1312429 六、發明說明： 【發明所屬之技術領域】 本發明係關於光學元件之加工方法，尤指粗糙度較 低、光學性能優良之導光板加工方法。 【先前技術】 近年來’隨著液晶顯示器的彩色化及大型化，其應用 領域更為廣泛’如筆記本式電腦、各種台式電腦、液晶電 視等。因液晶顯示器係-種被動元件，其本身不能發光， 因而需洲m⑽為液晶顯示^的光源，如背光模 組(Backlight Module)。 月光模組之導光板係作為將來自面光源之光線導入液 晶面板巾U學元件’根據其形討分為娜與平板形， 其中’圖1為具有楔形導光板之背光模組之示意圖：該背 光模組包括楔形導光板2，位於楔形導光板2下面之反射 板4、位於楔形導光板2上面之光擴散板5、設置在楔形導 光板2側面之光源7以及將光源7發出之光線導入楔形導 光板2内之燈罩8。工作時，光源7發出之光線由燈罩8 反射而射入楔形導光板2’大部分光直接通過楔形導光板2 進入光擴散板5 ’其餘由反射板4反射再次進入换形導光 板2，經過光擴散板5後光線均勻射入液晶面板1中。圖2 為具有平板形導光板之背光模組之示意圖，其與圖1中背 光核組結構之不同處係在平板形導光板3之兩側分別設置 光源7,以利於從光源7出射光線之亮度均勻分佈於平板 形導光板3中。 1312429 楔形與平板形導光板一般採用壓力克(PMMA)材質射 出成型（Injection)，而楔形導光板在注射時，由於欠注（樹 脂不轉動部分）與熔融樹脂隨冷卻固化發生體積收縮的不 足部分係通過保壓力補充，因通道至末端距離過長，壓力 起不到有效作用而發生收縮，導致模腔一面之賦形變壞， 因而使得導光板厚度不均勻，尺寸難於精確，而使光源之 光不能充分到達末端。另，因射出成塑之時間、溫度及射 出速度等較難控制，且模具表面的光滑度較低，因此製作 的成品之平面度與粗糙度較差，因而影響器件之光學品 質。又’要製不同形狀之楔形導光板以匹配液晶顯示器之 光源系統，則需開不同的模具，因模具成本較高，導光板 之加工成本亦較高。 而平板式導光板基材需要通過雷射切割兼作端面加工 進行切斷，在切斷後之薄片單面印刷或刻独反射圖案，以 形成成σσ。然，在切斷過程中，因基材厚度不均勻，將造 成後序印刷不均勾，並與框架嵌合時產生間隙而不能完全 因輯導紐表面進行加玉以減小表面粗糙度實為 【發明内容】 光學性能優良之導光板之 本發明之目的係提供粗糙度較低 加工方法。 -箱^叫光板之加工方法包括如下步驟：準備—平台、準備 表：:===;在平台上’該治具遠離於該平台的 十面具有一預定角度、準備待加工之導光板 1312429 基材並將其縣在治觸該表面上、料光板基材研磨至—定厚 度後再進雜光，即製成導級。更換其他雜之治具，可製 成各種形狀之導光板，其具雜好之辟性能。該製程省去各種 形狀之導光減具⑽發，減不但省去·成本，且治具更換 容易、製作成本較低。另，平板形導光板可直接將縣板基材膠 黏於平台上，紐對其研磨拋光，其加卫簡單、精度較高。 【實施方式】 如圖3所不，加工平台10可採用堅硬無變形之玻璃平台，其 具有平滑之表面；導祕基材14之材料最好· ?基丙稀樹脂; 可採用射出成型技術加卫，亦可採用樹脂薄板切出製程；概形治 具12可由堅硬錢形之不鏽鋼材㈣成，其具有優良之表面度， 且可加工成各種形狀以作為導歧基材14之支撐體；研磨抛光機 (圖未不）可採用英國Logitech公司生產之Lp_52機型。平台1〇 與楔形治具12之間、治具12與導光板基材14之間分別採用雙面 環氧樹脂膠帶11、13膠黏，其中該雙面環氧樹脂膠帶u、13為 UV環氧樹脂，其黏著力較強且退膠容易。 楔形導光板加工工序如下所述：首先將平台1〇徹底清洗以保 持表面光潔無異物，選定一角度為Θ之楔形治具12，進行徹底清洗 以確保其表面光潔無異物，該Θ角為該治具12遠離於該平台10的表 面122與該平台1〇所在的平面1〇2之間的夾角；用雙面環氧樹脂膠 帶11將楔形治具12與平台1〇進行膠黏，膠黏時要使其膠合面均勻 平4、無間隙，選定一待加工之導光板基材14，用雙面環氧樹脂 膠帶13將治具12的表面122與導光板基材14膠黏，膠黏時，亦要保 持膠合面均勻平滑無間隙，且將導光板基材14之待加工面141朝上 1312429 放置’然後’用研磨拋域對加卫面141進行^^，其巾，研磨壓 力為150gW、轉速為7〇RPM(R_d Per Minute)，待導光板基材 I4研磨至域需厚度厚20μηι時停止研磨，用切削力較強之三氧化 -銘材料對加1面14遞行清洗，制研舰光鑛其進行抛光， 1光£力為I20g/em、轉速為4GRPM，抛光至所需厚度時停止， 此時楔科光板紐14之表面粗糙度可降姐論以下，其具有較 佳之光學特性。最後，將楔科光板紐w退膠取下，用二氧化 鍺材料對其麵進行清洗崎去表面朗物麟膠物，以得到平 面度較佳、粗糙度較低之楔形導光板24，其楔形肢_，如圖* 用上述製作方法可以製成各種形狀之導光板，在操作時，僅 需^換网雜之治具，即可製成各種频導光板。如圖5所示， k疋、—肖㈣肋’重復上述步驟可將導歧基材％製得與三 tiT、15對稱之二㈣導妹26，如圖6所示。若要製得平板形 t板’可無需治具，將導光板基材直接膠黏在平台上，經過研 =序ΐ可製得粗糙度較低之平板形導光板。此製程可省去 具之開發，即僅[麵具製成導光板基 光加I成各種所需形狀之導光板，如此不但省去 =料板基龍具之成本，μ具更換科、製作成本較低， 在S又计研發及試產時尤為實用。 r :二學71件如光纖頭之柱狀透鏡、光學引擎中之分色 各式稜鏡等，亦可用該導光板之加工工序 、絲性缺狀各猶彡狀之元件。在玻璃平台 用又面•黏貼所需形狀或角度之不鱗鋼治具，用雙面膠帶將 1312429 待加工之光學元件基材膠黏在治具上，然後進行研磨加工工序， 直至所需之厚度，再對其研磨表面進行拋光，直至製成所需表面 度及精細度之成品。該製程可用以製作各種角度及形狀之光學元 件，且加工精度較高，更換治具較容易、成本較低。 綜上所述，本創作符合發明要件，爰依法提出專利申請。惟， 以上所述者僅為本發明之較佳實施例，舉凡熟悉本案技藝之人 士，在援依本案創作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】 圖1係習知具有楔形導光板之背光模組之示意圖。 圖2係習知具有平板形導光板之背光模組之示意圖。 圖3係本發明加工方法中楔形導光板基材與平台、治具之組 合示意圖。 圖4係藉本發明加工方法製成之楔形導光板之示意圖。 圖5係本發明加工方法中三角形導光板基材與平台、治具之 組合示意圖。 圖6係藉本發明加工綠製成之三角形導光板之示意圖。 【主要元件符號說明】 “ 雙面環氧樹脂膠帶 11、13 楔形導光板基材 14 楔形導光板 24 三角形治具 15 ’台具运離平台的表面 122 料 10 楔形治具 121312429 VI. Description of the Invention: [Technical Field] The present invention relates to a method of processing an optical element, and more particularly to a method of processing a light guide plate having a low roughness and excellent optical performance. [Prior Art] In recent years, with the colorization and enlargement of liquid crystal displays, applications have become more widespread, such as notebook computers, various desktop computers, and liquid crystal televisions. Since the liquid crystal display is a passive component, it cannot emit light by itself, and therefore the m (10) is a light source of the liquid crystal display, such as a backlight module. The light guide plate of the moonlight module is used to introduce the light from the surface light source into the liquid crystal panel, and the U-shaped component is divided into a navy and a flat plate according to the shape thereof. FIG. 1 is a schematic diagram of a backlight module having a wedge-shaped light guide plate: The backlight module includes a wedge-shaped light guide plate 2, a reflector 4 located under the wedge-shaped light guide plate 2, a light diffusing plate 5 located on the wedge-shaped light guide plate 2, a light source 7 disposed on the side of the wedge-shaped light guide plate 2, and a light source emitted from the light source 7. The lampshade 8 in the wedge-shaped light guide plate 2. During operation, the light emitted by the light source 7 is reflected by the lamp cover 8 and is incident on the wedge-shaped light guide plate 2'. Most of the light directly enters the light diffusion plate 5 through the wedge-shaped light guide plate 2, and the rest is reflected by the reflection plate 4 and enters the shape-changing light guide plate 2 again. After the light diffusing plate 5, the light is uniformly incident into the liquid crystal panel 1. 2 is a schematic view of a backlight module having a flat-plate light guide plate. The light source 7 is disposed on each side of the flat-plate light guide plate 3 at a difference from the backlight core group structure in FIG. 1 to facilitate light emission from the light source 7. The brightness is uniformly distributed in the flat plate-shaped light guide plate 3. 1312429 Wedge-shaped and flat-plate light guides are usually injection molded with pressure gram (PMMA) material, and the wedge-shaped light guide plate is insufficiently contracted due to underfill (residual non-rotating part of the resin) and molten resin with cooling solidification during injection. The pressure is supplemented by the pressure, because the distance from the channel to the end is too long, the pressure does not function effectively and shrinks, resulting in the deformation of one side of the cavity, thus making the thickness of the light guide plate uneven, the size is difficult to be precise, and the light of the light source Can not reach the end adequately. In addition, since the time, temperature, and injection speed of the injection molding are difficult to control, and the smoothness of the surface of the mold is low, the flatness and roughness of the finished product are poor, thereby affecting the optical quality of the device. Moreover, in order to fabricate wedge-shaped light guide plates of different shapes to match the light source system of the liquid crystal display, different molds need to be opened, and the processing cost of the light guide plate is also high due to the high cost of the mold. The flat type light guide plate substrate needs to be cut by laser cutting and end surface processing, and the cut sheet is printed on one side or the single reflection pattern is formed to form σσ. However, during the cutting process, due to the uneven thickness of the substrate, the subsequent printing will be unevenly hooked, and a gap will be generated when the frame is fitted, and the surface of the new surface cannot be completely added to reduce the surface roughness. SUMMARY OF THE INVENTION The object of the present invention is to provide a method of processing a lower roughness. - The processing method of the box ^ called light board comprises the following steps: preparation - platform, preparation table:: ===; on the platform 'the fixture is away from the ten masks of the platform, has a predetermined angle, ready to be processed light guide plate 1312429 The substrate is formed on the surface of the substrate and the substrate is ground to a predetermined thickness, and then the stray light is applied to form a guide. By replacing other miscellaneous fixtures, light guide plates of various shapes can be produced, which have excellent performance. This process saves the light guides (10) of various shapes, which saves not only the cost, but also the easy replacement of the jig and the low production cost. In addition, the flat-plate light guide plate can directly glue the county board substrate to the platform, and the black and white is polished and polished, and the decoration is simple and the precision is high. [Embodiment] As shown in Fig. 3, the processing platform 10 can adopt a hard and non-deformable glass platform, which has a smooth surface; the material of the guiding substrate 14 is preferably acryl-based resin; injection molding technology can be used. The utility model can also adopt a resin sheet cutting process; the outline jig 12 can be made of a hard money-shaped stainless steel material (four), which has excellent surface degree and can be processed into various shapes to serve as a support body of the guiding substrate 14; The grinding and polishing machine (not shown) can be used with the Lp_52 model manufactured by Logitech of the United Kingdom. The double-sided epoxy resin tapes 11 and 13 are respectively adhered between the platform 1〇 and the wedge-shaped jig 12, and between the jig 12 and the light guide plate substrate 14, wherein the double-sided epoxy tapes u and 13 are UV rings. Oxygen resin, which has strong adhesion and easy to remove glue. The processing procedure of the wedge-shaped light guide plate is as follows: firstly, the platform 1〇 is thoroughly cleaned to keep the surface smooth and free from foreign matter, and a wedge-shaped jig 12 with a certain angle is selected, and the surface is cleaned thoroughly to ensure that the surface is smooth and free from foreign matter. The jig 12 is away from the angle between the surface 122 of the platform 10 and the plane 1〇2 where the platform 1 is located; the double-shaped epoxy tape 11 is used to glue the wedge-shaped jig 12 to the platform 1〇, and the adhesive is glued. When the bonding surface is evenly flat 4, no gap, a light guide plate substrate 14 to be processed is selected, and the surface 122 of the jig 12 and the light guide plate substrate 14 are glued with the double-sided epoxy tape 13 to be adhesive. At the same time, it is also necessary to keep the glue surface even and smooth without gaps, and place the surface to be processed 141 of the light guide plate substrate 14 upwards 1312429, and then perform the grinding surface 141 with the grinding and polishing field, and the polishing pressure is 150gW, the rotation speed is 7〇RPM (R_d Per Minute), and the polishing is stopped when the substrate I4 of the light guide plate is ground to a thickness of 20μηι, and the first surface is cleaned by the trioxide-inscription material with strong cutting force. The research and development ship light mine is polished, 1 light power is I20g/em, Velocity 4GRPM, stop polished to the desired thickness, then the surface of the wedge plate, New York, Section 14 of the optical roughness can be reduced on the sister, which has a more excellent optical property. Finally, the wedge light board is removed and the surface is cleaned with a cerium oxide material to obtain a wedge-shaped light guide plate 24 with better flatness and lower roughness. Wedge limbs _, as shown in the figure * The light guide plates of various shapes can be made by the above-mentioned manufacturing method. In operation, only the jigs of the mesh miscellaneous materials can be replaced, and various frequency light guide plates can be prepared. As shown in Fig. 5, the k疋, - 肖(四) ribs' repeating the above steps can produce the guide substrate % to be symmetrical with the three tiT, 15 bis (four) guides 26, as shown in Fig. 6. In order to obtain a flat plate t-plate, the light guide plate substrate can be directly adhered to the platform without a jig, and a flat-shaped light guide plate having a low roughness can be obtained through research. This process can save development, that is, only [the mask is made of light guide plate base light plus I into various light guide plates of the desired shape, so that not only the cost of the material base rig, but also the replacement of the material. The cost is lower, especially when S is counted for R&D and trial production. r: 71 pieces of ray lenses such as fiber-optic heads, color separations in optical engines, etc., and the processing steps of the light guide plate and the components of the silky shape are still used. Use on the glass platform to cover the required shape or angle of the scale steel fixture, and use the double-sided tape to glue the 1312429 optical component substrate to be processed on the fixture, and then carry out the grinding process until the required thickness. The polished surface is then polished until the desired surface finish and fineness are finished. The process can be used to fabricate optical elements of various angles and shapes, and the processing accuracy is high, and the replacement of the jig is relatively easy and the cost is low. In summary, the creation meets the requirements of the invention, and the patent application is filed according to law. However, the above-mentioned ones are only preferred embodiments of the present invention. Any equivalent modifications or variations made by those skilled in the art of the present invention in the spirit of the present invention should be included in the scope of the following patent application. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a conventional backlight module having a wedge-shaped light guide plate. 2 is a schematic view of a conventional backlight module having a flat light guide plate. Fig. 3 is a schematic view showing the combination of a wedge-shaped light guide plate substrate, a stage, and a jig in the processing method of the present invention. 4 is a schematic view of a wedge-shaped light guide plate produced by the processing method of the present invention. Fig. 5 is a schematic view showing the combination of a triangular light guide plate substrate, a platform and a jig in the processing method of the present invention. Figure 6 is a schematic view of a triangular light guide plate made of green processed by the present invention. [Main component symbol description] "Double-sided epoxy tape 11, 13 wedge-shaped light guide substrate 14 wedge-shaped light guide 24 Triangle fixture 15 ' Surface of the platform away from the platform 122 Material 10 Wedge fixture 12
力口工面 “I 三角形導光板基材Μ 二角形導光板 26 1312429 平台所在的平面 1〇2Forced face "I triangular light guide substrate Μ two-dimensional light guide 26 1312429 plane where the platform is located 1〇2