JPS6388433A - Method and apparatus for detecting foreign matter - Google Patents

Abstract

PURPOSE:To enable the detecting of foreign matters in a solution accurately free from viscosity thereof, by detecting and comparing the position of bright spots of reflected lights from a foreign matter in the solution exposed to an irradiation light before and after the start of the rotation of a container. CONSTITUTION:A container 10 is irradiated with an irradiation light 13 of a light source 12 and reception data of reflected lights 15, 17 and 19 from a foreign matter 14 and the like as received with a camera tube 20 is taken into a comparator 22 separately as data signal 26 before the start of the rotation of the container 10 and after the stop of the rotation. Then, the data signals 26 are converted with the device 22 into binary-coded video signals from video signals and computed with a built-in comparison mechanism with the signal 26 before the start of the rotation as control. On the other hand, the marks of bright spots of reflected lights due to a surface flaw 16 and a foul 18 of the container 10 will not be projected on a CRT because the quantity of light of bright spots as negative value before the start of the rotation of the container 10 is cancelled by the quantity of light of bright spots as positive value after the stop of the rotation. This enables detection of bright spot marks 14A and 14B alone of the reflected light due to the foreign matter 14 thereby ensuring accurate detection of the foreign matter 14 being destinguished from the surface flaw 16 and foul 18.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a method and device for detecting foreign matter, and more particularly to a method and device for detecting foreign matter floating in a solution in a transparent container.

[Background of the invention]

Inspection of foreign objects in chemical ampoules or bottles requires visual inspection because it is difficult to automatically distinguish between foreign objects inside the bottle that could lead to product defects and scratches or stains on the bottle surface that are unrelated to product defects. It depends. However, this method cannot be applied to mass-produced ampoules due to the slow inspection throughput. In addition, with the method using digital image processing, the size of foreign matter inside the ampoule is as small as several tens of micrometers or less, which is approximately the same size as a scratch or stain on the surface of the ampoule bottle.
Difficult to identify. Therefore, normal image processing methods cannot be applied to foreign object detection.

On the other hand, recently, after rotating the ampoule at high speed, the brakes are applied to stop the ampoule suddenly and the foreign matter is suspended and rotated together with the internal solution, and the transmitted light is irradiated from the side of the ampoule. A device has been developed that detects changes in the image (changes in the amount of light) caused by occlusion and distinguishes between good and bad images.

FIG. 3 is an explanatory diagram of a conventional method for detecting foreign matter by rotating an ampoule at high speed and an apparatus therefor. As shown in FIG.
is irradiated via the light projecting lens 76. After the irradiation light 74 passes through the solution in the ampoule 70, it passes through the imaging lens 78 and reaches the light receiver 80. Foreign matter 82 in the ampoule, surface scratches 84 on the bottle, dirt 86, etc. block the irradiation light 74 and form an image. These images are projected onto the light receiver 80.

In such a conventional foreign object detection method and apparatus, the ampoule 70 is rotated at a high speed, and then the brake is applied to suddenly stop the ampoule 70. The foreign object 82 floats and rotates due to inertia and blocks the transmitted light 74 from the side. The image of the foreign object 82 fluctuates and is detected by the light receiver 80 as a variation in received light. In this case, the foreign matter 82 causes a change in the amount of light, but the scratches 84 and dirt 86 on the ampoule surface do not cause a change in the amount of light because they are stationary. Therefore, the foreign matter 82 can be distinguished from the scratches 84 and dirt 86 on the ampoule surface. In addition, the light receiving elements 8 are divided into certain areas corresponding to the size of the ampoule 70.
8 are installed, and phototubes or photodiodes are used for these light receiving elements 88, enabling quick inspection.

However, in this method of rotating the ampoule 70 at high speed to inertially rotate the foreign matter 82 in the solution,
It can be applied to foreign matter 82 in solutions with high viscosity (IOC3T or less), but foreign matter 82 in solutions with high viscosity (100C3T or more)
In No. 2, even if the ampoule 70 is rotated at high speed and then suddenly stopped by applying the brake, the internal solution does not undergo sufficient inertial rotation, and although the floating foreign matter 82 moves slightly, it is not rotated sufficiently. Therefore, the change in the image caused by blocking the transmitted light 74 of the foreign object is not sufficiently felt, and the amount of light does not change, making it impossible to detect the foreign object. Furthermore, if the ampoule 70 is rotated at high speed (about 3000 rpm or more) in order to impart inertial rotation to the foreign matter 82 in a high viscosity solution (100C3T or more), the ampoule may be damaged. For this reason, there is a limit to the practical ampoule rotation speed.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and particularly aims to provide a method and apparatus for detecting foreign matter in which foreign matter in a solution can be detected accurately without being affected by the viscosity of the internal solution.

[Summary of the invention]

In order to achieve the above object, the present invention provides a foreign object detection method for detecting foreign objects floating in a solution in a transparent container, in which the transparent container is rotated and positioned at the same position as the transparent container before the rotation starts. The light is irradiated onto the container, and the position of the bright spot of the reflected light emitted from the foreign matter in the solution that receives the irradiated light is detected and compared before the container starts rotating and after the rotation has stopped. It is characterized by detecting foreign objects.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the foreign object detection method and device according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is an explanatory diagram of a foreign object detection method and apparatus according to the present invention. As shown in FIG. 1, the container 10 is formed from a transparent container made of glass. In addition, depending on the case, the container 10
may be made of transparent plastic. The container 10 is rotated by a rotating device 11 at a rotational speed of 300 rpm or less. A step motor is used for the rotating device 11, and 36
The container 10 is rotated or stopped in units of 0°×N times.

Therefore, after the container IO has been rotated for a predetermined period of time, it is stopped at the same position as the container 10 before the rotation started. A light source 12 is provided below the container 10, and irradiation light 1 from the light source 12 is provided.
3 is irradiated toward the container 10 and the solution within the container 10 through a projection lens.

Foreign matter 14 in the solution in the container 10, surface scratches 16 on the container 10
and the dirt 18 receives the irradiation light 13 and reflects the reflected light 15.17.
Emit 19. An image pickup tube 20 is provided on the side of the container 10, and the image pickup tube 20 is a light receiver that receives reflected light 15, 17, and 19 from the foreign matter 14, surface scratches 16, and dirt 18.

A comparison device 22 is connected to the image pickup tube 20.
The data signal 26 of the reflected light 15, 17, and 19 received by the image pickup tube 20 is input manually. Data signals 26 before the rotation of the container 100 starts and after it stops are input to the comparison device 22, and each data signal 26 is processed by the comparison device 22 from a video signal to a binary video signal. The data signal 26 is two-dimensionally processed and detected as a bright spot trace of reflected light. The resolution of the detected H point trace is at least 640 (horizontal) x 512 (vertical) x 64 when monitored on a CRT.
(Brightness) gradation is possible.

The comparison device 22 has a built-in RAM mechanism and a comparison calculation mechanism, and the RAM mechanism receives the data signal 2 before the rotation of the container 10 starts.
Remember 6. Further, the comparison calculation mechanism compares and processes the data signal 26 before the rotation of the container 10 starts and the data signal 26 after the rotation has stopped. In this case, the data signal 2 before the start of rotation
6 is used as a reference, and the data value before the rotation starts is subtracted from the data value after the rotation stops. When the comparator 22 compares and processes the data signals 26 and 26 before the container starts rotating 100 times and after it stops rotating, and observes it on a CRT monitor, etc., as shown in FIG. Foreign object 1
The bright spots of the reflected light No. 4 are monitored as bright spot traces 14A and 14B at predetermined positions on the two-dimensional projection image. If the foreign object 14 is displaced within the solution in the container 10 before and after the rotation of the container 10 is started and after the rotation of the container 10 is stopped, the image of the bright spot trace of the reflected light of the foreign object 14 in the solution will be A bright spot trace 14A with a negative value (0 trace in FIG. 2) and a bright spot trace 14B with a positive value after the rotation has stopped (black trace in FIG. 2) are observed.

According to the foreign object detection method and device thereof according to the present invention configured as described above, the container 10 receives the irradiation light 13 from the light source 12.
is irradiated. The light reception data of the reflected light 15, 17, 19 from the foreign object 14, etc. received by the image tube 20 is taken in as a data signal 26 into the comparator 22 before the rotation of the container 1O starts and after the rotation is stopped, respectively. Each data signal 26 is converted from a video signal to a binary video signal by a comparator 22, and arithmetic processing is performed by a built-in comparison mechanism using the data signal 26 before the start of rotation as a comparison.
Due to the inertial force when the rotation is abruptly stopped after rotation, the position of the foreign object 14 in the solution before the rotation starts and after the rotation is stopped is shifted. In this case, even if the rotation speed of the container 10 is slow and the solution in the container 10 has a high viscosity, the foreign matter 1
The position of 4 easily causes displacement within the solution. The bright spot traces 14A and 14B of the reflected light from the foreign object 14 that has shifted are the second
As shown in the figure, the image is divided into a bright spot trace 14A with a negative value and a bright spot trace 14B with a positive value. On the other hand, container 10
The positions of the bright spot traces of the reflected light due to the surface scratches 16 and dirt 18 coincide because the positions of the container 10 are the same before the rotation of the container 10 starts and after the rotation of the container 10 is stopped. Therefore, bright spot traces of reflected light from the scratches 16 and dirt 18 on the container are not captured by the CRT because the bright spot light intensity with a negative value before the rotation of the container 10 starts and the bright spot light quantity with a positive value after the rotation of the container 10 has stopped are canceled out. .

Therefore, in the comparison device 22 processed in this manner, only the bright spots 14A and 14B of the light reflected by the foreign object 14 are clearly detected, and the foreign object 14 inside the container 10 is accurately distinguished from the surface scratches 16 and dirt 18. detected.

〔Effect of the invention〕

As explained above, according to the method and device for detecting foreign matter according to the present invention, a transparent container is rotated and stopped at the same position as the container before the start of rotation, and a solution that receives light irradiated onto the transparent container is Foreign matter in the solution is detected by measuring the bright spot of reflected light emitted from the foreign matter in the container before and after the container starts rotating, so foreign matter in the container is not affected by the viscosity of the solution. It is possible to clearly distinguish scratches, dirt, etc. on the surface of the container, and to ensure the detection of foreign substances.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the foreign object detection method and device according to the present invention, and FIG. 2 is a two-dimensional projected image diagram of a CRT monitor when a data signal is processed by the comparison device of the foreign object detection device of FIG. FIG. 3 is an explanatory diagram of a conventional foreign object detection device. 10... Container, 11... Rotating device, 12...
Light source, 14... Foreign object, 20... Image pickup tube, 22
...Comparison device. Applicant: Hitachi Plant Construction Co., Ltd. Figure 1 Figure 2 CRT ball;

Claims (2)

[Claims] (1) In a foreign object detection method for detecting foreign objects floating in a solution in a transparent container, the transparent container is rotated and stopped at the same position as the transparent container before the start of rotation, and the transparent container is exposed to light. Foreign matter in the solution is detected by detecting and comparing the positions of bright spots of reflected light emitted from foreign matter in the solution that has been irradiated with the irradiated light before the container starts rotating and after the rotation of the container has stopped. A foreign object detection method characterized by: (2) A foreign object detection device that detects foreign objects floating in a solution in a transparent container includes a rotating device that rotates the transparent container and stops it at the same position as before starting rotation, and a rotating device that illuminates the transparent container. A light source to irradiate, a light receiver that receives and detects the position of a bright spot of reflected light emitted from a foreign substance in a solution that receives light from the light source, and a bright spot of reflected light detected by the light receiver before rotation starts. A foreign object detection device comprising: a comparison device that compares a bright spot of reflected light detected after rotation has stopped.