1358579 17736twf.doc/r 九、發明說明： 【發明所屬之技術領域】 本發明是有關於一種背光模組，且特別是有關於一種 可以應用於背光模組中之混光裝置。 【先前技術】 . 現今社會多媒體技術相當發達，其多半受惠於半導體 .· 元件或顯示裝置的進步。就顯示器而言，具有高書質、空 間利用效率佳、低消耗功率、無輻射等優越特性之液晶顯 示器（Liquid crystal display)已逐漸成為市場之主流。 液晶顯示面板本身並不具有發光的功能，故在液晶顯 示面板下方必須配置一背光模組’以提供一面光源至液晶 顯示面板。由於發光二極體(Light Emitting Diode，LED) 具有亮度高、功率消耗低、使用壽命長、熱問題輕微等優 勢’因此目前發光二極體陣列已被廣泛地使用在背光模組 中。 圖1為習知之背光模組的剖面示意圖，而圖2A及圖 2B分別側邊發光型發光二極體之發光光形示意圖。請先參 .考圖1與圖2A，以直下式之背光模組ι1〇來說，其多半是 採用圖2A所示之側邊發光型發光二極體100 (Side ' EmittinS TyPe LED)作為發光源，且此側邊發光型發光二 . 極體100可透過本身封裝結構之透鏡部（Lens)(未繪 示）’而將點光源轉換為平面擴散之光源。也就是說，此 側邊發光型發光二極體1〇〇所發出之光線大部分集中於兩 侧之區域A1。 在背光模組110中，側邊發光型發光二極體1〇〇所組 1358579 17736twf.doc/r 成之陣列上方尚配置有一擴散板（Diffusion plate) 120。 在點亮背光模組110時’由不同位置之側邊發光型發光二 極體100所發出的光線在混光之後會經由擴散板丨2〇出 射，因而形成亮度均勻的面光源。 值得留意的是’若是擴散板120與側邊發光型發光二 極體100間的距離過小，則會導致背光模組所提俣之光線 會有混光不均勻的現象。為了使這些側邊發光型發光二極 體100所發出之光線有足夠的距離進行混光，目前的作法 是加大擴散板與側邊發光型發光二極體1〇〇之間的距離。 然而，這樣會使背光模組之整體厚度增加，因而與現今背 光模組輕薄的設計趨勢不符。1358579 17736twf.doc/r IX. Description of the Invention: [Technical Field] The present invention relates to a backlight module, and more particularly to a light mixing device that can be applied to a backlight module. [Prior Art] Today's social multimedia technology is quite developed, and most of them benefit from the advancement of semiconductors or components or display devices. As far as the display is concerned, a liquid crystal display having superior characteristics such as high book quality, good space utilization efficiency, low power consumption, and no radiation has gradually become the mainstream of the market. The liquid crystal display panel itself does not have the function of emitting light, so a backlight module ' must be disposed under the liquid crystal display panel to provide a light source to the liquid crystal display panel. Light Emitting Diodes (LEDs) have been widely used in backlight modules because of their high brightness, low power consumption, long life, and slight thermal problems. 1 is a schematic cross-sectional view of a conventional backlight module, and FIGS. 2A and 2B are schematic diagrams of light-emitting patterns of side-emitting light-emitting diodes, respectively. Please refer to Figure 1 and Figure 2A first. In the case of the direct-lit backlight module ι1〇, most of them use the side-emitting LED 100 (Side 'EmittinS TyPe LED) shown in Figure 2A as the light. The source and the side-emitting type light-emitting diodes 2. The pole body 100 can convert the point source into a plane-diffusing light source through a lens portion (not shown) of the package structure. That is to say, the light emitted by the side-emitting light-emitting diodes 1 大部分 is mostly concentrated in the area A1 on both sides. In the backlight module 110, a diffusion plate 120 is disposed above the array of the side-emitting light-emitting diodes 1358579 17736twf.doc/r. When the backlight module 110 is lit, light emitted by the side-emitting light-emitting diodes 100 at different positions is emitted through the diffusion plate 丨2 after being mixed, thereby forming a surface light source having uniform brightness. It is worth noting that if the distance between the diffuser 120 and the side-emitting LEDs 100 is too small, the light that is raised by the backlight module may be unevenly mixed. In order to make the light emitted by the side-emitting light-emitting diodes 100 have a sufficient distance for light mixing, the current practice is to increase the distance between the diffusion plate and the side-emitting light-emitting diodes 1〇〇. However, this will increase the overall thickness of the backlight module, which is inconsistent with the current thin design trend of the backlight module.
請同時參考圖1與圖2B，在背光模組110中，側邊 發，型發光二極體1〇〇所組成之陣列的邊緣處極有可能發 生混色不均的現象。由於紅色側邊發光型發光二極體 10〇R^藍色側邊發光型發光二極體10〇B與綠色側邊發光 型發光二極體1〇〇G之間分別相隔—間距，且各個側邊發 光型發光二極體（10011、100(}與1〇〇8)之照射範圍有限二 因此僅有鄰近邊緣處的綠色側邊發光型發光二極體i〇〇g =發出之光線可以照射到區域A 2，導致區域A 2内之光線 ，光不均勻，而有明顯偏單色（綠色）的現象。由此可知、·， 習知背光 110無法提供混光均勻之錄，而其將導致 液晶顯示器之顯示品質下降。 、 【發明内容】 本發明之一目的是提供一種混光裝置’以解決習知之 6 1358579 17736twf.doc/r 背光模組所提供之光線混光不均勻的問題。 北本f明之另一目的是提供一種背光模組，以解決習知 之月光核組必須加大整體之厚度才能提升混光均勻性 題。 .為達上述或是其他目的，本發明提出一種混光裝置， . 具包括一底板、多個側壁、-反射結構與多個側邊發光型 . 發光二極體。其中，底板與側壁相連接，而各側壁具有一 内表面，且各個内表面彼此相對。上述之側邊發光型發光 •=極體配置於底板上，且反射結構配置於側壁之内表面上。 在本發明之一實施例所述之混光裝置中，上述之各側 壁之内表面具有-側擴散區，且反射結構是暴露出此側擴 散區。 在本發明之-實施例所述之混光裝置中，上述之側擴 散區可以在反射結構之上方。 在本發明之一實施例所述之混光装置中，上述之底板 具有一擴散面，而側邊發光型發光二極體可以配置於擴散 _ 面上。 在本發明之一實施例所述之混光裝置，更包括一上擴 散板，其配置於側壁上方。 在本發明之一實施例所述之混光裝置中， • 散板與側壁上緣相隔一間距。 κ 在本發明之一實施例所述之混光裝置中，上述之反射 結構包括多個微型反射元件。 在本發明之一實施例所述之混光裝置中，上述之微型 7 1358579 17736twf.d〇c/r 反射元件為多個微透鏡。 在本發明之一實施例所述之混光裝置中，上述之反射 結構包括楔形反射片。 在本發明之一實施例所述之混光裝置，更包括一透光 折射板，其配置於側壁之間，且透光折射板位於上述之側 邊發光型發光二極體上方，而側邊發光型發光二極體所發 出之一光線適於被反射結構反射至透光折射板上。 在本發明之一實施例所述之混光裝置中，上述之透光 折射板之材料例如為聚曱基丙烯酸曱醋。 在本發明之一實施例所述之混光裝置中，上述之各側 壁未與底板連接之上緣具有一削尖部。 在本發明之一實施例所述之混光裝置中，上述之側邊 發光型發光二極體包括紅光側邊發光型發光二極體、綠光 側邊發光型發光二極體、藍光側邊發光型發光二極體及其 組合其中之一。 本發明提出一種背光模組，其包括一外框與多個上述 之混光裝置。其中，混光裝置配置於該外框内。 在本發明之一實施例所述之背光模組中，上述之混光 裝置彼此相鄰，且陣列排列於外框内。 本發明之混光裝置之側壁上有反射結構，因此可將各 ，側邊發光型發光二極體所發出之光線在混光裝置内進行 多次地反射，以增加光線的混光均勻性。由此可知，使用 本發明之混光裝置的背光模組可以提供混光更為均勻之光 線0 1358579 17736tAvf.d〇c/r 為讓本發明之上述和其他目的、特徵和優點能更明顯 易懂’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】 • 本發明之混光裝置可以應用於液晶顯示器之背光模 . 組中’下文將列舉數個本發明混光裝置之實施例，之後再 • 進一步說明如何以本發明之混光裝置組成背光模組。 第一實施例 • 圖3繪示為本發明第一實施例混光裝置之剖面示意 圖。請參考圖3,本發明之混光裝置200包括一底板21〇、 多個側壁212、一反射結構220與多個側邊發光型發光二 極體230。其中’底板210與側壁212彼此相連接，且底 板210可以是與這些側壁212 —體成型。 值得留意的是，本發明之混光裝置200所採用的發光 源為側邊發光型發光二極體230,且其是配置於底板21〇 上。一般而言，底板210上例如是具有螺孔或貫孔（未繪 齡示），而側邊發光型發光二極體230則例如是嵌設於螺孔 或貫孔内。此側邊發光型發光二極體230可以是紅光側邊 發光型發光二極體、綠光側邊發光型發光二極體或藍光側 ' 邊發光型發光二極體。 _ 在全彩顯示技術中’混光裝置200可以同時採用紅光 側邊發光型發光二極體、綠光側邊發光型發光二極體與藍 光側邊發光型發光二極體，以達到顯示彩色晝面之目的。 由於不同顏色之側邊發光型發光二極體所發出色光的亮度 9 1358579 17736twf.doc/r 會不相同，因此依據整體混光裝置200之顯示亮度的需 要，可將不同種類之側邊發光型發光二極體以不同比例之 數目配置於底板210上，來達到不同的混光效果。當然， 熟習此技藝者可以依據實際需求來調整配置於底板21〇上 之側邊發光型發光二極體230之顏色以及數目，以混出所 . 需之顏色或亮度。 • 請繼續參照圖3，上述之各個側壁212具有一内表面 212a，且各個内表面212a彼此相對。值得留意的是，上述 • 之反射結構220配置於側壁212之内表面212a上；意即， 反射結構220位於側邊發光型發光二極體23〇之側向。由 於本發明之混光裝置200採用側邊發光型發光二極體23〇 作為發光源，因此其所發出之光線大多射向反射結構 220。如此一來，各個側邊發光型發光二極體23〇所發出之 光線（例如是光線L1與L2)可以在這些側壁212之間進 行多次反射，以達到混光均勻的效果。 _ :般而言，為了使混光裝置200所提供之光線能夠均 • 勻地混光，本實施例例如是在各個側壁212之内表面212& 上配置-擴散片（DiffusionPlate)，以定義出一側擴散區 • A以使側邊發光型發光二極體230所發出之光線照射到此 擴散片後，均勾擴散至混光裝置300外。當然，在其他實 例中本發明也可以直接對表面進行粗化處理，而在側 壁212之内表面212a上定義出側擴散區A，在此並不侷限 形成侧擴散區A之方式。 值得适思的疋，反射結構220會暴露出此側擴散區 1358579 17736twf.doc/r A’而此側擴散區A之較佳位置是在反射結構220之上方。 如此一來’當側邊發光型發光二極體230所發出之光線L1 與L2經由反射結構220而在側壁212之間反射多次後， 可以透過位於反射結構220上方之側擴散區A而散射，進 一步使光線由混光裝置200出射後更為均勻。當然，本發 明並無意侷限住側擴散區A與反射結構220之相對位置。 承上述’本發明也可以於底板210上配置擴散片或對 底板210之表面進行粗化處理，以定義出一擴散面b，而 側邊發光型發光二極體230可以配置於擴散面B上。此擴 散面B可以將側邊發光型發光二極體230往底板210發出 之光線均勻地散射’以提升側邊發光型發光二極體230所 發出光線之利用效率。另外，本發明之混光裝置2〇〇更可 配置一上擴散板C於侧壁212上方，以使光線L1與L2在 側壁212之間進行多次反射以及散射之後，由上擴散板c 出射。如此一來，即可進一步提升混光裝置2〇〇所發出光 線之均勻性。 本發明之混光裝置200是讓光線在混光裝置2〇〇内進 行多次的反射，以增加光線於混光裝置2〇〇内之行進路 徑’進而達到均勻混光的目的。因此’本發明之混光裝置 200可在不增加混光裝置200之整體厚度的前提下，提高 光線的混光均勻度。 此外，由圖3可清楚得知，本發明之混光裝置2〇〇在 結構上為對稱之設計。也就是說，侧邊發光型發光二極體 230可以配置於底板210之中心處，以使側邊發光型發光 17736twf.doc/r 二極體230所發出之光線（例如光線Ll與L2)能有對稱 的行進路徑。如此一來’混光敦置200所提供之整體光線 之免度能更為均勻。另外’為了符合背光模組輕薄的設計 趨勢’在實務上，混光裝置200之側壁212高度可以小於 底板210之寬度的〇.6倍。 第二貫施例 圖4繪示為本發明第二實施例之混光裝置示意圖。請 參考圖4 ’本實施例與第一實施例類似’其中兩者主要不 同之處在於：本實施例之混光裝置200a之反射結構220 為楔形反射片。此楔形反射片之鏡面222會與側壁212夾 一角度，光線L3會被此傾斜鏡面222多次反射，以增加 在混光裝置200a内之行進路徑，進而使混光裝置2〇〇a所 提供之光線具有較佳的均勻性。 圖5繪示為本發明第二實施例之另一混光裝置示意 圖。由圖5可清楚可知’本實施例之混光裝置2〇〇b之反射 結構220為多個微型反射元件。此微型反射元件可以由多 個微透鏡（Micro lens)所組成，其適於將光線（L4與L5) 反射回底板210之擴散面B後，再由擴散面B將光線（L4 與L5)反射至側擴散區a。這樣同樣可以使混光裝置2〇〇b 所提供之光線具有較佳的均勻性。 第三實施例 圖6繪示為本發明第三實施例之混光裝置示意圖。請 參考圖6 ’本實施例與第—實施例主要不同之處在於：本 啦明之混光裝置20〇c更包括一透光折射板D，其位於側壁 12 17736twf.doc/r 212之間以及側邊發光型發光二極體230上方，而此透光 折射板D為南折射率材料’其例如是以聚曱基丙稀酸甲酉旨 (polymethyl methacrylate，PMMA)所製成。由側邊發光 型發光二極體2 3 0所發出之光線（例如是光線l 6 )會在反 射結構220、透光折射板D與擴散面b之間反覆傳遞，最 後再由透光折射板13出射。 詳細來說’由於透光折射板D的折射率大於空氣之折 射率，因此側邊發光型發光二極體230所發出之部分光線 (例如是光線L6)入射透光折射板d的入射角大於全反 射角’則光線L6會在透光折射板D表面產生全反射，而 在反射結構220、透光折射板D與擴散面b之間反覆傳遞， 直到光線L6以小於全反射角的角度入射透光折射板D， 進而由透光折射板D出射。由此可知，在側邊發光型發光 一極體230上方配置透光折射板D可以增加光線在混光事 置200c内之行進路控’進而使混光裝置2〇〇c所提供之光 線具有較佳之均勻性。 第四實施例 圖7A繪示為本發明背光模組之局部剖面示意圖，而 圖7B繪示為本發明背光模組之立體示意圖。請同時參考 圖7A與圖7B ’本發明之背光模組3〇〇包括—外框31〇與 多個第一貫施例之混光農置200。其中，混光裝置2〇〇陣 列排列於外框310内（如圖7B所示）。當然，混光裝置 200也可以採用上述第二實施例之混光裝置2〇〇a、第三實 施例之混光裝置200b或第四實施例之混光裝置2〇〇c，在 1358579 17736twf.doc/r 此並不特別限定。 由於各個混光裝置雇可以各自提供混光均句的光 Μ ^會叉到其他鄰近之混光裝置2 ◦ 〇所發出之光線的 &主反。相較於習知技術，即使在背光模組 300尺寸較 大抓況下’也不會發生混光不均的現象。此外，本發明 混光裝置細可以各自發出混光均句的光線。因 具有較㊄的配置靈活度。隨著f光模組尺寸的改變， 衣造人員可以對應配置適當數量的混光裝置期 310中即可。 1 τι~ 值得留意的是，在本發明之背光模組3〇〇中 板c與側壁212之上緣可以相隔—間距G，而此= C可以固定於外框310上。這樣可以避免 板$ 側壁212太過接近而於交界處Η產生暗線。此外各個 側壁2U之上緣可以設計為—削尖部勘，以進 於交界處Η產生暗線之現象。 Κ 綜上所述，本發明之背光模組及其混 有下列優點： 罝主^具 -:本發明混光裝置之側壁上有反射結構，因此 各個側邊發光型發光二歸所糾之紐纽光 以將光線均勻地混光’且亀整體; 二、本發明之混光裝置可以提供均勻的光線， 使在背光模組之邊緣處也不會有光線不均勻的情況 此外，不論背光模組尺寸的大小，製作人配_當 17736twf.doc/r 數量之混光裝置於底板上即可，毋須因應背光模組尺寸大 小而重新調整侧邊發光型發光二極體的排列方式。因此， 本發明之混光裝置可以被靈活地配置與運用。 三、由於本發明之混光裝置在結構上為對稱之設計。 這會使側邊發光型發光二極體所發出之光線能有對稱的行 進路徑。因此，整體之混光裝置所提供之光線亮度會更為 均勻。 曰 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繪示為習知之背光模組剖面示意圖。 圖2A及圖2B分別繪示為側邊發光型發光二極體之 光光形示意圖。 x 圖3繪示為本發明第一實施例之混光裝置之剖面示音 圖。 〜 圖4繪不為本發明第二實施例之混光裝置示意圖。 圖5繪示為本發明第二實施例之另一混光裝置示意 圖。 二 圖6繪示為本發明第三實施例之混光裝置示意圖。 圖7A纷示為本發明背光模組之局部剖面示意圖。 圖7B繪示為本發明背光模組之局部示意圖。 【主要元件符號說明】 1358579 17736twf.doc/r 100、230 :側邊發光型發光二極體 100R :紅色側邊發光型發光二極體 100B :藍色側邊發光型發光二極體 100G :綠色側邊發光型發光二極體 110、300 :背光模組 120 :擴散板 200、200a、200b、200c :混光裝置 210 :底板 212 :側壁 212a :表面 212b :削尖部 220 :反射結構 222 :楔形反射片之鏡面 310 :外框 A:側擴散區 A1 :亮度較均勻之區域 A2 :混色不均勻之區域 B :擴散面 C:上擴散板 D:透光折射板 G :間距 Η .父界處 U、L2、L3、L4、L5、L6 :光線 16Referring to FIG. 1 and FIG. 2B simultaneously, in the backlight module 110, the edge of the array of the side-emitting and light-emitting diodes 1 is extremely likely to cause uneven color mixing. Since the red side-emitting type light-emitting diode 10〇R^blue side-emitting type light-emitting diode 10〇B and the green side-side light-emitting type light-emitting diode 1〇〇G are respectively separated by a space, and each The side-emitting light-emitting diodes (10011, 100(} and 1〇〇8) have a limited illumination range. Therefore, only the green side-emitting light-emitting diodes at the adjacent edges can emit light. Irradiation to the area A 2 causes the light in the area A 2 to be uneven, and the phenomenon is obviously monochromatic (green). It can be seen that the conventional backlight 110 cannot provide a uniform light mixing, and The display quality of the liquid crystal display is degraded. [Invention] It is an object of the present invention to provide a light mixing device to solve the problem of uneven light mixing caused by the conventional 6 1358579 17736twf.doc/r backlight module. Another purpose of the present invention is to provide a backlight module to solve the problem that the conventional moonlight core group must increase the overall thickness to enhance the uniformity of the light mixing. To achieve the above or other purposes, the present invention proposes a light mixing Device, . a bottom plate, a plurality of side walls, a reflective structure and a plurality of side-emitting types. The light-emitting diodes, wherein the bottom plate is connected to the side walls, and each side wall has an inner surface, and each inner surface faces each other. The illuminating type illuminating body is disposed on the bottom plate, and the reflecting structure is disposed on the inner surface of the side wall. In the light mixing device according to the embodiment of the invention, the inner surface of each of the side walls has a side diffusion. And the reflective structure is exposed to the side diffusion region. In the light mixing device of the embodiment of the present invention, the side diffusion region may be above the reflective structure. In the light mixing device, the bottom plate has a diffusion surface, and the side light-emitting LEDs can be disposed on the diffusion surface. The light mixing device according to an embodiment of the invention further includes an upper diffusion plate. In a light mixing device according to an embodiment of the present invention, the scattering plate is spaced apart from the upper edge of the sidewall by a distance. κ In the light mixing device according to an embodiment of the present invention, the above Counter The structure comprises a plurality of micro-reflective elements. In the light mixing device according to an embodiment of the invention, the micro 7 1358579 17736twf.d〇c/r reflective element is a plurality of microlenses. In an embodiment of the invention In the light mixing device, the reflective structure includes a wedge-shaped reflective sheet. The light mixing device according to an embodiment of the present invention further includes a light-transmitting refraction plate disposed between the sidewalls and transparently refracting The plate is located above the side-emitting light-emitting diodes, and one of the light emitted by the side-emitting LEDs is adapted to be reflected by the reflective structure onto the light-refractive refractive plate. In the light mixing device, the material of the above-mentioned light-transmitting and refracting plate is, for example, polyacrylic acid vinegar. In the light mixing device according to an embodiment of the present invention, each of the side walls is not connected to the upper edge of the bottom plate. A sharpened part. In a light mixing device according to an embodiment of the present invention, the side light emitting type light emitting diode includes a red side light emitting type light emitting diode, a green side light emitting type light emitting diode, and a blue light side. One of the edge-emitting type light-emitting diodes and a combination thereof. The invention provides a backlight module comprising an outer frame and a plurality of the above-mentioned light mixing devices. The light mixing device is disposed in the outer frame. In a backlight module according to an embodiment of the invention, the light mixing devices are adjacent to each other, and the array is arranged in the outer frame. The light mixing device of the present invention has a reflective structure on the side wall, so that the light emitted by each of the side-emitting light-emitting diodes can be reflected multiple times in the light mixing device to increase the light mixing uniformity of the light. It can be seen that the backlight module using the light mixing device of the present invention can provide light with more uniform light mixing. 0 1358579 17736tAvf.d〇c/r To make the above and other objects, features and advantages of the present invention more obvious. It is to be understood that the following detailed description of the preferred embodiments and the accompanying drawings are set forth below. [Embodiment] The light mixing device of the present invention can be applied to a backlight module of a liquid crystal display. In the following, a plurality of embodiments of the light mixing device of the present invention will be exemplified, and then, how to further explain how to use the light mixing device of the present invention Form a backlight module. First Embodiment Fig. 3 is a cross-sectional view showing a light mixing device according to a first embodiment of the present invention. Referring to FIG. 3, the light mixing device 200 of the present invention includes a bottom plate 21A, a plurality of side walls 212, a reflective structure 220, and a plurality of side-emitting light-emitting diodes 230. Wherein the bottom plate 210 and the side walls 212 are connected to each other, and the bottom plate 210 may be integrally formed with the side walls 212. It is to be noted that the light source used in the light mixing device 200 of the present invention is a side light emitting type LED 230, and is disposed on the bottom plate 21A. Generally, the bottom plate 210 has, for example, a screw hole or a through hole (not shown), and the side light-emitting LED 230 is embedded in a screw hole or a through hole, for example. The side-emitting light-emitting diode 230 may be a red-light side-emitting light-emitting diode, a green-side light-emitting light-emitting diode, or a blue-side 'edge light-emitting type light-emitting diode. _ In the full color display technology, the 'light mixing device 200 can simultaneously use the red side light emitting type LED, the green side emitting type light emitting diode and the blue side emitting type light emitting diode to achieve display The purpose of color kneading. Since the brightness of the color light emitted by the side-emitting LEDs of different colors is different, the brightness of the color light 9 1358579 17736twf.doc/r will be different, so different types of side-emitting types can be selected according to the display brightness of the overall light mixing device 200. The light-emitting diodes are disposed on the bottom plate 210 in different proportions to achieve different light mixing effects. Of course, those skilled in the art can adjust the color and the number of the side-emitting LEDs 230 disposed on the bottom plate 21〇 according to actual needs to mix the desired color or brightness. • With continued reference to Figure 3, each of the side walls 212 described above has an inner surface 212a and each inner surface 212a is opposite one another. It is to be noted that the above-mentioned reflective structure 220 is disposed on the inner surface 212a of the side wall 212; that is, the reflective structure 220 is located laterally of the side-emitting light-emitting diode 23A. Since the light mixing device 200 of the present invention employs the side-emitting type light-emitting diode 23 〇 as a light-emitting source, most of the light emitted therefrom is directed toward the reflective structure 220. In this way, the light emitted by each of the side-emitting light-emitting diodes 23 (e.g., the light beams L1 and L2) can be reflected multiple times between the side walls 212 to achieve a uniform light mixing effect. _ : In general, in order to enable the light provided by the light mixing device 200 to be uniformly mixed, the present embodiment is configured to define a diffusion plate on the inner surface 212 of the respective side walls 212 to define a diffusion plate (DiffusionPlate). The side diffusion region A is irradiated to the diffuser by the light emitted from the side light-emitting diode 230, and then diffused to the outside of the light mixing device 300. Of course, in other embodiments, the present invention can also directly roughen the surface, and the side diffusion region A is defined on the inner surface 212a of the side wall 212, and the manner in which the side diffusion region A is formed is not limited herein. It is worthwhile to think that the reflective structure 220 will expose the side diffusion region 1358579 17736twf.doc/r A' and the preferred location of the side diffusion region A is above the reflective structure 220. In this way, when the light rays L1 and L2 emitted by the side-emitting LEDs 230 are reflected between the sidewalls 212 a plurality of times via the reflective structure 220, they can be scattered through the side diffusion regions A located above the reflective structures 220. Further, the light is further uniformly emitted by the light mixing device 200. Of course, the present invention is not intended to limit the relative position of the side diffusion region A and the reflective structure 220. According to the above aspect, the diffusion sheet may be disposed on the bottom plate 210 or the surface of the bottom plate 210 may be roughened to define a diffusion surface b, and the side light-emitting LED 230 may be disposed on the diffusion surface B. . The diffusing surface B can uniformly scatter the light emitted from the side-emitting light-emitting diode 230 to the bottom plate 210 to improve the utilization efficiency of the light emitted from the side-emitting light-emitting diode 230. In addition, the light mixing device 2 of the present invention can further configure an upper diffusing plate C above the sidewall 212 to allow the light beams L1 and L2 to be reflected and scattered multiple times between the sidewalls 212, and then emitted by the upper diffusing plate c. . In this way, the uniformity of the light emitted by the light mixing device 2 can be further improved. The light mixing device 200 of the present invention allows light to be reflected a plurality of times in the light mixing device 2 to increase the traveling path of light in the light mixing device 2 to achieve uniform light mixing. Therefore, the light mixing device 200 of the present invention can improve the light mixing uniformity of light without increasing the overall thickness of the light mixing device 200. Further, as is clear from Fig. 3, the light mixing device 2 of the present invention is structurally symmetrical. In other words, the side-emitting LEDs 230 can be disposed at the center of the bottom plate 210 so that the light emitted by the side-emitting illumination 17736twf.doc/r diode 230 (eg, light L1 and L2) can There is a symmetrical path of travel. In this way, the overall light provided by the Mixed Light 200 is more uniform. In addition, in order to conform to the trend of thin design of the backlight module, in practice, the height of the side wall 212 of the light mixing device 200 can be less than 〇6 times the width of the bottom plate 210. Second Embodiment FIG. 4 is a schematic view of a light mixing device according to a second embodiment of the present invention. Referring to FIG. 4, the present embodiment is similar to the first embodiment, wherein the two main differences are that the reflective structure 220 of the light mixing device 200a of the present embodiment is a wedge-shaped reflective sheet. The mirror surface 222 of the wedge-shaped reflection sheet is at an angle with the side wall 212, and the light beam L3 is reflected by the inclined mirror surface 222 multiple times to increase the traveling path in the light mixing device 200a, thereby providing the light mixing device 2A. The light has a better uniformity. Fig. 5 is a schematic view showing another light mixing device according to a second embodiment of the present invention. As is clear from Fig. 5, the reflection structure 220 of the light mixing device 2〇〇b of the present embodiment is a plurality of micro-reflective elements. The micro-reflective element may be composed of a plurality of microlenses adapted to reflect light (L4 and L5) back to the diffusing surface B of the bottom plate 210, and then reflect the light (L4 and L5) by the diffusing surface B. To the side diffusion zone a. This also allows the light provided by the light mixing device 2〇〇b to have better uniformity. Third Embodiment FIG. 6 is a schematic view showing a light mixing device according to a third embodiment of the present invention. Please refer to FIG. 6 'The main difference between this embodiment and the first embodiment is that the light mixing device 20〇c of the present invention further includes a light-transmitting refractive plate D located between the side walls 12 17736twf.doc/r 212 and The light-emitting refracting plate D is a south refractive index material, which is made of, for example, polymethyl methacrylate (PMMA). The light emitted by the side-emitting light-emitting diode 203 (for example, the light ray 16) is repeatedly transmitted between the reflective structure 220, the light-transmitting refracting plate D and the diffusing surface b, and finally by the light-transmitting refracting plate. 13 out. In detail, since the refractive index of the light-transmitting refractive plate D is greater than the refractive index of the air, the incident angle of a part of the light emitted by the side-emitting light-emitting diode 230 (for example, the light L6) incident on the light-transmitting refractive plate d is greater than The total reflection angle 'the light L6 will produce total reflection on the surface of the light-transmitting refracting plate D, and will be repeatedly transmitted between the reflective structure 220, the light-transmitting refracting plate D and the diffusion surface b until the light ray L6 is incident at an angle smaller than the total reflection angle. The light-transmitting refracting plate D is further emitted by the light-transmitting refracting plate D. Therefore, it can be seen that arranging the light-transmitting refracting plate D above the side-emitting light-emitting body 230 can increase the traveling path of the light in the light-mixing device 200c, and thus the light provided by the light-mixing device 2〇〇c has Better uniformity. 4A is a partial cross-sectional view of a backlight module of the present invention, and FIG. 7B is a perspective view of a backlight module of the present invention. Referring to FIG. 7A and FIG. 7B, the backlight module 3 of the present invention includes an outer frame 31A and a plurality of first light mixing farms 200. The array of light mixing devices 2 is arranged in the outer frame 310 (as shown in Fig. 7B). Of course, the light mixing device 200 can also adopt the light mixing device 2A of the second embodiment, the light mixing device 200b of the third embodiment, or the light mixing device 2〇〇c of the fourth embodiment, at 1358579 17736twf. Doc/r This is not particularly limited. Since each of the light mixing devices employs a light source that can provide a mixed light uniform, it will fork to the light of the light emitted by the other adjacent light mixing device 2 ◦ 主. Compared with the prior art, even when the backlight module 300 is in a large size, the phenomenon of uneven light mixing does not occur. Further, the light mixing device of the present invention can individually emit light of a mixed light. Because it has more than five configuration flexibility. As the size of the f-light module changes, the fabric manufacturer can configure an appropriate number of light mixing device periods 310. 1 τι~ It is worth noting that in the backlight module 3 of the present invention, the upper edge of the plate c and the side wall 212 may be spaced apart by a distance G, and this = C may be fixed to the outer frame 310. This avoids the panel $ sidewall 212 being too close and creating a dark line at the junction. In addition, the upper edge of each side wall 2U can be designed to be sharpened to create a dark line at the junction. In summary, the backlight module of the present invention and the following advantages are mixed: 罝 main tool-: the reflective structure on the side wall of the light mixing device of the present invention, so that each side of the light-emitting type illuminating New light to uniformly mix the light 'and the whole body; Second, the light mixing device of the present invention can provide uniform light, so that there is no uneven light at the edge of the backlight module. The size of the group size, the producer's _ when the 17736twf.doc/r number of light mixing devices can be on the bottom plate, no need to adjust the arrangement of the side-emitting light-emitting diodes according to the size of the backlight module. Therefore, the light mixing device of the present invention can be flexibly configured and utilized. Third, the light mixing device of the present invention is structurally symmetrical. This allows the light emitted by the side-emitting light-emitting diodes to have a symmetrical path of travel. Therefore, the brightness of the light provided by the overall light mixing device is more uniform. Although the present invention has been described above by way of a preferred embodiment, it is not intended to limit the invention, and it is obvious to those skilled in the art that the invention may be modified and retouched without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic cross-sectional view of a conventional backlight module. 2A and 2B are schematic diagrams showing the light-light shape of the side-emitting type light-emitting diodes, respectively. x Fig. 3 is a cross-sectional view showing a light mixing device according to a first embodiment of the present invention. ~ Figure 4 is a schematic view of a light mixing device not according to a second embodiment of the present invention. Fig. 5 is a schematic view showing another light mixing device according to a second embodiment of the present invention. FIG. 6 is a schematic diagram of a light mixing device according to a third embodiment of the present invention. FIG. 7A is a partial cross-sectional view showing the backlight module of the present invention. 7B is a partial schematic view of a backlight module of the present invention. [Description of main components] 1358579 17736twf.doc/r 100, 230: Side-emitting LEDs 100R: Red side-emitting LEDs 100B: Blue-side LEDs 100G: Green Side-emitting LEDs 110, 300: backlight module 120: diffusing plates 200, 200a, 200b, 200c: light mixing device 210: bottom plate 212: side wall 212a: surface 212b: sharpened portion 220: reflective structure 222: Mirror surface 310 of the wedge-shaped reflection sheet: outer frame A: side diffusion area A1: area of uniform brightness A2: area of uneven color mixture B: diffusion surface C: upper diffusion plate D: light-transmissive plate G: pitch Η. U, L2, L3, L4, L5, L6: Light 16