JPH0765973B2 - Dried seaweed contaminant detector - Google Patents

Description

TECHNICAL FIELD The present invention relates to an apparatus for detecting contaminants adhering to dry seaweed during production and processing of dry seaweed.

[Conventional technology]

In a selection line in the production and processing of dry seaweed, it is necessary to discriminate the shape and detect impurities adhering to the surface. Among them, a television camera is used for shape determination, and if the shape does not satisfy a predetermined shape, it is discharged out of the line by an ejecting device such as a shutter arranged in the line.

By the way, as foreign substances attached to dry seaweed, shells,
There are various things such as insects, vinyls, iron pieces, wood chips, straw chips, feathers, and paper (hereinafter, these foreign substances are referred to as foreign substances).
In the past, workers were placed in the line to remove dry seaweed with foreign matter from the line by manual work.

However, since the dry seaweed to which the foreign matter adheres is removed by human visual work, it is unavoidable to overlook the foreign matter that is difficult to confirm. Therefore, dry seaweed, which is not preferable as a product, passes through the line, so that the original purpose of the selection cannot be achieved, and the selection time becomes long, which is an obstacle to improving productivity.

Furthermore, during the selection process, workers have to be continuously assigned to the line, which increases the labor cost and also affects the product cost.

To counter such problems, the applicant of the present application previously developed the following foreign matter detection device (Japanese Patent Laid-Open No. 62-212553). This device has a pair of upper and lower foreign matter detection rolls arranged on a pass line of dry seaweed, one of the detection rolls can be vertically displaced with respect to the pass line, and a sensor for detecting the displacement is provided. When the dry seaweed mixed with the foreign matter is conveyed to the pass line, the foreign matter becomes thicker than the set thickness of the dry seaweed, and the detection roll is displaced. Therefore, this can be removed from the pass line as a defective product.

[Problems to be Solved by the Invention]

However, in the foreign matter detection device according to the previous proposal,
There is a problem that there is no effect on foreign matter that cannot be detected as vertical movement of the detection roll, and that the detection roll slightly moves up and down even when it bites an acceptable product of dry seaweed, which easily causes a malfunction.

The present invention has been made in view of the above conventional problems, and an object of the present invention is to accurately detect a foreign object by providing a detection unit that does not have a movable portion that causes a malfunction.

[Means for Solving the Problems]

In order to achieve this object, the dry seaweed foreign matter detection device of the present invention is provided with two seaweed transport belt conveyors provided at a predetermined interval in the dry seaweed transport direction and a gap between these seaweed transport belt conveyors. A light source disposed on one side of the seaweed transport surface so as to irradiate the seaweed, a line image sensor that is provided in the same direction as the light source with respect to the transport surface and receives reflected light of the light emitted from the light source, and the line A means for detecting a change in the amount of light entering the image sensor,
When the amount of light exceeds a set value, a contaminant mixing signal,
And a means for outputting to a sorting means for removing foreign matters.

Install the line image sensor at 60 ° ± 30 ° from the detection position and set the light source at 45 ° ± 30 in the same direction as the line image sensor.
By installing so that the optical axis is located at °, it is possible to prevent the detection of diffuse reflection on the surface of dry seaweed and to clearly detect the light and darkness of foreign matter and dry seaweed.

〔Example〕

Hereinafter, the present invention will be specifically described based on the embodiments shown in the drawings.

FIG. 1 is a schematic view showing an embodiment of the contaminant detection device of the present invention.

In the figure, A is a rectangular dry seaweed, 1 and 2 are belt conveyors for transporting seaweed, and 3 to 5 are pressing rollers. Guide plates 6 and 7 are provided between the belt conveyors 1 and 2, and the dried seaweed A is fed onto the guide plates 6 and 7. The center between the guide plates 6 and 7 is the detection position of the line image sensor 9, and the light source 8 is installed 45 ° ± 30 ° above this position. The line image sensor 9 is located in the same direction as the light source 60.
It is provided at a position of ± 30 °.

When a foreign object is detected by the line image sensor 9,
The shutter 10 operates and drops dry seaweed A into the defective product storage unit 11. The non-defective product passes through the shutter 10 and is transferred to the non-defective product storage portion 12 at the rear part. Reference numeral 13 in the figure denotes an entry sensor for detecting that the dried seaweed A has been carried in by the belt conveyor 1. Reference numeral 14 is an antireflection plate that prevents malfunction due to irregular reflection of the light source 8 when there is no dry seaweed.

When the dry seaweed A is transferred by the rollers on the guide plates 6 and 7, the foreign matter attached to the surface of the dry seaweed A reflects the light from the light source 8 and is imaged by the line image sensor 9. An image sensor such as a CCD array can be used as the line image sensor 9.

When a foreign object imaged by the line image sensor 9 is selected, if the ratio of the imaging level of dry seaweed and the foreign object is large, the selection is reliable. Cause. The detection angles of the line image sensor 9 and the light source 8 will be described as a means for increasing the ratio of the imaging level.

First, the angle θ _{1 of the} light source 8 is set to two types of 45 ° and 35 °, and the angle θ ₂ of the line image sensor 9 is changed,
At that time, the ratio of the reflected light levels of the foreign matter S (signal) and dry seaweed N (noise) was examined.

(A) When the light source is 45 ° (B) When the light source is 35 ° A graph of camera angle and S / N ratio based on the above measurement results is shown in FIG. As is clear from the figure, the light source angle is 45 °
It can be seen that the peak of the S / N ratio is around 60 ° of the camera angle for both and 35 °.

Since it was found that the S / N ratio peaked around the camera angle of 60 °, the camera angle was kept constant at 60 ° and the light source angle was changed to detect foreign matter S (signal) and dry seaweed N (noise).
The ratios of the reflection ratio levels were investigated. The results are shown in the table below.

(C) Line image sensor 60 ° A graph of the light source angle and the S / N ratio based on the above measurement results is shown in FIG. As is clear from the figure, when the light source angle is 45 °, there is a clear difference in the signal level between the foreign matter and the seaweed.

In this manner, the angle of the light source 8 is set to about 45 ° and the angle of the line image sensor 9 is set to about 60 °, so that it is possible to perform reliable foreign matter detection with a high S / N ratio.

FIG. 2 shows a flowchart of foreign matter detection. First, when dry seaweed A is carried in from the belt conveyor 1, the ingress sensor
13 detects this, and enters a standby state for foreign object detection. When the dried seaweed A is transferred onto the guide plates 6 and 7, the line image sensor 9 scans the light reflected from the light source 8 along the longitudinal direction of the light source 8. When there is a reflection of a foreign substance, that is, a portion where the amount of light increases in the scanning line, the size and position of the reflected image are recorded in a memory or the like. If there is reflected light at a position adjacent to a predetermined continuous row, it means that the foreign matter has a size larger than a certain size. The number of reflected images recognized as the foreign matter is stored in the memory. When the reflected image disappears and the scanning of all seaweed is completed, the number of foreign matter is read from the memory, and when one or more foreign matter is recorded, the solenoid for rotating the shutter 10 in FIG. Defective product storage
Drop to 11. If the number of foreign matter is 0, shutter
Since 10 does not operate, dry seaweed is transported to the good product storage 12. Alternatively, it can be carried out to the line of the dry seaweed shape determination device or the dry seaweed binding device in the next step.

As described above, the foreign matter can be continuously detected by detecting the change in the amount of light reflected by dry seaweed.

In the above embodiment, the ingress sensor 13 detects the introduction of dry seaweed, but the line image sensor 9
It is also possible to detect the beginning and end of dry seaweed using this image.

Further, in this embodiment, the foreign matter attached to the upper surface of the dry seaweed is detected, but a light source and a line image sensor may be installed on the lower side to detect the foreign matter on both sides. Furthermore, when the applicant of the present application previously proposed in Japanese Patent Application No. 63-191288, in combination with the method for detecting foreign matter of dry seaweed by transmitted light, in addition to the present invention effective for detecting foreign matter on the surface of dry seaweed, foreign matter detection inside dry seaweed is detected. Can also be done, and is perfect.

〔The invention's effect〕

As described above, in the present invention, the line image sensor detects changes in the reflected light on the surface of the dry seaweed while moving the dry seaweed, thereby detecting the seaweed with foreign matter. In this way, foreign matter can be detected without contacting dry seaweed, and malfunctions can be reduced, and even small foreign matter can be detected, which can improve the quality and yield of dry seaweed products. it can.

Further, by replacing the selection labor by the operator with the mechanization of the present invention, the rationalization of personnel can be achieved.

Furthermore, by setting the detection position of dry seaweed to be the gap between the two seaweed conveyor belt conveyors, the light emitted by the light source will not be reflected by belts other than dry seaweed. Can detect impurities with high accuracy without noise.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of the present invention, FIG. 2 is a flowchart of foreign matter detection processing in the present invention, FIG. 3 is a graph showing a measurement result of an installation angle of a line image sensor according to the present invention, and FIG. The figure is a graph showing the measurement results of the installation angle of the light source according to the present invention. A: Rectangular dry seaweed 1,2: Belt conveyor for transporting seaweed 3-5: Press roller, 6,7: Guide plate, 8: Light source 9: Line image sensor, 10: Shutter, 11: Defective product storage 12: Non-defective storage, 13: Ingress sensor, 14: Anti-reflection plate

Claims (2)

[Claims] 1. A nori seaweed transport belt conveyor, which is provided at a predetermined interval in the direction of transporting dry seaweed, and is arranged on one of the nori seaweed transport surfaces so as to illuminate the gap between these seaweed transport belt conveyors A light source, a line image sensor which is provided in the same direction as the light source with respect to the transport surface and receives reflected light of the light emitted from the light source, and means for detecting a change in the amount of light entering the line image sensor. And a means for outputting a contaminant mixing signal to a sorting means for removing contaminants when the light amount exceeds a set value, and a contaminant detecting device for dry seaweed. 2. The line image sensor is 60 ° from the detection position.
The dry seaweed foreign matter detection device according to claim 1, wherein the light source is installed at ± 30 ° and the light source is installed so that the optical axis is located at 45 ° ± 30 ° in the same direction as the line image sensor.