JP2001013261A - Contamination detection method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately detect contamination that cannot be detected by a method using an X-ray transmittance, a capturing method, and an infrared application method using static electricity. SOLUTION: Light at the wavelength region of UV and visible regions being emitted from a UV + visible lamp 20 to an object 2 to be carried being carried by a conveyor 1, the image of the object 2 to be carried at this time is picked up by a camera 22 through a UV filter 26 and a visible ND filter 27, an image through the UV filter 26 obtained by an image-processing device 30 is compared with an image being transmitted through the visible ND filter 27 by a contamination removal decision device 31 for judging contamination 2b, and the contamination 2b is sent to a contamination collection box 5 by a dropout conveyor 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to, for example, material selection at the time of food processing, and a foreign matter detection method for detecting foreign matter mixed in a conveyed material such as food material being conveyed by a conveyor or the like, and a method of detecting the same. Related to the device.

[0002]

2. Description of the Related Art In food material sorting in the food processing industry, foreign materials such as metals and stones are mixed from non-defective food materials. Therefore, foreign materials are detected from food materials being conveyed by a conveyor.

FIG. 5 is a schematic view of a method for detecting foreign matter by visual observation. A plurality of conveyors 1 are connected to form a transport line, and transport the transported object 2. In addition,
The conveyed product 2 is referred to as a non-defective product 2a and a foreign material 2 together.

[0004] A drop-out conveyor 3 is provided between the conveyors 1 of the foreign matter sorting section among these conveyors 1, and is rotated by operating a drop-out conveyor driving device 4. The foreign matter 2b is sent to the arranged foreign matter collection box 5. A non-defective collection box 6 is provided at the tip of each conveyor 1.
Is arranged.

In such a foreign matter detection method by visual observation, usually, two sorting workers 7a and 7b detect the foreign matter 2b conveyed on the transport line in one line and directly remove the foreign matter 2b by hand. When 2b is detected, the dropout conveyor driving device 4 is operated, the dropout conveyor 3 is rotated, and the foreign matter 2b is sent into the foreign matter collection box 5 together with some good products 2a.

However, this foreign matter detection method has a problem that when the line speed is high or the inspection time is long, the foreign matter 2b is easily overlooked due to a human error.

The following method has been used for detecting foreign matter, which has been performed by such a method, in order to increase the speed of a transport line and increase the accuracy of foreign matter detection.

FIG. 6 is a configuration diagram of a foreign substance detection device using X-rays. The conveyor 1 is provided with an X-ray transmitting foreign substance detection device 8 so as to surround the conveyor 1. This X-ray penetrating foreign matter detection device 8 has an X-ray generation unit arranged above and below the conveyed object 2 to be inspected, that is, either above or below the conveyor 1 and an X-ray detection unit arranged at the other. It has become.

The X-ray transmitting foreign object detecting device 8 irradiates the X-ray radiated from the X-ray generation unit to the conveyed object 2 conveyed to the conveyor 1, and detects the X-ray transmitted through the conveyed object 2 for X-ray detection. And outputs an electric signal corresponding to the X-ray transmission amount.

The image processing device 9 receives the electric signal output from the X-ray transmitting foreign object detecting device 8, creates an image signal corresponding to the amount of X-ray transmission based on the electric signal, and sends the image signal to the foreign object removal determining device 10. send.

The foreign matter removal determining apparatus 10 determines the foreign matter 2b by utilizing the difference in the amount of X-ray transmission between the non-defective article 2a and the foreign substance 2b in the conveyed article 2. Each X of the non-defective article 2a and the foreign substance 2b is determined. If there is a remarkable difference in the amount of X-ray transmission, for example, if a good product 2a of the conveyed product 2 contains a foreign substance 2b in the dried fish or tea leaves and a metal or a stone as a foreign substance 2b, the difference in the amount of X-ray transmission causes the foreign substance 2
b is determined, and the dropout conveyor driving device 4 is driven at this time.

This drop-out conveyor drive 4
Rotates the dropout conveyor 3 and sends the foreign matter 2b into the foreign matter collection box 5 together with a part of the good product 2a.

However, in this foreign matter detecting device, the difference between the X-ray transmission amounts of the non-defective product 2a and the foreign matter 2b is remarkable.
For example, when a good product 2a of the conveyed product 2 includes a dried fish or tea, and a foreign material 2b containing a metal or a stone as a foreign material 2b, the foreign material 2b can be detected with high sensitivity.
In the case where the X-ray transmittance a is close to, for example, a piece of wood or wood chips as the foreign substance 2b, it is extremely difficult to detect the foreign substance 2b. Therefore, the detection target of the foreign matter 2b is limited.

FIG. 7 is a diagram showing a collection method using static electricity applied to the detection of foreign matter 2b, for example, hair or fiber, which cannot be detected by the foreign matter detection device using X-rays shown in FIG. In this collection method, a corona discharge wire electrode 11 and a collection unit 12 are arranged on a conveyor 1 of a transport line,
Corona discharge is generated by the corona discharge wire electrode 11, and ions are generated in the air by the corona discharge.

In this state, if the non-defective product 2a conveyed to the conveyance line contains foreign matter 2b such as hair or fiber, ions adhere to the foreign matter 2b such as hair or fiber and the foreign matter 2b is charged. I do.

The collection unit 12 includes a foreign matter collection electrode to which a voltage having a polarity opposite to that of the charged electric charge is applied, and selectively collects the foreign matter 2b such as hair or fiber charged with ions.

However, according to the collection method using static electricity, only the light foreign matter 2b such as hair or fiber can be collected, but the heavy foreign matter 2b having electrical conductivity such as metal powder can be collected. Is in principle impossible to collect, and similarly to the X-ray transmission method, it is difficult to detect wood chips and wood chips.

FIG. 8 is a block diagram of an infrared irradiation type foreign substance detection device developed to detect the foreign substance 2b which is difficult to detect and collect by the above-mentioned X-ray transmission method or the collection method using static electricity.

In this infrared irradiation method, electric power is supplied from a lamp power supply 13 to a halogen lamp 14, and light is emitted from the halogen lamp 14 continuously or in a pulsed manner to irradiate the article 2. At this time, the infrared camera 15 captures an image of the transported object 2 irradiated with the light from the halogen lamp 14 and outputs an image signal thereof.

The image processing device 16 receives an image signal output from the infrared camera 15, creates an image signal representing thermal conductivity and specific heat based on the image signal, and sends it to the foreign matter removal determination device 17.

The foreign matter removal determining device 17 receives the image signal output from the image processing device 16 and determines the foreign matter 2b based on the difference between the thermal conductivity and the specific heat between the non-defective product 2a and the foreign matter 2b. Is determined, and the dropout conveyor driving device 4 is driven at this time.

This dropout conveyor driving device 4
Rotates the dropout conveyor 3 and sends the foreign matter 2b into the foreign matter collection box 5 together with a part of the good product 2a.

In this infrared irradiation type foreign matter detector,
If there is a large difference between the thermal conductivity and the specific heat of the non-defective product 2a and the foreign material 2b, it is possible to advantageously have the detection sensitivity for the foreign material 2b that cannot be detected by the apparatus using the X-ray transmission method. If there is no difference between the thermal conductivity and the specific heat of the foreign matter 2b, it is difficult to detect the foreign matter 2b.

[0024]

As described above, in the foreign matter detection method by visual observation, when the line speed is high or the inspection time is long, the foreign matter 2b is easily overlooked due to a human error. .

On the other hand, in the method using the X-ray transmittance, when the X-ray transmittance of the foreign matter 2b is close to the X-ray transmittance of the non-defective product 2a, it is extremely difficult to detect the foreign matter 2b. The detection target of 2b is limited, and in the collection method using static electricity, it is impossible in principle to collect foreign substances 2b having heavy conductivity or electrically conductive substances such as metal powder. In the infrared irradiation method, a good product 2a and a foreign material 2b
If there is no difference between the thermal conductivity and specific heat of
It becomes difficult to detect b.

Therefore, the present invention provides a foreign matter detection method and apparatus which can detect a foreign matter which cannot be detected by an infrared irradiation method with high accuracy even if the method uses an X-ray transmittance, a collection method using static electricity, or the like. To provide.

[0027]

According to the first aspect of the present invention,
In a foreign matter detection method for detecting foreign matter mixed in a plurality of conveyed objects being conveyed, irradiating the conveyed object and the foreign matter with light including each wavelength depending on a reflection characteristic of light for the conveyed object and the foreign matter,
The foreign object is detected by comparing the image of the transferred object and the foreign object obtained based on one of the wavelengths with the image of the transferred object and the foreign object obtained based on the other wavelength.

According to a second aspect of the present invention, in the foreign matter detection method according to the first aspect, light having a wavelength in the ultraviolet region and a wavelength in the visible region is irradiated on the conveyed object and the foreign matter during the transportation.

According to a third aspect of the present invention, there is provided a foreign matter detecting apparatus for detecting foreign matter mixed in a plurality of articles being conveyed,
An illumination optical system that irradiates the transport object and the foreign matter with light including each wavelength that depends on the reflection characteristics of light with respect to the transport object and the foreign object, and an imaging unit that captures an image of the transport object and the foreign object illuminated by the illumination optical system, A foreign object is detected by comparing the image of the transferred object and the foreign substance obtained based on one of the wavelengths obtained by the imaging by the imaging unit with the image of the transferred object and the foreign substance obtained based on the other wavelength. Determination means.

According to a fourth aspect of the present invention, in the foreign matter detection device according to the third aspect, the illumination optical system irradiates a light beam having a wavelength in the ultraviolet region and a wavelength in the visible region to the conveyed object and the foreign material being conveyed.

According to a fifth aspect of the present invention, in the foreign object detecting device of the fourth aspect, the illumination optical system emits pulsed light.

[0032]

(1) Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. The same parts as those in FIG. 5 are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 1 is a block diagram of the foreign matter detecting device. Above the conveyor 1, for example, a xenon lamp is disposed as a UV + visible lamp 20 that emits light in a wavelength region of an ultraviolet region (UV) and a visible region. The UV + visible lamp 20 has an optimal incident angle of light to the conveyed object 2 to be detected due to the light reflection characteristics of the non-defective product 2a and the foreign matter 2b to be sorted. When the irradiation angle is, for example, detected as a foreign substance 2b, a wood chip mixed in a dried and processed small fish, a good selection can be made at about 0 to 40 degrees.
Also, the conveyed material 2 of the light emitted from the UV + visible lamp 20
The direction in which the object 2 is irradiated may be the direction in which the article 2 is conveyed, the direction perpendicular to the direction of conveyance, or any direction between these directions. The UV + visible lamp 20 is lit by receiving power supply from a UV lamp power supply 21.

Above the conveyor 1, for example, an industrial television camera is arranged as the camera 22. In front of the camera 22, a filter holder 24 rotated by a motor 23 is rotatably arranged.
The motor 23 rotates at a predetermined rotation speed upon receiving power supply from the motor drive power supply 25.

In the filter holder 24, a UV filter 26 and a visible ND filter 27 are provided at intervals of, for example, 180 degrees on the circumference around the rotation axis. Among them, the UV filter 26 removes
In the case of detecting as b, one that transmits light in a wavelength region of, for example, 300 to 400 nm is used. By using the UV filter 26 in such a wavelength region, the UV
The image of the transported object 2 that has passed through the filter 26 (hereinafter, referred to as a UV image) has a reflection intensity of the boiled-out UV light of U of a wooden piece.
It becomes about 10 times or more higher than the reflection intensity of V light.

A photo-interrupter 28 is arranged around the circumference of the filter holder 24. The photo interrupter 28 is provided with a UV filter 26 or a visible ND filter 27 in the rotating filter holder 24.
Is detected within the field of view of the camera 22, and a detection signal is output and sent to the synchronization signal generator 29.

The synchronization signal generator 29 generates a synchronization signal when receiving a detection signal output from the photo interrupter 28 and sends it to the image processing device 30.

Each time the image processing device 30 receives each synchronization signal output from the synchronization signal generator 29, the camera 22
Input the image signal output from the
The image signal transmitted through the ND filter and the image signal transmitted through the visible ND filter 27 are respectively binarized at predetermined luminance levels, and the binarized image is subjected to the foreign matter removal determination device 3.
1 is provided.

In each of the images obtained by the image processing apparatus 30, in the UV image transmitted through the UV filter 26, the reflection intensity of the boiled UV light is about 10 times or more higher than the reflection intensity of the UV light of the wood chip. , Visible ND filter 27
In the image when the light is transmitted (referred to as a visible image), the reflection from the boiled and the piece of wood is detected at the same time.

The foreign matter removal judging device 31 includes the image processing device 3
The binarized image transmitted through the UV filter 26 and the binarized image transmitted through the visible ND filter 27 are compared and analyzed, and are detected in the UV image transmitted through the UV filter 26. However, it has a function of judging the position detected from the visible image transmitted through the visible ND filter 27 as a wooden piece as the foreign matter 2b and outputting the detection signal to the dropout conveyor driving device 4. .

Next, the operation of the above-configured device will be described.

Conveyed object 2 being conveyed by conveyor 1
Is irradiated with light in a UV region and a wavelength region of a visible region emitted from the UV + visible lamp 20.

On the other hand, the filter holder 24 is rotated at a predetermined rotational speed by receiving the power supply from the motor drive power supply 25, and in this state, the camera 22 moves the UV filter 26 or the visible ND filter 27 within its visual field. , Each image transmitted through the UV filter 26 or the visible ND filter 27 is captured, and the image signal is output.

At the same time, the photo interrupter 28
It detects that the UV filter 26 or the visible ND filter 27 in the rotating filter holder 24 has entered the field of view of the camera 22, outputs a detection signal and sends it to the synchronization signal generator 29.

The synchronization signal generator 29 generates a synchronization signal when receiving the detection signal output from the photo interrupter 28 and sends it to the image processing device 30.

The image processing device 30 inputs an image signal output from the camera 22 every time the synchronization signal output from the synchronization signal generator 29 is received, and outputs the image signal transmitted through the UV filter 26 and the visible ND signal. The image signal transmitted through the filter 27 is binarized at a predetermined luminance level, and the binarized data is converted into a foreign matter removal determination device 3.
Send to 1.

The foreign matter removal determination device 31 compares and analyzes a binary image transmitted through the UV filter 26 obtained by the image processing device 30 and a binary image transmitted through the visible ND filter 27. Of these, in the UV image transmitted through the UV filter 26, the reflection intensity of the boiled UV light is about 10 times or more higher than the reflection intensity of the UV light of the wood piece, and the visible image transmitted through the visible ND filter 27. In U.S.A., since reflections from boiled and wood chips are detected at the same time, U
The position which is not detected in the V image but is detected from the visible image when transmitted through the visible ND filter 27 is determined as a piece of wood as the foreign matter 2b, and the detection signal is output to the dropout conveyor driving device 4.

This dropout conveyor driving device 4
Rotates the dropout conveyor 3 and sends the foreign matter 2 b into the foreign matter collection box 5. Then, the non-defective product 2a passes through the drop-out conveyor 3, is conveyed as it is on the next conveyor 1, is collected in the non-defective product collection box 6, and the foreign matter sorting is completed.

As described above, in the first embodiment, the conveyed object 2 conveyed by the conveyor 1 is irradiated with light in the UV region and the visible region radiated from the UV + visible lamp 20. In this case, the transferred object 2 is UV
The image is taken by the camera 22 through the filter 26 and the visible ND filter 27, and the UV image transmitted through the UV filter 26 is compared with the visible image transmitted through the visible ND filter 27 to determine the foreign matter 2b. Since the foreign matter 2b is sent to the foreign matter collection box 5 in step 3, the sorting efficiency and the sorting accuracy of the non-defective 2a and the foreign matter 2b are significantly higher than the visual inspection by a human, and the conventional X-ray transmittance is used. Even if a foreign substance that cannot be detected in principle by a method, a collection method using static electricity, or an infrared irradiation method, for example, a wooden piece is mixed in a dried dish, this wooden piece can be detected with high accuracy as the foreign substance 2b.

(2) Next, a second embodiment of the present invention will be described with reference to the drawings. The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 2 is a block diagram of the foreign matter detecting device. Above the conveyor 1, a prism 32 that divides the reflected light from the conveyed object 2 is arranged, and a UV filter 26 is arranged in one of the dividing directions of the prism 32, and a visible ND filter 27 is arranged in the other. Of which UV
A UV camera 33 is arranged on the filter 26, and the visible N
A visual camera 34 is arranged on the D filter 27.

The UV camera 33 captures a UV image of the conveyed object transmitted through the UV filter 26, outputs an image signal of the image, and sends the image signal to the image processing device 30, and the visible camera 34 controls the visible ND filter 27. The image processing apparatus 30 captures a visible image of the conveyed article and outputs an image signal of the image.
To send to.

The image processing apparatus 30 is provided with a UV camera 3
3 and the respective image signals output from the visible camera 34 are input, and the image signal transmitted through the UV filter 26 and the image signal transmitted through the visible ND filter 27 are binary-coded at a predetermined luminance level. And a function of transmitting the binarized image to the foreign matter removal determination device 31.

Next, the operation of the device configured as described above will be described.

Conveyed object 2 being conveyed by conveyor 1
Is irradiated with light in a UV region and a wavelength region of a visible region emitted from the UV + visible lamp 20.

The reflected light from the conveyed object 2 irradiated with the light is split in two directions by a prism 32, and one of the lights is transmitted through a UV filter 26 and is incident on a UV camera 33, while the other is Are transmitted through the visible ND filter 27 and enter the visible camera 34.

The UV camera 33 picks up a UV image of the conveyed object transmitted through the UV filter 26 and outputs an image signal thereof.
7, and picks up a visible image of the conveyed object that has passed through 7 and outputs the image signal.

The image processing device 30 receives the respective image signals output from the UV camera 33 and the visible camera 34, and outputs the image signal when transmitted through the UV filter 26 and the image signal when transmitted through the visible ND filter 27. The image signal is binarized at a predetermined luminance level.
The digitized image is sent to the foreign matter removal determination device 31.

The foreign matter removal determination device 31 compares the binarized image transmitted through the UV filter 26 obtained by the image processing device 30 with the binarized image transmitted through the visible ND filter 27, and Similarly, in the UV image transmitted through the UV filter 26, the reflection intensity of the boiled UV light is about 10 times or more higher than the reflection intensity of the UV light of the wood chip, and in the visible image transmitted through the visible ND filter 27, Since the reflection from the boiled and the pieces of wood is detected at the same time, the foreign matter 2b is not detected in the UV image transmitted through the UV filter 26 but is detected in the visible image transmitted through the visible ND filter 27. The position is determined as a piece of wood, and the detection signal is output to the dropout conveyor driving device 4.

As a result, the drop-out conveyor driving device 4 rotates the drop-out conveyor 3 to
Is sent to the foreign matter collection box 5. Then, the non-defective product 2a passes through the drop-out conveyor 3, is conveyed as it is on the next conveyor 1, is collected in the non-defective product collection box 6, and the foreign matter sorting is completed.

As described above, in the second embodiment, the conveyed object 2 conveyed by the conveyor 1 is irradiated with light in the UV region and the visible region radiated from the UV + visible lamp 20. At this time, the reflected light from the conveyed object 2 is split by the prism 32 and imaged by the UV camera 33 and the visible camera 34 through the UV filter 26 and the visible ND filter 27, respectively. Image and visible ND filter 2
7, the foreign matter 2b is determined by comparing the image with the visible image transmitted through the foreign matter 7 and the foreign matter 2b is sent to the foreign matter collection box 5 by the drop-out conveyor 3. Therefore, as in the above-described second embodiment, Significantly better products compared to visual inspection by humans 2
a and foreign matter 2b, the sorting efficiency and the sorting accuracy are increased, and a conventional method using X-ray transmittance, a collection method using static electricity, a foreign matter which cannot be detected in principle by an infrared irradiation method,
For example, even if wood chips are mixed in the dried boiled water, the wood chips can be detected with high accuracy as the foreign matter 2b.

Further, the reflected light from the transported object 2 is split by the prism 32 and is simultaneously imaged by the UV camera 33 and the visible camera 34 through the UV filter 26 and the visible ND filter 27, so that the two cameras 33, 34 Thus, the image can be captured in real time, and the foreign matter 2b can be detected with high accuracy even when the transport line is fast.

(3) Next, a third embodiment of the present invention will be described with reference to the drawings. The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 3 is a block diagram of the foreign matter detecting device. Above the conveyor 1, a UV pulse lamp 35 and a visible pulse lamp 36 are arranged. A UV lamp power supply 37 is connected to the UV pulse lamp 35, a visible lamp power supply 38 is connected to the visible pulse lamp 36, and these lamp power supplies 37 and 38 receive a pulse signal generated by the pulse generator 39, and are fixed. The pulse power is supplied to the UV pulse lamp 35 and the visible pulse lamp 36 at each interval.

The pulse signal generated by the pulse generator 39 is also transmitted to the camera 22, and the conveyed object 2 is imaged by the camera 22 in synchronization with the UV pulse lamp 35 or the visible pulse lamp 36 which emits light alternately. It has become.

Next, the operation of the device configured as described above will be described.

While the conveyed object 2 is being conveyed by the conveyor 1, the pulse generator 39 generates pulse signals at regular intervals to generate the UV lamp power supply 37 and the visible lamp power supply 3.
8 and to the camera 22.

The UV lamp power supply 37 and the visible lamp power supply 38 receive pulse signals and supply pulsed power to the UV pulse lamp 35 and the visible pulse lamp 36, respectively. As a result, the UV pulse lamp 35 and the visible pulse lamp 36 emit the UV pulse light B and the visible pulse light R alternately at regular intervals, and irradiate the article 2.

The camera 22 receives the pulse signal output from the pulse generator 39 and, in synchronization with the pulse signal, reflects the reflected image when the object 2 is irradiated with the UV light B and the visible light R on the object 2. Is imaged at regular intervals with the reflected image when the light is irradiated, and the image signal is output.

The image processing device 30 receives an image signal output from the camera 22 and converts the image signal and the visible pulse light R when the UV pulse light B is applied to the article 2 into the article 2.
Are binarized at predetermined luminance levels, and the binarized image is sent to the foreign matter removal determination device 31.

The foreign matter removal determination device 31 is used to determine whether a binary image when the UV pulse light B obtained by the image processing device 30 is radiated on the conveyed object 2 and the visible pulse light R when the conveyed object 2 is radiated. Are compared with the binarized image, and those which are not detected from the image when the UV pulse light B is irradiated, but are detected from the visible image when the visible pulse light R is irradiated, The position is determined, and the detection signal is output to the dropout conveyor driving device 4.

As a result, the drop-out conveyor driving device 4 rotates the drop-out conveyor 3 to
Is sent to the foreign matter collection box 5. Then, the non-defective product 2a passes through the drop-out conveyor 3, is conveyed as it is on the next conveyor 1, is collected in the non-defective product collection box 6, and the foreign matter sorting is completed.

As described above, in the third embodiment, the UV pulse light B and the visible pulse light R are alternately provided at regular intervals from the UV pulse lamp 35 and the visible pulse lamp 36.
Is illuminated on the object 2, and a reflection image from the object 2 at this time is captured by the camera 22, and the binarized image and the visible pulse light R when the UV pulse light B is applied to the object 2 are obtained. The foreign matter 2b is compared with the binarized image when the article 2 is irradiated.
And the foreign matter 2b is sent to the foreign matter collection box 5 by the dropout conveyor 3, so that it is needless to say that the same effect as in the first embodiment can be obtained, and that the UV pulse is alternately provided at regular intervals. By irradiating the transport object 2 with the light B and the visible pulse light R, the sorting accuracy of the foreign matter 2b can be kept high even when the transport line is fast.

(4) Next, a fourth embodiment of the present invention will be described with reference to the drawings. The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 4 is a configuration diagram of the foreign matter detection device. The image signal output from the camera 22 is output to the high-speed image processing device 4.
0. The high-speed image processing device 40 receives an image signal output from the camera 22 and
A function of performing binarization processing using an optimal threshold value for extracting a difference in intensity of reflected light between a non-defective product 2a and a foreign substance 2b set in advance, and sending the binarized image to the foreign substance removal determination device 31 have.

Next, the operation of the device configured as described above will be described.

The transported object 2 being transported by the conveyor 1
Is irradiated with light in a UV region and a wavelength region of a visible region emitted from the UV + visible lamp 20.

The camera 22 simultaneously captures the reflected image from the transported object 2 irradiated with the light in the UV region and the visible region, and outputs the image signal.

The high-speed image processing device 40 receives an image signal output from the camera 22 and receives a preset non-defective product 2a.
A binarization process is performed using an optimum threshold value for extracting a difference in intensity difference between the reflected light and the foreign matter 2b, and the binarized image is sent to the foreign matter removal determination device 31.

The foreign matter removal determination device 31 captures the binary image obtained by the high-speed image processing device 40,
In the image irradiated with light, the reflection intensity of the boiled UV light is about 10 times or more higher than the reflection intensity of the UV light of the wood chip. The position of the foreign matter 2b is extracted based on the difference in the intensity, and the detection signal is output to the dropout conveyor driving device 4.

This drop-out conveyor driving device 4
Rotates the dropout conveyor 3 and sends the foreign matter 2 b into the foreign matter collection box 5. Then, the non-defective product 2a passes through the drop-out conveyor 3, is conveyed as it is on the next conveyor 1, is collected in the non-defective product collection box 6, and the foreign matter sorting is completed.

As described above, in the fourth embodiment, the UV + visible lamp 20 irradiates the light of the wavelength region of the UV region and the visible region to the conveyed object 2, and the reflected image from the conveyed object 2 at this time is obtained. High-speed image processing device 4
0 inputs an image signal output from the camera 22,
The binarization process is performed using an optimal threshold value for extracting a difference in intensity of reflected light between the non-defective product 2a and the foreign material 2b, which is set in advance, and the binarized image is sent to the foreign matter removal determination device 31. The position of the foreign matter 2b is extracted based on the difference in the intensity of the reflected light between the non-defective product 2a and the foreign matter 2b, and the foreign matter 2b is sent to the foreign matter collection box 5 by the dropout conveyor 3, so that the first and second embodiments are performed. The same effect as in the embodiment can be obtained.

The present invention is not limited to the first to fourth embodiments, but may be modified as follows.

For example, in the first to fourth embodiments, the wood pieces mixed during the drying are used. However, the present invention is not limited to this. Utilization can be used for foreign matter sorting.

Further, the present invention is not limited to the detection of wood chips mixed in boiled vegetables, but may be applied to the detection of foreign substances mixed in fruits, vegetables, and fish as conveyed objects in the case of food material selection in the food processing industry. Is applicable not only to the food processing industry but also to foreign substance detection in various industrial fields.

[0086]

As described above in detail, according to the present invention, an illumination optical system for irradiating a light beam having various wavelengths depending on the reflection characteristics of light to a conveyed object and a foreign object, and an illumination optical system for irradiating the conveyed object and the foreign object. Imaging means for imaging the transported object and foreign matter illuminated by the optical system; and an image of the transported article and foreign matter obtained based on one of the wavelengths obtained by imaging by the imaging means and the other wavelength. Determining means for detecting the foreign matter by comparing the obtained images of the conveyed object and the foreign matter;

Thus, the transport object and the foreign matter are irradiated with light having each wavelength depending on the reflection characteristic of the light to the transport object and the foreign matter, and the transport object and the foreign matter obtained based on one of the wavelengths are irradiated. Detecting foreign matter by comparing the image with the image of the conveyed object and foreign matter obtained based on the other wavelength, detection using a method using X-ray transmittance, a collection method using static electricity, or an infrared irradiation method It is possible to provide a foreign matter detection method and a foreign matter detection method capable of detecting a foreign matter that cannot be detected with high accuracy.

Further, since light having a wavelength in the ultraviolet region and a wavelength in the visible region is radiated to the conveyed object and the foreign matter during conveyance, the difference in the light reflection characteristics of the foreign matter mixed in the boiled product as the conveyed material is utilized. And a foreign matter detection method and device capable of performing highly accurate sorting.

Further, since the pulsed light is applied to the conveyed object and the foreign matter during the conveyance, it is possible to provide a foreign matter detecting method and apparatus capable of maintaining high foreign matter sorting accuracy even when the conveying line is fast.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a foreign object detection device according to the present invention.

FIG. 2 is a configuration diagram showing a second embodiment of the foreign matter detection device according to the present invention.

FIG. 3 is a configuration diagram showing a third embodiment of a foreign object detection device according to the present invention.

FIG. 4 is a configuration diagram showing a fourth embodiment of the foreign matter detection device according to the present invention.

FIG. 5 is a schematic view showing a conventional foreign matter detection method by visual observation.

FIG. 6 is a configuration diagram showing a conventional foreign matter detection device using X-rays.

FIG. 7 is a diagram showing a conventional collection method using static electricity.

FIG. 8 is a configuration diagram of a conventional infrared irradiation type foreign matter detection device.

[Explanation of symbols]

 1: Conveyor, 2: Conveyed object, 2a: Good product, 2b: Foreign material, 3: Dropout conveyor, 4: Dropout conveyor driving device, 5: Foreign material collection box, 6: Good product collection box, 20: UV + visible lamp, 21 : UV lamp power supply, 22: Camera, 23: Motor, 24: Filter holder, 25: Motor drive power supply, 26: UV filter, 27: Visible ND filter, 28: Photo interrupter, 29: Synchronous signal generator, 30: Image Processing device, 31: foreign matter removal determination device, 32: prism, 33: UV camera, 34: visible camera, 35: UV pulse lamp, 36: visible pulse lamp, 37: UV lamp power supply, 38: visible lamp power supply, 39: pulse generator, 40: high-speed image processing device.

Claims (5)

[Claims] 1. A foreign matter detection method for detecting foreign matter mixed in a plurality of conveyed objects during conveyance, comprising: transmitting light having respective wavelengths depending on a reflection characteristic of light to the conveyed object and the foreign matter; Irradiate foreign matter,
Detecting the foreign object by comparing the image of the transferred object and the foreign object obtained based on one of the wavelengths with the image of the transferred object and the foreign object obtained based on the other wavelength. Characteristic foreign matter detection method. 2. The foreign matter detection method according to claim 1, wherein light having a wavelength in an ultraviolet region and a wavelength in a visible region is irradiated to the conveyed object and the foreign matter during transportation. 3. A foreign matter detection device for detecting foreign matter mixed in a plurality of conveyed objects being conveyed, wherein light having respective wavelengths depending on light reflection characteristics of the conveyed object and the foreign matter is transmitted to the conveyed object and the foreign object. An illumination optical system for irradiating the foreign object; an imaging unit for imaging the transported object and the foreign object illuminated by the illumination optical system; and an imaging unit for obtaining an image based on one of the wavelengths obtained by the imaging unit. Determining means for detecting the foreign object by comparing the image of the transferred object and the foreign object obtained with the image of the transferred object and the foreign object obtained based on the other wavelength. apparatus. 4. The foreign matter detection device according to claim 3, wherein the illumination optical system irradiates the conveyed object and the foreign matter during transportation with light having a wavelength in an ultraviolet region and a wavelength in a visible region. 5. The foreign matter detection device according to claim 4, wherein the illumination optical system emits pulsed light.