Scanning head and scanning device for high-beam diameter and large-angle scanning range

Abstract

The embodiment of the utility model relates to a scanning head for a high beam diameter and a large-angle scanning range. The scanning head comprises a focus lens group, a first galvanometer, a concave reflecting mirror and a second galvanometer, the focusing lens group is used for focusing the incident laser beam; the first galvanometer is used for scanning the light beams emitted by the focusing lens group; the concave reflector performs deflection relay on the light beam emitted by the first galvanometer; and the second galvanometer scans the adjusted light beam. According to the invention, the mirror reflection principle is utilized, the concave reflector is used to realize deflection relay of an optical path, a large scanning range can be realized under the condition of the same outgoing beam diameter, an imaging area is effectively increased, and meanwhile, the effect of transmitting a high beam diameter under the condition of the same scanning angle can be realized.

Description

Technical Field

[0001] This utility model relates to the field of scanning heads, and more particularly to a scanning head and scanning device for high beam diameter and large angle scanning range. Background Technology

[0002] Existing scanning imaging systems typically utilize two scanning mirrors (in the X and Y directions) to deflect the laser beam and cover the target imaging area. However, as the laser beam diameter increases, the size of traditional mirrors limits their ability to accommodate larger beam diameters. Furthermore, the limited aperture of the objective lens places higher demands on the deflection angle of the laser emitted from the mirrors, making it difficult for conventional designs to simultaneously meet the requirements of high beam diameter and large scanning angle. Therefore, existing technologies still have limitations in improving scanning range and accommodating large beam diameters, necessitating an improved scanning head structure to optimize the optical path and enhance imaging quality. Utility Model Content

[0003] The purpose of this invention is to address the shortcomings of existing technologies by providing a scanning head and scanning device for high beam diameter and large-angle scanning range. This scanning head utilizes the principle of mirror reflection and uses a concave mirror to achieve optical path deflection and relay, which can achieve a large scanning range with the same output beam diameter, effectively increasing the imaging area. At the same time, it can also achieve the effect of transmitting high beam diameter under the same scanning angle.

[0004] To achieve the above objectives, in a first aspect, this utility model provides a scanning head for high beam diameter and large angular scanning range, comprising:

[0005] Focusing lens assembly, first galvanometer, concave mirror, and second galvanometer; among which,

[0006] The focusing lens group focuses the incident laser beam;

[0007] The first galvanometer scans the beam emitted from the focusing lens group in a first direction;

[0008] The concave reflector is located between the first galvanometer and the second galvanometer, and deflects and relays the light beam emitted from the first galvanometer.

[0009] The second galvanometer scans the beam after it has been adjusted by the concave mirror in a second direction, wherein the scanning direction of the second galvanometer is perpendicular to that of the first galvanometer, and the scanning axis positions of the first and second galvanometers are set to optically equal positions.

[0010] Preferably, the first galvanometer is a controllable rotating reflector driven by a motor, which scans the incident beam in the X direction.

[0011] Preferably, the second galvanometer is a controllable rotating reflector driven by a motor, which scans the incident beam in the Y direction.

[0012] Preferably, when the laser is not powered on, the projections of the direction of the laser incident on the first galvanometer and the direction of the laser incident on the second galvanometer onto the plane of the two galvanometers are parallel to each other.

[0013] The effective optical distance between the scanning axes of the first and second galvanometers is zero.

[0014] Preferably, the center direction of the laser emission from the second galvanometer forms a 45° angle with the direction of the laser incident on the first galvanometer.

[0015] Preferably, the focal length of the focusing lens group is twice the focal length of the concave mirror.

[0016] Preferably, the focal length of the focusing lens group is 80 to 120 mm;

[0017] The concave reflector is a spherical concave reflector with a radius of curvature of 40 to 60 mm.

[0018] Secondly, this utility model embodiment also provides a scanning device including the scanning head described in the first aspect, the scanning device comprising a focusing lens group, a first galvanometer, a concave reflecting mirror, a second galvanometer, a scanning lens group, a tube lens group, and an objective lens; wherein,

[0019] The focusing lens group focuses the incident laser beam;

[0020] The first galvanometer scans the beam emitted from the focusing lens group in a first direction;

[0021] The concave reflector is located between the first galvanometer and the second galvanometer, and deflects and relays the light beam emitted from the first galvanometer.

[0022] The second galvanometer scans the beam after it has been adjusted by the concave mirror in a second direction, wherein the scanning direction of the second galvanometer is perpendicular to that of the first galvanometer, and the scanning axis positions of the first and second galvanometers are set to optically equal positions.

[0023] The scanning lens group, located after the second galvanometer, performs imaging correction on the scanned beam.

[0024] The tube lens group controls the transmission path of the emitted beam, so that it forms a vignetting-free image at the objective lens.

[0025] The objective lens projects the adjusted scanning beam onto the target imaging area.

[0026] Preferably, the focal length of the scanning lens group is 20 to 50 mm;

[0027] The focal length of the tube lens group is 100 to 300 mm.

[0028] Preferably, with a maximum scanning angle of ±17°, the incident light diameter D = 4.4 mm is the maximum beam diameter without vignetting.

[0029] The present invention provides a scanning head and scanning device for high beam diameter and large angle scanning range, which has the following beneficial effects:

[0030] 1. Enhanced scanning range: Under the same output beam diameter, a larger scanning range can be achieved, improving the system's imaging capability.

[0031] 2. Adaptable to large beam diameters: By optimizing the optical path, it can accommodate larger beam diameters under the same scanning angle conditions, achieving higher optical efficiency.

[0032] 3. Reduce vignetting: By utilizing the principle of optical isostatics and focusing lens groups, beam distortion is reduced during scanning, thus improving image quality.

[0033] 4. Reduce the requirements for objective lens diameter: While ensuring high-quality imaging, reduce the requirements for objective lens diameter to make the system design more flexible. Attached Figure Description

[0034] Figure 1 A schematic diagram of the structure and optical path of a scanning head for high beam diameter and large angle scanning range provided for an embodiment of this utility model;

[0035] Figure 2 A schematic diagram of the optical path of a scanning device including a scanning head for high beam diameter and large angle scanning range, provided for an embodiment of the present invention;

[0036] Figure 3 A schematic diagram of the structure and optical path of a conventional scanning device provided in an embodiment of this utility model;

[0037] Figure 4 for Figure 3 Enlarged view of region A in the middle;

[0038] Figure 5 A schematic diagram of the image plane imaging position of a scanning device for high beam diameter and large angle scanning range provided for an embodiment of this utility model;

[0039] Figure 6 A schematic diagram of the image plane imaging position of a conventional scanning device provided in an embodiment of this utility model;

[0040] Figure 7 for Figure 2and Figure 3 Comparison of the relationship between the imaging spot size and the scanning angle of the scanning device Figure 1 ;

[0041] Figure 8 for Figure 2 and Figure 3 Comparison of the relationship between the imaging spot size and the scanning angle of the scanning device Figure 2 ;

[0042] Figure 9 A schematic diagram of the light trail of the first lens of the entrance objective of a scanning device for a high beam diameter and a large scanning angle range provided for an embodiment of this utility model (entrance pupil diameter 4.4mm);

[0043] Figure 10 A schematic diagram of the light trail of the first lens of the entrance objective lens of a scanning device for a high beam diameter and a large angle scanning range provided for an embodiment of this utility model (entrance pupil diameter 1.28mm);

[0044] Figure 11 A schematic diagram of the light trail of the first lens of the incident objective of the conventional scanning device provided in this embodiment of the utility model (entrance pupil diameter 0.64mm);

[0045] In the diagram: 1. Focusing lens group; 2. Galvanometer A; 3. Concave mirror; 4. Galvanometer B; 5. Scanning lens group; 6. Tube lens group; 7. Objective lens. Detailed Implementation

[0046] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments.

[0047] Figure 1 This is a schematic diagram of the structure and optical path of a scanning head for high beam diameter and large scanning angle range provided in an embodiment of the present invention. The scanning head for high beam diameter and large scanning angle range provided in this embodiment of the present invention includes a focusing lens group 1, a first galvanometer 2, a concave reflector 3, and a second galvanometer 4. The components and scanning process are described in detail below.

[0048] Focusing lens group 1 focuses the incident laser beam. Specifically, the incident laser beam enters focusing lens group 1, which performs preliminary focusing on the beam to ensure that the beam diameter entering the subsequent optical system is within the design range and to reduce the divergence angle. After focusing, the beam is directed toward the first galvanometer 2 at a set incident angle.

[0049] The first galvanometer 2 scans the beam emitted from the focusing lens group 1 in the first direction. It can be understood that changes in the angle of the first galvanometer 2 will cause a corresponding change in the angle of the reflected beam, thereby controlling the lateral distribution of the scanning range. The rotation axis of the first galvanometer 2 is precisely adjusted so that the reflected beam can be correctly incident on the concave reflecting mirror 3. In a specific example, the first galvanometer 2 is a controllable rotating reflecting mirror driven by a motor, causing the incident beam to scan in the X direction. It can be understood that the aforementioned first direction is the X direction.

[0050] A concave mirror 3 is located between the first galvanometer 2 and the second galvanometer 4. The light beam reflected from the first galvanometer 2 is projected onto the concave mirror 3, which then deflects and relays the light beam emitted from the first galvanometer 2. The concave mirror 3 serves two purposes: first, it changes the direction of the optical path, ensuring the light beam correctly enters the subsequent second galvanometer 4; second, it adjusts the optical isocentricity, allowing the scanning beam to maintain good focusing performance at different angles, thereby reducing aberrations and vignetting. Preferably, the focal length of the focusing lens group is twice the focal length of the concave mirror 3. The concave mirror 3 can image the scanning axis of the first galvanometer 2 onto the scanning axis of the second galvanometer 4, thus achieving the condition of optical isocentricity. Further preferably, the focal length of the focusing lens group 1 is 80 to 120 mm to ensure the tooling volume of the scanning head and the scanning range of the first galvanometer; the concave mirror 3 is a spherical concave mirror 3 with a radius of curvature set to 40 to 60 mm to ensure that the optical distance between the two galvanometers is 0, so that the deflection process of the beam will not affect the accuracy of the scanning angle.

[0051] The second galvanometer 4 receives the light beam reflected by the concave mirror 3. The second galvanometer 4 scans the light beam, adjusted by the concave mirror 3, in the second direction. In a specific example, the second galvanometer 4 is a controllable rotating mirror driven by a motor, which scans the incident light beam in the Y direction. It can be understood that the aforementioned second direction is the Y direction. The rotation angle of the second galvanometer 4 determines the degree of deflection of the light beam in the vertical direction. The scanning of the second galvanometer 4 enables the light beam to eventually cover a two-dimensional area (XY plane), thereby achieving a complete optical scan. The scanning direction of the second galvanometer 4 is perpendicular to that of the first galvanometer 2. The scanning axis positions of the first galvanometer 2 and the second galvanometer 4 are set to optically equal positions, that is, the effective optical distance between the scanning axes of the first galvanometer 2 and the second galvanometer 4 is zero. The rotation axes of the two galvanometers are optically equivalent to "the same position", even if the galvanometers are actually physically separated. Furthermore, the optical equidistant design ensures that the optical path difference between the two is zero. That is, no matter how the galvanometer rotates, the optical path of the laser from the first galvanometer 2 to the second galvanometer 4 remains unchanged. Beam offset compensation can also be performed, that is, the deflection angle of the galvanometer is automatically compensated through optical design to prevent the beam from deviating from the subsequent optical path.

[0052] It is understood that both the first galvanometer 2 and the second galvanometer 4 function as reflectors, and the vibration directions controlled by both are perpendicular to each other, with the rotation angle controlled by a motor. Preferably, when the laser is not powered on, the projections of the direction incident on the first galvanometer 2 and the direction incident on the second galvanometer 4 onto the plane of the two galvanometers are parallel. With the scanning directions of the first galvanometer 2 and the second galvanometer 4 perpendicular to each other, the parallel projection of the incident direction design ensures the relay transmission efficiency of the optical path. This optical path layout helps achieve compatibility with a large scanning range and a high beam diameter. More preferably, the center direction of the laser exiting the second galvanometer 4 forms a 45° angle with the direction incident on the first galvanometer 2. This 45° angle design ensures that the incident and reflection angles of the beam on the concave reflector 3 meet the optical path folding requirements, thereby achieving efficient optical path transmission within a limited space. Furthermore, the 45° angle optical path design can eliminate optical path difference through focal length matching of the concave reflector, thus achieving equidistant conditions.

[0053] It should be noted that the scanning device provided by this utility model embodiment includes the above-mentioned scanning head for high beam diameter and large angle scanning range. Its working process revolves around beam transmission, scanning and imaging, and mainly includes five key steps: beam incidence, galvanometer scanning, optical path adjustment, beam shaping and final imaging. Figure 2 This is a schematic diagram of the structured optical path of the scanning device, combined with... Figure 1 and Figure 2 As shown, the scanning device provided in this embodiment of the present invention includes a scanning head for high beam diameter and large angular scanning range, comprising a focusing lens group 1, a first galvanometer 2, a concave mirror 3, a second galvanometer 4, a scanning lens group 5, a tube lens group 6, and an objective lens 7. The focusing lens group 1, the first galvanometer 2, the concave mirror 3, and the second galvanometer 4 can be understood as a single scanning head. The following description, in conjunction with... Figure 1 and Figure 2 A detailed description of each component and the entire scanning process is provided.

[0054] Focusing lens group 1 focuses the incident laser beam. Specifically, the incident laser beam enters focusing lens group 1, which performs preliminary focusing to ensure that the beam diameter entering the subsequent optical system is within the design range and to reduce the divergence angle. After focusing, the beam is directed towards the first galvanometer 2 at a set incident angle. Preferably, the focal length of focusing lens group 1 is 80 to 120 mm to ensure the tooling volume of the scanning head and the scanning range of the first galvanometer.

[0055] The first galvanometer 2 scans the beam emitted from the focusing lens group 1 in the first direction. It can be understood that changes in the angle of the first galvanometer 2 will cause a corresponding change in the angle of the reflected beam, thereby controlling the lateral distribution of the scanning range. The rotation axis of the first galvanometer 2 is precisely adjusted so that the reflected beam can be correctly incident on the concave reflecting mirror 3. In a specific example, the first galvanometer 2 is a controllable rotating reflecting mirror driven by a motor, causing the incident beam to scan in the X direction. It can be understood that the aforementioned first direction is the X direction.

[0056] A concave reflector 3 is located between the first galvanometer 2 and the second galvanometer 4. The light beam reflected by the first galvanometer 2 is projected onto the concave reflector 3, which then deflects and relays the light beam emitted from the first galvanometer 2. The concave reflector 3 serves two purposes: first, it changes the direction of the optical path, ensuring the light beam correctly enters the subsequent second galvanometer 4; second, it adjusts the optical isocentric points, allowing the scanning beam to maintain good focusing performance at different angles, thereby reducing aberrations and vignetting. Preferably, the concave reflector 3 is a spherical concave reflector 3 with a radius of curvature set to 40 to 60 mm, ensuring that the optical distance between the two galvanometers is zero, so that the beam deflection process does not affect the accuracy of the scanning angle.

[0057] The second galvanometer 4 receives the light beam reflected by the concave mirror 3. The second galvanometer 4 scans the light beam, adjusted by the concave mirror 3, in the second direction. In a specific example, the second galvanometer 4 is a controllable rotating mirror driven by a motor, which scans the incident light beam in the Y direction. It can be understood that the aforementioned second direction is the Y direction. The rotation angle of the second galvanometer 4 determines the degree of deflection of the light beam in the vertical direction. The scanning of the second galvanometer 4 enables the light beam to eventually cover a two-dimensional area (XY plane), thereby achieving a complete optical scan. The scanning direction of the second galvanometer 4 is perpendicular to that of the first galvanometer 2. The scanning axis positions of the first galvanometer 2 and the second galvanometer 4 are set to optically equal positions, that is, the effective optical distance between the scanning axes of the first galvanometer 2 and the second galvanometer 4 is zero. The rotation axes of the two galvanometers are optically equivalent to "the same position", even if the galvanometers are actually physically separated. Furthermore, the optical equidistant design ensures that the optical path difference between the two is zero. That is, no matter how the galvanometer rotates, the optical path of the laser from the first galvanometer 2 to the second galvanometer 4 remains unchanged. Beam offset compensation can also be performed, that is, the deflection angle of the galvanometer is automatically compensated through optical design to prevent the beam from deviating from the subsequent optical path.

[0058] It is understood that both the first galvanometer 2 and the second galvanometer 4 function as reflectors, and the vibration directions controlled by both are perpendicular to each other, with the rotation angle controlled by a motor. Preferably, when the laser is not powered on, the projections of the direction incident on the first galvanometer 2 and the direction incident on the second galvanometer 4 onto the plane of the two galvanometers are parallel. With the scanning directions of the first galvanometer 2 and the second galvanometer 4 perpendicular to each other, the parallel projection of the incident direction design ensures the relay transmission efficiency of the optical path. This optical path layout helps achieve compatibility with a large scanning range and a high beam diameter. More preferably, the center direction of the laser exiting the second galvanometer 4 forms a 45° angle with the direction incident on the first galvanometer 2. This 45° angle design ensures that the incident and reflection angles of the beam on the concave reflector 3 meet the optical path folding requirements, thereby achieving efficient optical path transmission within a limited space. Furthermore, the 45° angle optical path design can eliminate optical path difference through focal length matching of the concave reflector, thus achieving equidistant conditions.

[0059] The scanning lens group 5, located after the second galvanometer 4, performs imaging correction on the scanned laser beam to maintain a good focus state throughout the scanning range and improve imaging accuracy. Preferably, the focal length of the scanning lens group 5 is 20 to 50 mm to ensure the incident light path of the light emitted from the second galvanometer while reducing the imaging light path length to optimize the optical path of the beam.

[0060] The tube lens group 6 controls the transmission path of the emitted beam, further adjusting the transmission direction and spot shape of the beam to form a vignetting-free image at the objective lens 7, thereby meeting the incident requirements of the objective lens 7; preferably, the focal length of the tube lens group 6 is 100 to 300 mm, realizing beam expansion and improving image quality.

[0061] Objective lens 7 is the final imaging component, which projects the adjusted scanning beam onto the target imaging area, that is, projects the optically optimized scanning beam onto the target area.

[0062] It is understood that the working process of the scanning device including a scanning head for high beam diameter and large angle scanning range provided in this embodiment of the present invention is summarized as follows:

[0063] 1. After being focused by the focusing lens group 1, the light beam enters the first galvanometer 2, and the first galvanometer 2 controls the scanning of the light beam in the X direction;

[0064] 2. The light beam is reflected to the concave mirror 3, changing the direction of the light path and making optical equalization adjustments;

[0065] 3. The beam is then incident on the second galvanometer 4, which controls the scanning of the beam in the Y direction;

[0066] 4. The beam is adjusted by the scanning lens group 5 and the tube lens group 6;

[0067] 5. Finally, the beam enters the objective lens 7 and is projected onto the target imaging area to form a vignetting-free scanning image.

[0068] To more specifically illustrate the advantages of the scanning device provided in this embodiment of the utility model, in conjunction with... Figures 2 to 11 As shown, the following description is provided through Example 1 and Comparative Example 1.

[0069] Example 1

[0070] Reference Figure 1 and Figure 2 As shown, the focal length of the scanning lens group 5 is 50mm, and the focal length of the focusing lens group 1 is 100mm; the size of the first galvanometer 2 and the second galvanometer 4 is 2.5mm*3mm, and their rotation angle is controlled by a motor; the focal length of the concave mirror 3 is 50mm. The focal length of the tube lens group 6 is 250mm; the diameter of the first lens of the objective lens 7 is 9.4mm.

[0071] Tests showed that, with a maximum scanning angle of ±17°, the incident light diameter D = 4.4 mm is the maximum beam diameter without vignetting.

[0072] Comparative Example 1

[0073] Reference Figure 3 and Figure 4 As shown, it includes a conventional galvanometer scanning structure, consisting of a first galvanometer 2, a second galvanometer 4, a scanning lens group 5, and a tube lens group 6. The objective lens 7 has a first lens with an aperture of 9.4 mm.

[0074] Tests showed that, with a maximum scanning angle of ±17°, the incident light diameter D = 0.64 mm is the maximum beam diameter without vignetting.

[0075] Specifically, refer to Figure 5 , 6 As shown, the image plane scanning range is read in an S-shape to obtain the final scanning angle. The scanning angle is ±17°, and the scanning angle within ±7° is controlled by using the method that the rotation angle values ​​of the first galvanometer 2 and the second galvanometer 4 are equal.

[0076] Furthermore, refer to Figure 7 , 8 As shown, Figure 2 The incident light diameter of the structure shown in this application is 1.28 mm. Figure 3The conventional structure shown has an incident light diameter of 0.64 mm. A comparison of the image spot size and scanning angle on the image plane is presented. The figure shows that, with twice the beam diameter, both SPT_RMS and SPT_GEO have a smaller optical path structure than the conventional galvanometer scanning optical path structure. SPT_RMS represents the root mean square distribution size of the spot energy, reflecting the energy concentration of the spot; the smaller the value, the more concentrated the energy. SPT_GEO represents the geometric distribution size of the spot, directly reflecting the actual coverage area of ​​the spot; the smaller the value, the smaller the spot. Therefore, even with double the beam diameter, the spot quality of this application is still superior to the conventional structure. This application can achieve a smaller spot with a larger beam diameter, thus supporting higher scanning accuracy and resolution. This advantage reduces the requirement for the objective lens aperture and allows for a larger scanning angle (e.g., ±17°), solving the problems of the conventional structure.

[0077] Reference Figure 9 , 10 As shown in Figure 11, Figure 2 The optical path structure shown in this application is... Figure 3 The diagram shows the light trail of the first lens of the conventional structured optical path incident on objective lens 7. From the diagram, it can be seen that: (1) Under the same maximum scanning angle of ±17°, without vignetting, the maximum beam diameter of the scanning head structured optical path of this application can reach 4.4 mm, while the maximum of the conventional galvanometer scanning structure is only 0.64 mm. Specifically, as shown in the diagram... Figure 9 and Figure 11 As shown; (2) When the incident beam diameter is twice that of the incident objective 7, the light trail range of the first lens satisfies that the optical path structure of the scanning head is smaller than that of the conventional galvanometer scanning optical path structure. That is to say, even if the beam diameter of the structure of this application is twice that of the conventional one, its light trail range is still smaller, thereby reducing the requirement for the objective aperture and supporting a larger scanning angle or beam diameter, as shown in the figure. Figure 10 and Figure 11 As shown.

[0078] This utility model provides a scanning device for high beam diameter and large scanning angle range. With the addition of a focusing lens group, the principle of optical isostatics can be used to achieve vignetting-free imaging through the objective lens, which increases the scanning range angle of the imaging beam and significantly reduces the aperture requirement of the objective lens. At the same time, it can also achieve vignetting-free imaging with high beam diameter.

[0079] In this utility model, the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "linking" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0080] In the description of this utility model, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0081] In the description herein, the terms "a specific embodiment," "some embodiments," "one embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0082] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above description is only a specific embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A scanning head for high beam diameter and large angular scanning range, characterized in that, The scanning head includes a focusing lens group, a first galvanometer, a concave reflecting mirror, and a second galvanometer; wherein... The focusing lens group focuses the incident laser beam; The first galvanometer scans the beam emitted from the focusing lens group in a first direction; The concave reflector is located between the first galvanometer and the second galvanometer, and deflects and relays the light beam emitted from the first galvanometer. The second galvanometer scans the beam after it has been adjusted by the concave mirror in a second direction, wherein the scanning direction of the second galvanometer is perpendicular to that of the first galvanometer, and the scanning axis positions of the first and second galvanometers are set to optically equal positions.

2. The scanning head for high beam diameter and large angular scanning range according to claim 1, characterized in that, The first galvanometer is a controllable rotating reflector driven by a motor, which scans the incident beam in the X direction.

3. The scanning head for high beam diameter and large-angle scanning range according to claim 1, characterized in that, The second galvanometer is a controllable rotating reflector driven by a motor, which scans the incident beam in the Y direction.

4. The scanning head for high beam diameter and large-angle scanning range according to claim 1, characterized in that, When the laser is not powered on, the projections of the direction of the laser incident on the first galvanometer and the direction of the laser incident on the second galvanometer onto the plane of the two galvanometers are parallel to each other. The effective optical distance between the scanning axes of the first and second galvanometers is zero.

5. The scanning head for high beam diameter and large-angle scanning range according to claim 1, characterized in that, The laser beam exits from the center of the second galvanometer at a 45° angle to the direction incident on the first galvanometer.

6. The scanning head for high beam diameter and large angular scanning range according to claim 1, characterized in that, The focal length of the focusing lens group is twice the focal length of the concave mirror.

7. The scanning head for high beam diameter and large angular scanning range according to claim 1, characterized in that, The focal length of the focusing lens group is 80 to 120 mm; The concave reflector is a spherical concave reflector with a radius of curvature of 40 to 60 mm.

8. A scanning apparatus comprising the scanning head according to any one of claims 1-7, characterized in that, The scanning device includes a focusing lens group, a first galvanometer, a concave reflecting mirror, a second galvanometer, a scanning lens group, a tube lens group, and an objective lens; wherein, The focusing lens group focuses the incident laser beam; The first galvanometer scans the beam emitted from the focusing lens group in a first direction; The concave reflector is located between the first galvanometer and the second galvanometer, and deflects and relays the light beam emitted from the first galvanometer. The second galvanometer scans the beam after it has been adjusted by the concave mirror in a second direction, wherein the scanning direction of the second galvanometer is perpendicular to that of the first galvanometer, and the scanning axis positions of the first and second galvanometers are set to optically equal positions. The scanning lens group, located after the second galvanometer, performs imaging correction on the scanned beam. The tube lens group controls the transmission path of the emitted beam, so that it forms a vignetting-free image at the objective lens. The objective lens projects the adjusted scanning beam onto the target imaging area.

9. The scanning device according to claim 8, characterized in that, The focal length of the scanning lens group is 20 to 50 mm; The focal length of the tube lens group is 100 to 300 mm.

10. The scanning device according to claim 8, characterized in that, With a maximum scanning angle of ±17°, the incident light diameter D = 4.4 mm is the maximum beam diameter without vignetting.

Images