WO2019132367A1 - Diffusion sheet having improved shielding performance and backlight unit comprising same - Google Patents

Diffusion sheet having improved shielding performance and backlight unit comprising same Download PDF

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Publication number
WO2019132367A1
WO2019132367A1 PCT/KR2018/016072 KR2018016072W WO2019132367A1 WO 2019132367 A1 WO2019132367 A1 WO 2019132367A1 KR 2018016072 W KR2018016072 W KR 2018016072W WO 2019132367 A1 WO2019132367 A1 WO 2019132367A1
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WIPO (PCT)
Prior art keywords
layer
light
pattern
scattering
sheet
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PCT/KR2018/016072
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French (fr)
Korean (ko)
Inventor
이기욱
이태준
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주식회사 엘엠에스
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Publication of WO2019132367A1 publication Critical patent/WO2019132367A1/en

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/02—Diffusing elements; Afocal elements
    • G02B5/0205—Diffusing elements; Afocal elements characterised by the diffusing properties
    • G02B5/0236—Diffusing elements; Afocal elements characterised by the diffusing properties the diffusion taking place within the volume of the element
    • G02B5/0242—Diffusing elements; Afocal elements characterised by the diffusing properties the diffusion taking place within the volume of the element by means of dispersed particles
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/02—Diffusing elements; Afocal elements
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/02—Diffusing elements; Afocal elements
    • G02B5/0273—Diffusing elements; Afocal elements characterized by the use
    • G02B5/0294—Diffusing elements; Afocal elements characterized by the use adapted to provide an additional optical effect, e.g. anti-reflection or filter
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0033—Means for improving the coupling-out of light from the light guide
    • G02B6/005—Means for improving the coupling-out of light from the light guide provided by one optical element, or plurality thereof, placed on the light output side of the light guide
    • G02B6/0051—Diffusing sheet or layer

Definitions

  • the present invention relates to a diffusion sheet having improved shielding performance, and more particularly, to a diffusion sheet having improved shielding performance including a shielding layer having a different haze value in a diffusion sheet and a backlight unit having the same.
  • the liquid crystal display requires a backlight unit that provides uniform light throughout the screen, unlike the conventional CRT.
  • the backlight unit is provided with a light source lamp, a light guide unit for reflecting the light of the lamp, and a light condensing sheet unit, and converts the light into a surface light source.
  • the light source is disposed adjacent to the side surface of the light guide portion, and the light incident into the light guide portion is transmitted to the upper portion and is condensed by the light condensing sheet portion.
  • the light transmitted from the light guiding portion to the light converging sheet portion is refracted and reflected by the lower portion and is transmitted to the upper portion, so that the light is not uniformly dispersed and a variation occurs in each region.
  • a diffusion sheet is provided between the light collecting sheet portion and the light guiding portion to diffuse the light transmitted from the lower portion and disperse the light uniformly.
  • the diffusion sheet is made of a light-transmitting material and is configured to have a certain pattern on the upper surface or lower surface.
  • the light transmitted from the lower portion is diffused and transmitted to the upper portion, so that light is uniformly condensed in the light condensing sheet portion.
  • the present invention has been made to solve the above problems and it is an object of the present invention to provide a liquid crystal display device having a shield layer having a different haze value and a pattern scattering layer having a scattering pattern on an upper surface thereof, And a backlight unit having the diffusion sheet, which is capable of minimizing the luminance degradation, and having improved shielding performance.
  • a diffusion sheet having an improved shielding performance according to one aspect of the present invention.
  • the diffusion sheet is formed of a light transmitting material and has a predetermined thickness.
  • the diffusion sheet has a predetermined haze value,
  • a shielding layer including a plurality of particles and a scattering pattern formed on at least one of an upper surface and a lower surface of the shielding layer, the scattering pattern having a part protruded therein, a plurality of beads dispersed therein, And a scattering layer, wherein the beads are formed in a size relatively smaller than the particles contained in the shielding layer.
  • a backlight unit including a diffusion sheet having improved shielding performance.
  • the present invention has the following effects.
  • the diffusion sheet is provided on the upper and lower surfaces with a shielding layer having a predetermined haze value, and a pattern scattering layer having a scattering pattern and scattering light is provided, so that the pattern of the light guide plate disposed under the diffusion sheet is prevented from being viewed by the user There is an advantage to be able to do.
  • a separate bead is provided in the pattern scattering layer to increase the scattering and diffusing effect of light transmitted from below, and the bead is formed to have a size where mie-scattering occurs, Is transmitted to the upper portion, thereby minimizing the decrease in luminance.
  • FIG. 1 schematically shows a structure of a backlight unit having a diffusion sheet with improved shielding performance according to an embodiment of the present invention
  • FIG. 2 is a side view of the backlight unit of FIG. 1;
  • FIG. 3 is a schematic view of the configuration of a diffusion sheet in the backlight unit of Fig. 1; Fig.
  • FIG. 4 is a view showing whether a lower pattern is visible depending on the presence or absence of a shielding layer in the diffusion sheet of FIG. 3;
  • FIG. 5 illustrates a configuration in which separate beads are included in a pattern scattering layer in the diffusion sheet of FIG. 1;
  • FIG. 6 is a diagram showing scattering of light according to the arrangement of beads in the pattern scattering layer of FIG. 5;
  • FIG. 7 is a view showing a form in which scattering of light occurs according to the size of particles in the diffusion sheet of FIG. 5;
  • FIG. 8 shows a modified form of the pattern scattering layer of FIG. 5 in the diffusion sheet of FIG. 1;
  • FIG. 9 is a view showing a state in which a shielding layer is composed of multiple layers in the diffusion sheet of FIG. 1; FIG. And
  • FIG. 10 is a view showing a pattern in which the pattern scattering layer in the diffusion sheet of FIG. 1 is composed of multiple layers.
  • the diffusion sheet with improved shielding performance will be described as an example in which the diffusion sheet is applied to a backlight unit of a flat panel liquid crystal display device such as an LCD or an LED panel.
  • the present invention is not limited to this, and may be used alone as a diffusion sheet with improved shielding performance, or may be a backlight unit applied to a mechanism other than that applied to a liquid crystal display, And any device that changes the path.
  • FIG. 1 a configuration of a backlight unit according to the present invention will be schematically described with reference to FIGS. 1 to 4.
  • FIG. 1 a configuration of a backlight unit according to the present invention will be schematically described with reference to FIGS. 1 to 4.
  • FIG. 1 is a schematic view of a backlight unit having a diffusion sheet with improved shielding performance according to an exemplary embodiment of the present invention
  • FIG. 2 is a side view of the backlight unit of FIG.
  • FIG. 3 is a schematic view of the structure of the diffusion sheet in the backlight unit of FIG. 1
  • FIG. 4 is a view illustrating whether or not the lower pattern is visible depending on the presence or absence of the shielding layer in the diffusion sheet of FIG.
  • a backlight unit (BLU) for providing light to a liquid crystal panel must be provided in a liquid crystal display device.
  • the backlight unit according to the present invention mainly includes a light source 100, a light guide unit 200, a light condensing sheet unit 300, and a diffusion sheet 400.
  • the light source 100 generates light at the side of the light guide unit 200 and transmits light to the light guide unit 200 to minimize the volume of the backlight unit.
  • a light emitting diode (LED) and a cold cathode fluorescent lamp (CCFL) may be selectively used.
  • the light source 100 is composed of at least one light source, and emits light toward the side of the light guide unit 200.
  • the light guiding portion 200 has a thickness and is formed in a flat plate shape to transmit the light incident through the side surface to the upper portion.
  • the light incident on the light guide unit 200 is totally reflected in the light guide unit 200 and is emitted upward.
  • the light guiding unit 200 moves the light transmitted from the light source 100 along a flat plate, and is transmitted as an upper surface light source.
  • the light guide unit 200 may include a reflection plate 210 at a lower portion thereof, and reflect the light transmitted through the light guide unit 200 to the lower portion.
  • the light collecting sheet unit 300 is stacked on the light guiding unit 200 and collects the light transmitted from the lower part and transmits the collected light to the upper part in the form of a surface light source.
  • the light collecting sheet unit 300 is formed by stacking a plurality of sheets so as to condense light, or to form a single sheet, and to transmit the light transmitted from the lower portion to the upper portion.
  • the light collecting sheet unit 300 includes a pair of lower optical sheets 310 and an upper optical sheet 320, and the lower optical sheet 310 includes a first base film 312, 1 light collecting portion 314.
  • the first base film 312 is formed of a light transmitting material and has a predetermined thickness and is formed in a flat plate shape.
  • the first light collecting part 314 is formed on the upper surface to condense the light transmitted from the lower part.
  • the first condensing unit 314 is formed on the upper surface of the first base film 312, and the first unit condenser is continuously and repeatedly formed with a decreasing cross sectional area.
  • the first light collecting part 314 collects light transmitted through the first base film 312 and transmits the light to the upper part, and a plurality of first unit light collectors are formed.
  • the first unit condenser has a sloped surface and a cross-sectional area becomes smaller toward the upper portion, so that light is condensed through the sloped surface.
  • the first unit condenser has a pair of inclined surfaces, and is formed in a prism shape having a triangular cross-section along the up-and-down direction.
  • first unit condensers may be formed in a protrusion shape.
  • each of the first unit condensers may be elongated in a strip shape to form the first base film 312 As shown in FIG.
  • the first light collecting part 314 has a plurality of first unit collecting bodies formed so that the upper and lower end faces of the triangular shape extend along one direction, and light is condensed through the first unit collecting bodies.
  • the upper optical sheet 320 is stacked on the lower optical sheet 310 and includes a second base film 322 and a second light collecting part 324 to form the lower optical sheet 310, Converge the light together.
  • the second base film 322 is formed in a shape similar to that of the first base film 312, and a second light collecting portion 324 is formed on the upper surface.
  • the second light collecting part 324 is provided on the upper surface of the second base film 322 to condense the light transmitted from the lower part. Specifically, the second light collecting part 324 is formed in a shape similar to that of the first light collecting part 314, and the second unit light collecting material whose cross-sectional area decreases as it goes upward is continuously and repeatedly formed.
  • the second unit condenser has a pair of inclined surfaces and is formed to have a triangular top and bottom surfaces to condense light through the inclined surfaces.
  • the second unit condensers are formed on the upper surface of the second base film 322, respectively, in the same manner as the first unit condensers.
  • the first and second light collecting parts 314 and 324 may be elongated to intersect with the first and second base films 312 and 322, do.
  • the light collecting sheet unit 300 includes the first base film 312 and the second base film 322, and collects light transmitted from the lower portion of the light collecting sheet unit 300 and transmits the collected light.
  • the diffusion sheet 400 is provided between the light collecting sheet unit 300 and the light guiding unit 200 to diffuse and shield the light transmitted to the upper part and transmit the light to the light collecting sheet unit 300.
  • the diffusion sheet 400 not only diffuses and diffuses the light transmitted from the lower part, but also shields the light to make it uniform.
  • the diffusion sheet 400 includes a shielding layer 410 and a pattern scattering layer 420.
  • the shielding layer 410 is formed of a light transmitting material and has a predetermined thickness and is formed in a sheet shape to prevent the pattern of the light guide plate from being visible to a user by shielding the light transmitted from the lower portion and transmitting the light. .
  • a plurality of particles 412 are dispersed therein to have a predetermined haze value.
  • the haze characteristic is a characteristic that, when light passes through a transparent material, it diffuses depending on the kind of the material, as well as reflection or absorption, depending on the intrinsic properties of the material.
  • the shielding layer 410 is formed in a shape in which the particles 412 are dispersed therein, and is formed in a sheet form at the lower portion of the light condensing sheet portion 300 and stacked.
  • the particles 412 are made of materials such as silica, PMMA, and PBMA and have a size of 1 to 9 ⁇ and have a refractive index of about 1.5 and are dispersed in the shielding layer 410.
  • the particles 412 have a non-uniform size and scatter light transmitted from the lower part to shield the pattern of the light guide plate 200 from being visible.
  • the shielding layer 410 has a thickness of 18 to 130 ⁇ ⁇ and includes a plurality of the particles 412 therein.
  • the shielding layer 410 shields the pattern of the light guide plate 200 from being visually recognized by dispersing the particles uniformly dispersed in the inside of the shielding layer 410 and diffusing light transmitted from the bottom.
  • the shielding layer 410 is configured such that the particles 412 are dispersed therein to have a predetermined haze value.
  • the shielding layer 410 may have a specific pattern on the surface of the shielding layer 410 It is possible.
  • the pattern scattering layer 420 is stacked or bonded to at least one of the upper surface and the lower surface of the shielding layer 410 and a scattering pattern 422 protruding at least partially is formed to diffuse the light transmitted from the lower portion. .
  • the pattern scattering layer 420 is formed on the upper surface or the lower surface of the shielding layer 410 as shown in FIG.
  • the pattern scattering layer 420 has a refractive index different from that of the shielding layer 410 and is laminated or bonded.
  • the pattern scattering layer 420 diffuses light through the scattering pattern 422.
  • the pattern scattering layer 420 is laminated on the upper and lower surfaces of the shielding layer 410, and the scattering patterns 422 are protruded in the upper and lower directions.
  • the scattering pattern 422 has a curved surface in a spherical shape, and a plurality of the scattering patterns 422 are protruded and formed with nonuniform density and size.
  • the diffusion sheet 400 includes the shielding layer 410 and the pattern scattering layer 420, and the particles 412 dispersed in the shielding layer 410 and the pattern scattering
  • the layer 420 may shield and diffuse light transmitted from below.
  • the shielding layer 410 diffuses the light transmitted from the lower portion through a unique haze value and maintains the pattern scattering layer 420 like the base film.
  • the pattern scattering layer 420 diffuses the light transmitted from the lower portion together with the shielding layer 410 to prevent the diffusion sheet 400 and the light guide plate 200 from being attracted to each other or from being abraded.
  • the shield layer 410 and the pattern scattering layer 420 are formed to have different materials and refractive indices.
  • a diffusion sheet 400 is stacked on top of a general pattern to photograph an image to be transmitted.
  • a lower pattern is visible depending on the presence or absence of the shielding layer 410 Can be confirmed.
  • the shielding layer 410 does not have a haze value.
  • the shielding layer 410 does not have a haze value equal to or higher than a certain level, it can be confirmed that scattering occurs, but the lower pattern is visible.
  • the shielding layer 410 has no haze value
  • the light transmitted from the lower portion is diffused by the pattern scattering layer 420, but the light is not dispersed by the shielding layer 410, ) Is visible to the user.
  • the shielding layer 410 and the pattern scattering layer 420 are not provided, the light transmitted from the light guide plate 200 does not have a sufficient diffusion effect, so that the pattern of the light guide plate 200, And can be projected and recognized by the user in the form of a spot, a pattern, or the like.
  • the diffusion sheet 400 according to the present invention is arranged in a laminated structure on a specific pattern as in FIG. 4A.
  • the shielding layer 410 is configured to have a predetermined haze value or more, and in such a case, the lower pattern is diffused to such an extent that it can not be recognized.
  • the luminance can be minimized as the light transmitted from the lower portion is transmitted to the upper portion of the scattered light in the course of passing through the shielding layer 410 and the pattern scattering layer 420, have.
  • the shape of the scattering layer 420 can be adjusted by using structural deformations of the pattern scattering layer 420 and a separate bead 424, and a specific structure thereof will be described later with reference to FIG.
  • the diffusion sheet 400 not only diffuses light, but also increases the shielding performance of the light transmitted by the shielding layer 410 so that it can be diffused evenly.
  • FIG. 5 a modified form of the diffusion sheet 400 according to the present invention will be described with reference to FIGS. 5 to 7.
  • FIG. 5 is a modified form of the diffusion sheet 400 according to the present invention.
  • FIG. 5 is a view showing a configuration in which a separate bead 424 is included in the pattern scattering layer 420 in the diffusion sheet 400 of FIG. 1
  • FIG. 6 is a schematic view of a pattern scattering layer according to the arrangement of beads in the pattern scattering layer of FIG.
  • FIG. 7 is a view showing a form in which scattering of light occurs according to the size of the particles 412 in the diffusion sheet 400 of FIG. 5.
  • the basic structure of the diffusion sheet 400 is similar to that described above, but further includes a separate bead 424 inside the pattern scattering layer 420.
  • the pattern scattering layer 420 is formed on at least one of the upper surface and the lower surface with respect to the shielding layer 410.
  • the pattern scattering layer 420 includes a plurality of beads 424 therein, and further increases the shielding performance by further scattering and diffusing the light transmitted from the bottom by the beads 424, At the same time, the decrease in luminance is reduced.
  • the beads 424 are added to the pattern scattering layer 420 to further diffuse and scatter light due to the main purpose of increasing the shielding performance of light transmitted from the bottom.
  • the beads 424 have a spherical shape and are uniformly dispersed in the pattern scattering layer 420, and a plurality of the beads 424 are formed to have a non-uniform size. At this time, the beads 424 are formed to have a different material or refractive index from the pattern scattering layer 420, so that light scattering occurs in the pattern scattering layer 420.
  • the pattern scattering layer 420 includes the beads 424 therein, light scattered from the bottom of the bead 424 as well as the scattering pattern 422 can be scattered and diffused.
  • the beads 424 have a size that causes mie-scattering corresponding to the wavelength of the light transmitted from the lower part, and the beads 424 are relatively smaller than the particles 412 contained in the shield layer 410 .
  • the size of the beads 424 according to the present invention has a fine size of several hundreds of nanometers to several micrometers, and is configured so that scattering of light transmitted from below can occur.
  • scattering is a phenomenon in which light collides with a specific particle and is scattered in various directions. It refers to a phenomenon in which waves or high-speed particle beams collide with many molecules, atoms, and particles to change direction of motion and scatter. Gas, liquid, and solid. However, in solid or liquid, scattered light is synthesized and is more likely to be refracted or reflected.
  • Representative scattering includes Rayleigh scattering and Mie-scattering.
  • Rayleigh scattering refers to scattering occurring when the size of particles causing scattering is very small and is smaller than the wavelength of light, which is inversely proportional to the fourth power of the wavelength of light. That is, the amount of scattered light decreases sharply as the wavelength becomes longer.
  • Such Rayleigh scattering scatters light both forward and backward when light collides against a specific particle as shown in FIG. 7 (a).
  • Such scattering is influenced by the density, size and shape of the particles, and particularly scattering occurs in spherical particles.
  • the bead 424 according to the present invention is configured such that no scattering occurs in which forward scattering occurs in order to diffuse and transmit the light transmitted from the light source 100 in the upward direction.
  • the beads 424 have a spherical shape and are configured to have a size corresponding to the wavelength of the visible light region so that the light generated from the light source 100 can be scattered forward.
  • the beads 424 may be formed of at least one of Alumina, TiO 2 , Melamine, Silica, PMMA, PBMA, and PDMS, and may be formed in a spherical shape.
  • the refractive index of the bead 424 is preferably 1.67.
  • the beads 424 are formed to have a size of 0.1 to 1 ⁇ and maximize the mie scattering effect of the light of the visible light wavelength band emitted from the light source 100, 424 in the forward direction.
  • the bead 424 is more than 1000 nm in size, the bead 424 is fragile due to breaking or being touched upon contact with the light guide plate 200, resulting in deterioration of quality.
  • the bead 424 according to the present invention can scatter the light transmitted from the lower portion and is not damaged by the interference with the light guide plate 200, thereby diffusing the light transmitted from the lower portion.
  • the pattern scattering layer 420 according to the present invention can efficiently transmit the light transmitted from the lower light guide plate 200 to the upper portion by including the beads 424 therein, The decrease in luminance due to the layer 410 can be minimized.
  • the beads 424 are arranged such that the distribution density is relatively increased in the pattern scattering layer 420 so as to be closer to the shielding layer 410, thereby reducing light directivity transmitted from the lower portion,
  • the shielding performance of the diffusion sheet 400 may be increased.
  • the pattern scattering layer 420 is formed on the upper and lower surfaces of the shielding layer 410, and the beads 424 are contained therein.
  • the pattern scattering layer 420 can be divided into an A region along the vertical direction and a B region adjacent to the shielding layer 410.
  • the scattering pattern 422 is formed in the A region and the shielding layer 410 In the direction away from the center.
  • the beads 424 are distributed in the A region and the B region as shown in the region adjacent to the shielding layer 410, but the beads 424 are distributed in the region B more than the A region, Is distributed.
  • the beads 424 are distributed more in the region B than the region A in the region B adjacent to the shielding layer 410 in the pattern scattering layer 420, thereby increasing the shielding performance of the diffusion sheet 400.
  • FIG. 6A shows a state in which the beads 424 are uniformly distributed in the pattern scattering layer 420 and FIG. 6B shows a state in which the beads 424 are scattered in the pattern scattering layer 420, And the distribution density increases in the vicinity of the shielding layer 410.
  • the probability that the beads 424 are adjacent to the shielding layer 410 and the light transmitted from the lower part increases, thereby causing a difference in scattering degree of light.
  • the distribution density of the beads 424 is relatively higher in a region adjacent to the shielding layer 410 than in a uniform shape, so that light transmitted from the lower portion passes through the beads 424.
  • the beads 424 are arranged such that the distribution density is relatively larger in the region adjacent to the shielding layer 410 than in the remaining regions, as shown in FIG. 6B, It is possible to increase diffusion and scattering of the transmitted light.
  • the pattern scattering layer 420 according to the present invention is formed such that the distribution density of the beads 424 is increased toward the shielding layer 410 and the diffusion effect of light transmitted from the lower part is increased, .
  • the beads 424 have a nonuniform size in a spherical shape as described above, and are formed to have a size such that light transmitted from the lower portion is not scattered.
  • FIG. 8 is a view showing a modified form of the pattern scattering layer 420 of FIG. 5 in the diffusion sheet of FIG.
  • the basic structure is similar to that of FIG. 5, but the arrangement of the beads 424 provided in the pattern scattering layer 420 is different.
  • the pattern scattering layer 420 is formed on the upper and lower surfaces with respect to the shielding layer 410.
  • the bead 424 has a density (density) closer to the shielding layer 410, Is increased.
  • the beads 424 are uniformly distributed in the lower pattern scattering layer 420.
  • the beads 424 are dispersed inside as described above with reference to FIG. 4, and the distribution density increases when the shielding layer 410 is adjacent to the upper pattern scattering layer 420, Minimizing the pathway maximizes scattering and diffusion effects.
  • the light passing through the shielding layer 410 is diffused and scattered by the upper pattern scattering layer 420 to improve the shielding performance.
  • the lower pattern scattering layer 420 uniformly distributes the beads 424 therein, thereby maximizing the non-scattering effect due to the beads 424.
  • the lower pattern scattering layer 420 may be formed using the bead (424) are uniformly distributed.
  • the beads 424 inside the lower pattern scattering layer 420 may not be distributed evenly, and may be configured to have a relatively high density at a specific position.
  • the diffusion sheet 400 includes the pattern scattering layer 420 on the upper surface of the shielding layer 410,
  • the bead 424 has a relatively high distribution density in the B region.
  • the beads 424 should be formed to have a size capable of causing non-scattering as described above, so that the brightness is not reduced.
  • the diffusion and shielding of light can be performed only with the diffusion sheet 400 according to the present invention without lowering the brightness.
  • FIG. 9 is a view showing a state in which the shielding layer 410 in the diffusion sheet 400 of FIG. 1 is composed of multiple layers.
  • the shielding layer 410 is composed of a plurality of sheets and each has a predetermined haze value.
  • the shielding layer 410 is not a single layer, but a plurality of sheets are stacked.
  • the shielding layer 410 is composed of a first sheet 410a and a second sheet 410b.
  • the first sheet 410a has a first haze value as a light transmitting material
  • the second sheet 410b has a second haze value.
  • the first sheet 410a and the second sheet 410b may have different thicknesses.
  • the first sheet 410a and the second sheet 410b have mutually different haze values and are stacked and bonded together to form the shielding layer 410, thereby increasing the shielding performance of light transmitted from the lower portion .
  • the first sheet 410a has a thickness L1 and the second sheet 410b has a thickness L2.
  • the first sheet 410a and the second sheet 410b are configured to have a first haze value and a second haze value, respectively.
  • the first sheet 410a and the second sheet 410b may include the particles 412, And is configured to have a different haze value.
  • the pattern scattering layer 420 is coupled to an upper portion of the shielding layer 410 including the first sheet 410a and the second sheet 410b.
  • the shielding layer 410 may be formed of a plurality of sheets and may have different thicknesses or different haze values to increase the shielding performance of light transmitted from the lower portion of the shielding layer 410, ) The entire thickness can be adjusted.
  • the pattern scattering layer 420 may further include the beads 424, and the light transmitted from the lower portion may be diffused by the beads 424, .
  • the beads 424 have a non-uniform size in a spherical shape and are dispersed in the pattern scattering layer 420.
  • the shielding layer 410 may be configured to have a plurality of layers and have different haze values, thereby increasing the shielding performance of light .
  • the pattern scattering layer 420 is formed of multiple layers in the diffusion sheet 400 of the present invention.
  • FIG. 10 is a diagram showing a pattern scattering layer 420 in the diffusion sheet of FIG. 1, which is composed of multiple layers.
  • the pattern scattering layer 420 is formed on the first layer 420a having the scattering pattern 422 and the first layer 420a having the scattering pattern 422. However, And a second layer 420b disposed between the first electrode layer 420 and the shielding layer 410.
  • the first layer 420a is continuously formed in the second layer 420b, and the scattering pattern 422 protruding upward is formed.
  • the scattering pattern 422 is the same as the structure described above with reference to FIG. 1, and scatters light transmitted from the bottom in a nonuniform form.
  • the bead 424 is not included in the first layer 420a.
  • the bead 424 may be formed at a relatively lower density than the second layer 420b, 424 may be provided.
  • the second layer 420b is formed in a sheet shape, and a plurality of the beads 424 are dispersed therein, and the beads 424 spread and scatter light.
  • the second layer 420b is laminated on the upper surface of the shielding layer 410 in a sheet form, and the first layer 420a is laminated on the upper layer.
  • the beads 424 provided in the second layer 420b have a size smaller than that of the particles 412 as described above and are formed to have a size capable of scattering light transmitted from below.
  • the pattern scattering layer 420 is composed of the first layer 420a and the second layer 420b and the bead 424 is included in the second layer 420b,
  • the beads 424 are concentratedly distributed on the entire surface of the substrate 420 adjacent to the shielding layer 410.
  • the distribution density of the beads 424 increases as the shielding layer 410 is closer to the shielding layer 410, thereby increasing diffusion and scattering effect of light transmitted from the lower portion.
  • the diffusion sheet 400 having improved shielding performance according to the present invention and the backlight unit including the diffusion sheet 400 have been described.
  • the diffusion sheet 400 includes a shielding layer 410 having a predetermined haze value, It is possible not only to diffuse the light to be scattered but also to increase the shielding performance through scattering.
  • the light can be uniformly transmitted by preventing the pattern of the light guide plate 200 from being transmitted to the upper portion, and the bead 424 is not scattered It is possible to minimize the luminance drop due to diffusion and scattering of light.

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  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Chemical & Material Sciences (AREA)
  • Dispersion Chemistry (AREA)
  • Optical Elements Other Than Lenses (AREA)

Abstract

The present invention provides a diffusion sheet having improved shielding performance, the diffusion sheet comprising: a shielding layer made of a light-transmitting material, formed to have a predetermined thickness, and containing a plurality of particles according to a predetermined haze value; and a patterned scattering layer formed on at least one of the upper surface and the lower surface of the shielding layer, including a partially protruding scattering pattern, and having a plurality of beads dispersed therein so as to diffuse light transmitted from the lower side thereof, wherein the beads are formed to have a relatively smaller size than the particles contained in the shielding layer.

Description

차폐 성능이 향상된 확산시트 및 이를 구비한 백라이트 유닛A diffusion sheet with improved shielding performance and a backlight unit having the diffusion sheet
본 발명은 차폐 성능이 향상된 확산시트에 관한 것으로, 확산시트에 별도의 헤이즈값을 가지는 차폐층을 포함하는 차폐 성능이 향상된 확산시트 및 이를 구비한 백라이트 유닛에 관한 것이다.The present invention relates to a diffusion sheet having improved shielding performance, and more particularly, to a diffusion sheet having improved shielding performance including a shielding layer having a different haze value in a diffusion sheet and a backlight unit having the same.
근래에 들어 평판 디스플레이 패널의 사용이 확대되고 있으며, 그 중 대표적으로 액정표시장치가 있다. 2. Description of the Related Art In recent years, the use of flat panel display panels has been expanding.
일반적으로, 상기 액정표시장치(LCD)는 종래의 브라운관 방식(CRT)과는 달리 화면 전체에 균일한 광을 제공하는 백라이트 유닛이 필요하다. 백라이트 유닛은 선광원인 램프와 상기 램프의 광을 반사시키는 도광부 및 집광시트부를 구비하여 광을 면광원으로 바꾸어준다.Generally, the liquid crystal display (LCD) requires a backlight unit that provides uniform light throughout the screen, unlike the conventional CRT. The backlight unit is provided with a light source lamp, a light guide unit for reflecting the light of the lamp, and a light condensing sheet unit, and converts the light into a surface light source.
이때, 광원은 도광부의 측면상에 인접하게 배치되며, 도광부 내부로 입사된 광은 상부로 전달되어 집광시트부에 의해 집광된다.At this time, the light source is disposed adjacent to the side surface of the light guide portion, and the light incident into the light guide portion is transmitted to the upper portion and is condensed by the light condensing sheet portion.
여기서, 일반적으로 도광부에서 집광시트부로 전달되는 광은 하부에서 광이 굴절 및 반사되어 상부로 전달되므로, 고르게 분산되지 않으며 영역별로 편차가 발생하게 된다.In general, the light transmitted from the light guiding portion to the light converging sheet portion is refracted and reflected by the lower portion and is transmitted to the upper portion, so that the light is not uniformly dispersed and a variation occurs in each region.
이에 집광시트부와 도광부 사이에는 확산시트가 구비되어 하부에서 전달되는 광을 확산시켜 고르게 분산한다.A diffusion sheet is provided between the light collecting sheet portion and the light guiding portion to diffuse the light transmitted from the lower portion and disperse the light uniformly.
일반적으로 확산시트는 광 투과성 소재로 구성되어 상면 또는 하면에 일정한 패턴을 가지도록 구성된다.Generally, the diffusion sheet is made of a light-transmitting material and is configured to have a certain pattern on the upper surface or lower surface.
그리고 이와 같이 형성된 패턴에 의해 하부에서 전달되는 광을 확산시켜 상부로 전달하며, 이에 따라 집광시트부에서 광을 고르게 집광시킨다.By the pattern thus formed, the light transmitted from the lower portion is diffused and transmitted to the upper portion, so that light is uniformly condensed in the light condensing sheet portion.
최근, 이러한 액정표시장치는 박형화가 주된 이슈이며, 이에 따라 백라이트 유닛 또한 박형화가 되고 있다.In recent years, thinning of such a liquid crystal display device is a major issue, and accordingly, the backlight unit is becoming thinner.
이와 같이 백라이트 유닛의 박형화에 따라 다양한 문제가 발생되고 있으며, 구체적으로 확산시트가 얇아지면서 확산시트 하부 도광판의 패턴이 시인되는 문제가 발생된다.Various problems have been caused by the thinning of the backlight unit. Specifically, the diffusion sheet is thinned and the pattern of the light guide plate under the diffusion sheet is visually recognized.
이러한 문제를 해결하기 위해 도광판의 패턴이 시인되지 않도록 고-헤이즈 값을 갖는 확산시트를 이용하는 방법이 제시되었으나, 헤이즈 값의 증가에 따른 휘도가 저하되는 또 다른 문제가 발생한다.In order to solve such a problem, a method of using a diffusing sheet having a high-haze value is proposed so that the pattern of the light guide plate is not visually recognized. However, another problem occurs in that the luminance decreases as the haze value increases.
즉, 도광판의 패턴이 시인되는 것을 방지하기 위해 단순히 헤이즈 값을 증가시키는 것만으로는 근본적인 해결책이 될 수 없다.That is, simply increasing the haze value to prevent the pattern of the light guide plate from being viewed can not be a fundamental solution.
따라서, 휘도 저하를 최소화시키면서 동시에 하부 패턴이 시인되는 것을 방지할 수 있는 확산시트의 개발이 필요하다.Therefore, it is necessary to develop a diffusion sheet capable of minimizing the decrease in brightness while preventing the lower pattern from being visually recognized.
본 발명은 상기와 같은 문제점을 해결하기 위한 것으로 본 발명의 과제는, 별도의 헤이즈값을 가지는 차폐층과 상 하면에 산란패턴을 가지는 패턴산란층을 구비하여 확산시트 하부 도광판의 패턴이 시인되는 것을 방지함과 동시에 휘도 저하를 최소화할 수 있는 차폐 성능이 향상된 확산시트 및 이를 구비한 백라이트 유닛을 제공함에 있다.SUMMARY OF THE INVENTION The present invention has been made to solve the above problems and it is an object of the present invention to provide a liquid crystal display device having a shield layer having a different haze value and a pattern scattering layer having a scattering pattern on an upper surface thereof, And a backlight unit having the diffusion sheet, which is capable of minimizing the luminance degradation, and having improved shielding performance.
상기와 같은 과제를 해결하기 위하여 본 발명의 일측면에 따른 차폐 성능이 향상된 확산시트는, 광 투과성 소재로 구성되어 일정한 두께를 가지도록 형성되며, 기설정된 값의 헤이즈(Haze) 값에 따라 내부에 복수 개의 입자를 포함하는 차폐층 및 상기 차폐층의 상면 또는 하면 중 적어도 어느 하나에 형성되며, 일부가 돌출된 산란패턴을 포함하고 내부에 복수 개의 비드가 분산되어 하부에서 전달되는 광을 확산시키는 패턴산란층을 포함하며, 상기 비드는 상기 차폐층 내부에 포함된 입자보다 상대적으로 작은 크기로 형성된다.According to an aspect of the present invention, there is provided a diffusion sheet having an improved shielding performance according to one aspect of the present invention. The diffusion sheet is formed of a light transmitting material and has a predetermined thickness. The diffusion sheet has a predetermined haze value, A shielding layer including a plurality of particles and a scattering pattern formed on at least one of an upper surface and a lower surface of the shielding layer, the scattering pattern having a part protruded therein, a plurality of beads dispersed therein, And a scattering layer, wherein the beads are formed in a size relatively smaller than the particles contained in the shielding layer.
상기와 같은 과제를 해결하기 위하여 본 발명의 다른 측면에 따른 백라이트 유닛은 상술한 차폐 성능이 향상된 확산시트를 포함한다.According to another aspect of the present invention, there is provided a backlight unit including a diffusion sheet having improved shielding performance.
상기 문제점을 해결하기 위해 본 발명에 따르면 다음과 같은 효과가 있다.In order to solve the above problems, the present invention has the following effects.
첫째, 확산시트가 기설정된 헤이즈 값을 가지는 차폐층과 상하면에 구비되어 산란패턴을 가지며 광을 산란시키는 패턴산란층을 구비함으로써, 확산시트 하부에 배치된 도광판의 패턴이 사용자로 하여금 시인되는 것을 방지할 수 있는 이점이 있다.First, the diffusion sheet is provided on the upper and lower surfaces with a shielding layer having a predetermined haze value, and a pattern scattering layer having a scattering pattern and scattering light is provided, so that the pattern of the light guide plate disposed under the diffusion sheet is prevented from being viewed by the user There is an advantage to be able to do.
둘째, 패턴산란층에 별도의 비드를 구비하여, 하부에서 전달되는 광의 산란 및 확산 효과를 증가시키며, 상기 비드는 미산란(Mie-scattering)이 발생하는 크기를 가지도록 형성함으로써, 확산되는 광의 대부분이 상부로 전달되어 휘도 저하를 최소화할 수 있는 이점이 있다.Secondly, a separate bead is provided in the pattern scattering layer to increase the scattering and diffusing effect of light transmitted from below, and the bead is formed to have a size where mie-scattering occurs, Is transmitted to the upper portion, thereby minimizing the decrease in luminance.
본 발명의 효과들은 상기 언급한 효과에 제한되지 않으며, 언급되지 않은 또 다른 효과들은 청구범위의 기재로부터 당업자에게 명확하게 이해될 수 있을 것이다.The effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned can be clearly understood by those skilled in the art from the description of the claims.
도 1은 본 발명의 실시예에 따른 차폐 성능이 향상된 확산시트를 구비한 백라이트 유닛의 의 구성을 개략적으로 나타낸 도면;FIG. 1 schematically shows a structure of a backlight unit having a diffusion sheet with improved shielding performance according to an embodiment of the present invention; FIG.
도 2는 도 1의 백라이트 유닛의 측면을 나타낸 도면;FIG. 2 is a side view of the backlight unit of FIG. 1;
도 3은 도 1의 백라이트 유닛에서 확산시트의 구성에 대해 개략적으로 나타낸 도면;3 is a schematic view of the configuration of a diffusion sheet in the backlight unit of Fig. 1; Fig.
도 4는 도 3의 확산시트에서 차폐층의 유무에 따라 하부의 패턴이 시인되는지 여부를 나타낸 도면;FIG. 4 is a view showing whether a lower pattern is visible depending on the presence or absence of a shielding layer in the diffusion sheet of FIG. 3; FIG.
도 5는 도 1의 확산시트에서 패턴산란층 내부에 별도의 비드가 포함된 구성을 나타낸 도면;5 illustrates a configuration in which separate beads are included in a pattern scattering layer in the diffusion sheet of FIG. 1;
도 6은 도 5의 패턴산란층에서 비드의 배치에 따른 광의 산란을 나타낸 도면;FIG. 6 is a diagram showing scattering of light according to the arrangement of beads in the pattern scattering layer of FIG. 5; FIG.
도 7은 도 5의 확산시트에서 입자의 크기에 따라 광의 산란이 발생하는 형태를 나타낸 도면;FIG. 7 is a view showing a form in which scattering of light occurs according to the size of particles in the diffusion sheet of FIG. 5; FIG.
도 8은 도 1의 확산시트에서 도 5의 패턴산란층의 변형된 형태를 나타낸 도면;FIG. 8 shows a modified form of the pattern scattering layer of FIG. 5 in the diffusion sheet of FIG. 1; FIG.
도 9는 도 1의 확산시트에서 차폐층이 다중 레이어로 구성된 상태를 나타낸 도면; 및FIG. 9 is a view showing a state in which a shielding layer is composed of multiple layers in the diffusion sheet of FIG. 1; FIG. And
도 10은 도 1의 확산시트에서 패턴산란층이 다중 레이어로 구성된 형태에 대해 나타낸 도면이다.10 is a view showing a pattern in which the pattern scattering layer in the diffusion sheet of FIG. 1 is composed of multiple layers.
이하 본 발명의 목적이 구체적으로 실현될 수 있는 본 발명의 바람직한 실시예를 첨부된 도면을 참조하여 설명한다. 본 실시예를 설명함에 있어서, 동일 구성에 대해서는 동일 명칭 및 동일 부호가 사용되며 이에 따른 부가적인 설명은 생략하기로 한다.DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In describing the present embodiment, the same designations and the same reference numerals are used for the same components, and further description thereof will be omitted.
본 발명의 실시예에 따른 차폐 성능이 향상된 확산시트는 LCD나 LED 패널 등의 평판 액정표시장치의 백라이트 유닛에 적용되는 것을 예로 들어 설명하기로 한다. 허나, 본 발명은 반드시 이에 한정되는 것은 아니며, 차폐 성능이 향상된 확산시트 단독으로 사용될 수도 있고, 또는 액정표시장치에 적용되는 것이 아닌 다른 기구에 적용되는 백라이트 유닛일 수도 있으며, 또는 조명기구 등 광의 특성 및 경로를 변화시키는 장치라면 어느 것에도 적용될 수도 있다.The diffusion sheet with improved shielding performance according to an exemplary embodiment of the present invention will be described as an example in which the diffusion sheet is applied to a backlight unit of a flat panel liquid crystal display device such as an LCD or an LED panel. However, the present invention is not limited to this, and may be used alone as a diffusion sheet with improved shielding performance, or may be a backlight unit applied to a mechanism other than that applied to a liquid crystal display, And any device that changes the path.
먼저, 도 1 내지 도 4를 참조하여 본 발명에 따른 백라이트 유닛의 구성에 대해 개략적으로 살펴보면 다음과 같다.First, a configuration of a backlight unit according to the present invention will be schematically described with reference to FIGS. 1 to 4. FIG.
도 1은 본 발명의 실시예에 따른 차폐 성능이 향상된 확산시트를 구비한 백라이트 유닛의 의 구성을 개략적으로 나타낸 도면이고, 도 2는 도 1의 백라이트 유닛의 측면을 나타낸 도면이다.FIG. 1 is a schematic view of a backlight unit having a diffusion sheet with improved shielding performance according to an exemplary embodiment of the present invention, and FIG. 2 is a side view of the backlight unit of FIG.
그리고 도 3은 도 1의 백라이트 유닛에서 확산시트의 구성에 대해 개략적으로 나타낸 도면이며, 도 4는 도 3의 확산시트에서 차폐층의 유무에 따라 하부의 패턴이 시인되는지 여부를 나타낸 도면이다.And FIG. 3 is a schematic view of the structure of the diffusion sheet in the backlight unit of FIG. 1, and FIG. 4 is a view illustrating whether or not the lower pattern is visible depending on the presence or absence of the shielding layer in the diffusion sheet of FIG.
일반적으로 액정표시장치를 구성함에 있어서, 액정패널에 광을 제공하는 백라이트 유닛(BLU: Back Light Module)이 필수적으로 구비되어야 한다.BACKGROUND ART [0002] Generally, a backlight unit (BLU) for providing light to a liquid crystal panel must be provided in a liquid crystal display device.
본 발명에 따른 백라이트 유닛은 크게 광원(100), 도광부(200), 집광시트부(300) 및 확산시트(400)를 포함한다.The backlight unit according to the present invention mainly includes a light source 100, a light guide unit 200, a light condensing sheet unit 300, and a diffusion sheet 400.
상기 광원(100)은 백라이트 유닛의 부피를 최소화하기 위해 상기 도광부(200)의 측부에서 광을 발생시키며, 상기 도광부(200)로 광을 전달한다. 이러한 광원(100)으로는 LED(Light Emitting Diode) 및 냉음극형광램프(Cold Cathode Fluorescent Lamp: CCFL) 등이 선택적으로 사용될 수 있다.The light source 100 generates light at the side of the light guide unit 200 and transmits light to the light guide unit 200 to minimize the volume of the backlight unit. As the light source 100, a light emitting diode (LED) and a cold cathode fluorescent lamp (CCFL) may be selectively used.
본 발명에서 상기 광원(100)은 적어도 하나 이상으로 구성되며, 상기 도광부(200)의 측부를 향해 광을 발광한다.In the present invention, the light source 100 is composed of at least one light source, and emits light toward the side of the light guide unit 200.
상기 도광부(200)는 두께를 가지며, 평판 형태로 형성되어 측면을 통해 입광되는 광을 상부로 전달시킨다.The light guiding portion 200 has a thickness and is formed in a flat plate shape to transmit the light incident through the side surface to the upper portion.
구체적으로 상기 도광부(200)로 입사된 광은 도광부(200) 내부에서 전반사를 일으키며 진행하며 상부로 방출된다. 이때, 상기 도광부(200)는 상기 광원(100)에서 전달된 광이 평판을 따라 이동하여 면광원 형태를 이루며 상부로 전달된다.Specifically, the light incident on the light guide unit 200 is totally reflected in the light guide unit 200 and is emitted upward. At this time, the light guiding unit 200 moves the light transmitted from the light source 100 along a flat plate, and is transmitted as an upper surface light source.
또한, 상기 도광부(200)는 별도로 하부에 반사판(210)을 구비할 수 있으며, 상기 도광부(200)를 통과하여 하부로 전달되는 광을 상부로 반사시키도록 구성된다.In addition, the light guide unit 200 may include a reflection plate 210 at a lower portion thereof, and reflect the light transmitted through the light guide unit 200 to the lower portion.
한편, 상기 집광시트부(300)는 상기 도광부(200)의 상부에 적층되며, 하부에서 전달되는 광을 집광시켜 면광원 형태로 상부에 전달한다.The light collecting sheet unit 300 is stacked on the light guiding unit 200 and collects the light transmitted from the lower part and transmits the collected light to the upper part in the form of a surface light source.
구체적으로, 상기 집광시트부(300)는 복수 개의 시트가 적층된 형태로 구성되어 광을 집광하거나 단일한 시트로 형성되어 하부에서 전달되는 광을 상부로 전달하며 집광한다.Specifically, the light collecting sheet unit 300 is formed by stacking a plurality of sheets so as to condense light, or to form a single sheet, and to transmit the light transmitted from the lower portion to the upper portion.
본 발명의 실시예에서 상기 집광시트부(300)는 한 쌍의 하부광학시트(310)와 상부광학시트(320)로 구성되며, 하부광학시트(310)는 제1베이스필름(312) 및 제1집광부(314)를 포함한다.In the embodiment of the present invention, the light collecting sheet unit 300 includes a pair of lower optical sheets 310 and an upper optical sheet 320, and the lower optical sheet 310 includes a first base film 312, 1 light collecting portion 314.
상기 제1베이스필름(312)은 광 투과성 소재로 구성되어 일정 두께를 가지며 평판 형태로 형성된다. 그리고 상면에는 상기 제1집광부(314)가 형성되어 하부에서 전달되는 광을 집광한다.The first base film 312 is formed of a light transmitting material and has a predetermined thickness and is formed in a flat plate shape. The first light collecting part 314 is formed on the upper surface to condense the light transmitted from the lower part.
상기 제1집광부(314)는 상기 제1베이스필름(312)의 상면에 형성되며, 상부로 갈수록 횡단면적이 감소하는 제1단위집광체가 연속적으로 반복하여 형성된다.The first condensing unit 314 is formed on the upper surface of the first base film 312, and the first unit condenser is continuously and repeatedly formed with a decreasing cross sectional area.
구체적으로 상기 제1집광부(314)는 상기 제1베이스필름(312)을 통과하여 전달되는 광을 집광시켜 상부로 전달하는 구성으로, 복수 개의 제1단위집광체가 형성된다.Specifically, the first light collecting part 314 collects light transmitted through the first base film 312 and transmits the light to the upper part, and a plurality of first unit light collectors are formed.
여기서, 상기 제1단위집광체는 경사면을 가지며 상부로 갈수록 횡단면적이 작아지는 형태로 형성되어 상기 경사면을 통해 광을 집광시킨다.Here, the first unit condenser has a sloped surface and a cross-sectional area becomes smaller toward the upper portion, so that light is condensed through the sloped surface.
본 실시예에서 상기 제1단위집광체는 한 쌍의 상기 경사면을 가지며, 삼각 형태의 상하방향에 따른 단면을 가지고 프리즘 형태로 형성된다.In this embodiment, the first unit condenser has a pair of inclined surfaces, and is formed in a prism shape having a triangular cross-section along the up-and-down direction.
여기서, 상기 제1단위집광체는 복수 개가 돌기 형태로 형성될 수도 있고, 이와 달리 본 실시예에 도시된 바와 같이 각각의 상기 제1단위집광체가 길게 띠 형태로 연장되어 상기 제1베이스필름(312)의 상면에 형성될 수도 있다.Alternatively, a plurality of first unit condensers may be formed in a protrusion shape. Alternatively, as shown in this embodiment, each of the first unit condensers may be elongated in a strip shape to form the first base film 312 As shown in FIG.
즉, 상기 제1집광부(314)는 삼각형상의 상하단면이 일 방향을 따라 연장되도록 형성된 복수 개의 제1단위집광체를 가지며, 이를 통해 광을 집광시킨다.That is, the first light collecting part 314 has a plurality of first unit collecting bodies formed so that the upper and lower end faces of the triangular shape extend along one direction, and light is condensed through the first unit collecting bodies.
그리고 상기 상부광학시트(320)는 상기 하부광학시트(310)의 상부에 적층되는 구성으로, 제2베이스필름(322) 및 제2집광부(324)를 포함하여 상기 하부광학시트(310)와 함께 광을 집광시킨다.The upper optical sheet 320 is stacked on the lower optical sheet 310 and includes a second base film 322 and a second light collecting part 324 to form the lower optical sheet 310, Converge the light together.
상기 제2베이스필름(322)은 상기 제1베이스필름(312)과 유사한 형태로 형성되며, 상면에 제2집광부(324)가 형성된다.The second base film 322 is formed in a shape similar to that of the first base film 312, and a second light collecting portion 324 is formed on the upper surface.
상기 제2집광부(324)는 상기 제2베이스필름(322)의 상면에 구비되어 하부에서 전달되는 광을 집광시킨다. 구체적으로 상기 제2집광부(324)는 상기 제1집광부(314)와 유사한 형태로, 상부로 갈수록 횡단면적이 감소하는 제2단위집광체가 연속적으로 반복되어 형성된다.The second light collecting part 324 is provided on the upper surface of the second base film 322 to condense the light transmitted from the lower part. Specifically, the second light collecting part 324 is formed in a shape similar to that of the first light collecting part 314, and the second unit light collecting material whose cross-sectional area decreases as it goes upward is continuously and repeatedly formed.
여기서, 상기 제2단위집광체는 한 쌍의 경사면을 가지며 삼각형태의 상하 단면을 가지도록 형성되어 상기 경사면을 통해 광을 집광시킨다.Here, the second unit condenser has a pair of inclined surfaces and is formed to have a triangular top and bottom surfaces to condense light through the inclined surfaces.
본 실시예에서 상기 제2단위집광체는 상기 제1단위집광체와 마찬가지로 각각이 길게 연장 형성되어 상기 제2베이스필름(322)의 상면에 구비된다.In the present embodiment, the second unit condensers are formed on the upper surface of the second base film 322, respectively, in the same manner as the first unit condensers.
이때, 상기 제1집광부(314)와 상기 제2집광부(324)는 길게 연장된 형태로 형성되며, 서로 교차되도록 상기 제1베이스필름(312)과 상기 제2베이스필름(322)이 적층된다.The first and second light collecting parts 314 and 324 may be elongated to intersect with the first and second base films 312 and 322, do.
이와 같이 상기 집광시트부(300)는 상기 제1베이스필름(312)과 상기 제2베이스필름(322)을 포함하며, 상호 적층되어 하부에서 전달되는 광을 집광하여 상부로 전달한다.The light collecting sheet unit 300 includes the first base film 312 and the second base film 322, and collects light transmitted from the lower portion of the light collecting sheet unit 300 and transmits the collected light.
한편, 상기 확산시트(400)는 상기 집광시트부(300)와 상기 도광부(200) 사이에 구비되어 상부로 전달되는 광을 확산 및 차폐하여 상기 집광시트부(300)로 전달한다.The diffusion sheet 400 is provided between the light collecting sheet unit 300 and the light guiding unit 200 to diffuse and shield the light transmitted to the upper part and transmit the light to the light collecting sheet unit 300.
이때, 상기 확산시트(400)는 하부에서 전달되는 광을 산란시켜 확산할 뿐만 아니라 이와 함께 광을 차폐하여 Uniform하게 만들어주는 역할을 한다.At this time, the diffusion sheet 400 not only diffuses and diffuses the light transmitted from the lower part, but also shields the light to make it uniform.
구체적으로 본 발명에 따른 상기 확산시트(400)는 크게 차폐층(410) 및 패턴산란층(420)을 포함한다.Specifically, the diffusion sheet 400 according to the present invention includes a shielding layer 410 and a pattern scattering layer 420.
상기 차폐층(410)은 하부에서 전달되는 광을 차폐하여 투과된 광에 의해 도광판의 패턴이 사용자에게 시인되는 것을 방지하기 위한 구성으로, 광투과성 소재로 구성되어 일정한 두께를 가지고 시트형태로 형성된다.The shielding layer 410 is formed of a light transmitting material and has a predetermined thickness and is formed in a sheet shape to prevent the pattern of the light guide plate from being visible to a user by shielding the light transmitted from the lower portion and transmitting the light. .
그리고 내부에 복수 개의 입자(412)가 분산되어 기설정된 헤이즈(Haze)값을 가지도록 구성된다.And a plurality of particles 412 are dispersed therein to have a predetermined haze value.
헤이즈 특성이란, 광이 투명한 재료를 통과할 때 재료의 종류에 따라 반사나 흡수 외에 그 재료의 고유 성질에 따라 확산되도록 하는 특성이다.The haze characteristic is a characteristic that, when light passes through a transparent material, it diffuses depending on the kind of the material, as well as reflection or absorption, depending on the intrinsic properties of the material.
본 발명에서 상기 차폐층(410)은 도시된 바와 같이 내부에 상기 입자(412)가 분산된 형태로 형성되며, 상기 집광시트부(300)의 하부에서 시트형태로 형성되어 적층 배치된다.In the present invention, the shielding layer 410 is formed in a shape in which the particles 412 are dispersed therein, and is formed in a sheet form at the lower portion of the light condensing sheet portion 300 and stacked.
이때, 상기 입자(412)는 Silica, PMMA, PBMA등의 소재로 구성되어 1~9 ㎛의 사이즈를 가지며 약 1.5의 굴절률을 가지도록 구성되어 상기 차폐층(410) 내부에 분산된다. 그리고, 상기 입자(412)는 불균일한 크기를 가지며, 하부에서 전달되는 광을 산란시켜 도광판(200)의 패턴이 시인되는 것을 차폐한다.At this time, the particles 412 are made of materials such as silica, PMMA, and PBMA and have a size of 1 to 9 탆 and have a refractive index of about 1.5 and are dispersed in the shielding layer 410. The particles 412 have a non-uniform size and scatter light transmitted from the lower part to shield the pattern of the light guide plate 200 from being visible.
여기서, 본 발명에 따른 상기 차폐층(410)은 18~130 ㎛의 두께를 가지며, 내부에 복수 개의 상기 입자(412)를 포함한다.Here, the shielding layer 410 according to the present invention has a thickness of 18 to 130 占 퐉 and includes a plurality of the particles 412 therein.
이와 같이 본 발명에 따른 상기 차폐층(410)은 내부에 상기 입자(412)가 균일하게 분산되며 하부에서 전달되는 광을 확산시켜 도광판(200)의 패턴이 시인되는 것을 차폐한다.As described above, the shielding layer 410 according to the present invention shields the pattern of the light guide plate 200 from being visually recognized by dispersing the particles uniformly dispersed in the inside of the shielding layer 410 and diffusing light transmitted from the bottom.
본 실시예에서 상기 차폐층(410)은 내부에 상기 입자(412)가 분산되어 기설정된 헤이즈 값을 가지도록 구성되어 있으며, 이와 달리 상기 차폐층(410)의 표면에 특정한 패턴을 가지도록 구성될 수도 있다.In the present embodiment, the shielding layer 410 is configured such that the particles 412 are dispersed therein to have a predetermined haze value. Alternatively, the shielding layer 410 may have a specific pattern on the surface of the shielding layer 410 It is possible.
한편, 상기 패턴산란층(420)은 상기 차폐층(410)의 상면 또는 하면 중 적어도 어느 하나에 적층 또는 접합되며, 적어도 일부가 돌출된 산란패턴(422)이 형성되어 하부에서 전달되는 광을 확산시킨다.The pattern scattering layer 420 is stacked or bonded to at least one of the upper surface and the lower surface of the shielding layer 410 and a scattering pattern 422 protruding at least partially is formed to diffuse the light transmitted from the lower portion. .
구체적으로 상기 패턴산란층(420)은 도시된 바와 같이 상기 차폐층(410)의 상면 또는 하면 상에 형성되어 하부에서 전달되는 광을 산란시켜 확산한다.Specifically, the pattern scattering layer 420 is formed on the upper surface or the lower surface of the shielding layer 410 as shown in FIG.
이때, 상기 패턴산란층(420)은 상기 차폐층(410)과 상이한 굴절률을 가지며 적층 또는 접합된다. 여기서, 상기 패턴산란층(420)은 상기 산란패턴(422)을 통해 광을 확산시킨다.At this time, the pattern scattering layer 420 has a refractive index different from that of the shielding layer 410 and is laminated or bonded. Here, the pattern scattering layer 420 diffuses light through the scattering pattern 422.
본 실시예에서 상기 패턴산란층(420)은 상기 차폐층(410)의 상면 및 하면에 모두 적층 형태로 접합되며, 각각 상부 및 하부방향으로 상기 산란패턴(422)이 돌출 형성된다.In this embodiment, the pattern scattering layer 420 is laminated on the upper and lower surfaces of the shielding layer 410, and the scattering patterns 422 are protruded in the upper and lower directions.
여기서, 상기 산란패턴(422)은 구 형태의 곡면을 가지며, 복수 개가 불균일한 밀도 및 크기를 가지고 돌출 형성된다.Here, the scattering pattern 422 has a curved surface in a spherical shape, and a plurality of the scattering patterns 422 are protruded and formed with nonuniform density and size.
이와 같이 본 발명에 따른 확산시트(400)는 상기 차폐층(410) 및 상기 패턴산란층(420)을 포함하며, 상기 차폐층(410)의 내부에 분산된 상기 입자(412)와 상기 패턴산란층(420)에 의해 하부에서 전달되는 광을 차폐 및 확산시킬 수 있다.As described above, the diffusion sheet 400 according to the present invention includes the shielding layer 410 and the pattern scattering layer 420, and the particles 412 dispersed in the shielding layer 410 and the pattern scattering The layer 420 may shield and diffuse light transmitted from below.
여기서, 상기 차폐층(410)은 고유한 헤이즈 값을 통해 하부에서 전달되는 광을 확산시킴과 동시에 베이스필름과 같이 상기 패턴산란층(420)을 유지시키는 역할을 수행한다.Here, the shielding layer 410 diffuses the light transmitted from the lower portion through a unique haze value and maintains the pattern scattering layer 420 like the base film.
또한, 상기 패턴산란층(420)은, 상기 차폐층(410)과 함께 하부에서 전달되는 광을 확산시키며, 확산시트(400)와 도광판(200)이 서로 흡착되거나 마모가 발생하는 것을 방지한다.The pattern scattering layer 420 diffuses the light transmitted from the lower portion together with the shielding layer 410 to prevent the diffusion sheet 400 and the light guide plate 200 from being attracted to each other or from being abraded.
또한, 상기 차폐층(410)과 상기 패턴산란층(420)은 소재 및 굴절률 등이 상이하게 형성된다.The shield layer 410 and the pattern scattering layer 420 are formed to have different materials and refractive indices.
특히, 도 4를 살펴보면 일반 패턴의 상부에 확산시트(400)를 적층하여 투과되는 이미지를 촬영한 것으로, 상기 확산시트(400)에서 상기 차폐층(410)의 유무에 따라 하부의 패턴이 시인되는지 여부를 확인할 수 있다.4, a diffusion sheet 400 is stacked on top of a general pattern to photograph an image to be transmitted. In the diffusion sheet 400, a lower pattern is visible depending on the presence or absence of the shielding layer 410 Can be confirmed.
구체적으로, 도 4의 (a)의 경우 상기 차폐층(410)이 헤이즈값을 가지지 않은 상태이다. 여기서, 상기 차폐층(410)은 일정 수준 이상의 헤이즈 값을 가지지 않는 경우 일부 산란이 발생하지만 하부의 패턴이 시인되는 것을 확인할 수 있다.4 (a), the shielding layer 410 does not have a haze value. Here, when the shielding layer 410 does not have a haze value equal to or higher than a certain level, it can be confirmed that scattering occurs, but the lower pattern is visible.
이와 같이 상기 차폐층(410)이 헤이즈값을 가지지 않는 경우 하부에서 전달되는 광은 상기 패턴산란층(420)에 의해 확산되지만, 상기 차폐층(410)에 의해 광이 분산되지 않아 상기 도광판(200)의 패턴이 사용자로 하여금 시인되게 된다.In the case where the shielding layer 410 has no haze value, the light transmitted from the lower portion is diffused by the pattern scattering layer 420, but the light is not dispersed by the shielding layer 410, ) Is visible to the user.
따라서, 상기 차폐층(410) 및 패턴산란층(420)이 구비되지 않는 경우 상기 도광판(200)에서 전달되는 광은 확산효과가 충분하지 않으며, 이에 따라 상기 도광판(200)의 패턴 등이 상부로 투영되어 얼룩이나 패턴 등의 형태로 사용자가 인식할 수 있다.Therefore, when the shielding layer 410 and the pattern scattering layer 420 are not provided, the light transmitted from the light guide plate 200 does not have a sufficient diffusion effect, so that the pattern of the light guide plate 200, And can be projected and recognized by the user in the form of a spot, a pattern, or the like.
하지만, 도 4의 (b)를 살펴보면, 상술한 도 4의 (a)와 마찬가지로 특정 패턴의 상부에 적층형태로 본 발명에 따른 확산시트(400)를 배치한 상태이다.However, as shown in FIG. 4B, the diffusion sheet 400 according to the present invention is arranged in a laminated structure on a specific pattern as in FIG. 4A.
여기서, 상기 차폐층(410)은 기설정된 헤이즈값 이상을 가지도록 구성되어 있으며, 이와 같은 경우 하부의 패턴이 인식할 수 없을 정도로 확산된다.Here, the shielding layer 410 is configured to have a predetermined haze value or more, and in such a case, the lower pattern is diffused to such an extent that it can not be recognized.
이는 상기 차폐층(410)이 상기 패턴산란층(420)과 함께 하부에서 전달되는 광을 산란 및 확산시켜 전체적인 차폐성능이 증가하였기 때문이며, 이에 따라, 상기 확산시트(400)에서 투과된 광이 사용자에게 시인되지 않도록 고르게 확산되며, 광의 휘도 저감을 최소화시킬 수 있다.This is because the shielding layer 410 scattering and diffusing the light transmitted from the lower portion together with the pattern scattering layer 420 increases the overall shielding performance, So that the luminance reduction of the light can be minimized.
이때, 휘도는 하부에서 전달되는 광이 상기 차폐층(410) 및 상기 패턴산란층(420)을 경유하는 과정에서 산란된 광의 대부분이 상부로 전달되어 고르게 확산됨에 따라 저하가 발생되는 것을 최소화할 수 있다.At this time, the luminance can be minimized as the light transmitted from the lower portion is transmitted to the upper portion of the scattered light in the course of passing through the shielding layer 410 and the pattern scattering layer 420, have.
이는 상기 패턴산란층(420)의 구조 변형 및 별도의 비드(424) 등을 이용하여 산란의 형태를 조절할 수 있으며, 구체적인 구성은 도 5를 참조하여 후술한다.The shape of the scattering layer 420 can be adjusted by using structural deformations of the pattern scattering layer 420 and a separate bead 424, and a specific structure thereof will be described later with reference to FIG.
이와 같이, 본 발명에 따른 확산시트(400)는 단순히 광을 확산시키는 것뿐만 아니라, 상기 차폐층(410)에 의해 투과되는 광의 차폐 성능을 증가시켜 고르게 확산될 수 있도록 한다.As described above, the diffusion sheet 400 according to the present invention not only diffuses light, but also increases the shielding performance of the light transmitted by the shielding layer 410 so that it can be diffused evenly.
이어서, 도 5 내지 도 7을 참조하여 본 발명에 따른 상기 확산시트(400)의 변형된 형태에 대해 살펴보면 다음과 같다.Next, a modified form of the diffusion sheet 400 according to the present invention will be described with reference to FIGS. 5 to 7. FIG.
도 5는 도 1의 확산시트(400)에서 패턴산란층(420) 내부에 별도의 비드(424)가 포함된 구성을 나타낸 도면이고, 도 6은 도 5의 패턴산란층에서 비드의 배치에 따른 광의 산란을 나타낸 도면이며, 도 7은 도 5의 확산시트(400)에서 입자(412)의 크기에 따라 광의 산란이 발생하는 형태를 나타낸 도면이다.5 is a view showing a configuration in which a separate bead 424 is included in the pattern scattering layer 420 in the diffusion sheet 400 of FIG. 1, and FIG. 6 is a schematic view of a pattern scattering layer according to the arrangement of beads in the pattern scattering layer of FIG. FIG. 7 is a view showing a form in which scattering of light occurs according to the size of the particles 412 in the diffusion sheet 400 of FIG. 5. FIG.
도시된 도면을 살펴보면, 상기 확산시트(400)의 기본적인 구성은 상술한 바와 유사하지만 상기 패턴산란층(420) 내부에 별도의 비드(424)를 더 포함한다.Referring to the drawing, the basic structure of the diffusion sheet 400 is similar to that described above, but further includes a separate bead 424 inside the pattern scattering layer 420.
구체적으로, 본 발명에 따른 상기 패턴산란층은(420), 상기 차폐층(410)을 중심으로 상면 또는 하면 중 적어도 어느 하나에 형성된다.Specifically, the pattern scattering layer 420 is formed on at least one of the upper surface and the lower surface with respect to the shielding layer 410.
이때, 도시된 바와 같이 상기 패턴산란층(420)은 내부에 복수 개의 비드(424)를 포함하며, 상기 비드(424)에 의해 하부에서 전달되는 광을 추가적으로 산란 및 확산시켜 차폐성능을 증가시킴과 동시에 휘도 저하를 감소시킨다.As shown in the figure, the pattern scattering layer 420 includes a plurality of beads 424 therein, and further increases the shielding performance by further scattering and diffusing the light transmitted from the bottom by the beads 424, At the same time, the decrease in luminance is reduced.
상기 비드(424)는 상기 패턴산란층(420)에 첨가되어 하부에서 전달되는 광의 차폐성능을 증가시키는 것을 주 목적으로 하여 광의 확산 및 산란을 추가적으로 발생시킨다.The beads 424 are added to the pattern scattering layer 420 to further diffuse and scatter light due to the main purpose of increasing the shielding performance of light transmitted from the bottom.
본 발명에서 상기 비드(424)는 구 형태를 이루며 상기 패턴산란층(420) 내부에서 고르게 분산되어 배치되고, 복수 개가 불균일한 크기를 가지도록 형성된다. 이때, 상기 비드(424)는 상기 패턴산란층(420)과 상이한 소재 또는 굴절률을 가지도록 구성되어 상기 패턴산란층(420) 내부에서 광의 산란이 발생하도록 한다.In the present invention, the beads 424 have a spherical shape and are uniformly dispersed in the pattern scattering layer 420, and a plurality of the beads 424 are formed to have a non-uniform size. At this time, the beads 424 are formed to have a different material or refractive index from the pattern scattering layer 420, so that light scattering occurs in the pattern scattering layer 420.
즉, 상기 패턴산란층(420)이 내부에 상기 비드(424)를 포함함으로써 상기 산란패턴(422)뿐만 아니라 상기 비드(424)에서도 하부에서 전달되는 광이 산란되어 확산시킬 수 있도록 구성된다.That is, since the pattern scattering layer 420 includes the beads 424 therein, light scattered from the bottom of the bead 424 as well as the scattering pattern 422 can be scattered and diffused.
이때, 상기 비드(424)는 하부에서 전달되는 광의 파장에 대응하여 미산란(Mie-scattering)이 발생하는 크기를 가지며, 상기 차폐층(410) 내부에 포함된 상기 입자(412)보다 상대적으로 작은 크기를 가지도록 구성된다.At this time, the beads 424 have a size that causes mie-scattering corresponding to the wavelength of the light transmitted from the lower part, and the beads 424 are relatively smaller than the particles 412 contained in the shield layer 410 .
본 발명에 따른 상기 비드(424)의 크기는 수백 나노에서 수 마이크로 단위의 미세한 크기를 가지며 하부에서 전달되는 광의 산란이 일어날 수 있도록 구성된다. The size of the beads 424 according to the present invention has a fine size of several hundreds of nanometers to several micrometers, and is configured so that scattering of light transmitted from below can occur.
일반적으로 산란이란 광이 특정 입자에 충돌하여 여러 방향으로 흩어지는 현상이며, 파동이나 빠른 속도의 입자선이 많은 분자, 원자, 미립자 등에 충돌하여 운동방향을 바꾸고 흩어지는 일을 가리킨다. 기체, 액체, 고체 내부에서 모두 일어나지만, 고체나 액체에서는 산란광이 합성되어 굴절광이나 반사광으로 보이는 경우가 더 많다.In general, scattering is a phenomenon in which light collides with a specific particle and is scattered in various directions. It refers to a phenomenon in which waves or high-speed particle beams collide with many molecules, atoms, and particles to change direction of motion and scatter. Gas, liquid, and solid. However, in solid or liquid, scattered light is synthesized and is more likely to be refracted or reflected.
대표적인 산란으로는 크게 레일리 산란(Rayleigh Scattering)과 미산란(Mie-Scattering)이 있다.Representative scattering includes Rayleigh scattering and Mie-scattering.
먼저, 레일리 산란은, 산란을 유발하는 입자의 크기가 매우 작아 광의 파장보다도 작을 때 일어나는 산란을 말하는 것으로, 광의 파장의 4 제곱에 반비례하는데, 즉 파장이 길어질수록 산란되는 광의 양이 급격히 줄어든다.First, Rayleigh scattering refers to scattering occurring when the size of particles causing scattering is very small and is smaller than the wavelength of light, which is inversely proportional to the fourth power of the wavelength of light. That is, the amount of scattered light decreases sharply as the wavelength becomes longer.
이와 같은 레일리 산란은 도 7의(a)와 같이 광이 특정 입자에 충돌 시 전방과 후방 양쪽으로 광을 산란시킨다.Such Rayleigh scattering scatters light both forward and backward when light collides against a specific particle as shown in FIG. 7 (a).
이에 반하여 미산란은 광과 충돌하는 특정 입자의 크기가 광의 파장과 비슷한 경우에 발생하며, 도 7의 (b)와 같이 전방산란이 현저하고 상대적으로 작은 에너지가 후방으로 산란한다.On the contrary, non-scattering occurs when the size of a specific particle colliding with light is similar to the wavelength of light, and forward scattering is remarkable and relatively small energy is scattered backward as shown in FIG. 7 (b).
이와 같은 미산란은 입자의 밀도, 크기 및 모양에도 영향을 받으며, 특히 구 형상의 입자에서 산란이 잘 일어난다.Such scattering is influenced by the density, size and shape of the particles, and particularly scattering occurs in spherical particles.
이에 따라 본 발명에 따른 상기 비드(424)는 상기 광원(100)으로부터 전달되는 광을 상부방향으로 확산시켜 전달하기 위해 전방산란이 발생하는 미산란이 일어나도록 구성되는 것이 바람직하다.Accordingly, it is preferable that the bead 424 according to the present invention is configured such that no scattering occurs in which forward scattering occurs in order to diffuse and transmit the light transmitted from the light source 100 in the upward direction.
본 실시예에서 상기 비드(424)는 구 형상을 가지며, 가시광영역대의 파장에 대응하는 크기를 가지도록 구성되어 상기 광원(100)으로부터 발생된 광이 전방으로 산란될 수 있도록 한다.In this embodiment, the beads 424 have a spherical shape and are configured to have a size corresponding to the wavelength of the visible light region so that the light generated from the light source 100 can be scattered forward.
구체적으로 상기 비드(424)는 Alumina, TiO2, Melamine, Silica, PMMA, PBMA, PDMS 중 적어도 어느 하나로 구성될 수 있으며, 구형으로 형성되는 것이 바람직하다. 그리고 상기 비드(424)의 굴절률은 1.67이 바람직하다.Specifically, the beads 424 may be formed of at least one of Alumina, TiO 2 , Melamine, Silica, PMMA, PBMA, and PDMS, and may be formed in a spherical shape. The refractive index of the bead 424 is preferably 1.67.
여기서, 상기 비드(424)는 0.1 ~ 1 ㎛ 크기로 형성되며, 상기 광원(100)에서 출사되는 가시광 파장 대역의 광의 미산란(Mie Scattering) 효과를 극대화 시킴으로써, 상기 광원(100)에서 상기 비드(424)를 향해 출사되는 광을 전방 산란시킬 수 있다.The beads 424 are formed to have a size of 0.1 to 1 탆 and maximize the mie scattering effect of the light of the visible light wavelength band emitted from the light source 100, 424 in the forward direction.
또한, 상기 비드(424)가 1000 nm 의 크기를 초과하는 경우, 상기 도광판(200)과 접촉 시 갈림이나 찍힘 등에 취약하여 품질저하가 발생하게 된다. If the bead 424 is more than 1000 nm in size, the bead 424 is fragile due to breaking or being touched upon contact with the light guide plate 200, resulting in deterioration of quality.
따라서, 본 발명에 따른 상기 비드(424)는 하부에서 전달되는 광의 미산란이 가능하며, 도광판(200)과의 간섭에 의해 파손되지 않는 크기로 구성되어 하부에서 전달되는 광을 확산시킨다.Accordingly, the bead 424 according to the present invention can scatter the light transmitted from the lower portion and is not damaged by the interference with the light guide plate 200, thereby diffusing the light transmitted from the lower portion.
이에 따라, 본 발명에 따른 상기 패턴산란층(420)은 내부에 상기 비드(424)를 포함함으로써 하부 도광판(200)에서 전달되는 광을 효율적으로 상부로 전달시킬 수 있으며, 미산란을 이용함으로써 차폐층(410)에 의한 휘도 저하를 최소화할 수 있다.Accordingly, the pattern scattering layer 420 according to the present invention can efficiently transmit the light transmitted from the lower light guide plate 200 to the upper portion by including the beads 424 therein, The decrease in luminance due to the layer 410 can be minimized.
한편, 본 발명에서 상기 비드(424)는 상기 패턴산란층(420) 내부에서 상기 차폐층(410)에 인접할수록 분포밀도가 상대적으로 증가하게 배치시켜 하부에서 전달되는 광 직진성을 감소시킴과 동시에 산란이 발생하여 상기 확산시트(400)의 차폐성능을 증가시킬 수도 있다.Meanwhile, in the present invention, the beads 424 are arranged such that the distribution density is relatively increased in the pattern scattering layer 420 so as to be closer to the shielding layer 410, thereby reducing light directivity transmitted from the lower portion, The shielding performance of the diffusion sheet 400 may be increased.
구체적으로 도 5를 살펴보면, 상기 차폐층(410)의 상하면에 각각 상기 패턴산란층(420)이 형성되며, 상기 비드(424)를 내부에 포함하고 있다. 여기서, 상기 패턴산란층(420)은 상하방향을 따라 A 영역과 상기 차폐층(410)과 인접한 B 영역으로 구분할 수 있으며, A 영역에는 상기 산란패턴(422)이 형성되며, 상기 차폐층(410)에서 멀어지는 방향에 위치하고 있다.5, the pattern scattering layer 420 is formed on the upper and lower surfaces of the shielding layer 410, and the beads 424 are contained therein. The pattern scattering layer 420 can be divided into an A region along the vertical direction and a B region adjacent to the shielding layer 410. The scattering pattern 422 is formed in the A region and the shielding layer 410 In the direction away from the center.
그리고 B 영역은 상기 차폐층(410)과 인접한 영역으로 도시된 바와 같이 상기 비드(424)가 상기 A 영역과 상기 B 영역에 분포되어 있으나, A 영역보다 B 영역에 상대적으로 많은 상기 비드(424)가 분포된 것을 알 수 있다.The beads 424 are distributed in the A region and the B region as shown in the region adjacent to the shielding layer 410, but the beads 424 are distributed in the region B more than the A region, Is distributed.
이와 같이 상기 패턴산란층(420)에서 상기 차폐층(410)에 인접한 B 영역에 상기 비드(424)가 A 영역보다 상대적으로 많이 분포됨으로써 상기 확산시트(400)의 차폐성능을 증가시킬 수 있다.As described above, the beads 424 are distributed more in the region B than the region A in the region B adjacent to the shielding layer 410 in the pattern scattering layer 420, thereby increasing the shielding performance of the diffusion sheet 400.
이에 대해 보다 상세하게 살펴보면 도 6에 도시된 바와 같이 상기 비드(424)가 상기 패턴산란층(420) 내에 분포되는 경우, 상기 차폐층(410)을 경유한 상기 광이 상기 패턴산란층(420) 내부에서 상기 비드(424)에 의해 산란이 일어난다.6, when the beads 424 are distributed in the pattern scattering layer 420, the light passing through the shielding layer 410 is scattered in the pattern scattering layer 420, Scattering occurs inside the bead 424.
여기서, 도 6의 (a)는 상기 비드(424)가 상기 패턴산란층(420) 내부에서 고르게 분포된 상태이고, 도 6의 (b)는 상기 비드(424)가 상기 패턴산란층(420) 내부에서 상기 차폐층(410)에 인접할수록 분포밀도가 증가하는 상태이다.6A shows a state in which the beads 424 are uniformly distributed in the pattern scattering layer 420 and FIG. 6B shows a state in which the beads 424 are scattered in the pattern scattering layer 420, And the distribution density increases in the vicinity of the shielding layer 410.
도시된 바와 같이 상기 비드(424)가 상기 차폐층(410)에 인접할수록 하부에서 전달되는 광과 만나게 될 확률이 증가하며, 이에 따라, 광의 산란 정도에서 차이가 발생한다.As shown in the drawing, the probability that the beads 424 are adjacent to the shielding layer 410 and the light transmitted from the lower part increases, thereby causing a difference in scattering degree of light.
도 6의 (a)와 같이 상기 비드(424)가 상기 패턴산란층(420)에 고르게 분포되어 있는 경우 상기 차폐층(410)을 통과한 광이 상기 비드(424)를 만날 때 까지의 경로가 길어지며, 이에 따라 상기 비드(424)로 인해 광의 산란 및 확산되는 양이 상대적으로 적어지게 된다.When the beads 424 are uniformly distributed on the pattern scattering layer 420 as shown in FIG. 6A, a path from the light passing through the shielding layer 410 until the beads 424 meet The amount of light scattering and diffusing due to the bead 424 is relatively reduced.
하지만, 도 6의 (b)에 도시된 바와 같이 상기 패턴산란층(420)에서 상기 비드(424)가 상기 차폐층(410)에 인접하게 배치된 경우 상기 차폐층(410)을 통과한 광이 상기 비드(424)를 만나는 경로 자체가 짧아지며, 이에 따라 상기 비드(424)에서 상대적으로 많은 산란이 발생한다.6 (b), when the bead 424 is disposed adjacent to the shielding layer 410 in the pattern scattering layer 420, light passing through the shielding layer 410 The path itself to meet the bead 424 is shortened, and accordingly, a relatively large scattering occurs in the bead 424.
즉, 상기 비드(424)의 분포밀도가 균일한 형태보다 상기 차폐층(410)에 인접한 영역에서 상대적으로 높게 분포됨으로써, 하부에서 전달되는 광이 더 많은 상기 비드(424)를 경유하게 된다.That is, the distribution density of the beads 424 is relatively higher in a region adjacent to the shielding layer 410 than in a uniform shape, so that light transmitted from the lower portion passes through the beads 424.
이에 따라, 도 6의 (a)와 달리 상기 비드(424)가 도 6의 (b)와 같이 상기 차폐층(410)에 인접한 영역에서 나머지 영역보다 상대적으로 분포밀도가 크도록 배치됨으로써, 하부에서 전달되는 광의 확산 및 산란 정도를 증가시킬 수 있다.6B, the beads 424 are arranged such that the distribution density is relatively larger in the region adjacent to the shielding layer 410 than in the remaining regions, as shown in FIG. 6B, It is possible to increase diffusion and scattering of the transmitted light.
이와 같이, 본 발명에 따른 상기 패턴산란층(420)은 상기 차폐층(410)에 인접할수록 상기 비드(424)의 분포밀도가 높게 형성되며, 하부에서 전달되는 광의 확산 효과를 증가시켜 차폐성능이 증가한다.As described above, the pattern scattering layer 420 according to the present invention is formed such that the distribution density of the beads 424 is increased toward the shielding layer 410 and the diffusion effect of light transmitted from the lower part is increased, .
여기서, 상기 비드(424)는 상술한 바와 같이 구 형태로 불균일한 크기를 가지며, 하부에서 전달되는 광이 미산란될 수 있는 크기로 형성된다.Here, the beads 424 have a nonuniform size in a spherical shape as described above, and are formed to have a size such that light transmitted from the lower portion is not scattered.
다음으로, 도 8을 참조하여 상술한 상기 패턴산란층(420)이 상기 차폐층(410)의 상 하부에 각각 형성되며, 각각에 포함된 상기 비드(424)의 분포가 상이한 구조에 대해 살펴보면 다음과 같다.Next, a structure in which the pattern scattering layer 420 described above with reference to FIG. 8 is formed on the upper and lower portions of the shielding layer 410 and the distribution of the beads 424 included in the pattern scattering layer 420 is different will be described. Respectively.
도 8은 도 1의 확산시트에서 도 5의 패턴산란층(420)의 변형된 형태를 나타낸 도면이다.FIG. 8 is a view showing a modified form of the pattern scattering layer 420 of FIG. 5 in the diffusion sheet of FIG.
도시된 도면을 살펴보면, 기본적인 구성은 상술한 도 5와 유사하게 형성되어 있으나, 상기 패턴산란층(420) 내부에 구비된 상기 비드(424)의 배치가 상이하다.5, the basic structure is similar to that of FIG. 5, but the arrangement of the beads 424 provided in the pattern scattering layer 420 is different.
구체적으로, 상기 패턴산란층(420)은 상기 차폐층(410)을 기준으로 상하면에 각각 형성되며, 상부 패턴산란층(420)에서 상기 비드(424)는 상기 차폐층(410)에 인접할수록 밀도가 증가하는 형태로 배치된다.Specifically, the pattern scattering layer 420 is formed on the upper and lower surfaces with respect to the shielding layer 410. In the upper pattern scattering layer 420, the bead 424 has a density (density) closer to the shielding layer 410, Is increased.
그리고 하부 패턴산란층(420)에는 상기 상부 패턴산란층(420)과 달리 상기 비드(424)가 내부에서 고르게 분포되는 형태로 배치된다.Unlike the upper pattern scattering layer 420, the beads 424 are uniformly distributed in the lower pattern scattering layer 420.
상기 상부 패턴산란층(420) 경우, 도 4에서 상술한 바와 같이 내부에 상기 비드(424)가 분산 구비되며, 상기 차폐층(410)에 인접함에 때라 분포 밀도가 증가하여 하부에서 전달되는 광의 이동경로를 최소화함으로써 산란 및 확산효과를 극대화시킨다.In the case of the upper pattern scattering layer 420, the beads 424 are dispersed inside as described above with reference to FIG. 4, and the distribution density increases when the shielding layer 410 is adjacent to the upper pattern scattering layer 420, Minimizing the pathway maximizes scattering and diffusion effects.
이에 따라 상기 차폐층(410)을 경유한 광이 상기 상부의 패턴산란층(420)에 의해 확산 및 산란되어 차폐성능이 향상된다.Accordingly, the light passing through the shielding layer 410 is diffused and scattered by the upper pattern scattering layer 420 to improve the shielding performance.
그리고 상기 하부 패턴산란층(420)은 상부 패턴산란층(420)과 달리 내부의 상기 비드(424)가 균일하게 분포되어 있으며, 이에 따라 상기 비드(424)에 의한 미산란 효과를 보다 극대화할 수 있다.Unlike the upper pattern scattering layer 420, the lower pattern scattering layer 420 uniformly distributes the beads 424 therein, thereby maximizing the non-scattering effect due to the beads 424. [ have.
이는 상기 상부 패턴산란층(420)과 상기 차폐층(410)에 의해 이미 충분한 차폐성능을 가질 수 있기 때문에 상기 하부 패턴산란층(420)에서는 미산란 효과를 이용하여 휘도 저하를 최소화하기 위해 상기 비드(424)를 균일하게 분포한다.Since the upper pattern scattering layer 420 and the shielding layer 410 may have a sufficient shielding capability, the lower pattern scattering layer 420 may be formed using the bead (424) are uniformly distributed.
또한, 상기 하부 패턴산란층(420)은 상기 산란패턴이 하부로 돌출 형성되어 있기 때문에 상기 도광판(200)의 상부에 적층 되더라도 상호 찍힘이나 긁힘 등이 발생하지 않아 차폐성능이 저하되는 것을 방지할 수 있다.In addition, since the scattering pattern of the lower pattern scattering layer 420 protrudes downward, even if the scattering pattern is stacked on the light guide plate 200, mutual shotting or scratching does not occur, have.
물론, 상기 하부 패턴산란층(420) 내부의 상기 비드(424) 역시 고르게 분포되지 않고 특정 위치에서 밀도가 상대적으로 높도록 구성할 수도 있다.Of course, the beads 424 inside the lower pattern scattering layer 420 may not be distributed evenly, and may be configured to have a relatively high density at a specific position.
이와 같이 본 발명에 따른 상기 확산시트(400)는 상기 차폐층(410)의 상 하면에 각각 상기 패턴산란층(420)이 구비되며, 차폐성능을 극대화시키기 위해 상기 상부 패턴산란층(420) 내부에서 상기 비드(424)는 B 영역에서 분포밀도가 상대적으로 높게 형성된다.In order to maximize the shielding performance, the diffusion sheet 400 according to the present invention includes the pattern scattering layer 420 on the upper surface of the shielding layer 410, The bead 424 has a relatively high distribution density in the B region.
여기서, 상기 비드(424)는 상술한 바와 같이 미산란이 발생할 수 있는 크기로 형성되어 휘도가 저하되지 않도록 구성되어야 한다.Here, the beads 424 should be formed to have a size capable of causing non-scattering as described above, so that the brightness is not reduced.
이에 따라, 최근 트렌드인 LCD의 박막화로 인해 백라이트 전체의 두께가 제한적으로 구성되더라도, 본 발명에 따른 상기 확산시트(400)만으로 휘도 저하 없이 광의 확산 및 차폐를 할 수 있다.Accordingly, even if the overall thickness of the backlight is limited due to the thinning of the LCD, which is a recent trend, the diffusion and shielding of light can be performed only with the diffusion sheet 400 according to the present invention without lowering the brightness.
이어서, 도 9을 참조하여 본 발명에 따른 확산시트(400)에서 차폐층(410)이 복수 개로 구성된 상태에 대해 살펴보면 다음과 같다.Next, referring to FIG. 9, a state in which a plurality of shielding layers 410 are formed in the diffusion sheet 400 according to the present invention will be described.
도 9은 도 1의 확산시트(400)에서 차폐층(410)이 다중 레이어로 구성된 상태를 나타낸 도면이다.FIG. 9 is a view showing a state in which the shielding layer 410 in the diffusion sheet 400 of FIG. 1 is composed of multiple layers.
도시된 바와 같이 상기 차폐층(410)은 복수 개의 시트로 구성되며 각각이 기설정된 헤이즈값을 가지도록 구성된다.As shown in the figure, the shielding layer 410 is composed of a plurality of sheets and each has a predetermined haze value.
구체적으로 상기 차폐층(410)은 단일한 레이어가 아니라 복수 개의 시트가 적층되며, 본 실시예에서 상기 차폐층(410)은 제1시트(410a) 및 제2시트(410b)로 구성된다.Specifically, the shielding layer 410 is not a single layer, but a plurality of sheets are stacked. In this embodiment, the shielding layer 410 is composed of a first sheet 410a and a second sheet 410b.
상기 제1시트(410a)는 광 투과성 소재로 제1헤이즈값을 가지며, 상기 제2시트(410b)는 제2헤이즈값을 가지도록 구성된다. 여기서, 상기 제1시트(410a)와 상기 제2시트(410b)는 서로 다른 두께로 구성될 수도 있다.The first sheet 410a has a first haze value as a light transmitting material, and the second sheet 410b has a second haze value. Here, the first sheet 410a and the second sheet 410b may have different thicknesses.
이와 같이 상기 제1시트(410a)와 상기 제2시트(410b)가 서로 다른 헤이즈값을 가지며 상호 적층 결합되어 상기 차폐층(410)을 형성함으로써, 하부에서 전달되는 광의 차폐성능을 증가시킬 수 있다.As described above, the first sheet 410a and the second sheet 410b have mutually different haze values and are stacked and bonded together to form the shielding layer 410, thereby increasing the shielding performance of light transmitted from the lower portion .
본 실시예에서 상기 제1시트(410a)는 L1의 두께를 가지며, 상기 제2시트(410b)는 L2의 두께를 가지고 상호 적층되어 형성된다. 이때, 상술한 바와 같이 상기 제1시트(410a)와 상기 제2시트(410b)는 각각 제1헤이즈값과 제2헤이즈값을 가지도록 구성되며, 각각 내부에 상기 입자(412)를 포함하여 서로 다른 헤이즈값을 가지도록 구성된다.In this embodiment, the first sheet 410a has a thickness L1 and the second sheet 410b has a thickness L2. As described above, the first sheet 410a and the second sheet 410b are configured to have a first haze value and a second haze value, respectively. The first sheet 410a and the second sheet 410b may include the particles 412, And is configured to have a different haze value.
그리고, 상기 제1시트(410a)와 상기 제2시트(410b)를 포함하는 상기 차폐층(410)의 상 하부에 상술한 상기 패턴산란층(420)이 결합된다.The pattern scattering layer 420 is coupled to an upper portion of the shielding layer 410 including the first sheet 410a and the second sheet 410b.
이와 같이 상기 차폐층(410)은 복수 개의 시트로 구성될 수 있으며, 각각이 서로 다른 두께 또는 서로 다른 헤이즈값을 가지도록 구성되어 하부에서 전달되는 광의 차폐성능을 증가시킴과 동시에 상기 차폐층(410) 전체의 두께를 조절할 수 있다. The shielding layer 410 may be formed of a plurality of sheets and may have different thicknesses or different haze values to increase the shielding performance of light transmitted from the lower portion of the shielding layer 410, ) The entire thickness can be adjusted.
이때, 본 실시예에서 도면에 도시되지는 않았지만 상기 패턴산란층(420)에는 추가적으로 상기 비드(424)가 더 포함될 수 있으며, 상기 비드(424)에 의해 하부에서 전달되는 광이 확산되어 차폐성능을 증가시킬 수 있다.In this case, although not shown in the drawing, the pattern scattering layer 420 may further include the beads 424, and the light transmitted from the lower portion may be diffused by the beads 424, .
여기서도 마찬가지로 상기 비드(424)는 구 형태로 불균일한 크기를 가지며, 상기 패턴산란층(420) 내부에 분산된다. 그리고 상기 패턴산란층(420) 내부에서 상기 비드(424)는 상기 차폐층(410)에 인접할수록 분포 밀도가 증가하는 것이 바람직하다.Likewise, the beads 424 have a non-uniform size in a spherical shape and are dispersed in the pattern scattering layer 420. In addition, it is preferable that the distribution density of the beads 424 in the pattern scattering layer 420 increases as the shielding layer 410 is closer to the shielding layer 410.
이와 같이 본 발명에 따른 상기 확산시트(400)는 상기 차폐층(410)이 복수 개의 레이어로 구성되어 각각이 서로 다른 헤이즈값을 가지도록 구성될 수 있으며, 이에 따라 광의 차폐성능을 증가시킬 수도 있다.As described above, in the diffusion sheet 400 according to the present invention, the shielding layer 410 may be configured to have a plurality of layers and have different haze values, thereby increasing the shielding performance of light .
한편, 도 10을 참조하여 본 발명의 확산시트(400)에서 패턴산란층(420)이 다중 레이어로 이루어진 구성에 대해 살펴보면 다음과 같다.Referring to FIG. 10, a structure in which the pattern scattering layer 420 is formed of multiple layers in the diffusion sheet 400 of the present invention will be described.
도 10은 도 1의 확산시트에서 패턴산란층(420)이 다중 레이어로 구성된 형태에 대해 나타낸 도면이다.FIG. 10 is a diagram showing a pattern scattering layer 420 in the diffusion sheet of FIG. 1, which is composed of multiple layers.
도시된 도면을 살펴보면 기본적인 구성은 상술한 상기 확산시트(400)와 유사하지만, 상기 패턴산란층(420)이 상기 산란패턴(422)을 가지는 제1층(420a) 및 상기 제1층(420a)과 상기 차폐층(410) 사이에 구비되는 제2층(420b)을 포함한다.The pattern scattering layer 420 is formed on the first layer 420a having the scattering pattern 422 and the first layer 420a having the scattering pattern 422. However, And a second layer 420b disposed between the first electrode layer 420 and the shielding layer 410.
상기 제1층(420a)은 상기 제2층(420b)에서 연속하여 형성되며, 상부로 돌출된 상기 산란패턴(422)이 형성된다. 상기 산란패턴(422)은 앞서 도 1을 참조하여 설명한 구성과 동일하며, 불 균일한 형태로 하부에서 전달되는 광을 산란시킨다.The first layer 420a is continuously formed in the second layer 420b, and the scattering pattern 422 protruding upward is formed. The scattering pattern 422 is the same as the structure described above with reference to FIG. 1, and scatters light transmitted from the bottom in a nonuniform form.
이때, 도시된 바와 같이 상기 제1층(420a)의 내부에는 별도로 상기 비드(424)가 포함되지 않도록 구성되어 있으나, 이와 달리 후술하는 상기 제2층(420b)보다 상대적으로 낮은 밀도로 상기 비드(424)가 구비될 수도 있다.At this time, as shown in the drawing, the bead 424 is not included in the first layer 420a. Alternatively, the bead 424 may be formed at a relatively lower density than the second layer 420b, 424 may be provided.
한편, 상기 제2층(420b)은, 시트형태로 형성되어 내부에 복수 개의 상기 비드(424)가 분산되며 상기 비드(424)에 의해 광을 확산 및 산란시킨다.Meanwhile, the second layer 420b is formed in a sheet shape, and a plurality of the beads 424 are dispersed therein, and the beads 424 spread and scatter light.
여기서, 상기 제2층(420b)은 시트형태로 상기 차폐층(410)의 상면에 적층 접합되며, 상부에 상기 제1층(420a)이 적층된다.Here, the second layer 420b is laminated on the upper surface of the shielding layer 410 in a sheet form, and the first layer 420a is laminated on the upper layer.
상기 제2층(420b)에 구비된 상기 비드(424)는 상술한 바와 같이 상기 입자(412)보다 상대적으로 작은 크기를 가지며, 하부에서 전달되는 광의 미산란이 가능한 크기로 형성된다.The beads 424 provided in the second layer 420b have a size smaller than that of the particles 412 as described above and are formed to have a size capable of scattering light transmitted from below.
즉, 상기 패턴산란층(420)이 상기 제1층(420a) 및 상기 제2층(420b)으로 구성되어 상기 제2층(420b)에 상기 비드(424)가 포함됨에 따라, 상기 패턴산란층(420) 전체에서 상기 차폐층(410)에 인접한 부분에 상기 비드(424)가 집중 분포된다.That is, as the pattern scattering layer 420 is composed of the first layer 420a and the second layer 420b and the bead 424 is included in the second layer 420b, The beads 424 are concentratedly distributed on the entire surface of the substrate 420 adjacent to the shielding layer 410.
그리고 상기 차폐층(410)에 인접할수록 상기 비드(424)의 분포 밀도가 증가함으로써, 하부에서 전달되는 광의 확산 및 산란 효과를 증가시킬 수 있다.The distribution density of the beads 424 increases as the shielding layer 410 is closer to the shielding layer 410, thereby increasing diffusion and scattering effect of light transmitted from the lower portion.
이와 같이 본 발명에 따른 차폐 성능이 향상된 확산시트(400) 및 이를 포함한 백라이트 유닛에 대해 살펴보았으며, 상기 확산시트(400)가 기설정된 헤이즈 값을 가지는 차폐층(410)을 포함하여 하부에서 전달되는 광을 단순히 확산시키는 것뿐만 아니라 산란을 통해 차폐성능을 증가시킬 수 있다.As described above, the diffusion sheet 400 having improved shielding performance according to the present invention and the backlight unit including the diffusion sheet 400 have been described. The diffusion sheet 400 includes a shielding layer 410 having a predetermined haze value, It is possible not only to diffuse the light to be scattered but also to increase the shielding performance through scattering.
이에 따라 상기 확산시트(400)에서 광의 차폐성능을 증가시킴으로써, 상기 도광판(200)의 패턴이 상부로 전달되는 것을 방지하여 광이 uniform하게 전달될 수 있도록 하고, 상기 비드(424)가 미산란이 가능한 크기로 형성됨으로써 광의 확산 및 산란에 의한 휘도 저하를 최소화할 수 있다.Accordingly, by increasing the shielding performance of the light in the diffusion sheet 400, the light can be uniformly transmitted by preventing the pattern of the light guide plate 200 from being transmitted to the upper portion, and the bead 424 is not scattered It is possible to minimize the luminance drop due to diffusion and scattering of light.
이상과 같이 본 발명에 따른 바람직한 실시예를 살펴보았으며, 앞서 설명된 실시예 이외에도 본 발명이 그 취지나 범주에서 벗어남이 없이 다른 특정 형태로 구체화 될 수 있다는 사실은 해당 기술에 통상의 지식을 가진 이들에게는 자명한 것이다. 그러므로, 상술된 실시예는 제한적인 것이 아니라 예시적인 것으로 여겨져야 하고, 이에 따라 본 발명은 상술한 설명에 한정되지 않고 첨부된 청구항의 범주 및 그 동등 범위 내에서 변경될 수도 있다.It will be apparent to those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit or scope of the invention as defined in the appended claims. It is obvious to them. Therefore, the above-described embodiments are to be considered as illustrative rather than restrictive, and the present invention is not limited to the above description, but may be modified within the scope of the appended claims and equivalents thereof.

Claims (12)

  1. 광 투과성 소재로 구성되어 일정한 두께를 가지도록 형성되며, 기설정된 헤이즈(Haze) 값에 따라 내부에 복수 개의 입자를 포함하는 차폐층; 및A shielding layer made of a light-transmitting material and formed to have a constant thickness, and including a plurality of particles therein according to a preset haze value; And
    상기 차폐층의 상면 또는 하면 중 적어도 어느 하나에 형성되며, 일부가 돌출된 산란패턴을 포함하고 내부에 복수 개의 비드가 분산되어 하부에서 전달되는 광을 확산시키는 패턴산란층;을 포함하며,And a pattern scattering layer formed on at least one of an upper surface and a lower surface of the shield layer and including a scattering pattern partially protruding and dispersing a plurality of beads in the lower part to diffuse light transmitted from the lower part,
    상기 비드는 상기 차폐층 내부에 포함된 입자보다 상대적으로 작은 크기로 형성되는 차폐 성능이 향상된 확산시트.Wherein the beads are formed in a size relatively smaller than the particles contained in the shielding layer.
  2. 제1항에 있어서,The method according to claim 1,
    상기 차폐층은,The shielding layer
    내부에 기설정된 크기의 상기 입자가 균일하게 분산되는 것을 특징으로 하는 차폐 성능이 향상된 확산시트.Wherein the particles having a predetermined size are uniformly dispersed in the inside of the diffusion sheet.
  3. 제1항에 있어서,The method according to claim 1,
    상기 차폐층은,The shielding layer
    광 투과성 소재로 제1헤이즈값을 가지는 제1시트; 및A first sheet having a first haze value as a light transmitting material; And
    상기 제1시트와 적층 결합되며 광 투과성 소재로 제2헤이즈값을 가지는 제2시트;를 포함하는 것을 특징으로 하는 차폐 성능이 향상된 확산시트.And a second sheet laminated to the first sheet and having a second haze value as a light-transmitting material.
  4. 제3항에 있어서,The method of claim 3,
    상기 제1시트와 상기 제2시트는 서로 다른 두께를 가지는 것을 특징으로 하는 차폐 성능이 향상된 확산시트.Wherein the first sheet and the second sheet have different thicknesses.
  5. 제1항에 있어서,The method according to claim 1,
    상기 패턴산란층은,The pattern scattering layer may be formed,
    상하방향을 따라 상기 차폐층에 인접할수록 상기 비드의 분포밀도가 상대적으로 높게 분포되는 것을 특징으로 하는 차폐 성능이 향상된 확산시트.And the distribution density of the beads is relatively higher in the vicinity of the shield layer along the vertical direction.
  6. 제1항에 있어서,The method according to claim 1,
    상기 패턴산란층은,The pattern scattering layer may be formed,
    상기 차폐층의 상면 및 하면에 각각 형성되며,And a shield layer formed on the upper and lower surfaces of the shield layer,
    상기 차폐층의 상면에 형성된 패턴산란층에서는 상기 차폐층에 인접할수록 상기 비드의 분포밀도가 높게 형성되고,In the pattern scattering layer formed on the upper surface of the shield layer, the distribution density of the beads is formed to be higher toward the shield layer,
    상기 차폐층의 하면에 형성된 패턴산란층에서는 상기 비드가 균일하게 분포되는 것을 특징으로 하는 차폐 성능이 향상된 확산시트.And the beads are uniformly distributed in the pattern scattering layer formed on the lower surface of the shielding layer.
  7. 제1항에 있어서,The method according to claim 1,
    상기 비드는,The bead
    0.1~1um 크기로 형성되며, 하부에서 전달되는 가시광 파장대의 광을 미산란(Mie-Scattering)시켜 휘도 저하를 최소화시키는 것을 특징으로 하는 차폐 성능이 향상된 확산시트.Wherein the diffusion sheet is formed to have a size of 0.1 to 1 μm and minimizes the luminance degradation by mie-scattering the light of the visible light wavelength range transmitted from the lower part.
  8. 제1항에 있어서,The method according to claim 1,
    상기 비드는,The bead
    구형으로, Alumina, TiO2, Melamine, Silica, PMMA, PBMA, PDMS 중 적어도 어느 하나의 소재로 구성되며,And is made of at least one material selected from the group consisting of Alumina, TiO 2 , Melamine, Silica, PMMA, PBMA, and PDMS,
    1.45~2.50의 굴절률을 가지는 것을 특징으로 하는 차폐 성능이 향상된 확산시트.Wherein the diffusion sheet has a refractive index of 1.45 to 2.50.
  9. 제1항에 있어서,The method according to claim 1,
    상기 입자는,The particles may be,
    Silica, PMMA, PBMA 중 적어도 어느 하나의 소재로 구성되며,And is made of at least one material selected from the group consisting of silica, PMMA, and PBMA,
    직경이 1~9 ㎛ 크기로 형성되는 것을 특징으로 하는 차폐 성능이 향상된 확산시트.Wherein the diffusion sheet has a diameter of 1 to 9 mu m.
  10. 제1항에 있어서,The method according to claim 1,
    상기 패턴산란층은,The pattern scattering layer may be formed,
    상기 돌출된 산란패턴을 포함하는 제1층; 및A first layer comprising the projected scattering pattern; And
    상기 차폐층과 상기 제1층 사이에서 상기 복수 개의 비드를 포함하는 제2층;을 포함하는 것을 특징으로 하는 차폐 성능이 향상된 확산시트.And a second layer comprising the plurality of beads between the shielding layer and the first layer.
  11. 제1항에 있어서,The method according to claim 1,
    상기 돌출된 산란패턴은,The protruding scattering pattern may be formed,
    불균일한 크기를 가지며 상기 패턴산란층의 일면 중 적어도 일부에 형성되는 것을 특징으로 하는 차폐 성능이 향상된 확산시트.Wherein the diffusing sheet has a non-uniform size and is formed on at least a part of one surface of the pattern scattering layer.
  12. 제1항의 확산시트를 포함하는 백라이트 유닛.A backlight unit comprising the diffusion sheet of claim 1.
PCT/KR2018/016072 2017-12-29 2018-12-18 Diffusion sheet having improved shielding performance and backlight unit comprising same WO2019132367A1 (en)

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