JPH11248644A - Defect inspecting method and device for container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make highly precisely detectable defects due to discoloring in various shapes of light transmissible containers. SOLUTION: This defect inspecting device includes strip plate materials having both ends opposed to each other at given distances and bent around the screw port 17 of a bottle 7 moved up to a predetermined height by an elevating rotor 3, a reflecting member 8 arranged concentrically with the screw port 17 for scattering and reflecting a light injected to the inner periphery and a face lighting device 9 almost square shaped in a plane view isolated a proper level from the reflecting member 8. A light is made incident from the face lighting device 9 on the inner periphery of the reflecting member 8 and the light reflected and scattered by the reflecting member 8 is radiated toward the screw port 17. Outside the reflecting member 8, an image pickup device 2 is arranged to be opposed to the opening 18 of the reflecting member 8 for giving an image obtained by picking up the image of the screw port 17 from the opening 18 to a computer 1 for judgement whether defects due to discoloring exist or not.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for inspecting a light-transmissive container such as a bottle and a plastic container for defects, and an apparatus used for performing the method.

[0002]

2. Description of the Related Art When manufacturing light-transmitting containers such as bottles and plastic containers, heat and foreign matter are mixed in the containers.
Discoloration may occur at the screw opening for screwing the lid. Since such a product is a defective product, it is necessary to inspect whether or not the threaded portion of each product is discolored, and if the discoloration occurs, the product must be excluded from shipping. Therefore, the inspection of the screw opening was performed as follows.

FIG. 4 is a schematic front view showing the configuration of a conventional inspection apparatus. In the figure, reference numeral 35 denotes a mounting table. On the mounting table 35, a bottle 37 having a screw opening 37a provided on the upper side is mounted. On one edge side of the mounting table 35, a rectangular surface illuminator 38 is disposed to face the screw opening 37a of the bottle 37, and the surface illuminator 38
Thus, planar light is applied to the screw opening 37a and its surroundings. On the other side of the mounting table 35, an image pickup device 32 for picking up an image of the screw opening 37a is disposed so as to face the surface illuminator 38, and the image pickup device 32 picks up an image of the screw opening 37a. The obtained image is provided to a computer 31 having an image processing function.

A computer 31 is connected to a screw opening from an image pickup device 32.
Given an image containing the image of 37a, capture it.
If there is discoloration in the screw opening 37a, that portion absorbs a greater amount of light emitted from the surface illuminator 38 than the other portions, so the brightness of the discolored portion in the image of the screw opening 37a is lower than that of the other portions. Lower than brightness. The computer 31 binarizes the captured image to generate a binarized image, determines whether an image having a predetermined diameter or more exists in the obtained binarized image, and determines whether the image exists. , It is determined that there is no discoloration, and if it does not exist, it is determined that there is no discoloration.

[0005]

However, the conventional inspection apparatus has the following problems. FIG.
FIG. 5 is an explanatory diagram illustrating a result of inspecting a screw opening by the conventional inspection device illustrated in FIG. 4, in which 47 is an image of the screw opening. The screw opening has a mountain-shaped screw-shaped convex on the peripheral surface of the cylindrical screw opening main body. In such a screw opening,
As shown in FIG. 4, when light is projected from one direction and an image of the screw opening is taken, light is refracted on the surface of the tapered side surface of the convex portion, and therefore, as shown in FIG. The discolored part image
In addition to the image 48, the double-helical tapered images 49, 49,
Are generated, so that there is a problem that an erroneous determination occurs. In order to solve this problem, the tapered part images 49, 49,
Is masked and excluded from the target of the inspection, but in this case, the tapered side surface of the convex portion is not inspected, and a defect due to discoloration occurring in that portion cannot be detected. was there.

The present invention has been made in view of the above circumstances, and an object of the present invention is to irradiate the container with light from the surroundings of the container to provide light-transmitting containers of various shapes. It is an object of the present invention to provide a container defect inspection method capable of detecting a defect with high accuracy and an apparatus used for implementing the method.

[0007]

According to a first aspect of the present invention, there is provided a method for inspecting a defect of a container, the method comprising irradiating a light-transmissive container with light, capturing an image of the container, and obtaining an image based on the image. In the defect inspection method, light is applied to the container from around the container.

A method for inspecting a defect of a container according to a second invention is the method according to the first invention, wherein the container has a substantially cylindrical shape, an opening is provided in a portion corresponding to an optical path for imaging of the container, and the light incident on the inner surface is provided. A reflection member that diffusely reflects the outside of the container,
Light is incident on the inner surface of the reflection member, and the diffusely reflected light is applied to the container.

[0009] A defect inspection method for a container according to a third invention is characterized in that, in the first or second invention, the screw opening of the container is irradiated with light to inspect a defect caused by discoloration occurring in the screw opening. I do.

According to a fourth aspect of the present invention, there is provided a container defect inspection apparatus which irradiates a container with light, irradiates the container with light, an image pickup apparatus for picking up an image of the container, and processes an image obtained by the image pickup apparatus to obtain a defect. And a means for judging the presence or absence of the defect. The light irradiation means is configured to irradiate the container with light from around the container.

According to a fifth aspect of the present invention, in the container defect inspection apparatus according to the fourth aspect, the light irradiating means has a substantially cylindrical shape, and an opening is provided in a portion corresponding to an optical path for imaging the container by the imaging device. A reflecting member for diffusing and reflecting the light incident on the inner surface, and a light source for incident light on the inner surface of the reflecting member. The reflecting member is externally fitted to the container, and is diffusely reflected by the reflecting member. Characterized in that the light is irradiated to the container.

According to the first, third and fourth aspects of the present invention, for example, a light-transmitting container is irradiated with light from around the container centering on an axis parallel to the central axis of the container. Light can be applied almost uniformly to the entire area of the inspection target part, and even if the container has various shapes, an image obtained by imaging the inspection target part includes a discolored portion generated in the inspection target part. Since an image having substantially uniform luminance can be obtained except for the above, a defect due to discoloration can be detected from the image with high accuracy.

According to the second and fifth aspects of the present invention, a substantially cylindrical reflecting member is disposed coaxially with the center axis of the container, light is incident on the inner surface of the reflecting member from a light source, and the light is diffusely reflected by the reflecting member. The irradiated light is irradiated on the portion of the container to be inspected. Such a light source and a reflecting member are inexpensive, and the apparatus cost is low.

[0014]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of an apparatus according to the present invention. In the figure, reference numeral 5 denotes a disk-shaped mounting table. The rod 4 is suspended from the center of the lower surface of the mounting table 5. The rod 4 is connected to the elevating / rotating device 3, and the elevating / rotating device 3 raises the rod 4 and the mounting table 5 to a predetermined height and then rotates one turn in the direction of the arrow, and then returns to the original height. Is dropped.

In the vicinity of the periphery of the mounting table 5, four claw-shaped clampers 6, 3, 6, (6) are shown in FIG. I have. At a substantially center of the mounting table 5, a bottle 7 having a screw opening 17 provided thereon is mounted, and the bottle 7 is provided with a clamper 6, 6, 6, and 6.
It is clamped by (6).

Around the screw opening 17 of the bottle 7 which has been raised to a predetermined height by the elevating / rotating device 3, both ends of a strip-shaped plate are bent so as to face each other at a predetermined distance,
A reflecting member 8 for diffusing and reflecting light incident on the inner peripheral surface is arranged concentrically with the screw opening 17, and a planar illuminator 9 having a substantially square shape in plan view is provided on the central axis of the reflecting member 8. Are arranged at an appropriate height from the reflecting member 8. For example, the following is used as the reflection member 8. That is, a strip-shaped metal plate whose one surface is mirror-finished is bent into a substantially annular shape such that both ends of the metal plate face each other at a predetermined distance with the mirror-finished surface facing inward, and a plurality of minute A sheet provided with substantially uniform irregularities is adhered to form the reflection member 8. Also,
The reflection member 8 may be formed by bending a strip-shaped metal plate having one surface roughened in the same manner as before.

Light is incident on the inner peripheral surface of the reflecting member 8 from the surface illuminator 9, and the light diffusely reflected by the reflecting member 8 is applied to the screw opening 17. The imaging device 2 is disposed outside the reflection member 8 so as to face the opening 18 of the reflection member 8. The imaging device 2 converts an image obtained by imaging the screw opening 17 from the opening 18 into a defect due to discoloration. The presence / absence is given to the computer 1.

When the rotation of the rod 4, the mounting table 5, and the bottle 7 is started after the rod 4, the mounting table 5, and the bottle 7 have been moved to predetermined positions, the lifting / rotating device 3 sends a rotation start signal to the imaging control unit 16 of the computer 1. In the imaging control unit 16, an imaging interval and the number of times of imaging according to the rotation speed of the rod 4 by the elevating and rotating device 3 are set in advance, and when the rotation start signal is given, the imaging control unit 16 2 is given an imaging command at the imaging interval until the number of times of imaging is reached. Each time an imaging command is given from the imaging control unit 16, the imaging device 2 takes an image of the screw opening 17 of the bottle 7, gives the obtained image to the frame memory 11 of the computer 1, and stores the image there. For example, when the field of view of the imaging device 2 is 90 ° and the rotation speed of the elevating / lowering rotation device 3 is 0.25 seconds / time, five frames are captured at an imaging interval of 0.016 seconds, and each image is a frame. Memory 11
Is stored.

When an image is stored in the frame memory 11,
The CPU 10 of the computer 1 causes the smoothing processing unit 12 to perform smoothing processing for smoothing the luminance of a plurality of pixels constituting each image, and then performs the binarizing unit 13 to binarize each image. Thus, a binarized image is obtained, and is provided to the calculation unit 14. Calculator
The step 14 projects the binarized image on the x-axis, calculates the diameter of the discolored part if it exists, and gives the obtained result to the determination unit 15. A threshold such as φ0.2 mm is set in the determination unit 15 in advance, and the determination unit 15 compares the diameter of the discoloration unit provided by the calculation unit 14 with the threshold. It is determined that there is a defect, and the alarm device 20 outputs an alarm.

FIG. 2 is an explanatory diagram for explaining an example of an image stored in the frame memory 11 shown in FIG.
27 is a screw mouth image. As shown in FIG.
Is irradiated with light diffusely reflected from the reflecting member 8,
Regardless of the unevenness of the screw opening 17, as shown in FIG. 2, a screw opening image 27 having substantially uniform luminance is obtained except for the discolored portion image 28.

FIG. 3 is an explanatory diagram for explaining a method of calculating the diameter of the discolored portion. FIG. 3A shows a binarized image, and FIG.
Is a graph showing the result of projecting the binarized image. FIG.
As shown in (a), only the discolored portion image 28 is extracted from the binarized image. By repeating the operation of accumulating the binarized values of each pixel constituting the binarized image in the y-axis direction in the x-axis direction, a projected image as shown in FIG. 3B is obtained. By calculating the width of this projected image, the diameter of the discolored portion image 28 in the x-axis direction is obtained.

[0022]

As described above in detail, the first, third and fourth embodiments are described.
According to the present invention, defects can be detected with high accuracy even in containers having various shapes.

According to the second and fifth aspects of the present invention, it is possible to detect a defect of a container with high accuracy at low equipment cost.
The present invention has excellent effects.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an apparatus according to the present invention.

FIG. 2 is an explanatory diagram illustrating an example of an image stored in a frame memory illustrated in FIG. 1;

FIG. 3 is an explanatory diagram illustrating a method of calculating a diameter of a discolored portion.

FIG. 4 is a schematic front view showing a configuration of a conventional inspection device.

FIG. 5 is an explanatory diagram illustrating a result of inspecting a screw opening by the conventional inspection device illustrated in FIG. 4;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 computer 2 imaging device 3 elevating and rotating device 4 rod 5 mounting table 7 bottle 8 reflecting member 9 surface illuminator 17 screw mouth 18 opening

Claims (5)

[Claims] 1. A method of irradiating a light-transmissive container with light, capturing an image of the container, obtaining an image, and inspecting the container for defects based on the image, comprising: A defect inspection method for a container, comprising irradiating light. 2. A container having a substantially cylindrical shape, wherein an opening is provided in a portion corresponding to an optical path for imaging of the container, and a reflecting member that diffuses and reflects light incident on an inner surface of the container is externally fitted to the container. The method for inspecting a defect of a container according to claim 1, wherein light is incident on an inner surface of the reflection member, and the light diffusely reflected is applied to the container. 3. The container according to claim 1, wherein the screw opening of the container is irradiated with light, and a defect caused by discoloration occurring in the screw opening is inspected.
Inspection method of the container described in the above. 4. A container comprising: light irradiating means for irradiating light to a container; an image pickup device for picking up an image of the container; and means for processing an image picked up by the image pickup device to determine the presence or absence of a defect. The defect inspection apparatus according to any one of claims 1 to 3, wherein the light irradiating means irradiates the container with light from around the container. 5. The light irradiating means has a substantially cylindrical shape, an opening is provided in a portion corresponding to an optical path for imaging the container by the imaging device, and a reflecting member for diffusing and reflecting light incident on an inner surface. And a light source for emitting light to an inner surface of the reflection member, wherein the reflection member is fitted on the container, and the light diffusely reflected by the reflection member is applied to the container. Item 5. A container defect inspection device according to Item 4.