TW201626071A - Optical sheet and optical display comprising the same - Google Patents

Abstract

Disclosed herein is an optical sheet and an optical display including the same. The optical sheet includes a base layer, an optical pattern layer formed on a light incident plane of the base layer and including at least one first optical pattern, and a composite layer formed on a light exit plane of the base layer. The composite layer includes a first refractive index pattern layer and a second refractive index pattern layer directly formed on the first refractive index pattern layer. The first refractive index pattern layer and the second refractive index pattern layer have different indices of refraction, and the first refractive index pattern layer includes at least one second optical pattern.

Description

Optical sheet and optical display including the same

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

The liquid crystal display includes a light collecting sheet. The light collecting sheet collects light emitted from the light guiding plate. As the light collecting sheet, an inverted cymbal sheet including a base layer and a ruthenium pattern formed on the light incident plane of the base layer can be used.

The inverted cymbal can improve luminous efficiency by collecting light emitted from the light guiding plate via total reflection of light by means of a pattern shape. In addition, the inverted cymbal can effectively achieve a reduction in thickness of the backlight unit as compared with a typical optical sheet.

However, inverted bracts may provide a narrow viewing angle via excessive light collection. Therefore, a bead-containing coating or microlens pattern can be formed on the upper surface of the inverted cymbal to increase the viewing angle. However, in this configuration, the viewing angle can be increased not only in the direction in which the light is incident on the inverted cymbal from the light source (ie, in the horizontal direction) but also from the light source on the inverted cymbal relative to the light. The direction increases in the vertical direction, thereby causing significant loss of brightness.

In addition, the inverted cymbal has a pointed top and may therefore experience friction with the light guide. The friction may damage the light guide plate, thereby causing a decrease in luminous efficiency. Although this problem can be solved by reducing the hardness of the inverted cymbal, there is a problem that the inverted cymbal may be damaged, thereby causing failure.

The background of the present invention is disclosed in Korean Patent Publication No. 10-2010-0136220 A.

The present invention can provide an optical sheet which can suppress luminance loss by widening a viewing angle in a horizontal direction while minimizing a viewing angle change in a vertical direction, and can be easily assembled to a polarizing plate to be integrated into a panel for an optical display. Thereby, the friction between the light guiding plate and the crucible is minimized, the thickness of the optical display can be reduced, the thickness is thin, and the sheet wrinkles can be prevented; and an optical display including the optical sheet.

According to an aspect of the invention, an optical sheet includes: a base layer; an optical pattern layer formed on a light incident plane of the base layer and including at least one first optical pattern; and a light exiting plane at the base layer a composite layer formed thereon, wherein the composite layer includes a first refractive index pattern layer and a second refractive index pattern layer formed directly on the first refractive index pattern layer, the first refractive index pattern layer and the The second index pattern layer has a different index of refraction, and the first index pattern layer includes at least one second optical pattern.

According to an aspect of the invention, the refractive index of the first refractive index pattern layer is lower than that of the second refractive index pattern layer.

According to an aspect of the invention, the refractive index of the first refractive index pattern layer is higher than that of the second refractive index pattern layer.

According to an aspect of the invention, the refractive index difference between the first refractive index pattern layer and the second refractive index pattern layer is in the range of 0.05 to 0.2.

According to an aspect of the invention, the refractive index of the first refractive index pattern layer is 1.45 or more.

According to an aspect of the invention, the refractive index of the second refractive index pattern layer is 1.45 or more.

According to an aspect of the invention, the first optical pattern comprises a meandering pattern having a triangular cross section.

According to an aspect of the invention, the second optical pattern includes at least one of an embossed pattern and an engraved pattern.

According to an aspect of the invention, the second optical pattern comprises at least one of: a lenticular lens pattern; a 稜鏡 pattern having an n-sided cross section (n is an integer of 3 to 10) and having a linear shape in a longitudinal direction thereof a crucible pattern having an n-sided cross section (n is an integer of 3 to 10) and having a corrugated shape in its longitudinal direction; having a curved surface at the top thereof and having an n-sided cross section (n is an integer of 3 to 10)稜鏡 pattern; microlens pattern; and embossed pattern.

According to an aspect of the invention, the difference in width between the first optical pattern and the second optical pattern is 3 micrometers or more.

According to an aspect of the invention, the ratio of the thickness of the first refractive index pattern layer to the thickness of the second refractive index pattern layer is in the range of 1:0.8 to 1:1.2.

According to an aspect of the invention, the optical sheet further comprises a polarizing plate formed on a light exiting plane of the composite layer.

According to an aspect of the invention, the optical sheet further comprises an adhesive layer disposed between the composite layer and the polarizing plate and comprising a light scattering agent.

According to an aspect of the invention, the optical sheet further comprises a reflective polarizing film disposed between the composite layer and the polarizing plate.

According to another aspect of the invention, an optical display comprising an optical sheet as set forth above is provided.

According to another aspect of the present invention, an optical display includes a liquid crystal panel, and an adhesive layer containing a light scattering agent is further included between the liquid crystal panel and the optical sheet.

According to another aspect of the present invention, an optical display includes a light guide plate including a base film, a first coating layer formed on one surface of the base film and including a third optical pattern, and a substrate A second coating formed on the other surface of the film and comprising a fourth optical pattern.

According to another aspect of the present invention, the third optical pattern includes at least one of: a lenticular lens pattern; a meandering pattern having a curved surface at a top thereof; a microlens pattern; and an embossed pattern, and the fourth The optical pattern includes at least one of: a microlens pattern; a meandering pattern having a polygonal cross section (n-sided cross section, n is an integer of 3 to 10); an embossed pattern; and a lenticular lens pattern.

The embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be understood that the present invention may be embodied in various forms and is not limited to the embodiments described below. In the drawings, parts that are not relevant to the description will be omitted for clarity. Throughout the specification, similar components will be referred to by like reference numerals.

As used herein, spatially relative terms such as "upper" and "lower" are defined with reference to the drawings. Therefore, it should be understood that the term "upper side (surface)" may be used interchangeably with the term "lower side (surface)". It will be understood that when a layer is referred to as being "on" another layer, the layer may be formed directly on the other layer, or an intervening layer may be present. On the other hand, when a layer is referred to as "directly on" another layer, there is no intervening layer.

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

As used herein, the term "radius of curvature" means a radius including an imaginary circle of a curved surface in the case where the optical pattern has a curved surface at the top thereof, or an ambiguous surface including a curved surface in the case of a 稜鏡 pattern. The radius of an imaginary circle tangent to a bevel and a bevel that is tangent to another bevel.

As used herein, the term "top" refers to the portion that is at the uppermost portion relative to the lowermost portion of a structure.

As used herein, the term "horizontal direction" means the direction in which light is received from a light source, and the term "vertical direction" means a direction perpendicular to the direction in which light is received from the light source. In the drawings, assuming that light is received in the Y-axis direction, the Y-axis direction means the horizontal direction and the X-axis direction means the vertical direction. In the drawings, the X-axis, the Y-axis, and the Z-axis are orthogonal to each other.

As used herein, the term "opportunity ratio" means the ratio of the total area of the embossed pattern portion of the microlens pattern to the total area of the layer on which the microlens pattern is formed.

As used herein, the term "(meth)acryl" means "acryl" and/or "methacryl". Optical sheet

Hereinafter, an optical sheet according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

1 is a perspective view of an optical sheet according to an embodiment of the present invention, and FIG. 2 is an exploded cross-sectional view taken along line I-II of FIG. 1.

Referring to FIG. 1, an optical sheet 100 according to an embodiment of the present invention may include a base layer 110; an optical pattern layer 120 including at least one first optical pattern 121; and a first refractive index pattern layer 131 and a second refractive index pattern. Composite layer 130 of layer 132.

The base layer 110 is disposed between the optical pattern layer 120 and the composite layer 130 to support the optical pattern layer 120 and the composite layer 130.

The lower surface of the base layer 110 may be a light incident plane, and the upper surface of the base layer 110 may be a light exiting plane. The base layer 110 is configured to allow light exiting the optical pattern layer 120 to pass therethrough into the composite layer 130.

The base layer 110 may be formed of an optically transparent resin. For example, the resin may include a polycarbonate resin; a polyester resin including poly(methyl) methacrylate; and a (meth)acrylic resin, and the like.

The base layer 110 may have a thickness of from 10 micrometers to 300 micrometers, such as from 25 micrometers to 100 micrometers. Within this range, the substrate layer 110 can be used in an optical display.

The optical pattern layer 120 is formed on one surface of the base layer 110 and is used to collect light received from a light guide plate or other optical sheets (not shown in FIG. 1) and to emit the collected light to the base layer 110, thereby increasing brightness. And luminous efficiency.

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

The refractive index of the optical pattern layer 120 may be 1.40 or more, for example, 1.40 to 1.60. Within this refractive index range, the optical pattern layer ensures light collection.

The optical pattern layer 120 may be formed of an optically clear UV curable resin. For example, the UV curable resin may include at least one of (meth)acrylic resin, polycarbonate resin, poly(methyl)methyl acrylate resin, urethane resin, and the like.

The thickness of the optical pattern layer 120 can range from 2 microns to 30 microns, such as from 5 microns to 15 microns. Within this thickness range, the optical pattern layer ensures light collection.

The optical pattern layer 120 may include at least one first optical pattern 121 formed on a lower surface of the optical pattern layer corresponding to the light incident plane.

The first optical pattern 121 may be formed on the base layer 110 and constitute a light incident plane. The first optical pattern 121 may collect light emitted from a light guide plate or other optical sheets (not shown in FIG. 1) via total reflection, thereby improving luminous efficiency.

The first optical pattern 121 may include a meandering pattern having a triangular cross section. FIG. 1 illustrates an optical sheet in which the first optical pattern 121 has a triangular cross section. Alternatively, the first optical pattern may include at least one of the following: a 稜鏡 pattern having an n-sided cross section (n is an integer of 4 to 10); and a curved surface at the top thereof and having an n-sided cross section (n is an integer 3 to 10) 稜鏡 pattern.

Referring to FIG. 2, the width P1 of the first optical pattern 121 may be 5 micrometers to 20 micrometers, for example, 7 micrometers to 18 micrometers. The height H1 of the first optical pattern 121 may be from 3 micrometers to 15 micrometers, for example, from 4 micrometers to 14 micrometers. The apex angle α1 of the first optical pattern 121 may be 55° to 75°, for example, 60° to 70°. Within these widths, heights, and apex angles, the first optical pattern can increase luminous efficiency via efficient light collection.

The aspect ratio of the first optical pattern 121 may be from 0.71 to 0.96, such as from 0.76 to 0.87. Within this range, the first optical pattern can improve luminous efficiency via efficient light collection.

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 the light is received from the light source (in the Y direction in FIG. 1).

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

The composite layer 130 is formed on the other surface of the base layer 110 and emits light received from the base layer 110 via light scattering therein. Thus, the composite layer 130 can increase the viewing angle in the horizontal direction while minimizing the viewing angle variation in the vertical direction as compared to an optical sheet that does not include such a composite layer. Furthermore, the composite layer 130 can minimize brightness loss compared to optical sheets in which the bead coating or microlens pattern is formed on the upper surface of the substrate layer.

The lower surface of the composite layer 130 may be a light incident plane, and the upper surface of the composite layer 130 may be a light exiting plane.

Composite layer 130 can have a thickness from 5 microns to 50 microns, such as from 5 microns to 25 microns. Within this range, the composite layer can be used in an optical display.

The composite layer 130 may include a first index pattern layer 131 and a second index pattern layer 132 formed directly on the first index pattern layer 131, wherein the first index pattern layer 131 and the second index pattern layer 132 may be Have different refractive indices. In the case of this composite layer structure, when the composite layer 130 receives light from the base layer 110, light scattering simultaneously passes through the composite layer 130, thereby minimizing the change in the viewing angle in the vertical direction while widening the viewing angle in the horizontal direction. Minimize brightness loss.

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

Referring to FIG. 2, a first refractive index pattern layer 131 is formed between the upper surface of the base layer 110 and the second refractive index pattern layer 132, and is used to emit light to the second via light scattering when receiving light from the base layer 110. Refractive index pattern layer 132.

The lower surface of the first refractive index pattern layer 131 may be a light incident plane, and the upper surface of the first refractive index pattern layer 131 may be a light exiting plane. That is, the first refractive index pattern layer 131 may be formed directly on the base layer and may be connected to its light exiting plane.

The refractive index of the first refractive index pattern layer 131 may be lower than that of the second refractive index pattern layer 132. In the case of this structure, the optical sheet can widen the viewing angle in the horizontal direction by promoting light scattering. For example, the difference in refractive index between the second refractive index pattern layer 132 and the first refractive index pattern layer 131 may be 0.2 or less, such as 0.05 to 0.2, such as 0.06 to 0.18. Within this range, it is possible to further widen the viewing angle in the horizontal direction.

The refractive index of the first refractive index pattern layer 131 may be 1.45 or more, for example, 1.50 to 1.65. Within this range, when the light received from the optical pattern layer emits the first refractive index pattern layer 131, the first refractive index pattern layer 131 widens the viewing angle in the horizontal direction while maintaining the viewing angle in the vertical direction, thereby reducing the luminance loss. .

The first refractive index pattern layer 131 may have a thickness of 2 micrometers to 20 micrometers, for example, 2 micrometers to 10 micrometers. Within this range, the first refractive index pattern layer 131 can be used for an optical display.

The first refractive index pattern layer 131 may be formed of an optically clear UV curable resin. For example, the resin may include (meth)acrylic resin, polyester resin, polycarbonate resin, styrene resin, and the like. The UV curable resin exhibits adhesion after curing, thereby promoting formation of the second refractive index pattern layer 132.

The first index pattern layer 131 includes a first surface 133 corresponding to its upper surface, and may include at least one second optical pattern 135 formed on the first surface 133.

The second optical pattern 135 scatters light received from the substrate layer 110 to widen the viewing angle in the horizontal direction, thereby minimizing luminance loss.

The second optical pattern 135 may be an embossed pattern having a curved surface. When light is emitted from the first refractive index pattern layer 131 to the second refractive index pattern layer 132, the curved surface may promote light scattering.

The second optical pattern 135 may be a lenticular lens pattern. 1 and 2 illustrate an optical sheet in which the second optical pattern 135 is a lenticular lens pattern. Alternatively, the second optical pattern may include at least one of the following: a 稜鏡 pattern having an n-sided cross section (n is an integer of 3 to 10) and having a linear shape in a longitudinal direction thereof; having an n-sided cross section (n is An integer of 3 to 10) and having a wavy shape in its longitudinal direction; a ruthenium pattern having a curved surface at its top and having an n-sided cross section (n is an integer of 3 to 10); a microlens pattern; Floral patterns, and similar patterns.

The height H2 of the second optical pattern 135 may be from 2 micrometers to 20 micrometers, for example, from 2 micrometers to 10 micrometers. The width P2 of the second optical pattern 135 may be from 5 micrometers to 30 micrometers, such as from 5 micrometers to 15 micrometers. The second optical pattern 135 may have a radius of curvature of from 3 micrometers to 50 micrometers, such as from 3 micrometers to 25 micrometers. Within these heights, widths, and radii of curvature, the second optical pattern ensures widening of the viewing angle in the horizontal direction.

The second optical pattern 135 may have an aspect ratio of 0.1 to 1.5, such as 0.3 to 1.0, such as 0.4 to 0.7. Within this range, the second optical pattern ensures the effect of widening the viewing angle in the horizontal direction.

In the case where the width of the second optical pattern 135 is narrower than that of the first optical pattern 121, it is possible to prevent the phenomenon of moiré. For example, the difference in width (P1-P2) between the first optical pattern 121 and the second optical pattern 135 may be 3 microns or greater than 3 microns, such as 3 microns to 15 microns. Within this width difference range, it is possible to prevent ripples.

The second optical patterns 135 may be aligned substantially in the same direction as the first optical patterns 121. As used herein, the expression "substantially in the same direction" includes not only the arrangement in exactly the same direction, but also the arrangement in which the directions are slightly different.

The second refractive index pattern layer 132 is directly formed on the first refractive index pattern layer 131, and when light is received from the first refractive index pattern layer 131 and the second optical pattern 135, light is emitted via light scattering, thereby widening The viewing angle in the horizontal direction simultaneously minimizes the brightness loss.

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

The lower surface of the second index pattern layer 132 includes a second plane 134 that can be formed directly on the first plane 133 of the first index pattern layer 131. The second plane 134 can have an optical pattern 136 formed thereon to face the second optical pattern 135.

The upper surface of the second refractive index pattern layer 132 is a flat surface, and can 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, for example, 1.50 to 1.65. Within this range, the second refractive index pattern layer can widen the viewing angle in the horizontal direction while reducing the luminance loss when the light is emitted after receiving the light from the optical pattern layer.

The second refractive index pattern layer 132 may be formed of an optically clear UV curable resin. For example, the resin may include (meth)acrylic resin, polyester resin, polycarbonate resin, styrene resin, and the like. The UV curable resin exhibits adhesion after curing, thereby promoting formation of polarizing plates 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 from 3 micrometers to 20 micrometers, such as from 5 micrometers to 15 micrometers. Within this range, the second index pattern layer 132 can be used in an optical display.

The thickness ratio of the first refractive index pattern layer 131 to the second refractive index pattern layer 132 may range from 1:0.8 to 1:1.2, for example, 1:0.9 to 1:1.1. Within this range, the optical sheet can have a widened 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 to further widen by further scattering light. The viewing angle in the horizontal direction. For example, the light scattering agent may include an inorganic light scattering agent, an organic light scattering agent, or a mixture thereof, and the like. The inorganic light scattering agent may include at least one of calcium carbonate, barium sulfate, titanium dioxide, aluminum hydroxide, cerium oxide, glass, talc, mica, white carbon, magnesium oxide, zinc oxide, and the like. The organic light scattering agent may include at least one of (meth)acrylic particles, siloxane beads, melamine particles, polycarbonate particles, styrene particles, and the like. Although not particularly limited to a certain size and shape, the light scattering agent may include spherical particles having an average particle diameter of from 1 μm to 5 μm. Within this range, the light scattering agent ensures light scattering without protruding from the optical sheet.

Moreover, although not shown in FIG. 1, the second optical pattern 135 may further include roughness to further promote light scattering.

Further, although not shown in FIG. 1, the second refractive index pattern layer 132 may further include an adhesive layer formed on the upper surface thereof to attach the optical sheet 100 to a panel for an optical display, such as a polarizing plate or a liquid crystal panel. . That is, the liquid crystal panel can be formed on the upper side of the optical sheet. The adhesive layer may be formed of a composition for an adhesive layer including an adhesive resin and a crosslinking agent. The adhesive resin may include at least one of (meth)acrylic resin, urethane resin, and anthrone resin. The composition for the adhesive layer may further include a light scattering agent to further scatter light. Alternatively, when the resin used for the second refractive pattern layer exhibits adhesiveness after curing, the adhesive layer may be omitted.

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

Figure 3 is a cross-sectional view of an optical sheet in accordance with another embodiment of the present invention.

Referring to FIG. 3, an optical sheet 200 according to another embodiment of the present invention may include a base layer 110; an optical pattern layer 120 including at least one first optical pattern 121; and a second surface 135a including at least one second optical pattern 135a formed thereon A composite layer 130a of a refractive index pattern layer 131a and a second refractive index pattern layer 132a. The optical sheet 200 according to this embodiment is substantially the same as the optical sheet according to the previous embodiment except that the second optical pattern 135a of the optical sheet 200 is an engraved lenticular lens pattern.

Subsequently, 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 in accordance with another embodiment of the present invention.

Referring to FIG. 4, an optical sheet 300 according to another embodiment of the present invention may include a base layer 110; an optical pattern layer 120 including at least one first optical pattern 121; and a second surface 135a including at least one second optical pattern 135a formed thereon A composite layer 130b of a refractive index pattern layer 131b and a second refractive index pattern layer 132b. The optical sheet 300 according to this embodiment is substantially the same as the optical sheet according to other embodiments except that the refractive index of the first refractive index pattern layer 131b is higher than that of the second refractive index pattern layer 132b.

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

Figure 5 is a cross-sectional view of an optical sheet in accordance with still another embodiment of the present invention.

Referring to FIG. 5, an optical sheet 400 according to still another embodiment may include: a base layer 110; an optical pattern layer 120 including at least one first optical pattern 121; and a first refraction including at least one second optical pattern 135c formed thereon The composite layer 130c of the pattern layer 131c and the second index pattern layer 132c. The optical sheet 400 according to this embodiment is substantially the same as the optical sheet according to the previous embodiment except that the second optical pattern 135c of the optical sheet 400 is a 稜鏡 pattern having a triangular cross section. Therefore, the following description will be given only for the second optical pattern 135c.

The height H3 of the second optical pattern 135c may be from 2 micrometers to 20 micrometers, for example, from 2 micrometers to 10 micrometers. The width P3 of the second optical pattern 135c may be from 5 micrometers to 30 micrometers, for example, from 5 micrometers to 15 micrometers. The apex angle α2 of the second optical pattern 135c may be 60° to 120°, for example, 65° to 100°, for example, 65° to 90°. Within these widths, heights, and apex angles, the second optical pattern 135c ensures widening of the viewing angle in the horizontal direction.

The second optical pattern 135c may have an aspect ratio of 0.1 to 1.5, such as 0.3 to 1.0, such as 0.4 to 0.7. Within this range, the second optical pattern 135c ensures the effect of widening the viewing angle in the horizontal direction.

Although the second optical pattern 135c according to the embodiment shown in FIG. 5 is shown as having a triangular cross section, the second optical pattern may include at least one of the following: having an n-sided cross section (n is an integer) 3 to 10) and a serpentine pattern having a linear shape in its longitudinal direction; a serpentine pattern having an n-sided cross section (n is an integer of 3 to 10) and having a corrugated shape in its longitudinal direction; a curved surface having an n-sided cross section (n is an integer of 3 to 10); a microlens pattern; an embossed pattern, and the like.

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

Figure 6 is a cross-sectional view of an optical sheet in accordance with still another embodiment of the present invention.

Referring to FIG. 6, an optical sheet 500 according to still another embodiment may include: a base layer 110; an optical pattern layer 120 including at least one first optical pattern 121; and a first refractive index including at least one second optical pattern 135 formed thereon a composite layer 130 of the pattern layer 131 and the second refractive index pattern layer 132; and a polarizing plate 140.

In the case where the polarizing plate 140 is further formed on the composite layer 130, that is, on the light exiting plane of the composite layer 130, the polarizing plate 140 may be bonded to a panel for an optical display (not shown in FIG. 6). Thereby the optical sheet can be fixed to the panel for the optical display. In the case of this structure, the friction between the optical sheet and the light guiding plate can be minimized, and the reduction in the thickness of the optical sheet ensures that the thickness of the optical display is reduced without sheet wrinkles.

The optical sheet according to this embodiment is substantially the same as the optical sheet according to the previous embodiment except that the optical sheet according to this embodiment further includes a polarizing plate. Therefore, the following description will be given only for the polarizing plate.

The polarizing plate 140 is disposed on the upper surface of the composite layer 130 to achieve polarization of light received from the composite layer 130.

The polarizing plate 140 may be integrated into the composite layer 130, the base layer 110, and the optical pattern layer 120. Therefore, the optical sheet is fixed to the panel for the optical display, thereby preventing the sheet from wrinkling while achieving the compact optical sheet. As used herein, the term "integrated" means that the polarizing plate, composite layer, substrate layer, and optical pattern layer are not separated from each other by physical forces into separate components.

The polarizing plate 140 may include a typical polarizing plate. In one embodiment, the polarizing plate can be used alone. In another embodiment, the polarizing plate may include a polarizer and a protective film formed on one or both surfaces of the polarizer. In another embodiment, the polarizing plate may include a polarizer and a protective layer formed on one or both surfaces of the polarizer.

As the polarizer, the protective film, and the protective layer, a typical polarizer, a protective film, and a protective layer known to those skilled in the art can be used.

The polarizer is used to allow display of a display device by polarized natural light or artificial light, and is mainly made of a polyvinyl alcohol film. In one embodiment, the polarizer can be fabricated by modifying a modified polyvinyl alcohol film (such as a formalized polyvinyl alcohol film and an acetamidine group) with iodine or a dichroic dye. The polyvinyl alcohol film was dyed and then the film was stretched in the machine direction (MD). For example, a polarizer is produced by swelling, dyeing, and stretching. One method of performing such processes is generally known to those skilled in the art. In another embodiment, the polarizer can be manufactured by using an acid catalyst impregnating membrane using a coating solution containing an acid catalyst and polyvinyl alcohol, and dipping the acid catalyst to dehydrate the membrane to provide a dehydrated film. The dehydrated film is then subjected to hydration, wet stretching and neutralization.

The polarizer may have a thickness of from 3 micrometers to 50 micrometers. Within this range, the polarizer can be used for an optical display.

A protective film is formed on one or both surfaces of the polarizer to protect the polarizer, and may include a typical optically transparent film. For example, the protective film may be formed of at least one of the following resins: a cyclic polyolefin (COP) such as an amorphous cyclic polyolefin resin; a poly(meth) acrylate resin; a polycarbonate resin; a polyester resin, Including polybutylene terephthalate (PET); cellulose esters, including triacetyl cellulose; polyether oxime resin; polyfluorene resin; polyamide resin; polyimine resin; polyolefin resin; Ester resin; polyvinyl alcohol resin; polyvinyl chloride resin; polyvinylidene chloride resin, and the like.

The thickness of the protective film may be from 10 micrometers to 200 micrometers, for example, from 30 micrometers to 120 micrometers, but is not limited thereto. Within this range, a protective film can be used for the optical display.

The protective layer is formed on one or both surfaces of the polarizer to protect the polarizer from heat and moisture while preventing cracks from occurring in the polarizer.

The protective layer may have a predetermined thickness range to strengthen the polarizing plate, which may suffer from a decrease in mechanical strength due to formation of an optical film only on one surface thereof; at the same time, achieve a thinner thickness. For example, the thickness of the protective layer can range from 1 micron to 30 microns, such as from 2 microns to 25 microns. Within this thickness range, the protective layer can be used for the polarizing plate and the polarizing plate can be strengthened.

The polarizing plate 140 may have a thickness of 30 micrometers to 200 micrometers, for example, 50 micrometers to 200 micrometers. Within this range, a polarizing plate can be used for an optical display.

Although not shown in FIG. 6, the polarizing plate 140 may be disposed on the composite layer 130 via an adhesive layer. The adhesive layer may be formed of a composition for an adhesive layer including an adhesive resin and a crosslinking agent. The adhesive resin may include at least one of (meth)acrylic resin, urethane resin, fluorenone resin, and the like. The composition for the adhesive layer may further include the aforementioned light scattering agent to promote light scattering. However, when the resin for the second refraction pattern layer exhibits adhesiveness after curing, the polarizing plate 140 may be formed directly on the composite layer 130 without an adhesive layer.

Further, although not shown in FIG. 6, an adhesive layer may be further formed on the upper surface of the polarizing plate 140 to bond the polarizing plate 140 to the panel for an optical display. The adhesive layer may be formed of the composition described above and may further include a light scattering agent.

Further, although not shown in FIG. 6, the reflective polarizing film may be further disposed between the composite layer 130 and the polarizing plate 140. A reflective polarizing film is used to minimize light loss and recover light, and has a multilayer structure in which two polymer layers having different refractive indices are alternately stacked one on another. The reflective polarizing film may reflect only the light component traveling in the oscillation direction parallel to the transmission axis while reflecting other light components by selectively reflecting and transmitting the light via the polarization separation function. By way of example, the reflective polarizing film has a structure in which a plurality of polymer layers having the same refractive index in the X-axis direction and different refractive indices on the Y-axis are alternately stacked one on another. Here, the X-axis direction providing the same refractive index corresponds to the transmission axis of the light transmission, and the Y-axis direction providing the different refractive indices corresponds to the reflection axis of the light reflection. Therefore, among the light components, the P wave is transmitted through the reflective polarizing film and the S wave is continuously reflected by the reflective polarizing film for reuse. As the reflective polarizing film, for example, a double brightness enhancement film (DBEF, 3M) can be used. The reflective polarizing film can be formed by alternately stacking a first polymer layer having a thickness of 15 μm to 25 μm and a refractive index of 1.45 to 1.49 and a second polymer layer having a thickness of 15 μm to 25 μm and a refractive index of 1.51 to 1.58. And formed. The total thickness of the reflective polarizing film may range from 120 microns to 150 microns.

The reflective polarizing film may be disposed between the composite layer 130 and the polarizing plate 140 via an adhesive layer. The adhesive layer can be formed of a composition for an adhesive. The adhesive layer may further include the light scattering agent described above. Manufacturing optical sheets

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

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

An optical pattern layer is formed on one surface of the base layer. For example, the optical pattern layer can be formed by applying a composition for the optical pattern layer onto the engraved pattern roll on which the engraved first optical pattern is formed, and making the light incident plane and coating of the base layer The composition on the engraved pattern roll is contacted and the composition is cured. The composition can be applied by any coating method such as die coating, slip coating, bar coating, and the like, but is not limited thereto. Curing can be achieved by UV curing, for example by irradiating UV light at a flux of from 100 mJ/cm to 250 mJ/cm.

A composite layer is formed on the other surface of the base layer, thereby producing an optical sheet. For example, the composite layer can 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 can be formed by applying a composition for the second optical pattern onto the engraved pattern roll on which the engraved second optical pattern is formed, and exposing the light of the base layer to the plane and coating. The composition on the engraved pattern roll is contacted and the composition is cured. The composition can be applied by any coating method such as, but not limited to, die coating, slip coating, and bar coating. Curing can be achieved by UV curing, for example by irradiating UV light at a flux of from 100 mJ/cm to 250 mJ/cm. The second refractive index pattern layer may be formed by directly coating a composition for the second refractive index pattern layer onto the first refractive index pattern layer, followed by coating. The composition can be applied by any coating method such as, but not limited to, die coating, slip coating, and bar coating. Curing can be achieved by UV curing, for example by irradiating UV light at a flux of from 100 mJ/cm to 250 mJ/cm.

Although the optical sheets are manufactured by sequentially forming an optical pattern layer and a composite layer on the base layer in the above embodiments, it should be understood that a composite layer may be formed in front of the optical pattern layer in the manufacture of the optical sheets.

After forming the composite layer, the polarizing plate may be stacked on the upper surface of the composite layer, that is, its light exiting the plane. For example, the polarizing plate can be formed by a typical method known in the art. For example, a polarizer is made using a polyvinyl alcohol resin, and then the protective film is bonded to one or both surfaces of the polarizer. Thereafter, in the case where the adhesive is applied onto the upper surface of the composite layer, the polarizing plate is attached to the upper surface of the composite layer via an adhesive, followed by curing.

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

Subsequently, a backlight unit according to an embodiment of the present invention will be described with reference to FIG.

Figure 7 is a cross-sectional view of a backlight unit in accordance with one embodiment of the present invention.

Referring to FIG. 7, a backlight unit 600 according to an embodiment of the present invention includes a light source 610, a light guiding plate 630 disposed to guide light received from the light source 610, a reflective sheet 620, and an optical sheet 640, wherein the optical sheet 640 may include An optical sheet of an embodiment of the present invention.

Light source 610 produces light and can be implemented by various light sources, such as line source lights, surface light sources, cold cathode fluorescent lamps (CCFLs), or light emitting diodes (LEDs). The backlight unit may further include a light source that covers the outside of the light source 610 and protects the light source.

The light source 610 can be disposed on one side of the light guide plate 630. However, the light source 610 can be disposed on the opposite side of the light guide plate 630 to increase brightness.

The reflective sheet 620 is disposed under the light guiding plate 630 and serves to reflect the light generated by the light source 610 so that the reflected light can enter the light guiding plate 630 again, thereby improving luminous efficiency.

When receiving light from the light source 610, the light guide plate 630 is used to guide the light to the optical sheet 640. Light guide plate 630 can include a typical light guide plate known to those skilled in the art.

Figure 8 is a perspective view of a light guide plate in accordance with the embodiment of Figure 7.

Referring to FIG. 8, a light guiding plate 630 according to the embodiment may include a base film 551; a first coating 554 formed on one surface of the base film 551 and including a third optical pattern 555 having a curved surface at the top thereof; A second coating 552 is formed on the other surface of the base film 551 and includes a fourth optical pattern 553. A light guide plate can be formed on the underside of the optical sheet.

The base film 551 can support the first coating 554 and the second coating 552, and can guide light to the optical sheet when receiving light from the light source.

The thickness of the base film 551 may be from 200 micrometers to 700 micrometers, for example, from 300 micrometers to 500 micrometers. Within this thickness range, the base film can be used in optical displays.

The refractive index of the base film 551 may be 1.50 or more, for example, 1.50 to 1.60. Within this range, the base film can increase the light emission ratio, thereby improving the luminous efficiency.

The base film 551 can be formed of a resin having a refractive index of 1.50 or more, for example, 1.50 to 1.60. For example, the base film may be formed of a polycarbonate resin, a poly(methyl) methacrylate resin, and the like. In particular, the polycarbonate resin is advantageous in terms of a reduction in the thickness of the base film.

The first coating layer 554 is formed on one surface of the base film 551 to increase the brightness by preventing light scattering, and allows light to be emitted when receiving light from the base film 551.

The first coating 554 can have a thickness of from 10 microns to 40 microns. Within this range, the first coating can be used in an optical display.

The first coating 554 can have a refractive index of 1.50 to 1.65. Within this range, the first coating layer can increase the light emission ratio, thereby improving the luminous efficiency.

The first coating 554 can be formed of a resin for the first coating having a refractive index of 1.50 to 1.65. The resin for the first coating layer may include a UV curable resin which may be selected from the group consisting of, for example, (meth)acrylic resin, polycarbonate resin, styrene resin, olefin resin, polyester resin, and combinations thereof .

The first coating 554 can include a third optical pattern 555.

The third optical pattern 555 is formed on one surface of the base layer 551 and may include an optical pattern having at least one curved surface at the top thereof. Although FIG. 8 illustrates a light guide plate having a lenticular lens pattern as the third optical pattern 555, it should be understood that there is no limitation with respect to the third optical pattern 555 as long as the third optical pattern has a curved surface at the top thereof. For example, the third optical pattern may include at least one selected from the group consisting of: a ruthenium pattern having a curved surface (having an n-sided cross section, n being an integer of 3 to 10) at the top thereof; a microlens pattern ; and embossed patterns.

The third optical pattern 555 may have an aspect ratio of 0.10 to 0.50, and the curved surface of the third optical pattern 555 may have a radius of curvature of 10 micrometers to 35 micrometers. Within this range, the third optical pattern 555 is used to guide and scatter the received light while narrowing the viewing angle in the vertical direction, thereby improving visual sensitivity and brightness.

The third optical pattern 555 may have a width of from 10 micrometers to 50 micrometers and a height of from 1 micrometer to 35 micrometers. Within this range, the third optical pattern can collect light in the left-to-right direction to improve luminous efficiency, and can be used to guide and scatter the received light while narrowing the viewing angle in the vertical direction, thereby improving visual sensitivity. And brightness.

Although the third optical pattern 555 can have a different refractive index than the first coating 554, the third optical pattern can be formed to have the same refractive index as the first coating to improve processability.

A second coating 552 is formed on the other surface of the base film 551 and can be used to prevent some of the light that has been scattered by the light of the base film 551 and used to reflect the light source from which it emits.

The second coating 552 may have a thickness of from 0.6 micrometers to 5 micrometers. Within this range, the second coating 552 can be used for a liquid crystal display.

The second coating 552 may have a refractive index of 1.50 to 1.65. Within this range, the second coating 552 can increase the light emission ratio, thereby improving the luminous efficiency.

The second coating 552 can be formed of a resin for the second coating having a refractive index of 1.50 to 1.65. The resin for the second coating layer may include a UV curable resin which may be selected from the group consisting of, for example, (meth)acrylic resin, polycarbonate resin, styrene resin, olefin resin, polyester resin, and combinations thereof . The second coating 552 may be formed of the same resin as the first coating 554 or a different resin.

The second coating 552 can include a fourth optical pattern 553.

The fourth optical pattern 553 is formed on the other surface of the base film 551 and may have an aspect ratio of 0.01 to 0.07. Within this range, the fourth optical pattern 553 can increase the efficiency of collecting light exiting the light guide plate. For example, the fourth optical pattern may have an aspect ratio of 0.01 to 0.06.

Although the fourth optical pattern 553 is shown as the microlens pattern in FIG. 8, there is no limitation regarding the fourth optical pattern as long as the aspect ratio of the fourth optical pattern 553 is 0.01 to 0.07. For example, the fourth optical pattern may be a meandering pattern having a polygonal cross section (n-sided cross section, n is an integer of 4 to 10); a meandering pattern having a triangular cross section; an embossed pattern; or a lenticular lens pattern. In one embodiment, the fourth optical pattern may be a ruthenium pattern having a triangular cross section having a width of 50 micrometers to 150 micrometers, a height of 0.5 micrometers to 5.0 micrometers, and an apex angle of 1.2 to 3.5 degrees.

The fourth optical pattern 553 may have a width of from 10 micrometers to 100 micrometers and a height of from 0.5 micrometers to 5 micrometers, such as from 1 micrometer to 5 micrometers. Within this range, the fourth optical pattern can have improved light collection efficiency, thereby improving luminous efficiency. In particular, the height of the fourth optical pattern 553 is lower than that of the typical light guide plate to reduce the aspect ratio, thereby improving the light-emitting efficiency by improving light collection even when a light collecting sheet having an inverted 稜鏡 pattern is used.

Although the fourth optical pattern 553 may have a different refractive index than the second coating 552, the fourth optical pattern may be formed to have the same refractive index as the second coating to improve workability.

In the light guiding plate 630 according to the embodiment, the third optical pattern 555 is disposed to have a certain aspect ratio and a radius of curvature range, and the fourth optical pattern 553 is also disposed to have a certain aspect ratio and a radius of curvature range to enter the light guide. The light of the plate can be emitted at a specific emission angle (for example, at 60° to 80° or, for example, 70° to 75°) with respect to the base film, thereby improving light emission even when a light collecting sheet having an inverted 稜鏡 pattern is disposed. effectiveness.

An optical display according to the present invention may include an optical sheet or a backlight unit including the same according to an embodiment of the present invention. The optical display can be a liquid crystal display. LCD Monitor

Subsequently, a liquid crystal display according to an embodiment of the present invention will be described with reference to FIG.

Figure 9 is a cross-sectional view of a liquid crystal display according to an embodiment of the present invention.

Referring to FIG. 9, a liquid crystal display 700 according to an embodiment of the present invention includes a liquid crystal panel 710; a first polarizing plate 720 formed on an upper surface of the liquid crystal panel 710; and a second polarizing plate formed on a lower surface of the liquid crystal panel 710. 730; and a backlight unit 740 disposed under the second polarizing plate 730, wherein the backlight unit 740 can include a backlight unit according to an embodiment of the present invention.

The liquid crystal panel 710 includes a liquid crystal cell layer encapsulated between the first substrate and the second substrate, wherein the liquid crystal cell layer can be a vertical alignment (VA) mode, an in-place switching (IPS) mode, a fringe field switching (FFS) mode, and a twist. Neighbor (TN) mode or similar mode.

Each of the first and second polarizing plates 720, 730 may include a typical polarizing plate. The first polarizing plate 720 and the second polarizing plate 730 are respectively disposed on the upper surface and the lower surface of the liquid crystal panel 710, and thus the protective film and/or the protective layer included in the upper and lower polarizing plates are in terms of material, thickness and the like. Words can have different characteristics. Further, a liquid crystal display including the first polarizing plate 720 instead of the second polarizing plate 730 is also within the scope of the present invention.

The backlight unit 740 may include a backlight unit according to an embodiment of the present invention. In the case where the backlight unit according to the embodiment of the present invention includes the structure of the optical sheet including the polarizing plate, the liquid crystal display 700 according to the embodiment can omit the second polarizing plate 730. The liquid crystal display 700 according to the embodiment may further include an adhesive layer disposed between the liquid crystal panel 710 and the optical sheets of the backlight unit 740. The adhesive layer may be formed of a composition for the adhesive layer, and may further include the light scattering agent described above.

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 via an adhesive layer, respectively. The adhesive layer may be formed of the aforementioned composition for the adhesive layer, and may further include the light scattering agent described above.

Although not shown in FIG. 9, the liquid crystal display may further include the foregoing reflective polarizing film disposed between the second polarizing plate 730 and the backlight unit 740.

The invention will then be described in more detail with reference to some examples. It is to be understood that the examples are provided for illustration only and are not to be construed as limiting the invention in any way. Example 1

A UV curable resin (551 CI, SDI Co., Ltd.) was applied to have an engraved enamel pattern (section: triangle, width: 17 μm, apex angle: 65.5°, aspect ratio: 0.78) Engraving on the pattern roll. One surface of a polycarbonate resin film (CCL600, I-Component Co., Ltd.) used for the base layer is in contact with the coating and solidified, thereby forming on the light incident plane of the base layer.稜鏡 pattern (refractive index: 1.57).

A UV curable resin (4803PT, Shina T&C) was applied to the other surface of the polycarbonate resin film and allowed to cure, and on the other surface of the polycarbonate resin film on the coating A second optical pattern having a triangular cross section and having the specifications listed in Table 1 was formed, followed by curing, thereby forming a first refractive index pattern layer having the specifications listed in Table 1.

A UV curable resin (581 CI, SDI Co., Ltd.) was directly coated onto the upper surface of the first refractive index pattern layer to form a flat upper surface, which was then cured to form a second having the specifications listed in Table 1. A refractive index pattern layer, thereby producing an optical sheet. Example 2

An optical sheet was produced in the same manner as in Example 1 except that a UV curable resin (152CI, SDI Co., Ltd.) was used instead of the UV curable resin (4803PT, Shina T&C). 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 listed in Table 1. Example 4

A ruthenium pattern was formed on the light incident plane of the underlayer in the same manner as in Example 1.

A UV curable resin (4803PT, Shina T&C) was applied to the light exit plane of the substrate layer to form a second optical pattern having the specifications listed in Table 1, and then cured, thereby forming the composition in Table 1. The first index pattern layer of the specification is listed.

A UV curable resin (581 CI, SDI Co., Ltd.) was directly coated onto the upper surface of the first refractive index pattern layer to form a flat upper surface, which was then cured to form a second having the specifications listed in Table 1. A refractive index pattern layer, thereby producing an optical sheet. Example 5

An optical sheet was produced in the same manner as in Example 4 except that a UV curable resin (162CI, SDI Co., Ltd.) was used instead of the UV curable resin (581 CI, SDI Co., Ltd.). Example 6

A ruthenium pattern was formed on the light incident plane of the underlayer in the same manner as in Example 1.

A UV curable resin (160CI, SDI Co., Ltd.) was applied to the light exit plane of the substrate layer to form a second optical pattern having the specifications listed in Table 1, and then cured, thereby forming the composition in Table 1. The first index pattern layer of the specification is listed.

A UV curable resin (4803PT, Shina T&C) was directly coated onto the upper surface of the first refractive index pattern layer to form a flat upper surface, which was then cured to form a second having the specifications listed in Table 1. A refractive index pattern layer, thereby producing an optical sheet. Example 7

A ruthenium pattern was formed on the light incident plane of the underlayer in the same manner as in Example 1.

A UV curable resin (4803PT, Shina T&C) was applied to the light exit plane of the substrate layer to form a second optical pattern having the specifications listed in Table 1, and then cured, thereby forming the composition in Table 1. The first index pattern layer of the specification is listed.

A UV curable resin (160CI, SDI Co., Ltd.) was directly coated onto the upper surface of the first refractive index pattern layer to form a flat upper surface, which was then cured to form a second having the specifications listed in Table 1. A refractive index pattern layer, thereby producing an optical sheet. Example 8

In the same manner as in Example 1, a ruthenium pattern was formed on the light incident plane of the underlying layer, and a first refractive index pattern layer and a second refractive index pattern layer were formed on the light exiting plane of the underlying layer. A polarizing plate (AMN-6143 CPG05, SDI Co., Ltd.) was attached to the upper surface of the second refractive index pattern layer, thereby fabricating an optical sheet. Example 9

In the same manner as in Example 2, a ruthenium pattern was formed on the light incident plane of the underlying layer, and a first refractive index pattern layer and a second refractive index pattern layer were formed on the light exiting plane of the underlying layer. A polarizing plate (AMN-6143 CPG05, SDI Co., Ltd.) was attached to the upper surface of the second refractive index pattern layer, thereby fabricating an optical sheet. Example 10

In the same manner as in Example 3, a ruthenium pattern was formed on the light incident plane of the underlying layer, and a first refractive index pattern layer and a second refractive index pattern layer were formed on the light exiting plane of the underlying layer. A polarizing plate (AMN-6143 CPG05, SDI Co., Ltd.) was attached to the upper surface of the second refractive index pattern layer, thereby fabricating an optical sheet. Example 11

In the same manner as in Example 4, a ruthenium pattern was formed on the light incident plane of the underlying layer, and a first refractive index pattern layer and a second refractive index pattern layer were formed on the light exiting plane of the underlying layer. A polarizing plate (AMN-6143 CPG05, SDI Co., Ltd.) was attached to the upper surface of the second refractive index pattern layer, thereby fabricating an optical sheet. Example 12

In the same manner as in Example 5, a ruthenium pattern was formed on the light incident plane of the underlying layer, and a first refractive index pattern layer and a second refractive index pattern layer were formed on the light exiting plane of the underlying layer. A polarizing plate (AMN-6143 CPG05, SDI Co., Ltd.) was attached to the upper surface of the second refractive index pattern layer, thereby fabricating an optical sheet. Example 13

In the same manner as in Example 6, a ruthenium pattern was formed on the light incident plane of the base layer, and a first refractive index pattern layer and a second refractive index pattern layer were formed on the light exit plane of the base layer. A polarizing plate (AMN-6143 CPG05, SDI Co., Ltd.) was attached to the upper surface of the second refractive index pattern layer, thereby fabricating an optical sheet. Example 14

In the same manner as in Example 7, a ruthenium pattern was formed on the light incident plane of the underlying layer, and a first refractive index pattern layer and a second refractive index pattern layer were formed on the light exiting plane of the underlying layer. A polarizing plate (AMN-6143 CPG05, SDI Co., Ltd.) was attached to the upper surface of the second refractive index pattern layer, thereby fabricating an optical sheet. Comparative example 1

A ruthenium pattern was formed on the light incident plane of the underlayer in the same manner as in Example 1.

A composition for a coating was prepared by mixing a UV curable resin (581 CI, SDI Co., Ltd.) and a diffusion bead (material: polymethyl methacrylate).

The prepared composition was applied onto the light exiting plane of the underlayer, and then cured, thereby producing an optical sheet having the bead-containing coating of Table 2. Comparative example 2

A ruthenium pattern was formed on the light incident plane of the underlayer in the same manner as in Example 1.

A UV curable resin (551 CI, SDI Co., Ltd.) was applied onto the light exit plane of the substrate layer to form an embossed microlens pattern layer having the specifications listed in Table 2, followed by curing, thereby fabricating optical sheet.

The specifications of the optical sheets manufactured in the examples and the comparative examples are shown in Tables 1 and 2.

The optical sheets manufactured in the examples and comparative examples were evaluated for the following properties, and the evaluation results are shown in Tables 1 and 2.

(1) Relative brightness: Reflective film (ESR, 3M Corporation), light guide plate (L-806T-MT01, SDI Co., Ltd.) and inverted iridium (I-Prism13P, SDI Co., Ltd.) (Reference) ) Stacked on a side edge type LED light source (the light source of MT330KKAA47A), and then measured the brightness (G1). At this time, the inverted raft is placed so that the 稜鏡 pattern constitutes a light incident plane. Subsequently, instead of the inverted iridium stacking example and the optical sheets manufactured in the comparative example, the luminance (G2) was subsequently measured. At this time, each of the optical sheets is placed so that the pattern of the optical sheets constitutes a light incident plane. The brightness was measured using an EZ contrast agent (ELDIM Co., Ltd.). The relative brightness (%) was calculated according to the following equation: G2/G1 × 100.

(2) Viewing angle: As shown in (1), the liquid crystal display is assembled, and then the brightness is measured. Assume that the front side is 0°, and the left, right, left, and right ends are negative (-) direction, positive (+) direction, -90°, and +90° with respect to the front side, respectively, and the horizontal angle of view means that the brightness can be measured. The angle of the brightness measured on the front side/2. In addition, it is assumed that the front side is 0°, and the lower side, the upper side, the lower end, and the upper end are respectively negative (-) direction, positive (+) direction, -90°, and +90° with respect to the front side, and the viewing angle in the vertical direction means Measure the angle of brightness (brightness/2 measured on the front side). The left and right sides have the same viewing angle value with respect to the front side, and the upper and lower sides have the same viewing angle value with respect to the front side. In Tables 1 and 2, the symbols + and - are omitted. Table 1 Table 2

As shown in Table 1, the optical sheets manufactured in Examples 1 to 7 can increase the viewing angle in the horizontal direction as compared with the reference value while minimizing the change in the viewing angle in the vertical direction, thereby minimizing the relative luminance loss.

Further, although not shown in Table 1, the optical sheets manufactured in Examples 8 to 14 exhibited the same relative brightness and viewing angle as the relative brightness and viewing angle of Examples 1 to 7, thereby realizing the advantageous effects of the present invention. .

In contrast, as shown in Table 2, both the optical sheet including the bead-coated layer and the optical sheet including the microlens pattern layer produced in Comparative Example 2 produced in Comparative Example 1 were increased in level as compared with the reference value. The viewing angle in the direction and in the vertical direction, thereby causing significant loss of brightness.

The exemplified embodiments have been disclosed herein, and are not intended to be limiting. In some instances, as will be apparent to those of ordinary skill in the art, the features, characteristics and/or elements described in the specific embodiments may be used alone or Used in combination with features, features, and/or elements described in relation to other embodiments. Therefore, it will be apparent to those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the invention as set forth in the appended claims.

100‧‧‧ optical film
110‧‧‧ basal layer
120‧‧‧Optical pattern layer
121‧‧‧First optical pattern
130‧‧‧Composite layer
131‧‧‧First refractive index pattern layer
132‧‧‧Second refractive index pattern layer
133‧‧‧ first surface
134‧‧‧ second plane
135‧‧‧second optical pattern
136‧‧‧ optical pattern
140‧‧‧Polar plate
200‧‧‧ optical film
300‧‧‧ optical film
400‧‧‧ optical film
500‧‧‧ optical film
551‧‧‧ Basement membrane
552‧‧‧Second coating
553‧‧‧fourth optical pattern
554‧‧‧First coating
555‧‧‧ Third optical pattern
600‧‧‧Backlight unit
610‧‧‧Light source
620‧‧‧reflector
630‧‧‧Light guide
640‧‧‧ optical film
700‧‧‧LCD display
710‧‧‧ LCD panel
720‧‧‧first polarizer
730‧‧‧Second polarizer
740‧‧‧Backlight unit
130a‧‧‧Composite layer
130b‧‧‧Composite layer
130c‧‧‧Composite layer
131a‧‧‧First refractive index pattern layer
131b‧‧‧First refractive index pattern layer
131c‧‧‧first refractive index pattern layer
132a‧‧‧second refractive index pattern layer
132b‧‧‧second refractive index pattern layer
132c‧‧‧second refractive index pattern layer
135a‧‧‧second optical pattern
135c‧‧‧second optical pattern
H1‧‧‧ Height
H2‧‧‧ Height
H3‧‧‧ Height
P1‧‧‧Width
P2‧‧‧Width
P3‧‧‧width α1‧‧‧ apex angle α2‧‧‧ top angle

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of an optical sheet in accordance with one embodiment of the present invention. Figure 2 is an exploded cross-sectional view taken along line I-II of Figure 1. Figure 3 is a cross-sectional view of an optical sheet in accordance with another embodiment of the present invention. 4 is a cross-sectional view of an optical sheet in accordance with another embodiment of the present invention. Figure 5 is a cross-sectional view of an optical sheet in accordance with still another embodiment of the present invention. Figure 6 is a cross-sectional view of an optical sheet in accordance with still another embodiment of the present invention. Figure 7 is a cross-sectional view of a backlight unit in accordance with one embodiment of the present invention. Figure 8 is a perspective view of a light guide plate of the backlight unit according to the embodiment shown in Figure 7. Figure 9 is a cross-sectional view of a liquid crystal display according to an embodiment of the present invention.

100‧‧‧ optical film

110‧‧‧ basal layer

120‧‧‧Optical pattern layer

121‧‧‧First optical pattern

130‧‧‧Composite layer

131‧‧‧First refractive index pattern layer

132‧‧‧Second refractive index pattern layer

Claims (18)

An optical sheet comprising: a base layer; an optical pattern layer formed on a light incident plane of the base layer and comprising at least one first optical pattern; and a composite layer formed on a light exiting plane of the base layer, wherein The composite layer includes a first refractive index pattern layer and a second refractive index pattern layer formed directly on the first refractive index pattern layer, and 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. The optical sheet of claim 1, wherein the first refractive index pattern layer has a lower refractive index than the second refractive index pattern layer. The optical sheet of claim 1, wherein the first refractive index pattern layer has a higher refractive index than the second refractive index pattern layer. The optical sheet of claim 1, wherein a refractive index difference between the first refractive index pattern layer and the second refractive index pattern layer is in a range of 0.05 to 0.2. The optical sheet of claim 1, wherein the first refractive index pattern layer has a refractive index of 1.45 or more. The optical sheet of claim 1, wherein the second refractive index pattern layer has a refractive index of 1.45 or more. The optical sheet of claim 1, wherein the first optical pattern comprises a meandering pattern having a triangular cross section. The optical sheet of claim 1, wherein the second optical pattern comprises at least one of an embossed pattern and an engraved pattern. The optical sheet of claim 1, wherein the second optical pattern comprises at least one of: a lenticular lens pattern; having an n-sided cross section (n is an integer of 3 to 10) and in a longitudinal direction thereof a ruthenium pattern having a linear shape; an 稜鏡 pattern having an n-sided cross section (n is an integer of 3 to 10) and having a wavy shape in a longitudinal direction thereof; a curved surface at the top thereof and an n-sided cross section ( n is an integer 3 to 10) 稜鏡 pattern; a microlens pattern; and an embossed pattern. The optical sheet of claim 1, wherein a difference in width between the first optical pattern and the second optical pattern is 3 micrometers or more. The optical sheet of claim 1, wherein a ratio of a thickness of the first refractive index pattern layer to a thickness of the second refractive index pattern layer is in a range of 1:0.8 to 1:1.2. The optical sheet of claim 1, further comprising: a polarizing plate formed on a light exiting plane of the composite layer. The optical sheet of claim 12, further comprising: an adhesive layer disposed between the composite layer and the polarizing plate and comprising a light scattering agent. The optical sheet of claim 12, further comprising: a reflective polarizing film disposed between the composite layer and the polarizing plate. An optical display comprising the optical sheet of any one of claims 1 to 14. The optical display of claim 15, wherein the optical display comprises a liquid crystal panel, and an adhesive layer containing a light scattering agent is further included between the liquid crystal panel and the optical sheet. The optical display of claim 15, wherein the optical display comprises a light guiding plate comprising a base film; a first coating formed on one surface of the base film and comprising a third optical pattern a layer; and a second coating layer formed on the other surface of the base film and including a fourth optical pattern. The optical display of claim 17, wherein the third optical pattern comprises at least one of: a lenticular lens pattern; a meandering pattern having a curved surface at a top portion thereof; a microlens pattern; and an embossing a pattern, and the fourth optical pattern comprises at least one of: a microlens pattern; a meandering pattern having a polygonal cross section (n-sided cross section, n is an integer of 3 to 10); an embossed pattern; and a lenticular pattern .