201103738 六、發明說明： 【發明所屬之技術領域】 本發明是關於一種光學膜與其製造方法，特別是一種 應用於液晶顯示器中的光學膜與其製造方法。 【先前技術】 近年來，傳統的陰極射線管顯示器（即俗稱的CRT 顯示器）已漸漸地被液晶顯示器所取代，主要原因在 於液晶顯示器所釋放出的輻射量遠遠小於CRT顯示 器，且液晶顯示器在這幾年的製造成本也顯著地降 低。一般來說’液晶顯示器包括背光模組與液晶面板 兩大部分，而背光模組的主要功用在於提供光源供液 晶顯不器使用。 一般來說，背光模組包括冷陰極螢光燈管、反射 罩、擴散板、擴散膜與增亮膜，冷陰極螢光燈管用以 產生光源’而反射罩則是用以將冷陰極螢光燈管所產 生的光線導引至朝擴散板之方向。擴散板的功用主要 是將冷陰極螢光燈管所發出的光線進行擴散，以使照 射至液晶面板（未繪示）的光線能更佳均勻，而較不 會在液晶顯示器的顯示面上產生亮度不均勻的現象。 此外’由於擴散板具有多個光擴散粒子，所以會造成 擴散板的穿透率降低。一般來說，擴散板的穿透率為 50%〜70% 〇 此外，擴散板往往仍不足以完全克服亮度不均勻 的現象，所以需加上擴散膜，以使光線更均勻地擴散， 201103738 擴散臈是一種於其表面上均勻塗佈有光擴散粒子的光 學膜。另外，為了增加於視角範圍的亮度，因此在擴 散膜的上方加上增亮膜。201103738 VI. Description of the Invention: [Technical Field] The present invention relates to an optical film and a method of manufacturing the same, and more particularly to an optical film applied to a liquid crystal display and a method of manufacturing the same. [Prior Art] In recent years, conventional cathode ray tube displays (commonly known as CRT displays) have gradually been replaced by liquid crystal displays. The main reason is that the amount of radiation emitted by liquid crystal displays is much smaller than that of CRT displays, and liquid crystal displays are The manufacturing costs in recent years have also been significantly reduced. Generally, a liquid crystal display includes a backlight module and a liquid crystal panel. The main function of the backlight module is to provide a light source for liquid crystal display. Generally, the backlight module includes a cold cathode fluorescent lamp, a reflector, a diffusion plate, a diffusion film and a brightness enhancement film, a cold cathode fluorescent lamp is used to generate a light source, and a reflector is used to cool the cathode. The light generated by the light tube is directed to the direction of the diffuser. The function of the diffusing plate is mainly to diffuse the light emitted by the cold cathode fluorescent lamp tube, so that the light irradiated to the liquid crystal panel (not shown) can be better and more uniform, and less generated on the display surface of the liquid crystal display. Uneven brightness. Further, since the diffusion plate has a plurality of light-diffusing particles, the transmittance of the diffusion plate is lowered. In general, the diffuser plate has a transmittance of 50% to 70%. In addition, the diffuser plate is still not enough to completely overcome the uneven brightness phenomenon, so a diffusion film is needed to diffuse the light more uniformly, 201103738 diffusion Niobium is an optical film uniformly coated with light-diffusing particles on its surface. Further, in order to increase the brightness in the viewing angle range, a brightness enhancement film is added above the diffusion film.
請參照圖1 ’圖1所繪示為增亮膜的前視圖，增亮 膜U0主要由一基板111與一結構層112所構成。其 中’基板111的厚度約為175 e m，其材質為透明的聚 對本一曱酸乙二醋（polyethylene terephthalate，簡稱 PET)，且基板111上塗佈有黏著劑。而結構層112的 厚度約為25ym’其材質則為壓克力樹脂(phot〇sensitive resin)，此結構層112是藉由上述黏著劑而與基板nl 相結合。由於增亮膜11〇的結構層112具有多個菱鏡 狀的微結構，故具有聚光的效果，可讓增亮膜110所 射出的光線1^之出光角度變小，進而增加背光模組在 視角範圍内所呈現的亮度。 然而，當光線的入射至增亮膜11〇的角度較小時， 例如·光線L2，則其便容易被結構層112所反射。而 且，光線L2被結構層112反射後，其在增亮膜11〇中 的j學路徑便增加了’而使光線L2的耗損率提高。這 樣一來’反而會使增亮膜11〇的出光效率降低。針對 這個問題，有部份廠商提出了在結構層112中加入了 擴散粒子的作法’例如中華民國專利1301548號。然 加擴散粒子的作法除了會增加製造成本與材料 从从陆纟於擴散粒子是由折射率較結構層112為大 ' 所構成，因此擴散粒子具有較大的吸光率，這 樣反而會使增亮㈣整_度降低。也因為上述之原 201103738 因，於結構層112中加入擴散粒子的作法目前只停留 在實驗階段，而尚未進入量產的階段。 因此，本案之發明人製作出一光學膜，此光學膜 可防止入射角度較小的光被結構層反射，進而提高光 學膜的輝度，同時還具有低廉的製造成本。 【發明内容】 本發明之目的疋&供一種光學膜，該光學膜除了 可提供較大的輝度，還具有較低的製造成本。 根據上述目的與其他目的，本發明提供一種光學 膜，此光學膜包括/本體與多個第一微結構。其中，於本 體的内部分佈有多姻微型氣泡，而第一微結構則設置於本體 的其中一側。此外，第一微結構的形狀可使通過其中的光線 進行聚集。 根據上述目的與其他目的，本發明提供一種光學膜 的製造方法’此製造方法包括下列步驟。首先，提供一第 一成型膠，此第〆成型膠主要是由光硬化樹脂與熱硬化 脂類進行混合而形成’其中熱硬化脂類相對於第一成型膠整 體的重量百分比約為1%〜5%。再來，於第一成型膠内形成 多個微型氣泡。之後’將第一光源所發出的光線照射在該第 一成型膠上，其中該第一光源所發出的光線與熱量會促使該 第一成型膠產生硬化。接著，將一第二成型膠塗佈於硬 化後的該第一成型膠上，此第二成型膠主要是由光硬化 樹脂與熱硬化脂類進行混合而形成，其中該熱硬化脂類相對 於該第二成型膠整體的重量百分比約為1%〜5%。然後，形 201103738 成多個第-微轉於該第二成娜上。再來，將—第二光源 所發出的光線照射在該第二成型膠上，其中該絲所發出的 光線與熱I會促使該第二成娜產生硬化，並使該第二成 型膠與該第-成郷姆合以成為—母光賴片。之後，硬 化後的母光學膜片分割成多個光學膜。 於上述之光學膜的製造方法中，第一微結構的形狀可 使通過其中的光線進行聚集。 當光線由空氣(光疏介質)進入光學膜（光密介質)時，其 ，，的折角會比入射角來的小，但是由於光學膜内部具有 高密度分佈的微型氣泡’且這些微型氣泡中的氣體是折射 率約等於1的光疏介質。如此，當光線由本體（光密介質） 入射至，型，泡（光疏介質）時，將使得光線折角大於入射 角度許多。是故’原本光入射角度較小的光線將因此微型氣 泡而變成折角為大的絲，更適於使光線沿著第—微結構的 兩侧而往上偏折集中，進而提高此光學膜的輝度。 ▲為讓本發明之上述目的、特徵和優點更能明顯易 懂，下文將以實施例並配合所附圖示，作詳細說明如 下。 【實施方式】 凊參閱圖2A，圖2A所繪示為本發明之光學膜的 第一實施例。此光學膜210包括一本體211與多個第一 微結構212，第一微結構212是設置在本體211的其中一 側。此外’第一微結構212的形狀為菱鏡柱狀，故當光線 通過第一微結構212時會產生收斂，而達到聚光的效果。當 201103738 然，本領域具有通常知識者也可將第一微結構212設計成其 他形狀，如：透鏡狀、金将料可朗聚纽果:形狀，、 或者也可設計成半圓球狀、凹槽料可達_散效果的形 狀。 另外，在本體211中分佈有多個微型氣泡213。在本 實施例中，這些微型氣泡213的平均粒徑是小於1〇μπι，較 佳的情況是小於2μιη。此外，微型氣泡213與相鄰的微型氣 泡213間的距離是愈小愈好，較佳的情況是須滿足以下的方 程式：L<4D，其中D代表微型氣泡213的平均粒徑，而l 則代表微型氣泡213與相鄰的微型氣泡213間的平均距離。 請繼續參閱圖2A，當光線由空氣(光疏介質)進入光學 膜210(光密介質)時，其光線的折角會比入射角來的小，但是 由於光學膜210内部具有高密度分佈的微型氣泡， 且這些微型氣泡213中的氣體是折射率約等於i的光疏介 質。如此’將會使得通過光密介質（即：本體211)的光線h 進入光疏介質（即：微型氣泡213 )，而當光線L3由本體213 (光密介質）入射至微型氣泡213 (光疏介質）時，將使得 光線折角大於入射角度許多。是故，原本光入射角度較小的 光線將因此微型氣泡213而變成折角為大的光線，更適於使 光線沿著第一微結構212的兩側而往上偏折集中，進而提高 此光學膜210的輝度。換言之，由於微型氣泡213的設置， 可減少光線被第一微結構212反射的機率。而且，相較 於圖1的光學膜110，光線於光學膜21()中的光學路徑也 較短，故光線的耗損較少，從而使光學膜210的輝度更 近一步提高許多。 201103738 請參照圖3 ’圖3所繪示為習知的光學膜與第 施例的光學膜之輝度比較圖，此輝度比較圖是經由實 腦光學模擬而得出。其中，橫軸代表角度，縱轴代1 輝度，而輝度在此以無因次參數表示，將習知的光學 膜Π0於垂直視角（即：0度）的輝度設為1。由圖^ 可知’在絕大部份的視角下，第一實施例的光學膜210 相較於習知的光學膜110具有較高的輝度。其中，在 垂直視角時，光學膜210的輝度更較光學膜110高出 17%。 光學膜210的輝度之所以會較光學膜11〇為高， 其原因除了光學膜210内分佈有微型氣泡213外，光學 膜210不具有基板也是一個原因。在習知的光學膜 中’基板111的設置也會導致光的耗損。另外，相較 於在光學膜中加入了擴散粒子的作法（如：中華民國 專利1301548號），由於微型氣泡213中的介質是空氣， 其吸光率較小，故光的耗損性也較低，而且微型氣泡213 的製造成本與材料成本也較擴散粒子為低。 請參閱圖2B，圖2B所緣示為本發明之光學膜的 第二實施例。圖2B之光學膜210’與圖2A之光學膜 210的不同點在於：光學膜210’更包括有一強化層 214 ’相對於第一微結構212，此強化層214是設置在本 體211的另外一侧，其材質例如為聚曱基丙烯酸甲酯 (polymethyl methacrylate)、聚碳酸脂（Polycarbonate) 或紫外線硬化膠。強化層214具有較高的硬度，故可 增強光學膜210’整體的機械強度，此外還有防靜電的 201103738 效果。在本實施例中，強化層214例如是由純祥實業 股份有限公司生產的紫外線硬化透明塗料（型號： CH-74003)所做成。 以下’將對第一實施例的光學膜210之製作方法 進行介紹。請參照圖4，圖4所繪示為第一實施例的 光學膜之製造流程圖。首先，進行步驟§31〇，提供一 第一成型膠，此第一成型膠主要是由光硬化樹脂與熱硬 化脂類進行混合而形成，其中熱硬化脂類相對於第一成型膠 鲁整體的重置百分比約為1%〜5%。再來，進行步驟s32〇， 使第一成型膠内形成多個微型氣泡。形成微型氣泡於第 一成型膠内的方式例如為將第一成型膠加熱並打入氣 體’以於第一成型膠内形成多個微型氣泡。打入氣體的 方式例如是使用氣泡機(bubble machine)，藉由控制氣 泡機以調整微型氣泡的粒徑，而且若打入的微型氣泡愈 多，則微型氣泡間的距離也會愈小。或者，也可使用攪拌 機，藉由攪拌第一成型膠而於該第一成型膠内形成多 • 個微型氣泡。之後，將成型膠冷卻至常溫，以使成型膠 的黏度提高，其黏度較佳為超過25〇cps，更佳為 250〜60〇cps。由於成型膠具有黏度，故其内部的微型氣 泡便不會經由表面而露出。 再來，凊同時參照圖4與圖5A，圖5A所繪示為 本實施例之光學膜的製造設備之前半部份。其令，具有微 型氣泡213的第一成型膠410是儲存在一容器4U'内， 容器411具有一閥門81a。在步驟幻3〇中，將第一成型 膠410塗佈在一離型膜413上。當閥門81a被打開後，第 201103738 成型膠41G便會經由閥門81a而流到離伽413上。此 第-離麵413是由透明材質所構成，例如為聚對苯二甲 酸乙二醋、拉伸聚丙烯或其他不會與第一成型膠41〇產生 ^橋的透明材質。此外，離型膜413的上方表面塗佈有輕 篁的黏著劑，以使第一成型膠410能與離型膜413相黏附 並往前傳送。離型膜413是由一離型膜釋放輪412釋放 ，，並藉由辅助輪414、417、418的拉力而往前移動。 需注意的是，辅助輪414、417、418除了有帶動離型 • 膜413的功用外，還可藉由辅助輪4M、417、418對離型 膜413所產生的張力而達到支標離型膜413的功用，以防止 離型膜413上的第一成型膠410因本身的重量產生變形。 於步驟S340中’將第一光源416a〜416b所發出的光線， 例如?外光，照射在第一成型膠上。待完成步驟S34〇 後’接著進行步驟S350，第一成型膠410會被傳送到一熱管 419的上方，此熱管419是位於輔助輪418與辅助輪 ，間。當第一成型膠410經過光源416a〜416b的照射與熱 鲁 =419的加熱後會產生硬化。在本實施例中，是先做 元步驟S340後再進行步驟s35〇，但步驟S340與步驟S350 其實也可同時進行’而熱管419也可改成其他型態的加熱 源，例如以熱風加熱的方式將第一成型膠410烘乾。此 外’本領域具有通常知識者也可不設置任何加鱗，因為光 源41如〜41你本身便會發出賴射熱，此轄射熱便可對第一成 型膠410產生加熱的效果。 請同時參照圖4與圖5B，圖5B所繪示為本實施例之 光學膜的製造設備之後半部份^接著，進行步驟S36〇 ,將 201103738 一第二成型膠510塗佈於硬化後的第一成型膠41〇上， 此第一成型膠510内部不具有微型氣泡。第二成型膠 510主要是由光硬化樹脂與熱硬化脂類進行混合而形成，其 中熱硬化脂類相對於第一成型膠整體的重量百分比約為 1%〜5%。 再來，進行步驟S370，將滾輪515滾壓在第二成型膠 510上。此滾輪515的表面515a上具有壓印圖案（未繪示）， 在本實施例中’壓印圖案為向内凹陷的微型結構^當滚輪515 滚壓過第一成型膠51〇後，滾輪515上的壓印圖案便會轉印 至第二成型膠51〇上，並形成多個第一微結構212於第二成 型膠510上。 ' 於步驟S380中，將第二光源516a〜516d所發出的光線， 例如：紫外光，照射在第二成型膠510上。在本實施例中， 步驟S370與步驟S380是同時進行地。待完成步驟S38〇後， 接著進行步驟S390，第二成型膠510會被傳送到一熱管519 的上方。當第二成型膠510經過第二光源516a〜516d的照 射與熱管519的加熱後會產生硬化。在本實施例中，是 先做完步驟S380後再進行步驟S39〇，但步驟S38〇與步驟 S390其實也可同時進行’而熱管519也可改成其他型態的加 熱源，例如以熱風加熱的方式將第二成型膠51〇烘乾。此 外，本領域具有通常知識者也可不設置任何加熱源，因為第 二光源516a〜516d本身便會發出輻射熱，此輻射熱便可對第 二成型膠510產生加熱的效果。 經過步驟S380與步驟S390後，硬化後的第二成型膠 510與第一成型膠41〇彼此相結合，並成為一母光學膜片〔 11 201103738 之後’於步驟S400中，將母光學膜片收納在一產品收納輪 520上。當然’本領域具有通常知識者也可將產品收 納輪520改設計為其他型態的產品收納裝置，只要能 將母光學膜片進行收納即可。 再來’於步驟S410中，將捲繞在產品收納輪520的 母光學膜片取下’並將其分割成多個如圖2A所示之光學膜 210。此時，光學膜210的下方還貼附有離型膜413，由於 離型膜413與光學膜210間只是藉由輕量的黏著劑而結合 在一起，故只要施加些微的力量便可將其撕離。當然，考 慮到光學膜210於搬運或保存時可能會受到外界環境的汙 染’故可專到欲使用光學膜210時再將離型膜413撕下即 可。而且，於搬運或保存時，光學膜210的上方表面還可 另外貼上保護膜，以保護其上的第一微結構212。 圖2B所繪示之光學膜210,的製造流程與光學膜 210的製造流程大同小異，主要不同點在於'將步驟 S330改為：將第一成型膠410塗佈在一強化膠上，而強化 膠則是置於離型膜上’此強化膠為強化層213的母片。 在此，將對上述之第一成型膠41〇與第二成型膠51〇 的材質作較詳細的敘述。第一成型膠41〇與第二成型膠51〇 是由光硬化樹脂與熱硬化脂類所混合而成，光硬化樹脂是 指：當受到某波段範圍的光線照射時’其會產生硬化。在本 實施例中’光硬化樹脂為紫化線硬化膠，亦即其受到紫化 線照射時會產生硬化。紫化線硬化膠以其具有良'好韌性、 成形容易且方便加工等特性而被廣泛應用，其主要是 由寡聚物(Oligomer)所組成，其中尚可添加有反應性稀 12 201103738 釋單體(Reactive monomer)及光起始劑（Ph〇t〇 initiat〇r) 等以增加其性質及反應速率。本發明所使用之紫化線 硬化膠的主要成分為聚自曰丙稀酸寡聚物（p〇lyester acrylic oligomer)、環氧丙烯酸寡聚物（Ep〇Xy acrylic oligomer)或聚氨基曱酸乙酯丙稀酸寡聚物 (Polyurethane acrylic oligomer)。另外，熱硬化脂類例如 為：聚酯或聚氨基甲酸乙酯。 另外，在第一實施例中，光學膜並未設置基板，本 領域具有通常知識者也可依於本體的下方貼附上基板，以 加強光學膜整體的機械強度。 本發明以實施例說明如上，然其並非用以限定本 發明所主張之專利權利範圍。其專利保護範圍當視後 附之申請專利範圍及其等同領域而定。凡本領域具有 通常知識者，在不脫離本專利精神或範圍内，所作之 更動或潤飾，均屬於本發明所揭示精神下所完成之等 效改變或設計，且應包含在下述之申請專利範圍内。 【圖式簡單說明】 圖1所繪示為光學膜的前視圖。 圖2A所繪示為本發明之光學膜的第一實施例。 圖2B所繪示為本發明之光學獏的第二實施例。 圖3所繪示為習知的光學膜與第一實施例的光學膜之 輝度比較圖。 Λ 圖4所繪示為第一實施例的光學膜之製造流程圖。 13 201103738 圖5A所繪示為本實施例之光學膜的製造設備之前半部 份。 圖5B所繪示為本實施例之光學膜的製造設備之後半部 份0 【主要元件符號說明】 φ <先前技術> 110 :增亮膜 111 :基板 112 :結構層 Li、L2 :光線 <實施方式> 210、210’ ：光學膜 ❿ 211 :本體 212 :第一微結構 213 :微型氣泡 L3 :光線 214 :強化層 S310〜S410 :流程圖符號 410 :第一成型膠 201103738 411 :容器 81a :閥門 412 :離型膜釋放輪 413 :離型膜 414、417、418 :輔助輪 416a〜416b:第一光源 419 :熱管 510 :第二成型膠 515 :滾輪 515a :表面 516a〜516d:第二光源 519 :熱管 520 :產品收納輪Referring to FIG. 1 , a front view of the brightness enhancement film is illustrated in FIG. 1 . The brightness enhancement film U0 is mainly composed of a substrate 111 and a structure layer 112 . The substrate 111 has a thickness of about 175 em and is made of a transparent polyethylene terephthalate (PET), and the substrate 111 is coated with an adhesive. The structural layer 112 has a thickness of about 25 μm' and is made of a phot 〇 sensitive resin. The structural layer 112 is bonded to the substrate n1 by the above-mentioned adhesive. Since the structural layer 112 of the brightness enhancement film 11 has a plurality of prismatic microstructures, it has the effect of collecting light, so that the light angle of the light emitted by the brightness enhancement film 110 is reduced, thereby increasing the backlight module. The brightness that is presented over the range of viewing angles. However, when the angle of incidence of light to the brightness enhancement film 11 is small, such as the light L2, it is easily reflected by the structure layer 112. Moreover, after the light ray L2 is reflected by the structural layer 112, its j-path path in the brightness enhancement film 11 is increased by ', and the loss rate of the light ray L2 is increased. In this way, the light-emitting efficiency of the brightness enhancement film 11〇 is lowered. In response to this problem, some manufacturers have proposed the addition of diffusion particles to the structural layer 112, such as the Republic of China Patent No. 1301548. However, the addition of the diffusion particle will increase the manufacturing cost and the material is composed of the diffusion particle being larger than the structural layer 112, so that the diffusion particle has a large absorption rate, which in turn will brighten up. (4) The overall _ degree is reduced. Also because of the above-mentioned original 201103738, the practice of adding diffusion particles to the structural layer 112 is currently only in the experimental stage, and has not yet entered the stage of mass production. Therefore, the inventors of the present invention have produced an optical film which can prevent light having a small incident angle from being reflected by the structural layer, thereby improving the luminance of the optical film and at the same time having an inexpensive manufacturing cost. SUMMARY OF THE INVENTION The object of the present invention is to provide an optical film which, in addition to providing a large luminance, has a low manufacturing cost. In accordance with the above and other objects, the present invention provides an optical film comprising/a body and a plurality of first microstructures. Among them, there are multiple microbubbles distributed inside the body, and the first microstructure is disposed on one side of the body. In addition, the shape of the first microstructure allows for the accumulation of light passing therethrough. In accordance with the above and other objects, the present invention provides a method of producing an optical film. This manufacturing method comprises the following steps. First, a first molding glue is provided. The second molding glue is mainly formed by mixing a photo-curing resin and a thermosetting grease to form 'the weight percentage of the thermosetting grease relative to the first molding compound as a whole is about 1%~ 5%. Further, a plurality of microbubbles are formed in the first molding compound. Then, the light emitted by the first light source is irradiated onto the first molding glue, wherein the light and heat emitted by the first light source cause the first molding glue to harden. Next, a second molding glue is applied to the first molding glue after curing, and the second molding glue is mainly formed by mixing a photo-curing resin and a thermosetting grease, wherein the thermosetting grease is opposite to the thermosetting resin. The weight percentage of the second molding compound as a whole is about 1% to 5%. Then, shape 201103738 into a number of first-micro-transfer on the second Cheng Na. Then, the light emitted by the second light source is irradiated onto the second molding glue, wherein the light emitted by the filament and the heat I cause the second forming to harden, and the second molding glue and the The first-to-become merged to become the mother-in-law. Thereafter, the hardened mother optical film is divided into a plurality of optical films. In the above method for producing an optical film, the shape of the first microstructure can concentrate light passing therethrough. When light enters the optical film (light-tight medium) by air (light-diffusing medium), the folding angle of the light is smaller than the incident angle, but due to the high-density distribution of micro-bubbles inside the optical film' and these micro-bubbles The gas is a light-draining medium having a refractive index approximately equal to one. Thus, when the light is incident on the body (light-tight medium) to the shape, the bubble (light-dissipating medium), the light-angle angle is made larger than the incident angle. Therefore, the light with a small incident angle of light will become a large-angled wire with a microbubble, and is more suitable for deflecting light along the two sides of the first microstructure to concentrate the optical film. Brightness. The above described objects, features, and advantages of the present invention will become more apparent from the description of the appended claims. [Embodiment] Referring to Fig. 2A, Fig. 2A shows a first embodiment of the optical film of the present invention. The optical film 210 includes a body 211 and a plurality of first microstructures 212. The first microstructures 212 are disposed on one side of the body 211. In addition, the shape of the first microstructure 212 is a prismatic column shape, so that when the light passes through the first microstructure 212, convergence occurs to achieve the effect of collecting light. When 201103738, those skilled in the art can also design the first microstructure 212 into other shapes, such as: lenticular, gold-like material can be used to form a nucleus: shape, or can also be designed as a semi-spherical, concave The material of the trough can reach the shape of the scattered effect. In addition, a plurality of microbubbles 213 are distributed in the body 211. In the present embodiment, the average particle diameter of these microbubbles 213 is less than 1 〇 μm, and preferably less than 2 μm. Further, the distance between the microbubbles 213 and the adjacent microbubbles 213 is as small as possible, and it is preferable to satisfy the following equation: L < 4D, where D represents the average particle diameter of the microbubbles 213, and l Represents the average distance between the microbubbles 213 and the adjacent microbubbles 213. Referring to FIG. 2A, when the light enters the optical film 210 (light-tight medium) by air (light-diffusing medium), the angle of the light is smaller than the incident angle, but due to the high density distribution inside the optical film 210 The bubbles, and the gas in these microbubbles 213 are light-draining media having a refractive index approximately equal to i. Such 'will cause the light h passing through the optically dense medium (ie, the body 211) to enter the light-diffusing medium (ie, the micro-bubbles 213), and when the light ray L3 is incident from the body 213 (the optically dense medium) to the micro-bubbles 213 (light-splitting) When the medium is used, it will make the light angle larger than the incident angle. Therefore, the light having a small angle of incidence of light will become a light having a large angle of the small bubble 213, and is more suitable for deflecting the light along the two sides of the first microstructure 212 to increase the optical. The brightness of the film 210. In other words, due to the arrangement of the microbubbles 213, the probability of light being reflected by the first microstructures 212 can be reduced. Further, compared with the optical film 110 of Fig. 1, the optical path of the light in the optical film 21 () is also short, so that the light is less worn, so that the luminance of the optical film 210 is further improved a little further. 201103738 Referring to Fig. 3, Fig. 3 is a graph showing the luminance comparison of a conventional optical film and an optical film of the first embodiment. The luminance comparison chart is obtained by real-world optical simulation. Here, the horizontal axis represents the angle, and the vertical axis represents 1 luminance, and the luminance is represented here by the dimensionless parameter, and the luminance of the conventional optical film Π0 at the vertical viewing angle (i.e., 0 degree) is set to 1. It can be seen from the figure that the optical film 210 of the first embodiment has a higher luminance than the conventional optical film 110 at most of the viewing angles. Among them, the optical film 210 has a luminance of 17% higher than that of the optical film 110 at a vertical viewing angle. The luminance of the optical film 210 is higher than that of the optical film 11 because the optical film 210 does not have a substrate in addition to the microbubbles 213 distributed in the optical film 210. In the conventional optical film, the arrangement of the substrate 111 also causes loss of light. In addition, compared with the method of adding a diffusion particle to an optical film (for example, the Republic of China Patent No. 1301548), since the medium in the microbubble 213 is air, the light absorption rate is small, so the light loss is low. Moreover, the manufacturing cost and material cost of the microbubbles 213 are also lower than those of the diffusion particles. Referring to Fig. 2B, Fig. 2B shows a second embodiment of the optical film of the present invention. The optical film 210' of FIG. 2B is different from the optical film 210 of FIG. 2A in that the optical film 210' further includes a reinforcing layer 214' relative to the first microstructure 212, which is another one disposed on the body 211. The side is made of, for example, polymethyl methacrylate, polycarbonate or ultraviolet curable glue. The reinforcing layer 214 has a high hardness, so that the mechanical strength of the optical film 210' as a whole can be enhanced, in addition to the anti-static effect 201103738. In the present embodiment, the reinforcing layer 214 is made, for example, of an ultraviolet curable clear coating (Model: CH-74003) produced by Chunxiang Industrial Co., Ltd. The method of fabricating the optical film 210 of the first embodiment will be described below. Referring to Fig. 4, Fig. 4 is a flow chart showing the manufacture of the optical film of the first embodiment. First, step §31〇 is performed to provide a first molding glue, which is mainly formed by mixing a photohardening resin and a thermosetting grease, wherein the thermosetting grease is integrated with the first molding gel. The reset percentage is approximately 1% to 5%. Then, step s32 is performed to form a plurality of microbubbles in the first molding compound. The manner in which the microbubbles are formed in the first molding compound is, for example, heating the first molding compound and driving it into the gas to form a plurality of microbubbles in the first molding compound. The method of inserting the gas is, for example, using a bubble machine, and the particle size of the microbubbles is adjusted by controlling the bubbler, and if the number of microbubbles is increased, the distance between the microbubbles is smaller. Alternatively, a mixer may be used to form a plurality of microbubbles in the first molding compound by agitating the first molding compound. Thereafter, the molding gel is cooled to a normal temperature to increase the viscosity of the molding gel, and the viscosity thereof is preferably more than 25 〇 cps, more preferably 250 to 60 〇 cps. Since the molding compound has a viscosity, the microbubbles inside it are not exposed through the surface. Further, referring to Fig. 4 and Fig. 5A, Fig. 5A shows the first half of the manufacturing apparatus of the optical film of the present embodiment. It is assumed that the first molding compound 410 having the microbubbles 213 is stored in a container 4U', and the container 411 has a valve 81a. In the step S1, the first molding compound 410 is coated on a release film 413. When the valve 81a is opened, the 201103738 molding compound 41G flows to the distance 413 via the valve 81a. The first-off face 413 is made of a transparent material, for example, polyethylene terephthalate, stretched polypropylene, or other transparent material that does not form a bridge with the first molding compound 41. Further, the upper surface of the release film 413 is coated with a lightly viscous adhesive so that the first molding compound 410 can adhere to the release film 413 and be transported forward. The release film 413 is released by a release film release wheel 412 and is moved forward by the pulling force of the auxiliary wheels 414, 417, 418. It should be noted that, in addition to the function of driving the release film 413, the auxiliary wheels 414, 417, and 418 can also achieve the release of the release film by the auxiliary wheels 4M, 417, and 418. The function of the film 413 is to prevent the first molding compound 410 on the release film 413 from being deformed by its own weight. In step S340, the light emitted by the first light sources 416a to 416b, for example, external light, is irradiated onto the first molding compound. After step S34 is completed, and then step S350 is performed, the first molding compound 410 is transferred to a heat pipe 419 which is located between the auxiliary wheel 418 and the auxiliary wheel. When the first molding compound 410 is irradiated by the light sources 416a to 416b and heated by heat = 419, hardening occurs. In this embodiment, the step S340 is performed after the step S340 is performed, but the steps S340 and S350 can be performed simultaneously. The heat pipe 419 can also be changed to other types of heating sources, for example, heated by hot air. The first molding compound 410 is dried in a manner. In addition, those who have the usual knowledge in the field may not set any scales, because the light source 41 such as ~41 will emit heat, which can heat the first molding glue 410. Referring to FIG. 4 and FIG. 5B simultaneously, FIG. 5B illustrates the latter part of the manufacturing apparatus of the optical film of the embodiment. Next, step S36 is performed, and the second molding adhesive 510 of 201103738 is applied to the hardened film. The first molding compound 41 has no microbubbles inside the first molding compound 41. The second molding compound 510 is mainly formed by mixing a photocurable resin and a thermosetting grease, wherein the weight percentage of the thermosetting grease to the entire first molding gel is about 1% to 5%. Further, in step S370, the roller 515 is rolled onto the second molding compound 510. The surface 515a of the roller 515 has an embossing pattern (not shown). In this embodiment, the embossing pattern is a micro structure that is recessed inward. When the roller 515 is rolled over the first molding compound 51, the roller 515. The upper embossed pattern is transferred onto the second molding compound 51, and a plurality of first microstructures 212 are formed on the second molding compound 510. In step S380, the light emitted by the second light sources 516a to 516d, for example, ultraviolet light, is irradiated onto the second molding compound 510. In this embodiment, step S370 and step S380 are performed simultaneously. After step S38 is completed, proceeding to step S390, the second molding compound 510 is transferred to a heat pipe 519. When the second molding compound 510 is irradiated by the second light sources 516a to 516d and heated by the heat pipe 519, hardening occurs. In this embodiment, step S39 is performed after step S380 is completed, but step S38 and step S390 can be simultaneously performed simultaneously, and the heat pipe 519 can be changed to other types of heating sources, for example, heated by hot air. The way the second molding glue is dried. In addition, those having ordinary knowledge in the art may not provide any heating source because the second light sources 516a to 516d themselves emit radiant heat, which can heat the second molding compound 510. After the step S380 and the step S390, the hardened second molding compound 510 and the first molding compound 41 are combined with each other to form a mother optical film [11 201103738 and thereafter] in step S400, the mother optical film is accommodated. On a product storage wheel 520. Of course, those skilled in the art can also design the product receiving wheel 520 into another type of product storage device, as long as the mother optical film can be stored. Further, in step S410, the mother optical film wound around the product storage wheel 520 is removed and divided into a plurality of optical films 210 as shown in Fig. 2A. At this time, the release film 413 is attached to the lower side of the optical film 210. Since the release film 413 and the optical film 210 are only bonded by a lightweight adhesive, it is possible to apply a slight force. Teared off. Of course, it is considered that the optical film 210 may be contaminated by the external environment during handling or storage, so that the release film 413 may be peeled off when the optical film 210 is to be used. Moreover, the upper surface of the optical film 210 may be additionally coated with a protective film to protect the first microstructures 212 thereon during handling or storage. The manufacturing process of the optical film 210 illustrated in FIG. 2B is similar to the manufacturing process of the optical film 210, and the main difference is that 'the step S330 is changed to: the first molding compound 410 is coated on a reinforced adhesive, and the reinforced adhesive is applied. Then, it is placed on the release film, and the reinforced adhesive is the mother layer of the reinforcement layer 213. Here, the materials of the first molding compound 41〇 and the second molding compound 51〇 described above will be described in more detail. The first molding compound 41〇 and the second molding compound 51〇 are formed by mixing a photocurable resin and a thermosetting resin, and the photocurable resin means that it is hardened when irradiated with light of a certain wavelength range. In the present embodiment, the photohardenable resin is a varnish, which is hardened when it is irradiated with a varnish. Zihuaid hardener is widely used because of its good toughness, easy forming and convenient processing. It is mainly composed of oligomers (Oligomer), which can be added with reactive rare 12 201103738 Reactive monomer and photoinitiator (Ph〇t〇initiat〇r) to increase its properties and reaction rate. The main component of the vitrified line hardening glue used in the present invention is p〇lyester acrylic oligomer, epoxy acrylate oligomer (Ep〇Xy acrylic oligomer) or polyamino phthalate Polyurethane acrylic oligomer. Further, the thermosetting grease is, for example, polyester or polyurethane. Further, in the first embodiment, the optical film is not provided with a substrate, and those skilled in the art can attach the substrate to the lower side of the body to enhance the mechanical strength of the entire optical film. The present invention is described by way of example, and is not intended to limit the scope of the claims. The scope of patent protection is subject to the scope of the patent application and its equivalent. Modifications or modifications made by those skilled in the art, without departing from the spirit or scope of the invention, are equivalent to the equivalents or modifications made in the spirit of the invention and should be included in the following claims. Inside. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a front view of an optical film. 2A illustrates a first embodiment of an optical film of the present invention. 2B illustrates a second embodiment of the optical pickup of the present invention. Fig. 3 is a graph showing the comparison of the brightness of a conventional optical film with the optical film of the first embodiment. 4 is a flow chart showing the manufacture of the optical film of the first embodiment. 13 201103738 Fig. 5A shows the first half of the apparatus for manufacturing an optical film of the present embodiment. 5B shows the latter half of the manufacturing apparatus of the optical film of the present embodiment. [Main element symbol description] φ <Prior Art> 110: Brightening film 111: Substrate 112: Structural layer Li, L2: Light <Embodiment> 210, 210': Optical film 211 211: Body 212: First microstructure 213: Micro bubble L3: Light 214: Strengthening layer S310 to S410: Flowchart symbol 410: First molding adhesive 201103738 411: Container 81a: Valve 412: Release film release wheel 413: Release film 414, 417, 418: Auxiliary wheels 416a to 416b: First light source 419: Heat pipe 510: Second molding glue 515: Roller 515a: Surfaces 516a to 516d: Second light source 519: heat pipe 520: product storage wheel
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