201248213 六、發明說明： 【發明所屬之技術領域】 本發明是有關於一種光源裝置，且特別是有關於一種背光 模組及其光學膜。 【先前技術】 液晶顯示器包括液晶顯示面板與背光模組，其中由於液晶 顯示面板本身不發光，所以需藉由背光模組提供液晶顯示面板 所需的顯示光源。 圖1是習知一種背光模組的示意圖。請參照圖i，習知背 光模組100包括光源110以及導光板120，其中光源配置 於導光板120的入光面122旁，以提供光線至導光板12〇，而 導光板120用以將光線轉換成從出光面124出射的面光源。此 外，為了提升面光源的均勻性，導光板12〇的出光面124上可 設置多個光學膜，這些光學膜由出光面方向向上層疊，依序包 括下擴散片130、下稜鏡片140、上稜鏡片150以及上擴散片 160。下擴散片先將面光源擴散，接著再依序藉由下稜鏡 片140與上稜鏡片15〇對面光源進行集光，之後再藉由上擴散 片160來調整光路徑，以達到均勻化面光源的目的。 然而，習知技術所使用的光學膜之數量過多，不僅導致背 光模組100的厚度較厚且重量較重，還需花費許多時間組裝光 學膜，造成背光模組100的生產效率較差。此外，在組裝^學 膜易產生組裝公差，而過多的光學膜會導致組裝公差的^積^ 以致於對面光源的品質造成顯著的不良影響。 ” 3 201248213 【發明内容】 本發明提供一種光學臈，其可應用於背光模組中，以減少 背光模組之光學膜的數量。 本發明另提供一種背光模組，其具有生產效率較佳、厚度 較薄、重量較輕以及面光源品質較佳的優點。 本發明提出一種光學膜，包括基材、多個第一集光結構、 多個第一擴散結構、多個第二集光結構以及多個第二擴散結 構。基材具有相對的出光面與入光面，第一集光結構與第一^ 散結構沿預定方向交替排列於出光面。第二集光結構與第二擴 散結構沿所述預定方向交替排列於入光面。 在本發明之一實施例中’上述之每一第一集光結構與每一 第二集光結構分別包括至少一稜鏡柱，且稜鏡柱的長軸垂直於 所述預定方向。 在本發明之一實施例中，上述之棱鏡柱為三角柱或半圓 柱。 在本發明之一實施例中’上述之稜鏡柱具有沿長軸之方向 延伸的凹陷’以形成位於凹陷兩側的二頂面以及位於凹陷内二 底面’且頂面為凸曲面，而底面為凹曲面。 在本發明之一實施例中，上述之每一頂面之頂端與底面之 底端的高度差介於1微米至30微米，頂端與底端沿所述預a 方向的間距大於1微米。 L疋 在本發明之一實施例中，上述之每一第一集光結構與 第一集光結構沿著垂直入光面與出光面之方向的高度八 微米至50微米。 1 ί 1 ^在本發明之一實施例中，上述之每一第一擴散結構與每一 第二擴散結構分別為霧化層，且霧化層的厚度介於丨^米至 201248213 30微米。 在本發明之一實施例中，上述之每一 第二擴散結構分別為露化戶，第一姐 ’、° -、母一 60%，^ 2祕θ第—擴散結構的誠介於S%〜 60/6而第二擴散結構的霧度介於5%〜90%。 在本發明之一實施例中，上述之每一第一擴散結構 :?擴散結構分別為霧化層，且霧化層内配置有多個擴:: 在本發明之一實施例中，上述之每一 ^二擴散結構分別為霧化層，且霧化層包括互相堆二 二介質層。第一介質層的折射率大於第二“，ς 、，，°構的第二介質層位於第—介質層與基材之間。 擴政 在本發明之—實施例中，上述之第一 二介質層的折射率的差值為G.G5。 a、射率與第 光面中一第-擴散結構之與出 底面面積相同，而每—第二擴散結構之面接觸的 在本發明入，接觸的底面面積相同。 x ^ 霄加例中，上述之第一隹出从 結構相對應，第—擴散結構與第二集光結構相;第二擴散 結構之底面於人光_正投f彡恰與第 、:。第一集光 重疊，第一擴散結構之底面於人光面‘二2的底面完全 構之底面完全重疊。 又如L與第二集光結 在本發明之一實施例中，上述筮一 結構相對應，且第-擴散結構與第二集光;第二擴散 5 201248213 本發明另提出一種背光模組，包括光學板、光源、兩片上 述的^學膜。光源配置於光學板旁，以提供光線至光學板。光 學膜疊置於光學板的出光方向上，且其中一片光學膜的預定方 向垂直另外一片光學膜的預定方向。 在本發明的背光模組及光學膜令，因基材的入光面與出光 面皆設有擴散結構與集光結構’所以具有對光線進行擴散及集 光的作用。換言之，本發明的一片光學膜可取代習知技術所使 用的一片擴散片及一片稜鏡片，因此本發明之背光模組僅需使 用兩片光學膜即可使面光源的品質符合需求，故能提升生產效 率。 ^為讓本發明之上述和其他目的、特徵和優點能更明顯易 f董，下文特舉較佳實施例，並配合所附圖式，作詳細說明如下。 【實施方式】 圖2是本發明一實施例之背光模組的示意圖，而圖3是圖 2中兩片光學膜的立體示意圖。請參照圖2與圖3，本實施例 之背光模組200包括光學板21〇、光源220以及兩片光學膜 300a、300b。光源220配置於光學板21〇旁，以提供光線222 至光學板210，而光學膜300a、3〇〇b疊置於光學板21〇的出 光方向上。本實施例之背光模組2〇〇例如是侧邊入光式的背光 模組，所以是用導光板作為光學板21〇。光學板21〇可將光源 220提供的光線轉換成從出光面212出射的面光源，且於光學 板210的底面214可設有反射片23〇,以將進入光學板21〇的 光線222反射至出光面212，進而提升光利用率。另外，在直 下式背光模組的實施例中，可選用擴散板作為光學板。 上述光學膜300a、300b包括基材31〇、多個第一集光結 201248213 構320、多個第一擴散結構330、多個第二集光結構340以及 多個第二擴散結構350。基材310具有相對的入光面312與出 光面314 ’第一集光結構320與第一擴散結構330沿預定方向 交替排列於出光面314，且第二集光結構340與第二擴散結構 350沿所述預定方向交替排列於入光面312。在本實施例中， 光學膜300a與光學膜300b的預定方向不同，其中光學膜300a 的預定方向例如是X轴，而光學膜300b的預定方向例如是垂 直於X轴的Y軸。換言之，光學膜3〇〇a的第一集光結構32〇 與第一擴散結構330沿X軸交替排列’而光學膜300a的第二 集光結構340與第二擴散結構35〇亦沿X軸交替排列。光學 膜3〇〇b的第一集光結構320與第一擴散結構330沿Y軸交替 排列’而光學膜300b的第二集光結構34〇與第二擴散結構35〇 亦沿Y軸交替排列。 *在本實施例中，光學膜300a、300b的第一集光結構320 與第二擴散結構350相對應，且第一擴散結構33〇與第二集光 結構340相，應。此外，每一第一集光結構32〇包括至少一稜 鏡柱^22 ’每一第二集光結構340包括至少-稜鏡柱342，而 在此是以，個棱鏡柱為例，但本發明並不限定每一第一集光結 構320或，：第二集光結構34〇的稜鏡柱的數量。稜鏡柱322、 342例t是三角柱’而稜鏡柱322、342的長軸例如是垂直於 所述預定方向。亦即，光學膜·日的棱鏡柱S22、342之長轴 垂直於X軸，而光學臈300b的棱鏡柱322、342之長軸垂直 於γ軸。但本發明並不限定複鏡柱322、342的長轴需於 所述預定方向。另外’每—第一集光結構32() 来 ，，沿著垂直人光面312與出光面314之方向（Hi 的局度例如是介於1微米至5(U絲，但不此為限。 201248213 承上述，每一第一擴散結構330與每一第二擴散結構35〇 例如分別為霧化層，第一擴散結構33〇的霧度例如是介於5% 〜60% ’而第二擴散結構350的霧度例如是介於5%〜9〇%。 在一實施例中，第一擴散結構33〇的霧度例如是小於第二擴散 結構350的霧度。此外，本實施例之霧化層内例如設有多個擴 散粒子301 ’以藉由擴散粒子3〇1的分佈密度來調整霧化層的 霧度。另外，霧化層的厚度例如是介於丨微米至微米，但 不此為限》 在本實施例之光學膜300a/300b中，因基材31〇的出光面 314 s又有第一擴散結構32〇與第一集光結構33〇，入光面 設有第二擴散結構34〇與第二絲結構別，且第—集光結構 320與第二擴散結構35G相對應，第一擴散結構別與第二集 光、t構340相對應，所以每一片光學膜3〇〇a、3娜同時具有 對光線進行擴散及減的作用^具體而言，如圖2所示，傳遞 至光干臈300a之第二擴散結構35〇的光線223會因擴散粒子 301,的作用而產生折射及散射，而通過第二擴散結構 350的部 刀:、’’ 223會通過第一集光結構33〇。當光線從第一集光 、’33G出射時’第一集光結構330會使光線223,的務I备唐201248213 VI. Description of the Invention: [Technical Field] The present invention relates to a light source device, and more particularly to a backlight module and an optical film thereof. [Prior Art] The liquid crystal display includes a liquid crystal display panel and a backlight module. Since the liquid crystal display panel itself does not emit light, it is necessary to provide a display light source required for the liquid crystal display panel by the backlight module. FIG. 1 is a schematic diagram of a conventional backlight module. Referring to FIG. 1 , the conventional backlight module 100 includes a light source 110 and a light guide plate 120 . The light source is disposed beside the light incident surface 122 of the light guide plate 120 to provide light to the light guide plate 12 , and the light guide plate 120 is used to light the light. It is converted into a surface light source that is emitted from the light exit surface 124. In addition, in order to improve the uniformity of the surface light source, a plurality of optical films may be disposed on the light-emitting surface 124 of the light guide plate 12, and the optical films are stacked upward from the light-emitting surface direction, and sequentially include the lower diffusion sheet 130, the lower jaw piece 140, and the upper surface. The cymbal 150 and the upper diffusion sheet 160. The lower diffusion sheet first diffuses the surface light source, and then sequentially collects the light source by the lower cymbal sheet 140 and the upper cymbal sheet 15 , opposite surface light source, and then adjusts the light path by the upper diffusion sheet 160 to achieve a uniform surface light source. the goal of. However, the excessive number of optical films used in the prior art not only causes the thickness of the backlight module 100 to be thicker and heavier, but also takes a lot of time to assemble the optical film, resulting in poor production efficiency of the backlight module 100. In addition, assembly tolerances are apt to create assembly tolerances, and excessive optical film can result in assembly tolerances that can cause significant adverse effects on the quality of the surface light source. 3 201248213 The present invention provides an optical cymbal that can be applied to a backlight module to reduce the number of optical films of the backlight module. The present invention further provides a backlight module, which has better production efficiency. The invention has an advantage that the thickness is thin, the weight is light, and the quality of the surface light source is better. The invention provides an optical film, comprising a substrate, a plurality of first light collecting structures, a plurality of first diffusion structures, a plurality of second light collecting structures, and a plurality of second diffusion structures: the substrate has opposite light-emitting surfaces and light-incident surfaces, and the first light-concentrating structure and the first diffusion structure are alternately arranged on the light-emitting surface along a predetermined direction. The second light-concentrating structure and the second diffusion structure are along The predetermined direction is alternately arranged on the light incident surface. In one embodiment of the present invention, each of the first light collecting structures and each of the second light collecting structures includes at least one mast, and the masts are The long axis is perpendicular to the predetermined direction. In an embodiment of the invention, the prism column is a triangular column or a semi-cylindrical. In one embodiment of the invention, the above-mentioned mast has a direction along the long axis. The recesses are formed to form two top surfaces on both sides of the recess and two bottom surfaces in the recesses, and the top surface is a convex curved surface, and the bottom surface is a concave curved surface. In one embodiment of the present invention, the top surface of each of the top surfaces is The height difference from the bottom end of the bottom surface is between 1 micrometer and 30 micrometers, and the distance between the top end and the bottom end in the pre-a direction is greater than 1 micrometer. In one embodiment of the invention, each of the first light collections described above The height of the structure and the first light collecting structure along the direction perpendicular to the light incident surface and the light exit surface is from 8 micrometers to 50 micrometers. 1 ί 1 ^ In one embodiment of the invention, each of the first diffusion structures and each of the above The second diffusion structure is an atomization layer, and the thickness of the atomization layer is from 丨^m to 201248213 30 micrometers. In one embodiment of the present invention, each of the second diffusion structures is a dew household, respectively A sister ', ° -, mother - 60%, ^ 2 secret θ first - diffusion structure between S% ~ 60 / 6 and the second diffusion structure of haze between 5% ~ 90%. In the present invention In one embodiment, each of the first diffusion structures: the diffusion structures are respectively an atomization layer, and the fog A plurality of expansions are disposed in the layer: In an embodiment of the invention, each of the two diffusion structures is an atomization layer, and the atomization layer comprises two dielectric layers stacked on each other. The second dielectric layer having a rate greater than the second ", ς,,, ° is located between the first dielectric layer and the substrate. Expansion In the embodiment of the present invention, the difference in refractive index of the first dielectric layer is G.G5. a, the rate of incidence is the same as the area of the bottom surface of a first-diffusion structure in the first plane, and the area of the bottom surface of each contact of the second diffusion structure is the same. In the x ^ 霄 addition example, the first 隹 output corresponds to the structure, the first diffusion structure and the second concentrating structure phase; the bottom surface of the second diffusion structure is in the human light _ positive projection f 彡 and the first, :. The first set of light overlaps, and the bottom surface of the first diffusing structure completely overlaps the bottom surface of the human light surface 'the bottom surface of the two sides completely. In another embodiment of the present invention, the first embodiment of the present invention, the first diffusion structure, the first diffusion structure and the second light collection; the second diffusion 5 201248213 further provides a backlight module. Including optical plate, light source, two pieces of the above-mentioned film. The light source is placed next to the optical plate to provide light to the optical plate. The optical film is stacked in the light-emitting direction of the optical plate, and a predetermined direction of one of the optical films is perpendicular to a predetermined direction of the other optical film. In the backlight module and the optical film of the present invention, since the light-incident surface and the light-emitting surface of the substrate are provided with a diffusion structure and a light collecting structure, the light is diffused and collected. In other words, an optical film of the present invention can replace a piece of diffusion sheet and a piece of film used in the prior art. Therefore, the backlight module of the present invention only needs to use two optical films to make the quality of the surface light source meet the demand, so Improve production efficiency. The above and other objects, features, and advantages of the present invention will become more apparent. 2 is a schematic view of a backlight module according to an embodiment of the present invention, and FIG. 3 is a perspective view of two optical films of FIG. Referring to FIG. 2 and FIG. 3, the backlight module 200 of the embodiment includes an optical plate 21, a light source 220, and two optical films 300a and 300b. The light source 220 is disposed beside the optical plate 21 to provide light 222 to the optical plate 210, and the optical films 300a, 3〇〇b are stacked in the light outgoing direction of the optical plate 21A. The backlight module 2 of the present embodiment is, for example, a side-lit backlight module, so that the light guide plate is used as the optical plate 21〇. The optical plate 21 转换 can convert the light provided by the light source 220 into a surface light source that is emitted from the light exit surface 212 , and the bottom surface 214 of the optical plate 210 can be provided with a reflective sheet 23 反射 to reflect the light 222 entering the optical plate 21 至 to The light exiting surface 212 further enhances light utilization. Further, in the embodiment of the direct type backlight module, a diffusion plate may be selected as the optical plate. The optical films 300a and 300b include a substrate 31A, a plurality of first light-collecting junctions 201248213, a plurality of first diffusion structures 330, a plurality of second light-concentrating structures 340, and a plurality of second diffusion structures 350. The substrate 310 has opposite light-incident surfaces 312 and light-emitting surfaces 314. The first light-collecting structure 320 and the first diffusion structure 330 are alternately arranged in the predetermined direction on the light-emitting surface 314, and the second light-concentrating structure 340 and the second diffusion structure 350. The light incident surface 312 is alternately arranged along the predetermined direction. In the present embodiment, the optical film 300a is different from the predetermined direction of the optical film 300b, wherein the predetermined direction of the optical film 300a is, for example, the X-axis, and the predetermined direction of the optical film 300b is, for example, the Y-axis perpendicular to the X-axis. In other words, the first light collecting structure 32〇 of the optical film 3〇〇a and the first diffusing structure 330 are alternately arranged along the X axis, and the second light collecting structure 340 and the second diffusing structure 35〇 of the optical film 300a are also along the X axis. Alternately arranged. The first light collecting structure 320 of the optical film 3〇〇b and the first diffusing structure 330 are alternately arranged along the Y axis, and the second light collecting structure 34〇 and the second diffusing structure 35〇 of the optical film 300b are also alternately arranged along the Y axis. . * In the present embodiment, the first light collecting structure 320 of the optical films 300a, 300b corresponds to the second diffusing structure 350, and the first diffusing structure 33'' is in contact with the second light collecting structure 340. In addition, each of the first light collecting structures 32A includes at least one column 22' each of the second light collecting structures 340 includes at least a mast 342, and here, a prism column is taken as an example, but The invention does not limit the number of masts of each of the first light collecting structures 320 or the second light collecting structures 34A. The masts 322, 342 are t-pillars and the long axes of the masts 322, 342 are, for example, perpendicular to the predetermined direction. That is, the long axes of the prism columns S22, 342 of the optical film day are perpendicular to the X axis, and the long axes of the prism columns 322, 342 of the optical disk 300b are perpendicular to the γ axis. However, the present invention does not limit the long axis of the mirror columns 322, 342 to be in the predetermined direction. In addition, each of the first light collecting structures 32 (), along the direction of the vertical human light surface 312 and the light emitting surface 314 (Hi's degree is, for example, between 1 micrometer and 5 (U wire, but not limited thereto) According to the above, each of the first diffusion structure 330 and each of the second diffusion structures 35 〇 is, for example, an atomization layer, respectively, and the haze of the first diffusion structure 33 例如 is, for example, 5% to 60% 'and the second The haze of the diffusion structure 350 is, for example, 5% to 9 %. In an embodiment, the haze of the first diffusion structure 33 is, for example, smaller than the haze of the second diffusion structure 350. Further, the embodiment The atomization layer is provided with, for example, a plurality of diffusion particles 301 ′ to adjust the haze of the atomization layer by the distribution density of the diffusion particles 3 〇 1 . Further, the thickness of the atomization layer is, for example, 丨 micrometers to micrometers, but In the optical film 300a/300b of the present embodiment, the light-emitting surface 314 s of the substrate 31 has a first diffusion structure 32 〇 and a first light-concentrating structure 33 〇, and the light-incident surface is provided with a first surface. The second diffusion structure 34 is different from the second filament structure, and the first light collection structure 320 corresponds to the second diffusion structure 35G, and the first diffusion structure Don't correspond to the second set of light and t structure 340, so each piece of optical film 3〇〇a, 3na has the function of diffusing and reducing light. Specifically, as shown in Figure 2, it is transmitted to the light. The light 223 of the second diffusion structure 35〇 of the 臈300a is refracted and scattered by the action of the diffusion particles 301, and the knives passing through the second diffusion structure 350: ''223 will pass through the first light collection structure 33〇 When the light is emitted from the first set of light, '33G', the first light-collecting structure 330 will cause the light 223,
關π干腸川㈨之對光線進行擴 之對光線進行擴散及集光的機制與光學膜300aThe mechanism of diffusing and collecting light by expanding the light of π dry sausage (9) and the optical film 300a
201248213 棱鏡片。具體而言，本實施例使用光學膜300a來取代圖1 下擴散片130及下稜鏡片140,並使用光學膜3〇%來取代圖1 之上棱鏡片150及擴散片.160。因此，本實施例之背光模組3〇〇 僅需使用兩片光學膜300a、300b即可使面光源的品質達到圖 1之旁光模組100的面光源品質。相較於習知技術，本實施例 之背光模組300使用光學膜的數量較少，所以可降低整體厚度 及重量。此外，由於本實施例使用較少的光學膜，因此能提^ 责光模組300的組裝效率以降低生產成本，並減少組裝公差的 累積以提升面光源的品質。 ' 為了使光學膜300a、300b達到較佳的功效，可限制每一 第一擴散結構330與每一第一集光結構32〇在出光面314的^ 佈面積之比例，並限制每一第二擴散結構35〇與每一第二集i 結構34G在入光面312的分佈面積之比例^在—較佳實施々 中’第一集光結構320與第二擴散結構35〇相對應 結=30與第二集光結構相對應。每—第—擴散結構抑 3^314接觸的底面331面積例如與每一第一集光結相 320之與出光面314接觸的底自切面積相同而每 散=350之與入光面312接觸的底面351面積例如與每一第 -集先結構34G之與入光面312接觸的底面3 言之，第-集光結構32〇 :相门換 與第二擴散結構350的底面351 的正投影恰 之底面如;m疊，第一擴散結構330 面34卜入曹A ^ μ的正投影恰與第二集光結構340之底 "BOOM； 300a 笛一隹，k 集先、、，°構集光並被擴散結構擴散。 三紐外Γ、:"構332()與第二集光結構340之稜鏡柱除了可為 一，柯以是其他形狀，以下將縣兩個不_鏡柱的 201248213 ，施例，但其並非用以限定本發明之稜鏡柱的形狀。在圖4所 示的實施例中，稜鏡柱322’、342,為半圓柱。在圖5所示的另 實施例中，第集光結構320’例如包括一個稜鏡柱，但本發 月並不限疋第一集光結構之稜鏡柱的數量。此棱鏡柱具有沿棱 鏡柱之長軸之方向延伸的凹陷323，以形成位於凹陷323兩側 的二頂面324以及位於凹陷323内的底面325，且頂面324為 凸曲面，而底面325為凹曲面。每一頂面324之頂端與底面 325之底端的咼度差D1例如介於！微米至3〇微米，而頂端與 底端沿所述預定方向的間距D2例如大於1微米。此外，第^ 集光結構340,的形狀例如是與第一集光結構32〇,的形狀相同。 、需注意的是’雖然上述第一集光結構與第二集光結構都是 以至少-個稜鏡柱為例，但在其他實施例中，每一稜鏡柱亦可 由沿直線排列的多個椎狀體取代。此外，雖然上述實施例中， 霧，層是利用設置擴散粒子來達到霧化的效果，但本發明並不 限疋霧化層的結構。以圖6所示的光學膜為例，其第 構330,為霧化層，且包括互相堆叠的第一介質層與第二介 質層334’其中第-介質層332位於第二介質層334與基材⑽ 之間。第-介質層332的折射率大於第二介質層334的 率’且第-介質層332與第二介質層334的接觸面如呈不規 則狀。第二擴散結構350,亦為霧化層，且包括互相堆疊的 =層352與第二介質層354,其中第二介質層说位於 負層352與基材310之間。第一介質層352的折射率大於第 :=r射率’且第-介質層352與第二介= 的接觸面353呈不規則狀。 伏：呈不的接觸面333、353為具有高低起 伙的不規則表面，且因互相連接的兩介質層的折射率不同，所 201248213 以光線可在接觸面333、353產生不同角度的折射 此可達到擴散光線的目的。在本實中 ：用肋如 如、狗雜《心峨332、㈣=；整=面 率之差值等方式來調整霧化層的霧度。在―較 佳實知例中，第—介質層332、352的折射率與第二介 334、354的折射率的差值例如為〇 〇5。 均 綜上所述’在本發明的背光模組及光學膜中，因基材的入 光面與出絲皆設有擴散結構與集光結構，所以具有對光線進 行擴散及钱的作用，故本發_ — #光學射f知技術的一 片擴散片及-片稜鏡片。如此’本發明之背光模組僅需使用兩 2光學膜即可使面光源的品質符合需求，因此具有厚度薄、重 里輕及生產效率佳的優點，而且還可減少組裝公差的累積以 提升面光源的品質。 雖然本發明已以較佳實施例揭露如上’然其並非用以限定 本發明，任何熟習此技藝者，在不脫離本發明之精神和範圍 内，當可作些許之更動與潤飾，因此本發明之保護範圍當視後 附之申請專利範圍所界定者為準。 【圖式簡單說明】 圖1是習知一種背光模組的示意圖。 圖2是本發明一實施例之背光模組的示意圖。 圖3是圖2中兩片光學膜的立體示意圖。 圖4是本發明另一實施例之光學膜的剖面示意圖。 圖5是本發明另一實施例之光學膜的剖面示意圖。 圖6是本發明另一實施例之光學膜的剖面示意圖。 201248213 【主要元件符號說明】 100、200 :背光模組 110、220 :光源 120 :導光板 122 :入光面 124、212 :出光面 130 :下擴散片 140 :下棱鏡片 150 :上棱鏡片 160 :上擴散片 210 :光學板 214、321、33卜 341、351、325 :底面 222、223、224 :光線 230 :反射片 300a、300b :光學膜 301 :擴散粒子 310 :基材 312 :入光面 314 :出光面 320、320’ ：第一集光結構 322、322’、342、342’ ：稜鏡柱 323 :凹陷 324 :頂面 330、330’ ：第一擴散結構 332、 352 :第一介質層 333、 353 :接觸面 12 201248213 334、354 :第二介質層 340、340’ ：第二集光結構 350 :第二擴散結構 D1 :高度差 D2 :間距 13201248213 Prism film. Specifically, the present embodiment uses the optical film 300a instead of the lower diffusion sheet 130 and the lower gusset 140 of FIG. 1, and replaces the prism sheet 150 and the diffusion sheet 160 with the optical film 〇%. Therefore, the backlight module 3 of the embodiment only needs to use two optical films 300a and 300b to achieve the quality of the surface light source of the light source module 100 of FIG. Compared with the prior art, the backlight module 300 of the present embodiment uses a small number of optical films, so that the overall thickness and weight can be reduced. In addition, since this embodiment uses less optical film, the assembly efficiency of the optical module 300 can be improved to reduce the production cost, and the accumulation of assembly tolerances can be reduced to improve the quality of the surface light source. In order to achieve better efficacy of the optical films 300a, 300b, the ratio of the area of each of the first diffusion structures 330 to each of the first light collecting structures 32 on the light-emitting surface 314 can be limited, and each second is limited. The ratio of the diffusion structure 35〇 to the distribution area of each second episode i structure 34G on the light incident surface 312 is in the preferred embodiment ' the first light collection structure 320 corresponds to the second diffusion structure 35 结 = 30 Corresponding to the second light collecting structure. The area of the bottom surface 331 of each of the first diffusion structures is, for example, the same as the bottom self-cutting area of each of the first light collection phases 320 that is in contact with the light exit surface 314, and is in contact with the light incident surface 312 per dispersion = 350. The bottom surface 351 is, for example, the bottom surface of each of the first-collector structures 34G that is in contact with the light-incident surface 312. The first-light-collecting structure 32: the front projection of the phase-changing and the bottom surface 351 of the second diffusion structure 350 Just like the bottom surface; m stack, the first diffusing structure 330 surface 34 into the Cao A ^ μ orthographic projection just below the bottom of the second light collecting structure 340 "BOOM; 300a flute, k set first,,, ° The light is collected and diffused by the diffusion structure. The three-outer Γ, : " 332 () and the second set of light structure 340 in addition to the column can be one, Ke Yi is other shapes, the following will be two county _ mirror column 201248213, the case, but It is not intended to define the shape of the mast of the present invention. In the embodiment illustrated in Figure 4, the masts 322', 342 are semi-cylindrical. In another embodiment shown in Fig. 5, the first set of light structures 320' includes, for example, a mast, but the present month is not limited to the number of masts of the first light collecting structure. The prism column has a recess 323 extending in the direction of the long axis of the prism column to form two top surfaces 324 on both sides of the recess 323 and a bottom surface 325 in the recess 323, and the top surface 324 is a convex curved surface, and the bottom surface 325 is Concave surface. The difference D1 between the top end of each top surface 324 and the bottom end of the bottom surface 325 is, for example, between! The micron is 3 to 3 micrometers, and the distance D2 between the top end and the bottom end in the predetermined direction is, for example, greater than 1 micrometer. Further, the shape of the first light collecting structure 340 is, for example, the same as that of the first light collecting structure 32A. It should be noted that although the first light collecting structure and the second light collecting structure are both exemplified by at least one mast, in other embodiments, each mast may also be arranged in a straight line. Replacement of the vertebrae. Further, in the above embodiment, the mist, the layer is formed by using the diffusion particles to achieve atomization, but the present invention is not limited to the structure of the atomization layer. Taking the optical film shown in FIG. 6 as an example, the first structure 330 is an atomization layer, and includes a first dielectric layer and a second dielectric layer 334' stacked on each other, wherein the first dielectric layer 332 is located in the second dielectric layer 334. Between the substrates (10). The refractive index of the first dielectric layer 332 is greater than the rate of the second dielectric layer 334 and the contact faces of the first dielectric layer 332 and the second dielectric layer 334 are irregular. The second diffusion structure 350 is also an atomization layer and includes a layer 352 and a second dielectric layer 354 stacked on each other, wherein the second dielectric layer is located between the negative layer 352 and the substrate 310. The refractive index of the first dielectric layer 352 is greater than the :=r radiance' and the contact surface 353 of the first dielectric layer 352 and the second dielectric layer is irregular. Volt: the contact faces 333, 353 are irregular surfaces with high and low framing, and due to the different refractive indices of the two dielectric layers connected to each other, the 201248213 ray can be refracted at different angles on the contact faces 333, 353. The purpose of diffusing light can be achieved. In the present embodiment, the haze of the atomized layer is adjusted by means of ribs such as the dog's "heart 332, (four) =; whole = face value difference). In the preferred embodiment, the difference between the refractive indices of the first dielectric layers 332, 352 and the refractive indices of the second dielectrics 334, 354 is, for example, 〇 〇 5. In the backlight module and the optical film of the present invention, since the light-incident surface and the light-emitting surface of the substrate are provided with a diffusion structure and a light collecting structure, the light diffuses and the money acts, so The present invention _ — #光射f knows a piece of diffusion film and a piece of film. Thus, the backlight module of the present invention only needs to use two optical films to make the quality of the surface light source meet the requirements, and therefore has the advantages of thin thickness, light weight, light weight and good production efficiency, and can also reduce the accumulation of assembly tolerances to enhance the surface. The quality of the light source. Although the present invention has been described in its preferred embodiments, the present invention is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a conventional backlight module. 2 is a schematic diagram of a backlight module according to an embodiment of the invention. Figure 3 is a perspective view of the two optical films of Figure 2. 4 is a schematic cross-sectional view showing an optical film according to another embodiment of the present invention. Figure 5 is a cross-sectional view showing an optical film according to another embodiment of the present invention. Figure 6 is a cross-sectional view showing an optical film according to another embodiment of the present invention. 201248213 [Description of main component symbols] 100, 200: backlight module 110, 220: light source 120: light guide plate 122: light-incident surface 124, 212: light-emitting surface 130: lower diffusion sheet 140: lower prism sheet 150: upper prism sheet 160 Upper diffuser 210: optical plates 214, 321, 33, 341, 351, 325: bottom surfaces 222, 223, 224: light 230: reflective sheets 300a, 300b: optical film 301: diffusing particles 310: substrate 312: light Face 314: light exiting surface 320, 320': first light collecting structure 322, 322', 342, 342': mast 323: recess 324: top surface 330, 330': first diffusing structure 332, 352: first Dielectric layer 333, 353: contact surface 12 201248213 334, 354: second dielectric layer 340, 340': second light collecting structure 350: second diffusion structure D1: height difference D2: spacing 13