Apparatus and method for checking of containers
A method for detecting one or more foreign substances in one or more containers filled with liquid, comprising of: transporting the containers filled with liquid in a substantially straight line at relatively high speed in a production environment; —illuminating each container with content with one or more fixedly disposed light sources; and —inspecting the container with content from preferably two or more different orientations using two or more cameras, wherein cameras and lighting are disposed substantially fixedly relative to each other, while the cameras and light sources are mutually connected such that in a short time two or more images of a container filled with liquid can be recorded with mutually differing illumination and/or angle of incidence; —comparing the foreign substances in the two or more images; and —wherein a container filled with liquid is rejected on the basis of the probability distribution obtained from the comparisons, wherein above a determined probability it is concluded that the foreign substance is a glass particle or other undesirable particle.
1. A method for detecting one or more foreign substances in one or more containers filled with liquid, comprising the steps of:
transporting one or more containers filled with liquid;
illuminating each container with content with one or more fixedly disposed light sources; and
inspecting each container from two or more different orientations using two or more cameras,
wherein cameras and lighting are disposed substantially fixedly relative to each other, while the cameras and light sources are mutually switched such that two or more images of each container can be recorded with mutually differing illumination and/or angle of incidence; and
comparing foreign substances in the two or more images;
wherein a container is rejected on the basis of a probability distribution obtained from the comparisons, and wherein above a determined probability it is concluded that a foreign substance is a glass particle or other undesirable particle.
2. The method as claimed in claim 1 , wherein illumination takes place by means of a number of light sources which are switched such that during transport of each container, images are recorded according to both a dark field technique and a bright field technique.
3. The method as claimed in claim 1 , wherein the light sources are switched as the lighting rotates around each container.
4. The method as claimed in claim 1 , wherein by using two cameras disposed at different angles, it is determined whether a foreign substance is situated inside or outside each container and/or whether the foreign substance is a glass particle.
5. The method as claimed in claim 1 , wherein use is made of polarized light.
6. The method as claimed in claim 1 , wherein use is made of infrared light.
7. The method as claimed in claim 1 , wherein the containers are transported over a transporting part provided with light-emitting diode (LED) light sources and wherein the LEDs are switched such that the lighting co-displaces with the containers filled with liquid.
8. The method as claimed in claim 1 , wherein a plurality of LEDs are arranged laterally of the containers, and each container is tilted on a transporting device so as to enable a camera to be directed at the bottom thereof and to cause a foreign substance to move to the image field of the camera.
9. A device for checking containers, comprising:
a conveyor for transporting containers;
one or more light sources;
two or more cameras; and
a control unit arranged on the light sources and the cameras,
wherein the method as claimed in claim 1 is performed by the device for checking containers.
10. The device as claimed in claim 9 , wherein two pairs of six pairs of cameras are disposed on either side of the conveyor, and wherein the orientation of each pair differs such that use can be made of stereovision.
11. The device as claimed in claim 9 , provided with two or more light sources which each consist of a plurality of LED elements arranged on either side of the conveyor respectively above and opposite a pair of cameras located opposite the conveyor or thereunder.
12. The device as claimed in claim 9 , provided with a polarizer for transmitting or holding back a light polarized in a determined manner.
13. The device as claimed in claim 9 , provided with a plurality of LEDs.
14. The device as claimed in claim 9 , provided with means for placing each container in oblique position and LED lighting which is disposed on either side of the container adjacent to the bottom of the container.
15. The device as claimed in claim 9 , wherein one or more prisms and/or mirrors are arranged between a camera and the container for recording images from different sides of the container.
16. The device as claimed in claim 9 , provided with a camera disposed adjacent a transition between a neck and a body of the container.