An expandable hood

Abstract

The invention discloses an expandable shade, which comprises a foldable chassis, a radial unfolding mechanism and an axial unfolding mechanism. The foldable chassis comprises a first chassis and a second chassis connected by hinges. When folded, the first The chassis is perpendicular to the second chassis, and when unfolded, the first chassis and the second chassis are on the same horizontal plane; the radial expansion mechanism includes a bracket and a pulley assembly, and the bracket includes a plurality of connecting rods and a plurality of tape springs hinged to each other in sequence, and the pulley assembly Installed at the hinge of the connecting rod and the spring of the tape measure, and cooperate with the running track on the chassis, when contracted, the spring of the tape measure bends inwards and folds, when unfolded, the spring of the tape measure releases the elastic potential energy, pushing the connecting rod to move in the radial direction; axially unfolds The mechanism includes a leaf spring assembly, a folded beam and a plurality of supports arranged along the axial direction, and two supports are connected to each other through the leaf spring assembly and the folded beam. The invention shrinks when not in use, and expands into a predetermined shape when working, and has the advantages of small volume and automatic ejection.

Description

technical field [0001] The invention belongs to the field of optical system shading design, and more specifically relates to an expandable shading. Background technique [0002] At present, there are two main factors affecting the imaging quality of the optical system, one is the design quality of the optical structure, and the other is the suppression of stray light in the system. For the space optical system, the shading cover and the light-blocking ring structure on it are an important part of the space optical system and an effective device for suppressing extraneous stray light. With the deepening of the analysis and research on stray light, the research on the hood has been continuously developed. In real life, hoods are widely used in the field of photography, with various varieties, such as square, round, petal-shaped hoods and so on. With the development of aerospace technology, the update of the sunshade has also been promoted, from the ordinary sunshade with fix...

AI Technical Summary

Problems solved by technology

However, the above-mentioned existing light shields can only be deployed in the axial direction, but cannot be deployed in the radial direction, and there are still problems of too large volume and too complicated structure.

For another example, CN200910022264.6 discloses a foldable and unfoldable optical camera shading cover, although it can realize axial and radial expansion, but because the shading cover adopts the form of a frame structure plus a shading cloth, the shading cloth resists harsh The environment is weak, which limits the scope of use of the entire structure, and it is not possible to add a light-blocking ring structure, which limits the light-shielding ability of the hood

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