JPH0210253A - Method for visual inspection of bottle - Google Patents

Abstract

PURPOSE:To improve the accuracy in visual inspection of a bottle by providing a position regulating mechanism by which the starting position of rotation at the outer surface of the bottle is set at the specified position based on the shape of the bottle when the rotation is started. CONSTITUTION:A bottle 1 is rotated and advanced straightly within an inspecting station 5 through a position regulating mechanism 4 with a belt conveyer 2. The image of the side surface of the mouth of the bottle 1 is picked up with several TV cameras 6 without dead areas. The pass or fail is judged with an image processing device 7. A cam 15 provided on a rotary disc 14 is engaged with a dimple 13 of the bottle 1, and the rotating direction and the rotation starting position of the bottle 1 are aligned with the mechanism 4. In this way, the starting end part S of a thread groove in the image screen of each camera can be grasped beforehand. A window region W1 including the starting end part S can be narrowly set accurately as shown in Figure (a). Therefore, the starting end part S can be made to appear at the known specified position beforehand at each scene. The image is not judged as a defect, thereby the accuracy in visual inspection is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for visually inspecting a bottle such as a Western liquor bottle to determine the presence or absence of defects (chips, cracks, etc.) by visual inspection.

[Conventional technology]

Conventionally, a multi-window type visual inspection device has been used for visual inspection of such bottles.

A multi-window visual inspection device captures an image of the inspection target area with a television camera, creates and imports binary image data, and compares this data with predetermined criteria to determine the quality of the target area. In this case, the area to be inspected is divided into multiple small areas (each small area is called a window) in advance.
This is an inspection device that makes it possible to judge the quality of each window by setting different criteria for each window.

Documents describing such multi-window type visual inspection equipment include pages 779 to 779 of the magazine "Fuji Jiho VOL, 59th floor 12.1986" published by Fuji Electric Co., Ltd.
Page 784 can be mentioned.

[Problem to be solved by the invention]

When inspecting the side of the mouth of a bottle using such a multi-window visual inspection device, the side of the mouth of the bottle is imaged with a television camera, and the differential binarized image of the imaged output is inspected. However, there were the following problems.

That is, although a screw groove for camping is formed in the mouth of the bottle, the starting end of this screw groove appears as a defect when viewed in a differential binarized image. In other words, the starting end of the screw groove is mistakenly recognized as a defect.

FIG. 2 is a differential binarized image of the imaging output of the side surface of the bottle mouth, but the starting end S of the cap screw groove is mistakenly recognized as a defect.

When inspecting the mouth of a bottle, in order to image the appearance of the mouth of the bottle to be inspected, it is necessary to rotate the bottle as it passes in front of a television camera and sequentially capture images over multiple scenes. Since the orientation of the bottle's rotation direction and the rotation start position were not fixed, it is not known exactly where the starting end of the screw groove will be in each scene, so the starting end of the screw groove is likely to be A wide range of areas are selected as one window, and the criteria for determining the window are as follows:
The image of the starting end of the screw groove was changed to be rough enough not to be judged as a defect.

In this way, if the window area is wide, there is a high probability that a genuine defect exists within it, and in that case, the defect will not be judged as a defect because the judgment criteria are rough in that window area, and the visual inspection of the bottle will be difficult. There was a problem in that the accuracy was lost.

It is an object of the present invention to solve the problem of visual inspection of bottles that occurs when the window area taken is too wide in order to avoid determining the image of the starting end of a screw groove as a defect in the visual inspection of bottles using a multi-window type visual inspection device. An object of the present invention is to provide a method for visually inspecting bottles that can prevent a decrease in accuracy.

[Failure to solve the problem]

In order to image the external appearance of the bottle to be inspected, the bottle is rotated and passed in front of a television camera to sequentially capture images over multiple scenes. A position regulating mechanism is provided to regulate the bottle to be in a specific predetermined position depending on the shape of the bottle.

FIG. 4 is an external view of the bottle, and it can be seen that a dimple 13 is formed at the lower side of the bottle 1 (this is generally formed in bottles such as Western liquor bottles).

FIG. 5 is a schematic diagram of the position regulating mechanism, which consists of a rotating disk 14 and a cam 15 formed around it.

When the bottle 1 starts to rotate, the cam 15 rotating together with the rotary disk 14 is hooked on the dimple 13 of the bottle 1 to drive the bottle 1 and start rotating.

[Effect]

As a result, the same specific area on the outer circumference of the bottle (starting end of the screw groove)
appears at a pre-known specific position in each scene, and as a result, the window area that is taken to prevent the image of the starting end of the screw groove from being judged as a defect is shown in Wl in Fig. 3. Compared to other window areas (shaded areas), it is possible to narrow the window area for each scene, thereby improving the accuracy of bottle appearance inspection.

〔Example〕

FIG. 1 is a plan view showing one embodiment of the present invention.

In the figure, 1 is a bottle, 2 is a belt conveyor, 3 is a lighting device, 4 is a position regulation mechanism, 5 is an inspection station, 6 is a television camera, 7 is an image processing device that constitutes a multi-window type visual inspection device, and 8 is the video signal.

The bottles 1 are conveyed to an inspection station 5 by a belt conveyor 2. Inside the inspection station 5, the bottle 1 moves straight while rotating. The side surface of the mouth of the bottle 1 is imaged by several television cameras 6 without blind spots, and an image processing device (multi-window type visual inspection device) 7 is used to judge the quality.

The image processing device 7 performs horizontal differentiation on the video signal 8 sent from the television camera 6, and uses it as an inspection image. If a screw groove for a cap is formed on a bottle, its starting end S appears in the inspection image as if it were a defect (see FIG. 2).

Therefore, a position regulating mechanism 4 for regulating the rotation start position (and rotation direction) of the bottle is provided upstream of the inspection station 5 to align the rotation direction and rotation start position of the bottle 1. Thereby, the position of the starting end S of the screw groove in the image captured by each television camera 6 can be known in advance.

Therefore, the window region W1 including the starting end S of the screw groove is
As seen in the figure, it can be set exactly narrow.

As already explained with reference to FIGS. 4 and 5, the position regulating mechanism 4 is configured to control the position of the bottle 1 by inserting a cam 15 provided on the rotary disk 14 into the dimple 13 of the bottle 1. This is to align the direction of rotation and the rotation start position.

〔Effect of the invention〕

As explained above, according to the present invention, by providing a position regulating mechanism for aligning the rotational direction of the bottle and the rotation start position at the front stage of the inspection station, the starting end of the screw groove in the image captured by the television camera is The position of S can now be accurately grasped, and the coarse window area that is used as a criterion for preventing the starting edge S from being detected can be accurately narrowed, which widens other areas and improves the accuracy of defect inspection. There are advantages.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an embodiment of the present invention, FIG. 2 is an explanatory view showing a differential binarized image of the imaging output of the side surface of the bottle mouth, FIG. 3 is an explanatory view of the window area, and FIG. The figure is an external view of the bottle, and FIG. 5 is a schematic diagram of the position regulating mechanism. Explanation of symbols 1... Bottle, 2... Belt conditioner, 3... Lighting H
14...Position regulation mechanism, 5...Inspection station,
6...TV camera, 7...Image processing device constituting the multi-window visual inspection device, 8...Video signal loading 1. Illustration agent, patent attorney Akio Namiki

Claims (1)

[Claims] 1) Binarized image data is created and imported by capturing an image of the inspection target area with a television camera, and when determining the quality of the target area by comparing the data with predetermined criteria, multiple inspection target areas are prepared in advance. In a method for visually inspecting bottles using a multi-window type visual inspection device, the bottle is divided into small areas (each small area is called a window), and the judgment criteria are different for each window to determine the quality of each window. In order to image the appearance of the bottle to be inspected, the first step is to rotate the bottle while passing in front of a television camera and sequentially capture images over multiple scenes, and the rotation start position on the outer periphery of the bottle prior to this step. a second step in which the bottle is regulated to be at a specific predetermined position due to the shape of the bottle, and thereby the same specific part on the outer periphery of the bottle is made to appear in a pre-known specific window in each of the scenes; , a third step in which the criteria for judgment in the specific window are made different from those in other windows, and the visual inspection of the bottle is characterized in that a specific part on the outer periphery of the bottle is not judged to be defective. Method.