CN113031238A - Multi-mirror integrated large-view-field long-focus off-axis four-mirror optical system - Google Patents
Multi-mirror integrated large-view-field long-focus off-axis four-mirror optical system Download PDFInfo
- Publication number
- CN113031238A CN113031238A CN202110399019.8A CN202110399019A CN113031238A CN 113031238 A CN113031238 A CN 113031238A CN 202110399019 A CN202110399019 A CN 202110399019A CN 113031238 A CN113031238 A CN 113031238A
- Authority
- CN
- China
- Prior art keywords
- mirror
- reflector
- optical system
- integrated
- axis
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000003287 optical effect Effects 0.000 title claims abstract description 39
- 238000001514 detection method Methods 0.000 abstract description 9
- 238000003384 imaging method Methods 0.000 abstract description 9
- 238000012545 processing Methods 0.000 abstract description 5
- 230000004075 alteration Effects 0.000 description 8
- 238000012546 transfer Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 230000005540 biological transmission Effects 0.000 description 3
- 238000009434 installation Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 206010010071 Coma Diseases 0.000 description 1
- 201000009310 astigmatism Diseases 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000007123 defense Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 210000001747 pupil Anatomy 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
- 239000013585 weight reducing agent Substances 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B17/00—Systems with reflecting surfaces, with or without refracting elements
- G02B17/02—Catoptric systems, e.g. image erecting and reversing system
- G02B17/06—Catoptric systems, e.g. image erecting and reversing system using mirrors only, i.e. having only one curved mirror
- G02B17/0647—Catoptric systems, e.g. image erecting and reversing system using mirrors only, i.e. having only one curved mirror using more than three curved mirrors
- G02B17/0663—Catoptric systems, e.g. image erecting and reversing system using mirrors only, i.e. having only one curved mirror using more than three curved mirrors off-axis or unobscured systems in which not all of the mirrors share a common axis of rotational symmetry, e.g. at least one of the mirrors is warped, tilted or decentered with respect to the other elements
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Lenses (AREA)
Abstract
The invention provides a multi-mirror integrated large-view-field long-focus off-axis four-mirror optical system, which belongs to the technical field of space optics and aims to solve the problems of large volume and high assembly and adjustment difficulty of the existing off-axis optical system, and the optical system comprises: the reflector comprises a main reflector, a secondary reflector, a third reflector and a fourth reflector, wherein the main reflector and the third reflector form an integrated mirror A, and the secondary reflector and the fourth reflector form an integrated mirror B; the light source emits light rays which are reflected by the main reflector, the secondary reflector, the third reflector and the fourth reflector in sequence and then converged on the focal plane. The system has the characteristics of compactness, easiness in assembly and adjustment and capability of greatly reducing the processing cost and the launching cost; the optical system can meet the requirements of visible light to infrared band imaging and multispectral detection.
Description
Technical Field
The invention belongs to the technical field of space optics, and particularly relates to a multi-mirror integrated large-view-field long-focus off-axis four-mirror optical system.
Background
When the large-view-field long-focus space camera is used for aerospace remote sensing observation, the large-view-field long-focus space camera can perform one-time high-definition imaging on a target in a large range, is widely applied to the fields of environmental monitoring, resource general survey, military, national defense and the like, and is a key research object in all countries in the world. The conventional space camera optical system mainly comprises a transmission type system, a coaxial reflection type system, a coaxial turn-back type system and an off-axis reflection type system, wherein the transmission type system cannot realize a large view field and a long focal length simultaneously due to the limitation of the size of materials and the optical and mechanical characteristics of the transmission type system, the coaxial reflection type system and the coaxial turn-back type system cannot realize the large view field although the long focal length is easily realized, and only the off-axis reflection type system has the characteristics of the large view field and the long focal length.
The off-axis system which is mature in the prior art and most widely applied is an off-axis three-mirror system, but the three-mirror system has relatively less optimized degree of freedom, so that the performance of the system is limited, although the degree of freedom can be increased by introducing a free curved surface, the processing difficulty is very high because the free curved surface is a non-rotational symmetric surface, and the detection and the assembly and adjustment of the system cannot adopt the traditional method, so that the processing cost and the assembly and adjustment difficulty can be greatly increased, and the off-axis system is difficult to popularize and use in a large range. In addition, the off-axis three-mirror system has the disadvantages of large volume and difficulty in weight reduction.
In order to solve the problem of less optimization freedom of the off-axis three-mirror system, an off-axis four-mirror system is introduced. The existing off-axis four-mirror system has the common defects of the off-axis system, namely, the off-axis four-mirror system is large in size, difficult to lighten and difficult to install, adjust and detect due to the adoption of a local surface type, so that the manufacturing cost and the emission cost are high, and large-scale deployment and quick response are difficult to realize. Therefore, it is necessary to design an off-axis four-mirror optical system with easy detection and adjustment.
Disclosure of Invention
The invention provides a multi-mirror integrated large-view-field long-focus off-axis four-mirror optical system, aiming at solving the problems of complex structure, large volume, difficulty in light weight and difficulty in adjustment and detection of the existing off-axis four-mirror system.
In order to solve the technical problems, the technical scheme of the invention is as follows:
the invention provides a multi-mirror integrated large-view-field long-focus off-axis four-mirror optical system, which comprises: the reflector comprises a main reflector, a secondary reflector, a third reflector and a fourth reflector, wherein the main reflector and the third reflector form an integrated mirror A, and the secondary reflector and the fourth reflector form an integrated mirror B;
the light source emits light rays which are reflected by the main reflector, the secondary reflector, the third reflector and the fourth reflector in sequence and then converged on the focal plane.
Preferably, the main reflector, the secondary reflector, the third reflector and the fourth reflector are coaxially arranged.
Preferably, the integral mirror A is a convex hyperboloid.
Preferably, the integral mirror B is a concave hyperboloid.
Preferably, the central curvature radius of the integral mirror A is 3722mm, the radius of the integral mirror B is 2351.74mm, and the central distance between the two groups of mirrors is 1439 mm.
The invention has the advantages of
The invention provides a multi-mirror integrated large-view-field long-focus off-axis four-mirror optical system, in the optical system,
1) the center positions of the main reflector and the third reflector are coincident, the surface type parameters are equal, and the positions participating in imaging in the light path are not coincident, so that the main reflector and the third reflector can be simultaneously processed by using one substrate, the main reflector and the third reflector form an integrated mirror A, a set of surface type correcting mirror and detection equipment can be shared when surface type detection is carried out, synchronous coaxial detection is realized, the processing time can be greatly shortened, and the cost is saved.
2) The secondary reflector part of the system is a complete quadric surface, so the installation and adjustment are simple, and the fourth reflector and the secondary reflector are coaxially arranged and form an integral mirror B, so the processing and detection time and the installation and adjustment time can be shortened, and the cost is saved.
3) All the mirror surfaces are not inclined relative to the optical axis, so that the detection and the adjustment are convenient.
4) The main reflector and the third reflector of the system share one reflector, and the secondary reflector and the fourth reflector share one reflector, so that only two mirror surface structure supporting pieces are needed in total, and compared with the existing off-axis four-reflector system which needs four supporting structures, the system can greatly reduce the volume of the whole machine and lighten the mass of the whole machine.
Drawings
FIG. 1 is a schematic structural diagram of a multi-mirror integrated large-field long-focus off-axis four-mirror optical system of the present invention.
FIG. 2 is a modulation transfer function curve diagram of the multi-mirror integrated large-field long-focus off-axis four-mirror optical system of the present invention.
FIG. 3 is a dot-column diagram of the multi-mirror integrated large-field long-focus off-axis four-mirror optical system of the present invention.
In FIG. 1, a main reflector, 2, a secondary reflector (aperture stop), 3, a third reflector, 4, a fourth reflector, 5 and a focal plane. In fig. 2, T represents a modulation transfer function curve of a meridional ray, S represents a modulation transfer function curve of a sagittal ray, DIFF, LIMIT represents a diffraction LIMIT of the modulation transfer function, DEG represents "degree", and is a unit of field angle.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings.
As shown in fig. 1, a multi-mirror integrated large-field long-focus off-axis four-mirror optical system includes:
a main mirror 1 as a first reflecting surface of the system; the secondary reflector 2 is used as an aperture diaphragm of the system, is coaxially arranged with the main reflector 1 and is arranged on a reflection light path of the main reflector 1; the third reflector 3 is coaxially arranged with the main reflector 1 and the secondary reflector 2 and is arranged on a reflection light path of the secondary reflector 2; the fourth reflector 4 is coaxially arranged with the main reflector 1, the secondary reflector 2 and the third reflector 3, is arranged on a reflection light path of the third reflector 3 and is a focal plane 5;
the central positions of the main reflector 1 and the third reflector 3 are superposed, the surface type parameters are equal, the positions participating in imaging are respectively arranged at the lower side and the upper side of an optical axis and can be realized by using one reflector to form an integral mirror A; the center positions of the secondary reflector 2 and the fourth reflector 4 are superposed, the surface type parameters are equal, the secondary reflector and the fourth reflector can be realized by using one reflector, an integral reflector B is formed, and the integral reflector B contains a reflector top, so that the assembly and the adjustment are convenient.
The system adopts a view field off-axis scheme, a central view field deflects anticlockwise relative to an optical axis, in a light path, the main reflector 1 is used for the lower half part of the integral mirror A, the third reflector is used for the upper half part of the integral mirror A, and the main reflector 1 and the third reflector 3 can be realized by the reflector integral mirror A.
The secondary reflector 2 coincides with the aperture diaphragm, the whole mirror surface participates in imaging, the fourth reflector 4 is the last reflecting surface of the system, the upper half part of the integral mirror B is only used in the off-axis imaging process, the aperture of the fourth reflector 4 is larger than that of the secondary reflector 2, namely the two reflecting surfaces can be realized through the integral mirror B of the reflector, and the aperture is only the sum of the radius of the fourth reflector 4 and the radius of the secondary reflector 2.
The integrated mirror A is a convex hyperboloid, the integrated mirror B is a concave hyperboloid, spherical aberration, coma aberration, astigmatism and distortion in primary aberration are corrected by utilizing the secondary surface coefficients of the reflectors in an initial structure, and curvature of image surfaces is eliminated by reasonably distributing the curvatures of the reflectors.
The light emitted by the light source is reflected by a main reflector 1 (namely, the lower half part of the integral mirror A), a secondary reflector 2 (namely, the lower half part of the integral mirror B), a third reflector 3 (namely, the upper half part of the integral mirror A) and a fourth reflector 4 (namely, the upper half part of the integral mirror B) in sequence and then converged on a focal plane 5.
The optical system adopts a field off-axis mode, and prevents the light path of the system from being blocked by adjusting the field off-axis angle instead of making the reflecting surface off-axis and eccentric, thereby avoiding the system from generating excessive aberration.
The surface type parameters of the main reflector 1 and the third reflector 3 are equal, the surface type parameters of the secondary reflector 2 and the fourth reflector 4 are equal, and the optical path of the system is actually equivalent to a symmetrical optical path, which is beneficial to off-axis aberration.
The present invention reduces the overall size of the optical system by increasing the curvatures of the sub-mirror 2 and the fourth mirror 4, while adjusting the conic constants and the high-order coefficients of the main mirror 1 and the third mirror 3 to balance the aberrations.
In the system, the central curvature radius of the integral mirror A is 3722mm, the radius of the integral mirror B is 2351.74mm, and the central distance between the two groups of reflectors is 1439 mm. All reflective surfaces are even aspheric and have no tilt with respect to the optical axis.
The off-axis amount of the field of view in the meridional direction of the system is 16 degrees, so that the lower initial aberration can be realized while the secondary mirror is prevented from shielding the light.
FIG. 2 is a graph of the modulation transfer function of the optical system of this embodiment, from which it can be seen that the imaging quality of the optical system of the present invention is close to the diffraction limit.
FIG. 3 is a point diagram of the system, and it can be seen that the maximum spot root mean square radius of the optical system is less than 5.237 μm, which is less than the pixel size of most imaging detectors.
The whole optical system does not contain a refraction element and cannot generate chromatic aberration, so that the imaging spectrum band is wide and can cover visible light to infrared bands.
The optical system is suitable for a long-focus large-view-field space camera, in particular to a space camera with the F/# (the ratio of the focal length to the diameter of an entrance pupil) between 5 and 8, the focal length between 1000mm and 2000mm and the field angle between 10 and 15 degrees.
When the focal length of the whole optical system is 1500mm, the transverse dimension can be smaller than 1220mm, the longitudinal dimension can be smaller than 2000mm, and the optical system can be carried on a light and small optical satellite.
The above description is only one of the embodiments of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention should be covered within the scope of the present invention.
Claims (5)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110399019.8A CN113031238A (en) | 2021-04-14 | 2021-04-14 | Multi-mirror integrated large-view-field long-focus off-axis four-mirror optical system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110399019.8A CN113031238A (en) | 2021-04-14 | 2021-04-14 | Multi-mirror integrated large-view-field long-focus off-axis four-mirror optical system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113031238A true CN113031238A (en) | 2021-06-25 |
Family
ID=76456599
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110399019.8A Pending CN113031238A (en) | 2021-04-14 | 2021-04-14 | Multi-mirror integrated large-view-field long-focus off-axis four-mirror optical system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113031238A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114815203A (en) * | 2022-04-11 | 2022-07-29 | 北京理工大学 | An off-axis four-reflection non-axial zoom imaging optical system with large relative aperture |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20030179444A1 (en) * | 2002-03-22 | 2003-09-25 | Cook Lacy G. | Fast, wide-field-of-view, relayed multimirror optical system |
| US6752500B1 (en) * | 1999-08-04 | 2004-06-22 | Sanyo Electric Co., Ltd | Rear surface projection type display device |
| EP2073049A1 (en) * | 2007-12-18 | 2009-06-24 | Thales | Wide-angle catoptric system |
| CN106094186A (en) * | 2016-08-16 | 2016-11-09 | 中国科学院长春光学精密机械与物理研究所 | A kind of long-focus coaxial optical system of total reflection of ultrashort tube length |
| CN109459844A (en) * | 2018-09-07 | 2019-03-12 | 北京空间机电研究所 | A kind of big visual field inter-embedding type optical system of total reflection of compact |
| CN111580258A (en) * | 2020-05-29 | 2020-08-25 | 中国科学院西安光学精密机械研究所 | Compact type large-view-field small-F # catadioptric optical system |
| CN111624752A (en) * | 2020-06-11 | 2020-09-04 | 苏州大学 | Compact type long-focus four-reflection telescopic optical system |
| CN111812829A (en) * | 2020-07-29 | 2020-10-23 | 中国科学院长春光学精密机械与物理研究所 | An integrated coaxial four-mirror optical system with three main mirrors |
-
2021
- 2021-04-14 CN CN202110399019.8A patent/CN113031238A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6752500B1 (en) * | 1999-08-04 | 2004-06-22 | Sanyo Electric Co., Ltd | Rear surface projection type display device |
| US20030179444A1 (en) * | 2002-03-22 | 2003-09-25 | Cook Lacy G. | Fast, wide-field-of-view, relayed multimirror optical system |
| EP2073049A1 (en) * | 2007-12-18 | 2009-06-24 | Thales | Wide-angle catoptric system |
| CN106094186A (en) * | 2016-08-16 | 2016-11-09 | 中国科学院长春光学精密机械与物理研究所 | A kind of long-focus coaxial optical system of total reflection of ultrashort tube length |
| CN109459844A (en) * | 2018-09-07 | 2019-03-12 | 北京空间机电研究所 | A kind of big visual field inter-embedding type optical system of total reflection of compact |
| CN111580258A (en) * | 2020-05-29 | 2020-08-25 | 中国科学院西安光学精密机械研究所 | Compact type large-view-field small-F # catadioptric optical system |
| CN111624752A (en) * | 2020-06-11 | 2020-09-04 | 苏州大学 | Compact type long-focus four-reflection telescopic optical system |
| CN111812829A (en) * | 2020-07-29 | 2020-10-23 | 中国科学院长春光学精密机械与物理研究所 | An integrated coaxial four-mirror optical system with three main mirrors |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114815203A (en) * | 2022-04-11 | 2022-07-29 | 北京理工大学 | An off-axis four-reflection non-axial zoom imaging optical system with large relative aperture |
| CN114815203B (en) * | 2022-04-11 | 2023-05-05 | 北京理工大学 | Off-axis four-reflection type non-axial zooming imaging optical system with large relative aperture |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104111520B (en) | Off-axis reflection imaging optical system | |
| CN104035188A (en) | Low-cost refracting-reflecting athermalizing medium wave infrared lens | |
| US20070177261A1 (en) | Catadioptric telescopes | |
| CN106383401A (en) | Ultra-wide field-of-view off-axis three-reflector optical imaging system | |
| CN105259647A (en) | Large visual field co-off-axis integrated three-mirror space optical system | |
| CN108957725A (en) | Improved Schmidt telescopic optical system | |
| CN205581391U (en) | Long burnt infrared optical system of catadioptric off -axis | |
| CN103018890B (en) | Optical system with four coaxial reflecting mirrors for 20-degree view field without central obscuration | |
| CN107643592A (en) | A kind of varifocal catadioptric optical system of long-focus | |
| CN112034605B (en) | A catadioptric Golay3 sparse aperture optical system | |
| US2817270A (en) | Telescope objective systems | |
| CN102621683A (en) | Improved reflective/diffractive hybrid wide field Cassegrain telescope | |
| CN111367066A (en) | A coaxial four-mirror optical system | |
| CN113126271B (en) | Free-form surface optical telescopic system | |
| CN114236798B (en) | Catadioptric Afocal Optical System | |
| CN114236796B (en) | Visible light-medium wave infrared afocal optical system | |
| JP2016212197A (en) | Catoptric system and astronomical observation device using the same | |
| CN113031238A (en) | Multi-mirror integrated large-view-field long-focus off-axis four-mirror optical system | |
| CN114719976A (en) | Push-broom type imaging spectrometer and imaging method thereof | |
| CN111190273B (en) | Large Field of View Compact Optical System for Space Remote Sensing Cameras | |
| CN111025615B (en) | an optical system | |
| CN113311577A (en) | Free-form surface off-axis two-reflection telescope objective system with compact structure | |
| CN217467333U (en) | Broadband coaxial four-reflector imaging optical system | |
| CN213302653U (en) | Catadioptric Golay3 sparse aperture optical system | |
| CN116300070A (en) | Dual-mode coaxial integrated optical system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20210625 |