Focusing Capability Improvement a Large Aperture Liquid Crystal Lens with Novel Electrodes
Paul C.-P. Chao
|關鍵字:||液晶透鏡;高聚焦品質;大孔徑;LC lens;hole and ring electrodes;index of refraction;large aperture|
This study is devoted to analyze and improve the performance of the liquid crystal (LC) lens with variable focusing length. An LC lens with hole-and-ring and multi-layered electrodes are designed in this study. The proposed electrode design aims to improve the optical performance of LC lens especially in the large aperture. The designed LC lens is suitable for being implemented in a camera module in a cell phone. For traditional single-hole type LC lens, the generated electric filed fails to form desired index distribution in the central region of the lens for effective large-aperture. It is found that when the effective aperture is larger than 2mm, the refractive index distribution is not formed in a uniform, parabolic-like shape. This study, therefore, designs a compensation thin ring and multi-layered ITO patterns inside of 4mm hole-patterned electrode for improving the intensity of electric field and also the distribution of index of refraction of LC lens for better focusing effects. Although the added ring or multi-layered pattern leads a non-uniform electric field, the effective focal length, one important performance index of the LC lens, is shorten under the same applied voltage.