A large telephoto ratio infrared continuous zoom optical system

Abstract

The present invention proposes an infrared continuous zoom optical system with a large telephoto ratio, in which a front fixed lens group G1 with a positive focal power and a single-lens zoom group G2 with a negative focal power are sequentially arranged according to the direction of the optical path from the object side to the image side , single-lens compensation group G3 with positive refractive power, and rear fixed lens group G4 with positive refractive power; the present invention is based on the optical zoom principle of mechanical compensation method, and the front fixed lens group adopts multiple high-refractive-index optical lenses to undertake the entire The main focal power of the optical system compresses the axial dimension of the optical path. At the same time, three folding mirrors are used to perform space Z-folding on the optical path to further optimize the spatial layout of the optical system and achieve a large telephoto ratio. reached 0.26. And by adopting the design of aspheric surface and diffractive surface, the high-level aberration, on-axis point and off-axis point aberration, thin beam and wide beam aberration of the entire optical system in the full zoom range are reduced. Satisfactory image quality is obtained within the aperture.

Description

technical field [0001] The invention belongs to the field of optical technology, and relates to an infrared continuous zoom optical system with a large telephoto ratio. Background technique [0002] The infrared continuous zoom thermal imager is an imaging system whose focal length can be changed continuously, while the position of the image plane remains stable and the image quality remains good during the zooming process. In order to obtain images of different sizes on the image plane of a fixed-focus infrared camera, the distance between the target object and the lens must be changed or a lens with a different focal length must be replaced. The infrared continuous zoom thermal imager can continuously change the focal length of the system. Therefore, it can obtain target images of continuously changing sizes on the image plane, which is very beneficial for photoelectric detection, reconnaissance, and tracking. [0003] The telephoto ratio refers to the ratio of the axial ...

AI Technical Summary

Problems solved by technology

Because the usual infrared continuous zoom lens covers a wide zoom section, the axial dimension of the entire optical lens is too long, and the telephoto ratio is between 0.8 and 1.2. It is necessary to refract the optical path through a plane mirror to shorten the axial dimension, which is As a result, the size in the width direction is too large, which is difficult to meet the actual use needs of high zoom ratio and large telephoto ratio

Images