Design Of Optical System With Continuously Adjustable Magnification For Machine Vision

The machine vision system consists of hardware and software.The hardware mainly includes industrial cameras,light sources,optical lenses and image acquisition systems.The imaging quality of the optical lens affects the resolution of the final acquired image.By studying the literature,this paper expounds the development status of machine vision at home and abroad and the research status of machine vision lenses.Based on this,combined with the development status of image sensing technology,several machine vision lenses and optical systems are designed:The thesis designed a large field-of-view continuous-magnification object-side telecentric lens with a magnification range of 0.5x-1.0x and matched to a maximum of 4/3-inch image sensor.A method for constructing the initial structure of the zoom system using a virtual lens in the optical design software is proposed innovatively.The virtual lens in the optical design software is used to simulate the variable magnification process of the variable magnification system.The focal length of each component in the variable magnification system and the interval between the components under different magnifications can be initially determined.The actual structure of the optical system can be obtained by replacing the virtual lens with an actual lens.Based on the initial structure,the design was optimized.After completing the tolerance analysis and cam curve design of the optical system,the product was produced and processed.The lens is combined with an independently developed industrial camera and supporting software system for size measurement experiments.It is proved that the measured data of the designed telecentric optical system with continuous zoom is reliable and repeatable.The thesis designed a continuous zoom digital microscope with high zoom ratio and ultra-short size.Its magnification range is 0.7x-5.6x,the working distance is 100mm,but the total length of the optical system is only 130mm.Compared with traditional optical microscopes,digital microscopes directly image on the surface of the image sensor without having to consider the design of the visual optical system,which simplifies the structure of the optical system and reduces the processing difficulty and production cost of the microscope optical system.At the same time,the digital microscope optical system combines the advantages of optical lenses and image sensing technology.It has continuously adjustable magnification and good imaging quality.After completing the optical design of the high zoom ratio ultra-short size continuous zoom digital microscope,tolerance analysis of the entire system and analysis of the cam curve of the system in different situations are performed to provid a theoretical design basis for future production and processing.The thesis designed a multi-conjugate distance magnification continuously adjustable portable digital microscope optical system based on optical lens movement.Based on the original optical zoom design principle of the zoom system the conditions for the continuous zoom of the optical system and the highest magnification that can be achieved are analyzed.The multi-conjugate distance magnification continuously adjustable portable digital microscope optical system based on optical lens movement is mainly composed of an optical lens,a hardware circuit and a mechanical structure.The designed optical lens has a focal length of 15mm and a working distance covering 25mm-97mm.which can achieve a continuous zoom of 0.2x-2.2x;the circuit part is composed of the main control circuit board and the lighting circuit board;the mechanical part includes the mechanical structure design of the optical lens and the entire system mechanical design.The method of using a moving optical lens to achieve zooming,while ensuring the imaging quality of the optical system.greatly simplifies the structure of the optical system.The thesis also designed a multi-conjugate distance magnification continuously adjustable portable digital microscope optical system based on image semsor movement.When the working distance of the optical system changes.clear imaging can be achieved by adjusting the position of the image sensor.Designed four optical lenses with focal lengths of 3mm.6mm.15mm and 23mm.Among them,the optical lens with a focal length of 1 5mm completes production and processing.and its working distance covers 20mm-200mm,which can achieve continuous zooming of 0.1x-3.3x.The circuit part is composed of a power circuit board,a main control circuit board,a sensor circuit board and a lighting circuit board.The mechanical part includes the mechanical structure design of the optical lens and the mechanical structure design of the entire system.The method of achieving zooming based on the movement of an image sensor has the advantages of enabling continuous changes in magnification,linear adjustment of magnification,and large zoom ratios,which are not available in current mainstream market products.With this thinking,this research is expected to be applied to the occasions where the magnification needs to be continuously and rapidly changed in the field of machine vision.