DE102024112132A1 - Processing head for a laser processing system with joint focusing of several partial beams, laser processing system and material processing methods - Google Patents

Abstract

The invention relates to a processing head (6), a laser processing system (1) equipped therewith, and a method for material processing therewith. The processing head (6) comprises a beam preparation device (7) for guiding laser radiation (4, 5, 8, 10, 36) along at least two different beam paths (30, 33, 34, 37), a deflection device (11) for independently and variably deflecting laser radiation (8, 9, 10, 36) within the processing head (6) and for generating an intermediate image (32) within the processing head (6), and a common focusing element (14) arranged thereafter. The processing head (6) also includes a control device (16) for controlling the beam preparation device (7) and/or the deflection device (11).

Description

The present invention relates to a processing head for a laser processing system, a laser processing system equipped with such a processing head and a method for processing materials therewith.

Lasers can fundamentally enable advantageous and useful processing of materials. For example, material can be separated (cut or drilled) using laser radiation, or selectively melted or hardened for additive manufacturing processes. However, with increasingly higher demands, such as material throughput (processing speed) and/or the quality of cut edges, problems and challenges can arise with conventional laser systems. Furthermore, laser systems and laser processing equipment should be as compact, cost-effective, and low-maintenance as possible. To achieve this, improvements are needed.

One approach is described by US 6 462 306 B1 A material processing device capable of providing multiple separate, discrete processing beams. Furthermore, each processing beam is equipped with a deflection device and a scanning lens with an input pupil. This input pupil is configured to receive the multiple independent beams from the deflection devices, the latter being positioned close to the input pupil.

Another approach describes the EP 1 987 911 A1 A laser processing device. This includes three devices for splitting an incident laser beam. Furthermore, it contains four pairs of scanners for deflecting the split laser beams, as well as a scanner lens.

The object of the present invention is to enable improved laser-based material processing.

The problem is solved by the subject matter of the independent claims. Further possible embodiments of the invention are specified in the dependent claims, the description, and the drawings. Features, advantages, and possible embodiments set forth in the description for one of the subject matter of the independent claims are to be regarded, at least analogously, as features, advantages, and possible embodiments of the respective subject matter of the other independent claims, as well as of any possible combination of the subject matter of the independent claims, optionally in conjunction with one or more of the dependent claims.

The processing head according to the invention is designed and configured for use in a laser processing system. A laser beam or laser radiation can, for example, be directed into the processing head, guided within or through it, and exit the processing head in the direction of the material or workpiece to be processed. The processing head has at least one beam input for at least one laser beam. This can be, for example, an opening or aperture, or a region transparent to the laser beam, within a housing of the processing head. Likewise, the beam input can be or comprise at least one optical element, such as a fiber optic beam guidance device or component, a lens, a prism, a modulator, or the like. If the processing head has multiple beam inputs, at least one individual laser beam can enter or be directed into each of these beam inputs.

The processing head also includes a beam conditioning unit, or beam preparation or modification unit. This unit is configured at least for guiding laser radiation entering the beam conditioning unit from the at least one beam input along at least two different, in particular distinct, beam paths or into at least two corresponding partial beams, which can propagate along the different beam paths through the processing head, within the processing head, or during operation of the corresponding laser processing system, to the material or workpiece to be processed. In a possible embodiment of the present invention, the beam conditioning unit is also configured at least for distributing or splitting the laser radiation or the at least one laser beam onto the at least two different beam paths, in a manner controllable, in particular, by means of the control unit. The different beam paths can already be distinct, i.e., separated from one another, within the beam conditioning unit itself, or they can run separated from one another, at least partially, through the processing head only after passing through the beam conditioning unit. Splitting the laser radiation, or at least one laser beam, across different beam paths can mean, for example, that the laser radiation or laser beam—that is, a corresponding intensity or power—is directed into the different beam paths in equal or different proportions, depending on the set split. In particular, the The beam preparation device, or the guidance and/or distribution of the laser radiation or laser beam across the various beam paths, can be variable, i.e., adjustable. The beam preparation device can then be controlled, particularly automatically, to direct the laser radiation into different possible beam paths and/or to set different distributions. For example, in an adjustable first distribution, 100% of the laser radiation or laser beam, or of several incoming laser beams, can be directed into one of the beam paths; in an adjustable second distribution, 100% of the laser radiation or laser beam, or of several incoming laser beams, can be directed into the other or a different beam path; and in one or more adjustable further distributions, a proportion of the laser radiation between 0% and 100% can be directed into several or all of the different beam paths. The beam preparation device can comprise one or more beam splitting elements, such as a beam splitter, an electro-optic modulator (EOM), an acousto-optic deflector (AOD), a half-wave plate, a deflecting polarizer, and/or similar components. The beam preparation device can therefore be designed and function as a beam splitter or a beam diverter. It can have multiple outputs, each carrying one of the various beam paths. The outputs themselves and/or the beam paths within the beam preparation device can be implemented using fiber optic beam guidance components or as such. This allows, among other things, increased flexibility in the design of the processing head, for example, a greater spatial distance and/or tolerance in the alignment of parts of the processing head relative to the workpiece. The beam preparation components and/or the processing head should therefore not necessarily be understood as physical components, but can potentially be considered functional components.

The processing head also includes a deflection device for the independent, variable deflection of laser radiation in the various beam paths entering or passing through the deflection device, i.e., for the independent variable deflection of the at least one laser beam or the various partial beams within the processing head and for generating an intermediate image within the processing head. The deflection device can, for example, have or comprise at least two independently controllable or adjustable deflection units or deflection elements for deflecting a partial beam each. These can be, for example, scanners, in particular galvanometer or galvo scanners, microsystems (MEMS: micro-electromechanical systems or MOEMS: micro-opto-electromechanical systems), electro-optic deflection elements, acousto-optic deflection elements, or the like. The deflection device can also include an intermediate optic for generating the intermediate image. With such an intermediate optic, several or all partial beams or beam paths in the far-field region, particularly a common or identical far-field region, of one or all deflection units or deflection elements, or of the deflection device as a whole, can be combined or combined. Such an intermediate image or intermediate optic can bring together the various beam paths or partial beams within the processing head. This makes it possible for the beam paths or partial beams, especially in a defined processing area outside the processing head where the material or workpiece to be processed can be positioned during operation, to have the same or only slightly different directions or angles. This reduces or minimizes the corresponding directional or angular difference of the various beam paths or partial beams compared to other laser processing systems or processing heads, while still allowing the use of different beam paths or partial beams that can be controlled independently of each other. This enables particularly advantageous material processing. Likewise, the intermediate optics of the processing head and/or a laser processing system equipped with it may have or fulfill further functions, for example, for beam shaping and/or focus position control and/or the like.

The deflection units or elements can be positioned at the location of a virtual image of the intermediate optics. In the far-field region located on the other side of the intermediate optics, i.e., on the output side of the deflection device, the beam paths or partial beams can be focused or collimated, or they can converge or merge, either physically or virtually. Alternatively, the beam waists of the partial beams can lie in the far-field region or within the area of the far-field region. Likewise, the deflection units or elements can be imaged into the far-field region by means of the intermediate optics.

Furthermore, the processing head includes a section according to the location of the intermediate image, i.e., according to the far-field region of the - in particular, overall A common focusing element or focusing optic is arranged on the output side of the focusing deflection device to focus the laser radiation from the various beam paths or partial beams into the specified processing area. This processing area can be a surface or spatial region in which, during the intended use or operation of the processing head in the laser processing system, the material or workpiece to be processed is positioned and then illuminated and processed by the laser radiation. The fact that the focusing element or focusing optic is a common focusing element or focusing optic means, in particular, that both, several, or all beam paths or partial beams pass through the same focusing element or focusing optic and converge upon it. With such a common focusing element, it is therefore unnecessary to house multiple focusing elements for the different beam paths or partial beams within the processing head. This allows for a particularly simple and compact design of the processing head, ensuring exceptional reliability and robustness. This is because, for example, the risk of misalignment, misalignment, or differing focus positions of partial beams passing through various focusing elements can be reduced or eliminated. A further advantage of using a common focusing element is that it enables a particularly small angular difference between the partial beams at a single processing position on the workpiece, compared to using separate focusing elements for individual partial beams or beam paths. The common focusing element can form a beam output of the processing head. From this common focusing element, the laser radiation can thus, in the intended use or operation of the processing head, be directed, in particular, directly to the material or workpiece being processed.

In the processing head according to the invention, the beam input, the beam conditioning unit, the deflection unit, and the common focusing element are arranged sequentially in the aforementioned order along a predetermined propagation direction for laser radiation through the processing head. The processing head according to the invention also includes a control unit for automatically controlling at least the deflection unit. The beam conditioning unit can also be controlled by means of the control unit, i.e., the distribution of the at least one incoming laser beam onto the various beam paths, or also the influencing of the laser beam or partial beams generated therefrom in or by means of the beam conditioning unit. The deflection of the laser beam or the partial beams in or by means of the deflection unit can be controlled by means of the control unit. The control unit can, for example, be or comprise a process unit, such as a microprocessor, microchip, or microcontroller, or an electronic circuit. The control unit can also include a computer-readable data storage device coupled to it. This may, for example, contain a corresponding operating or computer program that can be executed by the processing unit to control the beam preparation unit and/or the deflection unit. The control unit, in particular its processor and/or data storage and/or power supply, may be located in or on a housing of the processing head, in which its optical components, such as the beam preparation unit, the deflection unit, and the focusing element, may be located. Likewise, the control unit may be located wholly or partially outside such a housing or outside the rest of the processing head. To perform the control function, the control unit may then be connected, or connectable, to the rest of the processing head or to the equipment or components to be controlled, for example, via a wired or wireless signal or data connection.

The processing head according to the invention enables a particularly high-quality processing result and/or a particularly high throughput, i.e., a particularly high processing speed, to be achieved in a particularly simple and efficient manner. For example, the independent deflection of the laser radiation in the different beam paths allows different areas to be processed simultaneously or without interruption, or different processing steps to be carried out. Due to the particularly small directional or angular difference achievable between the different beam paths, especially in the processing area, a particularly uniform or constant shape and/or direction or inclination of, for example, cut edges or borehole walls, or the like, can be achieved when laser radiation is simultaneously or consecutively directed via different beam paths to the same position or two immediately adjacent positions. This shape and/or direction or inclination is at least essentially independent of the beam path used. Similarly, partial beams propagating along different beam paths can be used, for example, under Different beams exhibit different properties, such as varying intensities or intensity profiles, different intensity profile orientations, beam shapes, wavelengths, or power levels. By simultaneously and/or sequentially processing such different partial beams, a specific processing result can be achieved in a single operation or pass, or a particularly high degree of flexibility regarding the achievable processing results can be enabled. For example, such different partial beams can be focused at the same processing point or guided sequentially and simultaneously along the same processing contour. This allows, for example, the creation of complex cut edge shapes and/or a more favorable temperature profile in the respective material or workpiece being processed.

In one possible embodiment of the present invention, the beam conditioning device is configured to split or distribute at least the laser radiation or at least one laser beam onto at least two different beam paths, in particular controllable by means of the control device. Furthermore, the control device is configured to automatically switch or control the splitting or distribution of the laser radiation or at least one laser beam in or by means of the beam conditioning device synchronized with the deflection of the laser radiation by means of the deflection device. The control device is thus configured to perform this automatically synchronized, i.e., coordinated, or aligned process. This allows a maximized proportion of the incoming laser radiation or laser power to be used for the processing of the material or workpiece as intended in each individual case. For example, this prevents a situation where a changed splitting is set in the beam conditioning device, but a corresponding change in deflection in the deflection device is delayed by more or less than the time of flight from the beam conditioning device to the deflection device. This prevents, for example, a specific processing point from being subjected to excessively high or low laser power, at least briefly, or from laser radiation striking an unintended area within the processing head. When using a pulsed laser beam or pulsed laser power, this prevents a laser pulse from being lost within the processing head, i.e., not being guided as intended by the common focusing element. This can improve throughput or processing speed, processing quality, and processing efficiency. Furthermore, it can avoid or reduce the risk of damage from asynchronous laser pulses.

In a further possible embodiment of the present invention, the control device is configured to switch the beam conditioning device between different splits or distributions synchronously with the laser pulses or the modulation when a pulsed laser beam, i.e., a sequence of laser pulses, and/or a modulated continuous laser beam, i.e., modulated CW or continuous-wave laser radiation, is applied. This enables defined switching of pulsed and/or modulated laser radiation between different beam paths, for example, even with mode-locked laser beam sources. The synchronization proposed here with the laser pulses, i.e., a corresponding laser pulse frequency, or with the modulation, makes it possible, for example, to switch or change between different splits between two successive laser pulses or during a modulation minimum. This prevents, for example, a laser pulse or maximum region of the laser radiation from being directed into none of the intended beam paths or partially into several beam paths. This ultimately enables particularly precise, high-quality, and consistently high-quality processing. The control unit can, for example, have an input or communication interface for coupling with a laser source and/or be configured to control a pulsed and/or modulatable laser source.

In a further possible embodiment of the present invention, the deflection device is configured for scanning the deflection of the laser radiation from the various beam paths into individual, at least two-dimensionally extended working fields located within the processing area. The deflection device is designed, dimensioned, or configured such that at least two working fields overlap, and the size of the combined area of these working fields is at most twice the size of the overlapping area. In the embodiment of the present invention proposed here, the working fields can therefore overlap by at least 50%, in particular at least 60%, or at least 80%. The size can be the area or, in the case of three-dimensional working fields, for example, the area of a two-dimensional projection or the volume. Particularly useful process or processing strategies can be applied in the corresponding overlapping area, such as… The simultaneous processing, or processing in particularly flexible predefined temporal patterns, sequences, or ratios, using multiple partial beams. The proposed size of the overlap area can thus effectively and practically enable correspondingly improved material processing. This is supported by the fact that, due to the inventive design of the processing head, the various beam paths or partial beams can exhibit particularly small directional or angular differences throughout the entire overlap area. This allows for combined processing using multiple beam paths or partial beams at the same location or on adjacent areas or contours to be applied in a particularly beneficial, practical, and high-quality manner compared to conventional laser processing systems. At the same time, in the case of incomplete overlap of the working areas, the possibility and corresponding flexibility for larger processing patterns can be provided.

In a further possible embodiment of the present invention, the processing head as a whole, i.e., considering all individual beam paths or imaging paths or optics, has at least two beam inputs leading to independent scanners. These scanners are configured to deflect or transfer laser radiation into a common far-field region before it reaches the common focusing element. Thus, the intermediate images of the laser radiation from several or all different beam paths can be collected in a common far field. Here, the scanners are deflection units for scanning and deflecting laser radiation in an area of at least two dimensions. The scanners can, in particular, be part of the deflection device or the deflection units mentioned in connection with the deflection device, or a part thereof. The embodiment of the present invention proposed here can enable a particularly dense merging of the beam paths or the various partial beams, and thus particularly small directional or angular differences of the beam paths or partial beams on the material or workpiece being processed. In particular, this can also be possible with or for more than two beam paths or partial beams. The processing head can therefore have more than two, for example three, four, or more beam inputs, each leading to an independently controllable scanner. The processing head can also have one or more beam combining devices to combine, i.e., superimpose, different beam paths or partial beams, for example, by means of or in the form of coherent beam combining (CBC). This enables compact beam guidance and/or the generation of complex intensity profiles. Likewise, here—but also in other embodiments or further developments of the invention—laser radiation or a laser beam can be split into multiple beam paths or into multiple partial beams by means of CBC. For this purpose, the beam conditioning device can, for example, be configured for CBC or include a CBC device or element.

In a further possible embodiment of the present invention, the processing head is configured to combine laser radiation from at least two beam paths, in particular from two different beam inputs, by utilizing at least one inherent radiation property, for example in the intermediate image or in the same far-field region of the deflection device and/or in the processing area. Such an inherent radiation property can therefore be, in particular, a radiation property independent of or different from the propagation direction. For example, the wavelength or spectrum and/or the polarization and/or the phase of the laser radiation can be used as such a radiation property. This utilization of the radiation property for combining the laser radiation from different beam paths or different partial beams can, in particular, mean that the laser radiation is directed onto an optical element that deflects the laser radiation depending on the utilized radiation property, i.e., that its behavior or its influence on the laser radiation is sensitive or selective with respect to the utilized radiation property. Such optical elements can simultaneously and without mechanical movement enable different deflections of incident laser radiation with varying values of the utilized radiation property, regardless of the degree of deflection. This allows for a particularly simple design and robust operation of the processing head. Collinear merging of laser radiation from different beam paths or partial beams is possible, resulting in a near-ideal superposition of the laser radiation or partial beams. This, in turn, means that the different beam paths or partial beams exhibit no or only very slight differences in direction or angle within the processing area. As described elsewhere, this can lead to exceptionally high processing quality.

In another possible embodiment of the present invention, the processing head The system is designed and configured so that the laser radiation from several or all different beam paths can be combined in the processing area in such a way that the propagation directions differ by no more than five times the divergence angle of the laser radiation of a single beam path and/or by no more than 20°. In other words, the difference angle, i.e., the angular difference between the partial beams or their propagation directions or angles, can have a maximum value of 20°. This ensures that the different partial beams or the laser radiation guided along the corresponding different beam paths do not lead to significantly different processing results, which can occur with different angles of incidence or correspondingly larger differences in angle or direction.

In a further possible embodiment of the present invention, a relay optic is arranged in at least one of the beam paths, in particular in several or all beam paths, in the intended propagation direction upstream of the common focusing element, and especially directly upstream of it. Such a relay optic can be an optical relay system or a telescopic optic, with which a real image can be reproduced as a real image rotated by 180°. The relay optic can be provided in addition to, or include, or be part of, the intermediate optic, or constitute or function as the intermediate optic. The arrangement of such a relay optic proposed here in the processing head can enable the use of mechanically or geometrically relatively large deflection units, in particular scanners, and simultaneously allow for a particularly close or dense, or directionally aligned or similar, merging or superimposition of laser radiation guided in different beam paths or of different partial beams.

In a further possible embodiment of the present invention, the beam conditioning device is configured to vary the beam cross-section, i.e., the size and/or shape of the beam cross-section, and/or the position of the beam waist in the intended propagation direction, i.e., to adjust it to different values or positions. This allows, in particular, the beam cross-section and/or the beam waist position to be varied or adjusted within the processing area. Specifically, the beam conditioning device, the associated control unit, or the processing head as a whole can be configured to dynamically and flexibly vary the beam cross-section and/or the beam waist position during the intended operation or use of the processing head or the laser processing system equipped with it. This enables particularly flexible and precise material processing or the generation of complex processing patterns. For example, this allows for compensation of the different beam path lengths resulting from different angles of incidence or deflection of the laser radiation with respect to the material or workpiece being processed. This ensures that consistent processing quality and/or processing speed can be achieved particularly reliably across the entire processing area.

In a further possible embodiment of the present invention, the beam conditioning device is configured to set or generate different intensity profiles of the laser radiation and/or different orientations of at least one intensity profile of the laser radiation, particularly within at least one beam path. In other words, for example, a first intensity profile and/or a first orientation of an intensity profile can be set or generated in a specific beam path at a first time, and a different second intensity profile and/or a different second orientation can be set or generated at a second time that differs from the first. Such different intensity profiles can be, for example, a Gaussian profile, a flat-top profile, a ring profile, a multispot profile, or the like. Different orientations of an intensity profile can, for example, mean different rotation positions or rotation angles of the intensity profile about the beam axis, i.e., the propagation direction. For example, a beam or intensity profile can have a preferred direction. This can then be aligned, for example, relative to a direction of movement or trajectory in or along which the laser beam or a corresponding laser spot is guided over a material or workpiece to be processed, i.e., rotated in the plane of the material or workpiece. For this purpose, a beam-shaping element arranged in the beam path, such as a diffractive optical element, can be rotated. Likewise, the orientation of the beam or intensity profile can be changed or adjusted by means of so-called image rotators. Such a rotatably mounted Dove prism or the like, arranged in the respective beam path, can be or comprise such a rotatably mounted element. Particularly when insufficient dynamics of beam manipulation could impair the application or components, the processing head according to the invention can perform the beam manipulation. This means that the intensity profile or its orientation is only applied when the relevant beam path is not receiving power, i.e., when it carries no or only attenuated laser radiation. Such a lack of dynamics can be due to inertia or temporarily undefined parameters. Thanks to the processing head's multiple beam paths, the processing of a given material or workpiece can continue, at least almost uninterrupted, via another beam path while a corresponding setting or adjustment is being made in one beam path.

Similarly, the beam conditioning system can be configured to distribute the incoming laser radiation in different ways across the various beam paths and/or to adjust the orientations or positions of the different beam paths so that different intensity profiles result at the output, particularly in the processing area. This can be achieved, for example, by varying the beam position and/or the preferred direction or propagation direction in one or more beam paths. Depending on the technology used, this can be accomplished, for example, by varying the strength or gradient of an electric field in an EOM (Electro-Optical Microscope) and/or an acoustic frequency used in an AOD (Automatic Optical Optical Scope) and/or a tilt angle of a reflective, diffractive, or refractive optical element, or the like. The adjustability of different intensity profiles can enable particularly precise and flexible material processing for diverse requirements or processing tasks. This allows, for example, different processing tasks to be performed using the same processing head, thus enabling particularly fast and efficient operation.

In a further possible embodiment of the present invention, the beam conditioning device has at least one absorber output for laser radiation. The beam conditioning device is then configured to direct the incoming laser radiation temporarily and/or partially, i.e., upon appropriate control, into this absorber output. Such an absorber output can also be referred to as a dump output. The absorber output can be at least part of one of the beam paths, or at least one of the beam paths can lead to the absorber output. For example, such an absorber output can include or contain an absorber for laser radiation. Likewise, in a laser processing system comprising the processing head according to the invention, an absorber for laser radiation or a corresponding beam trap can be arranged downstream of the absorber output. Laser radiation directed into or emitted through the absorber output can be absorbed in the absorber, so that it does not reach the material being processed or the processing area.

The control unit can be configured to control the beam conditioning unit accordingly, so that, if required, laser radiation directed into the processing head flows completely or partially into the absorber output. This allows the processing head to be used with a continuous laser source while still enabling the generation of non-continuous processing patterns without having to switch off the laser source. This allows the laser source to be operated at a fixed operating point, resulting in particularly efficient and consistent operation. Thus, the laser source can be operated continuously and consistently, which can, for example, avoid or reduce thermal and/or electrical stress effects in the laser source, as well as additional wear due to switching the laser source on and off. This also allows for particularly uniform and consistent properties of the laser radiation, which can contribute to improved processing quality and consistency. Similarly, switching or splitting the laser radiation onto different beam paths, including a beam path leading to the absorber output, can potentially be performed faster here than by switching the laser source and any associated components off and on. Thus, the embodiment of the present invention proposed here can ultimately enable a further improved material throughput, a further improved processing speed, and/or a particularly consistent processing quality. The beam conditioning device can be configured as a beam switch or include a beam switch. In particular, the beam conditioning device can have at least one input, at least one absorber output, and at least two different outputs for emitting laser radiation for material processing.

The present invention also relates to a laser processing device or laser processing system, comprising at least one laser source for generating and outputting or providing at least one continuous and/or modulatable and/or pulsed laser beam, and a processing head according to the invention arranged downstream of this laser beam in the intended propagation direction. The laser processing system according to the invention can, in particular, perform the following functions: The laser processing system referred to as the processing head according to the invention may be related to or correspond to the laser processing system. The laser processing system can have several processing heads according to the invention. The laser processing system can then be configured not only for varying or controlling different properties and/or propagation paths of the laser radiation within a processing head or optic, but also for switching or changing between different processing heads or optics, particularly dynamically during processing. For example, laser radiation from a laser source can be switched back and forth between different processing heads or split or distributed among several processing heads. Likewise, laser radiation from several laser sources can be controlled or deflected with particular flexibility by means of several processing heads. Thus, multiple processing heads can potentially enable further improved flexibility and/or quality of the processing.

In one possible embodiment of the present invention, the laser processing system is configured to generate different beam properties in at least two or all of the different beam paths, either temporarily or at least temporarily. Such beam properties can include, for example, different repetition rates, laser pulse durations, laser pulse energies, focus positions, and/or polarizations. This allows for greater flexibility of the laser processing system and enables, for example, the generation of particularly complex processing patterns or particularly high processing accuracy. With a laser processing system configured in this way, various processing methods can be implemented, different processing requirements can be met, or the system can react dynamically to changing conditions during operation. For example, the repetition rate can be adjusted depending on the feed rate of the material or workpiece being processed. Similarly, a higher laser pulse energy can be set in a main processing beam than in a secondary processing beam following it, which can enable optimized thermal management or an optimized temperature gradient within the processed material or workpiece.

The present invention also relates to a method for material processing using the laser processing system according to the invention. In this method, the material or workpiece to be processed is positioned in the processing area. Laser radiation is then generated by the laser processing system and directed onto the material or workpiece to process it in a predetermined manner. The method can also generate relative movement between the laser processing system or its processing head on the one hand and the material or workpiece to be processed on the other. For this purpose, the laser processing system can have a corresponding traversing or adjusting device.

Further features of the invention may become apparent from the following description of the figures and from the drawings. The features and combinations of features mentioned above in the description, as well as the features and combinations of features shown below in the description of the figures and/or in the figures themselves, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention.

• 1 eine schematische Darstellung einer Laserbearbeitungsanlage und eines damit bearbeiteten Werkstücks;
• 2 eine ausschnittweise schematische Darstellung zur Veranschaulichung einer ersten Variante einer Strahlaufbereitungseinrichtung der Laserbearbeitungsanlage;
• 3 eine ausschnittweise schematische Darstellung zur Veranschaulichung einer zweiten Variante einer Strahlaufbereitungseinrichtung der Laserbearbeitungsanlage;
• 4 eine ausschnittweise schematische Darstellung zur Veranschaulichung einer dritten Variante einer Strahlaufbereitungseinrichtung der Laserbearbeitungsanlage;
• 5 eine ausschnittweise schematische Darstellung zur Veranschaulichung einer möglichen Ausgestaltung der Laserbearbeitungsanlage;
• 6 eine ausschnittweise schematische Darstellung zur Veranschaulichung einer ersten Variante einer Abbildungsoptik der Laserbearbeitungsanlage;
• 7 eine ausschnittweise schematische Darstellung zur Veranschaulichung einer zweiten Variante einer Abbildungsoptik der Laserbearbeitungsanlage;
• 8 eine ausschnittweise schematische Darstellung zur Veranschaulichung einer dritten Variante einer Abbildungsoptik der Laserbearbeitungsanlage;
• 9 eine ausschnittweise schematische Darstellung zur Veranschaulichung einer unabhängigen Teilstrahlablenkung in der Laserbearbeitungsanlage; und
• 10 eine ausschnittweise schematische Darstellung zur Veranschaulichung einer unabhängigen Teilstrahlablenkung in der Laserbearbeitungsanlage mit kleinen Winkeldifferenzen der Teilstrahlen im Bearbeitungsbereich.

The drawing shows in:

• 1 a schematic representation of a laser processing system and a workpiece processed with it;
• 2 a partial schematic representation to illustrate a first variant of a beam preparation device of the laser processing system;
• 3 a partial schematic representation to illustrate a second variant of a beam preparation device of the laser processing system;
• 4 a partial schematic representation to illustrate a third variant of a beam preparation device of the laser processing system;
• 5 a partial schematic representation to illustrate a possible design of the laser processing system;
• 6 a partial schematic representation to illustrate a first variant of an imaging optic for the laser processing system;
• 7 a partial schematic representation to illustrate a second variant of an imaging optic for the laser processing system;
• 8 a partial schematic representation to illustrate a third variant of an imaging optic for the laser processing system;
• 9 a partial schematic representation to illustrate an independent gigen partial beam deflection in the laser processing system; and
• 10 A partial schematic representation illustrating independent partial beam deflection in the laser processing system with small angular differences of the partial beams in the processing area.

Identical or functionally equivalent elements are marked with the same reference symbols in the figures.

1 Figure 1 shows a schematic representation of a laser processing system 1 for laser-based processing of a material or workpiece 2, which is schematically indicated here. The laser processing system 1 comprises at least one laser source 3 for generating at least one laser beam 4. For example, the laser source 3 can also generate one or more additional laser beams 5. Likewise, one and/or a further additional laser beam 5 can be generated by means of another laser source. The laser source 3 can generate, in particular, modulated, continuous, and/or pulsed laser radiation, for example, with a wavelength of 1030 nm and in at least one mode or beam profile, for example, as a Gaussian beam with a diameter of, for example, 5 mm at the beam waist. The laser source 3 can therefore generate one or more beams and accordingly have one or more beam outputs. Likewise, the laser source 3 can schematically represent several individual laser sources. The laser source 3 can also be configured to impose certain properties on the generated laser radiation, particularly variable or changeable properties, such as different modulations, polarizations, different phase differences between the laser beam 4 and the auxiliary laser beam 5, different wavelengths, different beam shapes, and/or the like. If the laser source 3 can generate multiple beams as shown here, it can be configured to generate and/or modulate these beams simultaneously and/or independently of one another, and/or to switch between them, i.e., to output only one of the laser beams 4 or 5 at a time, and/or to superimpose the different beams, for example, the laser beam 4 and the auxiliary laser beam 5, for example, by means of coherent two- or multi-beam superposition (CBC) or by means of a microlens array (MLA) or the like.

The laser processing system 1 also includes a processing head 6. This is positioned downstream of the laser source 3 in the intended beam propagation direction of the laser beam 4 and the auxiliary laser beam 5. The laser beams 4 and 5 can therefore be directed into one or more beam inputs of the processing head 6. From there, the laser beams 4 and 5 can enter a beam conditioning unit 7 within the processing head 6. The beam conditioning unit 7 can process the incoming laser radiation or the incoming laser beams 4 and 5, in particular by directing or distributing them along different beam paths, splitting them into different partial beams, or modifying one or more properties. The beam conditioning unit 7 can therefore, in particular, split the incoming laser radiation, i.e., laser beam 4 and/or the auxiliary laser beam 5 and/or further incoming laser beams, for example, into a first partial beam 8, a second partial beam 9, and a third partial beam 10, or corresponding beam paths. In particular, the distribution of the laser radiation, i.e., the intensity and/or power, among the different partial beams 8, 9, 10 can be dynamically varied during operation. For example, laser beam 4 can be split into the first partial beam 8 and the second partial beam 9, while the third partial beam 10 can correspond to the auxiliary laser beam 5. However, other distributions or mixtures of the laser radiation from laser beams 4 and 5 are also possible.

The beam conditioning unit 7 can also be configured to adjust the beam cross-section and the waist position in the beam propagation direction, particularly in the area of the workpiece 2, and/or to impose superimposed dynamic beam movements or beam position changes of the partial beams 8, 9, 10 within individual beam paths, and/or for beam shaping. The generation of the partial beams 8, 9, 10 and/or their modulation can be achieved, for example, using phased-array technology. For this purpose, CBC and/or a so-called light valve or the like can be used. In particular, the beam conditioning unit 7 can be configured for a variable or controllable reallocation of energy or power between several or all of the generated partial beams 8, 9, 10. This means that the energy or power of an incoming laser beam can be assigned sometimes to one of the partial beams 8, 9, 10 and sometimes to another of the partial beams 8, 9, 10. Therefore, different divisions or distributions cannot be generated solely by selectively attenuating the partial beams 8, 9, 10.

Similarly, the laser processing system 1 can, for example, include a controllable beam splitter, in particular a high-speed beam splitter. This can, for example, be arranged between the laser source 3 and the processing head 6, or be part of the laser source 3 or part of the processing head 6, in particular part of the beam splitter. The laser radiation emitted by the laser source 3 can then be directed into this beam switch and assigned to different outputs of the beam switch. Laser radiation emerging from one or more outputs of the beam switch can then be fed to one or more beam inputs of the processing head 6. Such a beam switch, or high-speed beam switch, can be configured, in particular, for switching speeds or switching times between different outputs of at most 10 µs or a corresponding switching frequency of at least 100 kHz.

The processing head 6 includes or contains a deflection device 11. This allows the incoming partial beams 8, 9, 10 to be controlled and deflected within a deflection range 12, which is shown schematically here. Deflection or deflection in various directions, in particular 3D deflection or 3D deflection, is possible.

The deflection device 11 can comprise several deflection units, in particular independently or individually controllable ones, each of which can impose a change in direction or angle on at least one of the partial beams 8, 9, 10. Such deflection units can, for example, be galvo scanners that have particularly large working fields with good scanning speed and performance. Likewise, the deflection units can each comprise, for example, one or more piezoelectric tilting mirrors. A deflection unit can enable deflection in two directions. In general, the deflection units can each address at least one angular or deflection range 12 of at least 10 mrad, in particular of at least 20 mrad, at least 50 mrad, or at least 200 mrad, in particular with a possible continuous rate or speed of at least 10 °/s.

Downstream of the deflection device 11, the processing head 6 includes a focusing optic or focusing device 13. This focusing device 13 comprises at least one common focusing element 14 through which all partial beams 8, 9, 10 pass or onto which all partial beams 8, 9, 10 strike. The focusing element 14 can, in particular, be or comprise a focusing lens. Likewise, the focusing element 14 can be designed to reflect or have at least one component or area that reflects the laser radiation. The focusing device 13 can form a beam output of the processing head 6. After leaving the focusing device 13, the partial beams 8, 9, 10 can then strike the workpiece 2. Although the workpiece 2 is located outside the laser processing system 1, the system can also have an internal receptacle for a workpiece 2 to be processed. By controlling, in particular, the deflection device 11, i.e., the deflection angles by which the partial beams 8, 9, 10 are deflected, and/or by controlling the beam conditioning device 7, i.e., for example, by varying the orientation or position of the individual beam paths, the partial beams 8, 9, 10 can be moved on the output side of the processing head 6 within a scan area 15, shown schematically here, in particular in a 2D or 2.5D area. The scan area 15 can, in particular, coincide with a surface of the workpiece 2 to be processed. In particular, some or all of the partial beams 8, 9, 10 or the corresponding individual beam paths can be combined within a single far-field area of the focusing device 13 or the focusing element 14. The partial beams 8, 9, 10 can be guided by the focusing device 13 at least substantially perpendicular to the surface of the workpiece 2 to be processed, i.e., for example, with a maximum angular deviation of 10° or 20° from the perpendicular or the optical axis. This is equivalent to a correspondingly close convergence of the partial beams 8, 9, 10 in the far field of the focusing device 13 in quasi-telecentric optics.

The laser processing system 1 also includes a control unit 16. This unit is configured at least for controlling the processing head 6, in particular for the synchronized or coordinated control of the beam conditioning unit 7 and the deflection unit 11. The control unit 16 can also be configured for controlling the laser source 3 and/or for acquiring operating signals from the laser source 3 as a basis for the coordinated control of the processing head 6. For this purpose, the control unit 16 includes, as schematically indicated here, a processor 17 and a data memory 18. Parts or components of the control unit 16 can also be spatially distributed, for example, integrated into the laser source 3 and/or the beam conditioning unit 7, or the like. If at least part of the laser radiation or laser beams supplied to the processing head 6 originates from the aforementioned switchable beam divider, the control unit 16 can also be configured to control this beam divider. The control unit 16 can therefore, in particular, control or coordinate several devices or components of the laser processing system 1 across multiple systems or components, i.e. Control them in a coordinated manner or synchronized with each other.

A multitude of scanner-based laser applications can be improved, or even realized, by using a scanner—that is, a controlled scanning deflection of the laser radiation over a working field extending in at least two spatial directions—if several independently manipulable partial beams 8, 9, 10 with overlapping working fields can be directed onto the workpiece 2 to be processed. This can be the case, in particular, if the power or energy input and/or the orientation and/or the beam shape of the several partial beams 8, 9, 10 can be dynamically controlled independently, i.e., controlled by the control unit 16.

Thus, when cutting with laser radiation, several successive partial beams 8, 9, 10 in the contour direction can be used to increase speed and/or quality. In particular, it can be useful to vary the distance and number of corresponding laser spots on the workpiece 2, as well as their power distribution, during the ongoing process, i.e., during processing. Furthermore, it can be useful to vary the laser spot size in the contour direction or along a processing contour and/or to impose or generate an offset of one or more of the partial beams 8, 9, 10 transversely or at an angle to the contour direction and/or the propagation direction in order to reduce burr formation on the contour or a corresponding cut edge. This can be useful for both straight and curved contours, i.e., processing paths, and is possible with the laser processing system 1 proposed here. For laser welding or laser-based additive manufacturing, the use of multiple partial beams 8, 9, 10 or multiple corresponding laser spots on or within the respective material or workpiece 2 is advantageous, particularly in a common or overlapping melting or process volume. To increase throughput, it can also be beneficial to allow or implement independent process zones or sections of work areas in which the workpiece 2 or multiple workpieces 2 can be processed simultaneously and/or sequentially using the laser processing system 1. For laser drilling, it can be advantageous to use several of the partial beams 8, 9, 10 simultaneously or with a time delay to produce separated, i.e., spatially spaced, holes more quickly. For example, the first partial beam 8 can be used to process a first point, while the second partial beam 9 or a corresponding deflection unit is repositioned and, if necessary, accelerated, so that after processing the first point, the first partial beam 8 can be deactivated and the corresponding laser power switched to the beam path for the second partial beam 9, in order to process another second point almost without interruption.

In the present case, this is made possible by the laser processing system 1, which allows, with the provision of at least one input beam, here for example the laser beam 4, several independently in an overlap area of working fields in a processing area 38 (see 9 The laser processing system 1 provides positionable beam paths or partial beams 8, 9, 10 for material processing, which can be dynamically manipulated with each other or with other components of the laser processing system 1, particularly with regard to other beam properties. The individual beam paths or partial beams 8, 9, 10, at least with appropriate settings of the beam conditioning unit 7 and/or the deflection unit 11, can exhibit only a small directional or angular difference in their beam axes, for example, a maximum of 20° or a maximum of 10°, in the overlap area of their working fields, especially with even a correspondingly slight change or variation of the angular difference in the entire overlap area or processing area 38. To bring the individual beam paths or partial beams 8, 9, 10 sufficiently close together, at least in the far-field region 32 or in the processing area 38, an intermediate image can be used or implemented within the processing head 6. The individual deflection units can be located in a virtual image. Because all beam paths or partial beams 8, 9, 10 pass through the common focusing element 14, they can each individually converge from the processing head 6 into the processing area 38 or their respective working field, i.e., in the intended application, onto the workpiece 2. In particular, the beam paths or partial beams 8, 9, 10 can be brought close together, at least substantially independent of their position on the workpiece 2, i.e., within the entire scan area 15 or the entire processing area 38, meaning they move only slightly relative to each other during scanning. For example, the laser processing system 1 can be configured to bring the beam paths or partial beams 8, 9, 10 together in the far-field region 32, at least to a predetermined multiple or fraction of the beam diameters or a beam diameter.

2 to 4 show schematic representations to illustrate various possible Variants of the beam splitting in the beam preparation unit 7 and/or the beam diverter possibly arranged upstream of or contained therein. In 2 For example, the laser beam 4 is directed through an input 19 and can then strike a first switching device 20. This switching device 20 can, for instance, be an electro-optical modulator for influencing the polarization direction of the laser beam 4. This can be controlled by the control device 16 to set different polarizations. The laser radiation thus polarized can then strike a first polarizer 21, in which the laser radiation can be split or directed in different directions or beam paths depending on its polarization. For example, part of the laser radiation can be deflected in the polarizer 21 to generate the first partial beam 8. The remaining part of the laser radiation can pass through the polarizer 21 in a straight line and then strike another switching device 20. A further polarizer 21 can be arranged downstream of this, at which, for example, the arriving laser power can be deflected completely or partially in the form of the second partial beam 9 or directed further, for example, towards an absorber 22. In this absorber 22, depending on the control or switching position of the switching devices 20, laser radiation 23 can be absorbed, which may correspond to part or all of the laser beam 4.

Optionally, a half-wave plate 24 and another deflecting polarizer 21 can be arranged between the second polarizer 21 and the absorber 22. This allows for the generation of an additional beam path or the third partial beam 10.

The switching devices 20 can be optional. For example, the laser beam 4 could strike the first polarizer 21 directly after the input 19, after which, for example, only the half-wave plate 24 and another polarizer 21, and optionally the absorber 22, or perhaps only a deflecting mirror, could be arranged. The polarization relevant for splitting or allocating the laser radiation to the various beam paths at the polarizers 21 can then already be generated or applied in the laser source 3. Combinations are also possible. If no laser radiation is to be emitted, i.e., supplied to the workpiece 2, then, for example, 100% of the laser radiation entering through the input 19 can be directed into the absorber 22, or the laser source 3 can be temporarily switched off.

In 3 For example, the laser beam 4 passes through input 19 and then encounters a switching device 20. This device can be an acousto-optic deflector (AOD) controlled by the control unit 16. Depending on the applied sound frequency, the AOD deflects the laser radiation to varying degrees, directing it or portions of the laser radiation to different beam paths with varying deflection angles. Several partial beams 8, 9, 10 can be generated, and the incoming power of the laser beam 4 can be distributed among them or switched between them. The different beam paths or partial beams 8, 9, 10 can be collimated or parallelized at an optical element 25 located downstream of the switching device 20. This also allows the beam path spacing to be widened or increased relative to the beam waist diameter, or maximized within the limits of the beam paths, either downstream or downstream of the optical element 25.

The beam paths or partial beams 8, 9, 10 can strike various deflecting elements, such as mirrors 26, arranged offset according to the distances between the beam paths, in order to output or provide the corresponding different beam paths or partial beams 8, 9, 10 at the output side of the beam conditioning unit 7. The absorber 22 can also be provided here. This absorber can be arranged, for example, such that when the switching device 20 is inactive or in a neutral position, the laser beam 4 passes directly into the absorber 22 without deflection or displacement by the mirrors 26, for example, with central illumination of the optical element 25, i.e., along its optical axis.

In 4 The offset mirrors 26 and the absorber 22 are also provided as examples. However, a beam combining device 27 is positioned upstream of these. Such an arrangement can be used when an input beam bundle 28, i.e., several individual laser beams, such as laser beam 4, auxiliary laser beam 5, or other laser beams, are introduced through the input 19. The beam combining device 27 can superimpose or coherently combine the laser beams of this input beam bundle 28 in various ways. This can be achieved, for example, by using different phase conditions or the like, to obtain different positions or exit directions of one or more resulting combined beams. Depending on the corresponding control of the beam combining device 27 by the control unit 16, one or more of the partial beams 8, 9, 10 can be generated in different beam paths by combining some or all of the individual beams of the input beam bundle 28. The beam combination device 27 can be a static component or one that can be modified, adjusted, or controlled only relatively slowly. The beam distribution can then be dynamically achieved by an imprint from the laser source 3. The arrangement proposed here can, for example, make it possible to use several, particularly relatively inexpensive, individual laser sources 3 to provide the input beam 28 and to achieve a higher laser power in one or more of the partial beams 8, 9, 10 than can be generated or provided by such a single laser source.

5 Figure 1 shows a schematic representation illustrating an intermediate image within the processing head 6. Here, a section or part of the deflection device 6 is shown, which has individual deflection units for the individual partial beams 8, 9, 10. For the first partial beam 8, such an individual deflection unit is indicated here as a single-beam scanner 29. This allows the first partial beam 8 to be deflected in different directions within its individual first beam path 30. An intermediate optic 31, designed here as a relay optic or telescopic optic, is also arranged in the first beam path 30. This allows the first partial beam 8 to be focused or imaged into a far-field region 32, schematically marked here, which lies within the processing head 6 upstream of the focusing device 13. The remaining partial beams 9, 10 can also be focused or imaged into this far-field region 32, or the focusing device 13 can be used to ensure that the beam waists lie in or near the far-field region 32. For example, the distance of the beam waists to the far-field region 32 or its plane can be at most twice the Rayleigh length. Likewise, the partial beams 8, 9, 10 can be collimated by the focusing device 13 or can be collimated in the far-field region 32. This can mean, for example, that the respective Rayleigh length there is at least 1000 times the beam radius at the respective beam waist.

To further illustrate this, shows 6 A partial schematic representation of a possible beam path within the processing head 6, in particular within the deflection device 11, for several partial beams, here exemplified by the first partial beam 8 and the second partial beam 9. The partial beams 8 and 9 can also be deflected here by individual deflection units or single-beam scanners 29. For the first partial beam 8, its first beam path 30 is indicated here, while the second partial beam 9 can be guided in a separate second beam path 33, either in a specific area or section. Here, too, an intermediate optic 31 is provided, which is designed in multiple parts or comprises several individual optical elements. For example, the intermediate optic 31 can have a lens for collimation or focusing in each of the beam paths 30 and 33. In addition, the intermediate optic 31 here includes a beam combiner in which the two partial beams 8 and 9 can be combined or superimposed. The beam combiner can, for example, include a polarizer and/or a dichroic mirror. This allows the partial beams 8 and 9 to be combined if they have different polarizations or different wavelengths. A focusing lens is also provided on the output side, by means of which the combined partial beams 8 and 9 can be focused or imaged into the far-field region 32.

7 Figure 1 shows a corresponding partial representation illustrating another possible configuration for the three partial beams 8, 9, 10. Here, too, the partial beams 8, 9, 10 can initially be deflected by means of a respective individual beam scanner 29. First, the individual beam 8 can travel individually along its first beam path 30, the second partial beam 9 along its individual second beam path 33, and the third partial beam 10 along an individual third beam path 34. The three correspondingly deflected partial beams 8, 9, 10 can then pass through several optical elements or components of the intermediate optics 31 and be focused or imaged together in the same far-field region 32. As indicated here by way of example, further deflection or deflection elements 35 can be arranged in this far-field region 32 to allow for even more precise and/or flexible adjustment or control of the directions of the individual beams 8, 9, 10.

8 Figure 1 shows a similar schematic representation illustrating a possible variant with three partial beams 8, 9, 10 and an additional fourth partial beam 36. Similar to the three partial beams 8, 9, 10, the fourth partial beam 36 can also be deflected by means of an individual single-beam scanner 29 and likewise travel in its own individual fourth beam path 37. In the variant shown here, the second partial beam 9 and the third partial beam 10 can first be combined in the multi-part intermediate optics 31. These two combined partial beams 9, 10 are then focused or imaged into the same far-field region 32, just like the first partial beam 8 and the fourth partial beam 36. From there, they could, for example, pass directly into the focusing device 13 or, as indicated here, be deflected by deflection elements 35.

The individual partial beams 8, 9, 10, 36 can be guided or scanned over the workpiece 2 or the processing area 38, in particular individually but in a coordinated manner, by appropriate control of the individual beam scanners 29 - if necessary in combination with appropriate control of the deflection elements 35.

To further illustrate this, shows 9 A partial schematic representation shows two independent beam deflections, one for each of the partial beams 8 and 9. Here, a first scanner mirror 29a and a second scanner mirror 29b are provided for deflecting the first partial beam 8 and the second partial beam 9, respectively. The combination of these two individual and independently controllable, tiltable, or rotatable scanner mirrors 29a and 29b allows the respective partial beam 8 and 9 to be deflected in two directions or dimensions to ultimately scan the two-dimensional processing area 38 on the workpiece 2. Within the processing head 6, the two partial beams 8 and 9 converge on their respective first scanner mirror 29a and from there on their respective second scanner mirror 29b, which directs them onto or through the focusing device 13 and the common focusing element 14, which is schematically indicated here. The focusing element 14 allows the deflected partial rays 8, 9, which may be incident obliquely onto the plane of the focusing element 14 or obliquely to its optical axis, to be focused or deflected such that they strike the processing area 38 or the workpiece 2 at least substantially perpendicularly. This can apply in particular to the entire processing area 38. Thus, at least substantially the same angle of incidence of the partial rays 8, 9 can be achieved across the entire processing area 38, resulting in particularly uniform processing of the workpiece 2.

In 9 An example of this situation is shown in which the two partial beams 8, 9 meet the workpiece 2 at different processing points 39 within the processing area 38. This allows simultaneous processing at different processing points 39.

10 Figure 1 shows a corresponding schematic representation for a different situation. Here, the two partial beams 8 and 9 are directed or focused on the same processing point 39. The partial beams 8 and 9 can therefore be directed or focused into identical or at least partially overlapping, in particular by at least 50%, working areas, i.e., they can scan these working areas. The combination of the individual working areas of the individual beams 8 and 9 can correspond to the processing area 38. Since individual deflection units or single-beam scanners 29, which are arranged at different positions, are used to deflect the partial beams 8 and 9, the partial beams 8 and 9, or their beam axes or propagation directions, can have a difference angle 40°. This difference angle can be relatively small here, for example less than 20° or less than 10°, especially in the entire overlap area of the working fields of the partial beams 8, 9. In particular, when the partial beams 8, 9 are aligned or focused on the same processing point 39, the difference angle 40 between the partial beams 8, 9, relative to the sum of the full divergence angles of the partial beams 8, 9, can be less than twice as large, in particular less than the sum of the divergence angles of the partial beams 8, 9. By directing or guiding the partial beams 8, 9 on the same processing point 39 and by controlling or varying the distance between the partial beams 8, 9, the combined or coupled effect of the partial beams 8, 9 on the workpiece 2 can be adjusted or controlled, especially in conjunction with time-synchronized or simultaneous power application.

Overall, the examples described show how a multi-beam scanner for multiple laser beams can be implemented and used in a corresponding laser system for material processing.

REFERENCE MARK LIST

1

Laser processing system

2

workpiece

3

laser source

4

laser beam

5

Additional laser beam

6

Processing head

7

Beam processing unit

8

first partial beam

9

second partial beam

10

third partial beam

11

Deflection device

12

Distraction zone

13

Focusing device

14

Focusing element

15

Scan area

16

Control unit

17

processor

18

Data storage

19

Entrance

20

Switching device

21

Polarizer

22

absorber

23

absorbed laser radiation

24

Half-wave plate

25

Optical element

26

Mirror

27

Beam combination device

28

Incoming beam

29

Single-beam scanner

29a

first scanner mirror

29b

second scanner mirror

30

first beam path

31

Intermediate optics

32

Far field region

33

second beam path

34

third beam path

35

distraction elements

36

fourth partial beam

37

fourth beam path

38

Processing area

39

Processing point

40

Different angle

QUOTES CONTAINED IN THE DESCRIPTION

This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• US 6 462 306 B1 [0003]
• EP 1 987 911 A1 [0004]

Claims (15)

Processing head (6) for a laser processing system (1), comprising: - at least one beam input (19) for at least one laser beam (4, 5), - a beam conditioning device (7) for guiding laser radiation (4, 5, 8, 9, 10, 36) along at least two different beam paths (30, 33, 34, 37) within the processing head, - a deflection device (11) for independently and variably deflecting laser radiation (8, 9, 10, 36) from different beam paths (30, 33, 34, 37) within the processing head (6) and for generating an intermediate image (32) within the processing head (6), and - a common focusing element (14) arranged downstream of the location of the intermediate image (32) for focusing the laser radiation (8, 9, 10, 36) of the different beam paths (30, 33, 34, 37) Beam paths (30, 33, 34, 37) into a predetermined processing area (38), which are arranged sequentially along a predetermined intended propagation direction for laser radiation (4, 5, 8, 9, 10, 36) through the processing head (6), and a control device (16) for controlling at least the deflection device (11). Processing head (6) after Claim 1 , characterized in that the beam processing device (7) is configured at least for the distribution of the at least one laser beam (4, 5) to the at least two different beam paths (30, 33, 34, 37), in particular controllable by means of the control device (16). Processing head (6) after Claim 2 , characterized in that the distribution of the at least one laser beam (4, 5) by means of the beam preparation device (7) can be automatically synchronized with the deflection by means of the deflection device (11) by means of the control device (16). Processing head (6) after Claim 2 or 3 , characterized in that the control device (16) is configured to switch the beam conditioning device (7) synchronously with the laser pulses (4, 5) or with the modulation between different distributions when a pulsed laser beam (4, 5) and/or a modulated continuous laser beam (4, 5) is applied. Processing head (6) according to one of the preceding claims, characterized in that the deflection device (11) is configured for scanning the deflection of the laser radiation (8, 9, 10, 36) of the various beam paths (30, 33, 34, 37) into each individual working field located in the processing area (38) with an extent of at least two dimensions, wherein the deflection device (11) is designed such that at least two working fields overlap and the size of the union of these working fields is at most twice the size of an overlap area of these working fields. Processing head (6) according to one of the preceding claims, characterized in that the processing head (6) has at least two beam inputs (19) leading to independent scanners (29) which are configured to direct laser radiation (8, 9, 10, 36) into a common far field region (32) before the common focusing element (14). Processing head (6) according to one of the preceding claims, characterized in that the processing head (6) is configured to combine laser radiation (8, 9, 10, 36) from at least two beam paths (30, 33, 34, 37) by exploiting at least one inherent radiation property, in particular the wavelength and/or the polarization and/or the phase of the laser radiation. Processing head (6) according to one of the preceding claims, characterized in that the processing head (6) is designed in such a way that the laser radiation (8, 9, 10, 36) of all different beam paths (30, 33, 34, 37) can be combined in the processing area (38) in such a way that the propagation directions differ there by at most five times the divergence angle of the laser radiation (8, 9, 10, 36) of a beam path (30, 33, 34, 37) and/or by at most 20°. Processing head (6) according to one of the preceding claims, characterized in that a relay optic (31) is arranged in at least one of the beam paths (30, 33, 34, 37) in front of, in particular directly in front of, the common focusing element (14). Processing head (6) according to one of the preceding claims, characterized in that the beam conditioning device (7) is configured to vary a beam cross-section and/or a beam waist position in the propagation direction, in particular in the area of the processing area (38). Processing head (6) according to one of the preceding claims, characterized in that the beam conditioning device (7) is configured to produce, in particular within at least one beam path (30, 33, 34, 37), different intensity profiles of the laser radiation (8, 9, 10, 36) and/or different orientations. tens of an intensity profile of the laser radiation (8, 9, 10, 36) to be set. Processing head (6) according to one of the preceding claims, characterized in that the beam preparation device (7) has at least one absorber output and enables temporary and/or partial routing of the incoming laser radiation (4, 5) into this absorber output. Laser processing system (1) comprising at least one laser source (3) for generating at least one laser beam (4, 5) and a processing head (6) arranged downstream of the laser beam (4, 5) in the intended propagation direction according to one of the preceding claims. Laser processing system (1) according Claim 13 , characterized in that the laser processing system (1) is configured to generate temporarily different beam properties in at least two different beam paths (30, 33, 34, 37), in particular a different repetition rate and/or laser pulse duration and/or laser pulse energy and/or focus position and/or polarization. Method for material processing using a laser processing system (1) according to Claim 13 or 14 , wherein a material to be processed (2) is positioned in the processing area (38) and laser radiation (8, 9, 10, 36) is generated and directed onto the material (2) by means of the laser processing system (1).