KR100993462B1 - Light diffusing color filter and method of menufacturing thereof - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light diffusing color filter for liquid crystal display device, comprising: a light diffusing liquid drop formed by forming a color filter resin for a color filter on a substrate; The surface of the light diffusion droplet is oxidized, and comprises an oxide layer formed in a shape surrounding the droplet, wherein the light diffusion droplet and the oxide layer is characterized in that to form an uneven structure on the surface of the substrate to cause light diffusion .

According to the present invention, it is possible to reduce the process time by using the same colored resin in the color filter itself, to prevent glare due to the formation of an oxide layer, and to reduce the cost of not using a separate light diffusing film or a high definition polarizing plate. .

Color filter, diffusion, coloring resin, oxide layer, refractive index, irregularities

Description

Light diffusing color filter and method of manufacturing the same

The present invention relates to a light diffusing color filter and a method for manufacturing the same, and more particularly, to a light diffusing color filter having an anti-glare structure having a concave-convex structure and having an anti-glare property therein, and a method of manufacturing the same. will be.

Liquid crystal displays (LCDs) inject a liquid crystal material, which is a mesophase of a solid and a gas, between a substrate having electrodes, apply a constant voltage, and change the molecular arrangement direction. The light transmittance is driven by adjusting light transmittance between polarizers having optical axes disposed perpendicular to each other.

Light diffusing film or anti-glare film is not only a liquid crystal display (LCD) but also a plasma display panel (PDP), a pre-developed light display (ELD), a cathode ray tube (CRT), and the like. In order to prevent the visibility of the image from being degraded due to indoor lighting such as fluorescent lamps, incidence of sunlight from a window, projection of a user's shadow, etc. on the surface of the image display apparatus, various image display apparatuses are provided. It is a film formed. That is, by causing the light diffusion or scattering by the fine concave-convex structure, it is made to prevent glare of the user.

Such a conventional light diffusing film is a type of forming an uneven shape on the surface of a light diffusing layer by agglomeration of particles such as coherent silica, and adding fine organic particles having a particle diameter greater than or equal to a film thickness in the coating film to the resin to form an uneven shape on the surface of the layer. There is a type of forming a type, using a roll having a concave-convex on the surface of the layer and the type to transfer the concave-convex shape or the type of forming a concave-convex shape on the surface of the polarizing plate.

For example, in Japanese Patent Publication No. 2001-194504, as shown in FIG. 1, the light-transmitting fine particles 3 composed of a binder resin 2 and a metal alkoxide on one surface of the transparent base film 1 and a hydrolyzate thereof. Disclosed is a light diffusing film formed by laminating a transparent resin layer as a main component.

However, in the conventional light diffusing film, by using a high-definition polarizing plate in which a separate film is produced in this way or by applying a resin composition containing the fine particles on the polarizing plate, a problem that is expensive and separate inorganic fine particles are used. There is a problem that the process time is long.

The present invention is to solve the above problems, an object of the present invention, unlike the light diffusion film manufactured by processing the surface of the polarizing plate, or using a separate material, using a colored resin used in the color filter, Since the difference in refractive index between the oxide layer formed by oxidizing and the color filter is used, the present invention provides a light diffusing color filter which can reduce the process time and cost by using the same material.

The present invention is to solve the above problems, the light diffusing color filter according to the present invention is a color diffusion liquid droplet formed of a color filter color resin in the form of droplets on one surface of the substrate; The surface of the light diffusion droplet is oxidized, and comprises an oxide layer formed in a shape surrounding the droplet, wherein the light diffusion droplet and the oxide layer is characterized in that to form an uneven structure on the surface of the substrate to cause light diffusion .

Here, the light diffusing color filter according to the first embodiment of the present invention further comprises a coating layer formed by coating the color resin coloring resin on the opposite surface of the substrate surface on which the light diffusing droplet and the oxide layer are formed. Therefore, when external light is reflected on the uneven structure, it causes diffuse reflection to prevent glare.

In addition, the light diffusing color filter according to the second exemplary embodiment of the present invention is mainly applied to a reflective liquid crystal display device, and further includes a coating layer formed by coating a color filter coloring resin on the oxide layer. Therefore, when the internal light passes through the uneven structure, light diffusion can be caused to widen the viewing angle.

In addition, the light diffusion droplets may be formed between adjacent black matrices formed on the substrate.

In addition, the light diffusing droplet and the coating layer is made of the same color filter color resin, it is preferable that the light diffusing droplet and the oxide layer is different in refractive index from each other for the process shortening and cost reduction.

In addition, the color filter manufacturing method according to the present invention, the spraying step of spraying a color resin for the color filter in the form of droplets on the substrate; And an oxidation step of forming an oxide layer on the sprayed droplets.

In the method of manufacturing a color filter according to the first embodiment of the present invention, a color filter is formed by applying a color filter coloring resin to an opposite surface of the substrate surface on which the light diffusion droplet and the oxide layer are formed, and then forming a color filter pattern. A step is made.

In addition, the color filter manufacturing method according to the second embodiment of the present invention comprises a color filter forming step of forming a color filter pattern after coating the color resin for the color filter on the oxide layer.

In addition, the method for manufacturing a color filter according to the second embodiment of the present invention further includes a black matrix forming step of forming a black matrix pattern before the spraying step, wherein the spraying step is not formed of the black matrix pattern. It is made by spraying colored resin for color filters in the form of droplets in the space.

In addition, the spraying step and the color filter forming step, it is preferable to use the same color filter color resin for the process shortening and cost reduction.

According to the present invention, it is possible to reduce the process time by using the same colored resin in the color filter itself, to prevent glare due to the formation of an oxide layer, and to reduce the cost of not using a separate light diffusing film or a high definition polarizing plate. .

Hereinafter, a light diffusing color filter and a method of manufacturing the same according to the present invention will be described with reference to embodiments and drawings of the present invention.

2 is a cross-sectional view of a liquid crystal display device including the light diffusing color filter according to the first embodiment of the present invention.

As shown in FIG. 2, the liquid crystal display according to the first embodiment of the present invention includes: a first substrate 10 including a thin film transistor T; A second substrate bonded to the first substrate 10 and including a black matrix 40, a color filter 50, and a light diffusing color filter 60 formed at a position corresponding to the thin film transistor T; 20; And a liquid crystal 30 filled and positioned between the first substrate 10 and the second substrate 20.

In the first substrate 10, the thin film transistor T includes a gate electrode 11, a gate insulating film 12, an active layer 13, and a source 14a / drain 14b. The active layer 13 constituting the thin film transistor T is made of a semiconductor material such as amorphous silicon. In addition, a passivation layer 15 made of an organic material is formed on the source 14a / drain 14b to cover the thin film transistor T, and the pixel electrode 16 is formed thereon.

In the second substrate 20, when the active layer 13 receives light, the bond between silicon and hydrogen is broken and photoelectrons move to the surface of the active layer 13, so that a leakage current may occur. Black matrix 40 is required to prevent light leakage to T). In addition, the color filter coating layer 50 including the sub color filters 50a / 50b for expressing the colors of R (Red), G (Green), and B (Blue) in each unit pixel region is mainly composed of a black mattress 40. It is formed on the lower surface of the formed second substrate 20.

Here, the light diffusing color filter 60 according to the first embodiment of the present invention, as shown in Figure 2, the upper surface of the second substrate 20 (that is, the black matrix 40 and the color filter 50) Light diffusing droplets 61 formed on the opposite side of the bottom surface of the second substrate 20 on which the second substrate 20 is formed, in which a color resin for color filters is formed in the form of droplets; And an oxide layer 62 formed by oxidizing the light diffusion droplet 61.

The color resin for the color filter used in the present invention is not particularly limited as long as it is a coloring composition generally used as a color filter, which is a binder resin and / or a monomer or a photopolymerization initiator in a solvent dispersion composition of color materials such as organic pigments and inorganic pigments. And a coloring photosensitive composition containing other components.

Here, a color material means coloring the colored curable resin composition of this invention. Although a dye pigment can be used as a coloring material, a pigment is preferable at the point of heat resistance, light resistance, etc. As the pigment, pigments of various colors such as blue pigments, green pigments, red pigments, yellow pigments, purple pigments, orange pigments, brown pigments and black pigments can be used. In addition, the structure includes azo, anthraquinone, phthalocyanine, quinacridone, benzimidazolone, isoindolin, dioxazine, indanthrene, perylene, diketopyrrolopyrrole, and quinophthalone. In addition to organic pigments, various inorganic pigments may be used.

As the binder resin, an acrylic or epoxy resin is used, and as a solvent, any one of organic solvents such as alcohol, acetate, ether, glycol, ketone, and carbonate may be used alone or in combination of two or more thereof. Can be.

When the colored photosensitive composition is sprayed onto the surface of the substrate in the form of droplets and exposed to air for a long time, an oxide layer is formed on the droplets, and the oxide layer has a different refractive index from the droplets, and due to the difference in the refractive index and the convexity or irregularities formed by the droplets. Light reflection or light diffusion occurs.

That is, the light diffusion droplet 61 and the oxide layer 62 form an uneven structure on the surface of the second substrate 20 to cause light diffusion, which is caused by the layer of oxide layer 62 between the air layer and the light diffusion droplet 61. This is because it acts as an 'foreign substance' causing the interface, that is, diffuse reflection.

Schematically speaking, as shown in FIG. 3, light from the outside is diffusely reflected by the irregularities of the oxide layer 62 of the color filter, thereby preventing glare from the user.

On the other hand, the present invention can be applied to a reflective liquid crystal display device having a configuration that can reduce the power loss due to the backlight by omitting the backlight and reflecting the external natural light or artificial light from the inside of the liquid crystal display device, such reflection In the liquid crystal display, for example, a reflecting plate (not shown) made of a metal such as aluminum (Al) or silver (Ag) having a reflectance of 90% or more is deposited on the first substrate 10 so that external light Reflected by the reflector plate is made of a form in which the transmittance is adjusted according to the arrangement of the liquid crystal (30).

However, when the reflecting plate has a flat surface in such a liquid crystal display device, since light is reflected by the mirror (or specular reflection) as if it is reflected from the mirror, the luminance of light is only in the specular reflection direction of the incident light depending on the position of the light source. Since there is a problem that the brightness of the front surface is high and the viewing angle is narrowed, in order to solve this problem, a scattering film for diffusing light to a region other than the specular reflection is generally applied.

The light diffusing color filter according to the second embodiment of the present invention is applied to such a reflective liquid crystal display, and serves as a scattering film to allow light reflected from an internal reflection plate to be diffused in various directions.

FIG. 4 is a view showing a path through which light emitted from the light diffusing color filter and the reflective liquid crystal display according to the second embodiment of the present invention is diffused through the light diffusing color filter.

As shown in Fig. 4, the light diffusing color filter as the second embodiment of the present invention is formed by being included in the sub-color filters 50a / 50b under the second substrate 20.

That is, as shown in Figure 4, the light diffusing color filter 50 according to the second embodiment of the present invention, the color filter in the space between the black matrix 40 formed in the contact portion with the second substrate 20 Light-diffusing droplets 51 in which the colored resin is formed in the form of droplets; An oxide layer 52 formed by oxidizing the light diffusion droplet 51; The coating layer 53 formed by coating the color filter coloring resin on the oxide layer 52 is sequentially stacked. In some cases, the light diffusing color filter 50 may be applied to the entire surface of the substrate 20 without the black matrix 40.

In addition, as shown in FIG. 4, in the reflective liquid crystal display device, light reflected from inside passes through the light diffusion droplet 51 and the oxide layer 52, causing light diffusion, thereby increasing the viewing angle. Can act as

Next, a method of manufacturing the light diffusing color filter according to the present invention will be described.

The light diffusing color filter manufacturing method according to the present invention includes a spraying step (S10), an oxidation step (S20), and a color filter forming step (S30).

The spraying step (S10) is a step of forming the light diffusion droplets 51 and 61 by spraying the color filter coloring resin on one surface of the substrate 20 in the form of droplets.

The colored resin for color filters is obtained by, for example, dispersing the above-mentioned colored photosensitive composition using a sand grinder, a pin mill, a slit mill, an ultrasonic disperser, or the like. In addition, before performing this dispersion, a strong shear force is applied by using two rolls, three rolls, a ball mill, a trom mill, a dispers, a kneader, a kneader, a homogenizer, a blender, a single screw, or a twin screw extruder. It is also possible to carry out kneading dispersion processing.

In order to precisely control and spray the colored resin for the color filter thus prepared in the form of droplets, it is preferable to follow the direct dropping method or the inkjet method using a dispenser or an inkjet ejector. Among them, the inkjet method is a method in which a plurality of ink droplets (droplets) are ejected from the inkjet head and fixed on the surface of the substrate, whereby the colored resin droplets for the color filter can be accurately discharged in a minute region.

The size of the discharged droplets is preferably controlled to a particle diameter of 0.1 to 100 m, more preferably 0.5 to 10 m.

By performing such a spraying step (S10), it is possible to perform precise work without using a photolithography method for forming a specific precise pattern, thereby reducing the process time and cost reduction effect of not performing a complicated process You can get it.

In the oxidizing step S20, the oxide layers 52 and 62 are formed on the injected light diffusion droplets 51 and 61. As a method of oxidizing the light diffusion droplets 51 and 61, a method of leaving the light diffusion droplets 51 and 61 at room temperature may be used, and electron beams, quantum rays, and neutron beams may be applied to the light diffusion droplets 51. A method of causing oxygen absorption by a method of irradiating radiation consisting of electromagnetic waves such as particle beams, gamma rays, X-rays, visible rays and ultraviolet rays may be used.

Color filter forming step (S30) is a step of forming a color filter pattern after applying the color resin for the color filter.

That is, the color filter forming step (S30) is the color filter coating layer 50 in the first embodiment of the present invention shown in FIG. 2 or the color filter coating layer in the second embodiment of the present invention shown in FIG. 53 is a step of forming.

In the first embodiment of the present invention shown in Fig. 2, the color filter forming step (S30) is a color filter coloring resin applied to the opposite side of the substrate surface on which the light diffusion droplet 61 and the oxide layer 62 is formed. Thereafter, the color filter pattern, i.e., the coating layer 50 is formed, and the color filter forming step S30 in the second embodiment of the present invention shown in FIG. 4 includes the light diffusion droplet 51 and the oxide layer 52. ) By additionally forming a coating layer (53).

As a method of apply | coating the coloring resin for color filters, if it is a general method conventionally used for color filter application | coating, it will not specifically limit. For example, it can transition to a spray coating method, a spin coating method, a micro gravure coating method, a gravure coating method, a slit coating method (also called die coating and cast coating), roll coating, screen printing, inkjet method, etc.

Thus, after apply | coating the coloring resin for color filters, forming a color filter pattern is based on a general color filter manufacturing method, and is not specifically limited to any one method. For example, after the coated colored resin film is dried, a color filter pattern may be formed using an exposure process using a mask and a developing process. Other methods include screen printing as described above, intaglio offset printing, and flat plate offset printing. Direct printing methods such as flexible printing, and inkjet methods can be used.

Here, after forming the black matrix 40 pattern, the color filter coating layer 50 may be formed between the formed black matrix 40 pattern.

Further, according to the first embodiment of the present invention shown in Fig. 2, since the light diffusing color filter 60 and the color filter coating layer 50 are formed on the opposite side of the substrate 20, respectively, the light diffusing color filter is formed. It will be appreciated that after performing step S30 first, the spraying step S10 and the oxidation step S20 may also be performed.

Although preferred embodiments of the present invention have been described above, the present invention may use various changes, modifications, and equivalents. It is clear that the present invention can be applied in the same manner by appropriately modifying the above embodiments. Accordingly, the above description does not limit the scope of the invention as defined by the limitations of the following claims.

1 is a cross-sectional view of a conventional light diffusing film.

2 is a cross-sectional view showing a liquid crystal display device including a light diffusing color filter according to a first embodiment of the present invention.

FIG. 3 is a diagram illustrating a path in which light entering through air from outside is diffusely reflected by the light diffusing color filter according to the first embodiment of the present invention.

4 is a view showing a path through which light emitted from the light diffusing color filter and the reflective liquid crystal display according to the second exemplary embodiment of the present invention is diffused through the light diffusing color filter.

Claims (11)

In the color filter formed on any one of a pair of substrates facing each other of the liquid crystal display device, A light diffusion droplet formed on one surface of the substrate by a color filter colored resin in the form of droplets; A surface of the light diffusion droplet is oxidized to include an oxide layer formed to surround the droplet, and the light diffusion droplet and the oxide layer form an uneven structure on the surface of the substrate to cause light diffusion. Light diffusing color filter for liquid crystal display device. The method of claim 1, And a coating layer formed by coating a color filter coloring resin on an opposite surface of the substrate on which the light diffusing droplets and the oxide layer are formed. The method of claim 1, And a coating layer formed by coating a color filter coloring resin on the oxide layer. The method of claim 3, And the light diffusion droplets are formed between adjacent black matrices formed on the substrate. The method according to any one of claims 1 to 4, The light diffusing color filter for liquid crystal display device, wherein the light diffusing droplet and the oxide layer have different refractive indices. The method according to any one of claims 2 to 4, The light diffusing color filter and the light diffusing color filter for a liquid crystal display device, characterized in that the coating layer is made of the same color filter color resin. In the color filter manufacturing method for forming a color filter on any one of a pair of substrates facing each other of the liquid crystal display device, A spraying step of spraying a color filter colored resin on the substrate in the form of droplets; And an oxidation step of forming an oxide layer on the sprayed droplets. The method of claim 7, wherein And a color filter forming step of forming a color filter pattern after applying the color filter coloring resin to an opposite surface of the substrate on which the light diffusing droplets and the oxide layer are formed. The method of claim 7, wherein And a color filter forming step of forming a color filter pattern after coating the color resin for color filter on the oxide layer. 10. The method of claim 9, Further comprising a black matrix forming step of forming a black matrix pattern before the spraying step,  The spraying step, the method of manufacturing a light diffusing color filter, characterized in that by spraying the color filter color resin in the form of droplets in the space where the black matrix pattern is not formed. The method according to any one of claims 8 to 10, The spraying step and the color filter forming step, the light diffusing color filter manufacturing method, characterized in that using the same color filter resin.

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