1283305 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導光板，尤其關於一 種具集光功能且出光輝度均勻之導光板及採用該導光板之 背光模組。 【先前技術】 由於液晶顯示器面板中之液晶本身不具發光特性，因 而，為達到顯示效果’須給液晶顯示器面板提供一光源裝 置，如背光模組，其功能在於向液晶顯示器面板供應輝度 充分且分佈均勻之面光源。導光板係背光模組之關鍵元 #，其必須具備良好之光學設計，使導光板能引導光源發 光轉換成輝度與色度均可達一定要求之面光源。 一種先前技術背光模組可參閱1996年8月20日公告之 美國專利第5,548,670號，如第一圖所示，該背光模組1包 括平行相對設置之光源101及102、一設置於光源101及102 間之導光板12、一設置於導光板12下方之反射板13及一位 於該導光板2上方之集光片14。該背光模組1中，由於導光 板12不具集光功能，為使得該背光模組1之出光輝度高，需 採用集光片14，此舉增加了該背光模組1之生產成本。另 外，由於採用集光片14，從光源1〇1及102出射之光線必須 多通過一光學介質（即集光片14)才能出射，會增加光能量 之損耗’即會降低光利用率。 又一種先前技術背光模組如第二圖所示，該背光模組2 包括一導光板22、位於該導光板22—侧之光源20及一設置 !2833〇5 於該導光板22下方之反射板23，該光源20由複數LED(Light Emitting Diode，發光二極體）構成，該導光板22包括一由複 數均句分佈之細微V形槽構成之出光面221。如上所述，該 出光面221相當於一微棱鏡陣列，其功用可等效於第一圖所 不之集光片14,因而，該背光模組2無需採用集光片即可達 到出光輝度高之目的。與背光模組i相比，該背光模組2之 生產成本較低，而且，由於從該背光模組2出射之光線比從 月光模組1出射之光線少通過一光學介質（即集光片14)，故 該背光模組2比背光模組1之光利用率高。 請參閱第三圖，係二顆LED之出射光於一空間平面之 月匕里分佈示意圖。由於led之出射光能量呈一圓錐分佈， 故’該LED光源201及202之出射光入射至一空間平面200 時’該空間平面200會存在出射光無法到達之區域261、262 及263，該區域261、262及263通常被稱為暗帶區。有鑑於 此’該背光模組2中，光源20入射至導光板22時，該導光板 22中會存在暗帶區。 請參閱第四圖，係二顆LED之出射光於光束角變小之 情形下，於一空間平面之能量分佈示意圖。若LED光源201 及202之出射光先通過某一介質使得光束角變小後再入射 至空間平面200，則，將形成暗帶區281、282及283，且該 暗帶區281、282及283之面積大於第三圖所示暗帶區261、 262及263之面積。如上所述，該導光板22之出光面221之功 用等效於一集光片，即該導光板22具集光功能，等效上使 得從光源20出射之光線之光束角減小，從而，將使得該背 光模組2中存在之暗帶區範圍擴大，進而影響該背光模組2 1283305 之出射光之空間分佈。 請參閱第五圖，係該背光模組2之部分光路示意圖。該 導光板22進一步包括一與出光面221相對設置之底面226， 為使光源20發出之光入射至導光板22後，能均勻分佈且能 從出光面221出射，通常於該導光板22之底面226設置複數 散射網點227，該散射網點227用於均勻散射該入射光並破 壞該入射光之全反射條件。惟，由於出光面221存在細微V 形槽，可能出現如下情形：從光源20入射至導光板22之光 線203經由散射網點227散射至出光面221時，被V形槽會聚 後出射；而光源20入射至導光板22之光線204經由散射網點 227散射至出光面221時，被V形槽反射回該導光板22内。 如上所述，由於出光面221之V形槽與底面226之散射網點 227共同作用，使得從光源20入射至該導光板22之光線不能 從該出光面221均勻出射，且於該出光面221上形成未均勻 分佈之亮帶。 有鑑於此，提供一種出光輝度高且均勻之導光板及採 用該導光板之背光模組實為必要。 【發明内容】 本發明之目的在於提供一種出光輝度高且均勻之導 光板。 本發明之又一目的在於提供一種採用出光輝度高且均 勻之導光板之背光模組。 本發明提供一種導光板，其包括一本體及一高透光介 質層，該本體包括一出光面及一與出光面相對設置之底 面，該出光面包括複數集光結構，該底面包括複數散射結 1283305 構，該高透光介質層位於該出光面與底面之間，並鄰近該 出光面設置，該高透光介質層採用材料之折射率小於導= 板本體材料之折射率。 、酋本發明又提供-種背光模組，其包括至少—點光源及 一導光板，該導光板包括一本體及一高透光介質層，該本 ，包括一出光面及一與出光面相對設置之底面，該點光源 设置於該導光板一侧，該出光面包括複數集光結構，該底 面包括複數散射結構，該高透光介質層位於該出光面與底 面之間，並鄰近該出光面設置’該高透光介質層採讀料 之折射率小於導光板本體材料之折射率。 相較於先前技術，本發明提供之導光板本體之出光面 包括複數集光結構，該底面包括複數散射結構，該導光板 =括一位於該出光面與底面間並鄰近出光面設置之高透光 介質層，且該高透光介質層之折射率小於導光板本體材料 之折射率，從而，入射至該導光板本體之光線經由底面散 射結構散射後再傳輸至高透光介質層時，可能會發生全反 射，並達到均勻分佈後入射至高透光介質層，平移後傳輸籲 至出光面，經該出光面之集光結構集光後出射或反射至高 透光介質層’此時’亦可能發生全反射，從而，該高透光 介質層有效隔離該集光結構及散射結構之作用，從而達到 出光輝度南且均勻之目的。 、，本發明又提供之背光模組採用上述導光板，則，該背 光模組不僅可實現生產成本較低及光利用率高，而且出光 輝度高且分佈均勻。 1283305 【實施方式】 本發明背光模組之第一實施方式如第六圖所示，該背 光模組3包括點光源301、302、303及304、分別設置於該點 光源301、302、303及304周圍之反射罩311、312、313及314 及一平板形導光板34，該導光板34包括一本體32及一高透 光介質層35，該本體32包括入光面322及323、與該入光面 322及323相鄰並相對設置之反射面324及325、一與該入光 面322及323相鄰之出光面321、一與該出光面321相對設置 之底面326,該高透光介質層35位於該出光面321及底面326 之間，並鄰近該出光面321設置。該點光源301及302設置於 該入光面322—侧，該點光源303及304設置於該入光面323 一侧，該出光面321包括複數均勻分佈之細微V形槽。 其中，該高透光介質層35之厚度大約為100//m，其係 採用等方性材料製成，其折射率小於本體32之材料折射 率，如該本體 32 之材料係 PMMA(Polymethyl Methacrylate， 聚曱基丙烯酸曱脂，亦稱為壓克力材料），其折射率為 1.49，該高透光介質層35之材料係二氧化矽（Si02)，其折 射率為1.45840。又，該本體32之入光面322及323鍍有增透 膜，該反射面324及325鍍有增反膜。 請參閱第七圖，係該背光模組3之部分光路示意圖。該 本體32之底面326上設置有複數散射網點327，該散射網點 327用以破壞入射至本體32之光線之全反射條件並將其均 勻散射。由於該高透光介質層35之折射率低於該本體32之 折射率，從而當光線從本體32傳輸至該高透光介質層35 時’可能會發生全反射，且光線從出光面321向外界傳輸 11 1283305 時，亦可能會發生全反射，故，該背光模組3之光路包括如 下三種情形： 從光源301出射之光線310進入本體32後被散射網點 327反射至高透光介質層35時，被該高透光介質層35平移後 傳輸至該出光面321，並被該出光面321之V形槽會聚後出 射。 從光源301出射之光線315進入本體32後被散射網點 327反射至高透光介質層35時，被該高透光介質層35平移後 傳輸至該出光面321，惟，由於發生全反射，該光線315被 出光面321之V形槽全部反射，而可能再次回到該高透光介 質層35，且亦極可能於該高透光介質層35上發生全反射， 即該光線315被出光面321之V形槽反射後並不直接回到散 射網點327，亦即該高透光介質層35將V形槽及散射網點 327對該光線315之作用隔離，故，由於該高透光介質層35 之存在不會影響該散射網點327對入射光線之均勻散射。 從光源301出射之光線316進入本體32後被散射網點 327反射至高透光介質層35時，發生全反射，該光線316被 反射至本體32之其他表面或散射網點上，被破壞全反射條 件後，再到達該高透光介質層35並通過。 如上所述，該高透光介質層35可有效隔離該出光面321 之V形槽及散射網點327，使得入射至該本體32之光線傳輸 至該高透光介質層35時，形成均勻分佈後再被V形槽集光 出射，從而達到出光輝度高且均勻之目的。 請參閱第八圖，係本發明背光模組之第二實施方式。 該背光模組4與第六圖所示之背光模組3之不同之處在於： 12 1283305 該背光模組4採用之導光板44係楔形，且該導光板44之本體 42包括一入光面422及一出光面421，點光源401及402設置 於該入光面422—侧，該出光面421包括複數起集光作用之 細微U形槽。 惟，本發明背光模組及其導光板並不限於上述實施方 式所述，如該點光源可為LED，該導光板可為碟形導光板， 該散射網點可為凸塊或凹槽所取代，該U形槽或V形槽可為 半圓柱所取代，該散射網點可均勻或非均勻分佈，該V形 槽及U形槽可均勻或非均勻分佈等。 _ 綜上所述，本發明確已符合發明專利之要件，爰依法 提出專利申請。惟，以上所述者僅為本發明之較佳實施方 式，本發明之範圍並不以上述實施例為限，舉凡熟習本案 技藝之人士援依本發明之精神所作之等效修飾或變化，皆 應涵蓋於以下申請專利範圍内。 【圖式簡單說明】 第一圖為一種先前技術背光模組之立體圖。 第二圖為又一種先前技術背光模組之立體圖。 * 第三圖為二顆LED之出射光於一空間平面之能量分佈 不意圖。 第四圖為二顆LED之出射光於光束角變小之情形下， 於一空間平面之能量分佈示意圖。 第五圖為第四圖所示背光模組之部分光路示意圖。 第六圖為本發明背光模組第一實施方式之立體圖。 第七圖為第六圖所示背光模組之部分光路示意圖。 13 1283305 第八為本發明背光模組第二實施方式之立體圖。 【主要元件符號說明】 背光模組 3、4 導光板 34、44 本體 32、42 散射網點327 出光面 高透光介質層 底面 光源 反射罩 321、421 反射面 324、325 35 光線 310、315、316 326 入光面 322、323、422 3(H、302、303、304、401、402 3H、312、313、3141283305 IX. INSTRUCTION DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a backlight module and a light guide plate thereof, and more particularly to a light guide plate having a light collecting function and uniform light emission and a backlight module using the light guide plate. [Prior Art] Since the liquid crystal in the liquid crystal display panel itself has no illuminating property, in order to achieve the display effect, it is necessary to provide a liquid crystal display panel with a light source device, such as a backlight module, whose function is to supply the liquid crystal display panel with sufficient brightness and distribution. Even surface light source. The light guide plate is the key element of the backlight module. It must have a good optical design, so that the light guide plate can guide the light source to be converted into a surface light source with a certain degree of brightness and chromaticity. As shown in the first figure, the backlight module 1 includes the light sources 101 and 102 disposed in parallel with each other, and is disposed on the light source 101 and The light guide plate 12 is disposed between the light guide plate 12 and the light guide plate 14 disposed above the light guide plate 2. In the backlight module 1, since the light guide plate 12 does not have a light collecting function, in order to make the light emitting brightness of the backlight module 1 high, the light collecting sheet 14 is required, which increases the production cost of the backlight module 1. In addition, since the light concentrating sheet 14 is used, the light emitted from the light sources 1〇1 and 102 must pass through an optical medium (i.e., the light concentrating sheet 14) to be emitted, which increases the loss of light energy, which reduces the light utilization efficiency. In another embodiment, the backlight module 2 includes a light guide plate 22, a light source 20 on the side of the light guide plate 22, and a reflection of the arrangement 2833〇5 under the light guide plate 22. The light source 20 is composed of a plurality of LEDs (Light Emitting Diodes), and the light guide plate 22 includes a light-emitting surface 221 formed by a fine V-shaped groove of a plurality of uniform sentences. As described above, the light-emitting surface 221 is equivalent to a micro-prism array, and its function can be equivalent to the light-collecting sheet 14 of the first figure. Therefore, the backlight module 2 can achieve high luminance without using a light collecting sheet. The purpose. Compared with the backlight module i, the backlight module 2 has a lower production cost, and the light emitted from the backlight module 2 passes through an optical medium (ie, a concentrating sheet) than the light emitted from the moonlight module 1. 14) Therefore, the backlight module 2 has higher light utilization efficiency than the backlight module 1. Please refer to the third figure, which is a schematic diagram of the distribution of light from two LEDs in a space plane. Since the outgoing light energy of the LED has a conical distribution, when the emitted light of the LED light sources 201 and 202 is incident on a spatial plane 200, the spatial plane 200 may have regions 261, 262 and 263 where the emitted light cannot reach. 261, 262, and 263 are often referred to as dark bands. In view of the fact, in the backlight module 2, when the light source 20 is incident on the light guide plate 22, a dark band region exists in the light guide plate 22. Please refer to the fourth figure, which is a schematic diagram of the energy distribution in a spatial plane in the case where the beam angle of the two LEDs becomes smaller. If the outgoing light of the LED light sources 201 and 202 first passes through a medium such that the beam angle becomes smaller and then enters the spatial plane 200, the dark band regions 281, 282, and 283 are formed, and the dark band regions 281, 282, and 283 are formed. The area is larger than the area of the dark zone 261, 262 and 263 shown in the third figure. As described above, the function of the light-emitting surface 221 of the light guide plate 22 is equivalent to a light-collecting sheet, that is, the light-guiding plate 22 has a light collecting function, which equivalently reduces the beam angle of the light emitted from the light source 20, thereby The dark band area existing in the backlight module 2 is enlarged, thereby affecting the spatial distribution of the outgoing light of the backlight module 2 1283305. Please refer to the fifth figure, which is a schematic diagram of a part of the optical path of the backlight module 2. The light guide plate 22 further includes a bottom surface 226 disposed opposite to the light-emitting surface 221, so that the light emitted from the light source 20 can be evenly distributed and can be emitted from the light-emitting surface 221 after being incident on the light-guide plate 22, usually on the bottom surface of the light guide plate 22. 226 sets a complex scattering dot 227 for uniformly scattering the incident light and destroying the total reflection condition of the incident light. However, since the light-emitting surface 221 has a fine V-shaped groove, there may be a case where the light 203 incident from the light source 20 to the light guide plate 22 is scattered to the light-emitting surface 221 via the scattering mesh point 227, and is condensed by the V-shaped groove to be emitted; When the light ray 204 incident on the light guide plate 22 is scattered to the light exit surface 221 via the scattering mesh point 227, it is reflected back into the light guide plate 22 by the V-shaped groove. As described above, since the V-shaped groove of the light-emitting surface 221 and the scattering mesh point 227 of the bottom surface 226 cooperate, the light incident from the light source 20 to the light guide plate 22 cannot be uniformly emitted from the light-emitting surface 221, and is disposed on the light-emitting surface 221. A bright band that is not evenly distributed is formed. In view of the above, it is necessary to provide a light guide plate with high lightness and uniformity and a backlight module using the light guide plate. SUMMARY OF THE INVENTION An object of the present invention is to provide a light guide plate having high light transmittance and uniformity. It is still another object of the present invention to provide a backlight module using a light guide plate having a high luminance and uniformity. The present invention provides a light guide plate comprising a body and a highly transparent dielectric layer, the body comprising a light emitting surface and a bottom surface opposite to the light emitting surface, the light emitting surface comprising a plurality of light collecting structures, the bottom surface comprising a plurality of scattering nodes 1283305, the high transparent dielectric layer is located between the light emitting surface and the bottom surface, and is disposed adjacent to the light emitting surface, wherein the high transparent dielectric layer adopts a refractive index of the material smaller than a refractive index of the material of the guiding plate body. The emirate invention further provides a backlight module comprising at least a point light source and a light guide plate, the light guide plate comprising a body and a high transparent medium layer, wherein the light emitting surface comprises a light emitting surface and a light emitting surface a light source is disposed on a side of the light guide plate, the light emitting surface includes a plurality of light collecting structures, the bottom surface includes a plurality of scattering structures, the high light transmitting medium layer is located between the light emitting surface and the bottom surface, and adjacent to the light emitting The surface setting 'the refractive index of the high transparent medium layer reading material is smaller than the refractive index of the material of the light guide plate body. Compared with the prior art, the light-emitting surface of the light guide plate body of the present invention includes a plurality of light collecting structures, and the bottom surface includes a plurality of scattering structures, and the light guide plate includes a high transparent layer disposed between the light emitting surface and the bottom surface and adjacent to the light emitting surface. The optical medium layer has a refractive index smaller than a refractive index of the material of the light guide plate, so that the light incident on the light guide plate body is scattered by the bottom scattering structure and then transmitted to the high transparent medium layer, and may be Total reflection occurs, and after reaching a uniform distribution, it is incident on the high-transmission dielectric layer, and is transmitted to the light-emitting surface after translation. After the light-collecting structure of the light-emitting surface is collected, the light is emitted or reflected to the high-transmission dielectric layer 'this time' may also occur. The total reflection, so that the high transparent medium layer effectively isolates the light collecting structure and the scattering structure, thereby achieving the purpose of uniformity and uniformity of light emission. In addition, the backlight module of the present invention uses the above-mentioned light guide plate, and the backlight module can not only achieve low production cost and high light utilization efficiency, but also has high light emission and uniform distribution. 1283305 [First Embodiment] A first embodiment of a backlight module of the present invention is as shown in a sixth embodiment. The backlight module 3 includes point light sources 301, 302, 303, and 304, and is disposed at the point light sources 301, 302, and 303, respectively. The reflective cover 311, 312, 313 and 314 around the 304 and a flat light guide 34, the light guide plate 34 comprises a body 32 and a high transparent medium layer 35, the body 32 includes light incident surfaces 322 and 323, and The light-incident surfaces 322 and 323 are adjacent to and opposite to the reflective surfaces 324 and 325, a light-emitting surface 321 adjacent to the light-incident surfaces 322 and 323, and a bottom surface 326 opposite to the light-emitting surface 321 The dielectric layer 35 is located between the light-emitting surface 321 and the bottom surface 326 and disposed adjacent to the light-emitting surface 321 . The point light sources 301 and 302 are disposed on the side of the light incident surface 322. The point light sources 303 and 304 are disposed on the side of the light incident surface 323. The light exit surface 321 includes a plurality of fine V-shaped grooves uniformly distributed. The high transparent dielectric layer 35 has a thickness of about 100/m, and is made of an isotropic material having a refractive index lower than that of the body 32. For example, the material of the body 32 is PMMA (Polymethyl Methacrylate). , polydecyl acrylate resin, also known as acryl material, has a refractive index of 1.49, and the material of the high transparent dielectric layer 35 is cerium oxide (SiO 2 ), and its refractive index is 1.45840. Further, the light incident surfaces 322 and 323 of the main body 32 are plated with an antireflection film, and the reflective surfaces 324 and 325 are plated with an antireflection film. Please refer to the seventh figure, which is a schematic diagram of a part of the optical path of the backlight module 3. The bottom surface 326 of the body 32 is provided with a plurality of scattering dots 327 for destroying the total reflection conditions of the light incident on the body 32 and uniformly scattering them. Since the refractive index of the high transparent dielectric layer 35 is lower than the refractive index of the body 32, when light is transmitted from the body 32 to the high transparent dielectric layer 35, total reflection may occur, and the light is emitted from the light emitting surface 321 When the external transmission 11 1283305 is transmitted, total reflection may occur. Therefore, the optical path of the backlight module 3 includes the following three situations: When the light 310 emitted from the light source 301 enters the body 32 and is reflected by the scattering mesh point 327 to the high transparent dielectric layer 35, After being translated by the high transparent medium layer 35, it is transmitted to the light-emitting surface 321 and is concentrated by the V-shaped groove of the light-emitting surface 321 to be emitted. When the light ray 315 emerging from the light source 301 enters the body 32 and is reflected by the scattering mesh point 327 to the high transparent dielectric layer 35, it is translated by the high transparent dielectric layer 35 and transmitted to the light emitting surface 321, but the total light is reflected. 315 is totally reflected by the V-shaped groove of the light-emitting surface 321 and may return to the high-transmissive dielectric layer 35 again, and it is also likely that total reflection occurs on the high-transmissive dielectric layer 35, that is, the light 315 is emitted by the light-emitting surface 321 The V-shaped groove does not directly return to the scattering dot 327 after reflection, that is, the high-transmissive dielectric layer 35 isolates the V-shaped groove and the scattering dot 327 from the action of the light 315, so that the high-transmissive dielectric layer 35 The presence does not affect the uniform scattering of incident light by the scattering dot 327. When the light 316 emerging from the light source 301 enters the body 32 and is reflected by the scattering mesh point 327 to the high transparent dielectric layer 35, total reflection occurs, and the light 316 is reflected to other surfaces of the body 32 or the scattering dots, after being destroyed by the total reflection condition. And reaching the high transparent medium layer 35 and passing. As described above, the high transparent dielectric layer 35 can effectively isolate the V-shaped groove and the scattering dot 327 of the light-emitting surface 321 so that the light incident on the body 32 is uniformly distributed after being transmitted to the high-transmissive dielectric layer 35. It is then collected by the V-shaped groove to achieve high and uniform brightness. Please refer to the eighth figure, which is a second embodiment of the backlight module of the present invention. The backlight module 4 is different from the backlight module 3 shown in FIG. 6 in that: 12 1283305 The light guide plate 44 of the backlight module 4 is wedge-shaped, and the body 42 of the light guide plate 44 includes a light-incident surface. 422 and a light-emitting surface 421, the point light sources 401 and 402 are disposed on the side of the light-incident surface 422, and the light-emitting surface 421 includes a plurality of fine U-shaped grooves for collecting light. However, the backlight module and the light guide plate of the present invention are not limited to the above embodiments. For example, the point light source may be an LED, and the light guide plate may be a dish-shaped light guide plate, and the scattering mesh point may be replaced by a bump or a groove. The U-shaped groove or the V-shaped groove may be replaced by a semi-cylindrical, and the scattering mesh points may be uniformly or non-uniformly distributed, and the V-shaped groove and the U-shaped groove may be uniformly or non-uniformly distributed. _ In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and the scope of the present invention is not limited to the above-described embodiments, and those skilled in the art will be able to make equivalent modifications or variations in accordance with the spirit of the present invention. It should be covered by the following patent application. [Simple Description of the Drawings] The first figure is a perspective view of a prior art backlight module. The second figure is a perspective view of yet another prior art backlight module. * The third picture shows the energy distribution of the exiting light of two LEDs in a spatial plane. The fourth picture is a schematic diagram of the energy distribution in a spatial plane in the case where the exit angle of the two LEDs becomes smaller. The fifth figure is a schematic diagram of a part of the optical path of the backlight module shown in the fourth figure. Figure 6 is a perspective view of a first embodiment of a backlight module of the present invention. The seventh figure is a schematic diagram of a part of the optical path of the backlight module shown in the sixth figure. 13 1283305 The eighth is a perspective view of a second embodiment of the backlight module of the present invention. [Main component symbol description] Backlight module 3, 4 Light guide plate 34, 44 Body 32, 42 Scattering dot 327 Light-emitting surface High-transmission dielectric layer Bottom light source Reflector 321, 421 Reflecting surface 324, 325 35 Light 310, 315, 316 326 light incident surfaces 322, 323, 422 3 (H, 302, 303, 304, 401, 402 3H, 312, 313, 314
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