Folding-axis three-mirror teleobjective without secondary blocking

Abstract

The invention relates to a folding-axis three-mirror teleobjective without secondary blocking. The folding-axis three-mirror teleobjective comprises a primary mirror, a secondary mirror, a third mirror, a deflection mirror and a focal plane, the rotation symmetry axes of the primary mirror, the secondary mirror and the third mirror are not on the same axis, and the aperture diaphragm is arranged on the primary mirror. The primary mirror surface is an ellipsoidal surface, and the secondary mirror and the third mirror surface are hyperboloid surfaces. The deflection reflecting mirror is located on an emergent light path of the third mirror and inclines relative to the third mirror so as to lead an image plane out of an optical axis to facilitate installation of the detector. The primary mirror and the secondary mirror form a middle real image and are close to an exit pupil, so that the deflection mirror is prevented from generating secondary blocking. According to the invention, through tiny eccentricity and inclination, the design of the folding-axis three-mirror telescope objective without secondary blocking is realized. According to the invention, a similar mechanical structure is maintained, but the field of view is relatively enlarged, and the optical system has the advantages of compact structure and small size, meets the requirement of miniaturization, is small in introduced eccentricity and inclination, is small in image quality approaching diffraction limit, is small in stray light influence, and is suitable for the optical imaging fields of area-array cameras, imaging spectrometer front-end systems and the like.

Description

technical field [0001] The invention relates to a telescopic objective lens which can be used for an area array camera and a front objective lens of an imaging spectrometer, in particular to a triple-reflective telescopic objective lens without secondary obscuration, which belongs to the technical field of imaging optics. Background technique [0002] In order to obtain high-resolution images of the ground, a telescopic objective with a long focal length is usually used. In order to reduce the development and launch costs, it is required to achieve high resolution while achieving miniaturization, which puts forward higher requirements for the design of the telescopic objective lens. Common telescopic objectives can generally be divided into three types: transmissive, catadioptric and reflective. The transmissive system is easy to process and adjust, but it is sensitive to color difference and temperature, so it is difficult to apply to wide-band. The catadioptric system ad...

AI Technical Summary

Problems solved by technology

In order to expand the field of view, an off-axis three-mirror structure is adopted, without center obstruction, and it is easy to realize the telecentricity of the image square, but there are problems such as difficult processing and adjustment, and large vertical size of the system.

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