JPH05113411A - Bottle inspecting apparatus - Google Patents

Abstract

PURPOSE:To obtain a bottle inspecting apparatus which can quickly and correctly detect a defect of an empty bottle and a bottle filled with a liquid, particularly, a defect present at the bottom of the bottle. CONSTITUTION:This bottle inspecting apparatus has a photographing means arranged below the bottom part of a bottle, a lens 3 and a light source 2 above the opening mouth of the bottle. The photographing means receives and converts the light passing through the bottom part of the bottle to an image signal. The light from the light source 2 is cast through the lens 3 only to the neck part and the shoulder part of the bottle. Images of foreign articles at the uniform inner and outer surfaces of the bottom part of the bottle and inside the bottle are obtained by the photographing means, and only the image of the foreign article within the bottle is extracted by an image processing means, thereby to judge the presence/absence of the foreign article. This apparatus makes it possible to automatically inspect the bottle and positively prevent an erroneous inspection, with improving the inspecting speed and inspecting accuracy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting whether or not there are defects such as foreign matter mixed in, cracked, chipped, and dirt at the bottom of a beverage bottle such as beer or juice by using image information.

[0002]

2. Description of the Related Art Generally, deposits and the like may remain on the inner surface of a bottle due to a cleaning error in the collection bottle, and there are also bottles with large scratches. However, this not only reduces the product value, but also poses a serious problem for food hygiene and safety. Conventionally, it has been visually inspected whether such defects exist.

In the case of visually observing the inside of a bottle to determine the presence or absence of a defect, the result depends on the physical condition and ability of the inspector, and sometimes an incredibly large defect is missed. It is an unavoidable problem that many defects are overlooked because the visual inspection relies heavily on human ability. Therefore, in recent years, various proposals have been made regarding a method for automatically detecting a defect in a bottle, and there are actually commercially available empty bottle defect detectors such as those manufactured by NEC and Matsushita Electric Works.

There are mainly those which inspect the bottle body and the bottle bottom, and those which inspect the bottle body (including the side surface of the bottle mouth) are designed so that the bottle to be inspected, which is rotating at a high speed, is exposed to light from one side. The transmission image is captured by a CCD camera installed on the opposite side, converted into an electric signal, and the presence or absence of a defect is determined by an image processing device. In the bottle bottom inspection, illumination is applied from the bottom of the bottle and the transmitted image is captured by a CCD camera installed at the top of the bottle mouth, and this signal is digitized and image processing is performed.

However, the above-mentioned conventional bottle inspection apparatus is mainly intended for empty bottles, and the bottle inspection after filling the liquid is mainly based on visual inspection.
Also, a particularly serious defect in the bottle after filling the liquid is when foreign matter or the like is mixed in the liquid or adheres to the bottle, and when it is present at the bottom of the bottle, the visual inspection also shows that It is difficult to confirm.

When automatically inspecting the bottom of the bottle after filling the liquid, an image from the TV camera above the bottle cannot give an image of the entire bottom of the bottle due to a crown or a stopper, and a defect in the bottom of the bottle may be detected in the bottle body. To image and inspect with a side TV camera,
Image processing by several cameras is required, resulting in cost and inspection time. For this reason, the lighting from the top of the bottle,
Alternatively, the image is input from the side of the bottle and the image is input by the TV camera installed below the bottle.

Generally, a bottle of beer, juice or the like has embossing or scratches on the side surface and knurling on the bottom surface. Has a problem that it is difficult to identify it as a defect due to a shadow or a bright portion caused by refraction / total reflection / diffuse reflection of light, and a process for removing the influence thereof is required.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and to quickly and accurately detect defects in empty bottles and liquid-filled bottles, especially in the bottoms of these bottles. To provide a detectable bottle inspection method.

[0009]

In order to achieve such an object, the present invention provides an image pickup means for receiving transmitted light from the bottle bottom and converting it into an image signal below the bottle bottom. A lens and a light source are provided above the mouth of the bottle, and the light emitted from the light source is emitted only through the lens from the bottle neck to the shoulder. And a bottle inspection apparatus that acquires an image of a foreign substance in a bottle, extracts only an image of the foreign substance in the bottle by an image processing unit, and determines the presence or absence of the foreign substance.

[0010]

In the present invention, the light emitted from the light source above the bottle mouth passes through the lens and is incident on the shoulder from the neck of the bottle due to diffraction, so compared with the case where the light source is simply irradiated from above the bottle mouth, for example, As a result, the embossment on the bottle shoulder does not appear as a shadow on the bottle bottom, and a uniform bright transmission image can be obtained.

Therefore, when there is a foreign matter or a defect such as a crack at the bottom in the bottle, a shadow (dark portion) of the defective portion appears in a uniform bottle bottom image, and it can be clearly identified as a defect.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. First, a bottle inspection device to which the present invention is applied will be described with reference to FIGS. 2 and 3. As shown in the figure, the bottle to be inspected 1 is held and conveyed by the rotating foil 6 and the bottle support plate 7,
When the bottle 1 to be inspected is positioned above the image pickup means (image pickup camera 4), the bottle bottom image is picked up by the image pickup camera 4, and then the image processing device 5 is used for the inspection.

At the image pickup position, as shown in the figure, an aperture plate 8 for the field of view of the camera, a light source 2 and a condenser lens 3 are installed above the image pickup camera 4, and the bottle to be inspected 1 comes to the inspection position. The bottle is irradiated when Here, the positions of the light source 2, the condenser lens 3, and the imaging camera 4 are set as follows.

The light emitted from the light source 2 is incident on the bottle 1 to be inspected and condensed by the condenser lens 3 and is refracted and transmitted at the surface of the bottle or at the interface between the bottle and the internal solution to pass through the bottom of the bottle. The refraction / transmission light is installed at a position where it can be captured by the imaging camera 4.
For this reason, the image captured by the imaging camera 4 is a transmission image of the bottle bottom portion shielded from light by foreign matter in the inner solution, chipping or cracking of the bottle bottom.

At this time, the light source 2 irradiates the bottle from directly above, and the condenser lens 3 uses a Fresnel lens to diffract the light to collect the light from the neck of the bottle, particularly from the lower part of the crown to the liquid surface or the shoulder. It is desirable to shine, and proper incident light on that site will result in a good transmission image at the bottom of the bottle. If a Fresnel lens is used, it is inexpensive and relatively easy to obtain. Therefore, it is not necessary to design and manufacture a condensing lens with a special specification, which is practical. When the image is picked up without using the condenser lens 3, an image as shown in FIG. 4 is obtained, and it becomes difficult to identify the defective portion.

The light source 2 is preferably a ring type or a light projecting type, the condenser lens 3 having a focal length of about 40 to 200 mm is suitable, and the distance between the light source 2 and the condenser lens 3 is:
It is preferable that the distance between the bottle to be inspected 1 and the condenser lens 3 is adjusted to 50 to 500 mm so that light is condensed from the neck portion to the shoulder portion of the bottle to be inspected 1 in accordance with the focal length of the condenser lens 3.

Further, the light amount of the light source is 2 to 2 per flash.
The energy may be about 8 joule. In this inspection, a defect image such as a foreign substance is taken out from the image (FIG. 3) by the transmitted light obtained by such an apparatus configuration.
As a method of image processing, since the brightness value of a foreign substance is lower than the brightness values of the surroundings other than that, if binarization processing or binarization is performed, shrinkage processing for removing minute noise is used.
Only foreign matter images can be detected.

Finally, after binarizing with a predetermined threshold value, the black-and-white area ratio ((number of white pixels) / (number of black pixels)) is calculated, and if the total is equal to or more than a preset value, it is defective. Judge as a bottle. Then, if necessary, a reject signal is output to remove this bottle from the transport system. It should be noted that the position detecting means, the defective bottle discharging means, and their operations, which are provided in association with the conveying means for obtaining the timing of the image pickup by the image pickup camera 4, are omitted.

[0019]

According to the present invention, it is possible to detect defects existing at the bottom of the bottle with a simpler process than the conventional empty bottle bottom inspection method and in a short time. Even in bottle inspection, the same effect can be expected with the same method. This allows visual inspection (bottom of bottle and part of bottle body)
The automation can be realized, the human error in the inspection result can be eliminated, the occurrence of inspection error can be prevented, the quality assurance can be secured, the inspection speed and the inspection accuracy can be improved.

[Brief description of drawings]

FIG. 1 is a schematic view showing the structure of a bottle inspection device for carrying out the present invention.

FIG. 2 is a schematic view showing the structure of a bottle inspection device for carrying out the present invention.

FIG. 3 is an explanatory diagram showing a bottle bottom image (without noise) in the embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a bottle bottom image when the lens 3 is not used.

Claims (1)

[Claims] 1. An image pickup means for receiving transmitted light from the bottom of the bottle and converting it into an image signal is arranged below the bottom of the bottle, and a lens and a light source are arranged above the mouth of the bottle. The light emitted from the light source is irradiated only through the lens from the bottle neck to the shoulder, and images of the uniform inner and outer surfaces of the bottle bottom and the foreign matter in the bottle are acquired from the imaging means, and the inside of the bottle is processed by the image processing means. A bottle inspection device, characterized in that only the image of the foreign substance is extracted and the presence or absence of the foreign substance is determined.