Illuminated turntable

Abstract

The invention relates to a turntable (16) for a container-handling device (10), wherein the turntable (16) has an axis of rotation and is at least partly made of transparent material, and wherein the turntable is designed so that light (28) can be coupled into the turntable material at the circumference with at least one component perpendicular to the axis of rotation of the turntable, and that the turntable (16) is also designed so that the light coupled into the turntable material at the circumference is deflected in a direction parallel to the axis of rotation of the turntable. The invention also relates to a container-handling device (10) comprising a turntable (16) of this kind, and to a corresponding method.

Description

[0001] Illuminated turntable

[0002] The present application relates to turntables for container processing systems. The turntables according to the invention enable container inspection during transport on the turntable. The invention also relates to a corresponding method.

[0003] In container processing lines in the food, beverage, and pharmaceutical industries, containers such as bottles, cans, or vials are transported at high speeds through a variety of container handling systems. The containers can be transported freestanding on a variety of conveyors or held in special holders.

[0004] For the inspection of containers, especially for the inspection of the bottom areas of filled, sealed containers, it is often necessary to illuminate the containers from below. In conventional inspection systems, containers are therefore transported via appropriate lighting devices. For example, the containers are clamped between two side elements and held freely suspended to achieve optimal and complete illumination of the container bottom.

[0005] Some container processing systems, such as labeling machines, can be equipped to rotate each container individually according to a programmable setting, allowing the containers to be precisely aligned with each labeling station. For this purpose, the containers are mounted on rotating supports called turntables. The turntables are typically driven by servo motors located underneath and can thus be rotated to the desired orientation. Rotary conveyors, called labeling carousels, are often used in labeling machines. The containers are moved from one processing station to the next on such a labeling carousel.

[0006] Containers transported on turntables in a rotary conveyor system have so far only been able to undergo a limited bottom inspection. Lighting from underneath is usually not an option, as there is often insufficient space for this.

[0007] Fundamentally, container handling systems must be designed as compactly as possible due to limited space. For reasons of compact design, it initially seems intuitive to integrate the lighting into a turntable. However, since turntables are in motion during operation, this solution is technically impractical. Both the power supply and lighting control are difficult to implement in this case and are often prone to errors.

[0008] The object of the present invention is therefore to provide a device in which a container can be simultaneously illuminated from below during transport on a turntable. This should not significantly increase the complexity of the device.

[0009] It would also be desirable if the containers could be inspected for foreign objects during transport on a turntable.

[0010] At least some of the above-mentioned objects can be achieved by a turntable for a container treatment device according to claim 1. The turntable has a rotation axis and is made at least partially of transparent material. The turntable is designed such that light can be coupled circumferentially into the material of the turntable with at least one component perpendicular to the rotation axis of the turntable. The turntable is further designed such that the light coupled circumferentially into the material of the turntable is deflected in a direction parallel to the rotation axis of the turntable.

[0011] By coupling the light used for illumination around the perimeter, container illumination can be achieved relatively easily while maintaining a compact design. The additional optical devices required for coupling the light and detecting the radiation coming from the container can be located around the perimeter of the turntable, i.e., in an area where comparatively more space is available.

[0012] The basic idea of ​​the present invention is to use the turntables on which the containers stand in a container handling device as lighting units. This allows the very precisely controllable turntables to be used even more universally and, in particular, to illuminate the containers during inspection. These turntables are particularly well-suited for use in labeling devices. The containers are guided on a rotating labeling carousel past one or more fixed lighting modules and camera positions. The lighting modules can be flash modules, for example. The flash modules and turntables can be designed so that the container base of the respective container is illuminated from below at the moment the camera takes the respective image.

[0013] The turntables can, in principle, have any suitable geometric shape. However, the turntables are preferably rotationally symmetrical. Particularly preferably, the turntables have a cylindrical shape with a circular cross-section. A rotationally symmetrical structure ensures homogeneous illumination of the turntables rotating during operation.

[0014] Since the turntables function as light guides, they are preferably made of transparent or semi-transparent material. In particular, the turntables can be made of Plexiglas. Plexiglas has the advantage of being comparatively inexpensive and very easy to process. Depending on the application or the requirements of the containers to be transported, other materials known to those skilled in the art can also be used.

[0015] In order to deflect the light coupled into the turntable at the circumference parallel to the rotation axis of the turntable, both material and structural measures can be taken.

[0016] One possible way to deflect the coupled light is to coat the transparent material of the turntable with reflector particles. The reflector particles ensure that the coupled light is scattered in all spatial directions. This also deflects a portion of the coupled light toward the container on the turntable. This design is particularly easy to implement. However, it results in increased light output losses due to the scattering in all spatial directions.

[0017] Alternatively, or in addition to modifying the material of the turntable, structural measures can also be taken. For example, a mirror could be incorporated into the body of the turntable, deflecting the coupled light in a direction parallel to the rotation axis of the turntable. The mirror is preferably shaped in particular so that the coupled light is deflected toward the container located on the turntable. By using a reflective surface, the loss of light output during the deflection of the beam direction can be reduced.

[0018] The incorporated mirror can have the shape of a truncated cone. For this purpose, the turntable can have a truncated cone-shaped recess. The outer surface of the truncated cone-shaped recess can be provided with a reflective surface. The opening angle of the truncated cone-shaped recess can be adapted to the specific conditions of the device in question. Typically, the light coupled in from the circumference will be deflected upwards by 90° from a substantially horizontal beam path in order to illuminate the container located on the turntable from below. In such cases, it is advisable to select an opening angle for the truncated cone-shaped recess that is between 30° and 60°. The opening angle can preferably be approximately 45°.

[0019] The turntable can include a diffuser element. The diffuser element can be designed so that the deflected light exits the turntable as diffused radiation. The diffuser element can be designed to create a diffused luminous surface. The diffuser element can, for example, be a layer of material located on the top side of the turntable. To protect the diffuser element, the surface of the diffuser element can in turn be provided with a transparent protective layer.

[0020] The turntable can also include a screen that can be used to limit the light emission area of ​​the turntable. When inspecting the bottom of the containers, it can be advantageous to direct the illumination only to a central area of ​​the container bottom. In particular, it may be useful to position the illumination so that the side walls of the containers are not directly illuminated. This can lead to light reflections, complicating the inspection.

[0021] The shape of the aperture can be selected to match the footprint of the container to be inspected. Since most containers are essentially circular-cylindrical, it is usually advisable to design the aperture, for example, as a single-ring-shaped element. The circular element can preferably be made of a non-transparent material. The interior of the circular element can either be open or made of a transparent material.

[0022] The aperture can be designed so that its outer and / or inner diameter can be variably adjusted. By using a variable aperture, the turntable can be optimally adapted to the geometry of the containers to be inspected.

[0023] The use of circular apertures is recommended when the containers to be inspected are generally circular-cylindrical in shape. However, the aperture can also be adapted to the geometry, particularly the cross-section, of the containers to be inspected.

[0024] The aperture can be a plastic element, such as a plastic film, located on top of the turntable. The aperture can then also serve as a base for the containers to be examined. Alternatively, the aperture can also be located on the bottom of the turntable. If the turntable consists of several layers of material, the aperture can also be located in an inner layer of the turntable.

[0025] The present invention also relates to a container treatment device comprising one or more container receptacles, each comprising a turntable as described here.

[0026] The container handling device may comprise a rotating conveyor. One or more container receptacles with turntables may be arranged on the rotating conveyor, particularly on its peripheral area.

[0027] Typically, such a container treatment device further comprises one or more treatment modules. For treatment, the containers located in the container receptacles are guided past the treatment modules by the rotating conveyor, where they undergo the respective treatment.

[0028] One or more of the treatment modules can each have a lighting module and a camera. The lighting module is arranged so that the light emitted by it can be coupled laterally into the cylindrical body of the turntable of the container holder. The coupled light is then deflected in the turntable toward the container. Typically, the coupled light is deflected upward to illuminate the container from below.

[0029] The camera of the treatment module is aimed at an area of ​​the container to be inspected. Which area of ​​a container is inspected and the current inspection task can vary greatly. In labeling units, for example, the inspection can be used to check that the labels are correctly positioned. However, it is also conceivable to perform a foreign body inspection, a bottom inspection, or a sidewall inspection. In principle, any inspection task that requires illumination from the underside of the container can be performed. The one or more lighting modules can be designed to emit light in different wavelength ranges. The lighting modules preferably emit visible light, UV light, or IR light. The visible light can be monochromatic light or white light. A lighting module can also consist of several independent light sources.In particular, a lighting module can be constructed from a plurality of LEDs.

[0030] The lighting modules can operate in continuous mode or flash mode. The type of lighting modules can be freely selected by the specialist depending on the inspection task.

[0031] Illuminating the containers from below is particularly suitable for identifying foreign objects such as glass fragments. Illuminating from below creates reflections at the interface between the glass fragments and the liquid contents. These reflections can be recorded with the one or more cameras of the container processing module.

[0032] In addition to the illumination provided by the turntable, additional lighting modules can be provided. These additional lighting modules can be arranged for incident or transmitted light illumination of the containers. This allows the containers to be inspected for various foreign bodies or defects in the treatment modules.

[0033] The illuminated turntables according to the invention can be used advantageously, particularly in labeling units. Such a labeling unit typically comprises a rotating conveyor, the so-called labeling ring. This labeling ring can be provided with a plurality of container receptacles, each of which comprises an illuminated turntable according to the invention. Various processing modules are arranged at the periphery of the labeling ring, where the processing steps required for applying a label are carried out. A visual inspection of the containers can also be carried out at one or more of these modules. This inspection can be used, for example, to check the correct fit of the labels, but also to inspect the containers for defects or foreign bodies.

[0034] In labeling units, the containers to be labeled must be repeatedly rotated and decelerated (spin-stop movement). In filled, closed containers, the inertia of the contents causes a relative movement between the container wall and the contents. If foreign bodies are present in the usually homogeneous contents, they can be detected relatively easily by optical inspection (spin-stop inspection) due to their relative movement to the container wall. This moment is therefore generally well suited to performing a spin-stop foreign body inspection, particularly in the base area of ​​the containers to be labeled. In conventional labeling units, there is usually no space available to implement such a foreign body inspection, including the required base lighting. The turntables according to the invention make it possible to provide base lighting that essentially requires no additional space.

[0035] The floor lighting can also be used for other inspection tasks in labeling units or other container handling devices. The space-saving and compact design of the floor lighting using the illuminated turntable according to the invention can be advantageously used in any container handling device.

[0036] The present invention also relates to a method for treating containers in a container treatment device. The containers are conveyed on a turntable made of at least partially transparent material. The turntable is designed such that light can be coupled circumferentially into the turntable material with at least one component perpendicular to the turntable's axis of rotation. The turntable is further designed such that the light coupled circumferentially into the turntable material is deflected in a direction parallel to the turntable's axis of rotation. A camera takes a picture of the irradiated container, and an evaluation device evaluates the resulting picture.

[0037] In the container processing device, the containers can be subjected to various treatments. The process can be used particularly advantageously in labeling units. Turntables are required in labeling units to position the containers standing on them in a targeted manner in front of the labeling modules. The illuminated turntables according to the invention also allow the containers to be illuminated from below and subjected to visual inspection.

[0038] As already described above, bottom lighting is particularly suitable for identifying foreign objects, such as glass fragments, on the bottom of the container.

[0039] Advantageously, the camera takes several consecutive images of a container. Furthermore, the container to be examined is rotated after each image so that the entire circumference of the container can be inspected.

[0040] The containers can be rotated with the turntables so fast that the rapid rotation sets foreign bodies in motion. Targeted acceleration and deceleration can create a relative movement between the container wall and any foreign bodies in the container. This relative movement allows for a particularly effective distinction between harmless container structures and unwanted foreign bodies in the contents.

[0041] The evaluation of the images taken of a container can involve comparing multiple images of the container. For example, several images taken directly one after the other can be compared to identify moving foreign objects in a container.

[0042] A container located on a turntable according to the invention can be inspected from different perspectives using multiple cameras. These images of the container under inspection, taken from different perspectives, allow for the differentiation between external glass structures or adhesions on the one hand, and unwanted internal foreign bodies on the other.

[0043] Features described in connection with individual aspects of the invention can usually also be used in connection with other aspects of the invention.

[0044] The present invention is described in more detail below with reference to the accompanying drawings, in which:

[0045] Fig. 1 a rotary conveyor with several turntables,

[0046] Fig. 2 a side view of an inspection station,

[0047] Fig. 3 shows an embodiment of a turntable according to the invention,

[0048] Fig. 4 shows a further embodiment of a turntable according to the invention, Fig. 5 shows a turntable according to the invention with a cover, and Fig. 6 shows a receptacle for a foreign body in a container.

[0049] Fig. 1 schematically shows a section of a labeling device 10. The labeling device 10 comprises a rotating conveyor 12, the so-called labeling ring, on whose circumference several container receptacles 14 are arranged. The container receptacles 14 are each provided with a turntable 16, each configured to receive a container 18. In this embodiment, the turntables 16 are formed from transparent Plexiglas.

[0050] During operation, the rotating conveyor 12 guides the containers 18 past the container processing stations 20, 21, 22 of the labeling device 10, which are arranged in the periphery of the rotating conveyor 12. The containers 18 are thus provided with labels in several successive process steps.

[0051] In addition to the container processing stations 20, 21, 22 required for labeling, three illumination devices 24 are arranged radially outside the labeling ring. Each illumination device 24 is assigned a detection device 26. The detection devices 26 in Fig. 1 are digital color cameras used to create photographic images of the containers 18.

[0052] As can be seen in the side view of Fig. 2, the turntables 16 made of Plexiglas are illuminated from the side by the lighting devices 24. The turntables 16 are designed such that the light coupled laterally into the body of the turntable 16 is scattered upwards and diffusely illuminates the containers 18 standing on the turntable 16. The detection device 26 assigned to the respective lighting device 24 creates photographs of the container 18 illuminated from below. As shown in Fig. 2, the detection device 26 can be directed towards a bottom region of the container 18 in order to inspect the bottom region of the container 18. However, the detection device 26 can just as easily be directed towards other container regions, such as the side wall or the mouth region of the container 18. Multiple detection devices 26 can also be provided.These detection devices 26 can take images of the illuminated container 18 simultaneously or at different times. The images can be taken from different perspectives and / or cover different container areas.

[0053] 3 and 4 illustrate different embodiments of turntables 16 according to the invention. The turntable 16 illustrated in Fig. 3 is made entirely of Plexiglas and comprises three functionally different layers 30, 32, 34. The light 28 emitted by the illumination device 24 is coupled into the material of the turntable 16 in the region of a middle layer 30. The Plexiglas material of this middle layer 30 is provided with reflector particles 36. These reflector particles 36 cause scattering of the coupled-in light 28. Advantageously, reflector particles 36 are used, which deflect the radiated light 28 primarily upwards, i.e., in the direction of the container 18 standing on the turntable 16. The upper material layer 32 of the turntable can additionally be designed as a diffuser layer. This diffuser layer has scattering centers that ensure that the upper side of the turntable 16 forms a diffuse luminous surface.

[0054] A similar lighting effect is achieved by the embodiment of the turntable 16 according to Fig. 4. The turntable 16 shown in Fig. 4 is also made of Plexiglas and likewise comprises three functionally different layers 30, 32, 34. The light 28 emitted by the illumination device 24 is coupled into the material of the turntable 16 in the region of the middle layer 30. The material of this middle layer has a truncated cone-shaped mirror 38 incorporated into the Plexiglas body. The light 28 coupled in from the side is deflected upwards at the mirror surface 40, i.e. in the direction of the container 18 located on the turntable 16. The upper material layer 32 of the turntable 16 is in turn designed as a diffuser layer, so that in this case too the upper side of the turntable 16 forms a diffuse luminous surface.

[0055] Illuminating the container 16 from below makes it easier to detect certain defects or foreign bodies in the container 16 than would be possible with lateral transmitted or incident light illumination. The light coming from below creates reflections at the interfaces between glass fragments and the liquid contents, which can be detected with a camera directed at the bottom of the container.

[0056] The turntable according to Fig. 5 largely corresponds to the turntable 16 from Fig. 4. In addition, the turntable 16 according to Fig. 5 also has a screen 39 on the top side of the turntable 16. The screen 39 is circular and made of a non-transparent plastic. On the one hand, the screen 39 serves as a base for a container to be inspected. On the other hand, the screen 39 limits the area of ​​the light exit surface of the turntable 16. The central opening of the screen 39 has a diameter that is smaller than the diameter of the container to be inspected. As a result, the areas on the outer container walls in particular are not directly illuminated. This dark field illumination makes glass splinters, for example, which are typically located in these areas, clearly visible.

[0057] Fig. 6 shows a photograph taken using a device according to the present invention. The image shows a bottom region of a filled glass bottle. The semicircularly illuminated bottle bottom 42, as well as embossed structures 44 (glass stampings) typically used on glass bottles, are clearly visible. In addition to these intentional structures, the outline of an irregularly shaped glass splinter 46 is also visible. The reflections occurring at the interface between the surface of the glass splinter 46 and the contents make it particularly easy to identify the contours of the glass splinter 46.

Claims

Patent claims 1. A turntable for a container treatment device, wherein the turntable has a rotation axis and is made at least partially of transparent material, and wherein the turntable is designed such that light can be coupled circumferentially into the turntable material with at least one component perpendicular to the rotation axis of the turntable, and that the turntable is further designed such that the light coupled circumferentially into the turntable material is deflected in a direction parallel to the rotation axis of the turntable.

2. Turntable according to claim 1, wherein the turntable is made of transparent material, such as Plexiglas, and has reflector particles which generate the deflection of the coupled light.

3. Turntable according to one of claims 1 or 2, wherein the turntable has a mirror incorporated in the body of the turntable, which deflects the coupled light in a direction parallel to the axis of rotation of the turntable.

4. Turntable according to claim 3, wherein the incorporated mirror has the shape of a truncated cone.

5. Turntable according to one of the preceding claims, wherein the turntable comprises a diaphragm which limits the size of the light exit surface on the upper side of the turntable.

6. Container treatment device comprising one or more container receptacles which comprise a turntable according to one of claims 1 to 5.

7. Container treatment device according to claim 6, comprising a rotating conveyor on the circumference of which one or more turntables are arranged, wherein the container treatment device further comprises one or more inspection modules which are arranged laterally and / or above the rotating conveyor.

8. Container treatment device according to claim 7, wherein each inspection module comprises at least one lighting module and at least one camera.

9. A method for treating containers in a container treatment device according to one of claims 6 to 8, wherein - the containers are irradiated by means of the lighting unit, - the camera takes a picture of the irradiated container and - an evaluation device evaluates the recording made.

10. The method according to claim 9, wherein a container is rotated so fast that foreign bodies in the container can be set in motion by the rapid rotation.

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