KR20100011638A - Optical sheet enhancing scratch resistance and filter comprising the same, and image displaying device having the sheet or the filter - Google Patents

Abstract

PURPOSE: An optical sheet with improved scratch resistance and an image display device having a filter and sheet are provided to reduce surface strain formation and improve image quality of the device. CONSTITUTION: An image display device comprises: a light penetration unit(210) having plural recesses which is separated; and plural external light absorbing units(220) which is arranged in the recesses. One of the light penetration unit and external light absorbing unit comprises a slip agent.

Description

 Optical sheet enhancing scratch resistance and filter comprising the same, and image displaying device having the sheet or the filter

The present invention relates to an optical sheet, a filter having the same, and an image display device including the optical sheet or the filter, and more particularly, an optical sheet having reduced surface unevenness and improved scratch resistance, and a filter having the same, and The present invention relates to an image display device having improved image quality by providing the optical sheet or filter.

Recently, many kinds of image display devices have been developed and put into practical use. Such image display devices are, for example, liquid crystal image display devices (LCDs), plasma display panels (PDPs), electroluminescent displays (FEDs), and cathode ray tube image display devices. (CRT), fluorescent display tubes, field emission display panels. Such image display devices display color images by implementing three primary colors of red, blue, and green in principle.

In addition, these image display devices include a panel assembly for forming an image, and a filter for shielding electromagnetic waves, near infrared rays, and / or orange light emitted from the panel assembly, and having a function such as surface reflection prevention and / or color correction. do. Since these filters are mounted on the front of the panel assembly, the light transmission must also be satisfied at the same time.

However, such a filter has a problem of lowering the brightness of an image display device by absorbing and / or reflecting light emitted from the panel assembly. In addition, in the image display apparatus, in an external bright condition, that is, a bright room condition, external ambient light may pass through a filter into the panel assembly. In this case, superimposition of the image light emitted in the panel assembly and the external environmental light introduced through the filter from the outside occurs, which results in a low contrast ratio under bright room conditions, resulting in poor display capability of the image display device. There is a problem.

In order to solve these problems, the optical sheet generally includes a transparent light transmitting portion and a wedge-shaped external light absorbing portion disposed at predetermined intervals. The external light absorbing part may be formed by filling a composition including a light absorbing material into a plurality of grooves formed in the light transmitting part, and the external light absorbing part may improve the contrast ratio of the image by absorbing external ambient light.

The process of forming the external light absorbing part is as follows. That is, the composition containing the light absorbing material in the form of a dispersion, and widely spread on the surface of the light transmitting portion, and then wiped (wiping) using a doctor blade or the like to form an external light absorbing portion by filling the groove in the light transmitting portion. do.

However, in the related art, the dispersion does not uniformly spread on the surface of the light transmitting part in the filling process, but shows a local thickness variation, so that spots appear on the surface of the external light absorbing part finally formed after filling.

In addition, since the hardness of the light transmitting part and / or the external light absorbing part is low, scratches are easily generated on these surfaces when contacted with an external material.

It is an object of the present invention to provide an optical sheet having an external light absorbing portion having reduced surface unevenness.

Another object of the present invention is to provide an optical sheet having improved scratch resistance.

It is still another object of the present invention to provide an optical sheet capable of improving contrast ratio in bright room conditions and reducing double image formation when employed in an image display device.

Still another object of the present invention is to provide a filter including the optical sheet.

Still another object of the present invention is to provide an image display device having an improved image quality by providing the optical sheet or the filter.

The present invention to solve the above problems,

A light transmitting portion having a plurality of groove portions disposed to be spaced apart from each other; And

It is provided with a plurality of external light absorbing portion disposed in the groove portion,

At least one of the light transmitting portion and the external light absorbing portion provides an optical sheet including a slip agent.

According to one embodiment of the invention, the external light absorbing portion is filled with a composition for forming an external light absorbing portion comprising a curable resin, a light absorbing material and a slip agent in the groove portion and the resin in the composition for forming the external light absorbing portion is cured Is formed.

According to another embodiment of the present invention, the curable resin is an ultraviolet curable resin.

According to another embodiment of the present invention, the amount of the slip agent included in the external light absorbing portion is 0.05 to 30 parts by weight based on 100 parts by weight of the entire external light absorbing portion.

According to another embodiment of the present invention, the amount of the slip agent included in the light transmitting part is 0.05 to 30 parts by weight based on 100 parts by weight of the entire light transmitting part.

According to another embodiment of the present invention, the slip agent comprises at least one selected from the group consisting of a silicone compound and a fluorine compound.

According to another embodiment of the present invention, the optical sheet further includes a base film attached to a surface opposite to the groove portion of the light transmitting portion to support the light transmitting portion.

According to another embodiment of the present invention, the pitch of the optical sheet is in the range of 40 to 150㎛, the width of the external light absorbing portion is in the range of 10 to 40㎛, the height of the external light absorbing portion is in the range of 50 to 200㎛.

According to another embodiment of the present invention, the cross-sectional shape in the thickness direction of the external light absorbing portion is triangular, square or trapezoidal.

According to another embodiment of the present invention, the external light absorbing portion is arranged in a stripe shape, a matrix shape, or a wave shape.

According to another embodiment of the present invention, the optical sheet is a contrast ratio improving sheet.

In addition, the present invention to solve the above problems,

Provided are a filter for an image display device including an optical sheet and a filter base according to any one of the above embodiments.

In addition, the present invention to solve the above problems,

An image display device having a filter for an optical sheet or an image display device according to any one of the above embodiments is provided.

According to the present invention, an optical sheet having an external light absorbing portion having reduced surface unevenness may be provided.

In addition, according to the present invention, an optical sheet having improved scratch resistance may be provided.

Further, according to the present invention, an optical sheet capable of improving contrast ratio in bright room conditions and reducing double image formation when employed in an image display device can be provided.

In addition, according to the present invention, a filter including the optical sheet may be provided.

Further, according to the present invention, an image display apparatus having an improved image quality by providing the optical sheet or the filter can be provided.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is an exploded perspective view of an image display apparatus equipped with a filter including an optical sheet according to an embodiment of the present invention, and FIG. 2A is an exploded cross-sectional view of a filter including an optical sheet according to an embodiment of the present invention. 2B is an exploded cross-sectional view of a filter having an optical sheet according to another embodiment of the present invention.

Referring to FIG. 1, an image display device 1 equipped with a filter including an optical sheet according to an embodiment of the present invention includes a case 10, a cover 50 covering an upper portion of the case 10, and the A driving circuit board 20 accommodated in the case 10, a panel assembly 30 for forming an image, and a filter 40 are included.

The visible image formed in the panel assembly 30 by the electrical signal applied from the driving circuit board 20 is emitted to the outside through the filter 40.

This filter 40, as shown in Figures 2a and 2b, includes a color correction film 100, an optical sheet 200, and a filter base (FB), the filter base (FB) is electromagnetic waves It comprises a shielding film 300, hard coating layer 400, and the anti-reflection film (500).

The color correction film 100 typically includes, for example, a neon light blocking dye, but may also include a near infrared absorbing compound or a dye. Neon light refers to unnecessary light around the wavelength of about 585 nm generated by the excitation of neon gas. Near-infrared rays cause malfunctions of peripheral electronic devices, and thus their shielding is necessary.

The optical sheet 200 includes a base film 230, a light transmitting unit 210, and an external light absorbing unit 220, and is disposed below the color correction film 100. The optical sheet 200 having such a configuration includes, for example, a contrast ratio improving sheet, but the present invention is not limited thereto. Here, the contrast ratio improvement sheet is a broad concept which collectively refers to the sheet used for the purpose of raising the contrast ratio of an image display apparatus.

The light transmitting portion 210 is a portion that transmits the light emitted from the panel assembly 30 of FIG. 1. The light transmitting part 210 may be formed of a curable resin. Specifically, the light transmitting part 210 may be used an acrylate resin or the like cured by ultraviolet rays or thermal energy.

In addition, the light transmitting unit 210 is preferably transparent, which means not only completely transparent but also to the extent that it can be recognized as transparent in the art. The light transmitting part 210 generally has a shape complementary to the shape of the external light absorbing part 220 to be described later, but the present invention is not limited thereto. That is, the light transmitting portion 210 is formed with a groove portion (g ₂₁₀ ) spaced apart from each other at a predetermined interval, the composition for forming an external light absorption portion comprising a light absorbing material and a curable resin in the groove portion (g ₂₁₀ ) Charged to form the external light absorbing unit 220. It is preferable that the refractive index of the light transmitting unit 210 is 1.3 to 1.8. If the refractive index is less than 1.3, it is not preferable because it is difficult to manufacture, and if it exceeds 1.8, the transmittance of the light transmitting unit 210 is significantly decreased and the contrast ratio is also reduced, which is not preferable because the overall resolution is reduced.

The light transmitting portion 210 is preferably formed to include a slip agent. As such, since the light transmitting part 210 includes the slip agent, the surface frictional force of the light transmitting part 210 is reduced, and thus, the dispersion including the composition for forming the external light absorbing part when forming the external light absorbing part 220 to be described later is the light transmitting part. It smoothly flows along the surface of 210 and spreads to a uniform thickness on the surface. Accordingly, the external light absorbing portion 220 may be formed by wiping the dispersion liquid having a uniform thickness on the surface of the light transmitting portion 210 using a doctor blade or the like to fill the groove portion g ₂₁₀ of the light transmitting portion 210. In this case, staining does not occur on the surface of the external light absorbing unit 220 finally formed. In this case, as the surface frictional force of the light transmitting portion 210 decreases, the scratch resistance of the light transmitting portion 210 increases. However, the present invention is not limited thereto, and the slip agent may not be included in the light transmitting unit 210 but may be included only in the external light absorbing unit 220.

When the light transmitting part 210 is formed including the slip agent, the amount of the slip agent included in the light transmitting part 210 is preferably 0.05 to 30 parts by weight based on 100 parts by weight of the entire light transmitting part 210. If the amount of the slip agent is less than 0.05 parts by weight, the effect of adding the slip agent is not preferable, and if it exceeds 30 parts by weight, interlayer separation may occur during storage of the light transmitting part-forming composition containing the slip agent. It is unpreferable because light transmittance falls.

The slip agent may include at least one selected from the group consisting of a silicon compound and a fluorine compound. When the silicon and / or fluorine compound is used, the silicon and / or fluorine element may have a light transmitting portion 210 due to its incompatibility. ), The surface energy can be lowered and the properties such as adhesion and friction resistance can be improved.

As the slip agent that can be used in the present invention, a silicone compound, such as silicone diacrylate or silicone polyether acrylate, polyether-modified dimethylpolysiloxane, which can be crosslinked by exposure to ultraviolet radiation, is preferably used. Although this invention is mentioned, it is not limited to this.

As described above, the external light absorbing part 220 is formed by filling a heat-curing or ultraviolet curable resin composition for forming a light absorbing part including a light absorbing material in a groove g ₂₁₀ formed in the light transmitting part 210, and the external environment. By absorbing light, the contrast ratio is improved in bright room conditions to maintain high resolution. 2A illustrates a case in which one end face of the external light absorbing unit 220 has a quadrangle shape, and FIG. 2B illustrates a case in which one end face of the external light absorbing unit 220 has a trapezoidal shape.

It is preferable that the same or similar material as that of the light transmitting part 210 is used as the curable resin.

The light absorbing material may include, for example, a black inorganic material, a black organic material, a blackened metal, and a mixture of two or more thereof. In the case of blackened metal, since the electrical resistance is low, when it is included in the external light absorbing unit 220, the electrical resistance can be adjusted by adjusting the content of the metal powder or the thickness of the metal thin film, so the external light absorbing unit 220 has an electromagnetic shielding function. You can also do Typically, the external light absorbing unit 220 may be formed of an ultraviolet curable resin containing carbon. The refractive index of the external light absorbing unit 220 is preferably in the range of 1.3 to 1.8, similar to the light transmitting unit 210.

The external light absorbing portion forming composition preferably further comprises a slip agent. As such, by adding a slip agent to the composition for forming the external light absorbing part, the flowability of the dispersion including the composition is improved. It smoothly flows along the surface of 210 and spreads to a uniform thickness on the surface. Accordingly, the external light absorbing portion 220 may be formed by wiping the dispersion liquid having a uniform thickness on the surface of the light transmitting portion 210 using a doctor blade or the like to fill the groove portion g ₂₁₀ of the light transmitting portion 210. In this case, staining does not occur on the surface of the external light absorbing unit 220 finally formed. In this case, the frictional force of the external light absorbing unit 220 is reduced due to the addition of the slip agent, thereby increasing the scratch resistance of the external light absorbing unit 220. However, the present invention is not limited thereto, and the slip agent may not be included in the external light absorbing part 220 but may be included only in the light transmitting part 220.

Also more preferably, the slip agent may be included in both the light transmitting portion 210 and the external light absorbing portion 220, in this case, not only does not stain the surface of the final light absorbing portion 220 is formed, but also the light transmitting portion 210 ) And the scratch resistance of both the external light absorbing unit 220 may be improved.

When the slip agent is added to the composition for forming the external light absorbing part, the amount of the slip agent included in the composition is 0.05 to 30 parts by weight relative to 100 parts by weight of the entire external light absorbing part 220 (that is, the entire composition). desirable. If the amount of the slip agent is less than 0.05 parts by weight, the effect of adding the slip agent is not preferable, and if it exceeds 30 parts by weight, interlayer separation may occur during storage of the composition for forming an external light absorbing part including the slip agent. It is not preferable because the external light absorption rate is lowered.

As the slip agent, the same slip agent as the slip agent included in the light transmitting part 210 may be used.

The base film 230 is disposed on one surface of the light transmitting portion 210, that is, the surface opposite to the recessed portion 220a. The base film 230 serves to support the light transmission unit 210 in which the external light absorbing unit 220 is disposed. Specifically, the base film 230 is polyethersulphone (PES, polyethersulphone), polyacrylate (PAR, polyacrylate), polyether imide (PEI, polyetherimide), polyethylene naphthalate (PEN, polyethylene naphthalate), polyethylene terephthalate (PET, polyethylene terephthalate), polyphenylene sulfide (PPS), polyallylate, polyimide, polycarbonate (PC), cellulose tri acetate (TAC), cellulose acetate propionate ( cellulose acetate propionate (CAP) may be formed of one or more substances selected from the group consisting of. Preferably, it may be polycarbonate (PC), polyethylene terephthalate (PET), cellulose tri acetate (TAC), or polyethylene naphthalate (PEN). In addition, the base film 230 is preferably formed of a material having the same or similar refractive index as the refractive index of the light transmitting unit 210.

In addition, the optical sheet 200 according to the present embodiment further includes a protective film 240 on one surface of the light transmitting unit 210, that is, the surface opposite to the base film 230, as shown in FIG. 3 to be described later. can do. The protective film 240 serves to protect the optical sheet 200 until the optical sheet 200 is mounted on the filter 40, it is generally separated from the optical sheet 200 when the filter 40 is assembled. to be. However, the present invention is not limited thereto.

2A and 2B, the filter base FB is disposed on one surface of the optical sheet 200 and includes an electromagnetic wave shielding film 300, a hard coating layer 400, and an antireflection film 500. It is not limited. The stacking order of these 300, 400, and 500 in the filter base FB may be variously changed, and a material having two or more functions may be mixed in one layer to form a layer.

The electromagnetic wave shielding film 300 is responsible for shielding electromagnetic waves. The electromagnetic wave shielding film 300 may have various configurations such as a conductive mesh layer, a metal thin film, a high refractive index transparent thin film, or a structure in which two or more of them are stacked. 2A and 2B, the electromagnetic wave shielding film 300 is illustrated as being composed of a single layer, but the present invention is not limited thereto, and may be formed of a multilayer including at least two layers.

The hard coating layer 400 has scratch resistance to prevent the electromagnetic wave shielding film 300 or the anti-reflection film 500 described later from being damaged due to contact with an external material. The hard coating layer 400 may be tempered glass itself, or may be a material including a polymer as a binder. In addition, the hard coating layer 400 may include an acrylic, urethane, epoxy, or siloxane polymer, or may include an ultraviolet curable resin such as an oligomer. In addition, a silica-based filler may be added to the hard coat layer 400 to improve the hardness.

The anti-reflection film 500 is responsible for minimizing eye fatigue of image display device users who watch for a long time by adjusting the transmittance of visible light. By arranging the antireflection film 500 in this way to adjust the visible light transmittance, in addition to the selective absorption effect of the visible light, it is possible to obtain an effect of improving the color reproduction range such as contrast ratio. 2A and 2B, the anti-reflection film 500 is illustrated as being composed of a single layer. However, the present invention is not limited thereto, and may be formed of a multilayer including at least two layers.

The anti-reflection film 500 has a visible light incident from the outside and reflected from the surface of the anti-reflection film 500, and then the visible light reflected from the interface between the anti-reflection film 500 and the hard coating layer 400 is reversed. The antireflection effect is obtained by the principle of phase disappearance and interference phenomenon.

As the anti-reflection film 500, a mixture of indium tin oxide (ITO) and silicon oxide (SiO ₃ ), a mixture of nickel chromate (NiCr) and silicon oxide (SiO ₂ ), and the like may be cured and adhered. In addition, a special fluorine resin of titanium oxide or low refractive index may be used as the antireflection film 500.

3 is an enlarged cross-sectional view of the optical sheet of FIG. 2A and illustrates a state before the optical sheet is mounted on the filter. Note that the protective film is not removed in FIG.

The same reference numerals as in the above-described drawings indicate the same member or parts of the same member.

The external light absorbing part 220 may be formed by a roll forming method or an injection molding method in which a thermosetting resin is filled into a light transmitting part 210 to which a groove g ₂₁₀ having a shape opposite to the pattern of the external light absorbing part 220 is transferred. Can be formed.

In addition, when the curable resin constituting the light transmitting unit 210 has an antireflection function, an electromagnetic shielding function, a color correction function, or a combination thereof, the optical sheet 200 may additionally perform these functions. .

Referring to FIG. 3, the optical sheet 200 according to the present embodiment includes a light transmitting part 210, an external light absorbing part 220, a base film 230, and a protective film 240. Here, the protective film 240 may be omitted by selection. FIG. 2A is a diagram illustrating a filter 40 equipped with the optical sheet 200 from which the protective film 240 is removed.

The relative arrangement of the light transmitting unit 210, the external light absorbing unit 220, the base film 230, and the protective film 240 is as described above.

The external light absorbing part 220 may be arranged in various shapes such as a stripe shape, a matrix shape, or a wave shape. In addition, the plurality of external light absorbing units 220 may be spaced apart from each other to allow light to pass therebetween. In addition, in FIG. 3, the external light absorbing unit 220 is illustrated as one end surface of a rectangular shape, but the present invention is not limited thereto. The shape of the one end surface may be various shapes such as triangle, trapezoid, or pentagon.

In addition, the pitch P200 of the optical sheet 200 is in the range of 40 to 150㎛, the width (W ₂₂₀ ) of the external light absorbing portion 220 is in the range of 10 to 40㎛, the height (h) of the external light absorbing portion 220 ₂₂₀ ) is in the range of 50-200 μm. Here, ultraviolet light means a width of the width (W ₂₂₀₎ is the image light source-side end of the absorbing channel 220, and the external light when a trapezoid is, as shown in shape Figure 2b of the absorption unit 220 has the width (W ₂₂₀ ) Denotes the width of the image light source side end of the external light absorbing unit 220, that is, the maximum width.

Although not shown here, the optical sheet 200 according to the present embodiment may further include a prism portion disposed on one surface of the base film 230, that is, the surface opposite to the light transmitting portion 210. The prism portion may be formed of the same or similar material as that of the light transmitting portion 210. By providing the prism portion as described above, the optical sheet 200 improves the external light absorption rate without large change in transmittance, thereby increasing the contrast ratio and improving the resolution.

An optical sheet or a filter having the above configuration can be provided in the image display device, thereby improving the image quality of the image display device and increasing the contrast ratio to achieve high resolution.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments, but the present invention is not limited thereto.

Example 1: Preparation of an optical sheet containing a slip agent in the external light absorbing portion

A molding roll was formed in which a plurality of protrusions having a square cross-sectional shape were formed on the surface. Subsequently, a low refractive index acrylic curable resin (Sartomer) was formed on one surface between the optical PET film (Toyobo Co., Ltd.) having a thickness of 188 μm constituting the forming roll and the base film using a pattern roll equipment equipped with an ultraviolet device (manufactured by Hirano). 100 g (refractive index: 1.48) of CN981) was hardened while slowly being added in the form of a mixed liquid. This obtained the light transmission part by which the protrusion part on the said molding roll was transferred in the groove shape. A dispersion (refractive index: 1.49) prepared by mixing 5 g of silicon polyether acrylate (Rad 2200, Tego) and 2 g of carbon black, which is a slip agent, and 100 g of the acrylic curable resin (CN985, manufactured by Sartomer) are dispersed in the transferred groove. A plurality of external light absorbing portions were completed in the grooves by wiping the dispersion using a Dr. blade made of a soft plastic to evenly fill the grooves. Then, it was cured with ultraviolet light to obtain an optical sheet as shown in FIG. Here, the pitch of the light transmitting part was 73.4 μm, the width and the height of the external light absorbing part were 22 μm and 102 μm, respectively, and the thickness of the light transmitting part was 150 μm. Here, the pitch of the light transmitting portion means the distance between the points corresponding to each other in the light transmitting portions of two adjacent portions partitioned by the external light absorbing portion.

Example 2: Preparation of an optical sheet containing a slip agent in both the light transmitting portion and the external light absorbing portion

An optical sheet was prepared in the same manner as in Example 1, except that 5 g of a silicone polyether acrylate (Rad 2200, Tego), a slip agent, was further added to the mixed solution containing 100 g of a low refractive index acrylic curable resin when forming the light transmitting part. Was prepared.

Example 3: Preparation of an optical sheet containing a slip agent in the light transmitting portion

Except for the addition of 5 g of a silicone polyether acrylate (Rad 2200, Tego), which is a slip agent, to a mixed solution containing 100 g of low refractive index acrylic curable resin when forming the light transmitting part without adding a slip agent when forming the external light absorbing part. Manufactured an optical sheet in the same manner as in Example 1.

Comparative Example 1: Preparation of an optical sheet containing no slip agent in both the light transmitting portion and the external light absorbing portion

An optical sheet was manufactured in the same manner as in Example 1, except that no slip agent was added when forming the external light absorbing part.

Evaluation example

For the optical sheets prepared in Examples 1 to 3 and Comparative Example 1, the surface hardness and the surface stain of each of the light transmitting part and the external light absorbing part were measured as follows.

(Surface hardness)

The coating hardness of the film was measured by pencil hardness according to the measurement method specified in ASTM D3363-93. The method is a method of measuring the surface hardness of the film coating film by determining whether or not scratching occurs when the coating film of the film is scratched with a pencil having a hardness prescribed by B ~ HB ~ H.

(Surface stain occurrence)

In addition, by visually observing the occurrence of surface staining in the external light absorbing portion and the results are shown in Table 1 below. When surface unevenness was observed visually, it was represented by (circle), and when it was not observed visually, it was represented by x.

TABLE 1

Evaluation item Example 1 Example 2 Example 3 Comparative Example 1 Surface hardness Light transmission H 6H 6H H External light absorbing part > 6H > 6H 3H 2H Surface staining occurs × × × ○

Referring to Table 1, Examples 1 to 3 belonging to the present invention are cases in which a slip agent is added to at least one of the light transmitting part and the external light absorbing part, and the part to which the slip agent is added has higher surface hardness than that of the other part. Found to be good. On the other hand, in the case of Comparative Example 1, in which the slip agent is not added, the surface hardness is the same as or lower than that of Examples 1 to 3, and thus, it is vulnerable to scratch generation.

In addition, in Examples 1 to 3, surface unevenness was not observed in the external light absorbing portion, whereas in Comparative Example 1, surface unevenness was clearly observed. From the above results, it can be seen that in Comparative Example 1, when the external light absorbing part was formed, the flowability of the composition for forming the external light absorbing part was poor, and thus the dispersion was not dispersed in a uniform thickness on the surface of the light transmitting part.

In the above described a preferred embodiment according to the present invention with reference to the drawings, but this is only exemplary, those skilled in the art can understand that various modifications and equivalent other embodiments are possible from this. There will be. Therefore, the protection scope of the present invention should be defined by the appended claims.

1 is an exploded perspective view showing a schematic configuration of an image display device equipped with a filter including an optical sheet according to an embodiment of the present invention.

2A is an exploded cross-sectional view of a filter having an optical sheet according to an embodiment of the present invention, and FIG. 2B is an exploded cross-sectional view of a filter having an optical sheet according to another embodiment of the present invention.

3 is an enlarged cross-sectional view of the optical sheet of FIG. 2A and illustrates a state before the optical sheet is mounted on the filter.

<Explanation of symbols for the main parts of the drawings>

1: image display device 10: case

20: drive circuit board 30: panel assembly

40: filter 50: cover

100: color correction film 200: optical sheet

210: light transmission unit 220: external light absorption unit

230: base film 240: protective film

300: electromagnetic wave shielding film 400: hard coating layer

500: antireflection film FB: filter base

g ₂₁₀ : groove

Claims (13)

A light transmitting portion having a plurality of groove portions disposed to be spaced apart from each other; And It is provided with a plurality of external light absorbing portion disposed in the groove portion, At least one of the light transmitting unit and the external light absorbing unit comprises a slip agent. The method of claim 1, The external light absorbing portion is an optical sheet, characterized in that the composition for forming an external light absorbing portion comprising a curable resin, a light absorbing material and a slip agent is filled in the groove portion and the resin in the composition for forming the external light absorbing portion is cured. The method of claim 2, Said curable resin is an ultraviolet curable resin, The optical sheet characterized by the above-mentioned. The method of claim 1, The amount of the slip agent included in the external light absorbing portion is an optical sheet, characterized in that 0.05 to 30 parts by weight based on 100 parts by weight of the entire external light absorbing portion. The method of claim 1, The amount of the slip agent included in the light transmitting part is an optical sheet, characterized in that 0.05 to 30 parts by weight based on 100 parts by weight of the entire light transmitting part. The method of claim 1, The slip sheet is an optical sheet, characterized in that at least one selected from the group consisting of a silicon compound and a fluorine compound. The method of claim 1, And a base film attached to a surface opposite to the groove portion of the light transmitting portion to support the light transmitting portion. The method of claim 1, The optical sheet has a pitch of 40 to 150㎛ range, the width of the external light absorbing portion is 10 to 40㎛ range, the height of the external light absorbing portion is 50 to 200㎛ range. The method of claim 1, The optical sheet, characterized in that the cross-sectional shape in the thickness direction of the external light absorbing portion is triangular, square or trapezoidal. The method of claim 1, And the external light absorbing portion is arranged in a stripe shape, a matrix shape, or a wave shape. The method according to any one of claims 1 to 10, And the optical sheet is a contrast ratio improving sheet. A filter for an image display device, comprising the optical sheet according to any one of claims 1 to 10, and a filter base. An image display device comprising the optical sheet according to any one of claims 1 to 10.

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