DE102016125709A1 - Device for inspecting labels equipped with labels - Google Patents

Abstract

The invention relates to a device for checking labels affixed to bodies and in particular to containers, having a transport device which transports the containers along a predetermined transport path, with a gas-applying device which is suitable and intended for at least a portion of the label and label arranged on the container in particular, to pressurize an end section with a gas stream and with an image recording device which is suitable and intended to observe at least the section acted upon by the gas stream.

Description

The present invention relates to an apparatus and method for inspecting labeled containers. Such methods and devices have been known for a long time from the prior art. There are many criteria to consider when applying labels. It is thus important to ensure that the label is arranged in each case in a specific orientation, for example, a straight alignment on the container. Care must also be taken that the label is placed on the container free of distortion. In addition, it can also cause interference, for example, if an edge portion of the label is not sufficiently provided with adhesive. This edge portion can then relatively quickly detach from the container.

From the internal state of the art of the application so-called flag recognition are known to control the bonding to wrap-around labels but also on non-rotating labels. These usually have a light barrier and a reflector and an injection nozzle. The containers lie on a driven by a servo motor plate. Likewise, a belt drive of this plate is provided as well as a Verstellschlitten to always be able to position the detection at the same angular position of the containers and at different container diameters along the transport path.

A tangentially arranged light barrier checks to see if the wrap-around label is projecting while the containers are being rotated in a labeller carousel. This serves as a check on whether the final gluing on the unit is working correctly. At a region of overlap between the label beginning and the label end, for example, a flat jet nozzle is arranged, which detects the wrap-around label in the event of an error, i. in the case of insufficient or missing gluing, causes it to stick or flutter. The light barrier is interrupted in the event of a fault.

Since, for different container diameters, the overlapping position on the container table is to be adapted to the type of product, the sensors are mounted on a segmented carriage which can be aligned to the respective position on the container table depending on the type of product. In addition, a depth adjustment for a precise flag detection and a height adjustment for the individual sensors is still necessary in order to adapt to different adhesive heights can. The 1a and 1b illustrate this approach.

A disadvantage of this approach is that the light barrier must always be located very close to the container wall or must rest. When changing the container, a corresponding mechanical adjustment must be made.

In addition, the permanent rotation of the container by turning away the label end makes it difficult to interrupt the light barrier in the event of a fault. Furthermore, it is disadvantageous in this embodiment that the sensor unit must always be adapted to the respective label height position during a grade change. Furthermore, the arrangement of the sensor of the light barrier and the reflector must be arranged on the outside of a labeling carousel, ie along the tangent to the trajectory.

Finally, the detection reliability is also disadvantageous. For example, if the label has an overlap of about 10 mm and the container has a cross-section of, for example, 54 mm, then the label is 190 mm long. If it now encloses the container to 270 ° and - as in the 1 b shown protrude shown, then lie 135.2 mm to the container and the rest of 58.8 mm stands as a flag. After deducting a container radius of 28.7 mm, in this case 26.1 mm remain beyond the outer tangent of the trajectory. In this case, the sensor must be about 10mm from the outer tangent to keep the error rate low. A sensor light spot of, for example, 7 mm diameter must be securely interrupted, so that in the example a reserve of about 9 mm remains.

A control of the label is not possible on the belt, because the container is transported in any rotational position, so no longer aligned. The machine outlet and / or transitions of conveyor belts and / or the friction between container and container or railing a similar rotational position of the container is prevented on the belt.

The present invention is therefore based on the object to make such a sensor detection more efficient and less error prone. In addition, preferably the effort in a changeover to different containers should be facilitated. These objects are achieved by the subject matters of the independent claims. Advantageous embodiments and further developments are the subject of the dependent claims.

A device according to the invention for checking labels affixed to bodies and in particular to containers has a transport device which transports the containers along a predetermined transport path. Furthermore, the device has a Gas impingement device which is suitable and intended to act on at least a portion of the label disposed on the container and in particular an end portion with a gas stream. Furthermore, the device has an image recording device, which is suitable and intended to observe at least the portion acted upon by the gas flow. Preferably, the image recording device is suitable and determined to record an image and preferably also a plurality of images of this section.

As will be described in more detail below, it is also possible to use a gas supply to generate a suction. If the gas supply is used to generate a suction, the location of the application in the transport direction is not critical in order to achieve the effect that the not properly glued edge of the label lifts or flutters.

If the gas supply is used to generate a suction, and accordingly location of the application is not critical, it can be established that, unlike in the prior art, recognition can also be established after labeling and after the machine at any location on the belt. Conveniently, in particular in this case, the gas admission and the image recording device are designed so that the detection covers 360 ° of the container circumferentially.

It is therefore proposed in comparison with the prior art that not only a light barrier unit is provided, which has, for example, a mere intensity detection, but that an image and in particular a spatially resolved image is taken. By taking an image, a desired inspection result can also be achieved if there is an inaccurate orientation on the container. Namely, while in the prior art, the light barrier must always abut the container, can be achieved in particular by the inclusion of two-dimensional or three-dimensional images that the detection limit is improved. The image recording device preferably has a two-dimensional image generator or else a three-dimensional image generator (preferably with an additional two-dimensional image-forming property).

Preferably, the image recording device is also suitable for determining distances. Thus, the image recording device preferably has a transit time measuring device for light emitted by a lighting device. It is possible to illuminate the container by means of a light pulse, and the image pickup device measures - preferably for each pixel - the time that the light takes to the object and back again.

The time required is directly proportional to the distance. The camera thus provides for each pixel the distance of the object imaged thereon. In contrast to the so-called laser scanning, there is the advantage that an entire scene, or here the container can be recorded at once and does not have to be scanned.

The image recording device preferably allows a refresh rate of at least 40 frames / second, preferably of at least 60 frames per second, preferably of at least 80 frames / second.

The image recording device is therefore preferably a so-called TOF camera (time of flight). In addition, image recording devices such as stereo cameras, light field cameras or triangulation methods can also be used. It is preferably an image recording device which is both suitable for outputting a depth information image and an intensity image. It would also be possible for the imaging to be divided into several units.

The image recording device is preferably the same image recording device, which also performs an overlap check of the labels attached to the container. Thus, the control position of the flag recognition is preferably carried out with the same camera, which is also performed for the overlap control. This may seem illogical in the first approach, since usually the frontal view is the worst way to detect a protruding label part. On the other hand, however, this approach offers the advantages explained in more detail below.

In a further advantageous embodiment, the loading device is oriented such that a label can lift off from the container by the application of the gas stream.

In a further advantageous embodiment, the device has a holding device for holding the containers. In this case, for example clamping means may be provided, which clamp certain areas of the containers. In a further preferred embodiment, the device has a holding device, which allows a rotation of the individual containers about their longitudinal axis. Thus, for example, a rotatable support for the containers, in particular but not exclusively a turntable be provided.

Furthermore, the transport device is advantageously a transport wheel on which the holding devices for the containers are arranged. Thus, the containers are preferably transported along a circular transport path. Thus, the transport device particularly preferably has a rotatable carrier.

Preferably, the bodies are bottles and in particular plastic bottles or glass bottles. Furthermore, the labels are preferably so-called peripheral labels which at least partially circulate the respective containers. Advantageously, the label is arranged on the container such that a beginning and an end region of this label overlap.

In a further advantageous embodiment, the device has a lighting device which is suitable and intended to illuminate at least a portion of the label arranged on the container and / or the label. Advantageously, the image pickup device records an image of the thus illuminated label. In a further preferred embodiment, the illumination device is suitable and intended for the output of light pulses. This means that the containers are not illuminated with continuous light but with pulses of light. Preferably, the image capture device is synchronized to the image capture device, i. the image pickup device is activated in each case when the illumination device emits light pulses. As mentioned above, a transit time determination device is also provided which determines a transit time of the light pulses emitted by the illumination device onto the containers.

Particularly preferably, a viewing direction under which the image recording device observes the label and a lighting device under which the label is illuminated differ from each other. It is thus possible, for example, that illumination takes place from the side, for example at an angle. This is similar to, for example, in a label control. For example, lights can be used on the left and right.

Advantageously, the image recording device and the illumination device are arranged such that a shadow cast of a label protruding from the container and illuminated by the illumination device can be detected by the image recording device. Thus, for example, it is possible that only one side lighting is used or, for example, a second is reduced in its thickness. In this way, by the lighting a shadow on the underlying label start and / or the container arise. The steeper the lighting, the greater the shadow cast. This shadow can be detected by the image pickup device. Specifically, it is possible that the image is searched with appropriate processing software specifically for Schattenwürfen. Thus, for example, intensity minima can be detected, which indicate such a shadow. In addition, it would also be possible to activate two or more lighting devices in a row, which should result in different Schattenwürfe. In this way, a shadow can also be identified (and, if necessary, be distinguished from optical artifacts) and thus a protruding label.

So it would be possible that two lighting devices are arranged at different positions. If these are activated one after the other, a shadow will also be in different places in the recorded image.

It is possible that more than one picture is taken. This can be done with different lighting directions and or illumination colors. The recordings can be made in a chronological or local sequence, and recorded by one or more image recording units.

As a loading device, for example, a blowing nozzle may be provided. In addition, however, it would also be possible for several tuyeres to be arranged at a height, with the nozzles which are suitable for the label height position being switched on during a grade change. This embodiment is particularly suitable for turntable controls.

In a further advantageous embodiment, the Gasbeaufschlagungseinrichtung, which is in particular a Luftbeaufschlagungseinrichtung, at least one nozzle device, which directs air directed at the end portion of the container arranged on the label. By this Luftbeaufschlagung causes a possibly already slightly protruding label is further removed from the container, so that this protrusion can be detected. In a preferred embodiment, the Gasbeaufschlagungseinrichtung is arranged such that the end portion of the label protrudes in or against the transport direction. In this way, a distance of the label from the container can be detected in a particularly favorable manner from the viewing direction of the camera. The recordings of Überlappunskontrolle and the flag control of the same container can be made at the same or different position. The control can take place in the same recording or in time, one after the other, virtually at virtually the same or the same transport location.

The image recording could capture a plurality of containers of the transport path, which are preferably preferably recorded in a different rotational position of the containers relative to the camera (essentially) simultaneously. Furthermore, it would be possible that an overlap is checked on one container and on the other container, a protrusion of the label. In this case, it would be possible for a plurality of loading devices or blowing nozzles to be provided for examining different phenomena, which can preferably also be switched over depending on the type of container. Furthermore, it is preferably possible for at least one nozzle device or an admission device to be adjustable with respect to their position. For example, it would be possible for the loading devices or nozzle devices to be adjustable in the vertical direction. In addition, a loading angle can be changed. It would also be possible for the image recording devices to be switchable between at least two operating modes, for example a mode for 2D recordings and a mode for 3D recordings.

In addition, it would also be possible for the nozzle itself to be modified in order, for example, to be able to form a gas or air jet wider or narrower. In addition, an application intensity and / or an amount of gas with which the labels are applied can preferably be set.

In a further advantageous embodiment, the gas-charging device is designed such that the label is drawn off from the container by a suction of the gas. In other words, there is a pull that makes a loose label stand out. Such a suction preferably results from aerodynamic effects, for example the so-called Bernoulli effect. In a preferred embodiment, the gas stream impinging on the label has a component which extends from a central region of the label towards the end of the label.

It should be noted that this embodiment, which makes use of the Bernoulli effect, can also be used independently of the embodiment described above.

The Applicant therefore reserves the right to claim protection for a device for checking labels affixed to bodies and in particular to containers, which has a transport device which transports the containers along a predetermined transport path and a gas impinging device which is suitable and intended for this purpose , to act upon at least a portion of the label arranged on the container and in particular an end portion with a gas stream, wherein in this embodiment according to the invention this Beaufschlagungseinrichtung is arranged such that a container is attracted or sucked by the gas stream. As a result of this embodiment, the application device can be positioned in a more favorable manner and even less hampers image acquisition.

In a further advantageous embodiment, the gas loading device acts on the label at an angle which, with a radial direction of the container, makes an angle of more than 20 °, preferably of more than 30 °, preferably of more than 40 °, preferably of more than 50 °, more preferably more than 60 ° and more preferably more than 70 °. Preferably, the gas loading device acts on the label at an angle which with the radial direction of the container at an angle of less than 90 °, preferably less than 80 °, preferably less than 70 ° and more preferably less than 60 °. In a further preferred method, the gas loading device acts on the label in a substantially tangential direction, wherein a substantially tangential direction is understood to mean a direction which is less than 20 °, preferably less than 20 °, and particularly preferred from the exactly tangential direction deviates by less than 10 °.

Furthermore, it is also possible, as in particular in the 4a - 4c show that the gas-applying device is arranged laterally next to the container,

It is possible that under the suction effect of Gasbeaufschlagungseinrichtung the suction also tugs on the label when the edge of the label does not look "forward". In this way can be deducted over time such a loose label. The extent to which this occurs, however, also depends on factors such as a wrap angle, adhesion and the like.

It should be noted that this suction effect can also be used in other types of transport of the containers, such as a belt transport. In addition, by the action of the suction, areas of the label can be lifted off, which are not at the beginning or end sections.

In a further advantageous embodiment, the image recording device has a focusing device and in particular an automatic focusing device. This embodiment is particularly interesting for two-dimensional recording, for example, to compensate for differences that differ on different Container dimensions are based. In addition, it would also be conceivable that a position of the Bilfaufnahmeinrichtung relative to the transport device and / or relative to the containers is variable and / or adjustable.

In a further preferred embodiment, the image recording device is synchronized to the transport device. This means that the images of the containers can be made at exactly determinable positions of the containers with respect to their transport path.

The present invention is further directed to a method for checking labels affixed to bodies and in particular to containers, the containers being transported along a predetermined transport path and by means of a gas applicator at least a portion of the label attached to the container and in particular an end portion having a gas flow is charged. In this case, this gas stream lifts this section from the container and it is further provided a sensor device, preferably an image pickup device, by means of which at least the acted upon with the gas flow portion and / or a shadow of this section is observed.

Therefore, it is also suggested on the method side that lifting of the label is detected by means of an image recording device. In a further method according to the invention, the lifting of the label takes place in that gas emanating from the gas-applying device generates a suction effect on the label and draws it from the container. Thus, in a preferred method, a portion of the label is lifted by a suction effect of the gas stream emanating from the gas applicator. It should be noted that the use of a suction effect mentioned here can also be used independently of the above-mentioned invention.

In the case of the suction effect generated by the gas-applying device, it is not absolutely necessary for the gas to act directly in the region of the end of the label. As can be seen in the drawings, the suction acts on any label locations and can thereby lift the label from the container, or withdraw in the course and leave to flutter (final).

To generate the gas admission, it is advantageous to position the admission at a distance in front of the vertex of the container. The distance should be> 100 mm, better more than 200 mm and preferably about 300 - 500 mm or even more.

If the principle of the suction effect is used, the gas supply does not have to be directly related to the lighting, end of the label and / or image acquisition.

In a further advantageous embodiment, it would also be possible that instead of one or more nozzles a line-shaped air jet is provided, i. an air jet extending along a line which is parallel, for example, with a longitudinal direction of the respective label. Thus, a so-called air knife (air knife) is used here.

In a further advantageous embodiment, the image recording device has a focus control. In this case, for example, an automatic or motor focus control can be provided. By this procedure, an adaptation to different container diameter can be done.

In addition, however, it would also be possible for an image recording device to be provided which uses or makes available three-dimensional information. In this case, it may be possible to dispense with an adjustment of the focus. Preferably, an image recording device is used, which also allows a pixel-by-pixel transit time measurement of light pulses.

It should also be noted that it does not matter how the labels are wound on the container. Also, the transport directions may be different than shown in the following figures.

By the present invention can be dispensed with a positioning of a sensor close to the container wall. In addition, the sensor positions no longer have to be changed with a change in diameter of the container to be determined with. In addition, it is no longer necessary that the sensor device is adapted to a label height position.

Furthermore, there is no longer the problem of a low detection reserve.

Another advantage is that the total overlap height can be controlled and not - as in the prior art - only a relatively small area, which was monitored by the local light barrier.

Furthermore, it is possible with the invention to detect smaller errors than before. In the prior art, the label must protrude at least 17 mm. With the proposed invention, a much smaller distance can already be detected. This depends only on the manufacturing tolerances and the labeling tolerances.

In a further advantageous embodiment, the device has a plurality of sensor devices or image recording devices. These can, for example, observe different areas of the labels.

The suggestion that the label lifts off and the connected property that the edge of the label does not have to be at a certain point to the suction surface also makes it possible, in principle, to build recognition on the tape where the orientation of the container is not defined. Again, the protrusion of the label end can be detected via one or more (image) recording units.

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

• 1a, 1b zwei Darstellungen zur Veranschaulichung einer Vorrichtung nach dem Stand der Technik;
• 2 eine Darstellung einer ersten Ausführungsform einer erfindungsgemäßen Vorrichtung;
• 3 eine weitere Darstellung zur Veranschaulichung einer erfindungsgemäßen Vorrichtung;
• 4a - 4c drei Darstellungen zur Veranschaulichung einer Sogwirkung; und
• 5 eine weitere Darstellung einer erfindungsgemäßen Vorrichtung.

Show:

• 1a . 1b two illustrations for illustrating a device according to the prior art;
• 2 a representation of a first embodiment of a device according to the invention;
• 3 a further illustration for illustrating a device according to the invention;
• 4a - 4c three illustrations to illustrate a suction effect; and
• 5 a further illustration of a device according to the invention.

The 1a and 1b illustrate a device according to the prior art. This is a container 10 shown, on which a container completely surrounding label is arranged. An end section 20a stands out of the container. Reference numeral 104 denotes an air impingement device, such as an air nozzle, which blows on this area and thus the protruding end portion 20a captured and - as in 1b shown - further away from the container. The reference number 108 indicates a photoelectric unit with a reflection element 110 , As in 1b shown, the end section protrudes 20a through this light barrier element and thus interrupts the light barrier. In this way, such a projection of the label can be detected. However, the light barrier must be located very close to the container to allow a corresponding detection. Also, as mentioned above, the position of the light barrier unit 108 . 110 be adapted to different container sizes.

2 shows a schematic representation of a device according to the invention 1 , This has a rotatable support here 2 on (but is shown only to a small extent), on which a plurality of holding elements (not shown) for holding the individual containers 10 is arranged. These containers in turn have a circulating label 20 on.

If through the Gasbeaufschlagungseinrichtung 4 again an end section 20a is acted upon by the label, this is pushed away from the container or stands further from this. The reference number 8th denotes an image pickup device, which at least also the end portion 20a of the label 20 observed. In this case, the reference numeral B the image pickup area of the image pickup device 8th , Due to this comparatively large image recording area, it is not necessary to readjust the image recording device very precisely or more frequently.

The reference number 6 indicates a lighting device, which also the container and in particular the label or the end portion 20a of the label 20 illuminated. In that area O overlap the end portion 20a and a corresponding beginning portion of the label. Furthermore, in this area by the lighting device 6 or their light cone L a shadow S generated. This shadow S can in turn be detected by the image pickup device. If such a shadow is detected, this is an indication that the label protrudes from the container.

In the image pickup device 8th As mentioned above, it can be both a 2D and a 3D camera. The reference number T indicates the transport path of the containers, but this is strictly circular. Furthermore, it is also possible to provide a turning device (not shown) which rotates the container about its longitudinal axis.

At the in 3 shown situation is the end section 20a of the label again relatively far from the container and this protruding can from the image pickup device 8th be recorded. In this embodiment, the image pickup device can recognize that the label end is not at the intended place or is completely absent.

As stated above, the Luftbeaufschlagungseinrichtung 4 be designed as an air strip, which also extends here along the longitudinal direction of the container (ie, here perpendicular to the plane of the figure). In addition, it would also be possible for the illumination device to obliquely illuminate the label section from above.

The 4a - 4c illustrate a sequence of a method according to the invention. These representations differ in particular with regard to the rotational positions of the container. In each case, the admission device 4 provided, which, however, supplies the air substantially tangentially here. This creates ( 4a ) in a central region of the label a suction effect, as illustrated by the arrows.

At the in 4b As shown by the suction effect, a part of the label was lifted. This can be done by the image capture device 8th be recorded. At the in 4c As shown by the suction effect has a portion of the label completely detached from the container. This section now flutters, also caused by the suction effect or by the application device. This detachment can also be detected by the image recording device.

5 shows a situation in which the suction effect of the applying device 4 acts on a projecting end of the label. This is lifted by the suction effect and this in turn can be detected by the image pickup device.

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 can 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

B

Imaging area

L

light cone

O

Area

S

shadow

T

transport path

X

direction of observation

Y

lighting direction

1

contraption

2

rotatable carrier / transport device

4

Gasbeaufschlagungseinrichtung / Luftbeaufschlagungseinrichtung

6

lighting device

8th

Image recording device / sensor device

10

Container / Body

20

(circulating) label

20a

End portion of the label

42

nozzle device

104

Luftbeaufschlagungseinrichtung

108

Photocells unit

110

Reflection element / light barrier unit

Claims (10)

Device (1) for checking labels (20) attached to bodies (10) and in particular to containers (10), having a transport device (2) which transports the containers (10) along a predetermined transport path, with a gas-applying device (4), which is suitable and intended to apply at least a portion (20a) of the container (10) arranged label (20) and in particular an end portion (20a) with a gas stream and with an image pickup device (8) which is suitable and intended to observe at least the portion (20a) charged with the gas flow. Device (1) according to Claim 1 , characterized in that the device (1) has a lighting device (6) which is suitable and intended to illuminate at least a portion of the label (20) arranged on the container (10). Device (1) according to Claim 2 , characterized in that an observation direction (X) under which the image recording device (8) observes the label and a lighting direction (Y), under which the label is illuminated, differ from each other. Device (1) according to at least one of the preceding claims, characterized in that the image recording device (8) and the illumination device (6) are arranged such that from the image recording device (8) a shadow of one projecting from the container and by the illumination device (6 ) illuminated label is detectable. Device (1) according to at least one of the preceding claims, characterized in that the Gasbeaufschlagungseinrichtung (4) at least one nozzle device (42), which air directed directed to the end portion of the container (10) arranged label. Device (1) according to at least one of the preceding claims, characterized in that the Gasbeaufschlagungseinrichtung (4) is arranged such that the end portion of the label protrudes in or against the transport direction. Device (1) according to at least one of the preceding claims, characterized in that the Gasbeaufschlagungseinrichtung (4) is arranged with respect to the label such that this label is lifted by a suction of the gas from the container. Device (1) according to Claim 7 , characterized in that the Gasbeaufschlagungseinrichtung (4) acts on the label at an angle with an angle of more than 20 ° with a radial direction of the container, preferably of more than 30 °, preferably of more than 40 °, preferably of more than 50 °, more preferably more than 60 °, and more preferably more than 70 °. Method for checking labels (20) attached to bodies (10) and in particular to containers (10), the containers being transported along a predetermined transport path and by means of a gas-applying device (4), at least one section (20a) of the container (10) arranged labels (20) and in particular an end portion is acted upon by a gas stream, which gas stream this section (20a) lifts from the container and by means of a sensor device (8), preferably an image pickup device (8) at least the acted upon with the gas stream section and / or a shadow of this section is observed. Method according to Claim 9 , characterized in that at least a portion of the label is lifted by a suction effect of the outgoing from the Gasbeauschlagungseinrichtung gas stream.

Images