CN217404561U

CN217404561U - Free-form surface lens, optical system and laser welding device thereof

Info

Publication number: CN217404561U
Application number: CN202221191834.1U
Authority: CN
Inventors: 邵华江; 王伟; 李思佳
Original assignee: Shanghai Empower Automation Technology Co ltd
Current assignee: Jiaqiang Shanghai Intelligent Technology Co ltd
Priority date: 2022-05-18
Filing date: 2022-05-18
Publication date: 2022-09-09
Anticipated expiration: 2032-05-18
Also published as: WO2023221318A1

Abstract

The utility model relates to an optical lens technical field especially relates to a free-form surface lens, optical system and laser welding device thereof. The free-form surface lens comprises an incident mirror surface facing the light source and an emergent mirror surface far away from the light source, the incident mirror surface comprises an incident plane and a convex cylindrical surface connected with the incident plane, and the emergent mirror surface comprises an emergent plane and a concave cylindrical surface connected with the emergent plane; the incident plane is parallel to the emergent plane, and the incident plane and the emergent plane are correspondingly arranged on one side of the free-form surface lens; the convex cylindrical surface and the concave cylindrical surface are correspondingly arranged on the other side of the free-form surface lens, and the effective focal length of a part of the lens formed by the convex cylindrical surface and the concave cylindrical surface is infinite. The utility model discloses a free-form surface lens simple structure and ingenious, the cost is lower relatively and high to the suitability of different optics configurations, effectively improves the condition that the welding splashes, improves welding quality.

Description

Free-form surface lens, optical system and laser welding device thereof

Technical Field

The utility model relates to an optical lens technical field especially relates to a free-form surface lens, optical system and laser welding device thereof.

Background

The laser welding utilizes the basic characteristic of the interaction between laser and substances, and has the advantages of high energy density, high speed, small welding deformation, wide fusion width, narrow heat affected zone and the like compared with other welding forms. However, during high power fiber laser welding, spatter is easily generated. The particles generated by splashing can be attached to the surface of a molten pool and a workpiece, so that the surface roughness change is easily caused, the base metal is scratched, and the reworking of parts, the damage of components such as protective glasses inside a laser welding head and the like can be caused in serious cases. Therefore, the laser spot energy distribution needs to be changed during laser welding, violent boiling of the base material in the welding process is avoided, and Gaussian distribution beams are not used as far as possible, so that the situation of laser welding splashing is reduced.

At present, there are roughly two methods for improving the energy distribution of a laser beam in the conventional art: firstly, adjusting the energy distribution of a light beam from a laser source; and secondly, adjusting the energy distribution of the light beam from the laser processing head. However, the first solution needs to use a multi-core coaxial fiber with extremely high quality requirement, which leads to a great increase in cost, and only the variation in energy distribution near the focus can be ensured by using the first solution, and when the defocusing amount is large, the energy distribution of the light beam gradually approaches gaussian distribution, which is not favorable for large spattering particle removal. The second solution has the problems that the adaptability of the lens parameters of the same specification to different fiber core diameters and different optical configurations is poor, the lens cost is high, the energy loss is large, and the annular distribution rule of the focused light beam after being out of focus is damaged, which is not beneficial to welding application.

SUMMERY OF THE UTILITY MODEL

Based on this, the utility model provides a free-form surface lens, optical system and laser welding device thereof, this free-form surface lens simple structure and ingenious, the cost is lower relatively and high to the suitability of different optics configurations, effectively improves the condition that the welding splashes, improves welding quality.

The utility model discloses a first aspect discloses a free-form surface lens, including the incident mirror face towards the light source and the emergent mirror face of keeping away from the light source, incident mirror face includes incident plane and the convex cylinder of being connected with incident plane, emergent mirror face includes emergent plane and the concave cylinder of being connected with emergent plane; the incident plane is parallel to the emergent plane, and the incident plane and the emergent plane are correspondingly arranged on one side of the free-form surface lens; the convex cylindrical surface and the concave cylindrical surface are correspondingly arranged on the other side of the free-form surface lens, and the effective focal length of a part of the lens formed by the convex cylindrical surface and the concave cylindrical surface is infinite.

In some embodiments, a first intersection line formed by the incident plane and the convex cylindrical surface is parallel to a second intersection line formed by the exit plane and the concave cylindrical surface, the incident plane and the exit plane are located on one side of the separation plane where the first intersection line and the second intersection line are located, and the convex cylindrical surface and the concave cylindrical surface are located on the other side of the separation plane where the first intersection line and the second intersection line are located.

In some of these embodiments, the incident plane is tangent to the convex cylinder at the first intersection line, and the exit plane is tangent to the concave cylinder at the second intersection line.

In some embodiments, the convex cylinder and the concave cylinder are aspheric cylinders or spherical cylinders.

In some embodiments, the projection of the incident mirror surface on the plane of the incident plane is a rotationally symmetric pattern, and the projection of the exit mirror surface on the plane of the exit plane is a rotationally symmetric pattern.

In some of the embodiments, the rotationally symmetric pattern is a centrosymmetric pattern.

The utility model discloses in a second aspect an optical system, the optical system includes the light source and any one of the aforesaid free-form surface lens and focus subassembly, free-form surface lens, focus subassembly set gradually in the light path that the light source formed; wherein the content of the first and second substances,

the free-form surface lens can rotate by taking an intersection line of the incident plane and the convex cylindrical surface as an axis; the free-form surface lens can move along the direction perpendicular to the central axis of the optical path and the intersection line; the free-form surface lens can rotate by taking the optical path central axis as an axis.

In some embodiments, the optical system further includes a collimating assembly disposed between the free-form surface lens and the light source and on the light path.

In some embodiments, the collimating assembly is a single collimating lens or a combination of a plurality of collimating lenses, and the focusing assembly is a convex lens or a lens group with a converging function composed of a plurality of lenses with optical power.

The third aspect of the present invention discloses a laser welding apparatus, which is characterized by comprising any one of the above optical systems.

Advantageous effects

The utility model discloses a free-form surface lens not only has infinite focus free-form surface optical lens piece characteristic, still has the tangent beam splitting characteristic of cutting apart under of the different parameters of single mirror surface, will the utility model discloses an among the free-form surface lens is applied to optical system, the position relation of adjustment free-form surface lens and light source, cooperation focus subassembly can realize optical system from the monofocal to the bifocal, the bifocal interval is adjustable, bifocal energy ratio adjustable function and obtain the scanning formula adjustable point annular energy distribution, it is stronger to compare traditional technical functionality, the cost is lower, various welded energy distribution adaptability has been improved by a wide margin, it is strong to different optical fiber core laser instrument compatibility, help improving the welding and splash and welding quality.

Drawings

Fig. 1 is a schematic view of a free-form surface lens according to the present invention in some embodiments;

fig. 2 is a schematic view of an optical system according to the present invention in some embodiments;

fig. 3 is a schematic diagram of a dual focus of an optical system according to the present invention in some embodiments;

fig. 4 is a schematic diagram of a bifocal energy ratio adjustment of an optical system according to the present invention in some embodiments;

fig. 5 is a focus and positive and negative defocus energy distribution diagram of the optical system according to the present invention in some embodiments;

fig. 6 is a schematic diagram of a distribution of spot energies of the optical system according to some embodiments of the present invention;

wherein, 1 is a collimation component, 2 is a free-form surface lens, 3 is a focusing component, 4 is a light source, 21 is an incident mirror surface, 22 is an emergent mirror surface, 211 is an incident plane, 212 is a convex cylindrical surface, 213 is a first intersection line, 221 is an emergent plane, 222 is a concave cylindrical surface, and 223 is a second intersection line.

Detailed Description

In order to make the above objects, features and advantages of the present invention more comprehensible, embodiments of the present invention are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The invention may be embodied in many other forms different from those described herein and similar modifications may be made by those skilled in the art without departing from the spirit and scope of the invention and, therefore, the invention is not to be limited to the specific embodiments disclosed below.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be interconnected within two elements or in a relationship where two elements interact with each other unless otherwise specifically limited. The specific meaning of the above terms in the present invention can be understood according to specific situations by those of ordinary skill in the art.

In the present application, unless expressly stated or limited otherwise, a first feature "on" or "under" a second feature may be directly contacting the second feature or the first and second features may be indirectly contacting the second feature through intervening media. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

Referring to fig. 1 and 2, fig. 1 is a perspective view of a free-form surface lens 2 according to an embodiment of the present invention, and fig. 2 is a schematic view of the free-form surface lens 2 applied to an optical system. As can be seen from fig. 2, the optical system includes a light source 4, and the free-form-surface lens 2 is disposed on the optical path of the light source 4. As can be seen from fig. 1, some embodiments of the present invention provide a free-form surface lens 2, including an incident mirror surface 21 facing a light source 4 and an exit mirror surface 22 away from the light source 4, where the incident mirror surface 21 includes an incident plane 211 and a convex cylindrical surface 212 connected to the incident plane 211, and the exit mirror surface 22 includes an exit plane 221 and a concave cylindrical surface 222 connected to the exit plane 221. The incident plane 211 is disposed parallel to the exit plane 221. Of course, in actual production, due to the existence of processing errors, the incident plane 211 may not be exactly parallel to the exit plane 221, and the angle between the incident plane 211 and the exit plane 221 is less than 3 °, i.e. the incident plane 211 and the exit plane 221 are considered to be parallel. The incident plane 211 and the exit plane 221 are correspondingly arranged on one side of the free-form surface lens 2; the convex cylindrical surface 212 and the concave cylindrical surface 222 are correspondingly arranged on the other side of the free-form surface lens 2, and the effective focal length of a part of the lens formed by the convex cylindrical surface 212 and the concave cylindrical surface 222 is infinite.

The utility model discloses a free-form surface lens 2 sets up some with incident mirror surface 21 into incident plane 211, sets up some of emergent mirror surface 22 into emergent plane 221 to correspond incident plane 211 and emergent plane 221 and set up the one side at free-form surface lens 2, this just makes the utility model discloses an incident plane 211 can constitute planar lens with emergent plane 221 in the free-form surface lens 2. This is just so when the utility model discloses a free-form surface lens 2 is applied to among the optical path system, parallel light beam that light source 4 sent is behind this part plane lens, and the direction of light path will not change, in other words, optical system's a focus will be located the light path center pin.

Similarly, by setting a part of the incident mirror surface 21 as the convex cylindrical surface 212, a part of the exit mirror surface 22 as the concave cylindrical surface 222, the convex cylindrical surface 212 and the concave cylindrical surface 222 are provided on the other side of the free-form surface lens 2 in correspondence, and the effective focal length of the partial lens constituted by the convex cylindrical surface 212 and the concave cylindrical surface 222 is set to infinity. This just makes the utility model discloses a when free-form surface lens 2 was applied to optical path, the parallel light beam that light source 4 sent was though taking place the refraction but can not take place to assemble after passing through this part lens.

Can know through the analysis, because the utility model discloses a free-form surface lens 2 not only has infinite focal length free-form surface optical lens piece characteristic, still has the tangent beam splitting characteristic of cutting apart under of the different parameters of single mirror face, will the utility model discloses an among the free-form surface lens is applied to optical system, adjust free-form surface lens 2 and light source 4's position relation, cooperation focus subassembly can realize that optical system goes to the bifocal from the monofocal, the bifocal interval is adjustable, bifocal energy ratio adjustable function and obtain the scanning formula adjustable point annular energy distribution, it is stronger to compare traditional technique functional, the cost is lower, improved various welded energy distribution adaptability by a wide margin, it is strong to different optical fiber core footpath laser instrument compatibility, help improving the welding and splash and welding quality.

Specifically, as shown in fig. 1, in some embodiments, a first intersection line 213 formed by connecting the incident plane 211 and the convex cylindrical surface 212 is parallel to a second intersection line 223 formed by connecting the exit plane 221 and the concave cylindrical surface 222, the first intersection line 213 and the second intersection line 223 are located on a virtual partition plane, the incident plane 211 and the exit plane 221 are located on one side of the partition plane, and the convex cylindrical surface 212 and the concave cylindrical surface 222 are located on the other side of the partition plane.

In some preferred embodiments, the entrance plane 211 is tangent to the convex cylinder 212 at a first line of intersection 213, and the exit plane 221 is tangent to the concave cylinder 222 at a second line of intersection. In this case, the first intersection line 213 is a virtual line drawn to conveniently represent the boundary between the incident plane 211 and the convex cylindrical surface 212, and the second intersection line 223 is a virtual line drawn to conveniently represent the boundary between the exit plane 221 and the concave cylindrical surface 222. According to the configuration, the utility model discloses a function realization of free-form surface lens 2 is favorable to.

As a specific example, as shown in fig. 1, the free-form surface lens 2 of the present invention has the convex cylindrical surface 212 and the concave cylindrical surface 222 arranged in parallel, so that the effective focal length of the part of the lens formed by the convex cylindrical surface 212 and the concave cylindrical surface 222 can be infinite.

It can be understood that, for the specific surface types of the convex cylinder 212 and the concave cylinder 222, the free-form surface lens of the present invention is not strictly limited, as long as the effective focal length of the part of the lens formed by the convex cylinder 212 and the concave cylinder 222 is infinite. For example, the convex cylinder 212 and the concave cylinder 222 may be both spherical cylinders, and the spherical cylinder of the convex cylinder 212 may be adapted to the spherical cylinder of the concave cylinder 222. Similarly, the convex cylinder 212 and the concave cylinder 222 may be both aspheric cylinders.

As for the specific parameters of spherical cylinder, aspherical surface cylinder, the utility model discloses a free-form surface lens does not put strict restriction, and the technical personnel in the field can adjust the parameter of convex cylinder 212 and concave cylinder 222 according to actual conditions, as long as can make the effective focal length infinity of the partial lens that convex cylinder 212 and concave cylinder 222 constitute. As a partially specific example, when convex cylinder 212 and concave cylinder 222 are spherical cylinders, the radius of curvature is 10mm to 200 mm.

In some embodiments, the free-form surface lens is cylindrical as a whole, and the incident mirror surface and the exit mirror surface are respectively disposed at two ends of the free-form surface lens in the extending direction. The projection of entrance mirror 21 on the plane of entrance plane 211 is a rotationally symmetric pattern, and the projection of exit mirror 22 on the plane of exit plane 221 is a rotationally symmetric pattern. Specifically, in the embodiment shown in fig. 1, the projections of the entrance mirror 21 and the exit mirror 22 are rectangular. Thus, the optical path can be ensured to pass through the expected position on the free-form surface lens 2 in the rotating process of the free-form surface lens 2, and the expected function is realized.

In some embodiments, the rotationally symmetric pattern is a centrosymmetric pattern. So set up, when reducing the processing degree of difficulty of free-form surface lens, still can maintain the utility model discloses a multi-functional of free-form surface lens.

Another aspect of the present invention discloses an optical system, as shown in fig. 2, the optical system includes a light source 4, and any one of the free-form surface lens 2 and the focusing assembly 3, the free-form surface lens 2 and the focusing assembly 3 are sequentially disposed on a light path formed by the light source 4;

the free-form surface lens 2 can rotate around the intersection line 213 between the incident plane 211 and the convex cylindrical surface 212, so that the optical system 2 has bifocal points, and the distance between the bifocal points of the optical system 2 changes according to the rotation angle. Specifically, in order to rotate the free-form-surface lens 2, the free-form-surface lens 2 may be driven by a motor.

The free-form surface lens 2 can move along the translation direction, so that the bifocal energy ratio of the optical system is changed, and the translation direction is vertical to the central axis of the optical path and the intersection line 213;

the free-form surface lens 2 can rotate by taking the central axis of the optical path as an axis, so that the optical system has adjustable scanning type light spots with annular energy distribution.

The above-described function implementation will be specifically explained below with reference to the drawings.

Referring to fig. 2, the free-form-surface lens 2 has an initial position shown in fig. 2 in the optical system where the central axis of the free-form-surface lens 2 coincides with the optical path central axis and the incident plane 211 is perpendicular to the optical path central axis. At this time, the light path directly passes through the flat lens formed by the incident plane 211 and the exit plane 221, and is converged into a focus point through the focusing assembly 4, that is, the optical system is a single focus point at this time, and the focus point is located on the central axis of the light path. As shown in the left drawing of fig. 3.

When the free-form surface lens 2 rotates with the intersection line 213 of the incident plane 211 and the convex cylindrical surface 212 as an axis relative to the initial position, the parallel light beam emitted by the light source 4 passes through the free-form surface lens 2 along the light path to realize beam splitting and shaping: a part of the parallel light beams still pass through the flat lens formed by the incident plane 211 and the emergent plane 221 and are converged into a focus through the focusing component 4, and the focus is positioned on the central axis of the light path; the other part of the parallel light beams are deflected after passing through a part of lenses formed by the convex cylindrical surface 212 and the concave cylindrical surface 222, and are converged into another focus through the focusing assembly 4, and the focus deviates from the central axis of the optical path. At this time, the optical path system changes from the single focus to the double focus, as shown in the second left diagram of fig. 3. Further increasing the angle of the free-form surface lens 2 that rotates around the intersection line 213 of the incident plane 211 and the convex cylindrical surface 212 as an axis, at this time, a part of the parallel light beams are deflected by a larger angle after passing through a part of the lens formed by the convex cylindrical surface 212 and the concave cylindrical surface 222, and finally, the focus formed by the part of the emergent parallel light beams after being converged by the focusing assembly 4 is further away from the central axis of the light path as shown in the middle of fig. 3, as shown in the right drawing of fig. 3.

When the free-form surface lens 2 is controlled to move in the translational direction perpendicular to the optical path central axis and the intersection line on the basis of the rotation of the free-form surface lens 2 shown in the right drawing of fig. 3, the energy ratio of the two focal points can be changed. Specifically, when the optical path center axis is closer to the flat lens composed of the incident plane 211 and the exit plane 221, as shown in the left diagram of fig. 4, the energy of the focal point on the optical path center axis will be more than that of the other focal point. When the optical path central axis is closer to the portion of the lens formed by convex cylinder 212 and concave cylinder 222, as shown in the second left diagram of fig. 4, the energy of the focal point on the optical path central axis will be less than the energy of the other focal point. Thus, the optical system of the present invention realizes the adjustment of the bifocal energy ratio.

On the basis that the free-form surface lens 2 shown in the right drawing of fig. 3 rotates, when the free-form surface lens 2 rotates for a certain angle along the direction perpendicular to the paper surface inwards, the light splitting of the negative defocusing beam segment is realized, and the corresponding focused beam segment focus and the energy distribution of the front and rear light spots refer to fig. 5.

On the premise of the realization result of fig. 5, the free-form surface lens 2 is rotated around the central axis of the optical path to obtain the scanning point annular light spot energy distribution, and the scanning point annular light spot energy distribution is rotated by 60 °, 120 °, 180 °, 240 °, 300 ° and 360 ° on the basis of the reference 0 position, and the focusing point of the focusing light beam section and the double light spot superposed energy distribution at the front and rear corresponding positions are referred to fig. 6.

Similarly, the results are realized by combining fig. 3, 4 and 5, the free-form surface lens 2 rotates around the central axis of the light path to obtain scanning point annular energy distribution, wherein the diameter of the scanning ring is adjustable, the energy ratio between the point and the scanning ring is adjustable, the light splitting scanning characteristic in the negative defocusing direction is realized, and the laser welding application is met.

As a partially concrete example, as shown in fig. 2, the optical system further includes a collimating assembly 1, and the collimating assembly 1 is disposed between the free-form-surface lens 2 and the light source 4 and is located on the optical path. So arranged, the light source 4 can use a more common laser spot to scatter a light source which will become a parallel beam after passing through the collimating assembly 1 for the aforementioned focus adjustment, etc.

It is understood that the collimating assembly 1 is a single collimating lens or a combination of a plurality of collimating lenses, and the focusing assembly 3 is a single convex lens or a converging lens group consisting of a plurality of lenses with optical power. In the embodiment shown in fig. 2, the collimating assembly 1 and the focusing assembly 3 are each formed by combining a plurality of lenses having optical power. The collimation assembly 1 and the focusing assembly 3 in the form of the multi-lens combination can obtain better imaging effect. Specifically, the collimating component 1 and the focusing component 3 are in the shape of a circular cylinder, and the lens material comprises one or more of fused quartz, sapphire and zinc sulfide.

A third aspect of the present application discloses a laser welding apparatus using any one of the optical systems described above. Through using the utility model discloses an optical system, the utility model discloses a laser welding device can be better when high power laser welding retrain the melting that has bigger power's the large granule that splashes on space and time, further improves the laser problem of splashing, improves welding quality.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only represent some embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the concept of the present invention, several variations and modifications can be made, which all fall within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. The free-form surface lens is characterized by comprising an incident mirror surface facing a light source and an emergent mirror surface far away from the light source, wherein the incident mirror surface comprises an incident plane and a convex cylindrical surface connected with the incident plane, and the emergent mirror surface comprises an emergent plane and a concave cylindrical surface connected with the emergent plane; the incident plane is parallel to the emergent plane, and the incident plane and the emergent plane are correspondingly arranged on one side of the free-form surface lens; the convex cylindrical surface and the concave cylindrical surface are correspondingly arranged on the other side of the free-form surface lens, and the effective focal length of a part of the lens formed by the convex cylindrical surface and the concave cylindrical surface is infinite.

2. The free-form surface lens of claim 1, wherein a first intersection line formed by the intersection of the incident plane and the convex cylindrical surface is parallel to a second intersection line formed by the intersection of the exit plane and the concave cylindrical surface, the incident plane and the exit plane are located on one side of a separation plane on which the first intersection line and the second intersection line are located, and the convex cylindrical surface and the concave cylindrical surface are located on the other side of the separation plane on which the first intersection line and the second intersection line are located.

3. The free-form lens of claim 2 wherein said entrance plane is tangent to said convex cylindrical surface at said first intersection and said exit plane is tangent to said concave cylindrical surface at said second intersection.

4. The free-form surface lens of claim 1, wherein the convex cylinder and the concave cylinder are aspheric cylinders or spherical cylinders.

5. The free-form surface lens of claim 1, wherein the projection of the entrance mirror onto the plane of the entrance plane is a rotationally symmetric pattern, and the projection of the exit mirror onto the plane of the exit plane is a rotationally symmetric pattern.

6. The free-form lens of claim 5 wherein the rotationally symmetric pattern is a centrosymmetric pattern.

7. An optical system, comprising a light source, the free-form surface lens according to any one of claims 1 to 6, and a focusing member, wherein the free-form surface lens and the focusing member are sequentially disposed on a light path formed by the light source; wherein the content of the first and second substances,

the free-form surface lens can rotate by taking an intersection line of the incident plane and the convex cylindrical surface as an axis; the free-form surface lens can move along the direction vertical to the central axis of the optical path and the intersection line; the free-form surface lens can rotate by taking the optical path central axis as an axis.

8. The optical system of claim 7, further comprising a collimating assembly disposed between the free form lens and the light source and located on the light path.

9. The optical system of claim 8, wherein the collimating component is a single collimating lens or a combination of a plurality of collimating lenses, and the focusing component is a convex lens or a converging lens group consisting of a plurality of lenses having optical power.

10. A laser welding apparatus comprising the optical system according to any one of claims 7 to 9.