Cassegrain optical system shading assembly

Abstract

A Cassegrain optical system shading assembly belongs to the field of lens hood designing and solves the problem that the existing lens hoods can not restrain stray light. The Cassegrain optical system shading assembly comprises a primary mirror shading tube, an inner shading tube, four right trapezoid blades and at least two cylindrical sleeves. All cylindrical sleeves are concentric but different in diameter and cylinder height. The diameters are in right proportion to the cylinder heights. All cylindrical sleeves are sleeved together and fixed on the four blades according to the rule that the diameters and the cylinder heights are gradually increased. The four blades are arranged in a cross shape along the diameter directions of all the cylindrical sleeves, the cylindrical sleeve on the innermost layer is fixed with the upper bottom edges of the four blades, the upper bottom edges of all the cylindrical sleeves and the right angular sides of the four blades are arranged in the same plane, gaps between adjacent two cylindrical sleeves are equal, and the lower bottom edges of the four blades are fixed on an inner wall of the primary mirror shading tube. A material high in stray light absorbing rate is coated on surfaces of the four blades and the inner surfaces and the outer surfaces of the cylindrical sleeves. The Cassegrain optical system shading assembly achieves effective restraining of stray light under the same central obscuration ratio.

Description

technical field [0001] The invention relates to the technical field of shading cover design, in particular to a Cassegrain optical system shading assembly. Background technique [0002] The Cassegrain optical system consists of a concave primary mirror and a convex secondary mirror, usually with a hole in the center of the primary mirror, and its focus is generally located behind the central hole of the primary mirror and imaged behind the primary mirror. focus. [0003] Most of the Cassegrain optical systems work in the space environment with strong background light outside the field of view of the optical system. It will cause a decrease in the signal-to-noise ratio, and in serious cases, the detector will not be able to detect. In order to reduce the impact of stray light in the space environment, it is generally necessary to add a suitable hood to the Cassegrain optical system to suppress the stray light in the space environment. [0004] Such as figure 1 As shown, th...

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Problems solved by technology

[0005] In order to solve the problem that the existing Cassegrain optical system shading cover cannot effectively suppress stray light, the present invention provides a Cassegrain optical system shading assembly

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