JPH0360380B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Fields This invention is applicable to pharmaceuticals (fine particles, granules, powder), electronic materials (ceramics powder), foods (powder raw materials,
The present invention relates to a powder inspection device that performs an appearance inspection of powder products such as bread crumbs, etc., and selects and removes defective products, foreign substances, etc.

Conventional technology The appearance inspection and sorting of this type of powder and granular materials has conventionally been carried out by placing the powder and granular materials in a sheet form on a belt conveyor, visually inspecting the sheet while conveying it, and detecting any defective products or foreign objects. However, inspection accuracy varied due to individual differences and fatigue among inspectors, and there was a high risk of overlooking defective products or foreign objects, resulting in low reliability. .
In addition, in order to improve inspection accuracy, it is necessary to slow down the conveyance speed of the powder and spread the powder into a sheet as thin as possible.
There was a problem that processing efficiency became extremely poor. Furthermore, there was the problem that it was difficult to create a closed system due to human intervention.

In order to solve these problems, a powder inspection device has been proposed that uses an image sensor to visually inspect powder and granule and automatically selects and removes defective products, foreign objects, and the like. This powder and granule inspection device allows powder and granules to fall naturally, illuminates them by reflection from the front side, and transmits light from the back, and sets the amount of reflected light and transmitted light to be equal for a good product. By taking an image from the front side and processing the image, it is possible to detect the presence of defective products and foreign objects whose brightness differs from that of non-defective products, and to select and remove them using an air gun or the like.

Problems to be Solved by the Invention The above-mentioned powder inspection device was configured to simply allow the powder to fall naturally, making it difficult to create a thin powder layer with a constant thickness, resulting in poor inspection accuracy. It is not stable, and if the powder or granules fall for a certain length, they will naturally spread out, making the powder passage unstable, and the powder will fly around, making it difficult to sort and remove it with an air gun, etc. There was a problem that it became impractical.

This invention was made in view of the above-mentioned problems, and it is possible to create a thin powder layer with a constant thickness, stabilize inspection accuracy, and easily and reliably separate and remove defective products and foreign objects. The purpose of the present invention is to provide a powder/grain material inspection device that can perform the following tests.

Means for Solving the Problems The powder and granule inspection device of the present invention is arranged side by side so as to face each other parallel to each other with a predetermined interval in the front and rear, and forms a powder and granule falling path at the mutually facing portions, and rotates a central axis. a pair of transparent rotating bodies that rotate as shafts; a powder transport means for conveying the powder and granular material in a sheet form by positioning a drop opening at the upper end of the powder and granular material falling passage; a sorting device installed in the vicinity of the powder and granular material falling path below to remove the powder and granular material; a cleaner that cleans mutually opposing surfaces of the pair of transparent rotating bodies at positions other than the powder and granular material falling path; a reflected light source that reflects and illuminates the powder and granular material falling in the powder and granular material falling path from a position in front of the pair of transparent rotating bodies; a transmitted light source that transmits illumination from a rear position of the transparent rotating bodies, an imaging device that images the powder and granular material falling in the powder and granular material falling path from a front position of the pair of transparent rotating bodies, and this imaging device an image processing means for detecting the presence of defective products, foreign objects, etc. in the powder or granule material falling in the powder or granule material falling path by processing the image signal of the powder or granule material and generating a defect signal; a sorting device control means that operates the sorting device for a predetermined period of time in response to a defective signal from the screen, thereby removing defective powder particles, powder particles containing foreign matter, etc.; The amount of light reflected by the non-defective granular material and the amount of light transmitted by the rear one of the pair of transparent rotating bodies of the light from the transmitted light source are set to be approximately equal.

Function In this way, by installing a pair of transparent rotating bodies at a predetermined interval, a powder falling passage is formed, and the powder falling through this powder falling passage, so that the powder and granules fall in one piece. By appropriately setting the interval between the transparent rotating bodies, a thin powder layer with a constant thickness can be easily created, and inspection accuracy can be stabilized. Furthermore, since the powder falling passage restricts the dispersion of the powder, defective products, foreign matter, etc. can be easily and reliably sorted and removed. Furthermore, since the transparent rotating body is cleaned with a cleaner, there is no possibility that particles will adhere to the transparent rotating body and make inspection impossible.

Embodiment An embodiment of the present invention will be described based on FIGS. 1 to 8. As shown in Figures 1 and 2, this powder inspection device consists of two transparent glass discs (which may be made of plastic) 1 and 2, which are partially spaced at a predetermined distance from front to back. The two glass disks 1 are arranged side by side on the left and right so as to face parallel to each other, and the two glass disks 1,
2 in parallel with a predetermined interval between the mutually opposing surfaces of 2.
By arranging two guide side plates 3 and 4 in parallel, a powder falling path S for the powder and granular material to be inspected is created, and a drop opening of a powder loading and conveying means such as a vibrating feeder 5 is connected to the powder and granular material to be inspected. A sorting device 6 which is positioned at the upper end of the falling passage S and uses suction (discharge) removal using air is installed near the falling route of the powder and granular material below the powder falling passage S, and the vibrating feeder 5 removes the powder. The granules 7 are smoothed into a thin sheet and conveyed,
The powder and granular material 7 is dropped through the powder and granule material falling passage S while regulating diffusion, and while the powder and granular material 7 is passing through the powder and granule material falling passage S, it is inspected to determine whether it contains defective products or foreign matter. If so, the sorting device 6 is operated to suction and remove the powder 7 in the area containing defective products or foreign matter, and the good products are accumulated in the good product collection container 8 placed directly under the powder drop passage S. I'm starting to do that. Reference numeral 9 denotes a guide that guides the powder or granular material 7 to the powder or granular material falling path S.

In this way, the two glass discs 1, 2 and the two guide side plates 3, 4 create a small powder/granular material falling path S, and the powder/granular material 7 passes through this powder/granular material falling path S. Since it passes through, the positioning accuracy of the falling powder 7 is good, and since the powder 7 can be made into a thin layer, the inspection accuracy can be improved. In addition, since the powder or granule material 7 does not spread, the powder or granule material 7 in the area containing defective products, foreign matter, etc., is detected by the sorting device 6.
Removal is also easy and reliable.

The two glass disks 1 and 2 mentioned above are
In order to remove dirt due to adhesion of powder and granular material 7, the central axis is the rotation axis and the directions are opposite to each other (arrows A ₁ and A ₂ ).
The cleaner 1 rotates at a constant speed (driven by a motor), and the mutually opposing surfaces
Cleaned by 0;11. This cleaner 10;
11 are two drums 10 arranged in parallel.
a, 10b; 11a, 11b and this drum 10
a, 10b; 11a, 11b; a loop-shaped cleaner cloth 10c; 11c; and the cleaner cloth 10
c; consists of an air suction section 10d; 11d that sucks and removes the powder particles 7 attached to the drum 11c, and one drum 10a;
Clean the surfaces of the glass disks 1, 2 with cleaner cloths 10c, 11c by rotating the drums 10a, 10b; 11a, 11b. Then, the powder 7 adhering to the cleaner cloth 10c; 11c is removed by the air suction part 10d; 11d, and the cleaner cloth 1
The surfaces of the glass disks 1 and 2 are repeatedly cleaned at 0c and 11c.

In this way, since the powder and granules 7 adhering to the glass discs 1 and 2 are constantly cleaned and removed by the cleaners 10 and 11, the powder and granules 7 do not adhere to the glass discs 1 and 2 while falling. This will not make the test impossible. Moreover, cleaning does not interfere with the inspection;
High inspection efficiency.

Next, the powder and granular material 7 is inspected as follows. That is, a television camera 12 is installed in front of the mutually opposing surfaces of the two glass disks 1 and 2, and the area including the inspection field of view P set on the mutually opposing surfaces of the two glass disks 1 and 2 is set on the television. A camera 12 is configured to take images at predetermined time intervals, and a half mirror 1 is provided between the television camera 12 and the glass disks 1 and 2.
3 and from the front position of the glass disks 1 and 2,
Light is irradiated from the reflected light source 14 to the falling powder or granular material 7 via the half mirror 13, and the reflected light from the powder or granular material 7 is transmitted via the half mirror 13 to the television camera 12.
Also, from the rear position of the glass discs 1 and 2, light is irradiated from the transmitted light source 15 toward the falling powder and granular material 7, and the gap between the glass discs 1 and 2 and the powder and granular material 7 is filled. The transmitted light is further transferred to a half mirror 1.
The light is made to enter the television camera 12 through 3. In this case, the amount of light reflected by the reflective light source 14 and the light from the transmitted light source 15 on the glass disk 2
The amount of transmitted light is set equally. in particular,
It is set by adjusting the transmittance of the glass disk 2, the light amount of the transmitted light source 15, etc.

With this configuration, the falling powder 7
If all of the items are in good condition, the TV camera 12
The image captured by this has the same brightness over the entire inspection field of view P, and the powder 7 is completely invisible. However, if defective products or foreign matter are mixed into the powder or granular material 7, the amount of reflected light of the defective product or foreign matter will be different from that of the non-defective product, that is, the brightness will be different from that of the non-defective product. Dark spots or bright spots will appear in the image No. 12 corresponding to defective products or foreign objects. Then, the image processing device 16, which will be described in detail below, detects the presence or absence of dark spots or bright spots in the image, and if there is a dark spot or bright spot, the sorting device control means 17 and 18 control the sorting device. 6 is operated for a certain period of time, and the powder and granular material 7 in the area containing defective products and foreign matter is removed by suction.

Next, the image processing device 12 and the sorting device control means 17, 18, which generate a defective signal based on the image of the television camera 12, will be explained in detail with reference to FIGS. 3 to 6.

As shown in FIG. 3, the image processing device 16 that processes the video signal from the television camera 12 amplifies the video signal and removes noise by passing the video signal through an amplification/filter circuit 16A, and further includes a differentiation circuit 16B. A characteristic signal corresponding to a singular point in the image is obtained by passing it through the image, and the level of this characteristic signal is discriminated by a positive/negative differential level comparator 16C.Meanwhile, an inspection field of view P is defined by a mask signal generation circuit 16D based on a synchronization signal. By generating a mask signal and controlling the AND gate 16E with this mask signal, a defect signal is output when a dark spot or bright spot occurs within the effective area (corresponding to the inspection field of view).

For example, if the image taken by the television camera 12 is as shown in FIG. 4 and there is a dark spot Z corresponding to a foreign object in the effective area Q, the video signal on the Mth scanning line l _M will be as shown in FIG. 5A. In the differential signal obtained by differentiating this video signal, pulses appear corresponding to the leading and trailing edges of the video signal as shown in Figure 5C, but these pulses correspond to the ON period of the mask signal in Figure 5B. Therefore, the defective signal from the AND gate 16E remains at the L level (only for non-defective products) as shown in FIG. 5D.

However, as shown in Figure 6A, the level of the video signal on the Nth scanning line l _N at the position intersecting the dark spot Z decreases at a timing corresponding to the position of the dark spot Z, and the (brightness) As shown in FIG. 6C, pulses appear in the differential signal corresponding to the leading and trailing edges of the video signal and the dark spot Z, and when the mask signal is turned on in FIG. 6B, A pulse within the period (corresponding to a dark spot) passes through the AND gate 16E and is output as a defect signal (H level).

Then, a defect signal (H level) as shown in FIG. 7A output from this AND gate 16E is applied to the retriggerable one-shot multivibrator 18 through the delay circuit 17. During the output pulse generation period, the sorting device 16 operates to suction and remove the particulate material 7. Above delay circuit 1
7 is to apply a defective signal to the retriggerable one-shot multivibrator 18 with a delay of Δt time, and after a defective product, foreign object, etc. is located within the inspection field of view S and a defective signal is generated, the defective product, foreign object, etc. is detected. The delay time Δt is determined in consideration of the time required for the powder to reach the suction port of the sorting device 6 and the delay in the operation of the sorting device 6, so as to reduce the loss of non-defective products of the powder and granular material 7.

Furthermore, the retriggerable one-shot multivibrator 18 outputs a pulse for an hour _t0 after inputting a defective signal, and is set to the time required for suctioning and removing defective products, foreign objects, etc., as shown in FIG. 7A. In response to a defective signal, a pulse as shown in FIG. 7B is output as a selection signal.

8A to 8H show the state of the image depending on the state of the transmitted light source 15 and the reflected light source 14, the amount of powder and granular material 7, and the presence or absence of defective products or foreign matter. FIG. 8A shows the case where there is only reflected light and the amount of powder 7 is small;
The powder 7 becomes white and the background becomes black. Figure 8B
indicates a case where there is only reflected light and there is an extremely large amount of powder 7 (the entire surface is covered with powder), and the entire surface is white. FIG. 8C shows a case where only transmitted light is transmitted and the amount of granular material 7 is small, and the granular material 7 becomes black and the background becomes white. FIG. 8D shows a case where there is only transmitted light and there is an extremely large amount of powder particles 7, and the entire surface becomes black. FIG. 8E shows a case where the reflected light and the transmitted light are balanced, there is little powder 7, and there are only good products, and the entire surface is white. FIG. 8F shows a case where the reflected light and the transmitted light are balanced, there is an extremely large amount of powder particles 7, and there are only good products, and the entire surface is white. Fig. 8G shows a case where the reflected light and the transmitted light are balanced, there is little powder 7, and there are hairs, different-colored particles, etc., and the hair and different-colored particles become dark spots, and the background becomes white. . FIG. 8H shows a case where reflected light and transmitted light are balanced, there is a large amount of powder and granules 7, and there are hairs and different colored grains, and the hair and different colored grains become dark spots and the background is white. becomes.

In the powder inspection device of this embodiment, since the position of the falling powder 7 is regulated by the two glass disks 1 and 2, the positioning accuracy is good, and a thin layer can be formed, allowing inspection. Accuracy can be improved, and defective products, foreign objects, etc. can be reliably removed.

In addition, by using the glass disks 1 and 2,
The amount of reflected and transmitted light can be easily adjusted (by adjusting the transmittance of the glass disks 1 and 2), and defective products can be easily optically extracted. Also,
By rotating the glass disks 1 and 2, the powder falling passage S
Since the powder adhesion surfaces of the glass disks 1 and 2 are cleaned by the cleaners 10 and 11 at other positions,
Cleaning can be performed without interrupting the inspection, and
Since cleaning is performed without interfering with the inspection, inspection accuracy can be guaranteed and efficiency can be increased.

In the above embodiment, the television camera 12 is used to capture two-dimensional images at regular intervals and image processing is performed, but a two-dimensional image sensor may be used to capture the images. Further, by obtaining a one-dimensional image using a one-dimensional image sensor and processing this image, it is also possible to inspect the powder or granular material. Note that the image capturing period is determined by the falling speed of the powder within the inspection field of view.

Effects of the Invention The powder and granule inspection device of the present invention forms a powder and granule falling passage by installing a pair of transparent rotating bodies at a predetermined interval, and the powder and granules pass through this powder and granule falling passage. Since it is made to fall, by appropriately setting the interval between the pair of transparent rotating bodies, a thin powder layer with a constant thickness can be easily created, and inspection accuracy can be stabilized. Furthermore, since the powder falling passage restricts the dispersion of the powder, defective products, foreign matter, etc. can be easily and reliably sorted and removed.
Furthermore, since the transparent rotating body is cleaned with a cleaner, there is no possibility that particles will adhere to the transparent rotating body and make inspection impossible.

[Brief explanation of drawings]

1 and 2 are schematic diagrams showing the configuration of an embodiment of the present invention, FIG. 3 is a detailed block diagram of the main part of FIG. 1, and FIG. 4 is a schematic diagram showing a television image. Figures 5 and 6 are waveform diagrams of each part in Figure 4, Figure 7 is a waveform diagram of each part in Figure 1, and Figure 8 is a schematic diagram showing the video of the effective area of the television image. . 1, 2... Glass disk (transparent rotating body), 3, 4
... Guide side plate, 5 ... Vibrating feeder (powder transport means), 6 ... Sorting device, 7 ... Powder and granule material, 10,
11...Cleaner, 12...TV camera (imaging device), 14...Reflected light source, 15...Transmitted light source,
16... Image processing device, 17... Delay circuit (sorting device control means), 18... Retriggerable one-shot multivibrator (sorting device control means).

Claims (1)

[Claims] 1. A pair of transparent rotating bodies that are arranged parallel to each other so as to face each other at a predetermined distance in the front and back so that the mutually facing portions form a powder/grain material falling path and rotate about a central axis as a rotation axis, and the powder/granular material falling path. A powder conveying means that positions a falling port at the upper end and conveys the powder in the form of a sheet, and is installed near the powder falling path below the powder falling path to remove the powder. a sorting device for cleaning the mutually opposing surfaces of the pair of transparent rotating bodies at positions other than the particle sizer falling passage; a reflected light source that illuminates the powder by reflection from a position in front of the pair of transparent rotating bodies; a transmitted light source that illuminates the powder falling in the powder falling path from a rear position of the pair of transparent rotating bodies; an imaging device that takes an image of the powder falling through the powder falling path from a position in front of the pair of transparent rotating bodies; image processing means for detecting the presence of defective products, foreign matter, etc. in the powder or granular material and generating a defect signal; and operating the sorting device for a predetermined period of time in response to the defect signal from the image processing means. and a sorting device control means for removing defective powder and granular materials, powder and granular materials containing foreign matter, etc., and controlling the amount of light reflected by the good powder and granular materials from the reflected light source and the light from the transmitted light source. A powder inspection device in which the amount of light transmitted through the rear transparent rotating body is set to be approximately equal to the amount of light transmitted through the rear transparent rotating body.