Assembly system and assembly method of off-axis optical system

Abstract

The invention provides an assembly system and an assembly method of an off-axis optical system, which are used for solving the technical problems that all optical elements of the existing off-axis optical system do not have a common optical axis, the assembly difficulty is high, and the high-precision assembly and adjustment of the off-axis optical system cannot be met by a traditional assembly and adjustment process method. The system comprises a three-coordinate measuring machine, a laser interferometer, a compensating mirror and an optical imaging camera. The device further comprises an auto-collimation theodolite, a target ball, an adjusting support and a five-dimensional adjusting table. And installing and adjusting the third reflector to obtain the position of the first target ball. The theoretical position of a second target ball is calculated according to the position of the first target ball, a main reflector is installed and adjusted, a compensation detection light path of the main reflector is set up, the focus position of the laser interferometer is obtained, finally, the focus position coincides with the theoretical position of the second target ball, and assembling of the off-axis type optical system is completed.

Description

Technical Field

[0001] The present invention relates to an optical assembly system and method, and more particularly to an assembly system and method for an off-axis optical system. Background Art

[0002] With the continuous improvement of the meta-resolution and spectral resolution of space payloads, the aperture and field of view of space payloads are getting larger and larger, and off-axis optical systems and free-form surface optical systems are widely used. During the use and assembly process, the structure of the truss structure or frame structure is the main body, and there are difficult problems such as high lightweight design of the mirror, compact space, few initial positioning references, great difficulty in micro-stress assembly, and many adjustment variables of the mirror. This places more stringent requirements on the assembly process method.

[0003] As Figure 1 shown, in a traditional off-axis reflection system, there is a common optical axis 6 among various optical elements, such as mirror 11, off-axis mirror A12, and off-axis mirror B13. Traditional assembly methods can be used for debugging and assembly. However, in an off-axis off-axis optical system, the optical axes 6 between optical elements are different, with eccentricity and inclination. Since there is no common optical axis 6 among its various optical elements, as Figure 2 shown, mirror 11, off-axis mirror A12, and off-axis mirror B13 are not coaxial. When assembling and adjusting an off-axis optical system, it is necessary to not only ensure the relative positional relationship between each mirror group, but also ensure the optical axis deviation angle 14 between the optical axis of off-axis mirror A12 and the optical axis of off-axis mirror B13, which brings great difficulties to the assembly and adjustment, and the assembly difficulty is greatly improved. Using traditional assembly and adjustment process methods can no longer meet the high-precision assembly and adjustment of this type of optical system. Summary of the Invention

[0004] The object of the present invention is to solve the technical problem that the traditional assembly and adjustment process method cannot meet the high-precision assembly and adjustment of the off-axis off-axis optical system, and to propose an assembly system and method for an off-axis optical system.

[0005] To solve the above technical problem, the technical solution provided by the present invention is as follows:

[0006] An assembly system for an off-axis optical system, the off-axis optical system includes a main mirror and a third mirror installed on an optical imaging camera, and is characterized in that: it includes a three-coordinate measuring machine, an autocollimation theodolite, a laser interferometer, a compensating mirror, which are horizontally placed, as well as a target ball and a high-precision five-axis adjustment table for placing the target ball;

[0007] The coordinate measuring machine is used to establish a spatial coordinate system and measure the coordinates of the target ball; the optical imaging camera is installed at one end of the test platform of the coordinate measuring machine, and the laser interferometer is located at the other end of the test platform; the autocollimating theodolite is located on the back of the optical imaging camera, and the front of the optical imaging camera faces the laser interferometer;

[0008] The laser interferometer and the compensating mirror are used to be coaxial with the third reflector on the first optical axis to form an offner compensation detection optical path for the third reflector to perform surface shape detection on the third reflector;

[0009] Alternatively, the laser interferometer and the compensating mirror are used to be coaxial with the primary mirror on the second optical axis to form an offner compensation detection optical path for the primary mirror to perform surface shape detection on the primary mirror;

[0010] The target ball is used to mark the focal point of the laser interferometer.

[0011] Furthermore, the laser interferometer is installed on the coordinate measuring machine through an adjustment bracket.

[0012] An assembly method for an off-axis optical system, based on the above-mentioned assembly system for an off-axis optical system, is characterized in that it includes the following steps:

[0013] 1) Install and adjust the third reflector: Install the third reflector on the bottom plate of the optical imaging camera, and use the autocollimating theodolite to monitor and adjust the attitude of the third reflector on the bottom plate so that the first optical axis of the third reflector is parallel to the test platform of the coordinate measuring machine;

[0014] 2) Determine the position of the first target ball:

[0015] 2.1) Set up the offner compensation detection optical path for the third reflector, use the laser interferometer to perform surface shape detection on the third reflector, and obtain the focal point position of the laser interferometer;

[0016] 2.2) Use the five-axis adjustment stage to set up the first target ball at the focal point position of the laser interferometer, and measure the spatial position coordinates of the first target ball through the coordinate measuring machine to obtain the position of the first target ball;

[0017] 3) Calculate and obtain the theoretical position of the second target ball:

[0018] 3.1) Obtain the straight-line distance l between the first target ball and the second target ball according to the design dimensions of the off-axis off-axis optical system;

[0019] 3.2) Calculate the theoretical position of the second target ball according to the position of the first target ball obtained in step 2 and the straight-line distance l obtained in step 3.1;

[0020] 3.3) Move the probe of the three - coordinate measuring machine to the theoretical position of the second target ball, set up the second target ball at this position using the five - dimensional adjustment table, and measure the spatial position coordinates of the second target ball through the three - coordinate measuring machine to obtain the theoretical position of the second target ball;

[0021] 4) Set up the laser interferometer: Adjust the yaw angle of the laser interferometer and perform translation until the interference fringes of the second target ball appear in the laser interferometer;

[0022] 5) Determine the initial position of the primary mirror: Install the primary mirror on the base plate of the optical imaging camera, and determine the angular change of the primary mirror through the autocollimation theodolite; Determine the translation amount of the primary mirror based on the third mirror as a reference; After the primary mirror simultaneously meets the angular change and the translation amount, pre - tighten the installation screws between the frame of the primary mirror and the base plate of the optical imaging camera;

[0023] 6) Determine the attitude of the primary mirror:

[0024] 6.1) According to the laser interferometer set up in step 4, build the offner compensation detection optical path for the primary mirror, and use the laser interferometer to perform surface shape detection on the primary mirror after determining the initial position in step 5 to obtain the focal position of the laser interferometer;

[0025] 6.2) Adjust the attitudes of the compensation mirror and the primary mirror until the focal position of the laser interferometer completely coincides with the theoretical position of the second target ball in step 3.3, and fix the position and attitude of the primary mirror to complete the assembly of the off - axis optical system.

[0026] Further, in step 3.2, the linear distance l is decomposed into the component Δx in the x - axis direction and the component Δy in the y - axis direction. In step 3.3, with the position of the first target ball as the origin, the probe of the three - coordinate measuring machine moves to the theoretical position of the second target ball according to the component Δx and the component Δy.

[0027] Further, in step 4, the interference fringes appearing in the laser interferometer are zero fringes.

[0028] Further, in step 2.1, it is required that the focal position of the laser interferometer and the high - low point positions of the third mirror are at the same height, and the position difference between the focal point and the high - low points is not greater than 5μm; The high point of the third mirror refers to the point farthest from the first optical axis in the sagittal plane, and the low point refers to the point closest to the first optical axis in the sagittal plane.

[0029] Further, in steps 2.2 and 3.3, the measurement accuracy of the three - coordinate measuring machine for measuring the spatial position coordinates of the first target ball and the second target ball is controlled within 5μm.

[0030] Further, in the pre - tightening process in step 5, it is required that the azimuth angle and pitch angle change of the primary mirror ≤1'.

[0031] Further, in step 2.1, the RMS of the third reflecting mirror surface shape is ≤ 0.03 wavelengths; in step 6.1, the RMS of the primary reflecting mirror surface shape is ≤ 0.03 wavelengths.

[0032] Further, in step 1, a plurality of slot holes are provided on the frame of the third reflecting mirror, and a plurality of mounting holes corresponding to the plurality of slot holes are provided on the base plate of the optical imaging camera. The slot holes and the corresponding mounting holes are connected by screws, and the slot holes are arranged along the direction of the straight line where the plurality of mounting holes are located.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0034] 1. The present invention provides an assembly system for an off-axis optical system, including a coordinate measuring machine for establishing a space coordinate system, a laser interferometer for building a compensation detection optical path, a compensation mirror, and an optical imaging camera. It also includes an autocollimation theodolite for adjusting the postures of the third reflecting mirror and the primary reflecting mirror, as well as a target ball, an adjustment bracket, and a five-axis adjustment stage. The off-axis optical system assembly system is established based on the measurement platform of the coordinate measuring machine. The overall structure of the system is simple and easy to build, and it can meet the assembly and posture adjustment of the primary reflecting mirror and the third reflecting mirror with different optical axes.

[0035] 2. The present invention also provides an assembly method for an off-axis optical system. After installing and adjusting the third reflecting mirror and building the compensation detection optical path of the third reflecting mirror, the position of the first target ball is obtained. According to the position of the first target ball, the theoretical position of the second target ball is calculated. After installing and adjusting the primary reflecting mirror and building the compensation detection optical path of the primary reflecting mirror, the focal position of the laser interferometer is obtained. Finally, the focal position is made to coincide with the theoretical position of the second target ball, and the assembly of the off-axis optical system is completed.

[0036] 3. The measurement accuracy of the spatial position coordinates of the first target ball and the second target ball in the assembly method of the off-axis optical system of the present invention is controlled within 5 μm. After testing, the deviation between the actual optical axis and the theoretical optical axis of the optical system assembled according to this method is less than 5′, meeting the high-precision assembly and adjustment of the off-axis optical system. Description of the Drawings

[0037] Figure 1 is a schematic optical path diagram of a traditional off-axis reflection system;

[0038] Figure 2 is a schematic optical path diagram of an off-axis off-axis reflection system;

[0039] Figure 3 is a schematic assembly structure diagram of the third reflecting mirror in the embodiment of the assembly system of the off-axis optical system of the present invention;

[0040] Figure 4Schematic diagram of the main mirror assembly structure in the assembly system embodiment of an off-axis optical system according to the present invention;

[0041] Figure 5 Schematic diagram of the positions of the first target ball and the second target ball in the assembly system embodiment of an off-axis optical system according to the present invention;

[0042] Figure 6 Schematic diagram of the structure of the slotted hole and the mounting hole in the assembly system embodiment of an off-axis optical system according to the present invention;

[0043] Figure 7 Flowchart of the embodiment of the assembly method of an off-axis optical system according to the present invention.

[0044] Explanation of reference numerals:

[0045] 1 - Autocollimator theodolite; 2 - Compensation mirror; 3 - Adjustment bracket; 4 - Laser interferometer; 5 - Five-axis adjustment stage; Optical axis 6, 61 - First optical axis, 62 - Second optical axis; 71 - First target ball, 72 - Second target ball; 8 - Coordinate measuring machine; 9 - Third mirror; 10 - Main mirror; 11 - Mirror; 12 - Off-axis mirror A; 13 - Off-axis mirror B; 14 - Optical axis declination; 15 - Slotted hole; 16 - Mounting hole. Detailed implementation manners

[0046] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0047] The present invention provides a system and method for the integrated assembly of the main mirror 10 and the third mirror 9 with high precision, which has a simple structure and is easy to operate. An assembly system for an off-axis optical system includes a horizontally placed coordinate measuring machine 8, an optical imaging camera placed on the measuring platform of the coordinate measuring machine 8, a laser interferometer 4, an autocollimator theodolite 1, a compensation mirror 2, a target ball, and a high-precision five-axis adjustment stage 5 for placing the target ball. The coordinate measuring machine 8 is used to establish a spatial coordinate system, including the x-axis, y-axis, and z-axis. The coordinate measuring machine 8 is also used to measure the coordinates of the target ball. The base of the optical imaging camera to be debugged is installed at one end of the test platform of the coordinate measuring machine 8 and fixed using a pressing plate. The laser interferometer 4 is located at the other end of the test platform of the coordinate measuring machine 8, and the laser interferometer 4 is installed on the coordinate measuring machine 8 through an adjustment bracket 3. In this embodiment, the laser interferometer 4 uses a ZYGO laser interferometer. The autocollimator theodolite 1 is located behind the optical imaging camera and is used to assist in adjusting the positions of the third mirror 9 and the main mirror 10. In this embodiment, the autocollimator theodolite 1 uses a Leica autocollimator theodolite. The front of the optical imaging camera faces the laser interferometer 4. The compensation mirror 2 is located between the laser interferometer 4 and the optical imaging camera. As Figure 3As shown in the figure, when assembling the third mirror 9, the first optical axis 61 of the laser interferometer 4, the compensating mirror 2, and the third mirror 9 are on the same straight line, and the spatial positions of the laser interferometer 4, the compensating mirror 2, and the third mirror 9 are fixed and unique, forming the offner compensation detection optical path for the third mirror. As Figure 4 shown in the figure, when assembling the main mirror 10, the second optical axis 62 of the laser interferometer 4, the compensating mirror 2, and the main mirror 10 are on the same straight line, and the spatial positions of the laser interferometer 4, the compensating mirror 2, and the main mirror 10 are fixed and unique, forming the offner compensation detection optical path for the main mirror.

[0048] An assembly method for an off-axis optical system, as Figure 7 shown in the figure, specifically includes the following steps:

[0049] 1) Install and adjust the third mirror 9:

[0050] The third mirror 9 to be debugged is installed on the bottom plate of the optical imaging camera. Multiple slotted holes 15 are provided on the frame of the third mirror 9 to facilitate increasing the adjustment direction of the third mirror 9. Multiple mounting holes 16 corresponding to the multiple slotted holes 15 are provided on the bottom plate of the optical imaging camera. The slotted holes 15 and the mounting holes 16 are connected by M5*15 hexagon socket head cap screws. As Figure 6 shown in the figure, the slotted holes 15 are arranged along the direction of the straight line where the multiple mounting holes 16 are located. Monitor and adjust the attitude of the third mirror 9 on the bottom plate by the autocollimation theodolite 1 to make its first optical axis 61 parallel to the test platform of the coordinate measuring machine 8.

[0051] 2) Determine the position of the first target ball 71:

[0052] 2.1) Build the offner compensation detection optical path for the third mirror, use the laser interferometer 4 to detect the surface shape of the third mirror 9, and require that the surface shape RMS of the third mirror 9 ≤ 0.030 wavelength to obtain the focal position of the laser interferometer 4;

[0053] 2.2) At the same time, require that the focal position of the laser interferometer 4 and the high and low point positions of the third mirror 9 are at the same height, and the position difference between the focus and the high and low points is not greater than 5μm; use the five-axis adjustment stage 5 to set up the first target ball 71 at the focal position of the laser interferometer 4. The target ball is a metal target ball. Determine the spatial position coordinates (x1, y1, z0) of the focus through the coordinate measuring machine 8 to obtain the position of the first target ball 71, and control the measurement accuracy within 5μm.

[0054] Among them, the high point of the third mirror 9 refers to the point farthest from the first optical axis 61 in the sagittal plane, and the low point of the third mirror 9 refers to the point closest to the first optical axis 61 in the sagittal plane.

[0055] 3) Calculate and obtain the theoretical position of the second target ball 72:

[0056] 3.1) When designing the optical system, the spatial positions of the primary mirror 10 and the third mirror 9 are unique. The focal positions during the surface shape detection of the primary mirror 10 and the third mirror 9 are also determined and unique. The focal position during the surface shape detection of the third mirror 9 is the position of the first target ball 71, and the focal position during the surface shape detection of the primary mirror 10 is the theoretical position of the second target ball 72. Therefore, according to the design drawing of the off-axis optical system, the straight-line distance l between the first target ball 71 and the second target ball 72 can be obtained.

[0057] 3.2) As Figure 5 shown, based on the spatial position coordinates (x1, y1, z0) of the first target ball 71 obtained in step 2 and the straight-line distance l between the first target ball 71 and the second target ball 72, the theoretical position of the second target ball 72 is calculated. The specific calculation process: Decompose the straight-line distance between the first target ball 71 and the second target ball 72 into the component Δx in the x-axis direction and the component Δy in the y-axis direction.

[0058] 3.3) Taking the position of the first target ball 71 as the origin, the probe of the coordinate measuring machine 8 moves according to the component Δx and the component Δy, and the second target ball 72 is mounted on the five-axis adjustment stage 5 at the moved position. The spatial position coordinates (x0, y0, z0) of the second target ball 72 are determined by the coordinate measuring machine 8 to obtain the theoretical position of the second target ball 72.

[0059] 4) Install the laser interferometer 4:

[0060] When the target ball is at the focal position of the laser interferometer 4, interference fringes can appear. Adjust the yaw angle and translation of the laser interferometer 4 until the interference fringes of the second target ball 72 appear in the laser interferometer 4 and the interference fringes are zero fringes, that is, the installation of the laser interferometer 4 is completed.

[0061] 5) Determine the initial position of the primary mirror 10:

[0062] Install the primary mirror 10 on the base plate of the optical imaging camera. Taking the back of the third mirror 9 and the primary mirror 10 as the reference, determine the angular change amounts of the azimuth angle and the pitch angle of the primary mirror 10 through the autocollimation theodolite 1; the coordinate measuring machine 8 measures the upper end face, the right end face and the back end face of the third mirror 9, and taking the intersection coordinates of the upper end face, the right end face and the back end face as the reference, determine the translation amounts of the primary mirror 10 in the x-axis, y-axis and z-axis directions of the space coordinate system. The primary mirror 10 simultaneously satisfies the angular change amount and the translation amount to complete the rough adjustment of the position of the primary mirror 10. Pre-tighten the installation screws between the frame of the primary mirror 10 and the base plate of the optical imaging camera. To avoid affecting the position of the primary mirror 10 during the pre-tightening process, it is required that the change amounts of the azimuth angle and the pitch angle of the primary mirror 10 during the pre-tightening process ≤ 1'. At this time, the initial position of the primary mirror 10 is determined.

[0063] 6) Determine the attitude of the primary mirror 10:

[0064] 6.1) According to the laser interferometer 4 set up in step 4, build the offner compensation detection optical path for the primary mirror, and use the laser interferometer 4 to perform surface shape detection on the primary mirror 10 after determining the initial position in step 5. It is required that the surface shape RMS of the primary mirror 10 ≤ 0.030 wavelength. Obtain the focal position of the laser interferometer 4.

[0065] 6.2) Adjust the attitudes of the compensation mirror 2 and the primary mirror 10 until the focal position of the laser interferometer 4 completely coincides with the theoretical position of the second target ball 72 in step 3.3, and fix the position and attitude of the primary mirror 10 to complete the assembly of the off-axis optical system.

Claims

1. An assembly system for an off-axis optical system, the off-axis optical system comprising a primary mirror (10) and a third mirror (9) mounted on an optical imaging camera, characterized in that: It includes a three - coordinate measuring machine (8) placed horizontally, an autocollimator theodolite (1), a laser interferometer (4), a compensating mirror (2), as well as a target ball and a high - precision five - dimensional adjustment table (5) for placing the target ball; The three - coordinate measuring machine (8) is used to establish a space coordinate system and measure the coordinates of the target ball; the optical imaging camera is installed at one end of the test platform of the three - coordinate measuring machine (8), and the laser interferometer (4) is located at the other end of the test platform; the autocollimator theodolite (1) is located at the back of the optical imaging camera, and the front of the optical imaging camera faces the laser interferometer (4); The laser interferometer (4) and the compensating mirror (2) are used to be co - located on the first optical axis (61) with the third mirror (9) to form a third mirror offner compensation detection optical path for surface shape detection of the third mirror (9); Alternatively, the laser interferometer (4) and the compensating mirror (2) are used to be co - located on the second optical axis (62) with the primary mirror (10) to form a primary mirror offner compensation detection optical path for surface shape detection of the primary mirror (10); The target ball is used to mark the focus of the laser interferometer (4).

2. An assembly system for an off - axis optical system according to claim 1, wherein: The laser interferometer (4) is installed on the three - coordinate measuring machine (8) through an adjustment bracket (3).

3. An assembly method for an off - axis optical system, based on the assembly system for an off - axis optical system according to claim 1 or 2, wherein: it includes the following steps: 1) Install and adjust the third mirror (9): Install the third mirror (9) on the bottom plate of the optical imaging camera, and use the autocollimator theodolite (1) to monitor and adjust the attitude of the third mirror (9) on the bottom plate so that the first optical axis (61) of the third mirror (9) is parallel to the test platform of the three - coordinate measuring machine (8); 2) Determine the position of the first target ball (71): 2.1) Set up the third mirror offner compensation detection optical path, use the laser interferometer (4) to perform surface shape detection on the third mirror (9), and obtain the focus position of the laser interferometer (4); 2.2) Use the five - dimensional adjustment table (5) to set up the first target ball (71) at the focus position of the laser interferometer (4), and measure the spatial position coordinates (x1, y1, z0) of the first target ball (71) through the three - coordinate measuring machine (8) to obtain the position of the first target ball (71); 3) Calculate and obtain the theoretical position of the second target ball (72): 3.1) Obtain the straight - line distance l between the first target ball (71) and the second target ball (72) according to the design dimensions of the off - axis off - axis optical system; 3.2) Calculate the theoretical position of the second target ball (72) according to the position of the first target ball (71) obtained in step 2 and the straight - line distance l obtained in step 3.1; 3.3) Move the probe of the three - coordinate measuring machine (8) to the theoretical position of the second target ball (72), set up the second target ball (72) at this position by using the five - dimensional adjustment table (5), and measure the spatial position coordinates (x0, y0, z0) of the second target ball (72) through the three - coordinate measuring machine (8) to obtain the theoretical position of the second target ball (72). 4) Set up the laser interferometer (4): Adjust the yaw angle of the laser interferometer (4) and perform translation until the interference fringes of the second target ball (72) appear in the laser interferometer (4). 5) Determine the initial position of the primary mirror (10): Install the primary mirror (10) on the base plate of the optical imaging camera, and determine the angular change of the primary mirror (10) through the autocollimation theodolite (1); determine the translation of the primary mirror (10) based on the third mirror (9); after the primary mirror (10) satisfies both the angular change and the translation, pre - tighten the mounting screws between the frame of the primary mirror (10) and the base plate of the optical imaging camera. 6) Determine the attitude of the primary mirror (10): 6.1) According to the laser interferometer (4) set up in step 4, build the offner compensation detection optical path for the primary mirror, and use the laser interferometer (4) to perform surface shape detection on the primary mirror (10) after determining the initial position in step 5 to obtain the focal position of the laser interferometer (4). 6.2) Adjust the attitudes of the compensation mirror (2) and the primary mirror (10) until the focal position of the laser interferometer (4) coincides exactly with the theoretical position of the second target ball (72) in step 3.3, and fix the position and attitude of the primary mirror (10) to complete the assembly of the off - axis optical system.

4. A method for assembling an off - axis optical system according to claim 3, wherein: In step 3.2, the linear distance l is decomposed into a component Δx in the x - axis direction and a component Δy in the y - axis direction. In step 3.3, with the position of the first target ball (71) as the origin, the probe of the three - coordinate measuring machine (8) moves to the theoretical position of the second target ball (72) according to the component Δx and the component Δy.

5. A method for assembling an off - axis optical system according to claim 4, wherein: In step 4, the interference fringes appearing in the laser interferometer (4) are zero fringes.

6. A method for assembling an off - axis optical system according to claim 5, wherein: In step 2.1, it is required that the focal position of the laser interferometer (4) and the high - low point position of the third mirror (9) are at the same height, and the position difference between the focal point and the high - low point is not greater than 5 μm; the high point of the third mirror (9) refers to the point farthest from the first optical axis (61) in the sagittal plane, and the low point refers to the point closest to the first optical axis (61) in the sagittal plane.

7. A method for assembling an off - axis optical system according to any one of claims 3 - 6, wherein: In steps 2.2 and 3.3, the measurement accuracy of the spatial position coordinates of the first target ball (71) and the second target ball (72) measured by the three - coordinate measuring machine (8) is controlled within 5 μm.

8. A method for assembling an off - axis optical system according to claim 7, wherein: In the pre-tightening process of step 5, it is required that the variation of the azimuth angle and the pitch angle of the primary mirror (10) ≤ 1'.

9. An assembly method of an off-axis optical system according to claim 8, characterized in that: In step 2.1, the surface form RMS of the third mirror (9) ≤ 0.03 wavelengths; in step 6.1, the surface form RMS of the primary mirror (10) ≤ 0.03 wavelengths.

10. An assembly method of an off-axis optical system according to claim 8, characterized in that: In step 1, a plurality of slotted holes (15) are provided on the frame of the third mirror (9), and a plurality of mounting holes (16) corresponding to the plurality of slotted holes (15) are provided on the bottom plate of the optical imaging camera. The slotted holes (15) and the corresponding mounting holes (16) are connected by screws, and the slotted holes (15) are arranged along the direction of the straight line where the plurality of mounting holes (16) are located.

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