Method for determining at least one parameter of a laser device, in particular laser plotter, by means of libs (laser induced breakdown spectroscopy) for machining a workpiece, and laser device for this purpose
Patent Information
- Application Number
- EP2023793343
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-11-24
- Filing Date
- 2023-10-19
- Publication Date
- 2025-10-01
AI Technical Summary
Existing laser devices, such as laser plotters, lack effective methods for determining material parameters during processing, leading to potential damage and safety hazards due to unsuitable materials being used, and there is a need for improved user-friendliness and reliability in material recognition.
The method employs LIBS (Laser Induced Breakdown Spectroscopy) to determine material parameters by vaporizing a small amount of the workpiece with a laser, recording the plasma with a spectrometer, and comparing the results to set parameters, which can be done manually or automatically, ensuring reliable material recognition and documentation, and preventing unsuitable materials from being processed.
This approach significantly enhances process reliability, safety, and user-friendliness by automatically recognizing materials, preventing damage to the device and ensuring safe operation, while allowing for easy documentation of materials used for warranty purposes.
Smart Images
Figure 1.1
Abstract
Description
[0001] Method for determining at least one parameter of a laser device, in particular a laser plotter, by means of LIBS (Laser Induced Breakdown Spectroscopy) for processing a workpiece, and laser device for this purpose
[0002] The invention relates to a method for determining at least one parameter of a laser device, in particular a laser plotter, by means of LIBS (Laser Induced Breakdown Spectroscopy) for processing a workpiece, as well as a laser device as described in claims 1, 13 and 14.
[0003] Various applications of LIBS (Laser Induced Breakdown Spectroscopy) are known from the prior art. For example, a sorting device is equipped with a LIBS laser device, according to EP 3967413 A1.
[0004] Laser-induced plasma spectroscopy, also known as LIBS, is a fast, non-contact technique for analyzing solid, liquid, or gaseous substances, as described in Wikipedia: https: / / de.wikipedia.ora / wiki / Laserinduzierte_Plasmaspektroskopie. By bombarding a material, especially a workpiece, with short laser pulses, a small volume of the material is vaporized and ionized into a plasma. When the plasma decays, light is emitted that is characteristic of the elements it contains. The spectrum of the radiation is recorded with a spectrometer, allowing the elemental composition of the material to be determined.
[0005] The object of the invention is to provide a method for determining at least one parameter of a laser device, in particular a laser plotter, using LIBS (Laser Induced Breakdown Spectroscopy) for processing a workpiece, and a laser plotter for this purpose, which, on the one hand, avoids the aforementioned disadvantages and, on the other hand, achieves a high level of user-friendliness and safety when processing a workpiece with the laser device. This object is achieved by the invention. Advantageous embodiments and / or method measures are described in the subclaims.
[0006] The object of the invention is achieved by a method for determining a parameter of a laser device, in particular a laser plotter, by means of LIBS (Laser Induced Breakdown Spectroscopy) for processing a workpiece, in which method a LIBS process (Laser Induced Breakdown Spectroscopy), in particular a material recognition process, is started manually or automatically by the laser device or an external component, in particular a laptop, connected to the laser device to determine the parameter "material", whereupon the workpiece is processed, in particular irradiated, in a known manner with a laser, in particular laser radiation, in such a way that a small amount of material of the workpiece is vaporized, wherein the vaporized material, in particular a plasma, is detected and evaluated via a spectrometer, whereupon the determined material is made available to the user on the laser device or the external component, in particular a laptop.displayed and / or the determined material is set as the parameter “Material” or compared with the set material of the parameter “Material”.
[0007] The advantage here is that the use of material detection through a so-called LIBS process (Laser Induced Breakdown Spectroscopy), which has been around for many years, significantly increases process reliability. This means that the inserted material is automatically detected. This means that, for example, a message is issued or processing is stopped if the material is unsuitable. It is also possible to compare the set parameters, in particular the laser power, material thickness, etc., with the detected material. This means that a warning is issued if the settings are unsuitable, for example if the laser power is too high. Furthermore, the inserted material can be easily set or accepted by simply starting the LIBS process on the laser device or the external component. The user therefore only needs to accept the detected and displayed material.Another very significant advantage is that the materials used can be automatically documented, so that in the event of damage or repairs, it is very quick and easy to trace whether the laser device was used as intended. Advantageous measures include the start of the LIBS process, followed by a cleaning irradiation of the surface of the workpiece or material. This is done before the actual LIBS process for generating and recording the plasma to evaluate the material or the "material" parameter is carried out. This ensures that contamination is removed before the actual LIBS process, so that reliable material detection can then be carried out. Preferably, the cleaning irradiation is activated as an option in the software, particularly in the operator software.It is also possible to perform multiple cleaning cycles consecutively. Preferably, the consecutive cleaning irradiations are activated manually, or the user can enter or select the number of cleaning cycles to be performed.
[0008] Measures that compare the identified material with stored materials are advantageous. In the case of unsuitable materials, such as leather and artificial leather containing chromium (VI), carbon fibers (carbon), polyvinyl chloride (PVC), polyvinyl butyral (PVB), polytetrafluoroethylene (PTEE / Teflon), beryllium oxide, etc., an error message or note will appear on the laser device and / or the external component. This prevents damage to the device on the one hand and the formation of substances or gases that are dangerous to the user on the other. Furthermore, this can be used to document the materials used or employed for any warranty claims against the manufacturer in order to record any improper use.
[0009] Advantageous measures include moving to a separate area in the processing room, particularly on the processing table, in particular a material detection area in which the spectrometer is positioned, to carry out the LIBS process. Preferably, the workpiece is first placed in this area, after which, after the LIBS process has started, the laser head is moved to a defined location to carry out the LIBS process. The workpiece is irradiated via the laser head and the generated plasma is recorded via the spectrometer arranged in the area. This means that the laser head or the focusing unit can be kept very compact, since the spectrometer is permanently mounted in the material detection area. This also means that there is no loss in the processing speed of the laser head or the focusing unit, since the laser head orthe focusing unit does not have to transport any additional mass and the overall size does not change. It is of course also possible for the laser head or focusing unit to be moved into the material detection area after the LIBS process has started. A prompt to "Insert material" appears on the laser device or external component, prompting the user to insert material into or beneath the material detection area. After confirming the prompt, the LIBS process is then carried out. Furthermore, the material detection area can be designed such that, after the laser head or focusing unit has been moved into the area, the opening to the processing area can be concealed or covered. This further reduces the amount of light entering the otherwise darkened material detection area, thereby advantageously influencing the accuracy of the LIBS process.
[0010] Advantageous measures include decoupled, in particular redirected, the laser beam from the beam path or beam path for the laser head when the LIBS process is activated. This ensures that the LIBS process, in particular the material detection process, can be carried out independently of the laser head or the focusing unit. This means that, in addition to the spectrometer, elements, in particular a lens, for laser processing of the inserted material or workpiece are also arranged in the material detection area. Thus, the laser head or the focusing unit no longer needs to be adjusted into the material detection area.
[0011] Measures in which the decoupled laser beam is guided into a separate material detection area, particularly a LIBS area, inside or outside the processing area are advantageous. This ensures that a material to be inserted is placed in a separate area for detection, so that the LIBS process can then be carried out. In this case, the material detection area is considerably smaller than the processing area, so that with larger workpieces only part of it protrudes or is placed into the material detection area and the remaining part of the workpiece can either be held or placed on a support. It is advantageous if the material detection area is equipped with sensors to detect whether a material is inserted, so that when material or workpiece is inserted, the LIBS process is started automatically.Furthermore, if another laser is available, processing can also be carried out simultaneously in the processing area with another workpiece, so that in the next processing cycle the last queried material is used by means of the LIBS process, ie that a processing process in the processing area and a material detection process in the material detection area are carried out simultaneously.
[0012] Measures in which the decoupled laser beam is redirected within a material detection zone in the processing area are advantageous. This ensures that the entire workpiece can be inserted into the processing area, especially in the material detection zone, independently of the laser head or focusing unit, and the LIBS process can be performed without adjusting the laser head.
[0013] Advantageous measures include arranging and using at least one spectrometer for recording the radiation emitted by a plasma during the LIBS process in the material detection area within the processing chamber and / or outside the processing chamber, and preferably a lens or lens unit for focusing the laser beam. This ensures that the laser head or focusing unit is equipped with as few additional components as possible, allowing the laser head or focusing unit to be moved or traversed with great agility.
[0014] Measures that create the material detection zone outside the processing area, either through a slot in the housing and / or a cover or lid on the housing, are advantageous. This ensures that the material detection zone is optimally equipped for the LIBS process, meaning that a special lens can be used to generate the plasma on the workpiece, and that the spectrometer is optimally positioned for detecting or recording the plasma.
[0015] Measures where the LIBS process accesses an external and / or internal database or cloud, particularly a materials library, to identify the material are advantageous. This ensures the highest possible recognition quality of the materials used.
[0016] Measures that collect data from the LIBS process for analysis, diagnosis, and / or documentation, especially in cases of misuse, are advantageous. This ensures that warranty claims can be easily verified in the event of errors occurring.
[0017] However, measures that activate a dedicated laser source or laser for the LIBS process, with its laser beam coupled into the beam path of the laser head or the material detection area, are also advantageous. This ensures reliable material detection, as an optimal laser is used to generate the laser pulses.
[0018] However, the object of the invention is also achieved by a laser plotter for cutting, engraving, marking and / or labeling a workpiece, in which the focusing unit or the laser head is equipped with a spectrometer for detecting a plasma generated by irradiation in a LIBS process.
[0019] The advantage here is that the LIBS process can be performed regardless of the workpiece's insertion position. First, the workpiece is placed at any position on the machining table, then the laser head is positioned on the workpiece, preferably with the laser pointer activated. The LIBS process is then started, preferably manually.
[0020] Furthermore, the object of the invention is also achieved by a laser device in the form of a laser plotter or galvo laser for cutting, engraving, marking and / or labeling a workpiece, in which the laser beam is decoupled from the usual beam path to carry out a LIBS process, wherein the laser beam is deflected into a material detection area which is arranged in the processing space or outside the processing space.
[0021] The advantage here is that the laser head or focusing unit does not have to be adjusted for the material detection of the workpiece, but rather a corresponding lens and spectrometer for the LIBS process are arranged in the material detection area.
[0022] An advantageous design is one in which at least one spectrometer for recording a plasma during the LIBS process is arranged in the material detection area. This allows the laser head or focusing unit to be moved very agilely, since no additional components are attached that would increase the weight of the laser head or focusing unit. The invention will now be described in the form of exemplary embodiments. It should be noted that the invention is not limited to the exemplary embodiments or solutions illustrated and described, but can be applied to equivalent solutions.
[0023] They show:
[0024] Fig.1 is a diagrammatic representation of a laser machine, in particular a laser plotter, for processing a workpiece and for carrying out a LIBS process, in a simplified, schematic representation;
[0025] Fig. 2a is a diagrammatic representation of the laser head with a spectrometer arranged thereon for a LIBS process with an activated laser for generating a plasma from the material of the workpiece, in a simplified, schematic representation;
[0026] Fig. 2b is a diagrammatic representation of the laser head with a spectrometer arranged thereon for a LIBS process with a deactivated laser and an activated spectrometer for recording the plasma from the material of the workpiece according to Figure 2a, in a simplified, schematic representation;
[0027] Fig. 3 is a plan view of the laser device with a schematically drawn material detection area with a spectrometer, in a simplified, schematic representation;
[0028] Fig. 3a is a further plan view of the laser device with a different placement of the material detection area, in a simplified, schematic representation;
[0029] Fig. 4 is a plan view of the laser device with its own material detection area in the processing area in which the laser beam is coupled out, in a simplified, schematic representation;
[0030] Fig.5 is a plan view of the laser device with its own material detection area arranged outside the processing area in the form of a flap or slot for inserting the workpiece for a LIBS process, in a simplified, schematic representation;
[0031] Fig. 6 shows a simplified, schematic representation of a galvo laser with a material detection area for a LIBS process. By way of introduction, it should be noted that in the various embodiments, identical parts are provided with identical reference symbols or component designations. The disclosures contained throughout the description can be applied analogously to identical parts with identical reference symbols or component designations. Furthermore, the positional information chosen in the description, such as top, bottom, side, etc., refers to the described figure and, if the position changes, must be applied analogously to the new position.
[0032] Figures 1 to 6 show exemplary embodiments of laser machines or laser devices 1, in particular a laser plotter 2a and a galvo laser 2b. Of course, application with a flatbed laser is also possible.
[0033] In the laser plotter 2a shown in Fig. 1, at least one, preferably two, radiation source(s) 4 or laser sources 4 in the form of lasers 5, 6 are arranged in a housing 3. The lasers 5 and 6 preferably act alternately on a workpiece 7 to be processed. The workpiece 7 is or will be positioned in a processing space 8 of the laser plotter 2a, in particular on a processing table 9, wherein the processing table 9 is preferably adjustable in height. A laser beam 10 emitted by a radiation source 4, in particular the laser 5 or 6, is directed via deflection elements 11 to at least one movable focusing unit 12 or
[0034] The laser beam 10 is sent to the laser head 12, from which the laser beam 10 is deflected toward the workpiece 7 and focused for processing. The control, in particular the position control of the laser beam 10 relative to the workpiece 7, is carried out via software running in a control unit 13. The workpiece 7 is processed by adjusting a carriage 14, on which the focusing unit 12 or the laser head 12 is also arranged for movement, preferably via a belt drive in the XY direction. It is possible, for example, that in the "engraving" processing process, the adjustment of the carriage 14 takes place line by line, whereas in the "cutting" processing process, the carriage 14 is moved according to the contour to be cut, i.e., not line by line.
[0035] In laser devices 1 of this type, in particular laser plotters 2a, it is necessary for safety reasons that a cover 15 or door 15, which is preferably at least partially transparent, must be closed in order to start processing the workpiece 7, as shown in Fig. 1. The operating personnel can then manually or automatically position the laser point or a light source 16, for example in the form of a laser pointer 16, in particular light beam 17 or laser pointer point 17, which is preferably coupled into the beam path of the laser 5, 6 and is deflected via the focusing unit 12 or laser head 12 in the direction of the processing table 8, on the inserted workpiece 7, whereupon a job 18 for processing the workpiece 7 can be started. At the end of the job 18, the carriage 14 and the focusing unit 12 orLaser head 12 is preferably adjusted to the starting position so that the finished workpiece 7 can be removed, whereupon a new machining process can be started by inserting a new workpiece 7 to be machined or a blank 7. It is advantageous if the end of the machining process is indicated visually or acoustically so that the user does not have to constantly monitor the laser machine, in particular the laser plotter 1. For the sake of completeness, it should be mentioned that the adjustment of the focusing unit 12 or laser head 12 with the light beam 17 activated is also possible when the cover 17 is open, but the laser 5, 6 cannot be activated.
[0036] So-called galvo lasers 2b or galvo marking lasers 2b, as shown in Fig. 6, are also known, in which the laser beam 10 of a laser 5 is deflected and positioned in the direction of the workpiece 7 via an adjustable mirror 19 in the laser head 12 or focusing unit 12 above the workpiece 7 positioned on the processing table 9. A light beam 17 (not shown) from a light source 16, in particular a laser pointer 16, can also be coupled into the beam path of the laser 5 or arranged on the laser head 12. A control unit 13 is again provided for controlling and regulating the individual elements. Of course, it is also possible for the laser head 12 of a galvo laser 2b to be adjusted in order to better process larger workpieces 7.
[0037] For the sake of completeness, it should be noted that the laser plotter 2a and the galvo marking laser 2b are or can be equipped with connections or lines for power supply or for connection to the intranet and / or internet 20. In this case, it is possible to connect to external components 22, such as a laptop 22a or computer, an automatic feed unit, a conveyor belt, a removal robot, etc., via a line 21 or wirelessly via WLAN or Bluetooth, so that data can be transmitted from the external components 22, in particular the laptop 22a. For this purpose, for example, a graphic 23 and / or text 23 is created or displayed on the external component 22, in particular a computer, laptop 22a or a control unit, using commercially available software 24, such as CorelDraw, Paint, etc., or using the company's own application software 24, in particular Ruby 24.loaded, which is exported or transferred to the control unit 13 of the laser device 1, preferably in the form of the job 18. Preferably, the data to be transferred is converted by the same or different software so that the control unit 13 can process the job 18. Of course, it is also possible for the input to be made directly on the laser plotter 2a or galvo laser 2b via the existing input means 25, such as a touchscreen or input keys, or for a corresponding job 18 to be loaded from a storage medium, such as a cloud 26, a USB stick 27, etc. After the data, in particular the job(s) 18, have been transferred or have been created directly or loaded from the storage medium, the job 18 is processed by the laser device 1, in particular its control unit 13. It is possible for several jobs 18 to be stored simultaneously in the laser machine 1 and processed one after the other.Furthermore, it is also possible that the application software 24 is installed in the cloud 26 and can be accessed from the cloud 26 via a web browser.
[0038] In order to simplify or support and / or automate the input of parameters 28, in particular the parameter “material” 28, a material recognition process, in particular a LIBS process 29 known from the prior art (https: / / de.wikipedia.org / wiki / Laserinduzierte Plasmaspektroskopie), is integrated into the laser device 1, in particular laser plotter 2a, flatbed laser (not shown) and / or galvo laser 2b.
[0039] For this purpose, for example, in Figures 1, 2a and 2b, the laser head 12 or the focusing unit 12 is equipped with a spectrometer 30 to detect the plasma 31 (Figure 2a) generated by the laser beam 10 (Figure 2b). For this purpose, the laser head 12 orthe focusing unit 12 is first positioned on the inserted workpiece 7, preferably by means of a laser pointer 16, whereupon the material detection process, in particular the LIBS process 29, is then started on the laser device 1, in particular on the input means 25, or on the external component 22, in particular on the laptop 22a, so that a radiation source 4, in particular a laser 5 or 6, is then activated, the laser beam 10 remaining activated until a part of the material from the workpiece 7 transforms into a plasma 31, according to Figure 2a, whereupon the laser beam 10 is preferably terminated and the spectrometer 30, according to Figure 2b, is activated, so that the plasma 31 is detected over a recording area 32 of the spectrometer 30 and the recorded data is sent to the control unit 13 or the external component 22.The spectrometer 30 or the control unit 13 or the external component 22 then evaluates the light recorded by the plasma 31, in particular the data transferred from the spectrometer 30, so that the material, in particular the characteristic optical spectrum, of the inserted workpiece 7 can be determined based on the scattering of the emitted light. After the material has been determined by the spectrometer 30 or by the control unit 13 or the external component 22, this is preferably displayed as the "Material" parameter 28 and / or the determined material is set as parameter 28 or compared with the set parameter 28. The determined material is preferably displayed for the set parameter 28 so that the user can decide by pressing an OK / Cancel button whether the newly determined material should be adopted as parameter 28 or whether the material set as parameter 28 should be retained.
[0040] For the laser plotter 2a, flatbed laser, and / or galvo laser 2b, a CO2 laser is preferably used for the LIBS process 29 to generate pulsed laser radiation 17. This CO2 laser is based on a pulse characteristic, so that a certain amount of time is required for the power build-up of the laser 5, 6. Subsequently, the high energy density of the laser 5, 6 or the laser radiation 17 generates a local plasma 31 on the workpiece 7, so that after the irradiation with the laser 5, 6 has ended, the plasma 31 cools down again, and the measurement is performed with the spectrometer 30. As the plasma 31 cools, element-specific light radiation is emitted by the plasma 31, which is recorded and processed by the spectrometer 30.It is also possible that instead of the spectrometer 30, only one or more light guides are arranged on the laser head 12, with which the emitted light radiation of the plasma 31 is received and this is then sent to a spectrometer 30 for further processing.
[0041] According to Figure 3, the laser device 1, in particular the laser plotter 2a, is shown from above with the cover 15 open or removed in order to better see the processing chamber 8 or processing table 9. Here, a separate material detection area 33 is now arranged, in which the spectrometer 30 is positioned, i.e., the spectrometer 30 is no longer arranged or attached to the laser head 12 or the focusing unit 12, but rather the spectrometer 30 is arranged or mounted in its own or separate area, namely the material detection area 33.
[0042] In order for a LIBS process 29, i.e., a material detection process, to be carried out, it is necessary that the workpiece 7 or a part or sample of the workpiece 7 is placed or positioned below the material detection area 33 so that the LIBS process 29 can then be started. After the LIBS process 29 has been started on the laser device 1 or on the external component 22, the laser head 12 or the focusing unit 12 is moved from any position (shown in solid lines) to a defined position in the material detection area 33 (shown with dashed lines).An optimal position of the laser head 12 relative to the spectrometer 30 is provided so that the laser 5 or 6 is subsequently activated, thus generating a plasma 31 of the material from the workpiece 7. Preferably, after the laser radiation has ended, the spectrometer 30 is activated and can receive and further process the emitted light beams of the plasma 31. To supply the laser head 12 with the laser beam 10, corresponding deflection elements 11a, 11b are provided, with one deflection element 11b being coupled to the laser head position or the carriage 14, so that the laser head 12 is always supplied with the laser beam 10.
[0043] It is of course also possible for the LIBS process 29 to be started first, after which you are then prompted to place material or the workpiece 7 below the material detection area 33 so that, after confirmation, the laser head 12 is moved into the material detection area 33 and the LIBS process 29 is carried out, or for the laser head 12 to be moved into the material detection area 33 first and you are then prompted to place material or the workpiece 7 below the material detection area 33 so that the LIBS process 29 can be carried out. For this purpose, it is also possible to use automatic material detection, for example in the form of light barriers or contacts to detect material or workpiece 7 placed below the material detection area 33.Workpiece 7 is used because, for example, this enables the execution of the LIBS process 29 or the LIBS process 29 is started automatically. The essential advantage of such a solution with a material detection area 33, in which at least the spectrometer 30 is arranged, is that the laser head 12 or the focusing unit 12 is designed to be very agile, since no additional components that make the laser head 12 or the focusing unit 12 sluggish are attached to the laser head 12 or the focusing unit 12. Thus, a very high speed and precise processing of the workpiece 7 with the laser head 12 or the focusing unit 12 is achieved, whereby a LIBS process 29, in which the spectrometer 30 is required to record a plasma, can still be carried out.
[0044] Preferably, the material detection area 33 is arranged in that area of the processing space 8 that is not used very frequently for the usual processing of a workpiece 7. In this case, in Figure 3, the workpiece 7 is usually inserted in the corner area of the two rulers, i.e., top left or rear, so that the material detection area 33 in Figure 3 is arranged on the top right or rear side, or that the material detection area 33 is possible on the right front side, according to Figure 3a, or on the left front side, according to the dashed lines in Figure 3a.
[0045] Figure 4 shows a further exemplary embodiment in which a material detection area 33 is again arranged in the processing space 8. The spectrometer 30 is again arranged in the material detection area 33, wherein a separate, independent lens unit 34 is now provided for focusing the laser radiation 10, so that the lens head 12 or the focusing unit 12 is no longer required for the LIBS process 29, i.e. the spectrometer 30 and the lens unit 34 are arranged in the material detection area 33, so that when the LIBS process 29 is carried out, the laser head 12 or the focusing unit 12 can remain in the rest position outside the material detection area 33.
[0046] In order for the lens unit 34 to be supplied with a laser beam 10, the laser beam 10 is decoupled from the beam path for the laser head 12 or the focusing unit 12 and guided to the lens unit 34 via corresponding deflection elements 11c. In the exemplary embodiment shown in Figure 4, the laser beam 10 is decoupled at the deflection element 11a, so that the laser beam 10 is subsequently deflected onto the deflection element 11c and the laser beam 10 is forwarded from the deflection element 11c to the lens unit 34, i.e. a separate beam path is arranged to the lens unit 34 and to the laser head 12 or to the focusing unit 12, wherein preferably the same beam path or one beam path is used over a partial area. It is also possible to use several deflection elements 11 or other optical elements for a laser beam 10 or light guides for transporting the laser beam 10.
[0047] The LIBS process 29 can therefore now be carried out easily by simply placing a workpiece in or below the material detection area 33, so that after the start of the LIBS process 29, this can take place before or after the insertion of the workpiece 7, the laser 5 or 6 is activated, wherein the laser beam 10 is now deflected onto the beam path for the lens unit 34 and the laser beam 10 is then directed onto the workpiece 7 via the lens unit 34, in which a lens for focusing the laser beam 10 onto the workpiece 7 is preferably arranged, so that a plasma 31 is generated from the material of the workpiece 7, whereupon the laser 6 or the laser beam 10 is preferably deactivated and the spectrometer 30 is activated so that the spectrometer 30 detects the emitted light rays of the plasma 31.Subsequently, the spectrometer 30 or the control unit 13 or the external component 22, in particular the laptop 22a or computer, can analyze the recorded data, preferably with a database or cloud, and then suggest, display, or change the "material" parameter 28. The user can then use the determined material or parameter 28 and can now remove the workpiece 7 from the material detection area 33 and place it in the usual insertion position for further processing, so that, for example, a job 18 with a normal beam path can then be started, for example via the deflection element 11b. Of course, with such a design of the material detection area 33 with lens unit 34 and spectrometer 30, other positions in the processing space 8, as shown, for example, in Figure 3a, are also possible.
[0048] Figures 5 and 6 show a further embodiment of an independent material detection area 33, in which the material detection area 33 is now arranged outside the processing space 8. In this case, an opening or receptacle, which is not connected to the processing space 8, is provided in the housing 3 of the laser device 1, into which a sample or the workpiece 7 can be inserted, i.e. a slot 35, as shown in Figure 6, for example, or an extra cover 36 or receptacle 36 is arranged in the housing 3 of the laser device 1, so that a part of the workpiece 7 or a material sample of the workpiece 7 can be pushed in or inserted from the outside. For larger workpieces 7, a storage area for placing the workpiece 7 can preferably be arranged, or the workpiece 7 is held in position for the short LIBS process 29.
[0049] Here, the spectrometer 30 and the lens unit 34, as described in Fig. 4, are again arranged in the external material detection area 33, so that by coupling out and deflecting the laser beam 10 via deflection elements 11 (11 a, 11 c), the lens unit 34 is supplied with a laser beam 10 when the LIBS process 29 is activated, so that the plasma 31 can then be recorded by the spectrometer 30. Of course, it is possible for the slot 35 to be arranged in the laser plotter 2a and the cover 36 or recording area to be arranged in the galvo laser 2b.
[0050] It is advantageous if automatic material detection, for example in the form of a light barrier, electrical contact, etc., is used to detect an inserted or pushed-in workpiece 7 or material, whereby the LIBS process 29 can be enabled or started automatically. The use of a separate or independent material detection area 33 advantageously ensures that a LIBS process 29 or material detection process can be carried out in parallel in the material detection area 33 during a machining process in the machining space 8, with the detected material being stored and / or used for the next machining process. A design is also possible in which an external material detection area 33 and an internal material detection area 33 are arranged, i.e. in the machining space 8, so that the user can choose which one they wish to use.
[0051] Furthermore, Figure 6 shows the design of the galvo laser 2b with a separate laser 37, in particular a so-called LIBS laser 37, i.e. for the LIBS process 29, the laser 5 or 6 used for normal processing is no longer used, but rather a special laser 37 is activated, its laser beam 10 being coupled into the beam path for the LIBS process 29. For the processing of the workpiece 7, the laser 37 is then deactivated and the laser 5 or 6 is activated. A laser 37 of this type for the LIBS process 29 can also be used in the other embodiments shown. Furthermore, Figure 6 shows a schematic representation of the parameter "Material" 28 in the user software on the external component 22, in particular a laptop 22a, in which the material 28 "Wood" has just been detected and set.In addition, the parameter “material thickness” 38 of 2 mm and the parameter “laser power” 39 of 500 watts are shown, whereby further parameters for the processing of the workpiece 7 can be set.
[0052] The integrated LIBS process 29 now makes it possible to perform documentation and / or diagnostics of the machined workpieces 7 during the normal setup process of a machining process, in particular a job 18. In the event of errors occurring in the laser device 1, the documentation and / or diagnostics can be used to track whether only approved material was processed or whether unsuitable, non-approved material was inserted, which would void the warranty claim. This makes it easy to detect misuse that, for example, causes a fire.
[0053] Notwithstanding this, the LIBS process 29 can significantly increase the safety of operating such a laser device 1, since, for example, the material "PVC" must never be processed, as this would generate hydrochloric acid. Thus, if "PVC" material is inserted, the LIBS process 29 would detect this and stop further processing.
[0054] Furthermore, through the use of LIBS 29, particularly according to the embodiment shown in Figures 1, 2a and 2b, unattended operation with preferably an automatic feeding and removal device for the workpiece 7 can be safely carried out, since before each processing of a newly inserted workpiece 7, the laser head 12 or the focusing unit 12 automatically performs a LIBS process 29 and can thus detect whether the correct material for the job 18 has been inserted or not. For different jobs 18 for different materials, the material of the inserted workpiece 7 can also be detected via the LIBS process 29, so that the corresponding job 18 is subsequently selected and executed.
[0055] As an alternative to the lasers 5 or 6, which are used for processing the workpieces 7, it is also possible for a special laser 37 for the LIBS process 29 to be integrated or used in the laser device 1, the laser beam of which is coupled into the beam path for the LIBS process 29, ie that on the one hand the laser beam is coupled into the beam path of the laser head 12 or the focusing unit 12 or on the other hand into the beam path for the material detection area 33.
[0056] It is advantageous if the material detection area 33 is darkened during the LIBS process 29 by flexible side walls or side parts closing off the free spaces, i.e., for example, in the case of an external material detection area 33, after the workpiece 7 or material 7 has been inserted, the cover 33 is closed and any remaining open spaces in the housing are closed off via flexible side walls or side parts. This can also be achieved with the arrangement of the slot 35, in which flexible side walls or side parts close off the free areas to the workpiece 7 or material 7. Furthermore, the internal material detection area 33 can be designed such that after the laser head or the focusing unit has been retracted, the opening to the processing space 8 is covered in order to further reduce the incidence of light into the otherwise darkened material detection area 33 and thus advantageously influence the accuracy of the LIBS process 29.By darkening the area, particularly the material detection area 33, a significant improvement in the detection of the inserted material is achieved during the LIBS process 29. It is also advantageous to use a process gas in the material detection area 33 to influence the material reaction in the LIBS process 29. For example, an inert gas can be supplied, which prevents the material or workpiece 7 from burning during irradiation by laser 5, 6.
[0057] If the laser beam 10 is coupled out for the LIBS process 29, it is advantageous if the lens unit 34 takes into account the focusing on the surface of the inserted workpiece 7 or material 7. For this purpose, for example, the lens of the lens unit 34 can be flexibly adjustable or adjustable so that, for different workpiece thicknesses, an optimal distance or focal point of the lens of the lens unit 34 from the workpiece / material 7 or the surface of the workpiece / material 7 is set.
[0058] After a LIBS process 29 has been carried out for a workpiece 7 to be machined, the parameter "material" 28, for example "wood" or "Holz", is recognized and displayed on the external component 22, in particular on the laptop 22a, and / or on the input means 25 of the laser device 1. The user can then select the desired processing type, in particular engraving or cutting, whereupon further processing parameters, such as laser parameters, travel speed, extraction parameters, etc., are set or adjusted. Thus, it is only necessary for the user to adopt or accept the recognized material 28 and set the processing type, so that the remaining parameters can then be set. However, it is also possible that, for example, when selecting "cutting", the user must set at least one further parameter, in particular the material thickness, before the further parameters are calculated orbe determined.
[0059] It should be noted that with a moving spectrometer 30 on the laser head 12 or focusing unit 12, the spectrometer 30 can also be activated during the engraving or cutting process. For example, the spectroscope 30 can record the optical emission from locations where flame formation is suspected.
[0060] It is advantageous if the surface is cleaned before the actual LIBS process 29. This means, for example, that after the start of the LIBS process 29, the surface of the workpiece 7 or material is first subjected to cleaning irradiation before the actual LIBS process 29 is carried out to generate and absorb the plasma for evaluating the material. For this purpose, the surface is irradiated with laser radiation 10, so that any contaminants or dirt are removed. The LIBS process 29 can then be carried out.
[0061] For the sake of clarity, it is pointed out that the invention is not limited to the embodiments shown, but may also include further designs and structures.
Claims
Patent claims: Method for determining at least one parameter (28, 38, 39) of a laser device (1), in particular a laser plotter (2a) or galvo laser (2b), by means of LIBS (29) (Laser Induced Breakdown Spectroscopy) for processing a workpiece (7), in which at least one radiation source (4) in the form of a laser (5, 6) is used in a housing (3) of the laser device (1), wherein upon activation of the radiation source (4) a laser beam (10) is directed via deflection elements (11) to a focusing unit (12) or laser head (12), characterized in that for determining the parameter "material" (28) for setting the laser device (1), a LIBS process (29) (Laser Induced Breakdown Spectroscopy), in particular a material recognition process, is carried out manually or automatically by the laser device (1) or an external component (22), in particular a laptop (22a), connected to the laser device (1), is started,whereupon the workpiece (7) is processed, in particular irradiated, in a known manner with a laser (5, 6, 37), in particular laser radiation (10), such that a small amount of material of the workpiece (7) is vaporized, wherein the vaporized material, in particular a plasma (31), is detected and evaluated via a spectrometer (30), whereupon the determined material is displayed to the user on the laser device (1) or the external component (22), in particular a laptop (22a), and / or the determined material is set as a "material" parameter (28), in particular material parameter (28), or compared with the set material. Method according to claim 1, characterized in that after the start of the LIBS process (29), a cleaning irradiation of the surface of the workpiece (7) or material is first carried out,before the actual LIBS process (29) for generating and recording the plasma for evaluating the material is carried out. Method according to claim 1 or 2, characterized in that the determined material is compared with stored materials, wherein in the case of unsuitable materials, such as leather and artificial leather with chromium (VI), carbon fibers (carbon), polyvinyl chlorides (PVC), polyvinyl butyrals (PVB), Polytetrafluoroethylene (PTEE / Teflon), beryllium oxide, etc. an error message or note appears on the laser device (1) and / or the external component (22). Method according to one of the preceding claims, characterized in that in the processing space (8), in particular on the processing table (9), a separate area, in particular a material detection area (33), in which the spectrometer (30) is positioned, is moved to for carrying out the LIBS process (29), wherein preferably the workpiece (7) is first placed in this area, whereupon, after the start of the LIBS process (29), the laser head (12) is moved to a defined location for carrying out the LIBS process (29), wherein the irradiation of the workpiece (7) via the laser head (12) and the recording of the generated plasma (31) takes place via the spectrometer (30) arranged in the area.Method according to one of the preceding claims 1 to 4, characterized in that the laser beam (10) is decoupled, in particular deflected, from the beam path or beam path for the laser head (12) upon activation of the LIBS process (29). Method according to claim 5, characterized in that the decoupled laser beam (10) is guided into a separate material detection area (33), in particular in a LIBS area, inside or outside the processing space (8). Method according to claim 5 or 6, characterized in that the decoupled laser beam (10) is deflected in a material detection area (30) in the processing space (8). Method according to one of the preceding claims, characterized in that in the area orAt least one spectrometer (30) for recording the plasma (31) generated during the LIBS process (29) and, preferably, a lens or lens unit (34) for focusing the laser beam (10) are arranged and used for the material detection area (33) in the processing space (8) and / or outside the processing space (8). Method according to one of the preceding claims, characterized in that the material detection area (33) is arranged and used outside the processing space (8). formed by a slot (35) in the housing (3) and / or a cover (36) or lid (36) on the housing (3). Method according to one of the preceding claims, characterized in that the LIBS process (29) accesses an external and / or internal database or cloud (26), in particular a material library, to determine the material. Method according to one of the preceding claims, characterized in that the data of the LIBS process (29) are collected for analysis, diagnosis and / or documentation, in particular of misuse. Method according to one of the preceding claims, characterized in that a separate laser source (37) or laser (37) is activated for the LIBS process (29), wherein its laser beam (10) is coupled into the beam path for the laser head (12) or the material detection area (33).Laser plotter (1) for cutting, engraving, marking and / or inscribing a workpiece (7), which has a processing space (8) for positioning the workpiece (7), at least one, but preferably two, radiation sources (4) in the form of lasers (5, 6) with corresponding deflection elements (11), and a control unit (13) for controlling a carriage (14), preferably operated via a belt drive, with a focusing unit (12) or laser head (12) arranged displaceably thereon, characterized in that the focusing unit (12) or the laser head (12) is equipped with a spectrometer (30) for detecting a plasma (31) generated by irradiation in a LIBS process (29).Laser device (1) in the form of a laser plotter (2a) or galvo laser (2b) for cutting, engraving, marking and / or inscribing a workpiece (7), which has a processing space (8) for positioning the workpiece (7), at least one, but preferably two, radiation sources (4) in the form of lasers (5, 6) with corresponding deflection elements (11) and a control unit (13) for controlling a carriage (14), which is preferably operated via a belt drive and has a focusing unit (12) or laser head (12) arranged so as to be movable thereon, characterized in that for carrying out an LIBS process (29) the. Laser beam (10) is decoupled from the usual beam path, wherein the laser beam (10) is deflected into a material detection area (33) which is arranged in the processing space (8) or outside the processing space (8).
15. Laser device (1) according to claim 14, characterized in that in Material detection area (33) at least one spectrometer (30) for recording a plasma (31) during the LIBS process (29) is arranged.
16. Laser device or laser plotter according to one of the preceding claims 13 to 15, characterized in that the laser plotter (1) and / or the laser device (1) is designed to carry out the method according to one of claims 1 to 12.