201005326 . 九、發明說明： .【發明所屬之技術領域】 本發明涉及一種背光模組及其擴散板，尤其涉及一種 用於液晶顯示之背光模組及其擴散板。 【先前技術】 請參見圖1，所示為一種習知之直下式背光模組100， 其包括框架11與設置於該框架11内部之複數光源12、及 設置於光源12上方並蓋住框架11之擴散板13。 Θ 使用時，由複數光源12產生之光線進入擴散板13後 可被擴散。然而，於經擴散板13擴散後，光線從擴散板13 之出射角度變得較為雜亂，使得其於特定視角範圍内之亮 度不高；並且由於光源12朝其正上方傳輸之光線較多，擴 散板13常常難以直接將來自光源12之光線擴散均勻，使 得從擴散板13出射之光線容易產生光源殘影，即出現光強 強弱不同之區域。 為提高背光模組100於特定視角範圍内之亮度，以及 ®避免光源殘影之產生，從而提高背光模組100出射光之均 勻性，通常於擴散板13上方還設置有一稜鏡片10與一上 擴散片14。稜鏡片10包括透明基板101及形成於透明基板 101上之稜鏡層103。稜鏡層103上具有複數長條形V型凸 起105。稜鏡片10之長條形V型凸起105可使出射光線發 生一定程度之聚集，從而提高背光模組100於特定視角範 圍内之亮度。上擴散片14可對從稜鏡片10出射之光線作 進一步擴散。 5 201005326 然，光線於稜鏡片10與上擴散片14中傳輸時，部分 光線會被吸收而造成光線損失；並且於稜鏡片10與上擴散 片14之間有空氣層，其會增加光線於傳輸過程中之介面數 量，增加光線傳輸之介面損失，降低光線利用率。 【發明内容】 雲於上述狀況，有必要提供一種可提高光線有效利用 率、出光均勻之背光模組及其擴散板。 —種擴散板，其由摻雜有擴散粒子之透明本體製成。 透二本體包括第-表面及與該第-表面相對上 =數表面具有複數長條狀弧形凸起，第二表面具有 开乂凸形凹槽’其中該第一表面上之複數長條狀弧 延伸方向=與第二表面上之複數長條狀弧形凹槽之 ❹ 位於兮插趣由、，、柩未、光源及擴散板，該光源 擴散：子：Γ該擴散板設置於該光源上方，其由摻雜有 忒第-表面相對之第二表面衣囟及興 ’第二表面具有複數長條狀弧:::複:d 形凸起與第二表面之長條狀狐形凹样之長條狀弧 生特定之折射、反射舆_-作板:： 6 201005326 之光線發生特定之擴散，從而提高特定視角範圍内之亮 ，度。同時’還可減弱甚至避免光源殘影，提高背光模組之 出光均勻性，進而避免採用上擴散片而產生之介面損失， 提升光線利用率。 【實施方式】 下面將結合附圖及實施例對本發明之背光模組及其擴 散板作進一步之詳細說明。 請參見圖2,所示為本發明較佳實施例-之擴散板20, 其由摻雜有擴散粒子205之透明本體製成。該透明本體包 括第-表面201及與第一表面2〇1才目對之第二表面2〇2。第 表面201具有複數長條狀弧形凸起2〇3，第二表面 具有複數長條狀弧形凹槽綱，其中複數長條狀孤形凸起 203之延伸方向與複數長條狀弧形凹槽謝之延伸方向正 交。 弟一 υι之複數長條狀弧形凸起2〇3之間相互平 ❹=。每一長條狀弧形凸起加之豎直截面為圓孤形。將長 凸起2〇3令圓弧之半徑記為^，相鄰長條狀弧形 最大、、果产ί為中Γ距記為Pl ’每一長條狀弧形凸起203之 山冰度δ己為Hl ’則RiU H滿足以下關係式·5 宅未如1.5毫米，Pl/4sRiS2Pi，〇 〇1毫米纽冰。 第一表面搬之複數長條狀弧形凹槽204之間相互平 每T長條狀弧形凹槽204之豎直截面為圓弧形。將長 條狀弧形凹槽204中圓弧之本^a今在u , 凹m… 2,相鄰長條狀弧形 凹槽204之中心間距記為？2，每一長條狀弧形凹槽綱之 7 201005326 •最大深度記為H2，則R2、P2及Η滿足以下關係式^.〇25 •毫米殳d.5毫米’ P2/4SR<2P2，〇.〇1毫米纽<R2。 擴散板20之總體厚度可為〇·5毫米至3毫米。擴散板 20可由聚曱基丙烯酸曱酯、聚碳酸酯、聚苯乙烯、笨乙烯_ 甲基丙烯酸曱醋共聚物中之一種或一種以上之材料摻雜擴 散粒子205後注塑成型而成。擴散粒子2〇5可為二氧化鈦 微粒、二氧化矽微粒與丙烯酸樹脂微粒中之一種或一種以 上之混合物。製備過程中需於模具上設置與長條狀孤形凸 起203及長條狀弧形凹槽2〇4相應之結構，以便使擴散板 20可於單次注塑過程甲成型。 當擴散板20用於背光模組時，擴散板2〇中之擴散粒 子205可使射入擴散板2〇 t之光線充分散&，同時射人擴 散板20中之光線於第一表自加之長條狀弧形凸起加與 第二表面202之長條狀弧形凹槽2〇4之協同作用下，可發 生預定之折射、反射與衍射等光學作用，使從擴散板2〇出 ❹射之光線發生預定之擴散，從而提高預定視角範圍内之亮 度。同時，還可減弱甚至避免光源殘影，提高背光模組之 出光均勻性，進而避免採用上擴散片而產生之介面損失， 提升光線利用率。另’第一表面2〇1之複數長條狀弧形凸 起03之L伸方向與第二表面2〇2複數長條狀弧形凹槽綱 、Κ申方向正又’可有效防止光線發生干涉現象，從而減 乂甚至4除干涉條紋以提高背光模組之光學效果。另第 表面201上複數長條狀弧形凸起203之延伸方向與第二 表面2〇2上複數長條狀凹槽204之延伸方向相交也能達到 參 ❹ 201005326 近似之效果。 請參見圖3，從擴散板2G出射之光線由—點光源分散 為-柔和之均句面光源。該柔和之均勾面光源係藉由擴散 粒子2〇5、長條狀弧形凸起2〇3與長條狀弧形凹槽綱協同 作用而得到之效果。由此可見，從擴散板2()出射之光線之 均勻性得到·改善。故擴散板⑼於背光模財應用時， 可減弱甚至避免光源殘影而獲得較均勾之出射光，從 略上擴散片之使用，提升光線利用率。 此外’擴散板20係採用注塑成型之方式一體成型，故 ί上之長條狀弧形凸起加及長條狀弧形凹槽204與擴散 之其他部分-起形成，可使得長條狀孤形凸起2〇3 = 長條狀弧形凹槽綱具有較高之結構 損壞:危:從而可避免或減少擴散板20於使用中被 =見圖4’所示為本發明較佳實施例二之擴散板％， 條擴散板2_’第一表面301具有複數長 3。3 I二3〇3。不同之處在於:每-長條狀弧形凸起 伸，。由於長條狀弧形凸起303沿曲線延 :之陣列可避免與液： = 散板佈:2之!況’從而防止衍射條紋之產生。另，擴 伸。〇之第二表面之複數長條狀弧形凹槽亦可沿曲線延 201005326 ‘請參見圖5,所示為本發明較佳實施例三之擴散板40， .其與實施例一之擴散板20相似，第二表面402具有複數長 條狀弧形凹槽404。不同之處在於：長條狀弧形凹槽404 之豎直截面均為橢圓弧形。另，擴散板400之第一表面之 長條狀弧形凸起403之豎直截面也可為橢圓弧形，且該長 條狀弧形凸起403與長條狀弧形凹槽404之豎直截面還可 為拋物線、正弦曲線等其他弧形。 請同時參見圖2與圖6,本發明較佳實施例之背光模組 ❹200包括擴散板20、框架21及光源22，光源22位於框架 21内，擴散板20設置於光源22上方。 框架21可由具有高反射率之金屬或塑膠製成，或塗佈 有高反射率塗層之金屬或塑膠製成。 光源22可為線光源或點光源，例如冷陰極螢光燈 (CCFL)與發光二極體（LED)。為使得背光模組200具有更高 之出光亮度，且更適於薄型化設計，本實施例之光源22優 _ 選為呈密集陣列排佈之複數LED。擴散板20中之擴散粒子 ❹ 205可使從LED發射之光線充分散射，同時從LED發射之 光線於第一表面201之長條狀弧形凸起203與第二表面202 之長條狀弧形凹槽204之協同作用下，可發生預定之折射、 反射與衍射等光學作用，使從擴散板20出射之光線發生預 定之擴散，從而可解決LED因具有更高之亮度及出光強度 而導致之更為突出之光源殘影及出光亮度不均勻之問題， 確保採用LED作為光源之背光模組200於具有更高出光亮 度之同時，具有較高之出光均勻性。 201005326 • 綜上所述，本發明確已符合發明專利之要件，遂依法 - 提出專利申請。惟，以上所述者僅為本發明之較佳實施方 式，自不能以此限制本案之申請專利範圍。舉凡熟悉本案 技藝之人士援依本發明之精神所作之等效修飾或變化，皆 應涵蓋於以下申請專利範圍内。 【圖式簡單說明】 圖1係一種習知之背光模組之剖面示意圖。 圖2係本發明較佳實施例一之擴散板之立體示意圖。 ® 圖3係圖2所示擴散板之光強測試圖。 圖4係本發明較佳實施例二之擴散板之俯視圖。 圖5係本發明較佳實施例三之擴散板之側視圖。 圖6係本發明較佳實施例之背光模組之剖視圖。 【主要元件符號說明】 (本發明） 擴散板 20 、 30 、 40 第一表面 201 、 301 第二表面 202 ' 402 長條狀弧形凸起 203、303 ' 403 長條狀弧形凹槽 204 、 404 擴散粒子 205 背光模組 200 框架 21 光源 22 11 201005326 (習知） 背光模組 100 框架 11 光源 12 擴散板 13 棱鏡片 10 上擴散片 14 透明基板 101 稜鏡層 103 長條形V型凸起 105 12The invention relates to a backlight module and a diffusing plate thereof, and more particularly to a backlight module for a liquid crystal display and a diffusing plate thereof. [Previous Art] Referring to FIG. 1 , a conventional direct type backlight module 100 includes a frame 11 and a plurality of light sources 12 disposed inside the frame 11 , and a light source 12 disposed above the cover 11 and covering the frame 11 . Diffuser plate 13. Θ When used, the light generated by the complex light source 12 enters the diffuser 13 and can be diffused. However, after the diffusion through the diffusion plate 13, the angle of light emitted from the diffusion plate 13 becomes disordered, so that the brightness thereof is not high in a specific viewing angle range; and since the light source 12 transmits more light directly above it, diffusion It is often difficult for the plate 13 to directly diffuse the light from the light source 12 uniformly, so that the light emitted from the diffusing plate 13 is liable to cause image sticking of the light source, that is, a region where the intensity of light is different. In order to improve the brightness of the backlight module 100 in a specific viewing angle range, and to avoid the generation of residual light of the light source, thereby improving the uniformity of the light emitted by the backlight module 100, a wafer 10 and an upper portion are usually disposed above the diffusion plate 13. Diffusion sheet 14. The cymbal sheet 10 includes a transparent substrate 101 and a ruthenium layer 103 formed on the transparent substrate 101. The ruthenium layer 103 has a plurality of elongated V-shaped projections 105 thereon. The elongated V-shaped projection 105 of the cymbal 10 causes a certain degree of convergence of the outgoing light, thereby increasing the brightness of the backlight module 100 over a particular viewing angle. The upper diffuser 14 allows for further diffusion of light emerging from the cymbal 10. 5 201005326 However, when light is transmitted through the cymbal 10 and the upper diffuser 14, some of the light is absorbed to cause light loss; and there is an air layer between the cymbal 10 and the upper diffuser 14, which increases light transmission. The number of interfaces in the process increases the interface loss of light transmission and reduces the light utilization rate. SUMMARY OF THE INVENTION In the above situation, it is necessary to provide a backlight module and a diffusing plate thereof which can improve the effective utilization of light and uniform light emission. A diffusing plate made of a transparent body doped with diffusing particles. The second body includes a first surface and a plurality of elongated arcuate protrusions on the surface opposite to the first surface, and the second surface has an open convex groove ‘the plurality of strips on the first surface The direction of the arc extension = the ridge of the plurality of long arc-shaped grooves on the second surface is located at the edge of the entanglement, the enthalpy, the light source, and the diffuser plate. The light source diffuses: the sub: the diffuser is disposed at the light source Above, the second surface is doped with a second surface-coated surface and the second surface has a plurality of long arcs::: complex: d-shaped protrusions and long strips of fox-shaped concave surface of the second surface The long strips of arc-like specific refraction, reflection 舆 _ _ _: 2010 201005326 The light spreads specifically, thereby improving the brightness, degree within a certain range of viewing angles. At the same time, it can also reduce or even avoid the residual image of the light source, improve the uniformity of the light output of the backlight module, thereby avoiding the interface loss caused by the upper diffusion sheet and improving the light utilization efficiency. [Embodiment] Hereinafter, a backlight module and a diffusion plate thereof according to the present invention will be further described in detail with reference to the accompanying drawings and embodiments. Referring to FIG. 2, there is shown a diffusion plate 20 of a preferred embodiment of the present invention, which is made of a transparent body doped with diffusion particles 205. The transparent body includes a first surface 201 and a second surface 2〇2 that is opposite to the first surface 2〇1. The first surface 201 has a plurality of elongated arc-shaped protrusions 2〇3, and the second surface has a plurality of long strip-shaped curved grooves, wherein the extending direction of the plurality of elongated elongated protrusions 203 and the plurality of long curved shapes The groove extension direction is orthogonal. The younger brother has a plurality of long curved protrusions 2〇3 which are flat with each other. Each strip-shaped arcuate protrusion has a vertical cross section which is rounded. The long bulge 2〇3 is used to make the radius of the arc be ^, the adjacent long arc is the largest, and the fruit is Γ is the middle Γ. The distance is Pl 'each long strip-shaped convex 203 Degree δ has been Hl ', then RiU H satisfies the following relationship. 5 House is not as 1.5 mm, Pl/4sRiS2Pi, 〇〇 1 mm New ice. The plurality of elongated arcuate grooves 204 of the first surface are flattened to each other. The vertical section of each of the long strip-shaped arcuate grooves 204 is a circular arc. The center of the arc in the long arc-shaped groove 204 is now in u, the concave m... 2, and the center-to-center spacing of the adjacent long arc-shaped groove 204 is recorded as ? 2, each long strip-shaped groove outline 7 201005326 • The maximum depth is recorded as H2, then R2, P2 and Η satisfy the following relationship ^.〇25 • mm殳d.5 mm' P2/4SR<2P2, 〇.〇1 mm New <R2. The overall thickness of the diffuser plate 20 can be from 5 mm to 3 mm. The diffusion plate 20 may be formed by doping the diffusion particles 205 with one or more of polydecyl methacrylate, polycarbonate, polystyrene, stupid ethylene-methacrylic acid vinegar copolymer, and then injection molding. The diffusion particles 2〇5 may be a mixture of one or more of titanium dioxide particles, cerium oxide particles and acrylic resin particles. During the preparation process, a structure corresponding to the elongated strip-shaped protrusions 203 and the strip-shaped arcuate grooves 2〇4 is provided on the mold so that the diffusion plate 20 can be formed in a single injection molding process. When the diffusing plate 20 is used in the backlight module, the diffusing particles 205 in the diffusing plate 2〇 can sufficiently scatter the light incident on the diffusing plate 2〇t, and at the same time, the light in the diffusing plate 20 is incident on the first table. In addition, the arcuate arcuate protrusions are combined with the long arcuate grooves 2〇4 of the second surface 202 to generate predetermined optical effects such as refraction, reflection and diffraction, so as to be ejected from the diffusion plate 2. The projected light is spread as intended to increase the brightness over a predetermined range of viewing angles. At the same time, it can also reduce or even avoid the residual image of the light source, improve the uniformity of the light output of the backlight module, thereby avoiding the interface loss caused by the upper diffusion sheet and improving the light utilization efficiency. In addition, the L-longitudinal direction of the plurality of elongated arc-shaped protrusions 03 of the first surface 2〇1 and the second surface 2〇2 are plural strip-shaped curved grooves, and the direction of the shape is positive and can effectively prevent light from occurring. The interference phenomenon, thereby reducing or even dividing the interference fringes to improve the optical effect of the backlight module. On the other surface 201, the extending direction of the plurality of elongated arcuate protrusions 203 intersects with the extending direction of the plurality of elongated strips 204 on the second surface 2〇2 to achieve the similar effect of the reference 201005326. Referring to Fig. 3, the light emitted from the diffusing plate 2G is dispersed by a point source into a soft uniform surface light source. The soft uniform hook light source is obtained by the synergistic action of the diffusion particles 2〇5, the long curved protrusions 2〇3 and the long curved grooves. From this, it can be seen that the uniformity of the light emitted from the diffusing plate 2 () is improved. Therefore, when the diffusion plate (9) is applied in the backlight mode, the light source residual image can be weakened or even avoided to obtain a relatively uniform light, and the use of the diffusion plate is slightly improved to improve the light utilization efficiency. In addition, the 'diffusion plate 20 is integrally formed by injection molding, so the long curved protrusions on the ί and the long curved grooves 204 are formed together with the other portions of the diffusion, which can make the long strips Shaped protrusion 2〇3 = long strip-shaped grooved groove has higher structural damage: dangerous: thereby avoiding or reducing the diffusion plate 20 in use is shown in Fig. 4' is a preferred embodiment of the invention Second, the diffusion plate %, the strip diffusion plate 2_'the first surface 301 has a complex length of 3. 3 I 2 3 〇 3. The difference is that each-long strip-shaped convex protrusion extends. Since the elongated arcuate projections 303 are stretched along the curve: the array can avoid the liquid: = loose cloth: 2; thus preventing the occurrence of diffraction fringes. In addition, expansion. The plurality of elongated arcuate grooves of the second surface of the crucible may also extend along the curve 201005326. Please refer to FIG. 5, which is a diffusion plate 40 according to a third embodiment of the present invention, and the diffusion plate of the first embodiment. Similarly, the second surface 402 has a plurality of elongated arcuate grooves 404. The difference is that the vertical sections of the elongated arcuate grooves 404 are all elliptical arcs. In addition, the vertical section of the elongated arcuate protrusion 403 of the first surface of the diffusion plate 400 may also be an elliptical arc shape, and the elongated arcuate protrusion 403 and the elongated arcuate groove 404 are vertical. The straight section can also be other arcs such as a parabola, a sinusoid, and the like. Referring to FIG. 2 and FIG. 6 simultaneously, the backlight module 200 of the preferred embodiment of the present invention includes a diffusing plate 20, a frame 21 and a light source 22. The light source 22 is located in the frame 21, and the diffusing plate 20 is disposed above the light source 22. The frame 21 may be made of metal or plastic having high reflectivity or metal or plastic coated with a high reflectivity coating. Light source 22 can be a line source or a point source such as a cold cathode fluorescent lamp (CCFL) and a light emitting diode (LED). In order to make the backlight module 200 have higher light-emitting brightness and is more suitable for the thin design, the light source 22 of the embodiment is preferably selected as a plurality of LEDs arranged in a dense array. The diffusing particles 205 in the diffuser 20 can sufficiently scatter the light emitted from the LED while the light emitted from the LED is elongated in the shape of a long arcuate projection 203 of the first surface 201 and the second surface 202. Under the synergistic action of the grooves 204, predetermined optical effects such as refraction, reflection and diffraction may occur, so that the light emitted from the diffusing plate 20 is preferentially diffused, thereby solving the problem that the LED has higher brightness and light intensity. The more prominent problem of residual light source and uneven brightness of the light source ensures that the backlight module 200 using LED as a light source has higher light-emitting uniformity while having higher light-emitting brightness. 201005326 • In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the present invention are intended to be included within the scope of the following claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic cross-sectional view of a conventional backlight module. 2 is a perspective view of a diffuser plate according to a preferred embodiment of the present invention. ® Figure 3 is a light intensity test chart of the diffuser shown in Figure 2. Figure 4 is a plan view of a diffuser plate in accordance with a second preferred embodiment of the present invention. Figure 5 is a side elevational view of a diffuser panel of the preferred embodiment 3 of the present invention. 6 is a cross-sectional view of a backlight module in accordance with a preferred embodiment of the present invention. [Main component symbol description] (Invention) diffusing plate 20, 30, 40 first surface 201, 301 second surface 202' 402 elongated arcuate projection 203, 303' 403 elongated arcuate groove 204, 404 Diffusion Particles 205 Backlight Module 200 Frame 21 Light Source 22 11 201005326 (Learn) Backlight Module 100 Frame 11 Light Source 12 Diffuser Plate 13 Prism Sheet 10 Upper Diffuser 14 Transparent Substrate 101 稜鏡 Layer 103 Long V-shaped bulge 105 12