200909866 九、發明說明： 【發明所屬之技術領域】 本發明係關於一種背光模組及其光學膜，特別關於 一種可達到增強雙軸方向亮度之背光模組及其光學膜。 【先前技術】 心著數位時代的來臨，平面顯示裝置之技術亦快速 成長，已成為不可或缺的電子產品之一，故大眾對於平 面顯示裝置之技術及功能要求亦越來越高。 、就平面顯示裝置而言，其主要係包含一平面顯示面 板以及老光模組。其中該平面顯示面板主要係具有彩 色f光基板、薄膜電晶體基板以及一夾設於兩基板間的 液日日層，而月光模組係作為背光源使用，其係可將來自 :光源的光線均勻地分佈在液晶面板之表面。傳統上， 係以冷陰極螢光燈（CCFL)來作為背光模組之光源， 、依據光源之a又置方式而使背光模組分為直下式及側 I =式背光模組。近來為了提升平面顯示裝置之亮度，且 需使光線在通過增亮膜之發射角縮小至正負30至40度 以内，故對於提升背光模組之增亮膜功能，已成為背光 模組不可或缺的技術之一。 一依據美國專利號碼6091547所述，請參照第1圖所 不，該背純組1A包括-光源u、至少—擴散膜14 乂及杧儿膜（brightness enhancement film) 12。倘若背 光模組1為—側光式背光模組，則擴散膜14及增亮膜 π依序設置於—導缺13之±。光源^係、發射一光線 200909866200909866 IX. Description of the Invention: [Technical Field] The present invention relates to a backlight module and an optical film thereof, and more particularly to a backlight module and an optical film thereof which can achieve enhanced brightness in a biaxial direction. [Prior Art] With the advent of the digital age, the technology of flat display devices has also grown rapidly and has become one of the indispensable electronic products. Therefore, the technical and functional requirements of the flat display devices are increasing. In the case of a flat display device, it mainly comprises a flat display panel and an old light module. The flat display panel mainly has a color f-light substrate, a thin film transistor substrate, and a liquid solar layer sandwiched between the two substrates, and the moonlight module is used as a backlight, which can light from the light source. Evenly distributed on the surface of the liquid crystal panel. Conventionally, a cold cathode fluorescent lamp (CCFL) is used as a light source of a backlight module, and a backlight module is divided into a direct type and a side I = type backlight module according to a mode of the light source. Recently, in order to improve the brightness of the flat display device, and to reduce the light emission angle of the brightness enhancement film to within plus or minus 30 to 40 degrees, the brightness enhancement film function of the backlight module has become an indispensable backlight module. One of the technologies. As described in U.S. Patent No. 6,091,547, the back-pure group 1A includes a light source u, at least a diffusion film 14 and a brightness enhancement film 12. If the backlight module 1 is an edge-lit backlight module, the diffusion film 14 and the brightness enhancement film π are sequentially disposed on the lead-out 13 . Light source ^, emit a light 200909866
Ll ’並设置於導光板13之一側。光線L1藉由導光板 13引導經由擴散膜14後，再進入增亮膜12，如第i圖 所示。倘若背光模組1B為一直下式背光模組，則擴^ 膜14及增亮膜12依序設置於光源u之上。光源u'之 光線L1直接進入擴散膜14，再進入增亮膜12，如第2 圖所示。 就增亮膜12而言，其係可將射入之光線u折射成 小角度的出射光’使大部份的光線L1的發射角能縮小 至正負30至40度以内，以使觀賞者在光軸正負3〇至 40度以内有更強的壳度視覺效果。請再參照第1圖所 示，其係為具有稜柱表面結構丨2丨之增亮膜丨2，而此 增亮膜12之稜柱表面結構121係以單一方向νι平行^ 列。然而，使用上述方式僅能提供單軸方向，例如Z平 方向或垂直方向之增亮效果。故倘若欲達到雙軸方向 即水平方向及垂直方向之增亮效果，則需採用兩… 膜12相互疊合，且兩片增亮膜12之稜柱表面結構^ 係分別以第一方向V2及第二方向V3平行排列，且 -方向V2及第二方向V3係相互垂直，如第2圖所示。 然而，使用兩片增亮膜12不僅會增加成本， 降低光線L1的穿透率。 K貧 山爰因於此，如何提供一種可同時達到雙軸方向之拗 =效果’並降低成本及提升光線穿透率之背光模組及日 光學骐’已成為重要課題之一。 200909866 【發明内容】 =鑑於上述課題’本發明之目的為提供—種 達到雙軸方向之增亮效果，並降低成本之 背光模組及其光學膜。 诙开穿透羊之 緣疋’為達上述目的’本發明之—種光學膜包括一 土反以及至j/ —微結構。該微結構係言免置於基板之一 :之一第—封閉面及一第二封閉面。其中該微結 =截面係具有至少—第—邊及至少―第二邊，第一邊 及第一邊分別環繞成封閉曲線以形成第—封閉面及第 一'封閉面。 為f上述目的，本發明之一種背光模組包括一光源 及一光學臈。光源係發射—光線’光學膜係接收入射 並具有—基板及至少—微結構，該微結構係設 置於基板之-面’並具有一第一封閉面及一第二封閉 面。其中該微結構之截面係具有至少一第一邊及至少一 ::邊，而第一邊及第二邊分別環繞一成封閉曲線以形 成第一封閉面及第二封閉面。 承上所述，本發明之背光模組及其光學膜係將光學 膜设置於錢所發射之光線的光路徑上，並藉由光學膜 ，各微結構設置於基板上，而微結構截面的第一邊及第 二邊係分別環繞成封閉曲面以形成第一封閉面及第二 封閉面。與習知技術相較’本發明僅使用具有微結構的 :片光學膜’其不僅可減少成本’且更可藉由微結構之 第一封閉面和第二封閉面與微結構截面之第一邊及第 200909866 二邊便可使光線在通過微結構時，達到雙軸方向亮度增 強效果，進而避免光穿透率的降低。 【實施方式】 以下將參照相關圖式，說明依據本發明較佳實施例 之一種背光模組及其光學膜。 請參照第3圖所示，本發明第—實施例之背光模組 2係包括-光源3、一光學膜4、_第一擴散片5以及 -導光板6。該背光模組2可為—直下式背光模組或一 側光式背光模組，在此係以背光模組2為一側光式背光 模組為例。 該第一擴散片5係設置於光學膜4之一側，而導光 板6係設置於料膜4之另—侧。光源3鄰設於導光板 6 ’且光源3發射一光線L2射向導光板6，而光線L2 係透過導光板6射向光學膜4。 請再同時參照第3圖與第4圖所示，光學膜4係接 收入射之光線L2，並具有一基板41及至少一微結構 42。該微結構42係設置於基板41之一面，並具有一第 一封閉面422及一第二封閉面423，且第一封閉面422 與第二封閉面423係相互連接，且第一封閉面422及第 二封閉面423於實施上係分別折射入射光學膜4之光線 L2。該光學膜4之材質係為一透光材質，例如一聚乙烯 對本一甲酸西旨（polyethylene terephthalate，PET)、一聚 礙酸醋（polycarbonate ’ PC)或一聚曱基丙烯酸曱酯 (PMMA)。 200909866 0月再同時參照第4圖至第6圖所示，該微結構42 設或凸設於基板41上。如第4圖所示’而當光學 膜4之微結構42凸設於基板時，則第—封閉面似係 凸设於基板，且第二封閉面423係凹設於第一封閉面 =2内，且微結構42更具有一底部似，其係與第二封 才1面423相連接。此外，底部424之形狀並無限制，可 為一圓形…橢圓形、-類三角形、—類菱形或一類矩 形更可為一多邊形’而在此係以底部424之形狀為圓 =為例如第5圖及第6圖所示，當光學膜4A之微結 才42凹叹於基板41時，則第—封閉面422係凹設於基 板4卜而第二封閉面423係凸設第一封閉面422内。 該微結構42更具有—頂部425，係與第二封閉面423 相連接，而頂部425之形狀可為一圓形、一橢圓形、一 類三角形、一類菱形或一類矩形，甚至為一多邊形，在 此係以頂部425之形狀為圓形為例（如第4圖及第5圖 所示）。 該光學膜4、4A之微結構42的截面s 1、S2係具 有至少一第一邊426、至少一第二邊427及一端部“A。 第一邊426及第二邊427係相互連接且為斜邊，而端部 則設置並連接於第一邊426及第二邊427之間，且 第二邊426及第二邊427係環繞一封閉曲線以分別 形成第一封閉面422及第二封閉面423。 明再同時參照第4圖、第6圖及第7A圖至第7E 圖所示’該微結構42之端部42A、42B、42C、42D、 200909866 42E可為一尖角形（如第4 SLA fLn ^ y： rg, 岡兴第7A圖所不）、一平；t曰 形（士第6圖所示）、一圓弧形 角形（如第7C HI恥（士第7B圖所不）或一倒尖 於實“ 此外’第一邊426與第二邊427 第7Β圖可)皆為直線（如第4圖、第6圖及第7Α圖至 7C圖所 一個邊為弧線而另-邊為直線(如第 2Β=)。故由第一邊你、第二邊⑺及端部似、 、你、421)、很所形成之微結構42的截面^、 S2说S3、S4、S5的形狀可為—三角形（如第*圖所示）、 ::形(如第6圖所示)、—半弧形(如第7A圖所示)、一 ;、員如第7B圖所不）或—山形（如第％圖所示）。 請參照第8A ffi至第8D圖所*，本實施例之封閉 曲線。、。、。、㈣之形^於實施上係為一圓 >(如第4圖所示）、一_形（如第Μ圖所示）一類三 角幵/(如第8B圖所不）' 一類菱形（如第8c圖所示）或— 類矩形（如帛8D圖所示），當然更可為-多邊形（圖未 不）’故藉由第-邊426及第二邊427環繞上述各種形 ，之封閉曲線C1、C2、C3、C4、C5峨之微結構 -形狀亦可在光學膜4B上各為一圓形（如第4圖所 :)、-橢圓形、一類三角形、一類菱形或一類矩形(如 第9圖所示）。 ,邊基板41及該微結構42可為一體成型或黏合成 型。在此係以基板41及各微結構42為一體成型為例， 且微結構42之製作方式並無限制，可使用軟壓、熱壓、 熱滾壓、紫外光固化、微機電技術中之類黃光、電鑄、 200909866 模造製程或精微製程等方式形成於基板41上。 此外，請參照f 10A圖與第1〇B圖所示 4C、4D更具有一光學擔勒暖 先學骐 又兴有A學擴散膜43，係相對於微結 而設置於基板41之另—面，且光學擴散膜43之材 包括一透光樹脂與微粒混合物（如第1〇A圖所示），當然 更可以為-具有表面微結構之透光材質（如第咖^ 示）。 f 該微結構42所設置於基板41的那面為出光面，而 相對基板41那面的另外一面則為入光面。 請參照第11圖所示，當光線入射光學膜4及其微 結構42時，光線折射成小角度而射出，經由模擬軟體 計算後得知從Α方向與β方向之視角與輝度增益的關 係，其結果顯示視角於正負3〇〜40度以内，其輝度的择 益值係大於1，故可大為提升光線之亮度。 e 本實施例之背光模組2不僅只需藉由單片光學祺 (,4 ’其微結構42的第一封閉面422及第二封閉面423相 配合’便可使光線L2在通過微結構42時達到雙軸方向 (即垂直方向及水平方向）的亮度增強效果，更可減少 成本及避免光穿透率的降低。 請參照第12圖所示，本發明第二實施例之背光模 組7係包含一光源71、一光學膜72以及一第一擴散片 73。該光源71、光學膜72及第一擴散片33係與上述 第一實施例（如第3圖所示）的背光模組2中之光源3、 光學膜4及第一擴散片5具有相同構成及功效，故於此 200909866 不再贅述。而本實施例之背光模組7與第一實施例之背 光模組2(如第3圖所示）不同之處在於前者更包含一第 二擴散片74。該第一擴散片73係設置於光學膜”之 一側，第二擴散片74係相對第一擴散片乃設置於光學 膜72之另一侧，而光源71係發射一光線L3，並相對 光學臈設置於第二擴散片74之—側，故本實施例之背 光模組7係為一直下式背光模組。 、，不上所述’本發明之背光模組及其光學膜係將光學 、设置於光源所發射之鱗的光路徑上，並藉由光學膜 之各微結構設置於基板上，而微結構之截面之相互連接 二至少第-邊及至少第二邊係環繞封閉曲面以分別形 成第-封閉面及第二封閉面。與習知技術相較，本發明 T僅使用單片光學膜且其具有微結構。此種方式不僅可 減少成本’且更可藉由微結構之第—封閉面和第二封閉 =以及微結構截面之第―邊和第二邊，便可使光線在 =微結構時達到雙軸方向亮度增強效果，進而避免光 穿透率的降低。 以上所述僅為舉例性，而非為限制性者。任何未脫 ，本發明之精神與料，而對其進行之等效修改或變 更，均應包含於後附之申請專利範圍中。 【圖式簡單說明】 第1圖為一種習知背光模組之示意圖； 第2圖為另一習知背光模組之示意圖； 第3圖為依據本發明第一實施例之一種背光模組 12 200909866 之示意圖； 第4圖係為第3圖之光學膜的立體剖面示意圖； 一第5圖為依據本發明第一實施例之光學膜之俯視 示意圖； 第6圖為第5圖之光學膜沿AA線的剖面示意圖； 第7A圖至第7C圖顯示依據本發明之微結構之各 種不同態樣的戴面示意圖； f 第8A圖至第8D圖顯示本發明之光學膜的示意圖； 一第9圖顯示本發明之光學膜之各種形狀微結構之 示意圖； 第10A圖及第10B圖分別顯示依據本發明第二和 第三實施例之光學膜的示意圖； 第11圖顯示本發明第一實施例之光學膜之光軸角 度與亮度之關係圖；以及 第12圖為顯示依據本發明第二實施例之一種背 I 模組之示意圖。 元件符號說明： 1、2、7 :背光模組 12 :增亮膜 13、6 :導光板 41 :基板 11、3、71 :光源 :稜柱表面結構 Μ :擴散膜 4、4A、4B、4C、4D、72:光學膜 42 .彳政結構 421 :基座 13 200909866 422 :第一封閉面 424 :底部 426 :第一邊L1' is disposed on one side of the light guide plate 13. The light ray L1 is guided by the light guide plate 13 through the diffusion film 14, and then enters the brightness enhancement film 12 as shown in Fig. i. If the backlight module 1B is a direct-type backlight module, the expansion film 14 and the brightness enhancement film 12 are sequentially disposed above the light source u. The light beam L1 of the light source u' directly enters the diffusion film 14, and then enters the brightness enhancement film 12, as shown in Fig. 2. In the case of the brightness enhancement film 12, it can refract the incident light u into a small angle of the outgoing light', so that the emission angle of most of the light L1 can be reduced to plus or minus 30 to 40 degrees, so that the viewer is The optical axis has a stronger shell visual effect within 3 to 40 degrees. Referring again to Fig. 1, it is a brightness enhancement film 丨2 having a prismatic surface structure ,2, and the prism surface structure 121 of the brightness enhancement film 12 is aligned in a single direction νι. However, the above-described manner can only provide a uniaxial direction, such as a Z-flat or vertical brightening effect. Therefore, if you want to achieve the biaxial direction, that is, the horizontal and vertical brightness enhancement effect, you need to use two... The film 12 is superposed on each other, and the prismatic surface structures of the two brightness enhancement films 12 are respectively in the first direction V2 and the first The two directions V3 are arranged in parallel, and the − direction V2 and the second direction V3 are perpendicular to each other, as shown in FIG. 2 . However, the use of the two brightness enhancing films 12 not only increases the cost, but also reduces the transmittance of the light L1. Because of this, how to provide a backlight module and a solar optical 骐 that can simultaneously achieve the 拗 = effect in the biaxial direction and reduce the cost and increase the light transmittance has become one of the important topics. 200909866 SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a backlight module and an optical film thereof which achieve a brightening effect in a biaxial direction and which reduce cost. The optical film of the present invention comprises a soil reverse and a j/-microstructure. The microstructure is exempt from one of the substrates: one of the first closed surface and one second closed surface. Wherein the micro-junction=section section has at least a first side and at least a second side, and the first side and the first side are respectively surrounded by a closed curve to form a first closed surface and a first 'closed surface. For the above purpose, a backlight module of the present invention includes a light source and an optical pickup. The light source is a light-emitting optical film that receives the incident and has a substrate and at least a microstructure that is disposed on the face of the substrate and has a first closed surface and a second closed surface. Wherein the cross section of the microstructure has at least a first side and at least one :: side, and the first side and the second side respectively surround a closed curve to form a first closed surface and a second closed surface. As described above, the backlight module of the present invention and the optical film thereof are disposed on the optical path of the light emitted by the money, and are disposed on the substrate by the optical film, and the microstructure is cross-sectioned. The first side and the second side are respectively surrounded by a closed curved surface to form a first closed surface and a second closed surface. Compared with the prior art, the present invention uses only a micro-structured: sheet optical film which not only reduces the cost' but also the first closed surface and the second closed surface and the first microstructured cross section of the microstructure. Both sides and the second layer of the second layer can achieve the brightness enhancement effect in the biaxial direction when the light passes through the microstructure, thereby avoiding the decrease of the light transmittance. [Embodiment] Hereinafter, a backlight module and an optical film thereof according to a preferred embodiment of the present invention will be described with reference to the related drawings. Referring to FIG. 3, the backlight module 2 of the first embodiment of the present invention includes a light source 3, an optical film 4, a first diffusion sheet 5, and a light guide plate 6. The backlight module 2 can be a direct-lit backlight module or an edge-lit backlight module. The backlight module 2 is a one-side optical backlight module. The first diffusion sheet 5 is disposed on one side of the optical film 4, and the light guide plate 6 is disposed on the other side of the film 4. The light source 3 is disposed adjacent to the light guide plate 6' and the light source 3 emits a light L2 to the light guide plate 6, and the light L2 is transmitted through the light guide plate 6 to the optical film 4. Referring to Figures 3 and 4 simultaneously, the optical film 4 is coupled to the incident light L2 and has a substrate 41 and at least one microstructure 42. The microstructure 42 is disposed on one surface of the substrate 41 and has a first closed surface 422 and a second closed surface 423. The first closed surface 422 and the second closed surface 423 are connected to each other, and the first closed surface 422 is connected. The second closed surface 423 is operative to refract the light L2 incident on the optical film 4, respectively. The material of the optical film 4 is a light transmissive material, such as a polyethylene to polyethylene terephthalate (PET), a polycarbonate 'PC or a poly(mercapto methacrylate) (PMMA). . 200909866 0. At the same time, referring to FIG. 4 to FIG. 6, the microstructure 42 is disposed or protruded on the substrate 41. As shown in FIG. 4, when the microstructure 42 of the optical film 4 is protruded from the substrate, the first closed surface is convexly disposed on the substrate, and the second closed surface 423 is recessed on the first closed surface = 2 The microstructure 42 is more like a bottom, which is connected to the second cover 423. In addition, the shape of the bottom portion 424 is not limited, and may be a circle...ellipse, a triangle-like shape, a diamond-like shape, or a type of rectangle may be a polygon, and here the shape of the bottom portion 424 is a circle=for example, 5 and FIG. 6, when the micro-junction 42 of the optical film 4A is sagged on the substrate 41, the first closed surface 422 is recessed on the substrate 4 and the second closed surface 423 is convexly closed. Inside the face 422. The microstructure 42 further has a top portion 425 connected to the second closed surface 423, and the top portion 425 can be a circle, an ellipse, a triangle, a diamond or a rectangle, or even a polygon. This is exemplified by the shape of the top 425 being circular (as shown in Figs. 4 and 5). The sections s 1 and S2 of the microstructure 42 of the optical film 4, 4A have at least a first side 426, at least a second side 427 and an end portion "A. The first side 426 and the second side 427 are connected to each other and The beveled edge is disposed at the end between the first side 426 and the second side 427, and the second side 426 and the second side 427 surround a closed curve to form the first closed surface 422 and the second Closed surface 423. Referring to Figures 4, 6 and 7A to 7E simultaneously, the end portions 42A, 42B, 42C, 42D, 200909866 42E of the microstructure 42 may be a pointed shape (e.g. 4th SLA fLn ^ y: rg, Gangxing No. 7A is not), one flat; t曰 shape (shown in Figure 6), a circular arc shape (such as 7C HI shame (No. 7B) ) or a sharp point in the real "other than the first side 426 and the second side 427 the seventh picture can be) are straight lines (such as Figure 4, Figure 6 and Figure 7 to Figure 7C one side of the curve is an arc and another - the edge is a straight line (such as the second Β =). Therefore, the first side of you, the second side (7) and the end of the like, you, 421), the formation of the microstructure of the structure 42 ^, S2 said S3, S4, The shape of S5 can be - triangle (as shown in Figure *), :: (as shown in Figure 6), - semi-arc (as shown in Figure 7A), one; or as in Figure 7B) or - Yamagata (eg Figure 100 shows). Please refer to the closed curve of this embodiment, which is referred to in Fig. 8A ffi to Fig. 8D. ,. ,. (4) The shape of the ^ is implemented as a circle > (as shown in Figure 4), a _ shape (as shown in the figure), a type of triangular 幵 / (as shown in Figure 8B) 'a type of diamond (such as Figure 8c) or - a rectangle (as shown in Figure 8D), of course, can be a - polygon (not shown), so the first side 426 and the second side 427 surround the above various shapes, which are closed The microstructures-shapes of the curves C1, C2, C3, C4, C5峨 may also be a circle on the optical film 4B (as shown in Fig. 4), an ellipse, a type of triangle, a type of diamond or a type of rectangle ( As shown in Figure 9). The side substrate 41 and the microstructure 42 may be integrally formed or bonded. In this case, the substrate 41 and the microstructures 42 are integrally formed as an example, and the manufacturing method of the microstructure 42 is not limited, and soft pressing, hot pressing, hot rolling, ultraviolet curing, micro electromechanical technology, and the like can be used. Yellow light, electroforming, 200909866 molding process or fine process is formed on the substrate 41. In addition, please refer to the f 10A map and the 1C and 4D shown in Fig. 1B, there is an optical stretcher and a diffuse film 43, which is disposed on the substrate 41 with respect to the microjunction. The material of the optical diffusion film 43 comprises a light-transmissive resin and a mixture of particles (as shown in FIG. 1A), and of course, a light-transmitting material having a surface microstructure (as shown in FIG. f The surface of the microstructure 42 disposed on the substrate 41 is a light-emitting surface, and the other surface of the substrate 41 is a light-incident surface. Referring to FIG. 11 , when light is incident on the optical film 4 and its microstructure 42 , the light is refracted at a small angle and emitted, and the relationship between the viewing angle from the Α direction and the β direction and the luminance gain is obtained after calculation by the simulation software. The result shows that the viewing angle is within plus or minus 3 〇 to 40 degrees, and the luminance value of the luminance is greater than 1, so that the brightness of the light can be greatly improved. The backlight module 2 of the present embodiment can make the light L2 pass through the microstructure not only by a single optical aperture (4' of the first closed surface 422 and the second closed surface 423 of the microstructure 42). At 42 o'clock, the brightness enhancement effect in the biaxial direction (ie, the vertical direction and the horizontal direction) is achieved, and the cost can be reduced and the light transmittance can be reduced. Referring to FIG. 12, the backlight module of the second embodiment of the present invention is shown. The seventh system includes a light source 71, an optical film 72, and a first diffusion sheet 73. The light source 71, the optical film 72, and the first diffusion sheet 33 are combined with the backlight module of the first embodiment (as shown in Fig. 3). The light source 3, the optical film 4, and the first diffusion sheet 5 in the group 2 have the same composition and function, and therefore will not be described again in the above. The backlight module 7 of the present embodiment and the backlight module 2 of the first embodiment ( The difference is that the former further includes a second diffusion sheet 74. The first diffusion sheet 73 is disposed on one side of the optical film, and the second diffusion sheet 74 is disposed opposite to the first diffusion sheet. On the other side of the optical film 72, the light source 71 emits a light L3 and is optically opposed. The backlight module 7 of the present embodiment is a backlight module of the present embodiment. The backlight module of the present invention and the optical film system thereof will be optical, Disposed on the light path of the scale emitted by the light source, and disposed on the substrate by the microstructures of the optical film, and the cross sections of the microstructure are connected to each other, at least the first side and at least the second side surround the closed surface to respectively The first closed surface and the second closed surface are formed. Compared with the prior art, the present invention T uses only a single optical film and has a microstructure. This method can not only reduce the cost but also can be made by the microstructure. - the closed face and the second closure = and the first side and the second side of the microstructure cross section, so that the light can achieve a brightness enhancement effect in the biaxial direction when the micro structure is formed, thereby avoiding a decrease in light transmittance. The present invention is intended to be illustrative, and not restrictive. Any changes and modifications of the present invention are intended to be included in the scope of the appended claims. Description] Figure 1 shows a conventional back 2 is a schematic diagram of another conventional backlight module; FIG. 3 is a schematic diagram of a backlight module 12 200909866 according to the first embodiment of the present invention; and FIG. 4 is an optical diagram of FIG. 3 is a schematic plan view of an optical film according to a first embodiment of the present invention; FIG. 6 is a schematic cross-sectional view of the optical film of FIG. 5 along line AA; and FIGS. 7A to 7C are shown Schematic diagram of various aspects of the microstructure according to the present invention; f Figures 8A to 8D show schematic views of the optical film of the present invention; Figure 9 shows a schematic view of various shapes of the optical film of the present invention 10A and 10B are schematic views showing optical films according to second and third embodiments of the present invention, respectively; and Fig. 11 is a view showing relationship between optical axis angle and brightness of the optical film of the first embodiment of the present invention; Figure 12 is a schematic view showing a back I module in accordance with a second embodiment of the present invention. Description of component symbols: 1, 2, 7: backlight module 12: brightness enhancement film 13, 6: light guide plate 41: substrate 11, 3, 71: light source: prism surface structure Μ: diffusion film 4, 4A, 4B, 4C, 4D, 72: optical film 42. 彳 structure 421: pedestal 13 200909866 422: first closed surface 424: bottom 426: first side
42A、42B、42C、42D 423 :第二封閉面 425 :頂部 427 :第二邊 42E :端部 43 :光學擴散膜 5、73 :第一擴散片 74 :第二擴散片 X、Y、Z ··軸42A, 42B, 42C, 42D 423: second closed surface 425: top 427: second side 42E: end portion 43: optical diffusion film 5, 73: first diffusion sheet 74: second diffusion sheet X, Y, Z ·axis
Cl、C2、C3、C4、C5 :封閉曲、線 L1、L2、L3 :光線 SI、S2、S3、S4、S5 :截面 14Cl, C2, C3, C4, C5: closed curve, line L1, L2, L3: light SI, S2, S3, S4, S5: section 14