阅读说明：本技术 用于激光加工装置的光束形成和偏转光学系统、以及使用激光束加工工件的方法 (Beam forming and deflecting optical system for laser processing apparatus, and method of processing workpiece using laser beam ) 是由 斯特凡·罗伊特尔 曼努埃尔·宾德尔 斯特凡·皮希勒 于 2020-03-10 设计创作，主要内容包括：本发明涉及一种用于激光加工装置的光束形成和偏转光学系统(1),其包括至少两个光学元件(2、3),所述光学元件在激光束(L)的方向(z)上一个接一个地布置并且由具有相应楔角(α-(i))的楔形件(5、6)形成,至少一个光学元件(2)连接到用于使所述光学元件(2)围绕光轴(c)旋转的驱动器,由此一个光学楔形件(5)可以相对于至少一个其他光学楔形件(6)旋转。本发明还涉及一种使用准直激光束(L)加工工件(W)的方法。为了在工件(W)上实现激光束(L)的不同形状,一个接一个地布置的每个光学楔形件(5、6)仅覆盖激光束(L)的一部分。(The invention relates to a beam-forming and deflecting optical system (1) for a laser processing device, comprising at least two optical elements (2, 3) which are arranged one after the other in the direction (z) of a laser beam (L) and have a respective wedge angle (alpha) i ) Is formed, at least one optical element (2) being connected to a drive for rotating said optical element (2) around the optical axis (c), whereby one optical wedge (5) can be rotated relative to at least one other optical wedge (6). The inventionA method for machining a workpiece (W) with a collimated laser beam (L) is also described. In order to achieve different shapes of the laser beam (L) on the workpiece (W), each optical wedge (5, 6) arranged one after the other covers only a part of the laser beam (L).)

1. A beam forming and deflecting optical system (1) for a laser processing device (10) comprises at least two optical elements (2, 3) arranged one after the other in the direction (z) of a collimated laser beam (L) and having respective wedge angles (α)₁) Wherein at least one optical element (2) is connected to a drive (4) for rotating the optical element (2) about an optical axis (c), whereby the optical wedge (5) can be rotated relative to at least one other optical wedge (6), characterized in that the optical wedges (5, 6) arranged one after the other cover in each case only a part of the laser beam (L).

2. Beam forming and deflecting optical system (1) according to claim 1, characterized in that all optical wedges (5, 6) have an equal number of wedge angles (| α)₁|)。

3. The beam forming and deflecting optical system (1) according to claim 1 or 2, characterized in that the optical wedges (5, 6) cover in each case between 25% and 50% of the laser beam (L).

4. The beam forming and deflecting optical system (1) according to any one of claims 1 to 3, characterized in that the optical wedges (5, 6) form a circular sector or a segment.

5. The beam forming and deflecting optical system (1) according to any one of claims 1 to 4, characterized in that the optical wedges (5, 6) are arranged in each case in hollow shafts (7, 8).

6. Beam forming and deflecting optical system (1) according to any one of claims 1 to 5, characterized in that the wedge angle (a) of the optical wedges (5, 6)₁) At least 1 mrad, preferably between 3 mrad and 15 mrad.

7. The beam forming and deflection optical system (1) according to any one of claims 1 to 6, characterized in that at least one actual value sensor (16) is provided for determining the position of the optical wedge (5, 6) or hollow shaft (7, 8) respectively.

8. Beam forming and deflecting optical system (1) according to any one of claims 1 to 7, characterized in that the optical wedges (5, 6) are made of quartz glass, borosilicate crown glass, zinc selenide or zinc sulfide.

9. The beam forming and deflecting optical system (1) according to any one of claims 1 to 8, characterized in that all optical wedges (5, 6) or hollow shafts (7, 8) are respectively connected to a respective driver (4) for independently rotating each optical wedge (5, 6) around the optical axis (c).

10. Beam forming and deflecting optical system (1) according to one of claims 1 to 9, characterized in that a drive (9) for the joint rotation of all the respective optical wedges (5, 6) or hollow shafts (7, 8) is provided.

11. Beam forming and deflecting optical system (1) according to one of claims 1 to 10, characterized in that the at least one driver (4, 9) is connected to a motor controller (11).

12. A method for machining a workpiece (W) with a collimated laser beam (L), wherein the collimated laser beam (L) passes through a beam forming and deflecting optical system (1) comprising a laser beam having a respective wedge angle (α)₁) At least two optical elements (2, 3) in the form of at least two optical wedges (5, 6) arranged one after the other in the beam direction (z) of the laser beam (L), and a focusing lens (15), wherein at least one optical wedge (5) is rotated about an optical axis (c) relative to at least one other optical wedge (6) of the beam forming and deflecting optical system (1), characterized in that the laser beam (L) is only partially covered by the optical wedges (5, 6) arranged one after the other.

13. Method according to claim 12, characterized in that the laser beam (L) passes through a beam having an equal number of wedge angles (| α)₁|) at least two optical wedges (5, 6).

14. Method according to claim 12 or 13, characterized in that the optical wedges (5, 6) are rotated at a rotational speed of between 100 and 10000U/min, preferably between 500 and 7000U/min.

15. Method according to any one of claims 12 to 14, characterized in that the position and rotation of the at least two optical wedges (5, 6) are detected using at least one actual value sensor (16).

Technical Field

The invention relates to a beam forming and deflecting optical system for a laser processing device, comprising at least two optical elements which are arranged one after the other in the direction of a collimated laser beam and are formed by wedges having respective wedge angles, wherein at least one optical element is connected to a drive for rotating the optical element about an optical axis, whereby the optical wedge can be rotated relative to at least one other optical wedge.

The invention further relates to a method for machining a workpiece using a collimated laser beam, wherein the collimated laser beam is passed through a beam forming and deflecting optical system comprising at least two optical elements in the form of at least two optical wedges having respective wedge angles, which are arranged one behind the other in the beam direction of the laser beam, and a focusing lens, wherein at least one optical wedge is rotated about an optical axis relative to at least one other optical wedge of the beam forming and deflecting optical system.

Background

The invention relates to a method and a device for machining workpieces, in particular laser welding or laser spot welding and brazing, using a laser beam, and a method and a device for machining workpieces by means of one or several laser beams in combination with an electric arc, for example using an electric arc in a hybrid laser welding method.

The workpiece can be welded, cut, joined by welding, or the surface of the workpiece can be machined by the heat introduced by means of the laser. Depending on the application and conditions of the workpiece, spots of laser beams of different diameters and shapes are required to be irradiated onto the surface of the workpiece. The formation of the laser beam typically takes place by means of corresponding optical elements which are arranged downstream of the laser generating device and possibly of the collimator lens in order to influence the laser beam. With this type of beam forming and deflecting optical system, laser beams of different spot shapes suitable for various tasks can be generated on the surface of a workpiece to be processed.

It may also be necessary to change the power density distribution of the laser beam during the continuous processing of the workpiece, for which purpose corresponding optical means comprising movably arranged optical elements are used.

For example, EP 2780131B 1 describes a method for laser welding, in which an optical element is rotated to improve the welding process and thus the laser beam is deflected accordingly.

EP 3250958B 1 describes a device and a method for machining a workpiece using a laser beam, wherein, for forming and deflecting the laser beam, at least one plate-shaped optical element is provided, one surface of which is provided with a circular pattern of sectors having different inclinations, whereby a laser focus in a focal plane is broken up into a plurality of spots, which are arranged in an annular manner around the optical axis of the beam path.

US 9,285,593B 1 describes a method for forming a laser beam to obtain a circular or square spot shape with a specific intensity distribution. For this purpose, a full-surface optical element having a relatively complex surface contour is inserted into the beam path of the laser beam.

From US 5,526,167 a and US 3,720,454 a an optical device for a scanning system is known, by means of which the laser beam can be deflected or the focus can be changed accordingly. The spot shape and power density of the laser beam do not change except in the technical field.

A disadvantage of the known methods and devices of the prior art is the lack of flexibility in the change of the spot shape during the machining of the workpiece and/or the complicated and elaborate structure of the beam forming and deflection optical systems, which does not provide a compact design of the laser machining device.

Disclosure of Invention

It is therefore an object of the present invention to create the above-mentioned beam forming and deflecting optical system of a laser processing apparatus and the above-mentioned method of processing a workpiece using a laser beam, whereby a simple and adaptive beam shape can be obtained for various applications. The change in beam shape should also be able to be made as quickly as possible during the laser machining process. The beam-forming and deflecting optical system is further constructed in a manner as space-saving as possible, so that beam-forming with a small interference profile is possible. The disadvantages of the known devices and methods are prevented or at least reduced.

The object according to the invention is solved by the above-mentioned beam forming and deflecting optical system of a laser machining device, in the case of which the optical wedges are arranged one after the other, in each case covering only a part of the laser beam. The invention provides a particularly simple construction by means of at least two optical wedges which can be rotated relative to one another. The optical wedges or optical prisms are each made of a suitable material, in particular glass, and can also be formed by a so-called diffractive beam former or diffractive optical element (DEO). A diffractive optical element is a structure made of glass or plastic that changes the phase distribution of a laser beam. The division of the laser beam into a plurality of spots and the modification of the spot shape at the workpiece surface can thereby be achieved in a particularly simple and fast manner. A particularly space-saving implementation is possible due to the simple construction, which has a small interference profile and provides a slim construction of the machining head. The beam shaping and beam deflection changes can also be carried out during the machining process by mutual rotation of at least two optical wedges and/or joint rotation of all optical wedges, and an optimal adaptation of the laser beam to the desired machining can be achieved. For example, the change of the spot shape for changing the gap bridging can be performed during the welding process without interrupting the process.

When the wedge angles of all the optical wedges are equal in number, the beam forming and deflecting optical system can be placed in a neutral position if necessary. In the case of a mutually corresponding position of the optical wedge in this neutral position, a cancellation of the deflection of the laser beam can be achieved and the laser beam is thus irradiated in a constant manner on the workpiece.

In all cases, the optical wedge advantageously covers 25% to 50% of the laser beam. Such a coverage value is appropriate depending on the number of optical wedges and the number of spots required on the surface of the workpiece to be machined.

The optical wedge is preferably formed in a circular sector or circular arc shape. By forming the optical wedges in the shape of circular sectors or circular arcs in their top view, a particularly space-saving arrangement of the beam forming and deflection optical system is achieved, since the outer contour does not change with the mutual rotation of the optical wedges or the joint rotation of all the optical wedges. Thus resulting in a space-saving design with a small interference profile.

When the optical wedges are in each case arranged in a hollow shaft, a relatively simple rotation of the optical wedges can be achieved by rotation of the respective hollow shaft. The optical wedge may also be protected from contamination within the hollow shaft. To operate quietly at high rotational speeds, the hollow shaft may be balanced.

The hollow shaft preferably has a diameter of between 25mm and 90 mm. A particularly space-saving and slim design of the beam forming and deflection optical system and thus of the entire laser machining device or machining head can be achieved accordingly, which allows an improvement in its mobility. This is of great significance, in particular in the case of robotic applications. In order to protect the hollow shaft and the adjacent components of the beam-forming and deflecting optical system from thermal overheating, for example, respectively due to absorption of scattered laser radiation and/or retro-reflected process radiation, the inner surface of the hollow shaft may optionally be provided with a reflective coating, in particular a gold coating.

The wedge angle of the optical wedge is at least 1 millirad (0.057 deg.), preferably between 3 millirad (0.17 deg.) and 15 millirad (0.859 deg.). Empirically, such a wedge angle is advantageous for obtaining a corresponding spot size and spot shape on the surface of the workpiece to be machined.

According to a further feature of the present invention, at least one actual value sensor is provided for determining the position of the optical wedge or hollow shaft, respectively. Accordingly, by means of a rotation sensor or a rotation angle sensor of this type, the position of the optical wedges relative to each other or of all the optical wedges relative to the workpiece can be optimally detected and controlled accordingly. The actual value sensor is usable in various embodiments and is small in overall size, whereby the size of the beam forming and deflecting optical system is not significantly enlarged. For example, the actual value sensor may be formed by an encoder (optical, inductive) or a resolver.

The optical wedge may be made of quartz glass, borosilicate crown glass, zinc selenide, or zinc sulfide. These materials are particularly suitable for deflection and formation of laser beams and are also relatively heat resistant.

All optical wedges or hollow shafts may be connected to respective drivers for independent rotation of each optical wedge about the optical axis, respectively. A high degree of flexibility is achieved in obtaining various beam forms.

A drive for jointly rotating all optical wedges or hollow shafts accordingly may also be provided. In addition to the formation of different spot shapes, a better coverage of the surface of the workpiece to be machined can also be achieved by rotating the entire device about the optical axis, i.e. the spot is correspondingly rotated about the zero point or the optical axis. Thus producing so-called dynamic beam forming.

At least one driver is connected to the motor controller so that the desired beam shape can be quickly and easily adjusted. Depending on the drive motor used, the motor control can be formed, for example, by a microcontroller or microprocessor.

The object according to the invention is also solved by the above-mentioned method of machining a workpiece using a collimated laser beam, wherein the laser beam is only partially covered by optical wedges arranged one after the other. The method according to the invention provides fast and adaptive beam forming with a simple design. With regard to further advantages, reference is made to the above description of the beam forming and deflection optical system.

When the laser beam passes through at least two optical wedges having an equal number of wedge angles, a cancellation of the beam formation and the deflection takes place in the case of corresponding positions of the optical wedges, whereby the laser beam impinges in a constant manner on the surface of the workpiece to be machined.

The optical wedge is rotated at a rotational speed of between 100 and 10000U/min, preferably between 500 and 7000U/min. This velocity value provides a fast change of the spot shape to be obtained, which is sufficient for most processes.

The position and rotation of at least two optical wedges may be detected using at least one actual value sensor. As described above, optimal control of the beam shaping and deflection optics may be achieved by detecting the position and rotation of all of the optical wedges using respective rotary encoders.

When the at least two optical wedges are rotated in the same direction at the same speed, a corresponding rotation of the spot shape formed by the mutual assignment of the at least two optical wedges around the zero point or the optical axis can be achieved. This corresponds to dynamic beam forming, whereby the area covered by the laser beam on the surface of the workpiece to be machined can be enlarged.

Periodic variations in spot shape are obtained during workpiece processing when at least two optical wedges are rotated at the same speed in opposite directions. The resulting pendulum effect, in which the power density of the laser beam moves back and forth in the workpiece plane, may be advantageous for certain applications.

The at least one optical wedge may also be rotated back and forth in a pendulum motion about a designated angular range. Each spot shape can thus be pivoted back and forth about a specified angular range, whereby a greater coverage of the area to be machined on the workpiece can be obtained. The specified angular range may be, for example, between 45 ° and-45 °.

According to a further feature of the present invention, the laser beam may also be formed in accordance with the position and movement of the processing head of the laser processing device relative to the workpiece to be processed, so that an optimum processing result can be obtained for each position and movement. For example, different spot shapes of the laser beam may be used in response to vertical processing, horizontal processing, or overhead processing of the workpiece. The beam forming can also be designed in dependence on the speed of the processing head. The position and movement of the machining head can be detected by corresponding sensors or, in the case of an automated laser machining device, can also be derived from possible robot movement data and can be provided correspondingly to the beam shaping and deflection optics of the optical wedge or its motor control.

In the case of the above-described laser hybrid welding device with a combination of at least one laser beam and at least one arc, the change of the spot shape of the at least one laser beam may provide advantages for certain applications depending on the welding parameters (welding current, welding voltage, feed speed of the welding wire, polarity of the welding current, etc.) or the phase of the welding process (short-circuit phase, pulse phase, arc phase, etc.).

In the case of laser mixing devices, the position of the laser beam relative to the arc may also be critical for the formation of the laser beam. For example, the spot shape of the laser beam may be advantageous for an upstream laser beam relative to the arc, except in the case where the laser beam is downstream of the arc.

Drawings

The invention is described in more detail on the basis of the accompanying drawings, in which:

fig. 1 shows a block diagram of an apparatus for machining a workpiece using a laser beam according to the prior art;

fig. 2 shows an embodiment alternative of a beam forming and deflection optical system according to the invention in a cut-away side view;

FIG. 3 shows a top view of the beam forming and deflecting optical system according to FIG. 2;

FIGS. 4A to 4D show various positions of two semicircular optical wedges of a beam forming and deflecting optical system relative to each other for obtaining various shapes of laser beams on a workpiece;

FIG. 5 illustrates in partial cutaway form an embodiment of a beam forming and deflecting optical system including a drive for moving the optical wedge;

FIG. 6 illustrates various beam shapes (static spots) for various angular positions of two optical wedges relative to each other;

FIG. 7A shows various spot shapes in response to additional rotation;

FIG. 7B shows the corresponding power density according to the spot shape of FIG. 7A; and

FIG. 8 shows the spot shape in response to the joint pendulum movement of the optical wedges.

Detailed Description

Fig. 1 shows a block diagram of an apparatus 10 for machining a workpiece W with a laser beam L according to the prior art. The machining device 10 comprises a laser generating device 12 and an optical fiber 13 via which the laser beam L is transmitted to the respective machining head. The laser beam L is collimated using, for example, a collimator lens 14 and focused on the surface of the workpiece W to be processed via a focusing lens 15. The laser beam L can be influenced via the beam forming and deflecting optical system 1 arranged between the collimator lens 14 and the focusing lens 15 in such a way that the spot shape S on the surface of the workpiece W to be processed can be changed. For this purpose, at least two optical elements 2, 3 are arranged one after the other in the beam path of the laser beam L in the beam forming and deflection optical system 1, which optical elements 2, 3 thus influence the collimated laser beam L such that the spot shape S on the surface of the workpiece W to be processed changes. By changing the orientation of the optical element 2 relative to the further optical element 3, a change of the spot shape S of the laser beam L can also occur during processing of the workpiece W. For this purpose, the optical elements 2 are connected to respective drivers 4. In the case of a laser hybrid welding device, the laser beam L is combined with at least one electric arc (not shown).

Fig. 2 shows an embodiment alternative of the beam forming and deflecting optical system 1 according to the invention in a sectional side view. At least two optical elements 2, 3 of the beam-forming and deflecting optical system 1 have respective wedge angles α₁、α₂Are formed by the optical wedges 5, 6. The optical wedges 5, 6 or prisms of this type are accordingly dependent on the wedge angle α₁、α₂The collimated laser beam L is deflected, whereby the irradiation point of the laser beam L on the surface of the workpiece W to be processed and thus the spot shape S are changed. Since the two optical wedge pieces 5, 6 cover in each case only a part of the laser beam L, the number of points at which the laser beam impinges on the surface of the workpiece W can be varied. In the exemplary embodiment shown, the two optical wedges 5, 6 cover in each case substantially 50% of the laser beam L. Downstream of the beam forming and deflection optical system 1, viewed in the direction z of the laser beam L, a focusing lens 15 is arranged via which the deflected laser beam L is to be viewedAnd accordingly focused on the surface of the workpiece W to be processed. By rotating at least one optical wedge 5, 6 about the optical axis c, a change of the spot shape S on the surface of the workpiece W can be achieved. By rotation of the entire beam shaping and deflection optical system 1 about the optical axis c, a dynamic beam shaping or rotation of the spot shape S about the optical axis c can be achieved accordingly. Having a wedge angle alpha₂May also be arranged mirror-inverted to the optical wedge 6 according to fig. 2, whereby other light beams and spot shapes S may be generated. For example, when the wedge angle α of the optical wedges 5, 6₁、α₂In equal number, the deflection of the collimated laser beam L with the respectively opposite orientation of the two optical wedge pieces 5, 6 relative to one another can take place via the optical wedge pieces 5, 6, whereby the collimated laser beam L is not significantly influenced by the beam forming and deflection optical system 1 and a spot shape S is produced on the surface of the workpiece W which corresponds to the spot shape S without the beam forming and deflection optical system 1. This means that there are an equal number of wedge angles a₁＝α₂With the respective opposite orientation of the optical wedges 5, 6, the beam forming and deflection of the laser beam L can be switched to a neutral position.

Fig. 3 shows a top view of the beam forming and deflecting optical system 1 according to fig. 2. The optical wedges 5, 6 are preferably formed in a circular sector or circular arc shape in plan view and have a radius R in the range of 10mm to 40mm, whereby the size of the beam forming and deflecting optical system 1 can be kept small and the overall size of the processing head of the laser processing device 10 can be reduced.

In fig. 4A to 4D, various positions of the two semicircular optical wedges 5, 6 of the beam forming and deflecting optical system 1 relative to each other are shown for obtaining various shapes of the laser beam L on the workpiece W. In the exemplary embodiment shown, the two optical wedges 5, 6 have opposite and equal angles α 1 — a 2. In the case of the positions of the two optical wedges 5, 6 according to fig. 4A, which have an angle Δ β of 180 ° to one another, the laser beam L is deflected by the optical wedges 5, 6 in the same direction, as a result of which a spot shape S is produced at the workpiece W, which corresponds to this spot shape SThe ground is deflected from the respective zero point N or center of the optical axis c. In the case of the positions of the two optical wedge pieces 5, 6 shown in fig. 4B, which have an angle Δ β of 135 ° between each other, the spot shape S is produced on the surface of the workpiece W, which depends on the wedge angle α of the optical wedge pieces 5, 6₁And alpha₂At each point around the optical axis c there are four irradiated points of the laser beam L, the deflection effects of which add up correspondingly in the overlap region. In the case of the arrangement according to fig. 4C with an angle Δ β of 90 ° between the optical wedges 5, 6, the respectively illustrated spot shape S results on the workpiece W. In the case of the mutual position of the optical wedges 5, 6 according to fig. 4D (angle Δ β ═ 0 °), there is a wedge angle α₁＝-α₂Thereby producing a spot shape S on the workpiece W, which is accordingly arranged at the center or zero point N of the optical axis c and corresponds to the spot shape S of the laser beam L without the beam forming and deflecting optical system 1.

Accordingly, by changing the mutual orientation of the two optical wedges 5, 6 or by changing the angle Δ β between the optical wedges 5, 6, a change in the spot shape S can thus be achieved on the surface of the workpiece W. By increasing the number of optical wedges, for example to three or more optical wedges, the number of spots in the spot shape S can be increased and the variation in the spot shape S that can be achieved can be further varied.

Fig. 5 shows an embodiment of the beam forming and deflecting optical system 1 in partial cut-away form, comprising a drive for moving the optical wedges 5, 6. The optical wedges 5, 6 of the beam-forming and deflecting optical system 1 are in each case arranged in hollow shafts 7, 8 which can be rotated about the optical axis c via respective drives 9. The drive 9 may be formed, for example, by a hollow shaft motor or a torque motor. In addition to the drive 9 for rotating the optical wedges 5, 6 or the hollow shafts 7, 8, a further drive 9 (not shown) for rotating the entire beam forming and deflecting optical system 1 about the optical axis c may be provided. Via a corresponding actual value sensor 16, the position of the optical wedge 5, 6 or the hollow shaft 7, 8 can be detected accordingly. The respective motor controller 11 controls the respective drive 9 as a function of settings of the operating unit 17 or on the basis of other specifications, for example on the basis of the position and movement of the machining head of the laser machining device 10 relative to the workpiece W or, in the case of laser hybrid applications, on the basis of parameters, for example on the basis of welding parameters (welding current, welding voltage, feed speed of the welding wire, polarity of the welding current, process phase, etc.). The beam forming and deflecting optical system 1 of the known type is characterized by a relatively small overall size and a compact embodiment. For example, a diameter dH of the hollow shaft 7, 8 in the range between 25mm and 90mm is achieved, thereby producing a small interference profile. Cooling ducts for guiding a cooling fluid (not shown) may optionally be arranged in the housing of the beam forming and deflecting optical system 1.

The various spot shapes S are reproduced in fig. 6 at various angles Δ β of the optical wedges 5, 6 with respect to each other. Using the example of two optical wedges 5, 6 with opposite and equal wedge angles α 1 ═ α 2, various spot shapes S are shown here, where the angular position Δ β of the two optical wedges 5, 6 to each other is varied in 30 ° steps. The resulting spot shape S on the surface of the workpiece W to be processed is shown below. By means of the various spot shapes S, the respective heat input or melt pool and cooling rate can be optimally adapted to the various machining tasks. For example, a higher gap bridging capability can be obtained by a wider spot shape S (sixth image from left with an angle Δ β of 150 °). In the case of an angular position Δ β of 180 °, a spot shape S results which is at most correspondingly offset around the zero point N or the optical axis c, but which remains unchanged.

Fig. 7A shows various spot shapes S in response to additional rotations of optical wedges 5, 6 about zero point N or optical axis c, respectively, in the same direction and at the same speed. Thereby maintaining the angle delta beta between the optical wedges 5, 6. A spot shape S that may be annular (the rightmost image according to fig. 7A with an angle Δ β of 180 °) may thereby be obtained. A rotary motion with a continuously variable angular position Δ β can be realized analogously.

The power density P of the laser beam L is shown in fig. 7B depending on the radial position xr at different angular positions Δ β according to fig. 7A_L. By corresponding rotation of the spot shape SDifferent energy inputs can be obtained on the surface of the workpiece W to be processed. Certain spot shapes S may be advantageous in case of various positions or movements of the laser beam L relative to the workpiece W, which is why they may also be selected depending on the position and movement. In the case of combined laser hybrid applications, the spot shape S of the laser beam can also be selected depending on the parameters of the arc or process stage.

Finally, fig. 8 shows the spot shape S in the case of a joint pendulum movement of the optical wedges 5, 6 around a specific angular range. In the exemplary embodiment shown, a constant angular position Δ β of optical wedges 5, 6 relative to each other of 135 ° is assumed, wherein optical wedges 5, 6 jointly move back and forth about a specified angular range Δ χ of 90 °. By means of this pendulum movement, a specified angular range Δ χ can be passed around the optical axis c and a corresponding heat distribution can be achieved accordingly on the surface or in the workpiece W. Pendulum movements with continuously variable angular position Δ β can be realized analogously.

The invention is characterized by a simple and adaptive formation of the laser beam L with a small interference profile.