Apparatus and method for marking packages

Abstract

The invention relates to an apparatus (10) for marking packages (20), in particular containers, wherein the apparatus (10) comprises the following: a laser (11) for applying a marking to the package (20), in particular on an outer wall (21) of the package; and a detection device (12) for detecting, in a contactless manner, the applied marking, wherein the laser (11) has a variable focus, and wherein the apparatus (10) has a measuring device (13) for measuring at least one measurement value of packages (20) to be marked, wherein the measurement value comprises a measured distance to a surface, to be marked, of the package (20) to be marked and / or a measured inclination of the surface to be marked. The invention further relates to a corresponding method for marking packages (20).

Description

[0001] Device and method for marking packaging

[0002] Technical area

[0003] The invention relates to a device for marking packaging, in particular containers. Furthermore, the invention relates to a corresponding method for marking packaging, in particular containers.

[0004] State of the art

[0005] A wide variety of devices and methods for marking packaging are known in the state of the art.

[0006] For example, DE 41 25 007 A1 discloses a marking device designed as a laser that applies markings to labels. The marking is done by burning the marking into the top layer of the label. It is also known to burn the marking directly into the outer wall of the packaging using a laser. This locally melts the surface of the packaging, creating a relief-like structure that is legible to the human eye.

[0007] These markings include, for example, a barcode, but also batch-specific information, in particular best-before dates, batch designations or information on the production resources used.

[0008] Particularly in certain industries, such as the beverage, cosmetics, household goods, or pharmaceutical industries, certain batch-specific data, such as the best-before date, is essential for the marketability of a product. Therefore, proper marking or labeling of the packaging is essential. Therefore, it is necessary to inspect the marked packaging to remove unmarked or incorrectly marked packaging from the product stream.

[0009] Therefore, devices and methods have been developed in the prior art in which the markings are read, particularly using camera technology, and their content can thus be verified. Such a device is known, for example, from DE 10 2011 056 436 A1.

[0010] While the state-of-the-art solutions are suitable for reliably marking and verifying consistent products, errors can occur during system adjustment, particularly during product changeovers, which can lead to packaging being identified as unreadable during subsequent inspection and being rejected accordingly.

[0011] Description of the invention

[0012] The invention is therefore based on the object of specifying a device for marking packaging, in particular containers, which eliminates the above-mentioned problems and disadvantages of the prior art. In particular, the invention is based on the object of specifying a device for marking packaging, in particular containers, which prevents defective rejects during a product changeover, ie

[0013] Packaging changeover is prevented or reduced. Furthermore, the object of the invention is to provide a method for marking packaging, in particular containers, which also eliminates the above-mentioned problems and disadvantages of the prior art.

[0014] These objects are achieved by the subject matter of the independent claims. Further possible embodiments of the invention are specified in particular in the dependent claims. The solution according to the invention consists, in particular, in providing a device for marking packaging, in particular containers. The device has a laser for applying a marking to the packaging. The laser is thus designed to apply a marking to a packaging to be marked.

[0015] In the following, a distinction is made between packaging to be marked and marked packaging to express whether the packaging has already been marked by the laser or not. In particular, the laser is designed to apply the marking to an outer wall of the packaging. Packaging is generally the outer shell of an object. In particular, the packaging is preferably a container.

[0016] Containers are formed in one piece or from several firmly connected parts. Each container preferably has a hollow space inside, which is defined by the outer wall to be marked. The containers can be, for example, containers for storing food and / or liquid, viscous, or pasty substances. Bottles or cans are particularly preferred. The containers can be, for example, plastic containers, but also containers made of other materials, such as glass.

[0017] In this context, "marking" refers in particular to any marking that can be applied to a surface, especially the outer wall of the packaging; however, this is preferably a laser marking. More generally, however, a marking device can be used to apply the marking, which is not necessarily a laser.

[0018] The laser is particularly designed to apply the marking by irradiating the outer wall. For example, the application involves a local melting of the outer surface of the packaging. Therefore, the marking is preferably applied directly to the packaging. Alternatively, the marking can also be applied indirectly, for example, to the label.

[0019] The device further comprises a detection device for contactless detection of the applied marking. The detection device is thus designed to detect the applied marking without contact.

[0020] According to the invention, the laser has a variable focus, particularly one that is structurally integrated. In other words, the focus, i.e., the focal point of the laser, is variably adjustable. In particular, the focal point is variably adjustable by means of an adjustment device that is structurally integrated into the laser.

[0021] The variable focus allows for variable focusing of the laser. This allows the focal length of the laser to be changed.

[0022] If, for example, a product is changed to a smaller or larger size, the distance of the laser from the product or packaging changes. Previously, it was necessary to decrease or increase the distance of the laser from the product so that the focal length was suitable for marking the packaging again. For this purpose, the lasers were typically mounted on a tripod with height and depth adjustment, and the depth was adjusted accordingly depending on the distance to the surface of the packaging to be marked.

[0023] According to the invention, the focus or focal length of the laser is now adjusted directly on the laser.

[0024] Preferably, the marking and detection of the packages takes place in an area where the packages are guided individually. Particularly preferably, these are guided with a fixed assignment to the guide device. For example, the guide device can be a transport star. Preferably, the marking is a machine- or computer-aided, evaluable marking, in particular a machine-readable marking. The marking preferably includes information typical for the packaging, in particular batch-specific information, such as a best-before date.

[0025] According to the invention, the device comprises a measuring device for measuring at least one measured value of packages to be marked. The measuring device is thus designed to measure at least one measured value of packages to be marked. The packages to be marked are packages that are to be marked by the laser in a subsequent step by applying a marking. Accordingly, the measuring device is located in particular in front of the laser, as seen in the transport direction of the packages.

[0026] According to the invention, the measured value comprises a measured distance to a surface of the packaging to be marked and / or a measured inclination of the surface to be marked.

[0027] In other words, the measuring device is designed to measure the distance to a surface to be marked, for example, a passing package, and / or to measure the inclination of the surface to be marked. Accordingly, the measuring device can be designed as a distance meter and / or an inclinometer.

[0028] The measuring device can therefore be used to record the dimensions of the new packaging relevant for marking during a product change. This allows the focus to be set to the measured distance to the surface to be marked. In the case of non-rotationally symmetrical packaging, the position, in particular the inclination, of the surface to be marked can also change. Since the measuring device can also be suitable for recording the inclination of the surface to be marked, the focus of the laser can be adjusted accordingly. The focus of the laser is preferably varied or adjusted automatically based on the measured value of the packaging to be marked. This means that the measuring device can be used to automatically adjust the focus of the laser.

[0029] This means that the focus of the laser can be automatically adjusted to the distance to the area to be marked or the inclination of the area to be marked, so that correct marking is possible.

[0030] According to an advantageous embodiment, the detection device comprises an optical detection device, in particular a camera.

[0031] The optical detection device is designed as an image recording device and is suitable for capturing an image of the area of ​​the packaging, in particular the outer wall, that has been provided with the marking. In other words, the optical detection device is designed to capture an image of the applied marking. As an alternative to the camera, it can also be a CCD sensor, for example.

[0032] In an advantageous development of the invention, the detection device, in particular an optical detection device, has a variable focus. In particular, the detection device has a structurally integrated variable focus. For example, the optical detection device has a corresponding lens for this purpose.

[0033] Thus, not only the focus of the laser is variable, but also the focus of the detection device. This allows the detection device to be precisely adjusted to the new products or packaging during a product changeover, particularly directly at the detection device. Only if the detection device is correctly adjusted, i.e., its focus is also adjusted to the marked outer wall, can the detection device reliably detect the marking. According to an advantageous development of the invention, the detection device is designed to detect and preferably evaluate quality-related measured variables of the applied marking in order to inspect the applied marking.

[0034] In other words, the detection device is designed as an inspection device. The quality-related metrics can include, for example, the presence of a marking, the legibility of a marking, or the correctness of a marking, which means that the marking contains the correct information intended for the packaging bearing the marking.

[0035] Particularly if the capture device is designed to also evaluate quality-related measured variables, the capture device can have a comparison device that compares the image captured by the capture device with at least one reference image and / or a reference value. Based on this comparison, it can be determined whether the quality-related measured variables are OK, i.e. whether the marking was applied correctly or not. In principle, however, another method, such as an optical character verification method or an optical character recognition method, can also be used to capture or evaluate the marking. Furthermore, reading 1D and 2D codes (Datamatrix, QR, Aztec code) and the like would also be possible.

[0036] If the detection device determines during its evaluation that the quality-related parameters are not satisfactory, the corresponding packaging is rejected. The device may be equipped with a corresponding rejection device for this purpose.

[0037] In an advantageous development of the invention, the measuring device is also designed to detect the presence of a package to be marked. In other words, the measuring device can indicate that a package to be marked is being transported toward the laser or the detection device. This allows the time of use of the laser and the triggering of the detection device to be timed accordingly. For example, the measuring device comprises a light barrier for this purpose.

[0038] Alternatively, the measuring device does not have an additional light barrier, but detects the presence of a package to be marked with the distance meter.

[0039] According to an advantageous development, the device comprises a control and / or regulating device. The control and / or regulating device is preferably connected to the laser and / or the detection device, or is designed to be connectable. Furthermore, the control and / or regulating device is preferably designed to vary the focus of the laser and / or the detection device. In other words, the control and / or regulating device makes it possible to adjust the focus or focal length of the laser and / or the detection device.

[0040] In general, the control and / or regulating device can be configured to generate a control command and / or output it to the laser or the detection device. The control command contains at least information about the focus or focal length to be readjusted, so that the laser or the detection device can adjust the focus or focal length accordingly upon receiving the control command.

[0041] According to an advantageous development of the invention, the control and / or regulating device is designed to vary the focus of the laser and the detection device synchronously and uniformly. Simply put, this means that the same focus or focal length is set on the laser and the detection device. Of course, this should also cover the case where the focal length of the laser and the detection device differ from one another when optimally adjusted; in this case, however, the laser and the detection device are adjusted synchronously and uniformly to one another at a constant ratio. According to an advantageous development of the invention, the control and / or regulating device is designed to vary the focus of the laser based on the quality-related measurement variable detected by the detection device.

[0042] This allows for a control process to be implemented. For example, if the detection device detects during inspection of the applied markings that the markings have not been applied, are illegible, or have been applied incorrectly to the packaging, the laser focus can be adjusted based on this, ensuring that the laser focus is correctly and legibly applied to the packaging. In other words, adjustments are made using test markings.

[0043] In an advantageous development of the invention, the control and / or regulating device is connected to the measuring device, or is designed to be connectable. Preferably, the control and / or regulating device is designed to vary or adjust the focus of the laser and / or the detection device based on the measured value of the packaging to be marked.

[0044] This allows the focus of the laser and / or the detection device to be adjusted to the distance to the surface to be marked or the inclination of the surface to be marked, thus enabling proper marking and reliable detection. Preferably, the measured value measured by the measuring device is processed by the control and / or regulating device, and a corresponding control command is generated that takes the measured value into account.

[0045] In general, the device can be used on a variety of machines, particularly in connection with beverage packaging or

[0046] Beverage containers. For example, the device can be used in coating systems, stretch blow molding machines, labeling machines, transfer wheels, or conveyor belts.

[0047] Furthermore, the object is achieved by means of a method for marking packaging, in particular containers. In particular, the method is used using one of the devices described above. Therefore, all individual aspects and advantages of the individual devices described are transferable to the method.

[0048] The method comprises a step for varying the focus of a marking device, in particular a laser. The focus is varied based on a measured value of a package to be marked, in particular a distance to a surface of the package to be marked or an inclination of the surface to be marked. Alternatively or additionally, the focus is varied based on a quality-related measured variable, in particular the presence, readability, and / or correctness of a mark on a marked package.

[0049] The measured value is preferably measured using the measuring device described above. The quality-related measured variable is preferably recorded using the recording device described above.

[0050] In general, varying the focus of the laser and the detection device involves changing the focal point relative to the laser or the detection device. This is therefore a change in the focal length. This does not apply to the case where the laser or the detection device has a fixed focus and focusing is achieved by moving the device itself.

[0051] According to an advantageous development of the invention, the method comprises a step for contactless detection of the marking applied by the marking device, in particular by means of an optical detection device. In an advantageous development of the invention, the method further comprises a step for varying a focus of the detection device. The focus of the detection device is determined based on a measured value from a package to be marked.

[0052] In particular, the measured value is a distance to a surface of the packaging to be marked or an inclination of the surface to be marked.

[0053] Short description of the drawings

[0054] The various and exemplary features described above can be combined with one another according to the invention, provided this is technically reasonable and suitable. Further features, advantages, and embodiments of the invention will become apparent from the following description based on exemplary embodiments and the figures.

[0055] The figures used to explain the embodiments show:

[0056] Fig. 1 is a plan view of a labeling machine with a device according to the invention for marking packages; and

[0057] Fig. 2 is a schematic diagram with four different packages to explain the functioning of the device according to the invention.

[0058] Fig. 1 shows a device 10 for marking packages 20. The device 10 is arranged, by way of example, on a labeling machine 100.

[0059] However, this is not intended to be limiting. Rather, it would also be conceivable, for example, to arrange the device 10 for marking packaging on coating systems, stretch blow molding machines, transfer wheels, or conveyor belts.

[0060] The labeling machine 100 has an infeed wheel 110, by means of which the packages 20 are fed to a labeling unit. After labeling, the packages 20 are removed by means of an outfeed wheel 120 and fed, for example, to a filling machine. In the example shown in Fig. 1, the device 10 for marking packages 20 is arranged on the outfeed wheel 120. The packages 20 are guided individually past the device 10 for marking packages by means of the outfeed wheel 120.

[0061] The device 10 for marking packaging 20 has a laser 11 for applying a marking to the packaging 20. The laser 11 can be configured to burn the marking directly into an outer wall 21 (see Fig. 2) of the packaging 20. As a result, the surface of the outer wall 21 is locally melted by means of a laser beam from the laser 11, creating a structure readable by the human eye. Alternatively, a label applied by the labeling machine can also be provided with a marking. The marking is achieved by burning into the top layer of the label.

[0062] In both variants, the laser beam of laser 11 must be focused. More precisely, the focus of laser 11 must be directed at least substantially toward the area to be marked.

[0063] The device 10 further comprises a detection device 12 for contactless detection of the marking applied by the laser 11. In particular, the detection device 12 comprises an optical detection device 14 for this purpose, by means of which an image of the surface of the packaging 20 to be marked or of the marking can be recorded.

[0064] The detection device 12 is then designed to inspect the applied marking. In doing so, it is checked in particular whether a correct and legible marking is present. The detection device 12 is designed to detect and preferably evaluate quality-related measured variables of the applied marking. The evaluation can take place in the detection device 12 or, alternatively, by means of a control and / or regulating device 15 discussed later. The apparatus 10 shown in Fig. 1 further comprises a measuring device 13. The measuring device 13 is designed to measure a measured value of the packaging 20 to be marked. In this case, the measuring device 13 measures in particular a measured value relevant to the marking.For example, the measuring device 13 is designed to measure a distance to a surface of the packaging 20 to be marked as a measured value or an inclination of the surface to be marked as a measured value.

[0065] Fig. 2 shows a simplified schematic diagram of the function of the device 10.

[0066] The schematic diagram on the left shows the marking of a first package 20. The package 20 is rotationally symmetrical with a first radius. As indicated, the package 20 is guided in the transport direction T along the individual devices of the device 10. First, the package 20 passes the measuring device 13, which is designed to measure the distance to a surface 21 of the package 20 to be marked. The package 20 then passes the laser 11, which is designed to apply a marking to the outer wall 21 of the package 20. Subsequently, the packaging 20 passes the detection device 12, which is designed to inspect the applied marking. In particular, the detection device 12 uses quality-related measured variables to determine whether the applied marking is correct and legible.Only if the applied marking is correct and legible will the packaging 20 remain in the further product flow and be filled, for example. Incorrectly marked packaging 20 can therefore be rejected.

[0067] If a product changeover now occurs, for example to a packaging 20 with a larger radius, as sketched in the second schematic diagram, without changing the focus of the laser 11 and the detection device 12, the packaging 20 would be recognized as unreadable and rejected. Therefore, the laser 11 and the detection device 12 have a variable focus. In addition, the device 10 has a control and / or regulating device 15. The control and / or regulating device 15 is connected to the laser 11, the detection device 12 and the measuring device 13, or is designed to be connectable. Of course, the control and / or regulating device 15 can be a separate component as shown in Fig. 2. Alternatively, the control and / or regulating device 15 can be part of the laser 11, part of the detection device 12, or part of the measuring device 13.

[0068] By means of the control and / or regulating device 15, it is possible to adjust the focus of the laser 11 and the focus of the detection device 12 based on the measured value measured by the measuring device 13. Thus, the focus of the laser 11 and the focus of the detection device 12 can be automatically adjusted to the new packaging 20 during product changeover.

[0069] Alternatively, it would also be conceivable for the device 10 not to have a measuring device 13. Then, via the control and / or regulating device 15, it would be possible, for example, to adjust the focus of the laser 11 in a control process based on the quality-related measurement variable detected by the detection device 12. Simply put, after marking, a check is carried out to determine whether the marking is legible. If it is not, the focus of the laser 11 is adjusted accordingly to produce a legible marking.

[0070] The third schematic diagram from the left shows a non-rotationally symmetrical package 20. With a non-rotationally symmetrical package 20, it may happen that it is held at an angle by a transport device, for example, by the discharge wheel 120 in Fig. 1.

[0071] As a result, the packaging 20 has, as shown in the last principle sketch in Fig. 2, an oblique or inclined surface to be marked.

[0072] Therefore, the measuring device 13 can be configured to measure the inclination of the surface to be marked. The focus of the laser 11 and / or the detection device 12 can then be adjusted accordingly based on the measured inclination, so that a clearly legible written image is generated or read. Accordingly, the control and / or regulating device 15 is configured to vary or change the focus of the laser 11 and the detection device 12 based on the measured inclination of the surface to be marked, i.e., the angular position of the surface to be marked.

[0073] Tracking the focus means, in particular, that the focus is varied, in particular continuously, as the area to be marked is moved past.

[0074] It is understood that in the present invention, there is a connection between, on the one hand, features described in connection with method steps and, on the other hand, features described in connection with corresponding devices. Thus, described method features are also to be regarded as device features belonging to the invention—and vice versa—even if this has not been explicitly mentioned.

[0075] It should be noted that the features of the invention described with reference to individual embodiments or variants, such as the type and design of the individual components as well as their precise dimensions and spatial arrangement, may also be present in other embodiments, unless otherwise stated or prohibited for technical reasons. Furthermore, such features of individual embodiments described in combination do not necessarily have to be implemented in a particular embodiment. Reference symbols

[0076] 10 Device

[0077] 11 lasers

[0078] 12 Recording device 13 Measuring device

[0079] 14 optical detection device

[0080] 15 Control and / or regulating device

[0081] 20 Packaging

[0082] 21 Area 100 Labeling Machine

[0083] 110 Inlet wheel

[0084] 120 outlet wheel

Claims

Patent claims 1. A device (10) for marking packaging (20), in particular containers, the device (10) comprising: a laser (11) for applying a marking to the packaging (20), in particular on an outer wall (21) of the packaging; a detection device (12) for contactlessly detecting the applied marking; and a measuring device (13) for measuring at least one measured value of packaging (20) to be marked, the laser (11) having a variable focus, and the measured value comprising a measured distance to a surface of the packaging (20) to be marked and / or a measured inclination of the surface to be marked.

2. Device (10) according to claim 1, wherein the detection device (12) comprises an optical detection device (14).

3. Device (10) according to claim 1 or 2, wherein the detection device (12) has a variable focus.

4. Device (10) according to one of the preceding claims, wherein the detection device (12) is designed to detect and preferably evaluate quality-related measured variables of the applied marking in order to inspect the applied marking.

5. Device (10) according to one of the preceding claims, wherein the measuring device (13) is designed to detect the presence of a packaging (20) to be marked.

6. Device (10) according to one of the preceding claims, wherein the device (10) has a control and / or regulating device (15) which is connected to the laser (11) and / or the detection device (12) is connected or connectable, and is designed to vary the focus of the laser (11) and / or the detection device (12).

7. Device (10) according to claim 6, wherein the control and / or regulating device (15) is designed to vary the focus of the laser (11) and the detection device (12) synchronously and uniformly.

8. Device (10) according to claim 6 or 7, wherein the control and / or regulating device (15) is designed to vary the focus of the laser (11) based on the quality-related measurement variable detected by the detection device (12).

9. Device (10) according to one of claims 6 to 8, wherein the control and / or regulating device (15) is connected or connectable to the measuring device (13) and is designed to vary the focus of the laser (11) and / or the focus of the detection device (12) based on the measured value measured by the measuring device (13).

10. A method for marking packaging (20), in particular containers, in particular by means of one of the devices (10) according to one of claims 1 to 9, wherein the method comprises the following step: Varying a focus of a marking device, in particular a laser (11), based on a measured value of a package (20) to be marked, in particular a distance to a surface of the package (20) to be marked or an inclination of the surface to be marked, and / or based on a quality-related measured variable, in particular the presence, readability and / or correctness, of a marking on a marked package (20).

11. Method according to claim 10, wherein the method comprises the following step: contactless detection of the marking applied by the marking device by means of a particularly optical detection device (12).

12. The method according to claim 11, wherein the method comprises the following step: varying a focus of the detection device (12) based on a measured value of a package (20) to be marked, in particular a distance to a surface of the package (20) to be marked or an inclination of the surface (21) to be marked.

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