KR101822706B1 - Optical sheet and optical display apparatus comprising the same - Google Patents

Abstract

A base layer; An optical pattern layer formed on one surface of the substrate layer and including at least one first optical pattern; And a composite layer formed on the other surface of the substrate layer, wherein one surface of the base layer is a light incident surface, and the composite layer has a first refractive index pattern layer and a second refractive index pattern layer formed directly on the first refractive index pattern layer Wherein the first refractive index pattern layer and the second refractive index pattern layer have different refractive indices and the first refractive index pattern layer includes at least one second optical pattern and an optical display device including the same / RTI >

Description

TECHNICAL FIELD [0001] The present invention relates to an optical sheet and an optical display device including the optical sheet.

The present invention relates to an optical sheet and an optical display device including the optical sheet.

The liquid crystal display device includes a light condensing sheet. The light condensing sheet can condense the light emitted from the light guide plate. An inverted prism sheet having a base layer and a prism pattern formed on a light incident surface of the base layer may be used as a light condensing sheet.

The inverse prism can collect light by totally reflecting light emitted from the light guide plate by the pattern shape, thereby increasing the efficiency of light. Further, the back prism sheet can make the backlight unit thinner than a normal optical sheet.

However, the reverse prism sheet can reduce the viewing angle due to excessive light condensation. A bead-containing coating layer or a micro lens pattern is formed on the upper surface of the reverse prism sheet to diffuse the light, thereby widening the viewing angle. However, in this case, the viewing angle increases in the direction in which light is incident from the light source, that is, in the horizontal direction, but the viewing angle increases in the vertical direction with respect to the direction in which light is incident from the light source.

Further, the inverted prism sheet may have a peak at its top and may have friction with the light guide plate. Such a friction may damage the light guide plate to lower the light efficiency. The hardness of the reverse prism can be lowered, but the reverse prism may be damaged and defective.

The background art of the present invention is described in Korean Patent Publication No. 2010-0136220.

An object of the present invention is to provide an optical sheet capable of increasing the viewing angle in the horizontal direction.

Another problem to be solved by the present invention is to provide an optical sheet capable of suppressing a luminance loss by minimizing a change in a viewing angle in a vertical direction.

Another object of the present invention is to provide an optical sheet capable of minimizing the friction between a light guide plate and a prism by being integrated with a panel for an optical display device because of easy polarizing plate and lamination.

Another object of the present invention is to provide an optical sheet capable of thinning an optical display device.

Another object to be solved by the present invention is to provide an optical sheet having a thin thickness and having no sheet peel.

Another object of the present invention is to provide an optical display device including the optical sheet.

The optical sheet of the present invention comprises a base layer; An optical pattern layer formed on one surface of the substrate layer and including at least one first optical pattern; And a composite layer formed on the other surface of the base layer, wherein one surface of the base layer is a light incident surface, and the composite layer has a first refractive index pattern layer and a second refractive index pattern layer formed directly on the first refractive index pattern layer Wherein the first refractive index pattern layer and the second refractive index pattern layer have different refractive indices and the first refractive index pattern layer may include one or more second optical patterns.

The optical display device of the present invention may include the optical sheet.

The present invention provides an optical sheet capable of increasing the viewing angle in the horizontal direction.

The present invention provides an optical sheet capable of suppressing a luminance loss by minimizing a change in viewing angle in a vertical direction.

The present invention provides an optical sheet capable of minimizing friction between a light guide plate and an inversed prism by being integrated with a polarizing plate and a panel for an optical display device.

The present invention provides an optical sheet capable of thinning a display.

1 is a perspective view of an optical sheet according to an embodiment of the present invention.
2 is an exploded view of a cross section taken along the line I-II in Fig.
3 is a cross-sectional view of an optical sheet according to another embodiment of the present invention.
4 is a cross-sectional view of an optical sheet according to another embodiment of the present invention.
5 is a cross-sectional view of an optical sheet according to another embodiment of the present invention.
6 is a cross-sectional view of an optical sheet according to another embodiment of the present invention.
7 is a cross-sectional view of a backlight unit according to an embodiment of the present invention.
8 is a perspective view of a light guide plate according to an embodiment of FIG.
9 is a cross-sectional view of a liquid crystal display device according to an embodiment of the present invention.

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same names are used for the same or similar components throughout the specification.

The terms "upper" and "lower" in this specification are defined with reference to the drawings, wherein "upper" may be changed to "lower", "lower" What is referred to as "on" may include not only superposition, but also intervening other structures in the middle. On the other hand, what is referred to as "directly on" or "directly above"

As used herein, the term "aspect ratio" means the ratio of the maximum height of the optical pattern to the maximum width of the optical pattern.

In the present specification, the "radius of curvature" refers to a radius of an imaginary circle having a part of the curved surface in an optical pattern having a curved top, or a radius of a virtual circle having a curved surface it means.

As used herein, the term "top part " refers to the uppermost part of the structure when the lowest part of the structure is assumed to be the basis.

The term " horizontal direction "means a direction in which light is incident from a light source, and" vertical direction "means a direction perpendicular to a direction in which light is incident from a light source. In the drawings of the present specification, when light is incident in the Y-axis direction, the Y-axis direction means a horizontal direction and the X-axis direction means a vertical direction. In the drawings of the present specification, the X axis, the Y axis, and the Z axis are orthogonal to each other.

In the present specification, the "occupancy rate" means the ratio of the total area of only the convex portion of the microlens pattern to the total area of the layer on which the microlens pattern is formed.

As used herein, "(meth) acrylic" means acrylic and / or methacrylic.

Hereinafter, an optical sheet according to an embodiment of the present invention will be described with reference to Figs. 1 and 2. Fig. FIG. 1 is a perspective view of an optical sheet according to an embodiment of the present invention, and FIG. 2 is an exploded view of a cross section taken along line I-II in FIG.

Referring to FIG. 1, an optical sheet 100 according to an embodiment of the present invention includes a base layer 110; An optical pattern layer (120) comprising at least one first optical pattern (121); And a composite layer 130 including a first refractive index pattern layer 131 and a second refractive index pattern layer 132.

    The base layer 110 may be formed between the optical pattern layer 120 and the complex layer 130 to support the optical pattern layer 120 and the complex layer 130.

The lower surface of the base layer 110 may be a light incidence surface, and the upper surface of the base layer 110 may be a light exit surface. The base layer 110 may emit light incident from the optical pattern layer 120 to the composite layer 130.

The base layer 110 may be formed of an optically transparent resin. Specifically, the resin may include at least one of a polyester including a polycarbonate, polymethyl (meth) acrylate and the like, and (meth) acrylic.

The base layer 110 may have a thickness of 10 mu m to 300 mu m, specifically, 25 mu m to 100 mu m. And can be used in an optical display device in the above range.

The optical pattern layer 120 is formed on one surface of the base layer 110 and collects the light incident from the light guide plate or another optical sheet (not shown in FIG. 1) to output the light to the base layer 110, .

The lower surface of the optical pattern layer 120 may be a light incidence surface, and the upper surface of the optical pattern layer 120 may be a light exit surface.

The refractive index of the optical pattern layer 120 may be 1.40 or more, specifically 1.40 to 1.60. The light converging effect may be in the above range.

The optical pattern layer 120 may be formed of an optically transparent ultraviolet curable resin. Specifically, the resin may include at least one of (meth) acrylic, polycarbonate, polymethyl (meth) acrylate, and urethane.

The optical pattern layer 120 may have a thickness of 2 탆 to 30 탆, specifically, 5 탆 to 15 탆. Within this range, there may be a focusing effect.

The optical pattern layer 120 may include at least one first optical pattern 121 on a lower surface that is a light incidence surface.

The first optical pattern 121 is formed on one surface of the base layer 110, and can form a light incident surface. The first optical pattern 121 totally reflects light incident from a light guide plate or another optical sheet (not shown in FIG. 1) to condense the light and increase the light efficiency.

The first optical pattern 121 may include a prism pattern having a triangular section. 1 shows an optical sheet in which the first optical pattern 121 is a prism pattern having a triangular section. However, the first optical pattern may include at least one of a prism pattern whose cross section is an n-angular shape (n is an integer of 4 to 10), a prism pattern whose curved surface is formed at the top and whose cross section is an n-angular shape (n is an integer of 3 to 10) .

Referring to FIG. 2, the width P1 of the first optical pattern 121 may be 5 占 퐉 to 20 占 퐉, specifically, 7 占 퐉 to 18 占 퐉. The height H1 of the first optical pattern 121 may be 3 占 퐉 to 15 占 퐉, specifically, 4 占 퐉 to 14 占 퐉. The first optical pattern 121 may have a vertex angle? 1 of 55 to 75 degrees, specifically 60 to 70 degrees. The light can be condensed in the range of width, height, and apex angle to increase the efficiency of light.

The aspect ratio of the first optical pattern 121 may be 0.71 to 0.96, specifically 0.76 to 0.87. In the above range, the efficiency of light can be increased by condensing the light.

The first optical pattern 121 may be arranged on the lower surface of the base layer 110 in the horizontal direction, that is, in the direction in which light is incident from the light source (Y-axis direction in FIG. 1).

The first optical pattern 121 may be formed of the same or different resin as the optical pattern layer 120.

The composite layer 130 is formed on the other surface of the base layer 110, and light incident from the base layer 110 can be diffused and emitted. As a result, the composite layer 130 has a wider viewing angle in the horizontal direction and a smaller viewing angle change in the vertical direction than the optical sheet in which the composite layer is not formed. Also, the loss of luminance compared to the optical sheet having the bead coating layer or the microlens on the upper surface of the base layer can be minimized.

The lower surface of the multiple layer 130 may be a light incident surface, and the upper surface of the multiple layer 130 may be a light exit surface.

The composite layer 130 may have a thickness of 5 占 퐉 to 50 占 퐉, specifically, 5 占 퐉 to 25 占 퐉. In the above range, it can be used in an optical display device.

The complex layer 130 includes a first refractive index pattern layer 131 and a second refractive index pattern layer 132 formed directly on the first refractive index pattern layer 131. The first refractive index pattern layer 131 and the second The refractive index pattern layer 132 may have different refractive indices. As a result, light incident from the base layer 110 diffuses through the composite layer 130, thereby widening the viewing angle in the horizontal direction and minimizing the viewing angle change in the vertical direction, thereby minimizing the luminance loss.

Hereinafter, the first refractive index pattern layer 131 and the second refractive index pattern layer 132 will be described with reference to FIG.

2, the first refractive index pattern layer 131 is formed between the upper surface of the substrate layer 110 and the substrate layer 110 and the second refractive index pattern layer 132, The incident light can be diffused and emitted to the second refractive index pattern layer 132.

The lower surface of the first refractive index pattern layer 131 may be a light incident surface and the upper surface of the first refractive index pattern layer 131 may be a light exit surface.

The refractive index of the first refractive index pattern layer 131 may be lower than that of the second refractive index pattern layer 132. As a result, the diffusing effect of light can be further increased, and the viewing angle in the horizontal direction can be further widened. Specifically, the refractive index difference between the second refractive index pattern layer 132 and the first refractive index pattern layer 131 may be 0.2 or less, more specifically 0.05 to 0.2, and more particularly 0.06 to 0.18. The viewing angle in the horizontal direction can be widened in the above range.

The refractive index of the first refractive index pattern layer 131 may be 1.45 or more, specifically 1.50 to 1.65. In the above range, it is possible to widen the viewing angle in the horizontal direction and to maintain the viewing angle in the vertical direction at the time of outputting the light incident from the optical pattern layer, thereby reducing the luminance loss.

The first refractive index pattern layer 131 may have a thickness of 2 탆 to 20 탆, specifically, 2 탆 to 10 탆. In the above range, it can be used in an optical display device.

The first refractive index pattern layer 131 may be formed of an optically transparent ultraviolet curable resin. Specifically, the resin may include a (meth) acrylic resin, a polyester resin, a polycarbonate resin, a styrene resin, or the like. The ultraviolet curable resin may be a self-adhesive resin after curing to facilitate the formation of the second refractive index pattern layer 132.

The first refractive index pattern layer 131 may include a first surface 133 which is a top surface and one or more second optical patterns 135 may be formed on the first surface 133.

The second optical pattern 135 can broaden the viewing angle in the horizontal direction and minimize the luminance loss by diffusing the light incident from the base layer 110.

The second optical pattern 135 may be a convex optical pattern having a curved surface. The curved surface can increase the diffusion effect at the time of light emission from the first refractive index pattern layer 131 to the second refractive index pattern layer 132. [

The second optical pattern 135 may be a lenticular lens pattern. 1 and 2 show an optical sheet in which the second optical pattern 135 is a lenticular lens pattern. However, the second optical pattern is a prism having a prism whose cross section is an n-angular shape (n is an integer of 3 to 10) and whose longitudinal direction is a linear shape, a prism whose cross section is an n-angular shape (n is an integer of 3 to 10) , And a prism, a microlens, and an emboss having a curved surface at the top and an n-square cross section (n is an integer of 3 to 10).

The height H 2 of the second optical pattern 135 may be 2 탆 to 20 탆, specifically, 2 탆 to 10 탆. The second optical pattern 135 may have a width P2 of 5 占 퐉 to 30 占 퐉, specifically, 5 占 퐉 to 15 占 퐉. The radius of curvature of the second optical pattern 135 may be 3 탆 to 50 탆, specifically 3 탆 to 25 탆. There may be an effect of increasing the viewing angle in the horizontal direction in the height, width, and radius of curvature.

The second optical pattern 135 may have an aspect ratio of 0.1 to 1.5, specifically 0.3 to 1.0, more specifically 0.4 to 0.7. There may be an effect of increasing the viewing angle in the horizontal direction within the above range.

The moire preventing effect can be obtained by making the width of the second optical pattern 135 smaller than that of the first optical pattern 121. Specifically, the difference (P1-P2) between the width of the first optical pattern 121 and the width of the second optical pattern 135 can be 3 占 퐉 or more, specifically 3 占 퐉 to 15 占 퐉. Moire prevention effect can be obtained in the above range.

The second optical pattern 135 may be arranged in substantially the same direction as the first optical pattern 121. The "substantially the same" includes cases where not only completely identical but also some errors are present.

The second refractive index pattern layer 132 is formed directly on the first refractive index pattern layer 131 and diffuses and exits the light incident from the first refractive index pattern layer 131 and the second optical pattern 135, Thereby widening the viewing angle and minimizing the luminance loss.

The lower surface of the second refractive index pattern layer 132 may be a light incident surface and the upper surface of the second refractive index pattern layer 132 may be a light exit surface.

The lower surface of the second refractive index pattern layer 132 includes a second surface 134 and the second surface 134 is formed directly on the first surface 133 of the first refractive index pattern layer 131 . On the second surface 134, an optical pattern 136 opposed to the second optical pattern 135 may be formed.

The upper surface of the second refractive index pattern layer 132 is a flat surface, and it is possible to facilitate stacking of the polarizing plate and other optical sheets.

The refractive index of the second refractive index pattern layer 132 may be 1.45 or more, specifically 1.50 to 1.65. It is possible to widen the viewing angle in the horizontal direction at the time of outputting the light incident from the optical pattern layer in the above range and to reduce the luminance loss.

The second refractive index pattern layer 132 may be formed of an optically transparent ultraviolet curable resin. Specifically, the resin may include a (meth) acrylic resin, a polyester resin, a polycarbonate resin, a styrene resin, or the like. The ultraviolet curable resin may become a self-adhesive resin after curing to facilitate the formation of the polarizing plate and other optical sheets on the upper surface of the second refractive index pattern layer 132.

The second refractive index pattern layer 132 may have a thickness of 3 탆 to 20 탆, specifically, 5 탆 to 15 탆. In the above range, it can be used in an optical display device.

Thickness of the first refractive index pattern layer 131: The thickness of the second refractive index pattern layer 132 may be 1: 0.8 to 1: 1.2, specifically 1: 0.9 to 1: 1.1. Within this range, there may be an effect of increasing the viewing angle.

Although not shown in FIG. 1, at least one of the first refractive index pattern layer 131 and the second refractive index pattern layer 132 may further include a light diffusing agent so as to further diffuse the light to widen the viewing angle in the horizontal direction. Specifically, the light-diffusing agent may include an inorganic light-diffusing agent, an organic light-diffusing agent, or a mixture thereof. The inorganic light-diffusing agent may include at least one of calcium carbonate, barium sulfate, titanium dioxide, aluminum hydroxide, silica, glass, talc, mica, white carbon, magnesium oxide and zinc oxide. The organic light-diffusing agent may include at least one of (meth) acryl-based particles, siloxane-based particles, melamine-based particles, polycarbonate-based particles and styrene-based particles. The shape and size of the light-diffusing agent are not particularly limited, but may include spherical particles having an average particle diameter of 1 탆 to 5 탆. Within this range, there is a diffusion effect and it may not protrude outside the optical sheet.

Although not shown in FIG. 1, the surface of the second optical pattern 135 may be further provided with concavities and convexities to increase the diffusion effect.

1, an adhesive layer is further formed on the upper surface of the second refractive index pattern layer 132 so that the optical sheet 100 can be attached to a panel for an optical display device such as a polarizing plate or a liquid crystal panel . The pressure-sensitive adhesive layer may be formed of a composition for a pressure-sensitive adhesive layer containing a pressure-sensitive adhesive resin and a crosslinking agent. The viscous resin may include at least one of a (meth) acrylic resin, a urethane resin, and a silicone resin. The composition for a pressure-sensitive adhesive layer may further include a light-diffusing agent as described above to further diffuse the light. However, when the resin for the second refractive layer pattern layer is a cured adhesive resin, the adhesive layer may be omitted.

Hereinafter, an optical sheet according to another embodiment of the present invention will be described with reference to FIG.

3 is a cross-sectional view of an optical sheet according to another embodiment of the present invention.

3, an optical sheet 200 according to another embodiment of the present invention includes a base layer 110, an optical pattern layer 120 including at least one first optical pattern 121, And a complex layer 130a including a first refractive index pattern layer 131a including the optical pattern 135a and a second refractive index pattern layer 132a. Is substantially the same as the optical sheet according to the embodiment of the present invention, except that the second optical pattern 135a is a concave lenticular lens pattern.

Hereinafter, an optical sheet according to another embodiment of the present invention will be described with reference to FIG. 4 is a cross-sectional view of an optical sheet according to another embodiment of the present invention.

4, an optical sheet 300 according to another embodiment of the present invention includes a base layer 110, an optical pattern layer 120 including at least one first optical pattern 121, And a composite layer 130b including a first refractive index pattern layer 131b including the first optical pattern 135a and a second refractive index pattern layer 132b. The first refractive index pattern layer 131b is substantially the same as the optical sheet according to another embodiment of the present invention except that the refractive index is higher than that of the second refractive index pattern layer 132b.

Hereinafter, an optical sheet according to another embodiment of the present invention will be described with reference to FIG. 5 is a cross-sectional view of an optical sheet according to another embodiment of the present invention.

5, an optical sheet 400 according to another embodiment of the present invention includes a base layer 110, an optical pattern layer 120 including one or more first optical patterns 121, And a composite layer 130c including a first refractive index pattern layer 131c including the first optical pattern 135c and a second refractive index pattern layer 132c. The second optical pattern 135c is substantially the same as the optical sheet according to an embodiment of the present invention, except that the second optical pattern 135c is a triangular prism pattern. Hereinafter, only the second optical pattern 135c will be described.

The height H3 of the second optical pattern 135c may be 2 占 퐉 to 20 占 퐉, specifically, 2 占 퐉 to 10 占 퐉. The second optical pattern 135c may have a width P3 of 5 占 퐉 to 30 占 퐉, specifically, 5 占 퐉 to 15 占 퐉. The second optical pattern 135c may have a vertex angle? 2 of 60 ° to 120 °, specifically 65 ° to 100 °, more specifically 65 ° to 90 °. There may be an effect of increasing the viewing angle in the horizontal direction in the range of width, height, and apex angle.

The second optical pattern 135c may have an aspect ratio of 0.1 to 1.5, specifically 0.3 to 1.0, more specifically 0.4 to 0.7. There may be an effect of increasing the viewing angle in the horizontal direction within the above range.

5 shows a prism pattern in which the second optical pattern 135c has a triangular section. In the second optical pattern, a prism having an n-square section (n is an integer of 3 to 10) and a linear shape in the longitudinal direction, a prism having an n-type (n is an integer of 3 to 10) and a longitudinal direction in a wave form, a prism pattern in which a curved surface is formed at the top and an n-square section (n is an integer of 3 to 10) .

Hereinafter, an optical sheet according to another embodiment of the present invention will be described with reference to FIG. 6 is a cross-sectional view of an optical sheet according to another embodiment of the present invention.

6, an optical sheet 500 according to another embodiment of the present invention includes a base layer 110, an optical pattern layer 120 including one or more first optical patterns 121, A composite layer 130 including a first refractive index pattern layer 131 and a second refractive index pattern layer 132 including an optical pattern 135; And a polarizer 140.

The polarizing plate 140 is further adhered to the optical display panel (not shown in FIG. 6) by forming the polarizing plate 140 on the light-emitting surface of the composite layer 130, May be fixed to the panel for the optical display device. Therefore, friction between the optical sheet and the light guide plate can be minimized, and even if the thickness of the optical sheet is made thin, the optical display device can be thinned because there is no sheet.

Is substantially the same as the optical sheet according to an embodiment of the present invention, except that a polarizing plate is further formed. Hereinafter, only the polarizing plate will be described.

The polarizing plate 140 may be formed on the upper surface of the complex layer 130 to realize polarization of light incident from the complex layer 130.

The polarizing plate 140 may be integrated with the composite layer 130, the base layer 110, and the optical pattern layer 120. Therefore, by fixing the optical sheet to the panel for the optical display device, it is possible to prevent sheet chipping and thin the optical sheet. Means that the polarizing plate, the multiple layer, the substrate layer and the optical pattern layer are not separated by a physical force in an independent state.

The polarizing plate 140 may include a conventional polarizing plate. In one embodiment, the polarizing plate may be composed of a polarizer alone. In other embodiments, the polarizing plate may comprise a polarizer and a protective film formed on one or both sides of the polarizer. In another embodiment, the polarizing plate may comprise a polarizer and a protective layer formed on one or both sides of the polarizer.

The polarizer, protective film and protective layer may be of any conventional type known to those skilled in the art.

The polarizer polarizes natural or artificial light so that a screen is visible on a display device, and can be mainly made of a polyvinyl alcohol-based film. In one embodiment, the polarizer is prepared by dyeing iodine or a dichroic dye to a modified polyvinyl alcohol film such as a partially-formalized polyvinyl alcohol film or an acetoacetyl-modified polyvinyl alcohol film and stretching it in an MD (machine direction) do. Specifically, it is produced through a swelling process, a dyeing process, and a stretching process. Methods of performing each step are commonly known to those skilled in the art. In another embodiment, the polarizer may be prepared by preparing an acid catalyst-impregnated film using a coating solution containing an acid catalyst and polyvinyl alcohol, dry-stretching the acid-catalyzed impregnated film and dehydrating the film to prepare a water- Followed by stretching and neutralization.

The polarizer may have a thickness of 3 탆 to 50 탆. And can be used in an optical display device in the above range.

The protective film is formed on one side or both sides of the polarizer to protect the polarizer, and may include an optically transparent ordinary film. For example, it is possible to use a polyester type, a polycarbonate type, a polycarbonate type, a polyethylene terephthalate (PET) or the like including a cyclic polyolefin type including a cyclic olefin polymer (COP) Polyether sulfone type, polysulfone type, polyamide type, polyimide type, polyolefin type, polyacrylate type, polyvinyl alcohol type, polyvinyl chloride type, polyvinyl chloride type Lt; RTI ID = 0.0 > and / or < / RTI >

The thickness of the protective film may be 10 탆 to 200 탆, specifically 30 탆 to 120 탆. And can be used in an optical display device in the above range.

The protective layer is formed on one side or both sides of the polarizer to protect the polarizer, prevent thermal shock and moisture penetration, and prevent cracking of the polarizer.

Since the protective layer has a thickness in a predetermined range, the optical film is formed only on one side, which can compensate the strength of the polarizing plate, which may deteriorate the mechanical strength, and can realize a thinning effect. Specifically, the protective layer may have a thickness of 1 占 퐉 to 30 占 퐉, for example, 2 占 퐉 to 25 占 퐉, and the protective layer may be used in the polarizing plate within the above range, and the mechanical strength of the polarizing plate may be compensated.

The polarizing plate 140 may have a thickness of 30 탆 to 200 탆, specifically, 50 탆 to 200 탆. And can be used in an optical display device in the above range.

Although not shown in Fig. 6, the polarizing plate 140 may be formed on the composite layer 130 by an adhesive layer. The pressure-sensitive adhesive layer may be formed of a composition for a pressure-sensitive adhesive layer containing a pressure-sensitive adhesive resin and a crosslinking agent. The viscous resin may include at least one of a (meth) acrylic resin, a urethane resin, and a silicone resin. The composition for a pressure-sensitive adhesive layer may further include a light-diffusing agent as described above to further diffuse the light. However, when the resin for the second refractive layer pattern layer is a self-adhesive resin after curing, the polarizer 140 may be adhered directly to the composite layer 130 without an adhesive layer.

6, an adhesive layer may be further formed on the upper surface of the polarizer 140 to attach the polarizer 140 to the panel for the optical display device. The adhesive layer may be formed of the above-mentioned composition for a pressure-sensitive adhesive layer, and the adhesive layer may further comprise a light-diffusing agent.

Further, although not shown in FIG. 6, a reflective polarizing film may be further formed between the complex layer 130 and the polarizer 140. The reflective polarizing film is a multi-layer film produced by alternately stacking two kinds of polymer layers having different refractive indices, which are introduced to minimize the loss of a light source and recycle a light source. The reflection type polarizing film is a film capable of transmitting only light in a vibration direction parallel to one transmission axis and reflecting other light by selectively reflecting and transmitting light through a polarization splitting function. For example, the reflective polarizing film has a structure in which a plurality of polymer layers having the same refractive index on the X axis and different refractive index on the Y axis are alternately laminated. The X axis having the same refractive index transmits light as the transmission axis, and the Y axis having the different refractive index It is possible to reflect light by the reflection axis. Therefore, the P wave of the light component is transmitted, and the S wave can be continuously reflected and recycled. An example of the reflection type polarizing film is a double brightness enhancement film (DBEF, Dual Brightness Enhancement Film, 3M). The reflective polarizing film may be a laminate of a first polymer layer having a thickness of 15 탆 to 25 탆 and a refractive index of 1.45 to 1.49 and a second polymer layer having a thickness of 15 탆 to 25 탆 and having a refractive index of 1.51 to 1.58 . The total thickness of the reflection type polarizing film may be 120 탆 to 150 탆.

The reflection type polarizing film may be formed between the composite layer 130 and the polarizing plate 140 by an adhesive layer. The adhesive layer may be formed from the composition for a pressure-sensitive adhesive described above. The adhesive layer may further comprise the light diffusing agent described above.

Hereinafter, a method of manufacturing an optical sheet according to an embodiment of the present invention will be described.

The method of manufacturing an optical sheet according to an embodiment of the present invention may include forming an optical pattern layer on one side of a base layer and forming a composite layer on the other side of the base layer.

And an optical pattern layer is formed on one surface of the base layer. Specifically, the optical pattern layer can be formed by coating a composition for forming an optical pattern layer on the engraved roll for forming the first optical pattern with a negative angle, bringing one surface of the substrate layer into contact with the other, and curing. The coating method is not particularly limited, but die coating, slip coating, bar coating and the like can be used. The curing includes ultraviolet curing, specifically, irradiation at a light amount of 100 mJ / cm ² to 250 mJ / cm ² .

A composite layer is formed on the other surface of the base layer to produce an optical sheet. Specifically, the composite layer may be formed by forming a first refractive index pattern layer, and then forming a second refractive index pattern layer. The first refractive index pattern layer may be formed by coating a second optical pattern forming composition on the pull-up roll for forming the second optical pattern, contacting the other surface of the substrate layer, and curing. The coating method is not particularly limited, but die coating, slip coating, bar coating and the like can be used. The curing includes ultraviolet curing, specifically, irradiation at a light amount of 100 mJ / cm ² to 250 mJ / cm ² . The second refractive index pattern layer may be formed by coating and curing the composition for forming a second refractive index layer directly on the first refractive index pattern layer. The coating method is not particularly limited, but die coating, slip coating, bar coating and the like can be used. The curing includes ultraviolet curing, specifically, irradiation at a light amount of 100 mJ / cm ² to 250 mJ / cm ² .

An optical pattern layer and a composite layer are formed in this order on the substrate layer. However, a composite layer may be formed first and an optical pattern layer may be formed.

After the composite layer is formed, the polarizing plate may be further adhered to the upper surface of the composite layer, that is, the light exit surface. Specifically, the polarizing plate can be manufactured by the above-mentioned ordinary method. Specifically, it can be produced by preparing a polarizer with a polyvinyl alcohol resin and bonding a protective film to one or both sides of the polarizer. Then, a pressure-sensitive adhesive is coated on the upper surface of the composite layer, and the polarizing plate is adhered and then cured.

The backlight unit of the present invention may include an optical sheet according to embodiments of the present invention.

Hereinafter, a backlight unit according to an embodiment of the present invention will be described with reference to FIG. 7 is a cross-sectional view of a backlight unit according to an embodiment of the present invention.

7, a backlight unit 600 according to an exemplary embodiment of the present invention includes a light source 610, a light guide plate 630 that guides light incident from a light source 610, a reflective sheet 620, (640), and the optical sheet (640) may include an optical sheet according to embodiments of the present invention.

The light source 610 generates light, and various light sources such as a linear light source lamp, a planar light source lamp, a CCFL, or an LED may be used. A light source cover may be further provided on the outside of the light source 610 for the purpose of protecting the light source.

The light source 610 may be disposed on one side of the light guide plate 630. However, the light sources 610 may be disposed on both sides of the light guide plate 630 to increase the brightness

The reflective sheet 620 is disposed under the light guide plate 630 and reflects the light generated by the light source 610 to be incident on the light guide plate 630 again.

The light guide plate 630 can guide the light incident from the light source 610 to the optical sheet 640. The light guide plate 630 may include a conventional light guide plate known to those skilled in the art. 8 is a perspective view of a light guide plate according to an embodiment of the present invention.

8, the light guide plate 550 according to the present embodiment includes a base film 551, a first coating layer 552 formed on one surface of the base film 551 and including a third optical pattern 555 having a curved top, And a second coating layer 552 formed on the other side of the base film 551 and including a fourth optical pattern 553. [

The base film 551 supports the first coating layer 554 and the second coating layer 552 and guides the light incident from the light source to be emitted to the optical sheet.

The thickness of the base film 551 may be 200 탆 to 700 탆, specifically 300 탆 to 500 탆. And can be used in an optical display device in the above range.

The refractive index of the base film 551 may be 1.50 or more and specifically 1.50 to 1.60. It is possible to increase the light output efficiency in the above range by increasing the light output efficiency.

The base film 551 may be formed of a resin having a refractive index of 1.50 or more, specifically 1.50 to 1.60. For example, the base film may be formed of polycarbonate, polymethyl (meth) acrylate, or the like. In particular, the polycarbonate resin may be advantageous for reducing the thickness of the substrate film.

The first coating layer 554 is formed on one side of the base film 551 so that the light is prevented from being scattered so that the brightness can be increased and the light incident from the base film 551 can be emitted.

The first coating layer 554 may have a thickness of 10 占 퐉 to 40 占 퐉. And can be used in an optical display device in the above range.

The first coating layer 554 may have a refractive index of 1.50 to 1.65. The light output efficiency can be increased by increasing the light output ratio in the above range.

The first coating layer 554 may be formed of a resin for the first coating layer having a refractive index of 1.50 to 1.65. The resin for the first coating layer includes an ultraviolet curable resin and may specifically be formed of a (meth) acrylic resin, a polycarbonate resin, a styrene resin, an olefin resin, a polyester resin, or a combination thereof.

The first coating layer 554 may include a third optical pattern 555.

The third optical pattern 555 may be formed on one surface of the base layer 551 and include an optical pattern in which at least one curved surface is formed at the top. FIG. 8 shows a light guide plate having a lenticular lens pattern formed by the third optical pattern 555, but the third optical pattern 555 is not limited if a curved surface is formed at the top. For example, the third optical pattern may include a prism (a cross section is n-angular and n is an integer of 3 to 10) formed with a curved top surface, a microlens pattern, an emboss pattern, or a combination thereof.

The third optical pattern 555 may have an aspect ratio of 0.10 to 0.50 and a radius of curvature of the curved surface of 10 mu m to 35 mu m. Light and diffusion of the light incident in the above range, and narrows the viewing angle in the vertical direction with respect to the third optical pattern, so that the visual feeling and the brightness can be increased.

The third optical pattern 555 may have a width of 10 mu m to 50 mu m and a height of 1 mu m to 35 mu m. The light can be condensed in the right and left directions in the above-mentioned range to increase the light efficiency, perform the function of light diffusion and diffusion with respect to the incident light, and narrow the viewing angle in the vertical direction.

Although the third optical pattern 555 may have a refractive index different from that of the first coating layer 554, the first coating layer and the third optical pattern may have the same refractive index to improve the processability.

The second coating layer 552 is formed on the other surface of the base film 551 so that part of the light passing through the base film 551 is not scattered and the light incident from the light source can be reflected and emitted.

The second coating layer 552 may have a thickness of 0.6 탆 to 5 탆 and may be used in a liquid crystal display in the above range.

The second coating layer 552 can have a refractive index of 1.50 to 1.65, and the light output efficiency can be increased in the above range to increase the light efficiency.

The second coating layer 552 may be formed of a resin for the second coating layer having a refractive index of 1.50 to 1.65. The resin for the second coating layer may be an ultraviolet curable resin, and for example, a (meth) acrylic resin, a polycarbonate resin, a styrene resin, an olefin resin, a polyester resin or a combination thereof may be used. The second coating layer 552 may be formed of the same or different resin as the first coating layer 554.

Second coating layer 552) may include a fourth optical pattern 553.

The fourth optical pattern 553 is formed on the other surface of the base film 551, and the aspect ratio may be 0.01 to 0.07. The light collection efficiency of light emitted from the light guide plate in the above range can be increased. Specifically, the aspect ratio may be 0.01 to 0.06.

8 shows the microlens pattern as the fourth optical pattern 553, but does not limit the microlens pattern with an aspect ratio of 0.01 to 0.07. For example, the fourth optical pattern may be a prism whose cross section is polygonal (n is an integer and n is an integer of 4 to 10), a prism pattern whose cross section is triangular, an emboss pattern, a lenticular lens pattern, or the like. In one embodiment, the fourth optical pattern may be a prism pattern having a cross section of a triangle having a width of 50 to 150 mu m, a height of 0.5 to 5.0 mu m, and an apex angle of 1.2 to 3.5 DEG.

The fourth optical pattern 553 may have a width of 10 탆 to 100 탆 and a height of 0.5 탆 to 5 탆, specifically 1 탆 to 5 탆. In this range, light condensation may be increased to increase light efficiency. In particular, the fourth optical pattern 553 can reduce the aspect ratio by lowering the height of the light guide plate compared to the conventional light guide plate, so that the light efficiency can be improved by increasing the light condensation even when the light converging sheet having the inverted prism is disposed.

Although the fourth optical pattern 553 may have a refractive index different from that of the second coating layer 552, the second coating layer and the fourth optical pattern may have the same refractive index to improve the processability.

The light guide plate 550 of the embodiment of the present invention is designed such that the third optical pattern 555 has a specific range of aspect ratio and radius of curvature and the fourth optical pattern 553 is designed to have an aspect ratio of a specific range, It is possible to increase the brightness even when the light-converging sheet having the inverted prism is disposed by allowing the light to exit at a specific angle of incidence specifically 60 to 80 degrees, more specifically 70 to 75 degrees with respect to the base film surface.

The optical display device of the present invention may include an optical sheet according to embodiments of the present invention or a backlight unit including the optical sheet. The optical display device may be a liquid crystal display device.

Hereinafter, a liquid crystal display device according to an embodiment of the present invention will be described with reference to FIG. 9 is a cross-sectional view of a liquid crystal display device according to an embodiment of the present invention.

9, a liquid crystal display 700 according to an exemplary embodiment of the present invention includes a liquid crystal panel 710, a first polarizer 720 formed on the upper surface of the liquid crystal panel 710, And a backlight unit 740 disposed under the second polarizer 730. The backlight unit 740 may include a backlight unit of an embodiment of the present invention. have.

The liquid crystal panel 710 includes a liquid crystal cell layer sealed between the first substrate and the second substrate and the liquid crystal cell layer may include a vertical alignment (VA) mode, an in place switching (IPS) mode, a fringe field switching and a twisted nematic mode.

The first polarizing plate 720 and the second polarizing plate 730 may each include a conventional polarizing plate. Since the first polarizing plate 720 and the second polarizing plate 730 are disposed on the upper and lower surfaces of the liquid crystal panel 710, the material and thickness of the protective film and / or the protective layer included in the polarizing plate have. However, a liquid crystal display device including the first polarizing plate 720 instead of the second polarizing plate 730 may be included in the scope of the present invention.

The backlight unit 740 may include the backlight unit of the embodiments of the present invention. When the backlight unit of the embodiments of the present invention includes the optical sheet including the polarizing plate, the second polarizing plate 730 may be omitted. In addition, an adhesive layer may be further included between the liquid crystal panel 710 and the optical sheet of the backlight unit 740. The adhesive layer may be formed of the above-described composition for a pressure-sensitive adhesive layer, and the adhesive layer may further comprise the above-described light-diffusing agent.

Although not shown in FIG. 9, the first polarizing plate 720 and the second polarizing plate 730 may be attached to the liquid crystal panel 710 by an adhesive layer, respectively. The adhesive layer may be formed of the above-described composition for a pressure-sensitive adhesive layer, and the adhesive layer may further comprise the above-described light-diffusing agent.

Although not shown in FIG. 9, the above-described reflective polarizing film may be further formed between the second polarizing plate 730 and the backlight unit 740.

Hereinafter, the configuration and operation of the present invention will be described in more detail with reference to preferred embodiments of the present invention. It is to be understood, however, that the same is by way of illustration and example only and is not to be construed in a limiting sense.

Example 1

An ultraviolet curable resin (551CI, SDI) was coated on the pull-down roll formed with a prismatic pattern having a negative angle (cross-section: triangle, width: 17 탆, apex angle: 65.5 属, aspect ratio: 0.78). One surface of a polycarbonate resin film (CCL600, I-Component) for a base layer was brought into contact with the obtained coating layer and cured to form a prism pattern (refractive index: 1.57) on one surface of the base layer.

(4803PT, Shin Ah T & C) was coated on the other surface of the polycarbonate resin film for the base layer, and a second optical pattern having a triangular cross section having the specifications of the following Table 1 was formed on the obtained coating layer and cured, 1 < / RTI > of the first refractive index pattern layer.

An optical sheet was prepared by coating a UV-curable resin (581CI, manufactured by SDI) directly on the first refractive index pattern layer to make the upper surface flat and curing to form a second refractive index pattern layer having the specifications shown in Table 1 below.

Example 2

An optical sheet was prepared in the same manner as in Example 1, except that an ultraviolet curable resin (152CI, manufactured by SDI) was used in place of the ultraviolet ray curable resin (4803PT, Shin A & T).

Example 3

An optical sheet was produced in the same manner as in Example 1, except that the specifications of the second optical pattern were changed as shown in Table 1 below.

Example 4

A prism pattern was formed on one surface of the substrate layer in the same manner as in Example 1. [

(4803PT, Shin-A & T Co., Ltd.) was coated on the other surface of the base layer and a second optical pattern having the specifications shown in the following Table 1 was formed and cured to obtain a first refractive index pattern layer having the specifications of Table 1 below .

An optical sheet was prepared by coating a UV-curable resin (581CI, manufactured by SDI) directly on the first refractive index pattern layer to make the upper surface flat and curing to form a second refractive index pattern layer having the specifications shown in Table 1 below.

Example 5

An optical sheet was prepared in the same manner as in Example 4, except that an ultraviolet curing resin (162CI, SDI) was used in place of the ultraviolet ray curable resin (581CI, SDI).

Example 6

A prism pattern was formed on one surface of the substrate layer in the same manner as in Example 1. [

(160CI, SDI) was coated on the other side of the substrate layer, and a second optical pattern having the specifications shown in Table 1 below was formed on the obtained coating layer and cured to obtain a first refractive index having a first refractive index Thereby forming a pattern layer.

An ultraviolet curable resin (4803PT, ShinA T & C) was coated on the first refractive index pattern layer to make the upper surface flat and cured to form an optical sheet by forming a second refractive index pattern layer having the specifications shown in Table 1 below.

Example 7

A prism pattern was formed on one surface of the substrate layer in the same manner as in Example 1. [

A second optical pattern having the specifications of the following Table 1 was formed by coating an ultraviolet curable resin (4803PT, Shin-A & T Co., Ltd.) on the other side of the substrate layer to form a first refractive index pattern layer having the specifications of Table 1 below .

An optical sheet was prepared by coating a UV-curable resin (160CI, manufactured by SDI) directly on the first refractive index pattern layer to make the upper surface flat and curing to form a second refractive index pattern layer having the specifications shown in Table 1 below.

Example 8

A prism pattern was formed on one surface of the substrate layer and a first refractive index pattern layer and a second refractive index pattern layer were formed on the other surface of the substrate layer in the same manner as in Example 1. [ A polarizing plate (AMN-6143 CPG05, SDI) was attached to the upper surface of the second refractive index pattern layer to prepare an optical sheet.

Example 9

A prism pattern was formed on one surface of the substrate layer and a first refractive index pattern layer and a second refractive index pattern layer were formed on the other surface of the substrate layer in the same manner as in Example 2. [ A polarizing plate (AMN-6143 CPG05, SDI) was attached to the upper surface of the second refractive index pattern layer to prepare an optical sheet.

Example 10

A prism pattern was formed on one side of the substrate layer and a first refractive index pattern layer and a second refractive index pattern layer were formed on the other side of the substrate layer in the same manner as in Example 3. [ A polarizing plate (AMN-6143 CPG05, SDI) was attached to the upper surface of the second refractive index pattern layer to prepare an optical sheet.

Example 11

A prism pattern was formed on one surface of the substrate layer and a first refractive index pattern layer and a second refractive index pattern layer were formed on the other surface of the substrate layer in the same manner as in Example 4. [ A polarizing plate (AMN-6143 CPG05, SDI) was attached to the upper surface of the second refractive index pattern layer to prepare an optical sheet.

Example 12

A prism pattern was formed on one surface of the substrate layer and a first refractive index pattern layer and a second refractive index pattern layer were formed on the other surface of the substrate layer in the same manner as in Example 5. [ A polarizing plate (AMN-6143 CPG05, SDI) was attached to the upper surface of the second refractive index pattern layer to prepare an optical sheet.

Example 13

A prism pattern was formed on one surface of the base layer and a first refractive index pattern layer and a second refractive index pattern layer were formed on the other surface of the base layer in the same manner as in Example 6. [ A polarizing plate (AMN-6143 CPG05, SDI) was attached to the upper surface of the second refractive index pattern layer to prepare an optical sheet.

Example 14

A prism pattern was formed on one surface of the substrate layer and a first refractive index pattern layer and a second refractive index pattern layer were formed on the other surface of the substrate layer in the same manner as in Example 7. [ A polarizing plate (AMN-6143 CPG05, SDI) was attached to the upper surface of the second refractive index pattern layer to prepare an optical sheet.

Comparative Example 1

A prism pattern was formed on one surface of the substrate layer in the same manner as in Example 1. [

A composition for a coating layer was prepared by mixing an ultraviolet curable resin (581CI, SDI) with a diffusion bead (material: polymethyl methacrylate).

The composition for a coating layer was coated on the other surface of the base layer and cured to prepare an optical sheet having a bead-containing coating layer shown in Table 2 below.

Comparative Example 2

A prism pattern was formed on one surface of the substrate layer in the same manner as in Example 1. [

An ultraviolet curable resin (551CI, manufactured by SDI) was coated on the other side of the substrate layer, and a micro-lens pattern-containing layer having positive angles and specifications as shown in Table 2 below was formed and cured to prepare an optical sheet.

The structures of the optical sheets prepared in Examples and Comparative Examples are shown in Tables 1 and 2 below.

The following properties of the optical sheets prepared in Examples and Comparative Examples were evaluated, and the results are shown in Tables 1 and 2 below.

(1) Relative luminance: Reflective film (3M company, ESR), light guide plate (SDI company, L-806T-MT01) and inverted prism (SDI company, I-Prism13P) were attached to a 1 side edge type LED light source (light source of MT330KKAA47A) (reference) were laminated and the luminance (G1) was measured. At this time, the prism pattern of the inverse prism was arranged so as to be a light incidence plane. Instead of the inverted prism, the optical sheets prepared in Examples and Comparative Examples of the present invention were laminated and the luminance (G2) was measured. Also in this case, the prism pattern of the optical sheet was arranged so as to be a light incident surface. Luminance was measured using EZcontrast (ELDIM). The relative luminance (%) was calculated as G2 / G1 x 100.

(2) Viewing Angle: The liquid crystal display was assembled in the same manner as in (1) and the luminance was measured. The viewing angle in the horizontal direction (the luminance measured at the front side / 2), when the front side is 0 °, the front side is the left side, the right side is the + direction, the left side is -90 °, Is an angle at which the luminance of the light source can be measured. When the front side is 0 °, the lower side is -90 °, the lower side is -90 °, the lower side is -90 °, the lower side is -90 °, the lower side is -90 °, 2) at which the luminance can be measured. The viewing angle is the same value on the left and right sides with respect to the front, and the upper and lower sides have the same values, and the + and - signs in Table 1 and Table 2 are omitted.

The refractive index of the first refractive index pattern layer The second optical pattern The refractive index of the second refractive index pattern layer opponent
Brightness (%) Viewing angle (°) shape Vertex angle
(°) Height
(탆) width
(탆) level
direction Perpendicular
direction Example 1 1.50 Prism of emboss 85 7.1 13 1.60 83.1 32.7 54.2 Example 2 1.54 Prism of emboss 85 7.1 13 1.60 92.2 28.4 54.8 Example 3 1.50 Prism of emboss 75 8.5 13 1.60 76.4 37.5 53.6 Example 4 1.50 Lenticular lens with emboss - 2 5 1.60 83.8 32.6 54.5 Example 5 1.50 Lenticular lens with emboss - 2 5 1.64 76.5 36.3 54.6 Example 6 1.62 Lenticular lens with negative angle - 2.5 5 1.50 74.5 33.1 54.6 Example 7 1.50 Lenticular lens with negative angle - 2.5 5 1.62 81.7 32.5 54.6

Bead containing coating layer The microlens pattern-containing layer opponent
Luminance
(%) Viewing angle (°) Bead
Particle size
(탆) Bead content
(weight%) The refractive index of the coating layer excluding the beads diameter
(탆) Aspect ratio Share
(%) Refractive index level
direction Perpendicular
direction reference - - - - - - - - 27.3 53.7 Comparative Example 1 2 2 1.60 - - - - 71.2 32.8 59.4 Comparative Example 2 - - - 20 0.12 90 1.57 73.5 32.3 55.5

As shown in Table 1, the optical sheets according to Examples 1 to 7 of the present invention can increase the viewing angle in the horizontal direction relative to the reference and minimize the change in the viewing angle in the vertical direction, thereby minimizing the loss of relative brightness.

Although not shown in Table 1, the optical sheets according to Examples 8 to 14 also have the same relative brightness and viewing angles as Examples 1 to 7, respectively, so that the effects of the present invention can be realized.

On the other hand, as shown in Table 2, Comparative Example 1, which is an optical sheet having a bead-containing coating layer formed thereon, Comparative Example 2, which is an optical sheet having a microlens layer formed, increases both the horizontal viewing angle and the vertical viewing angle, .

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (18)

A base layer; An optical pattern layer formed on one surface of the substrate layer and including at least one first optical pattern; And a composite layer formed on the other surface of the substrate layer,
One surface of the base layer is a light incidence surface,
Wherein the multiple layer includes a first refractive index pattern layer and a second refractive index pattern layer formed directly on the first refractive index pattern layer,
Wherein the first refractive index pattern layer and the second refractive index pattern layer have different refractive indices,
Wherein the first refractive index pattern layer comprises at least one second optical pattern,
The second optical pattern is arranged in the same direction as the first optical pattern,
The upper surface of the second refractive index pattern layer is a flat surface,
The aspect ratio of the first optical pattern is 0.71 to 0.96, and the aspect ratio of the second optical pattern is 0.4 to 0.7. The optical sheet according to claim 1, wherein the first refractive index pattern layer has a refractive index lower than that of the second refractive index pattern layer. The optical sheet according to claim 1, wherein the first refractive index pattern layer has a refractive index higher than that of the second refractive index pattern layer. The optical sheet according to claim 1, wherein a difference in refractive index between the first refractive index pattern layer and the second refractive index pattern layer is 0.05 to 0.2. The optical sheet according to claim 1, wherein the first refractive index pattern layer has a refractive index of 1.45 or more. The optical sheet according to claim 1, wherein the second refractive index pattern layer has a refractive index of 1.45 or more. The optical sheet according to claim 1, wherein the first optical pattern includes a prism pattern having a triangular section. The optical sheet according to claim 1, wherein the second optical pattern includes at least one of a relief pattern and a relief pattern. 2. The optical element according to claim 1, wherein the second optical pattern is a lenticular lens, a prism having an n-square section (n is an integer of 3 to 10) and a linear shape in a longitudinal direction, an n-square section (n is an integer of 3 to 10) Wherein the optical sheet includes at least one of a prism whose longitudinal direction is a wave shape, a prism whose curved surface is formed at a top portion and whose cross section is an n-square (n is an integer of 3 to 10), a microlens, and an emboss. The optical sheet according to claim 1, wherein a difference in width between the first optical pattern and the second optical pattern is 3 m or more. The optical sheet according to claim 1, wherein the thickness of the first refractive index pattern layer: the thickness of the second refractive index pattern layer is 1: 0.8 to 1: 1.2. The optical sheet according to claim 1, wherein a polarizing plate is further formed on a light exit surface of said multiple layer. 13. The optical sheet according to claim 12, further comprising a pressure-sensitive adhesive layer including a light-diffusing agent between the composite layer and the polarizing plate. The optical sheet according to claim 12, wherein a reflective polarizing film is further formed between the composite layer and the polarizing plate. An optical display device comprising the optical sheet according to any one of claims 1 to 14. The optical display device according to claim 15, wherein the optical display device comprises a liquid crystal panel, and further comprises a pressure-sensitive adhesive layer containing a light diffusing agent between the liquid crystal panel and the optical sheet. The liquid crystal display according to claim 15, wherein the optical display device comprises a light guide plate, wherein the light guide plate includes a base film, a first coating layer formed on one surface of the base film and including a third optical pattern, And a second coating layer including a fourth optical pattern. 18. The optical device according to claim 17, wherein the third optical pattern includes at least one of a lenticular lens pattern, a prism pattern having a curved top surface, a microlens pattern, and an emboss pattern, wherein the fourth optical pattern includes a microlens pattern, an emboss pattern, and a lenticular lens pattern, which are prisms (n angles and n is an integer of 3 to 10).

Images