JP2937324B2 - Defective foreign matter detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a defect foreign matter detecting device which detects a defective foreign matter from a three-dimensional stereoscopic image.

2. Description of the Related Art Conventionally, as a means for detecting a defect foreign substance inside an inspection object, a defect foreign substance is detected from a two-dimensional image processing of an X-ray transmission image in one direction of the inspection object. 3
Detection of defective foreign matter from two-dimensional image processing of X-ray transmission images in different directions independently of each other is used.

However, with such a means, since the inside of the object to be inspected can be viewed only two-dimensionally, not only the position of the defective foreign matter cannot be specified accurately, but also the blind spot of the inspection depending on the three-dimensional shape of the object to be inspected. There is a defect that high-precision defect detection cannot be expected.

(Problems to be Solved by the Invention) As described above, in the conventional defect detection apparatus, not only the position of the defective foreign matter cannot be accurately specified due to the fact that the inside of the inspection object can be viewed only two-dimensionally. However, depending on the three-dimensional shape of the object to be inspected, problems such as formation of a blind spot in the inspection and existence of an area which is difficult to inspect occur, and there is a defect that highly accurate defect detection cannot be expected.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a defect foreign matter detecting apparatus capable of accurately specifying the position of a defective foreign matter, eliminating blind spots in an inspection, and a region difficult to inspect, and expecting highly accurate detection of a defective foreign matter. To provide.

[Constitution of the Invention] (Means for Solving the Problems) The present invention relates to a transmissive radiation source for generating transmissive radiation for irradiating an object to be inspected, and a two-dimensional source arranged opposite to the transmissive radiation source. A radiation detector, a structural part for relatively moving the object to be inspected along the surface of the radiation detector, and the mechanism for relatively moving the object to be inspected along the surface of the radiation detector. Data collecting means for collecting a plurality of transmission image data of the object to be inspected by the output of the radiation detector during the operation, and a plurality of data necessary for creating one tomographic image for each tomographic plane by the data collecting means. A tomographic image reconstructing means for extracting and adding data from directions to create a tomographic image, and a continuous tomographic image obtained by the tomographic image reconstructing means is captured as a three-dimensional stereoscopic image. Missing from statue A three-dimensional image in the foreign substance detecting means for detecting a foreign object, a defect foreign matter detection device and an output means for outputting information of the detected defect foreign matter from the three-dimensional image in the foreign substance detecting means.

(Operation) As a result, the defect foreign object can be detected three-dimensionally from the three-dimensional image of the inspection object, so that the accurate position of the defect foreign object can be specified, and the blind spot of the inspection and the inspection are difficult. The region can be eliminated.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a circuit configuration of the embodiment. In the figure, reference numeral 1 denotes a control computer, which is an X-ray transmission data input interface 3, a tomographic image reconstruction processor (image addition processor) 4, and a three-dimensional stereo image memory (multiple tomographic images) via a multibus 2. A storage memory 5, a defective foreign matter detection / measurement device (binary processor, area numbering processor) 6, a defective foreign matter information output device 7, an X-ray control device 8, and a conveyor control device 9 are controlled. The X-ray transmission data input interface 3, the tomographic image reconstruction processor 4, the three-dimensional stereoscopic image memory 5, and the defective foreign matter detection / measurement device 6 exchange image data via the image bus 10.

On the other hand, an X-ray generator 11 generates X-rays when a high voltage is applied from a high voltage generator 12. A belt conveyor 13 is provided as a conveying means corresponding to the X-ray generator 11, and an object to be inspected is conveyed by the conveyor 13.
14 are being transported one after another. In this case, the conveyor 13 is driven at a predetermined speed by the conveyor control device 9,
The inspection object 14 is irradiated with X-rays from the X-ray generator 11. Then, when the inspection object 14 reaches a predetermined position, an output of the position detection device 15 is generated. The output of the position detecting device 15 is sent to the X-ray transmission data input interface 3.

The X-ray transmitted through the inspection object 14 is detected by the X-ray detector 16. In this case, the X-ray detector 16 is provided with a plurality of linear X-ray detectors 161 arranged along the width direction of the belt conveyor 13 as shown in FIG. The output is sent to the X-ray transmission data input interface 3.

Here, the X-ray transmission data input interface 3
The one-dimensional X-ray transmission data from each linear X-ray detector 161 of the X-ray detection device 16 is arranged in time series, and given as two-dimensional X-ray transmission image data for each line. In this case, the data collection timing is determined in consideration of the positional deviation of each linear X-ray detector 161 and the number of tomographic planes to be obtained from the point in time when the object 14 is detected by the position detection device 15. Done. The tomographic image reconstruction processor 4 performs a detector offset correction, a logarithmic conversion, an X-ray dose correction, a detector sensitivity correction, and the like on the data obtained through the X-ray transmission data input interface 3. Out of the two-dimensional images of the object to be inspected 14 necessary for creating one tomographic image for each tomographic plane from the two-dimensional images, and adding these images to create a tomographic image I do. Such a tomographic image is performed for each tomographic plane. The three-dimensional stereoscopic image memory 5 stores a continuous tomographic image created by the tomographic image reconstruction processor 4 as a three-dimensional stereoscopic image. The defect foreign matter detection / measurement device 6 detects a defect foreign matter area which is considered to be within a predetermined threshold range for each of the continuous tomographic images of the inspection object 14 in the three-dimensional stereoscopic image memory 5. Binary detection is performed, area numbering is performed, and the position of a defective foreign matter, the size of a circumscribed cuboid, and the like are measured. The defective foreign matter information output device 7 outputs information on the position and size of the defective foreign matter obtained by the defective foreign matter detection and measurement device 6.

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

In this case, the processing is executed according to the flowchart shown in FIG. First, in step A1, the inspection object 14 is transferred by the belt conveyor 13. In this state, the X-ray generator 11 irradiates the inspection object 14 with X-rays. Then, when the inspection object 14 reaches a predetermined position and an output is generated from the position detection device 15, one of the signals from each linear X-ray detector 161 is output.
X-ray transmission data input interface 3 which converts two-dimensional X-ray transmission data in time series as two-dimensional X-ray transmission image data
Is input to In this case, the timing of data collection is
From the point in time when the inspection object 14 is detected by the position detection device 15, the position deviation of each linear X-ray detector 161 and the number of tomographic planes to be obtained are taken into consideration. More specifically, when the linear X-ray detectors 161 of # 1 to #n are arranged with respect to the X-ray source X as shown in FIG. Among them, for example, a deviation of the # 1 detector 161 on the tomographic plane i with respect to the #j detector 161 is represented by Δli1j. Therefore, the data for reconstructing the tomographic plane i starts from the point in time when the output of the position detecting device 15 shown in FIG. 5A is given, as shown in FIG. The two-dimensional X-ray transmission image data of the linear X-ray detector 161 is sequentially acquired. In this case, the detector 16 of #j
Assuming that the detection time at 1 is T, the detection time Tl at the detector 161 of # 1 is T + Δli1j / v, and the detection time T at the detector 161 at # 2.
2 is T + Δli2j / v,..., The detection time Tn of the detector 161 is T + Δlinj / v. Here, v is the speed of the belt conveyor 13. In addition, the size of the tomographic image in this case is set to width L.
Assuming that n and length Ly are used, transmission X-ray images used little by little in the reconstruction of each tomographic image are different, so that an extra image of width lx and length ly can be collected. In particular,#
In the detector 161 of k, lx = Lx and ly = Ly + Δlmkj−Δ1kj.

Next, the process proceeds to step A2. In step A2, it is necessary to reconstruct one tomographic image for each tomographic plane 1 to m from the two-dimensional fluoroscopic image data (width lx, length ly) from each linear X-ray detector 161. Extraction of multiple 2D image data (width Lx, length Ly) from multiple directions
These images are added to create one tomographic image. This is performed for m sheets.

Next, the process proceeds to step A3. In this step A3, the continuous tomographic image obtained from the tomographic image reconstruction processor 4 is written into the memory 5 as a three-dimensional stereoscopic image.

Next, the process proceeds to step A4. In step A4, each of the tomographic images of the continuous tomographic image of the inspection object 14 written in the three-dimensional stereoscopic image memory 5 is within a certain threshold range by the defect foreign matter detection and measurement device 6. The area of the defective foreign matter which is considered to be detected is detected by binarization, and the area of the detected area is numbered, and the position of the defective foreign matter and the size of the circumscribed cuboid are measured by measuring the circumscribed cuboid.

Then, the process proceeds to Step A5. In step A5, information on the position and size of the defective foreign matter is output by the defective foreign matter information output device 7.

Therefore, in this way, a three-dimensional stereoscopic image including the inside of the object to be inspected is reconstructed, and it is possible to three-dimensionally detect a defective foreign substance based on the three-dimensional stereoscopic image. Because the inside of the object to be inspected can only be seen two-dimensionally, not only can the position of the defective foreign matter not be specified accurately, but depending on the shape of the object to be inspected, blind spots can be formed in the inspection, or there are areas where inspection is difficult. Such as
Compared to those that could not be expected to detect defective foreign matter with high accuracy, the position of defective foreign matter can be accurately specified to eliminate these defects, and blind spots in inspection and areas that are difficult to inspect can be eliminated. It is possible to expect the detection of defective foreign matter having a high density.

The present invention is not limited to the above-described embodiment, and can be appropriately modified and implemented without changing the gist. For example,
In the above-described embodiment, a linear X-ray detector is used. However, an image is input from a television camera using an area X-ray detector such as a fluorescent screen or an X-ray image intensifier, and each horizontal signal of a video signal is input. For a vertical signal, the same effect can be obtained by using the same tomographic image reconstruction and three-dimensional foreign object detection as described above. Further, in the above-described embodiment, the data is collected by moving the object to be inspected. However, the data acquisition system is moved by fixing the object to be inspected, or the object and the data collection system are moved together. It is only necessary that both move relatively. Furthermore, in the above description, a linear X-ray detector is used, and when a data is replaced on a tomographic plane, the data gap is not particularly corrected. In the case of an arc shape or a curved shape, when data is replaced on a tomographic plane, the correction of the data gap may be performed for the center portion and both end portions. Furthermore, in the above-described embodiment, one X-ray generator and n linear X-ray detectors are used. The effect is obtained.

[Effects of the Invention] According to the present invention, data collection means for collecting two-dimensional transmission image data from a plurality of directions with respect to a test object while maintaining relative movement with respect to the test object; Tomographic image reconstructing means for extracting and adding data from a plurality of directions necessary for producing one tomographic image for each tomographic image, and a three-dimensional continuous tomographic image obtained by the tomographic image reconstructing means. A three-dimensional stereoscopic image foreign matter detecting means for capturing a three-dimensional image and detecting a defective foreign matter from the three-dimensional stereoscopic image, and an output means for outputting information on the defective foreign matter detected by the three-dimensional three-dimensional image foreign matter detecting means. I have. This makes it possible to three-dimensionally detect a defective foreign matter from a three-dimensional image of the inspection object.
The position of the defective foreign matter can be accurately specified, and the blind spot of the inspection and the area where the inspection is hardly performed can be eliminated, so that the detection of the defective foreign matter with high accuracy can be expected.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a circuit configuration of an embodiment of the present invention, FIG. 2 is a perspective view showing a main part of the embodiment, FIG. 3 is a flowchart for explaining the operation of the embodiment, FIG. 4 and 5 are diagrams for explaining the same embodiment. 1 ... control computer, 3 ... X-ray transmission data input interface, 4 ... tomographic image reconstruction processor (image addition processor), 5 ... 3D stereoscopic image memory (multiple tomographic image storage memory), 6 ... defect Foreign object detection and measurement device (2
Value processor, area numbering processor) 7, Defective foreign matter information output device, 8 X-ray control device, 9 Conveyor control device, 11 X-ray generation device, 12 High-pressure generation device, 13 ... belt conveyor, 14 ... inspected object, 15 ... position detecting device, 16 ... X-ray detecting device, 161 ... linear X
Line detector.

Claims (1)

(57) [Claims] 1. A transmissive radiation source for generating transmissive radiation for irradiating an object to be inspected, a two-dimensional radiation detector arranged opposite to the transmissive radiation source, and a radiation detector along a surface of the radiation detector. A structure for relatively moving the object to be inspected, and the mechanism detects an output of the radiation detector while the object to be inspected relatively moves along the surface of the radiation detector. A data collection unit that collects a plurality of transmission image data of the object to be inspected; data from a plurality of directions necessary for creating one tomographic image for each tomographic plane are extracted and added from the data collection unit; A tomographic image reconstructing means for creating a tomographic image, and a continuous tomographic image obtained by the tomographic image reconstructing means being captured as a three-dimensional three-dimensional image, and a foreign matter in the three-dimensional three-dimensional image for detecting a defective foreign matter from the three-dimensional stereoscopic image. Detection hand When the defect the foreign material detecting device being characterized in that and an output means for outputting information of the detected defect foreign matter from the three-dimensional image in the foreign substance detecting means.