CN111929878A - Off-axis three-mirror short-focus front objective lens system of hyperspectral imager - Google Patents

Abstract

The invention provides an off-axis three-mirror short-focus front objective lens system of a hyperspectral imager, which solves the problems of the existing large relative aperture front imaging objective lens, such as poor stability of lens support, large volume and relatively simple adjustment of the degree of freedom of the lens. question. The system includes a support base plate and a primary mirror assembly, a secondary mirror assembly, a three-mirror assembly, a folding-axis mirror assembly, and a filter assembly arranged on the support base plate; The primary reflector on the primary mirror support base; the secondary mirror assembly includes a secondary mirror support base provided on the support base plate and a secondary mirror mounted on the secondary mirror support base; the three mirror assembly includes three mirrors set on the support base plate The support base and the third mirror installed on the three-mirror support base; the main mirror support base provides reliable mechanical support for the main mirror, and at the same time can realize multi-degree-of-freedom adjustment of the main mirror, the three-mirror support base and the main mirror support The seat structure is the same.

Description

An off-axis three-mirror short-focus front objective lens system for a hyperspectral imager

technical field

The invention relates to an objective lens system, in particular to an off-axis three-mirror short-focus front objective lens system of a hyperspectral imager.

Background technique

Hyperspectral imagers rely on obtaining two-dimensional spatial position information and one-dimensional spectral information of objects to image the shape of objects and obtain spectral characteristics of objects. It has the advantages of high spectral resolution, multiple bands, and the combination of image and spectrum, so it can be used to study surface objects, identify object types, identify material components, etc., which has attracted great attention and has been widely used in remote sensing and other fields. Applications.

The optical system of a hyperspectral imager is generally composed of a front imaging objective lens, a collimating objective lens, a spectroscopic system, an imaging objective lens and a detector. The front imaging objective lens images the ground target on the incident slit of the spectroscopic system, and the one-dimensional spectral information is separated by the spectroscopic system. Target object spatial information and spectral information. The front imaging objective lens is responsible for imaging the ground target on the object surface of the collimation-spectroscopy-imaging system in the system.

The front imaging objective lens is the key component of the hyperspectral imager to realize the ultra-wide field of view. The first two structural types are not suitable for broadband systems due to the inclusion of transmissive materials. The reflective structure is preferred. The reflective structure system has no chromatic aberration, good thermal resistance, and is suitable for light weight. The curved surface is used to correct the aberration, so that the system structure is simple and the image quality is excellent. Two-mirror, three-mirror, and multi-mirror systems are available for ultra-wide field of view designs. Because the optical system requires a large field of view, the image quality of the off-axis point of the general two-mirror optical system is poor. The free-form optical elements that have emerged in recent years can bring more design freedom to the two-mirror optical system and effectively improve the imaging quality of the system.

The development of the front imaging objective lens is closely related to the development of spectral imaging technology. In order to obtain more energy, the hyperspectral imager needs to continuously increase its relative aperture to improve its spectral resolution and spatial resolution. At the same time, in order to make the system's aberration small and compact, more research and development of hyperspectral imagers based on the Offner relay system are being conducted.

The Offner hyperspectral imaging system has the advantages of symmetry, compact structure, good image quality and low distortion. The width of the slit determines the spectral resolution of the system; the narrower the slit, the higher the spectral resolution of the system, but the energy entering the slit is weakened at this time, and the response sensitivity of the detector must be improved, which will increase the cost of the detector. rise. In this case, increasing the numerical aperture of the system is an effective way to improve the energy harvesting capability of the system and reduce the cost of the detector. Designers expect to increase the numerical aperture of the Offner-type spectral imager. However, only increasing the numerical aperture of the hyperspectral imaging system cannot completely solve the problem, and the numerical aperture of the matching front imaging objective must also be increased to achieve the real purpose. A Jet Propulsion Laboratory has listed many key technologies in its investigation report on the future development trend of slit-type hyperspectral imagers, among which the development of front-mounted imaging objectives with large relative apertures is one of the key points. Therefore, the development of a front imaging objective lens with a large relative aperture has become a necessary condition for the development of a slit-type hyperspectral imager, and its in-depth research is of great significance.

The front imaging objective lens with large relative aperture is an off-axis three-mirror system. At present, a single back or radial fixed support is mainly used for lens support, or a complex flexure structure is designed to realize transfer and fixed support. The support adopts a single back or radial fixed support, which has poor stability; the complex flexure structure is used to realize the transfer and fixed support, which makes the front imaging objective lens larger in size and complicated in the assembly process; and the adjustment of the degree of freedom of the lens is relatively simple.

SUMMARY OF THE INVENTION

In order to solve the technical problems that the existing front imaging objective lens with large relative aperture has poor support stability to the lens, or the front imaging objective lens is bulky, and the adjustment of the degree of freedom of the lens is relatively simple, the present invention provides a hyperspectral imaging method. The off-axis three-mirror short-focus front objective lens system of the instrument.

For achieving the above object, the technical scheme provided by the present invention is:

An off-axis three-mirror short-focus front objective lens system of a hyperspectral imager is special in that it includes a support base plate and a primary mirror assembly, a secondary mirror assembly, a three-mirror assembly, and a folding-axis mirror assembly arranged on the support base plate. , filter assembly;

The main mirror assembly includes a main mirror support seat arranged on the support base plate and a main reflector mounted on the main mirror support seat;

The secondary mirror assembly includes a secondary mirror support seat arranged on the support base plate and a secondary mirror mounted on the secondary mirror support seat;

The three-mirror assembly includes a three-mirror support base disposed on the support base plate and a third reflector mounted on the three-mirror support base;

The folding-axis mirror assembly includes a folding-axis mirror support seat arranged on the support base plate and a folding-axis mirror mounted on the folding-axis mirror support seat;

The filter assembly includes a filter support seat arranged on the support base plate and a filter installed on the filter support seat;

The primary reflector, the secondary reflector, the third reflector, the axis-folding mirror, and the filter are sequentially arranged along the beam transmission direction to form an off-axis three-reflection optical system;

The main mirror support base includes a mirror base, an adjustment plate and a support base;

The mirror seat includes a seat body, a groove arranged on the front end surface of the seat body and the shape of the bottom of the main reflector, a plurality of pressing plates arranged on the outer periphery of the groove, and a plurality of bonding columns arranged on the inner bottom surface of the groove. and a plurality of supporting columns; the top of each adhesive column is provided with adhesive, and the total height of the adhesive column and the adhesive is equal to the height of the supporting column; one end of each pressing plate is connected with the seat body, and the other end is used to The mirror is pressed and fixed in the groove, and there is a gap between the side surface of the main reflector and the groove wall;

The adjustment plate is connected with the rear end surface of the base body through a plurality of first adjustment units; each of the first adjustment units includes a jacking screw assembly and a locking and tightening screw assembly; the jacking screw assembly is arranged on the adjustment plate and The front end abuts against the rear end face of the seat body, and is used to adjust the distance between the adjustment plate and the seat body; the locking and tightening screw assembly includes a locking and tightening screw passing through the through hole on the adjustment plate, and the front end of the locking and tightening screw is connected to the seat. The rear end face of the body is threadedly connected to fix the adjustment plate and the seat body;

The support seat is a hollow frame body structure sleeved on the outside of the seat body and the adjustment plate, and the left and right sides of the lower end of the support seat are provided with connection ear seats; the connection ear seat is connected with the support bottom plate;

The support seat is connected with the side surface of the adjustment plate through a second adjustment unit; the second adjustment unit is arranged on the support seat and is used to adjust the translation of the adjustment plate in the up-down direction and the left-right direction;

The three-mirror support base has the same structure as the main mirror support base.

Further, guide bosses are provided on the supporting base plate with the connecting lugs of the main mirror support base and the connection lugs of the three mirror support bases; so that the main mirror support base can be along the incident central optical axis of the secondary mirror The direction moves on the guide boss, and the third reflector can move on the guide boss along the direction of the exit center optical axis of the secondary reflector.

Further, the conic coefficient of the main reflector is -9.34, the conic coefficient of the secondary reflector is 0.826, and the aspheric coefficient of the third reflector is: k=-0.861, A2=1.455e ^-3 , A4=8.667e- ¹⁰ ;

The mirror surfaces of the main reflector, the third reflector, the axis-folding mirror and the filter are all rectangular;

The mirror surface of the secondary reflector is circular.

Further, the secondary mirror support base includes a secondary mirror support frame arranged on the support base plate, a secondary mirror frame arranged on the secondary mirror support frame, a circular pressure plate for pressing the secondary mirror, and the secondary mirror frame is provided with a A circular opening for mounting the secondary mirror;

The folding-axis mirror assembly comprises a folding-axis mirror support frame arranged on the support base plate, a folding-axis mirror mounting frame arranged on the folding-axis mirror support frame, and a rectangular pressing plate for pressing the folding-axis mirror;

The secondary mirror support base and the folding-axis mirror support base form an included angle of 135° and are fixedly connected as a whole.

Further, an outer cover is provided on the support base plate, and the main mirror assembly, the secondary mirror assembly, the three mirror assembly, and the folding-axis mirror assembly are all located in the outer cover, and the filter assembly is arranged at the optical outlet of the outer cover;

The filter support seat comprises a filter seat perpendicular to the support bottom plate and mounted on the outer cover, a mounting seat arranged on the filter seat, and a vertical slot arranged on the mounting seat for installing the filter;

A long cylindrical front light shield is arranged at the optical entrance of the outer cover.

Further, the jacking screw assembly includes an external compression spring, a pressure plate, a moving column with a ball socket, an adjustment bracket and a jacking screw that are arranged in sequence from front to back;

The rear end surface of the seat body is provided with an outer spring seat, and the outer spring seat is an annular groove;

The adjustment plate is provided with stepped through holes, including a first through hole and a second through hole whose diameters decrease in sequence from front to rear;

The pressing plate is arranged in the first through hole, the front end surface of the pressing plate is provided with an annular outer spring support extending into the outer spring seat, and the rear end surface is provided with an adjusting ball head;

The outer compression spring is arranged in the annular groove, and the front end is limited by the bottom surface of the annular groove, and the rear end is sleeved on the annular outer spring support;

The moving column is arranged in the second through hole, and the ball socket at the front end is arranged on the adjusting ball head;

The adjustment bracket is fixed on the rear end surface of the adjustment plate, and the adjustment bracket is provided with a threaded hole, and the top tightening screw passes through the threaded hole and abuts against the rear end surface of the moving column with the ball socket.

Further, the tightening screw assembly also includes an inner compression spring coaxially arranged in the outer compression spring;

The rear end surface of the seat body is provided with an inner spring seat, and the inner spring seat is a cylindrical groove;

The front end surface of the pressing plate is provided with an inner spring column extending into the inner spring seat;

The inner compression spring is arranged in the cylindrical groove, the front end is limited by the bottom surface of the cylindrical groove, and the rear end is sleeved on the inner spring column.

Further, the rear end surface of the seat body is provided with a plurality of connection platforms, and the number of the connection platforms is equal to the number of the jacking screw assemblies and the positions are in one-to-one correspondence; the side surfaces of the connection platforms are provided with open slots for reducing stress. ;

The inner spring seat and the outer spring seat are both arranged on the rear end surface of the connection platform;

The adjustment plate is a rectangular structure;

The number of the first adjustment units is 4, and the 4 first adjustment units are arranged on the four corners of the adjustment plate in a rectangular shape;

Further, the support base is a rectangular hollow frame structure, comprising a left support plate, a lower support plate, a right support plate and an upper support plate connected end to end in sequence; the connection ear base and the support base plate are connected by screws;

The second adjustment unit includes a left-right adjustment component and an up-down adjustment component;

The left and right adjustment components include symmetrically arranged left adjustment screws and right adjustment screws, the left adjustment screws are arranged on the left support plate, and the inner end face abuts on the left end face of the adjustment plate; the right adjustment screws are arranged on the right support plate, and The inner end face abuts against the right end face of the adjustment plate;

The upper and lower adjustment components include symmetrically arranged upper adjustment screws and lower adjustment screws, the upper adjustment screws are arranged on the upper support plate, and the inner end face abuts the upper end face of the adjustment plate; the lower adjustment screws are arranged on the lower support plate, and the inner The end face abuts against the lower end face of the adjustment plate.

Further, the position where the left end face of the adjustment plate matches the left adjustment screw, the position where the right end face of the adjustment plate matches the right adjustment screw, the position where the end face of the adjustment plate matches the upper adjustment screw, the lower end face of the adjustment plate and the lower Positioning grooves are provided at the matching positions of the adjusting screws;

The range of the gap between the side surface of the main reflector and the groove is 0.06-0.15mm, and the gap is filled with adhesive;

The bottom of the groove groove of the seat body is provided with a central through hole; the middle part of the adjustment plate is provided with a hexagonal weight-reducing hole.

Compared with the prior art, the advantages of the present invention are:

1. The optical element of the front objective lens system of the present invention adopts an off-axis three-reflection optical system. The main mirror is installed through the main mirror support seat, and the main mirror is installed in the groove of the seat body. The column and the support column form the positioning reference of the bottom surface of the main reflector. By grinding the bonding column and the support column, a better installation plane accuracy of the main reflector can be ensured, and the main reflector can be pressed and fixed in the groove by the pressing plate. , to ensure that the main reflector is reliably supported in the base; the first adjustment unit and the second adjustment unit can realize the multi-degree-of-freedom high-precision rotation and translation adjustment of the main reflector; the third reflector is installed through the three-mirror support seat, the three-mirror The support base and the main mirror support base have the same structural form and adjustment method. Both the main reflector and the third reflector have multi-degree-of-freedom high-precision adjustment capabilities, which can meet the needs of optical adjustment and effectively ensure the excellent image quality of the objective lens. It is suitable for clamping and fixing and adjusting the degree of freedom of medium and large mirrors to achieve high adjustment accuracy.

2. The present invention is provided with a boss positioning surface on the support base plate, the main mirror support seat can be trimmed and adjusted along the direction of the incident central optical axis of the secondary mirror, and the third mirror can be along the exit central optical axis of the secondary mirror. The direction is trimmed and adjusted to ensure the axial distance between the primary reflector and the secondary reflector, and the secondary reflector and the third reflector, that is, to ensure the optical spacing requirements.

3. The off-axis three-mirror optical system of the present invention realizes a common optical axis design, has a compact structure, simplifies the installation and adjustment of the off-axis three-mirror system, and realizes a large numerical aperture and a large field of view under the premise of ensuring excellent image quality. , high spectral resolution and other characteristics, can meet the needs of offner and Dyson and other classic hyperspectral imagers for front imaging.

4. In the present invention, the secondary mirror support seat and the folding axis mirror support seat are fixedly connected into one body, that is, the secondary mirror and the folding axis mirror are integrally installed on a supporting structure, and the installation accuracy can be ensured by mechanical processing.

5. The first adjustment unit of the present invention includes a jacking screw assembly and a locking and tightening screw assembly. The distance between the adjustment plate and the seat body can be adjusted through the jacking screw assembly. After the distance is properly adjusted, the adjustment can be fixed by tightening the tightening screw assembly. plate and seat.

6. The tightening screw assembly of the present invention realizes the opposite and opposite movement of the pressure plate relative to the seat body by rotating the tightening screw. The position of the plate is slightly offset, and the spherical surface can quickly restore to the center position to ensure the smooth movement of the pressure plate; and the outer spring seat at the rear of the seat body is an annular groove, which improves the stability of the pressure plate movement, thereby ensuring the main reflector (or the first reflector). Accuracy of position adjustment of three mirrors).

7. The tightening screw assembly of the present invention also includes an inner compression spring, which provides a guiding function for the movement process of the outer compression spring, and further improves the stability of the movement of the pressing plate.

8. In order to facilitate the connection between the top-tightening screw assembly and the seat body, a connecting table is provided on the rear end surface of the seat body.

9. The adjustment plate of the present invention has a rectangular structure. There are 4 first adjustment units and they are arranged in a rectangular shape on the four corners of the adjustment plate. The angle is a fixed adjustment point, which is used as an adjustment reference and as an adjustment fulcrum; the upper left adjustment point is the up and down pitch rotation adjustment, the lower right adjustment point is the left and right azimuth rotation adjustment, and the upper right corner is used as the locking point for locking and fixing, which can achieve two The adjustment of the degree of freedom direction, and the adjustment method is simple.

10. The second adjustment unit of the present invention includes a left and right adjustment component and an up and down adjustment component. The left adjustment screw and the right adjustment screw are used together, and one loosens and one tightens to realize the left and right translational movement of the adjustment plate inside the support seat; the upper adjustment screw and the lower adjustment screw When used together, one loosening and one tightening can realize the up-and-down translation movement of the adjustment plate inside the support seat; and then realize the translation adjustment of the main reflector and the third reflector in the directions of the up and down and left and right degrees of freedom, and the adjustment method is simple.

11. In order to adjust the stability of the up and down translation and the left and right translation adjustment of the plate, there are positioning grooves on the four end faces of the adjustment plate, and the inner end faces of the four adjustment screws of the second adjustment unit are located in the positioning grooves.

12. The gap between the side surface of the main reflector and the third reflector and the groove of the present invention is in the range of 0.06-0.15mm, which is convenient for the installation of the main reflector (or the third reflector), and prevents damage to the main reflector (or the third reflector) during the installation process After the installation of the main mirror (or the third mirror) is completed, by filling the gap with the adhesive, the stability of the main mirror (or the third mirror) and the base body is improved.

13. An opening groove is provided on the connecting table of the present invention to reduce the influence of the connecting stress on the surface shape of the main reflector (or the third reflector).

14. The groove bottom of the base of the present invention is provided with a central through hole, which can reduce the weight of the base and facilitate adjustment; it can also be used as a process hole when the main reflector (or the third reflector) is installed.

Similarly, there is a hexagonal weight-reducing hole in the middle of the adjustment plate to reduce the weight of the adjustment plate and facilitate adjustment.

Description of drawings

Fig. 1 is the three-dimensional structure schematic diagram of the off-axis three-mirror short-focus front objective lens system of the hyperspectral imager of the present invention (remove part of the outer cover);

Fig. 2 is the side view of the off-axis three-mirror short-focus front objective lens system of the hyperspectral imager of the present invention (partial section is carried out to the three-mirror assembly);

3 is a plan view 1 of the off-axis three-mirror short-focus front objective lens system of the hyperspectral imager of the present invention (part of the housing is not shown);

Fig. 4 is the top view 2 of the off-axis three-mirror short-focus front objective lens system of the hyperspectral imager of the present invention (part of the outer cover is not shown, and the optical path is shown);

5 is a schematic diagram of an off-axis three-mirror optical system in an off-axis three-mirror short-focus front objective lens system of the hyperspectral imager of the present invention;

6 is a schematic structural diagram of a support base plate in an off-axis three-mirror short-focus front objective lens system of the hyperspectral imager of the present invention;

7 is a schematic structural diagram of the secondary mirror support base and the folding-axis mirror support base in the off-axis three-mirror short-focus front-end objective lens system of the hyperspectral imager of the present invention being fixedly connected into one;

Figure 8 is a partial cross-sectional view of the structure shown in Figure 7;

9 is a schematic structural diagram of a filter assembly in an off-axis three-mirror short-focus front objective lens system of the hyperspectral imager of the present invention;

10 is a schematic structural diagram of a primary mirror assembly in an off-axis three-mirror short-focus front objective lens system of a hyperspectral imager of the present invention;

11 is a schematic diagram of the explosion of the primary mirror assembly in the off-axis three-mirror short-focus front objective lens system of the hyperspectral imager of the present invention;

12 is a schematic view of the mirror base structure of the primary mirror assembly in the off-axis three-mirror short-focus front objective lens system of the hyperspectral imager of the present invention;

13 is a rear view of the mirror base of the primary mirror assembly in the off-axis three-mirror short-focus front objective lens system of the hyperspectral imager of the present invention;

14 is a schematic diagram of the assembly of the mirror base and the main reflector of the main mirror assembly in the off-axis three-mirror short-focus front objective lens system of the hyperspectral imager of the present invention;

15 is a schematic diagram of the assembly of the main mirror, the mirror base and the adjustment plate of the main mirror assembly in the off-axis three-mirror short-focus front objective lens system of the hyperspectral imager of the present invention;

16 is a cross-sectional view of the main mirror assembly in the off-axis three-mirror short-focus front objective lens system of the hyperspectral imager of the present invention (the locking and tightening screw assembly is not shown);

17 is a partial cross-sectional view of the screw assembly of the main mirror assembly in the off-axis three-mirror short-focus front objective lens system of the hyperspectral imager of the present invention;

Among them, the reference numerals are as follows:

01-Support base plate, 012-Guide boss, 02-Main mirror support seat, 03-Main mirror, 04-Secondary mirror support seat, 041-Secondary mirror support frame, 042-Secondary mirror frame, 043-Circular pressure plate, 05 -Secondary reflector, 06-Three mirror support base, 07-Third reflector, 08-Axis-folding mirror support base, 081-Axis-folding mirror support frame, 082-Axis-folding mirror mounting frame, 083-Rectangular platen, 09- Folding mirror, 010-filter support seat, 0101-filter seat, 0102-installation seat, 011-filter;

1-Seat body, 11-Groove, 12-Pressing plate, 13-Center through hole, 14-Adhesive column, 15-Support column, 16-Glue injection through hole, 17-Connecting table, 171-Open slot, 18-outer spring seat, 19-inner spring seat, 110-long hole, 111-round exhaust hole;

2-adjustment plate, 21-wedge plate, 22-first through hole, 23-second through hole, 24-upper end face, 25-left end face, 26-lower end face, 27-right end face, 28-positioning groove, 29 - Hexagonal weight reduction holes;

3-Support seat, 31-Left support plate, 32-Lower support plate, 33-Right support plate, 34-Upper support plate, 35-Connecting ear seat, 36-Screw, 37-Weight reduction hole;

41-left adjustment screw, 42-up adjustment screw, 43-right adjustment screw, 44-down adjustment screw;

5- Top tightening screw assembly, 51- External compression spring, 52- Pressure plate, 521- Ring outer spring bracket, 522- Adjusting ball head, 523- Inner spring post, 53- Moving post with ball socket, 54- Adjusting bracket, 55-top screw, 56-inner compression spring;

6- Tightening the tension screw assembly, 61- Tightening the tension screw, 62- Spherical washer;

81-outer cover, 82-long cylindrical front hood, 83-first edge aperture, 84-second edge aperture, 85-handle.

Detailed ways

The content of the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

As shown in Figures 1 to 4, an off-axis three-mirror short-focus front objective lens system of a hyperspectral imager includes a supporting base plate 01, a primary mirror assembly, a secondary mirror assembly, a three-mirror assembly, a folding-axis mirror assembly, a filter The light sheet assembly, the supporting base plate 01, the outer cover 81 and the light blocking assembly; the main mirror assembly includes the main mirror support base 02 arranged on the support base plate 01 and the main mirror 03 installed on the main mirror support base 02; the secondary mirror assembly includes The secondary mirror support base 04 arranged on the support base plate 01 and the secondary mirror 05 installed on the secondary mirror support base 04; the three-mirror assembly includes a three-mirror support base 06 arranged on the support base plate 01 and a three-mirror support base installed on the three-mirror support base The third reflector 07 on the The filter support base 010 on the support base 01 and the filter 011 installed on the filter support base 010 are supported.

As shown in Figure 5, the main mirror 03, the secondary mirror 05, the third mirror 07, the axis-refraction mirror 09, and the filter 011 are arranged in sequence along the beam transmission direction to form an off-axis three-mirror optical system, with a large relative aperture, High energy utilization.

Each component in the front objective lens system of this embodiment:

1. Off-axis three-mirror optical system

1.1 Optical parameters

The conic coefficient of the primary mirror 03 is -9.34, the conic coefficient of the secondary mirror 05 is 0.826, and the aspheric coefficient of the third mirror 07 is: k=-0.861, A2=1.455e ^-3 , A4=8.667e- ¹⁰ ; The exit pupil distance of the optical system is 5242mm, and its indicators are as follows:

a. Spectral range: 0.43～2.5μm;

b. Relative aperture: 1/3.75;

c. Focal length: f=400mm;

d. Field of view angle: 2ω=13.7°×2.85°;

e, like the telecentric system.

1.2 Optical lens parameters and tolerance requirements;

1) Lens parameters

Main reflector 03: Mirror shape is rectangle, length: 288mm, width: 188mm;

Secondary mirror 05: The mirror shape is circular, diameter: Φ73.4mm;

The third reflector 07: the shape of the mirror surface is rectangular, the length: 244mm, the width: 184mm;

Folding mirror 09: The mirror shape is rectangular, length: 160mm, width: 112mm, thickness: 14mm;

Filter 011: Mirror shape is rectangle, length: 130mm, width: 56mm, thickness: 2mm;

2) Optical adjustment accuracy

a. Air spacing: not more than 20μm;

b. Inclination tolerance: not more than 18";

c. Eccentricity tolerance: not more than 20μm;

2. The mechanical structure of the front objective lens system

In the design of the support structure (the primary mirror support base 02, the secondary mirror support base 04, the three mirror support base 06, the pivot mirror support base 08, and the filter support base 010) in this embodiment, on the one hand, it is necessary to provide the lenses of the optical system. Reliable mechanical support, on the other hand, must ensure the accuracy requirements of the optical system, and have a reliable degree of freedom adjustment mechanism to ensure that the position of the lens can be effectively adjusted with high precision.

The support structure is integrally installed on the support base plate 01 according to the positional requirements, and the optical performance is debugged by using the degree of freedom adjustment mechanism in the support structure to adjust the optical pointing with high precision. Among them, the main reflection mirror 03 and the third reflection mirror 07 have the same structure and form, so adopt the same support structure design, and have the ability of high-precision adjustment of six degrees of freedom respectively, which can meet the needs of optical adjustment. Due to the close distance between the secondary mirror assembly and the folding axis mirror assembly, in the structural design, the secondary mirror 05 and the folding axis mirror 09 can be integrated and installed on a supporting structure. According to the positional relationship of the optical system, the secondary reflection is guaranteed by the machining accuracy. The installation and positioning accuracy of the mirror 05 and the folding-axis mirror 09. In addition, the front objective lens system is designed with a hood and a light blocking structure as a series of diaphragms to meet the stray light suppression requirements of the system.

The weight and size of the front objective lens system in this embodiment are: the weight is 50Kg; the external dimensions: length×width×height: 650mm×660mm×430mm;

The exit central optical axis of the reflective surface of the primary mirror 03 coincides with the incident central optical axis of the reflective surface of the secondary mirror, and the exit central optical axis of the reflective surface of the secondary mirror 05 coincides with the incident central optical axis of the third mirror 07, so the primary reflection The air spacing (axial distance) between the mirror 03 and the secondary mirror 05, and the secondary mirror 05 and the third mirror 07 is adjusted along the optical axis direction of the secondary mirror 05 (the incident of the primary mirror 03 along the secondary mirror 05). The direction of the central optical axis and the direction of the third reflecting mirror 07 along the direction of the exiting central optical axis of the secondary reflecting mirror 05 are trimmed and adjusted to ensure the optical spacing requirements.

2.1 Support base plate 01

As shown in Figure 6, the supporting base plate 01 is designed as a flat plate structure with an overall thickness of 20mm. The weight reduction design is carried out through the setting of reinforcing ribs. The material is made of duralumin 2A12 plate, and the weight of the base plate does not exceed 10kg.

In order to ensure the installation accuracy of the support base plate 01, the corresponding installation surfaces of the support base plate 01 and the main mirror assembly, the secondary mirror assembly and the three mirror assembly are provided with coplanar guide bosses 012 of equal height. After grinding, the flatness is 0.015mm and the reference accuracy Can meet optical position tolerance requirements. The verticality of the table surface of the guide boss 012 relative to the installation reference surface is not greater than 0.015mm, which ensures the air spacing accuracy when the main reflector 03 and the third reflector 07 are axially adjusted relative to the secondary reflector 05 .

In order to facilitate handling, manual transfer handles 85 and hoisting threaded holes are provided around the support base plate 01, so that manual handling and transfer can be realized.

An integrated cover 81 is designed on the outside of the support base plate 01 to encapsulate the optical system together. And the filter assembly is arranged at the optical outlet of the housing 81 .

2.2 Main mirror support base 02

The main reflector 03 is a rectangular reflector, and the back is a plane positioning and installation reference;

As shown in Figure 10, Figure 11, Figure 15 and Figure 16, the main mirror support base 02 can realize the adjustment of the three translation degrees of freedom of the main mirror 03, the adjustment of the three rotational degrees of freedom and the support of the main mirror 03; The mirror support base 02 includes a mirror base, an adjustment plate 2, a support base 3, a second adjustment unit and a plurality of first adjustment units; the front end surface of the mirror base is installed with the main reflector 03, and the adjustment plate 2 is arranged on the rear end surface of the mirror base, The support base 3 is a hollow frame structure, which is sleeved on the outside of the mirror base and the adjustment plate 2 , and the second adjustment unit and the first adjustment unit can realize the rotation and translation adjustment of the main reflector 03 .

As shown in Figure 12 and Figure 13, the mirror base includes a base body 1, the base body 1 adopts a rectangular design, the front end surface of the base body 1 is provided with a groove 11, and the shape of the groove 11 is suitable for the bottom shape of the main reflector 03 Fitting; the groove 11 of the base body 1 is also provided with fitting holes, and the fitting holes include elongated holes 110 and circular exhaust holes 111 . In this embodiment, the bottom of the main reflector 03 is a rectangular structure, so the groove 11 is a rectangular groove, and the size of the rectangular groove is slightly larger than that of the bottom of the main reflector 03, so that the side surface of the main reflector 03 is connected to the groove wall of the groove 11. There is a gap between them, and the range of the gap can be 0.06-0.15mm, which is convenient for installing the main reflector 03 and prevents damage to the main reflector 03 during the installation process. A central through hole 13 is opened in the middle of the groove bottom of the groove 11 , and a plurality of bonding columns 14 and a plurality of supporting columns 15 are arranged on the outer periphery of the central through hole 13 at the bottom of the groove 11 . For the adhesive of the main mirror 03, the height of the support column 15 is equal to the sum of the thickness of the adhesive and the height of the bonding column 14, and the height of the support column 15 is less than the depth of the groove 11. In this embodiment, the height of the bonding column 14 and the support column 15 is The number is 4. In other embodiments, the number of the bonding pillars 14 and the supporting pillars 15 is reasonably designed according to actual needs. The outer side of the connecting column 14 is located on the four corners of the rectangular groove, and the 4 bonding columns 14 and the 4 supporting columns 15 form 8 supporting surfaces (4 bonding columns 14 and 4 supporting columns 15) and 4 1 adhesive fixing points (4 adhesive posts 14). The 8 supporting surfaces form the positioning reference for the bottom surface of the main reflector 03. By grinding the bonding column 14 and the support column 15, a better installation plane accuracy of the main reflector 03 can be ensured, so that the flatness of the main reflector 03 is not greater than 0.01mm; The four adhesive posts 14 in the middle of the groove 11 of the base body 1 are the adhesive positions. The diameter of the adhesive at the top of each adhesive post 14 is 20mm, and the thickness of the adhesive is 0.5mm, which has a large adhesive area and can meet the mechanical strength. According to the requirements, the diameter of the bonding column 14 should be slightly larger than 20mm.

As shown in Figure 14, in this embodiment, a unilateral 0.1mm gap is left between the periphery of the main reflector 03 and the groove wall of the groove 11 of the base body 1. During installation, a standard 0.1mm thick tooling is installed around it. The main reflector 03 is placed in the groove 11 of the base body 1. The groove wall of the groove 11 of the base body 1 is provided with a plurality of glue injection through holes 16. After the adhesive flows through the glue injection through holes 16, it is filled with To 0.1mm gap, improve the stability of the main mirror 03 and the base body 1 fixed.

The front end surface of the seat body 1 is also provided with a plurality of pressing plates 12, and the plurality of pressing plates 12 are arranged on the outer circumference of the long side of the rectangular groove. One end of each pressing plate 12 is hinged with the seat body 1, and the other end is used for Press and fix the main reflector 03 in the groove 11 of the base body 1 .

In this embodiment, the base body 1 and the bottom surface of the main reflector 03 are bonded and fixed by using four bonding and fixing points, and adhesives are used around the sides of the main reflector 03 for auxiliary bonding and fixing, and the pressing plate 12 is used for auxiliary bonding and fixing. The axial elasticity assists the pressing, so that the main reflector 03 can be stably fixed on the base body 1 .

11 and 15, the adjustment plate 2 is a rectangular plate arranged on the rear end surface of the base body 1, and the four outer sides of the adjustment plate 2 are provided with wedge-shaped pressing plates 21; the middle of the adjustment plate 2 is provided with a hexagonal weight-reducing hole 29 .

The support base 3 is a rectangular hollow frame structure that is sleeved on the outside of the base body 1 and the adjustment plate 2. The support base 3 is provided with a weight reduction hole 37; the support base 3 includes a left support plate 31, a lower support plate 32, a right The support plate 33 and the upper support plate 34; the second adjustment unit is arranged on the support base 3 and is used to adjust the translation of the adjustment plate 2 in the up-down direction and the left-right direction. Specifically, the second adjustment unit includes a left-right adjustment component and an up-down adjustment component The left and right adjustment components include symmetrically arranged left adjustment screws 41 and right adjustment screws 43, the left adjustment screws 41 are arranged on the left support plate 31, and the inner end face abuts on the left end face 25 of the adjustment plate 2; the right adjustment screws 43 are arranged in on the right support plate 33, and the inner end surface abuts against the right end surface 27 of the adjustment plate 2; the upper and lower adjustment components include symmetrically arranged upper adjustment screws 42 and lower adjustment screws 44, the upper adjustment screws 42 are arranged on the upper support plate 34, and The inner end face abuts against the upper end face 24 of the adjustment plate 2 ; the lower adjustment screw 44 is arranged on the lower support plate 32 , and the inner end face abuts against the lower end face 26 of the adjustment plate 2 .

The adjustment plate 2 is arranged in the support base 3 by means of four wedge-shaped pressing plates 21 in two orthogonal directions, and is respectively arranged by four adjustment screws (upper adjustment screw 42, lower adjustment screw 44, left adjustment screw 41 and right adjustment screw 43). Press the wedge-shaped pressure plate 21 to press and fix the adjustment plate 2 in the support base 3. In order to improve the adjustment accuracy, the four wedge-shaped pressure plates 21 are respectively matched with the position of the left adjustment screw 41, the position of the right adjustment screw 43, and the upper adjustment. Positioning grooves 28 are provided at the matching positions of the screws 42 and the matching positions of the lower adjusting screw 44 , and the inner end face of the adjusting screw 36 extends into the positioning grooves 28 . During translation adjustment, the left adjustment screw 41 and the right adjustment screw 43 are used together, one loosening and one tightening enables the adjustment plate 2 to perform left and right translational movement along the guide surface inside the support base 3; the upper adjustment screw 42 and the lower adjustment screw 44 are used together , one loosening and one tightening, to realize the up and down translation movement of the adjustment plate 2 along the guide surface inside the support base 3; and then realize the translation adjustment of the main reflector 03 in the up and down and left and right directions.

The outer sides of the lower ends of the left support plate 31 and the right support plate 33 are provided with connecting lugs 35 , the connecting lugs 35 are arranged on the supporting base plate 01 , and the lower end surfaces of the connecting lugs 35 are provided with guide bosses 012 on the supporting base plate 01 for positioning. The linear sliding guide rails with matching surfaces move the support base 3 along the positioning surface of the guide boss 012 on the support base plate 01 through the two external adjustment columns, so as to realize the translation adjustment of the main reflector 03 relative to the support base plate 01, with high translation Adjust the precision. The connection ear seat 35 is connected with the support base plate 01 by screws 36. By adjusting the screw 36 on the lower end of the left support plate 31 and the screw 36 on the lower end of the right support plate 33 to loosen and tighten, the support base 3 is relatively supported to the base plate 01. Rotation adjustment of the main mirror 03 is realized.

In order to improve the adjustment accuracy of the main reflector 03 on the mirror base and increase the adjustment line displacement reference, the adjustment plate 2 is connected to the rear end surface of the base body 1 through a plurality of first adjustment units. In this embodiment, the first adjustment unit is 4 The four first adjustment units are arranged in a rectangular shape on the four corners of the adjustment plate 2, and the four first adjustment units form a four-point adjustment component. The adjustment reference is also used as the adjustment fulcrum; the upper left adjustment point is the up and down pitch rotation adjustment, the lower right adjustment point is the left and right azimuth rotation adjustment, and the upper right corner is used as the locking point for locking and fixing.

Each first adjustment unit includes a jacking screw assembly 5 and a locking and tightening screw assembly 6; the jacking screw assembly 5 is arranged on the adjustment plate 2 and its front end abuts against the rear end surface of the seat body 1, and is used for adjusting the adjustment plate 2 and The distance of seat 1. As shown in FIG. 17, the jacking screw assembly 5 includes an outer compression spring 51, a pressure plate 52, a moving column 53 with a ball socket, an adjustment bracket 54 and a jacking screw 55, which are arranged in sequence from front to back; There are four connecting platforms 17 distributed in a rectangular shape, and the positions of the four connecting platforms 17 correspond one-to-one with the positions of the screw assemblies 5. The rear end surface of the connecting platforms 17 is provided with an outer spring seat 18, and the outer spring seat 18 is an annular groove. The adjustment plate 2 is provided with a stepped through hole, including a first through hole 22 and a second through hole 23 whose diameters decrease in turn from front to rear; An annular outer spring support 521 extending into the outer spring seat 18 is provided, and an adjusting ball head 522 is arranged on the rear end surface; the outer compression spring 51 is arranged in the annular groove, and the front end is limited by the bottom surface of the annular groove, and the rear end is sleeved on the annular outer spring Bracket 521; the moving column is arranged in the second through hole 23, and the ball socket at the front end is arranged on the adjustment ball head 522, and the outer inner wall of the second through hole 232 is provided with an annular limit boss; the adjustment bracket 54 is fixed by screws. On the rear end surface of the adjustment plate 2, the adjustment bracket 54 is provided with a threaded hole, and the jacking screw 55 passes through the threaded hole and abuts against the rear end surface of the moving column 53 with a ball socket. During the tension adjustment process, the outer compression spring always maintains the preload.

In order to improve the stability of the movement of the pressure plate 52, the rear end surface of the connection platform 17 is provided with an inner spring seat 19, the inner spring seat 19 is a cylindrical groove coaxially arranged in the annular groove, and the front end surface of the pressure plate 52 is provided with a cylindrical groove extending into The inner spring column 523; the inner pressure spring 56 is arranged in the cylindrical groove, the front end of the inner pressure spring 56 is limited by the bottom surface of the columnar groove, and the rear end is sleeved on the inner spring column 523, the inner spring seat 19 and the inner spring column 523 The cooperation provides a guide for the movement of the pressure plate 52 .

The locking and tightening screw assembly 6 includes a locking and tightening screw 61 with a spherical washer 62. The locking and tightening screw 61 passes through the through hole on the adjustment plate 2, and the front end is threadedly connected with the rear end surface of the seat body 1. It is used to fix the adjustment plate 2 and the base body 1.

In order to improve the stability of the seat body, after the position adjustment of the seat body is completed, screws are passed through the support seat and the seat body in sequence to fix the seat body and the support seat.

The rear end surface of the base body 1 is provided with four connecting platforms 17. The base body 1 is connected to the adjustment plate 2 through four points (four connecting platforms 17), and the side surface of the connecting platform 17 is provided with an opening slot 171, that is, the base body 1 is connected to the adjusting plate 2. The opening stress relief is carried out in the adjustment position, which can reduce the influence of the connection stress on the surface shape of the main reflector 03 .

The rotation adjustment accuracy of the main mirror support base 02 in this embodiment: the azimuth adjustment baseline distance is 154mm, the pitch adjustment baseline distance is 214mm, the screw pitch is 0.35mm, and the adjustment accuracy is 6″ in azimuth and 2.4″ in pitch.

The translation adjustment accuracy of the main mirror support base 02 in this embodiment: the translation adjustment depends on the manual rotation of the adjustment screw to push the adjustment plate 2 to translate. About: 0.007mm, which can meet the accuracy requirement of eccentric adjustment accuracy not greater than 20μm.

The main mirror support base 02 in this embodiment realizes the multi-degree-of-freedom adjustment process of the main mirror 03:

1) First, connect the four locking and tightening screws 61 between the base body 1 and the adjusting plate 2 in place, and loosen the 1/4-turn screws at the same time, relying on the elasticity of the outer compression spring and inner compression spring on the front side of the clamping screw 55 force to maintain the position of the seat body 1 and the adjustment plate 2;

2) According to the process detection method, adjust the top-up screw 55 in the upper left corner and the lower-right corner to realize the adjustment of the two radial rotational degrees of freedom of the main reflector 03 on the base body 1. After the adjustment is in place, tighten the top-up screw 55 in the upper right corner, and use The rear end surface of the pressure plate 52 adjusts the azimuth freedom of the ball head 522 and the ball socket at the front end of the moving column 53 with the ball socket, compresses the outer compression spring 51 in place, and uses the structural parts to tighten it to ensure the stability of the position; then tighten the four locks Tighten the tightening screw 61 to realize the fixing of the base body 1 and the adjustment plate 2;

3) Adjust the upper adjustment screw 42 and the lower adjustment screw 44 to loosen and tighten, adjust the up and down translation of the adjustment plate 2, and then adjust the up and down translation of the main reflector 03; adjust the left adjustment screw 41 and the right adjustment screw 43. Tighten, adjust the left and right translation of the adjustment plate 2, and then adjust the left and right translation of the main mirror 03;

4) By moving the support base 3 along the positioning surface of the guide boss 012 on the support base plate 01, the translation of the support base 3 along the central optical axis of the main reflector 03 is realized, and then the distance between the main reflector 03 and the secondary reflector 05 is adjusted ; By adjusting the screw 36 on the lower end of the left support plate 31 and the screw 36 on the lower end of the right support plate 33 to be loosened and tightened, the rotation of the support base 3 relative to the support base plate 01 is realized, and then the rotation of the main reflector 03 is realized.

2.3 Secondary mirror support base 04 and folding-axis mirror support base 08

As shown in FIG. 7 and FIG. 8 , the adjustment of the orientation of the optical system in this embodiment is based on the sub-reflector 05 as the reference, and the sub-reflector 05 is the reference position, so the sub-reflector 05 needs to be designed with a higher positioning reference; The mirror support base 04 includes a secondary mirror support frame 041 arranged on the supporting base plate 01, a secondary mirror frame 042 arranged on the secondary mirror support frame 041, and a circular pressure plate 043 for pressing the secondary mirror 05. The secondary mirror frame 042 is provided with There is a circular opening for installing the sub-reflector 05, which can measure the plane reference position of the sub-reflector 05 externally, which can ensure that the optical axis of the lens and the installation reference at the bottom of the support base plate 01 The parallelism error is not greater than 0.02mm, and has a high installation Benchmark; the secondary mirror frame 042 and the secondary mirror 05 are centering to realize the coaxiality of the optical axis of the lens and the central axis of the secondary mirror frame 042, and the installation and fixation are carried out relying on the mechanical matching accuracy of the secondary mirror frame 042 and the supporting base plate 01.

The folding-axis mirror assembly includes a folding-axis mirror support frame 081 arranged on the supporting base plate 01, a folding-axis mirror mounting frame 082 arranged on the folding-axis mirror supporting frame 081, and a rectangular pressing plate 083 for pressing the folding-axis mirror 09. The axis mirror 09 is pressed and fixed by a pressure plate, and a silicon rubber pad with a thickness of 2 mm is designed between the pressure plate and the folding axis mirror 09 to reduce the stress generated by the pressure plate pressing the folding axis mirror 09.

The axis-folding mirror 09 is mainly used to fold the optical path, which is convenient for docking and testing with the infrared hyperspectrometer. The mirror 05 and the folding mirror 09 are mounted on a support base. The included angle of the optical axis of the secondary reflector 05 and the folding-axis mirror 09 is 45°, and the installation accuracy is ensured by machining.

2.4 Three mirror support base 06

The third reflecting mirror 07 and the main reflecting mirror 03 are both rectangular reflecting mirrors. The structure of the three-mirror support base 06 is the same as that of the main mirror support base 02. The structure and adjustment method are the same, because the size of the third reflecting mirror 07 is smaller than that of the main reflecting mirror 03. About 40mm, then the groove size of the front face of the mirror base of the three mirror support base 06 is slightly smaller than the groove size of the front face of the main mirror support base 02; and the three mirror support base 06 is along the exit center optical axis of the secondary reflector 05 The direction is trimmed and adjusted to ensure the axial distance between the secondary mirror 05 and the third mirror 07 .

2.5 Filter holder 010

As shown in FIG. 9 , the filter support base 010 includes a filter base 0101, a rubber pad, a pressing block and a mounting base 0102. The filter base 0101 is perpendicular to the support base plate 01 and is fixed at the optical outlet of the housing. The mounting base 0102 It is set on the filter holder 0101, and a vertical slot for installing the filter 011 is opened on the mount 0102. When installing, insert the filter 011 directly into the slot from the top of the mount 0102, and the filter needs to be replaced. 011, just pull out the filter 011 from the slot, which is convenient for replacement during debugging. On the one hand, the slot of the filter 011 can be formed by machining and by installing the baffle, on the other hand, it can also be directly integrated by 3D printing.

2.6 Design of stray light diaphragm

The front objective lens system of this embodiment is further provided with a light blocking component (a diaphragm or a light blocking ring), and the light blocking component includes a long cylindrical front light shielding cover 82, an inner light blocking ring, a light blocking ring, a light blocking plate and an exit light shielding cover.

The long cylindrical front light shield 82 is arranged at the optical entrance of the outer cover 81 to reduce the influence of stray light;

The inner light-blocking ring is two edge apertures, namely the first edge aperture 83 and the second edge aperture 84, which are used to block external stray light; the first blade aperture 83 is set on the main reflector 03 to reflect On the outer side of the surface, the second edge aperture 84 is located in the outgoing light path of the long cylindrical front light shield 82, and in the light path reflected by the third reflecting mirror 07, for reducing the outermost and The stray light of the outermost outgoing beam of the third reflecting mirror 07;

The light blocking ring and the light blocking plate are arranged between the main reflector 03 and the secondary reflector 05 to reduce the influence of external stray light;

The extension design of the structure size of the mounting seat 0102 of the filter support seat can form an internal light blocking ring, which can be used as a light shield for the position of the system exit light path to reduce the influence of stray light.

The light-blocking components in this embodiment are all sandblasted and black anodized.

The above only describes the preferred embodiments of the present invention, and does not limit the technical solutions of the present invention to this. Any known deformations made by those skilled in the art on the basis of the main technical concept of the present invention belong to the protection of the present invention. technical category.

Claims (10)

1. The utility model provides a short burnt antelens system of off-axis three anti of hyperspectral imager which characterized in that: the optical filter comprises a support base plate (01), and a primary mirror assembly, a secondary mirror assembly, a three-mirror assembly, a folding axis mirror assembly and an optical filter assembly which are arranged on the support base plate (01);

the primary mirror assembly comprises a primary mirror support seat (02) arranged on the support bottom plate (01) and a primary mirror (03) arranged on the primary mirror support seat (02);

the secondary mirror assembly comprises a secondary mirror supporting seat (04) arranged on the supporting bottom plate (01) and a secondary reflector (05) arranged on the secondary mirror supporting seat (04);

the three-mirror assembly comprises a three-mirror support seat (06) arranged on the support base plate (01) and a third reflector (07) arranged on the three-mirror support seat (06);

the folding axis mirror assembly comprises a folding axis mirror supporting seat (08) arranged on the supporting base plate (01) and a folding axis mirror (09) arranged on the folding axis mirror supporting seat (08);

the optical filter assembly comprises an optical filter supporting seat (010) arranged on the supporting bottom plate (01) and an optical filter (011) arranged on the optical filter supporting seat (010);

the main reflector (03), the secondary reflector (05), the third reflector (07), the folding axis mirror (09) and the optical filter (011) are sequentially arranged along the light beam transmission direction to form an off-axis three-mirror optical system;

the main mirror supporting seat (02) comprises a mirror seat, an adjusting plate (2) and a supporting seat (3);

the mirror base comprises a base body (1), a groove (11) which is arranged on the front end face of the base body (1) and is matched with the bottom of the main mirror (03) in shape, a plurality of pressing plates (12) which are arranged on the periphery of the groove (11), a plurality of bonding columns (14) which are arranged on the inner bottom face of the groove (11) and a plurality of supporting columns (15); the top end of each bonding column (14) is provided with an adhesive, and the total height of the bonding columns (14) and the adhesive is equal to the height of the support column (15); one end of each pressing plate (12) is connected with the base body (1), the other end of each pressing plate is used for pressing and fixing the main reflector (03) in the groove (11), and a gap is formed between the side surface of the main reflector (03) and the groove wall of the groove (11);

the adjusting plate (2) is connected with the rear end face of the seat body (1) through a plurality of first adjusting units; each first adjusting unit comprises a jacking screw assembly (5) and a locking tensioning screw assembly (6); the jacking screw assembly (5) is arranged on the adjusting plate (2), the front end of the jacking screw assembly is abutted against the rear end face of the seat body (1), and the jacking screw assembly is used for adjusting the distance between the adjusting plate (2) and the seat body (1); the locking and tensioning screw assembly (6) comprises a locking and tensioning screw (61) penetrating through a through hole in the adjusting plate (2), and the front end of the locking and tensioning screw (61) is in threaded connection with the rear end face of the seat body (1) and is used for fixing the adjusting plate (2) and the seat body (1);

the supporting seat (3) is a hollow frame body structure sleeved on the outer sides of the seat body (1) and the adjusting plate (2), and the left side and the right side of the lower end of the supporting seat (3) are provided with connecting lug seats (35); the connecting lug seat (35) is connected with the supporting bottom plate (01);

the supporting seat (3) is connected with the side surface of the adjusting plate (2) through a second adjusting unit; the second adjusting unit is arranged on the supporting seat (3) and is used for adjusting the translation of the adjusting plate (2) in the vertical direction and the left-right direction;

the three-mirror supporting seat (06) has the same structure as the main mirror supporting seat (02).

2. The hyperspectral imager's off-axis three-mirror short focus front objective lens system of claim 1, characterized in that: the supporting baseplate (01) is provided with a guide boss (012) at the matching position of a connecting lug seat (35) of the primary mirror supporting seat (02) and a connecting lug seat (35) of the three-mirror supporting seat (06), so that the primary mirror supporting seat (02) can move on the guide boss (012) along the incident central optical axis direction of the secondary reflector (05), and the third reflector (07) can move on the guide boss (012) along the emergent central optical axis direction of the secondary reflector (05).

3. The hyperspectral imager's off-axis three-mirror short focus front objective lens system of claim 2, characterized in that: the conic coefficient of the primary mirror (03) is-9.34, the conic coefficient of the secondary mirror (05) is 0.826, and the aspheric coefficient of the third mirror (07) is: k is-0.861, A2 is 1.455e^-3，A4＝8.667e^-10；

The mirror surfaces of the main reflecting mirror (03), the third reflecting mirror (07), the folding axis mirror (09) and the optical filter (011) are all rectangular;

the mirror surface of the secondary reflector (05) is circular.

4. The hyperspectral imager's off-axis three-mirror short focus front objective lens system of claim 3, characterized in that: the secondary mirror supporting seat (04) comprises a secondary mirror supporting frame (041) arranged on the supporting bottom plate (01), a secondary mirror frame (042) arranged on the secondary mirror supporting frame (041), and a circular pressing plate (043) used for pressing the secondary reflector (05), wherein a circular opening used for installing the secondary reflector (05) is formed in the secondary mirror frame (042);

the folding axis mirror assembly comprises a folding axis mirror support frame (081) arranged on the support base plate (01), a folding axis mirror mounting frame (082) arranged on the folding axis mirror support frame (081), and a rectangular pressing plate (083) used for pressing the folding axis mirror (09);

the secondary mirror supporting seat (04) and the folding axis mirror supporting seat (08) form an included angle of 135 degrees and are fixedly connected into a whole.

5. The hyperspectral imager's off-axis three-mirror short focus front objective lens system of claim 4, characterized in that: the support base plate (01) is provided with an outer cover (81), the primary mirror assembly, the secondary mirror assembly, the three-mirror assembly and the folding axis mirror assembly are all positioned in the outer cover (81), and the optical filter assembly is arranged at an optical outlet of the outer cover (81);

the optical filter supporting seat (010) comprises an optical filter seat (0101) which is perpendicular to the supporting bottom plate (01) and is installed on the outer cover, an installation seat (0102) arranged on the optical filter seat (0101), and a vertical slot which is arranged on the installation seat (0102) and is used for installing the optical filter (011);

and a long cylindrical front light shield (82) is arranged at an optical inlet of the outer shield (81).

6. The hyperspectral imager of any of claims 1 to 5, wherein the hyperspectral imager is an off-axis three-mirror short-focus front objective lens system, and the hyperspectral imager is characterized in that: the jacking screw assembly (5) comprises an external compression spring (51), a pressing plate (52), a moving column (53) with a ball socket, an adjusting bracket (54) and a jacking screw (55) which are sequentially arranged from front to back;

the rear end face of the seat body (1) is provided with an outer spring seat (18), and the outer spring seat (18) is an annular groove;

the adjusting plate (2) is provided with step through holes, and the step through holes comprise a first through hole (22) and a second through hole (23) which are sequentially reduced in diameter from front to back;

the pressing plate (52) is arranged in the first through hole (22), the front end face of the pressing plate (52) is provided with an annular outer spring support (521) extending into the outer spring seat (18), and the rear end face of the pressing plate is provided with an adjusting ball head (522);

the outer compression spring (51) is arranged in the annular groove, the front end of the outer compression spring is limited by the bottom surface of the annular groove, and the rear end of the outer compression spring is sleeved on the annular outer spring support (521);

the moving column is arranged in the second through hole (23), and a ball socket at the front end is arranged on the adjusting ball head (522);

the adjusting support (54) is fixed on the rear end face of the adjusting plate (2), a threaded hole is formed in the adjusting support (54), and the jacking screw (55) penetrates through the threaded hole and abuts against the rear end face of the moving column (53) with the ball socket.

7. The hyperspectral imager's off-axis three-mirror short focus front objective lens system of claim 6, characterized in that: the jacking screw assembly (5) further comprises an inner compression spring (56) coaxially arranged in the outer compression spring (51);

the rear end face of the seat body (1) is provided with an inner spring seat (19), and the inner spring seat (19) is a cylindrical groove;

the front end surface of the pressure plate (52) is provided with an inner spring column (523) extending into the inner spring seat (19);

the internal pressure spring (56) is arranged in the cylindrical groove, the front end of the internal pressure spring is limited by the bottom surface of the cylindrical groove, and the rear end of the internal pressure spring is sleeved on the internal spring column (523).

8. The hyperspectral imager's off-axis three-mirror short focus front objective lens system of claim 7, wherein: the rear end face of the base body (1) is provided with a plurality of connecting tables (17), the number of the connecting tables (17) is equal to that of the jacking screw assemblies (5), and the connecting tables correspond to the jacking screw assemblies in position one by one; an open slot (171) for reducing stress is formed in the side surface of the connecting table (17);

the inner spring seat (19) and the outer spring seat (18) are both arranged on the rear end surface of the connecting table (17);

the adjusting plate (2) is of a rectangular structure;

the number of the first adjusting units is 4, and the 4 first adjusting units are arranged at four corners of the adjusting plate (2) in a rectangular shape.

9. The hyperspectral imager's off-axis three-mirror short focus front objective lens system of claim 8, characterized in that: the supporting seat (3) is of a rectangular hollow frame structure and comprises a left supporting plate (31), a lower supporting plate (32), a right supporting plate (33) and an upper supporting plate (34) which are sequentially connected end to end; the connecting lug seat (35) is connected with the supporting bottom plate (01) through a screw (36);

the second adjusting unit comprises a left-right adjusting component and an up-down adjusting component;

the left and right adjusting component comprises a left adjusting screw (41) and a right adjusting screw (43) which are symmetrically arranged, the left adjusting screw (41) is arranged on the left supporting plate (31), and the inner end surface of the left adjusting screw abuts against the left end surface (25) of the adjusting plate (2); the right adjusting screw (43) is arranged on the right support plate (33), and the inner end surface abuts against the right end surface (27) of the adjusting plate (2);

the up-down adjusting assembly comprises an upper adjusting screw (42) and a lower adjusting screw (44) which are symmetrically arranged, the upper adjusting screw (42) is arranged on the upper supporting plate (34), and the inner end surface of the upper adjusting screw abuts against the upper end surface (24) of the adjusting plate (2); the lower adjusting screw (44) is arranged on the lower supporting plate (32), and the inner end surface abuts against the lower end surface (26) of the adjusting plate (2).

10. The hyperspectral imager's off-axis three-mirror short focus front objective lens system of claim 9, characterized in that: the position where the left end face (25) of the adjusting plate (2) is matched with the left adjusting screw (41), the position where the right end face (27) of the adjusting plate (2) is matched with the right adjusting screw (43), the position where the upper end face (24) of the adjusting plate (2) is matched with the upper adjusting screw (42), and the position where the lower end face (26) of the adjusting plate (2) is matched with the lower adjusting screw (44) are all provided with positioning grooves (28);

the range of a gap between the side surface of the main reflector (03) and the groove (11) is 0.06-0.15mm, and the gap is filled with adhesive;

a central through hole (13) is formed in the bottom of the groove (11) of the seat body (1); the middle part of the adjusting plate (2) is provided with a hexagonal lightening hole (29).

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