Research On Miniaturization Technology Of Zoom Optical System

The zoom optical system allows to obtain different ratios of images with the camera position unchanged.Therefore,it has important applications in the military and civilian fields.With the increasing demand for zoom optical systems,in some work scenarios,such as aerospace,day and night integrated monitoring equipment,people have put forward new requirements for zoom optical systems,including miniaturization,high image quality,and operating band.It is necessary to include both visible and near-infrared bands.In order to realize the miniaturization of such a wide-band confocal focal length zoom optical system and improve the imaging quality,a plurality of sets of variable zoom optical system structures are adopted herein.The Gaussian optical structure of multi-variable zoom optical system is calculated by Gaussian brackets and combined with data visualization analysis method to analyze the zooming process of multiple sets of variable zoom optical systems.At the same time,in order to correct the secondary and tertiary spectra of the front group of the wide-band zoom optical system,a seed-band stitching optical glass combination selection method is proposed.The method divides the design band into multiple sub-band intervals,and stitches the sub-band intervals to generate a larger sub-band interval until the entire band is covered,and lists all possible optical glass combinations in each sub-band interval.Achromatic equations.By solving the equations by least squares method,the optimal glass combination which can effectively correct the secondary and tertiary spectra of the wide-band long focal length optical system is obtained.In the end,based on the multi-set zoom system structure and sub-band stitching method,a wide band with three moving groups,focal length variation ranging from 80 mm to 400 mm,F number of 5,and working band between 480 nm and 900 nm is completed.In the zoom optical system,the field of view MTF of the optical system can reach 0.6 at 70 lp/mm,the edge field of view MTF reaches 0.3 at 70 lp/mm,the total length of the optical system is 230 mm,and the relative length is 0.575.The design result satisfies the miniaturization requirement.