetate propinonate (CAP), and particularly preferably made of polyethylene terephthalate (PET). The base layer 100 should be excellent in adhesion to the first binder resin 310 of the prism sheet 200 or the pattern layer 300, the transmittance of the light incident from the rear side of 90% or more of the surface Smoothness should be uniform so that there is no variation in luminance. In addition, it is preferable that the thickness of the base layer 100 is 50 to 250 μm, but if the thickness is less than 50 μm, the handleability is poor in the manufacturing process, and if the thickness exceeds 250 μm, the substrate layer 100 has a structure contrary to the recent trend of thinning of the LCD module.

The prism sheet 200 is stacked on the upper surface of the base layer 100 to collect light passing through the base layer 100 to increase the brightness of the light. A plurality of prism portions 210 protrude from one surface of the prism sheet 200, and light may be emitted by the prism portion 210 in a direction perpendicular to the LCD screen. As shown in FIGS. 2A and 2B, the prism unit 210 may be formed in a shape having a triangular cross section, but is not limited thereto and may be formed in various shapes such as a spherical shape or a lens shape. .

The pattern layer 300 is formed of a first binder resin 310 having one surface micro patterned, and is laminated on the bottom surface of the base layer 100. The pattern layer 300 is a micro patterning process of the first binder resin 310 is to help concealment by primarily scattering the light incident from the light guide plate (not shown). That is, when the contact surface of the light guide plate (not shown) and the first binder resin 310 are micro-patterned to form a regular or irregular pattern, refraction, scattering, or diffuse reflection of light incident from the light guide plate may occur, thereby diffusing light. It can be. In addition, the pattern layer 300 may be stacked between the base layer 100 and the light guide plate to prevent scratches. The micro patterning process may be a method such as sand blasting or photolithography, and the pattern of the first binder resin 310 formed by the micro patterning process may be formed into various shapes such as concave or convex. Can be. It may also be formed regularly, preferably as shown in Figures 2a and 2b irregularly. This irregular pattern can adjust the haze to adjust brightness, diffusion, viewing angle or hiding power. Meanwhile, the first binder resin 310 may be made of a material such as UV type urethane acrylic resin, epoxy resin, or acrylic resin including silicon, and the first binder resin 310 may have a self-healing function to absorb shocks. A binder having can be used.

On the other hand, since the first binder resin 310 is micro patterned, an anti-blocking property is imparted to the pattern layer 300. Blocking generally refers to a phenomenon in which the inner surfaces of the films stick to each other, and blocking may occur between the light guide plate (not shown) and the pattern layer 300 stacked on the upper surface of the light guide plate, and such blocking may cause operational difficulties. In addition, the interference pattern is generated due to the adhesion between the pattern layer 300 and the light guide plate. Therefore, when one surface of the first binder resin 310, that is, one surface in contact with the light guide plate is micro patterned, the blocking area between the first binder resin 310 and the light guide plate may be reduced and contact with the light guide plate may be minimized. It can be prevented. Therefore, in addition to the effect of diffusing light by the pattern layer 300, it is possible to obtain an effect of preventing blocking.

The first binder resin 310 preferably has a tensile modulus of 300 MPa or less, which is to prevent scratches caused by friction with the light guide plate (not shown). When the tensile modulus of elasticity of the first binder resin 310 is 300 MPa or less, the elastic modulus of the acrylic resin laminated on the conventional light guide plate may be lower than 900 to 1000 MPa, which may prevent scratching. Scratch occurrence can be prevented at the same time. Meanwhile, an antistatic agent may be added to the inside of the first binder resin 310 to prevent the generation of static electricity, or an antiblocking agent may be added to prevent blocking, and as the antiblocking agent, silica, which is a fine particle of an inorganic mineral material, may be added. , Diatomaceous earth, kaolin or talc may be used.

The first binder resin 310 is not particularly limited as long as the material has a tensile modulus of 300 MPa or less. 2-acryloxyethyl) isocyanurate-2-propenoic acid (Tris (2-acryloxyethyl) isocyanurate-2-Propenoic acid), (1-methylethylidene) bis (4,1-phenyleneoxy- (1-methlyethyliden) bis (4,1-phenyleneoxy-2,1-ethanediyloxy-2,1-ethanediyl) ester and 1-hydroxy- More preferably, it consists of a terpolymer of 1-hydroxy-cyclohexyl-phenyl ketone. The terpolymer may be a block copolymer or a random copolymer, and has a glass transition temperature (Tg) of about 52 ° C. and a number average molecular weight of about 4500.

On the other hand, the pattern layer 300, as shown in Figure 2b, preferably further comprises a plurality of beads (BEAD) 312 contained in the first binder resin 310, the beads 312 ) Is preferably made of an acryl, nylon or silicone compound. Therefore, the light is primarily diffused by the pattern of the first binder resin 310 formed by the micro patterning process, and the light is re-diffused by the beads 312 so that the light diffusion effect is double in the pattern layer 300. It is possible to obtain the light diffusion effect can be maximized. In addition, since the light diffusion effect may be obtained with the pattern layer 300, since the light diffusion layer may not be separately provided on the upper surface of the base layer 100, the thickness of the optical laminated film may be reduced, resulting in a slimming of the backlight unit. There is an advantage to this.

A process of transmitting light through the multifunctional optical laminated film using the micro patterning of FIGS. 2A and 2B is as follows. First, light emitted from a light source (not shown) and guided by a light guide plate (not shown) is incident to the pattern layer 300, and primarily due to the micropatterned pattern of the first binder resin 312. In the case where the beads 312 are contained therein, the light is re-diffused by the beads 312 to be incident to the base layer 100 in a uniform distribution. Then, the light passes through the transparent base layer 100 and is focused on the prism sheet 200 to be incident on the LCD screen in a state where the brightness is high to illuminate the screen.

3A-3D are schematic partial cross-sectional views of another embodiment of a multifunctional optical laminated film using micro patterning according to the present invention. As shown in FIGS. 3A to 3D, the multifunctional optical laminated film using micro patterning includes a substrate layer 100, a prism sheet 200, and a pattern layer 300.

Since the base layer 100 and the pattern layer 300 have the same technical features as the base layer 100 and the pattern layer 300 of the embodiment of the multi-functional optical laminated film using the micro-patterning according to the present invention described above, The description will be omitted. The prism sheet 200 also has the same general technical characteristics as the prism sheet 200 of the embodiment of the multifunctional optical laminated film using micro-patterning according to the present invention described above, but differs from including the beads 212 and 214 separately. There is.

That is, the prism sheet 200 is for condensing the light passing through the base layer 100 to increase the brightness, but the viewing angle of the light collected by the prism sheet 200 may be narrowed, in order to improve such a point, As shown in FIGS. 3A and 3B, the plurality of beads 212 may be contained in the prism sheet 200. The bead 212 provided in the prism sheet 200 diffuses from the pattern layer 300 and passes through the substrate layer 100 to re-diffuse light focused on the prism sheet 200 so that the viewing angle may be compensated. It plays a role. The bead 212 may include one bead 212 at a lower portion of each prism 210 of the plurality of prism portions 210, but is not limited thereto, and the plurality of beads 212 may be regularly or irregularly. It may be contained, and the bead 212 content may be appropriately adjusted to adjust the brightness and the viewing angle. On the other hand, since the friction resistance is increased by the inclusion of the beads 212 in the prism sheet 200, a protective sheet for protecting the prism sheet 200 is unnecessary.

In addition, the prism sheet 200, as shown in Figures 3c and 3d, it is preferable that the surface of the prism portion 210 is coated with a plurality of beads 214. The bead 214 also serves to re-diffuse light so that the viewing angle of the light passing through the prism sheet 200 can be secured, and the prism portion 210 is protected because the bead 214 is coated on the entire surface. As a result, a protective sheet for protecting the prism sheet 200 is unnecessary.

In the process of transmitting light through the multifunctional optical laminated film using the micro patterning of FIGS. 3A to 3D, first, light emitted from a light source (not shown) and guided by a light guide plate (not shown) is patterned ( The light is first diffused due to the micropatterned pattern of the first binder resin 312, and when the bead 312 is contained therein, the light is re-diffused by the bead 312 and uniformly. It enters into the base material layer 100 in one distribution. Then, the light passes through the transparent base layer 100 and is focused on the prism sheet 200, and is simultaneously diffused by the beads 212 and 214 to be incident on the LCD screen with high brightness and a wide viewing angle. Revealed.

4 is a schematic partial cross-sectional view of another embodiment of a multifunctional optical laminated film using micro patterning according to the present invention. The multifunctional optical laminated film using micro patterning includes a substrate layer 100, a prism sheet 200, a pattern layer 300, and a light diffusion layer 400.

The base layer 100, the prism sheet 200, and the pattern layer 300 are the base layer 100, the prism sheet 200, and the pattern of the embodiment of the multifunctional optical laminated film using the micro-patterning according to the present invention described above. Since the technical features of the layer 300 are the same, a description thereof will be omitted.

The light diffusion layer 400 serves to spread the light evenly on the entire LCD screen by scattering or refracting the incident light which is stacked on the upper surface of the base layer 100, and the second binder resin 410 and The light diffusing agent 412 included in the second binder resin 410 is provided.

The light diffusing agent 412 serves to diffuse the light so that the light can be diffused, and as shown in FIG. 4, the light diffusing agent 412 may be regularly aligned, and the plurality of light diffusing agents 412 may be regularly aligned. The light diffusing agent 412 may be randomly contained. The light diffusing agent 412 is methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, normal butyl methacrylate, normal butyl methyl methacrylate, acrylic acid, methacrylic acid, copolymers or terpolymers, and the like. Olefinic particles such as acrylic, polyethylene, polystyrene, and polypropylene, copolymers of acryl and olefin, and particles of homopolymer, and then organic particles such as multi-layered multicomponent particles coated with different monomers on the layer. May be used, preferably polymethylmethacrylate (PMMA) may be used.

In addition, the light diffusing agent 412 has a specific gravity of 1.0 to 1.2 g / cm 3 and a coefficient of variation for the particle size is preferably 15% or less, which is to maximize the light diffusion effect. Here, the coefficient of variation is defined as 'variation coefficient = (standard deviation ÷ mean) × 100', and in general, although the standard deviation is used as a method of expressing the scatter diagram, in the present invention, the mean value is compared with the mean value rather than the standard deviation. Regardless, the distribution coefficient of light diffuser can be controlled and the coefficient of variation can be applied to the process. As can be seen from the definition, the coefficient of variation means that the closer the value is to '0', the smaller the variation between particles is. When the coefficient of variation of the light diffusing agent 412 exceeds 15%, even if the thickness of the light diffusing layer 400 is the same as the thickness of the light diffusing agent 412 in the coating process of the initial light diffusing layer 400, the light diffusing agent Due to the wide particle size distribution between the agents 412, the light diffusing agent 412 particles may be laminated in multiple layers instead of a single layer, thereby reducing the light diffusion effect. In addition, the specific gravity of the light diffusing agent 412 is a matter to be considered in relation to the specific gravity of the solvent used. If the specific gravity is less than 1.0 g / cm 3, the specific gravity may be smaller than that of the solvent which can be used, resulting in poor dispersibility. It is difficult to manage the thickness distribution of the coating in the production process, and if it exceeds 1.2g / cm 3, since the sedimentation rate in the solvent is large, a process loss of frequent re-stirring in the coating process may occur, thus causing 1.0 to 1.2 g. In the case of having a specific gravity of / cm 3, the above problem can be solved.

In this case, the second binder resin 410 has a light transmittance and a light diffusion rate different according to a ratio of the light diffusing agent 412 contained therein. In order to show a high light transmittance and a light diffusion rate, light diffusion included in the resin The content of the agent 412 is preferably 40 to 140 parts by weight based on 100 parts by weight of the second binder resin 410. When the content is less than 40 parts by weight, light diffusing effect due to scattering is insufficient. This is because the transmittance may drop. On the other hand, the second binder resin 410 is advantageous to have good adhesion to the substrate layer 100, the second binder resin 410 is to add a curing agent to improve the physical properties, that is, heat resistance, wear resistance, adhesiveness Can be.

In the process of transmitting light through the multifunctional optical laminated film using the micro patterning of FIG. 4, first, light emitted from a light source (not shown) and guided by a light guide plate (not shown) is transferred to the pattern layer 300. As it is incident, it is primarily diffused due to the micropatterned pattern of the first binder resin 312, and when the beads 312 are contained therein, light is re-diffused by the beads 312 to provide a uniform distribution. It is incident on the base layer 100. Then, the light passes through the transparent base layer 100 and enters the light diffusing layer 400 and is secondarily diffused by the light diffusing agent 410 contained in the light diffusing layer 400. The light is incident on the LCD screen in the state of condensing on the light and the brightness is increased, thereby illuminating the screen.

As described above, according to the multifunctional optical laminated film using the micro patterning according to the present invention, one surface of the pattern layer under the substrate layer of the optical laminated film is micro patterned, so that even if there is no light diffusing layer containing a separate light diffusing agent, Since the diffusion effect can be obtained, the number of parts can be reduced and the thickness of the optical laminated film can be reduced.

In addition, since the beads are contained in the prism sheet or the surface of the prism sheet is coated with the beads, the light is concentrated at the same time as the prism sheet and diffused to secure a sufficient viewing angle of the light passing through the prism sheet.

In addition, since the prism sheet may be protected by the bead contained inside the prism sheet or the surface is coated with the beads, a separate protective sheet is unnecessary, thereby reducing the number of parts.

Claims (6)

Base layer; A prism sheet laminated on an upper surface of the substrate layer and having a plurality of prism parts formed on one surface thereof; And A multi-layered optical laminated film using micro patterning, comprising: a patterned layer laminated on a lower surface of the base layer and having one surface formed of a first binder resin subjected to micro patterning. The method of claim 1, The pattern layer is a multi-functional optical laminated film using micro patterning, characterized in that further comprises a plurality of beads contained in the first binder resin. The method according to claim 1 or 2, A multi-functional optical laminated film using micro patterning, characterized in that a plurality of beads are contained in the prism sheet. The method according to claim 1 or 2, The prism portion of the prism sheet is a multi-functional optical laminated film using micro patterning, characterized in that the surface is coated with a plurality of beads. The method according to claim 1 or 2, The first binder resin is a UV curable urethane acrylic binder, a UV curable epoxy binder, or a UV curable binder including any one of the silicone, characterized in that the multi-functional optical laminated film using micro-patterning. The method according to claim 1 or 2, A light diffusing layer stacked between the base layer and the prism sheet, the light diffusing layer having a second binder resin and a plurality of light diffusing agents contained in the second binder resin; Multifunctional optical laminated film.

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