Chiu Chi-Wei, Lin Yu-Cheng, Chao Paul C-P, Fuh Andy Y-G
Department of Electrical and Control Engineering, National Chiao Tung University, Hsinchu, Taiwan.
Opt Express. 2008 Nov 10;16(23):19277-84. doi: 10.1364/oe.16.019277.
Aiming to equip commercial camera modules, such as the optical imaging systems with a CMOS sensor module in 3 Mega pixels, an ultra thin liquid crystal lens with designed hole-and-ring electrodes is proposed in this study to achieve high focusing power. The LC lens with proposed electrodes improves the central intensity of electric field which leads to better focusing quality. The overall thickness of the LC lens can be as thin as 1.2 mm and the shortest focal length of the 4 mm-aperture lens occurs at 20 cm under an applied voltage of 30 V at 1 KHz. The inner ring electrode requires only 40% of applied voltage of the external hole electrode. The applied voltages for this internal ring and external hole electrodes can simply be realized by a pre-designed parallel resistance pair and a single voltage source. Experiments are conducted for validation and it shows that the designed LC lens owns good image clearness and contrast at the focal plane. The proposed design reduces the thickness of LC lens and is capable of achieving relative higher focusing power than past studies with lower applied voltage.
旨在为商业相机模块（如配备300万像素CMOS传感器模块的光学成像系统）提供装备，本研究提出了一种具有设计的孔环电极的超薄液晶透镜，以实现高聚焦能力。具有所提出电极的液晶透镜提高了电场的中心强度，从而带来更好的聚焦质量。液晶透镜的整体厚度可薄至1.2毫米，4毫米孔径透镜在1千赫兹30伏的施加电压下，最短焦距出现在20厘米处。内环电极仅需要外环电极施加电压的40%。该内环和外环电极的施加电压可通过预先设计的并联电阻对和单个电压源简单实现。进行了实验以进行验证，结果表明所设计的液晶透镜在焦平面具有良好的图像清晰度和对比度。所提出的设计减小了液晶透镜厚度，并且能够在较低施加电压下实现比以往研究相对更高的聚焦能力。
