1323809 九、發明說明： 【發明所屬之技術領域】 % 本發明係相關於一種背光模組，尤指一種具有均勻亮度 • 分佈之背光模組。 【先前技術】 現今之液晶顯示器背光系統，大多採用冷陰極管（CCFL) • 作為其光源，由於兼具價格便宜與發展成熟等優點，所以， 冷陰極管被廣泛地應用於現今之液晶顯示器市場中。然 而，冷陰極管有演色性不佳（僅達65-75% )、需高驅動電壓、 含汞(Hg)、發光頻譜含紫外光(UV)波段、啟動速度慢、燈 管易破裂、及色度控制不易等諸多缺點，因此，新光源之 尋覓也就成為開發新一代液晶顯示器背光系統中最重要的 課題了。 發光一極體（light emitting diode, LED)的發光效率在近 十年來有著突破性的進步，由於具有高演色性、低驅動電 壓、不含汞、不放射紫外光' 快速點燈啟動、固態封裝不 易破裂、可動態調控色度等諸多優點，因而被視為新世代 光源的最佳選擇。為了獲得液晶顯示器背光系統所需要之 白色光源’大多利用白光LED或多色LED，例如紅(R)、 、綠（G)、及藍(B)三原色混光等方法。然而，這些利用LED 為光源的背光系統容易發生亮度均勻性、或是色彩均勻性 ⑤ 1323809 ； 不佳等問題，也就是在液晶面板顯示端的相異區域易產生 \ 亮度差或色差。一旦缺乏優良的混光系統，這種亮度差或 ' 色差問題將嚴重地影響到液晶顯示器之表現。 LED於各個角度的光強度分佈是影響背光源混光效果 的決定性因素，尤其是直下式背光系統，因為直下式背光 系統中之光源係不經導光板打散，而直接地導出至顯示 • 端，所以，LED本身各個角度的光強度分佈直接地左右著 背光系統的亮度均勻性與混色效果。尤其是利用三原色混 光的背光系統中，各個原色不佳的亮度均勻性更代表著不 佳的混色效果。 請參閱第1圖及第2圖，第1圖為先前技術一 LED 10 之示意圖，第2圖為LED晶片12之光強度分佈圖。LED 10 包含一用來發射光線18之LED晶片12、以及一罩設於LED 晶片12上之透鏡14,用來反折射LED晶片12所發射之光 線18。如第1圖所示，LED晶片12所發射之光線18，在 經過透鏡14之反折射後，其光線18大多集中在一中央軸 ' 16附近。這樣的LED 10若被置於如第3圖所示之液晶顯 1 _ 示器26中，會在液晶顯示器26之液晶顯示面板23上產生 嚴重的亮度集中問題，而造成其顯示品質下降。 為了改善亮度均勻性不佳的問題，液晶顯示器26之光 1323809 學膜片22及LED 10間需設置一混光距離足夠之混光空間 24，並配合多層的光學膜片22，例如是多層擴散板與擴散 片，以均勻化LED 10所發射之光線18。然而，如此一來， 背光系統20之厚度勢必會隨著混光空間24之厚度而增 加，另一方面，由於混光空間24之混光距離增加，加上需 要使用較多數目的光學膜片22，進而造成背光系統20之 LED 10之使用效率不佳。 為了改善第3圖所示之亮度不均的問題，一側光式LED 30被提出並應用，如第4圖所示。一特殊設計之透鏡34 被設置於LED晶片12上，用來將原本集中於中央軸16之 光線18，先導引至LED 30之側面，利用光線18相對於中 央軸16的大角度出射，使得光線18在經過背光模組反射 片的多重反射後，才均勻地導出於背光系統，以避免亮度 過於集中，以改善亮度的均勻度。然而，這樣的設計，會 在多重反射的過程中，大幅度地消耗光能，削減光的利用 率，並進而產生亮度不足的問題。 【發明内容】 因此本發明之主要目的在於提供一種具有均勻亮度分 佈之背光模組，以解決先前技術的缺點。 本發明之背光模組包含至少一光學膜片、複數個用來發 1323809 射光線至該光學膜片上之同色系光源、以及複數個光強度 調變裝置’其中每一光強度調變裝置皆係用來將其所對應 之光源所發出之光強度最大之光線約略投射至該光學膜片 上對應於該光源及與其相鄰之同色系光源之中間位置的位 置。 本發明另提供一種背光模組，其包含一光學膜片，具有 • 一光入射面、複數個同色系光源，用來發射光線至該光學 膜片上、以及複數個光強度調變裝置，設置於該複數個光 源上，以改變該光線之光強度，其中，該光線經該光強度 調變裝置後係實質上朝向該光學膜片的方向，並且該光學 膜片之該光入射面上之最大亮度與最小亮度之比值係小於 16°. 鲁 本發明另提供一種液晶顯示器，其包含一光學模組以及 一液晶顯示面板，用來接收該光學模組中該複數個同色系 光源發射之光線。該光學模組包含有一光學膜片、複數個 同色系光源’用來發射光線至該光學膜片上、以及複數個 光強度調變裝置，其中每-光強度調變裳置皆係用來將其 .所對應之光源所發出之光強度最大之光線約略投射至該^ 學膜片上對應於該光源及與其相鄰之同色系光源之中間位 置的位置。 8 1323809 ; 本發明另提供一種液晶顯示器，其包含一背光模組，以 - 及一液晶顯示面板，用來接收該背光模組中該複數個同色 ' 系光源發射之光線。該背光模組包含一光學膜片，具有一 • 光入射面、複數個同色系光源，用來發射光線至該光學膜 片上、以及複數個光強度調變裝置，設置於該複數個光源 上，以改變該光線之光強度，其中，該光線經該光強度調 變裝置後係實質上朝向該光學膜片的方向，並且該光學膜 • 片之該光入射面上之最大亮度與最小亮度之比值係小於 16 ° 【實施方式】 請參閱第5圖，第5圖為本發明之第一實施例中一背光 模組50之示意圖。背光模組50包含一基板.52、複數個設 置於基板52上之同色系LED 54、56、至少一光學膜片58， 其中該光學膜片58包含一光入射面58A、以及一設置於同 色系LED 54、56及光學膜片58間之混光空間60，其中， LED 54、56與光學膜片58間之距離h實質上係相等。 同色系LED 54、56皆用來發射光線66、68，光線66、 68在經過混光空間60後，到達光學膜片58上，並經由光 學膜片58的調變後入射到第3圖所顯示之液晶顯示器26 之液晶顯示面板23上。 1323809 ' 請參閱第6圖及第7圖，第6圖為LED 54(LED 56亦同） 所發射之光線66、68的相對光強度I與光線66、68入射 ' 至光學膜片58之入射角Θ的關係圖，第7圖為LED54(LED • 56亦同）之光強度分佈圖。 在本發明之第一實施例中，LED 54(LED 56亦同）所發射 之光線66、68之光強度I係隨著入射角Θ之增加而遞增， φ 具體言之，光強度I〜secn0，其中，1<η<5，換言之，直接 入射至光學膜片58上之光線66具有最小之光強度I，而傾 斜入射至光學膜片58上光線68則具有較大之光強度I，如 此一來，雖然光線68具有較大之光強度I，但因以較大角 度入射於光學膜片58，到達光學膜片58的光入射面58A 上之光線68的照度已和到達光學膜片58上之光線66之照 度相去不遠，所以，光學膜片58上光線68所照射到之表 I 面62之亮度，便會約略等於光線66所照射到之表面64之 亮度。整體而言，背光模組50之設置，可解決先前技術中 亮度不均之問題。 由於背光模組50中除了包含LED 54外，另包含有LED ‘· 56，因此，LED 54所發射之光線66、68只需照射至其上 方之光學膜片58即可，具體言之，LED 54所發射之光線 之光強度I的最大值Imax係約略發生於入射至光學膜片58 之入射角Θ等於tan-l[LED 54、56間之距離d/(2*LED 54(或 1323809 _ LE〇 56)至光學膜片58之距離h)]。如第5圖及第6圖所示， 背光模組50之LED 54(LED 56亦同）所發射之光線之光強 度1的最大值Imax係發生於入射至光學膜片58之入射角Θ ‘ 約略等於30度。當然，本發明之背光模組之LED所發射 之光線之光強度I的最大值Imax也可隨著該等LED間之 距離，與該等LED至光學膜片58之距離之不同而作更改。 舉例來說’如第8圖及第9圖所示，本發明之第二實施例 _ 中一背光模組150之同色系LED 154、156間之距離d係等 於2*LED 156(或LED 156)至光學膜片58之距離h，所以， LED 154所發射之光線之光強度I的最大值Imax係約略發 生於入射至光學膜片58之入射角θ等於tan_1(1)=45度時。 為了使LED 54所發射之光線66、68皆遵守〗〜secn0 (1<η<5) ’ LED 54必需包含適當的光強度調變裝置，例如 φ 是經過特別設計的透鏡、經過特別設計之光柵，或具有特 殊形狀的LED磊晶晶片等，以將[ED 54中一 LED晶片所 發射之光線反折射成遵守I〜se()n0之光線。該些遵守I〜 sec%之光線投射至光學膜片58上之一預定區間，而該預 定區間係介於光學膜片58上對應於該光源與其相鄰之同 色系光源之中間位置至對應於該光源位置之間所形成的區 間。請參閱第10圖，第10圖為LED 54(LED 56、LED 154、 及LED 156亦同）之示意圖。LED 54包含LED晶片12、以 及—罩設於LED晶片12上之透鏡7〇，用來將！^ΕΕ)晶片 1^23809 • 12所發射之光線72、74分別反折射成遵守I〜secne之光 . 線 66、68。 • 請參閱第π圖，第11圖為照射至先前技術之背光系統 20之光學膜片22上與照射至本發明之背光模組50之光學 膜片58上之光線的亮度與入射角Θ的比較關係圖，其中， 一第一曲線82係代表照射至先前技術之背光系統2〇之光 • 學膜片22的光入射面22A上之亮度與入射角Θ間之關係， 一第二曲線84係代表當背光模組50内之LED 54(LED 56 亦同）所發射之光線係遵守I〜sec0時，照射至本發明之背 .光模組50之光學膜片58的光入射面58A上之光線的亮度 與入射角Θ間之關係’一第三曲線86係代表當背光模組 5〇内之LED 54(LED 56亦同）所發射之光線係遵守hseA 時’照射至本發明之背光模組50之光學膜片58的光入射 φ 面5 8 A上之亮度與入射角θ間之關係，而一第四曲線μ 係代表當背光模組50内之LED 54(LED 56亦同）所發射之 光線係遵守第6圖之光強度分布時’照射至本發明之背光 模組50之光學膜片58的光入射面58A上之光線的亮度與 入射角Θ間之關係。由第11圖可明顯地看出，本發明之背 •光模組50之光學膜片58之亮度非常均勻，並且在入射角 —Θ在60°的範圍内，照射至光學膜片58的光入射面“A上 之光線的最大亮度與最小亮度間之比值岣不大於4,另外， 當背光模組50内之LED 54(LED 56亦同）所發射之光線係 12 1323809 ； 遵守第6圖之光強度分布時，照射至背光模組50之光學膜 片58的光入射面58A上之亮度係無關於入射角Θ，也就是 說，不管入射角Θ為何，光學膜片58上所有位置之亮度均 相同，光學膜片58上之亮度分佈非常均勻，反觀，在先前 技術之光學系統20中，照射至光學膜片22的光入射面22A 上之光線的最大亮度與最小亮度間之比值卻有可能高達16 以上，其亮度分佈非常不均勻。 本發明之第一實施例之背光模組50係包含複數個同色 系LED 54、56，然而，本發明之背光模組也可包含複數個 並非全然同色系之LED，只要這些LED中之同色系LED 所發出之光線係遵守I〜secn0，該背光模組仍可呈現相當 均勻且完美之贵度。 請參考第12圖。第12圖為本發明所揭露具有均勻亮度 • . 分佈之背光模組50之液晶顯示器126之示意圖。液晶顯示 器126包含有一背光模組50以及一液晶顯示面板123。背 光模組50包含有一光學膜片58,其具有一光入射面58A、 ' 複數個同色系光源54、一混光空間160以及複數個光強度 • · 調變裝置170。混光空間160係設置於複數個光源54及光 學膜片58之間、液晶顯示面板123則用來接收背光模組 50中複數個同色系光源54發射之光線。其中背光模組50 之工作原理如上所述，於此不再贅述。 13 13238091323809 IX. Description of the invention: [Technical field to which the invention pertains] % The present invention relates to a backlight module, and more particularly to a backlight module having uniform brightness distribution. [Prior Art] Today's liquid crystal display backlight systems mostly use cold cathode tubes (CCFL). • As their light source, cold cathode tubes are widely used in today's liquid crystal display market due to their advantages of low price and mature development. in. However, the cold cathode tube has poor color rendering (only 65-75%), requires high driving voltage, contains mercury (Hg), emits ultraviolet (UV) light in the spectrum, has a slow start-up speed, and is easily broken. Chroma control is not easy to wait for many shortcomings. Therefore, the search for new light sources has become the most important issue in the development of a new generation of liquid crystal display backlight systems. The luminous efficiency of light emitting diodes (LEDs) has made a breakthrough in the past decade, due to its high color rendering, low driving voltage, mercury-free, non-radiative UV 'fast lighting start, solid state package It is not easy to break, can dynamically adjust the color and many other advantages, so it is regarded as the best choice for the new generation of light source. In order to obtain a white light source required for a liquid crystal display backlight system, a white LED or a multi-color LED, for example, red (R), green (G), and blue (B) three primary colors are mixed. However, these backlight systems using LEDs as light sources are prone to brightness uniformity or color uniformity. 5 1323809; Poor and other problems, that is, in the different areas of the liquid crystal panel display end, it is easy to produce \ brightness difference or chromatic aberration. In the absence of an excellent light mixing system, this brightness difference or 'color difference problem' will seriously affect the performance of the liquid crystal display. The light intensity distribution of the LED at various angles is the decisive factor affecting the light mixing effect of the backlight, especially the direct-lit backlight system, because the light source in the direct-lit backlight system is directly discharged to the display terminal without being scattered by the light guide plate. Therefore, the light intensity distribution of each angle of the LED itself directly affects the brightness uniformity and color mixing effect of the backlight system. Especially in a backlight system that uses three primary colors to mix light, the poor uniformity of brightness of each primary color represents a poor color mixing effect. Please refer to FIG. 1 and FIG. 2, FIG. 1 is a schematic diagram of a prior art LED 10, and FIG. 2 is a light intensity distribution diagram of the LED chip 12. The LED 10 includes an LED chip 12 for emitting light 18 and a lens 14 overlying the LED wafer 12 for counter-refraction of the light 18 emitted by the LED chip 12. As shown in Fig. 1, the light 18 emitted by the LED chip 12, after being subjected to the refraction of the lens 14, is mostly concentrated near a central axis '16. If such an LED 10 is placed in the liquid crystal display unit 26 as shown in Fig. 3, a serious brightness concentration problem occurs on the liquid crystal display panel 23 of the liquid crystal display 26, resulting in deterioration of display quality. In order to improve the problem of poor brightness uniformity, the light of the liquid crystal display 26 is required to be provided with a light mixing space 24 having a sufficient light mixing distance between the film 22 and the LED 10, and is matched with the multilayer optical film 22, for example, a multilayer diffusion. The plate and the diffuser are used to homogenize the light 18 emitted by the LED 10. However, as a result, the thickness of the backlight system 20 is bound to increase with the thickness of the light mixing space 24, and on the other hand, the light mixing distance of the light mixing space 24 is increased, and a larger number of optical films 22 are required. In turn, the LED 10 of the backlight system 20 is inefficiently used. In order to improve the problem of uneven brightness shown in Fig. 3, a one-side optical LED 30 is proposed and applied as shown in Fig. 4. A specially designed lens 34 is disposed on the LED wafer 12 for directing the light 18 originally concentrated on the central axis 16 to the side of the LED 30, utilizing a large angle of light 18 relative to the central axis 16, such that The light 18 is evenly distributed to the backlight system after being subjected to multiple reflections of the backlight module reflection sheet to avoid excessive concentration of the brightness to improve the uniformity of the brightness. However, such a design consumes a large amount of light energy in the process of multiple reflections, reduces the utilization of light, and further causes a problem of insufficient brightness. SUMMARY OF THE INVENTION It is therefore a primary object of the present invention to provide a backlight module having a uniform brightness distribution to address the shortcomings of the prior art. The backlight module of the present invention comprises at least one optical film, a plurality of same-color light sources for emitting light to the optical film, and a plurality of light intensity modulation devices, wherein each of the light intensity modulation devices The light used to maximize the intensity of the light emitted by the corresponding light source is projected approximately to a position on the optical film corresponding to the intermediate position of the light source and the adjacent color light source adjacent thereto. The invention further provides a backlight module comprising an optical film having a light incident surface, a plurality of homochromatic light sources for emitting light onto the optical film, and a plurality of light intensity modulation devices, And a plurality of light sources for changing the light intensity of the light, wherein the light passes through the light intensity modulation device to substantially face the optical film, and the light incident surface of the optical film The ratio of the maximum brightness to the minimum brightness is less than 16°. The invention further provides a liquid crystal display comprising an optical module and a liquid crystal display panel for receiving light emitted by the plurality of tonal light sources in the optical module. . The optical module comprises an optical film, a plurality of tonal light sources for emitting light onto the optical film, and a plurality of light intensity modulation devices, wherein each light intensity modulation is used to The light having the highest intensity of light emitted by the corresponding light source is projected approximately to a position corresponding to the intermediate position of the light source and the homochromatic light source adjacent thereto. The invention further provides a liquid crystal display comprising a backlight module, and a liquid crystal display panel, for receiving light emitted by the plurality of tonal light sources in the backlight module. The backlight module comprises an optical film having a light incident surface, a plurality of homochromatic light sources for emitting light onto the optical film, and a plurality of light intensity modulation devices disposed on the plurality of light sources To change the intensity of the light of the light, wherein the light passes through the light intensity modulation device and is substantially oriented toward the optical film, and the maximum brightness and minimum brightness of the light incident surface of the optical film The ratio is less than 16 °. [Embodiment] Referring to FIG. 5, FIG. 5 is a schematic diagram of a backlight module 50 according to the first embodiment of the present invention. The backlight module 50 includes a substrate .52, a plurality of the same color LEDs 54 and 56 disposed on the substrate 52, and at least one optical film 58. The optical film 58 includes a light incident surface 58A and a color is disposed in the same color. The light mixing space 60 between the LEDs 54, 56 and the optical film 58 is substantially equal to the distance h between the LEDs 54, 56 and the optical film 58. The same color LEDs 54, 56 are used to emit light 66, 68. After passing through the light mixing space 60, the light rays 66, 68 reach the optical film 58, and are modulated by the optical film 58 and then incident on the third image. The liquid crystal display panel 23 of the liquid crystal display 26 is displayed. 1323809 ' Please refer to Fig. 6 and Fig. 7. Fig. 6 is the relative light intensity I of the light beams 66, 68 emitted by the LED 54 (the same as the LED 56) and the incidence of the light rays 66, 68 incident to the optical film 58 The relationship diagram of the corners, the seventh picture shows the light intensity distribution of LED54 (the same as LED • 56). In the first embodiment of the present invention, the light intensity I of the light beams 66, 68 emitted by the LEDs 54 (the same as the LEDs 56) is increased as the incident angle Θ increases, φ specifically, the light intensity I secn0 Wherein, 1 < η < 5, in other words, the light 66 directly incident on the optical film 58 has a minimum light intensity I, and the light 68 obliquely incident on the optical film 58 has a large light intensity I, In the meantime, although the light 68 has a large light intensity I, since it is incident on the optical film 58 at a large angle, the illuminance of the light 68 reaching the light incident surface 58A of the optical film 58 has reached and reaches the optical film 58. The illumination of the upper beam 66 is not far off, so that the brightness of the surface I 62 illuminated by the light 68 on the optical film 58 is approximately equal to the brightness of the surface 64 to which the light 66 is directed. Overall, the backlight module 50 is arranged to solve the problem of uneven brightness in the prior art. Since the backlight module 50 includes the LEDs 54 in addition to the LEDs 54, the light beams 66 and 68 emitted by the LEDs 54 need only be irradiated to the optical film 58 above them. Specifically, the LEDs The maximum value Imax of the light intensity I of the light emitted by 54 is approximately occurring at an incident angle 入射 incident to the optical film 58 equal to tan-1 [the distance between the LEDs 54, 56 d/(2*LED 54 (or 1323809 _ LE〇56) Distance to optical film 58 h)]. As shown in FIGS. 5 and 6, the maximum value Imax of the light intensity 1 of the light emitted by the LED 54 (the same as the LED 56) of the backlight module 50 occurs at an incident angle 入射 incident to the optical film 58. It is roughly equal to 30 degrees. Of course, the maximum value Imax of the light intensity I of the light emitted by the LED of the backlight module of the present invention may also vary depending on the distance between the LEDs and the distance from the LEDs to the optical film 58. For example, as shown in FIGS. 8 and 9, the distance d between the same-color LEDs 154 and 156 of a backlight module 150 in the second embodiment of the present invention is equal to 2*LED 156 (or LED 156). The distance h to the optical film 58 is such that the maximum value Imax of the light intensity I of the light emitted from the LED 154 occurs approximately when the incident angle θ incident on the optical film 58 is equal to tan_1(1)=45 degrees. In order for the light beams 66, 68 emitted by the LEDs 54 to comply with the s~secn0 (1 < η < 5) ' LED 54 must contain appropriate light intensity modulation means, such as φ is a specially designed lens, specially designed grating Or a special shape of an LED epitaxial wafer or the like to reverse-reflect the light emitted by an LED chip in the ED 54 into a light obeying I~se()n0. The light rays complying with I sec% are projected onto a predetermined interval on the optical film 58 , and the predetermined interval is located on the optical film 58 corresponding to the intermediate position of the light source adjacent to the same color source to correspond to The interval formed between the positions of the light sources. Please refer to FIG. 10, which is a schematic diagram of LED 54 (the same as LED 56, LED 154, and LED 156). The LED 54 includes an LED chip 12, and a lens 7 罩 that is placed over the LED chip 12 for use! ^ΕΕ) Wafer 1^23809 • The emitted rays 72, 74 are respectively reverse refracted to follow the light of I~secne. Lines 66, 68. • Referring to FIG. π, FIG. 11 is a view showing the brightness and incident angle of light incident on the optical film 22 of the backlight system 20 of the prior art and the optical film 58 irradiated onto the backlight module 50 of the present invention. Comparing the relationship diagram, wherein a first curve 82 represents the relationship between the brightness and the incident angle Θ on the light incident surface 22A of the light film 22 of the prior art backlight system, a second curve 84. It is shown that when the light emitted by the LED 54 (the same as the LED 56) in the backlight module 50 follows the I~sec0, it is irradiated onto the light incident surface 58A of the optical film 58 of the optical module 50 of the present invention. The relationship between the brightness of the light and the angle of incidence ′. A third curve 86 represents the backlight that is illuminated to the present invention when the light emitted by the LED 54 (the same as the LED 56) in the backlight module 5 is in compliance with hseA. The relationship between the brightness of the optical film 58 of the module 50 and the incident angle θ on the surface φ surface, and a fourth curve μ represents the LED 54 in the backlight module 50 (the same as the LED 56) The emitted light is irradiated to the backlight module 50 of the present invention when the light intensity distribution of FIG. 6 is observed. The relationship between the angle of incidence luminance Θ of the optical film on the light incident surface 58A 58 of the light. As is apparent from Fig. 11, the brightness of the optical film 58 of the back optical module 50 of the present invention is very uniform, and the light that is incident on the optical film 58 is incident at an incident angle of 60 60°. The ratio of the maximum brightness to the minimum brightness of the light on the incident surface "A" is not more than 4, and the light emitted by the LED 54 (the same as the LED 56) in the backlight module 50 is 12 1323809; When the light intensity is distributed, the brightness of the light incident surface 58A of the optical film 58 irradiated to the backlight module 50 is irrelevant to the incident angle Θ, that is, regardless of the incident angle ,, all positions on the optical film 58 The brightness is the same, and the brightness distribution on the optical film 58 is very uniform. In contrast, in the prior art optical system 20, the ratio of the maximum brightness to the minimum brightness of the light incident on the light incident surface 22A of the optical film 22 is The backlight module 50 of the first embodiment of the present invention includes a plurality of the same color LEDs 54 and 56. However, the backlight module of the present invention may also include a plurality of Full color L ED, as long as the light emitted by the same color LED of these LEDs complies with I~secn0, the backlight module can still exhibit a fairly uniform and perfect price. Please refer to Fig. 12. Fig. 12 is a Uniform Brightness • A schematic diagram of a liquid crystal display 126 of a distributed backlight module 50. The liquid crystal display 126 includes a backlight module 50 and a liquid crystal display panel 123. The backlight module 50 includes an optical film 58 having a light incident surface. 58A, 'a plurality of tonal light sources 54, a light mixing space 160, and a plurality of light intensities. · The modulation device 170. The light mixing space 160 is disposed between the plurality of light sources 54 and the optical film 58, and the liquid crystal display panel 123 Then, the light emitted by the plurality of the same color light sources 54 in the backlight module 50 is received. The working principle of the backlight module 50 is as described above, and will not be described here. 13 1323809
. 相較於先前技術’本發明之背光模組，因其内之LED ' 可發出遵守1〜secn0之光線，所以可呈現非常均勻且完美 . 之亮度。此外’由於本發明之背光模組50、150中之光學 膜片58上之亮度係均勻地分佈，所以，背光模組50、15〇 内便可設ί較薄的混光空間160及數量較少的光學膜片 58，如此·一來，在不影響發光品質之情形下，本發明之背 • 光模組具有較薄的尺寸及較便宜的製造成本，並且由於使 用較薄的潞光空間160及數量較少的光學臈片58，也可進 一步降低光強度的衰減而提昇光源的使用效率。再者，本 發明之背光模組’其光線實質上係直接向光學膜片的方向 投射，相較於先前技術需經多重反射的方式，可避免光能 消耗，進而提昇光利用效率。最後，本發明之背光模組不 僅可用於直下式背光系統中’也可用於側光式背光系統 φ 中，而其中之LED也可以其他光源加以取代，只要其為同 色系光源即< ° 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，皆應屬本發明之涵蓋範圍。 【圖式簡單說明】 第1圖為先前技術一 led之示意圖。 第2圖為第丨圖所顯示之LED晶片之光強度分佈圖。 1323809 • 第3圖為内含第1圖所顯示之LED之液晶顯示器之示意圖。 第4圖為先前技術中一側光式LED之示意圖。 第5圖為本發明之第一實施例中一背光模組之示意圖。 - 第6圖為第5圖所顯示之背光模組中一 LED所發射之光線 之相對光強度與該光線入射至一光學膜片之入射角的 關係圖。 第7圖為第6圖所顯示之LED之光強度分佈圖。 • 第8圖為本發明之第二實施例中一背光模組之示意圖。 第9圖為第8圖所顯示之背光模組中一LED之光強度分佈圖。 第10圖為第6圖所顯示之LED之示意圖。 第11圖為相對亮度與入射角之比較關係圖。 第12圖為本發明所揭露具有均勻亮度分佈之背光模組之 液晶顯不器之不意圖。 【主要元件符號說明】 10 發光二極體 12 發光二極體晶片 14,34,70 透鏡 16 中央轴 18,66,68,72,74 光線 20 背光系統 22,58 光學膜片 22A,58A 光入射面 23,123 液晶顯不面板 24,60,160 混光空間 26,126 液晶顯不斋 30 側光式發光二極體 50,150 背光模組 52 基板 54,56,154,156 同色系 LED 62,64 表面 ⑤ 15 1323809 82 第一曲線 84 第二 曲線 86 第三曲線 88 第四 曲線 170 光強度調變裝置 d，h 距離 ⑧ 16Compared with the prior art 'backlight module of the present invention, since the LED ' therein can emit light complying with 1 to secn0, it can exhibit a very uniform and perfect brightness. In addition, since the brightness of the optical film 58 in the backlight modules 50 and 150 of the present invention is uniformly distributed, the backlight module 50, 15 can be provided with a thin light mixing space 160 and a relatively large number. The optical film 58 is small, so that the back light module of the present invention has a thinner size and a relatively low manufacturing cost without affecting the light-emitting quality, and uses a thinner calender space. 160 and a small number of optical cymbals 58 can further reduce the attenuation of light intensity and improve the efficiency of use of the light source. Furthermore, the backlight module of the present invention is substantially directly projected in the direction of the optical film. Compared with the prior art, multiple reflections are required to avoid light energy consumption, thereby improving light utilization efficiency. Finally, the backlight module of the present invention can be used not only in a direct-lit backlight system but also in an edge-lit backlight system φ, and the LEDs therein can be replaced by other light sources, as long as they are the same color light source, ie, above The above are only the preferred embodiments of the present invention, and all changes and modifications made to the scope of the present invention should be within the scope of the present invention. [Simple description of the drawing] Fig. 1 is a schematic diagram of a prior art. Figure 2 is a diagram showing the light intensity distribution of the LED chip shown in the second figure. 1323809 • Figure 3 is a schematic diagram of a liquid crystal display incorporating the LEDs shown in Figure 1. Figure 4 is a schematic illustration of a prior art side light LED. Figure 5 is a schematic view of a backlight module in the first embodiment of the present invention. - Figure 6 is a graph showing the relationship between the relative light intensity of an LED emitted by an LED in the backlight module shown in Figure 5 and the incident angle of the light incident on an optical film. Fig. 7 is a light intensity distribution diagram of the LED shown in Fig. 6. • Figure 8 is a schematic view of a backlight module in a second embodiment of the present invention. Figure 9 is a light intensity distribution diagram of an LED in the backlight module shown in Figure 8. Figure 10 is a schematic diagram of the LED shown in Figure 6. Figure 11 is a graph showing the relationship between relative brightness and incident angle. Figure 12 is a schematic view of a liquid crystal display of a backlight module having a uniform brightness distribution according to the present invention. [Main component symbol description] 10 LEDs 12 LED chips 14, 34, 70 Lens 16 Center axis 18, 66, 68, 72, 74 Light 20 Backlight system 22, 58 Optical diaphragm 22A, 58A Light incident Face 23,123 LCD display panel 24,60,160 Mixing space 26,126 Liquid crystal display 30 Side light type LEDs 50,150 Backlight module 52 Substrate 54,56,154,156 Same color LED 62,64 Surface 5 15 1323809 82 First curve 84 Two curve 86 third curve 88 fourth curve 170 light intensity modulation device d, h distance 8 16