Design Of A Zoom Digital Microscope With Double-end Parallel Optical Paths

Continuous zoom digital microscope has now become a very widely used inspection tool in the electronics,packaging,printing,pharmaceutical and other manufacturing industries.Aiming at the problems of relatively small zoom range,fixed working distance,and low object resolution of some continuous zoom digital microscopes currently on the market,this paper proposes a continuous zoom digital microscope with high resolution,large zoom ratio and high imaging quality.Based on the principle of the continuous zoom optical system,a four-element mechanical compensation continuous zoom digital microscope optical system is designed.The working distance of the optical system is fixed,and the conjugate distance of the optical system is fixed while continuously zooming.The magnification range is 0.7×～5.6×.On the basis of the four-component mechanically compensated continuous zoom microscope optical system,the continuous zoom digital microscope with double-end parallel optical paths optical system is designed.By controlling the parallelism of the incident light from the object side of the continuous zoom main lens through the image side.The optical path between the front auxiliary objective lens and the continuous zoom main lens are parallel.the optical path between the continuous zoom main lens and the rear TV lens are parallel.This is the biggest feature of the microscope designed.The front auxiliary objective lens adopts an infinite image distance optical path structure,which can inject the light emitted from the object into the continuous zoom main lens with a parallel beam.and the rear TV lens focuses the parallel optical beam from the continuous zoom main lens on the cameras image sensor.The designed continuous zoom digital microscope has a basic magnification range of 0.7x～5.6×(using 1× auxiliary objective lens and 1×TV lens),working distance is 80mm,numerical aperture ranges from 0.03 to 0.086,and imaging distortion less than 0.5%.The thesis subsequently processed the continuous zoom objective lens,and after testing,it achieved the design goal.This paper also designs the auxiliary objective lens with different magnifications and the rear TV lens,including 0.5×,0.75×,1.5×,2× auxiliary objective lens and 0.5×,0.75×,1.5× rear TV lens.Through the combination of different magnification auxiliary objectives and TV lenses,the magnification range of the continuous zoom lens can be extended to 0.175×～16.8×,and the working distance can be extended to between 33mm and 160mm.Different types of illuminating light sources are also designed for microscopes to adapt to different use occasions,namely ordinary ring light sources,polarized ring light sources and coaxial illuminating light sources.By matching auxiliary objective lenses with different magnifications,TV lenses and illumination light sources,the functions of the microscope can be diversified,and the scope of use of the microscope can be broadened to adapt to a variety of application scenarios.Compared with the ordinary continuous zoom microscope optical system,the continuous zoom digital microscope with double-end parallel optical paths has much advantage.