Design And Analysis Study Of The Liquid-glass Apochromatic Optical System

The machine vision imaging optical systems are widely applied in security,industry detection,medical imaging and intelligent driving,and so on.For optical systems with higher imaging quality,the secondary spectrum needs to be corrected to achive apochrimatism.A zoom optical system using liquid lens can achieve a zoom process without mechanical structure.It has lighter weight,smaller size,and faster zooming speed than the traditional optical system.However,there are few studies on the apochromatism of liquid lens at present.An apochromatic zoom optical system combined with liquid lens and glass lens is designed in this thesis,which can achieve apochromat in all of the focal range.The optical system has the advantage of using no low-dispersion glass materials.In this thesis,the zooming process of the solid-liquid combined apochromatic lens is disscussed.The procedure of selecting the materials of the machine vision imaging system is based on Buchdahl dispersion vector method.An optical design procedure of initial optical structure design-first optimization-material replacing-second optimization-material replacing-further optimization is established.This design step includes several times of optimization and material replacing.It is concise and convenient.The apochromatic optical system designed by the step has a focal length of 60 mm,a field of view of 11°,a f-number of 5.45,and its image field of view is matched with 1" CMOS camera.The modulated transfer function(MTF)of all the fields are more than 0.2 at 200lp/mm.The influence of the liquid lens’ s focal power changes on the resolution and achromaticity of the optical system is analyzed.Selected glass and liquid materials those are suitable by observing the distribution of material points in Buchdahl dispersion coefficients diagram.The zoom optical system is optimized.In the full zoom range,all of the values of chromatic aberration and secondary spectrum are less than 3μm.