JP2004061479A - X-ray foreign matter detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make a foreign matter detector highly precisely detectable a foreign matter in an object to be examined with a large width. <P>SOLUTION: In this detector, a plurality of X-ray generators, a plurality of X-ray detectors arranged in positions separated by a distance capable of obtaining an X-ray transmission quantity required for detecting the foreign matter, corresponding to the respective X-ray generators, and arranged to overlap respective inspection areas so as to examine all the areas for the inspected object, and a plurality of diaphragming devices or shielding plates to prevent the X-ray detector in the area other than the corresponding area from being irradiated with X-rays emitted from the X-ray generators, are arranged. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an apparatus for automatically detecting foreign matter mixed in various products using X-rays.
[0002]
[Prior art]
The X-ray foreign matter detector irradiates X-rays from the X-ray generator to the inspection object such as raw materials, processing products, and products, and foreign matter such as metal enters the inspection object based on the amount of transmitted X-rays. It is a device that detects whether or not the device is operating.
As shown in FIG. 4, the detection unit of the X-ray foreign matter detection device mainly detects the X-ray amount transmitted from the X-ray generator 101, the conveyor belt conveyor 102, and the X-ray generator 101 through the inspection object 104. The X-ray detector 103 is arranged so as to perform The inspection object 104 passes between the X-ray detectors 103 while being irradiated with the X-rays of the X-ray generator 101 by the conveyor belt conveyor 102. Based on the X-ray fluoroscopic image signal from the X-ray detector 103 obtained at this time, a foreign substance mixed into the product is detected.
[0003]
[Problems to be solved by the invention]
However, in the conventional X-ray foreign matter detection device, the range that can be used for detecting foreign matter of X-rays emitted from the X-ray generator 101 is limited to the range indicated by the effective irradiation angle A in FIG. As shown in (1), in order to detect foreign substances in the entire region of the inspection object 104 having a wide width W, it is necessary to increase the mounting height H of the X-ray generator 101.
On the other hand, the irradiation intensity of X-rays has a property of rapidly attenuating as the irradiation distance increases, and in the conventional conventional X-ray foreign matter detection device, when the mounting height of the X-ray generator 101 is increased, it is necessary to detect foreign matter. Therefore, there is a problem that a sufficient amount of X-ray transmission cannot be obtained, and sufficient foreign matter detection accuracy cannot be obtained.
The present invention has been made to eliminate the above-mentioned disadvantages, and an object of the present invention is to apply a conventional X-ray generator to a wide inspection object by using a conventional X-ray generator. An object of the present invention is to provide an X-ray foreign matter detection device which can obtain a quantity of transmitted light and has sufficient foreign matter detection accuracy.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, an X-ray foreign matter detection device according to the present invention includes a plurality of X-ray generators and an X-ray transmission amount required for foreign matter detection corresponding to each of the X-ray generators. A plurality of X-ray detectors, which are arranged at positions distant from each other by a distance that can be obtained, and are arranged so that respective inspection regions overlap each other so that the entire region of the inspection object can be inspected; A plurality of aperture devices or shielding plates (hereinafter, the aperture devices include the shielding plates) provided to prevent the X-rays emitted from the device from being applied to the X-ray detectors in other regions.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
A first embodiment of the X-ray foreign matter detection device of the present invention will be described with reference to examples shown in the drawings. FIG. 1 is a schematic perspective view showing a detection unit of the X-ray foreign matter detection device according to the present invention. Two X-ray generators 1 and X-ray generators 2 and a distance facing each of the X-ray generators 1 and 2 so that an X-ray transmission amount necessary for foreign object detection can be obtained. The X-ray detector 6 and the X-ray detector 7 are arranged at positions apart from each other. The test object 5 is conveyed by a belt conveyor (not shown) in the direction of the arrow in FIG. 1 and passes between the X-ray generator 1, the X-ray generator 2, the X-ray detector 6, and the X-ray detector 7. .
Below the X-ray generator 1 and the X-ray generator 2, two aperture devices 3 provided to prevent the X-rays emitted from the X-ray generator from being applied to the X-ray detectors in other regions. An aperture device 4 is provided.
FIG. 2 shows the positional relationship between the X-ray generator 1 and the X-ray detector 6 and between the X-ray generator 2 and the X-ray detector 7 in the direction perpendicular to the transport direction of the inspection object 5. In addition, the respective inspection areas are arranged so as to overlap each other so that the entire area of the inspection object 5 can be inspected.
Further, the positional relationship between the X-ray generator 1 and the X-ray detector 6 and between the X-ray generator 2 and the X-ray detector 7 in the direction parallel to the transport direction of the inspection object 5 is as shown in FIG. In order to prevent the X-rays emitted from the X-ray generator from being incident on the X-ray detectors in other regions, the spread of the X-rays is regulated by the stop devices 3 and 4, respectively. They are placed apart.
[0009]
According to this embodiment, it is not necessary to increase the mounting height of the X-ray generator even for a wide inspection object, and it is possible to obtain an X-ray transmission amount necessary for foreign object detection. Accurate X-ray foreign matter detection becomes possible.
[0010]
In the embodiment of FIG. 1, the number of X-ray generators and X-ray detectors is two each. However, as another embodiment, if the number of X-ray generators and X-ray detectors is three or more, respectively, It is possible to perform a high-precision foreign substance inspection of a wide inspection object.
[0011]
【The invention's effect】
As described above, according to the present invention, by installing a plurality of X-ray generators and X-ray detectors, the mounting height of the X-ray generator can be reduced even for a wide inspection object. An X-ray transmission amount required for foreign object detection can be obtained without increasing the height, and a highly accurate X-ray foreign object detection device can be provided.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an embodiment of the present invention.
FIG. 2 is a front view for explaining a positional relationship between an X-ray generator and an X-ray detector according to the present invention.
FIG. 3 is a front view for explaining a positional relationship between an X-ray generator and an X-ray detector according to the present invention.
FIG. 4 is a perspective view showing a conventional technique.
FIG. 5 is a front view for explaining a positional relationship between a conventional X-ray generator and an X-ray detector.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... X-ray generator, 2 ... X-ray generator, 3 ... diaphragm apparatus, 4 ... diaphragm apparatus, 5 ... inspection object, 6 ... X-ray detector, 7 ... X-ray detector 101 ... X-ray generator, 102: Belt conveyor, 103: X-ray detector, 104: Inspection object

Claims (1)

A plurality of X-ray generators and, corresponding to each of the X-ray generators, are arranged at positions separated by a distance capable of obtaining an X-ray transmission amount necessary for foreign substance detection, and A plurality of X-ray detectors arranged so that the inspection areas overlap each other so that the entire area can be inspected, and X-rays emitted from the X-ray generator are not irradiated to X-ray detectors in other areas X-ray foreign matter detection device having a plurality of aperture devices or shielding plates provided for the purpose.

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