EA047366B1 - DEVICE AND METHOD FOR PRINTING ON LABELS - Google Patents

Description

The invention concerns a device for printing on labels according to the restrictive part of claim 1 of the formula, as well as a method for printing on labels according to the restrictive part of claim 15 of the formula.

Various methods of printing on labels, in particular product labels, are known from the prior art. These labels are either removable backing tape self-adhesive labels or linerless labels that are provided as an endless strip and are released by cutting. Labels and/or tape substrates may consist of paper or polymeric material. These types of labels, which in particular are provided in the form of roll material or leporello, also form part of the invention, which is described in detail below.

One of the known label printing devices (EP 1 280 705 B1), on which the invention is based, has several separate label supply devices, each of the label supply devices having an unwinder for unwinding the roll, which consists of a substrate tape and printed on with the ability to detach the labels, a rewinder for winding the backing tape that does not have labels, and a peeling head for deflecting the backing tape and thus detaching each label from the backing tape. The label supply devices are all intended for the same transport device, which in one embodiment has a conveyor belt as a transport means. The label feeders, once suitably activated, can supply labels to the transport device, which are then fed into one common printing device. After printing on the labels in a printing device, these labels, each individually or several, are applied to the product by means of an application device.

In the said prior art, in the transport direction in front of the printing device, which has as a printing head, for example a thermal head, an inkjet printing head or a laser printing head, a recording device is provided for recording the position of each label. This recording device is located in the gap between the transport belt and the roller forming the other transport means. Based on the registered position of the label, the print head can place the appropriate print on the label and transfer the label correctly to the applicator.

To register labels on a transport device, color recognition sensors are typically used to produce a stationary, highly focused beam of light. When this light beam hits a label that is directed past it, the light is reflected and the reflection is detected by the color recognition sensor/luminescent switch. That is, the color recognition sensor works on the principle of a light shutter. When a label is detected by a light beam, a corresponding recording signal is generated by the color recognition sensor, by means of which the print head is adjusted so that a print can be placed on the intended label.

However, what is problematic in the above-described prior art is that the label is registered by a recording device and a corresponding recording signal is generated even when the label is not optimally aligned with the print head. As a result, this often results in non-optimally placed print on the label, such as print that runs obliquely to the edges of the label or has an undesirable lateral or longitudinal shift, and in the worst case even extends beyond the edges of the label or pre-printed label.

The basis of the invention is the problem of making and improving a known device for printing labels in such a way that each label can be printed more accurately.

The above problem is solved by using a device for printing labels according to the restrictive part of claim 1 by using the features of the distinctive part of claim 1 of the claims.

In particular, it is proposed that the recording device has a camera with line or line-frame scanning, with which the side facing the labels in the intended use, in particular the top side, of the transport means and/or a gap formed in the transport direction between two sections of the transport means can optically register in the registration area. That is, the registration area of the recording device or, respectively, the camera is located and configured in such a way that the transport means and/or under certain conditions the existing transverse gap and at the same time also the labels that are transported by the transport means, under certain conditions through this gap, are registered by the registration area .

It is essential that the fundamental idea be used for recording labels on a transport means, for example a conveyor belt, instead of a color recognition sensor that creates only one single fixed point of light, a camera, namely a line scan or line scan camera. Such a camera has a noticeably larger registration area

- 1 047366 stration than a color recognition sensor and therefore allows, in particular, to register the label along its entire width (extent transverse to the direction of transport). In particular, the label can be recorded using a camera, both horizontal and horizontal-frame scanning, also along its entire length (extent in the direction of transportation). For a line scan camera, the recording area is defined as a line, that is, one-dimensionally, and has a correspondingly defined width. For a line-scan camera, the recording area is defined as a surface, that is, two-dimensionally, and has a correspondingly defined length and width.

In addition, a line-scan or line-scan camera is significantly more accurate than a color recognition sensor. Unlike a color sensor, which only generates information about the mere presence or absence of a label on a vehicle, a line scan or line scan camera can capture the entire outline of the label and, in addition, also provide position and/or orientation information each label on the vehicle. With such a camera, each type of label can also be identified, which in turn allows the use of a greater variety of labels, since the camera has a relatively high contrast and can still recognize labels on a transport vehicle even when the label has no or only a small color difference from the surface of the transport vehicle. In principle, it is even possible to register transparent labels and/or label thicknesses. Pre-printing on the label can also be accurately recognized. With the help of the information generated by the camera, printing on each label in the subsequent printing process can be carried out particularly accurately, that is, the printing can be optimally placed on the label, for example also precisely to the edges or corners of the label or pre-printed on it. Reliable identification of labels is also possible, that is, each label recorded by the camera can be compared with a specific or stored setting (expected label). Regardless of this, a camera with horizontal or horizontal-frame scanning is more economical to purchase than a color recognition sensor, and is also easier to install, simply because the camera is less sensitive to vibrations.

A horizontal scanning camera also has the particular advantage that, due to the horizontal and therefore relatively narrow registration area, it can also register labels through a narrow gap between two sections of the transport vehicle, in particular from below, which results in more possibilities for positioning the camera.

In accordance with the embodiment according to claim 1 of the claims, the camera with horizontal or horizontal-frame scanning is located vertically above the transport means, that is, in the direction of gravity above the transport means. In this case, in particular, the upper side of the transport means, on which the labels are placed, faces the camera. But in principle, other types of alignment or positioning of the camera relative to the transport vehicle and relative to the label being transported by it are also possible, as long as it is ensured that the label can be recorded as described. Thus, a line scan or line scan camera can also be positioned vertically below the transport vehicle. In this case, the camera is in particular directed towards or into the gap between two adjacent sections of the transport means in the transport direction, the labels crossing this gap during transport. Each section of the transport means is, for example, an integral part of a conveyor belt or a transport roller, that is, the gap is then located between two conveyor belts or between two sections of the same conveyor belt or between two transport rollers or between a transport roller and a conveyor belt.

The horizontal or horizontal scanning camera according to the embodiment according to claim 3 is, in particular, a monochrome or color camera. In this case, it is particularly preferably a Plug and Play camera, preferably a USB camera (USB: Universal Serial Bus). A recording device or camera, which can be connected to the device according to the invention via Plug and Play, that is, by simply being inserted into the appropriate interface, in particular a USB interface, is particularly easy to install. In particular, no separate power supply is required since, for example, the USB interface is suitable for both data transfer and power supply.

In the embodiment according to claim 4, the recording device has at least one lighting means, which, at least in certain areas, in particular completely illuminates the recording area. This allows for particularly precise registration of each label and, if necessary, pre-printing on the label.

Clauses 5-7 of the claims define preferred embodiments and locations of the registration area. This area lies in particular in the transport direction in front of the print head, whereby this registration area can cross the print area in the transport direction or can be adjacent to the print area in the transport direction or can be located at a distance from the print area in the transport direction. Below the print area

- 2 047366 refers to the area of the conveyor belt in which the print head can print. Within this printing area, printing on the label can then be carried out and in particular adapted.

According to an embodiment of claim 8, there is provided a reference point and/or a reference line against which the camera can be calibrated (along which the camera can be aligned) in the transport direction and/or transverse to the transport direction and/or perpendicular to the transport plane. This reference point or this reference line may be formed by the print head, in particular by its housing or by characteristic points or edges thereon, and may lie within or outside the recording area. For electronic calibration, the reference point or reference line preferably lies within the recording area; for mechanical calibration/alignment of the camera, the reference point or reference line can also lie outside the recording area. By reference point we mean the point that defines the zero point, in particular of a Cartesian coordinate system (X-Y coordinate system or X-Y-Z coordinate system). The reference line forms, in particular, the corresponding coordinate axis.

According to one of the preferred embodiments according to claim 9, a control device is provided. In one of the preferred embodiments, this control device, based on the label outline registered by the registration device and/or the preprinted or preprinted outline registered by the registration device, controls the printing process of this label. Additionally or alternatively, the control device can also be used to control slippage, which will be explained further below.

In particular, the printing process can adapt automatically as soon as a label passes through the registration area that has a different width, length, position and/or orientation than a predetermined nominal value of width, length, position and/or orientation, or a different width, length, position and/or orientation than the immediately previous label (claim 10). By position is meant a position relative to the lateral restrictions of the transport means or relative to the longitudinal markings on the transport means, that is, a position in the transverse direction, in which there may then also be a transverse shift between a given nominal position and the actual position of the label (actual position) or a transverse shift between two transported labels one after another. Orientation refers to the alignment of each label or the direction of the edges of the label relative to the direction of transport or, respectively, to the direction of the lateral restraints of the conveyance or the longitudinal markings on the conveyance, by which an angular offset can be found between the given nominal orientation and the actual orientation of the label (actual orientation) or angular shift between two labels transported one after the other. In this case, the printing process can be controlled and/or adapted, in particular, in such a way that printing extends to the outline (outer edges) of the label or to pre-printing.

According to another embodiment according to claim 12 of the claims, the printing device has, in particular, a thermal head having a thermal strip. But in principle, a laser print head or an inkjet print head can also be used.

The transport device may in turn have as a transport means at least one conveyor belt, preferably exactly one conveyor belt, or several conveyor belts, and/or at least one unit having one or more transport and/or pressure rollers (Clause 13 of the claims). Transport rollers refer to rollers on which the label can be transported. Pinch rollers are rollers that press the label during transport against another transport means, such as a conveyor belt or transfer rollers. The transport means can also have transport means sections located immediately next to each other in the transport direction, between which said gap is provided in the transport direction, these transport means sections being part of a conveyor belt or a transport roller assembly.

According to one of the particularly preferred embodiments according to claim 14, several label supply devices are provided, which are each configured to provide and supply labels and are intended for the same transport device, the same recording device and/or the same the same printing device. In the proposed manner, the label supply device used or the label supply devices used preferably have or preferably have an unwinder, a peeling head and a winder. The unwinder is used to accommodate a roll having a label strip, the label strip preferably being a backing strip having removably applied labels thereon. But in principle, a label strip can also be a strip of material from which labels are formed by cutting the strip

- 3 047366 material along the length. In the preferred case of a backing tape having removably applied labels thereon, the labels are released at the peeling head by strongly deflecting the backing tape, and the unlabeled backing tape is then wound onto a rewinder. If several such label feeders are provided, firstly, different types of labels can be supplied, and secondly, also one of the label feeders can support the supply of labels when the label stock of the previously active label feeder is exhausted. It is precisely in the case where labels are supplied via different label supply devices to the same print head that it is preferable to register the labels particularly accurately.

According to another theory according to claim 15, which is given independent meaning, the subject of the application is a method of printing on labels, in particular on labels provided on a backing tape, these labels being provided by at least one label supply device and fed to a transport device that transports the labels in a transport direction past the recording device to the printing device in which the labels are printed. An essential feature of this method, which can be carried out using a device as defined above, is that the labels in the recording area of the recording device are optically recorded by a line scan or line scan camera of the recording device. The same benefits are obtained as described above in connection with the device.

The invention is further explained in more detail with the help of the drawing, which shows only exemplary embodiments. The drawing shows:

fig. 1: schematic view of the proposed label printing device;

fig. 2: fragment ii of fig. 1

a) in an enlarged image and

b) in plan view.

In fig. 1 shows by way of example and purely schematically a device according to the invention for printing labels 1, in particular adhesive labels 1, which are provided here detachably on a backing tape 2. The device has several separate label supply devices 3, by means of which individual labels 1 are provided. and are fed to the transport device 4.

Each of the label supply devices 3 is built here on the same principle. Thus, the label supply devices 3 have an unwinder 3a, a stripper head 3b and a rewinder 3c. The unwinder 3 a serves to accommodate the roll 5, which here includes a backing tape 2 intended for unwinding, having labels 1 applied to it with the possibility of detachment. The backing tape 2, complete with labels, is directed from the unwinder 3a to the removal head 3b, on which the tape -the substrate is strongly deflected, here, for example, by more than 90°, as a result of which the labels 1 are each automatically detached from the substrate tape 2. Finally, the substrate tape 2, freed from labels, is then wound up again by the reeler 3c.

The individual components of the label supply device 3, in particular the unwinder 3 a, the removal head 3b and the rewinder 3c, are arranged here in a cassette 6, which can be removed from the device as a whole or replaced.

As shown in FIG. 1, the label supply device 3 and/or the unwinder 3a, the peeling head 3b and the rewinder 3 with a control wire assigned to them are connected to a device control device 8, which will be explained in more detail below. In addition, each individual label supply device 3 can be activated or deactivated if necessary. By activated it is meant that the label supply device 3 is positioned and/or configured so that individual labels 1 can be fed to the transport device 4. It is possible that the remaining label supply devices 3 are deactivated, that is, do not themselves supply labels 1. But it is also possible for other label feeders to also be activated and feed labels 1 at the same time.

The transport device 4 includes at least one transport means 9, 10, with which the labels 1 supplied by each label supply device 3 are transported in the transport direction. The transport means here is a conveyor belt 9, which interacts with another transport means in the form of a unit of several pressure rollers 10. The conveyor belt 9 has a drive, which is also connected to a control device 8. The pressure roller assembly 10 serves to press the labels 1 during transport against the surface of the conveyor belt 9 so that they remain as optimally positioned and aligned on the conveyor belt 9 as possible. The conveyor belt 9 here has two conveyor sections 17, 18, one of which is curved and one is straight. There is a gap 19 between them, through which each label 1 moves from the curved to the straight section of the transport vehicle.

The transport device 4 transports the individual labels 1, in particular continuously, in the transport direction to a printing device 11 having a print head 11a, which

- 4 047366 is configured for printing on labels 1 transported by the transport device 4. The printing device 11 is also connected by its own control wire 7 to the control device 8. The print head 11a is, in the embodiment described here, a thermal head having a thermal strip. With its help, a heat-sensitive medium can change color due to the targeted effect of heat, in particular, turn black. The corresponding printing method, so-called thermal printing, can be direct thermal printing, thermal transfer printing or thermal sublimation printing. But in principle, other printing methods are also included in the proposed solution, for example, a laser printing method or an inkjet printing method. Accordingly, a laser print head or an inkjet print head can also be provided as the print head.

Thus, individual labels can be supplied to said printing device 11 by each of the label supply devices 3 via the transport device 4, and these labels 1 are guided past the recording device 12 before reaching the printing device 11 to register the position and orientation of each label 1 in the area of the transport device 4 That is, the label supply devices 3, which can be activated independently of each other and here also can provide different labels, in the embodiment described here are intended for the same transport device 4, the same printing device 11 and the same. same recording device 12.

It is essential that the recording device 12 has a camera 13 with horizontal or line-frame scanning, with the help of which the side 1 facing the transported labels, here the upper side, of the conveyor belt 9 can be optically recorded in the registration area 14. Accordingly, when the label 1 passes through the registration area 14, the label 1 is also registered. This is shown in detail in Fig. 2a and b.

The recording device 12 is also connected to the control device 8 by its own control wire 7. Thus, data generated by the recording device 12 regarding the width, length, position and/or orientation of each label 1 passing through the registration area 14 is processed by the control device 8, which uses this data to adjust the print head 11a so that printing can optimally and with high precision placed on each label 1. Thus, with the help of a line scan or line scan camera 13, the geometry of even complex labels 1 can be recognized and the assigned printing process can be adapted accordingly. Since the registration area 14 can be chosen to be at least such a width that the label 1 can be completely registered in the transverse direction (transverse to the transport direction) and preferably can also be completely registered in the longitudinal direction or in the transport direction, it can, in particular, the position or lateral shift of the label and/or the orientation or angular shift of the label 1 is also detected and the printing process assigned to each label 1 is controlled or adapted accordingly. Another advantage of the relatively large recording area 14 is that the recording device 12 or the corresponding chamber 13 can be aligned particularly easily with respect to each transport means, here the conveyor belt 9. This is incomparably more difficult in the prior art, which uses a color recognition sensor.

Since the label 1 can be recorded in its entirety, which is also possible with a line scan camera 13 where the individual recorded lines are combined into a two-dimensional image, printing on each label 1 can, if necessary, even extend to its edges, that is, its outer contour, and in particular also to its corners. Also in the case where the label 11 supplied to the registration area 14 and further passing through the printing device 11 already has a pre-print, by registering this pre-print or the pre-print outline, the seal can also be positioned particularly precisely relative to the pre-print.

Using the device according to the invention and, in particular, the provided recording device 12, the printing process can also be adapted from one label to each subsequent one. In other words, it is possible to adapt the printing process in the time period from registering the outline of the label 1 to the start of the printing process assigned to the label 1. If then an immediately subsequent label 1, having a different position or orientation, reaches the registration area 14, the printing process assigned to this label 1 can be adapted directly to this next label 1. It can also be automatically checked even before printing whether the into the appropriate cassette 6 the correct label format for a given product ID.

Thanks to the connection of the control device 8 with the drive of the conveyor belt 9, on the one hand, and with the recording device 12, on the other hand, slippage control can also be implemented, in particular in such a way that the recording device 12 registers the markings provided on each conveyor means 9, according to which control device 8

- 5 047366 can find the actual speed of the conveyor 9, which it can then compare with the recorded actual speed of the drive of the conveyor belt 9. Then the difference between the found actual speed of the conveyor 9 and the recorded actual speed of the drive of the conveyor 9 indicates slippage and may, in particular, be displayed to the operator and/or adjusted automatically.

Next, using Fig. 2a and b describe other details of the recording device 12 of the proposed label printing device 1.

Thus, the horizontal or horizontal scan camera 13 of this embodiment is a color camera. But in principle, it is also possible to use a monochrome camera. The entire recording device 12 and at the same time also the camera 13 is here connected to the rest of the device and, in particular, to the control device 8 via a Plug and Play interface, in particular a USB interface, that is, an interface that allows both data transmission and power supply to the camera 13. Through it, it is also possible to supply power to individual lighting means 15 of the recording device 12, which, at least in certain areas, in particular completely illuminate the recording area 14. In the case shown here, the combination of the camera 13 and the lighting means 15 is connected to the device or control device 8 in the described manner via a Plug and Play interface or a USB interface.

As clearly illustrated by FIG. 2a, the recording device 12 or, respectively, the camera 13 with horizontal or line-frame scanning is located vertically above the transport means 9, at least vertically above the recording area 14. In this case, the recording device 12, in particular the camera 13 with horizontal or line-frame scan and/or lighting means 15, is aligned perpendicular to the surface of the transport vehicle 9 in the recording area 14. But in principle, it is also possible to align the recording device 12 or, respectively, the camera 13 and/or the lighting means 15 obliquely to the surface. Also, the recording device 12, in particular the line scan camera 13, could be located below the transport means 9 and/or be directed towards or into the gap 19 between two sections 17, 18 of the transport means, in order to then register the labels, in particular from below, when they cross the gap 19. It must only be ensured that the registration area 14 is aligned with respect to the transport means or the conveyor belt 9 so that the supplied label 1 can at least mostly, in particular completely, be registered transverse to the transport direction and preferably also in the direction of transport. Preferably, as clearly illustrated by FIG. 2b, the registration area 14 is even designed in such a way that the label 1 can be located completely in the registration area 14, that is, also along its entire length.

For this purpose, the registration area 14 has, in the embodiment described here, a length (extent in the transport direction) of at least 100 mm, preferably at least 150 mm, particularly preferably at least 200 mm, and has in particular a length that corresponds to at least one label length. Furthermore, the recording area here has a width (extent transverse to the transport direction) of at least 50 mm, preferably at least 100 mm, particularly preferably at least 150 mm, and in particular has a width that corresponds to at least one width labels. In shown in FIG. 2b example, the registration area 14 extends even to the side, that is, in the transverse direction, behind the transport means or the conveyor belt 9. In principle, the registration area 14 covers at least one of the side edges 9a, 9b, preferably both side edges 9a , 9b, the transport means or, respectively, the conveyor belt 9. By lateral edges in accordance with the invention are meant the edges that limit the transport means 9, 10 in the transverse direction.

The registration area 14, which is located in the transport direction in front of the print head 11a, is here at a distance from the printing area 16, in which printing can in principle take place and which is here defined by a thermal strip, in the transport direction. Preferably this distance is less than one length of the label, in particular this distance is a maximum of 100 mm, preferably a maximum of 50 mm, particularly preferably a maximum of 20 mm. But in principle, it is also possible for the registration area 14 to be adjacent to the printing area 16 in the transport direction or even to intersect the printing area 16 in the transport direction.

As also schematically shown in FIG. 2b, the line or line-frame camera 13 is calibrated or can be calibrated in the transport direction and/or transverse to the transport direction and/or perpendicular to the transport plane or, respectively, the surface of the transport vehicle relative to the reference point P and/or the reference line L. Here, the reference point P is a point or, respectively, a reference line L line on the print head 11a, wherein the reference point P and the reference line L are each located outside the registration area 14 here.

Finally, the present invention also concerns a method for printing on labels 1, in particular on labels 1 provided on a backing tape 2, which method can advantageously be carried out

-

Claims (9)

work with the previously described device. In the method according to the invention, the labels 1 are each provided by at least one label supply device 3 and are supplied to the transport device 4. The labels 1 are then transported by the transport device 4, as described in detail previously, past the recording device 12 to the printing device 11, in which printing is carried out on each of the labels 1. In particular, the printed labels 1 are then each applied to a product. According to the proposal, it is provided that the labels 1 are optically recorded in the registration area 14 by a camera 13 with a line scan or line-frame scan of the recording device 12. CLAIM 1. A device for printing on labels (1), having at least one device (3) for supplying labels for providing either self-adhesive labels (1) located on the backing tape (2), which are detachable from the backing tape (2) , or linerless labels (1), which are provided in the form of an endless strip and are separated by cutting, and the labels detached from the backing tape (2) or separated by cutting (1) are fed to the transport device (4), the transport device (4), including at least one transport means (9, 10) for transporting labels (1) supplied by the label supply device (3) in the direction of transport to the printing device (11), the printing device (11), including includes a print head (11a) for printing on labels (1) transported by the transport device (4) and a recording device (12) for registering the position of each label (1) on the section of the transport device (4), characterized in that the recording device (12) has a camera (13) with line or line-frame scanning, with the help of which the side of the transport means (9, 10) facing the labels (1) in the prescribed application and/or is made in the transport direction in front of the printing device (11) and between two sections (17, 18), of at least one transport means (9, 10), the gap (19) is optically registered in the registration area (14), and the label (1) in the transverse direction to the direction of transportation is completely registered by the recording device (12). 2. The device according to claim 1, characterized in that the camera (13) with line or line-frame scanning is located vertically above the transport vehicle (9, 10). 3. A device according to claim 1 or 2, characterized in that the camera (13) with horizontal or line-frame scan is a monochrome or color camera, and/or that the camera (13) with line or line-frame scan and/or a recording device ( 12) connects to the rest of the device via a Plug and Play interface, preferably a USB interface. 4. A device according to one of the previous paragraphs, characterized in that the recording device (12) has at least one lighting means (15), which, at least in certain areas, in particular completely illuminates the recording area (14). 5. Device according to one of the previous paragraphs, characterized in that the registration area (14) is located in the transport direction in front of the print head (11a), preferably, the registration area (14) intersects the print area in the transport direction or is adjacent to the print area (16 ) in the transport direction, or in the transport direction is located from the printing area (16) at a distance of in particular a maximum of 100 mm, preferably a maximum of 50 mm, particularly preferably a maximum of 20 mm. 6. Device according to one of the previous paragraphs, characterized in that the registration area (14) has a length of at least 100 mm, preferably at least 150 mm, particularly preferably at least 200 mm, and that the area The registration (14) has a width of at least 50 mm, preferably at least 100 mm, particularly preferably at least 150 mm. 7. Device according to one of the previous paragraphs, characterized in that the registration area (14) also registers one of the side edges (9a, 9b) or both side edges (9a, 9b) of the specified vehicle/s (9, 10) . 8. A device according to one of the previous paragraphs, characterized in that the camera (13) with line or line-frame scanning in the direction of transportation and/or transverse to the direction of transportation, and/or perpendicular to the transportation plane is calibrated or can be calibrated relative to a reference point (P ) or a reference line (L), it is preferable that this reference point (P) or this reference line (L) is a point or a line on the print head (11a) and/or lies inside or outside the registration area (14). 9. A device according to one of the previous paragraphs, characterized in that a control device (8) is provided, preferably this control device (8) is based on a registered register -