An axial variable magnification three-field long-wave infrared imaging optical system

Abstract

The invention relates to an axial-zooming tri-view-field long-wave infrared imaging optical system. The system comprises an objective lens, a zooming lens, a compensating lens, a focusing lens and a converging lens set which are sequentially arranged in the same optical axis from the object space to the image space, and the surface, close to the image space, of the compensating lens adopts a diffraction surface; design index parameters of the optical system are as followed: working waveband ranges from 7700 nm to 9500 nm, the focal distance of the system in a large view field is 22 mm, the focal distance of the system in a middle view field is 92 mm, and the focal distance of the system in a small view field is 550 mm; the working environment temperature ranges from minus 40 DEG C to 60 DEG C. According to the axial-zooming tri-view-field long-wave infrared imaging optical system, switching among the three view fields is achieved by axially moving the zooming lens and the focusing lens, and the zooming ratio can reach 25 times; in addition, by axially regulating the position of the focusing lens, focal point drifting on the image surface due to the temperature changes can be compensated, it is guaranteed that the image quality is not changed along with the temperature, and therefore the high-low temperature environmental suitability of the optical system is good.

Description

technical field [0001] The invention relates to an axial variable magnification three-field long-wave infrared imaging optical system. Background technique [0002] The implementation methods of infrared three-field continuous zoom optical system at home and abroad are divided into radial zoom mode and axial zoom mode, and the axial zoom mode is based on different positions of the zoom mirror and compensation mirror on the optical axis. Realizing the conversion of three fields of view has the advantages of small size and light weight, but it is difficult to correct aberrations in the actual design of an axial zoom optical system with a zoom ratio greater than 20 times. Contents of the invention [0003] The object of the present invention is to provide an axial variable magnification three-field long-wave infrared imaging optical system. [0004] In order to achieve the above object, the solution of the present invention includes an axial variable magnification three-fiel...

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Problems solved by technology

[0002] The implementation methods of infrared three-field continuous zoom optical system at home and abroad are divided into radial zoom mode and axial zoom mode, and the axial zoom mode is based on different positions of the zoom mirror and compensation mirror on the optical axis. Realizing the conversion of three fields of view has the advantages of small size and light weight, but it is difficult to correct aberrations in the actual design of the axial zoom optical system with a zoom ratio greater than 20 times

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