JP3307570B2 - Container cap inspection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a container cap inspection apparatus for inspecting a cap mounted on a container by photographing the cap with a camera.

[0002]

2. Description of the Related Art As a device for inspecting a side surface of a cap mounted on a container for defects such as irregularities, a projector for emitting diffused light to the side surface of the cap and a camera for photographing light from the cap. There is something. The containers are supplied in a row by a conveyor. Four cameras shoot the entire circumference of the side at 90 degrees. In the obtained image, a portion different in brightness from the background is determined as a defect.

In recent years, plastic caps have been widely used, and minute vertical cracks may occur as defects. Most of the vertical cracks can be confirmed from the front, but may not be confirmed depending on the width of the vertical cracks when viewed from the oblique direction. The aforementioned device is
Since it is only seen from four fronts, the range seen from the oblique is wide,
There is a problem that the defect detection accuracy is low. Therefore, if the number of cameras is increased, the cost becomes high. The present invention has been made in view of the above circumstances, and has as its object to provide a container cap inspection apparatus with a small number of cameras and high defect detection accuracy.

[0003]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention relates to a conveyor for conveying containers in a line, a projector for projecting diffused light to a side surface of a cap mounted on the container, and a conveyer. In a container cap inspection apparatus having a camera that captures light from a cap and that is arranged symmetrically, a light path that is disposed between the conveyor and the camera and reflects light from the cap and enters the camera is formed. A plurality of mirrors are provided, and the optical path is formed such that light emitted in a radial direction of the cap from a plurality of locations in a circumferential direction of the cap is incident on one camera.

According to the present invention, since light emitted in a radial direction of the cap from a plurality of locations in a circumferential direction of the cap is incident on one camera, a plurality of images can be obtained in one screen. For this reason, the side face of the cap is viewed from many fronts, and the range viewed obliquely becomes narrow. When the width of the defect is small, the number of cameras is increased and the number of optical paths with one camera is reduced in order to enlarge and shoot. When the width of the defect is large, the number of cameras is reduced and the number of optical paths in one camera is increased.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a container cap inspection apparatus according to the present invention will be described below with reference to FIGS. FIG. 1 is a front view showing the entire configuration of a container cap inspection device, and FIG. 2 is a plan view of the container cap inspection device. As shown in FIGS. 1 and 2, the container cap inspection device includes a conveyor 3 for conveying the containers 1 in a line, and a ring-shaped container for allowing diffused light to enter a side surface of a plastic cap 2 mounted on the container 1. A projector 5 having an illumination 4 and two sets of CCD cameras 6R ₁ , 6L ₁ ; 6R ₂ , which are arranged symmetrically with respect to the conveyor 3 and photograph light from the cap ₂ .
It is equipped with a 6L _2. Four CCD cameras 6R ₁ ~6L ₂
They are spaced 90 ° interval, the angle between the center line C of the optical axis 10 and the conveyor 3 of the CCD cameras 6R ₁ ~6L ₂ is 45 ° set.

[0006] The conveyor 3 and each CCD camera 6R _1-
6L ₂ , the light from the cap 2 is reflected and each C
Two optical paths L ₁ to be incident on the CD cameras 6R _{1 to} 6L ₂ ,
Four mirrors 7A ₁ composed of vapor deposition mirrors forming L ₂ ,
7A ₂ ; 7B ₁ and 7B ₂ are arranged. The optical path L ₁ ,
L ₂ is formed such that light emitted in the radial direction of the cap 2 from two locations spaced 45 ° in the circumferential direction of the cap 2 enters one CCD camera.

Therefore, the four CCD cameras 6R _1-
With 6L ₂ , images at _eight locations a _{1 to} a ₈ at equal intervals of 45 ° in the circumferential direction of the cap 2 are obtained. The two optical paths L ₁ and L ₂ correspond to the optical axis 1 of each of the CCD cameras 6R _{1 to} 6L _2.
Four mirrors 7A ₁ , 7A ₂ ; so that the two optical paths L ₁ , L ₂ intersect;
7B _1, of 7B ₂ position is set. Further, a light shielding plate 8 is disposed between the optical paths L ₁ and L ₂ . CCD
Camera 6R ₁ ~6L _2, mirror 7A ₁ ~7B ₂ and the light shielding plate 8 is supported on the base plate 9.

Next, the operation of the apparatus for inspecting the cap of a container constructed as described above will be described. The diffused light from the projector 5 enters the side surface of the cap 2. Light radiated in the radial direction of the cap ₂ from a ₁ , a ₂ spaced at 45 ° in the circumferential direction of the cap 2 reflects the light path L ₁ formed by the mirrors 7A ₁ , 7A ₂ and the mirror 7B ₁ , incident on the CCD camera 6L ₁ via the optical path L ₂ formed by 7B _2.
Light emitted from other points a ₃ ~a ₈ in the radial direction of the cap 2 in the circumferential direction of the cap 2 also, C via the optical path L _1, L ₂ formed by the mirror 7A ₁ ~7B ₂ respectively
The light enters the CD cameras 6R ₁ , 6R ₂ and 6L ₂ .

[0009] Each screen is formed by the CCD camera 6R ₁ ~6L _2, as shown in FIG. 3, two images 11A within one screen S, 11B is obtained. For this reason, one CCD
The side of the cap 2 is viewed from two fronts by the camera, and the range viewed from the oblique direction becomes narrow. Two light paths L ₁ and L ₂
The light shielding plate 8 disposed between the two images 11A and 11B
Are prevented from overlapping at the boundary of the image. As shown in FIG. 3, the fine irregularities 12 of the slip formed on the surface of the cap 2 appear faintly dark, but the vertical cracks 13 are formed.
Can be identified because it appears dark. In the figure, reference numeral 2c is the center of the cap.

Next, another embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to FIG. FIG. 4 is a front view showing the entire configuration of the container cap inspection device, and FIG. 5 is a plan view of the container cap inspection device. In this embodiment, the arrangement and number of CCD cameras and the arrangement and number of mirrors are different from those in the first embodiment. 4 and 5
As shown in FIG. 1, a pair of CCD cameras 6R ₁ and 6L ₁ are arranged symmetrically with respect to the conveyor 3. The angle between the optical axis 10 of each of the CCD cameras 6R ₁ and 6L ₁ and the center line C of the conveyor 3 is set to 90 °. Between the conveyor 3 and the CCD cameras 6R _1, 6L _1, forming a three optical paths L _1, L _2, L ₃ to be incident on the reflection light from the cap 2 to the CCD cameras 6R _1, 6L ₁ 9 mirrors to do 7
_{A 1, 7A 2, 7A 3} ; 7B 1, 7B 2, 7B 3; 7C 1, 7
C ₂ and 7C ₃ are arranged. The optical paths L ₁ , L ₂ , L ₃
Indicates that light emitted in three radial directions of the cap 2 from three places at equal intervals in the circumferential direction of the cap 2 is one CC.
It is formed so as to enter the D camera.

Therefore, two CCD cameras 6R ₁ ,
The 6L _1, the image of the point a ₁ ~a ₆ of circumferentially 60 ° equally spaced six caps 2 are obtained. Of the three optical paths L ₁ , L ₂ , L ₃ , two optical paths L ₁ , L ₂ are bilaterally symmetric with respect to the optical axis 10 of each CCD camera 6R ₁ , 6L _1. Six mirrors 7A ₁ , 7A ₂ , 7A ₃ ; 7B ₁ , 7B such that the _two optical paths L ₁ , L ₂ intersect.
₂ , 7B ₃ positions are set. The remaining light path L ₃ is
Located on the optical axis 10 of the CCD camera 6R _1, 6L ₁ in the vicinity of the vicinity and the cap 2 of the CCD camera 6R _1, 6L _1, three mirrors 7C to intersect with the optical path L ₁ or L ₂ in the intermediate position ₁ , 7C ₂ , 7C ₃ are set. Further, between the optical path L ₁ and L ₃ and the optical path L ₂ and L ₃ are the light shielding plate 8 is disposed.

Next, the operation of the apparatus for inspecting the cap of a container constructed as described above will be described. Light radiated in the radial direction of the cap 2 from three locations a ₁ , a ₂ , and a ₃ at equal intervals in the circumferential direction of the cap 2 is mirrors 7A ₁ , 7A.
A ₂ , an optical path L ₁ formed by 7A ₃ , a mirror 7B ₁ ,
7B _2, the optical path L ₂ and the mirror 7C ₁ is formed by 7B _3, 7C _2, through the optical path L ₃ formed by 7C ₃ incident on the CCD camera 6L _1. Light radiated in the radial direction of the cap 2 from other places a _{4 to} a ₆ in the circumferential direction of the cap 2 also passes through optical paths L ₁ , L ₂ , and L ₃ formed by the mirrors 7A _{1 to} 7C ₃ , respectively. CCD camera 6R ₁
Incident on.

As shown in FIG. 6, three images 11A, 11B, and 11C are obtained in one screen S of each screen formed by the CCD cameras 6R ₁ and 6L ₁ . For this reason, the side of the cap 2 is viewed from three fronts with one CCD camera, and the range viewed from the slant is narrowed. The optical path (the optical path L ₁ and L ₃ and the optical path L ₂ and L ₃₎ light shielding plate 8 disposed between the mutually adjacent, the image at the boundary of mutually adjacent pixels (picture 11A and 11C and the image 11B and 11C) Prevents overlap. As shown in FIG. 6, the fine irregularities 12 with a slip formed on the surface of the cap 2 appear faintly dark, but the vertical cracks 13 appear dark and can be identified.
In the figure, reference numeral 2c is the center of the cap.

The first embodiment shown in FIGS. 1 to 3 differs from the second embodiment shown in FIGS. 4 to 6 in the number of cameras. This is because, in the first embodiment, since the width of the defect is small, the number of cameras is increased and the number of optical paths for one camera is reduced in order to enlarge and shoot, and in the second embodiment, the width of the defect is reduced. This is because the number of optical paths is increased by one camera because the number of optical paths is large.

FIG. 7 is a plan view showing a comparative example of the present invention. In the present comparative example, light emitted from the cap 2 is transmitted through an optical path L formed by mirrors 7A ₁ and 7A ₂ .
₁ and the optical path L ₂ formed by the mirror 7B _1, 7B ₂
Incident on the CCD camera 6L ₁ through. Optical paths L ₁ and L _{2 that} are symmetrical to the optical axis 10 of the camera 6L ₁ do not intersect. Therefore, from the portion of the thickness T of the mirrors 7A ₂ and 7B ₂ , CC
Since light to D camera 6L ₁ is not incident, a portion corresponding to the thickness T becomes a gap in the screen, the effective range of the screen is reduced. On the other hand, in the present invention, as shown in FIGS. 2 and 5, the mirrors are arranged so that the optical paths symmetrical to the optical axis of the camera cross each other. Therefore, the effective range of the screen can be used to the maximum.

[0016]

As described above, according to the present invention, many images viewed from the front can be obtained by one camera.
Defects that are difficult to detect in an image viewed from an oblique direction can be detected with high accuracy with a small number of cameras.

[Brief description of the drawings]

FIG. 1 is a front view showing an entire configuration of an embodiment of a container cap inspection apparatus according to the present invention.

FIG. 2 is a plan view of one embodiment of a container cap inspection apparatus according to the present invention.

FIG. 3 is an explanatory diagram showing an image obtained by a camera in the embodiment shown in FIGS. 1 and 2;

FIG. 4 is a front view showing the overall configuration of another embodiment of the container cap inspection apparatus according to the present invention.

FIG. 5 is a plan view of another embodiment of the container cap inspection apparatus according to the present invention.

FIG. 6 is an explanatory view showing an image obtained by a camera in the embodiment shown in FIGS. 4 and 5;

FIG. 7 is a plan view showing a comparative example of the present invention.

[Explanation of symbols]

1 container 2 cap 3 conveyor 4 Lighting 5 projector _{6R 1, 6L 1, 6R 2} , 6L 2 CCD camera _{7A 1, 7A 2, 7A 3} , 7B 1, 7B 2, 7B 3, 7C 1,
7C ₂ , 7C ₃ mirror 8 Shield plate 10 Optical axis 11A, 11B, 11C Image

Continuing from the front page (72) Inventor Hosei Miwa 1-17-1 Raw Mugi, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Inside Kirin Techno System Co., Ltd. (72) Akira Fujiwara Akira Fujiwara 1170-14, Kinmei-cho, Soka-shi, Saitama Fujitronix, Inc. In-house (56) References JP-A-8-201042 (JP, A) JP-A-61-232195 (JP, A) JP-A-8-226902 (JP, A) Table 8-505947 (JP, A) (58) Fields surveyed (Int. Cl. ⁷ , DB name) G01N 21/88-21/90

Claims (2)

(57) [Claims] 1. A conveyor that conveys containers in a line, a projector that makes diffused light incident on a side surface of a cap mounted on the container, and a camera that is arranged symmetrically with respect to the conveyor and captures light from the cap. In a cap inspection apparatus for a container for inspecting a defect of a cap, the apparatus comprises a plurality of mirrors arranged between a conveyor and a camera to form an optical path for reflecting light from the cap and entering the camera, and the optical path of the cap is provided. The light emitted in the radial direction of the cap from multiple locations in the circumferential direction is formed so as to enter one camera, and the cap is made of plastic
A cap inspection apparatus for a container, comprising: a cap having vertical irregularities on its surface , wherein the defect is a vertical crack. 2. The method according to claim 1, wherein said one camera blocks light between adjacent optical paths.
The container cap inspection device according to claim 1, wherein a light plate is disposed .