METHOD AND DEVICE FOR INSPECTING CONTAINERS

Abstract

Provided is a method for inspecting containers, wherein the containers are conveyed along a predetermined transport path by a transport device and wherein an image recording device takes at least one locally resolved inspection image of at least one area of the containers during transport of the containers. A triggering of the inspection image recording of this locally resolved image is controlled, wherein this controlling takes place in consideration of a triggering image recording of an image of the container.

Claims

1. A method for inspecting a container, wherein the container is conveyed along a predetermined transport path by a transport device and wherein an image recording device takes at least one locally resolved inspection image of at least one area of the containers during transport of the containers, wherein a triggering of the inspection image recording of the at least one locally resolved image is controlled, wherein the controlling takes place in consideration of a triggering image recording of an image of the container.

2. The method according to claim 1, wherein the triggering image recording is carried out by the image recording device.

3. The method according to claim 1, wherein the triggering image recording and the inspection image recording differ at least in terms of a parameter being characteristic for the image recording.

4. The method according to claim 3, wherein the parameter is selected from a group of parameters comprising a resolution of the recorded image, a size of the recorded area of the container, a color depth of the recorded image, a refresh rate, an illumination parameter such as intensity of illumination, illumination color, and direction of illumination.

5. The method according to claim 1, wherein the inspection image recording is controlled in consideration of a transport speed and/or a path of the container.

6. The method according to claim 1, wherein the container is illuminated at least at times during the recording of the inspection image and/or during the triggering image recording.

7. The method according to claim 6, wherein the container is illuminated in a pulsed manner during the recording of the inspection image.

8. The method according to claim 1, wherein a position of the container is detected at a time and/or at a location prior to the performance of the triggering image recording.

9. The method according to claim 1, wherein the triggering of the inspection image recording takes place in consideration of a triggering condition, wherein the triggering condition is selected from the group comprising a change of the average brightness in a trigger image section, a change of a contrast of individual pixels in an image section, a change in the variance and/or spatial frequency of the image brightnesses of individual pixels, a detection of a specific pattern, and a detection of a specific color.

10. The method according to claim 9, wherein a plurality of triggering image recordings are performed.

11. An apparatus for inspection of a container, having a transport device which transports the containers along a predefined transport path, having a first image recording device to take at least one locally resolved inspection image of at least one area of the container during transport of the container, wherein the apparatus comprises a triggering device to control the triggering of the inspection image recording of the locally resolved image wherein the triggering device has at least one image recording device to record a triggering image of the container during transport of the container.

12. The apparatus according to claim 11, wherein the image recording device is switchable between at least a first image recording mode and a second image recording mod, wherein in the first image recording mode the inspection image is able to be recorded and in the second image recording mode the triggering image is able to be recorded.

13. The apparatus according to claim 11, wherein the apparatus has a detection device to detect a position of the container along the transport path.

14. The apparatus according to claim 11, wherein the apparatus has at least one illumination device to illuminate the containers at least during an image recording.

15. The method according to claim 10, wherein the plurality of triggering image recordings is repeated.

16. The method according to claim 15, wherein the plurality of triggering image recordings is repeated cyclically.

Description

BRIEF DESCRIPTION

[0093] Some of the embodiments will be described in detail, with references to the following Figures, wherein like designations denote like members, wherein:

[0094] FIG. 1 is a schematic illustration of an apparatus according to embodiments of the invention;

[0095] FIG. 2 is an illustration of a course of a method according to embodiments of the invention;

[0096] FIG. 3 is an illustration for explaining image recording; and

[0097] FIG. 4 is an illustration of the course of the method according to embodiments of the invention.

DETAILED DESCRIPTION

[0098] FIG. 1 shows a schematic illustration of an apparatus 1 according to embodiments of the invention for inspecting containers. Here, containers 10 are transported by a transport device 2 along a predetermined transport path T. Here, the transport device 2 has a conveyor belt on which the containers are conveyed.

[0099] Reference numeral 4 indicates an image recording device, which observes the containers being transported in the transport direction T. This image recording device 4 takes a spatially resolved image of the individual containers.

[0100] Reference numeral 8 indicates an illumination device, which is here with respect to the individual containers 10 arranged on the opposite side of the image capture device 4.

[0101] The reference numeral R1 roughly indicates the trigger condition. If this comes into effect, the image recording is triggered by the image recording device 4.

[0102] Reference numeral 12 indicates another light barrier, which detects the entrance of containers 10 in the apparatus 1 according to embodiments of the invention. Reference numeral 22 indicates a control device and in particular a rotary encoder, by which a position of the transport device or a rotational position of the drive of deflection pulleys of the transport device can be detected. These data are also taken into account in order to trigger an image recording by the image recording device 4.

[0103] FIG. 2 shows a schematic course of a method according to embodiments of the invention. First, in a step 30 a live camera is started. In a process step 31 the container is placed in a center of the picture. Furthermore, in a step 32 a trigger and optionally also a picture section is defined. However, the complete picture can also be evaluated for the actual recording. In a step 33 a trigger condition is defined or learned. In a step 34 a trigger condition can be activated. In a step 35 it is checked, for example by a high-speed recording in a small trigger section, whether the trigger condition is fulfilled. If the trigger condition is fulfilled (step 36), a picture recording of an entire picture or an image section is triggered. If the trigger condition 36 is not fulfilled, an image recording is again triggered following the step 35. That is, this loop is run through until the trigger condition is fulfilled.

[0104] After recording the image in step 37, the image is transmitted (step 38) (e.g. to a sorting unit).

[0105] FIG. 3 shows an illustration for creating an image recording. In this case, the reference numeral 40 refers to an overall picture which possibly has to be taken. The reference numeral 41 refers to the recording of an image section, in particular an image section, which contains a specific image. Within and/or outside of this image, the trigger condition can be defined, such as an area of the image that is particularly suitable for a trigger evaluation.

[0106] In this way, the trigger image is much smaller than the later recorded image, whereby in particular also a high refresh rate is made possible. It is conceivable for the image recording device to record images or trigger images at a refresh rate of up to several kHz. The image recording device may repeat the trigger recordings until the object is captured or located at an appropriate location.

[0107] If the trigger condition is fulfilled, the inspection image recording is performed. In this case, the inspection image recording is not limited to a picture, but may also comprise a multi-image recording, particularly with switching of the illumination direction or type of illumination.

[0108] FIG. 4 shows a further embodiment of a method according to embodiments of the invention. Here it first of all roughly determined by a trigger light barrier 66, whether a container is in a particular area which is situated before the actual image recording device 4. In this case, there can be a container frequency, for example at 72,000 containers per hour, that is, a refresh frequency from one container to the next can be at 20 Hz.

[0109] Hence, between two containers there is a time interval of about 50 ms. Once the position of a particular container has been detected, the path to the approximate position 52 of the image recording device can be determined by high-frequency pulses 56. The high-frequency pulses are determined by the encoder connected to the conveyor belt. The way from the trigger light barrier 66 to the approximate image recording device 4 is in FIG. 4 exemplified with 39 high-frequency pulses.

[0110] Starting from point 52, it will be proceeded like described in FIG. 3, i.e. by (high-frequency 53) trigger image recording the exact position of the container before the image recording device 62 is determined, in order to perform one or more inspection image recordings as soon as this position is achieved.

[0111] The reference number 54 indicates the area in which an illumination device and/or the image recording device is activated, for example in order to deactivate the illumination device in the period not being required, i.e. before and after 54, and thus to reduce the power consumption or heat development of the illumination source(s).

[0112] The image recording device has an exposure time which may be greater than 1 s, greater than 3 s, greater than 5 s, or greater than 10 s. An exposure time is selected which may be less than 1 s, less than 800 s, less than 500 s, less than 300 s, less than 200 s, or less than 100 s.

[0113] Although the present invention has been disclosed in the form of preferred embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.

[0114] For the sake of clarity, it is to be understood that the use of a or an throughout this application does not exclude a plurality, and comprising does not exclude other steps or elements. The mention of a unit or a module does not preclude the use of more than one unit or module.

LIST OF REFERENCE NUMERALS

[0115] 1 apparatus [0116] 2 transport device [0117] 4 image recording device [0118] 8 illumination device [0119] 10 containers [0120] 12 light barrier [0121] 22 control device [0122] 30-35 process steps [0123] 37-39 process steps [0124] 36 trigger condition [0125] 40 overall image [0126] 41 Recording of the image section [0127] 52 approximate position [0128] 53 high-frequency trigger image recordings [0129] 54 area where the illumination device is activated [0130] 55 area [0131] 56 high frequency pulses [0132] 62 image recording device [0133] 64 end of expectation area [0134] 66 roughly detected container; trigger light barrier [0135] R1 trigger condition [0136] T transport path