WO2013055112A1 - Optical sheet structure - Google Patents

Optical sheet structure Download PDF

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Publication number
WO2013055112A1
WO2013055112A1 PCT/KR2012/008232 KR2012008232W WO2013055112A1 WO 2013055112 A1 WO2013055112 A1 WO 2013055112A1 KR 2012008232 W KR2012008232 W KR 2012008232W WO 2013055112 A1 WO2013055112 A1 WO 2013055112A1
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WO
WIPO (PCT)
Prior art keywords
optical
optical sheet
adhesive layer
shape
patterns
Prior art date
Application number
PCT/KR2012/008232
Other languages
French (fr)
Korean (ko)
Inventor
조성식
조성민
김영일
민지홍
권오현
이태준
이우종
정진길
Original Assignee
주식회사 엘엠에스
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Filing date
Publication date
Application filed by 주식회사 엘엠에스 filed Critical 주식회사 엘엠에스
Publication of WO2013055112A1 publication Critical patent/WO2013055112A1/en

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/04—Prisms
    • 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
    • G02B6/0053—Prismatic sheet or layer; Brightness enhancement element, sheet or layer
    • 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
    • G02B5/30—Polarising elements
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • 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
    • G02B6/0081—Mechanical or electrical aspects of the light guide and light source in the lighting device peculiar to the adaptation to planar light guides, e.g. concerning packaging
    • G02B6/0086—Positioning aspects
    • G02B6/0088—Positioning aspects of the light guide or other optical sheets in the package

Definitions

  • the present invention relates to an optical sheet structure, and more particularly, to an optical sheet structure that can secure a certain level or more by maintaining the adhesion between the optical sheets while minimizing the degradation of the optical properties of the light passing through.
  • LCDs liquid crystal displays
  • Such a liquid crystal display device is applied with a backlight unit for irradiating light in the liquid crystal panel direction.
  • the backlight unit includes various kinds of optical sheets for refracting, condensing, and diffusing light such that light generated from the light source is uniformly incident on the front surface of the liquid crystal panel.
  • the optical sheet includes two optical sheets having a prism pattern of a triangular cross section in order to focus light in the liquid crystal panel direction, and the two optical sheets are stacked up and down so that each prism pattern crosses each other.
  • an adhesive layer is provided between two optical sheets having a prism pattern.
  • the adhesive layer is formed on the entire surface of the lower surface of the prism pattern optical sheet located on the top.
  • the conventional adhesive layer is provided on the front surface between two optical sheets having a prism pattern, in the conventional optical sheet structure, the entire upper end portion of the prism pattern penetrates into the adhesive layer, so that a wet-out phenomenon occurs and moiré occurs. Patterns are generated, and optical characteristics such as optical path change and luminance decrease by the adhesive layer are deteriorated.
  • the present invention is to solve the technical problem to provide an optical sheet structure that can secure a certain level or more by maintaining the adhesion between the optical sheets while minimizing the degradation of the optical properties of the light passing through.
  • a first optical sheet including an upper surface on which the optical structure is formed such that the heights of the upper end portions are different from each other;
  • optical sheet structure comprising a.
  • the optical structure is separated by at least a portion of the first optical structure and the plurality of first optical structures, and the plurality of second optics having a height higher than the height of the first optical structure It may include a structure.
  • the distance between the upper ends of the plurality of second optical structures can be formed constant.
  • the plurality of second optical structures may be formed of a prism structure formed linearly parallel to each other.
  • the first optical sheet, the surface connecting the upper end of the upper surface may have an embossed form.
  • the first optical sheet is a plurality of optical structures formed on one surface of the first refraction portion is linearly arranged at a predetermined distance from each other having a flat plate-shaped first refraction portion and an optical cross section It may include a second refractive portion having a pattern.
  • the curves interconnecting the ends of the plurality of optical structure patterns are formed to have convex portions or concave portions having different heights, and each of the plurality of optical structure patterns has different ends in the formed direction thereof. It may be formed to have a convex portion or a concave portion having a height.
  • the optical structure pattern may be a polygonal shape or a partial arc shape in the cross-sectional projection, or may have a shape in which the polygonal shape and the partial arc shape is complex.
  • the convex portion or concave portion formed by the curve interconnecting the ends of the plurality of optical structure patterns, or the convex portion or concave portion formed in the direction in which each of the plurality of optical structure patterns are formed The plurality of optical structure patterns may be formed at equal intervals.
  • the convex portion or concave portion formed by the curve interconnecting the ends of the plurality of optical structure patterns, or the convex portion or concave portion formed in the direction in which each of the plurality of optical structure patterns are formed may be formed at irregular intervals.
  • the adhesive layer may be formed in a dot shape on a portion of the upper surface of the first optical sheet.
  • the adhesive layer may be formed in a plurality of bands parallel to each other on a portion of the upper surface of the first optical sheet.
  • the adhesive layer may be formed in a mesh shape having a plurality of open areas in a portion of the upper surface of the first optical sheet.
  • the adhesive layer may have an area of 5% or more and 65% or less of the planar area of the first optical sheet.
  • the area in direct contact with the structured surface of the first optical sheet is reduced to reduce infiltration and moire patterns are generated. Can be suppressed.
  • an adhesive layer is formed only on a part of the surface to be bonded so that partial bonding is performed. While ensuring a firm bonding force between the light guide plate and the optical sheet, it is possible to minimize the optical characteristic variation due to the application of the adhesive layer. In particular, it is possible to further increase the effect of suppressing the moiré pattern by reducing the above-mentioned infiltration phenomenon.
  • the present invention by providing an appropriate bonding force by partial adhesion, it is possible to suppress problems such as warpage phenomenon, deformation and distortion that may appear when the ultra-thin optical sheet is applied. Through this, the thickness of the entire backlight unit can be reduced by enabling the use of a thinner optical sheet.
  • FIG. 1 is an exploded cross-sectional view of a liquid crystal display to which an optical sheet structure according to an embodiment of the present invention is applied.
  • FIGS. 2 to 14 are perspective views or cross-sectional views for describing the structure of the first optical sheet according to various embodiments of the present disclosure.
  • FIG. 15 is a view illustrating a dot-shaped adhesive layer and an optical sheet applied to an optical sheet structure according to an embodiment of the present invention.
  • 16 is a view showing a plurality of band-shaped adhesive layers and optical sheets applied to the optical sheet structure according to the embodiment of the present invention.
  • 17 is a view showing a mesh-shaped adhesive layer and an optical sheet applied to the surface light source device according to the embodiment of the present invention.
  • FIG. 18 is a graph illustrating measurement of luminance of light transmitted while varying a ratio of the thickness of the adhesive layer and the area of the entire optical sheet structure in the optical sheet structure according to various embodiments of the present disclosure.
  • FIG. 1 is an exploded cross-sectional view of a liquid crystal display to which an optical sheet structure according to an embodiment of the present invention is applied.
  • a liquid crystal display to which an optical sheet structure according to an exemplary embodiment of the present invention is applied includes a light guide plate for transmitting a light source 111 and light generated from the light source toward the liquid crystal display panel 170. 110, a light diffusion plate 120 for diffusing light transmitted from the light guide plate 110, a first optical sheet 130 and a second optical sheet 150 having an optical structured surface for condensing, An adhesive layer 140 interposed between the two optical sheets 130 and 140 to provide an adhesive force between the two optical sheets 130 and 150, and a polarizer 160 and a polarizer 160 disposed on the second optical sheet 150. It may be configured to include a liquid crystal display panel 170 disposed on.
  • various optical sheets provided to the liquid crystal display are stacked between the light guide plate 110 and the liquid crystal display panel 170.
  • the laminate structure of this optical sheet is optimized to achieve the desired special optical performance, and additional elements may be added or omitted as necessary.
  • the present invention relates to a laminated optical sheet structure in which two or more optical sheets are bundled and packaged through an adhesive layer 140 between optical sheets applied to the liquid crystal display described above.
  • an embodiment of the present invention may include a first optical sheet 130, an adhesive layer 140, and a second optical sheet 150.
  • the first optical sheet 130 and the second optical sheet 150 may be partially bonded by a plurality of adhesive layers 140.
  • the partial bonding or the partial bonding means that the adhesive layer or the adhesive layer is not evenly distributed on the entire surface of the surface to be bonded, and the adhesive layer is formed only on the corresponding region where the adhesive layer is formed by forming an adhesive layer only on a part of the surface to be bonded. Means that.
  • the first optical sheet 130 may have one surface (the surface corresponding to the upper surface in FIG. 1) as an optical structured surface.
  • the optical structured surface refers to a surface on which an optical structure capable of adjusting light paths to collect light incident from a lower surface of the first optical sheet 130 is formed.
  • a plurality of prism structures are adopted in the first optical sheet disposed on the light exit surface of the light guide plate in the same shape side by side in one direction.
  • the structured surface of the first optical sheet 130 is formed with an optical structure having regions where the ends have different heights. Due to the height difference between the ends, the infiltration phenomenon may be reduced by reducing the size of the region where the ends of the optical structure penetrate the bonding layer 140.
  • FIGS. 4 to 14 are views for explaining the structure of the first optical sheet according to various embodiments of the present invention.
  • 2 and 3 illustrate an example in which the heights of the optical structures themselves formed on the first optical sheet are different from each other
  • FIGS. 4 to 14 show convex portions formed by connecting upper ends of the optical structures formed on the first optical sheet.
  • the example formed in the embossed form which has curvature of a recessed part is shown.
  • the surface connecting the upper end is a virtual surface, and the same applies to various embodiments described below.
  • the first optical sheet 131 in the first optical sheet 131 according to an embodiment of the present invention, two types of optical structures 231 and 232 having different heights may be used as the first optical sheet 131. ) On the structured surface.
  • the first optical structure 231 is an optical structure having a lower height than the second optical structure 232.
  • the second optical structure 232 has a height higher than that of the first optical structure 231, and may be separately disposed by the first optical structure 231. That is, a predetermined number of first optical structures 231 may be disposed between the second optical structures 231.
  • the second optical structures 232 may have a constant distance between the upper ends thereof.
  • the second optical structure 232 is preferably formed of a prism structure formed in parallel to each other.
  • the second optical structure 232 penetrates into the adhesive layer 140 to form a second optical structure.
  • a junction may be formed with the sheet 150, and a gap may exist between the adhesive layer 140 or the second optical sheet 150 and the first optical structure 231.
  • the contact area between the first optical sheet 130 and the second optical sheet 150 or the contact area between the first optical sheet 130 and the adhesive layer 140 is reduced to prevent infiltration. Can be reduced.
  • the effect of reducing the infiltration phenomenon by the adhesive layer 140 formed to enable partial bonding, which will be described later, may be further increased.
  • the second optical sheet 150 bonded to the first optical sheet 130 via the adhesive layer 140 may be formed of an optical structure formed on the first optical sheet 130.
  • the second optical sheet 150 may be any type of optical sheet (for example, a polarizing sheet or a diffusion sheet) or an optical structure disposed on the structured surface of the first optical sheet 130 to realize optical characteristics. This may be the case.
  • FIGS. 4 to 14 show various embodiments of the first optical sheet 122 in which the surface connecting the upper end portion has an embossed shape.
  • the first optical sheet 122 may include a first refraction portion 310 and a second refraction portion 320 having an optical structure pattern formed on the first refraction portion 310.
  • the portions indicated by the dotted lines represent convex or concave embossed surfaces.
  • FIG. 4 is a perspective view of a first optical sheet according to an embodiment of the present invention
  • FIG. 5 is a cross-sectional view of the first optical sheet shown in FIG. 4.
  • the first optical sheet 132 transmits the first refraction portion 310 and the first refraction portion 310 having a flat plate shape. It may include a second refracting portion 320 having a plurality of optical structure patterns 321 for condensing the light emitted in the vertical direction.
  • the first refraction unit 310 may be provided in the form of a light transmitting film, and may be a substrate for bonding the second refraction unit 320 to an upper surface thereof.
  • the optical structure patterns 321 of the second refraction unit 320 are prismatic patterns having a triangular optical cross section in cross-sectional projection, and may be linearly arranged at predetermined intervals.
  • the optical structure patterns 321 may have a curved shape having a high peak and a low peak.
  • the curves connecting the ends of the plurality of optical structure patterns 321 are formed to have convex portions or concave portions having different heights.
  • each of the plurality of optical structure patterns is formed to have convex portions or concave portions having end portions different in height in the formed direction thereof.
  • the convex portions or the concave portions may be spaced apart from each other to form an embossed shape.
  • each of the plurality of optical structural patterns is an example including an arc-shaped convex part formed at regular intervals in the formed direction thereof.
  • the surface formed at the upper end of the optical structure pattern 321 may be embossed.
  • the upper surface of the embossed shape having a height difference may form a gap with the first optical structure 231 when bonding the adhesive layer 140 or the second optical sheet 150.
  • infiltration may be reduced by reducing the contact area between the first optical sheet 132 and the second optical sheet 150 or the contact area between the first optical sheet 132 and the adhesive layer 140.
  • the effect of reducing the infiltration phenomenon by the adhesive layer 140 formed to enable partial bonding, which will be described later, may be further increased.
  • the first refraction unit 310 and the second refraction unit 320 are any one of polycarbonate, PVC, PP, PE, PET, and acrylic polymers as a light transmissive material that can transmit light smoothly in the visible region. It can be molded into a single layer to form a unity with each other. Of course, depending on the conditions, the first refraction unit 310 and the second refraction unit 320 may be manufactured in a multi-layer structure that is bonded to each other after molding using the same material or different materials among the above-described materials.
  • the optical sheet 132 according to an embodiment of the present invention, as shown in Figure 6 and 7, the curve connecting the ends of the optical structure patterns 321 of the second refractive portion 320
  • the shape of the end portion of the optical structure pattern itself may include an ellipse or a polygonal upwardly projecting convex portion, and the convex portions may be formed in the form of embossed spaces.
  • the surface formed by the ends of the optical structure patterns 321 may be formed to have an embossed pattern having convex portions of various shapes.
  • a curved line connecting the ends of the optical structure patterns 321 of the second refraction unit 320, or the shape of the end portion of one optical structure pattern itself is circular.
  • the concave portion may have an ellipse, a polygonal shape, and have a concave portion recessed downward in cross section, and the concave portions may be formed in an embossed form spaced apart from each other.
  • the surface formed by the optical sheet 132 according to the embodiment of the present invention may be implemented in an embossed form in which a concave pattern is repeated.
  • the optical structure pattern 321 may be formed to have an optical cross section of a partial arc shape as shown in FIG. 12 in addition to the optical cross section of a triangular shape, and as shown in FIG.
  • the optical cross section of the triangular shape may be formed into a complex shape.
  • the convex or concave portions may be formed at irregular intervals, and the intervals between the optical structure patterns 321 may be regularly formed.
  • at least one or both of a curved line connecting the ends of the optical structure patterns 321 of the second refraction unit 320 or the shape of the end of the optical structure pattern itself and the optical structure pattern are mutually irregular. It may be formed as.
  • the first optical sheet 132 increases the luminance in the entire area of the liquid crystal panel (170 of FIG. 1) disposed on the upper part of the second mandrel 320, thereby increasing the luminance. High brightness can be achieved at the viewing angle.
  • the optical structure pattern 321 has a structure having end portions having different heights, it is possible to reduce the size of the area with other optical sheets in direct contact with the first optical sheet 130. As a result, the wet-out phenomenon can be minimized to suppress the generation of moire fringes.
  • the adhesive layer 140 is provided to provide an adhesive force to the bonding of the first optical sheet 130 and the second optical sheet 150, and the adhesive layer 140 is formed on the structured surface of the first optical sheet 110. It may be interposed between one surface of the second optical sheet 150 corresponding thereto.
  • the adhesive layer 140 may be an ultraviolet or visible light curable acrylic adhesive or a two-component curable adhesive used for the lamination of the PVA resin film as the material, but is not particularly limited as long as it is the lamination adhesive of the optical sheet.
  • 15 to 17 show various embodiments of an adhesive layer formed for partial bonding.
  • FIG. 15 illustrates a dot-shaped adhesive layer and an optical sheet applied to an optical sheet structure according to an embodiment of the present invention.
  • the dot-shaped adhesive layer 141 may be formed by being dispersed and formed on the structured surface of the first optical sheet 130 where contact is made.
  • the ratio of the area of the dot-shaped adhesive layer 141 to the entire surface of the structured surface of the first optical sheet 130 and the thickness thereof are the luminance of light emitted from the opposite surface of the structured surface of the first optical sheet 130. It may be adjusted accordingly depending on the quality.
  • FIG. 16 is a view showing a plurality of strip-shaped adhesive layers and optical sheets applied to the surface light source device according to the embodiment of the present invention.
  • one embodiment of the present invention has a plurality of adhesive layers 142 having a band shape disposed on the structured surface of the first optical sheet 130.
  • the plurality of adhesive layers 142 partially bond the second optical sheet 150 and the first optical sheet 130 to each other to provide a firm bonding force.
  • the plurality of adhesive layers 142 having a band shape may be implemented to have a plurality of band shapes arranged parallel to each other at a predetermined interval so that partial bonding may be performed.
  • the plurality of adhesive layers 142 may include a structured surface of the optical sheet 130, that is, a linear prism pattern (eg, 231 and 232 of FIG. 2) or an optical structure pattern (eg, 321 of FIG. 4). It may have a band shape formed extending in the same direction as the formed direction.
  • FIG. 17 is a view showing a mesh-shaped adhesive layer and an optical sheet applied to the surface light source device according to the embodiment of the present invention.
  • one embodiment of the present invention has a mesh-shaped adhesive layer 143 disposed on the structured surface of the optical sheet 130.
  • the mesh adhesive layer 143 is disposed between the second optical sheet 150 and the first optical sheet 130, and the front surface of the second optical sheet 150 and the first optical sheet 130 are not bonded to each other. Is provided in the form of a mesh having an open area (s) so as to partially bond the second optical sheet 150 and the first optical sheet 130.
  • the mesh adhesive layer 142 may be formed in such a manner that a plurality of bands arranged in parallel to each other cross each other.
  • the open region s may be formed by two band shapes arranged in parallel in one direction and two band shapes arranged in parallel in a direction crossing the plurality of band shapes.
  • FIG. 18 is a graph illustrating bonding two prism sheets and measuring luminance of light transmitted while varying the ratio of the thickness of the adhesive layer and the area of the entire optical sheet structure.
  • the reference luminance represents the luminance transmitted through two prism sheets without applying the adhesive layer.
  • the graph shown in FIG. 18 is commonly measured for the above-mentioned dot-shaped partial adhesive layer, strip-shaped partial adhesive layer, and mesh-shaped partial adhesive layer.
  • the luminance decreases as the thickness of the adhesive layer increases.
  • the total area of the adhesive layer is less than 65% of the area occupied by the entire optical sheet structure, it can be seen that the decrease in brightness due to the increase in thickness is significantly slowed down.
  • the area of the adhesive layer is preferably 5% or more and 65% or less of the area of the area where the light guide plate and the optical sheet are bonded, that is, the planar area of the optical sheet, so as to provide a deterioration phenomenon due to the adhesive layer and an appropriate bonding force.
  • a shading phenomenon may occur that occurs a region appearing darker than the surroundings. This shading phenomenon is undesirable because it prevents providing uniform light over the entire area of the display system.
  • This shading phenomenon mainly depends on the width of the dot or strip shape forming the partial junction and the prism pattern pitch of the first optical sheet. Table 1 shows a case where the light transmitted while changing the diameter of the dot and the prism pitch of the first optical sheet is visually observed when the dot-shaped adhesive layer is applied, and the shading phenomenon is not observed. If not, the result is indicated by an X table.
  • Tables 2 and 3 show O tables and shadings in which the transmitted light is visually observed while varying the width of the adhesive layer and the prism pitch of the first optical sheet in the band-shaped and mesh-shaped adhesive layers, respectively. It is the result which showed with the X table
  • the lower limit of the dot diameter of the adhesive layer in relation to the shading phenomenon is not limited to a specific value.
  • the dot-shaped adhesive layer is positioned between two peaks of the prism structure. In view of the fact that the adhesive force may be reduced by not contacting the adhesive layer with the peak portion of the prism structure, the adhesive layer dot diameter is preferably formed larger than the prism pitch.
  • the width of the adhesive layer is formed larger than the pitch of the prism pattern, and the upper limit thereof is preferably less than 10 times the pitch of the prism pattern.
  • the width of the adhesive layer that is, the width of the band structures that cross each other to form a mesh-shaped adhesive layer is less than 10 times the prism pattern pitch. It can be seen that it is preferable.
  • belt structure which mutually intersects to form a mesh-shaped adhesive layer is not limited to a specific value, It can determine suitably in consideration of the area ratio of the above-mentioned preferable adhesive layer.
  • embodiments of the present invention provide an adhesive layer only on a portion of a surface to be bonded to secure adhesion between the first optical sheet 130 having the structured surface and the second optical sheet 150 laminated to the structured surface. To form a partial junction. As a result, it is possible to secure a firm bonding force between the light guide plate and the optical sheet and to minimize variations in optical characteristics due to the application of the adhesive layer.
  • various embodiments of the present invention allow optical structures formed on the structured surface of the first optical sheet 130 to form regions having different heights, thereby directly contacting the structured surface of the first optical sheet 130. By reducing the area, it is possible to reduce the infiltration phenomenon and to suppress the generation of moire fringes.
  • embodiments of the invention can suppress problems such as warpage, deformation, and warpage that may occur when applying an ultra-thin optical sheet (prism sheet) by providing a proper bonding force by partial bonding. Through this, the thickness of the entire backlight unit can be reduced by enabling the use of a thinner optical sheet.

Abstract

Disclosed is an optical sheet structure whereby more than a certain level of robustness can be ensured by maintaining the adhesive force between optical sheets while minimising reduction in the optical characteristics of light passing through. The optical sheet structure comprises: a first optical sheet comprising an upper surface in which an optical structure is formed so as to have an area where the upper end part is at different heights; an adhesive layer which is formed on some of the area of the upper surface of the first optical sheet; and a second optical sheet which is disposed on the adhesive layer. The adhesive layer can be formed in the shape of a plurality of dots, in the shape of a plurality of belts or in the shape of a mesh having open areas so as to allow partial adhesion.

Description

광학시트 구조물Optical sheet structure
본 발명은 광학시트 구조물에 관한 것으로, 더욱 상세하게는 통과하는 빛의 광학 특성 저하를 최소화하면서 광학시트간 접착력을 유지하여 일정 수준 이상의 견고함을 확보할 수 있는 광학시트 구조물에 관한 것이다.The present invention relates to an optical sheet structure, and more particularly, to an optical sheet structure that can secure a certain level or more by maintaining the adhesion between the optical sheets while minimizing the degradation of the optical properties of the light passing through.
근래에, 액정 디스플레이(LCD)와 같은 광학 디스플레이는 이동전화, 개인 휴대 단말기, 태블릿 컴퓨터, 모니터 및 텔레비전 등 다양한 응용기기에 적용되고 있다.In recent years, optical displays such as liquid crystal displays (LCDs) have been applied to various applications such as mobile phones, personal digital assistants, tablet computers, monitors, and televisions.
이러한 액정 디스플레이 장치에는 액정 패널 방향으로 빛을 조사하기 위한 백라이트 유닛이 적용된다. 백라이트 유닛은, 광원으로부터 생성된 빛을 액정 패널의 전면으로 균일하게 입사되도록 빛을 굴절, 집광 및 확산시키기 위한 다양한 종류의 광학시트를 포함한다.Such a liquid crystal display device is applied with a backlight unit for irradiating light in the liquid crystal panel direction. The backlight unit includes various kinds of optical sheets for refracting, condensing, and diffusing light such that light generated from the light source is uniformly incident on the front surface of the liquid crystal panel.
특히, 상기 광학시트는 빛을 액정 패널 방향으로 집광하기 위해, 통상 삼각단면의 프리즘 패턴을 갖는 두 장의 광학시트를 구비하며, 이 두 장의 광학시트는 각각의 프리즘 패턴이 서로 교차되도록 상하 적층 된다. 이러한 적층 과정에서, 견고한 적층 구조를 유지하기 위해, 프리즘 패턴을 갖는 두 장의 광학시트 사이에는 접착층이 구비된다.In particular, the optical sheet includes two optical sheets having a prism pattern of a triangular cross section in order to focus light in the liquid crystal panel direction, and the two optical sheets are stacked up and down so that each prism pattern crosses each other. In this lamination process, in order to maintain a firm lamination structure, an adhesive layer is provided between two optical sheets having a prism pattern.
종래에, 접착층은 상부에 위치하는 프리즘 패턴 광학시트 하면의 전면에 형성되었다. 이와 같이, 종래의 접착층은, 프리즘 패턴을 갖는 두 장의 광학시트 사이의 전면에 구비되므로, 종래의 광학시트 구조물에서는 프리즘 패턴의 상단부 전체가 접착층에 침투함으로써 침윤(Wet-Out) 현상이 발생하여 모아레 무늬가 발생하고, 접착층에 의한 광경로 변경 및 휘도 감소 등과 같은 광학 특성이 저하되는 문제점이 발생하였다.Conventionally, the adhesive layer is formed on the entire surface of the lower surface of the prism pattern optical sheet located on the top. Thus, since the conventional adhesive layer is provided on the front surface between two optical sheets having a prism pattern, in the conventional optical sheet structure, the entire upper end portion of the prism pattern penetrates into the adhesive layer, so that a wet-out phenomenon occurs and moiré occurs. Patterns are generated, and optical characteristics such as optical path change and luminance decrease by the adhesive layer are deteriorated.
본 발명은, 통과하는 빛의 광학 특성 저하를 최소화하면서 광학시트간 접착력을 유지하여 일정 수준 이상의 견고함을 확보할 수 있는 광학시트 구조물을 제공하는 것을 해결하고자 하는 기술적 과제로 한다.The present invention is to solve the technical problem to provide an optical sheet structure that can secure a certain level or more by maintaining the adhesion between the optical sheets while minimizing the degradation of the optical properties of the light passing through.
상기 기술적 과제를 해결하기 위한 수단으로서, 본 발명은,As a means for solving the above technical problem, the present invention,
상단부의 높이가 상호 상이한 영역을 갖도록 광학 구조가 형성된 상면을 포함하는 제1 광학시트;A first optical sheet including an upper surface on which the optical structure is formed such that the heights of the upper end portions are different from each other;
상기 제1 광학시트 상면의 일부 영역에 형성된 접착층; 및An adhesive layer formed on a portion of an upper surface of the first optical sheet; And
상기 접착층 상에 배치되는 제2 광학시트A second optical sheet disposed on the adhesive layer
를 포함하는 광학시트 구조물을 제공한다.It provides an optical sheet structure comprising a.
본 발명의 일 실시형태에서, 상기 광학 구조는, 복수의 제1 광학 구조물 및 상기 제1 광학 구조물의 적어도 일부에 의해 분리되며, 상기 제1 광학 구조물의 높이보다 높은 높이를 갖는 복수의 제2 광학 구조물을 포함할 수 있다.In one embodiment of the present invention, the optical structure is separated by at least a portion of the first optical structure and the plurality of first optical structures, and the plurality of second optics having a height higher than the height of the first optical structure It may include a structure.
본 발명의 일 실시형태에서, 상기 복수의 제2 광학 구조물의 상단부들 사이의 거리는 일정하게 형성될 수 있다.In one embodiment of the present invention, the distance between the upper ends of the plurality of second optical structures can be formed constant.
본 발명의 일 실시형태에서, 상기 복수의 제2 광학 구조물은 상호 평행하게 선형으로 형성된 프리즘 구조로 형성될 수 있다.In one embodiment of the present invention, the plurality of second optical structures may be formed of a prism structure formed linearly parallel to each other.
본 발명의 일 실시형태에서, 상기 제1 광학시트는, 그 상면 상단부를 연결한 면이 엠보싱 형태를 가질 수 있다.In one embodiment of the present invention, the first optical sheet, the surface connecting the upper end of the upper surface may have an embossed form.
본 발명의 일 실시형태에서, 상기 제1 광학시트는, 평판 형상의 제1 굴절부 및 광학적 단면을 가지고 상호 소정의 간격을 두고 선형 배열되며, 상기 제1 굴절부의 일면에 형성되는 복수의 광학구조 패턴을 갖는 제2 굴절부를 포함할 수 있다. 이 실시형태에서, 상기 복수의 광학구조 패턴의 단부를 상호 연결한 곡선은 서로 다른 높이를 갖는 볼록부 또는 오목부를 갖도록 형성되며, 상기 복수의 광학구조 패턴 각각은 그 형성된 방향으로 그 단부가 서로 다른 높이를 갖는 볼록부 또는 오목부를 갖도록 형성될 수 있다.In one embodiment of the present invention, the first optical sheet is a plurality of optical structures formed on one surface of the first refraction portion is linearly arranged at a predetermined distance from each other having a flat plate-shaped first refraction portion and an optical cross section It may include a second refractive portion having a pattern. In this embodiment, the curves interconnecting the ends of the plurality of optical structure patterns are formed to have convex portions or concave portions having different heights, and each of the plurality of optical structure patterns has different ends in the formed direction thereof. It may be formed to have a convex portion or a concave portion having a height.
본 발명의 일 실시형태에서, 상기 광학구조 패턴은, 단면투영시 다각 형상 또는 부분원호 형상이거나, 상기 다각 형상과 부분원호 형상이 복합된 형상을 가질 수 있다.In one embodiment of the present invention, the optical structure pattern may be a polygonal shape or a partial arc shape in the cross-sectional projection, or may have a shape in which the polygonal shape and the partial arc shape is complex.
본 발명의 일 실시형태에서, 상기 복수의 광학구조 패턴의 단부를 상호 연결한 곡선이 형성하는 볼록부 또는 오목부, 또는 상기 복수의 광학구조 패턴 각각이 그 형성된 방향으로 형성하는 볼록부 또는 오목부는 등간격으로 형성되며, 상기 복수의 광학구조 패턴은 상호 등간격으로 형성될 수 있다.In one embodiment of the present invention, the convex portion or concave portion formed by the curve interconnecting the ends of the plurality of optical structure patterns, or the convex portion or concave portion formed in the direction in which each of the plurality of optical structure patterns are formed The plurality of optical structure patterns may be formed at equal intervals.
본 발명의 일 실시형태에서, 상기 복수의 광학구조 패턴의 단부를 상호 연결한 곡선이 형성하는 볼록부 또는 오목부, 또는 상기 복수의 광학구조 패턴 각각이 그 형성된 방향으로 형성하는 볼록부 또는 오목부는 상호 불규칙적인 간격으로 형성되며, 상기 복수의 광학구조 패턴은 상호 불규칙적인 간격으로 형성될 수 있다.In one embodiment of the present invention, the convex portion or concave portion formed by the curve interconnecting the ends of the plurality of optical structure patterns, or the convex portion or concave portion formed in the direction in which each of the plurality of optical structure patterns are formed The plurality of optical structure patterns may be formed at irregular intervals.
본 발명의 일 실시형태에서, 상기 접착층은, 상기 제1 광학시트 상면의 일부 영역에 도트 형상으로 형성될 수 있다.In one embodiment of the present invention, the adhesive layer may be formed in a dot shape on a portion of the upper surface of the first optical sheet.
본 발명의 일 실시형태에서, 상기 접착층은, 상기 제1 광학시트 상면의 일부 영역에 상호 평행한 복수의 띠 형상으로 형성될 수 있다.In one embodiment of the present invention, the adhesive layer may be formed in a plurality of bands parallel to each other on a portion of the upper surface of the first optical sheet.
본 발명의 일 실시형태에서, 상기 접착층은, 상기 제1 광학시트 상면의 일부 영역에 복수의 오픈 영역을 갖는 메쉬 형상으로 형성될 수 있다.In one embodiment of the present invention, the adhesive layer may be formed in a mesh shape having a plurality of open areas in a portion of the upper surface of the first optical sheet.
본 발명의 일 실시형태에서, 상기 접착층의 면적은 상기 제1 광학시트의 평면적의 5% 이상 65% 이하로 형성될 수 있다.In one embodiment of the present invention, the adhesive layer may have an area of 5% or more and 65% or less of the planar area of the first optical sheet.
본 발명에 따르면, 제1 광학시트의 구조화 표면에 형성된 광학 구조들이 서로 다른 높이를 갖는 영역을 형성하게 함으로써, 제1 광학시트의 구조화 표면에 직접 접촉되는 면적을 감소시켜 침윤현상을 줄이고 모아레 무늬 발생을 억제할 수 있다.According to the present invention, by allowing the optical structures formed on the structured surface of the first optical sheet to form regions having different heights, the area in direct contact with the structured surface of the first optical sheet is reduced to reduce infiltration and moire patterns are generated. Can be suppressed.
또한, 본 발명에 따르면, 구조화 표면을 갖는 제1 광학시트와 이 구조화 표면에 적층되는 제2 광학시트 사이의 접착력을 확보하기 위해 접합되는 면의 일부에만 접착층을 형성하여 부분 접합이 이루어지게 함으로써, 도광판과 광학시트 사이에 견고한 접합력을 확보함과 동시에 접착층의 적용에 따른 광학특성 변동을 최소화 할 수 있다. 특히, 전술한 침윤현상을 감소시켜 모아레 무늬 발생을 억제하는 효과를 더욱 증대시킬 수 있다.Further, according to the present invention, in order to secure the adhesive force between the first optical sheet having a structured surface and the second optical sheet laminated to the structured surface, an adhesive layer is formed only on a part of the surface to be bonded so that partial bonding is performed. While ensuring a firm bonding force between the light guide plate and the optical sheet, it is possible to minimize the optical characteristic variation due to the application of the adhesive layer. In particular, it is possible to further increase the effect of suppressing the moiré pattern by reducing the above-mentioned infiltration phenomenon.
또한, 본 발명에 따르면, 부분 접착에 의한 적절한 접합력을 제공함으로써, 초박형 광학시트를 적용하는 경우에 나타날 수 있는 휨현상, 변형 및 뒤틀림 등의 문제를 억제할 수 있다. 이를 통해, 더욱 얇은 두께의 광학시트를 사용 가능하게 함으로써 전체적인 백라이트 유닛의 두께를 감소시킬 수 있다.In addition, according to the present invention, by providing an appropriate bonding force by partial adhesion, it is possible to suppress problems such as warpage phenomenon, deformation and distortion that may appear when the ultra-thin optical sheet is applied. Through this, the thickness of the entire backlight unit can be reduced by enabling the use of a thinner optical sheet.
도 1은 본 발명의 일 실시형태에 따른 광학시트 구조물이 적용되는 액정 디스플레이의 분해 단면도이다.1 is an exploded cross-sectional view of a liquid crystal display to which an optical sheet structure according to an embodiment of the present invention is applied.
도 2 내지 도 14는 본 발명의 다양한 실시형태에 따른 제1 광학시트의 구조를 설명하기 위한 사시도 또는 단면도이다.2 to 14 are perspective views or cross-sectional views for describing the structure of the first optical sheet according to various embodiments of the present disclosure.
도 15는 본 발명의 일 실시형태에 따른 광학시트 구조물에 적용된 도트 형상의 접착층 및 광학시트를 도시한 도면이다.FIG. 15 is a view illustrating a dot-shaped adhesive layer and an optical sheet applied to an optical sheet structure according to an embodiment of the present invention.
도 16은 본 발명의 일 실시형태에 따른 광학시트 구조물에 적용된 복수의 띠 형상의 접착층 및 광학시트를 도시한 도면이다.16 is a view showing a plurality of band-shaped adhesive layers and optical sheets applied to the optical sheet structure according to the embodiment of the present invention.
도 17는 본 발명의 일 실시형태에 따른 면광원 장치에 적용된 메쉬 형상의 접착층 및 광학시트를 도시한 도면이다.17 is a view showing a mesh-shaped adhesive layer and an optical sheet applied to the surface light source device according to the embodiment of the present invention.
도 18은 본 발명의 다양한 실시형태에 따른 광학시트 구조물에서 접착층의 두께와 접착층이 전체 광학시트 구조물에서 차지하는 면적의 비를 변화시키면서 투과되는 빛의 휘도를 측정하여 도시한 그래프이다.FIG. 18 is a graph illustrating measurement of luminance of light transmitted while varying a ratio of the thickness of the adhesive layer and the area of the entire optical sheet structure in the optical sheet structure according to various embodiments of the present disclosure.
이하, 첨부된 도면을 참조하여 본 발명의 실시형태를 보다 상세하게 설명한다. 그러나, 본 발명의 실시형태는 여러 가지 다른 형태로 변형될 수 있으며, 본 발명의 범위가 이하 설명되는 실시형태로 한정되는 것은 아니다. 본 발명의 실시형태는 본 발명이 속하는 기술분야에서 통상의 지식을 가진 자에게 본 발명을 보다 완전하게 설명하기 위해서 제공되는 것이다. 또한, 본 발명을 설명함에 있어서, 정의되는 용어들은 본 발명에서의 기능을 고려하여 정의 내려진 것으로, 이는 당 분야에 종사하는 기술자의 의도 또는 관례 등에 따라 달라질 수 있으므로, 본 발명의 기술적 구성요소를 한정하는 의미로 이해되어서는 아니 될 것이다.Hereinafter, with reference to the accompanying drawings will be described in detail an embodiment of the present invention. However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. Embodiment of this invention is provided in order to demonstrate this invention more completely to the person skilled in the art to which this invention belongs. In addition, in the description of the present invention, terms defined are defined in consideration of functions in the present invention, which may vary according to the intention or convention of those skilled in the art, and thus limit the technical components of the present invention. It should not be understood as meaning.
도 1은 본 발명의 일 실시형태에 따른 광학시트 구조물이 적용되는 액정 디스플레이의 분해 단면도이다.1 is an exploded cross-sectional view of a liquid crystal display to which an optical sheet structure according to an embodiment of the present invention is applied.
도 1에 도시된 것과 같이, 본 발명의 일 실시형태에 따른 광학시트 구조물이 적용되는 액정 디스플레이는, 광원(111)과, 광원에서 발생하는 빛을 액정 디스플레이 패널(170) 방향으로 전달하는 도광판(110)과, 도광판(110)에서 전달된 빛을 확산시키는 광확산판(120)과, 집광을 위해 광학적인 구조화 표면을 갖는 제1 광학시트(130) 및 제2 광학시트(150)와, 두 개의 광학시트(130, 140) 사이에 개재되어 두 광학시트(130, 150) 간에 접착력을 제공하는 접착층(140)과, 제2 광학시트(150) 상에 배치되는 편광판(160) 및 편광판(160) 상에 배치되는 액정 디스플레이 패널(170)을 포함하여 구성될 수 있다.As shown in FIG. 1, a liquid crystal display to which an optical sheet structure according to an exemplary embodiment of the present invention is applied includes a light guide plate for transmitting a light source 111 and light generated from the light source toward the liquid crystal display panel 170. 110, a light diffusion plate 120 for diffusing light transmitted from the light guide plate 110, a first optical sheet 130 and a second optical sheet 150 having an optical structured surface for condensing, An adhesive layer 140 interposed between the two optical sheets 130 and 140 to provide an adhesive force between the two optical sheets 130 and 150, and a polarizer 160 and a polarizer 160 disposed on the second optical sheet 150. It may be configured to include a liquid crystal display panel 170 disposed on.
이와 같이, 액정 디스플레이에 제공되는 다양한 광학 시트들은 도광판(110)과 액정 디스플레이 패널(170) 사이에 적층 된다. 이 광학 시트의 적층 구조물은 목적하는 특별한 광학 성능을 얻을 수 있도록 최적화되며, 필요에 따라 추가적인 요소가 부가 또는 생략될 수 있다.As such, various optical sheets provided to the liquid crystal display are stacked between the light guide plate 110 and the liquid crystal display panel 170. The laminate structure of this optical sheet is optimized to achieve the desired special optical performance, and additional elements may be added or omitted as necessary.
특히, 본 발명은 전술한 액정 디스플레이에 적용되는 광학 시트들 사이에 접착층(140)을 개재하여, 둘 이상의 광학 시트를 번들링하여 패키지화한 적층된 광학시트 구조물에 관한 것이다.In particular, the present invention relates to a laminated optical sheet structure in which two or more optical sheets are bundled and packaged through an adhesive layer 140 between optical sheets applied to the liquid crystal display described above.
도 1에 도시된 것과 같이, 본 발명의 일 실시형태는 제1 광학시트(130)와, 접착층(140) 및 제2 광학시트(150)를 포함하여 구성될 수 있다. 본 발명의 일 실시형태에서, 제1 광학시트(130)와 제2 광학시트(150)는 복수의 접착층(140)에 의해 부분 접합될 수 있다. 본 발명에서 부분 접합 또는 부분 접착이란, 접착하고자 하는 표면의 전체 면에 접착제 또는 접착층이 고르게 분포하지 않고, 접착하고자 하는 표면의 일부 영역에만 접착층이 형성되어 접착층이 형성된 해당 부분에서만 접착이 이루어져 합지 되는 것을 의미한다.As shown in FIG. 1, an embodiment of the present invention may include a first optical sheet 130, an adhesive layer 140, and a second optical sheet 150. In one embodiment of the present invention, the first optical sheet 130 and the second optical sheet 150 may be partially bonded by a plurality of adhesive layers 140. In the present invention, the partial bonding or the partial bonding means that the adhesive layer or the adhesive layer is not evenly distributed on the entire surface of the surface to be bonded, and the adhesive layer is formed only on the corresponding region where the adhesive layer is formed by forming an adhesive layer only on a part of the surface to be bonded. Means that.
상기 제1 광학시트(130)는, 일면(도 1에서 상면에 해당하는 면)이 광학적인 구조화 표면으로 형성될 수 있다. 광학적인 구조화 표면이란 제1 광학시트(130)의 하면으로부터 입사되는 빛을 집광할 수 있도록 빛의 경로를 조정할 수 있는 광학적인 구조가 형성된 표면을 의미하는 것이다. 통상적인 액정 디스플레이에서, 도광판의 광출사면 상에 배치되는 제1 광학시트에는 일 방향으로 나란하게 동일한 형상으로 복수의 프리즘 구조가 채용된다. 이에 반해, 본 발명에서 제1 광학시트(130)의 구조화 표면은, 단부의 높이가 상호 상이한 영역을 갖는 광학 구조가 형성된다. 이러한 단부의 높이 차에 의해, 광학 구조의 단부가 접합층(140)에 침투하는 영역의 크기를 감소시켜 침윤현상을 감소시킬 수 있다.The first optical sheet 130 may have one surface (the surface corresponding to the upper surface in FIG. 1) as an optical structured surface. The optical structured surface refers to a surface on which an optical structure capable of adjusting light paths to collect light incident from a lower surface of the first optical sheet 130 is formed. In a conventional liquid crystal display, a plurality of prism structures are adopted in the first optical sheet disposed on the light exit surface of the light guide plate in the same shape side by side in one direction. In contrast, in the present invention, the structured surface of the first optical sheet 130 is formed with an optical structure having regions where the ends have different heights. Due to the height difference between the ends, the infiltration phenomenon may be reduced by reducing the size of the region where the ends of the optical structure penetrate the bonding layer 140.
도 2 내지 도 14는 본 발명의 다양한 실시형태에 따른 제1 광학시트의 구조를 설명하기 위한 도면이다. 도 2 및 도 3은, 제1 광학시트에 형성된 광학구조물 자체의 높이가 서로 다른 예를 도시하며, 도 4 내지 도 14는 제1 광학시트에 형성된 광학구조물의 상단부를 연결한 면이 볼록부 또는 오목부의 굴곡을 갖는 엠보싱 형태로 형성된 예를 도시한다. 상기 상단부를 연결한 면은 가상의 면으로 이하에서 설명되는 다양한 실시형태에 동일하게 적용된다.2 to 14 are views for explaining the structure of the first optical sheet according to various embodiments of the present invention. 2 and 3 illustrate an example in which the heights of the optical structures themselves formed on the first optical sheet are different from each other, and FIGS. 4 to 14 show convex portions formed by connecting upper ends of the optical structures formed on the first optical sheet. The example formed in the embossed form which has curvature of a recessed part is shown. The surface connecting the upper end is a virtual surface, and the same applies to various embodiments described below.
먼저, 도 2 및 도 3을 참조하면, 본 발명의 일 실시형태에 따른 제1 광학시트(131)는, 서로 다른 높이를 갖는 2 종의 광학 구조물(231, 232)이 제1 광학시트(131)의 구조화 표면에 형성될 수 있다.First, referring to FIGS. 2 and 3, in the first optical sheet 131 according to an embodiment of the present invention, two types of optical structures 231 and 232 having different heights may be used as the first optical sheet 131. ) On the structured surface.
제1 광학 구조물(231)은 제2 광학 구조물(232)보다 낮은 높이를 갖는 광학 구조이다. 제2 광학 구조물(232)는 제1 광학 구조물(231)보다 높은 높이를 가지며, 제1 광학 구조물(231)에 의해 분리 배치될 수 있다. 즉, 제2 광학 구조물들(231) 사이에 소정 개수의 제1 광학 구조물(231)이 배치될 수 있다. The first optical structure 231 is an optical structure having a lower height than the second optical structure 232. The second optical structure 232 has a height higher than that of the first optical structure 231, and may be separately disposed by the first optical structure 231. That is, a predetermined number of first optical structures 231 may be disposed between the second optical structures 231.
상기 제2 광학 구조물(232)들은 그 상단부들 사이의 거리가 일정하게 배치될 수 있다. 또한, 상기 제2 광학 구조물(232)은 상호 평행하게 선형으로 형성된 프리즘 구조로 형성되는 것이 바람직하다. The second optical structures 232 may have a constant distance between the upper ends thereof. In addition, the second optical structure 232 is preferably formed of a prism structure formed in parallel to each other.
이와 같이, 제1 광학 구조물(231)과 제2 광학 구조물(232)의 높이 차로 인해,광학시트 구조물을 형상함에 있어, 상기 제2 광학 구조물(232)은 접착층(140)에 침투하여 제2 광학시트(150)와의 접합을 형성하고, 접착층(140) 또는 제2 광학시트(150)와 제1 광학 구조물(231) 사이에는 간극이 존재할 수 있다. 본 발명의 일 실시형태는, 제1 광학시트(130)와 제2 광학시트(150) 사이의 접촉영역 또는 제1 광학시트(130)와 접착층(140) 사이의 접촉영역을 감소시켜 침윤 현상을 감소시킬 수 있다. 특히, 이후에 설명되는, 부분 접합이 가능하도록 형성된 접착층(140)에 의해 침윤 현상을 감소시키는 효과가 더욱 증대될 수 있다.As such, due to the height difference between the first optical structure 231 and the second optical structure 232, in forming the optical sheet structure, the second optical structure 232 penetrates into the adhesive layer 140 to form a second optical structure. A junction may be formed with the sheet 150, and a gap may exist between the adhesive layer 140 or the second optical sheet 150 and the first optical structure 231. In one embodiment of the present invention, the contact area between the first optical sheet 130 and the second optical sheet 150 or the contact area between the first optical sheet 130 and the adhesive layer 140 is reduced to prevent infiltration. Can be reduced. In particular, the effect of reducing the infiltration phenomenon by the adhesive layer 140 formed to enable partial bonding, which will be described later, may be further increased.
전술한 도 2 및 도 3의 설명에서, 제1 광학시트(130) 상에 접착층(140)을 개재하여 접합되는 제2 광학시트(150)는 통상 제1 광학시트(130)에 형성된 광학구조와 교차하는 방향으로 형성된 광학구조를 갖는 광학시트가 채용되는 것으로 설명되고 있으나, 본 발명은 이에 한정되지 않는다. 상기 제2 광학시트(150)는 광학 특성의 구현을 위해 제1 광학시트(130)의 구조화 표면 상에 배치되는 모든 종류의 광학시트(예를 들어, 편광시트 또는 확산시트) 또는 광학구조물이 이에 해당할 수 있다.In the above description of FIGS. 2 and 3, the second optical sheet 150 bonded to the first optical sheet 130 via the adhesive layer 140 may be formed of an optical structure formed on the first optical sheet 130. Although it has been described that an optical sheet having an optical structure formed in an intersecting direction is employed, the present invention is not limited thereto. The second optical sheet 150 may be any type of optical sheet (for example, a polarizing sheet or a diffusion sheet) or an optical structure disposed on the structured surface of the first optical sheet 130 to realize optical characteristics. This may be the case.
다음으로, 도 4 내지 도 14는, 상면 상단부를 연결한 면이 엠보싱 형태를 갖는 제1 광학시트(122)의 다양한 실시형태들을 도시한다. 이 실시형태에서, 제1 광학시트(122)는, 제1 굴절부(310)와 이 제1 굴절부(310) 상에 형성된 광학구조 패턴을 갖는 제2 굴절부(320)를 포함할 수 있다. 특히, 도 4, 도 6, 도 7, 도 8, 도 10 및 도 11에 도시된 사시도에서 점선으로 표시된 부분은 볼록 또는 오목하게 형성된 엠보싱 표면을 나타낸다.Next, FIGS. 4 to 14 show various embodiments of the first optical sheet 122 in which the surface connecting the upper end portion has an embossed shape. In this embodiment, the first optical sheet 122 may include a first refraction portion 310 and a second refraction portion 320 having an optical structure pattern formed on the first refraction portion 310. . In particular, in the perspective views shown in FIGS. 4, 6, 7, 8, 10 and 11, the portions indicated by the dotted lines represent convex or concave embossed surfaces.
도 4는 본 발명의 일 실시형태에 따른 제1 광학시트의 사시도이고, 도 5는 도 4에 도시된 제1 광학시트 단면도이다.4 is a perspective view of a first optical sheet according to an embodiment of the present invention, and FIG. 5 is a cross-sectional view of the first optical sheet shown in FIG. 4.
도 4 및 도 5에 도시된 바와 같이, 본 발명의 일 실시형태에 따른 제1 광학시트(132)은 평판 형상의 제1 굴절부(310)와, 상기 제1 굴절부(310)를 투과한 빛을 집광하여 수직방향으로 출사하는 복수의 광학구조 패턴(321)을 갖는 제2 굴절부(320)를 포함할 수 있다.As shown in FIGS. 4 and 5, the first optical sheet 132 according to the embodiment of the present invention transmits the first refraction portion 310 and the first refraction portion 310 having a flat plate shape. It may include a second refracting portion 320 having a plurality of optical structure patterns 321 for condensing the light emitted in the vertical direction.
상기 제1 굴절부(310)는 투광성을 갖는 필름의 형태로 제공되며, 그 상면에 제2 굴절부(320)를 접합하기 위한 기체가 될 수 있다.The first refraction unit 310 may be provided in the form of a light transmitting film, and may be a substrate for bonding the second refraction unit 320 to an upper surface thereof.
상기 제2 굴절부(320)의 광학구조 패턴(321)들은 단면 투영시 삼각형상의 광학적 단면을 갖는 프리즘 패턴으로서, 상호 소정의 간격을 두고 선형 배열될 수 있다. 이때, 광학구조 패턴(321)들은 상호 높은 피크와 낮은 피크를 갖는 굴곡진 형태를 가질 수 있다. 다시 설명하면, 상기 복수의 광학구조 패턴(321)의 단부를 상호 연결한 곡선은 서로 다른 높이를 갖는 볼록부 또는 오목부를 갖도록 형성된다. 또한, 상기 복수의 광학구조 패턴 각각은 그 형성된 방향으로 단부가 서로 다른 높이를 갖는 볼록부 또는 오목부를 갖도록 형성된다. 상기 볼록부 또는 오목부는 서로 이격되어 엠보싱 형태로 형성될 수 있다. 도 4 및 도 5의 실시형태는, 복수의 광학구조 패턴(321)의 단부를 상호 연결한 곡선이, 일정 간격으로 형성된 원호 형상의 볼록부를 포함하는 예이다. 마찬가지로, 상기 복수의 광학구조 패턴 각각이, 그 형성된 방향으로 일정 간격 형성된 원호 형상의 볼록부를 포함하는 예이다.The optical structure patterns 321 of the second refraction unit 320 are prismatic patterns having a triangular optical cross section in cross-sectional projection, and may be linearly arranged at predetermined intervals. In this case, the optical structure patterns 321 may have a curved shape having a high peak and a low peak. In other words, the curves connecting the ends of the plurality of optical structure patterns 321 are formed to have convex portions or concave portions having different heights. In addition, each of the plurality of optical structure patterns is formed to have convex portions or concave portions having end portions different in height in the formed direction thereof. The convex portions or the concave portions may be spaced apart from each other to form an embossed shape. 4 and 5 are examples where the curve which interconnected the edge part of several optical structure pattern 321 includes the arc-shaped convex part formed in fixed space | interval. Similarly, each of the plurality of optical structural patterns is an example including an arc-shaped convex part formed at regular intervals in the formed direction thereof.
이와 같은, 광학구조 패턴(321)들의 높이 차이로 인해, 광학구조 패턴(321)의 상단부가 형성하는 면은 엠보싱 형태로 구현될 수 있다. 높이 차이를 갖는 엠보싱 형태의 상면에 의해, 접착층(140) 또는 제2 광학시트(150)와의 접합 시, 제1 광학 구조물(231)과 간극을 형성할 수 있다. 이를 통해, 제1 광학시트(132)와 제2 광학시트(150) 사이의 접촉영역 또는 제1 광학시트(132)와 접착층(140) 사이의 접촉영역을 감소시켜 침윤 현상을 감소시킬 수 있다. 특히, 이후에 설명되는, 부분 접합이 가능하도록 형성된 접착층(140)에 의해 침윤 현상을 감소시키는 효과가 더욱 증대될 수 있다.As such, due to the height difference between the optical structure patterns 321, the surface formed at the upper end of the optical structure pattern 321 may be embossed. The upper surface of the embossed shape having a height difference may form a gap with the first optical structure 231 when bonding the adhesive layer 140 or the second optical sheet 150. Through this, infiltration may be reduced by reducing the contact area between the first optical sheet 132 and the second optical sheet 150 or the contact area between the first optical sheet 132 and the adhesive layer 140. In particular, the effect of reducing the infiltration phenomenon by the adhesive layer 140 formed to enable partial bonding, which will be described later, may be further increased.
상기 제1 굴절부(310)와 제2 굴절부(320)는 가시광역에서 빛을 원활하게 투과할 수 있는 광투과성 재료로서 폴리카보네이트, PVC, PP, PE, PET, 아크릴계 폴리머 중 어느 하나를 이용하여 상호 일체를 이루는 단일층으로 성형할 있다. 물론, 여건에 따라서 제1 굴절부(310)와 제2 굴절부(320)를 전술한 재료 중 동일한 재료 또는 상이한 재료를 이용하여 각각 성형한 후 상호 접하도록 결합되는 다층구조로 제작할 수도 있다.The first refraction unit 310 and the second refraction unit 320 are any one of polycarbonate, PVC, PP, PE, PET, and acrylic polymers as a light transmissive material that can transmit light smoothly in the visible region. It can be molded into a single layer to form a unity with each other. Of course, depending on the conditions, the first refraction unit 310 and the second refraction unit 320 may be manufactured in a multi-layer structure that is bonded to each other after molding using the same material or different materials among the above-described materials.
한편, 본 발명의 일 실시형태에 따른 광학시트(132)는, 도 6 및 도 7에 도시된 바와 같이, 제2 굴절부(320)의 광학구조 패턴들(321)의 단부를 상호 연결한 곡선, 또는 하나의 광학구조 패턴 자체가 갖는 단부의 형상이, 타원, 또는 다각형상의 상향 돌출된 볼록부를 포함하는 형상으로 이 볼록부는 상호 이격된 엠보싱 형태로 형성될 수도 있다. 이를 통해, 광학구조 패턴들(321)의 단부에 의해 형성되는 면은 다양한 형상의 볼록부를 갖는 엠보싱 형태의 패턴을 갖도록 형성될 수 있다.On the other hand, the optical sheet 132 according to an embodiment of the present invention, as shown in Figure 6 and 7, the curve connecting the ends of the optical structure patterns 321 of the second refractive portion 320 The shape of the end portion of the optical structure pattern itself may include an ellipse or a polygonal upwardly projecting convex portion, and the convex portions may be formed in the form of embossed spaces. Through this, the surface formed by the ends of the optical structure patterns 321 may be formed to have an embossed pattern having convex portions of various shapes.
또한, 도 8 내지 도 11에 도시된 바와 같이, 제2 굴절부(320)의 광학구조 패턴들(321)의 단부를 상호 연결한 곡선, 또는 하나의 광학구조 패턴 자체가 갖는 단부의 형상이 원, 타원, 다각형상을 가지고 단면 하향 함몰된 오목부를 포함하는 형상으로, 이 오목부는 상호 이격된 엠보싱 형태로 형성될 수도 있다. 이와 같이, 본 발명의 일 실시형태에 따른 광학시트(132)에 의해 형성되는 면은 오목한 형태의 패턴이 반복되는 엠보싱 형태로 구현될 수도 있다.In addition, as shown in FIGS. 8 to 11, a curved line connecting the ends of the optical structure patterns 321 of the second refraction unit 320, or the shape of the end portion of one optical structure pattern itself is circular. The concave portion may have an ellipse, a polygonal shape, and have a concave portion recessed downward in cross section, and the concave portions may be formed in an embossed form spaced apart from each other. As such, the surface formed by the optical sheet 132 according to the embodiment of the present invention may be implemented in an embossed form in which a concave pattern is repeated.
그리고, 광학구조 패턴(321)은 삼각형상의 광학적 단면 외에 도 12에 도시된 바와 같이, 부분 원호 형상의 광학적 단면을 갖도록 형성될 수도 있으며, 도 13에 도시된 바와 같이, 부분 원호 형상의 광학적 단면과, 삼각 형상의 광학적 단면이 복합된 형상으로 형성될 수도 있다.The optical structure pattern 321 may be formed to have an optical cross section of a partial arc shape as shown in FIG. 12 in addition to the optical cross section of a triangular shape, and as shown in FIG. The optical cross section of the triangular shape may be formed into a complex shape.
또한, 제2 굴절부(320)의 광학구조 패턴들(321)의 단부를 상호 연결한 곡선(c), 또는 하나의 광학구조 패턴 자체가 갖는 단부의 형상은, 도 14에 도시된 바와 같이, 상호 불규칙적인 간격으로 볼록 또는 오목부로 형성되고, 광학구조 패턴(321) 간의 간격이 상호 규칙적으로 형성될 수도 있다. 물론, 제2 굴절부(320)의 광학구조 패턴들(321)의 단부를 상호 연결한 곡선, 또는 하나의 광학구조 패턴 자체가 갖는 단부의 형상과 광학구조 패턴 중 적어도 어느 하나 또는 모두가 상호 불규칙적으로 형성될 수도 있다.In addition, the shape of the curve (c) connecting the ends of the optical structure patterns 321 of the second refraction portion 320, or the end of one optical structure pattern itself, as shown in FIG. The convex or concave portions may be formed at irregular intervals, and the intervals between the optical structure patterns 321 may be regularly formed. Of course, at least one or both of a curved line connecting the ends of the optical structure patterns 321 of the second refraction unit 320 or the shape of the end of the optical structure pattern itself and the optical structure pattern are mutually irregular. It may be formed as.
이러한 구조를 갖는 본 발명의 일 실시형태에 따른 제1 광학시트(132)는 제2 굴정부(320)의 상부에 배치되는 액정 패널(도 1의 170)의 전 영역에서 휘도를 증가시킴으로써, 넓은 시야각에서 고휘도를 발휘할 수 있다.The first optical sheet 132 according to the embodiment of the present invention having such a structure increases the luminance in the entire area of the liquid crystal panel (170 of FIG. 1) disposed on the upper part of the second mandrel 320, thereby increasing the luminance. High brightness can be achieved at the viewing angle.
또한, 광학구조 패턴(321)이 서로 다른 높이의 단부를 갖는 구조를 이루고 있기 때문에, 제1 광학시트(130)에 직접 접촉하는 타 광학시트와의 영역 크기를 감소시킬 수 있다. 이에 의해, 침윤(Wet-Out)현상이 최소화되어 모아레 무늬의 발생을 억제할 수 있다.In addition, since the optical structure pattern 321 has a structure having end portions having different heights, it is possible to reduce the size of the area with other optical sheets in direct contact with the first optical sheet 130. As a result, the wet-out phenomenon can be minimized to suppress the generation of moire fringes.
상기 접착층(140)은, 제1 광학시트(130)와 제2 광학시트(150)의 결합에 접착력을 제공하기 위해 마련된 것으로서, 상기 접착층(140)은 제1 광학시트(110)의 구조화 표면과 그에 대응하는 제2 광학시트(150)의 일면 사이에 개재될 수 있다. The adhesive layer 140 is provided to provide an adhesive force to the bonding of the first optical sheet 130 and the second optical sheet 150, and the adhesive layer 140 is formed on the structured surface of the first optical sheet 110. It may be interposed between one surface of the second optical sheet 150 corresponding thereto.
상기 접착층(140)은, PVA 수지 필름의 라미네이션을 위하여 사용되는 자외선 또는 가시광 경화성 아크릴계 접착제 또는 2액 경화형 접착제 등을 그 재료로 사용할 수 있으나, 광학시트의 라미네이션 접착제인 한 특별히 한정되지는 않는다.The adhesive layer 140 may be an ultraviolet or visible light curable acrylic adhesive or a two-component curable adhesive used for the lamination of the PVA resin film as the material, but is not particularly limited as long as it is the lamination adhesive of the optical sheet.
도 15 내지 도 17은 부분 접합을 위해 형성되는 접착층의 다양한 실시형태를 도시한 도면이다.15 to 17 show various embodiments of an adhesive layer formed for partial bonding.
먼저, 도 15는 본 발명의 일 실시형태에 따른 광학시트 구조물에 적용된 도트 형상의 접착층 및 광학시트를 도시한 도면이다.First, FIG. 15 illustrates a dot-shaped adhesive layer and an optical sheet applied to an optical sheet structure according to an embodiment of the present invention.
도 15에 도시된 것과 같이, 도트 형상의 접착층(141)은 접촉이 이루어지는 제1광학시트(130)의 구조화 표면에 분산되어 형성됨으로써 부분 접착이 이루어지게 할 수 있다. 상기 도트 형상의 접착층(141)이 제1 광학시트(130)의 구조화 표면의 전체 면에서 차지하는 면적의 비율이나 그 두께는, 제1 광학시트(130)의 구조화 표면의 반대 면에서 출사되는 광의 휘도나 품질에 따라 적절하게 조정될 수 있다.As illustrated in FIG. 15, the dot-shaped adhesive layer 141 may be formed by being dispersed and formed on the structured surface of the first optical sheet 130 where contact is made. The ratio of the area of the dot-shaped adhesive layer 141 to the entire surface of the structured surface of the first optical sheet 130 and the thickness thereof are the luminance of light emitted from the opposite surface of the structured surface of the first optical sheet 130. It may be adjusted accordingly depending on the quality.
다음으로, 도 16은 본 발명의 일 실시형태에 따른 면광원 장치에 적용된 복수의 띠 형상의 접착층 및 광학시트를 도시한 도면이다.Next, FIG. 16 is a view showing a plurality of strip-shaped adhesive layers and optical sheets applied to the surface light source device according to the embodiment of the present invention.
도 16에 도시한 바와 같이, 본 발명의 일 실시형태는 제1 광학시트(130)의 구조화 표면 상에 배치되는 띠 형상을 갖는 복수의 접착층(142)을 갖는다. 상기 복수의 접착층(142)은 제2 광학시트(150)와 제1 광학시트(130)를 서로 부분 접합하여 견고한 결합력을 제공한다.As shown in FIG. 16, one embodiment of the present invention has a plurality of adhesive layers 142 having a band shape disposed on the structured surface of the first optical sheet 130. The plurality of adhesive layers 142 partially bond the second optical sheet 150 and the first optical sheet 130 to each other to provide a firm bonding force.
이 실시형태에서, 띠 형상을 갖는 복수의 접착층(142)은, 부분 접합이 이루어질 수 있도록 서로 일정 간격으로 평행하게 배치된 복수의 띠 형상을 갖도록 구현될 수 있다. 특히, 상기 복수의 접착층(142)은 광학시트(130)의 구조화 표면, 즉 선형의 프리즘 패턴(예를 들어, 도 2의 231, 232) 또는 광학구조 패턴(예를 들어, 도 4의 321)이 형성된 방향과 동일한 방향으로 연장 형성된 띠 형상을 가질 수 있다. In this embodiment, the plurality of adhesive layers 142 having a band shape may be implemented to have a plurality of band shapes arranged parallel to each other at a predetermined interval so that partial bonding may be performed. In particular, the plurality of adhesive layers 142 may include a structured surface of the optical sheet 130, that is, a linear prism pattern (eg, 231 and 232 of FIG. 2) or an optical structure pattern (eg, 321 of FIG. 4). It may have a band shape formed extending in the same direction as the formed direction.
다음으로, 도 17은 본 발명의 일 실시형태에 따른 면광원 장치에 적용된 메쉬 형상의 접착층 및 광학시트를 도시한 도면이다.Next, FIG. 17 is a view showing a mesh-shaped adhesive layer and an optical sheet applied to the surface light source device according to the embodiment of the present invention.
도 17에 도시한 바와 같이, 본 발명의 일 실시형태는 광학시트(130)의 구조화 표면 상에 배치되는 메쉬 형상의 접착층(143)을 갖는다. 상기 메쉬 형상의 접착층(143)은 제2 광학시트(150)와 제1 광학시트(130)의 사이에 배치되며, 제2 광학시트(150)와 제1 광학시트(130)의 전면이 접합되지 않도록 오픈 영역(s)을 갖는 메쉬 형태로 제공되어 제2 광학시트(150)와 제1 광학시트(130)를 부분적으로 접합한다.As shown in FIG. 17, one embodiment of the present invention has a mesh-shaped adhesive layer 143 disposed on the structured surface of the optical sheet 130. The mesh adhesive layer 143 is disposed between the second optical sheet 150 and the first optical sheet 130, and the front surface of the second optical sheet 150 and the first optical sheet 130 are not bonded to each other. Is provided in the form of a mesh having an open area (s) so as to partially bond the second optical sheet 150 and the first optical sheet 130.
상기 메쉬 형태의 접착층(142)은, 상호 평행하게 배치되는 복수의 띠들이 상호 교차하는 형태로 형성될 수 있다. 이 복수의 띠 형상이 상호 교차되는 구조에서 일 방향으로 평행하게 배치된 두 개의 띠 형상과 그에 교차하는 방향으로 평행하게 배치된 두 개의 띠 형상에 의해 오픈 영역(s)이 형성될 수 있다.The mesh adhesive layer 142 may be formed in such a manner that a plurality of bands arranged in parallel to each other cross each other. The open region s may be formed by two band shapes arranged in parallel in one direction and two band shapes arranged in parallel in a direction crossing the plurality of band shapes.
특히, 본 발명의 일 실시형태에서는, 메쉬 형태의 접착층(142)을 구성하는 복수의 띠 형상들이 형성된 방향을, 광학시트(130)의 구조화 표면에 형성된 광학구조물의 형성 방향, 즉 선형의 프리즘 패턴(예를 들어, 도 2의 231, 232) 또는 광학구조 패턴(예를 들어, 도 4의 321)이 형성된 방향과 동일하지 않도록 형성할 수 있다.Particularly, in one embodiment of the present invention, the direction in which the plurality of band shapes constituting the adhesive layer 142 in the mesh form is formed in the direction in which the optical structure formed on the structured surface of the optical sheet 130, that is, the linear prism pattern For example, 231 and 232 of FIG. 2 or an optical structure pattern (for example, 321 of FIG. 4) may be formed so as not to be the same as the formed direction.
전술한 것과 같은 다양한 구조를 갖는 광학시트 구조물에서, 접착층의 두께와 면적은 광학시트 구조물을 통과하는 빛의 휘도와 밀접한 관계를 갖는다. 도 18은 두 장의 프리즘 시트를 접합하되 접착층의 두께와 접착층이 전체 광학시트 구조물에서 차지하는 면적의 비를 변화시키면서 투과되는 빛의 휘도를 측정하여 도시한 그래프이다. 도 18에 도시된 그래프에서, 기준 휘도는 접착층을 적용하지 않은 두 장의 프리즘 시트를 투과한 휘도를 나타낸다. 도 18에 도시된 그래프는 전술한 도트 형상의 부분 접착층, 띠 형상의 부분 접착층 및 매쉬 형상의 부분 접착층에 공통적으로 측정된 것이다.In an optical sheet structure having various structures as described above, the thickness and area of the adhesive layer have a close relationship with the luminance of light passing through the optical sheet structure. FIG. 18 is a graph illustrating bonding two prism sheets and measuring luminance of light transmitted while varying the ratio of the thickness of the adhesive layer and the area of the entire optical sheet structure. In the graph shown in FIG. 18, the reference luminance represents the luminance transmitted through two prism sheets without applying the adhesive layer. The graph shown in FIG. 18 is commonly measured for the above-mentioned dot-shaped partial adhesive layer, strip-shaped partial adhesive layer, and mesh-shaped partial adhesive layer.
도 18에 나타난 바와 같이, 접착층의 두께가 두꺼워질수록 휘도가 감소하는 것을 관찰할 수 있다. 또한, 접착층의 총 면적이 전체 광학시트 구조물에서 차지하는 면적의 65% 이하가 되는 경우 두께 증가에 따른 휘도 저하 현상이 현저히 둔화되는 것을 확인할 수 있다. 한편, 다양한 형태의 접착층이 적절한 접착력을 제공하기 위해서는 전체 접합면적의 5 % 이상 형성되는 것이 바람직하다. 접착층의 면적이 접합면적의 5 % 미만이 되는 경우에는, 가벼운 외력이 발생하는 경우 접착 상태가 파손될 위험도가 높아진다.As shown in FIG. 18, it can be observed that the luminance decreases as the thickness of the adhesive layer increases. In addition, when the total area of the adhesive layer is less than 65% of the area occupied by the entire optical sheet structure, it can be seen that the decrease in brightness due to the increase in thickness is significantly slowed down. On the other hand, it is preferable that at least 5% of the total bonding area is formed in order for the various types of adhesive layers to provide appropriate adhesion. If the area of the adhesive layer is less than 5% of the bonding area, the risk of breakage of the adhesive state is increased when a light external force is generated.
따라서, 접착층에 의한 휘도 저하 현상과 적절한 접합력을 제공할 수 있도록, 상기 접착층의 면적은 도광판과 광학시트가 접합되는 영역의 면적, 즉 광학시트의 평면적의 5 % 이상 65 % 이하인 것이 바람직하다.Therefore, the area of the adhesive layer is preferably 5% or more and 65% or less of the area of the area where the light guide plate and the optical sheet are bonded, that is, the planar area of the optical sheet, so as to provide a deterioration phenomenon due to the adhesive layer and an appropriate bonding force.
한편, 접착층을 적용하는 경우, 광학시트 구조물의 광 투과시 육안으로 관찰하였을 때, 주변보다 어둡게 나타나는 영역이 발생하는 쉐이딩 현상이 발생할 수 있다. 이러한 쉐이딩 현상은 디스플레이 시스템의 전체 영역에 균일한 빛을 제공하지 못하게 하므로 바람직하지 않다. 이러한 쉐이딩 현상은 주로 부분 접합을 형성하는 도트 형상 또는 띠 형상의 폭과 제1 광학시트의 프리즘 패턴 피치에 의존한다. 하기 표 1은 도트 형상의 접착층을 적용한 경우, 도트의 직경과 제1 광학시트의 프리즘 피치를 변화시키면서 투과되는 빛을 육안으로 관찰하여, 쉐이딩 현상이 관찰되는 경우를 O 표, 쉐이딩 현상이 관찰되지 않는 경우를 X 표로 나타낸 결과이다. 또한, 표 2 및 표 3은 각각 띠형상 및 매쉬형상의 접착층에서 접착층의 폭과 제1 광학시트의 프리즘 피치를 변화시키면서 투과되는 빛을 육안 관찰하여, 쉐이딩 현상이 관찰되는 경우를 O 표, 쉐이딩 현상이 관찰되지 않는 경우를 X 표로 나타낸 결과이다.On the other hand, in the case of applying the adhesive layer, when observed with the naked eye during the light transmission of the optical sheet structure, a shading phenomenon may occur that occurs a region appearing darker than the surroundings. This shading phenomenon is undesirable because it prevents providing uniform light over the entire area of the display system. This shading phenomenon mainly depends on the width of the dot or strip shape forming the partial junction and the prism pattern pitch of the first optical sheet. Table 1 shows a case where the light transmitted while changing the diameter of the dot and the prism pitch of the first optical sheet is visually observed when the dot-shaped adhesive layer is applied, and the shading phenomenon is not observed. If not, the result is indicated by an X table. Tables 2 and 3 show O tables and shadings in which the transmitted light is visually observed while varying the width of the adhesive layer and the prism pitch of the first optical sheet in the band-shaped and mesh-shaped adhesive layers, respectively. It is the result which showed with the X table | surface that a phenomenon is not observed.
표 1
피치＼직경 20 ㎛ 50 ㎛ 100 ㎛ 150 ㎛ 200 ㎛ 300 ㎛ 500 ㎛ 700 ㎛ 800 ㎛
15 ㎛ X X X O O O O O O
21 ㎛ X X X X X O O O O
25 ㎛ X X X X X O O O O
30 ㎛ X X X X X O O O O
40 ㎛ X X X X X X O O O
50 ㎛ X X X X X X O O O
80 ㎛ X X X X X X X X O
Table 1
Pitch ＼ Diameter 20 μm 50 μm 100 μm 150 μm 200 μm 300 μm 500 μm 700 μm 800 μm
15 μm X X X O O O O O O
21 μm X X X X X O O O O
25 μm X X X X X O O O O
30 μm X X X X X O O O O
40 μm X X X X X X O O O
50 μm X X X X X X O O O
80 μm X X X X X X X X O
표 2
피치＼폭 16 ㎛ 50 ㎛ 70 ㎛ 100 ㎛ 120 ㎛ 150 ㎛ 200 ㎛
10 ㎛ X X X O O O O
15 ㎛ X X X X X O O
20 ㎛ X X X X X X O
25 ㎛ X X X X X X X
40 ㎛ X X X X X X X
60 ㎛ X X X X X X X
80 ㎛ X X X X X X X
TABLE 2
Pitch width 16 μm 50 μm 70 μm 100 μm 120 μm 150 μm 200 μm
10 μm X X X O O O O
15 μm X X X X X O O
20 μm X X X X X X O
25 μm X X X X X X X
40 μm X X X X X X X
60 μm X X X X X X X
80 μm X X X X X X X
표 3
피치＼폭 16 ㎛ 50 ㎛ 70 ㎛ 100 ㎛ 120 ㎛ 150 ㎛ 200 ㎛
10 ㎛ X X X O O O O
15 ㎛ X X X X X O O
20 ㎛ X X X X X X O
25 ㎛ X X X X X X X
40 ㎛ X X X X X X X
60 ㎛ X X X X X X X
80 ㎛ X X X X X X X
TABLE 3
Pitch width 16 μm 50 μm 70 μm 100 μm 120 μm 150 μm 200 μm
10 μm X X X O O O O
15 μm X X X X X O O
20 μm X X X X X X O
25 μm X X X X X X X
40 μm X X X X X X X
60 μm X X X X X X X
80 μm X X X X X X X
도트 형상의 접착층을 갖는 실시형태의 실험 결과를 나타낸 상기 표 1에 따르면, 프리즘 피치가 작을수록 접착제 도트 크기도 작게 형성하여야 쉐이딩 현상이 발생하지 않는 것을 알 수 있다. 이를 접착층의 직경과 프리즘 피치의 비로써 표현하면, 접착층의 폭이 프리즘 패턴의 피치보다 대략 10배 이상 넓은 경우 쉐이딩 현상이 나타나는 것이 확인되었다. 상기 표 1에서, 쉐이딩 현상과 관련하여 접착층의 도트 직경이 갖는 하한에 대해서는 특정한 값으로 한정되지 않으나, 접착층의 도트 직경이 프리즘 피치 보다 작은 경우, 프리즘 구조의 두 피크 사이에 도트 형상의 접착층이 위치하여 프리즘 구조의 피크 부분에 접착층이 접촉하지 됨으로써 접착력이 저하될 수 있다는 점을 감안하여, 접착층 도트 직경은 프리즘 피치보다 크게 형성되는 것이 바람직하다.According to the above Table 1 showing the experimental results of the embodiment having a dot-shaped adhesive layer, it can be seen that the smaller the prism pitch, the smaller the adhesive dot size is to form the shading phenomenon. Expressing this as the ratio of the diameter of the adhesive layer to the prism pitch, it was confirmed that the shading phenomenon appeared when the width of the adhesive layer was approximately 10 times or more wider than the pitch of the prism pattern. In Table 1, the lower limit of the dot diameter of the adhesive layer in relation to the shading phenomenon is not limited to a specific value. However, when the dot diameter of the adhesive layer is smaller than the prism pitch, the dot-shaped adhesive layer is positioned between two peaks of the prism structure. In view of the fact that the adhesive force may be reduced by not contacting the adhesive layer with the peak portion of the prism structure, the adhesive layer dot diameter is preferably formed larger than the prism pitch.
또한, 띠 형상의 접착층을 갖는 실시형태의 실험 결과를 나타낸 상기 표 2에 따르면, 접착층의 폭이 프리즘 패턴의 피치보다 대략 10배 이상 넓은 경우 쉐이딩 현상이 나타나는 것이 확인되었다. 따라서, 띠 형상의 접착층을 갖는 실시형태에서, 접착층의 폭은 프리즘 패턴의 피치보다 크게 형성되되, 그 상한은 프리즘 패턴 피치의 10배 미만인 것이 바람직함을 알 수 있다.Further, according to the above Table 2 showing the experimental results of the embodiment having the band-shaped adhesive layer, it was confirmed that the shading phenomenon appeared when the width of the adhesive layer was approximately 10 times or more wider than the pitch of the prism pattern. Therefore, in the embodiment having the band-shaped adhesive layer, it can be seen that the width of the adhesive layer is formed larger than the pitch of the prism pattern, and the upper limit thereof is preferably less than 10 times the pitch of the prism pattern.
또한, 매쉬 형상의 접착층을 갖는 실시형태의 실험 결과를 나타낸 상기 표 3에 따르면, 접착층의 폭, 즉 메쉬 형상의 접착층을 형성하도록 상호 교차하는 띠 구조가 갖는 폭은 프리즘 패턴 피치의 10배 미만인 것이 바람직함을 알 수 있다. 또한, 메쉬 형상의 접착층을 형성하도록 상호 교차하는 띠 구조의 폭이 갖는 하한은 특정한 값으로 한정되지는 않으며, 전술한 바람직한 접착층의 면적비를 감안하여 적절하게 결정될 수 있다.Further, according to the above Table 3 showing the experimental results of the embodiment having the mesh-shaped adhesive layer, the width of the adhesive layer, that is, the width of the band structures that cross each other to form a mesh-shaped adhesive layer is less than 10 times the prism pattern pitch. It can be seen that it is preferable. In addition, the lower limit of the width of the strip | belt structure which mutually intersects to form a mesh-shaped adhesive layer is not limited to a specific value, It can determine suitably in consideration of the area ratio of the above-mentioned preferable adhesive layer.
이와 같이, 본 발명의 실시형태들은, 구조화 표면을 갖는 제1 광학시트(130)와 이 구조화 표면에 적층되는 제2 광학시트(150) 사이의 접착력을 확보하기 위해 접합되는 면의 일부에만 접착층을 형성하여 부분 접합이 이루어지게 한다. 이로써, 도광판과 광학시트 사이에 견고한 접합력을 확보함과 동시에 접착층의 적용에 따른 광학특성 변동을 최소화 할 수 있다. 특히, 본 발명의 다양한 실시형태들은, 제1 광학시트(130)의 구조화 표면에 형성된 광학 구조들이 서로 다른 높이를 갖는 영역을 형성하게 함으로써, 제1 광학시트(130)의 구조화 표면에 직접 접촉되는 면적을 감소시켜 침윤현상을 줄이고 모아레 무늬 발생을 억제할 수 있다.As such, embodiments of the present invention provide an adhesive layer only on a portion of a surface to be bonded to secure adhesion between the first optical sheet 130 having the structured surface and the second optical sheet 150 laminated to the structured surface. To form a partial junction. As a result, it is possible to secure a firm bonding force between the light guide plate and the optical sheet and to minimize variations in optical characteristics due to the application of the adhesive layer. In particular, various embodiments of the present invention allow optical structures formed on the structured surface of the first optical sheet 130 to form regions having different heights, thereby directly contacting the structured surface of the first optical sheet 130. By reducing the area, it is possible to reduce the infiltration phenomenon and to suppress the generation of moire fringes.
또한, 분 발명의 실시형태들은, 부분 접착에 의한 적절한 접합력을 제공함으로써, 초박형 광학시트(프리즘 시트)를 적용하는 경우에 나타날 수 있는 휨현상, 변형 및 뒤틀림 등의 문제를 억제할 수 있다. 이를 통해, 더욱 얇은 두께의 광학시트를 사용 가능하게 함으로써 전체적인 백라이트 유닛의 두께를 감소시킬 수 있다.In addition, embodiments of the invention can suppress problems such as warpage, deformation, and warpage that may occur when applying an ultra-thin optical sheet (prism sheet) by providing a proper bonding force by partial bonding. Through this, the thickness of the entire backlight unit can be reduced by enabling the use of a thinner optical sheet.
110: 도광판110: light guide plate
111: 광원111: light source
120: 광확산판120: light diffusion plate
130, 131, 132: 제1 광학시트130, 131, and 132: first optical sheet
140, 141, 142, 143: 접착층140, 141, 142, 143: adhesive layer
150: 제2 광학시트150: second optical sheet
160: 편광판160: polarizer
170: 액정 디스플레이 패널170: liquid crystal display panel
231: 제1 광학구조물231: first optical structure
232: 제2 광학구조물232: second optical structure
310: 제1 굴절부310: first refracting portion
320: 제2 굴절부320: second refracting portion

Claims (13)

  1. 상단부의 높이가 상호 상이한 영역을 갖도록 광학 구조가 형성된 상면을 포함하는 제1 광학시트;A first optical sheet including an upper surface on which the optical structure is formed such that the heights of the upper end portions are different from each other;
    상기 제1 광학시트 상면의 일부 영역에 형성된 접착층; 및An adhesive layer formed on a portion of an upper surface of the first optical sheet; And
    상기 접착층 상에 배치되는 제2 광학시트A second optical sheet disposed on the adhesive layer
    를 포함하는 광학시트 구조물.Optical sheet structure comprising a.
  2. 제1항에 있어서, 상기 광학 구조는,The method of claim 1, wherein the optical structure,
    복수의 제1 광학 구조물; 및A plurality of first optical structures; And
    상기 제1 광학 구조물의 적어도 일부에 의해 분리되며, 상기 제1 광학 구조물의 높이보다 높은 높이를 갖는 복수의 제2 광학 구조물을 포함하는 것을 특징으로 하는 광학시트 구조물.And a plurality of second optical structures separated by at least a portion of the first optical structures, the plurality of second optical structures having a height higher than the height of the first optical structures.
  3. 제2항에 있어서,The method of claim 2,
    상기 복수의 제2 광학 구조물의 상단부들 사이의 거리는 일정한 것을 특징으로 하는 광학시트 구조물.And a distance between upper ends of the plurality of second optical structures is constant.
  4. 제2항에 있어서,The method of claim 2,
    상기 복수의 제2 광학 구조물은 상호 평행하게 선형으로 형성된 프리즘 구조인 것을 특징으로 하는 광학시트 구조물.The plurality of second optical structure is an optical sheet structure, characterized in that the prism structure formed in parallel with each other in a linear.
  5. 제1항에 있어서, 상기 제1 광학시트는,The method of claim 1, wherein the first optical sheet,
    그 상면 상단부를 연결한 면이 엠보싱 형태를 갖는 것을 특징으로 하는 광학시트 구조물.Optical sheet structure, characterized in that the surface connecting the upper end of the upper surface has an embossed form.
  6. 제1항에 있어서, 상기 제1 광학 시트는,The method of claim 1, wherein the first optical sheet,
    평판 형상의 제1 굴절부; 및A first refracting portion having a flat plate shape; And
    광학적 단면을 가지고 상호 소정의 간격을 두고 선형 배열되며, 상기 제1 굴절부의 일면에 형성되는 복수의 광학구조 패턴을 갖는 제2 굴절부를 포함하며,It has an optical cross-section and are arranged linearly at a predetermined interval from each other, and includes a second refracting portion having a plurality of optical structure patterns formed on one surface of the first refracting portion,
    상기 복수의 광학구조 패턴의 단부를 상호 연결한 곡선은 서로 다른 높이를 갖는 볼록부 또는 오목부를 갖도록 형성되며,Curves interconnecting the ends of the plurality of optical structure patterns is formed to have convex portions or concave portions having different heights,
    상기 복수의 광학구조 패턴 각각은 그 형성된 방향으로 그 단부가 서로 다른 높이를 갖는 볼록부 또는 오목부를 갖도록 형성된 것을 특징으로 하는 광학시트 구조물.Wherein each of the plurality of optical structure patterns is formed to have convex portions or concave portions having end portions different in height in the formed direction thereof.
  7. 제6항에 있어서, 상기 광학구조 패턴은The method of claim 6, wherein the optical structure pattern
    단면투영시 다각 형상 또는 부분원호 형상이거나, 상기 다각 형상과 부분원호 형상이 복합된 형상을 갖는 것을 특징으로 하는 광학시트 구조물.Optical sheet structure, characterized in that the polygonal shape or a partial arc shape when projecting the cross-section, or the polygonal shape and the partial arc shape has a complex shape.
  8. 제6항에 있어서,The method of claim 6,
    상기 복수의 광학구조 패턴의 단부를 상호 연결한 곡선이 형성하는 볼록부 또는 오목부, 또는 상기 복수의 광학구조 패턴 각각이 그 형성된 방향으로 형성하는 볼록부 또는 오목부는 등간격으로 형성되며,Convex portions or recesses formed by curves interconnecting the ends of the plurality of optical structure patterns, or convex portions or recesses formed in the direction in which the plurality of optical structure patterns are formed, are formed at equal intervals.
    상기 복수의 광학구조 패턴은 상호 등간격으로 형성되는 것을 특징으로 하는 광학시트 구조물.The optical sheet structure, characterized in that the plurality of optical structure patterns are formed at equal intervals.
  9. 제6항에 있어서,The method of claim 6,
    상기 복수의 광학구조 패턴의 단부를 상호 연결한 곡선이 형성하는 볼록부 또는 오목부, 또는 상기 복수의 광학구조 패턴 각각이 그 형성된 방향으로 형성하는 볼록부 또는 오목부는 상호 불규칙적인 간격으로 형성되며,Convex portions or recesses formed by curves connecting the ends of the plurality of optical structure patterns, or convex portions or recesses formed in the direction in which the plurality of optical structure patterns are formed, are formed at irregular intervals.
    상기 복수의 광학구조 패턴은 상호 불규칙적인 간격으로 형성되는 것을 특징으로 하는 광학시트 구조물.The optical sheet structure, characterized in that the plurality of optical structure patterns are formed at irregular intervals.
  10. 제1항 내지 제9항 중 어느 한 항에 있어서,The method according to any one of claims 1 to 9,
    상기 접착층은, 상기 제1 광학시트 상면의 일부 영역에 도트 형상으로 형성된 것을 특징으로 하는 광학시트 구조물.The adhesive layer is an optical sheet structure, characterized in that formed in a dot shape on a portion of the upper surface of the first optical sheet.
  11. 제1항 내지 제9항 중 어느 한 항에 있어서,The method according to any one of claims 1 to 9,
    상기 접착층은, 상기 제1 광학시트 상면의 일부 영역에 상호 평행한 복수의 띠 형상으로 형성된 것을 특징으로 하는 면광원 장치.The adhesive layer is a surface light source device, characterized in that formed in a plurality of bands parallel to each other on a portion of the upper surface of the first optical sheet.
  12. 제1항 내지 제9항 중 어느 한 항에 있어서,The method according to any one of claims 1 to 9,
    상기 접착층은, 상기 제1 광학시트 상면의 일부 영역에 복수의 오픈 영역을 갖는 메쉬 형상으로 형성된 것을 특징으로 하는 면광원 장치.The adhesive layer is a surface light source device, characterized in that formed in a mesh shape having a plurality of open areas in a portion of the upper surface of the first optical sheet.
  13. 제1항 내지 제9항 중 어느 한 항에 있어서,The method according to any one of claims 1 to 9,
    상기 접착층의 면적은 상기 제1 광학시트의 평면적의 5% 이상 65% 이하인 것을 특징으로 하는 면광원 장치.The area of the adhesive layer is a surface light source device, characterized in that 5% or more and 65% or less of the planar area of the first optical sheet.
PCT/KR2012/008232 2011-10-11 2012-10-11 Optical sheet structure WO2013055112A1 (en)

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KR10-2011-0103604 2011-10-11
KR1020110103604A KR20130039127A (en) 2011-10-11 2011-10-11 Optical sheet structure and method for menufacturing the same

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