Laser marking of objects

Abstract

The invention relates, inter alia, to a method for laser marking objects (12), preferably containers. The method comprises: providing a representation (D) of a desired laser marking; applying a computer-aided procedure to the representation (D), which divides the representation (D) into several sub-areas (T1 - T5); and laser marking the several sub-areas (T1 - T5) onto an object (12) by means of several laser marking devices (20) for generating the representation (D) on the object (12), wherein the several laser marking devices (20) each laser mark one of the several sub-areas (T1 - T5) onto the object (12).

Description

Technical field

[0001] The invention relates to methods for laser marking of objects and a system for laser marking of objects. Technical background

[0002] Traditionally, containers are mostly equipped with labels. Typical options are paper or plastic labels, which are applied to the containers using hot or cold glue or are self-adhesive.

[0003] Labels can pose problems in the recycling process, for example, due to the printing ink used, waterproof papers, adhesives, etc. Within the context of the increasing global sustainability discussions, various technology-inherent characteristics can be considered disadvantages. These include, in particular, the use of plastics for container decoration, a poor CO2 footprint in label production (especially plastics) through logistics to application (especially shrink sleeves), and limited recyclability in standard waste streams. Similar issues can be raised regarding direct printing methods.

[0004] In principle, it is therefore desirable to eliminate labels altogether. Required information could, for example, be marked or written directly onto the containers using a laser marking system. Such a technique is already used, for instance, to laser-mark a production number or a best-before date. During laser marking, the laser beam and the heat generated on the container's surface can cause a physical change to the surface (e.g., whitening in PET containers), allowing the desired characters to be laser-marked onto the surface.

[0005] For example, GB 2576220 A discloses a laser marking device for marking containers.

[0006] The lasers currently in use have power limitations. Therefore, in combination with the requirements of, for example, high-performance filling systems, it is conceivable to use multiple lasers. However, the use of multiple lasers brings with it certain difficulties, which are addressed here.

[0007] The invention is based on the objective of creating an improved technique for laser marking of objects, preferably containers. The technique is preferably suitable for high-power applications and yet enables the production of visually appealing laser markings on the objects. Summary of the invention

[0008] The problem is solved by the features of the independent claims. Advantageous further developments are specified in the dependent claims and the description.

[0009] One aspect relates to a method for laser marking (e.g., using a system as disclosed herein) of objects, preferably containers. The method comprises: - Providing a (e.g. two-dimensional) representation (e.g. as an image file) of a desired laser marking (e.g. in a memory of a processing device); - Applying a computer-aided procedure, preferably an algorithm (e.g., a calculation algorithm; e.g., in the sense of a set of instructions) to the representation (e.g., by means of a processing device), which divides the representation into several sub-areas (e.g., as image files); and - Laser marking of several sub-areas onto an object using several laser marking devices to create the representation on the object, wherein the several laser marking devices each laser mark (only) one of the several sub-areas onto the object.

[0010] The proposed method enables a representation to be laser-marked to be automatically divided into sub-areas according to predefined criteria and boundary conditions. These sub-areas are then laser-marked onto the respective object sequentially, overlapping in time, or simultaneously by different laser marking devices. Using this procedure ensures that the sub-areas are not formed based on manual, subjective decisions, but rather in a traceable, repeatable, and optimized manner by a processing unit. Thus, the representation can be intelligently divided into sub-areas. The procedure can lead to the most optimal solution for the division of the sub-areas, for example, by...This allows for optimized marking times for each sub-area, essentially identical marking times for all laser marking devices, and the graphical creation of meaningful and visually appealing separation points / zones between the sub-areas. As a result, the laser technology used can be optimally utilized, since nearly identical marking times are achieved for each laser marking device. Furthermore, visually imperceptible / noticeable seams between the sub-areas can be achieved through clever division and subsequent stitching during the final laser marking process. This enables laser marking that remains visually appealing and legible even with tolerance-related positioning inaccuracies in the laser marking devices. This can lead to system simplification, as system tolerances resulting from substrate movement / positioning are less visually noticeable.the system can be designed with larger tolerances.

[0011] In one embodiment, at least one of the following is fulfilled: - the multiple sub-areas do not overlap, or the procedure divides the representation in such a way that the multiple sub-areas do not overlap; - the several sub-areas are adjacent to each other, or the procedure divides the representation in such a way that the several sub-areas are adjacent to each other; - the several sub-areas together form the representation (e.g. placed side by side (e.g. in vector graphics) or superimposed (e.g. in raster graphics)) or the procedure divides the representation in such a way that the several sub-areas together form the representation; - the several sub-sections have essentially the same number of characters; and - the several sub-areas have essentially the same processing time (e.g. sum of marking time and jump time); - A dividing line between the several sub-areas has several line segments angled towards each other, preferably straight.

[0012] In another embodiment, at least one of the following is fulfilled: - the multiple sub-areas are formed to reduce (e.g., minimize or prevent) cross-sub-area display elements (e.g., line, character) (or the procedure divides the display in such a way that the multiple sub-areas are formed to reduce cross-sub-area display elements); and - the multiple sub-areas are formed to optically reduce tolerance-related positioning inaccuracies at transitions between the multiple sub-areas during laser marking of the multiple sub-areas (or the procedure divides the representation in such a way that the multiple sub-areas and transitions between the multiple sub-areas are formed to optically reduce tolerance-related positioning inaccuracies during laser marking of the sub-areas).

[0013] This can advantageously improve the overall optical impression of the laser marking even with tolerance-related inaccuracies, thus allowing for the acceptance of larger tolerances overall, which can, for example, enable system simplification and / or increased performance.

[0014] Preferably, the multiple sub-areas can be formed to reduce sub-area-relevant deviations from a focus (e.g., that of several laser marking devices).

[0015] In one embodiment, applying the procedure exhibits: - Detecting one or more potential separation zones (e.g., in point form or in line form) in the representation that fulfill(s) at least one predefined separation criterion of the procedure, wherein the procedure divides the representation into the multiple sub-areas depending on the at least one detected potential separation zone, preferably such that the representation is divided at at least one of the detected potential separation zones (e.g., into two or more sub-areas).

[0016] Advantageously, the separation zones or seams between the sub-areas can be formed in such a way that the overall optical impression of the laser marking can be improved even in the case of tolerance-related inaccuracies, with the further advantages already explained.

[0017] In a further embodiment, the at least one predefined separation criterion comprises at least one of: - a blank zone separation criterion that is satisfied if a representation element-free zone of the representation exists; - a discontinuity separation criterion that is fulfilled if there is a discontinuous, preferably angled, line transition in the representation; - a density separation criterion that is satisfied if a zone of the representation has a lower point density and / or a lower line density relative to other zones of the representation and / or has an absolute point density and / or line density that is less than a specified limit; - a syntax separator criterion that is satisfied if there is a space between strings of consecutive characters; - a character count separator criterion that is satisfied between areas of the representation with essentially the same number of characters; and - a processing time synchronization separation criterion that is satisfied between areas of the display with essentially the same processing time (e.g. sum of marking time and jump time).

[0018] In this context, it is also conceivable that a predetermined preprocessing of the representation is carried out, in which potential separation zones can be specifically created in the representation.

[0019] In one implementation variant, applying the procedure results in: - Detecting one or more composite zones in the representation that meet at least one predefined composite criterion of the procedure, wherein the procedure divides the representation into the several sub-areas depending on the at least one detected composite zone, preferably such that the representation is not divided in at least one of the detected composite zones.

[0020] Advantageously, the sub-areas can be formed in such a way that no or hardly any visually unappealing separation points of the laser marking occur in the event of tolerance-related inaccuracies, with the further advantages already explained.

[0021] In another embodiment, the at least one predefined composite criterion has at least one of the following: - a fill zone composite criterion that is fulfilled if a representation element-filled zone of the representation is present; - a continuity criterion that is fulfilled if there is a continuous line transition in the representation; - a density composite criterion that is satisfied if a zone of the representation has a higher point density and / or a higher line density relative to other zones of the representation and / or has an absolute point density and / or line density that is greater than a predefined limit; and - a syntax join criterion that is satisfied when a string of contiguous characters is present; - a code combination criterion that is met when a visual code (e.g. QR code, barcode, Aztec code, Data Matrix, PDF417, AR code, etc.) consists of related code elements; - a processing time combination criterion that is met if a division into sub-areas is unnecessary due to a total processing time that is below a limit (i.e. sufficient).

[0022] It is possible that the procedure includes several predefined separation criteria and / or several predefined joining criteria, which preferably: - are at least partially weighted differently or can be weighted differently; and / or - are considered in a predetermined order in the procedure; and / or - can be selectively chosen when applying the procedure (e.g., via a user interface).

[0023] In one embodiment, at least one of the following is fulfilled: - the procedure divides the representation into several sub-areas depending on a predetermined maximum marking speed (maximum writing speed) of the multiple laser marking devices and / or a predetermined maximum stepping speed of the multiple laser marking devices; and - the procedure divides the representation into several sub-areas in such a way that the marking times of the several laser marking devices for laser marking the respective sub-area are essentially the same.

[0024] This makes it advantageous to optimally utilize the laser technology employed, as approximately the same marking times are enabled for each laser marking device.

[0025] In a further embodiment, the method also features: - Conveying the object using an object conveyor (e.g., rotary conveyor) during laser marking.

[0026] Preferably, the procedure can divide the representation into several sub-areas depending on a, preferably predetermined or predeterminable, conveying speed of the object conveyor; and / or divide it according to a (e.g., predetermined) object spacing of adjacent objects conveyed by the object conveyor; and / or divide it according to an overall movement profile (e.g., propulsion movement and / or rotation about each object's own vertical axis) of the objects during conveying.

[0027] This method offers the advantage of finding a configuration that enables optimal interaction with the object conveyor.

[0028] In one embodiment, the procedure estimates (approximately determines) the total marking time of the representation based on the maximum marking speed of the multiple laser marking devices. Optionally, the estimation can also take into account the maximum stepping speed of the multiple laser marking devices, the conveying speed of an object conveyor, and / or the target output (desired output) of the multiple laser marking devices. The estimated total marking time can then be divided, for example, by the number of multiple laser marking devices to calculate the individual marking time. Preferably, the multiple sub-areas can be defined based on the calculated individual marking time.

[0029] This makes it advantageous to achieve approximately the same marking times for each laser marking device.

[0030] In a further embodiment, the procedure can calculate and output (e.g., via a user interface) a required number of multiple laser marking devices for laser marking the multiple sub-areas, depending on the representation (e.g., size, shape, content, number of representation elements, point density and / or line density) and a maximum marking speed of the multiple laser marking devices (and optionally a maximum stepping speed of the multiple laser marking devices) and optionally an object conveying speed of an object conveyor and / or a (e.g., predetermined or predefinable) individual marking duration for the multiple laser marking devices.

[0031] This technique can be advantageous, for example, when initially assembling the entire system, or if, for example, it is desired that a representation is laser-marked with a minimal number of laser marking devices and any remaining laser marking devices remain in reserve or are temporarily conserved.

[0032] In one embodiment, the representation is a raster graphic. The procedure can divide the raster graphic into several sub-areas such that each sub-area is formed by multiple representation points of the raster graphic, which are distributed across the entire raster graphic and differ from the representation points of the other sub-areas. Preferably, the raster graphic can then be formed by superimposing the multiple sub-areas (e.g., flush).

[0033] In one embodiment, the representation is a vector graphic or a raster graphic. The procedure can divide the vector graphic or raster graphic into several sub-areas such that each sub-area extends only over a portion of the vector graphic or raster graphic and / or is essentially formed by interconnected representation elements of the vector graphic or raster graphic. Preferably, the vector graphic or raster graphic can then be rendered by juxtaposing the several sub-areas.

[0034] In one embodiment, the procedure is an AI procedure. Preferably, the AI ​​procedure can be trained by inputting representations and their respective subdivided areas. Alternatively or additionally, the AI ​​procedure can be trained by inputting one or more representations, the corresponding subdivided areas, and the result of laser marking of the multiple subdivided areas onto the object, captured by a sensor device, preferably camera-based. Advantageously, this reduces the programming effort for the procedure and creates a self-learning procedure.

[0035] Another aspect concerns a system for laser marking objects (e.g., containers). The system includes a processing unit configured to apply a computer-aided procedure (e.g., as disclosed herein), preferably an algorithm, to a provided (e.g., two-dimensional) representation (e.g., an image file) that divides the representation into several sub-areas. The system further includes several laser marking devices configured to receive the several sub-areas divided by the processing unit and laser-mark them onto the object to create the representation on the object, wherein each of the several laser marking devices laser-marks (only) one of the several sub-areas onto the object and preferably receives it. Optionally, the system can also include an object conveyor (e.g., a rotary conveyor).container conveyor) which is arranged to convey the objects along the multiple laser marking devices.

[0036] The system can advantageously achieve the same benefits that have already been explained with reference to the procedure.

[0037] It is understood that all features explained with reference to the procedure are also disclosed and claimable with regard to the system, and vice versa.

[0038] Another aspect of the present disclosure relates to a container handling system (e.g., for tempering, manufacturing, cleaning, coating, testing, filling, closing, pasteurizing, decorating, labeling, printing, marking, laser marking, and / or packaging containers for liquid or pasty media, preferably beverages, liquid food products, or products from the pharmaceutical or healthcare industries). The container handling system may comprise the system as disclosed herein. The container handling system may, for example, be a beverage filling plant.

[0039] For example, the containers can be designed as bottles, cans, canisters, cartons, vials, tubes, etc.

[0040] Preferably, the terms "control unit" and / or "processing device" can refer to electronics (e.g., implemented as a driver circuit or with microprocessor(s) and data storage) that, depending on its design, can perform control tasks, regulation tasks, and / or processing tasks. Although the term "control" is used here, it can also appropriately encompass or refer to "regulation" or "feedback control" and / or "processing." The processing device can, for example, be a central processing unit or comprise several decentralized or distributed processing units.

[0041] Another aspect concerns a computer program product comprising (e.g., at least one computer-readable storage medium with instructions stored thereon) that cause a computing device to execute a procedure as disclosed herein.

[0042] The preferred embodiments and features of the invention described above can be combined with one another in any way. Brief description of the characters

[0043] Further details and advantages of the invention are described below with reference to the accompanying drawings. These show: Fig. 1 a schematic representation of a system according to an exemplary embodiment; Fig. 2 a flowchart of a method for laser marking of objects according to an exemplary embodiment; Fig. 3. A division of a representation into several sub-areas; Fig. 4. A division of a representation into several sub-areas; Fig. 5. A division of a representation into several sub-areas; Fig. 6. A division of a representation into several sub-areas; Fig. 7 conceivable laser markings in the event of tolerance-related positioning inaccuracy of the laser marking devices, which affect the several sub-areas according to Fig. 6 laser marking; Fig. 8 a division of a representation into several sub-areas; and Fig. 9 a conceivable laser marking in the case of a tolerance-related positioning inaccuracy of the laser marking devices, which the several sub-areas according to Fig. 8 laser marking.

[0044] The embodiments shown in the figures are at least partially identical, so that similar or identical parts are provided with the same reference numerals and, to avoid repetition, reference is also made to the description of the other embodiments or figures for their explanation. Detailed description of exemplary embodiments

[0045] The Fig. Figure 1 shows a system 10 for laser marking of objects 12. Preferably, the objects 12 are designed as containers. Preferably, the system 10 can be included or arranged in a container handling system, e.g., a beverage bottling plant.

[0046] System 10 comprises several laser marking devices 20 and a processing unit 32. Preferably, system 10 may further comprise an object conveyor 14 and / or a sensor device 30.

[0047] The object conveyor 14 can transport the objects 12. Preferably, the object conveyor 14 is single-track. Preferably, the object conveyor 14 transports the objects 12 spaced apart from each other, e.g., in single-item transport.

[0048] The object conveyor 14 is preferably arranged to convey the objects 12 along the laser marking devices 20. For example, the laser marking devices 20 can be arranged laterally next to the object conveyor 14, e.g. inside or outside of it.

[0049] For example, the object conveyor 14 can be a rotary object conveyor (object conveyor carousel), as exemplified in Fig. Figure 1 shows the object conveyor 14, which can transport the objects 12 on a circular path.

[0050] Alternatively, the object conveyor 14 could, for example, be a linear object conveyor. The linear object conveyor can, for example, have a conveying element, preferably a circulating one, for transporting the objects 12. The linear object conveyor can, for example, be a belt, belt, chain, or plate conveyor. It is also possible that the linear object conveyor is designed as a long-stator linear motor object conveyor or a (magnetic) planar motor drive object conveyor, which can move the objects 12 independently of one another by means of motion devices (mover, shuttle).

[0051] The object conveyor 14 can support the objects 12 during transport, preferably from below and / or around the circumference and / or from above. The object conveyor 14 can have object holders for supporting the objects 12. The object holders can preferably hold the objects 12 in base handling or neck handling.

[0052] For example, each object holder can support one object 12. The object holders can each include, for example, a container plate, a centering bell, a container clamp, and / or an inflation device.

[0053] It is possible that the object conveyor 14 is designed to rotate the transported objects 12 about their own vertical axis. Preferably, the object holders for rotating the objects 12 about their respective vertical axes can be rotatable.

[0054] It is also possible that the object conveyor 14 does not have separate object holders and, for example, the objects 12 are simply supported on a, preferably circulating, conveying element (e.g. belt, strap, chain or plate) of the object conveyor 14.

[0055] The object conveyor 14 can be arranged downstream of an infeed conveyor 16. The infeed conveyor 14 can be, for example, a rotary object conveyor or a linear object conveyor. The object conveyor 14 can take over the objects 12 transported by the infeed conveyor 16.

[0056] The object conveyor 14 can be arranged upstream of an outlet conveyor 18. The outlet conveyor 18 can be, for example, a rotary object conveyor or a linear object conveyor. The object conveyor 14 can transfer the objects 12 (after laser marking by means of the laser marking devices 20) to the outlet conveyor 18.

[0057] The laser marking devices 20 can be arranged along the object conveyor 14. For example, the laser marking devices 20 can be arranged side by side or one behind the other along the object conveyor 14. Other arrangements, e.g., at least partially one above the other and / or on both longitudinal sides of the object conveyor 14, are also possible. The laser marking devices 20 can laser mark the objects 12 while the objects 12 are conveyed / transported by the object conveyor 14 along the laser marking devices 20.

[0058] The laser marking devices 20 can also be referred to as laser marking devices, laser coding devices, or laser marking devices. Preferably, the laser marking devices 20 can be CO2 laser marking devices, fiber laser marking devices, or UV laser marking devices.

[0059] For example, the laser marking devices 20 can each have a laser source 22, a marking head 24, a focusing optic 26 and / or their own control unit 28 (for clarity shown in Fig. 1 shown only for one of the laser marking devices 20).

[0060] The laser source 22 can, for example, be designed as a laser tube. The laser tube can be sealed. The laser tube can be filled with a gas, e.g., containing CO2, or a gas mixture, e.g., a CO2-N2-He gas mixture. Electrodes can also be arranged in the laser tube. A power supply unit can be connected to the electrodes (not shown in Fig. 1) The power supply unit can provide the laser source 22 with electrical energy. Using, for example, a high-frequency voltage, molecules, e.g., CO2 molecules, in the laser tube can be excited to vibrate and thus emit a laser beam S. The laser source 22 can also be referred to as an oscillator.

[0061] The laser beam S generated by the laser source 22 can be directed or guided to the marking head 24 directly or via mirrors. It is possible that a so-called telescope, for example, is arranged between the laser source 22 and the marking head 24 to expand the laser beam S.

[0062] The marking head 24 can also be referred to as a coding head, marking head, or writing head. The marking head 24 preferably comprises two movable mirrors and two drives for the mirrors. The first drive can rotate the first mirror about a first axis (e.g., x-axis). The first mirror can also be referred to, for example, as a movable scanner mirror, e.g., an X-scanner mirror. The second drive can rotate the second mirror about a second axis (e.g., y-axis). The second mirror can also be referred to, for example, as a movable scanner mirror, e.g., a Y-scanner mirror. The first axis and the second axis can preferably be perpendicular to each other.

[0063] The mirrors, moved by the drives, can direct the laser beam S according to the laser marking to be applied. The laser beam S can thus, for example, move across the surface of an object 12 in a writing motion.

[0064] The focusing optics 26 can also be referred to as a condenser or condenser optics. The focusing optics 26 are preferably a planar focusing optics. The planar focusing optics can define a planar focal plane. The planar focusing optics can, for example, be or have an F-theta lens. Before the laser beam S strikes the surface of the object 12, it can be focused by means of the focusing optics 26.

[0065] The focusing optics 26 can be integrated with the marking head 24 or arranged separately from the marking head 24.

[0066] The control unit 28 can operate the marking head 24 of the respective laser marking device 20 to generate a laser marking on a surface of the object 12.

[0067] For example, the control unit 28 can receive a portion of a two-dimensional representation (2D representation) of a desired laser marking, e.g., from the processing unit 32. This portion of the two-dimensional representation can preferably be received in the form of an image file. The two-dimensional representation and the portion thereof can, for example, be vector graphics or raster graphics.

[0068] The control units 28 of the laser marking devices 20 can receive different sub-areas of the desired laser marking representation. Together (e.g., superimposed or placed side by side), the sub-areas can form the (entire) representation.

[0069] Preferably, the control unit 28 can operate the drives of the marking head 24 depending on the received sub-area of ​​the two-dimensional representation. For example, the control unit 28 can generate movement commands, such as drive signals, for the drives depending on the received sub-area in order to produce the laser marking.

[0070] The sensor device 30 can be arranged next to the object conveyor 14 or, for example, downstream of it. With respect to the transport path of the objects 12 through the system 10, the sensor device 30 is preferably arranged downstream of the laser marking devices 20.

[0071] The sensor device 30 can, for example, be directed towards the object conveyor 14 or towards the objects 12 transported by the object conveyor 14.

[0072] The sensor device 30 can, for example, include a camera device, an LED detection device or a laser detection device.

[0073] The sensor device 30 can, for example, detect the laser markings on the objects 12. The detected laser markings can preferably each be captured as an image file.

[0074] The processing unit 32 can be, for example, a PC or a server. Alternatively, the processing unit 32 can be integrated with the control units 28, for example.

[0075] The processing unit 32 can, for example, communicate with the control units 28 of the laser marking devices 20. The processing unit 32 can send partial areas of a representation, preferably two-dimensional, to the control units 28 for laser marking.

[0076] The processing unit 32 is configured to apply a procedure to the display of the desired laser marking to divide the display into several sub-areas, as explained in more detail herein with reference to examples. In principle, it is possible that the procedure is implemented at least partially in hardware and / or at least partially in software.

[0077] The Fig. Figure 2 schematically shows a method for laser marking.

[0078] In step S10, a representation D of a desired laser marking, preferably two-dimensional, is provided, e.g., as an image file. For example, the representation D can be provided by the processing unit 32. The processing unit 32 may have received the representation D, for example, via a communication interface. It is also possible that the representation D is created by the processing unit 32, e.g., by user input.

[0079] In step S12, a computer-aided procedure, e.g., an algorithm, is applied to the representation D. The procedure divides the representation D into several sub-areas T1–T5. The sub-areas T1–T5 are preferably each in the form of image files. Preferably, the processing unit 32 can apply the procedure to the representation D.

[0080] It is understood that the number of sub-areas T1 - T5 may differ depending on the respective representation D and the available equipment, in particular laser marking devices 20. Preferably, the number of sub-areas T1 - T5 may be less than or equal to the number of laser marking devices 20.

[0081] The procedure can preferably divide the representation D such that the sub-areas T1–T5 do not overlap. Sub-areas T1–T5 can, for example, be adjacent to each other. Together, sub-areas T1–T5 can form the representation D.

[0082] If the representation D is essentially composed of characters (e.g., numbers, letters, etc.), the sub-areas T1 - T5 can preferably be formed in such a way that they have an essentially equal number of characters, e.g., with a tolerance of ± 10%, ± 15%, or ± 20%.

[0083] The procedure particularly preferentially divides the representation D such that the several sub-areas T1–T5 are formed to reduce representation elements that cross sub-areas, such as lines, characters, etc. The sub-areas T1–T5 can thus contribute to the optical reduction of tolerance-related positioning inaccuracies at transitions between the several sub-areas T1–T5 during laser marking of the sub-areas T1–T5.

[0084] Preferably, the procedure can detect one or more potential separation zones in the representation D that satisfy at least one predefined separation criterion of the procedure. The representation D can then be divided into several sub-areas T1 - T5 at one or more of the detected potential separation zones, e.g., depending on further parameters such as at least one of the number of laser marking devices 20, the maximum marking speed of the laser marking devices 20, the object conveying speed of the object conveyor 14, etc.

[0085] For example, the procedure can use an empty zone separation criterion. The empty zone separation criterion can be met if a representation element-free zone of representation D exists or is detected. This representation element-free zone can then be recognized as a potential separation zone.

[0086] As a further example, the procedure can use a discontinuity separation criterion. The discontinuity separation criterion can be met if a discontinuous, preferably angled, line transition (mathematical discontinuity point) is present in the representation D. This discontinuous line transition can then be identified as a potential separation zone.

[0087] It is also possible that the procedure uses a density separation criterion. The density separation criterion is met if a zone of the representation D has a lower point density and / or a lower line density relative to other zones of the representation D. This zone can then be identified as a potential separation zone. This criterion can alternatively or additionally be used, for example, as an absolute criterion with a limit value for the (point / line) density.

[0088] It is also possible that the procedure uses a syntax separator criterion. The syntax separator criterion can be satisfied if there is a space between strings of contiguous characters. The zone containing this space can then be recognized as a potential separator zone.

[0089] It is also possible that, for example, a processing time synchronization separation criterion is used. This can be fulfilled between areas of the representation with essentially the same (laser) processing time.

[0090] While the above-mentioned separation criteria are aimed at finding possible boundaries or separation lines / seams to delineate the sub-areas T1 - T5 to be formed, it is alternatively or additionally possible, for example, that the procedure recognizes one or more composite zones in the representation D that fulfill at least one predefined composite criterion of the procedure.

[0091] The identified bonding zones may be areas where a division into sub-areas T1–T5 is not advantageous, as even small tolerance-related positioning inaccuracies during laser marking can lead to a poor overall visual impression or significantly impair the legibility of the laser-marked representation D. Accordingly, the procedure can divide the representation D into sub-areas T1–T5 depending on the at least one identified bonding zone, preferably such that the representation D is not divided in at least one of the identified bonding zones.

[0092] For example, the procedure can use a fill zone combination criterion. This criterion can be met, for instance, if a representation element-filled zone of representation D is present or detected. Representation elements can be, for example, points, lines, characters, etc. The representation element-filled zone can then be recognized as a combination zone.

[0093] As a further example, the procedure can use a continuity-connection criterion. The continuity-connection criterion can be satisfied if a (mathematically) continuous line transition exists or is detected in the representation D. This continuous line transition can accordingly be recognized as a connection zone.

[0094] It is also possible that the procedure uses a density cluster criterion. The density cluster criterion can be met if a zone of the representation D has a higher point density and / or a higher line density relative to other zones of the representation D. This zone can then be identified as a cluster zone. This criterion can alternatively or additionally be used, for example, as an absolute criterion with a limit value for the (point / line) density.

[0095] It is also possible that the procedure uses a syntax join criterion. The syntax join criterion can be met if a string of contiguous characters is present or recognized (e.g., a word, a date, or a multi-digit number). This string can then be recognized as a join zone.

[0096] It is also possible to use a code association criterion, which is met when a visual code (e.g. QR code, barcode, Aztec code, Data Matrix, PDF417, AR code, etc.) consists of related code elements.

[0097] It is also possible to use a processing time-based combination criterion, which is met when a division into sub-areas is unnecessary due to a sufficient total processing time. The total processing time can, for example, be less than a predefined threshold. Thus, separation can be advantageously omitted if it is not required for reasons of time or machine performance.

[0098] It is understood that the procedure preferably uses several separation criteria and / or several joining criteria to divide the representation D into the several sub-areas T1 - T5, possibly depending on further parameters, as already mentioned.

[0099] If multiple criteria are used, they can, for example, be weighted differently, considered in a predetermined order in the procedure, and / or be selectively selectable when applying the procedure.

[0100] As mentioned previously, the procedure can divide the representation D into sub-areas T1–T5 depending on a predefined maximum marking speed of the laser marking devices 20. Optionally, a predefined maximum hop speed of the laser marking devices 20 can also be taken into account. This parameter(s) can be used by the procedure such that the representation D is divided into sub-areas T1–T5 in such a way that the marking times of the laser marking devices 20 for laser marking the respective sub-area T1–T5 are essentially the same. In other words, each laser marking device 20 requires approximately the same marking time to laser mark the respective sub-area T1–T5.

[0101] As already mentioned, the objects 12 can be conveyed by the object conveyor 14 during laser marking. Preferably, the procedure can divide the representation D into the sub-areas T1 - T5 depending on a conveying speed of the object conveyor 14 and / or on a (e.g., fixed) object distance (division) of adjacent objects 12 conveyed by the object conveyor 14.

[0102] Preferably, the procedure estimates (e.g., calculates) a total marking time of the representation D depending on a maximum marking speed of the laser marking devices 20 and optionally a maximum hop speed of the laser marking devices 20. The estimated total marking time can then be divided, for example, by the number of laser marking devices 20 to calculate an individual marking time. The sub-areas T1–T5 can then be formed, for example, depending on the calculated individual marking time, preferably such that each sub-area T1–T5 can be laser-marked by one laser marking device 20 for approximately the calculated individual marking time.

[0103] It is also possible for the procedure to calculate the required number of multiple laser marking devices 20 for laser marking the entire representation D and, for example, output this information to a user via a user interface of the system 10. For instance, the required number can be calculated depending on the representation D to be laser marked itself and other parameters, such as a maximum marking speed of the laser marking devices 20, a maximum stepping speed of the laser marking devices 20, an object conveying speed of the object conveyor 14, and / or a single marking duration for the laser marking devices 20.

[0104] It is even possible to design the procedure as an AI procedure (Artificial Intelligence procedure).

[0105] For example, the AI ​​procedure can be trained by inputting representations D and their respective manually or automatically divided sub-areas T1 - T5 to learn how to optimally divide a representation D into several sub-areas T1 - T5.

[0106] It is also conceivable that the AI ​​procedure could be performed by inputting the representation D, the divided sub-areas T1 - T5 and one by means of the sensor device 30 (see Fig. 1) The AI ​​procedure is trained on the recorded result of laser marking of representation D onto object 12. This allows the AI ​​procedure to learn, for example, how to form sub-areas T1 - T5 that are tolerant of positioning inaccuracies of the laser marking devices 20.

[0107] In step S14, the sub-areas T1–T5 are laser-marked onto the object 12 using multiple laser marking devices 20, resulting in the desired laser marking on the object 12 as shown in illustration D. Each of the multiple laser marking devices 20 laser-marks only one of the multiple sub-areas T1–T5 onto the object 12. For example, a first laser marking device 20 can mark a first sub-area T1 onto the object 12, a second laser marking device 20 can mark a second sub-area T2 onto the object 12, and so on.

[0108] The Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8 to Fig. Figure 9 serves to illustrate exemplary variants of the procedure and preferred criteria of the procedure.

[0109] In Fig. Figure 3 shows by way of example that a representation D of characters, e.g. text characters, can be divided into two sub-areas T1 and T2 for two laser marking devices 20.

[0110] The elongated / linear separating zone Z can be detected by the procedure, for example, using the syntax separator criterion and / or the syntax join criterion. The separating zone Z, shaped as a dividing line, between the two sub-areas T1 and T2 can have several angled, preferably straight, line segments. The two sub-areas T1 and T2 can advantageously be designed such that they require approximately the same marking time due to a substantially equal number of characters and similar spacing between them.

[0111] In Fig. Figure 4 shows by way of example that a pictorial representation D can be divided into two sub-areas T1, T2 for two laser marking devices 20.

[0112] The separation zone Z can be detected by the procedure, for example, using the empty zone separation criterion, the filled zone joining criterion, the density separation criterion, and / or the density joining criterion. The separation zone Z, shaped as a dividing line between the two sub-areas T1 and T2, can in turn have several angled, preferably straight, line segments. The two sub-areas T1 and T2 can advantageously be designed such that they require approximately the same marking time due to a substantially equal number of representation elements.

[0113] In Fig. Figure 5 shows by way of example that a pictorial representation D can be divided into five sub-areas T1 - T5 for five laser marking devices 20.

[0114] The procedure can identify the preferably linear separation zones Z using different criteria. For example, the separation zone Z between sub-areas T1 and T4 can be identified using the discontinuity separation criterion and / or the continuity joining criterion. Similarly, the separation zones Z between sub-areas T1 and T2, T2 and T3, T3 and T4, and T4 and T5 can be identified using the empty zone separation criterion and / or the filled zone joining criterion.

[0115] As can be deduced from the previous explanations, vector graphics, such as representation D in the Fig. 4 and Fig. 5, the sub-areas T1 - T5 of the procedure are preferably formed such that the sub-areas T1 - T5 each extend only over a part of the vector graphic and each are essentially formed by interconnected representation elements of the vector graphic.

[0116] This approach can in principle also be used for a representation D executed as a raster graphic, as in Fig. Figure 6 is shown as an example. Here, the procedure, using the aforementioned criteria, can divide the representation D into two sub-areas T1 and T2, e.g., as shown, or in another way. However, particularly with the division into sub-areas T1 and T2 shown, positioning inaccuracies of the laser marking devices 20 could lead to an aesthetically displeasing overall impression, as shown for two different examples (offset in the y-direction and offset in the x-direction) in Fig. Figure 7 is shown as an example.

[0117] As in Fig. As shown in Figure 8, it may therefore be preferred if the procedure divides a raster graphic representation D into sub-areas T1-T3 such that each sub-area T1-T3 is formed by several representation points of the raster graphic. The representation points of sub-areas T1-T3 can be distributed across the entire raster graphic and differ from the multiple representation points of the other sub-areas. Preferably, a (conceptual) superimposition of the multiple sub-areas T1-T3 can then again yield the raster graphic or representation D.

[0118] As in Fig. As shown in Figure 9, a representation laser-marked in this way can be less sensitive or more tolerant of positioning inaccuracies of the laser marking devices 20 and can still convey an optically appealing overall impression.

[0119] The invention is not limited to the preferred embodiments described above. Rather, a multitude of variants and modifications are possible, which also make use of the inventive concept and therefore fall within the scope of protection. In particular, the invention also claims protection for the subject matter and features of the dependent claims independently of the referenced claims. In particular, the individual features of independent claim 1 are each disclosed independently of one another. All range specifications herein are to be understood as disclosed in such a way that all values ​​falling within the respective range are disclosed individually, e.g., also as preferred narrower outer limits of the respective range. Reference symbol list 10 System 12 objects 14 object conveyors 16 inlet conveyors 18 discharge conveyors 20 Laser marking device 22 Laser source 24 marker heads 26 Focusing optics 28 Control unit 30 Sensor device 32 Processing unit S laser beam S10-S14 Procedure steps T1-T5 sub-area Z separation zone QUOTES INCLUDED IN THE DESCRIPTION

[0000] 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

[0000] GB 2576220 A

[0005]

Claims

Method for laser marking of objects (12), preferably containers, wherein the method comprises: providing a representation (D) of a desired laser marking; applying a computer-aided procedure, preferably an algorithm, to the representation (D) which divides the representation (D) into several sub-areas (T1 - T5); and laser marking of the several sub-areas (T1 - T5) onto an object (12) by means of several laser marking devices (20) for generating the representation (D) on the object (12), wherein the several laser marking devices (20) each laser mark one of the several sub-areas (T1 - T5) onto the object (12). The method of claim 1, wherein at least one of the following is fulfilled: the multiple sub-areas (T1 - T5) do not overlap each other; the multiple sub-areas (T1 - T5) are adjacent to each other; the multiple sub-areas (T1 - T5) together form the representation (D); the multiple sub-areas (T1 - T5) have a substantially equal number of characters; the multiple sub-areas (T1 - T5) have a substantially equal processing time; and a dividing line between the multiple sub-areas (T1 - T5) has several angled, preferably straight, line segments. Method according to claim 1 or claim 2, wherein at least one of the following is fulfilled: the multiple sub-areas (T1 - T5) are formed to reduce cross-sub-area representation elements; the multiple sub-areas (T1 - T5) are formed to optically reduce tolerance-related positioning inaccuracies at transitions between the multiple sub-areas (T1 - T5) during laser marking of the multiple sub-areas (T1 - T5). Method according to one of the preceding claims, wherein the application of the procedure comprises: detecting one or more potential separation zones (Z) in the representation (D) which fulfill at least one predetermined separation criterion of the procedure, wherein: the procedure divides the representation (D) into the several sub-areas (T1 - T5) depending on the at least one detected potential separation zone (Z), preferably such that the representation (D) is divided at at least one of the detected potential separation zones (Z). The method of claim 4, wherein the at least one predetermined separation criterion comprises at least one of: a blank zone separation criterion, which is satisfied if a representation element-free zone of the representation (D) is present; a discontinuity separation criterion, which is satisfied if a discontinuous, preferably angled, line transition is present in the representation (D); a density separation criterion, which is satisfied if a zone of the representation (D) has a lower point density and / or a lower line density relative to other zones of the representation (D) and / or has an absolute point density and / or line density that is less than a predetermined limit; a syntax separation criterion, which is satisfied if there is a space between strings of contiguous characters; a character count separation criterion, which is satisfied between areas of the representation (D) with a substantially equal number of characters;and a processing time synchronization separation criterion that is satisfied between areas of the representation with essentially the same processing time. Method according to one of the preceding claims, wherein the application of the procedure comprises: detecting one or more composite zones in the representation (D) that meet at least one predetermined composite criterion of the procedure, wherein: the procedure divides the representation (D) into the several sub-areas (T1 - T5) depending on the at least one detected composite zone, preferably such that the representation (D) is not divided in at least one of the detected composite zones. The method of claim 6, wherein the at least one predetermined combination criterion comprises at least one of: a fill zone combination criterion, which is satisfied if a representation element-filled zone of the representation (D) is present; a continuity combination criterion, which is satisfied if a continuous line transition is present in the representation (D); a density combination criterion, which is satisfied if a zone of the representation (D) has a higher point density and / or a higher line density relative to other zones of the representation (D) and / or has an absolute point density and / or line density that is greater than a predetermined limit; a syntax combination criterion, which is satisfied if a string of contiguous characters is present; a code combination criterion, which is satisfied if a visual code consisting of contiguous code elements is present;and a processing time combination criterion that is met if a division into sub-areas is unnecessary due to a total processing time below a threshold. Method according to one of the preceding claims, wherein at least one of the following is fulfilled: the procedure divides the representation (D) into the multiple sub-areas (T1 - T5) depending on a predetermined maximum marking speed of the multiple laser marking devices (20) and / or a predetermined maximum stepping speed of the multiple laser marking devices (20); and the procedure divides the representation (D) into the multiple sub-areas (T1 - T5) such that the marking times of the multiple laser marking devices (20) for laser marking the respective sub-area (T1 - T5) are substantially the same. A method according to one of the preceding claims, wherein the method further comprises: conveying the object (12) by means of an object conveyor (14) during laser marking, wherein preferably: the procedure divides the representation (D) into the several sub-areas (T1 - T5) depending on at least one of: - a conveying speed of the object conveyor (14), preferably predetermined or predeterminable; - an object spacing of adjacent objects (12) that are conveyed by the object conveyor (14); - an overall movement profile of the objects (12) during conveying. A method according to one of the preceding claims, wherein: the procedure estimates a total marking duration of the representation (D) depending on a maximum marking speed of the multiple laser marking devices (20) and optionally a maximum stepping speed of the multiple laser marking devices (20) and / or a conveying speed of an object conveyor (14) and / or a target output power of the multiple laser marking devices (20); divides the estimated total marking duration by a number of multiple laser marking devices (20) to calculate an individual marking duration; and the multiple sub-areas (T1 - T5) are formed depending on the calculated individual marking duration. Method according to one of the preceding claims, wherein: the procedure calculates and outputs a required number of the multiple laser marking devices (20) for laser marking the multiple sub-areas (T1 - T5) depending on the representation (D) and a maximum marking speed of the multiple laser marking devices (20) and optionally an object conveying speed of an object conveyor (14) and / or a single marking duration for the multiple laser marking devices (20). Method according to one of the preceding claims, wherein: the representation (D) is a raster graphic; and the procedure divides the raster graphic into the several sub-areas (T1 - T5) such that the several sub-areas (T1 - T5) are each formed by several representation points of the raster graphic, which are distributed over the entire raster graphic and differ from the several representation points of the respective other sub-areas (T1 - T5), wherein preferably a superimposition of the several sub-areas (T1 - T5) results in the raster graphic. Method according to any one of claims 1 to 11, wherein: the representation (D) is a vector graphic or raster graphic; and the procedure divides the vector graphic or raster graphic into the several sub-areas (T1 - T5) such that the several sub-areas (T1 - T5) each extend only over a part of the vector graphic or raster graphic and / or each are substantially formed by interconnected representation elements of the vector graphic or raster graphic, wherein preferably: a juxtaposition of the several sub-areas (T1 - T5) yields the vector graphic or raster graphic. Method according to one of the preceding claims, wherein: the procedure is an AI procedure, wherein preferably: the AI ​​procedure is trained by inputting representations (D) and each associated subdivided sub-areas (T1 - T5); and / or the AI ​​procedure is trained by inputting a representation (D), the associated subdivided sub-areas (T1 - T5) and a result of laser marking of the multiple sub-areas (T1 - T5) onto the object (12) captured by means of a sensor device (30), preferably camera-based. System (10) for laser marking objects (12), wherein the system (10) comprises: a processing unit (32) configured to apply a computer-aided procedure, preferably an algorithm, to a provided representation (D) that divides the representation (D) into several sub-areas (T1 - T5); and several laser marking devices (20) configured to receive the several sub-areas (T1 - T5) divided by the processing unit (32) and laser-mark them onto the object (12) to generate the representation (D) on the object (12), wherein each of the several laser marking devices (20) laser-marks and preferably receives one of the several sub-areas (T1 - T5) onto the object (12); and optionally an object conveyor (14) arranged to convey the objects (12) along the several laser marking devices (20).

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