﻿ 基于电润湿效应的自变焦补偿光学系统
 光学仪器  2020, Vol. 42 Issue (4): 20-24 PDF

Optical self-zoom system based on electrowetting
YU Zhijun, PENG Runling, GU Hao, LUO Yuanzhi
School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
Abstract: Optical zoom system is a key element in many optical devices such as cameras and video cameras. It is a long-term goal to realize miniaturization of optical zoom system and increase the zoom ratio of the system. In this paper, a three-liquid self-zoom lens is developed, which has the self-zoom function under the action of applied voltage. Therefore, the lens element itself can be used as a simple optical zoom system. The self-zoom function of the system is verified by the Gaussian optical theory and Zemax simulation. The results show that the focal length range of the system is 378−424 mm, and the zoom ratio is 1.217, which achieves the expected target and has a certain reference value for the research of optical zoom systems.
Key words: electrowetting    liquid lens    self-zoom lens    optical devices    optical system

1 基本结构与原理

 图 1 自变焦补偿液体透镜的结构示意图 Figure 1 Structure of self-zoom liquid lens

 $f = \frac{{{n_1}{R_1}{R_2}}}{{\left( {{n_1} - {n_2}} \right)\left[ {{d_2}\left( {{n_1} - {n_2}} \right) + {n_{\rm{1}}}\left( {{R_2} - {R_1}} \right)} \right]}}$ (1)

 $\varphi = {\varphi _1} + {\varphi _2} - \frac{{{d_2}}}{{{n_1}}}{\varphi _1}{\varphi _2}$ (2)

 $\begin{split} \left\{ {\begin{array}{*{20}{l}} {{d_1} = {k_1}{d_0} + \frac{{{a^2}\left[ { - 3 + 2\sqrt {1 - {{\left( {{a / {{R_1}}}} \right)}^2}} } \right]{R_1} + 2\left[ {1 - \sqrt {1 - {{\left( {{a / {{R_1}}}} \right)}^2}} } \right]{R_1}^3}}{{3{a^2}}}} \\ {{d_3} = {k_3}{d_0} + \frac{{{a^2}\left[ {3 - 2\sqrt {1 - {{\left( {{a / {{R_2}}}} \right)}^2}} } \right]{R_2} - 2\left[ {1 - \sqrt {1 - {{\left( {{a / {{R_2}}}} \right)}^2}} } \right]{R_2}^3}}{{3{a^2}}}} \\ \begin{array}{l} \!\!\!\!\! {d_2} = {d_0} - {d_1} - {d_3}\\ \end{array} \end{array}} \right. \end{split}$ (E3)

2 实验与测量 2.1 材料的选择及透镜的制备

2.2 透镜的测量

 图 2 三液体透镜的实物示意图 Figure 2 Photos of the three-liquid lens

 图 3 液体界面的外加电压U（U1或U2）与曲率半径R（R1 or R2）的关系 Figure 3 Relationship between the applied voltage U (U1 or U2) at the liquid interface and radius of curvature R (R1 or R2)

3 系统成像分析

 图 4 两液体界面的曲率1/R1与1/R2的关系 Figure 4 Relationship of curvature 1/R1 and 1/R2 of two liquid interfaces

 图 5 两液体界面的外加电压U1与U2的关系 Figure 5 Relationship between the applied voltages U1 and U2 at the two liquid interfaces

 图 6 液体界面1的外加电压U1与系统的总焦距f的关系 Figure 6 Relationship between the applied voltage U1 and the total focal length f of the system
4 结　论

 [1] 马晨, 程德文, 王其为, 等. 基于高斯括号法的液体透镜调焦眼底相机光学系统设计[J]. 光学学报, 2014, 34(11): 1122001. [2] ZENG Z, PENG R L, HE M. Effect of oil liquid viscosity on hysteresis in double-liquid variable-focus lens based on electrowetting[C]//Proceedings of SPIE International Conference on Optical and Photonics Engineering. Chengdu, China: SPIE, 2017: 1025012. [3] 程洪涛, 郭世俊, 吕杰, 等. 可调光焦度器件的变焦光学系统研究发展趋势[J]. 激光与光电子学进展, 2016, 53(8): 080007. [4] PENG R L, WANG D Z, CHEN J B, et al. Electrically-controlled and liquid-based optical imaging apparatus[J]. Acta Photonica Sinica, 2010, 39(10): 1836–1839. DOI:10.3788/gzxb20103910.1836 [5] OH S H, SEO J H, JEON J P, et al. Liquid lens based on electromagnetic actuation for high-performance miniature cameras[C]//Proceedings of the 18th International Conference on Solid-state Sensors, Actuators and Microsystems. Anchorage, AK, USA: IEEE, 2015: 2077 − 2080. [6] 操超, 廖志远, 白瑜, 等. 一种新型复合变焦光学系统[J]. 光学学报, 2017, 37(11): 1108001. [7] 潘逸君, 李湘宁, 李强, 等. 双液体透镜变焦系统的高斯光学分析[J]. 应用光学, 2016, 37(2): 198–202. [8] 王鸿鹤, 李湘宁, 潘文强, 等. 大变倍比液体透镜变焦系统设计[J]. 光子学报, 2016, 45(6): 0622001. [9] 潘文强, 李湘宁, 卢山, 等. 液体透镜变焦系统高斯理论分析[J]. 光学学报, 2016, 36(12): 1222003. [10] 赵瑞, 马建权, 党智勇, 等. 基于介电润湿三液体透镜的变焦光学系统的设计与分析[J]. 光子学报, 2017, 46(6): 0622005. [11] 罗远智, 彭润玲, 喻治俊. 可变焦补偿的液体透镜结构设计与分析[J]. 激光与光电子学进展, 2018, 55(8): 122301. [12] KOPP D, BRENDER T, ZAPPE H. All-liquid dual-lens optofluidic zoom system[J]. Applied Optics, 2017, 56(13): 3758–3763. DOI:10.1364/AO.56.003758 [13] 马迎军, 张葆, 洪永丰. 连续变焦光学系统的像差自动设计[J]. 光学学报, 2015, 35(8): 0822003. DOI:10.3788/AOS201535.0822003 [14] 李湘宁, 贾宏志, 张荣富, 等. 工程光学[M]. 2版. 北京: 科学出版社, 2010: 37 − 42. [15] LI H Z. Design of three-group flexible high ratio zoom optical system[J]. Laser & Optoelectronics Progress, 2016, 53(12): 122203. [16] 朱凌峰, 孔梅梅, 宋驰, 等. 电润湿双液体透镜的界面面型分析[J]. 光电工程, 2016, 43(12): 65–71. DOI:10.3969/j.issn.1003-501X.2016.12.011 [17] XIE Y Y, LI X N. Quantitative formula for automatic focimeter[J]. Journal of University of Shanghai for Science and Technology, 2013, 35(2): 161–164.