201024600 r υ〇υ j yj oivi^j 1TW^ 29458twf.doc/ d 六、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與應用此背光模組的液晶 顯示裝置，且特別是有關於一種具有塑膠背板與補強肋的背光 模組與應用此背光模組的液晶顯示裝置。 【先前技術】 在一般液晶顯示裝置中，由於液晶顯示面板並不具有主動 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 ❹供一面光源，使液晶顯示面板能達到顯示的目的。因此，背光 模組是液晶顯示裝置的關鍵零組件之一，目前已普遍應用於數 位相機、數位個人助理及平面電視等電子產品上。 目前市面上的電子產品皆以輕量化為訴求，液晶顯示裝置 的減重設計也愈來愈受到重視。在整個液晶顯示裝置中，重量 比重佔據最多的部分為背光模組的背板。在習知的背光模組 中，背板多以鍍鋅鋼板或是其他金屬材質製成。金屬背板雖然 具有良好的強度，但是重量也相當重，因此在輕量化設計中， 背板是最需要改良的部份。 ❿【發明内容】 本發明提供一種燈箱，可大幅減輕燈箱的重量。 本發明提供一種背光模組，可大幅減輕背光模組的重量。 本發明提供一種液晶顯示裝置，其背光模組的重量較輕。 本發明提出一種燈箱，此燈箱具有一塑膠背板與至少一補 強肋。補強肋埋設於塑膠背板，且補強肋的硬度大於塑膠背板 的硬度。 本發明提出一種背光模組，此背光模組包括一燈箱、一光 源與-光學膜片組。燈箱具有塑勝背板與補強肋，其中補強肋 3 201024600 ruo^^joivi^iXW 29458twf.doc/d 埋設於塑膠背板，且補強肋的硬度大於塑膠背板的硬度。光源 配置於燈箱中，且光源位於光學膜片組與塑膠背板之間。 本發明提出一種液晶顯示裝置，此液晶顯示裝置包括前述 的月光模組與一液晶面板，液晶面板配置於背光模組上。 在本發明之燈箱、背光模組與液晶顯示裝置的一實施例 中，前述的至少一補強肋包括互相平行的兩個第一直條補強 肋。此外’前述的至少一補強肋更可包括一第二直條補強肋， 其垂直這些第一直條補強肋且位於這些第一直條補強肋之間。 籲在本發明之燈箱、背光模組與液晶顯示裝置的一實施例 中，補強肋呈口字型、X字型、H字型或井字型。 在本發明之燈箱、背光模組與液晶顯示裝置的一實施例 中，補強肋具有至少一螺絲孔’塑膠背板暴露出螺絲孔。 在本發明之燈箱、背光模組與液晶顯示裝置的一實施例 中’補強肋的材質為金屬。 在本發明之背光模組與液晶顯示裝置的一實施例中，其中 光源包括多個冷陰極榮光燈管。 在本發明之背光模組與液晶顯示裝置的一實施例中，背光 ©模組更包括-反射片，配置於燈箱中且位於光源與塑膠背板之 在本發月之月光模組與液晶顯示裝置的一實施例中光學 膜片組包括二擴散板、—增W與―擴散片至少其中之一。 基於上述’在本發明之背域組與液錢示裝置中，塑膠 ιΐ可^減輕背光模組的重量，達到減重的目的。同時，埋 #板内的顯賴使塑膠背板具有足_強度支撐 月光挺組。 為讓本發明之上述特徵和優點能更明㈣懂，下文特舉實 201024600 太 "山vmlTW 29458twf.doc/d 施例，並配合所附圖式作詳細說明如下。 【實施方式】 圖1為本發明第一實施例之液晶顯示裝置的局部剖面 圖，圖2為圖1之液晶顯示裝置的塑膠背板的示意圖。請同時 參照圖1與圖2，液晶顯示裝置100包括一背光模組11〇與配 置於背光模組110上的一液晶面板120。 背光模組110包括一燈箱112、一光源114與一光學膜片 組116。燈箱112具有塑膠背板112a與補強肋112b，且補強 ❹肋112b的硬度大於塑膠背板112a的硬度。光源114配置於燈 箱112中，位於光學膜片組116與塑膠背板112a之間，而光 學膜片組116位於光源114與液晶面板120之間。光源114可 為冷陰極螢光燈管、發光二極體或是其他發光元件。在本實施 例中背光模組110更包括一反射片118,反射片118配置於燈 箱112中且位於光源114與塑膠背板112a之間。反射片118 可將光源114往塑膠背板112a方向射出的光線反射出燈箱 112 ’以提高光線使用率。在本實施例中光學膜片組116可包 括一擴散板116a、一增光片116b與一擴散片116c，用以將光 ® 源114發出的光線擴散為亮度均勻的面光源，並可提升面光源 之光學特性’以提升液晶顯示裝置100的顯示品質。 由於補強肋112b的硬度大於塑膠背板112a的硬度，因此 在塑膠背板112a中埋設補強肋ii2b能夠讓塑膠背板112a具 有足夠的強度支撐背光模組11〇。同時，由於塑膠背板U2a 的比重較輕，因此也可達成減少液晶顯示裝置1〇〇的整體重量 的目的。本實施例之補強肋112b為兩條互相平行的直條補強 肋。補強肋112b的材質可為金屬或其它硬度較大的材質。塑 骖为板112a與補強肋112b的材料硬度可利用美國材料測試學 5 201024600 29458twf.doc/d 會(American Society for Testing and Materials, ASTM)的標準物 質強度測試方法來測量，例如可根據ASTM-E-18進行洛氏硬 度試驗（Rockwell hardness test)，或是以 ASTM-E-10 進行布 氏硬度試驗（Brinell hardness test)。 在洛氏硬度試驗中，測試機台的壓頭會被施加一初始試驗 力，將壓頭垂直壓入待測材料表面。然後施加主試驗力，將壓 頭壓入試驗材料中並保持一段時間，再撤除主試驗力，而繼續 保持初始試驗力。施加主試驗力後與施加主試驗力前的壓痕深 ❿度的差值與材料的洛氏硬度值有著線形關係，在洛氏硬度標尺 上母2微米（μιη)的壓痕深度差值代表一個落氏硬度刻度， 藉此測得材料的洛氏硬度。 在布氏硬度試驗中，一般採用直徑為10公釐（mm)的球 型鋼頭。對球型鋼頭施以一定的試驗力壓入待測材料中，一般 (用的試驗力大小為3000公斤力（kgf)或是29千牛頓（kN)， 若疋用於軟質材料，則可施以較小的試驗力。將球型鋼頭魔入 材料一定時間後再卸除試驗力，並測量材料表面留下的壓痕之 直徑。把測得的數值代入布氏硬度的計算公式，即可得到材料 ❹的布氏硬度。布氏硬度的計算公式為：ΗΒθΡ/ίτΓΟαΧνΛ (D d))]’其中ρ為試驗力，d為壓頭直徑，d為壓痕直徑。 此外’補強肋112b可設計有螺絲孔H10’而塑膠背板112a 也將螺絲孔H10暴露出來。藉此，使用者在固定液晶顯示裝 置10〇時可將螺絲S10鎖附於補強肋112b上，例如是在將液 晶顯示裝置100固定於壁掛支架時（未繪示）。 另外，當補強肋112b採用金屬材質時，除了具有良好的 硬度外，還具有屏蔽電磁波的功效。具體而言，只要使補強肋 112b透過適當的路徑進行接地，即可產生屏蔽電磁波的功效。 6 201024600 ri TW 29458twf doc/d 例如’當補強肋112b藉由螺絲si〇固定於壁掛支架時，可將 壁掛支架接地以產生屏蔽電磁波的功效。在補強肋U2b的埋 設位置方面’可事先透過模擬分析找出塑膠背板n2a上所承 受的應力最大的位置而將補強肋112b埋設於此處。在製造方 面，例如可採用射出成形的方式形成塑膠背板U2a。補強肋 112b可放置於射出成形機台的模穴的相對位置，以使補強肋 112b在塑膠背板ll2a射出成形後即埋設於預定處。 本發明之背光模組與液晶顯示裝置的補強肋的形狀與配 置位置不限於前述實施例所述，以下另舉出數個實施例說明。 下列各實施例的液晶顯示裝置與圖i的液晶顯示裝置1〇〇大致 相同’以下僅針對不同之處進行說明。 圖3為本發明第二實施例之液晶顯示裝置的塑膠背板的 示意圖。請參照圖3 ’本實施例之液晶顯示裝置的塑膠背板212 中埋設兩個互相平行的直條補強肋214a以及一個直條補強肋 214b。其中，直條補強肋214b位於兩個直條補強肋214a之間 且垂直直條補強肋214a。 圖4至圖7為本發明另外四種實施例之液晶顯示裝置的塑 Φ膠背板的示意圖。請參照圖4，塑膠背板312内埋設的補強肋 314王口子型。請參照圖5 ’塑膠背板412内埋設的補強肋414 呈X字型。請參照圖6，塑膠背板512内埋設的補強肋514呈 Η字型。請參照圖7，塑膠背板612内埋設的補強肋614呈井 字型。 綜上所述，在本發明的背光模組中，採用塑膠材質的背板 而可大幅減輕背光模組的重量，使應用此背光模組的液晶顯示 裝置得以輕量化。同時，埋設於塑膠背板中的補強肋可增強塑 膠背板的整體強度’使塑膠背板不需要增加厚度即可維持足夠 7 201024600 J'UisujyiiiM^lTW 29458twf.doc/d 的強度。此外，採用金屬材質的補強肋時還可發揮屏蔽你 的功效。 兔域波 雖然本發明已以實施例揭露如上，然其並非用以限定本發 明、，任何所屬技術領域中具有通常知識者，在不脫離本發明^ 精神和範圍内，當可作些許之更動與潤飾，故本發明之保護範 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為本發明第一實施例之液晶顯示裝置的局部剖面圖。 鲁 圖2為圖1之液晶顯示裝置的塑膠背板的示意圖。 — 圖3為本發明第二實施例之液晶顯示裝置的塑膠背板的 不:意圖。 圖4至圖7為本發明另外四種實施例之液晶顯示奘1的塑 膠背板的示意圖。 【主要元件符號說明】 100 :液晶顯示裝置 110 :背光模組 112 :燈箱 112a、212、312、412、512、612 ··塑膠背板 % 112b、214、314、414、514、614 :補強肋 114 :光源 116 :光學膜片組 116a :擴散板 116b :增光片 116c :擴散片 118 :反射片 214a、214b :直條補強肋 120 ·液晶面板 H10 :螺絲孔 S10 :螺絲 8201024600 r υ〇υ j yj oivi^j 1TW^ 29458twf.doc/ d VI. Description of the Invention: [Technical Field] The present invention relates to a backlight module and a liquid crystal display device using the same, and In particular, there is a backlight module having a plastic back plate and a reinforcing rib, and a liquid crystal display device using the backlight module. [Prior Art] In a general liquid crystal display device, since the liquid crystal display panel does not have the function of active light emission, a backlight module must be disposed under the liquid crystal display panel to provide a light source for the liquid crystal display panel to achieve display. purpose. Therefore, the backlight module is one of the key components of the liquid crystal display device, and has been widely used in electronic products such as digital cameras, digital personal assistants, and flat-panel televisions. At present, electronic products on the market are all demanding for weight reduction, and the weight reduction design of liquid crystal display devices is receiving more and more attention. In the entire liquid crystal display device, the portion where the weight specific gravity occupies the most is the back plate of the backlight module. In the conventional backlight module, the back plate is mostly made of galvanized steel or other metal materials. Although the metal back plate has good strength, but the weight is also very heavy, in the lightweight design, the back plate is the most in need of improvement. SUMMARY OF THE INVENTION The present invention provides a light box that can greatly reduce the weight of the light box. The invention provides a backlight module, which can greatly reduce the weight of the backlight module. The invention provides a liquid crystal display device, wherein the backlight module has a light weight. The present invention provides a light box having a plastic backing plate and at least one reinforcing rib. The reinforcing ribs are embedded in the plastic backing plate, and the hardness of the reinforcing ribs is greater than the hardness of the plastic backing plate. The invention provides a backlight module, which comprises a light box, a light source and an optical film set. The light box has a plastic backing plate and a reinforcing rib, wherein the reinforcing rib 3 201024600 ruo^^joivi^iXW 29458twf.doc/d is embedded in the plastic back plate, and the hardness of the reinforcing rib is greater than the hardness of the plastic back plate. The light source is disposed in the light box, and the light source is located between the optical film set and the plastic back plate. The present invention provides a liquid crystal display device comprising the moonlight module and a liquid crystal panel, and the liquid crystal panel is disposed on the backlight module. In an embodiment of the light box, the backlight module and the liquid crystal display device of the present invention, the at least one reinforcing rib includes two first straight reinforcing ribs which are parallel to each other. Further, the aforementioned at least one reinforcing rib may further include a second straight reinforcing rib which is perpendicular to the first straight reinforcing ribs and located between the first straight reinforcing ribs. In an embodiment of the light box, the backlight module and the liquid crystal display device of the present invention, the reinforcing rib is in the form of a mouth shape, an X shape, an H shape or a well type. In an embodiment of the light box, backlight module and liquid crystal display device of the present invention, the reinforcing rib has at least one screw hole. The plastic back plate exposes the screw hole. In an embodiment of the light box, the backlight module and the liquid crystal display device of the present invention, the material of the reinforcing rib is metal. In an embodiment of the backlight module and liquid crystal display device of the present invention, wherein the light source comprises a plurality of cold cathode glory tubes. In an embodiment of the backlight module and the liquid crystal display device of the present invention, the backlight © module further includes a reflective sheet disposed in the light box and located in the moonlight module and the liquid crystal display of the light source and the plastic back sheet. In one embodiment of the apparatus, the optical film set includes at least one of a two diffusion plate, a W and a diffusion sheet. Based on the above, in the back domain group and the liquid money display device of the present invention, the plastic ι can reduce the weight of the backlight module and achieve the purpose of weight reduction. At the same time, the reliance on the buried plate makes the plastic back plate have a foot-strength support. In order to make the above features and advantages of the present invention more comprehensible (four), the following is a special example of the 201024600 too "Mountain vmlTW 29458twf.doc/d example, and is described in detail with the accompanying drawings. 1 is a partial cross-sectional view showing a liquid crystal display device according to a first embodiment of the present invention, and FIG. 2 is a schematic view showing a plastic back plate of the liquid crystal display device of FIG. 1. Referring to FIG. 1 and FIG. 2 simultaneously, the liquid crystal display device 100 includes a backlight module 11A and a liquid crystal panel 120 disposed on the backlight module 110. The backlight module 110 includes a light box 112, a light source 114 and an optical film set 116. The light box 112 has a plastic backing plate 112a and a reinforcing rib 112b, and the reinforcing rib 112b has a hardness greater than that of the plastic backing plate 112a. The light source 114 is disposed in the light box 112 between the optical film set 116 and the plastic backing plate 112a, and the optical film set 116 is located between the light source 114 and the liquid crystal panel 120. The light source 114 can be a cold cathode fluorescent tube, a light emitting diode or other light emitting element. In this embodiment, the backlight module 110 further includes a reflective sheet 118 disposed in the light box 112 and located between the light source 114 and the plastic back sheet 112a. The reflective sheet 118 reflects the light emitted from the light source 114 toward the plastic backing plate 112a out of the light box 112' to improve light utilization. In this embodiment, the optical film set 116 may include a diffusing plate 116a, a brightness enhancing plate 116b and a diffusing film 116c for diffusing the light emitted by the light source 114 into a uniform surface light source and lifting the surface light source. The optical characteristics 'to improve the display quality of the liquid crystal display device 100. Since the hardness of the reinforcing rib 112b is greater than the hardness of the plastic backing plate 112a, embedding the reinforcing rib ii2b in the plastic backing plate 112a enables the plastic backing plate 112a to have sufficient strength to support the backlight module 11〇. At the same time, since the plastic backing plate U2a has a light specific gravity, the object of reducing the overall weight of the liquid crystal display device 1 can also be achieved. The reinforcing rib 112b of this embodiment is two straight reinforcing ribs which are parallel to each other. The material of the reinforcing rib 112b may be metal or other material having a relatively high hardness. The material hardness of the plastic sheet 112a and the reinforcing rib 112b can be measured by the standard material strength test method of American Society for Testing and Materials (ASTM), for example, according to ASTM- E-18 is subjected to a Rockwell hardness test or a Brinell hardness test by ASTM-E-10. In the Rockwell hardness test, the indenter of the test machine is subjected to an initial test force to press the indenter vertically into the surface of the material to be tested. The main test force is then applied, the indenter is pressed into the test material for a period of time, and the main test force is removed, and the initial test force is maintained. The difference between the depth of the indentation before applying the main test force and the depth of the indentation before the application of the main test force has a linear relationship with the Rockwell hardness value of the material. The difference of the indentation depth of the 2 micron (μιη) on the Rockwell hardness scale represents A Rockwell hardness scale is used to measure the Rockwell hardness of the material. In the Brinell hardness test, a spherical steel head having a diameter of 10 mm (mm) is generally used. The spherical steel head is pressed into the material to be tested with a certain test force. Generally, the test force is 3000 kg force (kgf) or 29 kN (kN). If the crucible is used for soft materials, it can be applied. With a small test force, the spherical steel head is removed into the material for a certain period of time before the test force is removed, and the diameter of the indentation left on the surface of the material is measured. The measured value is substituted into the calculation formula of Brinell hardness. The Brinell hardness of the material is obtained. The Brinell hardness is calculated as: ΗΒθΡ/ίτΓΟαΧνΛ (D d))] where ρ is the test force, d is the diameter of the indenter, and d is the diameter of the indentation. Further, the reinforcing rib 112b may be designed with a screw hole H10' and the plastic back plate 112a also expose the screw hole H10. Thereby, the user can lock the screw S10 to the reinforcing rib 112b when fixing the liquid crystal display device 10, for example, when the liquid crystal display device 100 is fixed to the wall mount (not shown). Further, when the reinforcing rib 112b is made of a metal material, in addition to having a good hardness, it also has the effect of shielding electromagnetic waves. Specifically, as long as the reinforcing rib 112b is grounded through an appropriate path, the effect of shielding electromagnetic waves can be produced. 6 201024600 ri TW 29458twf doc/d For example, when the reinforcing rib 112b is fixed to the wall bracket by screws si, the wall bracket can be grounded to produce electromagnetic shielding. In terms of the embedding position of the reinforcing rib U2b, the reinforcing rib 112b can be buried therein by the simulation analysis to find the position where the stress on the plastic backing plate n2a is the largest. In terms of manufacturing, for example, the plastic back sheet U2a can be formed by injection molding. The reinforcing rib 112b can be placed at a position opposite to the cavity of the injection molding machine so that the reinforcing rib 112b is buried at a predetermined position after the plastic backing plate 11b is injection molded. The shape and arrangement position of the reinforcing ribs of the backlight module and the liquid crystal display device of the present invention are not limited to those described in the foregoing embodiments, and several embodiments will be described below. The liquid crystal display devices of the following embodiments are substantially the same as those of the liquid crystal display device 1 of Fig. i. Hereinafter, only differences will be described. Fig. 3 is a schematic view showing a plastic back sheet of a liquid crystal display device according to a second embodiment of the present invention. Referring to FIG. 3, two plastic parallel reinforcing ribs 214a and a straight reinforcing rib 214b are embedded in the plastic backing plate 212 of the liquid crystal display device of the present embodiment. Among them, the straight reinforcing rib 214b is located between the two straight reinforcing ribs 214a and the vertical straight reinforcing rib 214a. 4 to 7 are schematic views of a plastic Φ rubber back sheet of a liquid crystal display device according to still another embodiment of the present invention. Referring to FIG. 4, the reinforcing rib 314 is embedded in the plastic backing plate 312. Referring to Figure 5, the reinforcing ribs 414 embedded in the plastic backing plate 412 are X-shaped. Referring to FIG. 6, the reinforcing ribs 514 embedded in the plastic backing plate 512 are U-shaped. Referring to Figure 7, the reinforcing ribs 614 embedded in the plastic backing plate 612 are of a well type. In summary, in the backlight module of the present invention, the back plate of the plastic material can be used to greatly reduce the weight of the backlight module, and the liquid crystal display device to which the backlight module is applied can be lightened. At the same time, the reinforcing ribs embedded in the plastic backing plate can enhance the overall strength of the plastic backing plate. The plastic backing plate can maintain sufficient strength without increasing the thickness of the plastic backing plate. In addition, the use of metal reinforcement ribs can also play a role in shielding you. The present invention has been disclosed in the above embodiments, but it is not intended to limit the invention, and any one of ordinary skill in the art can make some changes without departing from the spirit and scope of the invention. The scope of protection of the present invention is defined by the scope of the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a partial cross-sectional view showing a liquid crystal display device according to a first embodiment of the present invention. Lu Figure 2 is a schematic view of the plastic back sheet of the liquid crystal display device of Figure 1. - Figure 3 is a schematic view of a plastic back sheet of a liquid crystal display device according to a second embodiment of the present invention. 4 to 7 are schematic views of a plastic back sheet of a liquid crystal display cartridge 1 according to still another embodiment of the present invention. [Description of main component symbols] 100: Liquid crystal display device 110: Backlight module 112: Light boxes 112a, 212, 312, 412, 512, 612 · Plastic back sheets % 112b, 214, 314, 414, 514, 614: Reinforcing ribs 114: light source 116: optical film group 116a: diffusion plate 116b: brightness enhancement sheet 116c: diffusion sheet 118: reflection sheet 214a, 214b: straight reinforcing rib 120 • liquid crystal panel H10: screw hole S10: screw 8