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液晶顯示裝置，特別關 於一種光源與導光板間相互定位之背光模組及液晶顯示 裝置。 【先前技術】 液晶顯示裝置（Liquid Crystal Display apparatus, LCD apparatus)因具備有重量輕、厚度薄、低驅動電壓及低耗電 流等特性，被廣泛的應用在各行各業上。液晶顯示裝置主 要包含有液晶顯示面板(Liquid Crystal Display Panel, LCD panel)及背光模組（Back Light Module)，因液晶本身不發 光，因此，背光模組的主要功能在於提供液晶顯示面板一 均勻分布之面光源。 背光模組可因光源設置位置的不同，而分為直下式 (Direct Type)及側光式(Edge light Type)兩種背光模組。 請參照圖1A及圖1B所示，其中，圖1A係為習知侧 光式背光模組之俯視平面示意圖，圖1B為習知侧光式背 光模組之側視剖面示意圖。背光模組1包含一光源11、一 導光板12、一電路板13及一背框14。光源11係為一發 光二極體，其設置於電路板13上，電路板13及導光板12 分別設置於背框14上，且電路板13之一側與背框14之 一接觸面141相接觸，其中，光源11鄰設於導光板12的 側邊，使得光線從導光板12側邊之入光面121射入導光 5 1351561 板12。 一般而言，光源11(尤其是發光二極體）與導光板12 間的距離D1需要有一固定預設值（約為5〜10mm)，以有效 控制光源11所發出之光線在導光板12内的混光距離。於 習知技術中，光源11係設置於電路板13上，而電路板13 導光板12之間並沒有相互定位的結構。因而在組裝時， 組裝人員係利用電路板13抵靠於背框14,而導光板12自 行結合於背框14上。因此會造成光源11與導光板12之 間的距離D1，受到上述三種組裝公差的影響（光源11、導 光板12及背框14)，易造成設置於電路板13上的光源11 與導光板12之入光面121間的距離D1不易維持在預設 值，易造成光源11射入導光板12的光線混光不均勻。 【發明内容】 有鑑於上述課題，本發明之目的為提供一種可準確且 快速定位光源與導光板間之距離的背光模組及液晶顯示 裝置。 緣是，為達上述目的，本發明係揭露一種背光模組， 背光模組包含一光源、一導光板及一電路板。導光板具有 一入光面及一第一定位部，且光源設置於電路板上並鄰設 於導光板的入光面，電路板具有一第二定位部，其中，第 一定位部與第二定位部相連結。 緣是，為達上述目的，本發明係揭露一種液晶顯示裝 置，液晶顯示裝置包含一液晶顯示面板及一背光模組。背 6 1351561 光模組與液晶顯不面板相鄰而設’且背光模組具有一光 源、一導光板及一電路板。導光板具有一入光面及一第一 定位部，且光源設置於電路板上並鄰設於導光板的入光 面，電路板具有一第二定位部，其中，第一定位部與第二 定位部相連結。 承上所述，於本發明之背光模組及液晶顯示裝置中， 因導光板之第一定位部與電路板之第二定位部相連結，所 以固定了導光板與電路板間的距離，進而使得設置在電路 板上的光源與導光板之入光面間的距離亦為〜定值。如此 一來，即減少了習知技術中’光源與導光板入光面間的距 離同時受到光源、背框及導光板三種組裝公差的影響。因 此’藉由上述結構可快速且準確地定位導光板盘電路板間 的距離’以縮短背光模組及液晶顯不裝置的組農時間，進 而增加背光模組及液晶顯示裝置的產量。 【實施方式】IX. Description of the Invention: [Technical Field] The present invention relates to a backlight module and a liquid crystal display device, and more particularly to a backlight module and a liquid crystal display device in which a light source and a light guide plate are mutually positioned. [Prior Art] A liquid crystal display device (LCD device) is widely used in various industries because of its characteristics such as light weight, thin thickness, low driving voltage, and low current consumption. The liquid crystal display device mainly includes a liquid crystal display panel (LCD panel) and a backlight module (Back Light Module). Since the liquid crystal itself does not emit light, the main function of the backlight module is to provide a uniform distribution of the liquid crystal display panel. The surface light source. The backlight module can be divided into two types of backlight modules: a direct type (Direct Type) and an edge light type (Edge light type) depending on the position of the light source. 1A and FIG. 1B, FIG. 1A is a schematic plan view of a conventional side-lit backlight module, and FIG. 1B is a side cross-sectional view of a conventional side-light backlight module. The backlight module 1 includes a light source 11, a light guide plate 12, a circuit board 13, and a back frame 14. The light source 11 is a light-emitting diode, which is disposed on the circuit board 13. The circuit board 13 and the light guide plate 12 are respectively disposed on the back frame 14, and one side of the circuit board 13 is connected to one of the contact faces 141 of the back frame 14. In the contact, the light source 11 is disposed adjacent to the side of the light guide plate 12, so that the light enters the light guide surface 51 from the light incident surface 121 of the light guide plate 12 side. In general, the distance D1 between the light source 11 (especially the light-emitting diode) and the light guide plate 12 needs to have a fixed preset value (about 5 to 10 mm) to effectively control the light emitted by the light source 11 in the light guide plate 12. The mixing distance. In the prior art, the light source 11 is disposed on the circuit board 13, and the circuit board 13 does not have a mutual positioning structure between the light guide plates 12. Therefore, at the time of assembly, the assembler uses the circuit board 13 against the back frame 14, and the light guide plate 12 is self-joined to the back frame 14. Therefore, the distance D1 between the light source 11 and the light guide plate 12 is affected by the above three assembly tolerances (the light source 11, the light guide plate 12 and the back frame 14), and the light source 11 and the light guide plate 12 disposed on the circuit board 13 are easily caused. The distance D1 between the light incident surfaces 121 is not easily maintained at a preset value, and the light mixed into the light guide plate 12 by the light source 11 is likely to be unevenly mixed. SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a backlight module and a liquid crystal display device which can accurately and quickly locate the distance between a light source and a light guide plate. Therefore, in order to achieve the above object, the present invention discloses a backlight module. The backlight module includes a light source, a light guide plate and a circuit board. The light guide plate has a light incident surface and a first positioning portion, and the light source is disposed on the circuit board and adjacent to the light incident surface of the light guide plate, and the circuit board has a second positioning portion, wherein the first positioning portion and the second positioning portion The positioning sections are connected. Therefore, in order to achieve the above object, the present invention discloses a liquid crystal display device comprising a liquid crystal display panel and a backlight module. The back 6 1351561 optical module is adjacent to the liquid crystal display panel and the backlight module has a light source, a light guide plate and a circuit board. The light guide plate has a light incident surface and a first positioning portion, and the light source is disposed on the circuit board and adjacent to the light incident surface of the light guide plate, and the circuit board has a second positioning portion, wherein the first positioning portion and the second positioning portion The positioning sections are connected. As described above, in the backlight module and the liquid crystal display device of the present invention, since the first positioning portion of the light guide plate is coupled to the second positioning portion of the circuit board, the distance between the light guide plate and the circuit board is fixed, and further The distance between the light source disposed on the circuit board and the light incident surface of the light guide plate is also set to a constant value. In this way, the distance between the light source and the light incident surface of the light guide plate in the prior art is reduced, and the three assembly tolerances of the light source, the back frame and the light guide plate are affected. Therefore, the distance between the light guide plate and the circuit board can be quickly and accurately positioned by the above structure to shorten the assembly time of the backlight module and the liquid crystal display device, thereby increasing the output of the backlight module and the liquid crystal display device. [Embodiment]
以下將參照相關圖式，說明依本發明較佳實施例之背 光模組及液晶顯示裝置，其中相同的元件係以相同的參照 符號加以說明。 w 較佳實施 首光，請參照圖2A至圖 之背光模組。 請參照圖2Α、圖2Β及圖2C所示，1中，回^ 八Τ，圖2Α為 發明之背光模組2的俯視平面示意圖，圖 ㈠ u_ 2Α之 光模組2的侧視剖面示意圖，圖2C為圖2Α之背光模句 的立體分解示意圖。背光模組2包含一光源21、一導光板 22、一電路板23及一背框24。在本實施例中，背光模組 2係以一侧光式液晶顯示裝置中之背光模組為例。 光源21設置在電路板23上，且光源21鄰設於導光 板22之一側，其中，光源21可為至少一發光二極體。於 本實施例中，光源21係為複數個發光二極體以形成一發 光二極體模組設置於電路板23上。 導光板22設置在背框24之上，且導光板22具有一 入光面221及一第一定位部222，光源21鄰設於導光板 22的入光面221。 本實施例中，電路板23為一發光二極體驅動電路板， 電路板23設置於背框24上，電路板23之一侧與背框24 之一接觸面241相抵靠而固定，且電路板23具有一第二 定位部231，第二定位部231與導光板22之第一定位部 222相連結。此外，第二定位部231可設置於電路板23之 長邊方向的兩側或任一位置上。 請參照圖2B及圖2C所示，導光板22之第一定位部 222係為一凹部，且電路板23之第二定位部231為一凸 塊，第一定位部222係與第二定位部231相連結，而連結 的方式可以是黏合、抵接、嵌合、卡合或螺合。於本實施 例中，第一定位部222與第二定位部231係為相互嵌合， 所以第一定位部222與第二定位部231之形狀係完全配 合。需注意者，第一定位部222與第二定位部231連結時， 也可具有一些空隙。 8 本實施例中，電路板23之一側與背框24之接觸面241 相抵靠’且導光板22及光源21皆設置在電路板23上， 其中’導光板22之第一定位部222與電路板23之第二定 位部231連結，因而使得導光板22在電路板23上的定位 更加快速且準確，並使得設置在電路板23上之光源21與 導光板22之入光面221間的距離D2維持在預設值中，使 光源21所射入導光板22的光線混光均勻。 當然，第一定位部222與第二定位部231之形狀只要 相配合即可，並不限定第一定位部222為一凹部，且第二 疋位部231為一凸塊。如圖3所示’導光板22之第一定 位部222係為一凸塊，且電路板23之第二定位部231為 一凹部，第一定位部222係與第二定位部231相連結，因 而可達到與上述實施例相同之效果。即，可使得設置在電 路板23上之光源21與導光板22之入光面221間的距離 D2維持在預設值中，以使光源21所射入導光板22的光線 混光均勻。 請參照圖4A及圖4B所示，其中，圖4A為本發明之 另一種背光模組2的俯視平面示意圖，圖4B為圖4A之背 光模組2的侧視剖面示意圖。於本實施例中，第一定位部 222與第二定位部231之形狀可不限定為長方體，如圖々I 及4B所示，導光板22之第一定位部222為一圓形凹部， 電路板23之第二定位部231為一圓形凸塊，第一定位部 222與第二定位部231相連結以達到與上述實施例相同之 效果，即，使得設置在電路板23上之光源21與導光板22 1351561 之入光面221間的距離D2維持在預設值中，以使光源21 所射入導光板22的光線混光均勻。 請參照圖5A及圖5B所示，其中，圖5A為本發明之 /種背光模組2的俯視平面示意圖，圖5B為圖5A之另一 種背光模組2的俯視平面示意圖。於本實施例中，電路板 23之第二定位部231為一發光二極體，且第二定位部231 設置於電路板23之長邊方向L1的兩側，導光板22之第 一定位部222為一凹部’且第一定位部222與第二定位部 231之發光二極體相連結。此外，電路板23之長邊方向 L1係與第二定位部231之長邊方向L2形成一角度Θ。 如圖5A所示，導光板22係與背框24之部分接觸面 241相抵靠，且導光板22覆蓋第二定位部231及部分電路 板23，以使導光板22與電路板23間的相互定位更穩固。 於圖5B所示，電路板23之長邊方向u的兩側係增加一 區域以設置第二定位部231。 承上，藉由上述設計中第二定位部231設置於電路板 23之長邊方向L1的兩側，且第二定位部231為發光二極 體，其中，電路板23之長邊方向li與第二定位部231之 長邊方向L2形成-角度θ。如此一來，作為第二定位部 231之發光二極體即可避免背光模組2中導光板22兩侧的 暗角發生。 最後，6t參照6以說明本發明始$實_之液晶顯 示裝置。 圖6為本發明之液晶顯示裝置3之的立體結構示意 10 1351561 圖，液晶顯示裝置3包含一背光模組31及一液晶顯示面 板32。在本實施例中，背光模組31即為先前實施例所述 之背光模組2，其功能、結構及設置關係已於先前實施例 中所敘述，在此不再贅述。於本實施例中’背光模組31 更具有一前框311以及一光學薄膜組312。其中’前框311 設置於背光模組31之出光面223與液晶顯示面板32間’ 益與背光模組31之背框24結合，以與背框24形成一容 置空間，容設光源21、導光板22及電路板23。光學薄膜 組312設置於導光板22及液晶顯示面板32間’光學薄膜 組312可為擴散膜、稜鏡片或任何具有光學功能之光學鏡 片，以提供光線的會聚、發散或改變光線的行進路徑等功 能。 液晶顯示面板32鄰設於背光模組31，液晶顯示面板 32包含薄膜電晶體基板、彩色濾光片基板及一液晶層°其 中，薄膜電晶體基板與彩色濾光片基板相對而設’ ^&曰00 層設置於薄膜電晶體基板及彩色濾光片基板之間° 综上所述，本發明之背光模組及液晶顯示裝Ϊ係利用 、 導光板之第一定位部與電路板之第二定位部相連結之技 術特徵’來達到導光板與電路板間的相互定位更加快速、 準確且穩固，以縮短背光模組及液晶顯示裝置的組裝時 間，進而增加背光模組及液晶顯示裝置的產量。此外，更 可利用第二定位部位於電路板之長邊方向=兩側且為一 發光二極體’及第二定值部之長邊方向與電路板之長邊方 向形成-角度之技術特徵，來補償習知背先模組中光源進 11 1351561 入導光板時，導光板的兩侧端點容易造成暗角之問題。 以上所述僅為舉例性，而非為限制性者。任何未脫離 本發明之精神與範疇，而對其進行之等效修改或變更，均 應包含於後附之申請專利範圍中。 【圖式簡單說明】 圖1A為一種習知侧光式背光模組之一俯視平面示意 圖，DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a backlight module and a liquid crystal display device according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings, wherein the same elements are described with the same reference numerals. w Preferred implementation First light, please refer to the backlight module of Figure 2A to Figure. Referring to FIG. 2A, FIG. 2A and FIG. 2C, in FIG. 1, FIG. 2 is a top plan view of the backlight module 2 of the invention, and FIG. 1 is a side cross-sectional view of the optical module 2 of the u_2Α. 2C is a perspective exploded view of the backlight mode of FIG. 2 . The backlight module 2 includes a light source 21, a light guide plate 22, a circuit board 23, and a back frame 24. In the embodiment, the backlight module 2 is exemplified by a backlight module in a one-side optical liquid crystal display device. The light source 21 is disposed on the circuit board 23, and the light source 21 is disposed adjacent to one side of the light guide plate 22. The light source 21 can be at least one light emitting diode. In this embodiment, the light source 21 is a plurality of light emitting diodes to form a light emitting diode module disposed on the circuit board 23. The light guide plate 22 is disposed on the back frame 24, and the light guide plate 22 has a light incident surface 221 and a first positioning portion 222. The light source 21 is adjacent to the light incident surface 221 of the light guide plate 22. In this embodiment, the circuit board 23 is a light-emitting diode driving circuit board, and the circuit board 23 is disposed on the back frame 24. One side of the circuit board 23 is fixed against a contact surface 241 of the back frame 24, and the circuit is fixed. The plate 23 has a second positioning portion 231 that is coupled to the first positioning portion 222 of the light guide plate 22 . Further, the second positioning portions 231 may be disposed on both sides or at any position in the longitudinal direction of the circuit board 23. As shown in FIG. 2B and FIG. 2C , the first positioning portion 222 of the light guide plate 22 is a recessed portion, and the second positioning portion 231 of the circuit board 23 is a bump, and the first positioning portion 222 is coupled to the second positioning portion. The 231 is connected, and the joining may be by bonding, abutting, fitting, snapping or screwing. In the present embodiment, since the first positioning portion 222 and the second positioning portion 231 are fitted to each other, the shapes of the first positioning portion 222 and the second positioning portion 231 are completely matched. It should be noted that when the first positioning portion 222 is coupled to the second positioning portion 231, it may have some gaps. In this embodiment, one side of the circuit board 23 abuts the contact surface 241 of the back frame 24 and the light guide plate 22 and the light source 21 are disposed on the circuit board 23, wherein the first positioning portion 222 of the light guide plate 22 is The second positioning portion 231 of the circuit board 23 is coupled, thereby making the positioning of the light guide plate 22 on the circuit board 23 faster and more accurate, and the light source 21 disposed on the circuit board 23 and the light incident surface 221 of the light guide plate 22 are disposed. The distance D2 is maintained at a preset value so that the light incident on the light guide plate 22 by the light source 21 is uniformly mixed. Of course, the shape of the first positioning portion 222 and the second positioning portion 231 may be matched, and the first positioning portion 222 is not limited to be a concave portion, and the second clamping portion 231 is a convex portion. As shown in FIG. 3, the first positioning portion 222 of the light guide plate 22 is a bump, and the second positioning portion 231 of the circuit board 23 is a recess, and the first positioning portion 222 is coupled to the second positioning portion 231. Thus, the same effects as the above embodiment can be achieved. That is, the distance D2 between the light source 21 disposed on the circuit board 23 and the light incident surface 221 of the light guide plate 22 can be maintained at a preset value so that the light incident on the light guide plate 22 by the light source 21 is uniformly mixed. 4A and 4B, wherein FIG. 4A is a top plan view of another backlight module 2 of the present invention, and FIG. 4B is a side cross-sectional view of the backlight module 2 of FIG. 4A. In this embodiment, the shape of the first positioning portion 222 and the second positioning portion 231 is not limited to a rectangular parallelepiped. As shown in FIGS. 1 and 4B, the first positioning portion 222 of the light guide plate 22 is a circular concave portion, and the circuit board is The second positioning portion 231 of the second positioning portion 231 is a circular protrusion, and the first positioning portion 222 is coupled to the second positioning portion 231 to achieve the same effect as the above embodiment, that is, the light source 21 disposed on the circuit board 23 is The distance D2 between the light incident surfaces 221 of the light guide plate 22 1351561 is maintained at a preset value so that the light incident on the light guide plate 22 by the light source 21 is uniformly mixed. 5A and 5B, wherein FIG. 5A is a top plan view of a backlight module 2 of the present invention, and FIG. 5B is a top plan view of another backlight module 2 of FIG. 5A. In this embodiment, the second positioning portion 231 of the circuit board 23 is a light emitting diode, and the second positioning portion 231 is disposed on both sides of the longitudinal direction L1 of the circuit board 23, and the first positioning portion of the light guide plate 22 222 is a recessed portion ′ and the first positioning portion 222 is coupled to the light emitting diode of the second positioning portion 231 . Further, the longitudinal direction L1 of the circuit board 23 forms an angle Θ with the longitudinal direction L2 of the second positioning portion 231. As shown in FIG. 5A, the light guide plate 22 abuts the partial contact surface 241 of the back frame 24, and the light guide plate 22 covers the second positioning portion 231 and a portion of the circuit board 23 so that the light guide plate 22 and the circuit board 23 are mutually connected. Positioning is more stable. As shown in Fig. 5B, an area is added to both sides of the longitudinal direction u of the circuit board 23 to set the second positioning portion 231. In the above design, the second positioning portion 231 is disposed on both sides of the longitudinal direction L1 of the circuit board 23, and the second positioning portion 231 is a light emitting diode, wherein the long side direction of the circuit board 23 is The longitudinal direction L2 of the second positioning portion 231 forms an angle -θ. In this way, as the light-emitting diode of the second positioning portion 231, the vignetting on both sides of the light guide plate 22 in the backlight module 2 can be avoided. Finally, 6t is referred to 6 to illustrate the liquid crystal display device of the present invention. FIG. 6 is a perspective view showing a three-dimensional structure of a liquid crystal display device 3 of the present invention. The liquid crystal display device 3 includes a backlight module 31 and a liquid crystal display panel 32. In the present embodiment, the backlight module 31 is the backlight module 2 of the previous embodiment. The functions, structures, and arrangement relationships of the backlight module 31 are described in the previous embodiments, and are not described herein again. In the embodiment, the backlight module 31 further has a front frame 311 and an optical film group 312. The front frame 311 is disposed between the light-emitting surface 223 of the backlight module 31 and the liquid crystal display panel 32, and is combined with the back frame 24 of the backlight module 31 to form an accommodation space with the back frame 24, and the light source 21 is accommodated. Light guide plate 22 and circuit board 23. The optical film set 312 is disposed between the light guide plate 22 and the liquid crystal display panel 32. The optical film set 312 can be a diffusion film, a cymbal or any optical lens having optical functions to provide convergence, divergence or change of light travel path. Features. The liquid crystal display panel 32 is disposed adjacent to the backlight module 31. The liquid crystal display panel 32 includes a thin film transistor substrate, a color filter substrate, and a liquid crystal layer. The thin film transistor substrate is opposite to the color filter substrate. The 曰00 layer is disposed between the thin film transistor substrate and the color filter substrate. In summary, the backlight module and the liquid crystal display device of the present invention utilize the first positioning portion and the circuit board of the light guide plate. The technical feature of the two positioning parts is coupled to achieve a faster, more accurate and stable mutual positioning between the light guide plate and the circuit board, so as to shorten the assembly time of the backlight module and the liquid crystal display device, thereby increasing the backlight module and the liquid crystal display device. Yield. In addition, the second positioning portion is located on the long side direction of the circuit board=the two sides, and the long side direction of the light emitting diode body and the second constant value portion forms a characteristic angle with the long side direction of the circuit board. In order to compensate for the light source entering the light module in the conventional module, the edge of both sides of the light guide plate is likely to cause a vignetting problem. The above is intended to be illustrative only and not limiting. Any equivalent modifications or alterations to the spirit and scope of the present invention are intended to be included in the scope of the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a schematic plan view of a conventional side-lit backlight module.
圖1B為一種習知侧光式背光模組之一側視剖面示意 圖； 圖2A為依據本發明較佳實施例之一種背光模組之一 俯視平面示意圖； 圖2B為依據本發明較佳實施例之一種背光模組之一 側視剖面示意圖； 圖2C為依據本發明較佳實施例之一種背光模組之一 立體分解示意圖；1B is a side elevational view of a conventional side-lit backlight module; FIG. 2A is a top plan view of a backlight module according to a preferred embodiment of the present invention; FIG. 2B is a schematic view of a preferred embodiment of the present invention; FIG. 2C is a perspective exploded view of a backlight module according to a preferred embodiment of the present invention; FIG.
圖3為依據本發崎佳實施例之-種背光模組之-側 視剖面示意圖； 圖4A為依據本發明另 之一俯視平面示意圖； 圖4B為依據本發明另 之一侧視剖面示意圖； 圖5A為依據本發明又 之一俯視平面示意圖； 較佳實施例之一種背光模組 較佳實施例之一種背光模組 較佳實施例之一種背光模 12 1351561 圖5B為依據本發明再一較佳實施例之一種背光模組 之一俯視平面示意圖；以及 圖6為依據本發明較佳實施例之一種液晶顯示裝置之Figure 3 is a side elevational cross-sectional view of a backlight module according to the present invention; Figure 4A is a plan view of another side view of the present invention; Figure 4B is a side elevational view of another embodiment of the present invention; 5A is a top plan view of a preferred embodiment of a backlight module according to a preferred embodiment of the present invention. A backlight module 12 1351561 is a preferred embodiment of the backlight module. FIG. 5B is a further perspective of the present invention. A schematic plan view of a backlight module of a preferred embodiment; and FIG. 6 is a liquid crystal display device according to a preferred embodiment of the present invention.
一側視剖面示意圖。 元件符號說明： 1 背光模組 11 光源 12 導光板 121 入光面 13 電路板 14 背框 141 接觸面 2 背光模組 21 光源 22 導光板 221 入光面 222 第一定位部 223 出光面 23 電路板 231 第二定位部 24 背框 241 接觸面 3 液晶顯不裝置 13 1351561 31 背光模組 311 前框 312 光學薄膜組 32 液晶顯示面板A schematic view of one side of the cross section. Description of the components: 1 backlight module 11 light source 12 light guide plate 121 light-in surface 13 circuit board 14 back frame 141 contact surface 2 backlight module 21 light source 22 light guide plate 221 light-in surface 222 first positioning portion 223 light-emitting surface 23 circuit board 231 Second positioning part 24 Back frame 241 Contact surface 3 Liquid crystal display device 13 1351561 31 Backlight module 311 Front frame 312 Optical film group 32 Liquid crystal display panel