微透鏡陣列(Micro Lens Arrays, MLA)為眾多微結構中最為廣泛使用之光學元件，本研究利用失焦輔助數位光處理(Digital Light Process, DLP)技術與數位光罩對玻璃載板上的樹脂進行曝光，成功製造具高解析度及高填充因子之球面微透鏡陣列，本製程有著加工時間極短、加工彈性高、成本低等優點，十分適合應用往後微透鏡陣列之學術研究。
本製程利用DLP技術投影高解析度(full HD 1920×1080 pixel)之全螢幕紫外光，搭配Matlab建立灰階圖檔作為數位光罩，能夠精準的調整數位光罩中每個單獨像素(pixel, px)的灰度值(0-255)以改變單像素(5μm)的曝光能量，並利用移動光軸改變焦點距離(精度:1μm)來產生失焦化用以改善DMD(Digital Micromirror Device)晶片在投影時造成的表面粗糙效果。
由於DLP製程為利用數位光罩對樹脂進行曝光，因此能利用各項參數調整微透鏡陣列的輪廓形貌，如：曝光能量、失焦距離、光罩直徑等，因此能夠因應不同需求生產出各種特性的微透鏡陣列，如：高數值孔徑、特定曲率、高解析度、高填充因子等。
本研究設計並執行了多種實驗，主要分為兩大階段，第一階段實驗用來了解製程中各項參數對樹脂成形的影響、成形均勻度。第二階段實驗用來檢視微透鏡成品的光學表現以及利用製程的特長進行高填充因子及多焦點微透鏡陣列的實作。第一階段實驗結果證實：(1)能量與透鏡成形高度成自然對數曲線增長，且曲率高度變異係數為0.05；(2)在相同能量下，改變灰度與時間的比例不影響成形高度；(3)改以灰階遞減數位光罩曝光使透鏡外型改為半球面狀，且不影響直徑及高度，證實遞減的光罩的透鏡有更好的光學效果；(4)失焦的方向以向上為佳，直徑及高度的失真度分別為1%及3%，且失焦後的微透鏡陣列有更好的解析度；(5)改變整體的填充因子並不影響單顆微透鏡的成形；(6)失焦距離越大能對高度越高的透鏡起到平滑化效果，需對應不同的曲率高度採取不同的失焦距離。第二階段的實驗結果證實：(1)本製程能夠生產聚焦平面一致的微透鏡陣列，且有高解析度為45.3lp/mm；(2)能夠於單次曝光下製作多種直徑的微透鏡陣列擁有多重焦點的特性，且能製造填充因子為100之微透鏡陣列。

Micro lens array (MLA) is the most widely used optical element in many microstructures. This research uses the defocusing assisted Digital Light Process (DLP) technology and the digital mask to exposure the resin on the glass. This process can product 100% fill factor MLA and mutifocus MLA with spherical profile, this manufacturing method has the advantages of extremely short manufacturing time, high flexibility on processing and low cost.
This process uses DLP technology to project full-screen ultraviolet light with 1920×1080 pixels, and uses Matlab to generate a grayscale image file as a digital mask, which can accurately adjust gray value of each pixel on picture to change the exposure energy of one single pixel (5μm), and moving the light source to change the focal distance from light source to froming platform can conduct defocusing effect to reduce the roughness due to the DMD chip.
Since DLP process project UV to curing resin by digital photomask, various parameters can be adjusted to control the profile of the MLA, such as exposure energy, defocusing distance, diameter of photomask, etc., so it can produce various types of MLA according to different needs. Such as: high numerical aperture, specific curvature, high resolution, high fill factor, etc.
There were multiple experiments had been designed and conduct, they were divided into two main phases, the first phase of experiment is about how parameters of processing effects to lens forming such as exposure energy, defocusing distance, diameter of photo mask. The purpose of second phase of experiment is test the optical performance of MLAs and use advantages to manufacture high fill factor and multi-focus MLAs. The results of first phase indicated the following: (1) Acrooding to energy, the forming height of MLA grow in a natural logarithmic curve, and the coefficient of variation of height is 0.05; (2) Base on same energy, changing the ratio of gray and time does not affect the forming height; (3) Exposure with a decreasing gray scale mask can get a hemispherical lens with better optical performance; (4) Upward direction of defocusing is preferably, and the distortion of diameter and height are 1% and 3% , defocused MLA has higher resolution on USAF1951; (5) Changing the filling factor of mask does not affect the profile of a single microlens;(6)Longer defocusing distance can smooth lens has higher sag height, acrroding to different sag height should apply different defocusing distance. The results of the second phase indicated the following: (1) Resulting MLA has uniform focal plane and has a high resolution in 45.3lp/mm; (2) This processing can manufacture MLAs with multiple diameters in one single exposure shows characteristics of multiple focal points and also can manufacture microlens arrays with 100% fill factor.

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