1259888 五、發明說明（1) •【發明所屬之技術領域】 本發明係有關於一種背光模組，特別儀有關於一種可 提升光源與導光元件兩者間之光耦合效率之背光模組。 【先前技術】 首先請參閱第1 a圖，該圖係表示一習知侧光式背光模 組中光源與導光板之示意圖。如圖所示，於一習知側光式 背光模組中，光源L (例如一發光二極體）係設置於導光元 件G之侧邊，上述光源L可入射光線至導光元件G内部，藉 以形成一面光源。然而，由於光源L與導光元件G之間存在 >有空氣間隙S，如此將導致部分光線將被導光元件G反射， 並嚴重影響光源L與導光元件G兩者間之光耦合效率。 再請參閱第1 b圖，該圖係表示一直下式背光模組中光 源與導光板之示意圖。如圖所示，一光源L (例如一發光二 極體）係設置於導光元件G之下方，並可入射光線至導光元 件G内部。同樣地，由於光源L與導光元件G之間存在有空 氣間隙S，如此將導致部分光線將被導光元件G反射而影響 光源L與導光元件G兩者間之光搞合效率。 有鑑於前述背光模組之缺點，因此如何能減少光線反 射，進而提升光源與導光元件兩者間之光耦合效率始成為 一重要之課題。 【發明内容】 本發明提供一種背光模組’包括一光源、一導光元件 以及一光學薄膜層。上述光學薄膜層係佈設於導光元件表 面，其中光學薄膜層之折射率N介於導光元件之折射率Ns以1259888 V. INSTRUCTION DESCRIPTION (1) • [Technical Field of the Invention] The present invention relates to a backlight module relating to a backlight module capable of improving the optical coupling efficiency between a light source and a light guiding element. [Prior Art] Referring first to Figure 1a, there is shown a schematic diagram of a light source and a light guide plate in a conventional edge-lit backlight module. As shown in the figure, in a conventional edge-lit backlight module, a light source L (for example, a light-emitting diode) is disposed on a side of the light guiding element G, and the light source L can inject light into the light guiding element G. In order to form a light source. However, since there is an air gap S between the light source L and the light guiding element G, this will cause partial light to be reflected by the light guiding element G, and seriously affect the optical coupling efficiency between the light source L and the light guiding element G. . Referring again to FIG. 1b, the figure shows a schematic diagram of a light source and a light guide plate in a backlight module. As shown, a light source L (e.g., a light emitting diode) is disposed under the light guiding element G and can inject light into the interior of the light guiding element G. Similarly, since there is an air gap S between the light source L and the light guiding element G, this will cause a part of the light to be reflected by the light guiding element G to affect the light combining efficiency between the light source L and the light guiding element G. In view of the shortcomings of the foregoing backlight module, how to reduce the light reflection and thereby improve the optical coupling efficiency between the light source and the light guiding element has become an important issue. SUMMARY OF THE INVENTION The present invention provides a backlight module 'includes a light source, a light guiding element, and an optical film layer. The optical film layer is disposed on the surface of the light guiding element, wherein the refractive index N of the optical film layer is between the refractive index Ns of the light guiding element
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及空氣之折射率nq之間 薄膜層而進入導光元件内部V 於車乂佳貝苑例中，如前所述之光學薄膜層包括禎 個光學薄Μ，上述光學薄膜至少一者之折射率俜 元件之折射率Ν:以及空氣之折射率Νΰ之間。 於〆杈佳貫施例中，前述光學薄膜層之折射率ν:(ν。 於一較佳實施例中 鍍膜之方式佈設於導光 於一較佳實施例中 之方式佈設於導光元件 於一較佳實施例中 鎂（MgF2 )材質。 ’如前所述之光學薄膜層係以真空 元件表面 ° ’如前所述之光學薄膜層係以貼附 表面。 ’如前所述之光學薄膜層具有氟化 於一較佳實施例中，如前所述之背光模組係為一側光 式背光模組（side-edge type backlight)。 於一較佳實施例中，如前所述之背光模組係為一直下 式背光模組（direct type backlight)。 於一較佳實施例中，前述光源係為一發光二極體。 於一較佳實施例中，前述導光元件係為聚甲基丙稀酸 甲酯材質（Polymethyl-methacrylate， PMMA )。 於一較佳實施例中，前述導光元件具有一凹陷部，前 述光源係設置於凹陷部内，而前述光學薄膜層則位於前述 導光元件以及光源之間。 為使本發明之上述及其他目的、特徵和優點能更明顯And the refractive index nq of the air between the film layer and the inside of the light guiding element V. In the example of the car, the optical film layer includes an optical thin film, and at least one of the optical films has a refractive index. The refractive index of the germanium element is Ν: and the refractive index 空气 of the air. In the embodiment of the present invention, the refractive index ν of the optical film layer is: ν. In a preferred embodiment, the coating film is disposed on the light guiding element in a manner of guiding light in a preferred embodiment. In a preferred embodiment, the material of magnesium (MgF2) is used. The optical film layer as described above is a surface of a vacuum element. The optical film layer as described above is attached to the surface. The layer has fluorination in a preferred embodiment, and the backlight module as described above is a side-edge type backlight. In a preferred embodiment, as described above The backlight module is a direct type backlight. In a preferred embodiment, the light source is a light emitting diode. In a preferred embodiment, the light guiding component is a polymer. In a preferred embodiment, the light guiding element has a recessed portion, the light source is disposed in the recessed portion, and the optical film layer is located in the guiding portion. Between the light element and the light source. The above and other objects of the invention, features, and advantages of the
0632-A50279TWf(5.0) ； AU0406001 ； TKlin.ptd 第7頁 1259888 五、發明說明0632-A50279TWf(5.0) ; AU0406001 ; TKlin.ptd Page 7 1259888 V. INSTRUCTION
對可見光波段38 0〜780nm而言’其平均之光耦合效率仍可 由/'τ、〜之9 6 % (未设置光學薄膜層T時）提升至g 7 7 %。 然而，前述光學薄膜層T亦可為一多層膜結構，直可 由複數個光學薄膜以真空鍍膜或者以貼附的方式形成、，直 中前述光學薄膜中之至少一者之折射率必須介於導光元^ G之折射率化以及空氣之折射率％之間，藉此可適當地提升 光源L與導光元件G兩者間之光輕合效率。 步提升短波長部分之光耦合效 舉例而言，為了進 率，Μ光學薄膜層T中含有氟化鎂材質（折射率為丨· 38)之 光學薄膜時，可另外鍍上折射率大於L5之光學薄膜而形 成上述多層膜結構，如此一來可提升並補強在短波長y 之光1¾合效率。 導光元件表面佈 同時可有效地提 綜上所述’本發明之背光模組透過在 設一光學薄膜層，藉此可避免光線反射， 升光源與導光元件兩者間之光耦合效率。 π U㈧询路如上，然盆诉 限定本發明，任何熟習此項技藝者，在 业非用以 神和範圍内，仍可作些許的更動與潤飾，因 =明之精For the visible light band 38 0 to 780 nm, the average optical coupling efficiency can still be increased to 6.75% by _ τ, 9.6% (when the optical film layer T is not provided). However, the optical film layer T may also be a multilayer film structure, which may be formed by vacuum coating or by attaching a plurality of optical films, and at least one of the optical films may have a refractive index of Between the refractive index of the light guide element G and the refractive index % of the air, the light coupling efficiency between the light source L and the light guiding element G can be appropriately improved. For example, in order to increase the optical coupling effect of the short-wavelength portion, in order to increase the optical film of the magnesium fluoride material (refractive index of 丨·38) in the optical film layer T, the refractive index may be additionally plated with a refractive index greater than L5. The above-mentioned multilayer film structure is formed by an optical film, so that the light efficiency at a short wavelength y can be enhanced and reinforced. The surface of the light guiding member can be effectively improved. The backlight module of the present invention is provided with an optical film layer, thereby avoiding light reflection and improving the optical coupling efficiency between the light source and the light guiding element. π U (eight) inquiry road as above, but the basin complains to limit the invention, any person skilled in the art, the industry is not used in the scope of God, can still make some changes and refinement, because = Ming Jing
護範圍當視後附之申請專利範圍所界定者為準本舍明之保The scope of protection is defined as the scope of the patent application scope attached to it.
0632-A50279TWf(5.0) ； AU0406001 ；Tklin.ptd 第10頁 1259888 圖式簡單說明 ^ 第1 a圖係表示一習知側光式背光模組之示意圖； 第1 b圖係表示一習知直下式背光模組之示意圖； 第2圖係表示本發明中側光式背光模組之示意圖； 第3圖係表示本發明中直下式背光模組之示意圖； 第4圖係表示當光學薄膜層之折射率1. 2 2時，光源 與導光元件對應不同波長（380〜780nm)之光柄合效率之示 意圖；以及 第5圖係表示當光學薄膜層之材質為氟化鎂時= 1.38)，光源與導光元件對應不同波長（380〜780nm)之光耦 _合效率之示意圖。 【主要元件符號說明】 L〜光源； G〜導光元件； S〜空氣間隙； C〜凹陷部； T〜光學薄膜層； R〜反射板； D〜半穿透膜。0632-A50279TWf(5.0) ; AU0406001 ;Tklin.ptd Page 10 1259888 Schematic description of the figure ^ Figure 1 a shows a schematic diagram of a conventional edge-lit backlight module; Figure 1 b shows a conventional direct-type 2 is a schematic view showing a side-lit backlight module of the present invention; FIG. 3 is a schematic view showing a direct-lit backlight module of the present invention; and FIG. 4 is a view showing a refractive index of an optical film layer; At a rate of 1.2 2, the light source and the light guiding element correspond to a light stalk combining efficiency of different wavelengths (380 to 780 nm); and the fifth figure shows that when the material of the optical film layer is magnesium fluoride = 1.38), the light source A schematic diagram of optocoupler-combination efficiency at different wavelengths (380 to 780 nm) corresponding to the light guiding element. [Main component symbol description] L ~ light source; G ~ light guiding element; S ~ air gap; C ~ depressed portion; T ~ optical film layer; R ~ reflecting plate; D ~ semi-transparent film.
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