1309321 九、發明說明： 【發明所屬之技術領域】 本發明係關於一種直下式背光模組(direct illuminance back light module)，尤指一種具有散熱孔設計之直下式背 光模組。 【先前技術】 隨著液晶顯示面板技術日益精進，液晶顯示面板已普遍 應用於數位相機、數位個人助理(PDA)、衛星導航系統以及 平面薄型化電視上。其中背光模組是液晶顯示器的關鍵零 組件之一。一般而言，背光模組係設於一液晶顯示面板的 下方，並利用至少一光源產生器與各種光學元件（如擴散 板、稜鏡等）的組合，以提供液晶顯示面板高亮度且均勻之 光源，然後再藉由控制液晶顯示面板上的像素電極以形成 適當的色彩，進而構成液晶顯示器使用者所觀察到之亮麗 影像。 根據光源之所在位置，背光模組可分成光源產生自液晶 顯示面板正下方的直下式背光模組或是光源來自液晶顯示 面板侧邊附近的侧光式（edge light)背光模組。其中直下式 1309321 背光模組係將光源產生器設於液晶顯示面板的正下方，可 提供較高亮度之光源，因此廣泛地應用於對亮度需求較高 或大尺寸的液晶顯示面板，例如電腦使用之液晶顯示器以 及家用液晶電視等。 請參考第1圖與第2圖，第1圖為一習知直下式背光模 組10外觀示意圖，第2圖為第1圖所示之直下式背光模組 10沿11’之剖面示意圖，其中為清楚表達直下式背光模組 10内部之配置，故第1圖中未顯示出擴散板等光學元件。 如第1圖與第2圖所示，習知直下式背光模組10包含有一 長方型之金屬背框(metal rear frame)12，作為直下式背光模 組10之基座，一環狀結構之殼體(housing) 14，垂直地欲固 於金屬背框12之四侧邊，以形成一容納空間，複數個光源 產生器（light source generator)16，容置於金屬背框12與殼 體14所形成之容納空間内，用以產生直下式背光模組10 所需之光源、一反射底板18設於金屬背框12之表面，用 以反射光源產生器16向下方發射出之光源以增加光的使 用率，一擴散板20，覆蓋於殼體14之側邊使上述容納空 間形成一近似密閉之空間，並將光源產生器16產生之光線 散射至上方之液晶顯示面板（圖未示）以提供均勻分散之光 線，以及複數片反射片22，分別以傾斜方式嵌固於殼體14 1309321 ^ ^樞12之邊緣位置，用以將光源產生器i6沿水平 的°射之光線反射至擴散板20。此外，-般在擴散板20 ^方通f另設有稜鏡，以進—步修正光源強度的差異， 液晶顯示面板接收到的光線能有—較均勻的照光強度 其中稜鏡之數量及順序可視需求加以變化。 大夕^又而S，由於直下式背光模組10中的光源產生器16 極、是由複數支燈官，如冷陰極螢光燈管（CCFL)或外部電 ^螢光燈官(EEFL)所構成，因此於放電時會產生高熱，此 為了要滿足尚凴度以及輕量化的要求，上述直下式背光 根細 〇中之光源產生器16係裝設於窄小的密閉空間中， 因此在操作時所產生的熱量往往無法順利的散發出去而會 不斷累積’然而一但操作時間稍長，會造成冷陰極螢光燈 官附近的溫度過高，影響螢光燈管的發光效率。 清參考第3圖，第3圖為一冷陰極螢光燈管之亮度與環 土兄溫度（ambient temperature)之關係圖。如第3圖所示，一 般較常作用光源產生器之冷陰極螢光燈管所產生之光源亮 度必需在週圍環境溫度約略在4(TC方能達到其最大值。然 而直下式背光模組1〇内部（特別是應用於大尺寸液晶顯示 面板之背光模組），由於冷陰極螢光燈管之數目較多，在長 1309321 時間運作後所產生之熱量無法排除造成溫度過高（一般大 尺寸液晶顯示面板之背光模組内部平均溫度往往高達50°C 以上），進而使發光效率下降而嚴重影響液晶顯示面板之亮 度表現。除此之外，直下式背光模組10内部溫度過大亦會 造成顯示品質的降低(例如部分區域的晝面容易產生晃動 或閃爍等現象），甚至大幅縮減周圍元件的使用壽命。 因此如何加強直下式背光模組的散熱能力，以維持穩定 的發光效率並保障元件壽命，實為當前之重要課題。 【發明内容】 因此本發明之主要目的即在於提供一種具有高散熱效 果之背光模組，以解決習知背光模組散熱效果不佳之問題。 於本發明之較佳實施例中，揭露了一種直下式背光模 組，其包含有至少一光源產生器用以提供光源、一殼體用 以容置該光源產生器，以及一金屬背框位於該殼體下方並 與該殼體相嵌合。該殼體相對於該光源產生器之表面上包 含有一反射底面以及二個第一反射斜面分別與該反射底面 之與該光源產生器平行的二側邊連接，以反射該光源產生 器之光源，且各該第一反射斜面上分別包含有至少一第一 1309321 散熱孔。該金屬背框與該等第一散熱孔對應之位置另包含 有複數個第二散熱孔，藉此與該等第一散熱孔形成複數個 散熱通道，利用熱對流方式排放該直下式背光模組内部之 熱能。 由於本發明所提供之直下式背光模組包含有複數個第 一散熱孔與第二散熱孔所構成之散熱通道，因此可達到有 效散熱之目的，同時各該散熱通道係為彎曲之通道，因此 可避免產生漏光問題。 為了使貴審查委員能更近一步了解本發明之特徵及 技術内容，請參閱以下有關本發明之詳細說明與附圖。然 而所附圖式僅供參考與辅助說明用，並非用來對本發明加 以限制者。 【實施方式】 請參考第4圖至第6圖，第4圖至第6圖為本發明直下 式背光模組50之一較佳實施例之示意圖，其中第4圖為直 下式背光模組50之外觀示意圖，第5圖為直下式背光模組 50沿4-4’方向之剖面圖，第6圖為直下式背光模組50之 元件分解圖。為清楚顯示直下式背光模組内部結構及配 1309321 置，第4圖中未顯示擴散板等光學元件。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a direct illuminance backlight module, and more particularly to a direct-type backlight module having a heat dissipation hole design. [Prior Art] With the increasing precision of liquid crystal display panel technology, liquid crystal display panels have been widely used in digital cameras, digital personal assistants (PDAs), satellite navigation systems, and flat thin televisions. The backlight module is one of the key components of the liquid crystal display. Generally, the backlight module is disposed under a liquid crystal display panel, and combines at least one light source generator with various optical components (such as a diffusion plate, a crucible, etc.) to provide a high brightness and uniformity of the liquid crystal display panel. The light source is then formed by controlling the pixel electrodes on the liquid crystal display panel to form an appropriate color, thereby constituting a bright image observed by the user of the liquid crystal display. Depending on the location of the light source, the backlight module can be divided into a direct-lit backlight module directly under the liquid crystal display panel or an edge light backlight module from the side of the liquid crystal display panel. The direct type 1309321 backlight module is provided with a light source generator directly under the liquid crystal display panel to provide a light source with higher brightness, and thus is widely used for a liquid crystal display panel with high brightness or large size, such as a computer. Liquid crystal display and home LCD TV. Please refer to FIG. 1 and FIG. 2 . FIG. 1 is a schematic diagram of a conventional direct type backlight module 10 , and FIG. 2 is a cross-sectional view of the direct type backlight module 10 taken along line 11 ′ of FIG. 1 . In order to clearly express the arrangement inside the direct type backlight module 10, optical elements such as a diffusion plate are not shown in Fig. 1. As shown in FIG. 1 and FIG. 2, the conventional direct type backlight module 10 includes a rectangular metal rear frame 12 as a base of the direct type backlight module 10, and a ring structure. The housing 14 is vertically fixed to the four sides of the metal back frame 12 to form a receiving space, and a plurality of light source generators 16 are received in the metal back frame 12 and the housing. The light source required for generating the direct-type backlight module 10 and the reflective bottom plate 18 are disposed on the surface of the metal back frame 12 for reflecting the light source emitted downwardly from the light source generator 16 to increase the light source formed by the light source generator 16 The use of light, a diffusing plate 20, covering the side of the casing 14 to form an approximately closed space of the accommodating space, and scattering the light generated by the light source generator 16 to the upper liquid crystal display panel (not shown) To provide uniformly dispersed light, and a plurality of reflective sheets 22, respectively, are embedded in an oblique manner at the edge of the housing 14 1309321 ^ pivot 12 for reflecting the light emitted by the light source generator i6 along the horizontal angle to the diffusion Board 20. In addition, in the diffuser plate 20 ^ square pass f is additionally provided with 稜鏡 to further correct the difference in the intensity of the light source, the light received by the liquid crystal display panel can have a relatively uniform illumination intensity, and the number and order of the 稜鏡Change as needed. Da Xi ^ and S, because the light source generator 16 in the direct type backlight module 10 is composed of a plurality of light officials, such as a cold cathode fluorescent tube (CCFL) or an external electric fluorescent lamp (EEFL). Since it is configured, high heat is generated during discharge, and in order to satisfy the requirements of reduction in weight and weight, the light source generator 16 in the direct type backlight backlight is installed in a narrow sealed space, so The heat generated during operation often cannot be smoothly dissipated and will accumulate continuously. However, once the operation time is slightly longer, the temperature near the cold cathode fluorescent lamp is too high, which affects the luminous efficiency of the fluorescent tube. Referring to Figure 3, Figure 3 is a graph showing the relationship between the brightness of a cold cathode fluorescent lamp and the ambient temperature. As shown in Fig. 3, the brightness of the light source generated by the cold cathode fluorescent lamp generally used as the light source generator must be approximately 4 in the ambient temperature (the TC can reach its maximum value. However, the direct type backlight module 1) 〇Inside (especially for backlight modules for large-size LCD panels), due to the large number of cold-cathode fluorescent tubes, the heat generated after the operation of 1309321 time cannot be ruled out to cause excessive temperature (generally large size) The average internal temperature of the backlight module of the liquid crystal display panel is often as high as 50 ° C or more, which further reduces the luminous efficiency and seriously affects the brightness performance of the liquid crystal display panel. In addition, the internal temperature of the direct-lit backlight module 10 is too large. The display quality is reduced (for example, the surface of the area is prone to sloshing or flickering), and the life of the surrounding components is greatly reduced. Therefore, how to enhance the heat dissipation capability of the direct type backlight module to maintain stable luminous efficiency and ensure components Lifetime is an important issue at present. [Invention] Therefore, the main object of the present invention is to provide a A backlight module having a high heat dissipation effect is provided to solve the problem of poor heat dissipation of the conventional backlight module. In a preferred embodiment of the present invention, a direct type backlight module is disclosed, which includes at least one light source generator for Providing a light source, a housing for accommodating the light source generator, and a metal back frame disposed under the housing and fitting the housing. The housing includes a reflective bottom surface on a surface of the light source generator And the two first reflective slopes are respectively connected to the two sides of the reflective bottom surface parallel to the light source generator to reflect the light source of the light source generator, and each of the first reflective slopes respectively includes at least one first 1309321 a plurality of second heat dissipation holes are disposed at the position corresponding to the first heat dissipation holes, thereby forming a plurality of heat dissipation channels with the first heat dissipation holes, and discharging the direct type by using heat convection Thermal energy inside the backlight module. The direct type backlight module provided by the present invention comprises a plurality of first heat dissipation holes and a second heat dissipation hole. This can achieve the purpose of effective heat dissipation, and each of the heat dissipation channels is a curved passage, thereby avoiding the problem of light leakage. In order to enable the reviewing committee to further understand the features and technical contents of the present invention, please refer to the following related to the present invention. The detailed description and the accompanying drawings are intended to be illustrative only, and are not intended to limit the scope of the invention. [Embodiment] Please refer to FIG. 4 to FIG. 6 and FIG. 4 to FIG. A schematic diagram of a preferred embodiment of the direct type backlight module 50 of the present invention, wherein FIG. 4 is a schematic diagram of the appearance of the direct type backlight module 50, and FIG. 5 is a view of the direct type backlight module 50 along the 4-4' direction. The cross-sectional view, Fig. 6 is an exploded view of the components of the direct-lit backlight module 50. In order to clearly show the internal structure of the direct-lit backlight module and the 1309321 arrangement, the optical components such as the diffusion plate are not shown in FIG.
如第4圖至第6圖所示，本發明直下式背光模組50包 含有一長方型之金屬背框52，作為直下式背光模組50之 基座，一環狀結構之殼體54，垂直地嵌固於金屬背框52 之四側邊，以形成一容納空間，複數個光源產生器56，容 置於金屬背框52與殼體54所形成之容納空間内，用以產 生直下式背光模組50所需之光源、一反射底板58設於金 屬背框52之表面，用以反射光源產生器56向下方發射出 之光源以增加光的使用率，一擴散板60覆蓋於殼體54之 側邊上使上述容納空間形成一近似密閉之反射腔室，並將 光源產生器56產生之光線散射至上方之液晶顯示面板（圖 未示），以提供均勻分散之光線，以及複數片反射片62，傾 斜方式嵌固於殼體54與金屬背框52之邊緣位置，以將光 源產生器56沿水平方向發射之光線反射至擴散板60。 一般而言，擴散板60的上方通常另設有稜鏡，以進一 步修正光源強度的差異，以使液晶顯示面板接收到的光線 能有一較均勻的照光強度分布，其中棱鏡之數量及順序可 視需求加以變化。金屬背框52係由鍍鋅鋼板、不銹鋼板、 鋁金屬板或鋁合金板等材質構成，以提供足夠的結構強度 10 1309321 與良好的熱傳導效果。光源產生器56係由複數條平行設置 於直下式背光模組50内之直線型冷陰極螢光燈管所構 成，亦可視需要使用U型冷陰極螢光燈管、外部電極螢光 燈管或發光二極體等，以提供液晶顯示面板足夠之光源需 求。反射底板58與反射片62之作用在於將光源產生器56 發射之光線反射至擴散板60，以增加光利用率，因此通常 係由高反射率材質構成，例如金屬或合金，亦或是利用表 面具有高反射材質之高分子材質所組成。 如上所述，由於冷陰極螢光燈管或其他類型之燈管於發 光時會伴隨著高熱之產生，同時為了提供良好的反射效果 以增加光利用率，直下式背光模組50内部均會儘量形成為 一密閉之反射腔室，更增加了散熱的困難。然而在高溫環 境下不僅冷陰極螢光燈管的發光效率會遞減，更會影響元 件壽命。因此為解決散熱問題，本發明直下式背光模組50 在與光源產生器56平行二相對侧邊之反射片62上包含有 複數個第一散熱孔64，且金屬背框52上鄰近第一散熱孔 64之位置亦包含有相對應之第二散熱孔66,藉此各第一散 熱孔64與相應應之第二散熱孔66會形成一彎曲之散熱通 道，以增加散熱效果。 1309321 當液晶顯示器實際使用時，冷陰極螢光燈管係呈水平方 向排列，換句話說，第一散熱孔64與第二散熱孔66所在 之二相對侧邊係位於液晶顯示器之底部與頂部，因此當冷 陰極螢光燈管產生之高熱能會因熱對流作用而自位於頂部 之第一散熱孔64與第二散熱孔66形成之散熱通道排出直 下式背光模組50之外，而外界温度較低之空氣亦會因熱對 流作用流入直下式背光模組50内部達到有效散熱的效 果。上述第一散熱孔64與第二散熱孔66設置於直下式背 光模組50之底部與頂部之目的除考量發揮熱對流作用而 有效散熱之外，冷陰極螢光燈管之電流平衡亦為設計上考 量之重點。而且第一散熱孔64與第二散熱孔66由於係與 冷陰極螢光燈管平行，因此同一燈管之溫度分佈不致相差 太大，進而可確保燈管之電流平.衡。另外值得注意的是， 為避免產生漏光問題而影響光利用率，本發明直下式背光 模組50所包含之第一散熱孔64係位於反射片62與反射底 板58接攘之位置，同時第二散熱孔66之位置與第一散熱 孔64係呈一彎曲角度設置，以形成一間接相通之散熱通 道。透過上述散熱通道設計，本發明直下式背光模組不僅 具有優良的散熱效果，同時亦可有效避免漏光情形。 經實際測試後，本發明直下式背光模組50之第一散熱 1309321 孔64與第二散熱孔66設計破實具有優良的散熱效果。為 顯示本發明直下式背光模組5〇之散熱效果，請參考第7圖· 與第8圖’第7圖為-應用於大尺寸液晶顯示面板之直下 式背光模組於長期間運作下内部之溫度分佈圖，第8圖為_ 包含有第-散熱孔64與第二散熱孔66設計之相同規格的, 直下式背光模組於相同的條件下内部之溫度分佈圖，其中 =一散熱孔64與第二散熱孔均為長方形之孔洞，且其寬度 分別為3mm與2.5mm。如第7圖與第8圖所示，一般直下馨 式背光模組於長時間運作後内部最大溫度高達6成，❿、 本發明直下式背紐組於相同條件下㈣最大溫度則為 58.〇t：，内部最大溫度下降超過代。此外部分位置之溫度 下降高達㈣，且平均溫度亦下降約穴。由此可顯示本 發=直下式背光模組5〇的確具有良好的散熱效果。此外， 由弟7圖與第8圖亦可發現直下式背光模組左右二側之溫 、月』下IV ’換句話說’透過第一散熱孔Μ與第二散熱孔暑 66 α又朽使得各冷陰㈣絲管内部之溫差減少，改善燈 管内部之電流平衡。 由上述可知本發明直下式背光模組的確具有良好的散 * 熱效果，然而第-散熱孔64與第二散熱孔66之數量與形 狀並不限制上述較佳實施例，而可視燈管之種類、數目、 13 1309321 光學設計與電流平衡等參數加以調整，以達到最佳散熱效 . 果。此外，直下式背光模組50之各元件可因不同設計需求 - 而具有異於上述較佳實施例揭露之結構。請參考第9圖， _ 第9圖為直下式背光模組50另一較佳實施例之分解示意 - 圖。如第9圖所示，直下式背光模組50主要包含有一金屬 屬 框架52、複數根光源產生器56、一反射底面58、一擴散 板60與二反射片62互相嵌合以形成一反射腔室，其中與 上述較佳實施例不同之處在於本較佳實施例之金屬框架52 ft 垂直於光源產生器5 6二側具有一體成型之傾斜反射面結 構，因此不需另設殼體藉以組合各元件，而反射底面58亦 可利用薄膜技術直接形成於金屬框架52之底表面。另外， 反射片62與金屬框架52分別包含有複數個錯位排列之第 一散熱孔64與第二散熱孔66，藉此發揮散熱之效果。 上述各實施例之組成結構雖略有差異，然而此類變化並 ® 不影響本發明之特徵與功效，即利用第一散熱孔與第二散 熱孔組成之間接散熱通道，在不影響光利用率與燈管内部 電流平衡的前提下有效利用熱對流作用快速散熱。另外值 得說明的是直下式背光模組因組裝需要，本身即具有不同 〈 用途之開孔，例如燈管之電極端開口，供燈管之電極端插 固並連接至一電源，或是其他結構開孔，如組裝孔或定位 14 1309321 孔，然而上述開孔於直下式背光模組組裝完成後均會被相 對應之元件或卡榫等所卡固而封閉，而有別於本發明之第 一散熱孔與第二散熱孔設計。 相較於習知技術，本發明直下式背光模組利用上述第一 散熱孔與第二散熱孔設計，經實際測試後不僅可加強散熱 效果與燈管之電流平衡，同時亦不會影響光利用率，因此 可有效提升直下式背光模組的發光效率，進而提升液晶顯 示面板之顯示效果。 以上所述僅為本發明之較佳實施例，凡依本發明申請專 利範圍所做之均等變化與修飾，皆應屬本發明專利之涵蓋 範圍。 【圖式fsi早說明】 第1圖為一習知直下式背光模組外觀示意圖。 第2圖為第1圖所示之直下式背光模組之剖面示意圖。 第3圖為一冷陰極螢光燈管之亮度與環境溫度之關係 圖。 第4圖至第6圖為本發明直下式背光模組之一較佳實施 例之示意圖。 15 1309321 第7圖為一習知直下式背光模組於長期間運作下内部之 溫度分佈圖。 第8圖為本發明直下式背光模組於相同的條件下内部之 溫度分佈圖。 第9圖為本發明直下式背光模組另一較佳實施例之分解 示意圖 【主要元件符號說明】 10 直下式背光模組 12 金屬背框 14 殼體 16 光源產生器 18 反射底板 20 擴散板 22 反射片_ 50 直下式背光模組 52 金屬背框 54 殼體 56 光源產生器 58 反射底面 60 擴散板 62 反射片 64 第一散熱孔 66 第二散熱孔As shown in FIG. 4 to FIG. 6 , the direct type backlight module 50 of the present invention comprises a rectangular metal back frame 52 as a base of the direct type backlight module 50 , and a ring-shaped structure 54 . The four sides of the metal back frame 52 are vertically embedded to form a receiving space, and a plurality of light source generators 56 are received in the receiving space formed by the metal back frame 52 and the housing 54 for generating a direct type. The light source and a reflective substrate 58 of the backlight module 50 are disposed on the surface of the metal back frame 52 for reflecting the light source emitted downwardly from the light source generator 56 to increase the light usage rate. A diffusion plate 60 covers the housing. The side of the 54 is configured to form an approximately closed reflective chamber, and the light generated by the light source generator 56 is scattered to the upper liquid crystal display panel (not shown) to provide uniformly dispersed light, and a plurality of The reflection sheet 62 is obliquely embedded at an edge of the housing 54 and the metal back frame 52 to reflect the light emitted from the light source generator 56 in the horizontal direction to the diffusion plate 60. Generally, the top of the diffuser plate 60 is usually further provided with a beak to further correct the difference in the intensity of the light source, so that the light received by the liquid crystal display panel can have a relatively uniform illumination intensity distribution, wherein the number and order of the prisms can be visually required. Change it. The metal back frame 52 is made of a galvanized steel plate, a stainless steel plate, an aluminum metal plate or an aluminum alloy plate to provide sufficient structural strength 10 1309321 and good heat conduction. The light source generator 56 is composed of a plurality of linear cold cathode fluorescent tubes disposed in parallel in the direct type backlight module 50. U-shaped cold cathode fluorescent tubes, external electrode fluorescent tubes or Light-emitting diodes, etc., to provide sufficient light source requirements for liquid crystal display panels. The reflection bottom plate 58 and the reflection sheet 62 function to reflect the light emitted from the light source generator 56 to the diffusion plate 60 to increase the light utilization efficiency, and thus are usually composed of a high reflectivity material such as a metal or an alloy, or a surface. It is composed of a polymer material with a highly reflective material. As described above, since the cold cathode fluorescent lamp or other types of lamps are accompanied by high heat generation while emitting light, and in order to provide a good reflection effect to increase the light utilization efficiency, the direct type backlight module 50 will try to be internal. Formed as a closed reflective chamber, it increases the difficulty of heat dissipation. However, in the high temperature environment, not only the luminous efficiency of the cold cathode fluorescent tube is degraded, but also the life of the element is affected. Therefore, in order to solve the problem of the heat dissipation, the direct-type backlight module 50 of the present invention includes a plurality of first heat dissipation holes 64 on the reflection sheet 62 opposite to the side opposite to the light source generator 56, and the first heat dissipation hole is adjacent to the metal back frame 52. The position of the hole 64 also includes a corresponding second heat dissipation hole 66, whereby each of the first heat dissipation holes 64 and the corresponding second heat dissipation hole 66 form a curved heat dissipation channel to increase the heat dissipation effect. 1309321 When the liquid crystal display is actually used, the cold cathode fluorescent lamp tubes are arranged in a horizontal direction. In other words, the opposite sides of the first heat dissipation hole 64 and the second heat dissipation hole 66 are located at the bottom and the top of the liquid crystal display. Therefore, when the high thermal energy generated by the cold cathode fluorescent lamp tube is discharged from the heat dissipation channel formed by the first heat dissipation hole 64 and the second heat dissipation hole 66 at the top due to the heat convection, the external temperature is discharged outside the direct type backlight module 50. The lower air also flows into the direct-type backlight module 50 due to thermal convection to achieve effective heat dissipation. The first heat dissipation hole 64 and the second heat dissipation hole 66 are disposed on the bottom and the top of the direct type backlight module 50. The current balance of the cold cathode fluorescent lamp is also designed in addition to the effective heat dissipation. The focus of the consideration. Moreover, since the first heat dissipation holes 64 and the second heat dissipation holes 66 are parallel to the cold cathode fluorescent lamp tube, the temperature distribution of the same lamp tube is not too different, thereby ensuring the current balance of the lamp tube. It is also noted that, in order to avoid the light leakage problem and affect the light utilization rate, the first heat dissipation hole 64 included in the direct type backlight module 50 of the present invention is located at the position where the reflection sheet 62 and the reflective bottom plate 58 are connected, and the second The position of the heat dissipation hole 66 is disposed at a bending angle with the first heat dissipation hole 64 to form an indirect communication heat dissipation channel. Through the above heat dissipation channel design, the direct type backlight module of the invention not only has excellent heat dissipation effect, but also effectively avoids light leakage. After the actual test, the first heat dissipation 1309321 hole 64 and the second heat dissipation hole 66 of the direct type backlight module 50 of the present invention are designed to be broken and have excellent heat dissipation effect. In order to show the heat dissipation effect of the direct type backlight module 5 of the present invention, please refer to FIG. 7 and FIG. 8 'the seventh picture is - the direct type backlight module applied to the large-size liquid crystal display panel is operated for a long period of time. The temperature distribution map, FIG. 8 is a temperature distribution diagram of the direct-type backlight module under the same conditions, wherein the first heat dissipation hole 64 and the second heat dissipation hole 66 are designed to have the same specifications, wherein = a heat dissipation hole Both the 64 and the second heat dissipation holes are rectangular holes, and the widths thereof are 3 mm and 2.5 mm, respectively. As shown in Fig. 7 and Fig. 8, the maximum internal temperature of the direct-lit sin-type backlight module is as high as 60% after long-term operation, and the maximum temperature of the direct-type back-up group of the present invention is (58). 〇t: The internal maximum temperature drops more than the generation. In addition, the temperature of some locations drops by as much as (4), and the average temperature also drops by about acupoints. Therefore, it can be shown that the present invention has a good heat dissipation effect. In addition, from the brothers 7 and 8 can also find the temperature of the left and right sides of the direct-lit backlight module, under the moon, IV 'in other words, 'through the first cooling hole Μ and the second cooling hole heat 66 α decay makes The temperature difference inside each cold (four) wire tube is reduced, and the current balance inside the lamp tube is improved. It can be seen from the above that the direct type backlight module of the present invention does have a good heat dissipation effect, however, the number and shape of the first heat dissipation hole 64 and the second heat dissipation hole 66 do not limit the above preferred embodiment, and the type of the visible light tube , number, 13 1309321 optical design and current balance parameters are adjusted to achieve the best heat dissipation. In addition, the components of the direct-lit backlight module 50 may have different structures than those disclosed in the above preferred embodiments due to different design requirements. Please refer to FIG. 9, FIG. 9 is an exploded schematic view of another preferred embodiment of the direct type backlight module 50. As shown in FIG. 9, the direct type backlight module 50 mainly includes a metal frame 52, a plurality of light source generators 56, a reflective bottom surface 58, a diffusion plate 60 and two reflection sheets 62 are fitted to each other to form a reflection cavity. The difference from the above preferred embodiment is that the metal frame 52 ft of the preferred embodiment has an integrally formed inclined reflecting surface structure perpendicular to the two sides of the light source generator 56, so that no separate housing is required to combine The components, while the reflective bottom surface 58 can also be formed directly on the bottom surface of the metal frame 52 using thin film technology. Further, the reflection sheet 62 and the metal frame 52 respectively include a plurality of first heat dissipation holes 64 and second heat dissipation holes 66 arranged in a misaligned manner, thereby exerting an effect of heat dissipation. Although the composition of the above embodiments is slightly different, such a variation does not affect the features and effects of the present invention, that is, the first heat dissipation hole and the second heat dissipation hole are used to form a heat dissipation channel, which does not affect the light utilization rate. Under the premise of balancing the internal current of the lamp tube, the heat convection is effectively utilized to quickly dissipate heat. It is also worth noting that the direct-lit backlight module itself has different openings for the purpose of assembly, such as the electrode end opening of the lamp tube, the electrode end of the lamp tube is inserted and connected to a power source, or other structure. Opening holes, such as assembling holes or positioning 14 1309321 holes, however, the above-mentioned openings are closed by the corresponding components or cassettes after the assembly of the direct-type backlight module is completed, and are different from the present invention. A heat dissipation hole and a second heat dissipation hole are designed. Compared with the prior art, the direct-type backlight module of the present invention utilizes the first heat dissipation hole and the second heat dissipation hole design, and after actual testing, not only can the heat dissipation effect and the current balance of the lamp tube be enhanced, but also the light utilization is not affected. The rate can effectively improve the luminous efficiency of the direct type backlight module, thereby improving the display effect of the liquid crystal display panel. The above are only the preferred embodiments of the present invention, and all changes and modifications made to the patentable scope of the present invention should be covered by the present invention. [Illustration of fsi early] Fig. 1 is a schematic view of the appearance of a conventional direct type backlight module. Fig. 2 is a schematic cross-sectional view of the direct type backlight module shown in Fig. 1. Figure 3 is a graph showing the relationship between the brightness of a cold cathode fluorescent lamp and the ambient temperature. 4 to 6 are schematic views showing a preferred embodiment of the direct type backlight module of the present invention. 15 1309321 Figure 7 is a diagram showing the temperature distribution inside a conventional direct type backlight module under long-term operation. Figure 8 is a diagram showing the temperature distribution inside the direct type backlight module of the present invention under the same conditions. FIG. 9 is an exploded perspective view of another preferred embodiment of the direct-lit backlight module of the present invention. [Main component symbol description] 10 Direct-type backlight module 12 Metal back frame 14 Housing 16 Light source generator 18 Reflecting substrate 20 Diffusion plate 22 Reflector _ 50 Direct Backlight Module 52 Metal Back Frame 54 Housing 56 Light Source Generator 58 Reflective Bottom Surface 60 Diffuser Plate 62 Reflector 64 First Cooling Hole 66 Second Cooling Hole