JP4177204B2 - Container foreign matter inspection system - Google Patents

Description

  INDUSTRIAL APPLICABILITY The present invention is suitable for a foreign matter inspection method and apparatus for detecting foreign matter mixed in a filling liquid of a product in which a container is filled with a liquid, particularly for a foreign matter inspection of a product filled with a light transmissive liquid in a light transmissive container. Related to the device.

  To inspect the presence of foreign matter in the filling liquid of a product filled with a light-transmitting liquid in a light-transmitting container, capture the inspection product, obtain the inspection image, and process the inspection image Thus, a technique based on an inspection image for detecting foreign matters is widely used. However, in this inspection image method, it is necessary to be able to discriminate between scratches on the container surface, dirt adhered to the container surface, and foreign matter. For example, in Patent Document 1 and Patent Document 2, rotation is given to the filling liquid in the container, and thereby the foreign matter in the filling liquid is moved so that the container can be distinguished from scratches and dirt.

  Specifically, the filling liquid in the container is rotated by applying rotation (autorotation) to the container, and then the rotation of the container is rapidly stopped. Then, even if the container is stopped, the filling liquid can be rotated by inertia. In this state, the filling liquid is photographed a plurality of times from the outside of the container to obtain a plurality of inspection images. Then, the presence or absence of foreign matter is determined from the plurality of inspection images by image processing or the like in distinction from the scratches and dirt on the container. That is, the plurality of inspection images are images in a state where the container is stopped and only the filling liquid is moving. Accordingly, the foreign matters mixed in the filling liquid rotate by the rotation of the filling liquid and appear at different positions as moving objects in a plurality of inspection images, while the scratches and dirt on the container are stopped by the container. Therefore, they appear at the same position in a plurality of inspection images. Therefore, the presence / absence of a foreign object is determined by determining whether or not there is an image of a moving object in a plurality of images. The foreign matter includes, for example, a glass piece, a plastic piece, a metal piece, or the like that enters the container in the container manufacturing process, and a filter piece or an impurity mixed in the liquid in the liquid manufacturing process.

JP 2002-267613 A JP 2003-107011 A

  In the inspection method for detecting foreign matter using an inspection image, it is necessary that the foreign matter in the filling liquid appears in the inspection image. However, some foreign materials are light transmissive, such as glass and plastic pieces, and the light transmittance is very close to that of the filling liquid, and it is difficult to capture the image of the foreign material in the inspection image by simply illuminating it with illumination light. However, it has been difficult to detect such foreign matter with conventional inspection techniques.

  Accordingly, an object of the present invention is to provide a foreign matter inspection apparatus that can reliably detect even a light transmissive foreign matter whose light transmittance is very close to that of a filling liquid.

The present invention is a container filling liquid foreign matter inspection apparatus for detecting foreign matter in a filling liquid whose light transmittance is close to that of the filling liquid in the container and whose refractive index is different from that of the filling liquid,
A foreign object image forming plate provided between the illumination light source and the detection target container, in which a pattern interval is smaller than the foreign substance and a regular pattern is formed,
A control means for rotating the container by giving a rotation pattern for foreign object inspection, and then stopping the container;
A camera for imaging the first and second transmitted light obtained through the container through the foreign substance image forming plate at at least two different timings during rotation of the filling liquid in the container after the rotation is stopped;
Processing means for taking a difference between the first and second captured images of the camera and inspecting whether or not the pattern image corresponding to the foreign object image forming plate is distorted and determining that there is a foreign object when there is distortion; ,
A foreign matter inspection apparatus for a container-filled liquid comprising:

  According to the foreign matter inspection method or inspection apparatus as described above, the regular pattern of the foreign matter image forming means is utilized by utilizing the fact that the refractive index of a foreign matter whose light transmittance is very close to that of the filling liquid is different from that of the filling liquid. As a distortion of the regular pattern image given to the inspection image, a foreign object image can be formed in the inspection image. As a result, it is possible to easily detect even a foreign object that has been difficult to detect with the conventional inspection image technique, and it is possible to further increase the accuracy of the foreign object inspection.

  Embodiments of the present invention will be described below. FIG. 1 schematically shows the configuration of an inspection apparatus according to an embodiment. The inspection apparatus according to the present embodiment is incorporated in a product production line in which a light transmissive container such as a plastic container, an ampule, or a vial is filled with a light transmissive liquid such as an injection solution, a nutrient, or a soft drink. This is a precondition for this. Specifically, as a transport system for inspection, a carry-in rotor 1 connected to a transport conveyor C from the upstream side of the production line and receiving a product M to be inspected, and a product M received by the carry-in rotor 1 for inspection A conveying rotor 2 that conveys the product M, an inspection product M that has been inspected from the conveying rotor 2 into a non-defective product and a defective product, an unloading rotor 3 that also serves as a sorting unit, and a non-defective conveyor 4 that is connected to the unloading rotor 3 and unloads the non-defective product And a defective product conveyor 5 which is connected to the carry-out rotor 3 and carries out defective products.

  In addition, as a rotation imparting system for rotating (spinning) the product M for the inspection of the foreign matter mixed in the liquid filled in the container, the product placed on the transport rotor 2 is arranged at regular intervals and placed on the product. A plurality of rotating units 11 formed so as to be able to give rotation to M; an angle detector 12 for detecting a mechanical angle of the transport rotor 2 used to determine the timing of rotation of the product M by the rotating unit 11; And a rotation control unit 13 for controlling the operation of the rotation unit 11. The rotation control unit 13 includes an angle information unit 14 that processes machine angle information from the angle detector 12, a motor control unit 15 that controls a motor described later included in the rotation unit 11, and the rotation unit 11. A rotation pattern instruction unit 16 for instructing and inputting a rotation pattern as described later is provided.

  Further, as an inspection system for foreign matter, a camera 21 that captures an inspection image of the product M for inspection, an illumination light source 22 for photographing by the camera 21, and a foreign matter image forming unit between the illumination light source 22 and the product M are provided. An imaging system including a foreign object image forming plate 23 is provided, and an inspection processing unit 24 that processes an inspection image from the camera 21 to determine the presence or absence of foreign substances. The inspection processing unit 24 is provided with an inter-image difference acquisition processing unit 25 and a foreign matter detection processing unit 26. The processing performed by the inspection processing unit 24 and the configuration of the foreign matter image forming plate 23 will be described later.

  The rotation unit 11 is configured as shown in FIG. 2 as an example. The rotating unit 11 of this example includes a rotating base 31 that rotates a product M filled with liquid Li in a container B, a holding cap 32 that holds the product M on the rotating base 31 so as to be fixed from above, A motor 33 that rotationally drives the table 31 and an encoder 34 that is a rotational speed detection means for detecting the rotational speed of the motor 33 are provided. The rotation speed information obtained by the encoder 34 is sent to the rotation control unit 13, and the motor 33 operates under the control of the rotation control unit 13.

  Hereinafter, the foreign substance inspection performed by this inspection apparatus will be described. FIG. 3 shows the flow of foreign object inspection processing. In the inspection of the foreign matter, first, the rotation unit 11 rotates the product M, that is, the container B (processing 101). This rotation is performed so that sufficient rotation can be left in the filling liquid Li in the container B even after the rotation of the container B is stopped. Next, the rotation of the container B is stopped (process 102). Then, the container B is stopped, and a plurality of still images of the filling liquid Li are taken as inspection images through the container B with only the filling liquid Li rotating in the container B (processing 103). This imaging is performed while moving the camera 21 to follow the conveyance of the product M (container B) by the conveyance rotor 2 under the control of the inspection processing unit 24 in FIG. Further, it is preferable that the illumination light source 22 and the foreign object image forming plate 23 are also moved corresponding to the movement with the camera 21.

  Here, the foreign material image forming plate 23 is a light-transmitting flat plate with a regular pattern, and an image is formed on the light-transmissive foreign material in the filling liquid Li by the regular pattern. That is, if the foreign matter mixed in the filling liquid Li is light transmissive and its light transmittance is close to that of the filling liquid Li, the image cannot be formed in the inspection image by simple transmission or reflection of illumination light. However, the refractive index of such foreign matter is almost different from that of the filling liquid Li. In other words, regarding the refractive index, it can be said that the light-transmitting foreign matter forms a different refractive index region in the filling liquid Li. When the regular pattern of the foreign matter image forming plate 23 is captured by the camera 21 so as to transmit the filling liquid Li in which the different refractive index region due to such foreign matter exists, the regular pattern is distorted by the different refractive index region. Produce. That is, an image of a light-transmitting foreign material can be formed in the inspection image as a regular pattern image distortion on the foreign material image forming plate 23.

  As can be seen from the above, it is desirable that the regular pattern on the foreign material image forming plate 23 as the foreign material image forming means has a pattern interval smaller than the size of the foreign material mixed in the filling liquid Li. On the other hand, the pattern itself is not particularly limited, and for example, a horizontal stripe pattern, a lattice pattern, or other appropriate patterns can be used. However, when detecting distortion of a pattern image by image processing or the like, a pattern as simple as possible is preferable in that it can be detected more easily, and a typical example is a horizontal stripe pattern. When the foreign object image forming means is configured as the foreign object image forming plate 23, as shown in FIG. 1, a foreign object image forming plate 23 is provided between the illumination light source 22 and the product M, and the illumination light source 22 illuminates from behind. It is necessary to form an imaging system in such an arrangement that the regular pattern of the foreign object image forming plate 23 that has passed through the filling liquid Li is captured by the camera 21.

  An example of an inspection image when a horizontal stripe pattern is used as the regular pattern of the foreign object image forming plate 23 is schematically shown in FIG. The filling liquid Li rotating in the container B is in a state of forming a concave surface on the liquid surface. In general, when the container B is a cylinder as is the case, the filling liquid Li exhibits a lens effect on the light transmitted therethrough. Therefore, the image Pf of the horizontal stripe pattern P on the foreign material image forming plate 23 appears in the inspection image in a state of being enlarged in the horizontal direction. If there is a light transmissive foreign substance in the filling liquid Li, it appears as a distortion Pd in the horizontal stripe pattern Pf. Further, the strain Pd appears at different positions in a plurality of inspection images because the filling liquid Li rotates and the foreign matter moves accordingly. Therefore, a difference between a plurality of inspection images is obtained by the inter-image difference acquisition processing means 25 (process 104), and the presence / absence of a foreign substance is determined by the foreign substance detection processing means 26 based on the result (process 105). This is because, as described above, for example, dirt attached to the container B may form a different refractive index region in the same manner as the light-transmitting foreign matter, and this is prevented from being mistaken as a foreign matter. It is. Then, finally, product selection is performed based on the determination result of the presence or absence of foreign matter (process 107). The product determined to be defective in this sorting process is mechanically sorted by the carry-out rotor 3 and directed to the defective product conveyor 5.

  As described above, in the present invention, by using a foreign matter image forming plate with a regular pattern, foreign matter whose light transmittance is very close to that of the filling liquid can be captured in the inspection image. . Therefore, according to the present invention, it is possible to easily detect a foreign object that has been difficult to detect with the conventional inspection image technique, and it is possible to further increase the accuracy of the foreign object inspection. In addition to the foreign substance inspection, the inspection apparatus is usually adapted to perform several inspections, but these are not shown and will not be described.

  In the above embodiment, the foreign object image forming plate 23 formed in the form of a light-transmitting flat plate with a regular pattern is used as the foreign object image forming unit. In addition to the foreign object image forming plate 23, various forms are possible. For example, it is possible to form a foreign image forming plate with a liquid crystal plate and generate a regular pattern by electrically controlling it. Further, for example, a configuration in which the foreign object image forming means is integrated with the illumination light source 22 by providing a regular pattern to the illumination light source 22 is also possible. Furthermore, for example, a liquid crystal device or a CRT device may be used as an illumination light source, and a regular pattern may be generated in the illumination light source itself.

  According to the present invention, by using a foreign substance image forming means that can form an image of a foreign substance with a regular pattern, a foreign substance whose light transmittance is very close to that of the filling liquid can be captured in the inspection image. ing. Therefore, according to the present invention, it is possible to easily detect a foreign object that has been difficult to detect with the conventional inspection image technique, and it is possible to further increase the accuracy of the foreign object inspection. Such an inspection technique is particularly effective in a manufacturing field where higher quality control is required, such as a pharmaceutical product, and can greatly contribute to the development of the manufacturing technique in such a field.

It is a figure showing typically the composition of the inspection device by one embodiment. It is a figure which shows typically the structural example of a rotation unit. It is a figure which shows the flow of a foreign material inspection process. It is a figure which shows typically the example of a test | inspection image.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Rotation unit 21 Camera 22 Illumination light source 23 Foreign material image formation board (foreign material image formation means)
24 Inspection processing part B Container Li filling liquid

Claims (1)

A foreign matter inspection device for a container-filled liquid that detects foreign matter in a filled liquid having a light transmittance close to that of the filled liquid in the container and having a refractive index different from that of the filled liquid,
  A foreign object image forming plate provided between the illumination light source and the detection target container, in which a pattern interval is smaller than the foreign substance and a regular pattern is formed,
  A control means for rotating the container by giving a rotation pattern for foreign object inspection, and then stopping the container;
  A camera for imaging the first and second transmitted light obtained through the container through the foreign substance image forming plate at at least two different timings during rotation of the filling liquid in the container after the rotation is stopped;
  Processing means for taking a difference between the first and second captured images of the camera and inspecting whether or not the pattern image corresponding to the foreign object image forming plate is distorted and determining that there is a foreign object when there is distortion; ,
  A foreign matter inspection apparatus for liquid filling a container.

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