Double-fast-reflection-mirror imaging system for compensating image motion
Technical Field
The invention relates to the field of optical systems of space remote sensing cameras, in particular to a double-fast-reflection-mirror imaging system for compensating image motion.
Background
In order to realize the imaging in the orbit in a large range, the remote sensing camera can expand the scanning range by rotating around a central shaft at a high speed, thereby realizing the large-amplitude wide observation on the ground. Due to the adoption of two-dimensional high-speed rotation around the central axis, image motion can be generated within an integral time, and the imaging quality is seriously influenced. In order to eliminate image motion caused by high-speed rotation, two single-axis rotating plane fast reflecting mirrors are adopted to compensate the image motion in an integration time, so that better imaging image quality is realized.
Disclosure of Invention
In order to solve the problems in the prior art, the invention designs a double-fast-reflection-mirror imaging optical system for compensating image motion.
The technical scheme adopted by the invention is as follows:
a double fast reflecting mirror imaging system for compensating image motion is designed. The double fast reflection mirror aberration-eliminating layout is characterized by comprising a main mirror 1, a secondary mirror 2, a three-mirror 3, a four-mirror 4, a first fast reflection mirror 5, a second fast reflection mirror 6 and an image surface 7. The light path is reflected to the primary mirror 1, the secondary mirror 2, the tertiary mirror 2, the quaternary mirror 3, the quaternary mirror 4, the fast mirror 5, the fast mirror 6 and the image plane 7 according to incident light. Wherein, primary mirror 1, secondary mirror 2, three mirrors 3 and four mirrors 4 form one set of coaxial four and reflect the light way overall arrangement, place two fast reflection mirrors between three mirrors 3 and four mirrors 4, fast reflection mirror 5 and fast reflection mirror two 6 respectively, fast reflection mirror 5 and fast reflection mirror two 6 are two level crossing, can rotate around its center pin, fast reflection mirror 5 and fast reflection mirror two 6 mounting means need satisfy axis of rotation mutually perpendicular between them.
The primary mirror 1 is a concave aspheric surface reflector;
the secondary mirror 2 is a convex aspheric reflector;
the three mirrors 2 are convex aspheric reflectors;
the four mirrors 4 are concave aspheric reflectors;
the first fast reflecting mirror 5 is a plane reflecting mirror;
the second fast reflecting mirror 6 is a plane reflecting mirror.
Compared with the prior art, the invention has the beneficial effects that: in order to eliminate image shift caused by high-speed rotation, two plane fast reflecting mirrors rotating along a single axis are adopted to compensate the image shift in an integral time, so that better imaging image quality is realized.
Drawings
FIG. 1 is a schematic diagram of a double fast-reflection imaging system for compensating image shift:
FIG. 2 is a schematic side view of a dual fast reflecting mirror imaging system for compensating image motion:
description of the labeling: the optical system comprises a 1-primary mirror, a 2-secondary mirror, a 3-tertiary mirror, a 4-quaternary mirror, a 5-fast reflection mirror I, a 6-fast reflection mirror II, a 7-image plane, an 8-fast reflection mirror I and a 9-fast reflection mirror II.
Detailed Description
The embodiments of the invention will be described in further detail with reference to the accompanying drawings and examples:
the implementation mode of the invention is as follows: the light path is a coaxial four-reflection light path. The focal length of the system is 10000mm, the main mirror 1 is a concave reflector, the radius value is 4500mm, the secondary mirror 2 is a convex reflector, the radius value is 1700mm, the three mirrors 3 are convex reflectors, the radius value is 4400mm, the four mirrors 4 are concave reflectors, and the radius value is 1700 mm. As shown in fig. 2, the first fast reflecting mirror 5 is a plane mirror and can rotate around a first rotating shaft 8 of the first fast reflecting mirror whose center is parallel to the Y axis, and the fast reflecting mirror 6 is also a plane mirror and can rotate around a second rotating shaft 9 of the second fast reflecting mirror whose center is perpendicular to the Y axis, and the rotating shafts of the two are perpendicular to each other.
When the optical system points to perform two-dimensional rotation or translation at high speed, an imaging point can generate a tailing phenomenon which is image motion, in order to compensate the phenomenon, two plane fast-reflecting mirrors are arranged between the three mirrors 3 and the four mirrors 4, the fast-reflecting mirror I5 is coaxial with the three mirrors 3 and the four mirrors 4 and used for converting light rays out at a certain angle, and then the fast-reflecting mirror II 6 is placed on a converted light path and used for converting the light rays to an image surface 7 for imaging.
The rotation directions of the two fast reflecting mirrors are mutually vertical, and the fast reflecting mirrors can be used for compensating image motion in two directions. The first fast reflecting mirror 5 is a plane reflecting mirror and can rotate around a rotating shaft 8 of the first fast reflecting mirror with the center parallel to the Y axis, the second fast reflecting mirror 6 is also a plane reflecting mirror and can rotate around a rotating shaft 9 of the second fast reflecting mirror with the center vertical to the Y axis, the rotating shafts of the first fast reflecting mirror and the second fast reflecting mirror are mutually vertical, and compensation for two-dimensional image shift can be realized when the two fast reflecting mirrors rotate around the rotating shafts respectively.
The fast reflection mirror in the light path eliminates image shift caused by high-speed rotation, two plane fast reflection mirrors rotating along a single axis compensate image shift in an integration time, and therefore better imaging image quality is achieved.