利用PDLC之固體步階調控光圈的設計與製作

Abstract

本研究開發出PDLC固體步階調變光圈，我們有效的利用間隙物(Spacer)來製作PDLC液晶盒並量測其特性，實驗中我們針對不同的PDLC重量百分比濃度及製程厚度進行量測，並將實驗結果繪製成V-T曲線，利用曲線趨勢分析穿透率、對比度、及臨界電壓，最後依據所量測的特性結果來選擇較好之PDLC來設計PDLC固體步階調變光圈。PDLC固體步階調變光圈擺脫傳統的光微影製程，使用新穎、低成本之製程方式，其製程利用雙面黏性薄膜、單面黏性薄膜、高分子聚二甲基矽氧烷(Polydimethylsiloxane, PDMS)、高分子導電塗料(Conductive and Transparent Polymer Coating, CTPC)、NOA65及PDLC，所開發之光圈元件可用於調變兩種不同孔徑大小。在量測方面，我們使用白熾燈泡與CMOS影像感光晶片來測量光圈孔徑，並配合MATLAB軟體將影像灰階轉換來獲得光圈孔徑大小與驅動電壓之關係，最後我們將PDLC固體步階調變光圈應用於攝影上，利用相機、鏡頭組以及本研究所開發之光圈元件拍攝影像，成功的拍攝出影像且能夠獲得景深影像之效果。

In this study, we develop a solid stepped-tuning optical diaphragm based on polymer dispersed liquid crystal (PDLC). First, we effectively use the spacer to make PDLC cells so as to measure different weight percentage concentration as well as various thickness for PDLC film. Secondly, according to such measured results, V-T curve is sketched, and then we get to analyze transmittance, contrast ratio, and threshold voltage. As a result of PDLC cells analysis, the most appropriate material comes to light for us to design stepped-tuning optical diaphragm. In this study, Photolithography is no longer required for the latest low-cost device. Instead, the device is done by making use of the slim double-sided tape, tape, polydimethylsiloxane (PDMS) mold, conductive and transparent polymer coating (CTPC), NOA65 and PDLC. The diaphragm is designed to switch between two different aperture sizes. To characterize the diaphragm, we use incandescent white-light source and the CMOS image sensor. Therefore, the entire optical diaphragm can be captured. Also, we adopt MATLAB to analyze the relationship between the diaphragm sizes and voltage. By means of the application, we capture images by using a camera, lens assembly and our developed optical diaphragm. Successfully, this aperture can achieve the ultimate goal of the real image and the depth of field effect.