Astigmatism eliminating three reflector system

A three-mirror, astigmatism-eliminating technology, applied in the field of optical systems, can solve problems such as high difficulty in processing and assembly, high development costs, and difficulty in mass production, so as to reduce processing difficulty and cost, eliminate the influence of occlusion, and Effect of Difficulty Reduction

CN1432836AInactive Publication Date: 2003-07-30TSINGHUA UNIV
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2003-07-30
Estimated Expiration
Not applicable · inactive patent

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Abstract

The astigmatism eliminating three-reflector system provided by the present invention aims at facilitating the machining and regulation of reflective optical system and reducing its development cost. The astigmatism eliminating three-reflector system includes three, primary, secondary and the third, reflectors with one common optical axis, the primary reflector and the third reflector are spherical mirror, and the secondary reflector has quadric oblate spherical reflecting surface. It system also has ar aperture diaphragm, and has abxial working field of view. The parallel light beam incident to the primary reflector is thrice reflected in the primary reflector, secondary reflector and the third reflector successively to image in the image plane. The present invention is easy to regulate and low in cost, and has relatively working field of view.
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Description

technical field

[0001] The invention belongs to the field of optical systems, in particular to a reflective optical imaging system. Background technique

[0002] Reflective astigmatism-eliminating optical systems are generally designed with the help of aspheric surfaces. In recent years, as the aspheric surface manufacturing process and assembly process have become increasingly mature, they have been more and more widely used, especially long-focus reflective astigmatism-eliminating optical systems. It is more common in aerospace applications. Generally, the three-reflection astigmatism elimination system is a type that has been studied more. For example, the three-reflection astigmatism elimination system mentioned in U.S. Patent No. 4,131,485, published on December 26, 1978, uses three The sub-aspherical design has 7 independent variables when the focal length is determined, which can better arrange the aberration and external dimensions. Sometimes, in order to expand the...

Examples

Embodiment 1

[0028] Embodiment 1 is an aerospace push-broom imaging optical system, and its structure is as follows: figure 1 Shown by:

[0029] Focal length f'=500mm; field of view is 10°×1°; relative aperture is 1 / 12;

[0030] Dimensions: (900×300×120)mm 3 ; Spectral segment: (0.5-0.78) micron;

[0031] System working field of view: X direction is (-5° to 5°); Y direction is (5° to 6°).

[0032] Structural parameters of primary mirror 1: radius of curvature is -1571.067mm (concave surface); spacing d1 between primary and secondary mirrors is -446.731mm; Y off-axis distance is -102.48mm; tilt is 0; eccentricity coefficient is 0; clear aperture (53.2×35.7)mm 2 .

[0033] Structural parameters of secondary mirror 2: radius of curvature is -473.5mm (convex); eccentricity coefficient is 2.2510; distance d5 from secondary mirror to third mirror is 875mm; Y off-axis is 0; tilt is 0; clear aperture diameter is 10.7mm.

[0034] The structural parameters of the third mirror 4: the radius of...

Embodiment 2

[0038] Embodiment 2 is a push-broom optical system for a microsatellite or a reconnaissance aircraft, and its structure is as follows: figure 2 Shown:

[0039] Focal length f'=500mm; field of view is 10°×1°; relative aperture is 1 / 12;

[0040] Dimensions: (482×440×260)mm 3 ; Spectral segment: (0.5-0.78) micron;

[0041] Offset field of view: (-3° to 3°) in the X direction; (4.2° to 5.0°) in the Y direction.

[0042] Structural parameters of primary mirror 1: radius of curvature is -1519.828mm (concave surface); distance d1 between primary mirror 1 and secondary mirror 2 is -440.791mm; Y off-axis is -101.35mm; inclination is 0; eccentricity coefficient is 0 ;The clear aperture is (67.7×31.9)mm 2 .

[0043] Structural parameters of the secondary mirror 2: the radius of curvature is -472.85mm (convex); the eccentricity coefficient is 2.1866; the distance d2 between the secondary mirror 2 and the folding mirror 3 is 450mm; the Y off-axis is 0mm; the tilt is 0; The aperture ...