1355519 九、發明說明： 【發明所屬之技術領域] 本發明涉及一種背光模組及其光學板， 用於液晶顯示之背光模組及其光學板。 尤其涉及一種 【先前技術】 '面光源裝 示器面板供 由於液晶顯示态面板之液晶本身不具 爲達到顯示效果需給液晶顯示器面板提x光特性，因而1355519 IX. Description of the Invention: [Technical Field] The present invention relates to a backlight module and an optical plate thereof, a backlight module for liquid crystal display and an optical plate thereof. In particular, it relates to a [prior art] 'surface light source display panel for providing liquid crystal display panel with x-ray characteristics because the liquid crystal display panel of the liquid crystal display panel itself does not have a display effect.
置，如背光模組。背光模組之作用係向液 應亮度充分且分佈均勻之面光源。 明^ 請參見圖1，所示爲一種習知之背光 括框架101、反射板102、擴散板103、稜100,其包 一發光二極體105。框架101包括一底板104及至少 底板1011邊緣向其同一側垂直延伸之側辟及後數從該 與複數侧壁1013共同形咸一腔體1017= 3。底板1011 包括出光部1051與基部1053，基部1〇53^先一極體105 示）相連並固定於底板1(m。擴散板103與棱鏡 次設置於複數懸期頂部。反射板1G2爲—小框體二 構，其可配置於框架101㈣。反射板102之底部開^ 與發光二極體105相對應之通孔（未標示），發光二極體 105之出光部1051穿過相應通孔。發光二極體1〇5之基部 1053頂持該反射板102。 工作時，發光二極體105産生之光線被反射板102反 射進入擴散板103 ’於擴散板103中被均勻擴散後光線繼 續進入稜鏡片104，於稜鏡片1〇4之作用下，出射光線發 生一定程度之聚集，使得背光模組於特定視角範圍内之亮 度提高。 然而，由於發光二極體105爲點光源，其到達擴散板 1355519 .103上各處之距離大小不相等，位於發光二極體ι〇5正上 方之擴散板103單位區域所接受光較多，位於發光二極體 105四周之擴散板1〇3單位區域所接受光較少，故容易於 發光一極體105正上方之區域形成亮區，而於其上方之四 周區域形成暗區，影響背光模組1〇〇之出光均勻性。爲此， 通常需於發光二極體105之上方設置反射片1〇6，以控 發光二極體105正上方之出光量。發光二極體1〇5與▲射 片106 ^搭配設計，可一定程度上減弱發光二極體⑽正 上方之亮區’惟，背光模组1〇〇仍有出光不均之缺點。 【發明内容】 及其述狀況，有必要提供一種出光均勾之背光模組 :種光學板，其包括至少一光學板單元，該光學板單 光面、與該出光面相對之底面及形成於該出光面 政射層’該底面形成有複數微凸起’每個微凸起包括至 =二個相互連接之側面，每個側面之水平寬度沿遠離該底 面之^向^漸縮小，且該底面開設有至少—光源容納部。 此*，力月光模且’其包括框架、至少一點光源及光學 板“亥框未包括底板及複數從該底 ’該複數側壁與該底板形成-腔體;該至少 内，該光=置於該腔體 出光面及與該出光面相對光學板單元包括 起，每個微凸起包括二，1面’5底面形成有複數微凸 之水羊官声土絲—少一個相互連接之側面，每個側面 一離遠底面之方向逐漸縮小，且該底面開設 之散部，料學板還包括—形成於該出光面 月’㈢^ 光源之出光部相應設置于該光源容納部 1355519 内。 上述背光模組之光學板之光學板單元包括光源容納 部與設於其底面上之複數微凸起以及設於其出光面上之 散射層，點光源之出光部容納於光源容納部内。從點光源 發出之光線藉由光源容納部之内側壁直接進入光學板内 部。由於光學板底面設置之微凸起具有變化之表面結構， 使得光線於光學板内傳輸至微凸起時，微凸起可將部分原 來於未設有微凸起之光學板内全反射傳播之光線調節後 從底面出射，於框架之反射作用下，此部分光線多次折射 後進入散射層進行進一步散射，最後從腔體開口均勻出 射，故背光模組之光學利用率可得到進一步提高。更進一 步地’點光源所發射之光線大部分於光學板内向四周傳 播’點光源被轉變成面光源，從而縮小了混光距離，故， 背光模組於採用較少之點光源數量情況下，可進行降低燈 箱咼度之。又。十，而且採用此具有散射層之導光板之背光模 組可省略習知擴散板之使用，從而使背光模組之成本與厚 度降低。 【實施方式】 一：下面將結合附圖及實施例對本發明之背光模組及其 光學板作進一步之詳細說明。 凊參見圖2,所示爲本發明較佳實施例一之背光模組 200 ’其包括一框架2卜一反射板22、一側光式點光源25 及塊光學板2〇。框架21包括一塊長方形底板211及從 底板211邊緣向其同一側垂直延伸並相互連接之四側壁 213四側壁213與底板211共同形成一腔體217，用於收 7 1355519 容點光源25、反射板22及光學板川等元件。 配之H見圖Γ光學板2G爲與框架21之底板⑴相搭 ^包括—出光面2〇2 一與該出光面202相 Μ二底面203中央開設有-光源容納部204, ^ HP 2G4爲從底面2G3貫穿至出光面2()2之通孔。 形成—均勻厚度之散射層2〇5，底面203形成 奴數圍么光源容納部2〇4之微凸起2〇6。Set, such as the backlight module. The backlight module functions as a surface light source with sufficient brightness and uniform distribution to the liquid. Referring to Fig. 1, there is shown a conventional backlight frame 101, a reflecting plate 102, a diffusing plate 103, and an rib 100, which comprises a light emitting diode 105. The frame 101 includes a bottom plate 104 and at least a side surface of the bottom plate 1011 extending perpendicularly to the same side thereof and a rearward number from the plurality of side walls 1013 to form a cavity 1017=3. The bottom plate 1011 includes a light-emitting portion 1051 and a base portion 1053, and the base portion 1 〇 53 先 first pole body 105 is connected and fixed to the bottom plate 1 (m. The diffusion plate 103 and the prism are disposed at the top of the plurality of suspensions. The reflection plate 1G2 is - small The frame structure can be disposed on the frame 101. The through hole (not labeled) corresponding to the light emitting diode 105 is opened at the bottom of the reflector 102, and the light exiting portion 1051 of the light emitting diode 105 passes through the corresponding through hole. The base 1053 of the light-emitting diode 1〇5 holds the reflector 102. During operation, the light generated by the LEDs 105 is reflected by the reflector 102 into the diffuser 103', and the light is continuously diffused into the diffuser 103. The cymbal 104, under the action of the cymbal 〇4, emits a certain degree of light, so that the brightness of the backlight module is increased within a specific viewing angle range. However, since the light-emitting diode 105 is a point light source, it reaches the diffusion. The distances of the plates 1355519 .103 are not equal, and the unit of the diffusing plate 103 located directly above the light-emitting diode ι 5 receives more light, and the diffusing plate is located around the light-emitting diode 105. Received light As a result, it is easy to form a bright area in the area directly above the light-emitting body 105, and a dark area is formed in the upper area of the light-emitting body 105, which affects the light uniformity of the backlight module 1. For this reason, it is usually required to emit light A reflection sheet 1〇6 is disposed above the body 105 to control the amount of light emitted directly above the light-emitting diode 105. The light-emitting diode 1〇5 and the ▲-shot film 106 are designed to reduce the light-emitting diode to a certain extent (10). The bright area directly above 'only, the backlight module 1〇〇 still has the disadvantage of uneven light emission. [Invention content] and the state thereof, it is necessary to provide a backlight module with a light-emitting hook: a kind of optical plate, which includes at least An optical plate unit, the single-gloss surface of the optical plate, the bottom surface opposite to the light-emitting surface, and the baffle layer formed on the light-emitting surface, the bottom surface is formed with a plurality of micro-protrusions each of the micro-protrusions including to two interconnected The side surface, the horizontal width of each side is gradually reduced away from the bottom surface, and the bottom surface is provided with at least a light source receiving portion. This *, the force moonlight mode and 'which includes the frame, at least a point of light source and the optical plate" The frame does not include the bottom plate and the complex Forming a cavity from the bottom of the plurality of sidewalls and the bottom plate; at least the light is disposed on the light exiting surface of the cavity and the optical plate unit is opposite to the light emitting surface, and each of the micro bumps includes two, one The surface of the surface of the '5 is formed with a plurality of micro-convex water-soiled sacred soils - one side that is connected to each other, and each side is gradually narrowed away from the far bottom surface, and the bottom portion is opened, and the material board also includes - The light exiting portion of the light source is formed in the light source receiving portion 1355519. The optical plate unit of the optical plate of the backlight module includes a light source receiving portion and a plurality of micro bumps disposed on a bottom surface thereof The scattering layer disposed on the light-emitting surface of the light source is housed in the light source housing portion. The light emitted from the point source directly enters the inside of the optical plate through the inner side wall of the light source housing. Since the micro-protrusions provided on the bottom surface of the optical plate have a varying surface structure, when the light is transmitted to the micro-protrusions in the optical plate, the micro-protrusions can partially transmit the total reflection in the optical plate not provided with the micro-protrusions. After the light is adjusted, it is emitted from the bottom surface. Under the reflection of the frame, the light is refracted multiple times and then enters the scattering layer for further scattering, and finally uniformly emerges from the cavity opening, so the optical utilization of the backlight module can be further improved. Further, the light emitted by the point source is mostly propagated around the optical plate. The point source is converted into a surface light source, thereby reducing the light mixing distance. Therefore, the backlight module uses a small number of point sources. It can reduce the brightness of the light box. also. 10. The backlight module using the light guide plate having the scattering layer can omit the use of the conventional diffusion plate, thereby reducing the cost and thickness of the backlight module. [Embodiment] A: The backlight module and the optical plate of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Referring to FIG. 2, a backlight module 200' according to a preferred embodiment of the present invention includes a frame 2, a reflective plate 22, a side light point source 25, and a block optical plate 2'. The frame 21 includes a rectangular bottom plate 211 and four side walls 213 extending from the edge of the bottom plate 211 to the same side and connected to each other. The four side walls 213 and the bottom plate 211 together form a cavity 217 for receiving 7 1355519 capacitive light source 25 and reflector 22 and optical plate and other components. In addition, the optical plate 2G is disposed on the bottom plate (1) of the frame 21, including the light-emitting surface 2〇2, and the light-emitting surface 202 is opposite to the bottom surface 203. The light source receiving portion 204 is provided, and the HP 2G4 is The through hole is penetrated from the bottom surface 2G3 to the light exit surface 2 () 2 . A scattering layer 2〇5 of uniform thickness is formed, and the bottom surface 203 forms a micro-bump 2〇6 of the light source housing portion 2〇4.
20=?=由擴散油墨固化而成’其包括透明樹脂 ”均勻摻雜於透明樹脂2052中之散射粒子2〇54。透 2052爲擴散油墨中之清漆固化而成，優選丙婦酸 $月“漆。散射粒子2〇54以一定比例摻入擴散油墨中， 選自以下之一種或多種粒子：二氧化矽顆粒、聚甲基 丙烯酸曱酯顆粒與玻璃微珠等。 土 本^施例中，該複數微凸起206呈規則之陣列式排 :，，且每個微凸起206爲正四面錐形凸起。請參見圖4 , 每個微凸起206兩相對侧面之夾角θ之較佳取值範圍爲6〇 至120度，相鄰微凸起2〇6之間距D優選爲〇 〇25 2毫米。 . "T以理解，微凸起206之形狀並不限於正四面錐形凸 起，亦可爲三面錐形凸起，多面錐形凸起等，即微凸起2〇6 之結構可概括爲包括至少三個相互連接之侧面，每個側面 之水平寬度沿遠離底面203之方向逐漸縮小。 請再參閱圖2,點光源25優選爲側光式發光二極體， 其包括一基部253，一固定於基部253上方之出光部251 與一反射片255。點光源25藉由電路板（未標示）固定於 底板211。光學板20設置於腔體217内，其出光面202面 向腔體217之開口。點光源2 5之出光部2 51容納於光學 板20之光源容納部2〇4内。反射片255設置於對應點光 1355519 .源25正上方之位置，用於覆蓋點光源25之頂部。反射片 255之面積等於或略大於出光部251之投影面積。反射板 22開設有一對應于點光源25之出光部251之通孔（未標 示）。反射板22設置於光學板20底面203之下方，點光 源25之出光部251穿過該通孔（未標示）。 ' 點光源25從出光部251發出之光線藉由光源容納部 204之内側壁直接進入光學板20内部。由於光學板20之 底面設置有微凸起206，微凸起206可將部分原來於未設 有微凸起206之光學板20内全反射傳播之光線調節後從 φ 底面203出射，於反射板22之辅助作用下，此部分光線 多次折射後進入散射層205進一步散射，最後從腔體217 開口均勻出射。故背光模組200之光學利用率亦將進一步 提高。更進一步地，由於採用側光式點光源25，點光源 25所發射之光線大部分於光學板20内向四周傳播，點光 源被轉變成面光源，從而縮小了混光距離，故，背光模組 .200於採用較少之點光源數量情況下.，可進行降低燈箱高 度之設計，從而使背光模組200之成本與厚度降低。 背光模組200還可包括一透明板（未標示），用於蓋 • 住腔體217之開口，亦可另於四側壁213頂部增加一棱鏡 片（未標示），用於提高該背光模組200於特定之視角範 圍内之均勻亮度。爲使光束於腔體内均勻混光與提尚光線 利用率，該反射板22可進一步包括複數反射側壁223。可 以理解，本實施例之反射板22可省略，尤其當框架21爲 高反射材料製成，或於底板211及/或側壁213内側塗覆高 反射塗層時。 請參見圖5,所示爲本發明較佳實施例二之光學板 30。該光學板30與較佳實施例一之光學板20相似，其不 同在於光學板30之微凸起306之頂角以及相鄰微凸起306 9 1355519 .形成之底部夾角均被圓角化，分別形成圓角R1與R2。該 R1與R2之圓角之取值範圍優選爲大於0且小於或等於1.1 毫米。被圓角化之微凸起306可使出射光束之出射角度之 變化趨於緩和，使採用光學板30之背光模組之出光均勻 性提高。可以理解，亦可於微凸起306之頂角以及相鄰微 ' 凸起306形成之底部夾角之其中之一單獨進行上述圓角化 設計。 請參見圖6,所示爲本發明較佳實施例三之光學板 • 40。該光學板40與較佳實施例一之光學板20相似，其不 φ 同在於光學板40之光源容納部404爲從底面403向光學 板40内部凹陷之盲孔。採用光學板40之背光模組可搭配 一未設反射元件之側光式點光源，或者於盲孔底部直接塗 覆高反射層。 ..請參見圖：7.，所示爲本發明較佳實施例四之光學板 .5,(U該光學板50,與較佳實施例一之光厚板20相似，其不 同在於光學板50之散射層505爲不連續分佈。本實施例 '中/，散射層505爲網點狀不規則排佈)。：？': 上:述實施例中，光學板20，30 .，40;，50都爲一整體 • 結構。本發明之大尺寸之光學板可由若干個上述整體結構 之光學板單元組合而成，或者每個光學板單元開設複數光 源容納部。光學板20，30，40，50之形狀除矩形外，還 可爲多邊形或圓形等。 本發明之光學板單元或組合光學板可設置複數光源 容納部，配合該複數光源容納部，可採用不同顏色之側光 式發光二極體製成白_光混光背光模組，或者採用相同顏色 之側光式發光二極體製成特定顏色之背光模組。 上述各實施例中光學板之間隔之散射層之分佈還可 以有以下變換設計。 10 1355519 如圖8所示，散射層605於出光面602之分佈爲：以 光源容納部604爲圓心，複數圓環狀之散射層605間隔分 佈，且越遠離光源容納部604，圓環狀之散射層605之徑 向厚度越大，此設計有利於提高光學板之出光均勻性。 如圖9所示，散射層705於出光面702之分佈爲：以 光源容納部704爲圓心，複數網點狀之散射層705沿著圓 環形執道間隔分佈，且越遠離光源容納部704，網點狀之 散射層705之直徑越大面積亦越大，此設計有利於提高光 學板之出光均勻性。 如圖10所示，散射層805於出光面802之分佈爲： 以光源容納部804爲圓心，複數相同大小之網點狀之散射 層805沿著圓環形軌道間隔分佈，且越遠離光源容納部 804，網點狀之散射層805之排佈密度越大，此設計有利 於提高光學板之出光均勻性。 綜上所述，本發明確已符合發.明專制要件，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例， 舉凡熟悉本案技藝之人士，於援依本案發明精神所作之等 效修飾或變化，皆應包含於以下之申請專.利範圍内。 【圖式簡單說明】 圖1係一種習知之背光模組之剖視圖。 圖2係本發明較佳實施例一之背光模組之剖視圖。 圖3係圖2所示背光模組之光學板之立體圖。 圖4係圖3所示光學板沿V-V線之剖視圖。 圖5係本發明較佳實施例二之光學板之剖視圖。 圖6係本發明較佳實施例三之光學板之剖視圖。 圖7係本發明較佳實施例四之光學板之剖視圖。 圖.8至圖10係本發明之光學板之散射層之各種分佈示意 1355519 圖。 【主要元件符號說明】 背光模組 200 光學板 20 ' 30 > 40 ' 50 框架 21 反射板 22 點光源 25 出光面 202 、 602 、 702 、 802 底面 203 、 403 光源容納部 204 ' 404 ' 604 、 704 ' 804 散射層 205 ' 505、605、705 ' 805 透明樹脂 2052 散射粒子 .，· ·、： 2054 ·· ·.· · · .： 微凸起 206 、 306 底板厂 211 側壁 213 腔體 217 反射側壁 223 出光部 251 基部 253 反射元件 25520=?=cured by the diffusion ink, which comprises a transparent resin uniformly dispersed in the transparent resin 2052. The transparent resin is formed by curing the varnish in the diffusion ink, preferably propylene glycol. paint. The scattering particles 2〇54 are incorporated into the diffusion ink in a certain ratio, and are selected from one or more of the following particles: cerium oxide particles, polymethyl methacrylate particles, glass beads, and the like. In the embodiment, the plurality of microprotrusions 206 are in a regular array of rows: and each of the microprotrusions 206 is a regular tetrahedral pyramid. Referring to FIG. 4, the angle θ of the opposite sides of each microprotrusion 206 preferably ranges from 6 至 to 120 degrees, and the distance D between adjacent micro protrusions 2 〇 6 is preferably 〇 25 2 mm. It is understood that the shape of the micro-protrusions 206 is not limited to the regular four-sided tapered protrusions, and may also be a three-sided tapered protrusion, a multi-faceted conical protrusion, etc., that is, the structure of the micro-protrusions 2〇6 can be summarized. To include at least three interconnected sides, the horizontal width of each side tapers in a direction away from the bottom surface 203. Referring to FIG. 2 again, the point source 25 is preferably an edge-lit LED, and includes a base 253, a light-emitting portion 251 fixed to the base 253 and a reflective sheet 255. The point source 25 is fixed to the bottom plate 211 by a circuit board (not shown). The optical plate 20 is disposed in the cavity 217 with its light exiting surface 202 facing the opening of the cavity 217. The light exiting portion 2 51 of the point light source 25 is housed in the light source housing portion 2〇4 of the optical plate 20. The reflection sheet 255 is disposed at a position directly above the source 25 for the corresponding spot light 1355519, and is used to cover the top of the point source 25. The area of the reflection sheet 255 is equal to or slightly larger than the projected area of the light exit portion 251. The reflection plate 22 has a through hole (not shown) corresponding to the light exit portion 251 of the point light source 25. The reflecting plate 22 is disposed below the bottom surface 203 of the optical plate 20, and the light exiting portion 251 of the spot light source 25 passes through the through hole (not shown). The light emitted from the light-emitting portion 251 by the point light source 25 directly enters the inside of the optical plate 20 through the inner side wall of the light source accommodating portion 204. Since the bottom surface of the optical plate 20 is provided with the micro protrusions 206, the micro protrusions 206 can adjust the light which is totally reflected and propagated in the optical plate 20 which is not provided with the micro protrusions 206, and then exit from the φ bottom surface 203 on the reflection plate. Under the auxiliary action of 22, the portion of the light is refracted multiple times and then enters the scattering layer 205 to be further scattered, and finally uniformly emerges from the opening of the cavity 217. Therefore, the optical utilization rate of the backlight module 200 will be further improved. Further, since the edge light source 25 is used, most of the light emitted by the point source 25 propagates around the optical plate 20, and the point source is converted into a surface light source, thereby reducing the light mixing distance. Therefore, the backlight module The .200 can reduce the height of the light box by using a smaller number of point sources, thereby reducing the cost and thickness of the backlight module 200. The backlight module 200 may further include a transparent plate (not shown) for covering the opening of the cavity 217, or a prism sheet (not labeled) may be added on the top of the four sidewalls 213 for improving the backlight module. 200 uniform brightness over a particular viewing angle range. In order to uniformly mix the light beam within the cavity and to enhance light utilization, the reflector 22 may further include a plurality of reflective sidewalls 223. It can be understood that the reflecting plate 22 of the present embodiment can be omitted, especially when the frame 21 is made of a highly reflective material or a highly reflective coating is applied to the inside of the bottom plate 211 and/or the side wall 213. Referring to Figure 5, there is shown an optical plate 30 in accordance with a second preferred embodiment of the present invention. The optical plate 30 is similar to the optical plate 20 of the first embodiment except that the apex angle of the micro-protrusions 306 of the optical plate 30 and the adjacent micro-protrusions 306 9 1355519 are formed by rounding the bottom corners. Fillets R1 and R2 are formed, respectively. The range of the rounded corners of R1 and R2 is preferably greater than 0 and less than or equal to 1.1 mm. The rounded micro-protrusions 306 tend to moderate the change in the exit angle of the outgoing beam, thereby improving the uniformity of light output from the backlight module using the optical plate 30. It can be understood that the above-described fillet design can also be separately performed on one of the apex angles of the micro-protrusions 306 and the bottom corner formed by the adjacent micro-bumps 306. Referring to Figure 6, there is shown an optical plate 40 of a preferred embodiment of the present invention. The optical plate 40 is similar to the optical plate 20 of the first preferred embodiment, and is not the same as the light source receiving portion 404 of the optical plate 40 being a blind hole recessed from the bottom surface 403 toward the inside of the optical plate 40. The backlight module using the optical plate 40 can be combined with an edge-light point source without a reflective element, or directly coated with a highly reflective layer at the bottom of the blind hole. Referring to Fig. 7, there is shown an optical plate .5 of the preferred embodiment 4 of the present invention. (U. The optical plate 50 is similar to the optical slab 20 of the preferred embodiment, except that the optical plate The scattering layer 505 of 50 is discontinuously distributed. In the present embodiment, the scattering layer 505 is a dot-like irregular arrangement. :? ': Above: In the embodiment, the optical plates 20, 30, 40, 50 are all integral. The large-sized optical plate of the present invention may be composed of a plurality of optical plate units of the above-described overall structure, or a plurality of light source accommodating portions may be provided for each of the optical plate units. The shape of the optical plates 20, 30, 40, 50 may be polygonal or circular, etc. in addition to the rectangular shape. The optical plate unit or the combined optical plate of the present invention may be provided with a plurality of light source accommodating portions, and the plurality of light source accommodating portions may be used, and the white light mixing backlight module of different colors may be used to make the white light mixing backlight module, or the same The side light-emitting diode of the color is made into a backlight module of a specific color. The distribution of the scattering layers at intervals of the optical plates in the above embodiments may also have the following conversion design. 10 1355519 As shown in FIG. 8 , the distribution of the scattering layer 605 on the light-emitting surface 602 is such that the light source accommodating portion 604 is centered, and the plurality of annular scattering layers 605 are spaced apart from each other, and the farther away from the light source accommodating portion 604, the annular shape The larger the radial thickness of the scattering layer 605, the better the uniformity of the light output of the optical plate. As shown in FIG. 9 , the distribution of the scattering layer 705 on the light-emitting surface 702 is such that the light-source accommodating portion 704 is centered, and the plurality of dot-like scattering layers 705 are distributed along the circular path and away from the light source accommodating portion 704 . The larger the diameter of the dot-like scattering layer 705 is, the larger the area is. This design is advantageous for improving the light uniformity of the optical plate. As shown in FIG. 10, the distribution of the scattering layer 805 on the light-emitting surface 802 is: centered on the light source receiving portion 804, and a plurality of dot-like scattering layers 805 of the same size are distributed along the circular orbital track, and the farther away from the light source receiving portion 804, the larger the arrangement density of the dot-like scattering layer 805, the design is advantageous for improving the light uniformity of the optical plate. In summary, the present invention has indeed met the requirements of the dictatorship of the hair, and has filed a patent application according to law. However, the above-mentioned embodiments are merely preferred embodiments of the present invention, and those skilled in the art will be able to include the following modifications and variations within the scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a conventional backlight module. 2 is a cross-sectional view of a backlight module in accordance with a preferred embodiment of the present invention. 3 is a perspective view of an optical plate of the backlight module shown in FIG. 2. Figure 4 is a cross-sectional view of the optical plate shown in Figure 3 taken along line V-V. Figure 5 is a cross-sectional view showing an optical plate of a preferred embodiment 2 of the present invention. Figure 6 is a cross-sectional view showing an optical plate according to a third preferred embodiment of the present invention. Figure 7 is a cross-sectional view showing an optical plate of a preferred embodiment 4 of the present invention. Fig. 8 to Fig. 10 are diagrams showing various distributions of the scattering layers of the optical sheets of the present invention, 1355519. [Main component symbol description] backlight module 200 optical plate 20 ' 30 > 40 ' 50 frame 21 reflector 22 point light source 25 light emitting surface 202 , 602 , 702 , 802 bottom surface 203 , 403 light source housing portion 204 ' 404 ' 604 , 704 '804 scattering layer 205 '505, 605, 705 '805 transparent resin 2052 scattering particles., · ·,: 2054 ······ · .: micro-bumps 206, 306 bottom plate factory 211 side wall 213 cavity 217 reflection Side wall 223 light exit portion 251 base portion 253 reflective element 255