1 December 1991 Combination of mechanical athermalization with manual in IR zoom telescope
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An infrared zoom telescope possessing the lenses made of germanium and working at -10 degree(s) to 40 degree(s)C and at 8 - 12 micrometers has been designed. The main problem to be solved is that the refraction index of Ge changes with the temperature, resulting in decollimation. For the purpose of lower production cost and reduced size and weight, a combination of mechanical passive athermalization by the collimating lens group with manual athermalization by the front lens which is chiefly utilized to focus the object is adopted. The lens mount is made of aluminum alloy. A pair of elements of mechanical passive athermalization, nylon/indium steel, is used to partially compensate the effect of variation of refraction index of Ge and expansion or contraction of aluminum alloy on the distance between the fixed and the collimating lens groups. The manually additional adjustment of the focusing lens, i.e., the front lens, is to partially compensate the distance between the front lens and the second lens group.
© (1991) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Ruiyi Chen, Ruiyi Chen, Dayue Zheng, Dayue Zheng, Xiuli Zhou, Xiuli Zhou, Xingde Zhang, Xingde Zhang, "Combination of mechanical athermalization with manual in IR zoom telescope", Proc. SPIE 1540, Infrared Technology XVII, (1 December 1991); doi: 10.1117/12.48770; https://doi.org/10.1117/12.48770


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