JP4361156B2 - Appearance inspection equipment for articles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to, for example, a beverage filling machine by a container beverage is filled Appearance or visual inspection equipment of the article for inspecting the appearance of industrial products such as machining products.
[0002]
[Prior art]
In general, industrial products such as machined products inspect whether or not the appearance of products conveyed by a conveyor is normal in the final inspection process. For example, a product on a conveyor is imaged by a camera, the image is processed to automatically check whether the appearance is normal, and only normal products are shipped.
[0003]
FIG. 4 shows whether or not the appearance of the container is normal in the final inspection process, that is, whether or not the lid is correctly attached in the final inspection process after filling the container with a certain amount of beverage and closing the lid. An example in the case of inspection is shown.
[0004]
In FIG. 4, 1 is a conveyor, and the product 2 is guided to the inspection process 3 by the conveyor 1. In the preceding process, the product 2 is filled with a certain amount of beverage in a pre-process, and then a lid (cap) 4 is mounted by a stoppering machine. In the inspection step 3, trigger sensors 5 a and 5 b that detect that the product 2 has been sent to a predetermined position, and the portion of the lid 4 of the product 2 is imaged from three directions by signals from the trigger sensors 5 a and 5 b. Electronic cameras 6a to 6c that perform the above, and an illumination device 7 that illuminates the product 2 from above are provided. Then, the images picked up by the electronic cameras 6a to 6c are sent to the image processing devices 8a to 8c, respectively. The image processing devices 8a to 8c include display devices 9a to 9c for displaying processed images, respectively.
[0005]
The image processing devices 8a to 8c digitize the images captured by the electronic cameras 6a to 6c to obtain a gray image normalized by “0-255”, and detect a change in light and shade caused by a shadow on the top of the cap of the image. Then, by comparing with a normal image stored in advance, it is inspected whether the appearance of the lid portion is normal, that is, whether the lid is normally attached. As a result of this inspection, in the case of a defective product, a reject device (not shown) is operated and rejected, and only normal products 2 are shipped.
[0006]
[Problems to be solved by the invention]
Conventionally, as described above, the images captured by the electronic cameras 6a to 6c are processed by the image processing devices 8a to 8c, and compared with a normal image stored in advance to determine whether or not the appearance of the product 2 is normal. The product is inspected, and in the case of a defective product, the reject device is operated and rejected, and only the normal product 2 is shipped. However, in the conventional inspection method, when the entire side of the product 2 is inspected, a plurality of electronic cameras 6a to 6c must be installed around the product 2 to image the product 2, and Accordingly, it is necessary to provide a plurality of image processing apparatuses 8a to 8c, and there is a problem that the configuration becomes complicated and expensive.
[0007]
The present invention has been made to solve the above problems, to provide a visual inspection equipment of low cost may constitute an article it is possible to the entire circumference examine aspects of product on one electronic camera Objective.
[0008]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided an appearance inspection apparatus for an article, the detection means for detecting that the observation object has been sent to a predetermined position, and an image of the observation object that is equiangularly arranged around the observation object. A plurality of reflecting mirrors that reflect upward, a single electronic camera that operates in response to a signal from the detection means and captures an image of the observation object reflected by the reflection mirror , and between the observation object and the electronic camera And an equiangular pyramid prism having the same number of equiangular surfaces as the plurality of reflecting mirrors, and an image captured by the electronic camera, and comparing the normal image stored in advance with the observation. An image processing device for inspecting the appearance of an object , wherein the apex of the equiangular pyramid prism is arranged on the incident side of the optical path, and the bottom surface is arranged on the front surface of the electronic camera. The plurality of reflections; A visual inspection apparatus of the articles to be distributed radially the same number of images and the reflecting optical system consisting of a plurality of reflecting mirrors between the electronic camera and the observation object is provided, the distance between the electronic camera and the observed object And a telecentric optical system is used as the reflection optical system.
[0010]
A second invention is characterized in that, in the first invention, the electronic camera and the reflection optical system are put in one box.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0013]
( Reference example )
FIG. 1 shows , as an example, a case where the appearance inspection apparatus for an article of a reference example is implemented in a beverage filling machine.
In FIG. 1, reference numeral 1 denotes a conveyor, and a product 2 that is an observation object is guided to an inspection process 3 by the conveyor 1. In the preceding process, the product 2 is filled with a certain amount of beverage in a container such as a glass bottle or a PET bottle, and then a lid 4 is attached by a stoppering machine. The inspection process 3 is provided with trigger sensors 5a and 5b for detecting that the product 2 has been sent to a predetermined position and, for example, a ring-shaped illumination device 7 for illuminating the product 2 from above, and the conveyor 1 An imaging device 11 is provided on one side of the mirror 1, and reflecting mirrors 12 a and 12 b are disposed on the other side of the conveyor 1.
[0014]
In the imaging device 11, an electronic camera 15 is arranged at one corner in the box 14, and reflecting mirrors 16a to 16c made of, for example, a telecentric optical system are arranged at the other three corners. Further, the box 14 is provided with a window 17 at an upper portion on the conveyor 1 side, that is, a portion facing the lid 4 of the product 2 conveyed by the conveyor 1. Further, the reflecting mirrors 12a and 12b are arranged so that the rear side portion of the lid 4 of the product 2 that has been conveyed to a predetermined position is seen from the window 17 of the box 14. That is, when the product 2 is sent to the inspection process 3 by the conveyor 1, the product 2 is detected by the trigger sensors 5a and 5b, the electronic camera 15 is operated, and the window 17 of the box 14 is passed through the reflecting mirrors 16a to 16c. The lid 4 of the product 2 is imaged directly and via the reflecting mirrors 12a and 12b. The imaging device 11 has an optical system composed of the reflecting mirrors 16 a to 16 c in the box 14 and an electronic camera 15 at the final part of the optical system, so that a sufficient imaging distance from the product 2 is obtained. To ensure a sufficient depth of field.
[0015]
And the said electronic camera 15 images three points of the front of the lid 4 part of the product 2 sent to the inspection process 3 and the rear side portion of the lid 4 imaged by the reflecting mirrors 12a and 12b. The image is sent to the image processing device 18. The image processing device 18 includes a display device 19 that displays a processed image. The image processing device 18 digitizes the image captured by the electronic camera 15 to obtain a grayscale image normalized by “0-255”, detects a grayscale change caused by the shadow of the top of the image cap, and stores it in advance. It is inspected whether the appearance of the lid portion is normal or not by comparing with a normal image. Then, if the result of the inspection is that the product is defective, the image processing device 18 operates to reject the defective device and sends only the normal product 2 to the shipping process.
[0016]
In the above configuration, when the product 2 is sent to the inspection process 3 by the conveyor 1, the trigger sensors 5a and 5b detect the product 2 and output a trigger signal to the electronic camera 15. The electronic camera 15 is operated by signals from the trigger sensors 5a and 5b, and the front of the lid 4 portion of the product 2 from the window 17 portion and the reflecting mirrors 12a and 12b through the reflecting mirrors 16a to 16c. The rear side is imaged and the image is output to the image processing device 18. The image processing device 18 digitizes an image picked up by the electronic camera 15, that is, binarizes it into a grayscale image normalized by “0-255”, and compares it with a normal image stored in advance. Therefore, whether or not the appearance of the lid 4 is normal, for example, whether or not the shape (contour) of the lid 4 is abnormal, whether the lid 4 is bent or not, and abnormalities are found in the slits formed in the lid 4. It is inspected whether or not there is a crack in the lid 4 and the processed image is displayed on the display device 19. The administrator of the inspection process 3 can confirm the operation states of the imaging device 11 and the image processing device 18 from the image displayed on the display device 19. Then, if the result of the inspection is that the product is defective, the image processing device 18 operates to reject the defective device and sends only the normal product 2 to the shipping process.
[0017]
According to the above reference example , the entire circumference of the side surface of the product 2 can be inspected by the single electronic camera 15, so that the configuration can be simplified and can be configured at low cost. Further, since the reflecting mirrors 16a to 16c are provided in the box 14 to increase the imaging distance, the depth of field can be increased and a clear image can be captured. In this case, it is possible to increase the depth of field by reducing the aperture under sufficient illumination conditions. Further, by using a telecentric optical system as the reflecting mirrors 16a to 16c, a change in image magnification can be suppressed even if there is an error in focusing due to a shift in the transport position of the product 2, etc. 2 can be measured all around.
[0018]
(First Embodiment)
Next, a first embodiment of the present invention will be described.
FIG. 2 is a configuration diagram of an appearance inspection apparatus for articles according to the first embodiment of the present invention. In the first embodiment, in the above-described reference example , a plurality of, for example, four reflecting mirrors 12a to 12d are arranged equiangularly around the lid 4 of the product 2 that has been transported to the inspection process 3, and the reflected light is halfway. For example, an equiangular pyramid (regular polygonal pyramid) prism 21 having the same number of equiangular surfaces as the reflecting mirrors 12 a to 12 d is provided on the front surface of the electronic camera 15. In this case, the reflecting mirror 22 is arranged at the center upper part of the ring-shaped lighting device 7, and the image of the lid 4 portion reflected on the four reflecting mirrors 12 a to 12 d is reflected on the window 17 portion of the box 14.
[0019]
That is, the electronic camera 15 can capture an image of the lid 4 portion of the product 2 reflected on the reflecting mirrors 12a to 12d through an optical path including the equiangular pyramid prism 21, the reflecting mirrors 16a to 16c, the window 17, and the reflecting mirror 22. It is configured as follows. At this time, as shown in FIG. 3, by arranging the equilateral pyramid prism 21 on the front surface of the electronic camera 15, the image picked up in the central part of the electronic camera 15 is removed, and the image picked up outside of the electronic camera 15 is set to the center side. I try to capture it.
[0020]
FIG. 3B shows an image picked up when the equilateral pyramid prism 21 is not provided. The top image of the lid 4 at the center is located, and the side images of the lid 4 reflected on the reflecting mirrors 12a to 12d at the four corners. Is located. FIG. 3C shows an image picked up when the equiangular pyramid prism 21 is provided. The image picked up at the center of the electronic camera 15 shown in FIG. The side images of the lid 4 shown in 12a to 12d are Wanhua images that are radially distributed. That is, in the prism, as shown in FIG. 3A, light is refracted according to Snell's law, and the optical path changes. For this reason, the light coming from the outside is refracted inward, and the inner light is totally reflected at the interface or projected onto a portion not reflected in the electronic camera 15, and only the portion indicated by the oblique line A enters the electronic camera 15. Therefore, by using the equilateral pyramid prism 21, it is possible to capture an image with a lens system having a larger magnification than when no prism is used, and it is possible to improve the imaging density and obtain a high resolution.
[0021]
The image captured by the electronic camera 15 is sent to the image processing device 18. The image processing device 18 digitizes the four images picked up by the electronic camera 15 in the same manner as in the first embodiment to obtain a gray image normalized by “0-255”, and stores the normal image stored in advance. By comparing, as shown in the first embodiment, it is inspected whether the appearance of the lid 4 part is normal, and the processed image is displayed on the display device 19. Then, if the result of the inspection is that the product is defective, the image processing device 18 operates to reject the defective device and sends only the normal product 2 to the shipping process.
[0022]
In the first embodiment, a plurality of reflecting mirrors 12a to 12d are equiangularly arranged around the product 2 conveyed to the inspection process 3, and images reflected on the reflecting mirrors 12a to 12d are guided to the electronic camera 15. In the middle of the reflected light, for example, an equilateral pyramid prism 21 having the same number of equiangular surfaces as the reflecting mirrors 12a to 12d is arranged on the front surface of the electronic camera 15, and the images reflected on the reflecting mirrors 12a to 12d are radially developed. Since all the images captured through the reflecting mirrors 12a to 12d are the same size, the entire circumference of the product 2 can be measured with one electronic camera 15. . In addition, by arranging the prism, the image captured at the center of the electronic camera 15 is removed, and the image captured at the outside of the electronic camera 15 appears on the center side. Resolution can be obtained. Further, by using a telecentric optical system as the reflecting mirrors 16a to 16c, similarly to the reference example , even if there is a focusing error due to a shift in the transport position of the product 2, a change in image magnification can be suppressed. It can always measure stably.
[0023]
In the above-mentioned reference example and embodiment, in the beverage filling device, the case of inspecting whether the lid 4 is normally attached to the container has been described. However, for other industrial products such as general machined products Of course, even in the case of inspecting whether or not the appearance of the manufactured product is normal, it can be carried out in the same manner as in the above embodiment.
[0024]
【The invention's effect】
As described above in detail, according to the present invention, a plurality of reflecting mirrors are equiangularly arranged around the product conveyed to the inspection process, and an image reflected on the reflecting mirror is guided to the electronic camera, and the reflected light path An equilateral pyramid prism having the same number of equiangular surfaces as the reflecting mirrors is arranged in the middle of the lens so that the image reflected on the reflecting mirrors is picked up as a radiantly developed Wanhua image. All the images captured in this way are the same size, and the entire circumference of the product can be measured with a single electronic camera. In addition, by arranging the prism, the image captured at the center of the electronic camera is removed, and the image captured at the outside of the electronic camera is reflected on the center side. Resolution can be obtained. Since the reflection optical system including a plurality of reflecting mirrors is provided in the optical path of the imaging device to increase the imaging distance, the depth of field can be increased, and a clear image can be captured. In addition, since a telecentric optical system is used as the reflecting optical system provided in the optical path, a change in image magnification can be suppressed even when there is an error in focusing due to a shift in the transport position of the product, and stable measurement is always possible. .
[Brief description of the drawings]
FIG. 1 is a configuration diagram of an appearance inspection apparatus for articles according to a reference example .
FIG. 2 is a configuration diagram of an article appearance inspection apparatus according to the first embodiment of the present invention.
FIG. 3 is a view for explaining the operation of the optical system in the embodiment.
FIG. 4 is a configuration diagram of a conventional article appearance inspection apparatus.
[Explanation of symbols]
1 Conveyor 2 Product 3 Inspection process 4 Lid 5a. 5b Trigger sensor 7 Illuminating device 8a-8c Image processing device 9a-9c Display device 11 Imaging device 12a-12d Reflector 14 Box 15 Electronic camera 16a-16c Reflector 17 Window 18 Image processor 19 Display device 21 Conical pyramid 22 Reflection mirror

Claims (2)

Detection means for detecting that the observation object has been sent to a predetermined position, a plurality of reflecting mirrors arranged equiangularly around the observation object and reflecting the image of the observation object upward, and from the detection means One electronic camera that operates according to a signal and captures an image of an observation object reflected by the reflecting mirror, and is provided in the middle of an optical path between the observation object and the electronic camera, and has the same number as the plurality of reflecting mirrors And an image processing device that inspects the appearance of the observation object by comparing an image captured by the electronic camera with a normal image stored in advance.
While placing the apex of the equilateral pyramid prism on the incident side of the optical path and the bottom surface on the front surface of the electronic camera,
An apparatus for inspecting the appearance of an article in which the same number of images as the plurality of reflecting mirrors are distributed radially around the center of a captured image by the equiangular pyramid prism, the plurality of reflecting mirrors being disposed between the electronic camera and the observation object. A visual inspection apparatus characterized in that a reflection optical system is provided, the distance between the electronic camera and the observation object is increased, and a telecentric optical system is used as the reflection optical system. Appearance inspection apparatus according to claim 1 Symbol placement of the article characterized by comprising putting said reflective optical system and the electronic camera in one box.

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