使用高分子分散型液晶製作多層式可調變固體光圈

Abstract

本研究擺脫傳統繁雜的光微影製程，提出一個簡易、低成本的方式來製作多層式可調變固體光圈。元件的調變機制是利用高分子分散型液晶(Polymer-Dispersed Liquid Crystal, PDLC)的特性，以不同電壓值來驅使高分子分散型液晶轉動，產生不同的穿透率，來定義光圈的亮暗區。 在元件設計中，光圈結構是將兩片氧化銦錫(Indium Tin Oxide, ITO)導電玻璃中間以聚對苯二甲酸乙二酯(Polyethylene Terephthalate, PET)薄膜當作間隙物(Spacer)，同時在兩ITO導電玻璃的中心滴入圓形的NOA65光學膠且以紫外光曝光固化黏合。將液晶E7與高分子NOA65以重量百分比6 : 4的比例混合調配PDLC，將其他區域以毛細現象的方式滲入調配好的PDLC，再次以紫外光曝光固化。最後形成一個中心為透明區，其他區為乳白色的固態光圈。以上述相同方式，滴入不同容量之NOA65光學膠來製作不同孔徑之光圈。照順序相疊各大小的光圈，以不同電極來調變各大小之光圈。 元件完成後，將元件黏上導電銀膠與銅導線延伸電極，再利用3D列印製作以聚乳酸(Polylactic Acid, PLA)為材料的黑色外殼封裝元件，以便架設在相機中，拍攝不同光圈大小造成的景深效果，最後再進行元件的特性量測與數據分析。

In this thesis, we replaced the traditional photolithography process with a simple way to fabricate a PDLC-Based Tunable Diaphragm. We used the characteristic of the Polymer-Dispersed Liquid Crystal (PDLC) to tune the diaphragm. Driving PDLC with different voltage result in different transmittance to define the bright and dark region of the diaphragm. In the design, the diaphragm structure is formed by two piece of Indium Tin Oxide (ITO) conductive glass and some Polyethylene Terephthalate (PET) film as spacer. Simultaneously, we dripped NOA65 optical adhesive into a circular area between the two ITO glass and exposed with the UV light to solidify the NOA65. We prepared PDLC with a specific weight ratio of E7 liquid crystal to NOA65 polymer. Fill in the prepared PDLC by capillary phenomenon and exposed with the UV light. A diaphragm which its center area is transparent and the other area is milky white will be done. By the same way as above, we dripped different volume of NOA65 to fabricate diaphragms of different diameter. Finally, we stacked the diaphragms in sequence and the assembled diaphragms could be tuned by changing its electrodes. After fabricating the diaphragm device, we stuck up the copper wires with some conductive silver paste to extend the electrodes. Moreover, we designed a black case to package the device by 3D printing which its material is Polylactic Acid (PLA) in order to set up in a camera more convenient. At last, we did some measurement and analysis on the device.