100年06月曰 1353474 六、發明說明： 【發明所屬之技術領域】 [0001] 本發明涉及一種背光模組用擴散片》 【先前技術】 [0002] 液晶顯示裝置被廣泛應用於個人數位助理、筆記型電腦 、數位相機、行動電話、液晶電視等電子産品中。但由 於液晶顯示裝置爲非自發光性，因此其需要借助背光模 組才能産生顯示功能。 [0003] 由於光源一般爲點光源或線光源，而背光模組爲達成亮 度均勻之顯示效果需使用面光源，因此背光模組要借助 光擴散元件將點光源或線光源轉換成面光源。該種光綠 擴散元件一般爲擴散片。 [0004] 請參閱圖1，一種習知之擴散片之剖面示意圖。該擴散片 10包括透明基片12與擴散層11 ;該擴散層11包括基體 111與擴散粒子112。其中，該基體111之材料可爲聚甲 基丙烯酸甲酯、聚碳酸酯或聚酯等樹脂；該擴散粒子112 可爲聚氣乙烯顆粒、聚丙稀酸顆粒或玻璃微珠，該擴散 粒子112起光線擴散作用β [0005] 然而，當入射該擴散片20不同處之光強度變化較大時， 由於該擴散粒子112與透明基體111之材料較爲相似，兩 者折射率接近，造成該擴散粒子112對光線發生折射之欵 果較差’使得該擴散片20很難對光強較強處之光線做充 分之擴散以避免光源亮影之産生，而容易影響光線擴散 之均勻性。 095129561 表單编號Α0101 第3頁/共13頁 1〇〇32〇5848~〇 1353474 [10^06月10曰修ΪΕ替换k [0006] 有鑑於此，提供一種光擴散效果強之擴散片實為必需。 【發明内容】 [0007] 以下將以實施例說明一種光擴散效果強之擴散片。 [0008] 一種擴散片，其包括擴散層，該擴散層包括透明樹脂基 材，以及摻雜於該透明樹脂基材中之第一散射粒子與第 二散射粒子，該第一散射粒子之折射率比該第二散射粒 子之折射率小，該第一散射粒子之粒徑大於該第二散射 粒子之粒徑。 [0009] 相較於習知技術，所述擴散片之擴散層包含第一散射粒 < 子及折射率比第一散射粒子大之第二散射粒子。使用時 ，該第一散射粒子可將大部分之光線擴散均勻；該第二 散射粒子可處於第一散射粒子之間，可使該第一散射粒 子分佈更均勻，繼而使得第一散射粒子均勻擴散光線之 功能增強；另，該第二散射粒子由於具有較大之折射率 ，而易於具有部分反射功能，通過該第二散射粒子之部 分反射功能，可使光強較強處之光線被進一步分散開而 擴散均勻，避免光源亮影之産生。故上述擴散片光具有 1 光擴散效果強之優點。 【實施方式】 [0010] 下面將結合附圖及實施例對擴散片做進一步詳細說明。 [0011] 請參閱圖2，本發明較佳實施例一之擴散片剖面示意圖。 該擴散片21包括透明樹脂基材211，以及摻雜於該透明樹 脂基材211中之第一散射粒子212與第二散射粒子213， 該第一散射粒子212之折射率比該第二散射粒子21 3之折 1003205848-0 095129561 表單編號A0101 第4頁/共13頁 1353474 [0012] [0013] 100年06月10日核正替换頁100年06月曰1353474 VI. Description of the Invention: [Technical Field] [0001] The present invention relates to a diffusion sheet for a backlight module. [Prior Art] [0002] A liquid crystal display device is widely used in personal digital assistants. In electronic products such as notebook computers, digital cameras, mobile phones, and LCD TVs. However, since the liquid crystal display device is not self-illuminating, it is necessary to use a backlight module to generate a display function. [0003] Since the light source is generally a point light source or a line light source, and the backlight module needs to use a surface light source for achieving a uniform brightness display effect, the backlight module converts the point light source or the line light source into a surface light source by means of the light diffusing element. The light green diffusing element is typically a diffuser. [0004] Please refer to FIG. 1, a schematic cross-sectional view of a conventional diffusion sheet. The diffusion sheet 10 includes a transparent substrate 12 and a diffusion layer 11; the diffusion layer 11 includes a substrate 111 and diffusion particles 112. The material of the substrate 111 may be a resin such as polymethyl methacrylate, polycarbonate or polyester; the diffusion particles 112 may be polyethylene particles, polyacrylic acid particles or glass beads, and the diffusion particles 112 Light diffusion effect β [0005] However, when the light intensity changes differently at different portions of the diffusion sheet 20, since the diffusion particles 112 are similar to the material of the transparent substrate 111, the refractive indices of the two are close to each other, resulting in the diffusion particles. 112 The poor effect of the refraction of the light ray makes it difficult for the diffuser 20 to sufficiently diffuse the light having a strong light intensity to avoid the occurrence of bright light of the light source, and easily affects the uniformity of light diffusion. 095129561 Form No. Α0101 Page 3 of 13 1〇〇32〇5848~〇1353474 [10^06月10曰修ΪΕ换k [0006] In view of this, it is provided that a diffuser with strong light diffusion effect is essential. SUMMARY OF THE INVENTION [0007] Hereinafter, a diffusion sheet having a strong light diffusion effect will be described by way of examples. [0008] A diffusion sheet comprising a diffusion layer, the diffusion layer comprising a transparent resin substrate, and first scattering particles and second scattering particles doped in the transparent resin substrate, refractive index of the first scattering particles The particle diameter of the first scattering particle is smaller than the particle diameter of the second scattering particle. [0009] Compared to the prior art, the diffusion layer of the diffusion sheet comprises a first scattering particle and a second scattering particle having a larger refractive index than the first scattering particle. In use, the first scattering particles can diffuse most of the light uniformly; the second scattering particles can be between the first scattering particles, so that the first scattering particles can be more evenly distributed, and then the first scattering particles are uniformly diffused. The function of the light is enhanced; in addition, the second scattering particle is easy to have a partial reflection function because of having a large refractive index, and the light having a strong light intensity is further dispersed by the partial reflection function of the second scattering particle. Open and spread evenly to avoid the occurrence of bright light. Therefore, the above-mentioned diffuser light has the advantage of being strong in light diffusion. [Embodiment] [0010] The diffusion sheet will be further described in detail below with reference to the accompanying drawings and embodiments. [0011] Please refer to FIG. 2, which is a cross-sectional view of a diffusion sheet according to a preferred embodiment of the present invention. The diffusion sheet 21 includes a transparent resin substrate 211, and first scattering particles 212 and second scattering particles 213 doped in the transparent resin substrate 211. The first scattering particles 212 have a refractive index higher than the second scattering particles. 21 3 fold 1003205848-0 095129561 Form No. A0101 Page 4 / Total 13 Page 1353474 [0013] [0013] June 10, 100 nuclear replacement page
射率小。其中，該透明樹脂基材2Π之重量百分含量可爲 5 〇至90/，6亥第一散射粒子212與第二散射粒子2之重 畺百刀3里之和可爲至;該第二散射粒子213與 第一散射粒子212重量百分含量之比可爲1/1〇〇至1/5。 該透明樹脂基材211可爲丙稀酸樹脂、丙稀酸氨基樹脂及 環氧樹脂之一或其組合。 該第一散射粒子212之折射率比第二散射粒子213的小， 該第一散射粒子212之折射率可爲1>4至17，該第二散 射粒子21 3之折射率可大於2，優㈣如卜例如，該 第散射粒子212爲聚苯乙稀顆粒、聚碳酸醋顆粒、苯乙 烯-丙烯腈共聚物顆粒、聚丙稀顆粒、二氧化梦顆粒、聚 甲基丙烯酸甲酯顆粒、玻璃微珠及石英粉之一或其組合 ’該第二散射粒子213爲二氧化欽、氧化錄、硫酸頻、硫 酸鋅、氧化鋅及碳酸鈣之—或其組合。爲使進入該擴散 片21之光線損失較少，可使第二散射粒子213之粒徑較小 ，並小於該第一散射粒子212之粒徑；例如，該第一散射 粒子212之粒徑爲丨至“微米，該第二散射粒子213之粒 徑爲0.01至1微米。 [0014] 使用時，該第一散射粒子212將大部分光線擴散均勻。該 第二散射粒子213處於第一散射粒子212之間，可使該第 一散射粒子212分佈更均勻，繼而使得第-散射粒子212 均勻擴散光線之功能增強。另外，該第二散射粒子213由 095129561 於具有#父大之折射率，因此還易具有部分反射功能；通 過4第一政射粒子213之部分反射功能，可使較強處之光 線被分散開而進一步被擴散均勻，避免光源亮影之産生 第 5 頁/共 13 頁 1003205848-0 表單编號A0101 1353474 丨100年06月10日梭正替換頁 [0015] 請參閱圖3，本發明較佳實施例二提供一種擴散片31，其 結構與擴散片21相似，亦包括第一散射粒子312與第二散 射粒子313 ;其不同在於：該擴散片31還摻雜有第三散射 粒子314，該第三散射粒子314爲熒光粒子，其可使進入 該擴散片之紫外線轉變成可見光，用於提高光利用率。 該第三散射粒子314之重量含量與第一散射粒子312之重 量含量之比可小於1 /10 0。 [0016] 本發明較佳實施例三提供一擴散片41，其成分組成同擴 散片21，其不同在於：該擴散片41做成具有不同厚度之 結構，使得該擴散片41於使用時厚度較大處可以與光強 較強處相對，例如與光源中心相對，以使光強較強處之 光線得到較多之散射，繼而使得該擴散片41更易於讓光 線擴散均勻。 [0017] 可以理解，擴散片厚度可以根據其所需之結構強度來確 定。如圖5所示，爲便於增強該擴散片21之強度，於該擴 散片21之一個表面上還可包括一個基片22。該基片22之 材料可爲聚碳酸酯、聚甲基丙烯酸曱酯、聚苯乙烯，甲 基丙烯酸曱酯苯乙烯共聚物之一或其組合。該基片22之 厚度可小於6毫来。 [0018] 與習知技術相比較，所述擴散片21包含第一散射粒子212 及折射率比第一散射粒子212大的第二散射粒子213。使 用時，該第一散射粒子212可將大部分光線擴散均勻；該 第二散射粒子213可處於第一散射粒子212之間，可使該 095129561 表單編號A0101 第6頁/共13頁 1003205848-0 1353474 100年06月10日修正替换頁 第一散射粒子212分佈更均勻，繼而使得第一散射粒子 212均勻擴散光線之功能增強；另外，該第二散射粒子 213由於具有較大之折射率，而易於具有部分反射功能， 通過該第二散射粒子213之部分反射功能，可使光強較強 處之光線被進一步分散開而擴散均勻’避免光源亮影之 産生。因此上述擴散片之光擴散效果強。 [0019] 綜上所述’本發明符合發明專利要件’奚依法提出專利 申請》惟，以上所述者僅為本發明之較佳實施方式，本 發明之範圍並不以上述實施方式為限，舉凡熟悉本案技 藝之人士，於援依本案發明精神所作之等效修飾或變化 ，皆應包含於以下之申請專利範圍内。 【圖式簡單說明】 _0]圖1係一種習知之擴散片之剖面示意圖。 [0021] 圖2係本發明擴散片較佳實施例一之剖面示意圖。 [0022] 圖3係本發明擴散片較佳實施例二之剖面示意圖。The rate of shot is small. Wherein, the transparent resin substrate may have a weight percentage of 5 〇 to 90/, and the sum of the first scattering particles 212 and the second scattering particles 2 may be up to; The ratio of the scattering particles 213 to the first scattering particles 212 by weight may be from 1/1 Torr to 1/5. The transparent resin substrate 211 may be one or a combination of an acrylic resin, an acrylic amino resin, and an epoxy resin. The refractive index of the first scattering particles 212 is smaller than that of the second scattering particles 213, and the refractive index of the first scattering particles 212 may be 1 > 4 to 17, and the refractive index of the second scattering particles 21 3 may be greater than 2, (d) For example, the first scattering particles 212 are polystyrene particles, polycarbonate particles, styrene-acrylonitrile copolymer particles, polypropylene particles, dioxide dioxide particles, polymethyl methacrylate particles, glass micro. One or a combination of beads and quartz powders 'The second scattering particles 213 are dioxin, oxidized, sulfuric acid, zinc sulfate, zinc oxide, and calcium carbonate - or a combination thereof. In order to reduce the light loss entering the diffusion sheet 21, the particle diameter of the second scattering particles 213 may be smaller and smaller than the particle diameter of the first scattering particles 212; for example, the particle diameter of the first scattering particles 212 is The particle size of the second scattering particle 213 is 0.01 to 1 micrometer. [0014] In use, the first scattering particle 212 diffuses most of the light uniformly. The second scattering particle 213 is in the first scattering particle. Between 212, the first scattering particles 212 can be distributed more uniformly, and then the function of uniformly diffusing the light by the first scattering particles 212 is enhanced. In addition, the second scattering particles 213 have the refractive index of #父129 It is also easy to have a partial reflection function; by the partial reflection function of the 4 first political particles 213, the stronger light can be dispersed and further spread evenly, avoiding the generation of light source highlights. Page 5 of 13 1003205848 -0 Form No. A0101 1353474 06June 10, 2006 Shuttle Replacement Page [0015] Referring to FIG. 3, a preferred embodiment of the present invention provides a diffusion sheet 31 having a structure similar to that of the diffusion sheet 21, including One The particles 312 are different from the second scattering particles 313; the difference is that the diffusion sheet 31 is further doped with a third scattering particle 314, which is a fluorescent particle, which converts the ultraviolet light entering the diffusion sheet into visible light. For improving the light utilization rate, the ratio of the weight content of the third scattering particles 314 to the weight content of the first scattering particles 312 may be less than 1/10. [0016] The preferred embodiment 3 of the present invention provides a diffusion sheet 41. The composition is the same as that of the diffusion sheet 21, and the difference is that the diffusion sheet 41 is formed into a structure having different thicknesses, so that the diffusion sheet 41 can be opposite to the light intensity when the thickness is large in use, for example, with the center of the light source. In contrast, the light having a stronger light intensity is more scattered, which in turn makes the diffusion sheet 41 easier to diffuse the light uniformly. [0017] It can be understood that the thickness of the diffusion sheet can be determined according to the required structural strength. As shown in FIG. 5, in order to enhance the strength of the diffusion sheet 21, a substrate 22 may be further included on one surface of the diffusion sheet 21. The material of the substrate 22 may be polycarbonate or polymethacrylic acid. One or a combination of decyl ester, polystyrene, methacrylic acid methacrylate styrene copolymer. The thickness of the substrate 22 may be less than 6 millimeters. [0018] Compared to the prior art, the diffusion sheet 21 comprises a first scattering particle 212 and a second scattering particle 213 having a larger refractive index than the first scattering particle 212. In use, the first scattering particle 212 can diffuse most of the light uniformly; the second scattering particle 213 can be in the first scattering Between the particles 212, the 095129561 Form No. A0101 Page 6 / Total 13 Page 1003205848-0 1353474 Correction Replacement Page The first scattering particles 212 are more evenly distributed, which in turn causes the first scattering particles 212 to spread evenly. The function of the light is enhanced; in addition, the second scattering particle 213 is easy to have a partial reflection function because of having a large refractive index, and the light having a strong light intensity can be made by the partial reflection function of the second scattering particle 213. Further spread and spread evenly to avoid the occurrence of bright light. Therefore, the diffusing sheet has a strong light diffusing effect. [0019] In summary, the invention is in accordance with the invention patent requirements, and the patent application is filed according to the law. However, the above description is only a preferred embodiment of the present invention, and the scope of the present invention is not limited to the above embodiment. Anyone who is familiar with the skill of the case, the equivalent modifications or changes made by the company in the spirit of the invention shall be included in the scope of the following patent application. [Simple description of the drawing] _0] Fig. 1 is a schematic cross-sectional view of a conventional diffusion sheet. 2 is a schematic cross-sectional view showing a preferred embodiment 1 of a diffusion sheet of the present invention. 3 is a schematic cross-sectional view showing a preferred embodiment 2 of the diffusion sheet of the present invention.
[0023] 圖4係本發明擴散片較佳實施例三之剖面示意圖。 [0024] 圖5係本發明擴散片較佳實施例四之剖面示意圖。 【主要元件符號說明】 [0025] (本發明） [0026] 擴散片：21、31、41 [0027] 第一散射粒子：212、312 [0028] 基片：22 095129561 表單編號A0101 第7 1/共丨3百 、 1003205848-0 1353474 100年06月Ιϋ日修正替换k4 is a schematic cross-sectional view showing a preferred embodiment 3 of the diffusion sheet of the present invention. 5 is a schematic cross-sectional view showing a preferred embodiment 4 of the diffusion sheet of the present invention. [Main component symbol description] [0025] (Invention) [0026] Diffusion sheet: 21, 31, 41 [0027] First scattering particle: 212, 312 [0028] Substrate: 22 095129561 Form No. A0101 No. 7 1/ Total 丨3, 1003205848-0 1353474 Correction of the replacement of k on the following day of June 100
[0029] 第二散射粒子： 213 、 313 [0030] 樹脂基材：211 [0031] 第三散射粒子： 314 [0032] (習知） [0033] 擴散片：10 [0034] 基體：111 [0035] 擴散層：11 [0036] 擴散粒子：112 [0037] 透明基片：12 1003205848-0 095129561 表單編號A0101 第8頁/共13頁[0029] Second scattering particles: 213, 313 [0030] Resin substrate: 211 [0031] Third scattering particles: 314 [0032] (Conventional) [0033] Diffusion sheet: 10 [0034] Substrate: 111 [0035 Diffusion layer: 11 [0036] Diffusion particles: 112 [0037] Transparent substrate: 12 1003205848-0 095129561 Form number A0101 Page 8 of 13