Multi-axis interferometer parallelism detection system and detection method

Abstract

The present invention provides a multi-axis interferometer parallelism detection system and detection method, the detection method comprising: after shaping the laser beam, the multi-axis interferometer divides the laser beam into a first light beam to be detected and a second light beam to be detected; adjusting the camera mirror in the detection module to be perpendicular to the x-direction; the detection module obtains the near-end imaging information and the far-end imaging information of the first light beam to be detected and the second light beam to be detected; calculating the parallelism of the second light beam to be detected with the first light beam to be detected; and calculating the angle for angle compensation when they are not parallel. The present invention accurately measures the parallelism of the light beams of the multi-axis interferometer by comparing the near-end and far-end imaging, and the measurement results are highly effective; at the same time, a reflection module is provided to ensure that the optical axis of the camera and the first light beam to be detected are perpendicular, thereby improving the measurement accuracy and effectiveness; in addition, a beam merging tool converges the light beams so that the camera does not need to move when imaging the two light beams to be detected, thereby improving the convenience of detection; finally, the imaging beam radius is set to adjust the beam collimation effect and improve the detection accuracy.

Description

Technical Field

[0001] The present invention belongs to the technical field of laser measurement, and in particular relates to a multi-axis interferometer parallelism detection system and a detection method. Background Art

[0002] With the development and demand for information science and semiconductor technology, the precision requirements for processing, assembly, and testing of various semiconductor equipment, instruments, and maintenance systems are increasing, leading to increasingly higher requirements for high-precision testing technology. Currently, nanometer-level precision testing is usually achieved using laser interferometers. In the manufacture and use of multi-axis interferometers, beam parallelism is a key indicator of the multi-axis interferometer and will directly affect the measurement accuracy of the multi-axis interferometer.

[0003] Although it is difficult to achieve a completely parallel setting for the beam parallelism of a multi-axis interferometer, if the parallelism between the optical axes can be accurately measured through high-precision measurement technology, the parallelism between the optical axes can be used to compensate or correct the impact of the non-parallel beam in the subsequent data processing and displacement solution. Therefore, even if there is a certain deviation in the parallelism of the beam during the manufacturing process, the deviation can be corrected through subsequent data processing, thereby ensuring the accuracy of the final measurement result.

[0004] However, in the existing technology, no effective detection method has been found to measure the parallelism of light beams between axes of a multi-axis interferometer. Traditional methods usually use visual inspection to subjectively judge the parallelism of light beams, resulting in low accuracy and poor repeatability of the actual measurement of light beam parallelism, making it difficult to improve the accuracy of the measurement results of the multi-axis interferometer.

[0005] Therefore, there is an urgent need for a structure or method that can effectively, accurately and highly precisely measure the parallelism between beams of a multi-axis interferometer.

[0006] It should be noted that the above introduction to the technical background is only for the convenience of providing a clear and complete description of the technical solutions of this application and for the convenience of understanding by those skilled in the art. It cannot be considered that the above technical solutions are well known to those skilled in the art simply because these solutions are explained in the background technology part of this application. Summary of the Invention

[0007] In view of the above shortcomings of the prior art, the purpose of the present invention is to provide a multi-axis interferometer parallelism detection system and detection method to solve the problem of low accuracy and poor effectiveness in the prior art of light beam parallelism measurement between multi-axis interferometers.

[0008] To achieve the above object, the present invention provides a multi-axis interferometer parallelism detection system, the detection system comprising: a light source module, a beam shaping module, a multi-axis interferometer, a detection module and a calculation module;

[0009] The laser beam emitted by the light source module is shaped into a collimated single-polarized incident light by the beam shaping module. The incident light is incident on the multi-axis interferometer and is divided into n beams, each of which includes one first beam to be detected and n-1 second beams to be detected, where n is an integer greater than or equal to 2. An x-direction is preset, and the optical axis of the first beam to be detected is parallel to the x-direction.

[0010] The detection module is configured to receive and measure proximal imaging information and distal imaging information of the first light beam to be detected and the second light beam to be detected on an imaging plane perpendicular to the x-direction in a proximal position area and a distal position area; the distance between the distal position area and the multi-axis interferometer along the x-direction is greater than the distance between the proximal position area and the multi-axis interferometer along the x-direction;

[0011] The calculation module is connected to the detection module, and is used to obtain the parallelism between the second light beam to be detected and the first light beam to be detected according to the proximal imaging information and the distal imaging information.

[0012] Optionally, the multi-axis interferometer parallelism detection system further includes a displacement device; the detection module is located on the displacement device, and the displacement device is used to drive the detection module to move between the distal position area and the proximal position area, and / or the displacement device is used to drive the detection module to move within the distal position area or the proximal position area.

[0013] Optionally, the multi-axis interferometer includes n exit holes;

[0014] The detection system further includes a beam merging tool, the beam merging tool including a merging tool plate and n-1 rhombic prisms, the merging tool plate including n light holes, the n light holes corresponding to the positions of the n exit holes one-to-one, and the n-1 rhombic prisms are respectively fixed to the side of the n-1 light holes away from the multi-axis interferometer;

[0015] The n light beams emitted by the multi-axis interferometer can respectively pass through the corresponding light-through holes from the n exit holes; the first light beam to be detected passes through the corresponding light-through hole and then enters the detection module, and n-1 second light beams to be detected respectively pass through the corresponding light-through hole and the rhombus prism and then enter the detection module.

[0016] Optionally, the beam shaping module comprises a linear polarizer, a converging lens, a light exit hole and a collimating lens arranged in sequence along the x-direction;

[0017] The laser beam emitted by the light source module is adjusted to single polarized light after entering the linear polarizer, and the single polarized light is converged into a convergent light beam after entering the converging lens. The convergent light beam is emitted as a collimated beam from the light exit hole and is collimated after entering the collimating lens to obtain collimated single polarized incident light.

[0018] Optionally, the collimating lens and the converging lens have the same parameters, the focal length of the converging lens is f, the aperture of the light exit is D1, the beam diameter of the laser beam incident on the beam shaping module is D2, and .

[0019] Optionally, the detection module includes a positioning hole and a camera, and the positioning hole is used to image the light beam incident on the camera in a central area of ​​the camera.

[0020] Optionally, the multi-axis interferometer parallelism detection system also includes a reflection module, which includes a camera mirror bracket and a reflector that are detachably mounted on the camera mirror of the detection module, and the reflector is mounted on the side of the camera mirror bracket away from the camera. The first light beam to be detected can be reflected to the multi-axis interferometer through the reflector.

[0021] The present invention also provides a multi-axis interferometer parallelism detection method, wherein the detection method uses any of the multi-axis interferometer detection systems described above to perform multi-axis interferometer parallelism detection, and the detection method includes:

[0022] The light source module emits a laser beam, which is shaped into a collimated single-polarized incident light by the beam shaping module. After the incident light enters the multi-axis interferometer, it is divided into 1 first beam to be detected and n-1 second beams to be detected, where n is an integer greater than or equal to 2;

[0023] Adjusting the mirror angle of the camera in the detection module so that the mirror of the camera is perpendicular to the first light beam to be detected;

[0024] The detection module receives and measures proximal imaging information of the first light beam to be detected and each of the second light beams to be detected on an imaging plane perpendicular to the first light beam to be detected in a proximal position area; the detection module receives and measures distal imaging information of the first light beam to be detected and each of the second light beams to be detected on an imaging plane perpendicular to the first light beam to be detected in a distal position area;

[0025] The calculation module determines the parallelism between each second light beam to be detected and the first light beam to be detected based on the proximal imaging information and the distal imaging information; when it is determined that the second light beam to be detected is not parallel to the first light beam to be detected, the calculation module calculates the angle θ between the second light beam to be detected and the first light beam to be detected, and performs angle compensation on the emission angle of the second light beam to be detected based on the calculated angle θ.

[0026] Optionally, the method for the detection module to receive and measure proximal-end imaging information includes:

[0027] When the n-1 second light beams to be detected emitted by the multi-axis interferometer are moved to a preset imaging position within the proximal position area where the detection module is fixed using a beam merging fixture, the detection module can simultaneously image one first light beam to be detected and at least one of the n-1 second light beams to be detected;

[0028] The detection module is fixed at the preset imaging position in the proximal position area, and the proximal imaging information received and measured by the detection module is the distance A1 between the coordinates of the imaging center position of the first light beam to be detected and the corresponding second light beam to be detected;

[0029] The method for the detection module to receive and measure remote imaging information includes:

[0030] When the n-1 second light beams to be detected emitted by the multi-axis interferometer are moved to a preset imaging position within the distal position area where the detection module is fixed using a beam merging fixture, the detection module can simultaneously image one first light beam to be detected and at least one of the n-1 second light beams to be detected;

[0031] The detection module is fixed at the preset imaging position in the remote position area, and the detection module receives and measures the remote imaging information as the distance A2 between the coordinates of the imaging center position of the first light beam to be detected and the corresponding second light beam to be detected;

[0032] Calculate whether A1 and A2 are equal. If A1 and A2 are equal, determine that the first light beam to be detected and the corresponding second light beam to be detected are parallel. If A1 and A2 are not equal, calculate the angle θ between the first light beam to be detected and the corresponding second light beam to be detected, and perform angle compensation according to the calculated angle θ corresponding to the emission angle of the second light beam to be detected.

[0033] Optionally, the method for the detection module to receive and measure proximal-end imaging information includes:

[0034] After the detection module is moved perpendicularly to the x-direction in the proximal position area until the first light beam to be detected forms an image at the center point of the camera, the detection module is moved perpendicularly to the x-direction by a preset distance with the position as the center position, and then receives and measures the proximal imaging information, which is the distance A1 between the imaging coordinates of one of the n-1 second light beams to be detected on the camera and the center point, where the preset distance is the designed optical axis spacing between the first light beam to be detected and the second light beam to be detected;

[0035] The method for the detection module to receive and measure remote imaging information includes:

[0036] The detection module is moved perpendicularly to the x-direction in the far-end position area until the first light beam to be detected forms an image at the center point of the camera. The detection module is moved perpendicularly to the x-direction by the designed optical axis distance with the position as the center position, and then receives and measures the far-end imaging information as the distance A2 between the imaging coordinates of one of the n-1 second light beams to be detected and the center point;

[0037] Calculate whether A1 and A2 are equal. If A1 and A2 are equal, determine that the first light beam to be detected and the corresponding second light beam to be detected are parallel. If A1 and A2 are not equal, calculate the angle θ between the first light beam to be detected and the corresponding second light beam to be detected, and perform angle compensation on the emission angle of the second light beam to be detected according to the calculated angle θ.

[0038] Optionally, the method for calculating the angle θ between the first light beam to be detected and the corresponding second light beam to be detected is as follows: the calculation module receives the proximal imaging information A1 and the distal imaging information A2 obtained by the detection module, and calculates the angle between the second light beam to be detected and the first light beam to be detected according to A1 and A2. , where B is the pixel size of the camera in the detection module, L1 is the distance between the imaging position of the detection module in the proximal position area and the exit hole of the multi-axis interferometer, and L2 is the distance between the imaging position of the detection module in the distal position area and the exit hole of the multi-axis interferometer.

[0039] Optionally, the method for adjusting the mirror angle of the camera in the detection module includes:

[0040] A reflective module is detachably mounted on the detection module, wherein the reflective module includes a camera mirror bracket and a reflective mirror, wherein the camera mirror bracket is mounted on the camera mirror surface of the detection module, and the reflective mirror is located on the camera mirror bracket so that the reflective mirror is parallel to the camera mirror surface;

[0041] The detection module is moved perpendicularly to the first light beam to be detected from a first position in a far-end position area or a near-end position area to a second position, the distance between the first position and the second position is fixed, the reflector fixedly mounted on the detection module can receive the first light beam to be detected at both the first position and the second position, and the first reflected light beam and the second reflected light beam after the first light beam to be detected is reflected by the reflector at the first position and the second position can be received by a multi-axis interferometer; the multi-axis interferometer receives the first reflected light beam reflected from the first position and the second reflected light beam reflected from the second position, and measures the reflection displacement between the first reflected light beam and the second reflected light beam received by the multi-axis interferometer; the mirror angle of the camera mounted parallel to the reflector is rotated until the reflection displacement is minimized, it is determined that the mirror of the camera is perpendicular to the first light beam to be detected at this time, and the angular position of the mirror of the camera is fixed at this time;

[0042] After the camera adjustment is completed, the reflection module is removed.

[0043] As described above, the multi-axis interferometer parallelism detection system and detection method of the present invention have the following beneficial effects:

[0044] The present invention can accurately measure the parallelism of the beam of the multi-axis interferometer by comparing the imaging information of the near-end and far-end detection modules. The measurement accuracy is high and the repeatability is strong, and the measurement results are highly effective.

[0045] The present invention adjusts the perpendicularity between the camera mirror and the optical axis of the first light beam to be detected by using corresponding reflective modules arranged at the distal and proximal ends, thereby further ensuring the accuracy and repeatability of the light beam parallelism measurement.

[0046] The present invention uses a beam merging tool to converge the beams of the multi-axis interferometer into a smaller area, so that the camera can image the two beams to be detected without moving, thereby improving the convenience of detection;

[0047] The present invention adjusts the collimation effect of the beam shaping module by adjusting the imaging beam radius of the near-end and far-end detection modules, thereby further improving the detection accuracy of the parallelism of the multi-axis interferometer beam. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It shows a schematic structural diagram of the multi-axis interferometer parallelism detection system in Example 1 of the present invention.

[0049] Figure 2 It shows a structural schematic diagram of the direction of the multi-axis interferometer output light beam in the multi-axis interferometer parallelism detection system in an example of embodiment 1 of the present invention.

[0050] Figure 3It shows a structural schematic diagram of the beam shaping module of the multi-axis interferometer parallelism detection system in Example 1 of the present invention.

[0051] Figure 4 It shows a schematic structural diagram of a detection module of a multi-axis interferometer parallelism detection system in Example 1 of the present invention.

[0052] Figure 5 It is a schematic structural diagram of the reflective module installed in the detection module of the multi-axis interferometer parallelism detection system in Example 1 of the present invention.

[0053] Figure 6 It shows a schematic structural diagram of a detection module and a reflection module in a multi-axis interferometer parallelism detection system according to embodiment 1 of the present invention.

[0054] Figure 7 It shows a schematic structural diagram of the detection module and the reflection module in the near-end position area in the multi-axis interferometer parallelism detection method of Example 1 of the present invention.

[0055] Figure 8 It shows a schematic diagram of the structure of the detection module and the reflection module in the remote position area in the multi-axis interferometer parallelism detection method of Example 1 of the present invention.

[0056] Figure 9 It shows a schematic diagram of the principle of calculating the angle in the multi-axis interferometer parallelism detection method of Example 1 of the present invention.

[0057] Figure 10 It shows a schematic diagram of the principle of calculating the approximate angle in the multi-axis interferometer parallelism detection method in Example 1 of the present invention.

[0058] Figure 11 It is a schematic diagram showing the adjustment of the camera mirror angle in the multi-axis interferometer parallelism detection method according to the first embodiment of the present invention.

[0059] Figure 12 It is a schematic diagram showing the principle of determining the camera mirror slope in the multi-axis interferometer parallelism detection method in embodiment 1 of the present invention.

[0060] Figure 13 It shows a schematic structural diagram of a multi-axis interferometer exit hole in a multi-axis interferometer parallelism detection system according to embodiment 2 of the present invention.

[0061] Figure 14 It shows a schematic structural diagram of the light beam merging tooling in the multi-axis interferometer parallelism detection system of embodiment 2 of the present invention.

[0062] Figure 15 It shows a schematic diagram of the structure of the light beam merging fixture outputting the light beam in the multi-axis interferometer parallelism detection system of embodiment 2 of the present invention.

[0063] Figure 16 It is a schematic diagram showing the principle of the multi-axis interferometer parallelism detection method according to the second embodiment of the present invention.

[0064] Explanation of Figure Numbers

[0065] 11. Light source module; 12. Beam shaping module; 13. Multi-axis interferometer; 14. Angle deflection structure; 15. Near-end position area; 16. Far-end position area; 17. Detection module; 17a. Near-end detection module; 17b. Far-end detection module; 18. Reflection module; 18a. Near-end reflection module; 18b. Far-end reflection module;

[0066] 21. Linear polarizer; 22. Converging lens; 23. Light exit aperture; 24. Collimating lens; 30, 31, 32. Exit apertures;

[0067] 41. Positioning hole; 42. Camera; 45. Reflector; 451. First reflected beam; 452. Second reflected beam; 46. Camera mirror bracket;

[0068] 51. Laser beam; 52. Single polarized light; 53. Converging light beam; 54. Collimated light beam; 55. Incident light; 56. First light beam to be detected; 57, 58. Second light beam to be detected;

[0069] 71. Joining tooling plate; 72, 73. Rhombic prisms; 74, 75, 76. Clear apertures. DETAILED DESCRIPTION

[0070] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0071] For example, when describing the embodiments of the present invention, schematic diagrams illustrating device structures may be partially enlarged for ease of explanation. These schematic diagrams are merely illustrative and should not limit the scope of the present invention. Furthermore, in actual production, three-dimensional dimensions, including length, width, and depth, should be included.

[0072] For convenience of description, spatially relative terms such as "under," "below," "below," "below," "above," and "upper" may be used herein to describe the relationship of one element or feature to other elements or features shown in the drawings. It will be understood that these spatially relative terms are intended to encompass other orientations of the device in use or operation in addition to the orientation depicted in the drawings.

[0073] In the context of the present application, a structure described as a first feature being "above" a second feature may include embodiments where the first and second features are in direct contact, and may also include embodiments where additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

[0074] It should be noted that the diagrams provided in this embodiment are only used to schematically illustrate the basic concept of the present invention. Therefore, the diagrams only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complex. The quantity range given in the present invention defaults to including the two boundary values ​​of the quantity range without special restrictions. Example 1

[0075] This embodiment provides a multi-axis interferometer 13 parallelism detection system, such as Figures 1 to 8 As shown, the detection system includes: a light source module 11, a beam shaping module 12, a multi-axis interferometer 13, a detection module 17 and a calculation module (not shown);

[0076] The laser beam 51 emitted by the light source module 11 is shaped into a collimated single-polarized incident light 55 by the beam shaping module 12. The incident light 55 enters the multi-axis interferometer 13 and is divided into n beams, including a first detection beam 56 and n-1 second detection beams 57, where n is an integer greater than or equal to 2. The x-direction is preset, and the optical axis of the first detection beam 56 is parallel to the x-direction.

[0077] The detection module 17 is used to receive and measure the proximal imaging information and the distal imaging information of the first light beam to be detected 56 and the second light beam to be detected 57 on the imaging plane perpendicular to the x-direction in the proximal position area 15 and the distal position area 16; the distance between the distal position area 16 and the multi-axis interferometer 13 along the x-direction is greater than the distance between the proximal position area 15 and the multi-axis interferometer 13 along the x-direction;

[0078] The calculation module is connected to the detection module 17 and is used to obtain the parallelism between the second light beam to be detected 57 and the first light beam to be detected 56 according to the proximal imaging information and the distal imaging information.

[0079] The present invention sets a detection module 17 to measure the proximal imaging information and distal imaging information of the first light beam to be detected 56 and the second light beam to be detected 57 on the imaging surface perpendicular to the x-direction in the proximal position area 15 and the distal position area 16. Since the first light beam to be detected 56 and the second light beam to be detected 57 are not parallel, the distance between the first light beam to be detected 56 and the second light beam to be detected 57 in the direction perpendicular to the first light beam to be detected 56 at different positions (the proximal position area 15 and the distal position area 16) is different. Therefore, whether the first light beam to be detected 56 and the second light beam to be detected 57 are parallel can be judged based on whether the distance between the first light beam to be detected 56 and the second light beam to be detected 57 obtained from the proximal imaging information and the distal imaging information is equal.

[0080] Specifically, Figure 1 Only one first light beam to be detected 56 and one second light beam to be detected 57 are shown in the figure. In actual application, the number of second light beams to be detected 57 can be set according to needs.

[0081] Specifically, Figure 1 In the figure, the movement of the detection module 17 between two different positions is shown for imaging the first light beam 56 to be detected and the second light beam 57 to be detected, and a dotted line guide is set between the light beam and the detection module 17. The actual detection module 17 needs to be positioned according to the imaging requirements in the detection method, and the light beam does not necessarily need to be offset before imaging.

[0082] In one embodiment, Figure 2 As shown, the first light beam to be detected 56 and the second light beam to be detected 57 emitted by the multi-axis interferometer 13 can pass through the angle deflection structure 14 (such as a reflective mirror, etc.) to change the direction of the light path and then pass through the preset proximal position area 15 and distal position area 16 for imaging. At this time, the preset x-direction is parallel to the optical axis direction of the incident proximal position area 15 and distal position area 16 of the first light beam to be detected 56; when the size of the site is limited, the arrangement method in this embodiment can be adopted to shorten the light path and facilitate measurement.

[0083] In one embodiment, the multi-axis interferometer parallelism detection system further includes a displacement device (not shown in the figure); the detection module 17 is located on the displacement device, and the displacement device is used to drive the detection module 17 to move between the distal position area 16 and the proximal position area 15, and / or the displacement device is used to drive the detection module 17 to move within the distal position area 16 or the proximal position area 15.

[0084] In one embodiment, the displacement device is a nano-scale piezoelectric displacement stage.

[0085] The present invention provides a displacement device to move the detection module 17, thereby accurately controlling the moving distance and direction of the detection module 17, thereby making the obtained measurement result more accurate.

[0086] In one embodiment, the light source module 11 is a dual-frequency laser, and the emitted laser beam 51 is orthogonal dual-polarized light and has interference rings.

[0087] In one embodiment, Figure 3 As shown, the beam shaping module 12 includes a linear polarizer 21, a converging lens 22, a light exit hole 23 and a collimating lens 24 arranged in sequence along the x direction;

[0088] The laser beam 51 emitted by the light source module 11 is adjusted to single polarized light 52 after entering the linear polarizer 21. The single polarized light 52 is converged into a convergent light beam 53 after entering the converging lens 22. The convergent light beam 53 is emitted as a collimated light beam 54 from the light exit hole 23 and is collimated after entering the collimating lens 24 to obtain a collimated single polarized incident light 55.

[0089] The present invention polarizes, converges and collimates the laser beam 51 in sequence by arranging the linear polarizer 21, the converging lens 22, the light exit hole 23 and the collimating lens 24 in the beam shaping module 12, thereby obtaining the incident light 55 emitted by the multi-axis interferometer 13 when it is in normal use, and shaping the chaotic irregular light beam into a better circular regular light spot, which is convenient for collecting the beam imaging information when detecting parallelism, improves the detection accuracy, and enables the laser after parallelism detection to be used in actual production.

[0090] Specifically, the beam shaping module 12 is located between the exit port of the light source module 11 and the entrance port of the multi-axis interferometer 13 .

[0091] In one embodiment, the linear polarizer 21 is used to adjust the laser beam 51 to horizontal linear polarized light to prevent the dual polarized light beams emitted by the light source module 11 from generating interference fringes that affect image recognition, thereby further ensuring the accuracy and effectiveness of the parallelism detection results.

[0092] In one embodiment, Figure 3 As shown, the collimating lens 24 has the same parameters as the converging lens 22, the focal length of the converging lens 22 is f, the aperture of the light exit hole 23 is D1, the beam diameter of the laser beam 51 incident on the beam shaping module 12 is D2, and .

[0093] Specifically, λ is the wavelength of the laser beam 51 .

[0094] In one embodiment, the position of the collimating lens 24 is adjusted to achieve the best collimation effect. Specifically, the collimated light beam 54 emitted from the collimating lens 24 is imaged directly on the detection module 17 in the near-end position area 15 and the far-end position area 16, respectively, to obtain the near-end collimated image and the far-end collimated image. In the calculation module, 1 / e of the intensity of the near-end collimated image and the far-end collimated image is used. 2 As the beam radius, the difference between the beam radius of the near-end collimated image and the beam radius of the far-end collimated image is compared, and the collimating lens 24 is moved back and forth along the optical axis of the collimated beam 54. When the difference between the beam radius of the near-end collimated image and the beam radius of the far-end collimated image is minimized, it indicates that the optimal collimation effect has been achieved. The position of the collimating lens 24 at this time is fixed to obtain the incident light 55 entering the multi-axis interferometer 13. Specifically, e is an irrational constant.

[0095] The present invention can further optimize the collimation effect of the beam shaping module 12 by setting the relationship between the aperture of the light exit hole 23 and the beam diameter of the laser beam 51, thereby improving the detection accuracy of the beam parallelism of the multi-axis interferometer 13.

[0096] In one embodiment, Figure 4 As shown, the detection module 17 includes a positioning hole 41 and a camera 42 . The positioning hole 41 is used to enable the light beam incident on the camera 42 to form an image in the central area of ​​the camera 42 .

[0097] The present invention sets a positioning hole 41 so that the light beam incident on the camera 42 is imaged in the central area of ​​the camera 42, and limits the position where the light beam to be detected reaches the camera 42, thereby ensuring the repeatability of the detection result, and the validity of the test result can be verified through multiple measurements to obtain more accurate detection results.

[0098] Specifically, Figure 1 FIG. 4 shows the positioning hole 41 and the camera 42 in the detection module 17 moving between two different positions, rather than two detection modules 17 being placed at the same time.

[0099] In one embodiment, Figure 5 and Figure 7 As shown, the multi-axis interferometer parallelism detection system also includes a reflection module 18, which includes a camera mirror bracket 46 and a reflector 45 that are detachably mounted on the mirror surface of the camera 42 of the detection module 17. The reflector 45 is mounted on the side of the camera mirror bracket 46 away from the camera 42. The first light beam 56 to be detected can be reflected to the multi-axis interferometer 13 through the reflector 45.

[0100] The present invention provides a camera mirror bracket 46 detachably mounted on the mirror surface of the camera 42 and a reflector 45 placed on the camera mirror bracket 46 in the reflection module 18. The camera mirror bracket 46 provides fixed support for the reflector 45 and makes the reflector 45 parallel to the mirror surface of the camera 42. Therefore, the reflected light reflected back to the multi-axis interferometer 13 by the reflector 45 can be used to judge whether the mirror surface of the camera 42 and the first light beam to be detected 56 are perpendicular, so as to reduce the distance difference between the first light beam to be detected 56 and the second light beam to be detected 57 to the detection module 17 caused by the slope error of the installation of the camera 42, ensure that the mirror surface of the camera 42 is perpendicular to 56, so that the imaging information obtained by the camera 42 can more accurately reflect the parallelism of the light beam of the multi-axis interferometer 13.

[0101] Preferably, the precision of the reflector 45 is at the nanometer level.

[0102] In one embodiment, Figure 6 As shown, the proximal position area 15 and the distal position area 16 respectively have corresponding proximal detection modules 17a, proximal reflection modules 18a, distal detection modules 17b and distal reflection modules 18b. The proximal detection modules 17a and proximal reflection modules 18a obtain proximal imaging information, and the distal detection modules 17b and distal reflection modules 18b obtain distal imaging information. When collecting distal imaging information, the proximal detection modules 17a and proximal reflection modules 18a are removed.

[0103] In another embodiment, Figure 7-Figure 8 As shown, only one detection module 17 and one reflection module 18 are provided, which move between the near-end position area 15 and the far-end position area 16 to obtain near-end imaging information and far-end imaging information respectively, as shown in FIG. Figure 7 FIG. 1 is a schematic diagram showing the detection module 17 and the reflection module 18 obtaining proximal imaging information in the proximal position area 15. Figure 8 It is a schematic diagram showing the detection module 17 and the reflection module 18 obtaining distal imaging information in the distal position area 16 .

[0104] like Figure 7-Figure 8 As shown, this embodiment further provides a method for detecting the parallelism of a multi-axis interferometer 13. The detection method uses any of the above-mentioned multi-axis interferometer 13 detection systems to perform parallelism detection on the multi-axis interferometer 13. The detection method includes:

[0105] The light source module 11 emits a laser beam 51, which is shaped into a collimated single-polarized incident light 55 by the beam shaping module 12. The incident light 55 enters the multi-axis interferometer 13 and is divided into a first detection beam 56 and n-1 second detection beams 57, where n is an integer greater than or equal to 2.

[0106] Adjust the mirror angle of the camera 42 in the detection module 17 so that the mirror of the camera 42 is perpendicular to the first light beam 56 to be detected;

[0107] like Figure 7 As shown, the detection module 17 receives and measures the proximal imaging information of the first light beam to be detected 56 and each second light beam to be detected 57 on the imaging plane perpendicular to the first light beam to be detected 56 in the proximal position area 15; Figure 8 As shown, the detection module 17 receives and measures the distal imaging information of the first light beam to be detected 56 and each second light beam to be detected 57 on the imaging plane perpendicular to the first light beam to be detected 56 in the distal position area 16;

[0108] The calculation module determines the parallelism between each second light beam to be detected 57 and the first light beam to be detected 56 based on the proximal imaging information and the distal imaging information; when it is determined that the second light beam to be detected 57 is not parallel to the first light beam to be detected 56, the angle θ between the second light beam to be detected 57 and the first light beam to be detected 56 is calculated, and the angle compensation is performed on the emission angle of the second light beam to be detected 57 based on the calculated angle θ.

[0109] Specifically, the proximal imaging information of the first light beam to be detected 56 and each second light beam to be detected 57 on the imaging plane perpendicular to the first light beam to be detected 56 in the proximal position area 15 is the distance between the centers of the light spots of the light spot image diagram of the first light beam to be detected 56 and the second light beam to be detected 57 of the camera 42 in the detection module 17 in the proximal position area 15.

[0110] Specifically, since the multi-axis interferometer 13 divides the incident light 55 into multiple light beams, one of them (the first light beam to be detected 56) is used as a reference light beam for judging the parallelism of the light beam. The x-direction is confirmed based on the optical axis direction of the first light beam to be detected 56 as the reference light beam to obtain the respective angles between the other light beams (n-1 second light beams to be detected 57) and the first light beam to be detected 56, so as to calculate and compensate the subsequent detection results of the multi-axis interferometer and correct the detection results of the multi-axis interferometer.

[0111] The present invention utilizes the proximal position and the distal position to amplify the distance perpendicular to the x-direction between the first light beam to be detected 56 and the second light beam to be detected 57 when they are not parallel, thereby amplifying the light beam angle that is originally difficult to clearly distinguish with the naked eye, and making the detection result of the multi-axis interferometer more accurate after correction.

[0112] Preferably, if Figure 7 As shown, the distance between the detection module 17 and the multi-axis interferometer 13 when receiving the proximal imaging information in the proximal position area 15 is L1, as shown in FIG. Figure 8As shown, when the detection module 17 receives the far-end imaging information in the far-end position area 16 , the distance between the detection module 17 and the multi-axis interferometer 13 is L2 , and L2 is much larger than L1 .

[0113] In one embodiment, the distance L1 between the detection module 17 and the multi-axis interferometer 13 is less than 100 mm when the detection module 17 receives proximal imaging information in the proximal position area 15, and the distance L2 between the detection module 17 and the multi-axis interferometer 13 is greater than 5000 mm when the detection module 17 receives distal imaging information in the distal position area 16.

[0114] In one embodiment, L2 can be a distance preset in the experiment or a distance measured in an actual experiment. The latter may yield a result with higher accuracy and may be selected based on the requirements of detection accuracy.

[0115] It should be noted that the above sequence does not strictly represent the sequence of the method for detecting the parallelism of the multi-axis interferometer 13 protected by the present invention, and those skilled in the art may change it according to the actual detection steps.

[0116] In one embodiment, the method for the detection module 17 to receive and measure proximal imaging information includes:

[0117] like Figure 7 As shown, after the detection module 17 is moved perpendicularly to the x-direction in the proximal position area 15 until the first light beam to be detected 56 forms an image at the center point of the camera 42, the detection module 17 moves perpendicularly to the x-direction by a preset distance with this position as the center position, and then receives and measures the proximal imaging information, which is the distance A1 between the imaging coordinates of one of the n-1 second light beams to be detected 57 on the camera 42 and the center point. The preset distance is the designed optical axis spacing between the first light beam to be detected 56 and the second light beam to be detected 57.

[0118] The method for the detection module 17 to receive and measure remote imaging information includes:

[0119] like Figure 8 As shown, the detection module 17 is moved perpendicularly to the x-direction in the far-end position area 16 until the first light beam to be detected 56 forms an image at the center point of the camera 42. The detection module 17 is moved perpendicularly to the x-direction by the designed distance of the optical axis with this position as the center position, and then receives and measures the far-end imaging information as the distance A2 between the imaging coordinates of one of the n-1 second light beams to be detected 57 on the camera 42 and the center point.

[0120] Calculate whether A1 is equal to A2. If so, determine that the first light beam to be detected 56 is parallel to the corresponding second light beam to be detected 57. If A1 is not equal to A2, calculate the angle θ between the first light beam to be detected 56 and the corresponding second light beam to be detected 57, and perform angle compensation on the emission angle of the second light beam to be detected 57 according to the calculated angle θ.

[0121] By obtaining a highly accurate and effective parallelism detection result, the present invention can compensate or correct the influence caused by the non-parallelism of the light beams in the subsequent data processing and displacement solution process according to the calculated angle between the light beams, thereby ensuring the accuracy of the final measurement result of the multi-axis interferometer 13.

[0122] Specifically, Figure 7-Figure 8 The two positions of the detection module 17 during the detection process are shown in the same figure. In practice, the detection module 17 needs to be moved to various positions.

[0123] Preferably, if Figure 9 As shown, when the detection module 17 moves a preset distance perpendicular to the x-direction, the direction of movement of the detection module 17 is parallel to the direction of the optical axis spacing line E, and the direction of the optical axis spacing line is the direction of the line E between the two corresponding exit holes designed when the first light beam to be detected 56 and the light beam to be detected are emitted from the multi-axis interferometer 13.

[0124] In one embodiment, Figure 9 As shown, the direction of the optical axis spacing line is the y direction in the figure, and can also be other corresponding optical axis spacing line directions.

[0125] In one embodiment, the detection module 17 is moved perpendicular to the x-direction until the first light beam to be detected 56 is imaged by the camera 42, and imaging may not be performed at the center point of the camera 42. However, this will increase the complexity of the subsequent calculation of the imaging positions of the first light beam to be detected 56 and the second light beam to be detected 57 on the camera 42, and will be more likely to produce calculation errors.

[0126] Specifically, the designed optical axis spacing is the optical axis spacing between the first light beam to be detected 56 and the second light beam to be detected 57 for comparison set by the multi-axis interferometer 13 , and is a fixed ideal parameter value.

[0127] Specifically, if Figure 9As shown, since the detection module 17 moves the same optical axis design spacing E perpendicular to the x-direction at the near-end position and the far-end position, the imaging positions of the first light beam 56 to be detected and the second light beam 57 to be detected on the camera 42 are used to judge whether the first light beam 56 to be detected and the second light beam 57 to be detected can still maintain the optical axis design value of the output multi-axis interferometer 13 when they are away from the multi-axis interferometer 13; at the same time, if only the near-end position is judged, the visible distance may not be displayed due to the small angle between the first light beam 56 to be detected and the second light beam 57 to be detected, resulting in a wrong judgment of parallelism. Therefore, the present invention compares the imaging position difference by setting the near-end position and the far-end position, so as to further improve the detection accuracy of the parallelism of the light beams, thereby improving the measurement accuracy of the multi-axis interferometer 13.

[0128] In one embodiment, Figure 9 As shown, the method for calculating the angle θ between the first light beam to be detected 56 and the corresponding second light beam to be detected 57 is as follows: the calculation module receives the proximal imaging information A1 and the distal imaging information A2 obtained by the detection module 17, and calculates the angle between the second light beam to be detected 57 and the first light beam to be detected 56 according to A1 and A2. , where B is the pixel size of the camera 42 in the detection module 17, L1 is the distance between the imaging position of the detection module 17 in the proximal position area 15 and the exit hole of the multi-axis interferometer 13, and L2 is the distance between the imaging position of the detection module 17 in the distal position area 16 and the exit hole of the multi-axis interferometer 13. Specifically, the calculation principle is as follows:

[0129] like Figure 9As shown, the first light beam to be detected 56 is translated perpendicularly to the x-direction by an optical axis design spacing E to obtain a straight line l, the first light beam to be detected 56 is the imaging center point O of the camera 42 in the near-end position area 15, and the point P reached after point O is translated perpendicularly to the x-direction by an optical axis design spacing is the position of the imaging center point of the camera 42 after the detection module 17 is translated, at this time, the imaging position of the second light beam to be detected 57 in the near-end position area 15 of the camera 42 is point P1, the imaging distance between point P and point P1 is A1, and the actual distance between point P and point P1 is the product A1B of A1 and the pixel B of the camera 42; similarly, the imaging center point M of the first light beam to be detected 56 in the far-end position area 16 of the camera 42 is obtained, and point M is translated perpendicularly to the x-direction by an optical axis design spacing Point N reached after distance E is the position of the imaging center point of the corresponding camera 42 after the detection module 17 is translated. At this time, the imaging position of the second light beam 57 to be detected in the camera 42 in the far-end position area 16 is point N1, the imaging distance between point N and point N1 is A2, and the actual distance between point N and point N1 is the product A2B of A2 and the pixel B of the camera 42; an end line i is made from point P1 along the direction parallel to the first light beam 56 to be detected, and the end line i intersects NN1 at point Q to obtain a triangle P1QN1. From the figure, it can be seen that the distance corresponding to (A2-A1)×B, the angle θ between the first light beam 56 to be detected and the second light beam 57 to be detected, and the spacing L2-L1 between the near-end position area 15 and the far-end position area 16 can be obtained by using the tangent angle relationship in the triangle. .

[0130] In one embodiment, Figure 10 As shown, since L2 is much larger than L1, when the accuracy requirement is low, L2-L1≈L2 can be approximated as .

[0131] In one embodiment, the method for adjusting the mirror angle of the camera 42 in the detection module 17 includes:

[0132] like Figure 5 and Figure 7 As shown, the detection module 17 is detachably mounted with a fixed reflective module 18, which includes a camera mirror bracket 46 and a reflective mirror 45. The camera mirror bracket 46 is mounted on the mirror surface of the camera 42 of the detection module 17, and the reflective mirror 45 is located on the camera mirror bracket 46 so that the reflective mirror 45 is parallel to the mirror surface of the camera 42.

[0133] like Figure 11As shown, the detection module 17 is moved from a first position in the distal position area 16 or the proximal position area 15 to a second position perpendicularly to the first light beam to be detected 56, and the distance between the first position and the second position is fixed. The reflector 45 fixedly mounted on the detection module 17 can receive the first light beam to be detected 56 at both the first position and the second position, and the first reflected light beam 451 and the second reflected light beam 452 after the first light beam to be detected 56 is reflected by the reflector 45 at the first position and the second position can be received by the multi-axis interferometer 13; the multi-axis interferometer 13 receives the first reflected light beam 451 reflected from the first position and the second reflected light beam 452 reflected from the second position, and measures the reflection displacement ΔC between the first reflected light beam 451 and the second reflected light beam 452 received by the multi-axis interferometer 13; the mirror angle of the camera 42 mounted parallel to the reflector 45 is rotated until the reflection displacement is minimized, and it is determined that the mirror surface of the camera 42 is perpendicular to the first light beam to be detected 56 at this time, and the angular position of the mirror surface of the camera 42 at this time is fixed;

[0134] After the camera 42 is adjusted, the reflection module 18 is removed.

[0135] The present invention installs a reflection module 18 to fix the reflector 45 and the mirror surface of the camera 42 in parallel, uses the reflector 45 to reflect the light beam emitted by the multi-axis interferometer 13 and then is received by the multi-axis interferometer 13, and uses the effect of the light reflected by the mirror surface of the camera 42, which is not perpendicular to the first light beam 56 to be detected, being offset after being translated perpendicular to the first light beam 56 to enlarge the angle between the mirror surface of the camera 42 and the first light beam 56 to be detected, so that the mirror surface of the camera 42 can be accurately adjusted to be perpendicular to the first light beam 56 to be detected, reducing the deviation of the detection result caused by the slope error of the mirror surface of the camera 42, so that the imaging information obtained by measuring the mirror surface of the camera 42 can more accurately reflect the parallelism between the light beams.

[0136] like Figure 12 As shown, the left figure is the reflection path when the mirror surface of the reflector 45 is perpendicular to the x-direction. It can be seen that moving the mirror surface of the reflector 45 from C1 to C2 perpendicular to the x-direction does not cause a reflection displacement ΔC, and the reflection displacement ΔC is always 0; the right figure is the reflection path when there is a slope error between the mirror surface of the reflector 45 and the direction perpendicular to the x-direction. It can be seen that moving the mirror surface of the reflector 45 from C1 to C2 perpendicular to the x-direction (the same translation distance G as in the left figure) will produce a reflection displacement ΔC, and the smaller the slope between the mirror surface of the reflector 45 and the direction perpendicular to the x-direction, the closer the reflection displacement ΔC is to 0.

[0137] In one embodiment, the reflection module 18 is moved along with the detection module 17 to a position where the distance between the reflection module 18 and the multi-axis interferometer 13 is less than 100 mm to adjust the angle of the camera 42 mirror in the proximal position area 15, and the reflection module 18 is moved along with the detection module 17 to a position where the distance between the reflection module 18 and the multi-axis interferometer 13 is greater than 5000 mm to adjust the angle of the camera 42 mirror in the distal position area 16.

[0138] Specifically, the distance between the reflection module 18 and the multi-axis interferometer 13 is not a fixed value and needs to be arranged according to the measurement result so that the multi-axis interferometer 13 can obtain the reflected light beam of the reflector 45 .

[0139] In one embodiment, a reflection module 18 is first set in the far-end position area 16 to minimize the reflection displacement measured by the multi-axis interferometer 13; then, a reflection module 18 is set in the near-end position area 15 to make the reflection displacement obtained by the multi-axis interferometer 13 as close to 0 as possible, so as to eliminate the slope of the camera 42 mirror in the near-end position area 15 and the far-end position area 16. Example 2

[0140] This embodiment provides a multi-axis interferometer 13 parallelism detection system. Other features of the multi-axis interferometer 13 parallelism detection system are substantially the same as those of the first embodiment, except that:

[0141] In this embodiment, Figure 13 As shown, the multi-axis interferometer 13 includes n exit holes;

[0142] The inspection system also includes beam combining tools, such as Figure 14 As shown, the beam merging fixture includes a merging fixture plate 71 and n-1 rhombic prisms. The merging fixture plate 71 includes n light holes, and the positions of the n light holes correspond one to one with the positions of the n exit holes. The n-1 rhombic prisms are respectively fixed to the side of the n-1 light holes away from the multi-axis interferometer 13;

[0143] like Figure 15 As shown, the n light beams emitted by the multi-axis interferometer 13 can pass through the corresponding light holes from the n exit holes respectively; the first light beam to be detected 56 passes through the corresponding light hole and enters the detection module 17, and n-1 second light beams to be detected 57, 58 ( Figure 15 2 are shown in FIG. 1 ) and then enter the detection module 17 after passing through the corresponding light holes and rhombus prisms.

[0144] In one embodiment, Figure 13 As shown, the multi-axis interferometer 13 has three exit holes 30, 31, and 32 for emitting the light beam to be detected; Figure 14As shown, the exit holes 30, 31, 32 correspond to the light holes 74, 75, 76 on the merging tooling plate 71, and rhombic prisms 72, 73 are fixed respectively at positions of the light holes 75, 76 on the merging tooling plate 71 away from the multi-axis interferometer 13; Figure 15 As shown, the second light beams to be detected 57 and 58 emitted from the exit holes 31 and 32 pass through the light holes 75 and 76 on the merging tooling plate 71 respectively, and then pass through the rhombus prisms 72 and 73 respectively to be converged to the detection module 17 for imaging; and the first light beam to be detected 56 emitted from the exit hole 30 passes through the light hole 74 on the merging tooling plate 71 and directly enters the detection module 17 for imaging, so that the three light beams are all converged to the detection module 17 at the same position for imaging.

[0145] The present invention offsets the second light beam to be detected 57 through a rhombus prism, so that the second light beam to be detected 57 is converged to the detection module 17. The imaging information of the first light beam to be detected 56 and the second light beam to be detected 57 can be measured without moving the detection module 17. At the same time, since the rhombus prism can achieve a translation effect with an unchanged light beam angle, the detection module 17 can still obtain the accurate parallelism between the first light beam to be detected 56 and the second light beam to be detected 57.

[0146] Specifically, if Figure 14 As shown, the exit hole of the beam merging fixture is located at the same position as the exit hole of the multi-axis interferometer 13 .

[0147] This embodiment further provides a method for detecting the parallelism of a multi-axis interferometer 13. The detection method uses the above-mentioned multi-axis interferometer 13 detection system to perform parallelism detection on the multi-axis interferometer 13. Other features of the detection method are substantially the same as those of the first embodiment, except that:

[0148] In this embodiment, Figure 15 As shown, the method for the detection module 17 to receive and measure proximal imaging information includes:

[0149] When the beam merging fixture moves the n-1 second beams to be detected 57 emitted by the multi-axis interferometer 13 to the preset imaging position where the detection module 17 is fixed in the proximal position area 15, the detection module 17 can simultaneously image the one first beam to be detected 56 and at least one of the n-1 second beams to be detected 57;

[0150] The detection module 17 is fixed at a preset imaging position in the proximal position area 15. The detection module 17 receives and measures the proximal imaging information as the distance A1 between the imaging center position coordinates of the first light beam 56 to be detected and the corresponding second light beam 57 to be detected;

[0151] The method for the detection module 17 to receive and measure remote imaging information includes:

[0152] When the beam merging fixture moves the n-1 second beams to be detected 57 emitted by the multi-axis interferometer 13 to the preset imaging position where the detection module 17 is fixed in the distal position area 16, the detection module 17 can simultaneously image the first beam to be detected 56 and at least one of the n-1 second beams to be detected 57;

[0153] The detection module 17 is fixed at a preset imaging position in the distal position area 16. The detection module 17 receives and measures the distal imaging information, which is the distance A2 between the imaging center position coordinates of the first light beam 56 to be detected and the corresponding second light beam 57 to be detected.

[0154] Calculate whether A1 is equal to A2. If so, determine that the first light beam to be detected 56 is parallel to the corresponding second light beam to be detected 57. If A1 is not equal to A2, calculate the angle θ between the first light beam to be detected 56 and the corresponding second light beam to be detected 57, and perform angle compensation according to the calculated angle θ corresponding to the emission angle of the second light beam to be detected 57.

[0155] The present invention sets a rhombus prism in the beam merging tooling so that the n-1 second light beams to be detected 57 emitted by the multi-axis interferometer 13 can be imaged together with the first light beam to be detected 56 at the same position where the detection module 17 is located. Therefore, it is not necessary to move the detection module 17 perpendicular to the x-direction to directly calculate the imaging distance between the first light beam to be detected 56 and any light beam to be detected at the preset imaging position of the detection module 17, thereby reducing the operations required for movement, improving the detection efficiency, and reducing the errors caused by the movement process, which can further improve the accuracy of the detection results.

[0156] Specifically, if Figure 16 As shown, due to the use of the beam merging fixture, the optical axis spacing e between the first light beam to be detected 56 and each second light beam to be detected 57 after passing through the beam merging fixture is greatly reduced, so that when in the near-end position area 15 or the far-end position area 16, the detection module 17 can directly measure at the same position to obtain the imaging distance A2-A1 of the first light beam to be detected 56 and the second light beam to be detected 57 in the camera 42, without moving an optical axis design spacing E to obtain the imaging information of the first light beam to be detected 56 and the second light beam to be detected 57.

[0157] In summary, the multi-axis interferometer parallelism detection system and detection method of the present invention can accurately measure the parallelism of the light beam of the multi-axis interferometer by comparing the imaging information of the near-end and far-end detection modules. The measurement accuracy is high and the repeatability is strong, and the measurement results are highly effective. At the same time, the vertical relationship between the camera mirror and the optical axis of the first light beam to be detected is adjusted by the reflection modules corresponding to the far-end and the near-end, so as to further ensure the accuracy and repeatability of the light beam parallelism measurement. In addition, the light beams of the multi-axis interferometer are converged in a smaller area through the beam merging tooling, so that the camera can image the two light beams to be detected without moving, thereby improving the convenience of detection. Finally, the collimation effect of the beam shaping module is adjusted by the imaging beam radius of the near-end and far-end detection modules, so as to further improve the detection accuracy of the parallelism of the light beam of the multi-axis interferometer.

[0158] Therefore, the present invention effectively overcomes various shortcomings of the prior art and has high industrial utilization value.

[0159] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A multi-axis interferometer parallelism detection system, characterized in that: The detection system comprises: a light source module (11), a beam shaping module (12), a multi-axis interferometer (13), a detection module (17) and a calculation module; The laser beam (51) emitted by the light source module (11) is shaped into collimated single-polarized incident light (55) by the beam shaping module (12), and the incident light (55) is incident on the multi-axis interferometer (13) and is divided into n beams, each of which includes one first beam to be detected (56) and n-1 second beams to be detected (57), where n is an integer greater than or equal to 2; an x-direction is preset, and the optical axis of the first beam to be detected (56) is parallel to the x-direction; The detection module (17) is used to receive and measure the proximal imaging information and the distal imaging information of the first light beam to be detected (56) and the second light beam to be detected (57) on an imaging surface perpendicular to the x-direction in a proximal position area (15) and a distal position area (16); the distance between the distal position area (16) and the multi-axis interferometer (13) along the x-direction is greater than the distance between the proximal position area (15) and the multi-axis interferometer (13) along the x-direction; The calculation module is connected to the detection module (17) and is used to obtain the parallelism between the second light beam to be detected (57) and the first light beam to be detected (56) based on the proximal imaging information and the distal imaging information.

2. The multi-axis interferometer parallelism detection system according to claim 1, characterized in that: The detection system further comprises a displacement device; the detection module (17) is located on the displacement device, and the displacement device is used to drive the detection module (17) to move between the distal position area (16) and the proximal position area (15), and / or the displacement device is used to drive the detection module (17) to move within the distal position area (16) or within the proximal position area (15).

3. The multi-axis interferometer parallelism detection system according to claim 1, characterized in that: The multi-axis interferometer (13) includes n exit holes (30); The multi-axis interferometer parallelism detection system further includes a beam merging tool, the beam merging tool including a merging tool plate (71) and n-1 rhombic prisms (72), the merging tool plate (71) including n light-through holes (74), the positions of the n light-through holes (74) corresponding to the positions of the n exit holes (30), and the n-1 rhombic prisms (72) are respectively fixed to a side of the n-1 light-through holes (74) away from the multi-axis interferometer (13); The n light beams emitted by the multi-axis interferometer (13) can respectively pass through the corresponding light-through holes (74) from the n exit holes (30); the first light beam to be detected (56) passes through the corresponding light-through hole (74) and then enters the detection module (17); and n-1 second light beams to be detected (57) respectively pass through the corresponding light-through hole (74) and the rhombus prism (72) and then enter the detection module (17).

4. The multi-axis interferometer parallelism detection system according to claim 1, characterized in that: The beam shaping module (12) comprises a linear polarizer (21), a converging lens (22), a light exit hole (23), and a collimating lens (24) arranged in sequence along the x-direction; The laser beam (51) emitted by the light source module is incident on the linear polarizer (21) and is adjusted to single polarized light (52). The single polarized light (52) is incident on the converging lens (22) and is converged into a convergent light beam (53). The convergent light beam (53) is emitted from the light exit hole (23) as a collimated light beam (54), and is incident on the collimating lens (24) and is collimated to obtain collimated single polarized incident light (55).

5. The multi-axis interferometer parallelism detection system according to claim 4, characterized in that: The collimating lens (24) has the same parameters as the converging lens (22), the focal length of the converging lens (22) is f, the aperture of the light exit hole (23) is D1, the beam diameter of the laser beam (51) incident on the beam shaping module (12) is D2, and , λ is the wavelength of the laser beam (51).

6. The multi-axis interferometer parallelism detection system according to claim 1, characterized in that: The detection module (17) comprises a positioning hole (41) and a camera (42), wherein the positioning hole (41) is used to enable a light beam incident on the camera (42) to form an image in a central area of ​​the camera (42).

7. The multi-axis interferometer parallelism detection system according to claim 6, characterized in that: The multi-axis interferometer parallelism detection system further includes a reflection module (18), wherein the reflection module (18) includes a camera mirror bracket (46) and a reflector (45) detachably mounted on the mirror surface of the camera (42) of the detection module (17), wherein the reflector (45) is mounted on a side of the camera mirror bracket (46) away from the camera (42), and the first light beam to be detected (56) can be reflected to the multi-axis interferometer (13) by the reflector (45).

8. A multi-axis interferometer parallelism detection method, characterized in that: The detection method uses the multi-axis interferometer (13) detection system according to any one of claims 1 to 7 to perform multi-axis interferometer parallelism detection, and the detection method includes: The light source module (11) emits a laser beam (51), and the laser beam (51) is shaped into a collimated single-polarized incident light (55) by the beam shaping module (12). The incident light (55) is incident on the multi-axis interferometer (13) and is divided into a first light beam to be detected (56) and n-1 second light beams to be detected (57), where n is an integer greater than or equal to 2. Adjusting the mirror angle of the camera (42) in the detection module (17) so that the mirror of the camera (42) is perpendicular to the first light beam (56) to be detected; The detection module (17) receives and measures proximal imaging information of the first light beam to be detected (56) and each of the second light beams to be detected (57) on an imaging plane perpendicular to the first light beam to be detected (56) in a proximal position area (15); the detection module (17) receives and measures distal imaging information of the first light beam to be detected (56) and each of the second light beams to be detected (57) on an imaging plane perpendicular to the first light beam to be detected (56) in a distal position area (16); The calculation module determines the parallelism between each second light beam to be detected (57) and the first light beam to be detected (56) according to the proximal imaging information and the distal imaging information; when it is determined that the second light beam to be detected (57) is not parallel to the first light beam to be detected (56), the angle θ between the second light beam to be detected (57) and the first light beam to be detected (56) is calculated, and angle compensation is performed on the emission angle of the second light beam to be detected (57) according to the calculated angle θ.

9. The multi-axis interferometer parallelism detection method according to claim 8, characterized in that: The method for the detection module (17) to receive and measure proximal imaging information includes: When the n-1 second light beams to be detected (57) emitted by the multi-axis interferometer (13) are moved to a preset imaging position where the detection module (17) is fixed in the proximal position area (15) by using a beam merging fixture, the detection module (17) can simultaneously image one first light beam to be detected (56) and at least one of the n-1 second light beams to be detected (57); The detection module (17) is fixed at the preset imaging position in the proximal position area (15), and the detection module (17) receives and measures the proximal imaging information, which is the distance A1 between the coordinates of the imaging center position of the first light beam to be detected (56) and the corresponding second light beam to be detected (57); The method for the detection module (17) to receive and measure remote imaging information includes: When the n-1 second light beams to be detected (57) emitted by the multi-axis interferometer (13) are moved to a preset imaging position where the detection module (17) is fixed in the remote position area (16) by using a beam merging fixture, the detection module (17) can simultaneously image one first light beam to be detected (56) and at least one of the n-1 second light beams to be detected (57); The detection module (17) is fixed at the preset imaging position in the remote position area (16), and the detection module (17) receives and measures the remote imaging information, which is the distance A2 between the coordinates of the imaging center position of the first light beam to be detected (56) and the corresponding second light beam to be detected (57); Calculate whether A1 is equal to A2. If A1 is equal to A2, determine that the first light beam to be detected (56) and the corresponding second light beam to be detected (57) are parallel. If A1 is not equal to A2, calculate the angle θ between the first light beam to be detected (56) and the corresponding second light beam to be detected (57), and perform angle compensation on the emission angle of the second light beam to be detected (57) according to the calculated angle θ.

10. The multi-axis interferometer parallelism detection method according to claim 8, characterized in that: The method for the detection module (17) to receive and measure proximal imaging information includes: The detection module (17) is moved perpendicularly to the x-direction in the near-end position area (15) until the first light beam to be detected (56) is imaged at the center point of the camera, and the detection module (17) is moved perpendicularly to the x-direction by a preset distance with the position as the center position, and then receives and measures the near-end imaging information as the distance A1 between the imaging coordinates of one of the n-1 second light beams to be detected (57) and the center point of the camera, wherein the preset distance is the optical axis design spacing between the first light beam to be detected (56) and the second light beam to be detected (57); The method for the detection module (17) to receive and measure remote imaging information includes: After the detection module (17) is moved perpendicularly to the x-direction in the remote position area (16) until the first light beam to be detected (56) is imaged at the center point of the camera, the detection module (17) is moved perpendicularly to the x-direction by the optical axis design spacing with the position as the center position, and receives and measures the remote imaging information as the distance A2 between the imaging coordinates of the camera and the center point of one of the n-1 second light beams to be detected (57); Calculate whether A1 is equal to A2. If A1 is equal to A2, determine that the first light beam to be detected (56) and the corresponding second light beam to be detected (57) are parallel. If A1 is not equal to A2, calculate the angle θ between the first light beam to be detected (56) and the corresponding second light beam to be detected (57), and perform angle compensation on the emission angle of the second light beam to be detected (57) according to the calculated angle θ.

11. The multi-axis interferometer parallelism detection method according to claim 9 or 10, characterized in that: The method for calculating the angle θ between the first light beam to be detected (56) and the corresponding second light beam to be detected (57) is as follows: the calculation module receives the proximal imaging information A1 and the distal imaging information A2 obtained by the detection module (17), and calculates the angle between the second light beam to be detected (57) and the first light beam to be detected (56) according to A1 and A2. , where B is the pixel size of the camera in the detection module (17), L1 is the distance between the imaging position of the detection module (17) in the near-end position area (15) and the exit hole (30) of the multi-axis interferometer (13), and L2 is the distance between the imaging position of the detection module (17) in the far-end position area (16) and the exit hole (30) of the multi-axis interferometer (13).

12. The multi-axis interferometer parallelism detection method according to any one of claims 8 to 10, characterized in that: The method for adjusting the mirror angle of the camera (42) in the detection module (17) includes: A fixed reflection module (18) is detachably mounted on the detection module (17), the reflection module (18) comprising a camera mirror bracket (46) and a reflector (45), the camera mirror bracket (46) being mounted on the mirror surface of the camera (42) of the detection module (17), and the reflector (45) being located on the camera mirror bracket (46) so that the reflector (45) is parallel to the mirror surface of the camera (42); The detection module (17) is moved perpendicularly to the first light beam to be detected (56) from a first position in the distal position area (16) or the proximal position area (15) to a second position, the distance between the first position and the second position being fixed, the reflector (45) fixedly mounted on the detection module (17) can receive the first light beam to be detected (56) at both the first position and the second position, and the first reflected light beam (451) and the second reflected light beam (452) after the first light beam to be detected (56) is reflected by the reflector (45) at the first position and the second position can be received by the multi-axis interferometer (13). The multi-axis interferometer (13) receives a first reflected light beam (451) reflected from a first position by the first light beam to be detected (56) and a second reflected light beam (452) reflected from a second position by the first light beam to be detected (56), and measures a reflection displacement between the first reflected light beam (451) and the second reflected light beam (452) received by the multi-axis interferometer (13); rotates the mirror angle of the camera (42) mounted parallel to the reflector (45) until the reflection displacement is minimized, determines that the mirror of the camera (42) is perpendicular to the first light beam to be detected (56) at this time, and fixes the angular position of the mirror of the camera (42) at this time; After the camera (42) is adjusted, the reflection module (18) is removed.

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