JPH0549183B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a lighting device for inspecting the side surface of a bottle, and in particular, it is used to detect defects such as streaks and wrinkles on the side surface of a bottle such as a glass bottle. This invention relates to a lighting device for inspecting the side surface of a bottle for projecting light onto the side surface.

[Conventional technology]

Glass bottles filled with beer, soft drinks, etc., whether they are new bottles blown in the bottle-making process or recycled bottles that are collected and reused, may have defects such as streaks or wrinkles on the side of the bottle, or may have foreign matter attached to them. There is something I did. Since these defects cause food hygiene and quality control problems, it is necessary to detect them and eliminate bottles with defects.

Various techniques for detecting defects on the side of a bottle have been proposed in the past, but in any case, in order to inspect the entire circumference of the bottle, it is necessary to rotate the bottle once and
A method is used in which a camera device such as a CCD camera captures a transmitted image of the entire circumference of the bottle due to illumination, and defects are detected from this image signal.

Next, a bottle inspection machine equipped with a conventional bottle side inspection illumination device will be described with reference to FIG.

FIG. 12 is a schematic plan view showing the overall configuration of the bottle inspection machine, which includes a bottle rotation conveyance device 30 (detailed structure is not shown) that revolves around the circumference of the bottle as it rotates. ), and an irradiation device 31 and a camera device 32 are arranged to face each other so as to sandwich the bottle rotation conveyance device 30 therebetween. The bottle held by the bottle rotation conveyance device 30 rotates once while being conveyed between the illumination device 31 and the camera device 32, and the entire bottle is inspected by the illumination device 31 and the camera device 32 during this period.

There is also a bottle inspection machine that once stops transporting the bottle, rotates it once at this stop position, and inspects the entire circumference of the bottle during this one rotation.

[Problem that the invention seeks to solve]

In the above-mentioned bottle inspection machine that inspects the bottle while it is being transported, in order to inspect the entire circumference of the bottle, it is necessary to capture an image of the bottle while the bottle rotates once, that is, for a certain distance. In the conventional lighting device, a wide diffused lighting device having a span l sufficient to cover the distance is used.

However, when using such an illumination device, defects that do not transmit light, such as opaque foreign objects, can be detected as dark shadow images, but faint bubbles, streaks,
In the case of a transmissive defect such as a wrinkle, the light emitted from the center of the illumination device facing the camera device will penetrate the defect as shown by the solid line in Figure 13, since it is a wide diffused light source. The light projected from the side of the illumination device is refracted or reflected at the defective portion d, as shown by the broken line, and does not reach the camera device, resulting in a dark shadow image. There is a problem that the defective part is difficult to detect because the defective part does not appear as a dark shadow image.

On the other hand, in a bottle inspection machine that once stops transporting the bottle, rotates it once at this stop position, and inspects the entire circumference of the bottle during this one rotation, a narrow lighting device is used. It has a rectangular light projecting part with a narrow width, and is designed to project light only onto a limited surface to be inspected within the side surface of the bottle. For example, the first
A rectangular bottle shown in Fig. 14-b is attached to a bottle having a narrow-diameter bottle opening 2a as shown in Fig. 4-a and a large-diameter bottle body 2b having a narrow constriction 2c in the center. When light is projected using a light projecting unit, the transmitted image of the bottle will theoretically be as shown in Figure 14-c, but in reality, the wall thickness of the bottle is uneven, so
The result is as shown in Figure d. That is, since the curvatures of the bottle mouth part 2a and the bottle body part 2b are different, their refraction angles are different, and the bottle mouth part 2 has a smaller diameter than the lighting device L.
The light projected onto a or the constriction 2c is the 15th-a
The light is refracted and formed into an image Im ₁ as shown in the figure, and the light projected onto the bottle body 2b having a large diameter forms an image Im ₂ as shown in Fig. 15-b. Therefore, the images of the bottle mouth part 2a and the constriction part 2c are much narrower than the images of the bottle body part 2b, and the inspection area must be selected according to this thin passing image, so the inspection area becomes extremely narrow and accurate inspection is impossible. The problem is that it cannot be done.

The present invention was created in view of the above circumstances, and
The purpose of this is to be able to accurately detect transparent defects such as light bubbles, streaks, and wrinkles formed on bottles, and to perform accurate inspections by obtaining transparent images of a wide area. An object of the present invention is to provide a lighting device for inspecting the side of a bottle.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention is provided in a bottle inspection machine that detects defects on the side surface of the bottle by projecting light onto the bottle to be inspected and receiving the transmitted light transmitted through the side surface of the bottle using a camera device. In a bottle side inspection illumination device for projecting light onto the side surface of a bottle, which is placed facing a camera device, the illumination device illuminates only a limited surface to be inspected within the side surface of the bottle facing the illumination device. This light projecting part has a narrow light projecting part that projects light onto a large diameter part of the bottle so that the image transmitted through the bottle has a substantially rectangular shape. The feature is that the portion that projects light onto a small portion of the lens is set to be wide.

[Effect]

According to the above-mentioned means, the illumination device has a narrow light projecting part so as to project light only onto a limited surface to be inspected within the side surface of the bottle, so that swirling bubbles on the surface to be inspected,
Light projected onto transparent defects such as streaks and wrinkles is refracted or reflected by the defect and does not reach the camera device, allowing transparent defects to be detected reliably and easily. The light emitting part of the device is set so that the part that emits light to the large diameter part of the bottle is narrow and the part that emits light to the small diameter part of the bottle is wide.
The transmitted image transmitted through the bottle has a generally rectangular shape with a wide area, and a wide inspection area can be selected from this area, allowing accurate inspection.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a lighting device for inspecting the side surface of a bottle according to the present invention will be described with reference to FIGS. 1 to 8.

FIG. 1 is a schematic plan view showing the entire bottle inspection machine M. In the figure, reference numeral 1 is a conveyor for conveying bottles, and the bottle 2 is transferred to the bottle inspection machine M by this conveyor 1. It's getting old. The bottle inspection machine M is equipped with a bottle transfer device 3 that revolves the bottle 2 along a certain circumference, and an inlet star wheel 11 and an outlet star wheel 12 are installed adjacent to the bottle transfer device 3.
and are provided.

Between the above inlet and outlet star wheels,
A camera device 13 consisting of a CCD camera or the like is disposed opposite the bottle transfer device 3, and this camera device 13 is connected to an arithmetic processing device (not shown). When using this processor, the pixel signals of the photoelectric conversion elements are processed by this arithmetic processing unit, and defects on the side surface of the bottle are detected.

As shown in FIGS. 2 and 3, the bottle transfer device 3 includes a lower star wheel 5 that holds a bottle body supported by a rotating shaft 4, and an upper star wheel 6 that holds a bottle mouth. A cylindrical light shielding plate 7 with slits is disposed between both star wheels 5 and 6, and a diffused light source 10 consisting of a point light source 8 and a diffuser plate 9 is located in the center of the light shielding plate 7 with slits. is installed. The light shielding plate 7 with slits and the diffused light source 10 constitute a lighting device L. The light shielding plate 7 with slits rotates together with the upper and lower star wheels 5 and 6, and the diffused light source 10 is fixed and does not move. ing.

Therefore, the light shielding plate 7 with slits, the diffused light source 1
0, the bottle 2 and the camera device 13 are arranged as shown in FIG. It is set so that only the surface to be inspected is illuminated. Further, as a detailed view of the slit S formed in the light shielding plate 7 is shown in FIG. 5, the slit S consists of a wide opening _S1 and a narrow opening _{S2 .} corresponds to the bottle opening 2a having a small diameter, and the opening _S2 is set to correspond to a bottle body 2b having a large diameter.

On the other hand, a running belt device 15 is arranged side by side along the former bottle transfer device 3, and this running belt device 15 has a driving pulley 16 and a driven pulley 17 to which a variable speed motor is directly connected. Both pulleys 1
An endless running belt 18 is wound between 6 and 17. Then, the running belt 18 moves the bottle transfer device 3
When traveling along the one side traveling path 19, it engages with the side surface of the bottle and causes the bottle 2 to rotate.

Next, the operation of the lighting device for inspecting the side surface of a bottle according to the present invention constructed as described above will be explained with reference to FIGS. 1 and 6.

The bottle 2 is conveyed to the entrance star wheel 11 by the bottle conveyor 1, which is conveyed in the direction of the arrow, and is transferred to the bottle transport device 3 by the entrance star wheel 11. Then, the bottle 2 is held and rotated by the upper and lower star wheels 5 and 6 of the bottle transport device 3, and the running belt 18 of the running belt device 15 starts to be engaged, and the bottle 2 is rotated and transported (revolving ) is rotated on its axis. At this time,
The slit shielding plate 7 rotates in synchronization with the bottle 2, and the diffused light from the diffused light source 10 is projected into a narrow beam by the slit S of the slit light shielding plate 7, so that only a limited surface to be inspected on the side of the bottle is illuminated. The transmitted light that is projected and transmitted through the bottle 2 is received by the camera device 13, and the image of the camera device 13 is processed by the arithmetic processing unit to detect defects in the bottle 2. Then, the bottle transfer device 3 and the running belt device 15
The speed and dimensions of the bottle 2 are set so that the bottle 2 makes one or more rotations within the inspection area within a predetermined field of view of the camera device 13, and the entire surface of the bottle 2 is inspected during this one rotation.

Therefore, in this embodiment, the diffused light source 10
The diffused light from the bottle passes through the slit S (consisting of _S1 and _S2 ) of the light shielding plate 7 shown in FIG.
The light projected onto the bottle body 2 has a relatively wide width.
The light projected onto b has a relatively narrow width and illuminates only a limited surface to be inspected on the side of the bottle. The light projected from the illumination device L onto the bottle opening 2a is refracted and formed into an image Im ₁ as shown in Fig. 6-a when it passes through the bottle 2, and is then projected onto the bottle body 2b. When the light passes through the bottle 2, it is refracted and formed into an image as shown in Figure 6-b.
Im ₂ , the widths of Im ₁ and Im ₂ are equal, and this transmitted image has a substantially rectangular shape with a wide area as shown in FIG. 7, is received by the camera device 13, and is inspected from the wide area. Since the area can be selected, accurate inspection of the entire side of the bottle is possible. In addition, since the light shielding plate 7 with slits rotates at the same rotational speed to follow the rotational conveyance of the bottle, if the surface to be inspected is normal, the transmitted light that has passed through the bottle 2 will be received by the camera device 13. If there is a defective part d on the inspection surface 2S, the light projected onto the bottle 2 will be refracted or reflected at the defective part d, as shown by the solid line in FIG. 8, and will not reach the camera device 13, resulting in a dark shadow. The image becomes. On the other hand, since there is no light projected from the side of the illumination device in FIG. 13 as shown by the broken line, there is no light that is refracted at the defective portion d and reaches the camera device 13. Therefore, transparent defects such as light bubbles, streaks, and wrinkles formed on the bottle can be accurately detected.

Next, a modification of the light shielding plate with slits shown in FIG. 5 will be described with reference to FIG. 9.

The light shielding plate 20 with slits shown in FIG. 9-b has a slit S consisting of a wide opening _S1 , a narrow opening _S2 , and an intermediate width opening _{S3 .} is set to correspond to the bottle opening 2a having a small diameter, the opening _S2 corresponds to the bottle body 2b having a large diameter, and the opening _S3 is set to correspond to the constriction 2c having a slightly smaller diameter. ing. In this modification as well, the transmitted image transmitted through the bottle 2 has a substantially rectangular shape with a wide area as shown in FIG. 7, and the inspection area can be selected from this wide area.

In the embodiment shown in FIGS. 1 to 9,
Although the shape of the light projecting part is made variable by selecting a fixed slit according to various shapes of the bottle, it may also be made variable by using a variable slit that allows the shape of the opening to be changed arbitrarily. Further, although the entire circumference of the bottle was inspected by rotating the bottle once during transportation, the entire circumference of the bottle may also be inspected by once stopping the transportation of the bottle and rotating the bottle once at this stop position.

Next, still another embodiment of the illuminating device for inspecting the side surface of a bottle according to the present invention will be described with reference to FIGS. 10 and 11.

In the embodiment shown in FIG. 10, a lighting device L and a camera device 13 are arranged to face each other with the bottle 2 in between.

The lighting device L includes a surface light source 22 formed by arranging a large number of small-diameter point light sources 21 made of LEDs or the like vertically and horizontally, and a diffuser plate 23 is disposed in front of the surface light source 22. And surface light source 2
2 is connected to a lighting point control circuit 24, and the lighting point of the point light source 21 is selected by the lighting point control circuit 24 programmed according to the bottle type.

A front view of the surface light source 22 is shown in FIG. 11-a, and a lighting location is shown in FIG. 11-b. In this embodiment, it is possible to arbitrarily change the shape of the light projecting section by using a surface light source with variable lighting locations and programming the lighting location control circuit. The variable light projecting section can be set to have a narrow part for projecting light onto the larger diameter part of the bottle, and a wider part for projecting light onto the smaller diameter part, so that the transmitted image transmitted through the bottle covers a wide area. Since the inspection area can be selected from this area, accurate inspection is possible.

〔Effect of the invention〕

As is clear from the description of the embodiments above, according to the present invention, since the illumination device has a narrow light projecting portion so as to project light only onto a limited surface to be inspected within the side surface of the bottle, the surface to be inspected can be Light projected onto transparent defects such as light bubbles, streaks, and wrinkles in the image will be refracted or reflected at the defect and will not reach the camera device, allowing the transparent defect to be detected reliably and easily. I can do it.

Further, according to the present invention, the light projecting section of the lighting device includes:
Since the part that projects light onto the large diameter part of the bottle is narrow and the part that projects light into the small diameter part of the bottle is set wide, the transmitted image that passes through the bottle has a roughly rectangular shape with a wide area. Accurate inspection is possible because a wide inspection area can be selected.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view of a bottle inspection machine equipped with a lighting device for inspecting the side of a bottle according to the present invention, FIG. 2 is a basic configuration diagram of the lighting device for inspecting the side of a bottle according to the present invention, and FIG. FIG. 4 is a perspective view of the illumination device for side inspection of the same bottle; FIG.
The figure is a front view of the light shielding plate with slits of the illumination device for inspecting the side of the bottle, Figure 6 is an explanatory diagram of the operation of the illumination device for inspecting the side of the bottle, and Figure 7 is a transmitted image of the illumination device for inspecting the side of the bottle. 8 is an explanatory diagram of the operation of the illumination device for inspecting the side surface of a bottle, FIG. 9 is a perspective view showing a variation of the light shielding plate with slits, and FIG. 10 is another illumination device for inspecting the side surface of a bottle according to the present invention. A basic configuration diagram showing an example,
FIG. 11 is an explanatory diagram of the operation of the embodiment shown in FIG.
FIG. 2 is a schematic plan view of a bottle inspection machine equipped with a conventional bottle side inspection illumination device, and FIGS. 13 to 15 are operation explanatory diagrams. 1...Conveyor, 2...Bottle, 3...Bottle transport device, 4...Rotating shaft, 5...Lower star wheel, 6...Upper star wheel, 7...Shading plate with slit, 8...Point Light source, 9... Diffusion plate, 10...
... Diffuse light source, 13 ... Camera device, 15 ... Running belt device, 16 ... Drive pulley, 17 ... Driven pulley, 18 ... Endless running belt, 20 ... Light shielding plate with slit, 21 ... Point light source, 22... Surface light source, 23... Diffusion plate, 24... Lighting point control circuit, L... Lighting device.

Claims (1)

[Scope of Claims] 1. Provided in a bottle inspection machine that detects defects on the side surface of the bottle by detecting defects on the side surface of the bottle by receiving the transmitted light that is projected onto the bottle to be inspected and transmitted through the side surface of the bottle, and facing the camera device. In a bottle side inspection illumination device for projecting light onto the side surface of a bottle, the illumination device is designed to illuminate only a limited surface to be inspected within the side surface of the bottle facing the illumination device. This light projecting part has a narrow part that projects light onto the large diameter part of the bottle, and a narrow part that projects light into the small diameter part so that the transmitted image transmitted through the bottle has a substantially rectangular shape. A lighting device for inspecting the side of a bottle, characterized in that the light emitting part is set widely. 2 The above lighting device consists of a diffused light source that emits diffused light and a light shielding plate having a slit, and the slit is narrow in the part corresponding to the large diameter part of the bottle and wide open in the part corresponding to the small diameter part of the bottle. An illumination device for inspecting a side surface of a bottle according to claim 1, wherein the illumination device is characterized in that: 3 The above lighting device consists of a surface light source formed by a large number of point light sources, and the lighting location of this surface light source is as follows.
2. The illumination device for inspecting the side surface of a bottle according to claim 1, wherein a portion corresponding to a large diameter portion of the bottle is narrow, and a portion corresponding to a small diameter portion of the bottle is wide.