Multi-level flexible support structure for large aperture optical lens

Abstract

The invention relates to a multi-level flexible support structure for a large-diameter optical lens. The multi-level flexible support structure includes a lens seat, a plurality of indium steel support pads and a plurality of flexible support units, and the indium steel support pads are evenly arranged on the mirror each flexible support unit is connected to the corresponding indium steel support pad and the lens seat, and each flexible support unit includes a radial flexible support unit and is connected to the The axially flexible support unit of the radially flexible support unit, the radially flexible support unit and the axially flexible support unit cooperate with each other to constrain the six freedoms of the large-diameter optical lens in space in terms of stiffness in four directions The radial support unit is used to compensate the thermal stress caused by the difference in thermal expansion coefficient of the lens material and the lens base material, and the axial flexible support unit is used to compensate the stress introduced by the structural deformation of the lens base and processing errors .

Description

technical field [0001] The invention relates to the technical field of ground-based large-scale optical telescope structures, in particular to a multi-stage flexible support structure for large-aperture optical lenses. Background technique [0002] In order to meet the needs of large-scale time-domain sky survey, Milky Way measurement, dark matter and dark energy detection, and extrasolar planet search, many large-field telescopes in the form of main focus have been built at home and abroad, such as the 8.2m Subaru Star Cluster Telescope of the Japanese Astronomical Observatory (Subaru ), the wide-field dark energy spectrometer (DESI) on the 4-meter telescope Mayall, the 8.4-meter wide-field telescope LSST, the 2.16-meter telescope at the Xinglong Observation Base, etc. In order to achieve a large relative aperture and a large field of view, one of the main features of the above-mentioned telescope is that a very large-diameter optical lens is used at the main focus position...

AI Technical Summary

Problems solved by technology

[0004] (1) In order to avoid optical occlusion, that is, to ensure the field of view of the large-diameter optical lens, the support structure can only be set at the edge of the large-diameter optical lens. Due to the small support contact surface, the force state of the large-diameter optical lens is bad , when the optical axis is in a vertical state, affected by the gravity of the large-aperture optical lens, the center deflection of the large-aperture optical lens is relatively large, which will directly affect the relative position accuracy of the lens;

[0005] (2) Also in order to avoid optical obstruction, the lens holder of the large-aperture optical lens can only be designed as a circular structure, and its inner and outer circles are strictly limited within a narrow size range

However, since the lens is attached to the mirror base as a whole, it is greatly affected by the processing error and structural deformation of the mirror base, and even a slight processing error or structural deformation will lead to a significant drop in the accuracy of the mirror surface shape

In addition, since there must be a difference in thermal expansion coefficient between the lens material and the lens holder material, this pressure ring method is significantly affected by temperature

Therefore, this method is difficult to apply to large-aperture optical lenses

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