Research On Design Method Of Portable Ultra Thin Telescope

Telescope is one of the common visual optical systems.Its history can be traced back to the 17th century.At present,most of the commonly used telescopes are hand-held binocular telescopes,which can not be used for a long time and is not convenient to carry.Therefore,it is of great significance to design a portable and miniaturized telescope.Based on the existing human eye models,this paper analyzes the internal structure of the human eye,and establishes the human eye model in ZEMAX.At the same time,based on the widely existing defects of human eyes,two eye models of myopia and hyperopia are established,and the three models are combined with the telescope system designed in this paper.Combined with the characteristics of the telescope system,based on the principle of single-chip multi surface optical system,the model of single-chip multi surface telescope system is established,and the expressions of central thickness and shielding ratio are constructed.According to the structure characteristics of the telescope system,the optical model and initial structure of the monolithic multi surface telescope system are established.According to the structure parameters of the human eye model and the requirements of the market for the telescope parameters,the parameters of the single-chip multi-surface telescope system designed in this paper are determined,and the initial structure of the single-chip multi-surface telescope system is established.After optimization,a portable and miniaturized telescope system is obtained.The telescope system is only composed of a single lens.The light is reflected four times in the lens,and each reflecting surface is an even aspheric surface.The operating wavelength of the system is visible light,the magnification is 5~×,the base of the lens is PMMA,the diameter is 15mm,the total length is 5mm,and the full field of view is1.15°.The MTF curve of the optimized optical structure combined with the normal human eye model is smooth,greater than 0.2 at 60lp/mm,and the imaging quality is good.At the same time,in order to expand the application scope of the system,the system is combined with the myopia and hyperopia models to optimize the design.The results show that the system can be applied to different diopters of human eyes by simply modifying the curvature and thickness.In order to analyze the process feasibility of the system,the tolerance analysis is carried out,and the machining tolerance requirements of the system are obtained.Then the existing machining methods and the machining accuracy can be investigated.The results show that single point diamond turning,injection molding and 3D printing technology can realize the processing of this system.The coating method of this system is also investigated.The results show that the all dielectric reflective film composed of silica and titanium dioxide and the metal aluminum film with silica as protective layer can meet the application requirements.Compared with the traditional Galileo telescope system,the telescope system designed in this paper is small and easy to carry.With the development of processing technology,mass production can be realized to meet the market demand for small telescope system.