| 摘要: | 今日有了許多先進的通訊系統與可攜式元件諸如個人數位助理與手機大大豐富了我們的日常生活。 通訊系統使得影像可以傳送且可攜式元件的成熟化使我們能夠隨時隨地觀賞生動的節目。雖然可攜式數位電話仍然持續在體積微小化上持續進步，同樣的投影系統也需要持續在體積微小化上有明顯的進步，而且除了體積太大以外，現在的投影機還仍然許多的缺點諸如高耗電量，吵雜的風扇聲和開啟關閉之間必須要有時間的延遲，這些需要持續改進的就是未來搭配其他可攜式的產品。本論文就是採用LED 光原取代傳統的的燈泡，由於LED 光源具有省電與可以高速開關的特性 再結合新型的TIR 菱鏡，投影機鏡頭與照系統讓體積大大的減少 此外 LED 光源的投影機所產生的主要三元色取代傳統燈泡搭配上彩色濾光片產生的機制，故此典型的色域範圍比標準sRGB 的規範面積大上120%。在本論文中 我們研發出一個75mm × 67 mm × 42 mm的LED微小化投影機對此投影機具有的光源系統 包括三個分別為紅綠藍的LED光源組，這個光源組的體積才只有 30 mm × 30 mm × 20 mm 這樣的體積才只有18 cm3此意味著我們將光源組大大的降低體積 讓體積變成之前光源組的60%。在照明系統方面 我們採用了微小鏡片矩陣來達成均勻光強度的目的，這樣的方法不到讓整個照明系統的總長度縮減下來而且使得均勻度達到93%。對於系統中光的分光源件 我們採用新型態的TIR 菱鏡設計來取代傳統TIR 菱鏡。這個新型態的菱鏡設計不但使得分光源件體積變小而且還大幅度提升整個系統的對比值到達3700:1。對於投影鏡頭方面 我們也開發出總長只有42mm 的遠心鏡頭組。此鏡頭組的在MTF 方面的表現在所有的視場皆大於0.5 此為空間頻率為36lp/mm 的狀況此優異的表現可以讓鏡頭的影像品質具有相當的銳利性，而在光學畸變，TV 畸變方面, 兩者的碕變量都控制在0.5%以下，這樣的變形量我們人眼很難感受出來。總而言之此遠心鏡頭的各項光學參數皆比傳統的設計來的佳。此外由於遠心 系統的設計讓鏡頭組的設計與照明系統設計可以分開設計。在本論文中已經詳細對微小化的投影機光學設計詳述這個部份包刮投影鏡頭組 含有準直鏡的LED光源組， 新型態的TIR 菱鏡與微小化鏡片陣列的強度勻化裝置。除了光學設計外 我們也對光學效率與色彩表現作深入的探討。 Nowadays, the advance of communication systems and portable devices such as the personal digital assistants (PDAs) and mobile-phones enrich our daily life. These communication systems make the transference of video information possible; miniaturization of portable devices lets us watch live programs online anytime, anywhere. lthough the improvement in size of the mobile devices has made much progress, the size of projector devices are still needed significant miniaturizations. Beside their overly large size, the current projectors still have several other disadvantages such as high power onsumption, noisy fans and delay when switching on and off. improvements need to be made in order to match other portable devices. In this thesis, a compact LED light source is used in place of conventional lamps, which makes for power conservation and faster on-off delay time. After combining this light source with a novel TIR prism, projection lens and illumination system , a reduction in the size of the whole system became possible. Moreover, the advantages of LED light source projection systems mean that primary colors can be created by the LED instead of being laboriously filtered from a white light source. The typical color gamut can be as much as above 120% over the sRGB standard [1-3]. In this thesis, we propose a pocket-size projector system with compact size of 75mm × 67 mm × 42 mm. For the LED light source, there are three discrete red, green, and blue (RGB) color LED sources. The size of the light source module is 30mm × 30 mm × 20 mm. The volume of the light source is only 18cm3, meaning a reduction in the size of the entire light source system of 60% that of a traditional light source module. Beside the volume issue, the collimating lens lets the collecting efficiency reach to 95 % at the divergence angle of 12.5 degree. For the illumination system, we use the micro lens array as intensity homogenizer. It can not only reduce the total track of illumination system but also reach high uniformity degree with 93%. For the light separator, we use a novel TIR prism design to replace the tradition TIR prism. The prism is consist of two triangle prisms .The novel prism can not only reduce the size of light separator but also increase the contrast ratio to 3700: 1 for whole system. For the projecting lens, a compact telecentric lens with a total track of 42mm is also developed. The MTF value of the lens can reach 0.5 at the spatial frequency of 36lp/mm. It will offer a sharpness image quality. The RMS spot size was controlled under 13.6 um2 for all fields. The fale phenomenon can’t be seen for the projected image. The optical distortion and TV distortion were controlled under 0.5%. The distortion phenomenon can’t visible by humen eye. The optical performance of this telecentric lens are better than that of the traditional designs. Moreover, the projection lens and the illumination system are designed independently via telecentric conditions. This thesis supports a detail description about LED projector with the projection lens, LED light source system with collimation parts, novel TIR prism and homogenizer. The efficiency and color performance are also discussed. |
