KR20090034684A - The manufacturing method of optical film - Google Patents

Abstract

A method for manufacturing an optical film is provided to widen a viewing angle and to uniformize a light by irradiating a light coming from a light source positioned in a bottom of an optical film on a diffusion sheet. A part of a first resin(120) temporary cured on a mold(110) is removed. The resin is removed by an air knife(130). The air knife controls pressure and flow rate of a process line, and removes moisture from a surface of an object. The part of the first resin is removed by spaying an air of a fixed pressure on the first resin formed on the mold through the air knife. If the first resin temporary cured on a bottom of the air knife is passed, the first resin on the mold passing the air knife is to be a first prism part(125) having a triangle shape.

Description

Manufacturing Method of Optical Film

The present invention relates to a display, and more particularly to a method of manufacturing an optical film.

In recent years, as the society enters the information age in earnest, the display field that visually expresses various electrical signal information is rapidly developing. Various flat panel display devices (FPDs) have been introduced to quickly replace the existing cathode ray tube (CRT).

Specific examples of such a flat panel display include a liquid crystal display (LCD), a plasma display panel (PDP), a field emission display (FED), an electroluminescent display ( Electroluminescence Display Device (ELD), etc. The dual liquid crystal display device has a large contrast ratio and shows excellent characteristics in moving image display, and is currently being used most actively in the display screen, monitor, and TV field for notebooks.

The liquid crystal display device is a passive device using a backlight unit on the back of the substrate. The backlight unit is composed of a fluorescent lamp and various optical films. The optical film may collect or diffuse light emitted from the backlight unit. The optical film is formed on the base portion made of very fine prisms made of a polymer resin.

In using the display manufacturing process or the finished display, the prisms may be damaged or broken by external impacts. Therefore, research into an optical sheet that can have a high brightness while having a high brightness of the display is being actively conducted.

The problem to be solved by the present invention is to provide a manufacturing method of an optical film that is durable and can increase the brightness of the display.

Technical problems to be achieved by the present invention are not limited to the above-mentioned technical problems, and other technical problems not mentioned above will be clearly understood by those skilled in the art from the following description. Could be.

Method for manufacturing an optical film according to an embodiment of the present invention is a step of applying a first resin on a mold, temporarily curing the first resin, a first resin having a triangular cross section by removing a portion of the first resin Forming a prism portion, applying a second resin onto the first prism portion, curing the first resin and the second resin, and forming a second prism portion having a trapezoidal shape in cross section; The resin and the second resin may be different materials.

Also, part of the first resin can be removed by the air knife.

In addition, the first resin may be an acrylic resin having a molecular weight of 10000 or more.

In addition, the first resin may be any one of urethane acrylate (polyurethane acrylate) or poly butadiene.

In addition, the second resin may be any one of a bromine compound, a Floren compound, or a biphenyl compound.

In addition, the refractive index of the second prism portion may be higher than the refractive index of the first prism portion.

In addition, the refractive index of the first prism portion may be 1.46 to 1.53, and the refractive index of the second prism portion may be 1.54 to 1.65.

In addition, the elongation of the first prism portion may be greater than the elongation of the second prism portion.

In addition, the elongation of the first prism portion may be 20 to 300%.

In addition, the first prism portion may be equal to or greater than the pencil hardness B.

In addition, the height of the first prism portion may be 3 to 50% of the total height of the first prism portion and the second prism portion combined.

In addition, the ratio of the height of the first prism portion and the height of the second prism portion may be 1: 1 to 1:32.

The manufacturing method of the optical film according to an embodiment of the present invention has the effect of producing an optical film and to increase the durability and brightness of the display.

Specific details of other embodiments are included in the detailed description and the drawings. Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. Like reference numerals refer to like elements throughout.

Hereinafter, a method of manufacturing an optical film according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1A to 3B illustrate a method of manufacturing the first prism part 125 in the optical film according to the exemplary embodiment of the present invention.

1 to 2, FIG. 1B is a cross-sectional view taken along line II ′ of a mold 110 having the same shape as that of FIG. 1A for manufacturing an optical film.

First, the first resin 120 may be coated on the mold 110 having a triangular cross section.

The first resin 120 may be made of an acrylic polymer resin having a molecular weight of 10000 or more. Urethane acrylate (Polyethane Acrylate) or poly butadiene (Poly Butadiene) and the like, but is not limited thereto.

After applying the first resin 120 to an empty space of the mold 110 having a triangular shape, the first resin 120 may be temporarily cured. At this time, the first resin does not completely harden the first resin because a part of the first resin should be removed in the process described later. That is, it is possible to adjust the environment in which the first resin is cured so that only a portion is removed by an air knife or the like during the manufacturing process. Depending on the environment in which the first resin 120 can be cured, UV (ultra violet) or heat may be applied.

3A to 3B, a portion of the first resin 120 temporarily hardened on the mold 110 may be removed. At this time, the first resin 120 may be removed by an air knife 130, but is not limited thereto.

Air knife 130 is a mechanism that is applied to the removal of water, drying (hot air), cooling on the surface of the object by adjusting the pressure and flow rate in the process line. In the present invention, a portion of the first resin 120 may be removed by injecting a predetermined pressure of air into the first resin 120 formed on the mold 110 through the air knife 130.

When the first resin 120 passes through the air knife 130 under the temporary hardening state, the first resin 120 on the mold 110 passing through the air knife 130 may have a triangular first prism. It may be a part 125.

When the mold 110 including the provisionally hardened first resin 120 passes through the air knife 130, as shown in FIG. 3B, the first resin 120 on the mold 110 may have a cross section. It may be formed of a first prism portion 125 having a triangular shape.

4 to 6 is a view showing a manufacturing method of the second prism portion in the optical film according to an embodiment of the present invention.

4 to 6, the second resin 140 may be coated on the mold 110 on which the first prism portion 125 is formed.

The second resin 140 may be made of any one of bromine compounds, florene compounds, or biphenyl compounds, but is not limited thereto.

After applying the second resin 140 on the mold 110 in which the first prism portion 125 is formed, the second resin 140 may be cured. At this time, the first resin hardened while the second resin is cured may be completely cured as well. Depending on the environment in which the second resin 140 may be cured, UV (ultra violet) or heat may be applied.

When the second resin 140 is cured, the second resin 140 may be a second prism portion having a trapezoidal cross section.

The mold 110 may be removed from the completed first prism portion 125 and the second prism portion 145.

The optical film having the above-described process may be formed on the second prism portion 145 having a trapezoidal shape and the first prism portion 125 having a triangular cross section. have.

At this time, the elongation of the first prism portion 125 may be 20% to 300%. Since the first prism portion 125 is a high elastic material having the above numerical value, it may not be easily broken or flawed in an external impact or manufacturing process. The elongation of the first prism portion 125 may be greater than the elongation of the second prism portion 145.

Elongation refers to the degree to which the volume or length of a specimen to be changed when a compressive or stretching force is applied. It can usually be expressed in% of the original volume or length. It is often referred to as strain.

In addition, the first prism portion 125 may have a pencil hardness B or more. The pencil hardness is the hardness of the black core used for the pencil. H stands for hard and stands for hardness. Pencil hardness can be divided into 9H> 8H> 7H> 6H> 5H> 4H> 3H> 2H> H> F> B> 2B> 3B> 4B> 5B> 6B. Since the first prism portion 125 has an elongation of the above-described numerical value and has a pencil hardness B or more, it may not be easily deformed in external impact.

That is, the durability of the optical film itself can be improved.

The refractive index of the second prism portion may be higher than the refractive index of the first prism portion 125. In more detail, the refractive index of the second prism portion 145 may be 1.54 to 1.65, and the refractive index of the first prism portion 125 may be 1.46 to 1.53.

The light from the light source positioned at the bottom of the optical film passes through a diffusion sheet, which diffuses the light and transmits the light toward the panel to make the luminance uniform and to widen the viewing angle. Since the light passing through the diffusion sheet is diffused in both horizontal and vertical directions, the luminance is decreased, so that the luminance may be increased by refracting or condensing the light through the optical film.

In the optical film, a second prism portion 145 having a high refractive index and a first prism portion 125 having a high elasticity and hardness may be formed on the base portion 150 to bring about an effect of increasing durability and luminance of the device. .

7 is a cross-sectional view of the first prism portion 125 and the second prism portion 145 according to an embodiment of the present invention.

Referring to FIG. 7, the height A of the first prism portion 125 is 3% to 50% of the total height A + B in which the first prism portion 125 and the second prism portion 145 are combined. Can be. Alternatively, the ratio of the height A of the first prism portion 125 to the height B of the second prism portion 145 may be 1: 1 to 1:32.

If the height B of the first prism portion 125 is 3% or more of the total height A + B in which the first prism portion 125 and the second prism portion 145 are combined, the prism portion, particularly the base portion 150 The lower end of the first prism portion 125 facing the lower portion of the) can be made an optical sheet having a high elasticity and hardness that does not break or scratch from an external impact. If it is less than 50%, the light converging effect can be enhanced in the relationship with the second prism portion 145 while having high elasticity and hardness.

8 is a view showing an optical film according to an embodiment of the present invention.

Referring to FIG. 8, a base portion 150 may be formed under the second prism portion 145.

The base unit 150 may be made of polyethylene terephthalate (PET), but is not limited thereto. PET is one of the strongest films among plastic resins, has excellent electrical properties, and can be used as an extremely thin film. In addition, since the heat resistance is strong and transparent, it can be a good material for the optical film 100 that must pass light and withstand heat. The base part 150 may be positioned below the first prism part 125 and the second prism part to support the prism part.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains can understand that the present invention can be implemented in other specific forms without changing the technical spirit or essential features. will be. Therefore, the above-described embodiments are to be understood as illustrative and not restrictive in all respects, and the scope of the present invention is indicated by the appended claims rather than the detailed description, and the meaning and scope of the claims and All changes or modifications derived from the equivalent concept should be interpreted as being included in the scope of the present invention.

1A to 3B illustrate a method of manufacturing a first prism part in an optical film according to an exemplary embodiment of the present invention.

4 to 6 is a view showing a manufacturing method of the second prism portion in the optical film according to an embodiment of the present invention.

7 is a cross-sectional view of the first prism portion and the second prism portion according to the embodiment of the present invention.

8 is a view showing an optical film according to an embodiment of the present invention.

(Explanation of symbols for the main parts of the drawing)

110: Mold

120: first resin

125: first prism portion

Claims (12)

Applying a first resin onto the mold; Temporarily curing the first resin; Removing a portion of the first resin to form a first prism portion having a triangular cross section; Applying a second resin onto the first prism portion; And Curing the first resin and the second resin and forming a second prism portion having a trapezoidal cross section; The method of claim 1, wherein the first resin and the second resin are different materials. The method of claim 1, A portion of the first resin is removed by an air knife. The method of claim 1, The first resin is a method for producing an optical film, characterized in that the acrylic resin having a molecular weight of 10000 or more. The method of claim 3, wherein The first resin is a method of manufacturing an optical film, characterized in that any one of urethane acrylate (Urethane Acrylate) or poly butadiene (Poly Butadiene). The method of claim 1, The second resin is any one of a bromine compound, a Floren compound, or a biphenyl compound. The method of claim 1, The refractive index of the second prism portion is higher than the refractive index of the first prism portion manufacturing method of the optical film. The method of claim 6, The refractive index of the first prism portion is 1.46 to 1.53, the refractive index of the second prism portion is 1.54 to 1.65 method of manufacturing an optical film. The method of claim 1, The elongation of the first prism portion is greater than the elongation of the second prism portion. The method of claim 10, The elongation of the first prism portion is 20 to 300% of the manufacturing method of the optical film. The method of claim 1, The first prism portion is a manufacturing method of the optical film, characterized in that the pencil hardness B or more. The method of claim 1, The height of the first prism portion is 3 to 50% of the total height combined with the first prism portion and the second prism portion. The method of claim 1, The ratio of the height of the first prism portion and the height of the second prism portion is 1: 1 to 1:32 manufacturing method of the optical film.

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