TWI334937B - Light-diffusing sheet for backlight unit - Google Patents

Light-diffusing sheet for backlight unit Download PDF

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Publication number
TWI334937B
TWI334937B TW096114676A TW96114676A TWI334937B TW I334937 B TWI334937 B TW I334937B TW 096114676 A TW096114676 A TW 096114676A TW 96114676 A TW96114676 A TW 96114676A TW I334937 B TWI334937 B TW I334937B
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Taiwan
Prior art keywords
light
particles
resin
film
monodisperse
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TW096114676A
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Chinese (zh)
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TW200839303A (en
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Sang-Pil Kim
Moon-Bok Lee
Kwang-Soo Kim
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Toray Advanced Mat Korea Inc
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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/02—Diffusing elements; Afocal elements
    • G02B5/0205—Diffusing elements; Afocal elements characterised by the diffusing properties
    • G02B5/0236—Diffusing elements; Afocal elements characterised by the diffusing properties the diffusion taking place within the volume of the element
    • G02B5/0242—Diffusing elements; Afocal elements characterised by the diffusing properties the diffusion taking place within the volume of the element by means of dispersed particles
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/02—Diffusing elements; Afocal elements
    • G02B5/0205—Diffusing elements; Afocal elements characterised by the diffusing properties
    • G02B5/021—Diffusing elements; Afocal elements characterised by the diffusing properties the diffusion taking place at the element's surface, e.g. by means of surface roughening or microprismatic structures
    • G02B5/0221—Diffusing elements; Afocal elements characterised by the diffusing properties the diffusion taking place at the element's surface, e.g. by means of surface roughening or microprismatic structures the surface having an irregular structure
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/02—Diffusing elements; Afocal elements
    • G02B5/0205—Diffusing elements; Afocal elements characterised by the diffusing properties
    • G02B5/021—Diffusing elements; Afocal elements characterised by the diffusing properties the diffusion taking place at the element's surface, e.g. by means of surface roughening or microprismatic structures
    • G02B5/0226—Diffusing elements; Afocal elements characterised by the diffusing properties the diffusion taking place at the element's surface, e.g. by means of surface roughening or microprismatic structures having particles on the surface
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/02—Diffusing elements; Afocal elements
    • G02B5/0273—Diffusing elements; Afocal elements characterized by the use
    • G02B5/0294—Diffusing elements; Afocal elements characterized by the use adapted to provide an additional optical effect, e.g. anti-reflection or filter
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0033—Means for improving the coupling-out of light from the light guide
    • G02B6/005—Means for improving the coupling-out of light from the light guide provided by one optical element, or plurality thereof, placed on the light output side of the light guide
    • G02B6/0051—Diffusing sheet or layer
    • 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
    • G02F1/133504—Diffusing, scattering, diffracting elements
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336—Illuminating devices
    • G02F1/133602—Direct backlight
    • G02F1/133606—Direct backlight including a specially adapted diffusing, scattering or light controlling members

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Nonlinear Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Mathematical Physics (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Dispersion Chemistry (AREA)
  • Optical Elements Other Than Lenses (AREA)
  • Liquid Crystal (AREA)

Description

1334937 九、發明說明： \ 【發明所屬之技術領域】 •本發明係有關一種使用於液晶顯示器(Liquid Crystal Display， LCD)中背光元件(backlight unit)之光擴散片（light-diffiision sheet)， 尤指一種能符合薄膜電晶體液晶顯示器（Thin Film Transistor . Liquid Crystal Display，TFT-LCD)或超扭轉向列型液晶顳示器 (Super-Twisted Nematic Liquid Crystal Display，STN-LCD)中背光元 φ 件之擴散能力（diffusion capability)以及遮罩能力（masking capability)需求之高規格光擴散片。 * · - · 【先前技術】 m 一般常見之液晶顯示器背光元件係有兩種結構：側光式結構 (side-type backlight)以及直下式結構(direct backlight)。其中，楔形 (wedge-shape)侧光式結構係由至少一個裝置在顯示器侧邊之線性 背光源(linear lamp)輸出非勻相光(non-uniform light)至一個楔形導 φ 光板_ guide Plate) ’ 再利用一個光擴散片(light-difiUsion sheet) 將該非勻相光轉換(convert)成以顯示器為中心之顯示正面向(ft〇nt direction)之勻相(uniform)面光源(walUight)。側光式結構之背光元 件由於採側邊入射之光源設計，擁有輕量、薄型、窄框化、低耗 電的特色作為車用導航機(car navigator)、行動電話(m〇biie • · · ·1334937 IX. Description of the invention: \ [Technical field to which the invention pertains] The present invention relates to a light-diffiision sheet for use in a backlight unit of a liquid crystal display (LCD), Refers to a backlight element that can conform to a Thin Film Transistor (Liquid Crystal Display) (TFT-LCD) or Super-Twisted Nematic Liquid Crystal Display (STN-LCD) A high-specification light diffuser that is required for diffusion capability and masking capability. * · - · [Prior Art] m Commonly used liquid crystal display backlight components have two structures: a side-type backlight and a direct backlight. Wherein, the wedge-shaped edge-light structure outputs non-uniform light to a linear guide φ light plate by at least one device on a linear lamp on the side of the display. ' A light-difiUsion sheet is used to convert the non-homogeneous light into a uniform surface light source (walUight) that displays the front side of the display. The backlight component of the edge-lit structure is designed to be light source, thin, narrow frame, and low in power consumption. It is used as a car navigator and a mobile phone (m〇biie • · · ·

Phone)、個人數位助理(PDA)、數位相機(digital camem)、可攜式 電視機以及數位攝影機(camcorder)等小面積顯示器背光用，亦可 用於如筆記型電腦(laptop PC)或桌上型電腦(；deskt〇p pc)等中大型 5 面積顯示器背光用。 對於超大尺寸之顯示器(如：大尺寸液晶電視與大^電腦榮 幕），側光式結構已經無法在重量、㈣電力及亮度上佔有優勢， 因此=導光板且歧放置於正下方的直τ型結構係為超大型尺 寸^丁”中月光7〇件之主要結構^這種直下式結構可隨顯示器大 小安置-聰支背光源在fc||f面(臟），如4陰極螢光燈管 (Cold Cathode Fiu〇rescent lamp，CCF lamp)或平面燈管伽 1咖p)， 直接透過反射板_ector)將光源反射至顯示器之顯示正面她⑽ direction)，從背光源射出之非句減經由光擴散片轉換，成為以 顯示器為中心之勻相面光源。 不論疋哪種f光元件結構，皆需要—個絲散片將來自發光 源之線光源(linear light)轉換以顯示器為中心之勻相面光源。傳統 光擴政片係利用表面之擴散粒子對線光源之多次折射來達到轉換 面光源的效果，而多次折射的結果也使得背光源亮度減弱不少。 已有:¾干發明利用透光樹脂附著劑(clear binder resin)在透明塑夥 膜(plastic film)上塗佈透光有機樹脂粒子(organic resin parti.cie)或是 透光無機粒子(inorganicparticle)，來達到增進光擴散片透光亮度之 效果，例如揭露在：JPTNo.7-174909 與 KPTNo.2000-0027862 and publishedΚΡΤΝ〇.1998-002·〇430 之專利。 然而，前者為了增加背光亮度而採用之透光樹脂膜與粒子， 會使光擴散片失去對線光源產生之線光點(bright line)的遮罩能力 1334937 (masking capability)。尤其’在越來越薄之背光元件發展中，線光 . 源產生之線光點將會越來越清楚，而光擴散片之遮罩能力也就越 . 來越重要。 【發明内容】 本發明之目的係提供一種應用於液晶顯示器中背光元件之光 擴散片’其特有之内擴散膜(internal diffusion film)基質(substrate) flb在長:供較佳務度(haze)時還保持高光穿透率(transmittance)。 • 本發明之另一目的係擎供一種應用於液晶顯示器中背光元件 之光擴散片，其基質上之特殊塗佈膜(coating)能大大增加光線折射 (refractlon)與光線散射(scattering)量，以此強化光擴散片之擴散能 力(difftision capability)達到理想之遮罩能力(masking capability)。 本發明之又一目的係奐供一種應用於液晶顯示器中背光元件 之光擴散片’供以解決傳統光擴散片對線光源產生之線光點(bright light)遮罩能力不足之問題，特別是薄型液晶顯示器中嚴重之線光 φ 點遮罩問題。 為達到上述目的，本發明之光擴散片之基質係不同於一般光 擴散片之透明樹脂膜(transparent resin film)基質，而為内擴散膜 ..··· f - · _ (internal diffusion film)基質’其内含有機擴散塑料(〇rganic diffiiser) ’除可大量增力口光擴散片之霧度(haze)達40%到95%，同 時’基質之光穿透率(transmittance)也達50%到95%。除此之外， 内擴散膜基質上之樹脂粒子(resin particle)塗佈膜(c〇ating)内含兩 7 1334937 種以上不同折射率(refraction index)之樹脂粒子，供以大大豐富光 - 擴散片之折射(refraction)與散射(scattering)量並強化光擴散片之擴 ....散能力(diffusion capability)，進而得到較佳之遮蔽效果，顯著解決 線光源產生之線光點現象。 為了能使本發明上述的内容、目的、優點與其他特徵能更明 顯易懂，以下配合圖式與較佳實施例詳細說明本發明。 【實施方式】 . 本發明之光擴散片係包括：一個内擴散膜(intemal趣si〇n film)基質與至少一層之光擴散層(light-dififbsion layer)，且該光擴散 層係利用樹月旨接著劑4(binder resin)將至少兩種以上擁有不同折射 率(refraction index)之樹脂粒子塗佈在(c〇ating)至少一側之該内擴 散膜上。 其中，該光擴散層中透光(clear)樹脂粒子係内含：一種單分散 粒子(m〇n〇diSpersi〇nparticle)，且該單分散粒子8〇%之粒子，其大 J控制在平均粒子大小(average particle size)之正負之内；以 及再混合至少-種樹脂粒子，且其相較於該單分散粒子具有較小 之平均粒子大小。 又，該透光樹驗子巾时—鮮分散粒子與兩種大小之樹 脂粒子’且該單分散粒子平均大小之最大值控制在1〇卿到5〇卿 之間’而該兩種樹脂粒子之平均大小小於該單分散粒子之最大 值’同時，該兩種樹蹄子平均粒子別、之最大值分別介於 1334937 到7㈣之間以及1 /a到3仰之間。 接著’將就本發明之較佳實施例參照例圖作更進一步之說 • 明，所附之圖示與實施例說明係為本發明眾多實施例之舉例，供 以提供清楚明瞭之說明用，並非限定本發明之結構樣態、化學形 式或尺寸大小，任何所屬技術領域中具有通常知識者之適當變化 • · · ·' · . ·.· ··_ 或修飾’皆應視為不脫離本發明之專利範嘴。 如圖1所示，該内擴散膜2係為一層包含有機擴散塑料 • 1 (呢如化出饰㈣之透明基質膜1 ’(transparent substrate fllm)。 為使該透明基賃膜Γ有較佳之表現，採用熱塑性樹脂 (thermoplastic resin)之聚自旨樹脂(p〇iyester resin)來作基質膜’例如： 聚乙烯對笨二甲酸酯(polyethylene terephthalate，PET)、聚萘二曱酸 乙二醇酯(p〇lyethylene-2,6-naphthalate)等等，亦可為上述聚酯樹脂 組成之共聚合物(copolymers based thereon)或是混合物(mixture thereof) ° 鲁 同樣地，使用熱塑性樹脂之聚烯烴樹脂(p〇lyolefin resin)為該 ··.·.····、····’·’ · · ·. ... · - 有機擴散塑料1以求有較佳之表現，例如：聚乙稀(polyethylene, PE)、聚丙烯(polypropylene, PP)、聚甲基戊烯(p〇iymethylpentene， PMP)等等’亦可為上述聚稀煙樹脂組成之共聚合物(C〇p〇lymerS based thereon)或是混合物。 其中，雙轴向聚乙·烯對苯二曱酸g旨（biaxially oriented polyethylene terephthalate)為該基質膜1’最佳材質實施例。因其具 9 1334937 有極佳之力學特性（mechanical, strength)、耐熱性能（heat . resistance)、透光度(transparency)與平坦度(flatness)等等特性，能使 . 該基質膜Γ達到本發明之目的。 對於使用光擴散塑料（light diffiiser)之該光擴散層 5(light-diffiision layer)而言，其光學特性係決定於光擴散塑料之材 質折射率(refraction index)與其所形成之鏡片弧面〇ens让啊— curv十越多種光擴散塑料形成之該光擴散層’就具有越多種折射 鲁率與鏡片弧面存在，也就會有越佳之遮罩與擴散能力。 為了使本發明之光擴散層擁有較大面積之鏡片弧面，該光擴 散層使用之光擴散塑料，其平均粒子大小至少要大於7…。本發 明患擴政塑.料較佳貫施例係為1Q./Λΐ).到之平均粒子木小， 以及80%的粒子大小皆不趄過其平均大小值之正負2〇%範圍之内 (本文中簡稱符合該大小分佈標準之粒子為單分散粒子 (monodisperion partide))。該粒子大小分佈情形可由c〇ulter公司生 • 產之光散射粒子大小分析儀(LS PARTICLE SIZE ANALYZER)量 出。然:而，在直下式背光元件中，尤其是裝在液晶電視背面之背 光燈源(lamp)，因其距離較近且光源較強，光線不能被光擴散層作 极的㈣與散射，姉在#光燈賴在之位置造賴謂之線光 點(brightlme)現象’而破壞句相面光源。因此，增進液晶顯示器面 板輝度係為最佳化擴散能力與消除線光點。 為了最佳化擴散能力.以成功消除線光點，本發明中採用的是 10 1334937 :言亥有機擴散塑料與該基質膜合為一體之該内擴散膜2,以及以兩種 ·.以上具有不同折射率之粒子組成各種鏡片弧面之該光擴散層5。為 .使呈現之鏡片弧面為最大，塗佈在該基質膜1，上之透絲型樹月旨 粒子大小钱大’且其大小分佈為單分散粒子％，而粒子大小至 乂大於7//m ’甚至是介於ϊ()肖彳5()㈣之間，以求光擴散層表層 鏡片弧面擁有足夠大之面積以達到較佳之擴散能力與遮罩能力。 但是，當光擴散層使甩之平均粒子大小大於等於5〇州時，便 #難以使用浸鑛塗佈法(wet coating)，同時，塗佈液(c〇athg h㈣也 很難均勻分佈。因此，使时均粒子ΑλΜ、於5(^之粒子為光擴 散層為較佳，同時，再混合比該單分散粒子平均大小小之至少兩 種以上之粒子3b，：3c，-樣塗佈在内擴散膜的表面上，以求最佳化 擴散能力與遮罩能力。 為求較佳之該光擴散層遮罩表現，該兩種以上之粒子平均大 小係分別介於3撕and 7卿與1炯and 3辦之間。 β "彡光擴散層5適用之光擴散塑料為透光之球狀粒子⑼伽 sphere particle)，可從有機粒子選擇，例如：壓克力(acfyl)、苯乙 烯(stylene)、矽樹脂(silicone)或其他相似材料粒子。亦可從有透光 性質之無機粒子中選擇，例如：合成樹脂(synthetic)、二氧化矽 (silica)、玻璃或是鑽石粒子等等。使用時可單獨使用一種材質或是 混合兩種以上材質來使用。 --·. · . · . 使該光擴散塑料5之粒子附著於該内擴散膜表面之樹脂附著 1334937 劑(binderresin)也必須是透光的。其材質可以是單一材質或是混合 - 兩種以上材質，例如：丙烯酸(acrylic)、氨基甲酸乙酯樹脂(urethane - resin)、環氧樹脂(ePoxy resin)、乙烯樹脂(vinyl resin)、聚脂樹脂 (polyester resin)與聚醯胺樹脂(p〇iyamide resin)像：聚曱基丙婦酸甲 醋（polymethyl methacrylate)或是甲基丙基酸與酯共聚物 (methacrylate ester copolymer)等等。不論使用何種透明樹脂附著 劑，皆必須注意該樹脂附著劑之折射率必要小於該基質膜丨，之折 鲁射率，否則，會在光線由該基質膜進入該光擴散層時產生過多之 介面(interface)折射，造成穿透過該光擴散片之穿透光作肪孤仏― light)損失；且，其與該基質膜之折射率的差別要在〇22之内。當 其折射率之差別大於0.22時，亦會有可觀的折射與散射充斥在該 光擴散層與該基質膜之介面，此時，便很難產生具有高輝度之光 擴散膜。 將該光擴散塑料與該有機樹脂附著劑之混合液體塗佈在該基 鲁 貝膜之操作貫施例之一係為浸鑛塗佈法(wet coating),例如：刮刀 塗佈(kn取 coating)、凹版轉印塗佈(gravure transfer c〇ating)、反相 滚筒塗佈(reverse roll coating)。 使用浸鍍塗佈法必需注意的是，該光擴散塑料與該有機樹脂 附著劑之混合液體之塗佈厚度必須大於其最大平均粒子大小之 150%，不然，容易造成塗佈不均的情形發生。 為增加本發明之光擴散片之擴散能力，亦可於該内擴散膜之 12 1334937 另一側再塗佈一層光擴散層。但是由於此舉將會使本發明之光擴 ； 散片兩側接面皆容易滑動，增加組裝時的困難度，因此，必需在 "一侧之該光擴散層另增加硬度以防止在切割過程或組裝過程中發 生刮傷意外；同時，也必需在接觸外在支撐物之一側上加上防靜 電(antistatic)措施。 實施例1係使用Toray公司出品之内擴散膜(qE31_125卿）， 其霧度(haze)為92而透光率(transmittance)為90，並在其一侧以_ • 個微凹版(micro gravure)將塗佈液(coating liquid)塗佈在該内擴散 膜之表面，形成一個光擴散片。而該塗佈液成份如下： - 18.2%比重之樹脂附著劑(binder resin)，係為Aeky〇ungx 化學公司代號A-811之產品，後續實施例之樹脂附著劑皆為 此材斜; 1.8%比重之堅膜劑(hardener)，係為Aekyoungx化學公司 代號DN980S之產品，後續實施例之堅膜劑皆為此材料； φ . 18·1°/〇比重之合成樹脂(synthetic resin)粒子，係為單分散 (monodispersion)粒子，其折射率為1.49，平均粒子大小為Μ IM ； 2.5%比重之合成樹脂(synthetic resin)粒子，係為多分散 (polydispersion)粒子，其折射率為1.48，平均粒子大小為15 ; 2.5%比重之合成樹脂(synthetic resin)粒子，係為單分散 13 1334937 (monodispersion)粒子，其折射率為1.59，平均粒子大小為5 fM ； 28.3%比重之丁明(Methyl ethyl ketone); 28.3%比重之甲苯(To丨uene);以及 0.3% 比重之分散劑(Wetting and dispersing agent) 〇 實施例2係使用Toray公司出品之内擴散膜(QE32-125 Μη)， 其霧度(haze)為40而透光率(transmittance)為92，並在其一側以一 鲁 個微凹版(micro gravure)將塗佈液(coating liquid)塗佈在該内擴散 膜之表面’形成一個光擴散片。而該塗佈液成份如下： 18.2%比重之樹脂附著劑(binder resin); 1.8%比重《緊:膜劑(hardener); . 2.5%比重之合成辞f脂(synthetic resin)粒子，係為單分散粒 子，其折射率為1.49，平均粒子大小為15州； 18.1%比重之合成樹脂(synthetic resin)粒子，係為多分散 鲁 粒子，其折射率為1.48，平均粒子大小為15 //m ; 2.5%比重之合成樹脂(syntheticresin)粒子，係為單分散粒 子，其折射率為1.59，平均粒子大小為5州； '28.3% 比重之丁嗣(Methyl ethyl ketone); 28.3%比重之曱苯(Toluene);以及 0.3% 比重之分散劑(Wetting and dispersing agent) 〇 . 實誨例3係使用Toray公司出品之内擴散膜(ργ_2_11〇叫，其 14 1334937 霧度(haze)為85而透光率(transmittance)為90，並在其一側以一個 微凹版(micro gravure)將塗佈液(coating liquid)塗佈在該内擴散膜 之表面，形成一個光擴散片。而該塗佈液成份如下： 18.2%比重之樹脂附著劑(binder resin); 1.8%比重之堅膜劑(hardener); 18.1%比重之合成樹脂(synthetic resin)粒子，係為單分散 .粒子，其折射率為1.49，平均粒子大小為15燜； 2.5%比重之合成樹脂(synthetic resin)粒子’係為多分散粒 子，其折射率為1.48，平均粒子大小為15聊； 2.5%比重之合成樹脂(syntheticresin)粒子，係為單分散粒 · · 子，其折射率為1.59，平均粒子大小為5卿； 28.3%比重之丁酮(Methyl ethyl ketone); 28.3%比重之曱苯(Toluene);以及 0.3%比重之分散劑(Wetting and dispersing agdnt)。 實施例4係使用Toray公司出品之内擴散膜(?丫-3-11〇焖），其 霧度(haze)為93而透光率(transmittance)為68，並在其一侧以一個 微四版(ipiprp gravure)將塗佈液(coating liquid)塗佈在該内婧散膜 之表面，形成一個光擴散片。而該塗佈液成份如下： 18.2%比重之樹脂附著劑(binder resin); 1.8%比重之堅膜劑(hardener); -· · . ·· - · · · 2.5%比重之合成樹脂(synthetic resin)粒子，係為單分散 15 1334937 (monodispersion)粒子，其折射率為[49，平均粒子大小為μ m ; 18.1%比重之合成樹脂(synthetic resin)粒子，係為單分散 粒子，其折射率為1.48，平均粒子大小為15卿； 2.5°/。比重之合成樹脂(syntheticresin)粒子，係為單分散粒 ..子.，.其折射率為1.59 ’平均粒子大小為5興；. 28.3%比重之丁闕(Methyl ethyl ketone); 28.3%比重之甲苯(Toluene);以及 0.3% 比重之分散劑(Wetting and dispersing agent)。 實施例5係使用Toray公司出品之内擴散膜(PY4-110煳），其 霧度(haze)為93而透光率(transmittance)為57，並在其一側以—個 微凹版(micro gravure)將塗佈液(coating liquid)塗佈在該内擴散膜 之表面，形成一個光擴散片。而該塗佈液成份如下： 18.2%比重之樹脂附著劑(binder resin); 1.8%比重之堅膜劑(hardener); 2.5%比重之合成樹脂(syntheticresin)粒子，係為單分散粒 子，其折射率為1.49，.平均粒子大小為15卿； 18.1%比重之合成樹脂(synthetic resin)粒子，係為單分散 粒子，其折射率為1.48，平均粒子大小為15/an ; .. -· 2.5%比重之合成樹脂(synthetic resin)粒子，係為單分散粒 子，其折射率為1.59，平均粒子大小為5卿； 16 山4937 2 8.3 % 比重之丁 _(Methyl ethyl ketone); 28.3%比重之甲苯(Toluene);以及 0.3% 比重之分散劑(wetting and dispersing agent)。 對照組1係對應至實施例1之光擴散膜，所有成份比重皆相 prj P ’不同的是，其中所有不同種類之合成樹脂粒子折射率皆等同 於5亥單分散合成樹脂折射率149。 對照組2係對應至實施例2之光擴散膜，所有成份比重皆相 prj ° ’不同的是’其中所有不同種類之合成樹脂粒子折射率皆等同 於§亥單分散合成樹脂折射率1.49。 對照組3係對應至實施例3之光擴散膜，所有成份比重皆相 同’不同的是，其中所有不同種類之合成樹脂粒子折射率皆等同 於該單分散合成樹脂折射率 1.49。 對照組4係對應至實施例4之光擴散膜，所有成份比重皆相 同’不同的是，其中所有不同種類之合成樹脂粒子折射率皆等同 於該單分散合成樹脂折射率1.49 〇 對照組5係對應至實施例5之光擴散膜，所有成份比重皆相 同’不同的是’其中所有不同種類之合成樹脂粒子折射率皆等同 於該單分散合成樹脂折射率1.49。 * ' " ' ' .. . · 實驗數據1係針對實施例1〜5以及對照組1〜5之光擴散片進 行霧度量測，使用基底為ASTM D-1003，而使用之儀器為NIPPON DENSHOKUKOGYO股份有限公司型號No.1000之測量儀器。 17 1334937 貫驗數據2係係針對實施例1〜5以及對照組丨〜5之光擴散片 進行遮罩能力量測，使用iopcon公司出品之bm-7測試機(tester) 以固定間隔30點(p〇int)量測背光表面之流明(face lurninance)，且 以以下公式得出量化之遮罩能力： 渡置能力流明値-平均最小流明値） 、 平均獅値 謂0 … A ^ 1 [表格1] Γ " 物理特性 結果 霧度 透光率 厚度 遮罩能力 --^ 一般結果 單位 % % fm % 實施例1 87.32 76.11 141.5 0.9 〜— Good 實施例2 85.82 75.94 147.5 0.9 Good 實施例3 93.43 .74.53 144.2 1.0 ----〜 Good 實施例4 94.23 74.24 148.1 0.8 ——*— Good 實施例5 94.63 72,12 145.3 0.6 Good 對照組1 87.12 •74.11 142.4 1/7 —--- Poor 對照組2 86.82 74.94 148.5 1.7 ------— Poor 對照組3 93.43 74.53 144.2 1.6 Poor 對照組4 93.23 76.23 148.2 1.7 ---^ Poor 對照組5 94.13 76.16 145.3 1.7 Poor — 從表格1之結果可以知道，當光擴散片含有兩種以上不同折 射率之粒子塗柄在内擴散膜上時，如：實施例1〜5，相較於其對照 1334937 組1〜5使用相同折射率之粒子，實施例丨〜5會得到較為傑出之遮 罩能力(表格1中被量化之遮罩能力數字越小，代表線光點現象越 不明顯，遮罩能力越好）。 由此可知’應用本發明之光擴散片於薄型液晶顯示器之背光 元件上確實可以解決因線光源距離光擴散片過近而造成之線光點 問題。 综上，依上述所揭示之圖式與說明，本發明包含：該有機擴 散塑料與該基質膜混合之該内擴散膜；以及配合塗佈其上之混合 兩種以上具有不同折射率之樹脂粒子之該光擴散層，確實能展現 傑出的擴散能力與高級的遮罩能力，達到預期之目的，可供產業 上之利用。 然而’前述之實施例或圖示並非限定本發明之實施順 序或成份’例如：有機擴散塑料、基質膜與塗佈液之材料 舉例；塗佈液之材料比重與配製；以及塗佈方式或塗佈所 而之介質等等，並不以上述實施例為限，任何所屬技術領 域中具有通常知識者之適當變化或修飾，皆應視為不脫離 本發明之專利範疇。 【圖式簡單說明】 第1圖係根據本發明背光元件之光擴散片（light-diffusion She0)之内含内擴散膜（internal diffusion film)實施例之一 剖面圖（cross-section)。 19 1334937 · 第2圖為第1圖之俯視圖(top view)。 - 【主要元件符號說明】 • 1 :有機擴散塑料 1’ ：基質膜 2:内擴散膜 3a :單分散樹脂粒子 3b、3c :平均粒子大小小衿單分散樹脂粒子之樹脂粒子 _ 4:樹脂接著劑 5:光擴散層 20Phone, personal digital assistant (PDA), digital camera (digital camem), portable TV and digital camera (camcorder), etc. for small-area display backlighting, can also be used for laptop PCs or desktops Medium (large) 5-area display backlights for computers (;deskt〇p pc). For large-size displays (such as large-size LCD TVs and large computer glory screens), the side-light structure can no longer have an advantage in weight, (4) power and brightness, so = light guide plate and the τ directly placed below The type structure is the main structure of the ultra-large size ^ Ding" Zhongyue 7 pieces. This direct type structure can be placed with the size of the display - Congzhi backlight in the fc||f surface (dirty), such as 4 cathode fluorescent lamp Tube (Cold Cathode Fiu〇rescent lamp, CCF lamp) or flat tube gamma (p), directly through the reflector _ector) to reflect the light source to the display front of the display (10) direction), the non-sentence reduction from the backlight Through the light diffusion sheet conversion, it becomes a uniform phase light source centered on the display. Regardless of the structure of the f-light element, it is necessary to use a piece of silk to convert the linear light from the light source to the center of the display. The phase light source. The traditional light expansion film uses the diffusion of particles on the surface to achieve the effect of converting the surface light source by multiple refraction of the line source, and the result of multiple refraction also makes the brightness of the backlight weaken a lot. hair Brightening resin is coated on a transparent plastic film with a transparent resin resin (organic resin parti.cie) or transparent inorganic particles (inorganic particles) to enhance light. The effect of the light transmission brightness of the diffusion sheet is disclosed, for example, in JPPT No. 7-174909 and KPT No. 2000-0027862 and published in 1998-002 〇 430. However, the former is a transparent resin film for increasing the brightness of the backlight. With the particles, the light diffusing film loses the masking ability of the line line generated by the line source 1334937 (masking capability). Especially in the development of thinner and thinner backlight elements, the line light. The line spot will become more and more clear, and the masking ability of the light diffusing sheet will become more important. SUMMARY OF THE INVENTION The object of the present invention is to provide a light diffusing sheet for a backlight element used in a liquid crystal display. The internal diffusion film matrix flb also maintains high light transmittance during long haze. • Another object of the present invention is A light diffusing sheet applied to a backlight element in a liquid crystal display, the special coating on the substrate can greatly increase the amount of light refractlon and light scattering, thereby enhancing the diffusion ability of the light diffusing sheet ( Difftision capability) achieves the desired masking capability. Still another object of the present invention is to provide a light diffusing sheet for a backlight element in a liquid crystal display to solve the problem that the conventional light diffusing sheet has insufficient bright light masking ability for the line light source, in particular, Severe line light φ point mask problem in thin LCDs. In order to achieve the above object, the matrix of the light-diffusing sheet of the present invention is different from the transparent resin film substrate of the general light-diffusing sheet, and is an internal diffusion film..···· f - · _ (internal diffusion film) The matrix contains 机rganic diffiiser. In addition to a large amount of haze, the haze of the diffuser is 40% to 95%, and the transmittance of the substrate is 50. % to 95%. In addition, the resin particle coating film on the inner diffusion film substrate contains two 7 1334937 kinds of resin particles of different refractive index for greatly enriching light-diffusion. The refraction and scattering amount of the sheet enhances the diffusion capability of the light diffusing sheet, thereby obtaining a better shielding effect, and significantly solving the line spot phenomenon generated by the line source. The present invention will be described in detail below with reference to the drawings and preferred embodiments. [Embodiment] The light diffusing film of the present invention comprises: an inner diffusing film and at least one light-dififbsion layer, and the light diffusing layer utilizes a tree moon The binder resin 4 applies at least two or more kinds of resin particles having a different refractive index to the inner diffusion film on at least one side. The clear resin particle in the light diffusion layer contains: a monodisperse particle (m〇n〇diSpersi〇nparticle), and the monodisperse particle is 8〇% of the particle, and the large J is controlled by the average particle. Within the positive and negative of the average particle size; and remixing at least one kind of resin particles, and having a smaller average particle size than the monodisperse particles. Moreover, the light-transmissive tree is in the form of freshly dispersed particles and resin particles of two sizes, and the maximum value of the average size of the monodisperse particles is controlled between 1 〇 到 and 5 〇 而 and the two resin particles The average size is smaller than the maximum value of the monodisperse particles. Meanwhile, the average values of the average particle sizes of the two tree hooves are between 1334937 and 7 (four) and between 1 / a and 3 pitch. The present invention will be described with reference to the preferred embodiments of the present invention. It is not intended to limit the structural form, chemical form or size of the present invention, and any suitable change in the art to those of ordinary skill in the art can be regarded as not departing from the present invention. The invention patent mouth. As shown in FIG. 1, the inner diffusion film 2 is a transparent substrate film 1 comprising an organic diffusion plastic material (1), in order to make the transparent substrate film better. The performance is as a matrix film using a thermoplastic resin (p〇iyester resin), for example: polyethylene terephthalate (PET), polyethylene naphthalate An ester (p〇lyethylene-2, 6-naphthalate) or the like may also be a copolymer of a polyester resin or a mixture thereof. Similarly, a polyolefin of a thermoplastic resin is used. The resin (p〇ly polyolefin resin) is the one that is organically diffused plastic 1 for better performance, for example, polyethyl b. Polyethylene (PE), polypropylene (PP), polymethylpentene (P〇iymethylpentene, PMP), etc. can also be a copolymer of the above-mentioned poly-smoke resin (C〇p〇lymerS based Exposure) or a mixture. Among them, biaxial polyethylene terephthalic acid g (biaxially oriented polyethylene terephthalate) is the best material example of the matrix film 1' because it has excellent mechanical properties, heat resistance, transparency and transparency. The properties of flatness and the like enable the matrix film to achieve the object of the present invention. For the light-diffiision layer using light diffiiser, the optical properties are The refractive index of the material of the light-diffusing plastic is determined by the refractive index of the lens formed by the light-diffusing plastic. The light-diffusion layer formed by the multiple light-diffusing plastics has more refractive index and lens curvature. If there is, there will be better masking and diffusion ability. In order to make the light diffusion layer of the invention have a larger area of the lens arc surface, the light diffusion layer uses light diffusion plastic, and the average particle size is at least greater than 7... The preferred embodiment of the present invention is 1Q./Λΐ). The average particle size is small, and 80% of the particle size does not exceed the average size of the positive and negative 2 % Of the range (herein referred to meet the particle size distribution of standard monodisperse particles (monodisperion partide)). The particle size distribution can be measured by a light scattering particle size analyzer (LS PARTICLE SIZE ANALYZER) produced by the company. However, in the direct type backlight component, especially the backlight source mounted on the back of the liquid crystal television, because the distance is relatively close and the light source is strong, the light cannot be polarized by the light diffusion layer (four) and scattering, In the position where the light is in the light, the phenomenon of the light point (brightlme) is broken, and the phase light source is destroyed. Therefore, the enhancement of the brightness of the panel of the liquid crystal display is to optimize the diffusion ability and eliminate the line spot. In order to optimize the diffusion ability, in order to successfully eliminate the line spot, the present invention adopts 10 1334937: the inner diffusion film 2 which is integrated with the matrix film, and has two types. The particles of different refractive indices constitute the light diffusing layer 5 of the various arcuate faces of the lens. In order to maximize the curvature of the lens, the film is coated on the matrix film 1, and the size of the particle is large and the size distribution is % of monodisperse particles, and the particle size is greater than 7/. /m 'Even between ϊ() 彳(5)(4), in order to achieve a sufficient area for the surface of the light diffusion layer to achieve better diffusion and masking ability. However, when the light diffusion layer has an average particle size of 甩 of 5 or more, it is difficult to use a wet coating, and at the same time, the coating liquid (c〇athg h (four) is also difficult to uniformly distribute. It is preferable that the particles of the time-average particle ΑλΜ are at 5 (the light-diffusion layer is preferable, and at least two or more particles 3b, which are smaller than the average size of the monodisperse particles, are further mixed, and are coated in The surface of the inner diffusion film is optimized for diffusion and masking ability. For better performance of the light diffusion layer mask, the average size of the two or more particles is between 3 and 7 and 1炯and 3 Between. β "Light diffusing layer 5 is suitable for light-diffusing plastics as light-transmitting spherical particles (9) gamma sphere particles, which can be selected from organic particles, such as: acrylic (acfyl), styrene (stylene), silicone or other similar material particles. It can also be selected from inorganic particles with light transmissive properties, such as synthetic, silica, glass or diamond particles, etc. Can be used alone or in combination The above materials are used. --······································································ Is a mixture - two or more materials, such as: acrylic, urethane-resin, ePoxy resin, vinyl resin, polyester resin and poly P〇iyamide resin such as: polymethyl methacrylate or methacrylate ester copolymer, etc. No matter which transparent resin adhesive is used It must be noted that the refractive index of the resin adhesive agent must be smaller than the refractive index of the matrix film, otherwise, excessive light will be generated when the light enters the light diffusion layer from the matrix film, resulting in wearing. The light transmitted through the light diffusing sheet is lost as a light loss; and the difference in refractive index from the matrix film is within 〇22. When the difference in refractive index is more than 0.22, considerable refraction and scattering are also applied to the interface between the light diffusion layer and the matrix film, and at this time, it is difficult to produce a light diffusion film having high luminance. One of the operation examples of applying the mixed liquid of the light-diffusing plastic and the organic resin-attaching agent to the base film is a wet coating, for example, knife coating (kn coating) ), gravure transfer coating, reverse roll coating. It is necessary to note that the coating thickness of the mixed liquid of the light-diffusing plastic and the organic resin-attaching agent must be greater than 150% of its maximum average particle size, otherwise it is easy to cause uneven coating. . In order to increase the diffusing ability of the light diffusing sheet of the present invention, a light diffusing layer may be further coated on the other side of the inner diffusing film 12 1334937. However, since this will make the light expansion of the present invention; the joint faces on both sides of the film are easily slid, which increases the difficulty in assembly, and therefore, it is necessary to increase the hardness on the side of the light diffusion layer to prevent cutting. A scratch accident occurs during the process or assembly; at the same time, antistatic measures must be added to the side of the contact external support. Example 1 uses an inner diffusion film (qE31_125) from Toray Co., having a haze of 92 and a transmittance of 90, and a micro gravure on one side thereof. A coating liquid is coated on the surface of the inner diffusion film to form a light diffusion sheet. The composition of the coating liquid is as follows: - a binder resin of 18.2% specific gravity is a product of Aeky〇ungx Chemical Co., Ltd. code A-811, and the resin adhesive agent of the subsequent examples is inclined for this material; 1.8% The hardener of specific gravity is the product of Aekyoungx Chemical Company code DN980S, and the hardener of the subsequent examples is this material; φ. 18·1°/〇 specific gravity synthetic resin particles, It is a monodispersion particle having a refractive index of 1.49 and an average particle size of Μ IM; 2.5% specific gravity of a synthetic resin particle, which is a polydispersion particle having a refractive index of 1.48, an average particle Synthetic resin particles having a size of 15; 2.5% specific gravity are monodisperse 13 1334937 (monodispersion) particles having a refractive index of 1.59 and an average particle size of 5 fM; 28.3% by weight of Methyl ethyl ketone ); 28.3% toluene (To丨uene); and 0.3% specific gravity dispersing agent (Wetting and dispersing agent) 〇 Example 2 uses Toray's internal diffusion film (QE32-125 Μη), its haze ( Haze) is 40 Transmittance (Transmittance) 92, and Lu in a dimpled Edition (micro gravure) coating liquid (coating liquid) coating the surface of the membrane in the diffusion thereof within the side 'form a light diffusion sheet. The composition of the coating liquid is as follows: 18.2% specific gravity of the binder resin; 1.8% specific gravity "tight: film (hardener); 2. 2.5% specific gravity of synthetic resin particles, is a single The dispersed particles have a refractive index of 1.49 and an average particle size of 15 states; 18.1% of the specific synthetic resin particles are polydisperse Lu particles having a refractive index of 1.48 and an average particle size of 15 //m; 2.5% of synthetic resin (syntheticresin) particles are monodisperse particles with a refractive index of 1.59, an average particle size of 5 states; '28.3% specific gravity of Methyl ethyl ketone; 28.3% specific gravity of benzene ( Toluene); and 0.3% of the dispersing agent (Wetting and dispersing agent) 〇. Example 3 uses the internal diffusion film produced by Toray (ργ_2_11 squeak, its 14 1334937 haze is 85 and the transmittance (transmittance) is 90, and a coating liquid is coated on the surface of the inner diffusion film on one side thereof with a micro gravure to form a light diffusion sheet. The composition of the coating liquid is as follows : 18.2% specific gravity of the binder resin (binder resin); 1.8 Hardener of % specific gravity; 18.1% of synthetic resin particles are monodisperse particles with a refractive index of 1.49 and an average particle size of 15焖; 2.5% specific gravity of synthetic resin (synthetic The resin's particles are polydisperse particles with a refractive index of 1.48 and an average particle size of 15 talk; 2.5% of synthetic resin (syntheticresin) particles are monodisperse particles · · · · · · · · · · · · · The particle size is 5 qing; 28.3% by weight of Methyl ethyl ketone; 28.3% of specific gravity of Toluene; and 0.3% of dispersing agent (Wetting and dispersing agdnt). Example 4 is produced by Toray. The diffusion film (?丫-3-11〇焖) has a haze of 93 and a transmittance of 68, and is coated on one side with a picogram gravure. A coating liquid is coated on the surface of the inner film to form a light diffusing sheet. The composition of the coating liquid is as follows: 18.2% specific gravity of the binder resin; 1.8% specific gravity hardener; -· · · · · · · · · 2.5% specific gravity synthetic resin The particles are monodisperse 15 1334937 (monodispersion) particles having a refractive index of [49, an average particle size of μ m; a synthetic resin particle of 18.1% specific gravity, which is a monodisperse particle having a refractive index of 1.48, average particle size is 15 qing; 2.5 ° /. The synthetic resin (syntheticres) particles are monodisperse particles.., whose refractive index is 1.59 'average particle size is 5 ;; 28.3% 3% of Methyl ethyl ketone; 28.3% Toluene; and a 0.3% Wetting and Dispersing Agent. Example 5 uses an inner diffusion film (PY4-110®) manufactured by Toray Co., having a haze of 93 and a transmittance of 57, and a micro gravure on one side thereof. A coating liquid is coated on the surface of the inner diffusion film to form a light diffusion sheet. The composition of the coating liquid is as follows: 18.2% specific gravity of the binder resin; 1.8% specific gravity hardener; 2.5% specific gravity synthetic resin (synthetic resin) particles, is a monodisperse particle, its refraction The ratio is 1.49, the average particle size is 15 qing; 18.1% specific gravity synthetic resin particles are monodisperse particles with a refractive index of 1.48 and an average particle size of 15/an; .. -· 2.5% The specific gravity synthetic resin particles are monodisperse particles with a refractive index of 1.59 and an average particle size of 5 qing; 16 shank 4937 2 8.3 % specific gravity _ (Methyl ethyl ketone); 28.3% specific gravity toluene (Toluene); and a 0.3% by weight dispersant (wetting and dispersing agent). The control group 1 corresponds to the light diffusing film of Example 1, and the difference in the specific gravity of all the components is prj P ', wherein the refractive index of all the different kinds of synthetic resin particles is equivalent to the refractive index 149 of the 5 hr monodisperse synthetic resin. The control group 2 corresponds to the light diffusing film of Example 2, and all of the components have a specific gravity prj ° '. The refractive index of all the different kinds of synthetic resin particles is equivalent to the refractive index of 1.39. The control group 3 corresponds to the light diffusing film of Example 3, and all the components have the same specific gravity. The difference in refractive index of all the different kinds of synthetic resin particles is equivalent to the refractive index of the monodisperse synthetic resin of 1.49. The control group 4 corresponds to the light diffusing film of Example 4, and all the components have the same specific gravity. The difference is that the refractive index of all the different kinds of synthetic resin particles is equal to the refractive index of the monodisperse synthetic resin 1.49 〇 control group 5 Corresponding to the light-diffusing film of Example 5, all the components have the same specific gravity 'the difference is that the refractive index of all the different kinds of synthetic resin particles is equivalent to the refractive index of the monodisperse synthetic resin of 1.49. * ' " ' ' . . . Experimental Data 1 For the light diffusion sheets of Examples 1 to 5 and Control Groups 1 to 5, the substrate was ASTM D-1003, and the instrument used was NIPPON. DENSHOKUKOGYO Co., Ltd. Model No. 1000 measuring instrument. 17 1334937 Continuation data 2 was used to measure the masking ability of the light diffusing sheets of Examples 1 to 5 and the control group 丨5, using a bm-7 tester (available from iopcon) at a fixed interval of 30 points ( P〇int) measures the surface lurninance of the backlight surface, and obtains the quantized masking ability by the following formula: 渡 能力 流 値 - average minimum lumen 値), average 値 値 0 0 ... A ^ 1 [Form 1] Γ " Physical Properties Results Haze Transmittance Thickness Masking Capability - ^ General Result Unit % % fm % Example 1 87.32 76.11 141.5 0.9 ~ - Good Example 2 85.82 75.94 147.5 0.9 Good Example 3 93.43 . 74.53 144.2 1.0 ----~ Good Example 4 94.23 74.24 148.1 0.8 ——*—Good Example 5 94.63 72,12 145.3 0.6 Good Control group 1 87.12 •74.11 142.4 1/7 —--- Poor Control group 2 86.82 74.94 148.5 1.7 ------—Poor control group 3 93.43 74.53 144.2 1.6 Poor control group 4 93.23 76.23 148.2 1.7 ---^ Poor control group 5 94.13 76.16 145.3 1.7 Poor — As can be seen from the results of Table 1, when light Diffusion tablets contain more than two types When the particles of the refractive index are coated on the inner diffusion film, such as: Examples 1 to 5, the particles of the same refractive index are used as compared with the control 1334937 group 1 to 5, and the examples 丨~5 will obtain a more excellent mask. Capabilities (The smaller the masking ability number quantified in Table 1, the less obvious the spot light spot phenomenon and the better the masking ability). From this, it can be seen that the application of the light diffusing sheet of the present invention to the backlight element of the thin liquid crystal display can solve the problem of the line spot caused by the line source being too close to the light diffusing sheet. In summary, according to the drawings and descriptions disclosed above, the present invention comprises: the internal diffusion film in which the organic diffusion plastic is mixed with the matrix film; and the resin particles having different refractive indexes mixed and coated thereon The light diffusing layer can indeed exhibit outstanding diffusion ability and advanced masking ability, and achieve the intended purpose, and can be utilized by the industry. However, the foregoing embodiments or illustrations are not intended to limit the implementation sequence or composition of the present invention, such as: materials for organic diffusion plastics, matrix films and coating liquids; specific gravity and formulation of coating liquids; and coating methods or coatings. The medium and the like of the present invention are not limited to the above-described embodiments, and any suitable changes or modifications of those skilled in the art should be considered as not departing from the scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross-section of an embodiment of an internal diffusion film containing a light-diffusion She0 of a backlight element according to the present invention. 19 1334937 · Fig. 2 is a top view of Fig. 1. - [Explanation of main component symbols] • 1 : Organic diffusion plastic 1': Substrate film 2: Internal diffusion film 3a: Monodisperse resin particles 3b, 3c: Resin particles having an average particle size smaller than monodisperse resin particles _ 4: Resin followed by Agent 5: light diffusion layer 20

Claims (1)

1334937 、 , 4 乂 . 十、申請專利範圍： …一——…一： 1、一種背光元件(backlight unit)之光擴散片（light — diffiision sheet)，包括： 一個内擴散膜(internal diffiision film)，其具有 40%到 95% 之霧度(haze)以及50%到95%之透光率(transmittance)，供以 作為基質(substrate)之用；以及 一個光擴散層(light—diffiision layer)，其係由兩種以上具 有不同折射率(refraction index)之透光樹脂粒子(clear resin particle) ’利用樹脂附著劑(恤如resin)塗佈(coating)在該内擴 散膜之至少一侧之表面所形成； 其中，該透光樹脂粒子係包括：一種單分散粒子 (monodispersionparticle) ’且該單分散粒子80%之粒子，其大 小控制在平均粒子大小(avemge partide ―)之正負2〇%之 内，以及再混合至少一種樹脂粒子，且其相較於該單分散粒 子具有較小之平均粒子大小。 2如申凊專利範圍第1項所述之光擴散片，其中，該透光樹脂 粒子中該單分散粒子平均大小之最大值控制在1〇⑽到％ 之間。 3、如申匕請專利範圍第1或2項所述之光擴散片，其中，該透光 樹月曰粒子之兩種樹絲子之平均大小小於該單分散粒子之最 大粒子大小’啊’麵觀脂粒子平均大小之最大值分別 介於3⑽到7姉之間以及1_到3 _之間。 211334937 、, 4 乂. X. Patent application scope: ...一——...一: 1. A light diffusing sheet of a backlight unit, including: an internal diffiision film , having a haze of 40% to 95% and a transmittance of 50% to 95% for use as a substrate; and a light-diffiision layer, It is coated on the surface of at least one side of the inner diffusion film by two or more kinds of clear resin particles having a different refractive index by a resin adhesion agent (shirt such as resin). The light-transmissive resin particle comprises: a monodispersion particle 'and 80% of the particles of the monodisperse particle, the size of which is controlled within a positive or negative 2% of the average particle size (avemge partide ―) And remixing at least one resin particle, and having a smaller average particle size than the monodisperse particle. The light-diffusing sheet of claim 1, wherein the maximum value of the average size of the monodisperse particles in the light-transmitting resin particles is controlled to be between 1 〇 (10) and %. 3. The light diffusing sheet according to claim 1 or 2, wherein the average size of the two kinds of the filaments of the light-transmitting tree ceramsite particles is smaller than the maximum particle size of the monodisperse particles. The average size of the apparent lipid particles is between 3 (10) and 7 以及 and between 1 and 3 _, respectively. twenty one
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CN104503010B (en) * 2014-12-23 2016-09-21 浙江大学宁波理工学院 A kind of scratch resistance type optical diffusion and preparation method thereof
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KR102062668B1 (en) * 2017-12-29 2020-01-06 주식회사 엘엠에스 Diffusion Sheet Having Light Shielding Function and Backlight Unit Having the Same
WO2020231195A1 (en) 2019-05-15 2020-11-19 Samsung Electronics Co., Ltd. Light-diffuser, light diffusing adhesive, light diffusing hard coat member, light diffusion film, and image forming apparatus including light diffusion film

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