Adjustable field of view angle magnification device and method for laser beam scanning system

Abstract

This invention discloses an adjustable field-of-view magnification device and method for a laser beam scanning system. The device includes: a laser emitter for incidenting a collimated laser beam onto a reflector; a reflector for reflecting the incident laser beam and then incident it onto a positive focal length lens; a positive focal length lens for focusing the incident beam and then incident it onto a scanning element; a scanning element for reflecting the focused laser beam at different angles into a negative focal length plano-concave lens after rotation; and a negative focal length plano-concave lens for collecting incident light and magnifying the angle of the outgoing beam. The magnification of the outgoing beam angle can be changed by adjusting the distance between the positive focal length lens and the scanning element or by adjusting the distance between the negative focal length plano-concave lens and the scanning element. This invention can use a refractive expansion and dynamic beam-shrinking structure to ensure the consistency of the beam shrinkage ratio across the entire field of view, significantly suppress large-angle incident aberrations, and improve beam quality. Based on multi-wavelength chromatic aberration correction, chromatic dispersion is eliminated while simplifying the system structure.

Description

Technical Field

[0001] This invention relates to the field of laser beam scanning technology, and in particular to an adjustable field-of-view magnification device and method for a laser beam scanning system. Background Technology

[0002] Laser beam scanning (LBS) technology precisely controls the reflection direction of the laser beam through a two-dimensional scanning element, and has achieved three-dimensional measurement and high-resolution imaging in fields such as lidar and projection display. However, its scanning angle is limited by the physical characteristics and manufacturing process of the scanning element: large-angle incident light will cause the system size to expand, the coating reflectivity to decrease and the aberration distortion to intensify. On the other hand, increasing the mirror size to adapt to the large-angle requirement will reduce the mechanical resonant frequency, increase the driving complexity and shorten the device life.

[0003] To overcome this bottleneck, existing technologies employ a scheme of configuring an optical angle-expanding device at the rear end of the scanning component, such as a double positive lens combination based on the Kepler telescope principle (i.e., Chinese patent CN201811106003.8) or a positive and negative lens group of the Galilean double telecentric system (i.e., Chinese patent CN202111021783.8). Both achieve the magnification of the scanning angle through the beam-contraction effect, and their angle-expanding magnification is determined by the lens focal length ratio.

[0004] However, this design has inherent drawbacks: the laser divergence angle increases linearly with the original scanning angle after the expansion, resulting in a significant deterioration in the beam quality of the edge field of view. It is necessary to rely on multiple lens groups to correct aberrations, which greatly increases the system complexity and size. At the same time, the requirement for long focal length forces the lens size and overall optical path length to increase, making it difficult to adapt to compact devices. In addition, the expansion magnification is fixed by the lens parameters and cannot be dynamically adjusted according to the application scenario, which limits the flexibility of the device. Summary of the Invention

[0005] The purpose of this invention is to provide an adjustable field-of-view magnification device and method for a laser beam scanning system, thereby solving all or one of the aforementioned problems in the prior art.

[0006] To solve the above-mentioned technical problems, the specific technical solution of the present invention is as follows:

[0007] On one hand, the present invention provides an adjustable field-of-view magnification device for a laser beam scanning system, comprising:

[0008] Laser emitter, reflector, positive focal length lens, scanning element, and negative focal length plano-concave lens;

[0009] The laser emitter is used to generate a collimated laser beam and to incident the collimated laser beam onto the reflector;

[0010] The reflector is located directly in front of the laser emitter; the reflector is used to fold the optical path, reflecting the incident laser beam before it enters the positive focal length lens.

[0011] The positive focal length lens is located in front of the entrance pupil of the reflector and is positioned diagonally above the reflector; the positive focal length lens is used to focus the incident light beam before it enters the scanning element.

[0012] The scanning element is located obliquely above the positive focal length lens and is used to reflect the converged laser beam at different angles into the negative focal length plano-concave lens after rotation.

[0013] The negative focal length plano-concave lens is located behind the exit pupil of the scanning element and positioned on one side of the scanning element; the negative focal length plano-concave lens is used to collect incident light and magnify the angle of the outgoing beam; the positive focal length lens is used to adjust the distance between the positive focal length lens and the scanning element to change the magnification of the outgoing beam angle; the negative focal length plano-concave lens is used to adjust the distance between the negative focal length plano-concave lens and the scanning element to change the magnification of the outgoing beam angle.

[0014] As an improved solution, the positive focal length lens includes: a spherical lens and an aspherical lens;

[0015] The positive focal length lens is further used to: converge the incident light beam and direct the incident light beam into the scanning element in a converged state.

[0016] The principal optical axis of the positive focal length lens coincides with the rotation center point of the scanning element.

[0017] As an improved solution, the lens of the scanning element is equipped with a reflective film;

[0018] The scanning element uses a two-dimensional MEMS galvanometer.

[0019] As an improved solution, the concave surface of the negative focal length plano-concave lens is positioned facing the scanning element;

[0020] The principal optical axis of the negative focal length plano-concave lens coincides with the rotation center of the scanning element.

[0021] As an improved solution, the positive focal length lens and the negative focal length plano-concave lens are configured to be matched together.

[0022] The absolute value of the focal length of the positive focal length lens is greater than the absolute value of the focal length of the negative focal length plano-concave lens.

[0023] When the positive focal length lens needs to meet the system space requirements, if the laser beam is in a single-wavelength state, the optical path between the positive focal length lens and the negative focal length plano-concave lens satisfies the sum of the focal lengths.

[0024] When the positive focal length lens needs to meet the system space requirements, if the laser beam is in a single-wavelength multi-wavelength combined state, the optical path between the positive focal length lens and the negative focal length plano-concave lens satisfies the sum of the focal lengths, and the positive focal length lens and the negative focal length plano-concave lens satisfy the principle of complementary chromatic aberration.

[0025] As an improved solution, the single-wavelength state includes: multiple laser beams with the same wavelength; the multi-wavelength combined state includes: multiple laser beams with different wavelengths.

[0026] As an improved solution, the color difference complementary principle includes:

[0027] At each wavelength, the sum of the focal lengths of the positive focal length lens (301) and the negative focal length plano-concave lens (302) is equal;

[0028] or,

[0029] At each wavelength, the absolute value of the difference between the sum of the focal lengths corresponding to any two wavelengths is not greater than the first threshold.

[0030] As an improved solution, the negative focal length plano-concave lens is further used to: adjust the magnification of the field of view by adjusting the distance between the negative focal length plano-concave lens and the scanning element.

[0031] As an improved solution, the scanning element is also specifically used for: achieving multi-wavelength laser scanning area alignment based on MEMS scanning galvanometers.

[0032] As an improved solution, the laser beam generated by the laser emitter includes: a single-wavelength collimated laser beam and a laser beam of multiple wavelengths collimated and combined by the laser.

[0033] The optical axes of all wavelengths within the combined laser beam are aligned, and the optical axis of the laser beam is aligned with the optical axis of the positive focal length lens.

[0034] On the other hand, the present invention also provides a method for adjusting the field of view of a laser beam scanning system, comprising the following steps:

[0035] The laser emitter generates a collimated laser beam, which is then incident on the reflector.

[0036] The reflector is used to fold the optical path, reflecting the incident laser beam so that it enters the positive focal length lens;

[0037] The incident light beam is focused and concentrated by a positive focal length lens before being incident on the scanning component;

[0038] The scanning element, after rotation, reflects the converged laser beam at different angles into the negative focal length plano-concave lens; the negative focal length plano-concave lens collects the incident light and magnifies the angle of the outgoing beam; during the magnification process, the magnification factor of the outgoing beam angle is changed by adjusting the distance between the positive focal length lens and the scanning element; the magnification factor of the outgoing beam angle is changed by adjusting the distance between the negative focal length plano-concave lens and the scanning element.

[0039] The beneficial effects of the technical solution of this invention are as follows: This invention adopts a refractive expansion and dynamic beam contraction structure to ensure the consistency of the beam contraction ratio across the entire field of view, significantly suppressing large-angle incident aberrations and improving beam quality; based on multi-wavelength chromatic aberration correction, it simplifies the system structure while eliminating dispersion, greatly reducing the back-end space requirements; this invention also decouples the focal length ratio and magnification relationship between the front and rear lens groups, ultimately achieving dynamic adjustment of the field of view, balancing low cost, miniaturization, and high image quality; it breaks through the performance bottleneck of traditional LBS systems, providing a high-precision, highly flexible, and compact solution for laser scanning applications. Attached Figure Description

[0040] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0041] Figure 1 This is a schematic diagram of the adjustable field-of-view magnification device of the laser beam scanning system described in Embodiment 1 of the present invention;

[0042] Figure 2 This is a schematic diagram of the adjustable field-of-view magnification device of the laser beam scanning system described in Embodiment 1 of the present invention in the basic expansion state;

[0043] Figure 3 This is a schematic diagram of the adjustable field-of-view magnification device of the laser beam scanning system described in Embodiment 1 of the present invention under the condition of reducing the magnification factor;

[0044] Figure 4 This is a schematic diagram of the adjustable field-of-view magnification device of the laser beam scanning system described in Embodiment 1 of the present invention under the condition of increasing the magnification factor;

[0045] Figure 5 This is a schematic diagram of the dispersion phenomenon of the adjustable magnification device for the laser beam scanning system described in Embodiment 1 of the present invention;

[0046] Figure 6 This is a flowchart illustrating the adjustable field-of-view magnification method of the laser beam scanning system described in Embodiment 2 of the present invention;

[0047] The markings in the attached diagram are explained as follows:

[0048] 100. Laser emitter; 101. Reflector; 102. Scanner; 201. Laser beam emitted from the laser emitter; 202. Laser beam emitted from the scanner; 203. Laser beam emitted after widening the angle; 301. Positive focal length lens; 302. Negative focal length plano-concave lens. Detailed Implementation

[0049] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.

[0050] In the description of this invention, it should be noted that the embodiments described in this invention are only some embodiments of this invention, not all embodiments; based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0051] The terms "first," "second," etc., used in this specification, claims, and accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, apparatus, product, or device that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0052] 1. MEMS (Micro-electro Mechanical Systems) refers to micro-electromechanical systems, specifically micro-electromechanical systems, micro-systems, micro-machines, etc., which are high-tech devices with dimensions of a few millimeters or even smaller.

[0053] 2. LBS (Laser Beam Scanning) is a technology that uses laser beam scanning to scan a laser beam point by point in space by means of reflection from the scanning device.

[0054] Example 1: This example provides an adjustable field-of-view magnification device for a laser beam scanning system, such as... Figures 1-5 As shown, it includes:

[0055] (1) A laser emitter 100 is used to generate a collimated laser beam that is incident on the reflector 101 and then incident on the focal lens 301 after reflection.

[0056] Specifically, the laser beam generated by the laser emitter 100 includes, but is not limited to: a single-wavelength collimated laser beam and a laser beam of multiple wavelengths collimated and combined by the laser.

[0057] Specifically, the optical axes of all wavelengths of the laser beam within the combined laser beam are aligned; the optical axis of the laser beam is aligned with the optical axis of the positive focal length lens 301, i.e., it is incident perpendicularly.

[0058] (2) Positive focal length lens 301 is located in front of the entrance pupil of the reflective scanning element 102. It includes a spherical lens and an aspherical lens. Positive focal length lens 301 is used to converge the beam. The laser beam enters the scanning element 102 in a converged state after passing through positive focal length lens 301. Its principal optical axis coincides with the rotation center point of the scanning element 102.

[0059] Specifically, the positive focal length lens 301 and the negative focal length plano-concave lens 302 are matched together and satisfy the following conditions:

[0060] A. Set the absolute value of the focal length of the positive focal length lens 301 to be greater than the absolute value of the focal length of the negative focal length lens;

[0061] B. If the laser beam is in a single-wavelength state (i.e., when multiple laser beams have the same wavelength), then the positive focal length lens 301 must meet the system space requirements, and the optical path between the positive focal length lens 301 and the negative focal length plano-concave lens 302 must satisfy the sum of the focal lengths.

[0062] C. If the laser beam is in a multi-wavelength combined state (i.e., when multiple laser beams have different wavelengths), then while satisfying condition B, the positive focal length lens 301 and the negative focal length lens must satisfy the principle of complementary chromatic aberration (at each wavelength, the sum of the focal lengths of the two lenses is equal or close). Here, the meaning of close is further explained, that is, at each wavelength, the absolute value of the difference between the sum of the focal lengths of the two lenses corresponding to any two wavelengths (because the difference may be negative, so the absolute value needs to be used for comparison) is not greater than a certain preset first threshold. This first threshold can be set according to the specific situation, such as 1 micrometer.

[0063] (3) Reflector 101, used for folding the optical path.

[0064] (4) Scanner 102, with a reflective film, uses a two-dimensional MEMS galvanometer to reflect the focused laser beam into the plano-concave lens at different angles after rotation.

[0065] (5) The negative focal length plano-concave lens 302 is located behind the exit pupil of the scanning element 102. Its concave surface faces the scanning element 102, and its optical axis coincides with the rotation center of the scanning element 102. The negative focal length plano-concave lens 302 is used to collect incident light rays, thereby magnifying the angle of the outgoing beam. By adjusting the distance between the positive focal length lens 301 and the scanning element 102, as well as the distance between the negative focal length plano-concave lens 302 and the scanning element 102, the magnification of the outgoing beam angle can be changed.

[0066] Specifically, based on the fact that the focal length of the negative focal length plano-concave lens 302 meets the above conditions, the concave surface of the negative focal length plano-concave lens 302 will collimate the incident converging beam again, and the laser beam will exit from the plane.

[0067] Specifically, when the negative focal length plano-concave lens 302 of this device translates along the optical axis, the positive focal length lens 301 also translates along the optical axis, maintaining a constant optical path. When the negative focal length plano-concave lens 302 is close to the scanning element 102, the magnification of the field of view decreases; when the negative focal length plano-concave lens 302 is far away from the scanning element 102, the magnification of the field of view increases. Within the allowable range of the emitted beam divergence angle, the field of view magnification can be adjusted in the above manner. To better illustrate the principle of this device, the above technical effects are verified based on the following calculation process:

[0068] (i) Define the focal length of the positive focal length lens 301 as F1, the absolute value of the focal length of the negative focal length plano-concave lens 302 as F2, the spherical radius of the negative focal length plano-concave lens 302 as R, the distance from the positive focal length lens 301 to the scanning element 102 as D1, and the distance from the negative focal length plano-concave lens 302 to the scanning element 102 as D2. Then, for this adjustable expansion magnification device, its basic expansion angle state is: when the center of the spherical surface of the plano-concave lens coincides with the rotation center of the scanning element 102, D2 = R. ,like Figure 2 Let the refractive index of the plano-concave lens material be n, where n > 1; let the half-angle of the original scanning field of view of the scanning element 102 be... In this state, the laser beam's optical axis is perpendicular to the incident spherical surface, and similarly within the lens... The incident plane, after refraction on the plane, exits; magnified, half-angle of the field of view. for:

[0069]

[0070] The magnification ratio α is:

[0071]

[0072] The laser beam reduction ratio β is:

[0073]

[0074] Among them, the angle expansion magnification ratio is only related to the refractive index of the material of the negative focal length plano-concave lens 302, and all current field angles are the same for the plano-concave spherical lens with perpendicular incidence. When the ratio of the laser beam width to the spherical radius is small, it can be regarded as a paraxial beam, with only a small spherical aberration. The laser beams emerging from all fields maintain consistency and have excellent aberration at the same time.

[0075] (ii) For this angle expansion adjustable magnification device, its state of reducing the angle expansion magnification is: the optical axis of the plano-concave lens coincides with the rotation center of the scanning part 102, and the distance between the two is less than the spherical radius value, that is: D2 < R. At this time , the optical path of the lens group remains unchanged, as Figure 3 ; in this state, the optical axis of the laser beam is not perpendicular to the spherical surface and refracts inside the lens, and enters the lens plane at an angle , then there is:

[0076]

[0077] Based on Equation (4), it can be seen that the refractive index n of the material is greater than 1, is less than , and at this time the half field angle of the laser beam emerging from the lens plane is:

[0078]

[0079] Based on Equation (5), it can be seen that is less than , achieving a reduction in the magnification ratio. At this time, there are partial aberrations in the outer edge field.

[0080] (iii) For this angle expansion adjustable magnification device, its state of increasing the angle expansion magnification is: the optical axis of the plano-concave lens coincides with the rotation center of the scanning part 102, and the distance between the two is greater than the spherical radius value, that is: D2 > R. At this time , the optical path of the lens group remains unchanged, as Figure 4 ; in this state, the optical axis of the laser beam is not perpendicular to the spherical surface and refracts inside the lens, and enters the lens plane at an angle , then there is:

[0081]

[0082] Based on Equation (6), it can be seen that the refractive index n of the material is greater than 1, is greater than , and at this time the half field angle of the laser beam emerging from the lens plane is:

[0083]

[0084] Based on Equation (7), it can be seen that is greater than This increases the magnification, but some aberrations exist at the outer edge of the field of view.

[0085] Based on (i) to (iii), it can be seen that by changing the distance between the negative focal length plano-concave lens 302 and the scanning element 102 when they translate along the optical axis, the magnification of the field of view can be dynamically adjusted.

[0086] Specifically, multi-wavelength laser scanning amplitude alignment is achieved based on MEMS scanning galvanometers, as follows:

[0087] Due to the dispersion of materials, the refractive index of materials varies with wavelength. As can be seen from equation (1), the magnification of the field of view is different for different wavelengths, resulting in dispersion. Figure 5 Then, the half-angle of the field of view for each wavelength after expansion is... for:

[0088]

[0089] Based on the characteristic of MEMS scanning mirrors continuously scanning in space, the lighting sequence of laser beams of different wavelengths is modulated, thereby aligning the emission angles of multiple beams, i.e., aligning the scanning areas of multiple wavelength lasers.

[0090] It should be noted that the above examples are merely for explaining the present invention and should not be construed as limiting the scope of protection of the present invention.

[0091] Example 2: This example is based on the same inventive concept as the adjustable field-of-view magnification device for a laser beam scanning system described in Example 1, and provides a method for adjustable field-of-view magnification of a laser beam scanning system, such as... Figure 6 As shown, it includes the following steps:

[0092] S100: Call the laser emitter to generate a collimated laser beam and then incident the collimated laser beam onto the reflector.

[0093] S200: The reflector is used to fold the optical path, and the incident laser beam is reflected and then incident on the positive focal length lens.

[0094] S300: The positive focal length lens is used to focus the incident beam and then project it onto the scanning component.

[0095] S400: The scanning element, after rotation, reflects the converged laser beam at different angles into the negative focal length plano-concave lens; the negative focal length plano-concave lens collects the incident light and magnifies the angle of the outgoing beam; during the magnification process, the magnification factor of the outgoing beam angle is changed by adjusting the distance between the positive focal length lens and the scanning element; the magnification factor of the outgoing beam angle is changed by adjusting the distance between the negative focal length plano-concave lens and the scanning element.

[0096] Unlike existing technologies, the adjustable field-of-view magnification device and method for a laser beam scanning system proposed in this application can employ refractive expansion and dynamic beam contraction structures to ensure consistent beam contraction ratios across the entire field of view, significantly suppressing large-angle incident aberrations and improving beam quality. Based on multi-wavelength chromatic aberration correction, it simplifies the system structure while eliminating dispersion, greatly reducing back-end space requirements. This invention also decouples the focal length ratio and magnification relationship between the front and rear mirror groups, ultimately achieving dynamic adjustment of the field of view while balancing low cost, miniaturization, and high image quality. It breaks through the performance bottlenecks of traditional LBS systems, providing a high-precision, highly flexible, and compact solution for laser scanning applications.

[0097] It should be understood that in the various embodiments of this document, the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this document.

[0098] It should also be understood that, in the embodiments herein, the term "and / or" is merely a description of the relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following associated objects have an "or" relationship.

[0099] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this document.

[0100] Those skilled in the art will understand that, for the sake of convenience and brevity, the methods and processes described above can be referred to the specific working processes of the corresponding systems, devices and units in the foregoing method embodiments, which will not be repeated here.

[0101] In the embodiments provided herein, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the couplings or direct couplings or communication connections shown or discussed may be indirect couplings or communication connections through some interfaces, devices, or units, or they may be electrical, mechanical, or other forms of connection.

[0102] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the embodiments described herein, depending on actual needs.

[0103] Furthermore, the functional units in the various embodiments of this document can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0104] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this paper, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this paper. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0105] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. An adjustable field-of-view magnification device for a laser beam scanning system, characterized in that, include: Laser emitter (100), reflector (101), positive focal length lens (301), scanning element (102) and negative focal length plano-concave lens (302); The laser emitter (100) is used to generate a collimated laser beam and to incident the collimated laser beam onto the reflector (101). The reflector (101) is located directly in front of the laser emitter (100); the reflector (101) is used to fold the optical path and reflect the incident laser beam into the positive focal length lens (301). The positive focal length lens (301) is located in front of the entrance pupil of the scanning element (102) and is positioned obliquely above the reflecting element (101); the positive focal length lens (301) is used to focus the incident light beam before it enters the scanning element (102). The scanning element (102) is located obliquely above the positive focal length lens (301) and is used to reflect the converged laser beam into the negative focal length plano-concave lens (302) at different angles after rotation. The negative focal length plano-concave lens (302) is located behind the exit pupil of the scanning element (102) and is positioned on one side of the scanning element (102). The negative focal length plano-concave lens (302) is used to collect incident light rays and magnify the angle of the outgoing beam. The positive focal length lens (301) is used to adjust the distance between the positive focal length lens (301) and the scanning element (102) to change the magnification of the outgoing beam angle. The negative focal length plano-concave lens (302) is used to adjust the distance between the negative focal length plano-concave lens (302) and the scanning element (102) to change the magnification of the outgoing beam angle. The positive focal length lens (301) and the negative focal length plano-concave lens (302) are configured to be used in conjunction with each other. The absolute value of the focal length of the positive focal length lens (301) is greater than the absolute value of the focal length of the negative focal length plano-concave lens (302). When the positive focal length lens (301) needs to meet the system space requirements, if the laser beam is in a single-wavelength state, the optical path between the positive focal length lens (301) and the negative focal length plano-concave lens (302) is equal to the sum of the focal lengths of the positive focal length lens (301) and the negative focal length plano-concave lens (302). When the positive focal length lens (301) needs to meet the system space requirements, if the laser beam is in a multi-wavelength combined state, the optical path between the positive focal length lens (301) and the negative focal length plano-concave lens (302) is equal to the sum of the focal lengths of the positive focal length lens (301) and the negative focal length plano-concave lens (302), and the positive focal length lens (301) and the negative focal length plano-concave lens (302) satisfy the principle of complementary chromatic aberration.

2. The adjustable field-of-view magnification device for the laser beam scanning system according to claim 1, characterized in that: The positive focal length lens (301) includes: a spherical lens and an aspherical lens; The positive focal length lens (301) is further used to: converge the incident light beam and incident the incident light beam into the scanning element (102) in a converged state. The principal optical axis of the positive focal length lens (301) coincides with the rotation center point of the scanning element (102).

3. The adjustable field-of-view magnification device for the laser beam scanning system according to claim 1, characterized in that: The lens of the scanning element (102) is equipped with a reflective film; The scanning element (102) is a two-dimensional MEMS galvanometer.

4. The adjustable field-of-view magnification device for the laser beam scanning system according to claim 1, characterized in that: The concave surface of the negative focal length plano-concave lens (302) is disposed facing the scanning element (102); The principal optical axis of the negative focal length plano-concave lens (302) coincides with the rotation center of the scanning element (102).

5. The adjustable field-of-view magnification device for the laser beam scanning system according to claim 1, characterized in that: The single-wavelength state includes: multiple laser beams having the same wavelength; The multi-wavelength beam combining state includes multiple laser beams with different wavelengths.

6. The adjustable field-of-view magnification device for the laser beam scanning system according to claim 1, characterized in that: The principle of complementary color differences includes: At each wavelength, the sum of the focal lengths of the positive focal length lens (301) and the negative focal length plano-concave lens (302) is equal; or, At each wavelength, the absolute value of the difference between the sum of the focal lengths corresponding to any two wavelengths is not greater than the first threshold.

7. The adjustable field-of-view magnification device for the laser beam scanning system according to claim 1, characterized in that: The negative focal length plano-concave lens (302) is also specifically used to: adjust the field of view magnification by adjusting the distance between the negative focal length plano-concave lens (302) and the scanning element (102); The scanning element (102) is also specifically used for: achieving multi-wavelength laser scanning area alignment based on MEMS scanning mirror.

8. The adjustable field-of-view magnification device for the laser beam scanning system according to claim 1, characterized in that: The laser beam generated by the laser emitter (100) includes: a single-wavelength collimated laser beam and a laser beam of multiple wavelengths collimated and combined by the laser. The optical axis directions of each wavelength laser beam within the combined laser beam are consistent, and the optical axis of the laser beam is consistent with the optical axis of the positive focal length lens (301).

9. A method for adjusting the field of view of an adjustable magnification device for a laser beam scanning system according to any one of claims 1 to 8, characterized in that, The method includes the following steps: The laser emitter generates a collimated laser beam, which is then incident on the reflector. The reflector is used to fold the optical path, reflecting the incident laser beam so that it enters the positive focal length lens; The incident light beam is focused and concentrated by a positive focal length lens before being incident on the scanning component; The scanning element, after rotation, reflects the converged laser beam at different angles into the negative focal length plano-concave lens; the negative focal length plano-concave lens collects the incident light and magnifies the angle of the outgoing beam; during the magnification process, the magnification factor of the outgoing beam angle is changed by adjusting the distance between the positive focal length lens and the scanning element; the magnification factor of the outgoing beam angle is changed by adjusting the distance between the negative focal length plano-concave lens and the scanning element.

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