201113562 六、發明說明： 【發明所屬之技術領域】 本發明是有關於一種光學膜，特別是指一種用於液晶 顯示器之背光模組的光學膜。 【先前技術】 液晶顯示器（LCD，Liquid Crystal Display)的背光模 組是提供光源的重要零組件，其中，光學膜（業界也稱為 稜鏡片）用於將行進方向雜亂的光聚集使其沿預定方向行 進，從而作最有效的發揮，更是背光模組内的關鍵元件之 —〇 參閱圖1，習知的光學膜丨主要包含一基材u，及多數 稜鏡結構體12。 該等稜鏡結構體12透光並呈長條狀，且彼此實質平行 地形成於該基材11上，每一稜鏡結構體的截面成V字型， 藉由該等稜鏡結構體12,使得當光通過時，產生折射及全 反射將光線聚集而實質沿著基材u的方向向量方向出光， 然而，由於每一稜鏡結構體12是固定寬度的規則條狀結構 ，且是以彼此平行排列地規則形成在該基材丨丨上，所以當 光通過後會產生光學干涉’而出現彩紋或明暗條紋。 因此，業界提出各式改良方法，如US 5919551號專利 案提出於基材上形成稜鏡結構體排列間距不同的技術手段 ，又如US 5771328號專利案提出於基材上形成不同高度的 稜鏡結構體的技術手段，試圖解決光學膜在光線通過後產 生的光學干涉現象。然而，前述專利案縱使於稜鏡結構體 201113562 的排列與向度上作變化，作自朵與^备由 彳一目光學角度而言，該等棱鏡結 構體仍>1規則排列而對於光學干涉的改善實屬有限。 【發明内容】 因此，本發明之目的，即在提供一種可避免光通過後 光學干涉發生的光學膜。 於是’本發明-種光學膜，包含—基材，及多數棱鏡 結構體。 該基材由可透光材質所構成。 該等棱鏡結構體透光並呈長條狀，且彼此實質平行地 形成於該透光基材上’每—稜鏡結構體包括至少-沿該稜 鏡結構體的一長向形成在該稜鏡結構體上的溝槽。 本發明之功效在於：藉由於棱鏡結構體上形成溝槽， 當光線通過光學料’―方面由稜鏡結構體產生折射及全 反射而提升-光線沿預定方向出光的一致性，一方面利用溝 槽增加此等沿預定方向出光時光行進方向的多樣性而在 提升整體光通過的亮度前提下，避免出光時的光學干涉發 生。 【實施方式】 有關本發明之前述及其他技術内容、特點與功效，在 以下配合參考圖式之一個較佳實施例的詳細說明中，將可 清楚的呈現。 在本發明被詳細描述之前，要注意的是，在以下的說 明内容中，類似的元件是以相同的編號來表示。 參閱圖2 ’本發明一種光學膜2的較佳實施例包含一基 201113562 材21，及多數棱鏡結構體22。 該基材21的構成材質為玻璃或塑膠，其中，塑膠材質 選自聚酯樹脂（polyester resin)、聚丙烯酸醋樹脂 (polyacrylate resin)、聚烯烴樹脂（p〇ly〇iefin resin)、聚碳酸 酯樹脂（polycarbonate resin)、聚胺基甲酸酯樹脂 (polyurethane resin)，或三醋酸纖維素（TAC，triacetate cellulose)等，該基材21的構成材質為熟悉此相關領域的技 藝人士所能簡單替換，在此不再一一贅述。 • 該等稜鏡結構體22以透光且折射率是ΐ·3〜2.0的材料 構成’並呈長條狀且實質平行地形成於該基材21上，具有 優異的聚光效果，在此’該等稜鏡結構體22是選自熱硬化 樹脂、丙烯酸酯類樹脂，或是紫外線硬化樹脂為材料構成 〇 .更詳.細而言’每一稜鏡結構體22包括二傾斜面221及 一溝槽222，該二傾斜面221分別自該基材21斜向上延伸 並成預定角度相交，使得每一棱鏡結構體22截面概呈三角 ^ 形，每一溝槽222沿該稜鏡結構體22的一長向分別形成在 母一稜鏡結構體22同一側的傾斜面221上。 藉由於每一稜鏡結構體22同一側的傾斜面221都形成 溝槽222，g光通過光學膜2時，不但藉由稜鏡結構體 22產生折射及全反射，而將光線集中收斂而實質沿著基材 21的方向向量方向出光，進而提昇整體的出光量·另外， 該等形成在稜鏡結構體22的溝槽222則界定出多數彼此不 平行的折射面，使得收斂而實質沿著基材21的方向向量方 201113562 向行進的光仍產生多樣性的行進方向，進 • ; 在徒野通過 光量的前提下，避免光學干涉的產生。 較佳地，該等溝槽222寬度介於1//m〜5〇以瓜之間， 且深度介於1…3”m之間，更佳地，溝槽222的二度 是介於ly m〜30#m之間，且深度是介於h 又 AWm 〜15//ηι 之 間。 還可以各種不同設置 所示，每一稜鏡結構 在此要特別說明的是，溝槽222 態樣形成於稜鏡結構體22上，如圖3 體22的每一傾斜面221分別具有一溝槽222;或是如圖* 所示，每一稜鏡結構體22同一側的傾斜面221都具有多數 溝槽222 ’且位於同一傾斜面221上的該等溝槽如可彼此 相交錯或不交錯’圖示中以二溝# 222相交錯做說明；或 是如圖5所示，每-棱鏡結構體22的每—傾斜面221分別 具有多數溝槽222的態樣，且位於同—傾斜面221上的該 等溝槽222可彼此相交錯或不交錯，圖示中以二溝槽扣 相交錯做說明’同樣可以達成一方面藉由棱鏡結構體Μ將 光線集中而實質沿著基材21的方向向量方向出光，另一方 的方向向量方向行進的 減少光學干涉的產生 面藉著溝槽222使實質沿著基材21 光’仍可以產生多樣性的行進方向 參閱圖6,此外，稜鏡結構體22截面也可以是概呈三 角形且頂冑223呈圓弧狀’藉此並配合溝槽瓜的設置， 也可以讓光通過❹生多樣性的行進方向減少光學干涉 的產生。 201113562 綜上所述，本發明主要是提供一種於稜鏡結構體上形 成有溝槽的光學膜，藉由溝槽的交錯設置，使棱鏡結構體 上形成多數不平行排列的折射面，當光線通過光學獏時， —方面由稜鏡結構體產生折射及全反射而提升光線沿預定 方向出光的一致性，進而產生聚光的效果，一方面利用溝 槽增加此等沿預定方向出光時光行進方向的多樣性，而在 提升整體光通過的亮度前提下，避免出光時的光學干涉發 生，確實改進習知光學膜會產生光學干涉的缺點，故確實 Φ 能達成本發明之目的。 惟以上所述者，僅為本發明之較佳實施例而已，當不 能以此限定本發明實施之範圍，即大凡依本發明申請專利 範圍及發明說明内容所作之簡單的等效變化與修飾，皆仍 屬本發明專利涵蓋之範圍内。 【圖式簡單說明】 圖1是一立體圖’說明習知的光學膜的構造； 圖2是一立體圖’說明本發明光學膜的一第一較佳實 Φ 施例，並說明每一稜鏡結構體同一側的傾斜面都具有一溝 槽； 圖3是一立體圖，說明本發明的光學膜在每一稜鏡結 構體的每一傾斜面皆分別具有一溝槽的型態； 圖4是一立體圖，說明本發明的光學膜在每一稜鏡結 構體同一侧的傾斜面上具有多數溝槽的型態； 圖5是一立體圖，說明本發明的光學膜在每一稜鏡結 構體的每一傾斜面上具有多數溝槽的型態；及 201113562 圖6是一立體圖，說明本發明的光學膜的棱鏡結構體 頂部截面呈圓弧狀。201113562 VI. Description of the Invention: [Technical Field] The present invention relates to an optical film, and more particularly to an optical film for a backlight module of a liquid crystal display. [Prior Art] A backlight module of a liquid crystal display (LCD) is an important component for providing a light source, wherein an optical film (also referred to as a cymbal) is used to gather light in a traveling direction to be distributed along a predetermined basis. The direction travels for the most effective use, and is a key component in the backlight module. Referring to FIG. 1, the conventional optical film stack mainly includes a substrate u and a plurality of germanium structures 12. The 稜鏡 structures 12 are light-transmissive and elongated, and are formed on the substrate 11 substantially in parallel with each other. Each 稜鏡 structure has a V-shaped cross section, and the 稜鏡 structure 12 is So that when light passes, refraction and total reflection are generated to concentrate the light and emit light substantially in the direction of the direction of the substrate u. However, since each of the structures 12 is a regular strip structure of a fixed width, Regularly arranged in parallel with each other is formed on the substrate crucible, so that optical interference occurs when light passes, and color lines or light and dark stripes appear. Therefore, various improvements have been proposed by the industry, such as the US Pat. No. 5,519,519, which discloses a technique for forming a different arrangement pitch of a tantalum structure on a substrate, and a method for forming different heights on a substrate as disclosed in US Pat. No. 5,771,328. The technical means of the structure attempts to solve the optical interference phenomenon of the optical film after the light passes. However, the aforementioned patents vary the arrangement and the orientation of the 稜鏡 structure 201113562, and the prism structures are still arranged in accordance with the optical angle of the 彳1. The improvement is limited. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an optical film which can prevent optical interference from occurring after light has passed. Thus, the present invention relates to an optical film comprising a substrate and a plurality of prism structures. The substrate is composed of a light transmissive material. The prism structures are light transmissive and elongated, and are formed substantially parallel to each other on the light transmissive substrate. 'Every 稜鏡 structure includes at least - a long direction along the ridge structure is formed at the rib a groove on the mirror structure. The effect of the invention is that: by forming a groove on the prism structure, when the light passes through the optical material, the refracting and total reflection of the 稜鏡 structure enhances the uniformity of the light exiting in a predetermined direction, and the groove is used on the one hand. The groove increases the diversity of the traveling direction of the light when the light is emitted in a predetermined direction, and avoids the occurrence of optical interference when the light is emitted while improving the brightness of the entire light. The above and other technical contents, features, and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments. Before the present invention is described in detail, it is noted that in the following description, similar elements are denoted by the same reference numerals. Referring to Fig. 2, a preferred embodiment of an optical film 2 of the present invention comprises a base 201113562 material 21, and a plurality of prism structures 22. The material of the substrate 21 is glass or plastic, wherein the plastic material is selected from the group consisting of polyester resin, polyacrylate resin, polyolefin resin (p〇ly〇iefin resin), and polycarbonate. A material such as a polycarbonate resin, a polyurethane resin, or a triacetate cellulose (TAC), the material of the substrate 21 can be easily replaced by those skilled in the relevant art. I will not repeat them here. • The 稜鏡 structure 22 is formed of a material that transmits light and has a refractive index of ΐ·3 to 2.0, and is formed in a strip shape and substantially parallel to the substrate 21, and has an excellent condensing effect. 'The 稜鏡 structure 22 is selected from a thermosetting resin, an acrylate resin, or an ultraviolet curable resin as a material. More specifically. 'Each 稜鏡 structure 22 includes two inclined faces 221 and a trench 222 extending obliquely upward from the substrate 21 and intersecting at a predetermined angle, such that each prism structure 22 has a triangular cross section, and each trench 222 is along the ridge structure. A long direction of 22 is formed on the inclined surface 221 on the same side of the mother-side structure 22, respectively. Since the groove 222 is formed by the inclined surface 221 on the same side of each of the structures 22, when the light passes through the optical film 2, the light is concentrated and totally reflected by the 稜鏡 structure 22, and the light is concentrated and converged. Light is emitted along the direction of the direction of the substrate 21, thereby increasing the overall amount of light emitted. Further, the grooves 222 formed in the 稜鏡 structure 22 define a plurality of refracting surfaces that are not parallel to each other, so that convergence substantially follows The direction vector of the substrate 21, 201113562, still produces a variety of directions of travel, and it is possible to avoid the occurrence of optical interference under the premise of passing the amount of light. Preferably, the widths of the grooves 222 are between 1//m and 5 〇 between the melons, and the depth is between 1 and 3" m. More preferably, the second degree of the grooves 222 is between ly. Between m~30#m, and the depth is between h and AWm~15//ηι. It can also be shown in various settings, each of which is specifically described here, the groove 222 Formed on the 稜鏡 structure 22, each inclined surface 221 of the body 22 of FIG. 3 has a groove 222 respectively; or as shown in FIG. *, the inclined surface 221 of the same side of each 稜鏡 structure 22 has The plurality of grooves 222 ′ and the grooves on the same inclined surface 221 may be staggered or not staggered with each other. The illustration is staggered by two grooves # 222; or as shown in FIG. 5 , each prism Each of the inclined faces 221 of the structure 22 has a plurality of grooves 222, and the grooves 222 on the same inclined surface 221 may be staggered or not interlaced with each other. Interlaced descriptions can also be achieved by concentrating the light by the prism structure to substantially illuminate the direction of the substrate along the direction of the substrate 21, and the other direction The reducing optical interference generating surface traveling in the quantitative direction can be substantially parallel to the substrate 21 by the groove 222. The traveling direction of the light can still be varied. Referring to FIG. 6, the 稜鏡 structure 22 can also be a substantially triangular cross section. Moreover, the top 胄 223 is in the shape of an arc, and the arrangement of the grooved melon can also reduce the generation of optical interference by the direction of travel of the twin diversity. 201113562 In summary, the present invention mainly provides a An optical film having a groove formed on the 稜鏡 structure, wherein a plurality of non-parallel refracting surfaces are formed on the prism structure by the staggered arrangement of the grooves, and when the light passes through the optical 貘, the 稜鏡 structure is generated by the 稜鏡 structure Refraction and total reflection enhance the uniformity of light exiting in a predetermined direction, thereby producing a concentrating effect. On the one hand, the groove is used to increase the diversity of the traveling direction of the light when exiting in a predetermined direction, and the brightness of the overall light passing through is improved. Under the circumstance, the occurrence of optical interference at the time of light extraction is avoided, and the disadvantage that optical interference occurs in a conventional optical film is indeed improved, so that Φ can achieve the object of the present invention. The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing the construction of a conventional optical film; FIG. 2 is a perspective view showing a first preferred embodiment of the optical film of the present invention. Φ embodiment, and the inclined surface on the same side of each 稜鏡 structure has a groove; FIG. 3 is a perspective view showing that the optical film of the present invention has each inclined surface of each 稜鏡 structure respectively Figure 4 is a perspective view showing the optical film of the present invention having a plurality of grooves on an inclined surface on the same side of each of the structures; Fig. 5 is a perspective view showing the present invention The optical film has a pattern of a plurality of grooves on each inclined surface of each of the 稜鏡 structures; and 201113562 is a perspective view showing that the prism structure of the optical film of the present invention has an arc-shaped top section.
8 201113562 【主要元件符號說明】 2 光學膜 221 傾斜面 21 基材 222 溝槽 22 稜鏡結構體 223 頂部8 201113562 [Description of main component symbols] 2 Optical film 221 Inclined surface 21 Substrate 222 Groove 22 稜鏡 Structure 223 Top