Research On Thickness Measurement Of Bent Glass Based On Chromatic Confocal Technology

With the development of smart phones,glass screen will enter the 3D curved glass era.The curved glass cover processing technology including turning and hot bending,resulting in large variation of thickness,the thickness of the glass surface detection therefore become necessary step for manufacturer of quality control.This paper first introduces the current situation of glass thickness measurement technology,through the research on the spectral confocal measurement method,using the Gauss fitting method,gray gravity method and least square line fitting method of image processing method based on the combination of design,the vertical axis in PC platform to achieve the direct monitoring system using signal processing methods;legal quasi Gauss the distribution,design and decoding system peak encoding system,reached the peak of sub-pixel positioning accuracy,and introduces the theoretical basis of the working principle of the system and related algorithms.Compared with the existing spectral confocal system,by increasing the optical axis verticality monitoring system,eliminates the error of measurement of thickness measurement of the optical axis and the measured surface tilt caused;double probe structure,due to the elimination of the hot bending process of the glass refractive index changes caused by measurement error.The system adopts double telecentric optical axis detection optical path design,which reduces the requirement of spot image processing while maintaining the measurement accuracy unchanged.And then completed a double probe system based on Windows platform is built,the design of VC image acquisition and processing,spectral peak decoding thickness measurement of user interface application based on system reaches the measuring range of 4mm(single probe range 2mm),the precision is better than 4 micron technology index.The application of dispersion confocal technique in the thickness measurement of curved glass was realized.Finally,the comparison test results show that the program has a good practical application value of the project.With high measurement accuracy,complete automation,high speed and other advantages.Provide a practical solution to 3D curved glass manufacturers.