KR20160017206A - Light guide plate, method for preparing the same, back light unit comprising the same and liquid crystal display comprising the same - Google Patents

Abstract

A base layer, a first coating layer formed on one side of the base layer and including a first optical pattern having a curved top, and a second coating layer formed on the other side of the base layer and including a second optical pattern, Wherein the first optical pattern has an aspect ratio of 0.10 to 0.50 and the curvature radius R of the curved surface is 10 mu m to 35 mu m and the aspect ratio of the second optical pattern is 0.01 to 0.07, A backlight unit including the light guide plate, and a liquid crystal display device including the light guide plate.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light guide plate, a method of manufacturing the same, a backlight unit including the same, and a liquid crystal display device including the same. BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to a light guide plate, a method of manufacturing the same, a backlight unit including the same, and a liquid crystal display including the same.

A liquid crystal display device includes a light source, a light guide plate (LGP) disposed on a side surface or an upper side of the light source, a light converging sheet disposed on the light guide plate to condense the light incident from the light guide plate, And a reflective sheet that reflects and re-enters the light guide plate. There is used a light collecting sheet comprising a base layer with a light collecting sheet and an inverted prism formed below the base layer. The light converging sheet including the inverted prism is excellent in the light condensing performance by allowing the light emitted from the light guide plate to be incident on one inclined face of the inverted prism and then being totally reflected on another inclined face in contact with the inverted prism.

The light guide plate guides the light incident from the light source and emits the light to the light collecting sheet. In order to increase the light collecting performance and brightness, it is necessary to control the structure of the upper and / or lower portion of the light guide plate. Particularly, in a liquid crystal display device using a light-converging sheet including an inverse prism, since a light incident from a light guide plate is incident on an inclined face of an inverse prism, a light guide plate for appropriately emitting an angle and having a light- need.

The background art of the present invention is disclosed in Japanese Laid-Open Patent Application No. 2009-043565.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a light guide plate capable of controlling the angle of incidence when using a light converging sheet including an inverted prism,

Another object of the present invention is to provide a light guide plate having high uniformity of light output regardless of its position from a light source when using a light converging sheet including an inverted prism.

Another problem to be solved by the present invention is to provide a light guide plate which has a good appearance when using a light converging sheet including an inverted prism and can narrow a viewing angle to increase brightness.

A light guide plate of the present invention includes a base layer, a first coating layer formed on one side of the base layer and including a first optical pattern whose top is curved, and a second coating layer formed on the other side of the base layer and including a second optical pattern Wherein the first optical pattern has an aspect ratio of 0.10 to 0.50 and a radius of curvature R of 10 mu m to 35 mu m of the curved surface and the second optical pattern has an aspect ratio of 0.01 to 0.07, The refractive index of the second coating layer may be the same or larger than that of the base layer.

The method of manufacturing a light guide plate of the present invention includes the steps of forming a first coating layer including a first optical pattern on one side of a base layer and forming a second coating layer including a second optical pattern on the other side of the base layer, Wherein the first optical pattern has at least one curved surface formed at the top thereof, the aspect ratio is 0.10 to 0.50, the curvature radius R of the curved surface is 10 mu m to 35 mu m, the aspect ratio of the second optical pattern is 0.01 to 0.07, The first coating layer and the second coating layer may have the same or larger refractive index than the base layer, respectively.

The backlight unit of the present invention includes a light guide plate and a light collecting sheet formed with an inverted prism disposed on the light guide plate, and the light guide plate may include the light guide plate of the present invention.

The liquid crystal display device of the present invention may include the backlight unit.

The present invention provides a light guide plate capable of controlling the angle of incidence when using a light-converging sheet including an inverted prism and having no light scattering and high light-condensing performance, thereby increasing brightness.

The present invention provides a light guide plate having a uniform light output uniformity regardless of a position from a light source when using a light converging sheet including an inverted prism.

The present invention provides a light guide plate having a good appearance and a narrow viewing angle when using a light converging sheet including an inverted prism to increase luminance.

1 is a perspective view of a light guide plate according to an embodiment of the present invention.
2 is a sectional view taken along the line X-X 'in FIG.
3 is a cross-sectional view taken along the line Y-Y 'in FIG.
4 is a perspective view of a light guide plate according to another embodiment of the present invention.
5 is a sectional view taken along the line Y-Y 'in FIG.
6 is a conceptual diagram of the arrangement of microlens patterns in FIG.
7 is a perspective view of a light guide plate according to another embodiment of the present invention.
8 is a cross-sectional view of a backlight unit according to an embodiment of the present invention.
9 is a cross-sectional view of an embodiment of a light collecting sheet in which an inverse prism is formed in a backlight unit according to an embodiment of the present invention.
10 is a cross-sectional view of a liquid crystal display device according to an embodiment of the present invention.
11 is a schematic view of a sample of a light guide plate for luminance measurement.

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 to the maximum width of the optical pattern (maximum height of the optical pattern / maximum width of the optical pattern).

In the present specification, "radius of curvature" refers to a radius of an imaginary circle having a curved surface as a part in an optical pattern whose top is a curved surface, or an imaginary circle having a curved surface which is in contact with another inclined surface in contact with the prism, It means radius.

In the present specification, "fill factor" means the ratio of the total area of the convex portions of the microlens pattern to the total area of the coating layer on which the microlens pattern is formed (total area of the coating layer on which the microlens pattern is formed / Total area).

In the drawings, "x axis", "y axis" and "z axis" mean width direction, length direction and height direction of the first optical pattern, respectively, Quot ;, "x axis "," y axis ", and "z axis"

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

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.

In this specification, the term light guide plate (LGP) includes a light guide film (LGF) having a thickness of 600 μm or less.

Hereinafter, a light guide plate according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view of a light guide plate according to an embodiment of the present invention, FIG. 2 is a sectional view taken along a line X-X 'in FIG. 1, and FIG. 3 is a sectional view taken along line Y-Y' in FIG.

1, a light guide plate 100 according to an embodiment of the present invention includes a base layer 101, a first coating layer 103a including one or more first optical patterns 102a, And a second coating layer 105a including a pattern 104a.

The substrate layer 101 supports the first coating layer 103a and the second coating layer 105a and guides the light incident from the light source to be emitted to a light collecting sheet (not shown in FIG. 1) on which an inverse prism is formed have.

The upper surface of the substrate layer 101 may be a light exit surface, the lower surface may be a surface on which light is incident from the second coating layer 105a, and the side surface may be a surface on which light is incident from a light source (not shown in FIG. 1) .

The base layer 101 may have a thickness of 200 mu m to 700 mu m, specifically 300 mu m to 500 mu m, and may be used in an optical display device in the above range.

The refractive index of the base layer 101 can be 1.50 or more, specifically 1.50 to 1.60, and the light emission efficiency can be increased by raising the light emission rate in the above range. The base layer 101 may be formed of a resin having a refractive index of 1.50 or more, specifically 1.50 to 1.60, for example, polycarbonate, polymethyl (meth) acrylate, or the like. In particular, the polycarbonate resin may be advantageous for reducing the thickness of the substrate layer.

The first coating layer 103a is formed on one surface of the base layer 101 so that light is not scattered and the brightness can be increased and light incident from the base layer 101 can be emitted. The first coating layer 103a may have a thickness of 10 mu m to 40 mu m and may be used in an optical display device in the above range.

The refractive index of the first coating layer 103a may be 1.50 to 1.65, and the light output efficiency may be increased in the above range to increase the light efficiency. The first coating layer 103a 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 103a may include a first optical pattern 102a.

The first optical pattern 102a may include an optical pattern formed on one surface of the base layer 101 and having at least one curved surface formed on the top thereof. FIG. 1 shows a light guide plate having a lenticular lens pattern formed by a first optical pattern 102a. However, the first optical pattern 102a is not limited if a curved surface is formed at the top. For example, the first optical pattern may include a prism pattern having a curved top surface, a microlens pattern, an emboss pattern, or a combination thereof.

The first optical pattern 102a may have an aspect ratio of 0.10 to 0.50, and a radius of curvature R of a curved surface may be 10 mu m to 35 mu m. Light and diffusion of the light incident in the above-mentioned range and to narrow the viewing angle in the vertical direction with respect to the first optical pattern, so that the sensation and the brightness can be increased.

The width P1 of the first optical pattern 102a may be 10 占 퐉 to 50 占 퐉 and the height H1 may be 1 占 퐉 to 35 占 퐉. In this range, the light can be condensed in the left and right directions to increase the light efficiency, to function as a light guide and diffusion for the incident light, and to narrow the viewing angle in the vertical direction of the first optical pattern, .

Referring to Fig. 2, the cross section of the first optical pattern 102a may be semicircular. However, if the aspect ratio is 0.10 to 0.50 and the curvature radius R of the curved surface is 10 占 퐉 to 35 占 퐉, the cross section of the first optical pattern may be a semi-circular deformed shape, a semi-elliptical shape or a semi-elliptical deformed shape.

Although the first optical pattern 102a may have a refractive index different from that of the first coating layer 103a, the first coating layer and the first optical pattern may have the same refractive index to improve the processability.

The second coating layer 105a is formed on the other surface of the base layer 101 so that part of the light passing through the base layer 101 is not scattered and the light incident from the light source can be reflected and emitted.

The second coating layer 105a may have a thickness of 0.6 占 퐉 to 5 占 퐉 and may be used in a liquid crystal display in the above range.

The second coating layer 105a 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 105a 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 105a may be formed of the same or different resin as the first coating layer 103a.

The second coating layer 105a may include a second optical pattern 104a.

The second optical pattern 104a is formed on the other surface of the base layer 101, 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.

1 shows a light guide plate in which a prism pattern having a triangular section is formed by the second optical pattern 104a, but does not limit the light guide plate with an aspect ratio of 0.01 to 0.07. For example, the second optical pattern may be a microlens pattern, a prism having a polygonal cross section (n is an integer of 4 to 10), an emboss pattern, a lenticular lens pattern, or the like.

Referring to FIG. 3, the second optical pattern 104a may have a width P2 of 50 占 퐉 to 150 占 퐉 and a height H2 of 0.5 占 퐉 to 5.0 占 퐉. In this range, . In particular, the height of the second optical pattern 104a is lower than that of the conventional light guide plate to reduce the aspect ratio, so that the light efficiency can be increased by increasing the light condensation even when the light converging sheet having the inverted prism is disposed.

The second optical pattern 104a can be used to condense the light without scattering even if a light-converging sheet having both inclination angles formed adjacent to the light source disposed on the side surface of the base layer 101 is formed lower than the conventional light-guiding plate and has an inverted prism. Specifically, the second optical pattern 104 may have an inclination angle? Of 1.2 to 3.5 degrees. The apex angle? Of the second optical pattern 104a can be 173 ° to 177 °, and the light efficiency can be increased in this range. The "vertex angle" means an angle formed by one sloped surface of the second optical pattern and another sloped surface in contact with the second optical pattern.

The second optical pattern 104a may have a refractive index different from that of the second coating layer 105a, but the second coating layer and the second optical pattern may have the same refractive index to improve the processability.

The longitudinal direction of the second optical pattern 104a and the longitudinal direction of the first optical pattern 102a are formed to form an angle of a predetermined range, for example, an angle of 85 ° to 95 °, so that the pitch moire ) Can be prevented while improving the luminance. For example, referring to Fig. 1, when the longitudinal direction of the first optical pattern 102a is the y-axis and the longitudinal direction of the second optical pattern 104a is the x-axis, the x-axis and the y-axis are perpendicular to each other.

When the light-converging sheet on which the inverted prism is formed is disposed on the light guide plate, the light emitted from the light guide plate passes through one inclined surface of the inverted prism and is passed through the other inclined surface of the inverted prism, This can make the brightness even higher. However, a pattern is not formed on the upper part but a pattern is formed only on the lower part. In a typical light guide plate having a height of a lower pattern, light can be scattered without being sufficiently incident on a reverse prism, and brightness can be lowered.

On the other hand, the light guide plate 100 of the embodiment of the present invention is designed such that the first optical pattern 102a has a specific range of aspect ratio and radius of curvature, and the second optical pattern 104a has a specific range of aspect ratio, The light emitted from the light guide plate is emitted at a specific angle of incidence of 60 to 80 degrees and more specifically 70 to 75 degrees with respect to the surface of the substrate layer. Specifically, the first optical pattern 102a condenses light in the left-right direction (the x-axis direction in Fig. 1) and the second optical pattern 104a condenses the light in the up-down direction (z- The light emitted from the light guide plate can be emitted without being spread vertically and / or horizontally, so that the light condensing performance can be enhanced and the luminance can be increased. In addition, by increasing the aspect ratio of the first optical pattern 102a to the aspect ratio of the second optical pattern 104a, the light condensing efficiency can be further increased. Specifically, the ratio of the aspect ratio of the first optical pattern to the aspect ratio of the second optical pattern (the aspect ratio of the first optical pattern / the aspect ratio of the second optical pattern) may be 2 to 50, specifically 2 to 30, It is possible to increase the light collection efficiency in the range.

The light guide plate 100 according to an exemplary embodiment of the present invention includes both a light guide plate and an extrusion light guide plate, and may be referred to as a light guide film (LGF).

Hereinafter, a light guide plate according to another embodiment of the present invention will be described with reference to FIG.

A light guide plate according to another embodiment of the present invention includes a substrate 101, a first coating layer 103a including at least one first optical pattern 102a, and a second coating layer 103b including at least one second optical pattern 104a. And the first coating layer 103a and the second coating layer 105a may have the same or larger refractive index than the base layer, respectively. Is substantially the same as the light guide plate of the embodiment of the present invention except that the refractive indexes of the first coating layer and the second coating layer are the same or larger than the refractive index of the base layer, respectively.

The refractive index of the first coating layer 103a is equal to or larger than that of the base layer 101, so that light loss can be prevented. Specifically, the ratio of the refractive index of the first coating layer 103a to the refractive index of the base layer 101 can be from 1 to 1.1, for example, from 1 to 1.04, and the light output efficiency and the light efficiency can be increased in the above range .

The refractive index of the second coating layer 105a is equal to or larger than that of the base layer 101 so that incident light can not be reflected and emitted only in the light guide plate. Specifically, the ratio of the refractive index of the second coating layer 105a to the refractive index of the base layer 101 can be from 1 to 1.1, for example, from 1 to 1.04. In this range, it is possible to increase the light output efficiency and the light efficiency have.

Hereinafter, a light guide plate according to another embodiment of the present invention will be described with reference to FIGS. 4 to 6. FIG. FIG. 4 is a perspective view of a light guide plate according to another embodiment of the present invention, FIG. 5 is a sectional view of Y-Y 'in FIG. 4, and FIG. 6 is a conceptual diagram of an arrangement of a micro lens pattern 104b in FIG.

4, a light guide plate 200 according to another embodiment of the present invention includes a substrate layer 101, a first prism pattern 102b formed on one surface of the base layer 101 and having a curved top surface, A coating layer 103b and a second coating layer 105b formed on the other surface of the base layer 101 and including a microlens pattern 104b. The light guide plate 200 of this embodiment can increase the brightness by preventing light emitted from the light guide plate from being scattered and emitting a specific exit angle, for example, 60 to 80 degrees, even if a light collecting sheet including an inverted prism is used.

In the light guide plate of this embodiment, a prism pattern in which a curved surface is formed in the top portion instead of the lenticular lens pattern as the first optical pattern is formed, and a microlens pattern is formed instead of the prism pattern in the second optical pattern. Is substantially the same as that of the light guide plate. Hereinafter, only the prism pattern and the microlens pattern having a curved top surface will be described.

The prism pattern 102b having a curved surface at the top may include a pattern in which a curved surface is formed at the top of a triangular prism pattern.

The microlens patterns 104b may be arranged in a hexagonal type regularly arranged lens as shown in FIG. 6 instead of randomly arranged at arbitrary positions so that the distance between adjacent microlens patterns 104b may be the same. 6, the " ortho-axial " lens refers to a state where imaginary hexagons 104b 'surrounding the micro lens pattern are formed adjacent to each other. Referring to FIG. 5, the spacing distance D between the microlens patterns 104b may be in the range of 1 to 200 占 퐉, and the fill factor may be included in the range to improve the luminance.

The microlens pattern 104b does not limit the shape of the cross section if the aspect ratio is satisfied. 5, the width P3 of the microlens pattern 104b may be 10 μm to 100 μm and the height H3 may be 1 μm to 5 μm. In the above range, Can be.

FIG. 4 shows a microlens pattern 104b having a relief shape, but a microlens pattern with a relief pattern can also be formed on the light guide plate of the present invention.

The second coating layer 105b on which the micro lens pattern 104b is formed may have a fill factor of 5% to 90%, specifically 10% to 88%. In this range, the light uniformity can be increased and the light efficiency can be increased. The fill factor can be achieved by controlling the spacing distance between microlens patterns and the arrangement of microlens patterns.

Hereinafter, a light guide plate according to another embodiment of the present invention will be described with reference to FIG. 7 is a perspective view of a light guide plate according to another embodiment of the present invention.

7, a light guide plate 300 according to another embodiment of the present invention includes a substrate layer 101, a first prism pattern 102b formed on one surface of the base layer 101 and having a curved top surface, A coating layer 103b and a second coating layer 105c formed on the other surface of the base layer 101 and including a microlens pattern 104b and the microlens pattern 104b is formed so as to be closer to the microlens pattern 104b 104b are close to each other and the density of the microlens pattern 104b can be increased. As a result, the light loss can be minimized and the luminance can be made uniform.

The distance between the microlens patterns is substantially the same as that of the light guide plate according to another embodiment of the present invention, except that the distance between the microlens patterns decreases as the distance from the light source is reduced and the pattern density is increased.

Hereinafter, a method of manufacturing a light guide plate according to an embodiment of the present invention will be described. The method of manufacturing a light guide plate according to embodiments of the present invention can manufacture a thin light guide film having a thickness of 600 탆 or less by manufacturing a light guide plate by imprinting using a pulling roll

A method of manufacturing a light guide plate according to an embodiment of the present invention includes forming a first coating layer including a first optical pattern on one side of a base layer and a second coating layer including a second optical pattern on the other side of the base layer , The first optical pattern has at least one curved surface formed at the top, an aspect ratio of 0.10 to 0.50, a curvature radius R of the curved surface of 10 to 35 占 퐉, and an aspect ratio of 0.01 to 0.07.

The first optical pattern may be formed by coating a resin for the first coating layer on a pulling roll in which the first optical pattern is formed at a negative angle, bringing the resin into contact with one surface of the base layer, and then curing. The second optical pattern may be formed by coating a resin for the second coating layer on a pulling roll in which the second optical pattern is formed at a negative angle, bringing the resin into contact with the other surface of the base layer, and then curing. The curing includes ultraviolet curing, which may include irradiation at a light amount of, for example, 100 mJ to 250 mJ. The order of forming the first optical pattern and the second optical pattern is not limited, and may be formed sequentially or simultaneously.

The first coating layer and the second coating layer may have the same or larger refractive index than the base layer, respectively.

Hereinafter, a backlight unit of an embodiment of the present invention will be described with reference to Figs. 8 and 9. Fig. FIG. 8 is a cross-sectional view of a backlight unit according to an embodiment of the present invention, and FIG. 9 is a cross-sectional view according to an embodiment of a light-converging sheet in which an inverse prism included in a backlight unit of an embodiment of the present invention is formed.

8, a backlight unit 400 according to an embodiment of the present invention includes a light source 301, a light guide plate 302 for guiding light incident from the light source 301, a reflective sheet 302 disposed below the light guide plate 302, And a light collecting sheet 304 disposed on the light guide plate 302 and having an inverted prism formed thereon. The light guide plate 302 may include a light guide plate according to embodiments of the present invention.

The light source 301 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 (not shown in FIG. 8) may be further formed on the outside of the light source for the purpose of protecting the light source.

The position of the light source 301 in the backlight unit is not limited, but may be an edge-type backlight unit disposed on the side surface of the light guide plate 302. [

The light guide plate 302 may serve to guide the light incident from the light source to the prism sheet.

The reflective sheet 303 reflects the light generated from the light source and is incident again on the light guide plate, thereby enhancing the light efficiency.

The light collecting sheet 304 on which the inverse prism is formed collects the light incident from the light guide plate and supplies it to the optical sheet. 9, the light collecting sheet 310 having an inverted prism may include a base film 305 and an inverted prism pattern 306 formed on a lower surface of the base film 305. [ The inverse prism pattern 306 may have a width p of 10 占 퐉 to 30 占 퐉, a vertex angle r of 65 占 to 70 占 and a height h of 7 占 퐉 to 24 占 퐉, . The "vertex angle" means an angle formed by one inclined surface of the inverted prism pattern and another inclined surface that meets the inclined surface.

In FIG. 9, an inverted prism pattern having a triangular cross section is shown. However, the shape of the cross section of the inverted prism pattern is not limited. For example, the cross section may be a polygon (an n-th type where n is an integer of 3 to 10) . Although not shown in FIG. 9, a light diffusion layer or the like may be further formed on one surface of the light collecting sheet on which the inverse prism is formed, and the light diffusion layer may be formed of one or more of a coating layer including a pattern of irregularities, .

Although not shown in FIG. 8, one or more protective sheets, a diffusion sheet, and the like may be further formed on the light collecting sheet 304 on which the inverted prisms are formed. Although not shown in FIG. 8, a polarizing plate may be positioned directly above the light-converging sheet 304 on which the reverse prisms are formed. The polarizing plate may include a polarizer, a protective film formed on at least one surface of the polarizer, or a retardation film.

Hereinafter, a liquid crystal display device according to an embodiment of the present invention will be described with reference to FIG. 10 is a cross-sectional view of a liquid crystal display device according to an embodiment of the present invention.

10, a liquid crystal display 500 according to an embodiment of the present invention includes a panel 501 for a liquid crystal display device, a polarizing plate 502 formed on the upper and lower surfaces of a panel 501 for a liquid crystal display, And a backlight unit 503 formed at the lower portion of the liquid crystal display panel 501. The backlight unit 503 may include a backlight unit of an embodiment of the present invention.

The liquid crystal cell layer includes a VA (vertical alignment) mode, an IPS (in place switching) mode, an FFS a fringe field switching mode, a twisted nematic (TN) mode, and the like.

The polarizing plate 502 may include a polarizer, and a protective film and / or a retardation film formed on the polarizer. 10 shows that the same polarizing plate is formed on the upper and lower surfaces of the liquid crystal display panel, but different types of polarizing plates having different polarizers, protective films, and retardation films may be formed on the upper and lower surfaces, respectively.

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

(Refractive index: 1.60, manufacturer: Shin-T & C Co., Ltd., trade name: PZPC-5503) was coated on a pulling roll having a negative lenticular lens pattern formed thereon and one side of a polycarbonate resin film (refractive index: 1.59, And irradiated with a light quantity of 200 mJ at UV wavelength to form a lenticular lens pattern having the specifications shown in the following Table 1 on one surface of the polycarbonate resin film. Then, an ultraviolet ray-curing resin (refractive index: 1.60, manufacturer: Shin-T & C Co., Ltd., trade name: PZPC-5503) was coated on a pulling roll provided with an engraved prism pattern and brought into contact with the other face of the polycarbonate resin film, And a prism pattern having the specifications shown in the following Table 1 was formed on the other surface of the polycarbonate resin film by irradiating a light quantity of 200 mJ at the UV wavelength so that the prism pattern having the following properties was formed on one surface of the polycarbonate resin film A light guide plate having a first coating layer including a lenticular lens pattern formed thereon and a second coating layer including a prism pattern formed on the other surface thereof was manufactured.

Examples 2 to 15

A light guide plate was manufactured in the same manner as in Example 1, except that the specifications of the lenticular lens pattern and the prism pattern were changed as shown in Table 1 below.

Example 16

(Refractive index: 1.60, manufacturer: Shin-T & C Co., Ltd., trade name: PZPC-5503) was coated on a pulling roll having a negative lenticular lens pattern formed thereon and one side of a polycarbonate resin film (refractive index: 1.59, And irradiated with a light quantity of 200 mJ at UV wavelength to form a lenticular lens pattern having the specifications shown in the following Table 2 on one side of the polycarbonate resin film. Then, an ultraviolet ray-curable resin (refractive index: 1.60, manufacturer: Shin-TAT & Co., trade name: PZPC-5503) was coated on a pulling roll provided with a negative microlens pattern and contacted with the other surface of the polycarbonate resin film, And a microlens pattern having the specifications in Table 2 below was formed on the other surface of the polycarbonate resin film by irradiating the light amount. A first coating layer including a lenticular lens pattern was formed on one surface of the polycarbonate resin film, and a microlens pattern was formed on the other surface .

Examples 17 to 24

A light guide plate was manufactured in the same manner as in Example 16 except that the specifications of the lenticular lens pattern and the microlens pattern were changed as shown in Table 2 below.

Example 25

(Refractive index: 1.60, manufacturer: Shin-T & C Co., Ltd., trade name: PZPC-5503) was coated on a pulling roll provided with a prism pattern having a curved top at a negative angle and a polycarbonate resin film And a light quantity of 200 mJ was irradiated at a UV wavelength to form a prism pattern having a top curved surface having the specifications of Table 3 on one surface of a polycarbonate resin film. Then, an ultraviolet ray-curable resin (refractive index: 1.60, manufacturer: Shin-TAT & Co., trade name: PZPC-5503) was coated on a pulling roll provided with a negative microlens pattern and contacted with the other surface of the polycarbonate resin film, And a microlens pattern having the specifications shown in the following Table 3 was formed on the other surface of the polycarbonate resin film by irradiating the light amount to manufacture a light guide plate having a prism pattern having a curved top on one surface of the polycarbonate resin film and a micro lens pattern on the other surface .

Examples 26 to 27

A light guide plate was manufactured in the same manner as in Example 25, except that the specifications of the prism pattern and the microlens pattern having curved tops were changed as shown in Table 3 below.

Example 28

(Refractive index: 1.60, manufacturer: Shin-T & C Co., Ltd., trade name: PZPC-5503) was coated on a pulling roll having a prismatic pattern having a curved top of the engraved surface and a polycarbonate resin film And a light quantity of 200 mJ was irradiated at a UV wavelength to form a prism pattern having a top curved surface having the specifications of Table 3 on one surface of a polycarbonate resin film. Then, an ultraviolet ray-curable resin (refractive index: 1.60, manufacturer: Shin-TAT & Co., trade name: PZPC-5503) was coated on a pulling roll provided with a negative microlens pattern and contacted with the other surface of the polycarbonate resin film, And a microlens pattern having the specifications shown in Table 3 below was formed on the other surface of the polycarbonate resin film by irradiating the light. At this time, the micro lens pattern was formed so that the distance between the patterns was closer to the other side of the polycarbonate resin film and the pattern density was increased. As a result, a light guide plate having a curved prism pattern formed on one surface of a polycarbonate resin film and a microlens pattern formed on the other surface was manufactured.

Example 29

A light guide plate was manufactured in the same manner as in Example 28, except that the specifications of the prism pattern and the microlens pattern having curved tops were changed as shown in Table 3 below.

Comparative Example 1

(Refractive index: 1.60, manufacturer: Shin-T & C Co., Ltd., trade name: PZPC-5503) was coated on a pulling roll having a negative prism pattern and the other face of a polycarbonate resin film (refractive index: 1.59, A light guide plate having a prism pattern having the specifications shown in Table 1 below was formed on the other surface of the polycarbonate resin film and a pattern was not formed on one surface of the polycarbonate resin film.

Comparative Examples 2 to 6

A light guide plate having a lenticular lens pattern and a prism pattern having the specifications shown in Table 1 below was produced in the same manner as in Example 1.

Comparative Example 7

(Refractive index: 1.60, manufacturer: Shin-T & C, trade name: PZPC-5503) was coated on a pulling roll having a negative microlens pattern formed thereon and the other face of a polycarbonate resin film (refractive index: 1.59, And a light quantity of 200 mJ was irradiated at UV wavelength to produce a light guide plate in which a micro lens pattern having the specifications in Table 2 was formed on the other surface of the polycarbonate resin film and a pattern was not formed on one surface of the polycarbonate resin film.

Comparative Examples 8 to 9

A light guide plate having a lenticular lens pattern and a microlens pattern having the specifications shown in Table 2 below was produced in the same manner as in Example 16. [

The light guide plate produced in the examples and the comparative examples was cut into the size (width x length, 181.6 mm x 111.0 mm) of FIG. 11, a light converging sheet having an inverted prism formed on the light guide plate was inserted, And optical uniformity were evaluated. The light-converging sheet on which the inverse prism was formed was formed on the lower surface of a 125 占 퐉 -thick polyethylene terephthalate film with an ultraviolet-curing resin (refractive index: 1.55) and having a width of 17 占 퐉, a height of 12.6 占 퐉, and a vertex angle of 68 占Prism pattern was used, and relative brightness and uniformity of light output were evaluated by the above-described method.

(1) Relative luminance (%): A light guide plate and a diffusion sheet having an inverted prism formed thereon were laminated in this order, and brightness was measured using a Tocon BM7 luminance meter among backlight units including a one-edge type LED light source. The relative luminance was calculated at the luminance (G2) of the embodiment and the comparative example / the luminance (G1) x 100 of the embodiment 1 or 20, with the luminance of the embodiment 1 or 20 as the reference luminance.

 (2) Uniformity of light output (%): Measured in the same manner as the relative luminance, the luminance of 17 points was measured at intervals of 10 mm along the center line of the light traveling direction (y axis) The light outgoing uniformity was calculated from the minimum value / maximum value) × 100 (%).

Lenticular lens pattern Prism pattern opponent
Brightness (%) Light emission
Uniformity
(%) Width (탆) Height (탆) Aspect ratio curvature
Radius
(탆) Width (탆) Height
(탆) Vertex angle
(°) Aspect ratio Example 1 45 14.1 0.313 25 150 4.6 173 0.031 100 64 Example 2 45 14.1 0.313 25 150 3.9 174 0.026 111 69 Example 3 45 14.1 0.313 25 150 3.3 175 0.022 111 73 Example 4 45 14.1 0.313 25 150 2.6 176 0.017 110 71 Example 5 45 14.1 0.313 25 150 2.0 177 0.013 107 66 Example 6 45 14.1 0.313 25 130 2.8 175 0.022 114 74 Example 7 45 14.1 0.313 25 110 2.4 175 0.022 117 74 Example 8 45 14.1 0.313 25 100 2.2 175 0.022 118 75 Example 9 45 14.1 0.313 25 90 2.0 175 0.022 116 73 Example 10 45 14.1 0.313 25 70 1.5 175 0.021 116 74 Example 11 45 14.1 0.313 25 50 1.1 175 0.022 114 74 Example 12 30 5.0 0.167 25 150 3.3 175 0.022 103 67 Example 13 40 10.0 0.250 25 150 3.3 175 0.022 112 66 Example 14 50 25.0 0.500 25 150 3.3 175 0.022 117 71 Example 15 20 2.1 0.105 25 150 3.3 175 0.022 102 73 Comparative Example 1 - - - - 150 3.3 175 0.022 86 70 Comparative Example 2 10 0.5 0.05 25 150 3.3 175 0.022 91 69 Comparative Example 3 45 14.1 0.313 25 150 1.3 178 0.008 86 72 Comparative Example 4 45 27 0.600 25 150 4.6 173 0.031 93 71 Comparative Example 5 9 2.8 0.311 5 150 4.6 173 0.031 82 62 Comparative Example 6 90 28.2 0.313 40 150 4.6 173 0.031 91 73

Lenticular lens pattern Micro lens pattern Relative luminance
(%) Light emission
Uniformity
(%) Width (탆) Height (탆) Aspect ratio curvature
Radius (㎛) Width (탆) Height (탆) Aspect ratio Example 16 45 14.1 0.31 25 50 1.0 0.02 124 72 Example 17 45 14.1 0.31 25 50 1.5 0.03 117 76 Example 18 45 14.1 0.31 25 50 2.0 0.04 114 74 Example 19 45 14.1 0.31 25 50 2.5 0.05 104 74 Example 20 45 14.1 0.31 25 50 3.0 0.06 100 76 Example 21 30 5.0 0.17 25 50 2.0 0.04 108 75 Example 22 40 10.0 0.25 25 50 2.0 0.04 113 73 Example 23 50 25.0 0.50 25 50 2.0 0.04 111 74 Example 24 20 2.1 0.105 25 50 2.0 0.04 107 73 Comparative Example 7 - - - - 50 2.0 0.04 72 69 Comparative Example 8 45 14.1 0.31 25 50 4.0 0.08 92 71 Comparative Example 9 90 28.2 0.313 50 50 3.0 0.06 92 68

A prism pattern whose top is curved Micro lens pattern Relative luminance (%) Uniformity of light output
(%) Width (탆) Height (탆) Aspect ratio curvature
Radius (㎛) Width (탆) Height (탆) Aspect ratio Example 25 45 14.1 0.31 25 50 1.0 0.02 131 87 Example 26 45 14.1 0.31 25 50 1.5 0.03 124 86 Example 27 45 14.1 0.31 25 50 2.0 0.04 122 88 Example 28 45 14.1 0.31 25 50 2.5 0.05 113 85 Example 29 45 14.1 0.31 25 50 3.0 0.06 109 83

As shown in Tables 1 to 3, the light guide plate of the present invention has high relative brightness and high light output uniformity when the diffusion sheet having the inverted prism is used on the top.

On the other hand, Comparative Examples 1 and 7 in which only a prism pattern or a micro-lens pattern is formed at the lower part of the light guide plate have a problem of lowering the brightness.

In Comparative Examples 2 to 6 and 8 to 9 in which the radius of curvature and the aspect ratio are out of the range of the present invention even if a lenticular lens pattern is formed on the upper side of the light guide plate and a prism pattern or a microlens array pattern is formed on the lower side of the light guide plate, .

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 (14)

Substrate layer,
A first coating layer formed on one surface of the base layer and including a first optical pattern whose top is curved,
And a second coating layer formed on the other surface of the substrate layer and including a second optical pattern,
Wherein the first optical pattern has an aspect ratio of 0.10 to 0.50, a radius of curvature (R) of the curved surface is 10 mu m to 35 mu m,
Wherein the second optical pattern has an aspect ratio of 0.01 to 0.07,
Wherein the first coating layer and the second coating layer have the same or larger refractive index than the substrate layer, respectively. The light guide plate according to claim 1, wherein the first 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. The light guide plate according to claim 1, wherein the second optical pattern includes at least one of a prism pattern, a microlens pattern, an emboss pattern, and a lenticular lens pattern. The light guide plate according to claim 1, wherein the base layer has a refractive index of 1.50 to 1.60. The light guide plate according to claim 1, wherein the refractive indexes of the first coating layer and the second coating layer are respectively 1.50 to 1.65. The light guide plate according to claim 1, wherein the second optical pattern is a micro lens pattern. The light guide plate according to claim 1, wherein the aspect ratio of the first optical pattern to the aspect ratio of the second optical pattern is 2 to 50. The light guide plate according to claim 1, wherein the first optical pattern is a lenticular lens pattern and the second optical pattern is a prism pattern. The light guide plate according to claim 1, wherein the first optical pattern is a prism pattern having a curved surface at its top, and the second optical pattern is a micro lens pattern. 2. The micro-lens array according to claim 1, wherein the first optical pattern is a prism pattern having a curved top at its top, the second optical pattern is a microlens pattern, and the distance between the adjacent microlens patterns And the pattern density is increased. Forming a first coating layer including a first optical pattern on one surface of a base layer and a second coating layer including a second optical pattern on the other surface of the base layer,
Wherein the first optical pattern has at least one curved surface formed at the top thereof, an aspect ratio of 0.10 to 0.50, a radius of curvature R of the curved surface of 10 mu m to 35 mu m,
Wherein the second optical pattern has an aspect ratio of 0.01 to 0.07,
Wherein the first coating layer and the second coating layer have the same or larger refractive index than the substrate layer, respectively. A light guide plate, and
And a light converging sheet disposed on the light guide plate and formed with an inverted prism,
The backlight unit according to any one of claims 1 to 10, wherein the light guide plate comprises a light guide plate. 13. The backlight unit of claim 12, further comprising a polarizer on a light condensing sheet formed with the inverted prism. A liquid crystal display device comprising the backlight unit of claim 12.

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