Research On Measurement Of Optical Lens Parameters Based On Digital Image Processing

Lens as indispensable basic optical components, widely used in astronomy, military,transportation, medical, industrial, civil and other fields, which are mounted in a varietyof high-precision laboratory instruments, measurement systems, production equipment,entertainment products. The quality and accuracy requirements of lens to differentsectors lens are not the same, resulting in a variety of different lens parameters.Currently, the main parameters of the lens segments including the effective focallength (EFL), the radius of curvature (R), the flange (BFL), the centering error, themodulation transfer function (MTF) and so on. For a long time, a lot of work havebeen done on the research of lens parameters measurement, a variety of measurementmethods have been find, and lots of high-precision automatic optical inspectionequipment have been developed which are based on these methods.The main research topic is to study the measurement of each parameter of lens.Based on the achievements created before, develop an optical lens multi-parametermeasurement platform which is high accuracy, good stability, lower-cost and can beapplied to the fast lens detection in the real industrial production.My major work is to study the various parameters of the optical lens measurementprinciple, to compare the advantages and disadvantages of different methods ofmeasurement, combined with digital image processing technology, to designmeasurement algorithms, involving auto focus, image filtering, automatic thresholdsegmentation, edge extraction and recognition, curve fitting and other aspects. Andwriting a system software and interface for the platform by using Visual C++. In orderto make sure the accuracy of the platform, different lens were measured, and the datesare used in the error analysis and correction.