A composite laser

Abstract

This application provides a composite laser, comprising a laser, a collimator, a beam splitter, and a focusing lens, wherein the beam splitter includes at least a ring lens. A collimator is disposed in the output optical path of the laser to adjust the laser emitted by the laser into collimated parallel light. A beam splitter is disposed in the output optical path of the collimator to split the collimated parallel laser beam output by the collimator. One portion is amplified into a ring beam by the ring lens of the beam splitter, and the other portion is focused into a central beam by the focusing lens. The central beam is used for laser processing of the workpiece, and the ring beam is used for auxiliary heating of the workpiece. This structural design makes the composite laser provided by this application both low-cost and able to reduce problems such as workpiece curling, spatter, bubbles, and cracks during laser processing.

Description

Technical Field

[0001] This invention relates to the field of laser processing technology, and more specifically, to a composite laser. Background Technology

[0002] In recent years, with the continuous development of laser processing technology, laser processing has been increasingly widely used in the field of industrial processing. At the same time, higher requirements are constantly being put forward for laser processing technology.

[0003] Traditional laser processing typically uses a Gaussian laser beam distribution. When the laser beam is Gaussian, the temperature at the processing center becomes too high, which can cause splashing during processing and damage the electronic components around the workpiece. At the same time, due to the large temperature difference between the processing center and the surrounding area, a temperature gradient is formed, resulting in uneven heating of the workpiece, which can easily lead to various problems such as deformation, bubbles, and cracks.

[0004] To address these issues, laser manufacturers typically require an additional ring-shaped light-assisted processing system to complement the existing laser. This system creates a ring-shaped heating field around the original processing location to reduce the temperature gradient and mitigate problems such as splashing, bubbles, and cracks.

[0005] Currently, there are two common types of ring-beam assisted processing systems. One type directly uses a separate ring laser to form a ring-shaped spot for auxiliary processing. The other type is a laser processing system with a ring fiber, developed by IPG. Specifically, the laser's fiber structure includes a central fiber and a ring fiber. The laser controls the central fiber and the ring fiber to form a central beam and a ring beam, respectively. The central beam performs laser processing, while the ring beam provides auxiliary processing. Both of these common laser processing systems are relatively complex and have high production costs.

[0006] Therefore, it is necessary to invent a composite laser that is simple in structure, low in cost, and easy to operate, which can also alleviate problems such as workpiece curling, splashing, bubbles, and cracks that occur during laser processing. Summary of the Invention

[0007] The purpose of this application is to provide a composite laser to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, this application provides the following technical solution: a composite laser, comprising, in sequence, a laser, a collimator, a beam splitter, and a focusing lens, wherein the beam splitter includes at least a ring lens. A collimator is disposed on the output optical path of the laser, used to adjust the laser emitted by the laser into collimated parallel light. A beam splitter is disposed on the output optical path of the collimator, used to split the collimated parallel laser beam output by the collimator. One portion is amplified into a ring beam by the ring lens of the beam splitter, and the other portion is focused into a central beam by the focusing lens. The central beam is used for laser processing of the workpiece, and the ring beam is used for auxiliary heating of the workpiece.

[0009] The unique feature of this application is that the annular lens of the beam splitter has a through-hole at its center, forming a lens structure that is thicker on the outer side and thinner on the inner side, i.e., the overall structure is a lens structure that gradually thins from the outside in. This structure facilitates the expansion of the annular beam, separating it from the central beam and forming two separate beams. This structural design, through the formation of an auxiliary heating field by the annular beam, reduces the temperature gradient between the laser processing location and its surroundings. Consequently, the composite laser provided in this application is both cost-effective and can mitigate problems such as workpiece curling, spatter, bubbles, and cracks during laser processing. Attached Figure Description

[0010] To more clearly illustrate the technical solutions of the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 A first structural schematic diagram of the composite laser provided in this application;

[0012] Figure 2 A first structural schematic diagram of the beam splitter of the composite laser provided in this application;

[0013] Figure 3 A schematic diagram of the second structure of the composite laser provided in this application;

[0014] Figure 4 A schematic diagram of the second structure of the beam splitter of the composite laser provided in this application;

[0015] Figure 5 A first structural schematic diagram of the annular lens of the composite laser provided in this application;

[0016] Figure 6 A schematic diagram of the third structure of the composite laser provided in this application;

[0017] Figure 7 This is a schematic diagram of the fourth structure of the composite laser provided in this application.

[0018] Reference numerals: 1. Laser, 2. Collimator, 3. Beam splitter, 4. Focusing lens, 5. Workpiece, 6. First reflecting mirror, 7. Second reflecting mirror, 8. Beam splitter, 81. Beam splitting aperture, 31. Ring lens, 32. Central splitting lens, L. Collimated parallel beam, L1. Ring beam, L2. Central beam. Detailed Implementation

[0019] To enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are merely some embodiments of the present application and are not intended to limit the scope of the present application. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without inventive effort are within the scope of protection of the present application.

[0020] Please see Figure 1 , Figure 1 The first structural schematic diagram of the composite laser provided in this application shows that the composite laser includes, in sequence, a laser 1, a collimator 2, a beam splitter 3, and a focusing lens 4. The beam splitter 3 includes at least an annular lens 31. The collimator 2 is disposed on the output optical path of the laser 1 to adjust the laser emitted by the laser 1 into a collimated parallel beam L. The beam splitter 3 is disposed on the output optical path of the collimator 2 to split the collimated parallel laser beam output by the collimator 2. One part is amplified into an annular beam L1 by the annular lens 31 of the beam splitter 3, and the other part is focused into a central beam L2 by the focusing lens 4. The central beam L2 is used for laser processing, and the annular beam L1 is used for auxiliary heating. That is, the annular beam L1 forms an annular auxiliary heating field around the processing point of the central beam L2. Laser processing here can cause the workpiece 5 to reach a molten state, while auxiliary heating cannot cause the workpiece 5 to reach a molten state, but it can still perform certain material modification on the workpiece 5. (It should be noted that "ring" here is not limited to a circular ring; it may also be an elliptical ring, or other shapes that are approximately circular, elliptical, circular, or elliptical.) This reduces the temperature gradient and mitigates problems such as splashing, bubbles, and cracks.

[0021] Please see Figure 2 , Figure 2This is a schematic diagram of the first structure of the beam splitter of the composite laser provided in this application. The annular lens 31 of the beam splitter 3 has a through hole at its center and is a lens structure that is thicker on the outer side and thinner on the inner side, that is, the thickness gradually decreases from h1 to h2 from the outside to the inside. Furthermore, this thinning lens structure facilitates the expansion of the annular beam L1 and its separation from the central beam L2. The thickness values ​​of h1 and h2 can be specifically designed according to the actual production and processing requirements for beam expansion. It should be noted that "gradually thinning from the outside to the inside" does not mean that the part closer to the outer edge is necessarily thinner than the part closer to the inner edge, but rather it is an overall trend of change.

[0022] In an optional embodiment, the annular lens 31 of the beam splitter 3 can move back and forth in the optical path output direction. At this time, the size of the spot of the annular beam L1 falling on the workpiece 5 after passing through the annular lens 31 will also change accordingly, thereby controlling the energy of the annular beam L1 acting on the workpiece 5 and the temperature of the appropriate heating field generated.

[0023] In the optional scheme, the diameter of the spot of the ring beam L1 on the workpiece 5 is D (if the spot of the ring beam L1 on the workpiece 5 is elliptical or approximately elliptical, D here can be understood as including the diameter D1 in the major axis direction and the diameter D2 in the minor axis direction), and the diameter of the spot of the central beam L2 on the workpiece 5 is d. In order to obtain a better auxiliary heating field, it is necessary to satisfy 2d≤D≤10d.

[0024] Please see Figure 3 , Figure 3 This is a second structural schematic diagram of the composite laser provided in this application, which is a preferred embodiment of this application. The focal point f2 of the central beam L2 of the composite laser acts on the workpiece 5 to achieve the strongest processing effect, while the focal point f1 of the ring beam L1 does not act on the workpiece 5. Optionally, when the workpiece 5 is a thin layer of metal material, the focal point f1 is located between the focusing lens 4 and the workpiece 5, which will produce a better processing effect; when the workpiece 5 is a thick layer of metal material, f1 is located on the side of the workpiece 5 away from the focusing lens 4, which will also produce a better processing effect.

[0025] In an optional embodiment, the beam splitter 3 may further include a central beam splitter 32, which is located in the through-hole of the annular lens 31. The central beam splitter 32 does not diffuse the central beam L2, that is, it can focus the central beam L2 or keep it in a parallel state. Existing experiments have found that double focusing is beneficial to reducing diffraction or interference problems and obtaining a better quality light spot.

[0026] In an optional embodiment, the annular lens 31 and the central split lens 32 of the beam splitter 3 are detachable.

[0027] Please see Figure 4 , Figure 4 This is a schematic diagram of the second structure of the beam splitter of the composite laser provided in this application. In this embodiment, the annular lens 31 of the beam splitter 3 is... Figure 2 Based on the annular lens 31, it can also have multiple annular concave-convex microstructures. Since the annular beam L1 needs to be focused by the focusing lens 4 at the rear... Figure 2 The beam splitter 3 shown, when splitting a straight parallel light L into an annular beam L1 or a central beam L2, will experience diffraction or interference after focusing, forming uncontrollable spots with multiple center points. This can even affect the spot quality of the central beam L2, and it is difficult to form a uniform temperature auxiliary heating field, which is not conducive to obtaining an ideal auxiliary heating field or to workpiece processing. Compared with the annular lens 31 of the beam splitter 3 in this embodiment... Figure 2 The annular lens 31 in this embodiment has multiple annular concave and convex microstructures, and the light spot formed will be homogenized to make the temperature of the auxiliary heating field more uniform.

[0028] Please see Figure 5 , Figure 5 This is a schematic diagram of the first structure of the annular lens of the composite laser provided in this application. In this embodiment, the inner and outer sides of the annular lens 31 also exhibit a structural change process from thin (h4) to thick (h3) and then from thick (h3) to thin (h4) when rotated clockwise. This structural design is to control the position and shape of the spot of the annular beam L1 acting on the workpiece 5. The annular lens 31 can rotate around the output direction of the collimated parallel light L as its rotation axis. During the rotation, the center of the spot of the annular beam L1 acting on the workpiece 5 can deviate from the center of the spot of the central beam L2 acting on the workpiece 5. In practical applications, the center of the spot of the annular beam L1 acting on the workpiece 5 can be closer to the workpiece position on the pre-processing direction side than the center of the spot of the central beam L2 acting on the workpiece 5. Moreover, more and more laser processing is non-linear processing, that is, more and more laser processing requires the workpiece 5 to follow curves or irregular complex lines, such as "8" or "S" lines. When the annular lens 31 rotates in this embodiment, the rotation can be flexibly controlled by the control mechanism to match the processing line. The thickness on the side closer to the pre-processing direction can be thinned or thickened. This flexible structural change capability allows the annular beam L1 to preheat the workpiece 5 in advance, better reducing problems such as workpiece curling, splashing, bubbles and cracks that occur during laser processing. Based on the actual production and processing requirements regarding the deviation of the center of the spot of the annular beam L1 acting on the workpiece 5 and the center of the spot of the central beam L2 acting on the workpiece 5, the thickness values ​​of h3 and h4 can be specifically designed.

[0029] Please see Figure 6 , Figure 6This is a schematic diagram of the third structure of the composite laser provided in this application. The composite laser, in... Figure 1 Based on the composite laser, it also includes a first reflecting mirror 6 and a second reflecting mirror 7. The first reflecting mirror 6 and the second reflecting mirror 7 are located between the beam splitter 3 and the focusing lens 4, and the movement of the ring beam L1 and the central beam L2 on at least two different axes on the workpiece 5 can be controlled by the swinging or moving of the first reflecting mirror 6 and the second reflecting mirror 7.

[0030] In a preferred embodiment, the axes through which the first reflector 6 and the second reflector 7 control the movement of the annular beam L1 and the central beam L2 are perpendicular to each other.

[0031] Please see Figure 7 , Figure 7 This is a schematic diagram of the fourth structure of the composite laser provided in this application. The composite laser, in... Figure 1 Based on the composite laser, it also includes a beam splitter 8, which is located between the collimator 2 and the focusing lens 4 (in this embodiment, the beam splitter 8 is located between the beam splitter 3 and the focusing lens 4; in other embodiments, the beam splitter 8 can also be located between the collimator 2 and the beam splitter 3). The beam splitter 8 has a ring-shaped structure with a beam splitting aperture 81 in the center. A reflective film is provided on the beam splitting aperture 81 inside the beam splitter 8. The beam splitter 8 can deflect back and forth in the optical path direction. When the beam splitter 8 is perpendicular to the output direction of the central beam L2, the central beam... L2 can be entirely output through beam splitter 81 to the next optical device. When beam splitter 8 is deflected to a position not perpendicular to the output direction of central beam L2, part of central beam L2 is reflected by the reflective film on beam splitter 81. Then, most of the reflected beam is deflected to the output direction contained in the ring beam L1. Different deflection angles affect the proportion of central beam L2. That is, the proportion of ring beam L1 that ultimately undergoes auxiliary heating and central beam L2 that undergoes laser processing can be flexibly redistributed through the deflection of beam splitter 8.

[0032] In an optional embodiment, the composite laser provided in this application also includes a temperature feedback adjustment mechanism (not shown in the figure). This temperature feedback adjustment mechanism can detect the temperature of the processing position and the temperature auxiliary field position of the workpiece 5 by infrared detection, and can adjust the ring beam L1 and the central beam L2 according to the real-time temperature feedback to the control mechanism to meet the good processing requirements of the workpiece 5.

[0033] In an alternative embodiment, the composite laser provided in this application further includes a moving stage (not shown in the figure) for moving the annular beam L1, the central beam L2, and the workpiece 5 relative to each other on at least two different axes.

[0034] In a preferred embodiment, the first reflector 6, the second reflector 7, and the moving stage can coexist and simultaneously control the movement of the annular beam L1, the central beam L2, and the workpiece 5 relative to each other on at least two different axes. However, if the first reflector 6 and the second reflector 7 only control the annular beam L1 and the central beam L2 to oscillate or move within a small angle range, such as 2 to 5 degrees, the moving stage can control the annular beam L1, the central beam L2, and the workpiece 5 to move over a large range relative to each other on at least two different axes. This is because controlling the annular beam L1 and the central beam L2 to oscillate or move over a large range with the first reflector 6 and the second reflector 7 would significantly increase the overall size and weight of the laser, thereby increasing production and usage costs.

[0035] In optional applications, the composite laser described in this application can be used in various laser processing applications such as laser cutting, laser welding, laser engraving, laser cleaning, and laser additive manufacturing.

[0036] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that the elements inherent in a process, method, article, or apparatus that includes a list of elements are included. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. Additionally, portions of the technical solutions provided in the embodiments of this application that are consistent with the implementation principles of corresponding technical solutions in the prior art have not been described in detail to avoid excessive elaboration.

[0037] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made to this application, as well as combinations of the various embodiments in this application, without departing from the principles of this application. These improvements, modifications, and combinations also fall within the protection scope of the claims of this application.

Claims

1. A composite laser, characterized in that, It includes, in sequence, a laser (1), a collimator (2), a beam splitter (3), and a focusing lens (4); A collimator (2) is provided on the output optical path of the laser (1). The collimator (2) is used to adjust the laser emitted by the laser (1) into collimated parallel light (L). A beam splitter (3) is provided on the output optical path of the collimator (2). The beam splitter (3) is used to split the collimated parallel laser beam output by the collimator (2). One part is expanded and magnified into a ring beam (L1) through the ring lens (31) of the beam splitter (3), and the other part is focused into a central beam (L2) through the focusing lens (4). The central beam (L2) is used for laser processing, and the ring beam (L1) is used for auxiliary heating. The beam splitter (3) includes at least an annular lens (31), which has a through hole in the center and is a lens structure that is thick on the outside and thin on the inside. The annular lens (31) of the beam splitter (3) has multiple annular concave and convex microstructures; The annular lens (31) rotates around the collimated parallel light (L) output direction as the rotation axis, and the inner and outer sides of the annular lens (31) also exhibit a structural change process from thin to thick and then from thick to thin when rotating clockwise. It also includes a beam splitter (8), which is located between the collimator (2) and the focusing lens (4). The beam splitter (8) has a ring-shaped structure with a beam splitting hole (81) in the center. A reflective film is provided on the beam splitting hole (81) inside the beam splitter (8). The beam splitter (8) deflects back and forth in the optical path direction.

2. The composite laser according to claim 1, characterized in that, The annular lens (31) of the beam splitter (3) can move back and forth in the optical path output direction.

3. The composite laser according to claim 1, characterized in that, The beam splitter (3) also includes a central beam splitter (32), which is located in the through hole of the ring lens (31). The central beam splitter (32) focuses or keeps the central beam (L2) parallel.

4. The composite laser according to claim 1, characterized in that, It also includes a first reflector (6) and a second reflector (7), which are located between the beam splitter (3) and the focusing lens (4), and the movement of the annular beam (L1) and the central beam (L2) on at least two different axes on the workpiece (5) is controlled by the swinging or moving of the first reflector (6) and the second reflector (7).

5. The composite laser according to claim 4, characterized in that, The axes by which the first reflector (6) and the second reflector (7) control the movement of the annular beam (L1) and the central beam (L2) are perpendicular to each other.

6. The composite laser as described in claim 1, characterized in that, It also includes a temperature feedback adjustment mechanism, which detects the temperature of the processing position of the workpiece (5) and the temperature auxiliary field position by infrared detection, and adjusts the ring beam (L1) and the central beam (L2) according to the real-time temperature feedback.

7. The composite laser as described in claim 1, characterized in that, It also includes a moving stage for moving the annular beam (L1), the central beam (L2) and the workpiece (5) relative to each other on at least two different axes.

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