EP3215367A1

EP3215367A1 - Device and method for controlling direct printing machines

Info

Publication number: EP3215367A1
Application number: EP15801343.3A
Authority: EP
Inventors: Andreas Sonnauer; Florian Lauterbach; Peter Lindner
Original assignee: Krones AG
Current assignee: Krones AG
Priority date: 2014-11-06
Filing date: 2015-11-05
Publication date: 2017-09-13
Anticipated expiration: 2035-11-05
Also published as: US20190084327A1; EP3215367B1; DE102014116201A1; CN107148355A; WO2016071444A1; US10144237B2; US20170313112A1; US11014376B2; CN107148355B

Abstract

The invention relates to a method for printing objects, in particular containers (10). The containers (10) are transported along a specified transport path (P), and the outer surface of the containers is printed at least temporarily by means of at least one printing assembly (4, 6, 7). A controller (14, 16, 17) controls the printing of the containers (10) by means of the at least one printing assembly (4, 6, 7) on the basis of at least one printing parameter. According to the invention, at least one object (10) to be printed is printed with at least one test marking in order to ascertain the printing parameter, and the object provided with the test marking is then inspected by means of at least one inspection device (8), wherein the printing parameter is derived from the result of the inspection.

Description

Apparatus and method for controlling direct printing machines

description

The present invention relates to an apparatus and a method for printing on containers. Devices and methods for labeling containers have long been known from the prior art. Recently, however, it has begun to provide containers with direct printing or multi-color printing. From the prior art, such devices and methods for printing on containers are known. Thus, for example, in the unpublished German patent application no. 10 2014 1 12 484.7 a device and a method for equipping containers is described. This application deals in particular with the question of how such directly printed containers can be inspected and how they can be reacted to a corresponding inspection of the containers. Thus, this application describes that a quality control is used during production and that the quality of the prints is sporadically checked visually. However, there is no proactive control of the direct printing machine, but at most a limited control of the color space by the different color methods, ie. H. additive or subtractive color methods and it can also be monitored only the currently applied pressure.

It is therefore an object of the present invention to provide a method and an apparatus which enable an improved control of the prints and also an improved error correction. These objects are according to the invention achieved by the subject matters of the independent claims. Advantageous embodiments and further developments are the subject of the dependent claims.

In a method according to the invention for printing on objects and in particular of containers, the objects are transported along a predetermined transport path and at least temporarily printed on their outer surface by means of at least one printing unit. In this case, a control device controls the printing of the containers by the at least one printing unit on the basis of at least one pressure parameter and preferably based on a plurality of pressure parameters.

According to the invention, at least one object to be printed is printed with at least one test mark (this being done, in particular, with the said printing unit), then this object provided with the test mark is inspected by means of at least one inspection device and an inspection result from this inspection of Derived and determined pressure parameters. The printing parameter can be any parameter which is characteristic of the pressure to be applied, such as a relative position of a print head relative to the container to be printed, a speed of movement of the containers relative to the print head, a response of individual printing elements and the like. In addition, the parameter can also be a characteristic of a color composition of the pressure parameters. Advantageously, it is a printing parameter from which it is possible to deduce, directly or indirectly, a readiness for printing of the corresponding printing unit or a parameter which is characteristic for the printing readiness of the printing unit. If, for example, the specified printing parameter is outside a specified tolerance range, this can be taken as an indication that the corresponding printing unit is not ready for operation. However, it would also be possible for a large number of printing parameters to be determined and readiness for printing to be confirmed only when all of these printing parameters satisfy given conditions (for example, within certain tolerance windows.

Preferably, the control device uses the at least one pressure parameter to control the printing unit. It is possible that printing parameters, which are preferably stored in a memory device, are changed and in particular also be changed automatically. However, such changes of pressure parameters are preferably logged and, in particular, also logged with additional data, such as a time of the change. It is therefore proposed to check the prints by means of a test program which preferably prompts the user to automatically check the printing units. For example, it would be possible for such a test to be run before production, but it would also be possible to use certain test cycles, for example every hour or after a certain container inlet and after production during a recipe change or ink change or even after manual prompt.

The said test mark may be the pressure to be applied later in regular work operation. Preferably, however, a special test mark or a special test pattern is used, which is particularly suitable for the evaluation and correction or for determining the printing parameters. In a first approach, it is possible to transmit to the pressure control a signal which causes an incomplete pressure. This known test pressure can be read out or recorded by the downstream inspection system or the inspection device, this test pressure preferably being known to this inspection device. Furthermore, in particular by comparison, this test pressure can be correspondingly identified and verified. Only if the particular previously known test feature is present, the machine is considered ready for operation and can produce or continue to produce.

It would in principle be possible for the printing system to receive the request to carry out a test run and to inform the inspection system what can be found. Conversely, however, it would also be possible for the inspection system to receive the request to test and accordingly to issue the request to the printing system or the printing unit to apply a specific pressure to the objects. In addition, it would also be conceivable for corresponding prints or features to be distributed via the machine control computer or an LMS (warehouse management system). In a further preferred method, in addition to the test print data can be printed, which identify the container in particular for later logging. In this case, for example, data could be printed, such as a date, a time, a name of the container, a manufacturer, data which characterize the printing unit and the like.

In a further preferred method, the inspection device has a color camera or generally an image recording device which is suitable for recording spatially resolved images.

In a further preferred method, it is possible for a printed container, which is also referred to below as a test container, to be ejected from a container stream. It would be possible that in the context of the test operation all containers are provided only with test marks and be ejected accordingly. However, it would also be possible for a test mode to be activated at short notice during production and only those or those containers which are printed in the context of this test mode to be ejected. In this case, for example, such a container can subsequently be detected and discharged by an inspection device, but it would also be conceivable that this container is additionally provided with a marking, which identifies it as a test container. In addition, it would be conceivable that already when printing the container with the test mark this is classified as a test container. Since, as mentioned above, preferably the containers are transported sporadically, an individual discharge of these containers is easily possible. In particular, as mentioned above, the objects are containers, and more preferably plastic containers, and more preferably plastic bottles. However, it would also be conceivable to apply the invention to other containers, for example glass containers and metal containers (e.g., white bleach or aluminum).

In a further preferred method, the objects are examined during a standstill, in particular inspected. This means that the containers are first printed and then preferably stopped in the area of the inspection device and thus can be examined. The test containers are preferred in the context a test operation clocked transported. It would be possible that the printing of the containers with the test mark at a predetermined operating speed and in particular at a normal production speed and the subsequent inspection with a changed speed, preferably a lower speed and especially during a standstill of the containers with respect to their transport path (but the containers can nevertheless be rotated about their longitudinal direction).

Advantageously, the applied pressure is a multi-color print.

In a further preferred method, the inspected container is assigned to the printing unit which has printed the inspected container. In this variant, it would be possible that a plurality of printing units are provided, which alternatively or successively attach the prints to the containers. The particular test pressure or the test mark is assigned in this procedure to the printing unit which has applied this test pressure. Preferably, at least two printing units apply pressure to at least partially identical areas of the container. In this case, these printing units, for example, attach different color components. However, it would also be possible for the printing units to apply complementary prints approximately along a longitudinal direction of the container, wherein preferably an overlap region of the container is provided which is printed by both printing units.

The printing units can be pressure units in the narrower sense. In the context of the invention, however, aggregates such as foliation modules are understood as printing units and serve to realize metallic effects. In this case, for example, a cold foil stamping (or an inline foliation) could be carried out. Such aggregates could at least partially replace the printing units described above. In addition, it would also be conceivable that the printing unit a

Printing the glue causes. Again, the test methods described here can find application. In a further preferred method, the inspection device records at least one image of the container to be inspected. Advantageously, instructions are issued to a user depending on the inspection result. Furthermore, it is possible that the inspection device receives a plurality of images of a print. In addition, it is also possible that the inspection device, the test mark (in particular visually and contactless) scans and scans, for example, during this scanning the container relative to the inspection device moves, for example, is rotated and or the inspection device is moved during this scanning in a longitudinal direction of the container.

In another method, it is also possible that the objects are printed by several printing units. It would be possible that each printing unit is assigned an inspection device. However, it makes economic sense to provide a central inspection device downstream of all printing units.

In a further advantageous method, the objects in particular containers are transported isolated. Thus, the containers preferably have a predetermined pitch among each other. Advantageously, the containers are guided along an at least partially circular transport path. For example, containers can be fed to a printing unit and transported with these individual printing units and delivered in a printed state back to a discharge device. Advantageously, it can be defined or defined when an inspection result deviates from a target result. This Soller result may be, for example, an ideal or desired imprint of a container.

Preferably, the at least one printing unit is stationary (relative to the transport path of the containers) and the containers are guided past this printing unit. However, it would also be conceivable that the printing unit is moved with the container.

In a further preferred method, the printing of the object with the test mark takes place in the context of a test mode of the device. In this case, this test mode can be switched in particular to a working mode or a production mode. As mentioned above, it would be possible to perform this test operation after a grade change or when resuming a work operation. In addition, it may also be possible for this test mode to be run during production, for example at predefined times. In a further preferred method, a marking, in particular a pressure, is also checked during operation of the device, in particular that marking or the pressure which is to be applied to the containers. Preferably, another inspection device is used for this inspection than the inspection device which is used for the test mode. It should be noted that preferably that inspection device that is used in the working mode, other criteria than the inspection device, which is used in the test mode. The inspection device, which inspects the containers in the operating mode, preferably has a camera and in particular a color image camera.

In another preferred method, another object is printed with a test mark. Thus, it is possible that first a first container is printed with a test mark, then this is inspected and particularly preferably in response to this inspection at least one printing parameter is adjusted or changed. Subsequently, the said further object is printed using the changed printing parameter. For example, during the first inspection it can be determined that two printing units are not completely correctly aligned with each other.

For example, the inspection device may instruct the control unit of the printing unit to displace a position of a printing element. Subsequently, another test container is in turn printed and preferably subsequently inspected again. If it is now determined that the pressure is correct, the production of the containers can be started. Thus, another object is preferably printed using a result of the first inspection. It is thus preferred for the test operation to adjust and / or calibrate the at least one pressure unit.

It would also be possible to print on multiple containers, in particular by means of a control loop. Preferably, at least two containers, preferably at least three containers, preferably at least four containers and preferably at least five containers, are printed with the test mark. However, in addition to or as an alternative to the control loop, it is also possible for an indication that an intervention may be made by a user in response to an inspection being performed. Advantageously, the inspection device thus recognizes whether an error can be eliminated automatically, about a position adjustment can be performed, or if the error can not be corrected automatically, such as if a pressure element is defective.

In a further advantageous method, the test mark is compared with at least one reference value and in particular a reference mark. It is possible that this reference mark is stored in the system or in a storage. On the basis of this comparison, a value can be output which is required, for example, for calibrating the (stored) pressure parameter or the printing aggregate. In a further advantageous method, the containers are printed with at least two printing units. These are preferably at least two controlled aggregates, which also use the respectively specific pressure parameters. It is possible that these printing units print the containers substantially simultaneously, but it would also be possible that the printing units print the containers one behind the other. As mentioned above, overlapping pressure ranges can be printed.

In a further preferred method, the printing units apply a multi-color print to the container. In a further preferred method, a multiplicity of inspection results can be assigned to the respective responsible printing units. In this way, statistics can be formed from a large number of recordings (for example by histograms or long-term average values). In this way, a trend can be visualized, taking into account the responsible equipment unit, which indicates a deterioration of, for example, a printed image. Also warning limits and intervention limits can be realized, i. H. For the inspection result, limits can be defined from which a container can no longer be considered acceptable.

In a further preferred method, the inspection device performs an evaluation of at least one color property of the marking. In particular, colored test prints are used and inspected. A color management system (CMS) is preferably used for the evaluation in order to reconcile the color spaces of an image recording device to be checked, such as a camera (in this case an additive color space) and the CMYK printing system (subtractive color space). In this case, methods can be used which use matrix profiles and / or LUT profiles. Preferably, LOT profiles are used. In a color management or color management system, a Look Up Table (LUT) can use completely different types of color profiles, such as the color space of the camera and that of the camera

CMYK printing system. The matrix profiles mentioned above are simpler, smaller and often used for monitors. In a matrix ICC profile, the input RGB values are transformed into profile connection space values using a mathematical operation (a 3x3 matrix). In the case of an LUT profile, tables are needed which contain entries for each combination of an input RGB value and a corresponding CIELAB value. Such approaches are used in particular as here for printers.

In a further procedure, a test print is first applied to the containers, such as the above-mentioned test pattern, and particularly preferably also a label which indicates that the container thus printed is a test container. These test containers are therefore also suitable as documentation to prove that the printing press or the printing unit works flawlessly. Advantageously, at least one type of error is detected by the inspection device.

Preferably, the inspection device is preferably suitable and determines to detect at least one error of the test mark and / or the printing unit. The inspection device preferably also carries out an evaluation of at least one color characteristic of the marking, in which case in particular colored test prints are used and read out.

Advantageously, this is a type of error selected from a group of types of errors including registration (front or back of non-round containers), a registration difference or a color register, smearing of the mark, and the like. In addition, errors can also be detected, such as a missing DOT series (for example as a result of nozzle failures), a faulty position of the printed image (in the XY direction relative to the container and / or a rotational position), or a wrong positioning or a skewed container , In this context, it is pointed out that with the inspection devices used in operation, in particular color cameras, essentially only geometrical features can be precisely checked, which relate on the one hand to the triggering or path control of the printing system or also to mechanical inadequacies or nozzle failures.

In a further preferred method, the inspection device inspects the test mark by means of an inspection element which is selected from a group of inspection elements which contains spectrophotometers, densitometers, in particular color densitometers and spectral densitometers. Preferably, the above-mentioned inspection device is activated only at the beginning of a test operation. It would be possible for that inspection device, which inspects the containers in the context of the work or production operation, to be correspondingly deactivated. Since a color camera with respect to the quality control of the colors or the color density measurement is only conditionally suitable for quality control, it is proposed here that in the test case, these are selectively switched by means of quality control. This means that a color camera can be used in a normal operating mode, but an inspection device of the type described above can be used for the said test mode. For example, during the production (eg hourly) a test pattern of the type described above can be applied to one or more cameras several containers are applied and preferably checked and discharged by means of CMOS or CCD camera. But it can also be changed to a system for color space control. In a further preferred method, the pressure, in particular for the test operation, automatically switched to a suitable media wedge. For example, Ugra Offset test wedges, Postscript control wedges or Ugra / Fogra media wedges CMYKV30 can be used. Through an automated optimization loop, color and position adjustments can be made quickly and accurately with defined criteria. In this way, human influence can be avoided. In addition, it is preferably possible to save considerable set-up time via automated routines, since measurements take place inline with direct feedback as long as certain tolerance values are not reached. It is likewise conceivable for a second or third color head (redundant) to be available as a backup in the event of a malfunction and to be adjusted according to the subject matter of the invention, ie calibrated.

It is also conceivable that such an optimization loop, in particular with sufficient computing power, even during ongoing production, without having to initiate a special procedure. In this way, continuous quality control would be possible. In this case, containers can be regularly printed with a test pattern, inspected and subsequently discharged from the production stream. The machine availability is thereby significantly increased compared to known from the prior art method with constant quality.

Preferably, the containers are illuminated during their inspection. In this case, a standardized light (for example white light) can be used to illuminate the containers. An inspection of the containers or the test marks can be carried out, for example, in an incident light method or in a transmitted light method.

Advantageously, the test mark is a test wedge and / or the test mark has a test wedge. This test wedge may have geometric characters or elements, which are particularly suitable for evaluation by an inspection device.

The present invention is further directed to an apparatus for printing on objects and in particular of containers. This device has a transport device which transports the objects along a predetermined transport path and at least one first printing unit which is suitable and intended to apply a pressure to an outer wall of the object during a working operation of the device. Furthermore, the device has a control device for controlling a first printing unit.

According to the invention, the first printing unit is furthermore suitable and intended to mount at least one test mark on an outer surface of the object during a test operation, and the apparatus further comprises a first inspection device for inspecting the objects printed with the test mark, these inspection devices being arranged downstream of the first printing unit in the direction of transport of the objects and outputting at least one inspection result usable by the control device for controlling the first printing aggregate.

It is therefore also proposed on the device side that a possibility is created to attach a marking and in particular a special test mark to the containers in a special test operation and in particular to achieve a calibration of the device on the basis of this marking. Advantageously, therefore, the device has a control device which regulates the at least first pressure unit on the basis of the inspection result.

In a further advantageous embodiment, the device has at least one second inspection device, which is suitable and intended for the inspection of prints applied to the objects during a working operation. This inspection device is an inspection device which controls the quality of the prints, especially during operation. However, it is possible that, depending on an inspection result of this second inspection device, other countermeasures are taken, such as a closure of a certain pressure unit or also a discharge of a container printed by this unit. Furthermore, it would also be possible and preferred that the same inspection device is used both for the calibration operations described here and during operation. In this case, the inspection device also used in the working mode can also be used for the test markings. In this case, however, the inspection device for checking the test mark can be switched to other parameters.

In a further advantageous embodiment, the device has a lighting device which illuminates the containers, in particular during their inspection by the first inspection device. In this way, a uniform illumination of the containers can be achieved.

Advantageously, the described first inspection device, which is used in particular in the test mode, is not used in the context of the ordinary work operation. That's the way it is possible that this first inspection device is moved in normal working mode from a position in which it can make inspections, in a rest position.

Since the scanning distances of the required measuring means are quite short and mechanical collisions can occur in the production operation, it is proposed that the first inspection device be moved or run in a protected area after the test, for example color fidelity and calibration. This can be done by means of an electric drive or manually operated. For example, telescopic rails and end stops can be present. In addition, this protected area should be protected, for example, by overpressure in the protective housing against spray mist caused by the printing operation.

In a further embodiment, therefore, the first inspection device is displaceable on the one hand between a working position (which is in particular a position taken during a test operation) on the one hand, and a rest position (which is also assumed in particular during working operation).

Further advantages and embodiments will be apparent from the attached drawings, in which:

Fig. 1 is a schematic representation of a device according to the invention; and

2 shows a flow chart for a method according to the invention. 1 shows a schematic representation of a device 1 according to the invention for printing on containers 10. The containers 10 are fed via a feed device 52 to the device and discharged via a discharge device 54. The device 1 further comprises a carrier 24, which is rotatable relative to a rotation axis D and is part of a transport device 2. Holding devices 22, which serve to hold the containers 10 to be equipped (only one shown), are arranged on this carrier. Furthermore, 24 pressure units 4, 6, 7 are arranged on the carrier, but only three of these equipment units are shown. The reference numerals 14, 16 and 17 respectively refer to control means for controlling the printing units 4, 6 and 7. In the embodiment shown in Fig. 1 are printing units, which attach a direct pressure to the containers 10. These printing units 4, 6, 7 can have a plurality of print heads, for example three print heads, which are arranged one above the other. Furthermore, the device has rotation means which allow each individual container 10 to be rotated with respect to its longitudinal direction (which is perpendicular to the plane of the figure).

The reference symbol P denotes the here circular transport path of the containers 10 to be equipped.

Downstream with respect to the holding elements and the equipment units an inspection device 8 is arranged, which checks the containers. This inspection device inspects these containers or their test marks, in particular during a test operation of the device. For this purpose, the inspection device can have a memory device 32 in which reference images are stored, in particular reference images of test prints. Furthermore, the device has a comparison device 34, which compares the recorded images of the test marks with the reference images. On the basis of this comparison, a pressure parameter of the control device can be changed, in particular in order to achieve an improvement of the pressure.

Fig. 2 shows a flow chart for a method according to the invention. Initially, a test program or test procedure is started. This start can, as mentioned above, by the user, ie, for example, manually triggered, but it would also be possible that the start automatically takes place according to certain specifications, such as after a product changeover. The reference numeral 18 denotes a storage device into which the inspection device, in particular during a production operation of the device 1 can be spent. Preferably, this storage device has a housing which protects the inspection device at least against impurities such as splashes of paint. In this case, the device may have a carrier (not shown), against which the inspection device 8 is displaceable so as to be displaced from a rest position (shown in dashed lines in FIG. 1) to a working position (during a test operation). The In addition, the device also has an allocation device (not shown), which assigns to an inspection result of the further inspection device the printing unit which has produced the pressure inspected, but it would be also possible that this inspection device is arranged directly on a movable support, such as the discharge device 54.

FIG. 2 now shows two branches, the right branch illustrating actions of the inspection device and the left branch actions of the printing units. First, with regard to the at least one printing unit, a conversion to the

Printing with the test mark. In addition, it is possible that in addition to the test mark metadata are still printed, as mentioned above, such as a date or time. In addition, an inspection device is activated at the beginning of the measurement program, which also serves to capture the test mark.

In this case, it is possible for this inspection device to be moved, for example, from a casing into a working or measuring position. Particularly preferably, a measuring sensor can be automatically brought into a suitable measuring position. Subsequently, a test object, such as in particular a container, retracted and printed with the test mark. This so-printed container is then inspected by the inspection device and at least one measurement is taken. As part of this inspection, it is possible to take one or more recordings of the test marks.

In a further method step, the recorded image or the measurements carried out are compared with reference images and in particular also reference colors.

If this comparison comes to the conclusion that there is sufficient agreement between the measured values and the reference values, this is an indication that the pressure is in order and production can begin. It is also possible to determine limits within which a test pressure carried out is still considered satisfactory. Outside these limits, the container and / or pressure thus obtained may be considered defective. In addition, documentation of the test can be carried out and for this purpose, in particular, the container provided with the test mark can be discharged. If the inspection concludes that the test mark is not satisfactory, a calibration, in particular a calibration of the control device and / or the printing unit. In this case, a container is retracted again and printed with the test mark. Subsequently, here again a measurement or an inspection of the test mark takes place and it is checked whether this corresponds to the given criteria. If necessary, these steps can be performed several times. In particular, the method described here can run automatically and thus, in particular during a production start, carry out a regulated calibration of the printing units.

In some cases, the available measuring equipment can not completely capture the test mark. Therefore, the transport of the printed containers in the area of the inspection device is preferably stopped or the container transport is stopped. In this position, scanning (scanning) of the container can then be made in a vertical direction. If, for example, a second scan is necessary, the machine can be advanced by the necessary amount and, if necessary, the rotational position of the container to the measuring means can be corrected again and another image or a further scan can be made.

After performing the measurement or the calibration, as mentioned above, the inspection device can be returned to a protected area.

The applicant reserves the right to claim all features disclosed in the application documents as essential to the invention, provided that they are novel individually or in combination with respect to the prior art. It is further pointed out that features have also been described in the individual figures, which in themselves may be advantageous. The person skilled in the art immediately recognizes that a particular feature described in one figure can also be advantageous without taking over further features from this figure. Furthermore, the person skilled in the art recognizes that advantages can also result from a combination of several features shown in individual or in different figures. LIST OF REFERENCE NUMBERS

1 device

transport means

, 6, 7 equipment sets

8 inspection device

10 container

14, 16, 17 control device for printing units

12 more inspection equipment

18 Storage device

22 holding device

24 carriers

32 storage device

34 Comparative device

52 feeder

54 discharge device

P transport path

D rotation axis

Claims

claims

1 . Method for printing objects and in particular containers (10), wherein the containers (10) are transported along a predetermined transport path (P) and at least temporarily printed on their outer surface by means of at least one printing unit (4, 6, 7), wherein a control device (14, 16, 17) controls the printing of the containers (10) by the at least one printing unit (4, 6, 7) on the basis of at least one printing parameter,

characterized in that

to determine this printing parameter, at least one object to be printed (10) is printed with at least one test mark and then this object provided with the test mark is inspected by means of at least one inspection device (8) and the print parameter is derived from an inspection result of this inspection.

2. The method according to claim 1,

characterized in that

the printing of the object (10) with the test mark takes place in the context of a test mode.

3. The method according to at least one of the preceding claims,

characterized in that

another object is printed with the test mark.

4. The method according to at least one of the preceding claims,

characterized in that

the test mark is compared with at least one reference value.

5. The method according to at least one of the preceding claims,

characterized in that the container (10) with at least two printing units (4, 6, 7) is printed.

6. The method according to at least one of the preceding claims,

characterized in that

the inspection device (8) carries out an evaluation of at least one color property of the marking.

7. The method according to at least one of the preceding claims,

characterized in that

the inspection device (8) is suitable and intended to detect at least one error of the test mark.

8. The method according to at least one of the preceding claims,

characterized in that

the inspection device (8) inspects the test mark by means of an inspection element which is selected from a group of inspection elements which contains spectrophotometers, densitometers, in particular color densitometers and spectral densitometers.

9. An apparatus for printing on objects and in particular containers (10), with a transport device (2), which transports the objects along a predetermined transport path, with at least one first printing unit (4, 6, 7), which is suitable and intended, in the context of a working operation, to apply a pressure to an outer wall of the object (10) and to a control device (14, 16, 17) for controlling the first pressure unit (4, 6, 7), characterized in that

the first printing unit (4, 6, 7) is furthermore suitable and intended to apply at least one test mark to an outer surface of the object (10) during a test operation, and to a first inspection device (8) for inspecting the objects printed with the test mark (10), which inspection device (8) is arranged in the transporting direction of the objects (10) downstream of the first printing unit (4, 6, 7) and which outputs at least one inspection result, which is controlled by the control device (14, 16, 17) of first printing unit (4, 6, 7) is usable.

10. Device (1) according to claim 9,

characterized in that

the device (1) has at least one second inspection device (12) which is suitable and intended for inspecting the prints attached to the objects (10) during a working operation.