TW201741747A - Optical sheet for liquid crystal display device, backlight unit for liquid crystal display device and production method of optical sheet for liquid crystal display device - Google Patents
Optical sheet for liquid crystal display device, backlight unit for liquid crystal display device and production method of optical sheet for liquid crystal display device Download PDFInfo
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- TW201741747A TW201741747A TW106116123A TW106116123A TW201741747A TW 201741747 A TW201741747 A TW 201741747A TW 106116123 A TW106116123 A TW 106116123A TW 106116123 A TW106116123 A TW 106116123A TW 201741747 A TW201741747 A TW 201741747A
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- 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
- G02B6/0035—Means for improving the coupling-out of light from the light guide provided on the surface of the light guide or in the bulk of it
- G02B6/0036—2-D arrangement of prisms, protrusions, indentations or roughened surfaces
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- 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
- G02B6/0035—Means for improving the coupling-out of light from the light guide provided on the surface of the light guide or in the bulk of it
- G02B6/004—Scattering dots or dot-like elements, e.g. microbeads, scattering particles, nanoparticles
- G02B6/0043—Scattering dots or dot-like elements, e.g. microbeads, scattering particles, nanoparticles provided on the surface of the light guide
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- 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
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- 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
- G02F1/1336—Illuminating devices
- G02F1/133615—Edge-illuminating devices, i.e. illuminating from the side
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- Optics & Photonics (AREA)
- Nonlinear Science (AREA)
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- Crystallography & Structural Chemistry (AREA)
- Planar Illumination Modules (AREA)
- Optical Elements Other Than Lenses (AREA)
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Abstract
Description
本發明涉及一種液晶顯示裝置用光學片、液晶顯示裝置用背光單元及液晶顯示裝置用光學片的製造方法。The present invention relates to an optical sheet for a liquid crystal display device, a backlight unit for a liquid crystal display device, and a method for producing an optical sheet for a liquid crystal display device.
作為透射型的液晶顯示裝置,從背面對液晶層進行照射的背光源方式得到普及,在液晶層的背面側裝備有邊緣光型(側光型)、正下方型等的背光單元。如圖19所示,該側光型的背光單元101一般具備光源102、沿著端部配置於該光源102的方形板狀的導光片103和在該導光片103的表面側重疊配置的多個光學片104。該光學片104具有對透射光線的擴散、折射等光學功能,例如使用配置於導光片103的表面側且主要具有光擴散功能的光擴散片105、配置於光擴散片105的表面側且具有朝向法線方向側的折射功能的棱鏡片106。As a transmissive liquid crystal display device, a backlight system that irradiates a liquid crystal layer from the back surface is widely used, and a backlight unit such as an edge light type (side light type) or a direct type is provided on the back side of the liquid crystal layer. As shown in FIG. 19, the sidelight type backlight unit 101 generally includes a light source 102, a square plate-shaped light guide sheet 103 disposed along the end portion of the light source 102, and a light-emitting sheet 103 disposed on the front surface side of the light guide sheet 103. A plurality of optical sheets 104. The optical sheet 104 has an optical function such as diffusion and refraction of transmitted light. For example, the light diffusion sheet 105 disposed on the surface side of the light guide sheet 103 and having a light diffusion function is disposed on the surface side of the light diffusion sheet 105 and has The prism sheet 106 having a refractive function toward the normal direction side.
若對該背光單元101的功能進行說明,則首先,從光源102入射至導光片103的光線被導光片103的背面的反射點或反射片(省略圖示)及各側面加以反射,並從導光片103的表面出射。從導光片103的表面出射的光線入射至光擴散片105並且被擴散而從表面出射。從光擴散片105的表面出射的光線入射至棱鏡片106,在形成於表面的多個凸條棱鏡部的作用下朝向法線方向側折射而被出射,進而對表面側的未圖示的液晶層整個表面進行照明。予以說明,雖然未圖示,但是,作為上述光學片104,也使用配置於棱鏡片106的表面側且通過使光線略微擴散來抑制由棱鏡片106的多個凸條棱鏡部的形狀等所致的亮度不均的上用光擴散片、具有朝向法線方向側的折射功能及廣角度的光擴散功能的微透鏡片等。When the function of the backlight unit 101 is described, first, the light incident from the light source 102 to the light guide sheet 103 is reflected by the reflection point or the reflection sheet (not shown) and the side surfaces of the back surface of the light guide sheet 103, and It is emitted from the surface of the light guiding sheet 103. Light emitted from the surface of the light guiding sheet 103 is incident on the light diffusion sheet 105 and is diffused to be emitted from the surface. The light emitted from the surface of the light-diffusing sheet 105 is incident on the prism sheet 106, and is refracted toward the normal direction side by the plurality of ridge prism portions formed on the surface, and is emitted to the liquid crystal (not shown) on the surface side. The entire surface of the layer is illuminated. In addition, as the optical sheet 104, the optical sheet 104 is disposed on the surface side of the prism sheet 106, and the light is slightly diffused to suppress the shape of the plurality of ridge prism portions of the prism sheet 106. The upper light-diffusing sheet having uneven brightness, the microlens sheet having a refractive function toward the normal direction side, and a wide-angle light diffusing function.
光學片104具有如上述那樣對透射光線的擴散、折射等光學功能,並且出於背光單元的亮度的均勻化、正面方向的高亮度化等目的而被使用。關於該光學片104,若以光擴散片105為例,則如圖20所示,具有以合成樹脂為主成分的基體材料層111(光學層)、在該基體材料層111的表面側層疊的光擴散層112和在該基體材料層111的背面側層疊的防黏附層113。該防黏附層113會防止因光擴散片105的背面與導光片103的表面黏附(密合)而產生莫爾條紋的不良。該防黏附層113一般具有球狀的珠114及覆蓋該珠114的黏結劑115,利用因珠114產生的向背面側突出的凸部來防止黏附(參照日本特開2010-26231號公報)。The optical sheet 104 has an optical function such as diffusion and refraction of transmitted light as described above, and is used for the purpose of uniformizing the luminance of the backlight unit and increasing the luminance in the front direction. In the optical sheet 104, as shown in FIG. 20, the optical material sheet 104 has a base material layer 111 (optical layer) mainly composed of a synthetic resin, and is laminated on the surface side of the base material layer 111. The light diffusion layer 112 and an anti-adhesion layer 113 laminated on the back side of the base material layer 111. The anti-adhesion layer 113 prevents the occurrence of moire fringes due to adhesion (adhesion) between the back surface of the light diffusion sheet 105 and the surface of the light guide sheet 103. The anti-adhesion layer 113 generally has a spherical bead 114 and a binder 115 that covers the bead 114, and is prevented from adhering by a convex portion that protrudes toward the back side by the bead 114 (refer to Japanese Laid-Open Patent Publication No. 2010-26231).
然而,如上述那樣具有珠114及黏結劑115的以往的防黏附層,因珠114的突出而形成凸部,因此該凸部容易成為與珠114的形狀近似的形狀。因此,該凸部的平均徑及平均高度容易成為相同程度,凸部的前端部(下端部)的R容易變小。因此,根據上述以往的防黏附層113,有在與上述凸部抵接的導光片103的表面產生損傷的風險。而且,若如此地在導光片103的表面產生損傷,則有因入射至該損傷的光線而產生亮度不均的風險。However, since the conventional anti-adhesion layer having the beads 114 and the binder 115 as described above forms a convex portion by the protrusion of the beads 114, the convex portion is likely to have a shape similar to the shape of the beads 114. Therefore, the average diameter and the average height of the convex portion are likely to be the same, and the R of the tip end portion (lower end portion) of the convex portion is likely to be small. Therefore, according to the conventional anti-adhesion layer 113 described above, there is a risk of damage to the surface of the light guiding sheet 103 that is in contact with the convex portion. Further, if damage occurs on the surface of the light guiding sheet 103 as described above, there is a risk that unevenness in brightness occurs due to the incident light.
現有技術文獻:Prior art literature:
專利文獻1:日本特開2010-26231號公報。Patent Document 1: Japanese Laid-Open Patent Publication No. 2010-26231.
本發明是鑒於此種情況而完成的發明,其目的在於提供能夠防止黏附並且能夠防止在背面側配置的其他光學構件的損傷的液晶顯示裝置用光學片及液晶顯示裝置用光學片的製造方法。另外,本發明的目的還在於提供能夠防止黏附並且能夠防止光學構件的損傷的液晶顯示裝置用背光單元。The present invention has been made in view of such circumstances, and an object of the invention is to provide an optical sheet for a liquid crystal display device and a method for producing an optical sheet for a liquid crystal display device which can prevent adhesion of other optical members disposed on the back side while preventing adhesion. Further, another object of the present invention is to provide a backlight unit for a liquid crystal display device which can prevent adhesion and can prevent damage of an optical member.
為了解決上述課題而完成的本發明涉及的液晶顯示裝置用光學片,其特徵在於,其是在背面以散點狀具備多個凸部的液晶顯示裝置用光學片,上述凸部為扁平的半球體或前端部被弄成圓狀的扁平的錐體。An optical sheet for a liquid crystal display device according to the present invention, which is provided with a plurality of convex portions on a back surface of the optical sheet, and the convex portion is a flat hemisphere. The body or the front end is rounded into a flat cone.
該液晶顯示裝置用光學片由於在背面以散點狀具備多個凸部,因此該液晶顯示裝置用光學片及在該液晶顯示裝置用光學片的背面側配置的其他光學構件利用該多個凸部而部分抵接。因此,該液晶顯示裝置用光學片可以防止與在背面側配置的其他光學構件的黏附。進而,該液晶顯示裝置用光學片通過是上述凸部為扁平的半球體或前端部被弄成圓狀的扁平的錐體,從而使多個凸部的前端部(下端部)的彎曲面比較平緩,由此可以防止在背面側配置的其他光學構件的表面的損傷。In the optical sheet for a liquid crystal display device, a plurality of convex portions are provided in a scattered manner on the back surface, and the optical sheet for a liquid crystal display device and other optical members disposed on the back side of the optical sheet for the liquid crystal display device are used for the plurality of convex portions. Partially partial. Therefore, the optical sheet for a liquid crystal display device can prevent adhesion to other optical members disposed on the back side. Further, in the optical sheet for a liquid crystal display device, the curved surface of the front end portion (lower end portion) of the plurality of convex portions is compared by a flattened cone having a flattened hemisphere or a tip end portion being rounded. It is gentle, whereby damage to the surface of other optical members disposed on the back side can be prevented.
上述凸部適宜為半分割旋轉橢圓體。如此,通過使上述凸部為半分割旋轉橢圓體,從而可以更可靠地防止配置於該液晶顯示裝置用光學片的背面側的其他光學構件的表面的損傷。The convex portion is preferably a semi-divided ellipsoid. By making the convex portion a semi-divided ellipsoid, it is possible to more reliably prevent damage to the surface of another optical member disposed on the back side of the optical sheet for a liquid crystal display device.
作為上述多個凸部的佔有面積比,優選2%以上且80%以下。如此,通過使上述多個凸部的佔有面積比為上述範圍內,從而既能充分防止與配置於背面側的其他光學構件的黏附,又能更可靠地防止對其他光學構件的表面的損傷。The ratio of the area occupied by the plurality of convex portions is preferably 2% or more and 80% or less. By setting the area ratio of the plurality of convex portions to the above-described range, adhesion to other optical members disposed on the back side can be sufficiently prevented, and damage to the surface of the other optical members can be more reliably prevented.
作為上述凸部的平均徑,優選5μm以上且60μm以下,作為平均高度,優選0.5μm以上。如此,通過使上述凸部的平均徑及平均高度為上述範圍內,從而可以更可靠地防止與在該液晶顯示裝置用光學片的背面側配置的其他光學構件的黏附。The average diameter of the convex portion is preferably 5 μm or more and 60 μm or less, and is preferably 0.5 μm or more as an average height. When the average diameter and the average height of the convex portion are within the above range, adhesion to other optical members disposed on the back side of the optical sheet for a liquid crystal display device can be more reliably prevented.
在背面中不存在上述多個凸部的區域,適宜具備定向為一個方向的多條狀的光柵形狀。如此,通過在背面中不存在上述多個凸部的區域具備定向為一個方向的多條狀的光柵形狀,從而可以使光向該光柵形狀的寬度方向擴散,並且可以充分確保該寬度方向的視角。A region in which the plurality of convex portions are not present in the back surface is preferably provided with a plurality of grating shapes oriented in one direction. In this manner, by providing a plurality of stripe shapes oriented in one direction in a region where the plurality of convex portions are not present on the back surface, light can be diffused in the width direction of the grating shape, and the viewing angle in the width direction can be sufficiently ensured. .
上述光柵形狀適宜呈現朝向一個方向的擦過痕或發線狀。如此,通過使上述光柵形狀呈現朝向一個方向的擦過痕或發線狀,從而可以使光容易且可靠地向該光柵形狀的寬度方向擴散。The above-mentioned grating shape is suitable for exhibiting a scratch or hairline shape in one direction. As described above, by making the grating shape appear in a rubbing or hairline shape in one direction, light can be easily and reliably diffused in the width direction of the grating shape.
在上述多個凸部的背面側也適宜具有與上述光柵形狀連續的光柵形狀。如此,通過在上述多個凸部的背面側也具有與上述光柵形狀連續的光柵形狀,從而可以使光更均勻地向該光柵形狀的寬度方向擴散,並且可以更準確地確保該光柵形狀的寬度方向的視角。It is also preferable to have a grating shape continuous with the grating shape on the back side of the plurality of convex portions. By also having a grating shape continuous to the grating shape on the back side of the plurality of convex portions, light can be more uniformly diffused in the width direction of the grating shape, and the width of the grating shape can be more accurately ensured. Direction of view.
為了解決上述課題而完成的本發明涉及的液晶顯示裝置用背光單元,其特徵在於,其具備:將從端面入射的光線引向表面側的導光片、沿著該導光片的上述端面配置的1個或多個LED光源、和在上述導光片的表面側重疊的1個或多個光學片,上述1個光學片或多個光學片的至少一個使用該光學片。A backlight unit for a liquid crystal display device according to the present invention, which is provided with a light guide sheet that guides light incident from an end surface toward a surface side, and is disposed along the end surface of the light guide sheet. One or a plurality of LED light sources and one or a plurality of optical sheets superposed on the surface side of the light guiding sheet, and at least one of the one optical sheet or the plurality of optical sheets is used.
該液晶顯示裝置用背光單元具備該光學片,因此可以如上述那樣防止該光學片及配置於該光學片的背面側的其他光學構件的黏附,並且可以防止其他光學構件的表面的損傷。Since the backlight unit for a liquid crystal display device includes the optical sheet, adhesion of the optical sheet and other optical members disposed on the back side of the optical sheet can be prevented as described above, and damage to the surface of the other optical member can be prevented.
進而,為了解決上述課題而完成的本發明涉及的液晶顯示裝置用光學片的製造方法,其特徵在於,其是在背面以散點狀具備多個凸部的液晶顯示裝置用光學片的製造方法,上述凸部為扁平的半球體或前端部被弄成圓狀的扁平的錐體,該製造方法具備:使用表面具有以散點狀具備上述多個凸部的背面形狀的翻轉形狀的輥,向該輥表面運送帶狀的樹脂膜的工序;向該樹脂膜及上述輥之間供給紫外線固化型樹脂組合物的工序;和對上述紫外線固化型樹脂組合物照射紫外線的工序。Further, a method for producing an optical sheet for a liquid crystal display device according to the present invention, which is a method for producing an optical sheet for a liquid crystal display device having a plurality of convex portions on a back surface The convex portion is a flat hemisphere or a flat cone whose front end portion is rounded, and the manufacturing method includes a roll having a reverse shape having a back surface shape in which the plurality of convex portions are scattered in a surface. a step of transporting a strip-shaped resin film onto the surface of the roll, a step of supplying an ultraviolet curable resin composition between the resin film and the roll, and a step of irradiating the ultraviolet curable resin composition with ultraviolet rays.
該液晶顯示裝置用光學片的製造方法,可以利用表面具有形成為扁平的半球體狀或前端部被弄成圓狀的扁平的錐體狀的多個凸部的翻轉形狀的輥,而在樹脂膜的一面形成多個扁平的半球體狀或前端部被弄成圓狀的扁平的錐體狀的凸部。因此,該液晶顯示裝置用光學片的製造方法,可以製造通過利用多個凸部與其他光學構件部分抵接而能夠防止黏附且能夠防止與多個凸部抵接的其他光學構件的損傷的光學片。In the method for producing an optical sheet for a liquid crystal display device, it is possible to use a roll having a reversed shape in which a flattened hemispherical shape or a flattened tapered shape of a tip end portion is rounded, and the resin is used. One side of the film is formed into a plurality of flat hemispherical shapes or flattened pyramid-shaped convex portions whose front end portions are rounded. Therefore, in the method for producing an optical sheet for a liquid crystal display device, it is possible to manufacture an optical article capable of preventing adhesion by using a plurality of convex portions in contact with other optical member portions, thereby preventing adhesion of other optical members that are in contact with the plurality of convex portions. sheet.
予以說明,在本發明中,「表面側」是指液晶顯示裝置的觀看者側,「背面側」是指其相反側。「半球體」為意指將球形以一個平面進行分切後的立體形狀且包含「球缺」的概念,具體是指具有圓形或橢圓形的底面及從該底面的周邊連續的球面的形狀。「錐體」為包含圓錐及角錐的概念。「扁平的半分割旋轉橢圓體狀」是指將使橢圓以短軸為中心旋轉的假想旋轉橢圓體用包含長軸的與短軸垂直的垂直面進行對半分割的形狀。「多個凸部的佔有面積比」是指多個凸部的佔有面積相對於形成多個凸部的面的平面面積之比。各凸部的「直徑」是指基底的直徑,「凸部的平均徑」是指任意抽取10個凸部並將各凸部的基底的最大徑與最小徑的中間值加以平均所得的值。各凸部的「高度」是指從各凸部的基底到突出端的長度,「凸部的平均高度」是指任意抽取10個凸部並將從各凸部的基底到突出端的長度加以平均所得的值。「光柵形狀」並不限定於嚴密調整光學特性的光柵形狀,而是廣義上對入射光產生衍射的形狀。「朝向一個方向的擦過痕狀或發線狀」是指如使多個細長的損傷定向為一個方向所形成的形狀。In the present invention, the "surface side" means the viewer side of the liquid crystal display device, and the "back side" means the opposite side. The term "hemisphere" means a three-dimensional shape in which a spherical shape is cut in one plane and includes a "spherical defect", specifically a circular or elliptical bottom surface and a spherical shape continuous from the periphery of the bottom surface. . The "cone" is a concept that includes a cone and a pyramid. The "flat semi-divided ellipsoid" refers to a shape in which a virtual spheroid that rotates an ellipse around a minor axis is split in half by a vertical plane perpendicular to the minor axis including a long axis. The "occupation area ratio of the plurality of convex portions" means the ratio of the occupied area of the plurality of convex portions to the planar area of the surface on which the plurality of convex portions are formed. The "diameter" of each convex portion means the diameter of the base, and the "average diameter of the convex portion" means a value obtained by arbitrarily extracting ten convex portions and averaging the intermediate values of the maximum diameter and the minimum diameter of the base of each convex portion. The "height" of each convex portion means the length from the base of each convex portion to the protruding end, and "the average height of the convex portion" means that 10 convex portions are arbitrarily extracted and the length from the base to the protruding end of each convex portion is averaged. Value. The "raster shape" is not limited to a grating shape in which optical characteristics are closely adjusted, but a shape in which the incident light is diffracted in a broad sense. "Scratch or hairline in one direction" means a shape formed by orienting a plurality of elongated lesions into one direction.
發明效果:Invention effect:
如以上說明的那樣,本發明的液晶顯示裝置用光學片,能夠防止黏附,並且能夠可靠地防止在背面側配置的其他光學構件的損傷。本發明的液晶顯示裝置用背光單元,能夠防止黏附,並且能夠可靠地防止光學構件的損傷。另外,本發明的液晶顯示裝置用光學片的製造方法可以製造能夠防止黏附且能夠可靠地防止在背面側配置的其他光學構件的損傷的光學片。As described above, the optical sheet for a liquid crystal display device of the present invention can prevent adhesion and can reliably prevent damage of other optical members disposed on the back side. The backlight unit for a liquid crystal display device of the present invention can prevent adhesion and can reliably prevent damage of the optical member. Further, in the method for producing an optical sheet for a liquid crystal display device of the present invention, it is possible to manufacture an optical sheet capable of preventing adhesion and reliably preventing damage of other optical members disposed on the back side.
以下,適當參照附圖對本發明的實施方式進行詳細敍述。Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
《第一實施方式》First Embodiment
《背光單元》"Backlight unit"
圖1的液晶顯示裝置用背光單元(以下也簡稱為「背光單元」)1為側光型背光單元,並且是使用多個LED光源的液晶顯示裝置用背光單元。該背光單元1具備作為將從端面入射的光線引向表面側的導光片的導光膜2、沿著導光膜2的上述端面配置的多個LED光源3、和重疊於導光膜2的表面側的多個液晶顯示裝置用光學片(以下也簡稱為「光學片」)。該背光單元1具有直接(不間隔其他片等)重疊於導光膜2的表面的光擴散片5和直接(不間隔其他片等)重疊於光擴散片5的表面的棱鏡片6作為多個光學片。另外,該背光單元1還具備在導光膜2的背面側配置的反射片7。光擴散片5使從背面側入射的光線擴散並向法線方向側聚光(聚光擴散)。棱鏡片6使從背面側入射的光線向法線方向側折射。反射片7使從導光膜2的背面出射的光線反射並再度入射至導光膜2。予以說明,在圖1中分別分離記載了反射片7、導光膜2、光擴散片5及棱鏡片6,但實際上反射片7的表面及導光膜2的背面、導光膜2的表面及光擴散片5的背面、光擴散片5的表面及棱鏡片6的背面相抵接。The backlight unit for a liquid crystal display device of FIG. 1 (hereinafter also simply referred to as "backlight unit") 1 is a side light type backlight unit, and is a backlight unit for a liquid crystal display device using a plurality of LED light sources. The backlight unit 1 includes a light guiding film 2 that guides light incident from the end surface toward the light guide sheet on the front surface side, a plurality of LED light sources 3 that are disposed along the end surface of the light guiding film 2, and a light guide film 2 that is superposed on the light guiding film 2 A plurality of optical sheets for liquid crystal display devices on the surface side (hereinafter also simply referred to as "optical sheets"). The backlight unit 1 has a light diffusion sheet 5 that is directly superimposed on the surface of the light guiding film 2 (without spacing of other sheets or the like), and a prism sheet 6 that is directly superposed on the surface of the light diffusion sheet 5 (without spacing other sheets or the like) as a plurality of Optical sheet. Further, the backlight unit 1 further includes a reflection sheet 7 disposed on the back side of the light guiding film 2. The light-diffusing sheet 5 diffuses light incident from the back side and collects light (concentrated light diffusion) toward the normal direction side. The prism sheet 6 refracts light incident from the back side toward the normal direction side. The reflection sheet 7 reflects the light emitted from the back surface of the light guiding film 2 and re-enters the light guiding film 2 again. Incidentally, in FIG. 1, the reflection sheet 7, the light guide film 2, the light diffusion sheet 5, and the prism sheet 6 are separately separated, but actually the surface of the reflection sheet 7 and the back surface of the light guide film 2 and the light guide film 2 are separated. The surface and the back surface of the light diffusion sheet 5, the surface of the light diffusion sheet 5, and the back surface of the prism sheet 6 are in contact with each other.
<光擴散片><Light diffusion sheet>
如圖2所示,光擴散片5具備基體材料層11、層疊於基體材料層11的表面側的光擴散層12和層疊於基體材料層11的背面側的背層13。另外,光擴散片5在背面(背層13的背面)以散點狀具備作為防黏附部的多個凸部13a。多個凸部13a與背層13一體成形(即,一體地形成多個凸部13a及背層13)。光擴散片5形成為俯視下的方形狀。光擴散片5由基體材料層11、光擴散層12、背層13及多個凸部13a構成(即,光擴散片5不具有除基體材料層11、光擴散層12、背層13及多個凸部13a以外的其他層)。As shown in FIG. 2, the light diffusion sheet 5 is provided with a base material layer 11, a light diffusion layer 12 laminated on the surface side of the base material layer 11, and a back layer 13 laminated on the back side of the base material layer 11. Further, the light diffusion sheet 5 has a plurality of convex portions 13a as anti-adhesion portions on the back surface (back surface of the back layer 13) in a scattered manner. The plurality of convex portions 13a are integrally formed with the back layer 13 (that is, a plurality of convex portions 13a and back layers 13 are integrally formed). The light diffusion sheet 5 is formed in a square shape in plan view. The light diffusion sheet 5 is composed of the base material layer 11, the light diffusion layer 12, the back layer 13, and the plurality of convex portions 13a (that is, the light diffusion sheet 5 does not have the base material layer 11, the light diffusion layer 12, the back layer 13, and the like. Other layers than the convex portion 13a).
(基體材料層)(base material layer)
基體材料層11需要使光線透射,因此形成為透明。基體材料層11以合成樹脂為主成分。作為基體材料層11的主成分,並無特別限定,可列舉例如聚對苯二甲酸乙二醇酯、聚萘二甲酸乙二醇酯、丙烯酸樹脂、丙烯酸-聚氨酯樹脂、聚碳酸酯、聚苯乙烯、聚烯烴、醋酸纖維素、耐氣候性氯乙烯等。其中,優選透明性優異且強度高的聚對苯二甲酸乙二醇酯,特別優選彎曲性能得到改善的聚對苯二甲酸乙二醇酯。予以說明,「主成分」是指含量最多的成分,例如是指含量為50品質%以上的成分。The base material layer 11 needs to transmit light, and thus is formed to be transparent. The base material layer 11 is mainly composed of a synthetic resin. The main component of the base material layer 11 is not particularly limited, and examples thereof include polyethylene terephthalate, polyethylene naphthalate, acrylic resin, acrylic-urethane resin, polycarbonate, and polyphenylene. Ethylene, polyolefin, cellulose acetate, weather resistant vinyl chloride, etc. Among them, polyethylene terephthalate having excellent transparency and high strength is preferable, and polyethylene terephthalate having improved bending properties is particularly preferable. In addition, the "main component" means the component which has the most content, and is a component of 50 mass % or more, for example.
作為基體材料層11的平均厚度的下限,優選10μm,更優選23μm,進一步優選38μm。另一方面,作為基材層11的平均厚度的上限,優選為500μm,更優選為250μm,進一步優選為188μm。若基體材料層11的平均厚度不足上述下限,則在利用塗敷形成光擴散層12的情況下存在發生卷邊的風險。另外,若基體材料層11的平均厚度不足上述下限,則存在容易發生彎曲的風險。相反,若基體材料層11的平均厚度超出上述上限,則存在該背光單元1的亮度降低的風險,並且存在未依照該背光單元1的薄型化要求的風險。予以說明,「平均厚度」是指任意10點的厚度的平均值。The lower limit of the average thickness of the base material layer 11 is preferably 10 μm, more preferably 23 μm, still more preferably 38 μm. On the other hand, the upper limit of the average thickness of the base material layer 11 is preferably 500 μm, more preferably 250 μm, still more preferably 188 μm. If the average thickness of the base material layer 11 is less than the above lower limit, there is a risk of occurrence of curling in the case where the light diffusion layer 12 is formed by coating. Further, if the average thickness of the base material layer 11 is less than the above lower limit, there is a risk that bending tends to occur. On the contrary, if the average thickness of the base material layer 11 exceeds the above upper limit, there is a risk that the brightness of the backlight unit 1 is lowered, and there is a risk that the thinning of the backlight unit 1 is not required. In addition, "average thickness" means the average value of the thickness of arbitrary 10 points.
(光擴散層)(light diffusion layer)
光擴散層12構成光擴散片5的最外表面。光擴散層12具有多個珠14及其黏結劑15。珠14被黏結劑15包圍。光擴散層12分散含有多個珠14,從而使從背面側向表面側透射的光線大致均勻地擴散。另外,光擴散層12因多個珠14而在表面大致均勻地形成細小凹凸,該細小凹凸的各凹部及凸部形成為透鏡狀。光擴散層12利用該細小凹凸的透鏡作用而發揮優異的光擴散功能,並且具有因該光擴散功能而使透射光線向法線方向側折射的折射功能及使透射光線宏觀上向法線方向聚光的聚光功能。The light diffusion layer 12 constitutes the outermost surface of the light diffusion sheet 5. The light diffusion layer 12 has a plurality of beads 14 and a binder 15 therefor. The beads 14 are surrounded by a binder 15. The light diffusion layer 12 is dispersed and contains a plurality of beads 14 so that light transmitted from the back side to the surface side is substantially uniformly diffused. Further, in the light-diffusing layer 12, fine irregularities are formed substantially uniformly on the surface of the plurality of beads 14, and the concave portions and the convex portions of the fine uneven portions are formed in a lens shape. The light-diffusing layer 12 exhibits an excellent light-diffusing function by the lens action of the fine unevenness, and has a refractive function of refracting the transmitted light toward the normal direction side by the light-diffusing function and causing the transmitted light to be macroscopically concentrated toward the normal direction. The concentrating function of light.
珠14為具有使光線擴散的性質的樹脂粒子。作為珠14的主成分,可列舉例如丙烯酸樹脂、丙烯腈樹脂、聚氨酯、聚氯乙烯、聚苯乙烯、聚醯胺、聚丙烯腈等。其中,優選透明性高的丙烯酸樹脂,特別優選聚甲基丙烯酸甲酯(PMMA)。The beads 14 are resin particles having a property of diffusing light. The main component of the beads 14 may, for example, be an acrylic resin, an acrylonitrile resin, a polyurethane, a polyvinyl chloride, a polystyrene, a polyamide or a polyacrylonitrile. Among them, an acrylic resin having high transparency is preferable, and polymethyl methacrylate (PMMA) is particularly preferable.
對珠14的形狀並無特別限定,可列舉例如球狀、立方狀、針狀、棒狀、紡錘形狀、板狀、鱗片狀、纖維狀等,其中,優選光擴散性優異的球狀。The shape of the bead 14 is not particularly limited, and examples thereof include a spherical shape, a cubic shape, a needle shape, a rod shape, a spindle shape, a plate shape, a scaly shape, and a fiber shape. Among them, a spherical shape excellent in light diffusibility is preferable.
作為珠14的平均粒徑的下限,優選1μm,更優選2μm,進一步優選5μm。另一方面,作為珠14的平均粒徑的上限,優選15μm,更優選10μm,進一步優選8μm。若珠14的平均粒徑不足上述下限,則光擴散層12的表面的凹凸變小,存在無法滿足作為光擴散片5所需的光擴散性的風險。相反,若珠14的平均粒徑超出上述上限,則存在光擴散片5的厚度增大且難以均勻擴散的風險。予以說明,「珠的平均粒徑」是指由以鐳射衍射法測定的體積基準粒度分佈計算的多個珠的平均粒徑。The lower limit of the average particle diameter of the beads 14 is preferably 1 μm, more preferably 2 μm, still more preferably 5 μm. On the other hand, the upper limit of the average particle diameter of the beads 14 is preferably 15 μm, more preferably 10 μm, still more preferably 8 μm. When the average particle diameter of the bead 14 is less than the above lower limit, the unevenness on the surface of the light diffusion layer 12 is small, and there is a risk that the light diffusibility required as the light diffusion sheet 5 cannot be satisfied. On the other hand, if the average particle diameter of the beads 14 exceeds the above upper limit, there is a risk that the thickness of the light diffusion sheet 5 increases and it is difficult to uniformly diffuse. Incidentally, the "average particle diameter of the beads" means the average particle diameter of the plurality of beads calculated from the volume-based particle size distribution measured by the laser diffraction method.
作為珠14的配入量(在作為黏結劑15的形成材料的聚合物組合物中相對於聚合物成分100品質份的換算成固體成分的配入量)的下限,優選10品質份,更優選20品質份,進一步優選50品質份。另一方面,作為珠14的配入量的上限,優選500品質份,更優選300品質份,進一步優選200品質份。若珠14的配合量不足上述下限,則存在使光擴散性不充分的風險。相反,若珠14的配入量超出上述上限,則存在珠14未被黏結劑15準確固定的風險。The lower limit of the amount of the beads 14 to be added (the amount of the polymer component as the material for forming the binder 15 to the amount of the polymer component in terms of the amount of the polymer component) is preferably 10 parts by mass, more preferably 20 parts by mass, more preferably 50 parts by mass. On the other hand, the upper limit of the amount of the beads 14 to be added is preferably 500 parts by mass, more preferably 300 parts by mass, and still more preferably 200 parts by mass. If the blending amount of the beads 14 is less than the above lower limit, there is a risk that the light diffusibility is insufficient. On the contrary, if the blending amount of the beads 14 exceeds the above upper limit, there is a risk that the beads 14 are not accurately fixed by the binder 15.
黏結劑15通過使包含基體材料聚合物的聚合物組合物固化(交聯等)而形成。利用黏結劑15在基體材料層11的整個表面大致等密度地配置固定珠14。予以說明,除此以外,用於形成黏結劑15的聚合物組合物還可以適宜配合例如微小無機填充劑、固化劑、增塑劑、分散劑、各種均化劑、抗靜電劑、紫外線吸收劑、抗氧化劑、黏性改性劑、潤滑劑、光穩定化劑等。The binder 15 is formed by curing (crosslinking, etc.) a polymer composition containing a polymer of a base material. The fixing beads 14 are disposed at substantially equal density over the entire surface of the base material layer 11 by the bonding agent 15. In addition, the polymer composition for forming the binder 15 may be suitably blended with, for example, a micro inorganic filler, a curing agent, a plasticizer, a dispersant, various leveling agents, an antistatic agent, and an ultraviolet absorber. , antioxidants, viscosity modifiers, lubricants, light stabilizers, etc.
(背層)(back layer)
背層13需要使光線透射,因此形成為透明。背層13以合成樹脂為主成分來形成。作為背層13的主成分,並無特別限定,可列舉例如熱固化型樹脂、活性能量射線固化型樹脂等。The back layer 13 needs to transmit light, and thus is formed to be transparent. The back layer 13 is formed mainly of a synthetic resin. The main component of the back layer 13 is not particularly limited, and examples thereof include a thermosetting resin and an active energy ray-curable resin.
作為上述熱固化型樹脂,可列舉例如環氧樹脂、矽酮樹脂、酚醛樹脂、尿素樹脂、不飽和聚酯樹脂、三聚氰胺樹脂、醇酸樹脂、丙烯酸樹脂、醯胺官能性共聚物、聚氨酯樹脂等。Examples of the thermosetting resin include an epoxy resin, an anthrone resin, a phenol resin, a urea resin, an unsaturated polyester resin, a melamine resin, an alkyd resin, an acrylic resin, a guanamine functional copolymer, a polyurethane resin, and the like. .
作為上述活性能量射線固化型樹脂,可列舉:通過照射紫外線而交聯、固化的紫外線固化型樹脂;通過照射電子射線而交聯、固化的電子束固化型樹脂等。可以從聚合性單體及聚合性低聚體中適當選擇使用。其中,作為上述活性能量射線固化型樹脂,優選丙烯酸系、氨基甲酸乙酯系或丙烯酸氨基甲酸乙酯系紫外線固化型樹脂。Examples of the active energy ray-curable resin include an ultraviolet curable resin which is crosslinked and cured by irradiation with ultraviolet rays, and an electron beam curable resin which is crosslinked and cured by irradiation with an electron beam. It can be suitably selected and used from a polymerizable monomer and a polymeric oligomer. In particular, the active energy ray-curable resin is preferably an acrylic, urethane or urethane urethane-based ultraviolet curable resin.
多個凸部13a使用與背層13相同的主成分與背層13一體成形(即,一體地形成多個凸部13a及背層13)。The plurality of convex portions 13a are integrally formed with the back layer 13 using the same main component as the back layer 13 (that is, a plurality of convex portions 13a and back layers 13 are integrally formed).
各凸部13a為扁平的半球體或前端部被弄成圓狀的扁平的錐體,尤其在本實施方式中,為如圖3(a)、(b)所示那樣的扁平的半分割旋轉橢圓體。通過使各凸部13a為扁平的半分割旋轉橢圓體,從而可以更可靠地防止在背面側配置的其他光學構件的表面的損傷。多個凸部13a無規地(不具有規則性)突出設置於背層13的背面。該光擴散片5通過無規地突出設置多個凸部13a,從而可以防止基於多個凸部13a而產生莫爾條紋的情況。予以說明,「半分割旋轉橢圓體狀」不限於嚴密意義上的半分割旋轉橢圓體狀,包括基底為正圓狀且外表面被彎曲面形成為圓頂狀的形狀。Each of the convex portions 13a is a flat hemisphere or a flat cone whose front end portion is rounded, and in particular, in the present embodiment, is a flat half-segment rotation as shown in Figs. 3(a) and 3(b). Ellipsoid. By making each convex portion 13a a flat semi-divided spheroid, it is possible to more reliably prevent damage of the surface of another optical member disposed on the back side. The plurality of convex portions 13a are randomly (not regular) protruded from the back surface of the back layer 13. In the light-diffusing sheet 5, by providing a plurality of convex portions 13a in a random manner, it is possible to prevent the occurrence of moire fringes based on the plurality of convex portions 13a. Incidentally, the "semi-segmented ellipsoidal shape" is not limited to a semi-divided ellipsoidal shape in a strict sense, and includes a shape in which the base is a perfect circle and the outer surface is formed into a dome shape by a curved surface.
作為凸部13a的前端部的平均曲率半徑的下限,優選20μm,更優選50μm。另一方面,作為凸部13a的前端部的平均曲率半徑的上限,優選200μm,更優選100μm。若上述平均曲率半徑不足上述下限,則有在配置於光擴散片5的背面側的導光膜2的表面產生損傷的風險。相反,若上述平均曲率半徑超出上述上限,則凸部13a與導光膜2的表面的抵接面積變大,存在因入射至該抵接部分的光線而產生亮度不均的風險。予以說明,「凸部的前端部的平均曲率半徑」是指任意抽取的10個凸部的背層的背面平均介面與最遠離的部分的曲率半徑的平均值。The lower limit of the average radius of curvature of the front end portion of the convex portion 13a is preferably 20 μm, and more preferably 50 μm. On the other hand, the upper limit of the average radius of curvature of the tip end portion of the convex portion 13a is preferably 200 μm, and more preferably 100 μm. When the average radius of curvature is less than the lower limit, there is a risk that damage occurs on the surface of the light guiding film 2 disposed on the back side of the light diffusing sheet 5. On the other hand, when the average radius of curvature exceeds the above upper limit, the contact area between the convex portion 13a and the surface of the light guiding film 2 becomes large, and there is a risk that unevenness in brightness occurs due to light incident on the abutting portion. Incidentally, the "average curvature radius of the tip end portion of the convex portion" means an average value of the curvature radius of the back surface average interface and the farthest portion of the back layer of the arbitrarily extracted ten convex portions.
作為凸部13a的平均徑D1的下限,優選5μm,更優選7μm,進一步優選10μm。另一方面,作為凸部13a的平均徑D1的上限,優選60μm,更優選50μm,進一步優選40μm,特別優選20μm。若凸部13a的平均徑D1不足上述下限,則為了充分確保凸部13a的高度H而使凸部13a的前端部的曲率半徑過小,有在配置於光擴散片5的背面側的導光膜2的表面產生損傷的風險。相反,若凸部13a的平均徑D1超過上述上限,則為了將凸部13a的前端部的曲率半徑保持在優選的範圍而使凸部13a的高度過大,有違反背光單元的薄型化要求的風險。The lower limit of the average diameter D1 of the convex portion 13a is preferably 5 μm, more preferably 7 μm, still more preferably 10 μm. On the other hand, the upper limit of the average diameter D1 of the convex portion 13a is preferably 60 μm, more preferably 50 μm, still more preferably 40 μm, and particularly preferably 20 μm. When the average diameter D1 of the convex portion 13a is less than the lower limit, the radius of curvature of the distal end portion of the convex portion 13a is too small to sufficiently ensure the height H of the convex portion 13a, and the light guiding film disposed on the back side of the light diffusion sheet 5 is provided. The surface of 2 is at risk of injury. On the other hand, when the average diameter D1 of the convex portion 13a exceeds the above upper limit, the height of the convex portion 13a is excessively large in order to keep the radius of curvature of the distal end portion of the convex portion 13a in a preferable range, and there is a risk of violating the requirement for thinning of the backlight unit. .
作為凸部13a的平均高度H的下限,優選0.5μm,更優選0.8μm,進一步優選1.0μm。另一方面,作為凸部13a的平均高度H的上限,優選6μm,更優選5μm,進一步優選4μm。若凸部13a的平均高度H不足上述下限,則即使在除凸部13a以外的部分,光擴散片5及導光膜2也容易抵接,存在因入射至該抵接部分的光線而產生亮度不均的風險。相反,若凸部13a的平均高度H超出上述上限,則有違反背光單元的薄型化要求的風險,並且有損傷配置於背面側的其他光學構件(導光膜2)的表面的風險。The lower limit of the average height H of the convex portion 13a is preferably 0.5 μm, more preferably 0.8 μm, still more preferably 1.0 μm. On the other hand, the upper limit of the average height H of the convex portion 13a is preferably 6 μm, more preferably 5 μm, still more preferably 4 μm. When the average height H of the convex portion 13a is less than the lower limit, the light diffusion sheet 5 and the light guiding film 2 are likely to be in contact with each other except for the convex portion 13a, and light is generated due to light incident on the abutting portion. The risk of unevenness. On the other hand, when the average height H of the convex portion 13a exceeds the above upper limit, there is a risk of violating the requirement for the thinning of the backlight unit, and there is a risk of damaging the surface of the other optical member (light guiding film 2) disposed on the back side.
多個凸部13a之間優選使其高度H均勻。作為多個凸部13a的高度H的變動係數的上限,優選0.2,更優選0.1,進一步優選0.05。若多個凸部13a的高度H的變動係數超出上述上限,則多個凸部13a的高度H變得不均勻,載荷偏向高度大的凸部13a,存在基於此而使導光膜2的表面產生損傷的風險。另一方面,作為多個凸部13a的高度H的變動係數的下限,並無特別限定,例如可以為0。予以說明,多個凸部的高度的「變動係數」是指任意抽取的20個凸部的高度的標準偏差除以平均高度所得的值。It is preferable that the heights H are uniform between the plurality of convex portions 13a. The upper limit of the coefficient of variation of the height H of the plurality of convex portions 13a is preferably 0.2, more preferably 0.1, still more preferably 0.05. When the coefficient of variation of the height H of the plurality of convex portions 13a exceeds the above upper limit, the height H of the plurality of convex portions 13a becomes uneven, and the convex portion 13a having a large load deflection is present, and the surface of the light guiding film 2 is formed thereon. The risk of injury. On the other hand, the lower limit of the coefficient of variation of the height H of the plurality of convex portions 13a is not particularly limited, and may be, for example, zero. Incidentally, the "variation coefficient" of the heights of the plurality of convex portions refers to a value obtained by dividing the standard deviation of the heights of the 20 convex portions that are arbitrarily extracted by the average height.
作為多個凸部13a的平均高度H相對於平均徑D1的比(H/D1)的下限,優選0.02,更優選0.05,進一步優選0.10。另一方面,作為上述比(H/D1)的上限,優選0.2,更優選0.15,進一步優選0.12。若上述比(H/D1)不足上述下限,則多個凸部13a與導光膜2的表面的抵接面積變大,存在因入射至該抵接部分的光線而產生亮度不均的風險。相反,若上述比(H/D1)超出上述上限,則多個凸部13a的前端部變得過於銳利,存在使導光膜2的表面產生損傷的風險。The lower limit of the ratio (H/D1) of the average height H of the plurality of convex portions 13a to the average diameter D1 is preferably 0.02, more preferably 0.05, still more preferably 0.10. On the other hand, the upper limit of the above ratio (H/D1) is preferably 0.2, more preferably 0.15, still more preferably 0.12. When the ratio (H/D1) is less than the lower limit, the contact area between the plurality of convex portions 13a and the surface of the light guiding film 2 is increased, and there is a risk that unevenness in brightness occurs due to light incident on the abutting portion. On the other hand, when the ratio (H/D1) exceeds the above upper limit, the tip end portions of the plurality of convex portions 13a become too sharp, and there is a risk that the surface of the light guiding film 2 is damaged.
作為凸部13a的平均間距的下限,優選200μm,更優選300μm,進一步優選400μm。另一方面,作為凸部13a的平均間距的上限,優選1000μm,更優選900μm,進一步優選800μm。若凸部13a的平均間距不足上述下限,則凸部13a的數量過多,存在使導光膜2的表面產生損傷的風險。另外,若凸部13a的平均間距不足上述下限,則凸部13a的數量過多,在如後述的實施方式那樣在凸部13a的形成面形成有光柵形狀的情況下,存在使光柵性能降低的風險。相反,若凸部13a的平均間距超出上述上限,則存在凸部13a的數量不足而無法充分防止黏附的風險。予以說明,凸部的「平均間距」是指:任意抽取10個凸部,所抽取的各個凸部及與這些凸部最鄰接的其他凸部的間距的平均值。The lower limit of the average pitch of the convex portions 13a is preferably 200 μm, more preferably 300 μm, still more preferably 400 μm. On the other hand, the upper limit of the average pitch of the convex portions 13a is preferably 1000 μm, more preferably 900 μm, still more preferably 800 μm. When the average pitch of the convex portions 13a is less than the above lower limit, the number of the convex portions 13a is too large, and there is a risk that the surface of the light guiding film 2 is damaged. In addition, when the average pitch of the convex portions 13a is less than the lower limit, the number of the convex portions 13a is too large, and when a grating shape is formed on the surface on which the convex portions 13a are formed as in the embodiment to be described later, there is a risk of lowering the grating performance. . On the other hand, if the average pitch of the convex portions 13a exceeds the above upper limit, there is a risk that the number of the convex portions 13a is insufficient and the adhesion cannot be sufficiently prevented. Incidentally, the "average pitch" of the convex portions means an average value of the pitches of the extracted convex portions and the other convex portions adjacent to the convex portions.
作為多個凸部13a的佔有面積比的下限,優選2%,更優選3%,進一步優選4%。另一方面,作為多個凸部13a的佔有面積比的上限,優選80%,更優選70%,進一步優選60%,特別優選40%。若多個凸部13a的佔有面積比不足上述下限,則存在無法充分防止黏附的風險。相反,若多個凸部13a的佔有面積比超出上述上限,則存在使導光膜2的表面產生損傷的風險。The lower limit of the occupied area ratio of the plurality of convex portions 13a is preferably 2%, more preferably 3%, still more preferably 4%. On the other hand, the upper limit of the area ratio of the plurality of convex portions 13a is preferably 80%, more preferably 70%, still more preferably 60%, and particularly preferably 40%. When the ratio of the area occupied by the plurality of convex portions 13a is less than the above lower limit, there is a risk that the adhesion cannot be sufficiently prevented. On the other hand, if the area ratio of the plurality of convex portions 13a exceeds the above upper limit, there is a risk that the surface of the light guiding film 2 is damaged.
作為凸部13a的平均徑D1相對於珠14的平均粒徑之比的下限,優選3,更優選4,進一步優選5。另一方面,作為上述比的上限,優選為9,更優選為8,進一步優選為7。若上述比不足上述下限,則存在入射至凸部13a的光量不足而難以利用凸部13a充分引入光的風險,並且存在使被該光擴散片5的背層13的背面所鏡面反射的光量變大的風險。相反,若上述比超出上述上限,則存在凸部13a的彎曲形狀過於平緩而難以利用凸部13a引入光線的風險。The lower limit of the ratio of the average diameter D1 of the convex portion 13a to the average particle diameter of the beads 14 is preferably 3, more preferably 4, still more preferably 5. On the other hand, the upper limit of the above ratio is preferably 9, more preferably 8, and still more preferably 7. When the ratio is less than the lower limit, the amount of light incident on the convex portion 13a is insufficient, and it is difficult to sufficiently introduce light by the convex portion 13a, and the amount of light that is specularly reflected by the back surface of the back layer 13 of the light diffusion sheet 5 is changed. Big risk. On the other hand, when the above ratio exceeds the above upper limit, there is a risk that the curved shape of the convex portion 13a is too gentle and it is difficult to introduce light by the convex portion 13a.
多個凸部13a以合成樹脂為主成分來形成。另外,多個凸部13在內部不包含珠。該光擴散片5由於多個凸部13a不含有珠,因此可以防止因珠的脫落而損傷配置於該光擴散片5的背面側的導光膜2的表面的情況。The plurality of convex portions 13a are formed mainly of a synthetic resin. In addition, the plurality of convex portions 13 do not include beads inside. In the light-diffusing sheet 5, since the plurality of convex portions 13a do not contain beads, it is possible to prevent the surface of the light-guiding film 2 disposed on the back surface side of the light-diffusing sheet 5 from being damaged by the falling of the beads.
<棱鏡片><Prism sheet>
如圖4所示,棱鏡片6具備基體材料層16、層疊於基體材料層16的表面側的棱鏡列17和層疊於基體材料層16的背面側的背層18。棱鏡列17通過平行地配置多個凸條棱鏡部17a來構成。另外,棱鏡片6在背層18的背面以散點狀具備作為防黏附部的多個凸部18a。棱鏡片6由基體材料層16、棱鏡列17、背層18及多個凸部18a構成(即,棱鏡片6不具有除基體材料層16、棱鏡列17、背層18及多個凸部18a以外的其他層)。棱鏡片6形成為俯視下的方形狀。As shown in FIG. 4, the prism sheet 6 is provided with a base material layer 16, a prism array 17 laminated on the surface side of the base material layer 16, and a back layer 18 laminated on the back side of the base material layer 16. The prism array 17 is configured by arranging a plurality of ridge prism portions 17a in parallel. Further, the prism sheet 6 is provided with a plurality of convex portions 18a as anti-adhesion portions on the back surface of the back layer 18. The prism sheet 6 is composed of a base material layer 16, a prism array 17, a back layer 18, and a plurality of convex portions 18a (that is, the prism sheet 6 does not have the base material layer 16, the prism array 17, the back layer 18, and the plurality of convex portions 18a. Other layers than others). The prism sheet 6 is formed in a square shape in plan view.
基體材料層16及棱鏡列17需要使光線透射,因此形成為透明。基體材料層16及棱鏡列17以合成樹脂為主成分來構成。作為基體材料層16及棱鏡列17的主成分,可列舉與光擴散片5的基體材料層11的主成分同樣的合成樹脂。另外,作為基體材料層16及棱鏡列17的主成分,也可以使用與光擴散片5的多個凸部13a同樣的熱固化型樹脂、活性能量射線固化型樹脂等。棱鏡列17的方向(多個凸條棱鏡部17a的山脊線方向)在本實施方式中與光源3的光線出射方向垂直。The base material layer 16 and the prism array 17 need to transmit light, and thus are formed to be transparent. The base material layer 16 and the prism array 17 are composed of a synthetic resin as a main component. The main component of the base material layer 16 and the prism array 17 is the same as the main component of the base material layer 11 of the light diffusion sheet 5. In addition, as the main component of the base material layer 16 and the prism array 17, a thermosetting resin, an active energy ray-curable resin, or the like similar to the plurality of convex portions 13a of the light diffusion sheet 5 may be used. The direction of the prism array 17 (the ridge line direction of the plurality of ridge prism portions 17a) is perpendicular to the light emission direction of the light source 3 in the present embodiment.
作為從棱鏡片6的基體材料層16的背面到凸條棱鏡部17a的頂點的高度的下限,優選50μm,更優選100μm。另一方面,作為上述高度的上限,優選為200μm,更優選為180μm。作為棱鏡片6的多個凸條棱鏡部17a的平均間距的下限,優選10μm,更優選20μm。另一方面,作為多個凸條棱鏡部17a的平均間距的上限,優選100μm,更優選60μm。作為凸條棱鏡部17a的頂角,優選85°以上且95°以下。另外,作為凸條棱鏡部17a的底角,優選42°以上且48°以下。作為棱鏡片6的折射率的下限,優選1.5,更優選1.55。另一方面,作為棱鏡片6的折射率的上限,優選1.7。予以說明,「凸條棱鏡部的平均間距」是指任意抽取的連續的10個凸條棱鏡部的平均間距。另外,「折射率」是指波長589.3nm的光(鈉的D射線)的折射率,是指使用一邊為70mm且厚度為2mm的平板狀的試驗片並在溫度23℃下測定的試驗次數為3次的平均值。另外,「棱鏡片的折射率」是指凸條棱鏡部的折射率。The lower limit of the height from the back surface of the base material layer 16 of the prism sheet 6 to the apex of the ridge prism portion 17a is preferably 50 μm, more preferably 100 μm. On the other hand, the upper limit of the above height is preferably 200 μm, and more preferably 180 μm. The lower limit of the average pitch of the plurality of ridge prism portions 17a of the prism sheet 6 is preferably 10 μm, more preferably 20 μm. On the other hand, the upper limit of the average pitch of the plurality of ridge prism portions 17a is preferably 100 μm, more preferably 60 μm. The apex angle of the ridge prism portion 17a is preferably 85° or more and 95° or less. Further, the base angle of the ridge prism portion 17a is preferably 42° or more and 48° or less. The lower limit of the refractive index of the prism sheet 6 is preferably 1.5, and more preferably 1.55. On the other hand, the upper limit of the refractive index of the prism sheet 6 is preferably 1.7. Incidentally, the "average pitch of the ridge prism portions" means the average pitch of the contiguous ten ridge prism portions that are arbitrarily extracted. In addition, the "refractive index" means a refractive index of light having a wavelength of 589.3 nm (D-ray of sodium), and is a test piece having a flat shape of 70 mm and a thickness of 2 mm and measuring at a temperature of 23 ° C. The average of 3 times. Further, the "refractive index of the prism sheet" means the refractive index of the ridge strip portion.
背層18需要使光線透射,因此形成為透明。背層18以合成樹脂為主成分來形成。作為背層18的主成分,可以與上述的光擴散片5的背層13的主成分同樣。The backing layer 18 needs to transmit light and is thus formed to be transparent. The back layer 18 is formed mainly of a synthetic resin. The main component of the back layer 18 can be the same as the main component of the back layer 13 of the above-described light diffusion sheet 5.
多個凸部18a使用與背層18相同的主成分與背層18一體成形(即,一體地形成多個凸部18a及背層18)。The plurality of convex portions 18a are integrally formed with the back layer 18 using the same main component as the back layer 18 (that is, a plurality of convex portions 18a and back layers 18 are integrally formed).
多個凸部18a構成該棱鏡片6的最背面。各凸部18a為扁平的半球體或前端部被弄成圓狀的扁平的錐體,尤其在本實施方式中為扁平的半分割旋轉橢圓體。多個凸部18a無規地(不具有規則性)突出設置於背層18的背面。多個凸部18a的具體的形狀與光擴散片5的多個凸部13a同樣。The plurality of convex portions 18a constitute the rearmost surface of the prism sheet 6. Each of the convex portions 18a is a flat hemisphere or a flat cone whose front end portion is rounded, and is particularly a flat semi-divided ellipsoid in the present embodiment. The plurality of convex portions 18a are randomly (not regular) protruded from the back surface of the back layer 18. The specific shape of the plurality of convex portions 18a is the same as that of the plurality of convex portions 13a of the light diffusion sheet 5.
作為凸部18a的平均徑相對於凸條棱鏡部17a的平均間距之比的下限,優選0.1,更優選0.3,進一步優選0.5。另一方面,作為上述比的上限,優選6.0,更優選3.0,進一步優選1.0。若上述比不足上述下限,則存在入射至凸部18a的光量不足而難以利用凸部18a充分引入光的風險,並且存在使被該棱鏡片6的背層18的背面所鏡面反射的光量變大的風險。相反,若上述比超出上述上限,則存在凸部18a的彎曲形狀過於平緩而難以利用凸部18a引入光線的風險。The lower limit of the ratio of the average diameter of the convex portions 18a to the average pitch of the ridge prism portions 17a is preferably 0.1, more preferably 0.3, still more preferably 0.5. On the other hand, the upper limit of the above ratio is preferably 6.0, more preferably 3.0, still more preferably 1.0. When the ratio is less than the lower limit, the amount of light incident on the convex portion 18a is insufficient, and it is difficult to sufficiently introduce light by the convex portion 18a, and the amount of light that is specularly reflected by the back surface of the back layer 18 of the prism sheet 6 is increased. risks of. On the other hand, when the above ratio exceeds the above upper limit, there is a risk that the curved shape of the convex portion 18a is too gentle and it is difficult to introduce light by the convex portion 18a.
<導光膜><light guide film>
導光膜2將從端面入射的光線從表面大致均勻地出射。導光膜2形成為俯視下的大致方形狀,並且形成為厚度大致均勻的板狀(非楔形狀)。導光膜2在背面具有向表面側凹陷的多個凹部9。另外,導光膜2在背面具有防黏附部。具體而言,導光膜2具有存在於多個凹部9的周圍且向背面側突出的多個***部8作為上述防黏附部。***部8與凹部9鄰接設置,***部8的內側面與凹部9的形成面連續。The light guiding film 2 emits light that is incident from the end surface substantially uniformly from the surface. The light guiding film 2 is formed in a substantially square shape in plan view, and is formed into a plate shape (non-wedge shape) having a substantially uniform thickness. The light guiding film 2 has a plurality of concave portions 9 recessed toward the surface side on the back surface. Further, the light guiding film 2 has an anti-adhesion portion on the back surface. Specifically, the light guiding film 2 has a plurality of raised portions 8 that are present around the plurality of concave portions 9 and protrude toward the back side as the above-described anti-adhesion portion. The raised portion 8 is provided adjacent to the concave portion 9, and the inner side surface of the raised portion 8 is continuous with the surface on which the concave portion 9 is formed.
作為導光膜2的平均厚度的下限,優選100μm,更優選150μm,進一步優選200μm。另一方面,作為導光膜2的平均厚度的上限,優選600μm,更優選580μm,進一步優選550μm。若導光膜2的平均厚度不足上述下限,則存在使導光膜2的強度不充分的風險,並且存在無法將從光源3出射的光線充分入射至導光膜2的風險。相反,若導光膜2的平均厚度超出上述上限,則存在未依照該背光單元1的薄型化要求的風險。The lower limit of the average thickness of the light guiding film 2 is preferably 100 μm, more preferably 150 μm, still more preferably 200 μm. On the other hand, the upper limit of the average thickness of the light guiding film 2 is preferably 600 μm, more preferably 580 μm, still more preferably 550 μm. When the average thickness of the light guiding film 2 is less than the above lower limit, there is a risk that the strength of the light guiding film 2 is insufficient, and there is a risk that light emitted from the light source 3 cannot be sufficiently incident on the light guiding film 2 . On the contrary, if the average thickness of the light guiding film 2 exceeds the above upper limit, there is a risk that the thinning of the backlight unit 1 is not required.
多個凹部9作為使入射光向表面側散射的光散射部發揮功能。各凹部9形成為在俯視下的大致圓形狀。另外,各凹部9以向表面側逐漸縮徑的方式形成。作為凹部9的形狀,並無特別限定,可以為半球狀、半橢圓體狀、圓錐狀、圓錐梯形狀等。其中,作為凹部9的形狀,優選半球狀或半橢圓體狀。通過使凹部9為半球狀或半橢圓體狀,從而可以提高凹部9的成形性,並且適合使入射至凹部9的光線散射。The plurality of concave portions 9 function as a light scattering portion that scatters incident light toward the surface side. Each of the recesses 9 is formed in a substantially circular shape in plan view. Further, each of the concave portions 9 is formed to gradually reduce the diameter toward the surface side. The shape of the concave portion 9 is not particularly limited, and may be a hemispherical shape, a semi-elliptical shape, a conical shape, a conical ladder shape or the like. Among them, the shape of the concave portion 9 is preferably a hemispherical shape or a semi-elliptical shape. By making the concave portion 9 hemispherical or semi-elliptical, the formability of the concave portion 9 can be improved, and the light incident on the concave portion 9 can be suitably scattered.
***部8從導光膜2的背面的與導光膜2的厚度方向垂直的面連續地形成。詳細而言,***部8從導光膜2的背面的平坦面連續形成。***部8以包圍凹部9的方式形成為俯視下的大致圓環狀。導光膜2通過以***部8包圍凹部9的方式形成為俯視下的大致圓環狀,從而可以容易且可靠地防止凹部9及凹部9近邊與在導光膜2的背面側配置的反射片7密合。The raised portion 8 is continuously formed from a surface of the back surface of the light guiding film 2 that is perpendicular to the thickness direction of the light guiding film 2. Specifically, the ridge portion 8 is continuously formed from the flat surface of the back surface of the light guiding film 2 . The raised portion 8 is formed in a substantially annular shape in a plan view so as to surround the concave portion 9. The light guiding film 2 is formed in a substantially annular shape in a plan view so as to surround the concave portion 9 with the raised portion 8, so that the concave portion 9 and the near side of the concave portion 9 and the reflection disposed on the back side of the light guiding film 2 can be easily and reliably prevented. Sheet 7 is tight.
導光膜2具有柔性。導光膜2通過具有柔性,從而可以抑制配置於背面側的反射片7的損傷。導光膜2需要使光線透射,因此形成為透明。導光膜2以合成樹脂為主成分來構成。The light guiding film 2 has flexibility. By having flexibility, the light guiding film 2 can suppress damage of the reflection sheet 7 disposed on the back side. The light guiding film 2 needs to transmit light, and thus is formed to be transparent. The light guiding film 2 is composed of a synthetic resin as a main component.
作為導光膜2的主成分,可列舉聚碳酸酯、丙烯酸樹脂、聚對苯二甲酸乙二醇酯、聚萘二甲酸乙二醇酯、聚苯乙烯、(甲基)丙烯酸甲酯-苯乙烯共聚物、聚烯烴、環烯烴聚合物、環烯烴共聚物、醋酸纖維素、耐氣候性氯乙烯、活性能量射線固化型樹脂等。其中,作為導光膜2的主成分,優選聚碳酸酯或丙烯酸樹脂。聚碳酸酯由於透明性優異且折射率高,因此通過使導光膜2包含聚碳酸酯作為主成分,從而在導光膜2的上背面容易發生全反射,可以使光線有效地傳播。另外,聚碳酸酯具有耐熱性,因此不易發生由光源3的發熱所致的劣化等。進而,聚碳酸酯與丙烯酸樹脂等相比吸水性更小,因此尺寸穩定性高。因此,導光膜2可以通過包含聚碳酸酯作為主成分而抑制經年劣化。另一方面,丙烯酸樹脂由於透明度高,因此可以減少導光膜2的光的損耗。Examples of the main component of the light guiding film 2 include polycarbonate, acrylic resin, polyethylene terephthalate, polyethylene naphthalate, polystyrene, and methyl (meth)acrylate-benzene. Ethylene copolymer, polyolefin, cycloolefin polymer, cyclic olefin copolymer, cellulose acetate, weather resistant vinyl chloride, active energy ray-curable resin, and the like. Among them, as the main component of the light guiding film 2, polycarbonate or acrylic resin is preferable. Since the polycarbonate is excellent in transparency and has a high refractive index, the light guide film 2 contains polycarbonate as a main component, so that total reflection easily occurs on the upper and lower surfaces of the light guiding film 2, and light can be efficiently transmitted. Further, since polycarbonate has heat resistance, deterioration or the like due to heat generation of the light source 3 is less likely to occur. Further, since polycarbonate has a smaller water absorption property than an acrylic resin or the like, the dimensional stability is high. Therefore, the light guiding film 2 can suppress deterioration over the years by including polycarbonate as a main component. On the other hand, since the acrylic resin has high transparency, the loss of light of the light guiding film 2 can be reduced.
<LED光源><LED light source>
多個LED3沿著導光膜2的一個端面配置。多個LED光源3以使各光線出射面與導光膜2的一個端面對置(或抵接)的方式配置。The plurality of LEDs 3 are arranged along one end surface of the light guiding film 2. The plurality of LED light sources 3 are disposed such that each light emitting surface faces and faces (or abuts) one end surface of the light guiding film 2.
<反射片><reflection sheet>
反射片7以與在導光膜2的背面形成的多個***部8抵接的方式配置於導光膜2的背面側。反射片7使從導光膜2的背面出射的光線向上側反射。作為反射片7,可列舉:在聚酯等基體材料樹脂中分散含有填充物的白色片、通過在由聚酯形成的膜的表面蒸鍍鋁、銀等金屬而提高鏡面反射性的鏡面片等。The reflection sheet 7 is disposed on the back side of the light guide film 2 so as to be in contact with the plurality of raised portions 8 formed on the back surface of the light guiding film 2 . The reflection sheet 7 reflects the light emitted from the back surface of the light guiding film 2 to the upper side. The reflective sheet 7 is a white sheet in which a filler is dispersed in a base material resin such as polyester, and a mirror sheet having a specular reflectance by vapor-depositing a metal such as aluminum or silver on the surface of a film formed of polyester. .
<優點><advantage>
該光學片(光擴散片5及棱鏡片6)在背面以散點狀具備多個凸部13a、18a,因此該光學片及在該光學片的背面側配置的其他光學構件利用該多個凸部13a、18a部分抵接。因此,該光學片可以防止與在背面側配置的其他光學構件的黏附。進而,該光學片的上述凸部13a、18a為扁平的半球體或前端部被弄成圓狀的扁平的錐體,因此多個凸部13a、18a的前端部(下端部)的彎曲面比較平緩,由此可以防止配置於背面側的其他光學構件的表面的損傷。Since the optical sheets (the light-diffusing sheet 5 and the prism sheet 6) are provided with a plurality of convex portions 13a and 18a in a scattered manner on the back surface, the optical sheet and other optical members disposed on the back side of the optical sheet use the plurality of convex portions. The portions 13a and 18a are partially abutted. Therefore, the optical sheet can prevent adhesion to other optical members disposed on the back side. Further, since the convex portions 13a and 18a of the optical sheet are flat hemispheres or flat cones whose front end portions are rounded, the curved surfaces of the front end portions (lower end portions) of the plurality of convex portions 13a and 18a are compared. The gradation makes it possible to prevent damage to the surface of other optical members disposed on the back side.
該背光單元1具備該光學片(光擴散片5及棱鏡片6),因此可以如上述那樣防止該光學片及在該光學片的背面側配置的其他光學構件的黏附,並且可以防止其他光學構件的表面的損傷。Since the backlight unit 1 includes the optical sheet (the light diffusion sheet 5 and the prism sheet 6), adhesion of the optical sheet and other optical members disposed on the back side of the optical sheet can be prevented as described above, and other optical members can be prevented. Damage to the surface.
<光學片的製造方法><Method of Manufacturing Optical Sheet>
接著,對該光學片的製造方法進行說明。在此,對該光學片為上述的光擴散片5時的製造方法進行說明。該光學片的製造方法具備樹脂膜運送工序、紫外線固化型樹脂組合物供給工序和紫外線照射工序。另外,該光學片的製造方法具備光擴散層層疊工序。Next, a method of manufacturing the optical sheet will be described. Here, a method of manufacturing the optical sheet in the above-described light diffusion sheet 5 will be described. The method for producing an optical sheet includes a resin film transport step, an ultraviolet curable resin composition supply step, and an ultraviolet irradiation step. Moreover, this optical sheet manufacturing method has the light-diffusion layer lamination process.
(製造裝置)(manufacturing device)
該光學片的製造方法使用例如圖5的製造裝置21來進行。製造裝置21具有以平行鄰接的方式配置的一對壓輥22、23。一對壓輥22、23設有溫度控制手段,以能夠將表面(圓周面)溫度控制為最佳溫度的方式構成。作為一對擠壓輥22、23,優選使用包含金屬輥和表面覆蓋有彈性體的柔性輥的金屬彈性輥。另外,一個壓輥23在表面(圓周面)具有多個凹部。具體而言,一個壓輥23在表面具有以散點狀具備上述多個凸部13a的背面形狀的翻轉形狀。The method of manufacturing the optical sheet is performed using, for example, the manufacturing apparatus 21 of Fig. 5 . The manufacturing apparatus 21 has a pair of press rolls 22, 23 arranged in parallel adjacent manner. The pair of press rolls 22 and 23 are provided with temperature control means so that the surface (circumferential surface) temperature can be controlled to an optimum temperature. As the pair of pressing rolls 22, 23, a metal elastic roll comprising a metal roll and a flexible roll whose surface is covered with an elastomer is preferably used. Further, one press roller 23 has a plurality of recesses on the surface (circumferential surface). Specifically, the one pressure roller 23 has an inverted shape in which the back surface shape of the plurality of convex portions 13a is provided in a scatter manner on the surface.
(樹脂膜運送工序)(Resin film transport process)
在上述樹脂膜運送工序中,向一對壓輥22、23的表面運送帶狀的樹脂膜A。具體而言,在上述樹脂膜運送工序中,將形成光擴散片5的基體材料層11的樹脂膜A運送到一對壓輥22、23之間。In the resin film transporting step, the strip-shaped resin film A is transported to the surfaces of the pair of press rolls 22 and 23. Specifically, in the resin film transport step, the resin film A forming the base material layer 11 of the light diffusion sheet 5 is transported between the pair of press rolls 22 and 23.
(紫外線固化型樹脂組合物供給工序)(Ultraviolet curable resin composition supply step)
在上述紫外線固化型樹脂組合物供給工序中,向上述樹脂膜A及一個壓輥23間供給紫外線固化型樹脂組合物。在該紫外線固化型樹脂組合物供給工序中,將上述樹脂膜A及供給至該樹脂膜A的一個面的紫外線固化型樹脂組合物用一對壓輥22、23進行擠壓。在該紫外線固化型樹脂組合物供給工序中,在層疊於上述樹脂膜A的一個面的紫外線固化型樹脂組合物的外表面(一個側面)轉印多個凸部13a。In the ultraviolet curable resin composition supply step, an ultraviolet curable resin composition is supplied between the resin film A and one of the press rolls 23. In the ultraviolet curable resin composition supply step, the resin film A and the ultraviolet curable resin composition supplied to one surface of the resin film A are pressed by a pair of press rolls 22 and 23. In the ultraviolet curable resin composition supply step, a plurality of convex portions 13a are transferred on the outer surface (one side surface) of the ultraviolet curable resin composition laminated on one surface of the resin film A.
(紫外線照射工序)(UV irradiation process)
在上述紫外線照射工序中,對利用上述紫外線固化型樹脂組合物供給工序轉印有多個凸部13a的紫外線固化型樹脂組合物照射紫外線,使該紫外線固化型樹脂組合物固化。利用該紫外線照射工序,在上述樹脂膜A的一個面形成多個凸部13a。In the ultraviolet irradiation step, the ultraviolet curable resin composition in which the plurality of convex portions 13a are transferred by the ultraviolet curable resin composition supply step is irradiated with ultraviolet rays to cure the ultraviolet curable resin composition. In the ultraviolet irradiation step, a plurality of convex portions 13a are formed on one surface of the resin film A.
(光擴散層層疊工序)(Light diffusion layer lamination process)
在上述光擴散層層疊工序中,在上述紫外線照射工序後將包含多個珠14及黏結劑組合物的塗布液塗布於上述樹脂膜A的另一個面,再使所塗布的塗布液乾燥及固化。利用該光擴散層層疊工序,在上述樹脂膜A的另一個面層疊光擴散層12。In the light diffusion layer laminating step, after the ultraviolet irradiation step, a coating liquid containing a plurality of beads 14 and a binder composition is applied onto the other surface of the resin film A, and the applied coating liquid is dried and cured. . In the light diffusion layer lamination step, the light diffusion layer 12 is laminated on the other surface of the resin film A.
予以說明,在此,對形成多個凸部13a後層疊光擴散層12的步驟進行了說明,該光擴散片的製造方法並不限定於該步驟,也可以在層疊光擴散層12後形成多個凸部13a。Here, the step of laminating the light diffusion layer 12 after forming the plurality of convex portions 13a has been described. The method for producing the light diffusion sheet is not limited to this step, and may be formed after laminating the light diffusion layer 12. Projections 13a.
另外,在此,對該光學片為光擴散片5時的製造方法進行了說明,但是在該光學片為棱鏡片6時也可以使用上述同樣的樹脂膜運送工序、紫外線固化型樹脂組合物供給工序及紫外線照射工序來製造。具體而言,作為該棱鏡片6的製造方法,可列舉:(a)在上述紫外線照射工序後將活性能量射線固化型樹脂塗布於上述樹脂膜的另一個面,將其按壓於具有棱鏡列17的翻轉形狀的薄片模具、模具或輥模具,向未固化的活性能量射線固化型樹脂上轉印形狀,照射活性能量射線使活性能量射線固化型樹脂固化的方法;(b)在另一壓輥23的圓周面形成棱鏡列17的翻轉形狀,向上述樹脂膜的另一個面通入熔融狀態的樹脂,轉印上述形狀的方法等。另外,作為該棱鏡片的製造方法,也可以在形成棱鏡列17後形成多個凸部。In the case where the optical sheet is the light-diffusing sheet 5, the same resin film transport step and ultraviolet curable resin composition supply can be used. It is manufactured by a process and an ultraviolet irradiation process. Specifically, as a method of producing the prism sheet 6, (a) the active energy ray-curable resin is applied to the other surface of the resin film after the ultraviolet irradiation step, and is pressed against the prism array 17 a sheet mold, a mold or a roll mold having an inverted shape, a shape transferred onto an uncured active energy ray-curable resin, and a method of irradiating an active energy ray to cure the active energy ray-curable resin; (b) another pressure roller The circumferential surface of 23 forms an inverted shape of the prism array 17, and a resin in a molten state is introduced into the other surface of the resin film, and the above-described shape is transferred. Further, as the method of manufacturing the prism sheet, a plurality of convex portions may be formed after the prism rows 17 are formed.
<優點><advantage>
該光學片的製造方法可以利用表面具有扁平的半球體狀或前端部被弄成圓狀的扁平的錐體狀的多個凸部13a、18a的翻轉形狀的輥24,在樹脂膜的一個面形成多個凸部13a、18a。因此,該液晶顯示裝置用光學片的製造方法,可以製造通過利用多個凸部13a、18a與其他光學構件部分抵接而防止黏附、並且可以防止與多個凸部13a、18a抵接的其他光學構件的損傷的光學片(光擴散片5及棱鏡片6)。In the method for producing the optical sheet, a roll 24 having a flat hemispherical shape or a flat pan-shaped convex portion 13a, 18a having a rounded front end portion can be used, and one surface of the resin film can be used. A plurality of convex portions 13a, 18a are formed. Therefore, in the method for producing an optical sheet for a liquid crystal display device, it is possible to prevent adhesion by a plurality of convex portions 13a and 18a from coming into contact with other optical member portions, and to prevent contact with the plurality of convex portions 13a and 18a. Optical sheets (light diffusing sheets 5 and prism sheets 6) damaged by optical members.
《第二實施方式》Second Embodiment
《背光單元》"Backlight unit"
圖6的液晶顯示裝置用背光單元31為側光型背光單元,並且是使用多個LED光源的液晶顯示裝置用背光單元。該背光單元31具備:作為將從端面入射的光線引向表面側的導光片的導光膜2、沿著導光膜2的上述端面配置的多個LED光源3和重疊於導光膜2的表面側的多個光學片32。該背光單元31具有直接(不間隔其他片等)重疊於導光膜2的表面的微透鏡片33和直接(不間隔其他片等)重疊於微透鏡片33的表面的棱鏡片6作為多個光學片32。另外,該背光單元31還具備在導光膜2的背面側配置的反射片7。予以說明,在圖6中分別分離記載了反射片7、導光膜2、微透鏡片33及棱鏡片6,但實際上反射片7的表面及導光膜2的背面、導光膜2的表面及微透鏡片33的背面、微透鏡片33的表面及棱鏡片6的背面相抵接。該背光單元31的導光膜2、LED光源3、棱鏡片6及反射片7與圖1的背光單元1同樣,因此標記同一符號而省略對其的說明。The backlight unit 31 for a liquid crystal display device of FIG. 6 is a side light type backlight unit, and is a backlight unit for a liquid crystal display device using a plurality of LED light sources. The backlight unit 31 includes a light guide film 2 that guides light incident from the end surface toward the light guide sheet on the front surface side, a plurality of LED light sources 3 that are disposed along the end surface of the light guide film 2, and a light guide film 2 that is superposed on the light guide film 2 A plurality of optical sheets 32 on the surface side. The backlight unit 31 has a lenticular sheet 33 that is directly superimposed on the surface of the light guiding film 2 (without spacing of other sheets or the like), and a prism sheet 6 that directly overlaps the surface of the lenticular sheet 33 (without spacing other sheets, etc.) as a plurality of Optical sheet 32. Further, the backlight unit 31 further includes a reflection sheet 7 disposed on the back side of the light guiding film 2. In addition, in FIG. 6, the reflection sheet 7, the light guide film 2, the microlens sheet 33, and the prism sheet 6 are separately described, but actually, the surface of the reflection sheet 7, the back surface of the light-guide film 2, and the light-guide film 2 are isolate|separated. The surface and the back surface of the lenticular sheet 33, the surface of the lenticular sheet 33, and the back surface of the prism sheet 6 are in contact with each other. The light guide film 2, the LED light source 3, the prism sheet 6, and the reflection sheet 7 of the backlight unit 31 are the same as those of the backlight unit 1 of Fig. 1, and therefore the same reference numerals will be given thereto, and the description thereof will be omitted.
<微透鏡片><Microlens sheet>
如圖7所示,微透鏡片33具備基體材料層34、在基體材料層34的表面側層疊的微透鏡陣列35和在基體材料層34的背面側層疊的背層36。微透鏡陣列35由突出設置於基體材料層34的表面的多個微透鏡35a構成。另外,微透鏡片33在背層36的背面以散點狀具備作為防黏附部的多個凸部36a。微透鏡片33由基體材料層34、微透鏡陣列35、背層36及多個凸部36a構成(即,微透鏡片33不具有除基體材料層34、微透鏡陣列35、背層36及多個凸部36a以外的其他層)。微透鏡片33形成為在俯視下的方形狀。As shown in FIG. 7, the lenticular sheet 33 includes a base material layer 34, a microlens array 35 laminated on the surface side of the base material layer 34, and a back layer 36 laminated on the back side of the base material layer 34. The microlens array 35 is composed of a plurality of microlenses 35a projecting from the surface of the base material layer 34. Further, the lenticular sheet 33 has a plurality of convex portions 36a as anti-adhesion portions on the back surface of the back layer 36 in a scattered manner. The lenticular sheet 33 is composed of a base material layer 34, a microlens array 35, a back layer 36, and a plurality of convex portions 36a (that is, the lenticular sheet 33 does not have the base material layer 34, the microlens array 35, the back layer 36, and the like. Other layers than the convex portion 36a). The lenticular sheet 33 is formed in a square shape in plan view.
基體材料層34及微透鏡陣列35需要使光線透射,因此形成為透明。基體材料層34及微透鏡陣列35以合成樹脂為主成分來構成。作為基體材料層34及微透鏡陣列35的主成分,可列舉與光擴散片5的基體材料層11的主成分同樣的合成樹脂。另外,作為基體材料層34及微透鏡陣列35的主成分,也可以使用與光擴散片5的背層13同樣的熱固化型樹脂、活性能量射線固化型樹脂等。The base material layer 34 and the microlens array 35 need to transmit light, and thus are formed to be transparent. The base material layer 34 and the microlens array 35 are composed of a synthetic resin as a main component. The main component of the base material layer 34 and the microlens array 35 is the same as the main component of the base material layer 11 of the light diffusion sheet 5. In addition, as the main component of the base material layer 34 and the microlens array 35, a thermosetting resin, an active energy ray-curable resin, or the like similar to the back layer 13 of the light diffusion sheet 5 may be used.
作為基體材料層34的平均厚度,例如可以與上述的光擴散片5的基體材料層11的平均厚度同樣。微透鏡陣列35可以與基體材料層34一體成形(即,可以與基體材料層34一體地形成),也可以與基體材料層34分開形成。The average thickness of the base material layer 34 can be, for example, the same as the average thickness of the base material layer 11 of the light diffusion sheet 5 described above. The microlens array 35 may be integrally formed with the base material layer 34 (i.e., may be integrally formed with the base material layer 34) or may be formed separately from the base material layer 34.
微透鏡35a形成為半球狀(也包括近似於半球的形狀)。予以說明,微透鏡35a可以如圖7所示那樣形成為凸透鏡狀,也可以形成為凹透鏡狀。多個微透鏡35a被較密且幾何學性地配置於基體材料層34的表面。具體而言,多個微透鏡35a在基體材料層34的表面以正三角形格子圖案進行配置。因此,多個微透鏡35a的間距及透鏡間距離S1全部恒定。該配置圖案也可以最密地配置多個微透鏡35a。予以說明,作為多個微透鏡35a的配置圖案,並不限於能夠稠密填充的上述三角形格子圖案,例如也可以為正方形格子圖案或無規圖案。根據該無規圖案,在與其他光學構件重疊時降低莫爾條紋的產生。The microlens 35a is formed in a hemispherical shape (including a shape similar to a hemisphere). Incidentally, the microlens 35a may be formed in a convex lens shape as shown in FIG. 7, or may be formed in a concave lens shape. The plurality of microlenses 35a are densely and geometrically disposed on the surface of the base material layer 34. Specifically, the plurality of microlenses 35a are arranged on the surface of the base material layer 34 in an equilateral triangle lattice pattern. Therefore, the pitch of the plurality of microlenses 35a and the inter-lens distance S1 are all constant. The arrangement pattern can also arrange the plurality of microlenses 35a most densely. Incidentally, the arrangement pattern of the plurality of microlenses 35a is not limited to the above-described triangular lattice pattern which can be densely filled, and may be, for example, a square lattice pattern or a random pattern. According to this random pattern, generation of moire fringes is reduced when overlapping with other optical members.
作為微透鏡35a的平均徑D2的下限,優選10μm,更優選100μm,進一步優選200μm。另一方面,作為微透鏡陣列35a的平均徑D2的上限,優選1000μm,更優選700μm,進一步優選500μm。若微透鏡35a的平均徑D2不足上述下限,則衍射的影響變大,變得容易引起光學性能的降低或顏色分解。相反,若微透鏡35a的平均徑D2超出上述上限,則存在容易發生厚度增大或亮度不均的風險。予以說明,「微透鏡的平均徑」是指將任意抽取的10個微透鏡的基底的平均徑加以平均所得的值。另外,各微透鏡的平均徑是指基底的最大徑與最小徑的中間值。The lower limit of the average diameter D2 of the microlens 35a is preferably 10 μm, more preferably 100 μm, still more preferably 200 μm. On the other hand, the upper limit of the average diameter D2 of the microlens array 35a is preferably 1000 μm, more preferably 700 μm, still more preferably 500 μm. When the average diameter D2 of the microlens 35a is less than the above lower limit, the influence of diffraction becomes large, and it is easy to cause deterioration of optical performance or color decomposition. On the other hand, if the average diameter D2 of the microlens 35a exceeds the above upper limit, there is a risk that the thickness is increased or the brightness is uneven. Incidentally, the "average diameter of the microlens" means a value obtained by averaging the average diameters of the bases of the arbitrarily extracted ten microlenses. In addition, the average diameter of each microlens means the intermediate value of the largest diameter and the minimum diameter of a base.
作為微透鏡35a的高度相對於曲率半徑的高度之比的下限,優選0.6,更優選0.75。另一方面,作為上述高度比的上限,優選1。通過使上述高度比為上述範圍內,從而有效發揮微透鏡35a的透鏡的折射作用,顯著提高該微透鏡片33的聚光等光學功能。The lower limit of the ratio of the height of the microlens 35a to the height of the radius of curvature is preferably 0.6, and more preferably 0.75. On the other hand, as the upper limit of the above height ratio, 1 is preferable. When the height ratio is within the above range, the refractive action of the lens of the microlens 35a is effectively exhibited, and the optical function such as condensing of the lenticular sheet 33 is remarkably improved.
作為微透鏡35a的平均透鏡間距離S1相對於平均徑D2的間隔比(S1/D2)的上限,優選0.5,更優選0.2。通過如此使上述間隔比(S1/D2)為上述上限以下,從而降低無助於光學功能的平坦部,顯著提高該微透鏡片33的聚光等光學功能。The upper limit of the interval ratio (S1/D2) of the average inter-lens distance S1 of the microlens 35a with respect to the average diameter D2 is preferably 0.5, and more preferably 0.2. By setting the above-described spacing ratio (S1/D2) to the above upper limit or lower, the flat portion that does not contribute to the optical function is reduced, and the optical function such as condensing of the lenticular sheet 33 is remarkably improved.
作為多個微透鏡35a的填充率的下限,優選40%,更優選60%。通過如此使多個微透鏡35a的填充率為上述下限以上,從而提高多個微透鏡35a的佔有面積,顯著提高該微透鏡片33的聚光等光學功能。予以說明,多個微透鏡的「填充率」是指在俯視下的每單位面積的微透鏡的面積比。The lower limit of the filling ratio of the plurality of microlenses 35a is preferably 40%, more preferably 60%. By setting the filling ratio of the plurality of microlenses 35a to the above lower limit or more, the area occupied by the plurality of microlenses 35a is increased, and the optical function such as the condensing of the lenticular sheet 33 is remarkably improved. Incidentally, the "filling rate" of the plurality of microlenses refers to the area ratio of the microlenses per unit area in plan view.
作為微透鏡陣列35的折射率的下限,優選1.3,更優選1.45。另一方面,作為微透鏡陣列35的折射率的上限,優選1.8,更優選1.6。另外,作為微透鏡陣列35的折射率,特別優選1.5。通過使微透鏡陣列35的折射率為上述範圍內,從而有效發揮微透鏡陣列35中透鏡的折射作用,提高該微透鏡片33的聚光等光學功能。The lower limit of the refractive index of the microlens array 35 is preferably 1.3, more preferably 1.45. On the other hand, the upper limit of the refractive index of the microlens array 35 is preferably 1.8, and more preferably 1.6. Further, as the refractive index of the microlens array 35, 1.5 is particularly preferable. When the refractive index of the microlens array 35 is within the above range, the refractive action of the lens in the microlens array 35 is effectively exhibited, and an optical function such as condensing of the lenticular sheet 33 is improved.
背層36需要使光線透射,因此形成為透明。背層36以合成樹脂為主成分來形成。作為背層36的主成分,可以與上述的光擴散片5的背層13的主成分同樣。The backing layer 36 needs to transmit light and is thus formed to be transparent. The back layer 36 is formed mainly of a synthetic resin. The main component of the back layer 36 can be the same as the main component of the back layer 13 of the above-described light diffusion sheet 5.
多個凸部36a使用與背層36相同的主成分與背層36一體成形(即,一體地形成多個凸部36a及背層36)。The plurality of convex portions 36a are integrally formed with the back layer 36 using the same main component as the back layer 36 (that is, the plurality of convex portions 36a and the back layer 36 are integrally formed).
多個凸部36a構成該微透鏡片33的最背面。各凸部36a為扁平的半球體或前端部被弄成圓狀的扁平的錐體,尤其在本實施方式中為扁平的半分割旋轉橢圓體。多個凸部36a無規(不具有規則性)地突出設置於背層36的背面。多個凸部36a的具體的形狀與光擴散片5的多個凸部13a同樣。The plurality of convex portions 36a constitute the rearmost surface of the lenticular sheet 33. Each of the convex portions 36a is a flat hemisphere or a flat cone whose front end portion is rounded, and is particularly a flat semi-divided ellipsoid in the present embodiment. The plurality of convex portions 36a are protruded from the back surface of the back layer 36 randomly (without regularity). The specific shape of the plurality of convex portions 36a is the same as that of the plurality of convex portions 13a of the light diffusion sheet 5.
作為凸部36a的平均徑相對於微透鏡35a的平均徑D2之比的下限,優選0.05,更優選0.07,進一步優選0.1。另一方面,作為上述比的上限,優選1,更優選0.5,進一步優選0.3。若上述比不足上述下限,則存在入射至凸部36a的光量不足而難以利用凸部36a充分引入光的風險,並且存在使被該微透鏡片33的背層36的背面所鏡面反射的光量變大的風險。相反,若上述比超出上述上限,則存在凸部36a的彎曲形狀過於平緩而難以利用凸部36a引入光線的風險。The lower limit of the ratio of the average diameter of the convex portion 36a to the average diameter D2 of the microlens 35a is preferably 0.05, more preferably 0.07, still more preferably 0.1. On the other hand, the upper limit of the above ratio is preferably 1, more preferably 0.5, still more preferably 0.3. When the ratio is less than the lower limit, the amount of light incident on the convex portion 36a is insufficient, and it is difficult to sufficiently introduce light by the convex portion 36a, and the amount of light that is specularly reflected by the back surface of the back layer 36 of the lenticular sheet 33 is changed. Big risk. On the other hand, when the above ratio exceeds the above upper limit, there is a risk that the curved shape of the convex portion 36a is too gentle and it is difficult to introduce light by the convex portion 36a.
<微透鏡片的製造方法><Method of Manufacturing Microlens Sheet>
該微透鏡片33可以使用與上述的該光擴散片5的製造方法同樣的樹脂膜運送工序、紫外線固化型樹脂組合物供給工序及紫外線照射工序來製造。具體而言,作為該微透鏡片33的製造方法,可列舉:(a)在上述紫外線照射工序後將活性能量射線固化型樹脂塗布於上述樹脂膜的另一個面,將其按壓於具有微透鏡陣列35的轉印模的薄片模具、模具或輥模具,向未固化的活性能量射線固化型樹脂上轉印形狀,照射活性能量射線使活性能量射線固化型樹脂固化的方法;(b)在另一壓輥的圓周面形成微透鏡陣列35的翻轉形狀,向上述樹脂膜的另一個面通入熔融狀態的樹脂,轉印上述形狀的方法等。予以說明,作為該微透鏡片的製造方法,也可以在形成微透鏡陣列35後形成多個凸部。The microlens sheet 33 can be produced by using the same resin film transporting step, ultraviolet curable resin composition supplying step, and ultraviolet irradiation step as the above-described method of manufacturing the light diffusing sheet 5. Specifically, as a method of producing the lenticular sheet 33, (a) the active energy ray-curable resin is applied to the other surface of the resin film after the ultraviolet ray irradiation step, and is pressed against the microlens. a sheet mold, a mold or a roll mold of a transfer mold of the array 35, a shape transferred onto an uncured active energy ray-curable resin, and a method of irradiating an active energy ray to cure the active energy ray-curable resin; (b) another method The circumferential surface of one pressure roller forms an inverted shape of the microlens array 35, and a resin in a molten state is introduced into the other surface of the resin film to transfer the shape. Incidentally, as the method of manufacturing the lenticular sheet, a plurality of convex portions may be formed after the microlens array 35 is formed.
<優點><advantage>
該微透鏡片33在背面以散點狀具有多個凸部36a,因此如已經敍述的那樣可以防止與在背面側配置的其他光學構件的黏附,並且可以防止其他光學構件的表面的損傷。Since the lenticular sheet 33 has a plurality of convex portions 36a in a scatter manner on the back surface, adhesion to other optical members disposed on the back side can be prevented as described above, and damage of the surface of other optical members can be prevented.
該微透鏡片的製造方法能夠容易且可靠地製造如已經敍述的那樣可以防止與在背面側配置的其他光學構件的黏附、並且可以防止其他光學構件的表面的損傷的該微透鏡片33。The manufacturing method of the microlens sheet can easily and reliably manufacture the microlens sheet 33 which can prevent adhesion to other optical members disposed on the back side as described above and can prevent damage of the surface of other optical members.
《第三實施方式》Third Embodiment
<光擴散片><Light diffusion sheet>
圖8的光擴散片41代替圖2的光擴散片5被用於圖1的背光單元1。該光擴散片41具備基體材料層11、在基體材料層11的表面側層疊的光擴散層12和在基體材料層11的背面側層疊的背層42。另外,該光擴散片41在背層42的背面以散點狀具備作為防黏附部的多個凸部13a。多個凸部13a與背層42一體成形(即,一體地形成多個凸部13a及背層42)。該光擴散片41形成為在俯視下的方形狀。該光擴散片41由基體材料層11、光擴散層12、背層42及多個凸部13a構成(即,該光擴散片41不具有除基體材料層11、光擴散層12、背層42及多個凸部13a以外的其他層)。該光擴散片41的基體材料層11、光擴散層12及多個凸部13a與圖2的光擴散片5同樣,因此標記同一符號並省略對其的說明。The light diffusion sheet 41 of Fig. 8 is used for the backlight unit 1 of Fig. 1 instead of the light diffusion sheet 5 of Fig. 2 . The light diffusion sheet 41 includes a base material layer 11 , a light diffusion layer 12 laminated on the surface side of the base material layer 11 , and a back layer 42 laminated on the back surface side of the base material layer 11 . Further, the light diffusion sheet 41 has a plurality of convex portions 13a as anti-adhesion portions on the back surface of the back layer 42 in a scatter manner. The plurality of convex portions 13a are integrally formed with the back layer 42 (that is, a plurality of convex portions 13a and back layers 42 are integrally formed). The light diffusion sheet 41 is formed in a square shape in plan view. The light diffusion sheet 41 is composed of a base material layer 11, a light diffusion layer 12, a back layer 42 and a plurality of convex portions 13a (that is, the light diffusion sheet 41 does not have a base material layer 11, a light diffusion layer 12, and a back layer 42. And other layers than the plurality of convex portions 13a). The base material layer 11, the light-diffusing layer 12, and the plurality of convex portions 13a of the light-diffusing sheet 41 are the same as those of the light-diffusing sheet 5 of FIG. 2, and therefore the same reference numerals will be given, and the description thereof will be omitted.
背層42需要使光線透射,因此形成為透明。背層42以合成樹脂為主成分來形成。作為背層42的主成分,可以與上述的光擴散片5的背層13的主成分同樣。The back layer 42 needs to transmit light, and thus is formed to be transparent. The back layer 42 is formed mainly of a synthetic resin. The main component of the back layer 42 can be the same as the main component of the back layer 13 of the above-described light diffusion sheet 5.
該光擴散片41在背層42的背面(該光擴散片41的背面)中不存在多個凸部13a的區域具備定向為一個方向的多條狀的光柵形狀43。光柵形狀43具有沿著一個方向形成有多個凹凸條的形狀。該光擴散片41具備光柵形狀43,由此可以使到達光柵形狀43的光線向該光柵形狀43的寬度方向(多個凹凸條的平均定向方向的垂直方向)擴散。光柵形狀43優選呈現朝向一個方向的擦過痕或發線狀。該光擴散片41通過使上述光柵形狀43呈現朝向一個方向的擦過痕或發線狀,從而可以使光線容易且可靠地向該光柵形狀43的寬度方向擴散。予以說明,「多個凹凸條的平均定向方向」是指構成多個凸條的多個凹部的平均定向方向。The light diffusion sheet 41 has a plurality of stripe shapes 43 oriented in one direction in a region where the plurality of convex portions 13a are not present in the back surface of the back layer 42 (the back surface of the light diffusion sheet 41). The grating shape 43 has a shape in which a plurality of concave and convex strips are formed in one direction. The light-diffusing sheet 41 is provided with the grating shape 43 so that the light reaching the grating shape 43 can be diffused in the width direction of the grating shape 43 (the vertical direction of the plurality of uneven strips in the average orientation direction). The grating shape 43 preferably exhibits a scratch or hairline shape that is oriented in one direction. In the light-diffusing sheet 41, the grating shape 43 is caused to have a rubbing or hairline shape in one direction, so that light can be easily and reliably diffused in the width direction of the grating shape 43. Incidentally, the "average orientation direction of the plurality of embossed strips" means the average orientation direction of the plurality of concave portions constituting the plurality of ridges.
光柵形狀43遍佈背層42的背面的除多個凸部13a以外的全部區域而大致均勻地(大致等密度地)形成。另外,如圖9、10所示,形成光柵形狀43的多個凹凸條,其長度方向沿著與背層42的背面的一端平行的方向。具體而言,上述多個凹凸條的長度方向沿著來自光源的光線的出射方向(即,上述多個凹凸條定向為來自光源的光線的出射方向)。作為各凹凸條的光線相對於出射方向的傾斜角的上限,優選±30°,更優選±15°,進一步優選±5°。進而,各凹凸條可以在上述傾斜角的範圍內無規地定向(即,各凹凸條的定向方向可以不完全一致)。如此,通過使各凹凸條的定向方向處於無規狀態,從而可以抑制因多個凹凸條而使液晶顯示裝置產生彩虹狀不均的情況。予以說明,多個凹凸條的凹部彼此優選在控制光線的擴散方向的基礎上各自獨立地形成,但是也可以使一部分的凹部彼此交叉。The grating shape 43 is formed substantially uniformly (substantially equal in density) over all the regions except the plurality of convex portions 13a on the back surface of the back layer 42. Further, as shown in FIGS. 9 and 10, a plurality of irregular strips of the grating shape 43 are formed, and the longitudinal direction thereof is along a direction parallel to one end of the back surface of the back layer 42. Specifically, the longitudinal direction of the plurality of embossed strips is along the outgoing direction of the light from the light source (that is, the plurality of embossed strips are oriented in the outgoing direction of the light from the light source). The upper limit of the inclination angle of the light ray of each of the uneven strips with respect to the emission direction is preferably ±30°, more preferably ±15°, still more preferably ±5°. Further, each of the embossed strips may be randomly oriented within the range of the above-described tilt angle (that is, the orientation directions of the embossed strips may not be completely uniform). As described above, by causing the orientation direction of each of the embossed strips to be in a random state, it is possible to suppress the occurrence of rainbow-like unevenness in the liquid crystal display device due to the plurality of embossed strips. Incidentally, the concave portions of the plurality of concave and convex strips are preferably formed independently of each other in addition to the direction in which the light is diffused, but a part of the concave portions may be intersected with each other.
多個凹凸條的凹部的長度方向可以遍佈背層42的兩端而連續,但是,例如多個凹凸條的凹部的平均長度優選相對於凹部的平均寬度為10000倍以下,更優選為5000倍以下。另外,作為多個凹凸條的凹部的平均長度的下限,優選相對於凹部的平均寬度為2倍以上,更優選為3倍以上。若多個凹凸條的凹部的平均長度超出上述上限,則存在難以為了抑制液晶顯示裝置的彩虹狀不均的發生而使多個凹凸條處於無規的定向方向且高密度形成的風險。相反,若多個凹凸條的凹部的平均長度不足上述下限,則存在無法使向光柵形狀43的寬度方向擴散的光量相對於到達光柵形狀43的光線的光量充分增加的風險。予以說明,「多個凹凸條的凹部的平均長度」是指任意抽取的20個凹部的長度的平均值。The longitudinal direction of the concave portion of the plurality of concave and convex strips may be continuous over both ends of the back layer 42. For example, the average length of the concave portions of the plurality of concave and convex strips is preferably 10000 times or less, and more preferably 5,000 times or less with respect to the average width of the concave portion. . Moreover, it is preferable that the lower limit of the average length of the concave portion of the plurality of uneven strips is twice or more, and more preferably three times or more with respect to the average width of the concave portions. When the average length of the concave portions of the plurality of embossed strips exceeds the above upper limit, there is a risk that it is difficult to form a plurality of embossed strips in a random orientation direction and to form a high density in order to suppress occurrence of rainbow unevenness in the liquid crystal display device. On the other hand, when the average length of the concave portions of the plurality of embossed strips is less than the lower limit, there is a risk that the amount of light diffused in the width direction of the grating shape 43 cannot be sufficiently increased with respect to the amount of light reaching the grating shape 43. Incidentally, the "average length of the concave portions of the plurality of concave and convex strips" means an average value of the lengths of the 20 concave portions that are arbitrarily extracted.
另外,多個凹凸條的凹部的長度優選無規。該光擴散片41通過使多個凹凸條的凹部的長度為無規,從而可以抑制因多個凹凸條而使液晶顯示裝置產生彩虹狀不均的情況。Further, the length of the concave portion of the plurality of embossed strips is preferably random. In the light-diffusing sheet 41, the length of the concave portion of the plurality of concave-convex strips is random, and it is possible to suppress the occurrence of rainbow-like unevenness in the liquid crystal display device due to the plurality of uneven strips.
多個凹凸條的凹部的寬度L1優選為無規。另外,如圖9所示,各凹凸條的凹部的寬度L1優選沿著該凹凸條的凹部的長度方向無規地變化。該光擴散片41通過使多個凹凸條的凹部的寬度L1為無規,從而可以抑制因多個凹凸條而使液晶顯示裝置產生彩虹不均的情況。The width L1 of the concave portion of the plurality of embossed strips is preferably random. Further, as shown in FIG. 9, the width L1 of the concave portion of each of the uneven strips is preferably changed randomly along the longitudinal direction of the concave portion of the uneven strip. In the light-diffusing sheet 41, the width L1 of the concave portion of the plurality of uneven strips is made random, and it is possible to suppress the occurrence of rainbow unevenness in the liquid crystal display device due to the plurality of uneven strips.
作為多個凹凸條的凹部的平均寬度的下限,優選10nm,更優選50nm,進一步優選100nm。另一方面,作為多個凹凸條的凹部的平均寬度的上限,優選30μm,更優選20μm,進一步優選10μm。若多個凹凸條的凹部的平均寬度不足上述下限,則存在光柵形狀43的成形性降低的風險。相反,若多個凹凸條的凹部的平均寬度超出上述上限,則存在無法充分確保向光柵形狀43的寬度方向擴散的光量的風險。予以說明,各凹凸條的凹部的寬度優選在上述範圍內沿著長度方向無規地形成。通過使各凹凸條的凹部的寬度在上述範圍內無規地形成,從而可以防止由與具有週期性間距的其他構件(棱鏡片或液晶盒)等的干涉所致的莫爾條紋,並且可以防止有規則地發生顏色分解,防止彩虹狀不均等。予以說明,「多個凹凸條的凹部的平均寬度」是指任意抽取的20個凹部的除去長度方向兩端部分之外的任意點的多個凹凸條的凸部的前端的平均介面的寬度的平均值。The lower limit of the average width of the concave portions of the plurality of embossed strips is preferably 10 nm, more preferably 50 nm, still more preferably 100 nm. On the other hand, the upper limit of the average width of the concave portion as the plurality of embossed strips is preferably 30 μm, more preferably 20 μm, still more preferably 10 μm. When the average width of the concave portions of the plurality of embossed strips is less than the above lower limit, there is a risk that the formability of the grating shape 43 is lowered. On the other hand, when the average width of the concave portions of the plurality of embossed strips exceeds the above upper limit, there is a risk that the amount of light diffused in the width direction of the grating shape 43 cannot be sufficiently ensured. Incidentally, the width of the concave portion of each of the uneven strips is preferably randomly formed in the longitudinal direction within the above range. By randomly forming the width of the concave portion of each of the uneven strips within the above range, it is possible to prevent moire fringes caused by interference with other members (prism sheets or liquid crystal cells) having a periodic pitch, and can be prevented. Color decomposition occurs regularly to prevent rainbow inequality. In addition, the "average width of the concave portion of the plurality of concave and convex strips" means the width of the average interface of the front end of the convex portion of the plurality of concave and convex strips at any point other than the both end portions in the longitudinal direction except for the arbitrarily extracted 20 concave portions. average value.
多個凹凸條的間距優選為無規。該光擴散片41通過使多個凹凸條的間距為無規,從而可以抑制因多個凹凸條而使液晶顯示裝置產生彩虹不均的情況。予以說明,「多個凹凸條的平均間距」是指在與多個凹凸條的平均定向方向垂直的直線上鄰接的20個凹凸條的間距的平均值。The pitch of the plurality of embossed strips is preferably random. In the light-diffusing sheet 41, the pitch of the plurality of uneven strips is made random, and it is possible to suppress the occurrence of rainbow unevenness in the liquid crystal display device due to the plurality of uneven strips. Incidentally, the "average pitch of the plurality of embossed strips" means an average value of the pitches of the 20 embossed strips adjacent to each other on a straight line perpendicular to the average orientation direction of the plurality of embossed strips.
作為多個凹凸條的平均間距的下限,優選10nm,更優選50nm,進一步優選100nm。另一方面,作為多個凹凸條的平均間距的上限,優選40μm,更優選30μm,進一步優選20μm、特別優選10μm。若多個凹凸條的平均間距不足上述下限,則存在光柵形狀43的成形性降低的風險。相反,若多個凹凸條的平均間距超出上述上限,則存在無法充分增加向光柵形狀43的寬度方向擴散的光量的風險。The lower limit of the average pitch of the plurality of embossed strips is preferably 10 nm, more preferably 50 nm, still more preferably 100 nm. On the other hand, the upper limit of the average pitch of the plurality of embossed strips is preferably 40 μm, more preferably 30 μm, still more preferably 20 μm, and particularly preferably 10 μm. When the average pitch of the plurality of embossed strips is less than the above lower limit, there is a risk that the formability of the grating shape 43 is lowered. On the other hand, if the average pitch of the plurality of embossed strips exceeds the above upper limit, there is a risk that the amount of light diffused in the width direction of the grating shape 43 cannot be sufficiently increased.
作為多個凹凸條的間距的標準偏差的上限,優選10μm,更優選9μm,進一步優選7μm。若多個凹凸條的間距的標準偏差超出上述上限,則多個凹凸條的間距過於不均勻,存在無法使向光柵形狀43的寬度方向擴散的光量在多個凹凸條的整個形成區域中均勻增加的風險。另一方面,作為多個凹凸條的間距的標準偏差的下限,從容易將多個凹凸條配置於較無規的方向的觀點出發,可以設為例如4μm。予以說明,「多個凹凸條的間距的標準偏差」是指任意抽取的20個凹凸條的間距的標準偏差。The upper limit of the standard deviation of the pitch of the plurality of embossed strips is preferably 10 μm, more preferably 9 μm, still more preferably 7 μm. When the standard deviation of the pitch of the plurality of embossed strips exceeds the above upper limit, the pitch of the plurality of embossed strips is too uneven, and the amount of light that cannot be diffused in the width direction of the grating shape 43 is uniformly increased in the entire formed region of the plurality of embossed strips. risks of. On the other hand, the lower limit of the standard deviation of the pitch of the plurality of embossed strips can be, for example, 4 μm from the viewpoint of easily arranging the plurality of embossed strips in a random direction. Incidentally, the "standard deviation of the pitch of the plurality of embossed strips" means the standard deviation of the pitch of the 20 embossed strips arbitrarily extracted.
作為與多個凹凸條的平均定向方向垂直的方向上的多個凹凸條的凹部每單位長度的平均存在個數的下限,優選10根/mm,更優選50根/mm,進一步優選100根/mm。另一方面,作為上述平均存在個數的上限,優選10000根/mm,更優選5000根/mm,進一步優選1000根/mm。若上述平均存在個數不足上述下限,則存在無法使向光柵形狀43的寬度方向擴散的光量相對於到達光柵形狀43的光線的光量充分增加的風險。相反,若上述平均存在個數超出上述上限,則存在光柵形狀43的成形性降低的風險。The lower limit of the average number of per-unit lengths of the concave portions of the plurality of concave-convex strips in the direction perpendicular to the average orientation direction of the plurality of embossed strips is preferably 10 pieces/mm, more preferably 50 pieces/mm, still more preferably 100 pieces/ Mm. On the other hand, the upper limit of the average number of the above-mentioned average is preferably 10,000 pieces/mm, more preferably 5,000 pieces/mm, still more preferably 1,000 pieces/mm. When the number of the averages is less than the lower limit, there is a risk that the amount of light diffused in the width direction of the grating shape 43 cannot be sufficiently increased with respect to the amount of light reaching the grating shape 43. On the other hand, if the average number of the above-described upper limits exceeds the above upper limit, there is a risk that the formability of the grating shape 43 is lowered.
作為多個凹凸條的凹部的平均深度D3的下限,優選10nm,更優選500nm,進一步優選1μm,特別優選2μm。另一方面,作為上述平均深度D3的上限,優選10μm,更優選5μm,進一步優選3μm。若上述平均深度D3不足上述下限,則存在無法充分增加向光柵形狀43的寬度方向擴散的光量的風險。相反,若上述平均深度D3超出上述上限,則存在背層42的強度降低的風險。予以說明,「多個凹凸條的凹部的平均深度」是指從多個凹凸條的凸部的前端的平均介面到任意抽取的20個凹部的底部的深度的平均值。The lower limit of the average depth D3 of the concave portion of the plurality of embossed strips is preferably 10 nm, more preferably 500 nm, further preferably 1 μm, and particularly preferably 2 μm. On the other hand, the upper limit of the average depth D3 is preferably 10 μm, more preferably 5 μm, still more preferably 3 μm. When the average depth D3 is less than the lower limit, there is a risk that the amount of light diffused in the width direction of the grating shape 43 cannot be sufficiently increased. On the contrary, if the average depth D3 exceeds the above upper limit, there is a risk that the strength of the back layer 42 is lowered. In addition, the "average depth of the concave portion of the plurality of embossed strips" means an average value of the depth from the average interface of the tips of the plurality of embossed strips to the bottom of the arbitrarily extracted 20 recesses.
另外,作為多個凹凸條的凹部的深度的標準偏差的上限,優選4μm,更優選3μm,進一步優選2.5μm。若上述深度的標準偏差超出上述上限,則多個凹凸條的凹部的深度過於不均勻,存在無法使向光柵形狀43的寬度方向擴散的光量在光柵形狀43的整個形成區域中均勻增加的風險。另一方面,作為上述深度的標準偏差的下限,並無特別限定,可以設為例如0.3μm。予以說明,「多個凹凸條的深度的標準偏差」是指任意抽取的20個凹凸條的凹部的深度的標準偏差。Further, the upper limit of the standard deviation of the depth of the concave portion of the plurality of embossed strips is preferably 4 μm, more preferably 3 μm, still more preferably 2.5 μm. When the standard deviation of the depth exceeds the above upper limit, the depth of the concave portion of the plurality of embossed strips is too uneven, and there is a risk that the amount of light diffused in the width direction of the grating shape 43 cannot be uniformly increased in the entire formation region of the grating shape 43. On the other hand, the lower limit of the standard deviation of the depth is not particularly limited, and may be, for example, 0.3 μm. In addition, the "standard deviation of the depth of a plurality of embossed strips" means the standard deviation of the depth of the recessed part of the 20 embossing strips arbitrarily extracted.
作為形成光柵形狀43的外表面(未形成多個凸部13a的背層42的背面)的以與多個凹凸條的定向方向平行的方向為基準的算術平均粗糙度(Ra)的下限,優選0.005μm,更優選0.05μm,進一步優選0.1μm。另一方面,作為形成光柵形狀43的外表面(未形成多個凸部13a的背層42的背面)的以與多個凹凸條的定向方向平行的方向為基準的算術平均粗糙度(Ra)的上限,優選1.5μm,更優選1.2μm,進一步優選1μm。若上述算術平均粗糙度(Ra)不足上述下限,則存在使後述的熱點的發生抑制效果不充分的風險。相反,若上述算術平均粗糙度(Ra)超出上述上限,則向與多個凹凸條的定向方向平行的方向擴散的光量相對於向光柵形狀43的寬度方向擴散的光量變大,存在無法充分確保與光源的光線出射方向垂直的方向的視角的風險。予以說明,「算術平均粗糙度(Ra)」是指依據JIS-B0601:1994而截止λc為0.8mm、評價長度為4mm時的值。The lower limit of the arithmetic mean roughness (Ra) based on the direction parallel to the direction in which the plurality of embossed strips are oriented is the outer surface of the grating shape 43 (the back surface of the back layer 42 where the plurality of convex portions 13a are not formed), preferably 0.005 μm, more preferably 0.05 μm, further preferably 0.1 μm. On the other hand, the arithmetic mean roughness (Ra) based on the direction parallel to the orientation direction of the plurality of embossed strips as the outer surface (the back surface of the back layer 42 where the plurality of convex portions 13a are not formed) forming the grating shape 43 The upper limit is preferably 1.5 μm, more preferably 1.2 μm, still more preferably 1 μm. When the arithmetic mean roughness (Ra) is less than the lower limit, there is a risk that the effect of suppressing occurrence of a hot spot to be described later is insufficient. On the other hand, when the arithmetic mean roughness (Ra) exceeds the above upper limit, the amount of light diffused in a direction parallel to the direction in which the plurality of embossed strips are oriented is increased with respect to the amount of light diffused in the width direction of the grating shape 43, and the amount of light that is diffused in the width direction of the grating shape 43 is large. The risk of a viewing angle in a direction perpendicular to the direction in which the light exits the light source. In addition, "arithmetic mean roughness (Ra)" means a value when the λc is 0.8 mm and the evaluation length is 4 mm in accordance with JIS-B0601:1994.
作為形成光柵形狀43的外表面(未形成多個凸部13a的背層42的背面)的以與多個凹凸條的定向方向垂直的方向為基準的算術平均粗糙度(Ra)的下限,優選0.01μm,更優選0.1μm,進一步優選0.5μm。另一方面,作為形成光柵形狀43的外表面(未形成多個凸部13a的背層42的背面)的以與多個凹凸條的定向方向垂直的方向為基準的算術平均粗糙度(Ra)的上限,優選5μm,更優選3μm,進一步優選1.5μm。若上述算術平均粗糙度(Ra)不足上述下限,則存在無法充分增加向光柵形狀43的寬度方向擴散的光量。相反,若上述算術平均粗糙度(Ra)超出上述上限,則存在難以控制光線的出射角度的風險。The lower limit of the arithmetic mean roughness (Ra) based on the direction perpendicular to the direction in which the plurality of embossed strips are oriented is the outer surface of the grating shape 43 (the back surface of the back layer 42 where the plurality of convex portions 13a are not formed), preferably 0.01 μm, more preferably 0.1 μm, further preferably 0.5 μm. On the other hand, the arithmetic mean roughness (Ra) based on the direction perpendicular to the orientation direction of the plurality of embossed strips as the outer surface (the back surface of the back layer 42 where the plurality of convex portions 13a are not formed) forming the grating shape 43 The upper limit is preferably 5 μm, more preferably 3 μm, still more preferably 1.5 μm. When the arithmetic mean roughness (Ra) is less than the lower limit, the amount of light diffused in the width direction of the grating shape 43 cannot be sufficiently increased. On the contrary, if the arithmetic mean roughness (Ra) exceeds the above upper limit, there is a risk that it is difficult to control the exit angle of the light.
另外,形成光柵形狀43的外表面(未形成多個凸部13a的背層42的背面)的以與多個凹凸條的定向方向平行的方向為基準的算術平均粗糙度(Ra)及以與多個凹凸條的定向方向垂直的方向為基準的算術平均粗糙度(Ra),優選均包含在上述範圍內。該光擴散片41通過使以與多個凹凸條的定向方向平行的方向為基準的算術平均粗糙度(Ra)及以與多個凹凸條的定向方向垂直的方向為基準的算術平均粗糙度(Ra)為上述範圍內,從而使向光柵形狀43的寬度方向擴散的光量充分增加,容易使與光源的光線出射方向垂直的方向的視角充分拓寬。Further, the arithmetic mean roughness (Ra) based on the direction parallel to the direction in which the plurality of embossed strips are oriented is formed on the outer surface of the grating shape 43 (the back surface of the back layer 42 where the plurality of convex portions 13a are not formed) and The arithmetic mean roughness (Ra) based on the direction in which the orientation directions of the plurality of embossed strips are perpendicular is preferably included in the above range. The light diffusion sheet 41 has an arithmetic mean roughness (Ra) based on a direction parallel to the orientation direction of the plurality of embossed strips and an arithmetic mean roughness based on a direction perpendicular to the orientation direction of the plurality of embossed strips ( Ra is in the above range, so that the amount of light diffused in the width direction of the grating shape 43 is sufficiently increased, and the angle of view in the direction perpendicular to the light emission direction of the light source is easily widened.
作為形成光柵形狀43的外表面(未形成多個凸部13a的背層42的背面)的以與多個凹凸條的定向方向垂直的方向為基準的算術平均粗糙度(Ra)與以與多個凹凸條的定向方向平行的方向為基準的算術平均粗糙度(Ra)之差的下限,優選0.5μm,更優選0.7μm,進一步優選1μm。通過使上述算術平均粗糙度(Ra)之差為上述下限以上,從而使向光柵形狀43的寬度方向擴散的光量充分增加,容易使與光源的光線出射方向垂直的方向的視角充分拓寬。另一方面,作為上述算術平均粗糙度(Ra)之差的上限,可以設為例如1.9μm。As the outer surface of the grating shape 43 (the back surface of the back layer 42 where the plurality of convex portions 13a are not formed), the arithmetic mean roughness (Ra) and the ratio are based on the direction perpendicular to the direction in which the plurality of concave and convex strips are oriented. The direction in which the orientation directions of the embossed strips are parallel is the lower limit of the difference in the arithmetic mean roughness (Ra) of the reference, preferably 0.5 μm, more preferably 0.7 μm, still more preferably 1 μm. When the difference between the arithmetic mean roughness (Ra) is equal to or higher than the lower limit, the amount of light diffused in the width direction of the grating shape 43 is sufficiently increased, and the angle of view in the direction perpendicular to the light emission direction of the light source is easily widened. On the other hand, the upper limit of the difference in the arithmetic mean roughness (Ra) may be, for example, 1.9 μm.
作為形成光柵形狀43的外表面(未形成多個凸部13a的背層42的背面)的以與多個凹凸條的定向方向平行的方向為基準的最大高度(Ry)的下限,優選0.1μm,更優選1μm,進一步優選1.5μm。另一方面,作為形成光柵形狀43的外表面(未形成多個凸部13a的背層42的背面)的以與多個凹凸條的定向方向平行的方向為基準的最大高度(Ry)的上限,優選3μm,更優選2.5μm,進一步優選2μm。若上述最大高度(Ry)不足上述下限,則存在使熱點的發生抑制效果不充分的風險。相反,若上述最大高度(Ry)超出上述上限,則向與多個凹凸條的定向方向平行的方向擴散的光量相對於向光柵形狀43的寬度方向擴散的光量變大,存在無法充分確保與光源的光線出射方向垂直的方向的視角的風險。予以說明,「最大高度(Ry)」是指依據JIS-B0601:1994而在截止λc為0.8mm、評價長度為4mm時的值。The lower limit of the maximum height (Ry) based on the direction parallel to the direction in which the plurality of embossed strips are oriented is the outer surface of the grating shape 43 (the back surface of the back layer 42 where the plurality of convex portions 13a are not formed), preferably 0.1 μm. More preferably, it is 1 μm, and further preferably 1.5 μm. On the other hand, as the upper limit of the maximum height (Ry) based on the direction parallel to the direction in which the plurality of embossed strips are oriented, the outer surface of the grating shape 43 (the back surface of the back layer 42 where the plurality of convex portions 13a are not formed) Preferably, it is 3 μm, more preferably 2.5 μm, further preferably 2 μm. When the maximum height (Ry) is less than the lower limit, there is a risk that the effect of suppressing the occurrence of hot spots is insufficient. On the other hand, when the maximum height (Ry) exceeds the upper limit, the amount of light diffused in a direction parallel to the direction in which the plurality of concave and convex strips are oriented increases with respect to the amount of light diffused in the width direction of the grating shape 43, and the light source cannot be sufficiently ensured. The risk of the angle of view of the light exiting the direction of the vertical direction. In addition, "maximum height (Ry)" means a value when the cutoff λc is 0.8 mm and the evaluation length is 4 mm in accordance with JIS-B0601:1994.
作為形成光柵形狀43的外表面(未形成多個凸部13a的背層42的背面)的以與多個凹凸條的定向方向垂直的方向為基準的最大高度(Ry)的下限,優選4μm,更優選5μm,進一步優選6μm。另一方面,作為形成光柵形狀43的外表面(未形成多個凸部13a的背層42的背面)的以與多個凹凸條的定向方向垂直的方向為基準的最大高度(Ry)的上限,優選12μm,更優選10μm,進一步優選9μm。若上述最大高度(Ry)不足上述下限,則存在無法充分增加向光柵形狀43的寬度方向擴散的光量的風險。相反,若上述最大高度(Ry)超出上述上限,則存在難以控制光線的出射角度的風險。The lower limit of the maximum height (Ry) based on the direction perpendicular to the direction in which the plurality of embossed strips are oriented, which is the outer surface of the grating shape 43 (the back surface of the back layer 42 where the plurality of convex portions 13a are not formed), is preferably 4 μm. It is more preferably 5 μm, further preferably 6 μm. On the other hand, as the upper limit of the maximum height (Ry) based on the direction perpendicular to the direction in which the plurality of embossed strips are oriented, the outer surface of the grating shape 43 (the back surface of the back layer 42 where the plurality of convex portions 13a are not formed) Preferably, it is 12 μm, more preferably 10 μm, further preferably 9 μm. When the maximum height (Ry) is less than the lower limit, there is a risk that the amount of light diffused in the width direction of the grating shape 43 cannot be sufficiently increased. On the contrary, if the maximum height (Ry) exceeds the above upper limit, there is a risk that it is difficult to control the exit angle of the light.
作為形成光柵形狀43的外表面(未形成多個凸部13a的背層42的背面)的以與多個凹凸條的定向方向垂直的方向為基準的最大高度(Ry)與以與多個凹凸條的定向方向平行的方向為基準的最大高度(Ry)之差的下限,優選4μm,更優選5μm,進一步優選6μm。通過使上述最大高度(Ry)之差為上述下限以上,從而使向光柵形狀43的寬度方向擴散的光量充分增加,容易使與光源的光線出射方向垂直的方向的視角充分拓寬。另一方面,作為上述最大高度(Ry)之差的上限,可以設為例如11μm。As the outer surface (the back surface of the back layer 42 where the plurality of convex portions 13a are not formed) forming the grating shape 43, the maximum height (Ry) with respect to the direction perpendicular to the orientation direction of the plurality of concave and convex strips The direction in which the orientation direction of the strips is parallel is the lower limit of the difference in the maximum height (Ry) of the reference, preferably 4 μm, more preferably 5 μm, still more preferably 6 μm. When the difference between the maximum heights (Ry) is equal to or greater than the lower limit, the amount of light diffused in the width direction of the grating shape 43 is sufficiently increased, and the angle of view in the direction perpendicular to the light emission direction of the light source is easily widened. On the other hand, the upper limit of the difference in the maximum height (Ry) may be, for example, 11 μm.
作為形成光柵形狀43的外表面(未形成多個凸部13a的背層42的背面)的以與多個凹凸條的定向方向平行的方向為基準的十點平均粗糙度(Rz)的下限,優選0.1μm,更優選0.5μm,進一步優選1μm。另一方面,作為形成光柵形狀43的外表面(未形成多個凸部13a的背層42的背面)的以與多個凹凸條的定向方向平行的方向為基準的十點平均粗糙度(Rz)的上限,優選2.5μm,更優選2μm,進一步優選1.5μm。若上述十點平均粗糙度(Rz)不足上述下限,則存在使熱點的發生抑制效果不充分的風險。相反,若上述十點平均粗糙度(Rz)超出上述上限,則向與多個凹凸條的定向方向平行的方向擴散的光量相對於向光柵形狀43的寬度方向擴散的光量變大,存在難以充分確保與光源的光線出射方向垂直的方向的視角的風險。予以說明,「十點平均粗糙度(Rz)」是指依據JIS-B0601:1994而在截止λc為0.8mm、評價長度為4mm時的值。The lower limit of the ten-point average roughness (Rz) based on the direction parallel to the direction in which the plurality of embossed strips are oriented, as the outer surface of the grating shape 43 (the back surface of the back layer 42 where the plurality of convex portions 13a are not formed), It is preferably 0.1 μm, more preferably 0.5 μm, still more preferably 1 μm. On the other hand, as the outer surface forming the grating shape 43 (the back surface of the back layer 42 where the plurality of convex portions 13a are not formed), the ten-point average roughness (Rz) based on the direction parallel to the orientation direction of the plurality of concave-convex stripes The upper limit of the) is preferably 2.5 μm, more preferably 2 μm, still more preferably 1.5 μm. When the ten-point average roughness (Rz) is less than the above lower limit, there is a risk that the effect of suppressing the occurrence of hot spots is insufficient. On the other hand, when the ten-point average roughness (Rz) exceeds the above-described upper limit, the amount of light diffused in a direction parallel to the direction in which the plurality of embossed strips are oriented is increased with respect to the amount of light diffused in the width direction of the grating shape 43, and it is difficult to sufficiently The risk of ensuring a viewing angle in a direction perpendicular to the direction in which the light exits the light source. In addition, the "ten-point average roughness (Rz)" is a value when the cutoff λc is 0.8 mm and the evaluation length is 4 mm in accordance with JIS-B0601:1994.
作為形成光柵形狀43的外表面(未形成多個凸部13a的背層42的背面)的以與多個凹凸條的定向方向垂直的方向為基準的十點平均粗糙度(Rz)的下限,優選4μm,更優選5μm,進一步優選6μm。另一方面,作為形成光柵形狀43的外表面(未形成多個凸部13a的背層42的背面)的以與多個凹凸條的定向方向垂直的方向為基準的十點平均粗糙度(Rz)的上限,優選10μm,更優選8μm,進一步優選7μm。若上述十點平均粗糙度(Rz)不足上述下限,則存在無法充分增加向光柵形狀43的寬度方向擴散的光量的風險。相反,若上述十點平均粗糙度(Rz)超出上述上限,則存在難以控制光線的出射角度的風險。The lower limit of the ten-point average roughness (Rz) based on the direction perpendicular to the orientation direction of the plurality of embossed strips as the outer surface of the grating shape 43 (the back surface of the back layer 42 where the plurality of convex portions 13a are not formed), It is preferably 4 μm, more preferably 5 μm, further preferably 6 μm. On the other hand, as the outer surface forming the grating shape 43 (the back surface of the back layer 42 where the plurality of convex portions 13a are not formed), the ten-point average roughness (Rz) based on the direction perpendicular to the orientation direction of the plurality of concave-convex stripes The upper limit of the layer is preferably 10 μm, more preferably 8 μm, still more preferably 7 μm. When the ten-point average roughness (Rz) is less than the above lower limit, there is a risk that the amount of light diffused in the width direction of the grating shape 43 cannot be sufficiently increased. On the contrary, if the ten-point average roughness (Rz) exceeds the above upper limit, there is a risk that it is difficult to control the exit angle of the light.
作為形成光柵形狀43的外表面(未形成多個凸部13a的背層42的背面)的以與多個凹凸條的定向方向垂直的方向為基準的十點平均粗糙度(Rz)與以與多個凹凸條的定向方向平行的方向為基準的十點平均粗糙度(Rz)之差的下限,優選3μm,更優選4μm,進一步優選4.5μm。通過使上述十點平均粗糙度(Rz)之差為上述下限以上,從而使向光柵形狀43的寬度方向擴散的光量充分增加,容易使與光源的光線出射方向垂直的方向的視角充分拓寬。另一方面,作為上述十點平均粗糙度(Rz)之差的上限,可以設為例如9μm。As the outer surface of the grating shape 43 (the back surface of the back layer 42 where the plurality of convex portions 13a are not formed), the ten-point average roughness (Rz) and the reference with respect to the direction perpendicular to the orientation direction of the plurality of concave and convex strips The direction in which the orientation directions of the plurality of embossed strips are parallel is the lower limit of the difference between the ten-point average roughness (Rz) of the reference, preferably 3 μm, more preferably 4 μm, still more preferably 4.5 μm. When the difference between the ten-point average roughness (Rz) is equal to or higher than the lower limit, the amount of light diffused in the width direction of the grating shape 43 is sufficiently increased, and the angle of view in the direction perpendicular to the light-emitting direction of the light source is easily widened. On the other hand, the upper limit of the difference of the ten-point average roughness (Rz) may be, for example, 9 μm.
作為形成光柵形狀43的外表面(未形成多個凸部13a的背層42的背面)的以與多個凹凸條的定向方向平行的方向為基準的均方根斜率(RΔq)的下限,優選0.05,更優選0.2,進一步優選0.25,特別優選0.3。另一方面,作為形成光柵形狀43的外表面(未形成多個凸部13a的背層42的背面)的以與多個凹凸條的定向方向平行的方向為基準的均方根斜率(RΔq)的上限,優選0.5,更優選0.45,進一步優選0.4。若上述均方根斜率(RΔq)不足上述下限,則存在使熱點的發生抑制效果不充分的風險。相反,若上述均方根斜率(RΔq)超出上述上限,則向與多個凹凸條的定向方向平行的方向擴散的光量相對於向光柵形狀43的寬度方向擴散的光量變大,存在難以充分確保與光源的光線出射方向垂直的方向的視角的風險。予以說明,「均方根斜率(RΔq)」是指依據JIS-B0601:2001求得的值。The lower limit of the root mean square slope (RΔq) based on the direction parallel to the direction in which the plurality of embossed strips are oriented is the outer surface of the grating shape 43 (the back surface of the back layer 42 where the plurality of convex portions 13a are not formed), preferably 0.05, more preferably 0.2, further preferably 0.25, particularly preferably 0.3. On the other hand, as the outer surface (the back surface of the back layer 42 where the plurality of convex portions 13a are not formed) forming the grating shape 43, the root mean square slope (RΔq) based on the direction parallel to the orientation direction of the plurality of concave and convex strips The upper limit is preferably 0.5, more preferably 0.45, further preferably 0.4. When the root mean square slope (RΔq) is less than the above lower limit, there is a risk that the effect of suppressing the occurrence of hot spots is insufficient. On the other hand, when the root mean square slope (RΔq) exceeds the above upper limit, the amount of light diffused in a direction parallel to the direction in which the plurality of uneven strips are oriented increases with respect to the amount of light diffused in the width direction of the grating shape 43, and it is difficult to sufficiently ensure the amount of light. The risk of a viewing angle in a direction perpendicular to the direction in which the light exits the light source. Incidentally, the "root mean square slope (RΔq)" means a value obtained in accordance with JIS-B0601:2001.
作為形成光柵形狀43的外表面(未形成多個凸部13a的背層42的背面)的以與多個凹凸條的定向方向垂直的方向為基準的均方根斜率(RΔq)的下限,優選0.5,更優選0.7,進一步優選1。另一方面,作為形成光柵形狀43的外表面(未形成多個凸部13a的背層42的背面)的以與多個凹凸條的定向方向垂直的方向為基準的均方根斜率(RΔq)的上限,優選2.5,更優選2,進一步優選1.8。若上述均方根斜率(RΔq)不足上述下限,則存在無法使向光柵形狀43的寬度方向擴散的光量充分增加的風險。相反,若上述均方根斜率(RΔq)超出上述上限,則存在難以控制光線的出射角度的風險。The lower limit of the root mean square slope (RΔq) based on the direction perpendicular to the direction in which the plurality of embossed strips are oriented is the outer surface of the grating shape 43 (the back surface of the back layer 42 where the plurality of convex portions 13a are not formed), preferably 0.5, more preferably 0.7, further preferably 1. On the other hand, as the outer surface (the back surface of the back layer 42 where the plurality of convex portions 13a are not formed) forming the grating shape 43, the root mean square slope (RΔq) based on the direction perpendicular to the orientation direction of the plurality of concave and convex strips The upper limit is preferably 2.5, more preferably 2, further preferably 1.8. When the root mean square slope (RΔq) is less than the lower limit, there is a risk that the amount of light diffused in the width direction of the grating shape 43 cannot be sufficiently increased. On the contrary, if the root mean square slope (RΔq) exceeds the above upper limit, there is a risk that it is difficult to control the exit angle of the light.
作為形成光柵形狀43的外表面(未形成多個凸部13a的背層42的背面)的以與多個凹凸條的定向方向垂直的方向為基準的均方根斜率(RΔq)與以與多個凹凸條的定向方向平行的方向為基準的均方根斜率(RΔq)之差的下限,優選0.5,更優選0.7,進一步優選1。通過使上述均方根斜率(RΔq)之差為上述下限以上,從而使向光柵形狀43的寬度方向擴散的光量充分增加,容易使與光源的光線出射方向垂直的方向的視角充分拓寬。另一方面,作為上述均方根斜率(RΔq)之差的上限,可以設為例如2.2。As the outer surface (the back surface of the back layer 42 where the plurality of convex portions 13a are not formed) forming the grating shape 43, the root mean square slope (RΔq) with respect to the direction perpendicular to the orientation direction of the plurality of concave and convex strips The lower limit of the root mean square slope (RΔq) of the reference parallel direction of the embossed strips is preferably 0.5, more preferably 0.7, still more preferably 1. When the difference between the root mean square slopes (RΔq) is equal to or greater than the lower limit, the amount of light diffused in the width direction of the grating shape 43 is sufficiently increased, and the angle of view in the direction perpendicular to the light emission direction of the light source is easily widened. On the other hand, the upper limit of the difference in the root mean square slope (RΔq) may be, for example, 2.2.
<亮度不均降低功能><Brightness unevenness reduction function>
接著,參照圖11及圖12,對該光擴散片41及具備該光擴散片41的該背光單元的亮度不均降低功能進行說明。首先,參照圖11對從圖1的背光單元1的多個LED光源3出射且入射至導光膜2的光線的光量進行說明。從多個LED光源3出射的光線自導光膜2的與多個LED光源3對置的端面(入射端面)大致垂直地入射,並朝向與該入射端面對置的端面傳播。此時,從多個LED光源3出射的光線由於指向性強而尤其在導光膜2的光線入射部附近產生光量極大的區域X。另一方面,多個LED光源3由於空出規定的間隔進行配置,因此在導光膜2的上述光線入射部附近之間(鄰接的區域X之間)產生光量極小的區域Y。Next, a function of reducing the luminance unevenness of the light diffusion sheet 41 and the backlight unit including the light diffusion sheet 41 will be described with reference to FIGS. 11 and 12 . First, the amount of light emitted from the plurality of LED light sources 3 of the backlight unit 1 of FIG. 1 and incident on the light guiding film 2 will be described with reference to FIG. The light emitted from the plurality of LED light sources 3 is incident substantially perpendicularly from the end surface (incident end surface) of the light guiding film 2 facing the plurality of LED light sources 3, and propagates toward the end surface opposed to the incident end surface. At this time, the light emitted from the plurality of LED light sources 3 generates a region X in which the amount of light is extremely large, particularly in the vicinity of the light incident portion of the light guiding film 2, due to the strong directivity. On the other hand, since the plurality of LED light sources 3 are arranged at a predetermined interval, a region Y having a very small amount of light is generated between the vicinity of the light incident portion of the light guiding film 2 (between the adjacent regions X).
接著,參照圖12對光擴散片41及具備該光擴散片41的該背光單元的亮度不均降低功能進行說明。從上述的區域X嚮導光膜2的表面側出射的光線大多以沿著多個LED光源3的光線出射方向的狀態入射至該光擴散片41的背層42的背面。而且認為入射至該光擴散片41的背層42的背面的光線通過具有沿著多個LED光源3的光線出射方向的多個凹凸條的光柵形狀43而向光柵形狀43的寬度方向擴散。即,認為入射至光柵形狀43的光線如圖12所示那樣在俯視下向區域Y方向擴散。由此認為在俯視下的區域X的光量及區域Y的光量均勻化,降低該背光單元的亮度不均。Next, a function of reducing the luminance unevenness of the light diffusion sheet 41 and the backlight unit including the light diffusion sheet 41 will be described with reference to FIG. The light emitted from the surface side of the light-guide film 2 from the above-described region X is often incident on the back surface of the back layer 42 of the light diffusion sheet 41 in a state in which the light is emitted along the plurality of LED light sources 3. Further, it is considered that the light incident on the back surface of the back layer 42 of the light diffusion sheet 41 is diffused in the width direction of the grating shape 43 by the grating shape 43 having the plurality of irregularities along the light emission direction of the plurality of LED light sources 3. That is, it is considered that the light incident on the grating shape 43 is diffused in the direction of the region Y in plan view as shown in FIG. Therefore, it is considered that the amount of light in the region X in the plan view and the amount of light in the region Y are made uniform, and the luminance unevenness of the backlight unit is lowered.
<光擴散片的製造方法><Method of Manufacturing Light-Diffusing Sheet>
接著,對該光擴散片41的製造方法進行說明。該光擴散片41的製造方法具備樹脂膜運送工序、紫外線固化型樹脂組合物供給工序和紫外線照射工序。另外,該光學片41的製造方法還具備光擴散層層疊工序。該光擴散片41使用表面具有具備上述的多個凸部13a及光柵形狀43的背面形狀的翻轉形狀的壓輥代替上述的一個壓輥23,除此以外,可以利用與上述的該光擴散片5的製造方法同樣的方法來製造。Next, a method of manufacturing the light diffusion sheet 41 will be described. The method for producing the light diffusion sheet 41 includes a resin film transport step, an ultraviolet curable resin composition supply step, and an ultraviolet irradiation step. Moreover, the manufacturing method of this optical sheet 41 further has the light-diffusion layer lamination process. In the light-diffusing sheet 41, a pressure roller having a reverse shape having a back surface shape of the plurality of convex portions 13a and the grating shape 43 described above is used instead of the one pressure roller 23 described above, and the light diffusion sheet described above can be used. The manufacturing method of 5 is manufactured in the same manner.
<優點><advantage>
該光擴散片41在背面以散點狀具備多個凸部13a,因此如已經敍述的那樣可以防止與在背面側配置的其他光學構件的黏附,並且可以防止其他光學構件的表面的損傷。進而,該光擴散片41在背面中不存在多個凸部13a的區域具備定向為一個方向的多條狀的光柵形狀43,因此可以使光向該光柵形狀43的寬度方向擴散,並且可以充分確保該寬度方向的視角。Since the light diffusion sheet 41 is provided with a plurality of convex portions 13a in a scattered manner on the back surface, adhesion to other optical members disposed on the back side can be prevented as described above, and damage of the surface of other optical members can be prevented. Further, the light diffusion sheet 41 has a plurality of grating shapes 43 oriented in one direction in a region where the plurality of convex portions 13a are not present in the back surface, so that light can be diffused in the width direction of the grating shape 43 and can be sufficiently Make sure that the angle of view is in the width direction.
該光擴散片的製造方法如已經敍述的那樣能夠容易且可靠地製造可以防止與在背面側配置的其他光學構件的黏附、可以防止其他光學構件的表面的損傷、並且可以充分確保光柵形狀43的寬度方向的視角的該光擴散片41。The method for producing the light-diffusing sheet can be easily and reliably manufactured, as described above, to prevent adhesion to other optical members disposed on the back side, to prevent damage of the surface of other optical members, and to sufficiently secure the grating shape 43. The light diffusion sheet 41 of the viewing angle in the width direction.
《第四實施方式》Fourth Embodiment
<光擴散片><Light diffusion sheet>
圖13的光擴散片46代替圖2及圖8的光擴散片5、41而被用於圖1的背光單元。該光擴散片46除了在多個凸部13a的背面側也具有與光柵形狀43連續的光柵形狀47以外,與圖8的光擴散片41同樣地構成。The light diffusion sheet 46 of Fig. 13 is used for the backlight unit of Fig. 1 instead of the light diffusion sheets 5, 41 of Figs. 2 and 8. The light-diffusing sheet 46 is configured similarly to the light-diffusing sheet 41 of FIG. 8 except that it has a grating shape 47 continuous with the grating shape 43 on the back side of the plurality of convex portions 13a.
<光擴散片的製造方法><Method of Manufacturing Light-Diffusing Sheet>
該光擴散片46的製造方法具備樹脂膜運送工序、紫外線固化型樹脂組合物供給工序和紫外線照射工序。另外,該光學片46的製造方法還具備光擴散層層疊工序。該光擴散片46使用表面具有具備上述的多個凸部13a、光柵形狀43及與該光柵形狀43連續而形成於多個凸部13a的背面側的光柵形狀47的背面形狀的翻轉形狀的壓輥代替上述的一個壓輥23,除此以外,可以利用與上述的該光擴散片5的製造方法同樣的方法來製造。The method for producing the light diffusion sheet 46 includes a resin film transport step, an ultraviolet curable resin composition supply step, and an ultraviolet irradiation step. Moreover, the manufacturing method of this optical sheet 46 further has the light-diffusion layer lamination process. The light-diffusing sheet 46 has a surface having a reverse shape including a plurality of convex portions 13a, a grating shape 43 and a back surface shape of the grating shape 47 formed on the back side of the plurality of convex portions 13a in succession with the grating shape 43. In addition to the above-described one pressure roller 23, the roller can be manufactured by the same method as the above-described method of manufacturing the light diffusion sheet 5.
<優點><advantage>
該光擴散片46在多個凸部13a的背面側也具有與光柵形狀43連續的光柵形狀47,因此可以使光從該光柵形狀43、47的寬度方向更均勻地擴散,並且可以更準確地確保該光柵形狀43、47的寬度方向的視角。The light diffusion sheet 46 also has a grating shape 47 continuous with the grating shape 43 on the back side of the plurality of convex portions 13a, so that light can be more uniformly diffused from the width direction of the grating shapes 43, 47, and can be more accurately The viewing angle in the width direction of the grating shapes 43, 47 is ensured.
該光擴散片的製造方法如已經敍述的那樣能夠容易且可靠地製造可以防止與在背面側配置的其他光學構件的黏附、可以防止其他學構件的表面的損傷、並且可以更準確地確保光柵形狀43、47的寬度方向的視角的該光擴散片46。The method for producing the light-diffusing sheet can be easily and reliably manufactured as described above to prevent adhesion to other optical members disposed on the back side, to prevent damage of the surface of other members, and to more accurately ensure the shape of the grating. The light diffusing sheet 46 has a viewing angle of 43 and 47 in the width direction.
《其他實施方式》Other Implementations
予以說明,本發明的光學片、背光單元及光學片的製造方法,除上述形態以外,還可以以實施了各種變型、改良後的形態來實施。例如該光學片並不限於具有上述構成的光擴散片、棱鏡片及微透鏡片。例如該光學片可以為利用壓紋加工而在光擴散層的表面形成有細小凹凸的光擴散片。另外,在該光學片為光擴散片的情況下,未必需要是在導光片的正上方配置的下用光擴散片,也可以是配置於棱鏡片的表面側並且通過使光線略微擴散而抑制因棱鏡片的棱鏡列的形狀等所致的亮度不均的上用光擴散片。予以說明,在該光學片為上用光擴散片且該光學片具有光柵形狀的情況下,可以使從光源出射且入射至光柵形狀的光路較長,因此容易提高光線向光柵形狀的寬度方向的擴散效果。因此,在該光學片為上用光擴散片的情況下,容易提高背光單元的亮度不均抑制效果。In addition to the above-described embodiments, the optical sheet, the backlight unit, and the optical sheet manufacturing method of the present invention may be implemented in various modifications and improvements. For example, the optical sheet is not limited to the light diffusion sheet, the prism sheet, and the lenticular sheet having the above configuration. For example, the optical sheet may be a light-diffusing sheet in which fine irregularities are formed on the surface of the light-diffusing layer by embossing. Further, when the optical sheet is a light-diffusing sheet, it is not necessarily required to be a lower-light diffusing sheet disposed directly above the light guiding sheet, or may be disposed on the surface side of the prism sheet and suppressed by slightly diffusing light. The upper light diffusing sheet is uneven in brightness due to the shape of the prism array of the prism sheet or the like. In the case where the optical sheet is a light diffusion sheet and the optical sheet has a grating shape, the optical path that is emitted from the light source and incident on the grating shape can be made long, so that it is easy to increase the width of the light in the width direction of the grating shape. Diffusion effect. Therefore, when the optical sheet is a light diffusion sheet, it is easy to improve the brightness unevenness suppression effect of the backlight unit.
該光學片可以具有除上述實施方式記載的各層以外的其他層。例如該光學片可以在基體材料層與光學層(光擴散層、棱鏡列、微透鏡陣列)之間或者基體材料層與背層之間層疊其他樹脂層。The optical sheet may have other layers than the layers described in the above embodiments. For example, the optical sheet may have another resin layer laminated between the base material layer and the optical layer (light diffusion layer, prism array, microlens array) or between the base material layer and the back layer.
在該光學片具有光柵形狀的情況下,該光學片也優選配置在貼合2片棱鏡片的片體的背面。貼合2片棱鏡片的片體在棱鏡片間不易形成空氣層,因此隱蔽性低。與此相對,就在上述片體的背面配置有該光學片的背光單元而言,該光學片可以使光向光柵形狀的寬度方向擴散,因此可以充分提高隱蔽效果。In the case where the optical sheet has a grating shape, the optical sheet is also preferably disposed on the back surface of the sheet body to which the two prism sheets are bonded. The sheet to which the two prism sheets are bonded is less likely to form an air layer between the prism sheets, and thus the concealing property is low. On the other hand, in the backlight unit in which the optical sheet is disposed on the back surface of the sheet body, the optical sheet can diffuse light in the width direction of the grating shape, so that the concealing effect can be sufficiently enhanced.
該光學片可以在除背面以外的部分形成光柵形狀。例如該光學片可以在基體材料層的表面或光學層(光擴散層、棱鏡列、微透鏡陣列)的背面形成光柵形狀。The optical sheet can be formed into a grating shape at a portion other than the back surface. For example, the optical sheet may have a grating shape on the surface of the base material layer or the back surface of the optical layer (light diffusion layer, prism array, microlens array).
上述光柵形狀可以例如如圖14所示那樣進行配置。在圖14中,光柵形狀51從背層52的一端(在俯視下為與光源53對置的一側的端緣)到另一端側形成在一定區域。另外,背層52的背面的未形成光柵形狀51的區域構成平坦面。予以說明,光柵形狀51的具體構成與圖8的光擴散片41同樣。The grating shape described above can be arranged, for example, as shown in FIG. In FIG. 14, the grating shape 51 is formed in a certain area from one end of the back layer 52 (the edge on the side opposite to the light source 53 in plan view) to the other end side. Further, a region of the back surface of the back layer 52 where the grating shape 51 is not formed constitutes a flat surface. Incidentally, the specific configuration of the grating shape 51 is the same as that of the light diffusion sheet 41 of Fig. 8 .
作為形成柵形狀51的區域的一端及另一端間的長度L3相對於背層52的背面的一端及另一端間的長度L2之比(L3/L2)的下限,優選0.15,更優選0.2,進一步優選0.25。另一方面,作為上述長度比(L3/L2)的上限,優選0.5,更優選0.45,進一步優選0.4。若上述長度比(L3/L2)不足上述下限,則存在難以全面抑制熱點發生的風險。相反,若上述長度比(L3/L2)超出上述上限,則存在容易使除熱點以外的區域的光線向光柵形狀51的寬度方向擴散的風險。The lower limit of the ratio (L3/L2) of the length L3 between the one end and the other end of the region forming the gate shape 51 to the length L2 between the one end of the back layer 52 and the other end is preferably 0.15, more preferably 0.2, further Preferably 0.25. On the other hand, the upper limit of the length ratio (L3/L2) is preferably 0.5, more preferably 0.45, still more preferably 0.4. If the length ratio (L3/L2) is less than the above lower limit, there is a risk that it is difficult to suppress the occurrence of hot spots in an all-round manner. On the other hand, when the length ratio (L3/L2) exceeds the above upper limit, there is a risk that light rays in a region other than the hot spot are easily diffused in the width direction of the grating shape 51.
另外,上述光柵形狀可以例如如圖15所示那樣進行配置。圖15的光柵形狀61從背層62的背面的一端(在俯視下為與光源63對置的一側的端緣)到另一端側凹凸條的存在比例逐漸變少。該光學片利用該構成還可以抑制熱點的發生。另外,該光學片由於從與光源63對置的端緣到另一端側凹凸條的存在比例逐漸變少,因此可以在除熱點以外減少向光柵形狀61的寬度方向擴散的光量。Further, the grating shape described above can be arranged, for example, as shown in FIG. The grating shape 61 of Fig. 15 gradually decreases from the one end of the back surface of the back layer 62 (the edge on the side facing the light source 63 in plan view) to the other end side uneven strip. With this configuration, the optical sheet can also suppress the occurrence of hot spots. Further, since the optical sheet gradually decreases from the edge facing the light source 63 to the other end side uneven strip, the amount of light diffused in the width direction of the grating shape 61 can be reduced in addition to the hot spot.
作為上述光柵形狀的具體形狀,並不限定於上述的實施方式的形狀,可以為例如如圖16所示那樣具有截面角U字形的凹部的形狀、如圖17所示那樣具有截面為三角形的凹部的形狀、如圖18所示那樣具有狹縫狀的凹部的形狀等。另外,上述多個凹凸條可以定向為與光源的光線出射方向垂直的方向。The specific shape of the grating shape is not limited to the shape of the above-described embodiment, and may be, for example, a shape having a concave portion having a U-shaped cross section as shown in FIG. 16 and a concave portion having a triangular cross section as shown in FIG. The shape of the recessed portion having a slit shape as shown in FIG. 18 is as shown in FIG. Further, the plurality of embossed strips may be oriented in a direction perpendicular to the direction in which the light source exits.
該背光單元優選具有多個LED光源,但是也可以僅具有1個LED光源。另外,對該背光單元的光學片的具體種類並無特別限定。該背光單元優選在導光片的表面側具有多個光學片,但是也可以僅具有1個光學片。The backlight unit preferably has a plurality of LED light sources, but may have only one LED light source. Further, the specific type of the optical sheet of the backlight unit is not particularly limited. The backlight unit preferably has a plurality of optical sheets on the surface side of the light guiding sheet, but may have only one optical sheet.
作為上述導光片,並不需要為上述的導光膜,也可以為例如厚度較大的導光板。The light guide sheet is not necessarily the light guide film described above, and may be, for example, a light guide plate having a large thickness.
該背光單元並不需要為側光型背光單元,也可以為正下方型背光單元。The backlight unit does not need to be an edge type backlight unit, and may be a direct type backlight unit.
另外,即使在該背光單元為側光型背光單元的情況下,也無需為僅沿著導光片的一個端面配置有LED光源的單側側光型背光單元,也可以為沿著導光片的對置的一對端面配置有LED光源的兩側側光型背光單元、沿著導光片的各端面配置有LED光源的全周圍側光型背光單元。In addition, even when the backlight unit is a side light type backlight unit, it is not necessary to be a single-sided side light type backlight unit in which an LED light source is disposed only along one end surface of the light guide sheet, and may be along the light guide sheet. The opposite pair of end faces are provided with a side light type backlight unit of the LED light source, and a full peripheral side light type backlight unit in which the LED light source is disposed along each end surface of the light guide sheet.
該背光單元可以用於個人電腦、液晶電視等比較大型的顯示裝置、智慧手機等移動電話終端、平板終端等便攜型資訊終端。The backlight unit can be used for a portable information terminal such as a relatively large display device such as a personal computer or a liquid crystal television, a mobile phone terminal such as a smart phone, or a tablet terminal.
實施例:Example:
以下,利用實施例進一步詳細說明本發明,但本發明並不受這些實施例的限定。Hereinafter, the present invention will be described in further detail by way of examples, but the invention should not be construed as limited.
《No.1》No.1
使用在一個壓輥23的圓周面大致等密度地形成有同一形狀的多個凹部的圖5的製造裝置21來製造光擴散片。首先,將以丙烯酸聚氨酯樹脂為主成分並形成光擴散片的基體材料層的樹脂膜運送至一對壓輥22、23間。另外,向上述樹脂膜及一個壓輥23之間供給以丙烯酸聚氨酯樹脂為主成分的紫外線固化型樹脂組合物,將上述樹脂膜及紫外線固化型樹脂組合物用一對壓輥22、23進行擠壓。由此,在上述紫外線固化型樹脂組合物的外表面轉印多個凹部的翻轉形狀即半分割旋轉橢圓體狀的多個凸部。再對轉印有多個凸部的紫外線固化型樹脂組合物照射紫外線,使該紫外線固化型樹脂組合物固化。接著,在上述樹脂膜的與層疊有紫外線固化型樹脂組合物的一側相反的一側的面塗布包含多個珠及黏結劑組合物的塗布液,使該塗布液乾燥及固化,由此形成光擴散層,得到No.1的光擴散片。No.1的多個凸部的平均高度、平均徑、平均高度相對於平均徑之比及佔有面積比如表1所示。The light-diffusing sheet was produced using the manufacturing apparatus 21 of FIG. 5 in which a plurality of concave portions having the same shape were formed at substantially equal density on the circumferential surface of one pressure roller 23. First, a resin film mainly composed of an acrylic urethane resin and forming a base material layer of a light diffusion sheet is transported between a pair of press rolls 22 and 23. In addition, an ultraviolet curable resin composition containing an urethane urethane resin as a main component is supplied between the resin film and the one pressure roller 23, and the resin film and the ultraviolet curable resin composition are extruded by a pair of press rolls 22 and 23. Pressure. Thereby, a plurality of convex portions of a semi-divided spheroidal shape, which is an inverted shape of a plurality of concave portions, are transferred onto the outer surface of the ultraviolet curable resin composition. Further, the ultraviolet curable resin composition to which a plurality of convex portions are transferred is irradiated with ultraviolet rays to cure the ultraviolet curable resin composition. Next, a coating liquid containing a plurality of beads and a binder composition is applied to a surface of the resin film opposite to the side on which the ultraviolet curable resin composition is laminated, and the coating liquid is dried and solidified to form a coating liquid. The light diffusion layer was obtained as a light diffusion sheet of No. 1. The ratio of the average height, the average diameter, and the average height of the plurality of convex portions of No. 1 to the average diameter and the occupied area are as shown in Table 1.
《No.2~No.6》"No. 2 to No. 6"
利用與No.1同樣的製造方法,製造除多個凸部的平均高度、平均徑、平均高度相對於平均徑之比及佔有面積比如表1所示以外具有與No.1同樣的構成的No.2~No.6的光擴散片。In the same manufacturing method as in No. 1, the ratio of the average height, the average diameter, the average height to the average diameter, and the occupied area of the plurality of convex portions are the same as those of No. 1 except for those shown in Table 1. Light diffusing sheets of .2 to No. 6.
《No.7~No.13》"No. 7 to No. 13"
利用與No.1同樣的製造方法,製造除多個凸部的佔有面積比如表1所示以外具有與No.1同樣的構成的No.7~No.13的光擴散片。In the same manner as in No. 1, the light-diffusing sheet of No. 7 to No. 13 having the same configuration as that of No. 1 except for the area occupied by the plurality of convex portions was produced.
<密合性><adhesion>
將No.1~No.13的光擴散片配置在導光膜與棱鏡片之間,再沿著該導光膜的1個端面配置多個LED光源,形成側光型的背光單元。在該背光單元的棱鏡片的表面配置20mm見方的玻璃板,將該玻璃板的表面以5kgf的壓力進行擠壓。在該擠壓狀態下從多個LED光源對導光膜的端面出射光線,再在該光線出射狀態下釋放玻璃板表面的擠壓。在擠壓狀態及擠壓後的狀態下從玻璃板的表面側觀察有無亮點,按照以下的基準進行了評價。其評價結果如表2所示。The light-diffusing sheets of No. 1 to No. 13 are disposed between the light-guiding film and the prism sheet, and a plurality of LED light sources are disposed along one end surface of the light-guiding film to form a side-light type backlight unit. A 20 mm square glass plate was placed on the surface of the prism sheet of the backlight unit, and the surface of the glass plate was pressed at a pressure of 5 kgf. In the pressed state, light is emitted from the plurality of LED light sources to the end faces of the light guiding film, and the surface of the glass plate is released in the state in which the light is emitted. The presence or absence of a bright spot was observed from the surface side of the glass plate in the squeezed state and the state after extrusion, and it evaluated based on the following criteria. The evaluation results are shown in Table 2.
A:在擠壓狀態及擠壓後的狀態中的任一狀態下均未觀察到亮點。A: No bright spots were observed in any of the extruded state and the extruded state.
B:僅在擠壓狀態下於玻璃板表面的30%以下的區域觀察到亮點。B: A bright spot was observed only in the region of 30% or less of the surface of the glass plate in a pressed state.
C:僅在擠壓狀態下於玻璃板表面的超過30%的區域觀察到亮點。C: A bright spot was observed only in a region of more than 30% of the surface of the glass plate in a pressed state.
D:在擠壓狀態下於玻璃板表面的超過30%的區域觀察到亮點,且在擠壓後也觀察到數秒左右的亮點。D: A bright spot was observed in a region of more than 30% of the surface of the glass plate in a pressed state, and a bright spot of about several seconds was also observed after the extrusion.
E:在擠壓狀態下於玻璃板表面的超過30%的區域觀察到亮點,且在擠壓後也持續地觀察到與擠壓狀態同樣的亮點。E: A bright spot was observed in a region of more than 30% of the surface of the glass plate in a pressed state, and the same bright spot as the pressed state was continuously observed after the pressing.
<損傷性><damage>
將No.1~No.13的光擴散片配置於導光膜與棱鏡片之間,沿著該導光膜的1個端面配置多個LED光源。再在上述導光膜的背面側依次配置反射片及鋁板,並且在上述棱鏡片的表面配置液晶面板。在該狀態下使160g的球狀的丙烯酸制球從距離上述液晶面板的表面為300mm的高度位置落下。之後,從上述多個LED光源對導光膜的端面出射光線,在該光線出射狀態及光線出射後的狀態下觀察導光膜表面有無損傷,按照以下的基準進行了評價。其評價結果如表2所示。The light diffusion sheets of No. 1 to No. 13 are disposed between the light guiding film and the prism sheet, and a plurality of LED light sources are arranged along one end surface of the light guiding film. Further, a reflection sheet and an aluminum plate are disposed in this order on the back side of the light guiding film, and a liquid crystal panel is disposed on the surface of the prism sheet. In this state, 160 g of spherical acrylic balls were dropped from a height position of 300 mm from the surface of the liquid crystal panel. Thereafter, light was emitted from the end faces of the light guiding film from the plurality of LED light sources, and the surface of the light guiding film was observed to be damaged in the state in which the light was emitted and the light was emitted, and the evaluation was performed according to the following criteria. The evaluation results are shown in Table 2.
A:在光線出射狀態及光線出射後的狀態中的任一狀態下均完全未觀察到損傷。A: No damage was observed at all in any of the state in which the light was emitted and the state after the light was emitted.
B:僅在光線出射狀態下觀察到略發白的損失。B: A slight whitening loss was observed only when the light was emitted.
C:僅在光線出射狀態下觀察到淺白色的損傷,但是損傷的輪廓看起來較模糊。C: Light white damage was observed only in the light-emitting state, but the contour of the damage appeared to be blurred.
D:僅在光線出射狀態下觀察到較深的白色損傷。D: A deep white damage was observed only in the light-emitting state.
E:在光線出射狀態及光線出射後的狀態中的任一狀態下均觀察到損傷。E: Damage was observed in any of the state in which the light was emitted and the state after the light was emitted.
《評價結果》"Evaluation results"
如表1及表2所示,可知:多個凸部的平均高度為1.1μm、平均徑為10.2μm、平均高度相對於平均徑之比為0.11的No.1的光擴散片,充分防止與導光膜的密合,並且也未產生對導光膜的損傷。與此相對,如No.2及No.3所示,隨著多個凸部的平均高度及平均徑比變小,利用上述的密合性試驗觀察到亮點。該亮點產生的原因在於:因光擴散片的凸部被破壞等而使光擴散片及導光膜之間的密合區域變大,在該密合區域中光線的透射變高。進而,如No.4~No.6所示,可知:與No.1相比,隨著多個凸部的平均高度及平均徑比變大,容易因多個凸部而使導光膜的表面發生損傷。As shown in Table 1 and Table 2, it is understood that the light diffusion sheet of No. 1 having an average height of a plurality of convex portions of 1.1 μm, an average diameter of 10.2 μm, and an average height to an average diameter of 0.11 is sufficiently prevented. The light guiding film is in close contact and no damage to the light guiding film is caused. On the other hand, as shown in No. 2 and No. 3, as the average height and the average diameter ratio of the plurality of convex portions became small, bright spots were observed by the above-described adhesion test. This bright spot is caused by the fact that the convex portion of the light diffusion sheet is broken or the like, and the adhesion region between the light diffusion sheet and the light guiding film is increased, and the light transmission is high in the adhesion region. Further, as shown in No. 4 to No. 6, it is found that the average height and the average diameter ratio of the plurality of convex portions are larger than those of No. 1, and the light guiding film is easily formed by the plurality of convex portions. Damage to the surface.
另外,如表1及表2所示,可知:關於多個凸部的平均高度為1.1μm、平均徑為10.2μm、平均高度相對於平均徑之比為0.11的光擴散片,多個凸部的佔有面積比為5%~30%的No.1、No.9及No.10的光擴散片充分防止與導光膜的密合,並且也不產生對導光膜的損傷。與此相對,如No.7及No.8所示,可知:隨著多個凸部的佔有面積比低於2%,發生光擴散片與導光膜的密合。認為這是由於:光擴散片容易在除多個凸部以外的部分與導光膜相抵接。進而,如No.11~No.13所示,可知:隨著多個凸部的佔有面積比超過50%,光擴散片與導光膜的密合性變差。認為這是由於:若多個凸部的佔有面積比過高,則容易因多個凸部與導光膜的表面的抵接部分而招致光學功能的降低。另外,如No.11~No.13所示,可知:隨著多個凸部的佔有面積比超過50%,光擴散片對導光膜表面的損傷性變差。認為這是由於:若導光膜的表面與多個凸部的抵接部分過多,則容易因多個凸部與導光膜的表面的抵接部分而產生損傷。Further, as shown in Tables 1 and 2, it is understood that the plurality of convex portions have an average height of 1.1 μm, an average diameter of 10.2 μm, and a ratio of the average height to the average diameter of 0.11, and a plurality of convex portions. The light diffusion sheets of No. 1, No. 9 and No. 10 having an area ratio of 5% to 30% were sufficiently prevented from adhering to the light guiding film, and damage to the light guiding film was not caused. On the other hand, as shown in No. 7 and No. 8, it is understood that the light diffusion sheet and the light guiding film are adhered to each other as the area ratio of the plurality of convex portions is less than 2%. This is considered to be because the light diffusion sheet is likely to abut against the light guiding film at a portion other than the plurality of convex portions. Furthermore, as shown in No. 11 to No. 13, it is understood that the adhesion between the light-diffusing sheet and the light-guiding film deteriorates as the area ratio of the plurality of convex portions exceeds 50%. This is considered to be because if the ratio of the area occupied by the plurality of convex portions is too high, the optical function is likely to be lowered due to the contact portion between the plurality of convex portions and the surface of the light guiding film. Further, as shown in No. 11 to No. 13, it is understood that the damage of the light-diffusing sheet to the surface of the light-guiding film deteriorates as the area ratio of the plurality of convex portions exceeds 50%. This is considered to be because when the contact surface between the surface of the light guiding film and the plurality of convex portions is excessive, damage is likely to occur due to the contact portion between the plurality of convex portions and the surface of the light guiding film.
產業上的可利用性:Industrial availability:
綜上所示,本發明的光學片可以防止黏附,並且可以防止在背面側配置的其他光學構件的損傷,因此適合於高品質的透射型液晶顯示裝置等各種液晶顯示裝置。As described above, the optical sheet of the present invention can prevent sticking and prevent damage of other optical members disposed on the back side, and is therefore suitable for various liquid crystal display devices such as high-quality transmissive liquid crystal display devices.
1、31‧‧‧液晶顯示裝置用背光單元(背光單元)
2‧‧‧導光膜
3、53、63‧‧‧光源
32‧‧‧液晶顯示裝置用光學片(光學片)
5、41、46‧‧‧光擴散片
6‧‧‧棱鏡板
7‧‧‧反射片
8‧‧‧***部
9‧‧‧凹部
11、16、34‧‧‧基體材料層
12‧‧‧光擴散層
13a、18a、36a‧‧‧凸部
14‧‧‧珠
15‧‧‧黏結劑
17‧‧‧棱鏡列
17a‧‧‧凸條棱鏡部
21‧‧‧製造裝置
22、23‧‧‧壓輥
33‧‧‧微透鏡片
35‧‧‧微透鏡陣列
35a‧‧‧微透鏡
13、18、36、42、52、62‧‧‧背層
43、47、51、61‧‧‧光柵形狀
101‧‧‧背光單元
102‧‧‧光源
103‧‧‧導光片
104‧‧‧光學片
105‧‧‧光擴散片
106‧‧‧棱鏡板
111‧‧‧基體材料層
112‧‧‧光擴散層
113‧‧‧防黏附層
114‧‧‧珠
115‧‧‧黏結劑
A‧‧‧樹脂膜1, 31‧‧‧Backlight unit for liquid crystal display device (backlight unit)
2‧‧‧Light guide film
3, 53, 63‧‧‧ Light source
32‧‧‧Optical sheets for optical display devices (optical sheets)
5, 41, 46‧ ‧ light diffuser
6‧‧ ‧ Prism board
7‧‧‧reflector
8‧‧‧ Uplift
9‧‧‧ recess
11, 16, ‧ ‧ ‧ base material layer
12‧‧‧Light diffusion layer
13a, 18a, 36a‧‧ ‧ convex
14‧‧‧ beads
15‧‧‧Adhesive
17‧‧‧ Prism column
17a‧‧‧ convex strip prism
21‧‧‧ Manufacturing equipment
22, 23‧‧‧ pressure roller
33‧‧‧Microlens
35‧‧‧Microlens array
35a‧‧‧microlens
13, 18, 36, 42, 52, 62‧‧ ‧ back layer
43, 47, 51, 61‧‧‧ raster shapes
101‧‧‧Backlight unit
102‧‧‧Light source
103‧‧‧Light guide
104‧‧‧ optical film
105‧‧‧Light diffuser
106‧‧ ‧ Prism board
111‧‧‧ base material layer
112‧‧‧Light diffusion layer
113‧‧‧Anti-adhesion layer
114‧‧‧ beads
115‧‧‧Adhesive
A‧‧‧ resin film
圖1為表示本發明的一個實施方式涉及的液晶顯示裝置用背光單元的示意性端視圖。 圖2為表示圖1的背光單元的光擴散片的示意性部分放大圖。 圖3為表示圖2的光擴散片的凸部的示意性放大圖,(a)為側視圖,(b)為後視圖。 圖4為表示圖1的背光單元的棱鏡片的示意性部分放大圖。 圖5為表示圖2的光擴散片的製造裝置的示意圖。 圖6為表示與圖1的背光單元不同的實施方式涉及的背光單元的示意性端視圖。 圖7為表示圖6的背光單元的微透鏡片的示意性部分放大圖。 圖8為表示與圖2的光擴散片不同的實施方式涉及的光擴散片的示意性端視圖。 圖9為圖8的光擴散片的示意性後視圖。 圖10為圖8的光擴散片的A-A線部分端視圖。 圖11為表示液晶顯示裝置用背光單元的熱點的示意性俯視圖。 圖12為用於說明圖8的光擴散片的亮度不均降低功能的示意圖。 圖13為表示與圖2及圖8的光擴散片不同的實施方式涉及的光擴散片的示意性後視圖。 圖14為表示本發明的其他實施方式涉及的光學片的示意性後視圖。 圖15為表示與圖14的光學片不同的光學片的示意性後視圖。 圖16為表示本發明的其他實施方式涉及的光柵形狀的示意性端視圖。 圖17為表示與圖16的光柵形狀不同的形態涉及的光柵形狀的示意性端視圖。 圖18為表示與圖16及圖17的光柵形狀不同的形態涉及的光柵形狀的示意性端視圖。 圖19為表示以往的側光型的背光單元的示意性立體圖。 圖20為表示以往的光擴散片的示意性端視圖。FIG. 1 is a schematic end view showing a backlight unit for a liquid crystal display device according to an embodiment of the present invention. FIG. 2 is a schematic partial enlarged view showing a light diffusion sheet of the backlight unit of FIG. 1. FIG. Fig. 3 is a schematic enlarged view showing a convex portion of the light diffusion sheet of Fig. 2, wherein (a) is a side view and (b) is a rear view. 4 is a schematic partial enlarged view showing a prism sheet of the backlight unit of FIG. 1. Fig. 5 is a schematic view showing a manufacturing apparatus of the light diffusion sheet of Fig. 2; FIG. 6 is a schematic end view showing a backlight unit according to an embodiment different from the backlight unit of FIG. 1. FIG. Fig. 7 is a schematic partial enlarged view showing a lenticular sheet of the backlight unit of Fig. 6. Fig. 8 is a schematic end view showing a light diffusion sheet according to an embodiment different from the light diffusion sheet of Fig. 2 . Figure 9 is a schematic rear view of the light diffusing sheet of Figure 8. Fig. 10 is a partial end elevational view, taken along line A-A of the light diffusing sheet of Fig. 8. Fig. 11 is a schematic plan view showing a hot spot of a backlight unit for a liquid crystal display device. Fig. 12 is a schematic view for explaining a function of reducing the luminance unevenness of the light diffusion sheet of Fig. 8; FIG. 13 is a schematic rear view showing a light diffusion sheet according to an embodiment different from the light diffusion sheet of FIGS. 2 and 8. Fig. 14 is a schematic rear view showing an optical sheet according to another embodiment of the present invention. Fig. 15 is a schematic rear view showing an optical sheet different from the optical sheet of Fig. 14. Fig. 16 is a schematic end view showing a grating shape according to another embodiment of the present invention. Fig. 17 is a schematic end view showing a grating shape according to a form different from the grating shape of Fig. 16; Fig. 18 is a schematic end view showing a grating shape according to a form different from the grating shape of Figs. 16 and 17; 19 is a schematic perspective view showing a conventional sidelight type backlight unit. Fig. 20 is a schematic end view showing a conventional light diffusion sheet.
1‧‧‧液晶顯示裝置用背光單元(背光單元) 1‧‧‧Backlight unit for liquid crystal display device (backlight unit)
2‧‧‧導光膜 2‧‧‧Light guide film
3‧‧‧光源 3‧‧‧Light source
5‧‧‧光擴散片 5‧‧‧Light diffuser
6‧‧‧棱鏡板 6‧‧ ‧ Prism board
7‧‧‧反射片 7‧‧‧reflector
8‧‧‧***部 8‧‧‧ Uplift
9‧‧‧凹部 9‧‧‧ recess
11、16‧‧‧基體材料層 11, 16‧‧‧ base material layer
12‧‧‧光擴散層 12‧‧‧Light diffusion layer
13a、18a‧‧‧凸部 13a, 18a‧‧‧ convex
14‧‧‧珠 14‧‧‧ beads
15‧‧‧黏結劑 15‧‧‧Adhesive
17‧‧‧棱鏡列 17‧‧‧ Prism column
17a‧‧‧凸條棱鏡部 17a‧‧‧ convex strip prism
13、18‧‧‧背層 13, 18‧‧‧ back layer
Claims (9)
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JP2016-098290 | 2016-05-16 | ||
JP2016098290 | 2016-05-16 | ||
JP2017-083197 | 2017-04-19 | ||
JP2017083197A JP2017207736A (en) | 2016-05-16 | 2017-04-19 | Optical sheet for liquid crystal display device, backlight unit for liquid crystal display device and production method of optical sheet for liquid crystal display device |
Publications (2)
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TW201741747A true TW201741747A (en) | 2017-12-01 |
TWI639871B TWI639871B (en) | 2018-11-01 |
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TW106116123A TWI639871B (en) | 2016-05-16 | 2017-05-16 | Optical sheet for liquid crystal display device, backlight unit for liquid crystal display device and production method of optical sheet for liquid crystal display device |
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JP (1) | JP2017207736A (en) |
KR (1) | KR102049301B1 (en) |
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CN113056617A (en) * | 2019-03-27 | 2021-06-29 | 住友理工株式会社 | Developing roller for electrophotographic apparatus and method for manufacturing developing roller for electrophotographic apparatus |
TWI797516B (en) * | 2019-12-16 | 2023-04-01 | 日商惠和股份有限公司 | Light diffusion sheet and backlight unit for liquid crystal display device |
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JP6815438B2 (en) * | 2018-08-31 | 2021-01-20 | 旭化成エレクトロニクス株式会社 | Optical waveguide and optical concentration measuring device |
JP7446766B2 (en) * | 2019-10-24 | 2024-03-11 | 日東電工株式会社 | Light diffusion film and polarizing plate with light diffusion film |
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CA2413700C (en) * | 2000-07-11 | 2007-01-09 | 3M Innovative Properties Company | Backlight with structured sufaces |
JP4170084B2 (en) * | 2002-12-04 | 2008-10-22 | 三菱電機株式会社 | Planar light source device and display device |
US7672051B2 (en) * | 2003-05-22 | 2010-03-02 | Hitachi Chemical Co., Ltd. | Optical film and surface light source using it |
JP4695509B2 (en) * | 2005-12-28 | 2011-06-08 | 三菱レイヨン株式会社 | Light diffusion film and composite optical element using the same |
TWI417609B (en) * | 2007-11-09 | 2013-12-01 | Eternal Chemical Co Ltd | Optical film |
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JP2010026231A (en) | 2008-07-18 | 2010-02-04 | Jiroo Corporate Plan:Kk | Optical sheet and backlight unit using the same |
TWI397743B (en) * | 2008-08-22 | 2013-06-01 | Shenzhen China Star Optoelect | Prism sheet and backlight module |
JP5075234B2 (en) * | 2009-09-02 | 2012-11-21 | ソニー株式会社 | Optical element and display device |
JP2011064745A (en) * | 2009-09-15 | 2011-03-31 | Toppan Printing Co Ltd | Optical sheet, backlight unit and display apparatus |
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JP2011133555A (en) * | 2009-12-22 | 2011-07-07 | Toppan Printing Co Ltd | Optical sheet, backlight unit, and display device |
JP5598010B2 (en) * | 2010-02-19 | 2014-10-01 | 凸版印刷株式会社 | Backlight unit and display device |
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JP2012063670A (en) * | 2010-09-17 | 2012-03-29 | Hitachi Displays Ltd | Liquid crystal display device |
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- 2017-04-19 JP JP2017083197A patent/JP2017207736A/en active Pending
- 2017-05-12 KR KR1020170059458A patent/KR102049301B1/en active IP Right Grant
- 2017-05-16 TW TW106116123A patent/TWI639871B/en active
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
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CN113056617A (en) * | 2019-03-27 | 2021-06-29 | 住友理工株式会社 | Developing roller for electrophotographic apparatus and method for manufacturing developing roller for electrophotographic apparatus |
TWI797516B (en) * | 2019-12-16 | 2023-04-01 | 日商惠和股份有限公司 | Light diffusion sheet and backlight unit for liquid crystal display device |
Also Published As
Publication number | Publication date |
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JP2017207736A (en) | 2017-11-24 |
KR102049301B1 (en) | 2019-11-27 |
TWI639871B (en) | 2018-11-01 |
KR20170129061A (en) | 2017-11-24 |
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