JP3949531B2 - X-ray inspection equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an X-ray inspection apparatus that inspects an article being conveyed.
[0002]
BACKGROUND OF THE INVENTION
In recent years, there has been an increasing demand for safety regarding various products, and it is necessary to surely find out that foreign matters have been mixed, particularly in articles such as food. Thus, for example, an X-ray inspection apparatus using X-rays as disclosed in Japanese Patent Application Laid-Open No. 9-113631 or Japanese Patent Application Laid-Open No. 9-1207017 has been put into practical use.
Such an X-ray inspection apparatus irradiates an article conveyed by a conveyor with X-rays from an X-ray irradiating means, and causes X-rays transmitted through the article to enter an X-ray detector (line sensor). Foreign matter is detected by continuously processing the output from the computer.
[0003]
By the way, as shown in FIG. 5A, the X-ray L is irradiated on the irradiation area A indicated by oblique lines on the transport surface 51 of the conveyor 5. The article M transported from the back toward the front passes through the irradiation area A as shown in FIG. 5B, and foreign matter detection is performed. However, as shown in FIG. 5 (c), when the article M is conveyed while being biased in the left-right direction, the article M is out of the irradiation area A, and a protruding portion Br in which foreign matter cannot be detected is generated. The reliability of inspection decreases.
[0004]
Therefore, a method is disclosed in which two sets of optical systems each consisting of an X-ray irradiation means and an X-ray detector are provided, and the irradiation areas of the two sets of optical systems are set to different areas (Japanese Patent Laid-Open No. 61). -205851).
However, in this conventional technique, since two sets of optical systems are used, it is inevitable that the cost is increased. Further, it is necessary to adjust the irradiation distance and the irradiation angle for each optical system, and the design and adjustment are complicated.
[0005]
On the other hand, as disclosed in Japanese Patent Laid-Open No. 2000-241368, it is conceivable to relatively move the X-ray irradiation means and the X-ray detector according to the article.
However, since the X-ray irradiation distance is changed by the movement, the sensitivity adjustment of the line sensor becomes complicated. In addition, since the position of the X-ray irradiation means changes, depending on the position of the X-ray irradiation means, the irregularly reflected X-rays may leak to the outside.
[0006]
The present invention has been made in view of such conventional problems, and an object of the present invention is to prevent X-ray leakage without increasing the cost and to improve the reliability of inspection of the X-ray inspection apparatus. .
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the X-ray inspection apparatus of the present invention irradiates an X-ray on the article while the article is being conveyed by a conveyor for conveying the article, and images the X-rays that have passed through the article. An X-ray inspection apparatus for processing and inspecting an article, wherein a passage area of the article on the conveyor when the article is conveyed most biased to the left and right ends in the width direction is from an irradiation area irradiated with X-rays In the case of protruding, it is provided with means for changing the passage area of the article before the article is conveyed .
[0008]
According to the present invention, whether the area check the article is transported in a state of protruding is performed before Symbol irradiation region. Therefore, according to the determination result by the area check, it can be set to always convey the article into the irradiation area, so that the reliability of the inspection can be improved.
Further, the cost can be reduced because two sets of optical systems are not used and the X-ray irradiation means and detector are not moved. Furthermore, since the X-ray irradiation means is not moved, it is possible to prevent the irregularly reflected X-rays from leaking outside.
[0009]
Further, if a detection means for detecting the size of the article is provided, it is possible to determine whether or not the article protrudes from the irradiation region for each article even if the article has a random size. As such a detection means, for example, an image processing means for obtaining a passing area of the article corresponding to the irradiation area based on an imaging signal from an imaging means for imaging the article is used.
The “size of the article” may include not only the width and height of the article but also the projected area of the article on the vertical plane. Furthermore, in the “extrusion determination” in the present invention, it may be determined whether or not the article protrudes from the irradiation region in consideration of the shape of the article in addition to the size of the article.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 5 show a first embodiment.
FIG. 1 is a partially cutaway side view of the X-ray inspection apparatus 1, and FIG. As shown in FIGS. 1 and 2, the X-ray inspection apparatus 1 provided on the article conveyance line has X-ray shield boxes 1S provided with an inlet 1a and an outlet 1b for the article M on both sides thereof. Yes. A conveyor (conveying means) 5 is disposed in the X-ray shield box 1S. The articles M carried in from the inlet 1a by the conveyor 5 are conveyed on the conveying surface 51 of the conveyor 5, and after being subjected to foreign matter inspection as will be described later, are carried out from the outlet 1b.
[0011]
In the X-ray shield box 1S of FIG. 1, an optical system 20, a guide 31, a guide driving means 30, and the like are provided.
The optical system 20 includes an X-ray irradiation means 21 and an X-ray detector 22. The X-ray irradiation means 21 generates X-rays L and irradiates the X-rays L toward the X-ray detector 22. 5 is a cross-sectional view taken along line AA of the main part in FIG. As shown in FIG. 5 (a), the X-ray irradiation means 21 and the conveyor 5 are arranged in a plane perpendicular to the conveying direction Y (FIG. 2) of the article M by the X-rays L emitted from the X-ray irradiation means 21. An irradiation area A is formed between the transfer surface 51 and the transfer surface 51.
The X-ray detector 22 shown in FIG. 1 includes a line sensor in which a large number of pixels are arranged at predetermined intervals in the width direction of the conveyor.
[0012]
As shown in FIG. 2, guide driving means 30 and guides 31 are provided on the left and right sides of the conveyor 5, respectively. When the guide driving unit 30 moves the guide 31 provided on the conveyor 5 in a substantially horizontal direction as shown in FIG. If it is, the article M comes into contact with the guide 31 and the conveyance path is changed. Therefore, the guide driving means 30 and the guide 31 constitute a conveyance path changing means (means for changing the passage area) for changing the conveyance path of the article M.
A sorting device 9 for line-out of defective articles is provided downstream of the X-ray inspection apparatus 1.
[0013]
Next, the control configuration of the X-ray inspection apparatus will be described.
As shown in FIG. 3A, the X-ray inspection apparatus 1 is connected to a sorting apparatus 9. The X-ray inspection apparatus 1 has a microcomputer 10. The microcomputer 10 is connected to the display 7, the numeric keypad 8, the X-ray irradiation means 21, the X-ray detector 22, the guide driving means 30 and the local control device 25 via an interface (not shown).
[0014]
The microcomputer 10 includes a CPU 11 and a memory (storage means) 12. The memory 12 includes an article information storage unit 12a and an area storage unit 12b.
As shown in FIG. 3 (b), in the article information storage unit 12a, for each article No., the article name including the article name including the article width and height is stored in advance in association with each other. Yes. As shown in FIG. 5B, the width and height of the article are determined by dimensions in the width direction X and the height direction Z of the article M orthogonal to the conveyance direction Y of the article M.
The area storage unit 12b stores the size and position of the irradiation area A.
[0015]
As will be described later, when the article M is designated, the CPU 11 reads the width and height of the article associated with the article number.
As will be described below, the CPU 11 constitutes a discriminating unit that performs a region check as to whether or not an article is conveyed in a protruding state based on the size and position of the article with respect to the irradiation area A. .
[0016]
First, the CPU 11 calculates a passing area B shown in FIG. 5B based on the width and height of the article M. This passing area B is an area of the article M on the conveyor 5 when the article M is conveyed to the left and right ends. The passing area B is determined by the width and height of the article M and the position of the article M on the conveyor 5 in the width direction. Next, the CPU 11 superimposes the passage area B of FIG. 5B on the irradiation area A of the X-ray L shown in FIG. 5A, and whether or not the passage area B protrudes from the irradiation area A. Check.
As shown in FIG. 5C, when the protruding portion Br occurs as a result of the region check, the protruding portion Br disappears based on the passage region B by the CPU 11 as shown in FIG. Thus, the movement distance α of the guide 31 is calculated.
Based on the moving distance α, the left and right guide driving means 30 move the guides 31 in the directions approaching each other by the moving distance α.
[0017]
The article M on the conveyor 5 is transported to the X-ray irradiating means 21 after the transport path is changed by the guide 31, and is imaged by the X-ray irradiating means 21.
The CPU 11 shown in FIG. 3 includes an X-ray image processing unit 11a.
The X-ray image processing unit 11a continuously processes the output from the X-ray detector 22 in the order of reception, thereby creating an image having a light and dark distribution corresponding to the amount of transmitted X-rays. The CPU 11 determines whether or not a foreign matter is attached to or mixed in the article M by determining whether or not there is a part whose brightness is significantly different from the surrounding parts in the image. Judge pass / fail.
When the CPU 11 determines that a foreign matter is attached or mixed in the article M as a result of the foreign matter detection, the CPU 11 rejects the article M and transmits a sorting signal to the sorting device 9.
[0018]
Next, the operation of the X-ray inspection apparatus will be described based on the flowchart shown in FIG.
After the operator performs a predetermined operation and designates an article to be inspected, the apparatus is started. The designation of the article may be designated based on article information from an upstream controller.
When the apparatus starts, in step S1, the CPU 11 of FIG. 3 reads the width and height associated with the article number of the article from the article information storage unit 12a, and proceeds to step S2.
In step S2, the passage area B of the article M is calculated. That is, when the article M is most biased to the left and right ends as shown in FIG. 5 (b) based on the read width and height and the initial position of the guide 31 on the conveyor 5, The passage area B of the article M when the article M comes into contact with the guide 31 at the initial position is calculated, and the process proceeds to step S3.
[0019]
In step S3, the passage area B is compared with the irradiation area A in FIG. 5A, and an area check is performed to determine whether or not the protruding portion Br in FIG. 5C occurs. If the protruding portion Br is generated, the process proceeds to step S4. On the other hand, when the protruding portion Br does not occur, the process proceeds to step S6.
[0020]
In step S4, as shown in FIG. 5 (d), the movement distance α of the guide 31 that eliminates the protruding portion Br is calculated, and the process proceeds to step S5.
In step S5, the guide 31 is moved inward by the movement distance α, and the process proceeds to step S6.
[0021]
In step S6, foreign matter inspection is performed on the article M conveyed below the X-ray irradiation means 21. That is, the X-ray image processing unit 11 a creates an image based on the transmission X-ray detection signal from the X-ray detector 22, and the CPU 11 displays the image on the display 7. At the same time, the CPU 11 performs foreign object detection based on the image. In the foreign object detection, when it is determined that the foreign object is rejected because foreign matter is attached or mixed in the article M, a distribution signal is transmitted to the distribution device 9.
[0022]
Here, when the article M is conveyed in a biased direction in either the left or right direction, the conveyance path is changed so that the article M comes into contact with the guide 31 and enters the irradiation area A.
Thereafter, the article M is conveyed from the outlet 1b to the outside of the X-ray shield box 1S and sent to the sorting device 9 downstream.
[0023]
As described above, when the area of the article M is checked and the article M protrudes from the irradiation area A, the article M protrudes from the irradiation area A by moving the guide 31 and changing the conveyance path of the article M. It can be prevented from being conveyed. Accordingly, since the article M is always conveyed in the irradiation area A, the reliability of the inspection can be improved.
[0025]
FIG. 6 shows a second embodiment.
As shown in FIG. 6, a CCD camera (imaging means) 6 is connected to the microcomputer 10 of the X-ray inspection apparatus 1A. The CCD camera 6 is provided upstream of the X-ray irradiation means 21, images the article M on the conveyor 5, and outputs luminance information (imaging information) to the microcomputer 10.
[0026]
The CPU 11 of the microcomputer 10 is provided with a captured image processing unit (image processing means) 11b in addition to the X-ray image processing unit 11a. The captured image processing unit 11b detects the position of the planar edge Me of the article M based on the luminance information input from the CCD camera 6, and further determines the width and height of the article M from the position of the edge Me. Then, a passing area B composed of the position of the article M on the conveyor 5 is calculated. Therefore, the CCD camera 6 and the captured image processing unit 11b constitute detection means for detecting the size of the article M.
As a method for calculating the width and height of the article M, there is a known method disclosed in JP-A-11-337315 (Japanese Patent Application No. 10-162888).
Other configurations are the same as those in the first embodiment, and the same parts or corresponding parts are denoted by the same reference numerals, and detailed description and illustration thereof are omitted.
[0027]
The captured image processing unit 11 b calculates the width and height of the article M every time the article M is conveyed below the CCD camera 6. The CPU 11 calculates the passage area B of the article M based on the width and height, and performs an area check.
Based on the determination result of the area check, the CPU 11 moves the guide 31 by the moving distance α corresponding to the article M when the article M protrudes. The CPU 11 repeats the area check and the movement of the guide 31 for each article.
[0028]
Thus, since the area check is performed for each article M and the guide 31 is moved, for example, an article having a random size such as a fruit or a vegetable can surely enter the irradiation area A. Can be conveyed. Therefore, the reliability of inspection is significantly improved.
[0029]
Incidentally, as shown in FIG. 1, it is not necessary to irradiate the X-ray L in the direction orthogonal to the transport surface 51. For example, as shown in FIG. 7, X-ray L may be emitted from the X-ray irradiation unit 21 toward the transport surface 51. In this case, the irradiation area A is stored in a size projected onto a virtual plane P1 orthogonal to the transport direction Y. That is, the irradiation area A is formed between the X-ray irradiation means 21 and the conveyance surface 51 in the orthogonal plane P1, and is determined based on the conveyance direction Y of the conveyance surface 51 of the article M and the position of the X-ray irradiation means 21. The
[0030]
In both the embodiments, the calculation of the protruding portion Br is not necessarily required. For example, the X-ray image processing unit 11a stores the movement distance α in advance in association with each article number, and the article M is designated. Then, the movement distance α corresponding to the article M may be read out.
[0031]
【The invention's effect】
As described above, according to the present invention, there is no possibility of causing the inspection mistake that goods products not inspected protrude from the irradiation area.
Further, it is not necessary to use two sets of optical systems or move the X-ray irradiation means and the detector, so that the cost is not increased.
Furthermore, since the X-ray irradiation means is not moved, the irregularly reflected X-rays are difficult to leak to the outside.
[0034]
Further, as passing area of the article is fit on the irradiation region, so to change the passage region of the article, because it so things article enters the irradiation area, automatic, and can be performed continuously inspected.
[Brief description of the drawings]
FIG. 1 is a schematic side view, partially in section, showing an X-ray inspection apparatus according to a first embodiment of the present invention.
FIG. 2 is a schematic plan view showing the X-ray inspection apparatus.
FIG. 3A is a schematic configuration diagram showing an X-ray inspection apparatus, and FIG. 3B is a chart showing storage contents of a storage unit.
FIG. 4 is a flowchart showing the operation of the X-ray inspection apparatus.
FIG. 5 is a schematic front view of a main part illustrating a method for changing a conveyance path.
FIG. 6 is a schematic configuration diagram showing an X-ray inspection apparatus according to a second embodiment of the present invention.
FIG. 7 is a hypothetical perspective view for illustrating a concept of an X-ray irradiation region.
[Explanation of symbols]
5: Conveyor (conveying means)
6: CCD camera (detection means)
7: Indicator (Warning means)
11: CPU (discriminating means)
11b: Captured image processing unit (detection means)
12: Memory (storage means)
30: Guide driving means (conveyance path changing means)
31: Guide (conveyance path changing means)
A: Irradiation area B: Passing area M: Article L: X-ray Y: Transport direction

Claims (2)

An X-ray inspection apparatus that inspects an article by irradiating the article with X-rays while the article is being conveyed by a conveyor that conveys the article, and performing image processing on the X-ray that has passed through the article,
When the article passing area on the conveyor protrudes from the irradiation area irradiated with X-rays when the article is conveyed most biased to the left and right ends in the width direction, the article is conveyed before the article is conveyed. X-ray inspection apparatus provided with a means for changing the passage area . In Claim 1, the means for changing comprises a guide that comes into contact with the article when the article on the conveying surface is conveyed to the left and right in the width direction, and a driving means for moving the guide,
  An X-ray inspection apparatus in which the passing area is changed by the drive means moving the position of the guide.

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