201003132 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、設置於該框架11内部之複數光源12及設 置於光源12上方之擴散板13。 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，光線經擴散板13擴散後，從擴散板13之 出射角度變得較為雜亂，使其於特定視角範圍内之亮度不 高；且由於光源12朝其正上方傳輸之光線較多，擴散板13 難以直接將來自光源12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上方設置有一稜鏡片10與一上擴 散片14。 如圖2所示，稜鏡片10包括透明基板101及形成於透 明基板101上之棱鏡層103。稜鏡層103上具有複數長條形 V形凸起105。稜鏡片10之長條形V形凸起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可對從擴散板10出射之 6 201003132 光線作進一步擴散。 ::光線於編10與上擴散片14中 •光線會被吸收而造成光線損失；且因稜鏡片iq 1曰4之間有空氣層，其會增加光線於傳輸過程中之1 = 里，增加光線傳輸之介面損失，降低光線利。 【發明内容】 寥於上述狀況，有必旅祖祝 .. 率、出光均勾之擴散板。種可提高光線有效利用 子之成其ί括—本體，該本體由分散有散射粒 子之透月材科I成。本體包括第 對之第二表面。本體之第—表面為平一 數三棱錐凹槽，其中有四個三棱錐凹槽具== 該四個三稜錐凹槽圍成-平行四邊形外形。 一種背光模組，其包括框架、光源及擴散板。光源位 =架:有!餘位於該光源上方。擴散板包括-本體， 刀政有政射粒子之透明材料製成。本體包括第一表 面第該：一表面相對之第二表面。本體之第一表面為平 _呈有:具有複數三棱錐凹槽’其中有四個三稜錐凹 =有共同連接點且該四個三棱錐凹槽圍成一平行四邊形 上述擴散板之第二表面具有特定排佈之三稜錐凹槽， 射擴散板之光線發生特定之折射、反射與繞 、、—干，進而可使從擴散板出射之光線於一特定之 視角範圍聚集。與此同_，該第二纟 201003132 還可與擴散板内之散射粒子協同作用而使光線發生擴散， ，以減弱甚至避免光源殘影，提高背光模組之出光均勻性， ，避免了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擴散板作進一步 之詳細說明。 請參見圖3至圖4,所示為本發明較佳實施例一之擴散 板2〇，其包括一本體，該本體由分散有散射粒子202之透 明材料製成。本體包括第—表面2〇1及與第一表面斯相 ::第：表面203。第一表面2〇1為平面’第二表面2〇3 $複數二稜錐凹槽2〇4。其中有四個三稜錐凹槽具有共同 、接點且該四個三稜錐凹槽圍成一平行四邊形外形。 =表面2〇3之複數三稜錐凹槽謝之間緊密相連， :盆相 =互f接之具有共同連接點之三稜錐凹槽2〇4 ϊ陣= 形成四角星形2〇6。複數四角星形2此 延伸之V r二:稜錐凹槽204可由複數沿第-方向X1 脊°構、複數沿第二方向χ2延伸之V报卷沾 向xHt 伸之V形脊結構及複數沿第四方 ::結構與沿第四方向X4延伸之 第—方向Xl延伸之V形脊結構與沿第三方广精由沿 形脊結構之間之交點。其中該四方向x-方向延伸之V 鄰兩方向之間之夾角Α 45 # 1 2、Χ3及Χ4相 之取值範圍可為直截面頂角 。上相鄰ν形脊結構 201003132 之間之中心距離可為0.025毫米至i毫米。本實施例中，四 ，方向Xi、X2、X3及I相鄰V形脊結構之間之中心距離分 .另D! I>2 D3 與 D4 ’ 。此外，藉由調整 貝角之大小，可於一定程度上調整擴散板2〇之增光率及出 光視角。 擴散板20之總體厚度τ可為〇4毫米至4毫米。擴散 板20可由聚甲基丙烯酸甲酯、聚碳酸酯、聚苯乙烯、苯乙 烯-甲基丙烯酸甲酯共聚物中之一種或一種以上之材料摻雜 散射粒子202後注塑成型而成。散射粒子2〇2可為二氧化 鈦微粒、二氧化矽微粒和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三稜錐凹槽 204相應之凸起結構，以便使擴散板2〇可於單次注塑過^ 中成型。可理解，藉由調整散射粒子搬與構成透明本體 之材料之間之比例可調節擴散板2G之透過率，但將擴散板 20之透光率控制於80%以上為較佳選擇。 使用時，可讓第一表面201靠近光源作為入光面而第 一表面203遠離光源作為出光面。由於擴驗2〇本體内且 ^散射粒子202，且擴散板2〇之第二表面2〇3具有特定排 :之三稜錐凹槽204之傾斜表面結構，射入擴散板2〇之光 線可發生特定之折射、散射、反射與繞射等光學作用，從 而可使從擴散板20出射之紐發生特定之擴散，以減弱甚 至避免光源殘影’提高背光模組之出光均勻性，進 知用上擴散片而產生之介面損失’提升光線利用率。 為進-步驗證擴散板20可對入射其中之光線起特定之 201003132 擴散作用，特別以一發光二極體作為光源進行測試，其結 ,果如圖5所示。由圖所示，從一發光二極體發出之光線經 擴散板20後被擴散成複數虛擬點光源。由此可見，擴散板 20具有較強之擴散效果。此外，擴散板20之透光率約為 90%。 另，由於擴散板20第二表面203之三稜錐凹槽204由 複數分別沿四方向XpXz'Xs及X4之V形脊結構所形成， 因此，從第二表面203出射之光線可於四分別與X!、X2、 X3及X4方向相垂直之之平面上使光線聚集，從而充分利用 各方向之光線以提高背光模組之正面出射光亮度。進一 步，擴散板20採用注塑成型之方式一體成型，因此其上三 棱錐凹槽204和擴散板20之其他部分一起形成，可使得三 棱錐凹槽204具有較高之結構強度，同時還能提升三稜錐 凹槽204和擴散板20其他部分之結合力，因此可避免或減 少三稜錐凹槽204於使用中被損壞。 請參閱圖6,所示為本發明較佳實施例二之擴散板30。 擴散板30與實施例一之擴散板20相似，第二表面303具 有複數三稜錐凹槽304。其中有四個三稜錐凹槽304具有共 同連接點之且該四個三棱錐凹槽304圍成一矩形外形，且 還有四個相互連接之三稜錐凹槽304及其相互連接之側壁 形成四角星形306。第二表面303上之三棱錐凹槽304與四 稜錐形凹槽308可由複數沿第一方向Xi延伸之V形脊結 構、複數沿第二方向X2延伸之V形脊結構、複數沿第三方 向X3延伸之V形脊結構及複數沿第四方向X4延伸之V形 201003132 :結構交錯形成。其中四個方向Χι、χ 向之間之夾角為45 。 2 3及又4相鄰兩 之中間為一四_形;3；；81二二^四角星形施 V形脊結構與沿第四 /0弟—方向X2延伸之 隔藉由沿第一方向χ ° 4 之ν形脊結構週期性之間 Μ他' Xl延伸之V形脊結構鱼沪笛—士人 延伸之V形脊結構之間之交點。四個方向、二方向Χ3 Χ4上之相鄰V形脊結構之間 ！、Χ2、X3及 距離滿足以下關係式·· 擴散散板务 =:r 射:子=:=== 〜一 3具有複數三稜錐凹槽404。 八不同在於.父錯圍成三稜錐凹 :::;Γν形脊結構之頂部被平面化容=:塑 成型過程中，V形脊結構之頂部被損壞。 凊參_ 8 ’所示為本發明較佳實施例之背光模組 細。其包括擴散板20、框架21及光源22，光源22位於 框架21内，擴散板2〇設置於光源22上方。 一框架21可由具有高反射率之金屬或塑膠製成，或塗佈 有南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，例如冷陰極熒光燈與發 光一極體。為獲得較強照射光，本實施例之光源22採用複 數雄集排列之發光二極體，然而由於發光二極體具有較高 之冗度及出光強度，其光源殘影及出光亮度不均勻之問題 11 201003132 更為犬$⑥本發明之擴散板2〇之三稜錐凹槽綱與散射 ，粒子2〇2協同作用，使射入擴散板20之光線可發生特定之 ，折射放射、反射與繞射等光學作用，從而可使從擴散板 2〇出射之光線發生特定之擴散，形成-柔和之均勾面光 源，可減弱甚至避免光源殘影，提高背光模組之出光 性。 ,=上所述，本發明符合發明專利要件，爰依法提出專 利申清。惟，以上所述者僅為本發明之較佳實施方式，本 《明之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，^ 應包含於以下之申請專利範圍内。 【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係圖1所示背光模組之擴散板之立體圖。 圖3係本發明較佳實施例一之擴散板之立體示意圖。 圖4係圖3所示擴散板之沿iV_IV線之剖視圖。 圖5係圖3所示擴散板之光強測試圖。 圖6係本發明較佳實施例二之擴散板之俯視圖。 圖7係本發明較佳實施例三之擴散板之剖視圖。 圖8係本發明較佳實施例四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 背光模組 200 12 201003132 散射粒子 . 第一表面 第二表面 三稜錐凹槽 四角星形 四稜錐形凹槽 框架 光源 (習知） 背光模組 透明基板 長條形v形凸起 光源 上擴散片 202 ' 402 201 、 401 203 ' 303 ' 403 204、304 ' 404 206 、 306 308 21 22 100 稜鏡片 10 101 棱鏡層 103 105 框架 11 12 擴散板 13 14 13[Technical Field] The present 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. [Prior Art] Referring to FIG. 1, a conventional direct type backlight module 100 includes a frame 11, a plurality of light sources 12 disposed inside the frame 11, and a diffusion plate 13 disposed above the light source 12. In use, the light generated by the complex light source 12 enters the diffusing plate 13 and can be diffused. However, after the light is diffused through the diffusing plate 13, the angle of the exit from the diffusing plate 13 becomes disordered, so that the brightness is not high in a specific viewing angle range; and since the light source 12 transmits more light directly above it, the diffusing plate 13 It is difficult to directly diffuse the light from the light source 12 uniformly, so that the light emitted from the diffusing plate 13 is likely 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 diffusion are generally disposed above the diffusion plate 13. Sheet 14. As shown in Fig. 2, the cymbal sheet 10 includes a transparent substrate 101 and a prism 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 projections 105 of the cymbal 10 allow a certain degree of convergence of the emitted light, thereby increasing the brightness of the backlight module 100 over a particular viewing angle. The upper diffusion sheet 14 can further diffuse the light of the 201003132 emitted from the diffusion plate 10. :: Light is applied to the 10 and the upper diffuser 14 • Light is absorbed to cause light loss; and because there is an air layer between the wipers iq 1曰4, it increases the light in the transmission 1 = Light loss interface loss, reducing light profit. [Summary of the Invention] In view of the above situation, there is a must-have ancestral wish. The species can be used to improve the effective use of light, and the body is formed by a transparent material that is dispersed with scattering particles. The body includes a second surface of the pair. The first surface of the body is a flat triangular pyramid groove, wherein there are four triangular pyramid grooves == The four triangular pyramid grooves are enclosed in a parallelogram shape. A backlight module includes a frame, a light source, and a diffusion plate. Light source position = frame: Yes! The rest is above the light source. The diffuser plate comprises a body, which is made of a transparent material of the government. The body includes a first surface: a surface opposite the second surface. The first surface of the body is flat _ there is: a plurality of triangular pyramid grooves 'where there are four triangular pyramid concaves = there are common connection points and the four triangular pyramid grooves enclose a parallelogram of the above diffusion plate The two surfaces have a specially arranged triangular pyramid groove, and the light of the diffusing plate is specifically refracted, reflected and wound, and dried, so that the light emitted from the diffusing plate can be concentrated in a specific viewing angle range. In the same way, the second 纟201003132 can also cooperate with the scattering particles in the diffusing plate to diffuse the light, so as to weaken or even avoid the residual image of the light source, improve the uniformity of the light output of the backlight module, and avoid the use of the light. The interface loss caused by the diffusion sheet improves the light utilization efficiency. [Embodiment] Hereinafter, a diffusion plate of the present invention will be further described in detail with reference to the accompanying drawings and embodiments. Referring to Figures 3 through 4, there is shown a diffuser panel 2 according to a preferred embodiment of the present invention, comprising a body made of a transparent material having dispersed scattering particles 202. The body includes a first surface 2〇1 and a first surface: :: surface: 203. The first surface 2〇1 is a plane 'the second surface 2〇3$the plurality of pyramidal grooves 2〇4. There are four triangular pyramid grooves having a common, joint and the four triangular pyramid grooves enclosing a parallelogram shape. = The surface of the surface 2〇3 is a series of triangular pyramidal grooves that are closely connected. The basin phase = mutual f-connected triangular pyramid groove with common connection points 2〇4 ϊ array = four-pointed star 2〇6 . The complex four-corner star 2 extends the V r two: the pyramid groove 204 can be formed by a plurality of V-shaped ridge structures extending along the first direction X1 ridge structure and extending in the second direction χ2, and the V-shaped ridge structure and the complex edge of the xHt extension The fourth side: the intersection of the structure and the V-shaped ridge structure extending in the first direction X1 extending in the fourth direction X4 and the ridge structure along the third direction. The angle between the two directions of V in the x-direction extending in the four directions Α 45 # 1 2, Χ3 and Χ4 phases may be a straight section apex angle. The center distance between the adjacent v-shaped ridge structures 201003132 may be 0.025 mm to i mm. In this embodiment, four, the center distance between the adjacent X-shaped ridge structures of the directions Xi, X2, X3 and I is divided into another D! I > 2 D3 and D4'. In addition, by adjusting the size of the bellhorn, the brightness enhancement and the viewing angle of the diffusing plate 2 can be adjusted to some extent. The overall thickness τ of the diffuser plate 20 can be from 4 mm to 4 mm. The diffusion plate 20 may be formed by doping the scattering particles 202 with one or more of polymethyl methacrylate, polycarbonate, polystyrene, styrene-methyl methacrylate copolymer and then injection molding. The scattering particles 2〇2 may be one or a mixture of one or more of titanium dioxide fine particles, cerium oxide fine particles, and acrylic resin fine particles. During the preparation process, a convex structure corresponding to the triangular pyramid groove 204 is provided on the mold, so that the diffusion plate 2 can be formed in a single injection molding. It is understood that the transmittance of the diffusing plate 2G can be adjusted by adjusting the ratio between the scattering particles and the material constituting the transparent body. However, it is preferable to control the light transmittance of the diffusing plate 20 to 80% or more. In use, the first surface 201 can be placed close to the light source as the light incident surface and the first surface 203 can be moved away from the light source as the light exit surface. Due to the expansion of the body 2 and the scattering of the particles 202, and the second surface 2〇3 of the diffusing plate 2 has a specific row: the inclined surface structure of the triangular pyramid groove 204, the light incident on the diffusing plate 2 Specific optical effects such as refraction, scattering, reflection, and diffraction occur, so that the diffusion from the diffuser 20 can be specifically diffused to weaken or even avoid the residual image of the light source to improve the uniformity of the light output of the backlight module. The interface loss caused by the upper diffusion sheet improves the light utilization. For the step-by-step verification, the diffusion plate 20 can perform a specific 201003132 diffusion effect on the light incident thereon, especially using a light-emitting diode as a light source, and the result is shown in FIG. As shown in the figure, light emitted from a light-emitting diode is diffused into a plurality of virtual point light sources through the diffusion plate 20. Thus, the diffusion plate 20 has a strong diffusion effect. Further, the diffusing plate 20 has a light transmittance of about 90%. In addition, since the triangular pyramid groove 204 of the second surface 203 of the diffusion plate 20 is formed by a plurality of V-shaped ridge structures respectively in the four directions XpXz'Xs and X4, the light emitted from the second surface 203 can be respectively divided into four The light is concentrated on a plane perpendicular to the X!, X2, X3, and X4 directions, thereby making full use of the light in all directions to improve the brightness of the front side of the backlight module. Further, the diffusion plate 20 is integrally formed by injection molding, so that the upper triangular pyramid groove 204 and other portions of the diffusion plate 20 are formed together, so that the triangular pyramid groove 204 has high structural strength and can also be raised by three. The combination of the pyramid groove 204 and other portions of the diffuser plate 20 can thereby avoid or reduce the triangular pyramid groove 204 from being damaged in use. Please refer to FIG. 6, which shows a diffusion plate 30 according to a second embodiment of the present invention. The diffuser plate 30 is similar to the diffuser plate 20 of the first embodiment, and the second surface 303 has a plurality of triangular pyramid grooves 304. There are four triangular pyramid grooves 304 having a common connection point and the four triangular pyramid grooves 304 enclosing a rectangular outer shape, and there are four interconnected triangular pyramid grooves 304 and their interconnected sidewalls. A four-pointed star 306 is formed. The triangular pyramid groove 304 and the quadrangular pyramid groove 308 on the second surface 303 may be a plurality of V-shaped ridge structures extending in the first direction Xi, a plurality of V-shaped ridge structures extending in the second direction X2, and a plurality along the third The V-shaped ridge structure extending in the direction X3 and the V-shaped 201003132 extending in the fourth direction X4 are formed by staggering structures. The angle between the four directions Χι and χ is 45. 2 3 and 4 are in the middle of a quadruple shape; 3;; 81 2 2 ^ four-pointed star V-shaped ridge structure and along the fourth / 0 brother - direction X2 extended by the first direction The ν-shaped ridge structure of χ ° 4 periodically circulates between the intersection of the V-shaped ridge structure of the fish X-extension and the V-shaped ridge structure extended by the scholar. Between four adjacent directions, two directions Χ3 Χ4 between adjacent V-shaped ridge structures! , Χ 2, X3, and the distance satisfy the following relationship: · Diffusion plate =: r 射: 子 =: === ~ A 3 has a plurality of triangular pyramid grooves 404. The difference is that the parent is surrounded by a triangular pyramid. :::; The top of the Γν-shaped ridge structure is flattened. =: During the molding process, the top of the V-shaped ridge structure is damaged. The ginseng _ 8 ' is a thinner backlight module according to a preferred embodiment of the present invention. It comprises a diffuser panel 20, a frame 21 and a light source 22, the light source 22 being located within the frame 21, and the diffuser panel 2 being disposed above the light source 22. A frame 21 may be made of metal or plastic having a high reflectivity or a metal or plastic coated with a south reflectivity coating. Light source 22 can be a line source or a point source, such as a cold cathode fluorescent lamp and a light emitting body. In order to obtain a strong illumination light, the light source 22 of the embodiment adopts a plurality of light-emitting diodes arranged in a plurality of males. However, since the light-emitting diode has a high degree of redundancy and light-emitting intensity, the residual light source and the brightness of the light source are uneven. Question 11 201003132 More dogs $6 The diffuser plate of the present invention has a triangular pyramidal groove and scattering, and the particles 2〇2 cooperate to make the light incident on the diffusing plate 20 specific, refractive radiation, reflection and The optical action such as diffraction can cause the light emitted from the diffusing plate 2 to be specifically diffused, forming a soft-junction hook light source, which can weaken or even avoid the residual image of the light source and improve the light output of the backlight module. According to the above, the invention complies with the requirements of the invention patent, and the patent application is filed according to law. However, the above description is only a preferred embodiment of the present invention, and the present disclosure is not limited to the above-described embodiments, and those skilled in the art will be equivalently modified or changed in the spirit of the invention. ^ Should be included in the scope of the following patent application. 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 diffusion plate of the backlight module shown in FIG. 1. 3 is a perspective view of a diffuser plate according to a preferred embodiment of the present invention. Figure 4 is a cross-sectional view of the diffuser plate of Figure 3 taken along line iV_IV. Fig. 5 is a light intensity test chart of the diffusion plate shown in Fig. 3. Figure 6 is a plan view of a diffusion plate of a preferred embodiment 2 of the present invention. Figure 7 is a cross-sectional view showing a diffusion plate of a preferred embodiment 3 of the present invention. 8 is a cross-sectional view of a backlight module in accordance with a fourth preferred embodiment of the present invention. [Main component symbol description] (Invention) Diffuser 20, 30, 40 backlight module 200 12 201003132 Scattering particles. First surface second surface triangular pyramid groove four-corner star-shaped quadrangular pyramid groove frame light source Known) Backlight module transparent substrate long v-shaped convex light source upper diffusion plate 202 ' 402 201 , 401 203 ' 303 ' 403 204, 304 ' 404 206 , 306 308 21 22 100 稜鏡 10 101 prism layer 103 105 frame 11 12 diffuser 13 14 13