Long-focus television optical system for eliminating thermal difference

Abstract

The invention relates to a long-focus television optical system for eliminating thermal difference, and belongs to the technical field of optics. A first front objective, a second front objective, a diaphragm and a rear objective form a light path of the system and are imaged on a CCD focal plane; the first front objective and the second front objective are used for bearing the main focal power of the system; the second front objective is made of an optical material with high thermal refractive index coefficient change; and the front surface of the rear objective is non-spherical and used forcorrecting aberration. The long-focus television optical system for eliminating the thermal difference realizes thermal difference elimination of the optical system in a wide temperature range of between 40 DEG C below zero and 60 DEG C by using the combination of different optical materials under the condition of reasonably distributing the focal power of the optical system; optical passive thermal compensation is realized, an active compensation structure in the system is saved and an optical-mechanical structure is simplified, so the system configuration is simple; and because the system has no moving component, the optical-mechanical structure is simple and the installation and adjustment are simple and feasible.

Description

technical field [0001] The invention relates to an adiabatic telephoto television optical system, which belongs to the field of optical technology. Background technique [0002] The temperature range of the working environment of most military optical instruments is relatively large, and the curvature, thickness, and refractive index of optical elements will change when the temperature changes. Although the temperature coefficient of refractive index of visible light materials is one or two orders of magnitude smaller than that of infrared optical materials, The impact of ambient temperature changes on the TV optical system is relatively small. However, for the telephoto TV optical system, due to the longer focal length and the wider range of ambient temperature changes, the image plane will drift, resulting in a significant decline in imaging quality. Therefore, an active or passive compensation mechanism must be added to the TV optical system to compensate for the system p...

AI Technical Summary

Problems solved by technology

Because the system is not designed for adiabatic difference, when the ambient temperature changes, the focal plane of the optical system will drift, so that the focal plane of the optical system does not coincide with the CCD image plane, and the imaging quality of the optical system will decline, which cannot meet the needs of use.

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