六角形液晶透鏡應用於光場顯微鏡之延展景深

Depth Enhancement of Light Field Microscope with Hexagonal Liquid Crystal Lens Array

朱昭宇(Chao-Yu Chu)

指導教授 ： 黃乙白 ； 謝漢萍

國立交通大學/電機學院/光電工程系所/碩士(2016年)

摘要

隨著生物、醫療科技的進步，3維影像的資訊擷取逐漸被重視。廣泛的顯微鏡只能擷取2D的影像資訊，然而隨著生物、醫學技術的發達，2D的資訊已不足以滿足研究需求。共焦式顯微鏡為目前常見的3D 顯微鏡，藉由機械式的移動改變焦平面來擷取三維的影像資訊；需層層掃描十分的耗時。因此3D光場顯微鏡系統被提出，由於不需耗時的機械式移動，逐漸為研究發展的主流。 3D光場顯微鏡運用微透鏡陣列紀錄光場資訊，以達到快速擷取3維影像之目的，避免冗長的等待。
而本篇論文則是將利用可變焦高阻值液晶透鏡陣列取代傳統3D光場顯微鏡的固定焦距透鏡陣列，可藉由驅動頻率、電壓調變高阻值液晶透鏡之焦距以提升3D光場顯微鏡景深擷取，並且六角形的液晶透鏡結構設計可減少光場顯微鏡系統中不可用的區塊。在拍攝的實驗結果中調變驅動頻率，液晶透鏡焦距變化範圍從1.7 mm至3.1 mm並配合時序性的方法，進而將物平面深度重建範圍從0.27 mm提升到0.8 mm。

關鍵字

光場 ； 液晶透鏡 ； 顯微鏡

並列摘要

With the development of technology, 3D information becomes more and more important. In general, microscope is designed for 2D image capturing. However, with the development of biological and medical science, 3D microscope becomes more and more popular. Confocal microscope is the most common 3D microscope by using mechanical movement to capture 3D image. However, this kind of microscope is time consuming. Therefore, 3D light field microscope has proposed, by using a micro-lens array in front of sensor to capture light field information and reconstruct the 3D image. Furthermore, 3D light field microscope captured without mechanical movement, so it saved a lots of observation time.

In this thesis, we proposed a hexagonal liquid crystal lens array instead of fixed lens array for 3D light field microscope. The focal length of liquid crystal lens can adjust electrically. The refocusing range of light field microscope was well extended. Besides, the dense packing design of our liquid crystal lens array can reduce blinded area in the light field system. In our experimental result, by different driving frequency, the focal length of liquid crystal lens can control from 1.7 mm to 3.1 mm. By this way, refocusing range of object plane can extend from 0.27 mm to 0.8 mm.

並列關鍵字

Light field ； Liquid crystal lens ； microscope

參考文獻

[2]M. Levoy, Z. Zhang, and I. McDowall, "Recording and controlling the 4D light field in a microscope using microlens arrays," Journal of microscopy, vol. 235, pp. 144-162, 2009.

[3]G. Lippmann, "Epreuves reversibles. photographies integrals," Comptes-Rendus Academie des Sciences, vol. 146, pp. 446-451, 1908.

[7]J.-S. Jang and B. Javidi, "Improved viewing resolution of three-dimensional integral imaging by use of nonstationary micro-optics," Optics letters, vol. 27, pp. 324-326, 2002.

[9]C. Perwass and L. Wietzke, "Single lens 3D-camera with extended depth-of-field," in IS&T/SPIE Electronic Imaging, 2012, pp. 829108-829108-15.

[10]M. Ye, S. Hayasaka, and S. Sato, "Liquid crystal lens array with hexagonal-hole-patterned electrodes," Japanese journal of applied physics, vol. 43, p. 6108, 2004.