Laser processing system and complementary conical mirror group

Abstract

The present application provides a laser processing system and a complementary conical mirror group. Among them, the laser processing system includes: a laser generating device; a collimating mirror whose focal point is collinear with the light source of the laser generating device; a complementary conical mirror group arranged in the laser propagation direction, adjacent to the collimating mirror and coaxially distributed; a focusing mirror arranged in the laser propagation direction and coaxially distributed with the collimating mirror, and adjacent to the other side opposite to the side adjacent to the complementary conical mirror group and the collimating mirror; wherein, the complementary conical mirror group includes: a negative conical mirror; a positive conical mirror paired with the negative conical mirror and rotatable coaxially relative to the negative conical mirror; the projections of the negative conical mirror and the positive conical mirror in the collimated light beam propagation direction are fan-shaped. In this way, by adjusting the angle between the negative conical mirror and the positive conical mirror, the propagation direction of the laser beam can be changed, thereby realizing the adjustment of the spot shape on the working surface, and effectively improving the energy distribution in the central area of the output laser.

Description

Technical Field

[0001] This application relates to the field of laser processing technology, and particularly to a laser processing system and a complementary conical mirror group. Background Art

[0002] Laser welding is one of the important application directions of laser processing technology. When performing laser welding, when the laser is focused on a point, the energy density in the focusing area is large, the heat affected zone is small, and the processing process has the characteristics of less pollution, less material consumption, deep penetration, and strong adaptability. The application of laser welding is also becoming more and more extensive.

[0003] In the process of implementing the existing technology, the inventor found that:

[0004] Due to the excessive concentration of energy in the central region of the directly output laser, when applied to thin plate welding, problems such as spatter and perforation are likely to occur, and the welding effect is poor. Moreover, when the gap between the workpiece plates is large, problems such as incomplete welds and unstable welding processes are likely to occur.

[0005] Therefore, it is necessary to provide a laser processing system whose output laser energy can be adjusted to adjust the output laser energy according to the actual situation of the workpiece, so as to effectively solve problems such as welding spatter and perforation. Summary of the Invention

[0006] The embodiments of this application provide a laser processing system capable of adjusting the energy distribution of the output laser to solve the technical problem of the concentrated energy in the central region of the output laser.

[0007] Specifically, a laser processing system, characterized in that it includes:

[0008] A laser generating device that generates a light source in an excited state;

[0009] A collimating mirror, the focus of the collimating mirror being collinear with the light source of the laser generating device;

[0010] A complementary conical mirror group disposed in the laser propagation direction, adjacent to the collimating mirror and coaxially distributed;

[0011] A focusing mirror disposed in the laser propagation direction, coaxially distributed with the collimating mirror, and adjacent to the other side opposite to the side adjacent to the collimating mirror of the complementary conical mirror group;

[0012] Wherein, the complementary conical mirror group includes:

[0013] A negative conical mirror;

[0014] A positive conical mirror paired with the negative conical mirror and rotatable coaxially relative to the negative conical mirror;

[0015] The negative conical mirror includes:

[0016] The first core area;

[0017] A negative conical platform area adjacent to the first core area;

[0018] The positive conical mirror includes:

[0019] A second core area corresponding to the first core area and used to realize the central light spot;

[0020] A positive conical platform area adjacent to the second core area and corresponding to the negative conical platform area.

[0021] Furthermore, the negative conical mirror further includes:

[0022] An edge area adjacent to the negative conical platform area.

[0023] Furthermore, the taper sizes of the negative conical platform area and the positive conical platform area are equal in value.

[0024] Furthermore, the negative conical mirror includes:

[0025] Two centrosymmetric sectors;

[0026] The radian of each sector is a preset angle.

[0027] Furthermore, the negative conical mirror includes:

[0028] Two discrete sub - mirrors;

[0029] Each sub - mirror has a sector with a radian of a preset angle;

[0030] The two sub - mirrors are centrosymmetrically distributed.

[0031] Furthermore, the negative conical mirror is composed of a preset number of discrete sub - mirrors;

[0032] Each sub - mirror has a sector with a radian of a preset angle.

[0033] The embodiment of the present application also provides a complementary conical mirror group.

[0034] Specifically, a complementary conical mirror group for a laser processing system, characterized by including:

[0035] A negative conical mirror;

[0036] A positive conical mirror paired with the negative conical mirror and rotatable coaxially relative to the negative conical mirror;

[0037] Wherein, the negative conical mirror includes:

[0038] The first core area;

[0039] A negative conical table area adjacent to the first core area;

[0040] The positive conical mirror includes:

[0041] A second core area corresponding to the first core area for realizing a central light spot;

[0042] A positive conical table area adjacent to the second core area and corresponding to the negative conical table area.

[0043] Further, the negative conical mirror further includes:

[0044] An edge area adjacent to the negative conical table area.

[0045] Further, the taper sizes of the negative conical table area and the positive conical table area are numerically equal.

[0046] Further, the negative conical mirror includes:

[0047] Two centrally symmetric sectors;

[0048] The radian of each sector is a preset angle.

[0049] The technical solution provided by the embodiments of the present application has at least the following beneficial effects:

[0050] By rotating the positive conical mirror or the negative conical mirror to adjust the angle between the negative conical mirror and the positive conical mirror, the propagation direction of the laser beam can be changed, so as to realize the adjustment of the light spot shape on the working surface, and effectively improve the energy distribution in the central area of the output laser. Description of the Drawings

[0051] The drawings described herein are used to provide a further understanding of the present application, and constitute a part of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application, and do not constitute an improper limitation to the present application. In the drawings:

[0052] Figure 1 It is a schematic structural diagram of a laser processing system provided by an embodiment of the present application.

[0053] Figure 2 It is a schematic diagram of the propagation of a laser beam provided by an embodiment of the present application.

[0054] Figure 3 It is a schematic structural diagram of a negative conical mirror provided by an embodiment of the present application.

[0055] Figure 4 It is a side view of a negative conical mirror provided by an embodiment of the present application.

[0056] Figure 5 It is a schematic structural diagram of a positive conical mirror provided by an embodiment of the present application.

[0057] Figure 6 This is a side view of a positive conical mirror provided by an embodiment of the present application.

[0058] Figure 7 This is a projection view of a positive / negative conical mirror provided by an embodiment of the present application in the propagation direction of a parallel laser beam.

[0059] Figure 8 This is a projection view of a complementary conical mirror group provided by an embodiment of the present application in the propagation direction of a parallel laser beam.

[0060] Figure 9 This is a spot distribution diagram of an output laser beam provided by an embodiment of the present application.

[0061] Figure 10 This is another projection view of a complementary conical mirror group provided by an embodiment of the present application in the propagation direction of a parallel laser beam.

[0062] Figure 11 This is another spot distribution diagram of an output laser beam provided by an embodiment of the present application.

[0063] Figure 12 This is another schematic diagram of the propagation of a laser beam provided by an embodiment of the present application.

[0064] Figure 13 This is a projection view of a positive / negative conical mirror sub-mirror provided by an embodiment of the present application in the propagation direction of a parallel laser beam.

[0065] Figure 14 This is a projection view of a complementary conical mirror group provided by an embodiment of the present application in the propagation direction of a parallel laser beam.

[0066] Figure 15 This is a schematic structural diagram of a lens of a laser processing system provided by an embodiment of the present application.

[0067] Figure 16 This is a schematic structural diagram of a rotating mechanism provided by an embodiment of the present application.

[0068] 100 Laser processing system

[0069] 11 Laser generating device

[0070] 12 Collimating mirror

[0071] 13 Complementary conical mirror group

[0072] 131 Negative conical mirror

[0073] 1311 First core area

[0074] 1312 Negative conical step area

[0075] 1313 Edge region

[0076] 132 Positive conical mirror

[0077] 1321 Second core region

[0078] 1322 Positive conical platform region

[0079] 14 Focusing mirror

[0080] 15 Lens barrel

[0081] 151 Collimating lens barrel

[0082] 152 Focusing lens barrel

[0083] 1521 Rotating mechanism

[0084] 15211 Inner rotating ring

[0085] 15212 Outer rotating ring

[0086] 15213 Connecting piece Detailed implementation manners

[0087] To make the objectives, technical solutions and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with the specific embodiments of this application and the corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of this application.

[0088] It is understandable that the laser processing system has a wide range of applications, such as in the optoelectronic field, material processing field, military field, etc. The laser processing system provided in this application is mainly applied to the material processing field, for example, material cutting, circuit board processing, material welding and other fields. Due to the high stability and high efficiency of the laser, it can easily perform precise processing on industrial materials. When the laser is focused on a point, the energy density in the focused area is large, the heat affected zone is small, and it has the characteristics of less pollution, less material consumption, deep penetration, strong adaptability, etc. during the processing. However, due to the concentrated energy of the directly output laser, when applied to thin plate welding, adverse phenomena such as spatter and perforation are likely to occur, and when the gap between the workpiece plates is large, problems such as unstable welding process and incomplete weld seam are likely to occur. Although the energy distribution at the edge of the annular light spot is uniform, it can effectively solve problems such as welding spatter and perforation. However, the divergence angle of the semiconductor laser is large. If a structure with a long optical path is used, it is easy to cause a large device aperture and is not convenient for application. The existing lens combinations for realizing the annular light spot structure, such as the double conical lens structure or the folding and reflecting optical path structure, have a long optical path and are not suitable for the laser processing system.

[0089] It should be noted that during laser welding, the energy distribution is related to the ratio of the transmitted beam area. From this, it can be known that the laser energy distributed in the annular light spot area and the point light spot area is different. By adjusting the areas of the point light spot area and the annular light spot area, the energy distribution adjustment between the annular light spot area and the point light spot area can be achieved. To adjust the area of the annular light spot area, the annular light spot can be converted into several arc-shaped light spots. By adjusting the sum of the central angle angles corresponding to the arc-shaped light spots, the area of the arc-shaped light spots changes accordingly. When the area of the arc-shaped light spots increases, the energy in the arc-shaped light spot area increases. Correspondingly, the energy in the central light spot area becomes lower. To adjust the areas of the point light spot area and the annular light spot area, a corresponding lens combination can be used. That is, in the collimating and focusing optical path, a lens combination that can adjust the area ratio of the point light spot area and the annular light spot area is added to change the propagation direction of all or part of the laser beam, so as to achieve the purpose of changing the light spot shape. Adding a lens combination that can adjust the area ratio of the point light spot area and the annular light spot area on the basis of the original optical path of the laser processing system can meet the processing requirements in different application scenarios. Moreover, the structure is compact and has little influence on the optical path length.

[0090] Please refer to Figure 1-7, this application discloses a laser processing system 100, which is provided with a complementary conical mirror group 13 capable of adjusting the area ratio of the point light spot area to the annular light spot area. By rotating the negative conical mirror 131 or the positive conical mirror 132 in the complementary conical mirror group 13 and adjusting the included angle between the two, arc-shaped light spots of different sizes can be obtained. When the overlapping part of the two lenses is large, the energy of the central light spot is high and the energy of the arc-shaped light spot is low; when the overlapping part is small, the energy of the central light spot is low and the energy of the arc-shaped light spot is high. Specifically, a laser processing system 100 includes:

[0091] A laser generating device 11 that generates a light source in an excited state;

[0092] A collimating mirror 12, the focus of the collimating mirror 12 is collinear with the light source of the laser generating device 11;

[0093] A complementary conical mirror group 13 disposed in the laser propagation direction, adjacent to the collimating mirror 12 and coaxially distributed;

[0094] A focusing mirror 14 disposed in the laser propagation direction and coaxially distributed with the collimating mirror 12, adjacent to the other side opposite to the side adjacent to the complementary conical mirror group 13 and the collimating mirror 12;

[0095] Wherein, the complementary conical mirror group 13 includes: a negative conical mirror 131; a positive conical mirror 132 paired with the negative conical mirror 131 and rotatable coaxially relative to the negative conical mirror 131;

[0096] The negative conical mirror 131 includes: a first core area 1311; a negative conical platform area 1312 adjacent to the first core area 1311;

[0097] The positive conical mirror 132 includes: a second core area 1321 corresponding to the first core area 1311 for realizing the central light spot; a positive conical platform area 1322 adjacent to the second core area 1322 and corresponding to the negative conical platform area 1312.

[0098] It can be understood that the generation of laser is inseparable from stimulated emission. In the thermal equilibrium state, the number of high-energy state particles is less than the number of low-energy state particles. Stimulated emission requires the number of high-energy state particles to be more than the number of low-energy state particles. Therefore, the necessary condition for generating laser is that the working substance is in the state of population inversion distribution. Here, the laser generating device 11 is used to generate a light source in an excited state, that is, to realize population inversion and generate a laser beam. The laser light source generated by the laser generating device 11 here can generate different types of laser beams according to different active substances. It can be understood that the specific type of active substance selected by the laser generating device 11 here obviously does not limit the protection scope of this application.

[0099] The collimating mirror 12 is mainly used to convert the laser beam generated by the laser generating device 11 into a parallel laser beam. It can be understood that the laser beam generated by the light source at the laser generating device 11 has a certain divergence angle. The incident light beam of the collimating mirror 12 is the laser beam with a certain divergence angle. After being refracted by the collimating mirror 12, the outgoing laser beam is a parallel beam. In practical applications, the collimating mirror 12 is generally a convex lens. When light propagates through a convex lens, the light beam passing through the optical center does not change its propagation direction; the light beam parallel to the principal optical axis is refracted through its focal point; the light beam passing through the focal point is refracted parallel to the principal optical axis. Thus, it can be known that if the laser beam propagating through the collimating mirror 12 is a parallel beam, in addition to the focal point of the collimating mirror 12 and the light source of the laser generating device 11 being collinear, it is also necessary to make the light source of the laser generating device 11 coincide with the focal point of the collimating mirror 12. Here, the specific preparation material and shape of the collimating mirror 12 can be flexibly selected according to the actual situation.

[0100] A complementary conical mirror group 13 is arranged in the laser propagation direction, adjacent to the collimating mirror 12 and coaxially distributed. The complementary conical mirror group 13 here is mainly used to adjust the area ratio between the point light spot area and the annular light spot area. The complementary conical mirror group 13 includes: a negative conical mirror 131, and a positive conical mirror 132 that is paired with the negative conical mirror 131 and can rotate coaxially relative to the negative conical mirror 131.

[0101] For details, please refer to Figure 3-7 , the negative conical mirror 131 includes: a first core area 1311; a negative conical platform area 1312 adjacent to the first core area 1311. The first core area 1311 here can be understood as the area where the propagation direction of the parallel laser beam does not change. That is, the parallel laser beam propagates through the first core area 1311 of the negative conical mirror 131, and the propagation direction does not change. In practical applications, the first core area 1311 can be the area where the light beam incident surface and the light beam outgoing surface of the negative conical mirror 131 are parallel, or a virtual, entity-free hollow area in the laser beam propagation direction. The negative conical platform area 1312 here can be understood as the area where the conical surface is located above the light beam outgoing surface of the first core area 1311 in the light beam propagation direction. The angle between the conical surface and the first core area 1311 can be designed according to the actual situation. Here, the adjacency can be understood as that the first core area 1311 and the negative conical platform area 1312 are in a connected relationship in space.

[0102] It should be noted that the conical surface of the negative conical platform area 1312 is not a continuous conical surface. That is, the central angle corresponding to the edge arc of the negative conical platform area 1312 is not 360°. That is, it can be referred to Figure 7 , the projection of the negative conical platform area 1312 in the parallel laser beam propagation direction is not circular, but fan-shaped.

[0103] Further, in a preferred embodiment provided by the present application, the negative conical mirror 131 further includes an edge region 1313 adjacent to the negative conical region 1312. The provision of the edge region 1313 facilitates the processing and protection of the negative conical mirror 131. It can be understood as the region in the negative conical mirror 131 that is non-coplanar with the negative conical region 1312. Since the exit surface of the edge region 1313 is non-coplanar with the negative conical region 1312, that is, the included angle between the extension surface of the edge region 1313 and the exit surface of the first core region 1311 is different from the included angle between the negative conical region 1312 and the exit surface of the first core region 1311, the propagation directions of the parallel laser beams on the exit surface of the edge region 1313 and the laser beam exiting from the negative conical region 1312 are different. If the included angle between the extension surface of the edge region 1313 and the exit surface of the first core region 1311 is smaller than the included angle between the negative conical region 1312 and the exit surface of the first core region 1311, that is, the inclination of the extension surface of the edge region 1313 relative to the exit surface of the first core region 1311 increases, the propagation of the laser beam exiting from the edge region 1313 is more diffused. If the included angle between the extension surface of the edge region 1313 and the exit surface of the first core region 1311 is greater than the included angle between the negative conical region 1312 and the exit surface of the first core region 1311, that is, the inclination of the extension surface of the edge region 1313 relative to the exit surface of the first core region 1311 decreases, the propagation of the laser beam exiting from the edge region 1313 is more convergent. If the edge region 1313 is parallel to the first core region 1311, the propagation direction of the beam remains unchanged compared to the incident light ray.

[0104] In a preferred embodiment provided by the present application, the plane where the edge region 1313 is located is perpendicular to the axis of the negative conical mirror 131, that is, the edge region 1313 is parallel to the first core region 1311. The propagation direction of the beam exiting from the edge region 1313 remains unchanged. In this way, it is convenient for the installation of the negative conical mirror 131 in the lens, and the chipping phenomenon during its processing is prevented, improving the processing yield of the negative conical mirror 131.

[0105] The positive conical mirror 132 includes: a first core area 1311 corresponding to the first core area 1311 and a second core area 1321 for realizing a central light spot; a positive conical platform area 1322 adjacent to the second core area 1321 and corresponding to the negative conical platform area 1312. The second core area 1321 here can be understood as an area adjacent to the first core area 1311 with a comparable size and that does not change the propagation direction of the parallel laser beam. That is, the parallel laser beam propagating through the first core area 1311 propagates through the second core area 1321 of the positive conical mirror 132, and the propagation direction remains unchanged. In a specific implementation provided by the present application, the projection of the second core area 1321 on the propagation direction of the parallel laser beam overlaps with the first core area 1311. In practical applications, the second core area 1321 can be an area adjacent to the first core area 1311 with a comparable size and whose light beam incident surface and exit surface are parallel, or a virtual hollow area without any entity in the propagation direction of the parallel laser beam. The size of the gap between the second core area 1321 and the first core area 1311 has a relatively small impact on the entire optical path length and can be ignored. Generally speaking, a gap of less than 1 mm is reserved to prevent scratches on the negative conical mirror 131 and the positive conical mirror 132. The positive conical platform area 1322 here can be understood as the area where the conical surface complementary to the negative conical platform area 1312 is located in the light beam propagation direction. It should be noted that complementary refers to the spatial relationship presented between the positive conical platform area 1322 and the negative conical platform area 1312 when they overlap. Here, adjacent can be understood as a connection relationship in space between the second core area 1321 and the positive conical platform area 1322. The angle between the conical surface of the positive conical platform area 1322 and the second core area 1321 can be designed according to the angle between the negative conical platform area 1312 and the first core area 1311. The conical surface of the positive conical platform area 1322 is not a continuous conical surface. That is, the central angle corresponding to the edge arc of the positive conical platform area 1322 is not 360°. That is, referring to Figure 7 , the projection of the positive conical platform area 1322 on the propagation direction of the parallel laser beam is not circular but fan-shaped. The conical surface of the positive conical platform area 1322 can be designed according to the conical surface of the negative conical platform area 1312, as long as the positive conical mirror 132 can rotate coaxially relative to the negative conical mirror 131.

[0106] In a specific implementation provided by the present application, the side (incident surface) of the negative conical mirror 131 close to the collimating mirror 12 can be a plane perpendicular to the light beam propagation direction; the side (exit surface) of the positive conical mirror 132 far from the collimating mirror 12 can be a plane perpendicular to the light beam propagation direction. And, a space for facilitating the rotation of the lens is provided between the negative conical mirror 131 and the positive conical mirror 132.

[0107] Specifically, the side of the negative conical mirror 131 close to the collimating mirror 12 (the incident surface) can be a plane perpendicular to the beam propagation direction, that is, the parallel laser beam propagating through the collimating mirror 12 is perpendicularly incident on the incident plane of the negative conical mirror 131. In other words, the projections of the first core region 1311, the negative conical terrace region 1312, and the edge region 1313 in the parallel laser beam propagation direction together constitute the incident surface of the negative conical mirror 131. At this time, for the laser beam propagating through the first core region 1311, since its exit surface is parallel to the incident surface, the propagation direction of the laser beam remains unchanged. For the laser beam propagating through the negative conical terrace region 1312, since there is a certain angle between its exit surface and the incident surface, the laser beam diverges.

[0108] The side of the positive conical mirror 132 away from the collimating mirror 12 (the exit surface) can be a plane perpendicular to the beam propagation direction, that is, in the parallel laser beam propagation direction, the exit surface of the positive conical mirror 132 is parallel to the incident surface of the negative conical mirror 131. In other words, the projections of the second core region 1321 and the positive conical terrace region 1322 in the parallel laser beam propagation direction together constitute the incident surface of the positive conical mirror 132. The incident surface of the positive conical mirror 132 is the second core region 1321 corresponding to the first core region 1311 and the positive conical terrace region 1322 corresponding to the negative conical terrace region 1312. Since the second core region 1321 corresponds to the first core region 1311, the propagation direction of the parallel laser beam emitted from the first core region 1311 remains unchanged after passing through the second core region 1321. Moreover, the laser beam incident through the positive conical terrace region 1322 can be converged.

[0109] It should be noted that the projections of the negative conical terrace region 1312 and the conical terrace region in the parallel laser beam propagation direction are not circular but fan-shaped. And since the negative conical mirror 131 and the positive conical mirror 132 can rotate relative to each other, the angle between them can be adjusted by rotating the negative conical mirror 131 or the positive conical mirror 132. To reduce the influence of the rotational clearance between the positive conical mirror 132 and the negative conical mirror 131 on the laser beam propagation and ensure the stable rotation of the positive conical mirror 132 and the negative conical mirror 131, in a preferred embodiment provided in the present application, the taper sizes of the negative conical terrace region 1312 and the positive conical terrace region 1322 are equal. And to ensure the same propagation effect of the positive conical mirror 132 and the negative conical mirror 131 on the laser beam, in a preferred embodiment provided in the present application, the negative conical mirror 131 and the positive conical mirror 132 are made of materials with the same light refraction coefficient. The specific refraction coefficients of the negative conical mirror 131 and the positive conical mirror 132 can be selected according to actual situations.

[0110] It can be understood that the relative positions of the negative conical mirror 131 and the positive conical mirror 132 determine the propagation direction of the laser beam emitted through the complementary conical mirror group 13. When the included angle between the negative conical mirror 131 and the positive conical mirror 132 is adjusted by rotating the negative conical mirror 131 or the positive conical mirror 132, the relative positions of the first core region 1311 and the second core region 1321 will not change.

[0111] When the negative conical mirror 131 coincides with the positive conical mirror 132, the rotation angle between them is 0°. At this time, the projections of the negative conical platform region 1312 and the positive conical platform region 1322 in the direction of the parallel laser beam propagation overlap. Since the incident surface of the negative conical mirror 131 is a plane perpendicular to the beam propagation direction, and the exit surface of the positive conical mirror 132 is a plane perpendicular to the beam propagation direction, the incident surface and the exit surface of the complementary conical mirror group 13 are parallel. And the distance between them is small, which is equivalent to inserting a parallel flat plate in the optical path. When the incident light is a parallel beam, the propagation direction will not be changed. At this time, a part of the parallel laser beam emitted by the collimating mirror 12 propagates through the complementary conical mirror group 13. Since the projections of the negative conical platform region 1312 and the conical platform region in the direction of the parallel laser beam propagation are fan-shaped, there is still a part of the parallel laser beam emitted by the collimating mirror 12 that does not propagate through the complementary conical mirror group 13. This part of the laser beam will not change the propagation direction and directly enters the focusing mirror 14. In summary, when the negative conical mirror 131 coincides with the positive conical mirror 132, the propagation direction of the parallel laser beam emitted by the collimating mirror 12 will not change.

[0112] Starting from the position where the negative conical mirror 131 coincides with the positive conical mirror 132, rotating any lens in the complementary conical mirror group 13 around the axis in any direction will change the angle between the negative conical mirror 131 and the positive conical mirror 132. During the rotation, if there is still a partially overlapping area between the negative conical mirror 131 and the positive conical mirror 132, the propagation direction of the parallel laser beam propagating through this overlapping area remains unchanged. At this time, there are partially non-overlapping areas on the negative conical mirror 131 and the positive conical mirror 132 respectively, and the negative conical platform area 1312 and the projection of the conical platform area on the propagation direction of the parallel laser beam partially overlap. That is, the incident surface of the complementary conical mirror group 13 includes, in addition to the incident surface of the negative conical mirror 131, a part of the positive conical platform area 1322 of the positive conical mirror 132; the exit surface of the complementary conical mirror group 13 includes, in addition to the exit surface of the positive conical mirror 132, a part of the negative conical platform area 1312 of the negative conical mirror 131. At this time, a part of the parallel laser beam emitted by the collimating mirror 12 directly enters the non-overlapping positive conical platform area 1322, and the light beam converges. A part of the parallel laser beam emitted by the collimating mirror 12 also directly exits from the non-overlapping negative conical platform area 1312, and the light beam diverges. It should be noted that there may still be a part of the parallel laser beam emitted by the collimating mirror 12 that does not propagate through the complementary conical mirror group 13. This part of the laser beam will not change its propagation direction and directly enters the focusing mirror 14. In summary, when the negative conical mirror 131 and the positive conical mirror 132 are rotated and there is a partially overlapping area, after the parallel laser beam emitted by the collimating mirror 12 propagates through the complementary conical mirror group 13, laser beams in a converging, diverging, and parallel state compared to the original parallel beam can be obtained respectively.

[0113] During the rotation process, if there is no overlapping area between the negative conical mirror 131 and the positive conical mirror 132, that is, there is no overlapping area in the projection of the negative conical area 1312 and the positive conical area 1322 in the direction of the parallel laser beam propagation. At this time, the incident surface of the complementary conical mirror group 13 includes the positive conical area 1322 of the positive conical mirror 132 in addition to the incident surface of the negative conical mirror 131; the exit surface of the complementary conical mirror group 13 includes the negative conical area 1312 of the negative conical mirror 131 in addition to the exit surface of the positive conical mirror 132. At this time, part of the parallel laser beam emitted by the collimator 12 directly enters the positive conical area 1322, and the light beam converges. Part of the parallel laser beam emitted by the collimator 12 also directly exits from the negative conical area 1312, and the light beam diverges. It should be noted that there may still be part of the parallel laser beam that does not propagate through the complementary conical mirror group 13. This part of the laser beam will not change its propagation direction and directly enters the focusing mirror 14. Since the relative positions of the first core area 1311 and the second core area 1321 do not change when the angle between the negative conical mirror 131 and the positive conical mirror 132 is adjusted by rotation, the propagation direction of the laser beam propagating through the first core area 1311 and the second core area 1321 remains unchanged and is still a parallel beam. To sum up, when the negative conical mirror 131 and the positive conical mirror 132 are rotated and there is no overlapping area, after the parallel laser beam emitted by the collimator 12 propagates through the complementary conical mirror group 13, laser beams that are convergent, divergent, and parallel compared to the original parallel beam can be obtained respectively.

[0114] The parallel laser beam emitted by the collimator 12 propagates through the complementary conical mirror group 13 in any state and will enter the focusing mirror 14. It should be noted that the laser beam incident on the focusing mirror 14 may include, in addition to the laser beam emitted by the complementary conical mirror group 13, the parallel laser beam that does not propagate through the complementary conical mirror group 13. The focusing mirror 14 is arranged coaxially with the laser propagation direction and the collimator 12, and is adjacent to the other side opposite to the side adjacent to the collimator 12 of the complementary conical mirror group 13. That is, the focusing mirror 14 is coaxially distributed with the collimator 12 and the complementary conical mirror group 13, and the incident surface of the focusing mirror 14 is adjacent to the positive conical mirror 132 in the complementary conical mirror group 13. The focusing mirror 14 is mainly used to focus the laser beam emitted by the complementary conical mirror group 13. In practical applications, the collimator 12 is generally a convex lens. When light propagates through a convex lens, the light passing through the optical center does not change its propagation direction; the light parallel to the principal axis is refracted through its focus; the light passing through the focus is refracted parallel to the principal axis. If the incident beam of the focusing mirror 14 is a parallel beam, after passing through the focusing mirror 14, a spot with concentrated energy is finally obtained.

[0115] In a specific embodiment provided by the present application, when the negative conical mirror 131 coincides with the positive conical mirror 132 and the light beam emitted by the complementary conical mirror group 13 is incident on the focusing mirror 14, a spot with concentrated energy is obtained. The size of the spot is achieved by adjusting the distance between the surface of the workpiece to be processed and the focusing mirror 14. Here, the specific preparation material and shape of the focusing mirror 14 can be flexibly selected according to the actual situation.

[0116] It can be understood that when the negative conical mirror 131 and the positive conical mirror 132 are rotated, laser beams that are convergent, divergent, and parallel to the parallel light beam emitted by the collimating mirror 12 are obtained respectively. Among them, the laser beam that is parallel to the parallel light beam emitted by the collimating mirror 12, after propagating through the focusing mirror 14, can obtain a point spot on the working surface. That is, when the negative conical mirror 131 and the positive conical mirror 132 partially overlap, the light beam propagating through the overlapping part of the complementary conical mirror group 13 forms a central spot after propagating through the focusing mirror 14. Or, the part of the parallel laser beam that does not propagate through the complementary conical mirror group 13 also forms a central spot after propagating through the focusing mirror 14. The laser beam that is divergent with respect to the parallel light beam emitted by the collimating mirror 12, after propagating through the focusing mirror 14, can obtain two symmetric arc spots on the working surface. The laser beam that is convergent with respect to the parallel light beam emitted by the collimating mirror 12, after propagating through the focusing mirror 14, the light beam first converges at the focal point and then diverges when continuing to propagate. When the working surface is located behind the focal point, two symmetric arc spots with the same size as the above can be obtained on the working surface. It should be noted that different sizes of arc spots can be obtained when the rotation angles of the negative conical mirror 131 and the positive conical mirror 132 are different. The length of the obtained arc spot here is determined by the design values of the central angles of the negative conical area 1312 and the positive conical area 1322.

[0117] Specifically, when the overlapping portion of the negative conical mirror 131 and the positive conical mirror 132 is relatively large, the area of the obtained arc-shaped light spot is relatively small. At this time, the area ratio of the arc-shaped light spot region to the point light spot region is relatively small, the energy of the central light spot is high, and the energy of the arc-shaped light spot is low. When the overlapping portion of the negative conical mirror 131 and the positive conical mirror 132 is relatively small, the area of the obtained arc-shaped light spot is relatively large. Here, the change in the area of the arc-shaped light spot is mainly reflected in the change in the arc length parameter of the arc-shaped light spot, and its width value in the radial direction does not change. At this time, the area ratio of the arc-shaped light spot region to the point light spot region is relatively large, the energy of the central light spot is low, and the energy of the arc-shaped light spot is high. In addition, the outer diameter size of the arc-shaped light spot is determined by the angle between the negative conical stage area 1312 and the first core area 1311, and the angle between the positive conical stage area 1322 and the second core area 1321. The larger the angle between the negative conical stage area 1312 and the first core area 1311, and the larger the angle between the positive conical stage area 1322 and the second core area 1321, the larger the offset angle of the arc-shaped light spot. At this time, under the condition of a certain focal length and working distance, the outer diameter of the annular light spot is larger. The angles between the negative conical stage area 1312 and the first core area 1311, and between the positive conical stage area 1322 and the second core area 1321 can be designed according to the actual usage method and requirements.

[0118] Tests have shown that the energy distribution between the arc-shaped light spot and the point light spot is related to the ratio of the transmitted beam area, and the energy and angle change show a linear relationship. For example, when the negative conical mirror 131 and the positive conical mirror 132 partially overlap, the light beam propagating through the overlapping portion of the complementary conical mirror group 13 forms a central light spot after passing through the focusing mirror 14. If the total energy percentage of all laser beams emitted from the focusing mirror 14 is 100%, and the proportion of the light beam passing through this part is 50%, then the theoretical energy ratio between the edge and the center is 1:1. The overlapping area of the projections of the negative conical mirror 131 and the positive conical mirror 132 in the propagation direction of the parallel laser beam includes: the overlapping area of the first core area 1311 and the second core area 1321; the overlapping area of the projections of the negative conical stage area 1312 and the positive conical stage area 1322 in the propagation direction of the parallel laser beam. Among them, the overlapping area of the projections of the negative conical stage area 1312 and the positive conical stage area 1322 in the propagation direction of the parallel laser beam is related to the angle corresponding to the overlapping sector. The sizes of the first core area 1311 and the second core area 1321 can be designed according to the energy requirements of the central light spot and can be designed as circular. And, the overlapping area of the first core area 1311 and the second core area 1321 does not change with the rotation angle of the negative conical mirror 131 and the positive conical mirror 132.

[0119] In a preferred embodiment provided by the present application, the sum of the central angles corresponding to the sectors obtained by projecting the negative conical area 1312 and the positive conical area 1322 in the propagation direction of the parallel laser beam is 360°, that is, the sum of the central angles corresponding to the edge arcs of the negative conical area 1312 and the positive conical area 1322 is 360°. In this way, when the negative conical mirror 131 and the positive conical mirror 132 are rotated to a certain angle, the negative conical area 1312 and the positive conical area 1322 are projected as a circle in the propagation direction of the parallel laser beam. At this time, a complete annular light spot can be obtained on the workpiece surface. As the negative conical mirror 131 and the positive conical mirror 132 rotate, the projections of the negative conical area 1312 and the positive conical area 1322 in the propagation direction of the parallel laser beam change accordingly, showing a plurality of sector distributions. At this time, several arc-shaped light spots can be obtained on the workpiece surface. In this way, various different-shaped light spots can be obtained on the workpiece surface, and can be flexibly switched according to the actual processing scenario.

[0120] Further, in a preferred embodiment provided by the present application, please refer to Figure 8 , the negative conical mirror 131 includes: two centrally symmetric sectors; the radian of each sector is a preset angle. Here, the two centrally symmetric sectors mean that the projection of the negative conical mirror 131 in the propagation direction of the parallel laser beam includes two centrally symmetric sectors. In a specific embodiment provided by the present application, the radian of each sector is 90 degrees, that is, the central angle corresponding to the sector projection of the negative conical mirror 131 in the propagation direction of the parallel laser beam is 90°. At this time, correspondingly, the positive conical mirror 132 includes two centrally symmetric sectors, and the radian of each sector is 90 degrees.

[0121] When the positive conical mirror 132 and the negative conical mirror 131 completely overlap, the propagation direction of the light beam transmitted through the complementary conical mirror remains unchanged. At this time, the projection of the complementary conical mirror group 13 in the propagation direction of the parallel laser beam includes two centrally symmetric sectors, and the radian of each sector is 90 degrees. Under the action of the focusing mirror 14, the laser beam emitted from the complementary conical mirror group 13 finally forms a point light spot on the workpiece surface.

[0122] Please refer to Figure 9. When either the positive conical mirror 132 or the negative conical mirror 131 is rotated by 90 degrees, and there is no overlapping area between the positive conical mirror 132 and the negative conical mirror 131, the projection of the complementary conical mirror group 13 in the propagation direction of the parallel laser beam is circular, including four sectors, each with a radian of 90 degrees. At this time, except that the first core area 1311 coincides with the second core area 1321, the rest of the positive conical mirror 132 and the negative conical mirror 131 are completely separated. The incident surface of the complementary conical mirror group 13 is the incident surface of the negative conical mirror 131 and the positive conical platform area 1322 of the positive conical mirror 132. The laser beam incident on the incident surface of the negative conical mirror 131 exits from the negative conical platform area 1312 and is incident on the focusing mirror 14. After passing through the focusing mirror 14, two symmetric quarter-circular light spots are finally formed on the workpiece surface. The laser beam incident on the positive conical platform area 1322 of the positive conical mirror 132 exits from the exit surface of the positive conical mirror 132 and is incident on the focusing mirror 14. After passing through the focusing mirror 14, the light beam first converges at the focal point and diverges when it continues to propagate. When the working surface is behind the focal point, two symmetric quarter-circular light spots with the same size as above can be formed on the workpiece surface. It should be noted that the light beam incident through the first core area 1311 exits through the second core area 1321, and the propagation direction of the light beam remains unchanged. After passing through the focusing mirror 14, a point light spot is finally formed on the workpiece surface. The four quarter-arc light spots form a complete annular light spot, which together with the central point light spot constitutes a point-annular light spot.

[0123] Please refer to Figures 10-11 When either the positive conical mirror 132 or the negative conical mirror 131 is rotated to any angle between 0° and 90°, for example, 60°, the positive conical mirror 132 and the negative conical mirror 131 partially overlap. The projection of the complementary conical mirror group 13 in the propagation direction of the parallel laser beam is a sector. At this time, except that the first core area 1311 coincides with the second core area 1321, there is an overlapping area with a 30° angle between the negative conical platform area 1312 and the positive conical platform area 1322. The parallel laser beam passes through the overlapping area (including the first core area 1311 and the second core area 1321), and the outgoing light beam is still a parallel beam and is incident on the focusing mirror 14. After passing through the focusing mirror 14, this part of the light beam finally forms a point light spot on the workpiece surface. The parallel laser beam passes through the non-overlapping area of the complementary conical mirror group 13 and finally forms four discontinuous arc-shaped light spots on the workpiece surface. The central angle corresponding to each arc-shaped light spot is 60°, which is the same as the rotation angle of the positive / negative conical mirror. By continuously adjusting the rotation angle of either the positive conical mirror 132 or the negative conical mirror 131, arc-shaped light spots in different distribution states can be obtained, so as to meet different requirements in different application scenarios.

[0124] It should be noted that the positive conical mirror 132 and the negative conical mirror 131 are designed as two centrally symmetric sectors, and the radian of each sector is 90 degrees. In this way, the switching between the circular light spot and the arc light spot can be realized with the fewest lenses, which has little influence on the optical path length and has a compact structure.

[0125] Furthermore, in a preferred embodiment provided by the present application, the negative conical mirror 131 includes: two discrete sub-mirrors; each sub-mirror has a sector with a radian of a preset angle; the two sub-mirrors are centrally symmetrically distributed. Here, "discrete" can be understood as that there is no common connecting part between the two sub-mirrors in the negative conical mirror 131. In a specific embodiment provided by the present application, the preset angle is 90°. At this time, the projections of the two sub-mirrors in the propagation direction of the parallel laser beam are two sectors that are centrally symmetric and have no connection relationship, and the radian of each sector is 90°. Here, the two discrete sub-mirrors in the negative conical mirror 131 can achieve their spatially centrally symmetric distribution relationship by being fixed to the same lens barrel. The incident surfaces of the two sub-mirrors are coplanar and located in the same plane perpendicular to the optical axis. Correspondingly, the positive conical mirror 132 includes two centrally symmetric sectors, and the radian of each sector is 90 degrees; the two sub-mirrors are centrally symmetrically distributed. Similarly, the two discrete sub-mirrors in the positive conical mirror 132 can also achieve their spatially centrally symmetric distribution relationship by being fixed to the same lens barrel. Moreover, the incident surfaces of the two discrete sub-mirrors in the positive conical mirror 132 are coplanar and located in the same plane perpendicular to the optical axis. At this time, the first core area 1311 and the second core area 1321 can be understood as virtual areas without any entities in the propagation direction of the parallel laser beam, which is a circular hole, and the center line of the circular hole coincides with the beam axis. The center line of the circular hole coincides with the beam axis.

[0126] When the positive conical mirror 132 and the negative conical mirror 131 completely overlap, the propagation direction of the beam propagating through the complementary conical mirror remains unchanged. At this time, the projection of the complementary conical mirror group 13 in the propagation direction of the parallel laser beam is two sectors that are centrally symmetric and have no connection relationship, and the radian of each sector is 90°. Under the action of the focusing mirror 14, the laser beam emitted from the complementary conical mirror group 13 finally forms a point light spot on the workpiece surface.

[0127] When either the positive conical mirror 132 or the negative conical mirror 131 is rotated by 90 degrees and there is no overlapping area between the positive conical mirror 132 and the negative conical mirror 131, the projection of the complementary conical mirror group 13 in the propagation direction of the parallel laser beam is circular, including four sectors, each with a radian of 90 degrees. At this time, the positive conical mirror 132 and the negative conical mirror 131 are completely separated. The incident surface of the complementary conical mirror group 13 is the incident surface of the negative conical mirror 131 and the positive conical platform area 1322 of the positive conical mirror 132. The laser beam incident on the incident surface of the negative conical mirror 131 exits from the negative conical platform area 1312 and is incident on the focusing mirror 14. After passing through the focusing mirror 14, two symmetric quarter-circular light spots are finally formed on the workpiece surface. The laser beam incident on the positive conical platform area 1322 of the positive conical mirror 132 exits from the exit surface of the positive conical mirror 132 and is incident on the focusing mirror 14. After passing through the focusing mirror 14, the light beam first converges at the focal point and diverges when it continues to propagate. When the working surface is behind the focal point, two symmetric quarter-circular light spots with the same size as above can be formed on the workpiece surface. It should be noted that the light beam incident through the first core area 1311 exits through the second core area 1321, and the propagation direction of the light beam remains unchanged. After passing through the focusing mirror 14, a point light spot is finally formed on the workpiece surface. The four quarter-circular light spots form a complete annular light spot, which together with the central point light spot constitutes a point-annular light spot.

[0128] When either the positive conical mirror 132 or the negative conical mirror 131 is rotated to any angle between 0° and 90°, for example, 60°, the positive conical mirror 132 and the negative conical mirror 131 partially overlap. The projection of the complementary conical mirror group 13 in the propagation direction of the parallel laser beam is fan-shaped. At this time, there is an overlapping area with a 30° angle between the negative conical platform area 1312 and the positive conical platform area 1322. The parallel laser beam passes through the overlapping area (including the first core area 1311 and the second core area 1321), and the outgoing light beam is still a parallel beam and is incident on the focusing mirror 14. After passing through the focusing mirror 14, this part of the light beam finally forms a point light spot on the workpiece surface. The parallel laser beam passes through the non-overlapping area of the complementary conical mirror group 13 and finally forms four discontinuous arc-shaped light spots on the workpiece surface. The central angle corresponding to each arc-shaped light spot is 60°, which is the same as the rotation angle of the positive / negative conical mirror. By continuously adjusting the rotation angle of either the positive conical mirror 132 or the negative conical mirror 131, arc-shaped light spots in different distribution states can be obtained, so as to meet different requirements in different application scenarios.

[0129] It should be noted that the positive conical mirror 132 and the negative conical mirror 131 are designed as centrosymmetric discrete sub-mirrors, and each sub-mirror has a sector with a radian of 90 degrees. Similarly, the switching between a circular light spot and an arc-shaped light spot can be achieved with the fewest lenses, with less impact on the optical path length and a compact structure. According to actual usage needs, each sub-mirror can also be sequentially installed in different rotating lenses to achieve more changes in the light spot shape. However, at this time, if a uniformly distributed light spot is required, at least two sub-mirrors need to be rotated simultaneously.

[0130] In practical applications, the number of sub-mirrors in the positive / negative conical mirror can also be designed according to the actual needs of the output laser light spot. However, to ensure the flexible switching between a circular ring-shaped and an arc-shaped light spot, it should be ensured that the sum of the radian angles of the sectors corresponding to the projections of all sub-mirrors in the positive conical mirror 132 and the negative conical mirror 131 in the propagation direction of the parallel light beam is 360 degrees. To obtain several uniformly distributed arc-segment light spots to ensure uniform distribution of laser energy, the angle between adjacent sub-mirrors in the positive / negative conical mirror can be set to the same angle. In a preferred embodiment provided by the present application, the negative conical mirror 131 can also be composed of a preset number of discrete sub-mirrors; and each sub-mirror has a sector with a radian of a preset angle. For example, the negative conical mirror 131 is composed of three discrete sub-mirrors; each sub-mirror has a sector with a radian of 60 degrees; the three sub-mirrors are centrosymmetrically distributed. In this way, more different types of output light spots can be obtained, providing more diverse choices for users.

[0131] Please refer to Figures 15-16 , in a specific embodiment provided by the present application, the collimating mirror 12, the complementary conical mirror group 13, and the focusing mirror 14 are sequentially arranged in the lens barrel 15. The lens barrel 15 includes: a collimating lens barrel 151; a focusing lens barrel 152 connected to the collimating lens barrel 151. The collimating mirror 12 and the negative conical mirror 131 in the complementary conical mirror group 13 are sequentially installed in the collimating lens barrel 151; the positive conical mirror 132 in the complementary conical mirror group 13 and the focusing mirror 14 are installed in the focusing lens barrel 152. Among them, the focusing lens barrel 152 is provided with a rotating mechanism 1521, including: an inner rotating ring 15211, an outer rotating ring 15212, and a connecting member 15213. The positive conical mirror 132 is connected to the inner rotating ring 15211. One end of the focusing lens barrel 152 close to the negative conical mirror 131 is provided with a guiding hole for installing the rotating mechanism 1521. The length of the guiding hole can be designed to be any length according to the requirement of the rotation angle. In this embodiment, the length of the guiding hole is designed to be one-fourth of the circumference of the focusing lens barrel 152, corresponding to a rotatable angle of 0° to 90°, and its width matches the connecting member 15213.

[0132] Specifically, the inner rotating ring 15211 of the rotating mechanism 1521 is installed inside the focusing lens barrel 152, and the outer rotating ring 15212 is installed outside the focusing lens barrel 152. That is, one end of the focusing lens barrel 152 close to the collimating lens 12 barrel is embedded in the groove formed by the inner rotating ring 15211 and the outer rotating ring 15212 of the rotating mechanism 1521. Mounting holes are provided on the surfaces of both the inner rotating ring 15211 and the outer rotating ring 15212. The mounting holes are distributed along the radial direction of the rotating mechanism 1521, are collinear with the guiding holes provided on the focusing lens barrel 152, and have the same aperture size. The connecting piece 15213 passes through the guiding holes of the focusing lens barrel 152 and the inner rotating ring 15211 and the outer rotating ring 15212 of the rotating mechanism 1521, thereby fixing the inner rotating ring 15211 and the outer rotating ring 15212 to the focusing lens barrel 152. In addition, marks of the rotation angles of the positive conical mirror 132 and the negative conical mirror 131 are provided on the surface of the outer rotating ring 15212, which is convenient for accurately adjusting the rotation angle of the positive conical mirror 132.

[0133] According to the rotation angle marks provided on the outer rotating ring, rotating the rotating mechanism can drive the positive conical mirror 132 to rotate, thereby adjusting the shape of the output light spot. When the rotation angle is 0°, the positive conical mirror 132 and the negative conical mirror 131 coincide, and a point light spot is output; when the rotation angle is 90°, the center of the output light spot is a point light spot, and a complete circular ring light spot is around it; when the included angle between the lens axes is between 0° and 90°, the center of the output light spot is a point light spot, and there are 4 symmetric arc light spots around it.

[0134] The embodiment of the present application also provides a complementary conical mirror group 13 for a laser processing system. The uses of laser processing systems are very extensive, and they have been in the directions of optoelectronics, material processing, military, etc. The laser processing system provided by the present application is mainly applied to the field of material processing, for example, material cutting, circuit board processing, material welding and other fields. Due to the high stability and high efficiency of the laser, it can easily perform precise processing on industrial materials. When the laser is focused at a point, the energy density in the focused area is large, the heat affected zone is small, and it has the characteristics of small pollution, less material consumption, deep penetration, strong adaptability, etc. during the processing. However, due to the concentrated energy of the directly output laser, when applied to thin plate welding, problems such as spatter and perforation are likely to occur, and when the gap between the workpiece plates is large, problems such as unstable welding process and incomplete weld seams are likely to occur. Although the energy distribution at the edge of the circular ring light spot is uniform, it can effectively solve problems such as welding spatter and perforation. However, the divergence angle of the laser processing system is large. If a structure with a long optical path is used, it is easy to cause a large device aperture and is not convenient for application. The existing lens combinations for realizing the circular ring light spot structure, such as the structure of double conical lenses or the structure of refractive and reflective optical paths, have a long optical path and are not suitable for laser processing systems.

[0135] It should be noted that during laser welding, the energy distribution is related to the ratio of the transmitted beam area. Thus, it can be seen that the laser energy distributed in the annular spot area and the point spot area is different. By adjusting the areas of the point spot area and the annular spot area, the energy distribution in the annular spot area and the point spot area can be adjusted. To adjust the area of the annular spot area, the annular spot can be converted into several arc-shaped spots. By adjusting the sum of the central angles corresponding to the arc-shaped spots, the area of the arc-shaped spots changes accordingly. As the area of the arc-shaped spots increases, the energy in the arc-shaped spot area increases. Correspondingly, the energy in the central spot area becomes lower. To adjust the areas of the point spot area and the annular spot area, a corresponding lens combination can be used. That is, in the collimation and focusing optical path, a lens combination that can adjust the area ratio of the point spot area and the annular spot area is added to change the propagation direction of all or part of the laser beam, thereby achieving the purpose of changing the spot shape. Adding a lens combination that can adjust the area ratio of the point spot area and the annular spot area on the basis of the original optical path of the laser processing system can meet the processing requirements in different application scenarios. Moreover, the structure is compact and has little impact on the optical path length.

[0136] Therefore, the present application also provides a complementary conical mirror group 13 that can change the propagation direction of the laser beam to adjust the areas of the point spot area and the annular spot area. In a specific embodiment provided by the present application, the complementary conical mirror group 13 can be used to propagate parallel laser beams, that is, the beam incident on the complementary conical mirror group 13 is a parallel laser beam, including:

[0137] A negative conical mirror 131;

[0138] A positive conical mirror 132 that is paired with the negative conical mirror 131 and can rotate coaxially relative to the negative conical mirror 131;

[0139] Among them, the negative conical mirror 131 includes: a first core area 1311; a negative conical table area 1312 adjacent to the first core area 1311;

[0140] The positive conical mirror 132 includes: a second core area 1321 corresponding to the first core area 1311 and used to realize the central spot; a positive conical table area 1322 adjacent to the second core area 1321 and corresponding to the negative conical table area 1312.

[0141] The negative conical mirror 131 includes: a first core region 1311; and a negative conical platform region 1312 adjacent to the first core region 1311. Here, the first core region 1311 can be understood as the region that does not change the propagation direction of the parallel laser beam. That is, the parallel laser beam propagates through the first core region 1311 of the negative conical mirror 131, and the propagation direction does not change. In practical applications, the first core region 1311 can be the region where the light incident surface and the light exit surface of the negative conical mirror 131 are parallel, or a virtual, entity-free hollowed-out region in the propagation direction of the laser beam. Here, the negative conical platform region 1312 can be understood as the region where the conical surface is located in the light propagation direction and above the light exit surface of the first core region 1311. The angle between the conical surface and the first core region 1311 can be designed according to the actual situation. Here, the adjacency can be understood as a connection relationship between the first core region 1311 and the negative conical platform region 1312 in space.

[0142] It should be noted that the conical surface of the negative conical platform region 1312 is not a continuous conical surface. That is, the central angle corresponding to the edge arc of the negative conical platform region 1312 is not 360°. That is, the projection of the negative conical platform region 1312 in the parallel laser beam propagation direction is not circular, but fan-shaped.

[0143] Furthermore, in a preferred embodiment provided by the present application, the negative conical mirror 131 further includes: an edge region 1313 adjacent to the negative conical platform region 1312. The setting of the edge region 1313 facilitates the processing and protection of the negative conical mirror 131. It can be understood as the region in the negative conical mirror 131 that is not coplanar with the negative conical platform region 1312. Since the light exit surface of the edge region 1313 is not coplanar with the negative conical platform region 1312, that is, the included angle between the extension surface of the edge region 1313 and the light exit surface of the first core region 1311 is different from the included angle between the negative conical platform region 1312 and the light exit surface of the first core region 1311, the propagation direction of the parallel laser beam on the light exit surface of the edge region 1313 is different from the propagation direction of the laser beam exiting from the negative conical platform region 1312. If the included angle between the extension surface of the edge region 1313 and the light exit surface of the first core region 1311 is smaller than the included angle between the negative conical platform region 1312 and the light exit surface of the first core region 1311, that is, the inclination degree of the extension surface of the edge region 1313 with respect to the light exit surface of the first core region 1311 increases, the propagation of the laser beam exiting from the edge region 1313 is more divergent. If the included angle between the extension surface of the edge region 1313 and the light exit surface of the first core region 1311 is greater than the included angle between the negative conical platform region 1312 and the light exit surface of the first core region 1311, that is, the inclination degree of the extension surface of the edge region 1313 with respect to the light exit surface of the first core region 1311 decreases, the propagation of the laser beam exiting from the edge region 1313 is more convergent. If the edge region 1313 is parallel to the first core region 1311, the propagation direction of the light beam is unchanged compared to the incident light.

[0144] In a preferred embodiment provided by the present application, the plane where the edge region 1313 is located is perpendicular to the axis of the negative conical mirror 131, that is, the edge region 1313 is parallel to the first core region 1311. The propagation direction of the light beam exiting through the edge region 1313 remains unchanged. In this way, it is convenient to install the negative conical mirror 131 in the lens, and the edge chipping phenomenon during its processing is prevented, improving the processing yield of the negative conical mirror 131.

[0145] The positive conical mirror 132 includes: a second core region 1321 corresponding to the first core region 1311 and used to realize the central light spot; a positive conical stage region 1322 adjacent to the second core region 1321 and corresponding to the negative conical stage region 1312. The second core region 1321 here can be understood as a region adjacent to the first core region 1311 with a comparable size and does not change the propagation direction of the parallel laser beam. That is, the parallel laser beam propagating through the first core region 1311 propagates through the second core region 1321 of the positive conical mirror 132, and the propagation direction remains unchanged. In a specific embodiment provided by the present application, the projections of the second core region 1321 and the first core region 1311 overlap in the propagation direction of the parallel laser beam. In practical applications, the second core region 1321 can be a region adjacent to the first core region 1311 with a comparable size, where the light incident surface and the light exit surface are parallel, or a virtual hollow region without any entity in the propagation direction of the parallel laser beam. The size of the gap between the second core region 1321 and the first core region 1311 has a relatively small impact on the entire optical path length and can be ignored. Generally speaking, a gap less than 1 mm is reserved to prevent scratching of the negative conical mirror 131 and the positive conical mirror 132. The positive conical stage region 1322 here can be understood as the region where the conical surface complementary to the negative conical stage region 1312 is located in the light beam propagation direction. It should be noted that complementary refers to the spatial relationship presented when the positive conical stage region 1322 and the negative conical stage region 1312 overlap. Here, adjacent can be understood as a connection relationship in space between the second core region 1321 and the positive conical stage region 1322. The angle between the conical surface of the positive conical stage region 1322 and the second core region 1321 can be designed according to the angle between the negative conical stage region 1312 and the first core region 1311. The conical surface of the positive conical stage region 1322 is not a continuous conical surface. That is, the central angle corresponding to the edge arc of the positive conical stage region 1322 is not 360°. That is to say, the projection of the positive conical stage region 1322 in the propagation direction of the parallel laser beam is not circular but fan-shaped. The conical surface of the positive conical stage region 1322 can be designed according to the conical surface of the negative conical stage region 1312 to ensure that the positive conical mirror 132 can rotate coaxially relative to the negative conical mirror 131.

[0146] In a specific embodiment provided by the present application, the incident surface of the negative conical mirror 131 is perpendicular to the beam propagation direction; the exit surface of the positive conical mirror 132 is perpendicular to the beam propagation direction. Moreover, a space facilitating the rotation of the lenses is provided between the negative conical mirror 131 and the positive conical mirror 132.

[0147] Specifically, the incident surface of the negative conical mirror 131 is perpendicular to the beam propagation direction, that is, the projections of the first core region 1311, the negative conical terrace region 1312, and the edge region 1313 in the direction parallel to the propagation direction of the laser beam together form the incident surface of the negative conical mirror 131. At this time, for the laser beam propagating through the first core region 1311, since its exit surface is parallel to the incident surface, the propagation direction of the laser beam remains unchanged. For the laser beam propagating through the negative conical terrace region 1312, since there is a certain angle between its exit surface and the incident surface, the laser beam diverges.

[0148] The exit surface of the positive conical mirror 132 is perpendicular to the beam propagation direction, that is, in the direction parallel to the propagation direction of the laser beam, the exit surface of the positive conical mirror 132 is parallel to the incident surface of the negative conical mirror 131. In other words, the projections of the second core region 1321 and the positive conical terrace region 1322 in the direction parallel to the propagation direction of the laser beam together form the incident surface of the positive conical mirror 132. The incident surface of the positive conical mirror 132 is the second core region 1321 corresponding to the first core region 1311 and the positive conical terrace region 1322 corresponding to the negative conical terrace region 1312. Since the second core region 1321 corresponds to the first core region 1311, the propagation direction of the parallel laser beam exiting from the first core region 1311 remains unchanged after passing through the second core region 1321. Moreover, the laser beam incident through the positive conical terrace region 1322 can be converged.

[0149] It should be noted that the projections of the negative conical terrace region 1312 and the positive conical terrace region 1322 in the direction parallel to the propagation direction of the laser beam are not circular but fan-shaped. Moreover, since the negative conical mirror 131 and the positive conical mirror 132 can rotate relative to each other, the angle between them can be adjusted by rotating the negative conical mirror 131 or the positive conical mirror 132. In a preferred embodiment provided by the present application, in order to reduce the influence of the rotational gap between the positive conical mirror 132 and the negative conical mirror 131 on the propagation of the laser beam and ensure the stable rotation of the positive conical mirror 132 and the negative conical mirror 131, the taper sizes of the negative conical terrace region 1312 and the positive conical terrace region 1322 are equal. Moreover, in a preferred embodiment provided by the present application, in order to ensure the same propagation effect of the positive conical mirror 132 and the negative conical mirror 131 on the laser beam, the negative conical mirror 131 and the positive conical mirror 132 are made of materials with the same light refraction coefficient. The specific refraction coefficients of the negative conical mirror 131 and the positive conical mirror 132 can be selected according to the actual situation.

[0150] It can be understood that the relative positions of the negative conical mirror 131 and the positive conical mirror 132 determine the propagation direction of the laser beam emitted through the complementary conical mirror group 13. When the included angle between the negative conical mirror 131 and the positive conical mirror 132 is adjusted by rotating the negative conical mirror 131 or the positive conical mirror 132, the relative positions of the first core region 1311 and the second core region 1321 will not change.

[0151] When the negative conical mirror 131 coincides with the positive conical mirror 132, the rotation angle between them is 0°. At this time, the projections of the negative conical stage region 1312 and the positive conical stage region 1322 in the direction of the parallel laser beam propagation overlap. Since the incident surface of the negative conical mirror 131 is a plane perpendicular to the beam propagation direction and the exit surface of the positive conical mirror 132 is a plane perpendicular to the beam propagation direction, the incident surface and the exit surface of the complementary conical mirror group 13 are parallel. And the distance between them is small, which is equivalent to inserting a parallel plate in the optical path. When the incident light is a parallel beam, the propagation direction will not be changed. At this time, a part of the parallel laser beam emitted through the collimating mirror 12 propagates through the complementary conical mirror group 13. Since the projections of the negative conical stage region 1312 and the conical stage region in the direction of the parallel laser beam propagation are fan-shaped, there is still a part of the laser beam that does not propagate through the complementary conical mirror group 13. This part of the laser beam will not change its propagation direction. In summary, when the negative conical mirror 131 coincides with the positive conical mirror 132, the propagation direction of the parallel laser beam emitted through the collimating mirror 12 will not change.

[0152] Starting from the position where the negative conical mirror 131 coincides with the positive conical mirror 132, rotating any lens in the complementary conical mirror group 13 around the axis in any direction will change the angle between the negative conical mirror 131 and the positive conical mirror 132. During the rotation, if there is still a partial overlapping area between the negative conical mirror 131 and the positive conical mirror 132, the propagation direction of the parallel laser beam propagating through this overlapping area remains unchanged. At this time, there are partially non-overlapping areas on the negative conical mirror 131 and the positive conical mirror 132 respectively, and the negative conical platform area 1312 and the projection part of the conical platform area in the propagation direction of the parallel laser beam partially overlap. That is, the incident surface of the complementary conical mirror group 13 includes, in addition to the incident surface of the negative conical mirror 131, a part of the positive conical platform area 1322 of the positive conical mirror 132; the exit surface of the complementary conical mirror group 13 includes, in addition to the exit surface of the positive conical mirror 132, a part of the negative conical platform area 1312 of the negative conical mirror 131. At this time, a part of the parallel laser beam directly enters the positive conical platform area 1322 of the non-overlapping part, and the beam converges. There is also a part of the parallel laser beam exiting from the collimating mirror 12 that directly exits from the negative conical platform area 1312 of the non-overlapping part, and the beam diverges. It should be noted that there may still be a part of the incident parallel laser beam that does not propagate through the complementary conical mirror group 13. This part of the laser beam will not change its propagation direction. In summary, when the negative conical mirror 131 and the positive conical mirror 132 are rotated and there is a partial overlapping area, after the parallel laser beam propagates through the complementary conical mirror group 13, laser beams in a converging, diverging, and parallel state compared to the original parallel beam will be obtained respectively.

[0153] During rotation, if there is no overlapping area between the negative conical mirror 131 and the positive conical mirror 132, that is, there is no overlapping area in the projection of the negative conical area 1312 and the positive conical area 1322 in the direction of the parallel laser beam propagation. At this time, the incident surface of the complementary conical mirror group 13 includes, in addition to the incident surface of the negative conical mirror 131, the positive conical area 1322 of the positive conical mirror 132; the exit surface of the complementary conical mirror group 13 includes, in addition to the exit surface of the positive conical mirror 132, the negative conical area 1312 of the negative conical mirror 131. At this time, part of the parallel laser beam directly enters the positive conical area 1322, and the beam converges. There is also a part of the parallel laser beam that directly exits from the negative conical area 1312, and the beam diverges. It should be noted that there may still be a part of the parallel laser beam that does not propagate through the complementary conical mirror group 13. This part of the laser beam will not change its propagation direction. Since the relative positions of the first core area 1311 and the second core area 1321 do not change when adjusting the angle between the negative conical mirror 131 and the positive conical mirror 132 by rotation, the propagation directions of the laser beams propagating through the first core area 1311 and the second core area 1321 remain unchanged and are still parallel beams. In summary, when the negative conical mirror 131 and the positive conical mirror 132 are rotated and there is no overlapping area, after the parallel laser beam propagates through the complementary conical mirror group 13, laser beams that are convergent, divergent, and parallel compared to the original parallel beam can be obtained respectively.

[0154] The parallel laser beam can be incident on the focusing mirror 14 when propagating through the complementary conical mirror group 13 in any state. It should be noted that the laser beam incident on the focusing mirror 14 may include, in addition to the laser beam exiting from the complementary conical mirror group 13, the parallel laser beam that does not propagate through the complementary conical mirror group 13. The focusing mirror 14 is arranged coaxially with the complementary conical mirror group 13 in the laser propagation direction and is adjacent to the exit surface of the complementary conical mirror group 13. That is, the focusing mirror 14 is coaxially distributed with the complementary conical mirror group 13, and the incident surface of the focusing mirror 14 is adjacent to the positive conical mirror 132 in the complementary conical mirror group 13. The focusing mirror 14 is mainly used to focus the laser beam exiting from the complementary conical mirror group 13. In practical applications, the focusing mirror 14 is generally a convex lens. When light propagates through a convex lens, the light passing through the optical center does not change its propagation direction; the light parallel to the principal axis is refracted and passes through its focal point; the light passing through the focal point is refracted and parallel to the principal axis. If the incident beam of the focusing mirror 14 is a parallel beam, after passing through the focusing mirror 14, a spot with concentrated energy is finally obtained.

[0155] In a specific embodiment provided by the present application, when the negative conical mirror 131 coincides with the positive conical mirror 132, and the light beam emitted from the complementary conical mirror group 13 is incident on the focusing mirror 14, a spot with concentrated energy is obtained. The size of the spot is achieved by adjusting the distance between the surface of the workpiece to be processed and the focusing mirror 14. Here, the specific preparation material and shape of the focusing mirror 14 can be flexibly selected according to the actual situation.

[0156] It can be understood that when the negative conical mirror 131 and the positive conical mirror 132 are rotated, laser beams converging, diverging, and parallel to the parallel light beam emitted from the collimating mirror 12 are respectively obtained. Among them, for the laser beam parallel to the parallel light beam, after passing through the focusing mirror 14, a point spot can be obtained on the working surface. That is, when the negative conical mirror 131 and the positive conical mirror 132 partially overlap, the light beam passing through the overlapping part of the complementary conical mirror group 13 forms a central spot after passing through the focusing mirror 14. Or, the part of the parallel laser beam that does not pass through the complementary conical mirror group 13 also forms a central spot after passing through the focusing mirror 14. For the laser beam diverging with respect to the parallel light beam, after passing through the focusing mirror 14, two symmetric arc spots can be obtained on the working surface. For the laser beam converging with respect to the parallel light beam, after passing through the focusing mirror 14, the light beam first converges at the focal point and then diverges when continuing to propagate. When the working surface is located behind the focal point, two symmetric arc spots with the same size as above can be obtained on the working surface. It should be noted that different sizes of arc spots can be obtained when the rotation angles of the negative conical mirror 131 and the positive conical mirror 132 are different. The length of the arc spot obtained here is determined by the designed central angle of the negative conical stage area 1312 and the positive conical stage area 1322.

[0157] Specifically, when the overlapping part of the negative conical mirror 131 and the positive conical mirror 132 is relatively large, the area of the obtained arc-shaped light spot is relatively small. At this time, the area ratio of the arc-shaped light spot area to the point light spot area is relatively small, the energy of the central light spot is high, and the energy of the arc-shaped light spot is low. When the overlapping part of the negative conical mirror 131 and the positive conical mirror 132 is relatively small, the area of the obtained arc-shaped light spot is relatively large. The change in the area of the arc-shaped light spot here is mainly reflected in the change in the arc length parameter of the arc-shaped light spot, and its width value in the radial direction does not change. At this time, the area ratio of the arc-shaped light spot area to the point light spot area is relatively large, the energy of the central light spot is low, and the energy of the arc-shaped light spot is high. In addition, the outer diameter size of the arc-shaped light spot is determined by the angle between the negative conical platform area 1312 and the first core area 1311, and the angle between the positive conical platform area 1322 and the second core area 1321. The larger the angle between the negative conical platform area 1312 and the first core area 1311, and the larger the angle between the positive conical platform area 1322 and the second core area 1321, the larger the offset angle of the arc-shaped light spot. At this time, under the condition of a certain focal length and working distance, the outer diameter of the annular light spot is larger. The angles between the negative conical platform area 1312 and the first core area 1311, and between the positive conical platform area 1322 and the second core area 1321 can be designed according to the actual usage method and requirements.

[0158] Tests have shown that the energy distribution between the arc-shaped light spot and the point light spot is related to the ratio of the transmitted beam area, and the energy has a linear relationship with the angle change.

[0159] For example, when the negative conical mirror 131 and the positive conical mirror 132 partially overlap, the light beam propagating through the overlapping part of the complementary conical mirror group 13 forms a central light spot after passing through the focusing mirror 14. If the total energy percentage of all the laser beams emitted by the focusing mirror 14 is 100%, and the proportion of the light beam passing through this part is 50%, then the theoretical energy ratio between the edge and the center is 1:1. The overlapping area of the projections of the negative conical mirror 131 and the positive conical mirror 132 in the propagation direction of the parallel laser beam includes: the overlapping area of the first core area 1311 and the second core area 1321; the overlapping area of the projections of the negative conical platform area 1312 and the positive conical platform area 1322 in the propagation direction of the parallel laser beam. Among them, the overlapping area of the projections of the negative conical platform area 1312 and the positive conical platform area 1322 in the propagation direction of the parallel laser beam is related to the angle corresponding to the overlapping sector. The area sizes of the first core area 1311 and the second core area 1321 can be designed according to the energy requirements of the central light spot and can be designed as circular. And, the overlapping area of the first core area 1311 and the second core area 1321 does not change with the rotation angle of the negative conical mirror 131 and the positive conical mirror 132.

[0160] In a preferred embodiment provided by the present application, the sum of the central angles corresponding to the sectors obtained by projecting the negative conical region 1312 and the positive conical region 1322 in the propagation direction of the parallel laser beam is 360°, that is, the sum of the central angles corresponding to the edge arcs of the negative conical region 1312 and the positive conical region 1322 is 360°. In this way, when the negative conical mirror 131 and the positive conical mirror 132 are rotated to a certain angle, the projections of the negative conical region 1312 and the positive conical region 1322 in the propagation direction of the parallel laser beam are circular. At this time, a complete annular light spot can be obtained on the workpiece surface. As the negative conical mirror 131 and the positive conical mirror 132 rotate, the projections of the negative conical region 1312 and the positive conical region 1322 in the propagation direction of the parallel laser beam change accordingly and are distributed in several sectors. At this time, several arc-shaped light spots can be obtained on the workpiece surface. In this way, various different-shaped light spots can be obtained on the workpiece surface and can be flexibly switched according to the actual processing scenario.

[0161] Furthermore, in a preferred embodiment provided by the present application, the negative conical mirror 131 includes: two centrally symmetric sectors; the radian of each sector is a preset angle. The two centrally symmetric sectors here mean that the projection of the negative conical mirror 131 in the propagation direction of the parallel laser beam includes two centrally symmetric sectors. In a specific embodiment provided by the present application, the radian of each sector is 90 degrees, that is, the central angle corresponding to the sector projection of the negative conical mirror 131 in the propagation direction of the parallel laser beam is 90°. At this time, correspondingly, the positive conical mirror 132 includes two centrally symmetric sectors, and the radian of each sector is 90 degrees.

[0162] When the positive conical mirror 132 and the negative conical mirror 131 completely overlap, the propagation direction of the beam transmitted through the complementary conical mirror remains unchanged. At this time, the projection of the complementary conical mirror group 13 in the propagation direction of the parallel laser beam includes two centrally symmetric sectors, and the radian of each sector is 90 degrees. Under the action of the focusing mirror 14, the laser beam emitted from the complementary conical mirror group 13 finally forms a point light spot on the workpiece surface.

[0163] When either the positive conical mirror 132 or the negative conical mirror 131 is rotated by 90 degrees and there is no overlapping area between the positive conical mirror 132 and the negative conical mirror 131, the projection of the complementary conical mirror group 13 in the propagation direction of the parallel laser beam is circular, including four sectors, each with a radian of 90 degrees. At this time, except that the first core area 1311 coincides with the second core area 1321, the rest of the positive conical mirror 132 and the negative conical mirror 131 are completely separated. The incident surface of the complementary conical mirror group 13 is the incident surface of the negative conical mirror 131 and the positive conical platform area 1322 of the positive conical mirror 132. The laser beam incident through the incident surface of the negative conical mirror 131 exits from the negative conical platform area 1312 and is incident on the focusing mirror 14. After passing through the focusing mirror 14, two symmetric quarter-circular light spots are finally formed on the workpiece surface. The laser beam incident through the positive conical platform area 1322 of the positive conical mirror 132 exits from the exit surface of the positive conical mirror 132 and is incident on the focusing mirror 14. After passing through the focusing mirror 14, the light beam first converges at the focal point and diverges when continuing to propagate. When the working surface is behind the focal point, two symmetric quarter-circular light spots with the same size as above can be formed on the workpiece surface. It should be noted that the light beam incident through the first core area 1311 exits through the second core area 1321, and the propagation direction of the light beam remains unchanged. After passing through the focusing mirror 14, a point light spot is finally formed on the workpiece surface. The four quarter-arc light spots form a complete annular light spot, which together with the central point light spot constitutes a point-annular light spot.

[0164] When either the positive conical mirror 132 or the negative conical mirror 131 is rotated to any angle between 0° and 90°, for example, 60°, the positive conical mirror 132 and the negative conical mirror 131 partially overlap. The projection of the complementary conical mirror group 13 in the propagation direction of the parallel laser beam is a sector. At this time, except that the first core area 1311 coincides with the second core area 1321, there is an overlapping area with a 30° angle between the negative conical platform area 1312 and the positive conical platform area 1322. The parallel laser beam passes through the overlapping area (including the first core area 1311 and the second core area 1321), and the outgoing light beam is still a parallel beam and is incident on the focusing mirror 14. After passing through the focusing mirror 14, this part of the light beam finally forms a point light spot on the workpiece surface. The parallel laser beam passes through the non-overlapping area of the complementary conical mirror group 13 and finally forms four discontinuous arc-shaped light spots on the workpiece surface. The central angle corresponding to each arc-shaped light spot is 60°, which is the same as the rotation angle of the positive / negative conical mirror. By continuously adjusting the rotation angle of either the positive conical mirror 132 or the negative conical mirror 131, arc-shaped light spots in different distribution states can be obtained, so as to meet different requirements in different application scenarios.

[0165] It should be noted that the positive conical mirror 132 and the negative conical mirror 131 are designed as two centrally symmetric sectors, and the radian of each sector is 90 degrees. In this way, the switching between the circular light spot and the arc light spot can be realized with the fewest lenses, which has little influence on the optical path length and has a compact structure.

[0166] Furthermore, in a preferred embodiment provided by the present application, the negative conical mirror 131 includes: two discrete sub-mirrors; each sub-mirror has a sector with a radian of a preset angle; the two sub-mirrors are centrally symmetrically distributed. Here, "discrete" can be understood as that there is no common connecting part between the two sub-mirrors in the negative conical mirror 131. In a specific embodiment provided by the present application, the preset angle is 90°. At this time, the projections of the two sub-mirrors in the propagation direction of the parallel laser beam are two sectors that are centrally symmetric and have no connection relationship, and the radian of each sector is 90°. Here, the two discrete sub-mirrors in the negative conical mirror 131 can achieve their spatially centrally symmetric distribution by being fixed to the same lens barrel. The incident surfaces of the two sub-mirrors are coplanar and located in the same plane perpendicular to the optical axis. Correspondingly, the positive conical mirror 132 includes two centrally symmetric sectors, and the radian of each sector is 90 degrees; the two sub-mirrors are centrally symmetrically distributed. Similarly, the two discrete sub-mirrors in the positive conical mirror 132 can also achieve their spatially centrally symmetric distribution by being fixed to the same lens barrel. Moreover, the incident surfaces of the two discrete sub-mirrors in the positive conical mirror 132 are coplanar and located in the same plane perpendicular to the optical axis. At this time, the first core area 1311 and the second core area 1321 can be understood as virtual areas without any entity in the propagation direction of the parallel laser beam, which is a circular hole, and the center line of the circular hole coincides with the beam axis. The center line of the circular hole coincides with the beam axis.

[0167] When the positive conical mirror 132 and the negative conical mirror 131 completely overlap, the propagation direction of the beam propagating through the complementary conical mirror remains unchanged. At this time, the projection of the complementary conical mirror group 13 in the propagation direction of the parallel laser beam is two sectors that are centrally symmetric and have no connection relationship, and the radian of each sector is 90°. Under the action of the focusing mirror 14, the laser beam emitted from the complementary conical mirror group 13 finally forms a point light spot on the workpiece surface.

[0168] When either the positive conical mirror 132 or the negative conical mirror 131 is rotated by 90 degrees and there is no overlapping area between the positive conical mirror 132 and the negative conical mirror 131, the projection of the complementary conical mirror group 13 in the propagation direction of the parallel laser beam is circular, including four sectors, each with a radian of 90 degrees. At this time, the positive conical mirror 132 and the negative conical mirror 131 are completely separated. The incident surface of the complementary conical mirror group 13 is the incident surface of the negative conical mirror 131 and the positive conical area 1322 of the positive conical mirror 132. The laser beam incident on the incident surface of the negative conical mirror 131 exits from the negative conical area 1312 and is incident on the focusing mirror 14. After passing through the focusing mirror 14, two symmetric quarter-circular light spots are finally formed on the workpiece surface. The laser beam incident on the positive conical area 1322 of the positive conical mirror 132 exits from the exit surface of the positive conical mirror 132 and is incident on the focusing mirror 14. After passing through the focusing mirror 14, the light beam first converges at the focal point and diverges when continuing to propagate. When the working surface is behind the focal point, two symmetric quarter-circular light spots with the same size as above can be formed on the workpiece surface. It should be noted that the light beam incident through the first core area 1311 exits through the second core area 1321, and the propagation direction of the light beam remains unchanged. After passing through the focusing mirror 14, a point light spot is finally formed on the workpiece surface. The four quarter-circular light spots form a complete annular light spot, which together with the central point light spot constitutes a point-annular light spot.

[0169] When either the positive conical mirror 132 or the negative conical mirror 131 is rotated to any angle between 0° and 90°, for example, 60°, the positive conical mirror 132 and the negative conical mirror 131 partially overlap. The projection of the complementary conical mirror group 13 in the propagation direction of the parallel laser beam is fan-shaped. At this time, there is an overlapping area with a 30° angle between the negative conical area 1312 and the positive conical area 1322. The parallel laser beam propagates through the overlapping area (including the first core area 1311 and the second core area 1321), and the outgoing light beam is still a parallel beam and is incident on the focusing mirror 14. After passing through the focusing mirror 14, this part of the light beam finally forms a point light spot on the workpiece surface. The parallel laser beam propagates through the non-overlapping area of the complementary conical mirror group 13 and finally forms four discontinuous arc-shaped light spots on the workpiece surface. The central angle corresponding to each arc-shaped light spot is 60°, which is the same as the rotation angle of the positive / negative conical mirror. By continuously adjusting the rotation angle of either the positive conical mirror 132 or the negative conical mirror 131, arc-shaped light spots in different distribution states can be obtained, so as to meet different requirements in different application scenarios.

[0170] It should be noted that the positive conical mirror 132 and the negative conical mirror 131 are designed as centrosymmetric discrete sub - mirrors, and each sub - mirror has a sector with a radian of 90 degrees. Similarly, the switching between circular spots and arc - shaped spots can be achieved with the fewest number of lenses, which has a small impact on the optical path length and a compact structure. According to actual usage requirements, the sub - mirrors can also be sequentially installed in different rotating lenses to achieve more spot shape changes. However, at this time, if a uniformly distributed spot is required, at least two sub - mirrors need to be rotated simultaneously.

[0171] In practical applications, the number of sub - mirrors in the positive / negative conical mirror can also be designed according to the actual requirements for the output laser spot. However, in order to ensure the flexible switching between circular - ring and arc - shaped spots, it should be ensured that the sum of the radian angles of the sectors corresponding to the projections of all sub - mirrors in the positive conical mirror 132 and the negative conical mirror 131 in the propagation direction of the parallel beam is 360 degrees. In order to obtain several uniformly distributed arc - segment spots to ensure uniform laser energy distribution, the angle between adjacent sub - mirrors in the positive / negative conical mirror can be set to the same angle. In a preferred embodiment provided in the present application, the negative conical mirror 131 can also be composed of a preset number of discrete sub - mirrors; and each sub - mirror has a sector with a radian of a preset angle. For example, the negative conical mirror 131 is composed of three discrete sub - mirrors; each sub - mirror has a sector with a radian of 60 degrees; and the three sub - mirrors are centrosymmetrically distributed. In this way, more different types of output spots can be obtained, providing more diverse choices for users.

[0172] It should be noted that the term "including", "comprising" or any other variant thereof is intended to cover non - exclusive inclusion, so that a process, method, commodity or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such a process, method, commodity or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, commodity or device including the said element.

[0173] The above description is only for the embodiments of the present application and is not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

Claims

1. A laser processing system, characterized in that, Comprising: A laser generating device that generates a light source in an excited state; A collimating mirror, the focus of the collimating mirror being collinear with the light source of the laser generating device; A complementary conical mirror group disposed in the laser propagation direction, adjacent to the collimating mirror and coaxially distributed; A focusing mirror disposed in the laser propagation direction and coaxially distributed with the collimating mirror, adjacent to the other side opposite to the side adjacent to the collimating mirror of the complementary conical mirror group; Wherein, the complementary conical mirror group includes: A negative conical mirror; A positive conical mirror paired with the negative conical mirror and coaxially rotatable relative to the negative conical mirror; The negative conical mirror includes: A first core region; A negative conical platform region adjacent to the first core region; Two centrally symmetric sectors; The arc of each sector is a preset angle; The positive conical mirror includes: A second core region corresponding to the first core region for realizing a central light spot; A positive conical platform region adjacent to the second core region and corresponding to the negative conical platform region; Two centrally symmetric sectors, and the arc of each sector is 90 degrees; The sum of the central angles corresponding to the sectors obtained by projecting the negative conical platform region and the positive conical platform region in the propagation direction of the parallel laser beam is 360 degrees.

2. The laser processing system according to claim 1, wherein The negative conical mirror further includes: An edge region adjacent to the negative conical platform region.

3. The laser processing system according to claim 1, wherein, The taper sizes of the negative conical platform region and the positive conical platform region are equal in value.

4. The laser processing system according to claim 3, wherein The negative conical mirror includes: Two discrete sub-mirrors; Each sub-mirror has a sector with an arc of a preset angle; The two sub-mirrors are centrally symmetrically distributed.

5. The laser processing system according to claim 3, wherein, The negative conical mirror is composed of a preset number of discrete sub-mirrors; Each sub-mirror has a sector with an arc of a preset angle.

6. A complementary conical mirror group for a laser processing system, characterized in that, Comprising: A negative conical mirror; A positive conical mirror paired with the negative conical mirror and coaxially rotatable relative to the negative conical mirror; Wherein, the negative conical mirror includes: A first core region; A negative conical platform region adjacent to the first core region; Two centrally symmetric sectors; The arc of each sector is a preset angle; The positive conical mirror includes: A second core region corresponding to the first core region for realizing a central light spot; A positive conical platform region adjacent to the second core region and corresponding to the negative conical platform region; Two centrally symmetric sectors, and the arc of each sector is 90 degrees; The sum of the central angles corresponding to the sectors obtained by projecting the negative conical platform region and the positive conical platform region in the propagation direction of the parallel laser beam is 360 degrees.

7. The complementary conical mirror group according to claim 6, wherein, The negative conical mirror further includes: An edge region adjacent to the negative conical platform region.

8. The complementary conical mirror group according to claim 7, characterized in that, The taper sizes of the negative conical platform region and the positive conical platform region are equal in value.

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