JPS62220844A - Inspection device for foreign matter - Google Patents

Abstract

PURPOSE:To enable sure and high-speed detection of foreign matter even if the amt. of the foreign matter is small by rotating a material to be inspected to move the foreign matter, and taking the absolute value of the difference between the images at the different points thereby offsetting the videos except the video of the foreign matter. CONSTITUTION:The material 1 to be inspected is held static for a while in order to stabilize the foam in the liquid contained therein and the liquid surface; thereafter, the material 1 is rotated at a specified number of revolutions. Gentle flow to the extent of obviating the generation of foam and vortex in the liquid in the material to be inspected is generated by such rotation, by which the foreign matter incorporated therein is excited and moved. The light which is illuminated from an illuminating source 2 and is transmitted through or reflected by the material 12 is taken into an industrial camera 3 and the image of the material 1 is taken as a input image A into a processor 4. The image is again taken as an input image B into the processor after the specified time. The absolute value of the difference form the first input image A is obtd., by which the vessel and background videos of the material 1 are offset and only the synthesized images at the two points of the moving foreign matter is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a foreign matter inspection device in a transparent fluid, and particularly to a foreign matter inspection device that can detect foreign matter reliably and at high speed even when the amount of foreign matter is small.

[Background of the invention]

Conventionally, in order to inspect for foreign substances mixed into liquid containers such as eye drops and syringes, it has been necessary to rely on manual visual inspection. However, with this method, many things are overlooked, and it is difficult to detect minute foreign objects and to save labor and speed up the inspection process. In addition, recently, foreign object detection has been performed using image processing processors, but since the amount of foreign object information contained in the input image varies greatly depending on the size of the foreign object and the illumination angle, etc. It has been extremely difficult to improve detection accuracy.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a foreign matter inspection device that can reliably determine the presence or absence of minute foreign matter or minute foreign matter, and that can perform high-speed detection.

[Summary of the invention]

The present invention moves the foreign object by a method such as rotating the object to be inspected, inputs images twice at a fixed time interval, and calculates the absolute value of the difference between the two images. This method is characterized in that images of objects other than the foreign object are canceled out to obtain an image of only the foreign object.

[Embodiments of the invention]

FIG. 1 shows an embodiment of a foreign matter inspection device according to the present invention. The object to be inspected 1 is mounted on a rotary table 5.

The illumination 2 illuminates the object 1 to be inspected optimally for the industrial camera 3, and a light source with a predetermined wavelength is adopted in consideration of the transparency of the liquid, the sensitivity of the camera, and the like. Further, the illumination light is fixed at a position on the object 1 to be inspected where it does not cause diffused reflection or the like. The transmitted or reflected light of the illumination light from the inspected object 1 is captured by the industrial camera 3, and an image of the inspected object 1 including the moving foreign matter is input to the image processing processor 4.

FIG. 2 is a flowchart showing the operation of this embodiment.
FIG. 3 is a diagram showing an example of an image processing process. In FIG. 2, in step 100, a pretreatment is performed in which the object 1 to be inspected is kept in a stationary state for a while in order to stabilize the bubbles in the liquid content and the surface of the liquid, and then in step 101, the rotating table 5 is rotated. The object to be inspected 1 is rotated a certain number of times. This rotation generates a gentle flow that does not create bubbles or vortices in the liquid in the object to be inspected, and excites and moves the mixed foreign matter. In step 102, the image of the object to be inspected 1 is taken into the processor 4 as an input image. The image at this time includes an image 6 of the container and an image 7 of mixed foreign matter, like the first image P1 in FIG. Then, after a certain period of time, the image is captured again as input image B (step 103). In the following step 104, the absolute value of the difference between the first input image A and the second input image B is determined. Through this calculation, the container and background image of the object to be inspected 1 are canceled out, and the first image Q in Fig. 3 is obtained.
The image after calculation processing as shown in 1. The person is a moving foreign object. 2
Only the composite image at the point will be displayed. Furthermore, the above operation is repeated a plurality of times to obtain an integrated image of the composite image. That is, the next input image B is input and added to the composite image A (Q, in Fig. 3') (steps 106 and 107) to obtain the image P2 in Fig. 3.
In step 103, the next input image B is input, and in step 104, this is subtracted from the image P2 to perform absolute value calculation, thereby obtaining the third drawing image Q2. If such processing is repeated, for example, three times, only the image of the foreign object mixed in the object to be inspected will be integrated, and an image Q4 of only the moving trajectory of the foreign object will be obtained.

This image Q4 is an image that emphasizes only the presence or absence of foreign matter in the object 1 to be inspected, and the presence or absence of foreign matter can be reliably detected even in the case of minute foreign matter or trace amounts of foreign matter. As described above, according to this embodiment, foreign matter can be detected with high accuracy without being affected by the shape of the container or the presence or absence of scratches. Also, the image memory for storing image data is the image A9 of the processing in FIG.
Arithmetic processing is possible if there are two screens shown as image B.

Next, if the object 1 to be inspected is left in a stationary state, one foreign object may sink to the bottom. In such a case, the flowchart shown in FIG. 2 is changed and an image of the object to be inspected 1 before being rotated is first input as the standard image A.

This image A can be regarded as an image free of foreign matter. Next, there is a method of rotating the inspection object 1, capturing images B, , B, . . . at regular intervals, and integrating the differences with the standard image A. That is, the calculation ΣB, -A 1 11 is performed. This method has the following advantages. In other words, when the movement of the foreign object is slight, the processing method shown in Figure 2 causes the foreign object to overlap between the two images to be subtracted, and the overlap is canceled out. It is possible to emphasize the overlap. In addition, if it is possible to secure sufficient image memory capacity, the images inserted at fixed time intervals after rotation are stored in Bl + B2.
+..., the overlap of the foreign object in the two images can be minimized by integrating the absolute value of the difference between the two images separated by a certain distance, for example, by performing calculations such as can be suppressed to

The above application examples are based on the flow rate of the liquid inside the object to be inspected, and are generally combined with methods that optimize the flow rate based on the viscosity of the liquid, the internal shape of the object to be inspected, the rotation speed, etc. , it is necessary to improve inspection accuracy and shorten inspection time. In general, in order to shorten the inspection time, it is better to rotate the inspection object less often, and in order to increase the rotation speed of the liquid inside the inspection object in a short time, the internal shape of the inspection object is circular. It is best to avoid this. Examples of internal shapes that take this point into consideration are shown in FIGS. 4A to 4C. Fig. 4A shows one with a rectangular internal shape; Figure B shows a circular vessel with protruding plates to agitate the internal liquid, and Figure 4C has a protrusion on the bottom to make it easier to suspend precipitated foreign matter.

Further, in the above embodiment, the object to be inspected is rotated, but it can also be applied to a case where the object to be inspected moves at a constant speed on a line, such as in the inspection process of bottled products. That is, in this case, by synchronizing with the speed of the line and making the moving image stand still, it is possible to excite the liquid in the object to be inspected and capture the image after movement. If a curved part or a wavy part is provided in a part of the line, the liquid can be excited and moved more reliably even without providing any means for supporting the object to be inspected.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to quickly and reliably inspect minute foreign matter or minute foreign matter mixed into a liquid product.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the foreign object inspection device according to the present invention, FIG. 2 is a flowchart showing the operation of the embodiment of FIG. 1, and FIG. 3 is a diagram showing the image processing in the embodiment of FIG. 1. FIG. 4 is a diagram showing an example of the shape of the object to be inspected. DESCRIPTION OF SYMBOLS 1... Inspection object, 2... Illumination, 3... Industrial camera, 4... Image processing processor, 5... Inspection object rotating table, 6... Image of container, 7. ...Contaminated foreign object image.

Claims (1)

[Scope of Claims] 1. Supporting and driving means that supports a transparent container and moves the transparent fluid contained in the container, a camera that captures an image of the transparent container, and arithmetic processing of the output image of the camera. and an image processing device means, and the image processing means includes:
By calculating the absolute value of the difference between the first image of the transparent container taken at a certain point in time and the second image of the transparent container taken when the transparent fluid was moved by the drive by the support drive means, A foreign matter inspection device characterized by having a function of extracting an image of a mixed foreign matter. 2. The first and second images are images of the transparent container taken at two different times after the transparent fluid was driven by the support driving means. Foreign matter inspection device according to item 1. 3. The first and second images are images of the transparent container taken before and after the transparent fluid is driven by the support driving means, respectively, according to claim 1. Foreign matter inspection equipment. 4. The image processing means has a function of repeating the process of capturing the first and second images and calculating the absolute value of the difference therebetween multiple times, and superimposing and outputting the resulting image of the contaminated foreign object. A foreign matter inspection device according to claim 1, characterized in that the foreign matter inspection device has: 5. The foreign matter inspection device according to claim 1, wherein the transparent fluid is driven by the support drive mechanism by applying rotational or vibrational driving to the transparent container and then stopping the driving.