Research On Measurement System Based On Chromatic Aberration Confocal Technology

In the process of China's optical cold processing industry moving from a large labor intensive manufacturing country to a powerful country of cold processing automation and intelligent manufacturing,the demand for precision measurement technology is getting higher and higher.Chromatic aberration confocal measurement,a new non-contact measurement method with super-high precision and super-stability,can process automatic measurement quickly,simply and steadily which has been widely used in many measurement fields.In this paper,the important factors and key technologies affecting the performance of the center thickness of the lens measurement system are systematically studied by theoretical analysis,simulation and experimental research,based on the principle of Chromatic aberration confocal measurement of the center thickness of the lens.According to the current development trend of optical processing industry and measurement requirements,a set of Chromatic aberration confocal system with lens centering system is used to measure the center thickness of the lens.In this paper,the principle of thickness measurement based on chromatic aberration confocal method is studied in detail.,it is proved that the method of thickness measurement based on chromatic aberration confocal principle is simple,fast,stable and reliable.According to the principle of measurement,the structure of the whole system of chromatic aberration confocal thickness measurement system is designed.At the same time,the design index and feasibility of the whole system is determined based on the requirement of measurement and its feasibility is analyzed.The subsystems of the chromatic aberration confocal thickness measurement system are designed,including the design of the confocal aperture with a diameter of 50 um,the design of the 5mm and 30 mm dispersion lens,and the design of lens center positioning system.The processing methods of spectral data are studied,including dark background noise processing,median filtering,and the calibration method of dispersion lens.According to the principle of measurement and the requirement of measurement,the thickness automatic measurement software was developed.The modularization idea of the three-layer architecture was used to give the implementation methods of each function sub-module in detail,and the flow chart and key algorithms of each function were attached.Using the thickness measurement system studied in this paper,a series of parallel plate and spherical mirrors with standard thickness are measured.The experimental results show that the accuracy of the measurement system is high,and the measurement time meets the requirements of industrial large-scale lens detection.