JP5577862B2 - Radiation imaging method and radiation imaging system - Google Patents

Description

  The present invention relates to a radiation imaging method and a radiation imaging system for irradiating an object with radiation and detecting the radiation transmitted through the object with a detector.

  By irradiating a sample with a known thickness with X-rays and causing the X-rays that have passed through the sample to reach the detector, a signal of a level corresponding to the amount (or intensity) of X-rays received from the detector Is output. Here, since the X-ray dose reaching the detector has a corresponding relationship with the thickness of the sample, the thickness of the sample can be specified based on the level of the output signal of the detector. Further, when the sample contains foreign matter, the level of the output signal of the detector is different, so that foreign matter can be detected based on the output signal of the detector (see, for example, Patent Document 1). .

Japanese Patent Laid-Open No. 10-318943 JP 2000-229076 A JP 2005-017028 A JP-A-01-277709 JP 2004-055325 A Japanese Patent No. 2567060

  When a sample having a plurality of regions having different thicknesses is irradiated with X-rays, the X-ray dose reaching the detector varies depending on each region of the sample. FIG. 11 shows a configuration in which a sample 102 is disposed between the X-ray source 100 and the detector 101, and the sample 102 has a plurality of regions having different thicknesses. In FIG. 11, the vertical axis indicates the X-ray dose reaching the detector 101, and the horizontal axis indicates the detection position of the detector 101. As shown in FIG. 11, when the sample 102 is arranged, the X-ray dose reaching the detector 101 varies depending on the areas A1 to A4 of the detector 101.

  The X-rays that reach the region A1 are transmitted through the thickest portion of the sample 102 and are most attenuated by the sample 102, so that the X-ray dose reaching the region A1 is minimized. Since the X-rays that reach the region A2 are transmitted through the second thickest portion of the sample 102, the X-ray dose in the region A2 is the second smallest.

  Since the X-rays that reach the region A3 are transmitted through the third thickest portion of the sample 102, the X-ray dose in the region A3 is the third smallest. Since the X-ray from the X-ray source 100 directly reaches the area A4, the X-ray dose in the area A4 is the largest.

  Here, when X-ray irradiation is repeated while the sample 102 is fixed at the position shown in FIG. 11, X-rays having different X-ray doses (intensities) repeatedly reach the regions A1 to A4 of the detector 101. It will be. If the detector 101 continues to be irradiated with X-rays, the deterioration is likely to proceed. Therefore, the degree of deterioration may differ depending on the regions A1 to A4.

  If the progress of deterioration in the areas A1 to A4 is different, the detection performance of the detector 101 also varies between the areas A1 to A4.

First aspect of the invention, is irradiated to the object by performing an imaging operation for detecting the radiation transmitted through the object at the detector, a radiation imaging method for obtaining radiation data corresponding to the object, the object Has a plurality of regions having different thicknesses , and after performing an imaging operation a plurality of times, a radiation dose (for example, total radiation) that reaches each of the plurality of detection regions in the detector through the object. The imaging operation is performed a plurality of times while changing the region of the target object through which the radiation that reaches each detection region is transmitted so that the dose or the average value of the radiation dose is directed to the reference value. It is characterized by. X-rays can be used as the radiation.

Here, while changing the orientation of the object relative to detector, it is possible to perform the imaging operation of a plurality of times. Specifically, the direction of the object relative to the detector can be changed by rotating the object around a reference axis that extends in the radiation irradiation direction and is located within the radiation irradiation region.

Furthermore, it is possible to perform while a plurality of times of imaging operations by changing the position of the object within the irradiated region of the radiological. A second invention of the present application is a radiation imaging method for obtaining radiation data corresponding to an object by performing an imaging operation in which radiation detected on the object and transmitted through the object is detected by a detector. Includes a plurality of objects having different thicknesses of regions through which radiation passes, and after a plurality of imaging operations, the plurality of objects are transmitted through each of the plurality of detection regions in the detector. While changing the object to be positioned in the radiation irradiation region so that the radiation dose (for example, the total radiation dose or the average value of the radiation dose) reaches the reference value, The image pickup operation is performed once.

A radiation imaging system according to a third invention of the present application includes a radiation source that irradiates an object having a plurality of regions having different thicknesses , a detector that performs an imaging operation by detecting radiation transmitted through the object, and And a support member that supports the object. Here, after the imaging operation is performed a plurality of times, the radiation dose (for example, the total radiation dose or the average value of the radiation dose) that reaches the respective detection regions in the detector through the object is reached. Each time the imaging member performs an imaging operation, the support member changes the arrangement state of the target object with respect to the detector so that the region of the target object through which the radiation that reaches each detection region is transmitted is the plurality of regions. It is characterized by changing between .
A radiation imaging system according to a fourth invention of the present application includes a radiation source that irradiates a target with radiation, a detector that detects radiation transmitted through the target and performs an imaging operation, and a support member that supports the target. The object includes a plurality of objects having different thicknesses of regions through which radiation is transmitted, and after performing the imaging operation a plurality of times, each of the plurality of detection regions in the detector Each time the imaging operation is performed, the support member changes the object to be positioned in the radiation irradiation region so that the amount of radiation that passes through the plurality of objects reaches the reference value, and changes the target in each detection region. It is characterized in that the object through which the arriving radiation passes is changed among a plurality of objects.

  According to the present invention, the amount of radiation reaching each detection region in the detector can be adjusted by changing the thickness of the object. Then, after performing the imaging operation a plurality of times, if the radiation dose (for example, the total radiation dose or the average value of the radiation dose) reaching each detection region in the detector is brought close to the reference value, Variations in radiation dose can be suppressed in a plurality of detection regions in the detector. Thereby, it can suppress that the deterioration degree by radiation irradiation varies in the several detection area | region in a detector.

It is a perspective view which shows the external appearance of the reference | standard piece used in Example 1 of this invention. 1 is a diagram illustrating an X-ray imaging system in Embodiment 1. FIG. It is a figure which shows the relationship between the output signal of a detector, and the thickness of a reference | standard piece. 1 is a diagram illustrating an X-ray imaging system in Embodiment 1. FIG. In Example 1, it is a figure when a reference | standard piece is seen from the X-ray source side. In Example 1, it is a figure which shows the X-ray dose which reaches | attains a detector. In Example 1, it is the schematic explaining the mechanism which rotates a reference | standard piece. In the modification of Example 1, it is a figure which shows the stage which supports two types of reference | standard pieces. In Example 2 of this invention, it is a figure which shows the structure which equalizes the X-ray integration amount in a detector. In Example 3 of this invention, it is a figure which shows the structure which equalizes the X-ray integration amount in a detector. It is a figure explaining the structure by the conventional X-ray irradiation.

  Examples of the present invention will be described below.

  An X-ray imaging system (radiation imaging system) in Embodiment 1 of the present invention will be described. In the X-ray imaging system of the present embodiment, X-ray data corresponding to the reference piece is obtained by irradiating the reference piece with X-rays and receiving the X-ray transmitted through the reference piece. Here, an operation for obtaining X-ray data (radiation data) corresponding to the reference piece is referred to as an imaging operation.

  First, the reference | standard piece (object) used with the X-ray imaging system of a present Example is demonstrated using FIG. FIG. 1 is a perspective view showing an appearance of a reference piece.

  The reference piece 10 is configured by stacking three plates 11 to 13. The three plates 11 to 13 have the same thickness T1. The region R1 of the reference piece 10 has a thickness T3 (T1 × 3), the region R2 has a thickness T2 (T1 × 2), and the region R3 has a thickness T1. ing.

  In this embodiment, three plates 11 to 13 having the same thickness are used, but the thicknesses of at least two plates may be different from each other. Further, in this embodiment, the reference piece 10 is configured by laminating the three plates 11 to 13, but the reference piece 10 having three thicknesses T1 to T3 can be integrally formed. . Moreover, although the reference | standard piece 10 of a present Example has three thickness T1-T3, it is not restricted to this, If it has multiple (two or four or more) thickness Good.

  A plate 12 is laminated on the upper surface of the plate 11, and the plates 11 and 12 are arranged with three end faces (outer edges) aligned. The plate 12 is shorter than the plate 11 in the direction indicated by the arrow X in FIG. The region R2 is a region where only the plates 11 and 12 overlap.

  A plate 13 is laminated on the upper surface of the plate 12, and the plates 12 and 13 are arranged with three end faces (outer edges) aligned. In the direction indicated by the arrow X in FIG. 1, the plate 13 is shorter than the plate 12. The region R1 is a region where the three plates 11 to 13 overlap each other.

  Next, the X-ray imaging system of the present embodiment will be described with reference to FIG. FIG. 2 is a schematic diagram showing the configuration of the X-ray imaging system.

  The reference piece 10 is disposed between the X-ray source (radiation source) 20 and the detector 30, and the X-ray source 20 emits X-rays toward the detector 30. Here, most of the reference piece 10 is located within the X-ray irradiation range. Moreover, it is preferable that the X-rays irradiated to the reference piece 10 travel substantially parallel to the thickness direction of the reference piece 10.

  The detector 30 receives X-rays from the X-ray source 20 and outputs a signal having a level corresponding to the X-ray dose (in other words, X-ray intensity). The detector 30 includes a plurality of detection elements 31, and the plurality of detection elements 31 can be arranged in a one-dimensional direction or a two-dimensional direction. In this embodiment, it is necessary to arrange a plurality of detection elements 31 side by side in at least the X direction.

  Among the X-rays irradiated from the X-ray source 20, some components pass through the reference piece 10 and reach the detector 30, and other components do not pass through the reference piece 10, and the detector 30. To reach directly. In FIG. 2, the X-ray from the X-ray source 20 directly reaches the area (detection area) A14 of the detector 30, and the X-ray dose in the area A14 is the largest.

  X-rays that have passed through the region R1 of the reference piece 10 reach the region (detection region) A11 of the detector 30. Among the reference pieces 10, the region R <b> 1 has the largest thickness, so that the X-rays transmitted through the region R <b> 1 are most attenuated by the reference piece 10. For this reason, the X-ray dose reaching the region A11 is the smallest, and the level of the output signal from the region A11 of the detector 30 is the lowest.

  X-rays that have passed through the region R2 of the reference piece 10 reach the region (detection region) A12 of the detector 30. Further, the X-ray that has passed through the region R3 of the reference piece 10 reaches the region (detection region) A13 of the detector 30. The X-ray dose reaching the region A12 is larger than the X-ray dose in the region A11 and smaller than the X-ray dose in the region A13. Further, the X-ray dose in the region A13 is smaller than the X-ray dose in the region A14. The level of the output signal of the detector 30 increases in the order of the regions A12, A13, A14.

  By using the reference piece 10 whose thicknesses T1 to T3 are measured in advance, it is possible to obtain the correspondence between the thickness T1 to T3 of the reference piece 10 and the signal level output from the detector 30. That is, the level of the output signal in the region A11 corresponds to the thickness T1 of the reference piece 10, the level of the output signal in the region A12 corresponds to the thickness T2 of the reference piece 10, and the level of the output signal in the region A13 is This corresponds to the thickness T3 of the reference piece 10.

  If the relationship between the level of the output signal of the detector 30 and the thickness of the reference piece 10 is plotted, as shown in FIG. 3, the data (correspondence between the level of the output signal and the thickness of the reference piece 10 is shown. Data). Here, by using the reference piece 10 having regions R1 to R3 having different thicknesses, output signals corresponding to three thicknesses can be obtained by one X-ray imaging operation. And corresponding data can be efficiently acquired compared with the case where the reference | standard piece which has one thickness is used.

  If the correspondence data is used, the thickness of the object can be specified based on the output signal of the detector 30. Further, when X-rays are irradiated to an object having a known thickness, the level of the output signal of the detector 30 is different from the signal level specified from the thickness of the object and the corresponding data. It is possible to determine that the object contains a foreign object.

  By using the X-ray imaging system of the present embodiment, for example, it can be determined whether or not a foreign substance is included in the members constituting the battery. As a member constituting the battery, for example, there is an electrode element disposed with an electrolyte layer interposed therebetween. The electrode element includes a current collecting plate and an electrode active material layer formed on the surface of the current collecting plate. The electrode active material layer includes a conductive agent and a binder in addition to the active material of each electrode (positive electrode and negative electrode).

  In the X-ray imaging system of the present embodiment, the imaging operation shown in FIG. 4 is performed after the imaging operation shown in FIG. 2 is performed. In the imaging state illustrated in FIG. 4, the position and orientation of the reference piece 10 with respect to the X-ray source 20 and the detector 30 are changed with respect to the imaging state illustrated in FIG. 2. Specifically, the reference piece 10 shown in FIG. 2 and the reference piece 10 shown in FIG. 4 have a rotationally symmetric relationship with respect to the reference axis RL. The reference axis RL is a virtual axis that extends in the X-ray irradiation direction and is located within the X-ray irradiation range.

  FIG. 5 is a view when the reference piece 10 is viewed from the X-ray source 20 side, and the reference axis RL is also shown. As shown in FIG. 5, the reference piece 10 can rotate in the direction of the arrow RD about the reference axis RL. The reference piece 10 indicated by a solid line in FIG. 5 corresponds to the state shown in FIG. 2, and the reference piece 10 indicated by a dotted line in FIG. 5 corresponds to the state shown in FIG.

  In the imaging state shown in FIG. 4, some components of the X-rays emitted from the X-ray source 20 pass through the reference piece 10 and reach the regions A21 to A23 of the detector 30. Other components of the X-ray directly reach the region A24 of the detector 30 without passing through the reference piece 10.

  The X-ray transmitted through the region R1 of the reference piece 10 reaches the region A21, the X-ray dose reaching the region A21 is the smallest, and the level of the output signal in the region A21 is the lowest. Here, a region A21 shown in FIG. 4 corresponds to a region A14 shown in FIG. The X-ray dose reaching the region A24 is the largest, and the level of the output signal in the region A24 is the highest. Here, the area A24 shown in FIG. 4 corresponds to the area A11 shown in FIG.

  X-rays that have passed through the region R2 of the reference piece 10 have arrived at the region A22, and X-rays that have passed through the region R3 of the reference piece 10 have arrived at the region A23. The X-ray dose reaching the region A22 is smaller than the X-ray dose reaching the region A21 and larger than the X-ray dose reaching the region A23. Further, the X-ray dose reaching the region A23 is smaller than the X-ray dose reaching the region A24. A region A22 shown in FIG. 4 corresponds to a region A13 shown in FIG. 2, and a region A23 shown in FIG. 4 corresponds to a region A12 shown in FIG.

  When the imaging operation shown in FIG. 4 is performed after the imaging operation shown in FIG. 2 is performed, the X-ray intensity distribution reaching the detector 30 can be varied as described above. FIG. 6 shows the X-ray dose distribution ID1 reaching the detector 30 in the imaging operation shown in FIG. 2 and the X-ray dose distribution ID2 reaching the detector 30 in the imaging operation shown in FIG. ing. Distribution ID3 is a distribution obtained by adding distributions ID1 and ID2. The distribution ID4 is a distribution indicating an average value of the distributions ID1 and ID2.

  As shown in FIG. 6, when distribution ID1 and distribution ID2 are added, distribution ID3 in which variation in X-ray dose is suppressed is obtained. Moreover, even if the average value of the distribution ID1 and the distribution ID2 is calculated, the distribution ID4 in which the variation in the X-ray dose is suppressed is obtained. The X-ray dose in distribution ID3 and distribution ID4 is a reference value in the present invention.

  In FIG. 6, the distribution ID <b> 3 matches the predetermined reference value, but it is not necessary to match this reference value, and the integrated value of the X-ray dose reaching the detector 30 may be made closer to the reference value. Similarly, in FIG. 6, the distribution ID 4 matches the predetermined reference value. However, it is not necessary to match this reference value, and the average value of the X-ray dose reaching the detector 30 is made closer to the reference value. That's fine. Thus, if the integrated value or the average value is brought close to the reference value, variation in deterioration in the detector 30 can be suppressed. This reference value is set as appropriate.

  Making the X-ray of distribution ID1 and the X-ray of distribution ID2 alternately incident on the detector 30 is equivalent to making the X-ray of distribution ID3 incident on the detector 30. That is, variations in the accumulated amount of received X-rays at the detector 30 can be suppressed. Thereby, it can suppress that a deterioration degree changes according to the detection position of the detector 30. FIG. In other words, all the detection elements 31 in the detector 30 can be deteriorated at substantially the same rate of change, and a specific detection element 31 is prevented from being deteriorated before the other detection elements 31. Can do. Thereby, the lifetime of the detector 30 can be improved.

  Here, in the case of detecting foreign matter with high accuracy, it is preferable to suppress variation in deterioration in the detector 30. For example, since the electrode active material layer of the electrode element is made of metal particles or non-metal particles, uneven distribution of particles is likely to occur. The uneven distribution of particles appears as uneven distribution of the X-ray dose reaching the detector 30. In order to detect foreign matter in the state where the uneven distribution of X-rays is generated, the detector 30 is highly accurate. Detection capability is required. For this reason, if the X-ray imaging method of the present embodiment is used, a change in the X-ray dose accompanying a foreign substance can be achieved even in a state where uneven distribution of the X-ray dose occurs by suppressing partial deterioration of the detector 30. Can be detected.

  When performing the imaging operation shown in FIG. 2 and the imaging operation shown in FIG. 4, as shown in FIG. 7, the reference piece 10 is attached to the stage (support member) 40, and the stage 40 is attached to the reference axis (rotation axis) RL. Just rotate around. Thereby, the reference | standard piece 10 can be moved to the position shown in FIG. 2, and the position shown in FIG.

  On the other hand, when the imaging operation shown in FIG. 2 and the imaging operation shown in FIG. 4 are performed, the configuration shown in FIG. 8 can be used.

  In FIG. 8, two types of reference pieces 10 </ b> A and 10 </ b> B are attached to the stage 40. The reference piece 10A is a reference piece used when performing the imaging operation shown in FIG. 2, and the reference piece 10B is the reference piece 10 used when performing the imaging operation shown in FIG. By moving the stage 40 in the X direction, the reference piece 10A can be positioned in the X-ray irradiation region, and the reference piece 10B can be positioned in the X-ray irradiation region.

  In the configuration shown in FIG. 8, the stage 40 is linearly moved in the X direction, but the present invention is not limited to this. For example, the reference pieces 10A and 10B are attached to a stage that rotates about a predetermined axis, and the reference piece 10A or the reference piece 10B can be positioned within the X-ray irradiation range by rotating the stage.

  In this embodiment, X-rays are used, but other radiation can be used. Even in this case, variation in deterioration in the detector 30 can be suppressed.

  In this embodiment, the variation in the integrated amount of X-rays reaching the detector 30 is suppressed by two imaging operations. However, the present invention is not limited to this. Specifically, variation in the integrated amount of X-rays reaching the detector 30 can be suppressed by three or more imaging operations. That is, after preparing the number (type) of reference pieces 10 corresponding to the number of imaging operations, changing the reference piece 10 each time an imaging operation is performed, and performing a plurality of imaging operations, the detector 30. It is only necessary that the accumulated amount of X-rays reaching the point is substantially uniform.

  Furthermore, in the configuration shown in FIGS. 2 and 4, a part of the X-rays emitted from the X-ray source 20 reaches the detector 30 directly, but this is not restrictive. That is, all the X-rays irradiated from the X-ray source 20 can reach the detector 30 after passing through the reference piece 10. Even in this case, the same imaging operation as in the present embodiment may be performed.

  An X-ray imaging system in Embodiment 2 of the present invention will be described. Here, members having the same functions as those described in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the present embodiment, variation in the accumulated amount of X-rays reaching the detector 30 is suppressed by sliding the reference piece 10 stepwise within the X-ray irradiation range. This will be specifically described with reference to FIG.

  In this embodiment, two reference pieces 10C and 10D shown in FIG. 9 are arranged on the stage, and the imaging operation is performed a plurality of times while the stage is slid in the direction of the arrow X. The reference piece 10C has the same configuration as the reference piece 10 described in the first embodiment, and includes regions R1 to R3 having thicknesses T1 to T3. The reference piece 10D has two regions R2 and R3, the region R2 has a thickness T2, and the region R3 has a thickness T3.

  In the direction of the arrow X, spaces S1 and S2 are provided at positions sandwiching the reference piece 10C, and the space S2 is located between the reference pieces 10C and 10D. The reference pieces 10C and 10D can move integrally while maintaining the positional relationship shown in FIG. Spaces S1 and S2 are areas where the reference pieces 10C and 10D do not exist, and are areas where the X-rays from the X-ray source 20 reach the detector 30 directly.

  In the first imaging operation, the space S1 and the reference piece 10C are positioned within the X-ray irradiation range. A range indicated by an arrow in FIG. 9 indicates an X-ray irradiation range. The X-rays that have passed through the space S1 reach the region A31 of the detector 30, and the X-rays that have passed through the region R3 of the reference piece 10C reach the region A32 of the detector 30. The X-ray transmitted through the region R2 of the reference piece 10C reaches the region A33 of the detector 30 and the X-ray transmitted through the region R1 of the reference piece 10C reaches the region A34 of the detector 30.

  In the second imaging operation, the reference piece 10C and the space S2 are positioned within the X-ray irradiation range. The X-ray that has passed through the region R3 of the reference piece 10C reaches the region A31 of the detector 30, and the X-ray that has passed through the region R2 of the reference piece 10C reaches the region A32 of the detector 30. The X-ray that has passed through the region R1 of the reference piece 10C reaches the region A33 of the detector 30, and the X-ray that has passed through the space S2 reaches the region A34 of the detector 30.

  In the third imaging operation, a part of the reference pieces 10C and 10D and the space S2 are positioned within the X-ray irradiation range. The X-rays that have passed through the region R2 of the reference piece 10C reach the region A31 of the detector 30, and the X-rays that have passed through the region R1 of the reference piece 10C reach the region A32 of the detector 30. The X-ray that has passed through the space S2 reaches the region A33 of the detector 30, and the X-ray that has passed through the region R3 of the reference piece 10D reaches the region A34 of the detector 30.

  In the fourth imaging operation, a part of the reference piece 10C, the reference piece 10D, and the space S2 are positioned within the X-ray irradiation range. The X-ray that has passed through the region R1 of the reference piece 10C reaches the region A31 of the detector 30, and the X-ray that has passed through the space S2 reaches the region A32 of the detector 30. The X-ray transmitted through the region R3 of the reference piece 10D reaches the region A33 of the detector 30, and the X-ray transmitted through the region R2 of the reference piece 10D reaches the region A34 of the detector 30.

  In the present embodiment, the integrated amount of X-rays reaching the areas A31 to A34 of the detector 30 after performing the imaging operation four times can be made substantially equal. Here, the integrated amount of X-rays reaching the region A31 of the detector 30 is the sum of the amount of X-rays that have passed through the space S1 and the amount of X-rays that have passed through the regions R1 to R3 of the reference piece 10C. . The other areas A32 to A34 in the detector 30 are also equal to the integrated amount of X-rays in the area A31. By suppressing variations in the X-ray accumulated amount in the regions A31 to A34 of the detector 30, variations in deterioration in the detector 30 can be suppressed.

  In this embodiment, the integrated amount of X-rays is equalized by four imaging operations, but the present invention is not limited to this. That is, it is only necessary to equalize the accumulated amount of X-rays in a plurality of detection regions in the detector 30 by a plurality of imaging operations while sliding the reference piece 10 stepwise in the X direction. Here, in the present embodiment, the detector 30 has the four detection areas A31 to A34. However, the present invention is not limited to this and can be set as appropriate.

  An X-ray imaging system according to Embodiment 3 of the present invention will be described. Here, members having the same functions as those described in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. In the present embodiment, a plurality of types of reference pieces are used to equalize the accumulated amount of X-rays reaching the detector 30 and suppress variations in deterioration of the detector 30. The reference piece used in the present embodiment will be described with reference to FIG.

  In the first imaging operation, the reference piece 10E is used. The reference piece 10E includes a region R4 having a thickness T41 and a region R5 having a thickness T42. Among the X-rays emitted from the X-ray source 20, some components pass through the region R4 of the reference piece 10E, and the remaining components pass through the region R5 of the reference piece 10E. The X-ray transmitted through the region R4 reaches the region A41 of the detector 30, and the X-ray transmitted through the region R5 reaches the region A42 of the detector 30.

  In the second imaging operation, the reference piece 10F is used. The reference piece 10F has a region R6 having a thickness T43 and a region R7 having a thickness T44. Among the X-rays emitted from the X-ray source 20, some components pass through the region R6 of the reference piece 10F, and the remaining components pass through the region R7 of the reference piece 10F. The X-ray transmitted through the region R6 reaches the region A41 of the detector 30, and the X-ray transmitted through the region R7 reaches the region A42 of the detector 30.

  In the third imaging operation, the reference piece 10G is used. The reference piece 10G has a region R8 having a thickness T45 and a region R9 having a thickness T46. Among the X-rays emitted from the X-ray source 20, some components pass through the region R8 of the reference piece 10G, and the remaining components pass through the region R9 of the reference piece 10G. The X-ray transmitted through the region R8 reaches the region A41 of the detector 30, and the X-ray transmitted through the region R9 reaches the region A42 of the detector 30.

The reference pieces 10E, 10F, and 10G have the following relational expression (1). In this embodiment, the thicknesses T41 to T46 are set to different values.
T41 + T43 + T45 = T42 + T44 + T46 (1)

  When the thicknesses T41 to T46 of the reference pieces 10E, 10F, and 10G are set so as to satisfy the above expression (1), the variation in the X-ray accumulated amount in the detector 30 after performing the imaging operation three times is suppressed. be able to. After performing the imaging operation three times, the integrated amount of X-rays reaching the region A41 of the detector 30 depends on the thickness (T41 + T43 + T45) of the reference pieces 10E, 10F, 10G. Further, after performing the imaging operation three times, the integrated amount of X-rays reaching the region A42 of the detector 30 depends on the thickness (T42 + T44 + T46) of the reference pieces 10E, 10F, 10G.

  Considering the above equation (1), the integrated amount of X-rays in the regions A41 and 42 of the detector 30 can be made substantially equal. Thereby, the variation in deterioration in the detector 30 can be suppressed.

  In the present embodiment, the integrated amount of X-rays is equalized after three imaging operations are performed, but the present invention is not limited to this. That is, the integrated amount of X-rays can be equalized after performing the imaging operation a plurality of times (two times or four times or more). In this embodiment, the X-ray integrated amounts in the two regions A41 and A42 are equalized, but the number of regions to be equalized can be set as appropriate.

10: Reference piece (object)
11-13: Plate 20: X-ray source (radiation source)
30: Detector 40: Stage (support member)

Claims (13)

A radiation imaging method for obtaining radiation data corresponding to the object by performing an imaging operation of detecting radiation that is irradiated onto the object and transmitted through the object with a detector,
The object has a plurality of regions having different thicknesses,
In After several times the imaging operation, the amount of radiation reaching transmitted through said object in each of a plurality of detection regions within the detector so as to be directed to the reference value, reaches a pre-Symbol the detection areas A radiation imaging method, wherein the imaging operation is performed a plurality of times while changing a region of the object through which radiation is transmitted between the plurality of regions . A radiation imaging method for obtaining radiation data corresponding to the object by performing an imaging operation of detecting radiation that is irradiated onto the object and transmitted through the object with a detector,
The object includes a plurality of objects having different thicknesses of regions through which radiation is transmitted,
After performing the imaging operation a plurality of times, within the radiation irradiation region, the radiation dose transmitted through the plurality of objects and reaching each of the plurality of detection regions in the detector is directed to a reference value. The radiation imaging method, wherein the imaging operation is performed a plurality of times while changing the object to be positioned between the plurality of objects. While changing the orientation of the object relative to prior Symbol detector, radiation imaging method according to claim 1, characterized in that the imaging operation of the plurality of times.   4. The orientation of the object relative to the detector is changed by rotating the object around a reference axis that extends in the radiation irradiation direction and is located within the radiation irradiation region. The radiation imaging method described in 1. While changing the position of the object in the irradiation area of radiological, radiation imaging method according to claim 1, characterized in that the imaging operation of the plurality of times. The amount of radiation reaching the respective detection region, any one of claims 1 to 5, characterized in that the radiation dose in total after the imaging operation was performed a plurality of times or an average value of radiation dose The radiation imaging method described in 1.   The radiation imaging method according to claim 1, wherein the radiation is an X-ray. A radiation source for irradiating an object having a plurality of regions having different thicknesses ;
A detector that detects radiation transmitted through the object and performs an imaging operation;
A support member for supporting the object,
After the imaging operation is performed a plurality of times, the support member is configured to perform the imaging operation so that a radiation amount that passes through the object and reaches each of a plurality of detection regions in the detector is directed to a reference value. each time performing, by changing the arrangement of the object relative to the detector, and wherein the region of the object by changing between said plurality of regions radiation before SL reaches the respective detection regions is transmitted Radiation imaging system. A radiation source for irradiating the object with radiation;
A detector that detects radiation transmitted through the object and performs an imaging operation;
A support member for supporting the object,
The object includes a plurality of objects having different thicknesses of regions through which radiation is transmitted,
After the imaging operation is performed a plurality of times, the support member is configured so that the radiation dose that passes through the plurality of objects and reaches each of the plurality of detection regions in the detector is directed to a reference value. Each time an imaging operation is performed, the object positioned in the radiation irradiation region is changed, and the object through which the radiation reaching each detection region is transmitted is changed between the plurality of objects. Radiation imaging system. Before Symbol support member extends in the irradiation direction of the radiation, about a reference axis located in the irradiation area of the radiation, by rotating the object, and changing the arrangement of the object The radiation imaging system according to claim 8 . Before Symbol support member, by changing the position of the object in the irradiation area of the radiation, the radiation imaging system according to claim 8, characterized in that to change the arrangement of the object. The amount of radiation reaching the respective detection region, any one of claim 8, wherein 11 said radiation dose of total after the imaging operation was performed a plurality of times or an average value of radiation dose The radiation imaging system described in 1. The radiation imaging system according to claim 8, wherein the object is a member constituting a battery.

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