Apparatus and method for printing labels

Abstract

An apparatus and method for printing labels (1), in particular labels provided on a liner (2). The apparatus includes at least one label feed device (3) for providing and feeding labels, a transport device (4) including at least one transport element (9, 10) for transporting the labels, which have been fed by the label feed device, in a transport direction, a printing device (11) including a printing head (11a) for printing the labels transported by the transport device, and a capturing device (12) for capturing the position of the respective label in a section of the transport device. The capturing device has a line-scan or area-scan camera (13) with which the side of the transport element that faces the labels during correct use and/or a gap (19) formed between two transport element sections (17, 18) in the transport direction is optically capturable in a capturing region (14).

Claims

1. An apparatus for printing individual labels, the apparatus comprising: a transport device; a capturing device; and a printing device; wherein the transport device is configured to transport individual labels in a transport direction, wherein the transport device has a first transport section and a second transport section, wherein the second transport section is downstream of the first transport section in the transport direction, wherein the first transport section of the transport device comprises a transport belt having a surface for receiving a feed of the individual labels that have either been detached from a liner or have been singulated from a strand by cutting, wherein the capturing device comprises a line-scan or area-scan camera configured to optically capture a position and orientation of a respective one of the individual labels transported by the transport device in a capturing region located in the second transport section of the transport device, wherein the printing device is located downstream in the transport direction of the capturing device, and wherein the printing device is configured to print the respective one of the individual labels in a printing region based on the position and orientation of the respective one of the individual labels captured in the capturing region by the capturing device.

2. The apparatus according to claim 1, wherein the second transport section comprises an additional transport belt.

3. The apparatus according to claim 2, wherein the line-scan or area-scan camera is arranged above the additional transport belt.

4. The apparatus according to claim 2, wherein a gap exists between the transport belt and the additional transport belt, and wherein the line-scan or area-scan camera is arranged to optically capture the position and orientation of the respective one of the individual labels in the gap from below.

5. The apparatus according to claim 1, wherein the second transport section comprises the same transport belt as the first transport section.

6. The apparatus according to claim 5, wherein the line-scan or area-scan camera is arranged above the transport belt.

7. The apparatus according to claim 5, wherein the transport belt is arranged such that a gap exists between the first transport section and the second transport section, and wherein the line-scan or area-scan camera is arranged to optically capture the position and orientation of the respective one of the individual labels in the gap from below.

8. The apparatus according to claim 1, wherein the line-scan or area-scan camera is a color camera.

9. The apparatus according to claim 1, wherein the capturing device has at least one light-emitting element for illuminating at least a portion of the capturing region.

10. The apparatus according to claim 1, wherein the capturing region overlaps the printing region.

11. The apparatus according to claim 1, wherein the capturing region adjoins the printing region.

12. The apparatus according to claim 1, wherein the capturing region is located a distance of 100 mm or less from the printing region.

13. The apparatus according to claim 1, wherein the capturing region has a length of at least 100 mm or the capturing region has a width of at least 50 mm.

14. The apparatus according to claim 3, wherein the capturing device is configured to also capture one or both lateral peripheries of the additional transport belt.

15. The apparatus according to claim 6, wherein the capturing device is configured to also capture one or both lateral peripheries of the transport belt.

16. The apparatus according to claim 3, wherein the line-scan or area-scan camera is configured to be calibrated with respect to a reference point or with respect to a reference line extending in the transport direction or a reference line extending transverse to the transport direction or with respect to a reference line extending perpendicularly to a plane of the additional transport belt.

17. The apparatus according to claim 6, wherein the line-scan or area-scan camera is configured to be calibrated with respect to a reference point or with respect to a reference line extending in the transport direction or a reference line extending transverse to the transport direction or with respect to a reference line extending perpendicularly to a plane of the transport belt.

18. The apparatus according to claim 1, further comprising a control device configured to control, based on a contour of the respective one of the labels captured by the capturing device or based on a pre-print or a contour of a pre-print on the respective one of the labels captured by the capturing device, an assigned printing process.

19. The according to claim 3, further comprising a control device configured to monitor or indicate or adjust slip of the additional transport belt element based on marks on the additional transport belt captured by the capturing device.

20. The according to claim 6, further comprising a control device configured to monitor or indicate or adjust slip of the transport belt element based on marks on the transport belt captured by the capturing device.

21. The apparatus according to claim 18, wherein the control device is configured to automatically adapt the assigned printing process when it is determined that one or both of the position and orientation of the respective one of the individual labels transported by the transport device in the capturing region has: a different width, length, position and/or orientation than a specified target value for the width, length, position and/or orientation; or a different width, length, position and/or orientation compared to an immediately preceding one of the individual labels in the capturing region.

22. The apparatus according to claim 21, wherein the control device is configured automatically adapt the assigned printing process within a time period from the capturing of the contour of the respective one of the labels by the capturing device and a start of the assigned printing process for the respective one of the individual labels.

23. The apparatus according to claim 22, wherein the control device is configured to adapt the assigned printing process such that the print reaches all the way to the contour of the respective one of the individual labels.

24. The apparatus according to claim 1, wherein the printing device has print head, and wherein the print head is one of a thermal head with a thermal strip, a laser printing head or an ink jet printing head.

25. The apparatus according to claim 1, wherein the transport device further comprises one or more transport rollers and/or pressure rollers.

26. The apparatus according to claim 1, further comprising a plurality of label feed devices configured in each case for providing and feeding labels to the surface of the transport belt.

27. The apparatus according to claim 26, wherein the plurality of label feed devices are independently activatable relative to one another to provide individual labels that are different from each other.

28. A method for printing labels comprising: feeding individual labels that have either been detached from a liner or have been singulated from a strand by cutting to a surface of a transport belt of a first transport section of a transport device of an apparatus according to claim 1; optically capturing the position and orientation of a respective one of the individual labels in the capturing region using the line-scan or area-scan camera; and printing the respective one of the individual labels in the printing region based on the position and orientation of the respective one of the individual labels captured in the capturing region.

Description

(1) The invention will be explained in more detail below with reference to a drawing illustrating merely exemplary embodiments. In the drawing

(2) FIG. 1 shows a schematic view of an apparatus according to the proposal for printing labels, and

(3) FIG. 2 shows the detail ii from FIG. 1

(4) a) in an enlarged illustration, and b) in a plan view.

(5) FIG. 1 shows, by way of example and purely schematically, an apparatus according to the proposal for printing labels 1, in particular adhesive labels 1, which are provided here detachably on a liner 2. The apparatus has a plurality of separate label feed devices 3 via which the individual labels 1 are provided and fed to a transport device 4.

(6) Each of the label feed devices 3 is here constructed according to the same principle. The label feed devices 3 thus have a decoiler 3a, a stripper head 3b, and a take-up spool 3c. The decoiler 3a serves for holding a till roll 5, which here comprises a liner 2 to be unwound having labels 1 that are detachably provided thereon. The liner 2, on which the labels 1 are arranged, is guided from the decoiler 3a to the stripper head 3b, at which the liner 2 is strongly deflected, here for example by more than 90°, as a result of which the labels 1 automatically detach in each case from the liner 2. The liner 2, which has now rid itself of the labels 1, is finally wound up again by the take-up spool 3c.

(7) The individual constituent parts of the label feed device 3, in particular decoiler 3a, stripper head 3b, and take-up spool 3c, are arranged here in a cartridge 6, which is capable of being removed from the apparatus and/or replaced in its entirety.

(8) As shown in FIG. 1, the label feed device 3 and/or the decoiler 3a, the stripper head 3b and/or the take-up spool 3c is/are connected to a control device 8 of the apparatus via an assigned control line 7, as will be explained in more detail below. Thereby, each individual one of the label feed devices 3 can be activated or deactivated, as required. “Activate” is understood to mean that the label feed device 3 is positioned and/or controlled such that individual labels 1 can be fed to the transport device 4. It is conceivable that the remaining label feed devices 3 are deactivated in that case, that is to say do not feed any labels 1 themselves. However, it is also conceivable that further ones of the label feed devices are likewise activated and feed labels 1 at the same time.

(9) The transport device 4 comprises at least one transport means 9, 10 with which the labels 1, which have been fed by the respective label feed device 3, are transported in a transport direction. One of the transport means is here a transport belt 9 that cooperates with another transport means in the form of a unit made from a plurality of pressure rollers 10. The transport belt 9 has a drive, which is likewise coupled to the control device 8. The unit made of pressure rollers 10 serves for pressing the labels 1 against the surface of the transport belt 9 as they are being transported so that they remain positioned and aligned on the transport belt 9 as optimally as possible. The transport belt 9 here has two transport means sections 17, 18, one of which is curved and the other is straight. A gap 19, across which the respective label 1 is conveyed from the curved to the straight transport means section, is formed between them.

(10) The transport device 4 transports the individual labels 1, in particular continuously, in the transport direction to a printing device 11 having a printing head 11a configured for printing the labels 1 that are transported by the transport device 4. The printing device 11 is also connected to the control device 8 via a separate control line 7. The printing head 11a in the exemplary embodiment described here is a thermal head having a thermal strip. In this way, a thermally sensitive medium can be changed in terms of color, in particular blackened, by way of a point-type introduction of heat. The corresponding printing method, known as thermal printing, can be direct thermal printing, thermal transfer printing or thermal sublimation printing. However, the solution according to the proposal in principle also encompasses other printing methods, for example laser printing methods or ink jet printing methods. Accordingly, it is also possible for a laser printing head or an ink jet printing head to be provided as the printing head.

(11) It is now possible to feed individual labels from each of the label feed devices 3 to said printing device 11 by means of the transport device 4, wherein the labels 1 are guided past a capturing device 12 for capturing the position and orientation of the respective label 1 in a section of the transport device 4 before they reach the printing device 11. The label feed devices 3, which are able to be activated independently of one another and here can also provide different labels, are thus assigned, in the exemplary embodiment described here, to the same transport device 4, the same printing device 11 and the same capturing device 12.

(12) What is important is now that the capturing device 12 has a line-scan or area-scan camera 13 with which the side of the transport belt 9 facing the transported labels 1, here the upper side of the transport belt 9, is optically capturable in a capturing region 14. Accordingly, when a label 1 passes through the capturing region 14, the respective label 1 is captured. This is illustrated in detail in FIGS. 2a and b.

(13) The capturing device 12 is also connected to the control device 8 via a separate control line 7. In this way, data, generated by the capturing device 12, relating to the width, length, position and/or orientation of the label 1 that respectively passes through the capturing region 14 can be processed by the control device 8, which uses said data to control the printing head 11a such that a print can be placed optimally and with great precision on the respective label 1. It is thus possible to identify the geometry even of complex labels 1 using a line-scan or area-scan camera 13 and to correspondingly adapt an assigned printing process. Since the width of the capturing region 14 can be chosen to be at least such that a label 1 can be captured in its entirety in the transverse direction (transverse to the transport direction) and can preferably also be captured in its entirety in the longitudinal direction or transport direction, it is possible in particular to also detect the position or the transverse offset of a label and/or the orientation or an angular offset of the label 1 and to correspondingly control or adapt a printing process that is assigned to the respective label 1. A further advantage of the comparatively large capturing region 14 is that a capturing device 12 or a corresponding camera 13 can be aligned particularly easily with respect to the respective transport means, in the present case the individual transport belt 9. By contrast, this is more difficult in the prior art, in which a color detection sensor is used.

(14) Since the label 1 can be captured in its entirety, which is also possible using a line-scan camera 13 if the individual captured lines are combined into a two-dimensional image, the respective label 1 can be printed if required even up to its edges, that is to say to its outer contour, and in particular also up to its corners. Even in the case in which the label 1 that is fed to the capturing region 14 and, in the further continuation, to the printing device 11 already has a pre-print, it is also possible to place a print with particular precision relative to the pre-print by capturing the pre-print or the contour of the pre-print.

(15) Using the apparatus according to the proposal and in particular using the capturing device 12 provided, the printing process can also be adapted from one label to the respectively next label. In other words, adaptation of the printing process is possible within the time period from capturing the contour of the label 1 to the start of the printing process assigned to the label 1. If an immediately following label 1 having a different position or orientation subsequently reaches the capturing region 14, the printing process assigned to said label 1 can be immediately adapted for said subsequent label 1. It is also possible to automatically check before printing whether the correct label format for the respective product ID is being fed or is placed into the corresponding cartridge 6.

(16) By coupling the control device 8 to the drive of the transport belt 9 and also to the capturing device 12, it is also possible to implement slip monitoring, in particular such that the capturing device 12 captures marks provided on the respective transport means 9 via which the control device 8 can ascertain the actual speed of the transport means 9 and which it can then compare to the captured actual rotational speed of the drive of the transport belt 9. A difference between the ascertained actual speed of the transport means 9 and the captured actual rotational speed of the drive of the transport belt 9 then indicates slip and can be indicated in particular to an operator and/or be automatically corrected.

(17) Further details of the capturing device 12 of the apparatus according to the proposal for printing labels 1 will be described below with reference to FIGS. 2a and b.

(18) The line-scan or area-scan camera 13 according to the exemplary embodiment is thus a color camera. The use of a monochrome camera is in principle however also conceivable. The entire capturing device 12 and thus also the camera 13 is connected to the remaining apparatus and in particular to the control device 8 via a plug-and-play interface, in particular a USB interface, that is to say an interface that permits the transmission of data and the supply of power to the camera 13. The supply of separate light-emitting means 15 of the capturing device 12 with power is also possible thereby, with said light-emitting means 15 illuminating the capturing region 14 at least in a section-wise manner, in particular completely. In the case illustrated here, the totality of the camera 13 and the light-emitting means 15 is connected to the apparatus or the control device 8 by means of the plug-and-play interface or USB interface in the manner described.

(19) As is illustrated in FIG. 2a, the capturing device 12 or the line-scan or area-scan camera 13 is arranged vertically above the transport means 9, at least vertically above the capturing region 14. The capturing device 12, in particular the line-scan or area-scan camera 13 and/or the light-emitting means 15, is or are directed here perpendicularly at the surface of the transport means 9 in the capturing region 14. In principle, however, it is also conceivable to direct the capturing device 12 or the camera 13 and/or the light-emitting means 15 onto the surface at an angle. It is also possible for a capturing device 12, in particular a line-scan camera 13, to be arranged below the transport means 9 and/or be directed at or into a gap 19 between two transport means sections 17, 18 in order to then capture the labels in particular from below when they pass the gap 19. It is only necessary to ensure that the capturing region 14 is aligned with the transport means or transport belt 9 such that at least the majority of a fed label 1, in particular all of it, can be captured transversely to the transport direction and preferably also in the transport direction. With preference, as illustrated in FIG. 2b, the capturing region 14 is even formed such that a label 1 is able to be arranged entirely, that is to say including over its entire length, in the capturing region 14.

(20) In the exemplary embodiment described here, the capturing region 14 for this purpose has a length (extent in the transport direction) of at least 100 mm, preferably at least 150 mm, with particular preference at least 200 mm, and has in particular a length corresponding to at least one label length. Here, the capturing region furthermore has a width (extent transverse to the transport direction) of at least 50 mm, preferably at least 100 mm, with particular preference at least 150 mm, and has in particular a width corresponding to at least one label width. In the example illustrated in FIG. 2b, the capturing region 14 even extends laterally, i.e. in the transverse direction, beyond the transport means or transport belt 9. In principle, the capturing region 14 captures at least one of the lateral peripheries 9a, 9b, preferably both lateral peripheries 9a, 9b of the transport means or transport belt 9. “Lateral peripheries” within the meaning of the invention are understood to mean the peripheries delimiting the transport means 9, 10 in the transverse direction.

(21) The capturing region 14, which is arranged upstream of the printing head 11a in the transport direction, is here located at a distance from the printing region 16, in which in principle printing can take place and which is defined here by the thermal strip, in the transport direction. The distance is preferably less than one label length. In particular, the distance is at most 100 mm, preferably at most 50 mm, with particular preference at most 20 mm. It is also conceivable in principle that the capturing region 14 adjoins the capturing region 16 in the transport direction or even overlaps the printing region 16 in the transport direction.

(22) As FIG. 2b also schematically illustrates, the line-scan or area-scan camera 13 is calibrated or able to be calibrated with respect to a reference point P and/or a reference line L in the transport direction and/or transversely to the transport direction and/or perpendicularly to the transport plane or transport means surface. Here, the reference point P is a point, or the reference line L is a line, at the printing head 11a, wherein the reference point P and the reference line L are arranged here in each case outside the capturing region 14.

(23) The present invention finally also relates to a method for printing labels 1, in particular labels 1 provided on a liner 2, which method is able to be carried out preferably using the apparatus described above.

(24) In the method according to the proposal, the labels 1 are provided in each case via at least one label feed device 3 and fed to a transport device 4. The labels 1 are then transported by the transport device 4, as described above in detail, past a capturing device 12 to a printing device 11, in which the labels 1 are printed in each case. In particular, the printed labels 1 are subsequently applied in each case to goods. Provision is made according to the proposal for the labels 1 to be optically captured in a capturing region 14 by a line-scan or area-scan camera 13 of the capturing device 12.