SUPPORT RING CENTERING FOR CLOSURE INSPECTION

Abstract

A method for inspecting containers with closures with a cap portion and a circumferential edge extending around the mouth of the containers. The containers are transported along a transport path by a transport device. During transport, the mouth regions of the containers with closures are illuminated by an illumination device, and at least one image recording device records at least one image of the mouth regions of the containers with closures, and records at least one spatially resolved image of a portion of the circumferential edge and one structure on the circumferential edge is detected, and, at least one value of this structure, a value characteristic of a relative position of the closure relative to the container and/or relative to the rotationally symmetrical element and/or of the closure is determined.

Claims

1. A method for inspecting containers provided with closures, wherein the closures having a cap portion and a circumferential edge extending around a mouth of the containers, wherein the containers are transported along a predetermined transport path by a transport device, and during said transport the mouth regions of the containers provided with the closures are illuminated by an illumination device, and at least one image recording device records at least one image of the mouth regions of the containers provided with the closures, wherein the image recording device records at least one spatially resolved image of a portion of the circumferential edge, and at least one structure present on the circumferential edge is detected, and, taking into account at least one value characteristic of this structure, a value characteristic of a relative position of the closure relative to the container and/or relative to the rotationally symmetrical element and/or of the closure is determined.

2. The method according to claim 1, wherein the containers have a rotationally symmetrical element arranged in a region of the mouth of the containers, wherein the closure ending above the support ring in a longitudinal direction of the container.

3. The method according to claim 1, wherein imaging parameters are determined by calibration.

4. The method according to claim 1, wherein at least one color-coded image is recorded and at least one measure is carried out to increase the contrast.

5. The method according to claim 4, wherein this at least one measure is selected from a group of measures including processing the image in a brightness channel, processing the image in a complementary channel, processing the image in a saturation channel, combinations of these measures.

6. The method according to claim 5, wherein at least two structures are detected on the circumferential edge and, taking into account at least one value characteristic of said two structures, the value characteristic of a relative position of the closure relative to the container and/or of the closure is determined.

7. The method according to claim 1, wherein the portion of the circumferential edge and/or the support ring includes an angle that is greater than 90?.

8. The method according to claim 1, wherein at least one second image recording device records at least one spatially resolved image of a portion of the circumferential edge and/or at least one portion of the rotationally symmetrical element.

9. The method according to claim 1, wherein a development image is formed at least from the image recorded by the first image recording device and the image recorded by the second image recording device.

10. The method according to claim 1, wherein the closure is selected from a group of closures selected from the group consisting of flat caps, sports caps, tethered caps, snap caps, screw caps, and crown caps.

11. The method according to claim 1, wherein the structure has a plurality of webs and/or ribs extending in a longitudinal direction of the closures and parallel to one another.

12. The method according to claim 1, wherein at least one image recording device records the containers from a direction which, with a direction perpendicular to the longitudinal direction of the container, includes an angle of less than 30?.

13. An apparatus for inspecting containers provided with closures, wherein the closures having a cap portion and a circumferential edge extending around a mouth of the containers, having a transport device configured to transport the containers along a predetermined transport path, and an illumination device configured to illuminate the mouth regions of the containers provided with the closures, and having at least one image recording device which is configured for recording at least one spatially resolved image of the mouth regions of the containers provided with the closures, wherein a processor device is provided which is configured for determining, from a structure of the circumferential edge that is detected in this image, a value characteristic of a relative position of the closure relative to the container and/or a value characteristic of the closure.

14. The apparatus according to claim 13, wherein the processor device is configured for increasing the contrast of a recorded image.

15. The apparatus according to claim 13, wherein the apparatus has at least two image recording devices.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0091] In the drawings:

[0092] FIG. 1 shows a representation to illustrate the circumstances underlying the invention;

[0093] FIG. 2 shows images recorded in the context of an inspection;

[0094] FIG. 3 shows examples of recorded images;

[0095] FIG. 4 shows a development of the images recorded in FIG. 3;

[0096] FIG. 5 shows a representation for preprocessing of the recorded images;

[0097] FIG. 6 shows a representation for determining the structures;

[0098] FIG. 7 shows a representation in the presence of multiple structures;

[0099] FIG. 8 shows a representation for evaluating an image shown in FIG. 7;

[0100] FIG. 9 shows a representation of a recording and a development without correction;

[0101] FIG. 10 shows a representation of a recording and a development with correction;

[0102] FIG. 11 shows obtained measurement results without correction;

[0103] FIG. 12 shows obtained measurement results with correction; and

[0104] FIG. 13 shows a rough schematic representation of an apparatus for inspecting containers.

DETAILED DESCRIPTION OF THE DRAWINGS

[0105] FIG. 1 shows four representations of a container, in this case a plastic container 10 having a container closure 15. Preferably, this container closure is screwed onto a mouth of the container 10.

[0106] The reference numeral L refers to a longitudinal direction of the container and also to a longitudinal direction of the container closure 15.

[0107] The container closure has a cap portion 15a and a circumferential edge 15b. A structure (not shown) may be formed on the circumferential edge 15b.

[0108] Reference numeral 10 a refers to a support ring arranged on the container 10. As shown below, sad support ring is preferably also recorded.

[0109] FIG. 2 shows an actual image recorded of a container closure, wherein the lower image on the right side showing an enlargement. Here too, the cap section 15a and the circumferential edge can be seen. In addition, a security ring 15c also can be seen, which makes it possible to determine whether the container has already been opened.

[0110] Furthermore, a structure S can also be seen at the circumferential edge of the container closure. This structure can also be used to determine a closed state of the container.

[0111] A further improvement of the image evaluation is possible by using several structures. In addition, as explained above, it is also possible to incorporate the support ring centering and thus better reconstruct the 360? development.

[0112] FIG. 3 shows an example in which four images of a container closure have been recorded. This recording can be carried out, for example, by means of four cameras from different sides.

[0113] Here, a camera recording was carried out approximately in a 90? arrangement. FIG. 4 shows a reconstruction of the closure cap of the security ring, of the connecting elements and of the support ring in a 360? development. In this development, both the security ring 15c and the support ring 10a are visible.

[0114] FIG. 5 again shows the image shown in FIG. 4, wherein a region 16 is shown in which structures on the circumferential edge 15b are evaluated. In the lower partial image of FIG. 5, measures are shown that serve to enhance contrast. In addition, a preprocessing of the image is preferably carried out in this step of the image evaluation.

[0115] FIG. 6 shows an enlarged section of a recorded image. From this image, relevant structural data of the circumferential edge can be determined.

[0116] From this image a determination of the relevant structure of the circumferential edge can be carried out. More precisely, the determination is made here on the basis of the shown development, i.e., a 360? structure is evaluated. Advantageously, relevant structural parameters such as mean value, elongation, characteristic sections, etc. are determined or registered.

[0117] Preferably, the obtained structural parameters are evaluated with respect to position and/or slanted position. In addition, further evaluations are also possible, such as with regard to deformation, in particular by deviation from a reference set of structural parameters.

[0118] FIG. 7 shows an illustration of a closure having several structures. A horizontal lip 22 and also a stiffening structure 24 of the closure cap edge can be seen here. Furthermore, it can be seen that the end points of the short ribs are shiny. This information can also be used for image evaluation and ultimately for detecting a position of the closure.

[0119] FIG. 8 shows a representation of the image evaluation of the image recorded in FIG. 7. In the upper partial image, a contrast enhancement was carried out in order to better highlight a horizontal lip.

[0120] The lower image also shows a contrast increase for determining the end points of the short ribs.

[0121] FIGS. 9 and 10 each show four recorded images of a container closure, i.e., images recorded from four directions. It can be seen here that the orientation of these closures is not exactly uniform, for example because the container has a slightly slanted neck.

[0122] In both images, a 360? development was performed, each of which was shown in the lower portion of the image. In the case shown in FIG. 9, no correction was made, which leads to a sinuous line like representation.

[0123] In the representation shown in FIG. 10, a correction was carried out based on the position of the support ring, resulting in the corresponding straight course.

[0124] More precisely, in the case of FIG. 10, a determination of the plane position or normal vector of the support ring was performed.

[0125] FIGS. 11 and 12 again show the corresponding images together with the resulting evaluation. While the evaluation without correction (FIG. 11) results in the result that the container is faulty (BAD), the evaluation with correction (FIG. 12) results in the container being evaluated as proper (OK).

[0126] FIG. 13 shows a rough schematic representation of an apparatus 1 according to the invention for inspecting containers 10. This apparatus has a transport device such as a transport belt 2, which transports the containers 10 along a predetermined transport path, in this case a straight transport path.

[0127] The reference numerals 4 and 4a refer to image recording devices which respectively record images of the filled and closed containers 10.

[0128] Advantageously, four such image recording devices 4, 4a are provided, which particularly preferably each record four images of the containers from different directions.

[0129] The reference numerals 6 refer to illumination devices which are preferably associated with the image recording devices and which illuminate the containers 10 at least during image recording.

[0130] The reference numeral 12 schematically indicates an evaluation device which evaluates the images recorded by the image recording device(s) and in doings so preferably also carries out the corrections described above.

[0131] The applicant reserves the right to claim all features disclosed in the application documents as essential to the invention, provided that they are novel over the prior art individually or in combination. It is also pointed out that features which can be advantageous in themselves are also described in the individual figures. The person skilled in the art will immediately recognize that a particular feature described in a figure can be advantageous even without the adoption of further features from this figure. Furthermore, the person skilled in the art will recognize that advantages can also result from a combination of several features shown in individual or in different figures.