KR100796479B1 - Optical sheet and back light assembly equipped with the prism sheet - Google Patents

Abstract

An optical sheet and a backlight assembly having the same are provided to improve brightness of light emitted from a light source and improve viewing angle. An optical sheet comprises a body part and a protrusion part having a structured pattern in a side of the body part. The protrusion part comprises plural main patterns(211,212) and plural sub patterns(221,222,223) formed in an area between the main patterns. A section length of the main pattern is about 5‘í to 70‘í. A section length of the sub pattern is about 1‘í to 20‘í. The main pattern is a micro lens pattern which is irregularly arranged.

Description

Optical sheet and back light assembly equipped with the prism sheet

1 is a cross-sectional view showing the configuration of a conventional liquid crystal display device.

FIG. 2 is a cross-sectional view of the prism sheet shown in FIG. 1. FIG.

3 is a planar photograph of an optical sheet according to an embodiment of the present invention.

Figure 4 is a photograph showing the shape of the optical sheet according to an embodiment of the present invention.

5 is a view for explaining an optical phenomenon of the optical sheet according to the embodiment of the present invention.

6 to 9 are views for explaining the shape of the optical sheet according to the embodiment of the present invention.

10 is a graph for explaining the optical properties of the optical sheet according to the embodiment of the present invention.

11 to 13 are views for explaining the configuration of the various backlight assembly according to an embodiment of the present invention.

14 and 15 are configuration diagrams for explaining a method for manufacturing an optical sheet according to an embodiment of the present invention.

The present invention relates to a backlight assembly of a liquid crystal display device, and more particularly, to an optical sheet.

Recently, various flat panel displays have been developed to reduce weight and volume, which are disadvantages of cathode ray tubes. Such flat panel displays include liquid crystal displays (LCDs), field emission displays (FEDs), plasma display panels (PDPs), and organic luminescence displays (OLEDs). In order to improve the display quality and to make a large screen for the same flat panel display device, studies are being actively conducted.

In particular, the liquid crystal display (LCD) has been gradually improved due to the results of active research of high power and viewing angle, which has been pointed out as a disadvantage thereof.

Unlike other display devices, the liquid crystal display is not a light emitting material that emits light, but a light emitting material that displays light on the screen by controlling the amount of light from the outside. A separate device for irradiating light, that is, a backlight assembly, is essential.

The backlight assembly includes a mold frame in which a storage space is formed, a reflection sheet installed on a base surface of the storage space to reflect light toward the liquid crystal display panel, a light guide plate installed on an upper surface of the reflection sheet to guide light, and sidewalls of the light guide plate and the storage space. A lamp unit disposed between and emitting light, optical sheets stacked on an upper surface of the light guide plate to diffuse and collect light, and installed on an upper side of the mold frame to reach a side of the mold frame at a predetermined position of the edge of the liquid crystal display panel. It consists of a top chassis covering the area.

Here, the optical sheets include a diffusion sheet for diffusing light, a prism sheet for condensing the light diffused and stacked on the upper surface of the diffusion sheet, and transferring the light to the liquid crystal display panel, and a protective sheet for protecting the diffusion sheet and the prism sheet. It is composed.

1 is a cross-sectional view showing the configuration of a conventional liquid crystal display device.

Referring to FIG. 1, a conventional liquid crystal display device 60 includes a backlight assembly 50 for generating light and an upper side of the backlight assembly 50, and receives light from the backlight assembly 50 to receive an image. A display unit 40 for displaying is included.

In detail, the backlight assembly 50 includes a lamp unit 51 for generating light and a light guide unit for guiding the light generated by the lamp unit 51 to the liquid crystal display panel 10.

In addition, the display unit 40 includes the liquid crystal display panel 10, an upper polarizing plate 30 positioned above and below the liquid crystal display panel 10, and a lower polarizing plate 20. The liquid crystal display panel 10 includes a TFT substrate on which electrodes are formed, color filter substrates 11 and 12, and a liquid crystal layer (not shown) injected between the TFT substrate and the color filter substrates 11 and 12. .

In detail, the lamp unit 51 includes a lamp 51a for generating light and a lamp reflector 51b surrounding the lamp 51a. The light generated from the lamp 51a is incident to the light guide plate 52, which will be described later, and the lamp reflector 51b reflects the light generated from the lamp 51a to the light guide plate 52, whereby the light guide plate 52 is disposed. It increases the amount of light incident on the).

The light guiding unit includes a reflecting plate 54, a light guiding plate 52, and optical sheets 53, and the light guiding plate 52 is provided at one side of the lamp unit 51 to receive light from the lamp unit 51. Serves as a guide.

In addition, the lower portion of the light guide plate 52 is provided with a reflector plate 54 for reflecting light leaked from the light guide plate 52 back to the light guide plate 52 side.

Meanwhile, a plurality of optical sheets 53 are provided on the light guide plate 52 to improve the efficiency of the light guided by the light guide plate 52. Specifically, the optical sheet is composed of a diffusion sheet 53a, a prism sheet 53b, and a protective sheet 53c, and is sequentially stacked on the light guide plate 52.

In detail, the diffusion sheet 53a scatters the light incident from the light guide plate 52 to even the luminance distribution of the light.

In addition, the prism sheet 53b has a triangular prism repeatedly formed on an upper surface thereof, and collects the light diffused by the diffusion sheet 53a in a direction perpendicular to the plane of the liquid crystal display panel 10. Accordingly, most of the light passing through the prism sheet 53b proceeds perpendicularly to the plane of the liquid crystal display panel 10 to have a uniform luminance distribution.

In addition, the protective sheet 53c provided on the prism sheet 53b serves to protect the surface of the prism sheet 53b.

FIG. 2 is a cross-sectional view of the prism sheet shown in FIG. 1.

Referring to FIG. 2, the conventional prism sheet 100 has an isosceles triangular pillar-shaped structure in which a body portion 110 into which light diffused by a light guide plate and a diffusion sheet is first introduced, and the diffused light are uniformly progressed. The protrusion 120 is configured, and the protrusion 120 is linearly arranged in a stripe shape on the body 110.

In addition, the isosceles triangular pillar-shaped protrusion 120 has a pitch of 10 μm to 100 μm, and the angle of the vertex angle α of the triangular pole is acute, and the viewing angle is narrowed instead of increasing luminance.

On the other hand, as shown in Figure 2, when the projection 120 in the shape of a triangular pillar is installed toward the front, that is, when the projection toward the liquid crystal display panel diffused light flowing through the body portion 110 Although the light is refracted forward and collected, the light incident on the inclined surface of the protrusion is lost due to total internal reflection without being contributed to the improvement of the brightness of the front.

In order to solve this problem, it is proposed to configure the triangular shape of the prism sheet 100 into an isosceles shape or to arrange the prism sheet in reverse so that the protrusion of the prism sheet 100 faces the light guide plate. It is very difficult to achieve the desired result both in terms of and viewing angle.

The present invention is proposed to solve the above problems, and an object of the present invention is to propose a light diffusing sheet and a backlight assembly provided with the optical sheet capable of improving the brightness of light emitted from a light source.

In addition, an object of the present invention is to propose an optical sheet capable of improving the viewing angle of light emitted through the panel and a backlight assembly provided with the optical sheet.

Optical sheet according to an embodiment of the present invention for achieving the above object is a body portion; And a protrusion having a pattern structured on one surface of the body portion, wherein the protrusion has a plurality of main patterns and a plurality of sub patterns formed in an area between the main patterns, and a cross-sectional length of the main pattern is It is made in the range of 5㎛ to 70㎛, characterized in that the cross-sectional length of the sub pattern is made in the range of 1㎛ to 20㎛.

The sub pattern may be formed at a predetermined distance from the main pattern.

The sub-pattern may be formed by mixing a first sub-pattern having a prism shape and a second sub-pattern having a shape of a micro lens in a region between the main patterns.

In addition, the optical sheet of the present invention is formed in the first pattern portion consisting of a plurality of main micro lens patterns, and in the region between the micro lens patterns, having a smaller size than the micro lens pattern, the diameter of each It has a structured surface consisting of a second pattern portion consisting of sub-micro lens patterns formed within the range of 1 μm to 20 μm.

In addition, the backlight assembly of the present invention includes a lamp unit for generating light, a light guide plate for guiding the light generated from the lamp unit to the panel side, and an optical sheet provided between the light guide plate and the panel, the optical sheet is At least one surface is composed of a body portion having a flat surface, and a protrusion formed on one surface of the body portion, the protrusion is composed of a plurality of main patterns and a plurality of sub-patterns that can be classified according to the size of the cross-sectional length, Each of the main patterns has a cross-sectional length in a range of 5 μm to 70 μm, and a cross-sectional length of the sub pattern is in a range of 1 μm to 20 μm.

Hereinafter, an optical sheet according to an embodiment of the present invention will be described in detail. However, the matters described in the drawings and the detailed description of the present application are merely one embodiment for realizing the technical idea of the present invention. It does not limit the scope of the present application by.

3 is a planar photograph of an optical sheet according to an embodiment of the present invention, and FIG. 4 is a photograph showing a shape of an optical sheet according to an embodiment of the present invention.

3 and 4 show the shape of the pre-fabricated sheet to verify the optical properties of the optical sheet according to the embodiment of the present invention.

That is, the optical sheet according to the present invention includes a first pattern portion 210 formed of a plurality of micro lenses and a second pattern portion formed in a space between the micro lenses constituting the first pattern portion 210. 220).

According to another aspect, the optical sheet according to the embodiment of the present invention is formed in a region between the first pattern portion 210 made of a plurality of micro lens patterns (main patterns) and the micro lens patterns. And a second pattern portion 220 formed of sub-micro lens patterns (sub-patterns) having a smaller size than the micro lens pattern and having diameters within the range of 1 μm to 20 μm, respectively. Has a face.

In detail, the first pattern portion 210 is formed of micro lenses having a diameter in the range of 45 μm to 70 μm, and the second pattern portion 220 is formed of patterns having a diameter in the range of 1 μm to 20 μm. Is done.

Here, the term "diameter" is used for the horizontal or vertical size on the plane of the first pattern portion 210 and the second pattern portion 220, but the first pattern portion 210 and the second pattern portion ( The size of the microlenses forming the 220 is only for comparing the size of the microlenses constituting the first pattern portion 210 and the second pattern portion 220 does not necessarily represent a circle.

The second pattern portion 220 is formed in the space between the micro lenses constituting the first pattern portion 210, the cross-sectional shape of the pattern forming the second pattern portion 220 may be made in various ways. This should be examined in more detail.

5 is a view for explaining an optical effect by the first pattern portion 210 and the second pattern portion 220, the light is refracted by the first pattern portion 210 in FIG. It is shown that the light introduced into the optical sheet by the second pattern unit 220 is scattered.

This is because, as the plurality of patterns constituting the second pattern portion 220 are formed to have a fine shape, the light introduced into the optical sheet is scattered by the second pattern portion 220, and thus is shown to the user side. The brightness of the light emitted through the losing panel can be improved.

That is, the second pattern portion (which is smaller than the size of the lens patterns constituting the first pattern portion 210 and its horizontal or vertical length (or simply referred to as diameter) may be 1 μm or more) By 220, the light is scattered by the minute shape of the second pattern part 220, thereby reducing the amount of light reflected into the optical sheet.

Hereinafter, to look at the shape of the pattern formed on the optical sheet according to an embodiment of the present invention in more detail, it will be described with reference to FIGS.

For reference, in order to understand what is shown in FIG. 6, it may be helpful to refer to the photograph of FIG. 3, and to understand what is shown in FIG. 7, it may be helpful to refer to the photograph in FIG. 4.

6 and 7 illustrate cross-sectional shapes of the optical sheet of the present invention. Hereinafter, the first pattern portion and the second pattern portion will be described in detail using the cross-sectional shape of the optical sheet. However, in obtaining a cross-sectional shape of the optical sheet as shown in FIGS. 6 and 7, the reference line or reference plane for the optical sheet is not necessarily determined.

First, an optical sheet according to an embodiment of the present invention will be described with reference to FIG. 6.

Referring to FIG. 6, the optical sheet according to the embodiment of the present invention includes a body portion 200 having a flat surface and at least one surface, and a protrusion formed on one surface of the body portion 200, and the protrusion is formed. The first pattern part 210 and the second pattern part 220 are classified according to the size of the pattern.

The body portion 200 and the protrusion may be integrally formed, and when the protrusion is formed on the body portion 200 using the body portion 200 as a substrate, the body portion ( The protrusions are coated on 200).

And, the body portion 200 includes, but is not limited to, a plastic film made of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), oriented polypropylene, polycarbonate, triacetate, and the like.

For example, polyester films such as Tetron® film, MELINEX® film and the like can be used as the substrate.

The protrusion may be made of a UV curable acrylate or a thermosetting resin, and coated on the surface of the body part 200.

Meanwhile, the first pattern part 210 constituting the protrusion is composed of main patterns 211 and 212 having a size in a range of 45 μm to 70 μm of any one of horizontal or vertical cross sections thereof. The shape and the size of 211 and the second main pattern 212 do not necessarily need to be the same.

The first main pattern 211 and the second main pattern 212 may have a cross sectional length of 45 μm to 70 μm within the first main pattern 211 and the second main pattern 212. Can be circular or elliptical in its planar shape.

In FIG. 6, the cross-sectional length of the first main pattern 211 is shown as d1, and the cross-sectional length of the second main pattern 212 is shown as d2. As described above, the d1 and d2 are 45 μm to It belongs to the range of 70 micrometers.

Sub-patterns 221, 222, and 223 forming the second pattern part 220 are formed in the spaces between the first main pattern 211 and the second main pattern 212. The third sub-pattern in which the cross-sectional shape has a circle or ellipse shape, the second sub-pattern 222 having a prism shape, and the pattern having a circle or ellipse shape are continuously arranged ( 223 is shown.

The sub patterns 221, 222, and 223 may be formed continuously with the main patterns, indicating that the sub patterns 221, 222, and 223 may be irregularly arranged.

In particular, the second pattern portion 220 is formed such that the cross-sectional lengths d3, d4, and d5 of the sub-patterns 221, 222, and 223 are all within the range of 1 μm to 20 μm, and in particular, the cross-sectional shape is formed of a prism shape. The cross-sectional length d4 of the two sub patterns 222 is manufactured to fall within the range of 2 μm to 15 μm, and as shown in FIG. 9, the cross-sectional length of the sub pattern having a trapezoidal or pyramidal shape also has a length of 2 μm to 15 μm. It is manufactured to fall within the micrometer range.

Next, the pattern shape of the optical sheet according to the exemplary embodiment of the present invention will be described with reference to FIG. 7.

Referring to FIG. 7, the cross-sectional shape of the optical sheet is illustrated similarly to the cross-sectional shape shown in FIG. 6, and the cross-sectional height of the first main pattern 211 constituting the first pattern portion 210 is h1. The cross-sectional height of the second main pattern 212 is shown by h2.

The cross-sectional heights of the first main pattern 211 and the second main pattern 212 constituting the first pattern portion 210 may be different from each other, but the first constituting the first pattern portion 210 is different. The height h1 of the main pattern 211 and the height h2 of the second main pattern are both 1/3 to the average of the cross-sectional lengths d1 and d2 of the main patterns constituting the first pattern portion 210. Falls within the 2/3 range.

The main patterns constituting the first pattern portion 210 according to the embodiment of the present invention are also manufactured so that the cross-sectional length thereof is varied, whereby the average cross-sectional length A of the main patterns may be changed. The average value also falls within the range of 45 μm to 70 μm. In addition, the average cross-sectional height B of the main patterns constituting the first pattern portion 210 may be a value within a range of 15 μm to 46.7 μm.

That is, the average value of the cross-sectional height h1 of the first main pattern 211 and the cross-sectional height h2 of the second main pattern 212 may be in a range of 15 μm to 46.7 μm.

7 illustrates cross-sectional heights of the sub patterns 221 and 222 constituting the second pattern part 220. The cross-sectional height of the first sub pattern 221 is h3, and the second sub pattern 222 is illustrated in FIG. 7. The cross-sectional height of is shown as h4.

The cross-sectional height h3 of the first sub-pattern 221 constituting the second pattern portion 220 and the cross-sectional height h4 of the second sub-pattern are both molded to be within the range of 2 μm to 15 μm.

Therefore, as can be seen from the name of the configuration, the reason why it is divided into the main pattern and the sub-pattern is also molded so that the main pattern is larger than the sub-pattern in both the cross-sectional length and the cross-sectional height. This molding method will be described with reference to FIG. 14.

In addition, the plurality of main patterns constituting the first pattern part 210 may have a planar shape of a circle or an ellipse, and are irregularly arranged. In addition, a plurality of sub-patterns constituting the second pattern part 220 are formed in an area between the main patterns, which are also irregularly arranged. This is illustrated in FIG. 8.

9 is a cross-sectional view of the sub-patterns constituting the second pattern portion according to the embodiment of the present invention.

That is, the sub patterns formed on one surface of the body portion of the optical sheet may include a first sub pattern 221 having a cross-sectional shape of a circle or an ellipse, a second sub pattern 222 having a prism shape of a cross section, and the second pattern. The second sub-pattern 222 and the fourth sub-pattern 224 having a difference in cross-sectional height, the fifth sub-pattern 225 in which the cross-sectional shape is trapezoidal or pyramid, and the sixth sub-cross in the shape of a hook It may consist of patterns 226.

The shape of such a subpattern can be formed in various ways depending on the shape of the molding mold used to manufacture the optical sheet and the process conditions to separate the resin from the molding mold.

However, although various shapes of the sub patterns are disclosed in FIG. 9, each of the cross-sectional heights of the first to sixth sub-patterns is within a range of 1 μm to 15 μm, and the cross-sectional lengths of the first to sixth sub-patterns may be Each falls within the range of 1 μm to 20 μm.

10 is a graph showing the results of examining the optical characteristics of the optical sheet according to an embodiment of the present invention through an experiment.

In the graph of FIG. 10, optical characteristics appearing according to the average length of the cross-sectional lengths of the sub-patterns are shown. In this graph, the pattern area rate (%) is calculated by the following equation.

pattern area rate (%) =

Here, r represents the average cross-sectional length of the sub patterns, n represents the number of sub patterns per 300㎛ ² .

In the graph of FIG. 10, as the r, the average cross-sectional length of the sub-patterns is divided into 0 μm (when only the main patterns are formed in the optical sheet), 2.5 μm, 5 μm, 7 μm, 10 μm, 15 μm, and 20 μm. The brightness gain for each is shown.

This is organized into a table.

 size 0 (only main pattern)  2.5  5  7  10  15  20 pattern area rate (%)  78.54  78.55  79.07  79.59  80.68  83.35  87.08 brightness gain 100 99.93 99.25 100.70 102.65 104.64 107.07

Here, the luminance value is the contrast ratio of the luminance with respect to the light transmitted through the optical sheet, with 100 being the case where only the main patterns are formed without sub-patterns being formed in the optical sheet.

As can be seen from the graph of FIG. 10 and Table 1, as the area occupied by the sub-patterns on one surface of the optical sheet increases, the luminance value increases accordingly.

On the other hand, the optical characteristics according to the cross-sectional length of the first sub-pattern 221 whose cross-sectional shape is a lens pattern and the second sub-pattern 222 whose cross-sectional shape is a prism shape were tested. Table 2 below.

 Optical Characteristics by Subsize Section Length Size  Optical property  Luminance  Viewing angle Haze TLT DT PT Horizontal Vertical only main pattern 77.46 56.79 44.15 12.64 One 106 ° 110 ° First subpattern 1 ~ 3㎛ 85.92 65.23 56.04 9.18 0.9756 126 ° 126 ° 3 ~ 6㎛ 87.5 61.7 54 7.71 1.0013 124 ° 120 ° Mix the first subpattern and the second subpattern Mixing the first subpattern of 3 to 6 mu m and the second subpattern of 3 mu m    89    62.63    55.74    6.89    1.0077    124 °    120 °

Table 2 above shows a case in which only the first pattern portion 210 is formed on the optical sheet (only main pattern), and the second pattern portion 220 or sub in the space between the first pattern portions 210. The patterns may be divided into a case of forming patterns. In the case of forming a subpattern, a cross-sectional shape of the first subpattern 221 having a curvature or an ellipse may be formed. 221 and the second sub-pattern 222 having a prism shape in cross-sectional shape were also formed.

As a result, when the second sub-pattern 222 having a cross-sectional length d4 of 3 µm is formed together with the first sub-pattern 221, the haze rises to about 90%, and PT (parallel) The amount of light is reduced to 6.89. Thus, while forming the second pattern portion 220 together with the first pattern portion 210 in the optical sheet, the second sub-pattern 221 as well as the first sub-pattern 221 as the second pattern portion 220. In the case of forming the mixture, it can serve as a high luminance optical film.

In addition, as the area occupied by the first pattern portion 210 and the second pattern portion 220 in the optical sheet increases, the luminance value increases, and without decreasing the luminance value than in the case where only the first pattern portion 210 is formed. Can increase haze by more than 10%

11 to 13 illustrate some components of a backlight assembly according to example embodiments.

First, referring to FIG. 11, the backlight assembly 600 includes a lamp unit 640 for generating light and a light guide unit for guiding light generated by the lamp unit 640 to the liquid crystal display panel 650. do.

The lamp unit 640 includes a lamp 641 for generating light and a lamp reflector 642 surrounding the lamp 641. The light generated from the lamp 641 is incident to the light guide plate 620.

In this case, the lamp reflector 642 reflects the light generated from the lamp 641 toward the light guide plate 620 to increase the amount of light incident to the light guide plate 620.

In addition, the light guide unit according to the embodiment of the present invention includes a reflecting plate 630, a light guide plate 620 and an optical sheet 610, the optical sheet 610 is a plurality of micro lenses (main pattern) as described above And a second pattern portion including sub patterns formed in a space between the main patterns.

The light guide plate 620 is provided at one side of the lamp unit 640 to guide the light generated from the lamp unit 640 to be moved to the liquid crystal display panel 650.

The lower portion of the light guide plate 620 is further provided with a reflecting plate 630 for reflecting light leaked from the light guide plate back to the light guide plate 620.

Meanwhile, an optical sheet 610 is disposed above the light guide plate 620 to improve optical characteristics of light moved by the light guide plate 620, and the optical sheet 610 is an optical sheet according to an embodiment of the present invention. Although one sheet is illustrated as being used, two or more optical sheets having a pattern surface irregularly formed in a plurality of micro lenses with different sizes may be used according to an embodiment of the present invention.

Next, referring to FIG. 12, the backlight assembly 700 of the present invention includes a lamp unit 740 for generating light and a diffusion for guiding light generated from the lamp unit 740 toward the liquid crystal display panel 750. Unit is included.

The lamp unit 740 includes a lamp 741 for generating light, and a lamp reflector 742 surrounding the lamp 741. Light emitted from the lamp 741 is incident to the light guide plate 720. For reference, although the light guide plate 720 may also be referred to as a diffusion plate, it will be referred to as a light guide plate in the present invention.

The lamp reflector 742 reflects the light generated from the lamp 741 toward the light guide plate 720 to increase the amount of light incident to the light guide plate 720.

In addition, the diffusion unit includes the light guide plate 720 and the optical sheet 710, the light guide plate 720 is disposed above the lamp unit 740, the light generated from the lamp unit 740 Diffuses and guides it to be moved to the liquid crystal display panel 750.

In addition, since the light guide plate 720 is disposed above the lamp unit 740, light leaked from the light guide plate 720 may be guided back to the light guide plate 720 by the lamp reflection plate 742.

In addition, light that is moved by the light guide plate 720 is disposed above the light guide plate 720.

13, a lamp unit 840 including a lamp 841 and a lamp reflector 842 for generating light, and the lamp assembly 800 according to another embodiment of the present invention; A light guide unit for guiding the light generated by the unit 840 to the liquid crystal display panel 850 is included.

In addition, the light guide unit includes the reflective plate 830, the light guide plate 820, and the optical sheet 810 as described above.

In particular, optical sheets having various shapes according to the embodiment of the present invention are used, in which case the optical sheet is positioned so that the protrusion formed on the optical sheet faces the light guide plate 820, and one optical sheet is formed. Although shown, the optical sheets according to various embodiments of the present invention may be used to stack several sheets.

It is a block diagram for demonstrating the manufacturing apparatus of the optical sheet which concerns on the Example of this invention.

Referring to FIG. 14, in the apparatus for manufacturing an optical sheet according to an embodiment of the present invention, the first roll 1200 on which the base film 1100 is wound and the second roll on which the patterned optical sheet 1120 is wound are wound. And a guide roll 1300a to 1300e for transferring the base film 1100 and the optical sheet 1120 on which the pattern is formed.

The guide rolls 1300a to 1300e may have a first guide roll 1300a, a second guide roll 1300b, a third guide roll 1300c, a fourth guide roll 1300d, and a fifth according to the position where the guide rolls 1300a to 1300e are formed. The guide rolls 1300e may be divided, and the guide rolls 1300a to 1300e may be changed in various numbers and positions thereof according to the embodiments of the present invention.

The optical sheet manufacturing apparatus according to an embodiment of the present invention is provided between the third guide roll 1300c and the fourth guide roll 1300d to apply the patterned coating liquid to the base film 1100. The pattern molding part 1400 is further provided, and the pattern molding part 1400 serves as a pattern roll.

However, the pattern molding part 1400 has a main coating area and a pre-coating area, and in particular, the pattern molding part 1400 is injected by dividing the coating liquid into the pattern layer of the molding mold at least twice. . This technical configuration will be described in more detail with reference to the drawings.

The pattern molding part 1400 is formed by pattern molding the coating solution according to the pattern provided on the molding mold 1420 and the injection molding liquid 1420, the injection molding liquid is in close contact with the molding mold 1420. The master roll 1440 for applying to the base film 1100 and the pattern guide rolls 1460a and 1460b for transferring the molding mold 1420 are included.

In addition, the molding mold 1420 is a pattern layer on which a pattern is implemented on a film-shaped base layer, is formed in a belt type, and serves to pattern-form the coating liquid as described above with the pattern roll.

For reference, only a part of the pattern implemented in the pattern layer of the molding mold 1420 illustrated in FIG. 14 is illustrated, and in some embodiments, the pattern may be implemented in the entire molding mold.

In addition, the installation of the molding mold 1420 wraps an extension line connecting the master roll 1440 and the pattern guide rolls 1460a and 1460b with the molding mold 1420 and then ends both ends of the molding mold 1420. Can be done by connecting.

In particular, when the molding mold 1420 moves in the direction of the arrow shown in the pattern molding part 1400, the molding mold 1420 freely injects a coating liquid into the pattern layer of the intaglio pattern of the molding mold 1420. Coating areas 2000, 2010 and 2020 are formed.

That is, the pre-coating regions 2000, 2010, and 2020 are first filled (or 'coated') with the coating liquid in the molding mold 1420 in the pattern molding unit 1400, and the first in the pre-coating region. The filled molding mold is transferred to the master roll 1440. In addition, the transferred molding mold 1420 is secondaryly filled by the coating liquid coming out of the coating liquid injection means 1600 provided on one side of the master roll 1440.

Therefore, the composition for injecting the coating liquid into the molding mold 1420 may be composed of the primary filling in the pre-coating region and the secondary filling in the vicinity of the master roll 1440.

However, although the pre-coated regions 2000, 2010, and 2020 are shown as three regions, the pre-coating regions 2000, 2010, and 2020 may be more than this. For reference, the pre-coating region illustrated in FIG. 15 will be described using the pre-coating region 2000 formed between the first pattern guide roll 1460a and the second pattern guide roll 1460b as an example.

In addition, the optical sheet manufacturing apparatus according to an embodiment of the present invention, the coating film injection means 1600 for injecting the coating liquid in the area where the base film 1100 is introduced into the pattern molding portion 1400, and heat or UV ( UltraViolet) includes a curing means 1700 for curing the coating solution.

On the other hand, the operation of the optical sheet manufacturing apparatus according to the embodiment of the present invention will be described below.

First, the base film 1100 wound on the first roll 1200 is transferred by the guide rolls 1300a to 1300e. In this case, the molding mold 1420 provided in the pattern molding part 1400 is also transferred / rotated while the master roll 1440 and the pattern guide rolls 1460a and 1460b are wound.

In addition, since the master roll 1440 is engaged with the third guide roll 1300c and the fourth guide roll 1300d, the base film 1100 is formed by the third guide roll 1300c. 1420).

In particular, the third guide roll 1300c plays a gap control role of controlling the thickness of the pattern layer of the completed optical sheet 1120 by adjusting the thickness of the coating liquid applied to the base film 1100.

In detail, as the third guide roll 1300c is attached to the master roll 1440, the thickness of the pattern layer of the optical sheet is thinner, and conversely, the third guide roll 1300c is spaced apart from the master roll 1440. The thickness of the pattern layer of an optical sheet is formed thick. The thickness of the pattern layer of the optical sheet may be adjusted by the viscosity of the coating liquid, the patterning speed, and the tension of the base film in addition to the gap between the third guide roll 1300c and the master roll 1440.

On the other hand, the coating liquid is injected by the coating liquid injection means 1600 in the predetermined region where the base film 1100 is engaged with the third guide roll 1300c and the master roll 1440, and the molding mold 1420 The filling is pushed through the pattern of. Here, before the coating liquid is filled between the patterns of the molding mold by the coating liquid injection means 1600, the coating liquid stored in the coating liquid container (to be described later) in the pre-coating region (2000, 2010, 2020) of the molding mold The pattern is filled first.

The coating liquid supplied from the coating liquid injection means 1600 is uniformly distributed on the base film 1100 by the pressure between the third guide roll 1300c and the master roll 1440 to form a pattern. In addition, the coating liquid distributed between the patterns is cured by heat or UV emitted from the curing means 1700.

The base film 1100 on which the patterned coating solution is cured and applied is guided by the fourth guide roll 1300d, separated from the molding mold 1420, and the finished optical sheet 1120 is separated from the fifth guide. It is conveyed by the roll 1300e and wound on the second roll 1500.

Here, the fourth guide roll 1300d serves to separate the optical sheet 1120 to which the coating liquid is applied from the molding mold 1420. In other words, the fourth guide roll 1300d separates the optical sheet 1120 having the pattern layer from the molding mold 1420.

In the above-described embodiment of the present invention, the base film 1100 and the completed optical sheet 1120 are classified according to whether the coating liquid is applied according to the embodiment of the present invention while being connected to each other.

That is, the base film 1100 refers to a state before the pattern is formed, and the optical sheet 1120 refers to a state in which a coating liquid formed by patterning is applied to the base film while passing through the pattern molding unit 1400. do. In FIG. 14, only a part of the pattern layer formed on the optical sheet 1120 is illustrated, and in fact, the optical sheet wound on the second roll 1500 is also in a state where the pattern layer is formed.

Hereinafter, the precoat apparatus and the precoat method of the manufacturing apparatus of the optical sheet which concerns on the Example of this invention are demonstrated in detail.

15 is an enlarged view of a part of a configuration of an apparatus for manufacturing an optical sheet according to an embodiment of the present invention.

In FIG. 15, the structure of a precoat area | region is enlarged in the manufacturing apparatus of an optical sheet. Next, an example in which a pre-coating region is provided between the first pattern guide roll 1460a and the second pattern guide roll 1460b in FIG. 14 will be described.

Referring to FIG. 15, a molding mold inverted to a pattern shape of an optical sheet to be manufactured is moved along a first pattern guide roll 1460a and then first coated in the pre-coating region 2000 and then the second mold. It is conveyed along the pattern guide roll 1460b.

Here, the molding mold is made of a base layer and a pattern layer, as described above, and the pattern layer is formed with an intaglio pattern that is inverted in phase with the first pattern portion and the second pattern portion.

The pre-coating region 2000 includes a first pre-coating roll 2010 and a second pre-coating roll 2020 for transferring a molding mold. In addition, a portion of the second pre-coating roll 2020 is contained in the coating liquid container 2100 so that the coating liquid may be injected into the molding mold by the second pre-coating roll 2020.

Therefore, as the second pre-coating roll 2020 is rotated, the coating liquid stored in the coating liquid container 2100 is transferred to the first pre-coating roll 2010 and the second pre-coating roll 2020. It is injected into a pattern layer.

That is, since the coating liquid (the raw material of the optical sheet) for filling the intaglio pattern formed in the molding mold is a material having a predetermined viscosity, the coating liquid stored in the coating liquid container 2100 may be formed on the surface of the second pre-coating roll 2020. As a result, the mold may be touched.

On the other hand, the coating liquid container 2100 may be manufactured to a size that can accommodate the second pre-coating roll 202 and other pre-coating rolls located on one side thereof.

According to various embodiments of the present invention, there is an advantage that an excellent effect can be obtained with respect to optical characteristics such as brightness and viewing angle.

By the optical sheet of the present invention and the backlight assembly provided with the optical sheet as proposed, there is an advantage to improve the viewing angle and brightness.

Claims (15)

Body portion; And Includes; a protrusion having a structure structured on one surface of the body portion, The protrusion With a plurality of main patterns, Has a plurality of sub-patterns formed in the region between the main patterns, The cross-sectional length of the main pattern is made in the range of 5㎛ 70㎛, the cross-sectional length of the sub-pattern is made in the range of 1㎛ 20㎛. The method of claim 1, The main sheet is an optical sheet, characterized in that the irregularly arranged micro lens pattern. The method of claim 1, The sub-pattern is formed at a predetermined distance from the main pattern. The method of claim 1, And the sub-pattern is irregularly arranged in the region between the main patterns. The method of claim 1, And the sub-pattern is formed adjacent to the main pattern. The method of claim 1, The sub-pattern is an optical sheet, characterized in that its cross-sectional shape is a prism shape or a circle or ellipse shape. The method of claim 1, The sub-pattern may include a first sub-pattern having a prism shape in a cross section between the main patterns and a second sub-pattern having a cross-sectional shape in the shape of a micro lens. The method of claim 7, wherein The cross-sectional height of the first sub-pattern has a value in the range of 2 μm to 15 μm. The method of claim 1, The said subpattern is an optical sheet whose cross-sectional shape is a pyramid shape. A first pattern portion consisting of a plurality of main micro lens patterns, A second pattern portion formed in a region between the micro lens patterns and having a smaller size than the micro lens pattern, the second pattern portion including sub micro lens patterns each having a diameter within a range of 1 μm to 20 μm Optical sheet having a face. The method of claim 10, And the main micro lens patterns are each formed to have a diameter within a range of 45 μm to 70 μm. A lamp unit for generating light, A light guide plate for guiding the light generated from the lamp unit toward the panel; An optical sheet provided between the light guide plate and the panel; The optical sheet is composed of a body portion having a flat surface at least one side, and a protrusion formed on one surface of the body portion, The protrusion is composed of a plurality of main patterns and a plurality of sub-patterns that can be classified according to the size of the cross-sectional length, Each of the main patterns has a cross-sectional length in a range of 5 μm to 70 μm, and a cross-sectional length of the sub pattern is in a range of 1 μm to 20 μm. The method of claim 12, And the protrusion of the optical sheet is disposed to face the panel side. The method of claim 12, And a body portion of the optical sheet is disposed to face the panel side. The method of claim 12, Two or more optical sheets are provided between the panel and the light guide plate.

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