Infrared large-view-field front-fixed-group-free zoom optical system capable of eliminating cold images

Abstract

The invention relates to an infrared large-view-field front-fixed-group-free zoom optical system capable of eliminating cold images. The core of the configuration of the optical system is to cancel afront fixed lens group in a zoom optical path of a common mechanical compensation method, thereby eliminating the influence of the front fixed lens group on cold images at each zoom position. The optical system is composed of a zoom lens group, a compensation lens group, a fixed lens group, a secondary imaging lens group and a detector. According to the infrared large-view-field front-fixed-group-free zoom optical system configuration design for eliminating cold images, the configuration of the optical system is determined on the basis of a front-fixed-group-free mechanical compensation zoom principle and near-axis optical system theoretical calculation and analysis, aberration of the optical system is corrected through optical structure parameter optimization, aberration balance and aspheric surface, and the image quality is optimal.

Description

technical field [0001] The invention belongs to the field of optical technology, and relates to an infrared large field of view zoom optical system without a front fixed group for eliminating cold images. Background technique [0002] Depending on the distance of the target to be observed, the photoelectric observation and monitoring system usually requires the optical system to have multiple focal lengths, which are used for detection, identification and large-scale monitoring of targets at different distances. The zoom thermal imager can change the focal length of the optical system. Therefore, target images of different sizes can be obtained on the image plane, which is very beneficial for photoelectric observation and monitoring. [0003] Since high-performance thermal imaging cameras usually use cooled detectors, the cold reflection effect should be considered in system design, otherwise it will have a serious impact on the imaging effect. Most of the implementation me...

AI Technical Summary

Problems solved by technology

When designing this configuration, the contribution of the narcissus intensity of the shared objective lens to different fields of view is different. It is difficult to take into account the narcissus intensity of each field of view in the design to reach the tolerance of the system, which usually results in large field of view narcissus. The effect is serious and difficult to eliminate, seriously affecting the imaging quality and observation effect of the large field of view

For the infrared large field of view zoom optical system, this imaging defect is unacceptable

[0004] At present, the method of electric correction is usually adopted at home and abroad to improve or weaken the intensity of narcissus, and to compensate or weaken its adverse influence on the image, but this method can only be aimed at a specific zoom position, and cannot take into account the entire zoom range. , the scene changes, the correction effect will degrade, which will seriously affect the image quality

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