Industrial X-ray CT control method and industrial X-ray CT control device

Abstract

The object of the present invention is to provide an industrial X-ray CT control method and an industrial X-ray CT control device that can effectively perform imaging according to the size of large specimens. [Solution] The present invention provides an industrial X-ray CT control method for which a specimen is placed on a rotary table and the rotary table is rotated to perform X-ray CT imaging, characterized in that a first irradiation is performed such that the X-ray irradiation axis passes over the central axis of the rotary table and includes a range parallel to the detection surface of the X-ray detection device at a first distance from the central axis, and a second irradiation is performed such that the X-ray source and the X-ray detection device are slid in a direction parallel to the detection surface and X-ray CT imaging is performed such that a range parallel to the detection surface of the X-ray detection device is greater than or equal to a first distance from the central axis and less than or equal to the radius of the rotary table.

Description

Technical Field

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[0001] The present invention relates to an industrial X-ray CT control method and an industrial X-ray CT control apparatus.

Background Art

[0002] Industrial X-ray CT is a technique for evaluating the internal structure of a specimen by irradiating the specimen with X-rays from an X-ray source and measuring the intensity of the X-rays attenuated and transmitted by the internal structure of the specimen.

[0003] In Patent Documents 1 and 2, techniques for offsetting a plurality of X-ray irradiation points, changing the irradiation direction, and performing CT imaging are disclosed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the imaging methods of Patent Documents 1 and 2, for example, imaging a large specimen on a large table with a diameter of 3000 mm is not considered.

[0006] An object of the present invention is to provide an industrial X-ray CT control method and an industrial X-ray CT control apparatus that can effectively perform imaging according to the size of a large specimen.

Means for Solving the Problems

[0007] The present invention provides an industrial X-ray CT control method for which a specimen is placed on a rotary table and the rotary table is rotated to perform X-ray CT imaging, characterized in that a first irradiation is performed such that the X-ray irradiation axis passes over the central axis of the rotary table and includes a range parallel to the detection surface of the X-ray detection device at a first distance from the central axis, and a second irradiation is performed such that the X-ray source and the X-ray detection device are slid in a direction parallel to the detection surface and X-ray CT imaging is performed such that a range parallel to the detection surface of the X-ray detection device is greater than or equal to a first distance from the central axis and less than or equal to the radius of the rotary table.

[0008] Alternatively, the industrial X-ray CT control device of the present invention is an industrial X-ray CT control device that places a specimen on a rotary table and controls the rotation of the rotary table to perform X-ray CT imaging, and is characterized by comprising an X-ray source moving device and a detection device moving device that slide the X-ray source and the X-ray detection device in a direction parallel to the detection surface so as to include a range that is greater than or equal to a first distance from the central axis and less than or equal to the radius of the rotary table in a direction parallel to the detection surface of the X-ray detection device. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide an industrial X-ray CT control method and an industrial X-ray CT control device that can effectively image large specimens. [Brief explanation of the drawing]

[0010] [Figure 1] This is an explanatory diagram of the first irradiation by the industrial X-ray CT system of this embodiment. [Figure 2] This is an explanatory diagram of the second irradiation using the industrial X-ray CT system in this embodiment. [Figure 3] This is an explanatory diagram of the third irradiation by the industrial X-ray CT system in this embodiment. [Figure 4] This diagram illustrates the first to third irradiations performed by the industrial X-ray CT system in this embodiment. [Figure 5] This figure shows the configuration of the industrial X-ray CT system in this embodiment. [Modes for carrying out the invention]

[0011] The following describes embodiments of an industrial X-ray CT control device, an industrial X-ray CT control method, and an industrial X-ray CT system with reference to the drawings. Note that these embodiments are illustrative examples for explaining the present invention, and have been omitted and simplified as appropriate for clarity of explanation. The invention can also be implemented in various other forms. Unless otherwise specified, each component may be singular or plural. The positions, sizes, shapes, and ranges of the components shown in the drawings may not represent the actual positions, sizes, shapes, and ranges, in order to facilitate understanding of the invention. Therefore, the present invention is not necessarily limited to the positions, sizes, shapes, and ranges disclosed in the drawings. [Examples]

[0012] An example of performing CT imaging of a specimen cross-section using an industrial X-ray CT scanner will be described. Figure 5 shows the configuration of the industrial X-ray CT system in this example. The industrial X-ray CT system comprises an X-ray source 1 that irradiates fan-beam X-rays, a rotary table 2, an X-ray detection device 3 in which a large number of X-ray detection elements are arranged in a single row parallel to the surface of the rotary table 2, an imaging control device 21, an image processing device 20, a rotary table control device 22, and an X-ray source control device 24.

[0013] The imaging control device 21 identifies the placement area of ​​the sample 26 from the obtained image, determines the imaging field of view, and transmits the imaging field of view parameters to the image processing device 20. The imaging control device 21 calculates the rotation angle of the rotary table 2 according to the imaging field of view and issues a rotation instruction to the rotary table control device 22.

[0014] The rotary table control device 22 controls the rotation of the rotary table 2. It also transmits signals to the X-ray source control device 24 and the X-ray detection device 3 to perform X-ray irradiation and X-ray detection in synchronization with the rotation.

[0015] When the X-ray source control device 24 receives a signal for X-ray irradiation from the rotary table control device 22, it irradiates X-rays from the X-ray source 1. When the X-ray detection device 3 receives a signal for X-ray detection from the rotary table control device 22, it detects the X-rays 25 that have passed through the specimen 26 and transmits the detection data to the image processing device 20. The image processing device 20 refers to the central angle of the imaging field received from the imaging control device 21, extracts the full projection data of the imaging field from the detection data received from the X-ray detection device 3, and reconstructs an image of the cross-section of the imaging field.

[0016] The X-ray source moving device 27 moves the X-ray source 1 in a direction perpendicular to the X-ray irradiation central axis 10b in the horizontal direction. The X-ray detection device moving device 28 moves the X-ray detection device in the same direction as the X-ray source moving device 27, that is, in a direction perpendicular to the X-ray irradiation central axis 10b in the horizontal direction. The moving device control device 29 controls the X-ray source moving device 27 and the X-ray detection device moving device 28 to move the same distance. That is, the slides of the X-ray source 1 and the X-ray detection device 3 can be moved the same distance and in the same direction.

[0017] In this way, by providing the X-ray source moving device 27 and the X-ray detection device moving device 28 that slide the X-ray source 1 and the X-ray detection device 3 in a direction parallel to the detection surface of the X-ray detection device 3 so as to include a range from a first distance or more from the central axis to a radius of the rotary table or less in a direction parallel to the detection surface, the first irradiation, the second irradiation, the third irradiation, etc. described later can be implemented.

[0018] The X-ray detection device 3 in this embodiment includes a collimator and a detection unit (for example, an array detection unit). As described in FIG. 1 of Japanese Patent Laid-Open No. 2000-9662, the collimator is disposed on the X-ray source side of the array detector. The collimator is provided with slits through which X-rays pass corresponding to the number of detection units. One detection unit is disposed opposite to one slit. The imaging resolution is limited by the size and arrangement of this detection unit. The resolution will be described in the third irradiation described later.

[0019] FIG. 1 is an explanatory diagram of the first irradiation by the industrial X-ray CT system of this embodiment. It is a top view of the measurement by the X-ray CT system. The X-ray passes through the specimen on the rotary table from the X-ray source 1 and is detected by the X-ray detector 3. Here, the X-ray is irradiated in the range between the left end 10c of the X-ray irradiation and the right end 10a of the X-ray irradiation around the X-ray irradiation central axis 10b which is the irradiation axis of the X-ray.

[0020] In this first irradiation, X-ray CT imaging is performed such that the irradiation axis of the X-ray passes through the central axis of the rotary table 2 and includes a range that is separated from the central axis by a first distance in a direction parallel to the detection surface of the X-ray detector 3. The first distance is the distance that connects the left end 10c of the X-ray irradiation and the right end 10a of the X-ray irradiation in a direction parallel to the X-ray detector 3 from the center of the rotary table.

[0021] The rotary table has a radius R, the distance from the X-ray source 1 to the center of the rotary table 2 is T1, and the distance from the X-ray source 1 to the X-ray detector 3 is T2.

[0022] FIG. 2 is an explanatory diagram of the second irradiation by the industrial X-ray CT system of this embodiment. It is a top view of the measurement by the X-ray CT system. Compared with the first irradiation in FIG. 1, the X-ray source 1 and the X-ray detector 3 are moved by a distance T3 in a direction perpendicular to the X-ray irradiation central axis 10b in the horizontal direction by the X-ray source moving device 27 and the X-ray detector moving device 28. Here, the X-ray is irradiated in the range between the left end 11c of the X-ray irradiation and the right end 11a of the X-ray irradiation around the X-ray irradiation central axis 11b which is the irradiation axis of the X-ray.

[0023] In this second irradiation, the X-ray source 1 and the X-ray detector 3 are slid by a distance T3 in a direction parallel to the detection surface, and X-ray CT imaging is performed so as to include a range that is not less than the first distance from the central axis and not more than the radius R of the rotary table in a direction parallel to the detection surface of the X-ray detector 3.

[0024] The irradiation ranges of the first irradiation and the second irradiation are each made to be not less than the radius of the rotary table in total, so that the imaging range of a large specimen on a large rotary table can be appropriately covered.

[0025] As described above, by performing the first and second irradiations, large specimens can be effectively CT scanned using a large rotating table.

[0026] Figure 3 is an explanatory diagram of the third irradiation using the industrial X-ray CT system of this embodiment. It is a top view of the measurement using the X-ray CT system, and compared to the second irradiation in Figure 2, the X-ray source 1 and X-ray detection device 3 have been moved by a distance of T3+α in the horizontal direction perpendicular to the X-ray irradiation center axis 11b by the X-ray source moving device 27 and the X-ray detection device moving device 28. Here, the X-rays are irradiated around the X-ray irradiation center axis 12b, which is the X-ray irradiation axis, in the range from the left end 12c to the right end 12a of the X-ray irradiation area.

[0027] In this third irradiation, compared to the second irradiation, the X-ray source 1 and the X-ray detector are slid α distance parallel to the detection surface, and X-ray CT imaging is performed.

[0028] As mentioned above, the X-ray detection device 3 in this embodiment includes a collimator and a detection unit (for example, an array detection unit). The collimator is provided with slits through which X-rays pass, one for each detection unit, and one detection unit is positioned opposite one slit. The size and arrangement of these detection units limit the imaging resolution, so a third irradiation is performed by sliding the detection unit by an α distance. The α distance can be set by the size and arrangement of the collimator and detection units.

[0029] In this way, the X-ray source is slid a predetermined distance (α distance) in the same direction as the sliding direction during the second irradiation from the X-ray source position during the second irradiation, and X-ray CT imaging is performed. As a result, even in areas where the image quality was poor during the second irradiation because the detection unit was not positioned, the image quality can be improved in the third irradiation by appropriately setting the distance α, thereby complementing the second irradiation.

[0030] Here, α is a value calculated from the spacing β of the detection units provided in the X-ray detection device 3. For example, by using half the value of β, an image can be obtained that is complemented by the second and third irradiations.

[0031] As described above, by performing a third irradiation in addition to the first and second irradiations, the resolution problem caused by the detection limitations of the X-ray detection device 3 can be solved, and the resolution can be improved.

[0032] Figure 4 is an explanatory diagram of the first to third irradiations using the industrial X-ray CT system of this embodiment. It is a schematic diagram of the first to third irradiations and explains the relationship between each irradiation range.

[0033] Let R1 be the distance from the center of the rotating table 2 to the left edge 10c of the X-ray irradiation for the first irradiation. Here, R1 is perpendicular to the left edge 10c of the X-ray irradiation. Let R3 be the distance to the left edge 11c of the X-ray irradiation for the second irradiation. Here, R3 is perpendicular to the left edge 11c of the X-ray irradiation. Let R3+ΔR be the distance to the left edge 12c of the X-ray irradiation for the third irradiation. Here, R3+ΔR is perpendicular to the left edge 12c of the X-ray irradiation.

[0034] Let R2 be the distance from the center of the rotating table 2 to the right edge 11a of the X-ray irradiation area for the second irradiation. Here, R2 is perpendicular to the right edge 11a of the X-ray irradiation area. Let R2 + ΔR be the distance from the center of the rotating table 2 to the right edge 12a of the X-ray irradiation area for the third irradiation. Here, R2 + ΔR is perpendicular to the right edge 12a of the X-ray irradiation area.

[0035] In the first irradiation, the area from the center (0) of the rotary table to R1 can be irradiated, and in the second irradiation, the area from R2 to R3 of the rotary table can be irradiated. In this way, large specimens placed on the large rotary table 2 can be imaged.

[0036] In addition to the first and second irradiations, the third irradiation can target the area from R2+ΔR to R3+ΔR. By performing a third irradiation that is α-distance slid from the second irradiation in this way, the resolution can be improved regardless of the detection limitations of the X-ray detector 3. [Explanation of Symbols]

[0037] 1...X-ray source, 2...rotating table, 3...X-ray detection device, 26...sample, 21...imaging control device, 20...image processing device, 22...rotating table control device, 24...X-ray source control device.

Claims

1. In an industrial X-ray CT control method for placing a specimen on a rotary table and controlling the rotation of the rotary table to perform X-ray CT imaging, A first irradiation is performed to take X-ray CT images such that the X-ray irradiation axis passes over the central axis of the rotating table and includes a range parallel to the detection surface of the X-ray detection device at a first distance from the central axis, An industrial X-ray CT control method characterized by sliding the X-ray source and the X-ray detection device in a direction parallel to the detection surface, and performing a second irradiation that includes a range in a direction parallel to the detection surface of the X-ray detection device that is greater than or equal to a first distance from the central axis and less than or equal to the radius of the rotating table.

2. In the industrial X-ray CT control method according to claim 1, An industrial X-ray CT control method characterized in that the combined irradiation ranges of the first irradiation and the second irradiation are greater than or equal to the radius of the rotary table.

3. In the industrial X-ray CT control method according to claim 1, An industrial X-ray CT control method characterized by performing a third irradiation by sliding the X-ray source a predetermined distance in the same direction as the slide from the X-ray source position of the second irradiation, thereby performing X-ray CT imaging.

4. In the industrial X-ray CT control method according to claim 3, An industrial X-ray CT control method characterized in that the predetermined sliding distance is set based on a value calculated based on the spacing of detection units provided in the X-ray detection device.

5. In the industrial X-ray CT control method according to claim 1, An industrial X-ray CT control method characterized in that the slides of the X-ray source and the X-ray detection device move the same distance and in the same direction.

6. In an industrial X-ray CT control device that places a specimen on a rotary table and controls the rotation of the rotary table to perform X-ray CT imaging, An industrial X-ray CT control device is characterized by comprising an X-ray source moving device and a detection device moving device that slide the X-ray source and the X-ray detection device in a direction parallel to the detection surface, so as to include a range that is greater than or equal to a first distance from the central axis and less than or equal to the radius of the rotary table in a direction parallel to the detection surface of the X-ray detection device.

7. In the industrial X-ray CT control device according to claim 6, An industrial X-ray CT control device is characterized by comprising a movement device control device that controls the movement of the X-ray source and the slide of the X-ray detection device by the same distance and in the same direction.

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