Fastening of a mirror to a support

Patent metadata

Field	Value
Publication number	US-11822147-B2
Application number	US-202117926554-A
Country	US
Kind code	B2
Filing date	May 11, 2021
Priority date	May 20, 2020
Publication date	Nov 21, 2023
Grant date	Nov 21, 2023

Abstract

A system for fastening a mirror to a support is disclosed including intermediate structures, for example bipod structures. At least some of the intermediate structures are provided with torsion devices making it possible to at least partially compensate for optical aberrations of an instrument that includes the mirror. Each torsion device may comprise an elastic element and a variator. The variator is designed to control a deformation of the elastic element, resulting in a torque which is applied to the mirror.

First claim

The invention claimed is:

1. A fastening system for fastening a mirror to a support of said mirror, comprising the following components:
at least three intermediate structures, each configured to be connected to the support by a first interface of the intermediate structure, and to be rigidly connected to the mirror by a second interface of the intermediate structure, so that the at least three intermediate structures perform together a rigid fastening of the mirror to the support, the intermediate structures being angularly distributed around a center of the mirror while being apart from said center,
wherein the fastening system further comprises at least one torsion device, each torsion device being dedicated to only one of the intermediate structures and comprising:
at least one elastic element, which has two ends, a first of said ends being connected to the first interface of the intermediate structure, and a second of said ends being rigidly connected to the second interface of said intermediate structure, the elastic element being arranged to apply a torque to the mirror, directly to said mirror or through the second interface of the intermediate structure;
a variator, which is coupled to the elastic element so as to modify a value of the torque applied to the mirror directly or through the second interface of the intermediate structure;

wherein each elastic element comprises a strip which extends between the first and the second end of said elastic element, and
wherein the variator is configured to move the first end so as to produce a bending deformation to the strip, the bending deformation producing, at the second end, the torque which is applied to the mirror.

2. The fastening system according to claim 1 , wherein a material of the elastic element of each torsion device is identical to a material of the intermediate structure to which said torsion device is dedicated.

3. The fastening system according to claim 1 , wherein each variator has a mechanical operation or an operation based on at least one piezoelectric cell, for moving the first end of the elastic element relative to the support.

4. The fastening system according to claim 3 , wherein each variator has a mechanical operation suitable for manual actuation, or said variator is suitable for remote actuation by means of an electrical command sent to said variator.

5. The fastening system according to claim 1 , comprising two or three intermediate structures which are each provided with a torsion device independent of the torsion device of each other intermediate structure.

6. The fastening system according to claim 1 , wherein each intermediate structure is connected to the mirror by the second interface of said intermediate structure, at a peripheral edge of the mirror, and said second interface is adapted for applying the torque to the peripheral edge of the mirror.

7. A radiation collecting or optical instrument, comprising the mirror, the support, and the fastening system according to claim 1 , said fastening system rigidly connecting the mirror to the support.

8. The optical instrument according to claim 7 , forming a telescope, and wherein the mirror which is connected to the support by the fastening system is a primary mirror of the telescope.

9. A method for adjusting a radiation collecting or optical instrument, wherein said instrument comprises the mirror, the support, and the fastening system according to claim 1 ,
the mirror being rigidly fastened to the support by means of intermediate structures,
the method comprising executing at least once a sequence which comprises the following steps:
1) wherein at least one optical aberration of the instrument which at least partially results from a deviation in a shape of the mirror, relative to a reference shape identified for said mirror; and
2) For at least one of the intermediate structures, adjusting the variator of the torsion device which is dedicated to said intermediate structure, so as to reduce said at least one optical aberration of the instrument.

10. The method according to claim 9 , wherein the optical aberration that is reduced by executing step (2) comprises at least an astigmatism of the instrument, a trefoil of the instrument, or a combination of astigmatism and trefoil of the instrument.

11. The method according to claim 9 , wherein the radiation collecting or optical instrument is installed on board a satellite, and wherein the sequence which comprises steps 1) and 2) is executed during an integration of the instrument into the satellite, on Earth before launching said satellite, and/or executed or repeated on board the satellite after said satellite has been placed in orbit around the Earth.

12. A fastening system for fastening a mirror to a support of said mirror, comprising the following components:
at least three intermediate structures, each configured to be connected to the support by a first interface of the intermediate structure, and to be rigidly connected to the mirror by second interface of the intermediate structure, so that the at least three intermediate structures perform together a rigid fastening of the mirror to the support, the intermediate structures being angularly distributed around a center of the mirror while being apart from said center,
wherein the fastening system further comprises at least one torsion device, each torsion device being dedicated to only one of the intermediate structures and comprising:
at least one elastic element, which has two ends, a first of said ends being connected to the first interface of the intermediate structure, and a second of said ends being rigidly connected to the second interface of said intermediate structure, the elastic element being arranged to apply a torque to the mirror, directly to said mirror od through the second interface of the intermediate structure;
a variator, which is coupled to the elastic element so as to modify a value of the torque applied to the mirror directly or through the second interface of the intermediate structure, wherein the variator is configured to move the first end of the elastic element to produce a bending deformation of the elastic element; and,

wherein each torsion device is arranged so that the torque which is applied to the mirror, by being generated by said torsion device, is parallel to a first axis which is directed towards the center of the mirror, or is parallel to a second axis which is tangent to a peripheral edge of the mirror at a location of the mirror which is closest to the intermediate structure to which said torsion device is dedicated.

13. A fastening system for fastening a mirror to a support of said mirror, comprising the following components: at least three intermediate structures, each configured to be connected to the support by a first interface of the intermediate structure, and to be rigidly connected to the mirror by a second interface of the intermediate structure, so that the at least three intermediate structures perform together a rigid fastening of the mirror to the support, the intermediate structures being angularly distributed around a center of the mirror while being apart from said center, wherein the fastening system further comprises at least one torsion device, each torsion device being dedicated to only one of the intermediate structures and comprising: at least one elastic element, which has two ends, a first of said ends being connected to the first interface of the intermediate structure, and a second of said ends being rigidly connected to the second interface of said intermediate structure, the elastic element being arranged to apply a torque to the mirror, directly to

Assignees

• Airbus Defence & Space Sas

Inventors

• Castel Didier
• Chaumeil Frédéric
• Carminati Lionel

Classifications

• G02B7/183 Primary

  specially adapted for very large mirrors, e.g. for astronomy, {or solar concentrators} · CPC title

• G02B7/185

  with means for adjusting the shape of the mirror surface · CPC title