非球面液滴微透镜的轮廓测量方法

对液滴透镜面形的精确测量是用液滴法制作非球面液滴透镜的关键问题之一。提出了一种基于数字图像处理的测量非球面液滴微透镜轮廓的方法，利用光学成像系统将非球面液滴透镜的轮廓成像在CCD接收面上，通过图像采集卡读入计算机，并经图像处理得出透镜面形表达式，以便研究液滴微透镜在不同电场强度下轮廓的变化规律。图像处理的主要步骤包括：对特定区域采取平滑预处理，去除噪声；利用阈值法将灰度图二值化；对二值化后的图像进行轮廓检测；提出了一种简单有效的方法矫正图像的水平偏转；对矫正过后的液滴轮廓的数据进行多项式拟合，分析液滴透镜在不同电压下的各个拟合参数的变化。实验证明：这种方法用于测量非球面液滴微透镜简单、有效，解决了非球面微透镜制作过程中的液滴轮廓的实时测量问题,有助于低像差非球面液滴微透镜的研制。

Measurement on surface profile of aspherical liquid micro-lens

Precise measurement of surface profile of liquid is one of key problems for fabrication of aspherical lens liquid micro-lens. A measurement method of surface profile of aspherical liquid micro-lens based on digital image processing was proposed. The surface profile image of the aspherical liquid lens was imaged on a CCD camera by an objective,and then read in computer by an image grabber. In order to study the deformation of the liquid lens shape with the increase of the electrostatic force, a serious of image processing approaches were employed to obtain the polynomial expression of the lens surface profile. The main measurement approaches included collecting image, reducing noise, creating a binary image using threshold method,detecting the image edge,rectifying horizontal deflexion to obtain the coordinate of the single pixel, polynomial fitting, etc.The key technology was solved and the actual measuring experiment was carried out. This measurement method is accurate and useful for the fabrication of aspherical liquid lenses with fine optical performance.