Five-piece compact medium-wave refrigeration continuous zoom lens

Abstract

The invention discloses a five-piece compact medium-wave refrigeration continuous zoom lens which comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens which are arrangedin order from an object side to a target surface. Three groups of lenses (including the second lens, the third lens and the fourth lens) move in the optical system. Besides a zoom group (the second lens) and a compensation group (the third lens) in the conventional sense, the fourth lens in a secondary imaging group also participates in a zoom process. The optical system is compact in axial dimension, avoids installation and adjustment difficulty caused by using a reflector to change the optical path, has high optical axis precision and optical transmittance, is suitable for 3-5[mu]m medium-wave refrigerating movement, has a focal length range from 20mm to 200mm, and an optical total length not more than 130mm, can be used in applications which require small optical load sizes and light weight, such as UAVs, pods, forest fire monitoring and the like.

Description

technical field [0001] The invention relates to a five-piece compact medium-wave cooling continuous zoom lens, which belongs to the technical field of optical elements. Background technique [0002] Mid-wave infrared applications such as drones, forest fire prevention, and frontier monitoring require infrared optical systems that can simultaneously provide high-magnification small-field images and low-magnification large-field images to complete the system’s search, aiming and tracking functions for targets. Compact structure, light weight and excellent imaging quality are required. [0003] At present, the medium-wave cooling infrared continuous zoom lens is used in conjunction with the refrigeration core, and uses secondary imaging to achieve 100% cold aperture effect, and at the same time achieves the purpose of compressing the volume of the optical system. This technical solution will cause the axial dimension of the optical path system to be too long. Therefore, Usuall...

AI Technical Summary

Problems solved by technology

[0003] At present, the medium-wave cooling infrared continuous zoom lens is used in conjunction with the refrigeration core, and uses secondary imaging to achieve 100% cold aperture effect, and at the same time achieves the purpose of compressing the volume of the optical system. This technical solution will cause the axial dimension of the optical path system to be too long. Therefore, Usually, two reflectors are added to fold the light path, and the number of existing optical system components is more than 7. For example, the patent application with publication number CN 102213822 A adopts 7 lenses and two reflectors; the publication number is CN 102590990A The patent application for which the publication number is CN 103389570A adopts 8 lenses; the patent application whose publication number is CN 203981958 U adopts 8 lenses; the patent application whose publication number is CN 104849834A The application uses 7 lenses; the patent application with publication number CN 107193116A uses 7 lenses plus two mirrors; the above-mentioned lenses all have the problem of low system transmittance

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