Ultra-wide field-of-view off-axis three-reflector optical imaging system

Abstract

The invention discloses an ultra-wide field-of-view off-axis three-reflector optical imaging system which comprises a main reflector with positive focal power, a second reflector with negative focal power, and a third reflector with positive focal power. The reflecting surface of the main reflector is a spherical surface. The reflecting surfaces of the secondary mirror and the third reflector are flat spherical secondary curved surfaces. The curvature radii of top points of the three reflectors approximately satisfy a flat image field condition. The main reflector generates a real image of a far scene between the main reflector and the second reflector. The second reflector and the third reflector perform relay imaging of the real image on an image plane. An aperture diaphragm is placed on the front focal plane of the third reflector, thereby realizing an image-side telecentric optical path. The main reflector inclines along an X-axis relative to incident main light of a central field-of-view. The second reflector is coaxial with the third reflector. After the main light of the central field-of-view in a meridian plane is reflected by the main reflector, an included angle is formed between the reflected main light and the common symmetric axis of the second reflector and the third reflector. The ultra-wide field-of-view off-axis three-reflector optical imaging system has advantages of ultra-wide field-of-view, intermediate relative aperture, wide working wave band, no image-side telecentric barrier, small object-side distortion, high imaging quality, etc. The ultra-wide field-of-view off-axis three-reflector optical imaging system is suitable for earth imaging observation field of a spatial camera, an imaging spectrometer, etc.

Description

technical field [0001] The present invention relates to a telescopic objective lens that can be used for space cameras and imaging spectrometer front objective lenses, in particular to an ultra-wide field of view off-axis telecentric three-mirror telescopic objective lens that can work in the ultraviolet to infrared band, which belongs to optical imaging technology field. Background technique [0002] In recent years, wide coverage of large field of view has become an important development trend of optical remote sensing instruments. The field of view is an important indicator of the earth observation instrument, which determines the global coverage and revisit period of the observation instrument. The larger the field of view, the shorter the revisit period, and the higher the time resolution. [0003] The off-axis reflective optical system has the advantages of simple structure, no chromatic aberration, no central occlusion, easy to enlarge the relative aperture, good hea...

AI Technical Summary

Problems solved by technology

However, it is difficult for this system to achieve a wide-line field of view of more than 100° while obtaining better image quality

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