200925740 八、發明說明： - 【發明所屬之技術領域】 本發明是有關於一種發光二極體背光模組、其擴散片 及其製造方法’且特別是有關於一種具有螢光粉之擴散片 的發光二極體背光模組及其製造方法。 【先前技術】 於背光模組中’導光層（lightguide)的擴散片其功能為 ® 提供液晶顯示器一個均.勻的面_光源，一般的擴散片是在樹 脂基材中加入擴散劑使光線產生折射.、反射與散射來.造成 光學擴散的效果。 由於導光層的輝度均勻度必須仰賴.光源來控制，而目 前的背光模組色度區塊越來越小，需使用led來提供狹窄 的光源。然而’相較於使用傳統冷陰極燈管之背光模組， LED背光模組面板雖然具有超薄、高輝度、光源壽命長的 優點’但白光LED不但成本高，.發光效率較低，也需要比 © 冷陰極燈管更大的混色空間才能獲得均勻的面光源。 【發明内容】 因此本發明就是在提供一種發光二極體背光模組及 擴散片，產生色度集中度高的白光以提升背光模組出光的 均勻性。 根據本發明提出一種應用於發光二極體背光模組的 擴散片及其製造方法，於擴散片製造過程中添加螢光粉於 200925740 透明塑料中，形成具有螢光粉之擴散片。應用此擴散片之 發光二極體背光模組，可利用發光二極體激發螢光粉物 質’產生色度集中度高的白光。 依照上述可知本發明利用於擴散片製造過程中添加 螢光粉於透明塑料中，形成具有螢光粉之擴散片，配合適 當的光源（例如藍光發光二極體），可在藍光通過擴散片 時，激發螢光粉得到白光，藉由擴散片物料的改變，大幅 提昇背光模組出光均勻性，並提高白光的色度集中度。此 ® 外，使用藍光發光二極艎作為光源亦可降低背光模組光源 的成本。 【實施方式】 本發明實施例之擴散片製造方法包含提供一透明塑 料，並於透明塑料中添加擴散劑及一螢光粉（例如黃色螢光 粉），最後固化此透明塑料，以形成含有螢光粉之擴散片。 依照本發明之實施例，透明塑料之材料可包含聚碳酸醋， © 形成之擴散片可具有一出光面及入光面，螢光粉可均勻分 佈於透明塑料中，或分佈於靠近擴散片之出光面處。擴散 劑可包含三氧化二鋁。 請參照第1圖’為本發明一實施例之擴散片的示意 圖。擴散片100為一透明塑料所製成的片體，内含登光粉 110及擴散劑120,均勻地分佈於擴散片100之中。 參照第2圖’為本發明另一實施例之擴散片的示意 圖。擴散片200為一透明塑料所製成的片體，包含一本體， 200925740 本體具有一出光面202及一入光面204,擴散片200的本 - 體内含有螢光粉210及擴散劑220，螢光粉210分佈於靠 近出光面202處。 參照第3圖，為本發明一實施例之發光二極體背光模 組的示意圖。 發光二極體背光模組300包含一殼體310,具有一容 置空間，殻體310之内側表面具有一反光層312，可用以 反射光線。一導光板320設於殻體310之容置空間中，其 ® 中，導光板320具有一入光面322，一藍光發光二極體裝 置314設於容置空間之一側，對應於入光面322設置。一 擴散片330疊置於導光板320之上，其中擴散片330包含 螢光粉332 (黃色螢光粉）。稜鏡片350及棱鏡片360依序 疊置於擴散片330之上。 藍光發光二極體裝置314(即為一光源）發出之光線可 直接通過入光面322或經由反光層312反射後通過入光面 322進入導光板320,再藉由折射原理將光線由平行轉為 © 90度向上，經過擴散片330時，藍光激發螢光粉332可得 到白光，再經由棱鏡片350及棱鏡片360形成背光模組所 射出之白光。 雖然本發明已以數實施例揭露如上，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，當可作各種之更動與潤飾，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。 7 200925740 【圖式簡單說明】 為讓本發明之上述和其他目的、特徵、優點與實施例 能更明顯易懂，所附圖式之詳細說明如下： 第1圖是本發明一實施例之擴散片的示意圖。 第2圖為本發明另一實施例之擴散片的示意圖。 第3圖為本發明一實施例之發光二極體背光模組的示 意圖。 110 :螢光粉 200 =擴散片 【主要元件符號說明】 100 :擴散片 120 :擴散劑 202 :出光面 204 :入光面 210 :螢光粉 220 :擴散劑 300 :發光二極體背光模組 310 :殻體 312 :反光層 © 320 :導光板 330 :擴散片 350 :稜鏡片 314 :藍光發光二極體裝置 322 :入光面 332 :螢光粉 360 :稜鏡片200925740 VIII. Description of the Invention: - Technical Field of the Invention The present invention relates to a light-emitting diode backlight module, a diffusion sheet thereof, and a method of manufacturing the same, and more particularly to a diffusion sheet having a phosphor powder. Light-emitting diode backlight module and method of manufacturing the same. [Prior Art] In the backlight module, the diffuser of the lightguide functions as a uniform surface of the liquid crystal display. The general diffuser is a diffusing agent added to the resin substrate to make the light. Produces refraction, reflection and scattering to cause optical diffusion. Since the brightness uniformity of the light guiding layer must be controlled by the light source, and the current backlight module chromaticity block is getting smaller and smaller, it is necessary to use led to provide a narrow light source. However, compared with the backlight module using the traditional cold cathode lamp, the LED backlight module panel has the advantages of ultra-thin, high luminance and long life of the light source. However, the white LED is not only costly, but also has low luminous efficiency. A larger color mixing space than a cold cathode lamp can achieve a uniform surface source. SUMMARY OF THE INVENTION Accordingly, the present invention provides a light-emitting diode backlight module and a diffusion sheet, which generate white light with high chroma concentration to improve the uniformity of light output of the backlight module. According to the present invention, a diffusion sheet for a backlight module of a light-emitting diode and a method for fabricating the same are provided. In the manufacturing process of the diffusion sheet, a phosphor powder is added to the transparent plastic in 200925740 to form a diffusion sheet having a phosphor powder. The light-emitting diode backlight module using the diffusion sheet can use the light-emitting diode to excite the fluorescent powder material to produce white light with high chroma concentration. According to the above, the present invention can be used to add a fluorescent powder to a transparent plastic during the manufacturing process of the diffusion sheet to form a diffusion sheet having a fluorescent powder, and a suitable light source (for example, a blue light emitting diode) can be used when the blue light passes through the diffusion sheet. The fluorescent powder is excited to obtain white light, and the uniformity of the light output of the backlight module is greatly improved by the change of the diffusion sheet material, and the chromaticity concentration of the white light is improved. In addition to this ® , the use of a blue light-emitting diode as a light source can also reduce the cost of the backlight module source. [Embodiment] The method for manufacturing a diffusion sheet according to an embodiment of the present invention comprises providing a transparent plastic, adding a diffusing agent and a fluorescent powder (for example, a yellow fluorescent powder) to the transparent plastic, and finally curing the transparent plastic to form a fluorescent material. A diffuser of light powder. According to an embodiment of the present invention, the transparent plastic material may comprise polycarbonate, and the formed diffusion sheet may have a light emitting surface and a light incident surface, and the fluorescent powder may be uniformly distributed in the transparent plastic or distributed near the diffusion sheet. Out of the light. The diffusing agent may comprise aluminum oxide. 1 is a schematic view of a diffusion sheet according to an embodiment of the present invention. The diffusion sheet 100 is a sheet made of a transparent plastic, and contains a polishing powder 110 and a diffusing agent 120, and is evenly distributed in the diffusion sheet 100. Referring to Fig. 2', there is shown a schematic view of a diffusion sheet according to another embodiment of the present invention. The diffusion sheet 200 is a sheet made of a transparent plastic, and comprises a body. The body of the 200925740 has a light-emitting surface 202 and a light-incident surface 204. The body of the diffusion sheet 200 contains a phosphor powder 210 and a diffusing agent 220. The phosphor powder 210 is distributed near the light exit surface 202. Referring to Fig. 3, there is shown a schematic diagram of a light-emitting diode backlight module according to an embodiment of the present invention. The LED backlight module 300 includes a housing 310 having an accommodating space. The inner surface of the housing 310 has a reflective layer 312 for reflecting light. A light guide plate 320 is disposed in the accommodating space of the housing 310. The light guide plate 320 has a light incident surface 322. A blue light emitting diode device 314 is disposed on one side of the accommodating space, corresponding to the light entering. Face 322 is set. A diffusion sheet 330 is stacked on the light guide plate 320, wherein the diffusion sheet 330 contains the phosphor powder 332 (yellow phosphor powder). The cymbal sheet 350 and the prism sheet 360 are sequentially stacked on the diffusion sheet 330. The light emitted by the blue light emitting diode device 314 (ie, a light source) can be directly reflected by the light incident surface 322 or reflected by the light reflecting layer 312 and then enters the light guide plate 320 through the light incident surface 322, and then the light is rotated by the refraction principle. When it is 90 degrees upward, when passing through the diffusion sheet 330, the blue light excitation phosphor 332 can obtain white light, and then the prism light 350 and the prism sheet 360 form the white light emitted by the backlight module. The present invention has been disclosed in the above embodiments, and is not intended to limit the present invention, and it is obvious to those skilled in the art that various changes and modifications can be made 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 attached. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features, advantages and embodiments of the present invention will become more <RTIgt; Schematic diagram of the piece. Fig. 2 is a schematic view showing a diffusion sheet according to another embodiment of the present invention. Fig. 3 is a schematic view of a light-emitting diode backlight module according to an embodiment of the present invention. 110: Fluorescent powder 200 = diffuser [Main component symbol description] 100: diffuser 120: diffusing agent 202: light emitting surface 204: light incident surface 210: fluorescent powder 220: diffusing agent 300: light emitting diode backlight module 310: housing 312: reflective layer © 320: light guide plate 330: diffusion sheet 350: cymbal 314: blue light emitting diode device 322: light incident surface 332: fluorescent powder 360: cymbal