Radiograph acquisition device and radiograph acquisition method

Abstract

An X-ray image acquisition device 1 comprises: an X-ray source 2 having an electron gun 21 and a target 22; a control unit 3 that controls an incident position of an electron beam EB between a first incident position and a second incident position; an X-ray detection unit 4 that acquires an X-ray image of an object OJ; and a processing unit 5 that processes a first image acquired as an X-ray image in a first state where the incident position is the first incident position, and that processes a second image acquired as an X-ray image in a second state where the incident position is the second incident position. By controlling the incident position between the first incident position and the second incident position on the basis of the magnification ratio of the X-rays from the object OJ to the X-ray detection unit 4, the control unit 3 moves at least a part of the image of the object OJ so as to extend across the boundary between adjacent pixels 41 between the first state and the second state.

Description

Radiation image acquisition device and radiation image acquisition method 【0001】 This disclosure relates to a radiographic image acquisition device and a radiographic image acquisition method. 【0002】 Patent Document 1 describes an X-ray CT apparatus comprising a cathode that generates thermionic electrons and an anode that receives thermionic electrons irradiated from the cathode and generates X-rays. This X-ray CT apparatus has a control unit that controls the focal position of thermionic electrons at the anode while maintaining a constant irradiation angle of thermionic electrons to the anode. In this X-ray CT apparatus, by employing FFS (flying focal spot) which changes the focal position in the Z-axis direction (body axis direction), the number of data points in the Z-axis direction can be increased and the spatial resolution can be improved. Patent Document 2 describes an X-ray CT apparatus employing an FFS method that can improve spatial resolution. 【0003】 Japanese Patent Publication No. 2019-92585, International Publication No. 2013 / 191001 【0004】 In X-ray CT scanners as described in Patent Documents 1 and 2, sufficient resolution is ensured by changing the focal position of thermionic electrons (the position where X-rays are generated). However, in medical X-ray CT scanners, the positional relationship between the X-ray tube, the subject, and the X-ray detection unit is generally constant. In X-ray CT scanners for non-destructive testing of food, batteries, etc., various materials, sizes, shapes, and aspect ratios of the objects to be inspected, and different resolutions depending on the object, may be considered, and the positional relationship between the radiation source, the object being imaged, and the radiation detection unit may not be constant. Even in such cases, it is desirable to ensure sufficient resolution and detect the object with high accuracy. 【0005】 Therefore, the purpose of this disclosure is to provide a radiation image acquisition device and a radiation image acquisition method that can accurately detect objects. 【0006】 The gist of the radiation image acquisition apparatus and radiation image acquisition method relating to one aspect of this disclosure is as follows [1] to

[15] . 【0007】[1] A radiation source for irradiating an object with radiation, comprising: a beam emission unit for emitting a beam; a radiation generating member for generating radiation when the beam is incident on it; a control unit for controlling the incident position of the beam in the radiation generating member between a first incident position and a second incident position; a radiation detection unit having a plurality of pixels for detecting the radiation that has passed through the object, and for acquiring a radiation image of the object based on the radiation detection results by the plurality of pixels; and a processing unit for processing a first image acquired as the radiation image in a first state where the incident position is the first incident position, and a second image acquired as the radiation image in a second state where the incident position is the second incident position, wherein the control unit controls the incident position between the first incident position and the second incident position based on the magnification ratio of the radiation from the object to the radiation detection unit, thereby moving at least a part of the image of the object between the first state and the second state so as to straddle the boundary between adjacent pixels. 【0008】 In the radiation image acquisition device described in [1] above, even if the magnification (the positional relationship between the radiation source, the object, and the radiation detection unit) changes each time an object is detected, the incident position is controlled based on the magnification, so that at least a portion of the image of the object can be moved between the first and second states so as to cross the boundary between adjacent pixels. By using the first and second images acquired in this way, the information between pixels can be complemented to improve the effective resolution. Therefore, with the radiation image acquisition device described in [1] above, objects can be detected with high accuracy. 【0009】[2] The radiation image acquisition apparatus according to [1], wherein the control unit determines the distance D between the first incident position and the second incident position based on the following formula (1). P × α = (M - 1) × D ... (1) In the above formula (1), P is the size of each of the plurality of pixels, α is the ratio of the amount of movement of the image of the object to the plurality of pixels between the first state and the second state to the size, and M is the magnification factor. In this case, the distance D between the first incident position and the second incident position necessary to achieve the amount of movement P × α of the image of the object can be easily determined based on the magnification factor. 【0010】 [3] The radiation generating member extends along a predetermined direction intersecting the central axis of the radiation, and the plurality of pixels are arranged along the predetermined direction, the radiation image acquisition device according to [1] or [2]. In this case, the image of the object can be suitably moved with respect to the plurality of pixels between the first state and the second state. 【0011】 [4] The radiation image acquisition apparatus according to any one of [1] to [3], wherein the radiation source is an X-ray source that irradiates X-rays as radiation, the beam emission unit is an electron gun that emits an electron beam as the beam, and the radiation generating member is a target that generates X-rays when the electron beam is incident on it. In this case, the target object can be detected with high accuracy using X-rays. 【0012】 [5] The radiation image acquisition apparatus according to [4], wherein the X-ray source further has a deflection unit for deflecting the electron beam, and the control unit controls the incident position between the first incident position and the second incident position by deflecting the electron beam with the deflection unit. In this case, the incident position of the beam can be easily controlled between the first incident position and the second incident position. 【0013】[6] The radiation image acquisition apparatus according to [4], wherein the beam emission unit comprises a first electron gun that emits the electron beam toward the first incident position and a second electron gun that emits the electron beam toward the second incident position, and the control unit controls the incident position between the first incident position and the second incident position by switching the on / off state of at least one of the first electron gun and the second electron gun. In this case, the incident position of the beam can be easily controlled between the first incident position and the second incident position. 【0014】 [7] The control unit outputs the position where the radiation is generated in the radiation generating member. A radiation image acquisition device according to any one of [1] to [6]. In this case, the user of the radiation image acquisition device can easily grasp the position where the radiation is generated in the radiation generating member. 【0015】 [8] The radiation detection unit corrects the detection result by the plurality of pixels based on the location where the radiation output by the control unit is generated, and acquires the corrected first image and second image based on the corrected detection result, and the processing unit processes the corrected first image and second image, as described in [7]. In this case, the first image and second image can be suitably acquired by correcting the detection result by the plurality of pixels based on the location where the radiation is generated. As a result, the target object can be detected with greater accuracy. 【0016】 [9] The radiation image acquisition apparatus according to any one of [1] to [8], wherein the radiation source or the control unit outputs first information including the timing of emitting the beam toward the first incident position and second information including the timing of emitting the beam toward the second incident position, and the radiation detection unit controls the detection of the radiation based on the first information and the second information. In this case, for example, it is possible to start the exposure of the pixels of the radiation detection unit at the timing of emitting the beam toward the first incident position and the timing of emitting the beam toward the second incident position. As a result, radiation can be detected efficiently. 【0017】

[10] The processing unit acquires a composite image of the first image and the second image, as described in any one of [1] to [9]. In this case, a composite image which is substantially high resolution can be acquired, and as a result, the target object can be detected with greater accuracy. 【0018】

[11] The processing unit acquires height information of the object based on the first image and the second image, a radiation image acquisition device according to any one of [1] to

[10] . In this case, the height information of the object can be acquired with high accuracy. 【0019】

[12] The radiation detection unit acquires a plurality of first images, each of which is the first image, and a plurality of second images, each of which is the second image. The radiation detection unit or the processing unit integrates at least one of the plurality of first images and the plurality of second images. The processing unit processes at least one of the integrated plurality of first images and the plurality of second images. The radiation image acquisition apparatus according to any one of [1] to

[11] . In this case, the accuracy of detecting an object in at least one of the plurality of first images and the plurality of second images can be improved. As a result, the object can be detected with greater accuracy. 【0020】

[13] The radiation detection unit acquires a plurality of first images, each of which is the first image, and a plurality of second images, each of which is the second image, and the radiation detection unit or the processing unit each generates a plurality of pairs composed of the first image and the second image. The radiation image acquisition device according to any one of [1] to

[12] . In this case, the processing unit can easily perform accurate detection of the target object. 【0021】

[14] The radiation detection unit has the processing unit as described in any one of [1] to

[13] . In this case, the processing unit can be configured by the radiation detection unit. 【0022】

[15] A first step of emitting a beam toward a first incident position in a radiation generating member that generates radiation when a beam is incident on it, and irradiating the object with the radiation; a second step of using a radiation detection unit having a plurality of pixels for detecting the radiation to detect the radiation that has passed through the object in a first state where the incident position of the beam is the first incident position, and acquiring a first image which is a radiation image of the object based on the radiation detection result; a third step of emitting a beam toward a second incident position in the radiation generating member, and irradiating the object with the radiation; and using the radiation detection unit, when the incident position of the beam is forward A radiation image acquisition method comprising: a fourth step of detecting the radiation that has passed through the object in a second state which is the second incidence position, and acquiring a second image which is the radiation image of the object based on the radiation detection result; and a fifth step of processing the first image and the second image, wherein in at least one of the first and third steps, the incidence position is controlled between the first incidence position and the second incidence position based on the magnification ratio of the radiation from the object to the radiation detection unit, thereby moving at least a part of the image of the object between the first state and the second state so as to straddle the boundary between adjacent pixels. 【0023】 In the radiation image acquisition method described in

[15] above, even if the magnification (the positional relationship between the radiation source, the object, and the radiation detection unit) changes each time an object is detected, the incident position is controlled based on the magnification, so that at least a portion of the image of the object can be moved between the first and second states so as to cross the boundary between adjacent pixels. By using the first and second images acquired in this way, the information between pixels can be complemented to improve the effective resolution. Therefore, according to the radiation image acquisition method described in

[15] above, objects can be detected with high accuracy. 【0024】 According to this disclosure, objects can be detected with high accuracy. 【0025】This is a schematic diagram showing the configuration of the X-ray image acquisition device according to the first embodiment. (a) to (c) are schematic diagrams showing the configuration of the X-ray source. (a) to (c) are schematic diagrams showing the configuration of the X-ray source. This is a diagram showing the control of X-ray detection in the X-ray detection unit. This is a diagram showing the movement of the object's image between the first state and the second state. This is a diagram for explaining the attenuation of X-rays within the target. This is a flowchart for explaining the processing performed in the X-ray image acquisition device. This is a diagram for explaining the composite image acquired by the processing unit. This is a flowchart for explaining the processing performed in the X-ray image acquisition device. This is a diagram for explaining the composite image acquired by the processing unit. This is a flowchart for explaining the processing performed in the X-ray image acquisition device. This is a schematic diagram showing an example of X-ray irradiation of an object when the processing in Figure 11 is performed. This is a schematic diagram showing the X-ray image of the object in Figure 12. (a) and (b) are schematic diagrams showing the configuration of the X-ray source provided in the X-ray image acquisition device according to the second embodiment. (a) and (b) are schematic diagrams showing the configuration of the X-ray source in the X-ray image acquisition device according to the third embodiment. These are schematic diagrams showing the configuration of the X-ray source in the X-ray image acquisition device according to the fourth embodiment. These are schematic diagrams showing the configuration of the X-ray source in the X-ray image acquisition device according to the fifth embodiment. (a) and (b) are schematic diagrams showing the configuration of the X-ray source in the X-ray image acquisition device according to the sixth embodiment. This is a flowchart for explaining the first example of the correction method. (a) to (c) are diagrams for explaining the second example of the correction method. This is a diagram for explaining the second example of the correction method. This is a diagram for explaining a method for obtaining the X-ray focal position from an X-ray image. This is a diagram for explaining a method for obtaining the X-ray focal position from an X-ray image. This is a diagram showing the state in which a chart is placed in the X-ray image acquisition device. This is a flowchart for explaining a method for obtaining the X-ray focal position using a chart. This is a diagram showing the state in which a mesh is placed in the X-ray image acquisition device. This is a flowchart for explaining a method for obtaining the X-ray focal position using a mesh. This is a diagram for explaining the amount of image displacement of the mesh in the X-ray image. This is a schematic diagram showing the configuration of an X-ray image acquisition device according to a modified example.This diagram shows an object with areas for focused inspection and areas for simple inspection positioned in an X-ray image acquisition device. This diagram shows the control of X-ray detection in the X-ray detection unit. This diagram illustrates the circuit diagram of a pixel. 【0026】 Hereinafter, with reference to the drawings, preferred embodiments of a radiation image acquisition apparatus and a radiation image acquisition method relating to one aspect of this disclosure will be described in detail. [First Embodiment] 【0027】 Figure 1 is a schematic diagram showing the configuration of an X-ray image acquisition device according to the first embodiment. Figures 2(a) to 2(c) and 3(a) to 3(c) are schematic diagrams showing the configuration of an X-ray source. The X-ray image acquisition device 1 (radiation image acquisition device) shown in Figure 1 is a device for acquiring an X-ray image (radiation image) of an object OJ placed on an imaging table (not shown). The X-ray image acquisition device 1 is composed of an X-ray source 2 (radiation source), a control unit 3, an X-ray detection unit 4 (radiation detection unit), a processing unit 5, an X-ray source fixing jig 6, and a detection unit fixing jig 7. The X-ray image acquisition device 1 is a device used, for example, in X-ray non-destructive testing to magnify and observe an object OJ. In this case, in the X-ray image acquisition device 1, the positional relationship (magnification) between the X-ray source 2, the object OJ (imaging table), and the X-ray detection unit 4 can be adjusted according to the purpose of observing the object OJ. 【0028】 The object OJ is positioned between the X-ray source 2 and the X-ray detection unit 4 in direction D1. In the following description, the direction perpendicular to direction D1 is referred to as direction D2 (a predetermined direction), and the direction perpendicular to both directions D1 and D2 is referred to as direction D3. Directions D2 and D3 are also directions that intersect the optical axis (central axis) of the X-ray. The X-ray source 2 is fixed to the X-ray source fixing jig 6, and the X-ray detection unit 4 is fixed to the detection unit fixing jig 7. As a result, the positions of the X-ray source 2 and the X-ray detection unit 4 are fixed. 【0029】The X-ray source 2 emits X-rays along direction D1 and irradiates the target object OJ with these X-rays. The X-ray source 2 is a so-called transmission-type X-ray source. The X-ray source 2 includes an electron gun 21 (beam emitter), a target 22 (radiation generating member), a first deflection unit 23A, a second deflection unit 23B, a third deflection unit 23C, and a fourth deflection unit 23D. Note that in Figure 1, the target 22 and the deflection units 23A to 23D are not shown. The X-ray source 2 has, for example, a housing (not shown) that houses the electron gun 21 and the target 22, and the space inside the housing is a vacuum-sealed space. The X-ray source 2 is communicated with the control unit 3, the X-ray detection unit 4, and the processing unit 5, respectively. 【0030】 The electron gun 21 emits an electron beam EB toward the target 22 along direction D1. The electron gun 21 consists of a thermal cathode that emits thermionic electrons, and an electron lens that adjusts the focusing of the electron beam EB. The target 22 is a transmission-type target that generates X-rays when the electron beam EB is incident on it. Examples of materials that make up the target 22 include tungsten, molybdenum, cobalt, copper, silver, iron, or rhodium. The target 22 is formed in the shape of a plate extending along a plane perpendicular to direction D1. That is, the target 22 extends at least along direction D2. The target 22 may be formed on another support by methods such as deposition or sputtering, or it may be embedded in the support. For example, the support can be made of a material with high X-ray transparency such as beryllium, aluminum, diamond, carbon, silicon, or glass. 【0031】 Each of the first deflection section 23A, the second deflection section 23B, the third deflection section 23C, and the fourth deflection section 23D is composed of, for example, a deflection electrode. A positive or negative potential is applied to each of the deflection sections 23A to 23D by the control unit 3, which will be described later. In Figures 2(a) to (c), the deflection sections 23A and 23B are shown, while the deflection sections 23C and 23D are omitted. In Figures 3(a) to (c), the deflection sections 23C and 23D are shown, while the deflection sections 23A and 23B are omitted. 【0032】The first deflection unit 23A and the second deflection unit 23B are arranged so as to straddle the trajectory of the electron beam EB in direction D2. Figure 2(a) shows the state in which the electron beam EB is not deflected (the state in which no potential is applied to the first deflection unit 23A and the second deflection unit 23B). Figure 2(b) shows the state in which the electron beam EB is deflected towards the second deflection unit 23B due to the electric field formed between the first deflection unit 23A and the second deflection unit 23B. Figure 2(c) shows the state in which the electron beam EB is deflected towards the first deflection unit 23A due to the electric field formed between the first deflection unit 23A and the second deflection unit 23B. 【0033】 The third deflection section 23C and the fourth deflection section 23D are positioned to straddle the trajectory of the electron beam EB in direction D3. Figure 3(a) shows the state in which the electron beam EB is not deflected (the state in which no potential is applied to the third deflection section 23C and the fourth deflection section 23D). Figure 3(b) shows the state in which the electron beam EB is deflected towards the fourth deflection section 23D due to the electric field formed between the third deflection section 23C and the fourth deflection section 23D. Figure 3(c) shows the state in which the electron beam EB is deflected towards the third deflection section 23C due to the electric field formed between the third deflection section 23C and the fourth deflection section 23D. 【0034】 Each deflection section 23A to 23D only needs to be able to deflect the electron beam EB, and may be composed of deflection coils. Furthermore, the number and arrangement positions of the deflection sections are not particularly limited and may be determined as appropriate. 【0035】The control unit 3 is communicably connected to each of the X-ray source 2 and the processing unit 5, and is constituted by, for example, a computer including a processor (CPU), a RAM and a ROM which are recording media. Further, the control unit 3 includes, for example, a potential application unit for applying a potential to the deflection units 23A to 23D. The control unit 3 controls the deflection of the electron beam EB by the deflection units 23A to 23D by controlling the potential applied to the deflection units 23A to 23D. When the electron beam EB is deflected, the incidence position of the electron beam EB on the target 22 changes. That is, in the X-ray image acquisition device 1, the control unit 3 controls the incidence position of the electron beam EB by deflecting the electron beam EB by the deflection units 23A to 23D. 【0036】 As an example, as shown in (b) of FIG. 2, the control unit 3 controls the incidence position of the electron beam EB to the first incidence position Y1 (an incidence position located on the side of the second deflection unit 23B with respect to the incidence position Y0 in a state where the electron beam EB is not deflected). Further, as shown in (c) of FIG. 2, the control unit 3 controls the incidence position of the electron beam EB to the second incidence position Y2 (an incidence position located on the side of the first deflection unit 23A with respect to the incidence position Y0). As shown in (b) of FIG. 3, the control unit 3 controls the incidence position of the electron beam EB to the third incidence position Y3 (an incidence position located on the side of the fourth deflection unit 23D with respect to the incidence position Y0). As shown in (c) of FIG. 3, the control unit 3 controls the incidence position of the electron beam EB to the fourth incidence position Y4 (an incidence position located on the side of the third deflection unit 23C with respect to the incidence position Y0). 【0037】 Thereby, the control unit 3 controls the incidence position of the electron beam EB between the incidence positions Y1 to Y4. The incidence position of the electron beam EB is the focal position of the electron beam EB on the target 22, and in other words, it is the generation position of the X-ray (the focal position of the X-ray) on the target 22. That is, it can be said that the control unit 3 controls the focal position of the X-ray. Details of the control method will be described later. 【0038】As described above, in the X-ray image acquisition apparatus 1, the X-rays generated by the electron beam EB incident on each of the incident positions Y1 to Y4 can be irradiated onto the object OJ. The X-rays transmitted through the object OJ enter the X-ray detection unit 4. In the following description, the state where the incident position of the electron beam EB is the first incident position Y1 is referred to as the "first state", the state where the incident position of the electron beam EB is the second incident position Y2 is referred to as the "second state", the state where the incident position of the electron beam EB is the third incident position Y3 is referred to as the "third state", and the state where the incident position of the electron beam EB is the fourth incident position Y4 is referred to as the "fourth state". It can be said that the control unit 3 switches the detection state among the first to fourth states. 【0039】 In FIGS. 2(a) to (c) and FIGS. 3(a) to (c), the incident position of the electron beam EB moves along the direction D2 or the direction D3. However, the control unit 3 can control the potential applied to the deflection units 23A to 23D to move the incident position of the electron beam EB along a direction inclined with respect to both the direction D2 and the direction D3 (for example, a direction inclined at 45 degrees with respect to each of the direction D2 and the direction D3). That is, the positions of the incident positions Y1 to Y4 in the first to fourth states are not limited to the positions shown in FIGS. 2(a) to (c) and FIGS. 3(a) to (c). 【0040】 The X-ray detection unit 4 detects the X-rays transmitted through the object OJ and acquires an X-ray image of the object OJ based on the detection result. The X-ray detection unit 4 is communicably connected to each of the X-ray source 2 and the processing unit 5. The X-ray detection unit 4 has a plurality of pixels 41 (see FIG. 5) for detecting the X-rays transmitted through the object OJ. The plurality of pixels 41 are arranged at least along the direction D2. The X-ray detection unit 4 is, for example, an area sensor in which the plurality of pixels 41 are arranged two-dimensionally. The X-ray detection unit 4 may be a line sensor in which the plurality of pixels 41 are arranged one-dimensionally. In the following description, the X-ray image acquired by the X-ray detection unit 4 in the first state is referred to as the "first image", the X-ray image acquired by the X-ray detection unit 4 in the second state is referred to as the "second image", the X-ray image acquired by the X-ray detection unit 4 in the third state is referred to as the "third image", and the X-ray image acquired by the X-ray detection unit 4 in the fourth state is referred to as the "fourth image". 【0041】 Figure 4 is a diagram showing the control of X-ray detection in the X-ray detection unit 4. The X-ray source 2 or control unit 3 outputs first information including the timing of emitting the electron beam EB toward the first incident position Y1, and second information including the timing of emitting the electron beam EB toward the second incident position Y2. Each of the first and second pieces of information may include a time interval for emitting the electron beam EB. Figure 4 shows a configuration in which the electron beam EB is alternately emitted toward the first incident position Y1 and the second incident position Y2, with a time interval to allow the incident position to move between the first incident position Y1 and the second incident position Y2. 【0042】 The X-ray detection unit 4 controls X-ray detection based on the first and second information. In Figure 4, the X-ray detection unit 4 starts exposure of the pixel 41 when the electron beam EB is emitted toward the first incident position Y1, and ends exposure of the pixel 41 when the emission of the electron beam EB ends. The X-ray detection unit 4 also starts exposure of the pixel 41 when the electron beam EB is emitted toward the second incident position Y2, and ends exposure of the pixel 41 when the emission of the electron beam EB ends. In other words, the X-ray detection unit 4 controls the pixel 41 to remain unexposed while the incident position is moving between the first incident position Y1 and the second incident position Y2. Thus, the first and second information can be considered synchronization signals that communicate the exposure timing to the X-ray detection unit 4. 【0043】 The X-ray source 2 or the control unit 3 may output information including the timing for emitting the electron beam EB toward the third incident position Y3 and information including the timing for emitting the electron beam EB toward the fourth incident position Y4, and the X-ray detection unit 4 may control the detection of X-rays based on this information. 【0044】The processing unit 5 is connected to the X-ray source 2, the control unit 3, and the X-ray detection unit 4 in a communicative manner, and is composed of a computer including, for example, a processor (CPU), and recording media such as RAM and ROM. The processing unit 5 processes the X-ray image output from the X-ray detection unit 4. The processing unit 5 may acquire height information of the object OJ. The processing unit 5 may acquire a composite image of the first image and the second image. The processing unit 5 may acquire a tomographic image or a three-dimensional image of the object OJ based on the first image and the second image. Note that the X-ray detection unit 4 may have a processing unit 5. In other words, the X-ray detection unit 4 may function as the processing unit 5. 【0045】 As shown in Figure 4, the X-ray detection unit 4 may acquire multiple first images and multiple second images by having the control unit 3 switch the detection state between a first state and a second state multiple times. In this case, the X-ray detection unit 4 or the processing unit 5 may integrate at least one of the multiple first images and the multiple second images. The processing unit 5 may process at least one of the integrated multiple first images and the multiple second images. The X-ray detection unit 4 or the processing unit 5 may generate multiple pairs (sets of first and second images), each consisting of a first image and a second image. 【0046】 The X-ray detection unit 4 may acquire multiple third images and multiple fourth images by switching the detection state by the control unit 3. In this case, the X-ray detection unit 4 or the processing unit 5 may integrate at least one of the multiple third images and the multiple fourth images, and the processing unit 5 may process at least one of the integrated multiple third images and the multiple fourth images. [Details of incident position control by the control unit] 【0047】Figure 5 shows the movement of the object's image between the first and second states. The control unit 3 controls the incident position of the electron beam EB between the first incident position Y1 and the second incident position Y2 based on the magnification of the X-rays from the object OJ to the X-ray detection unit 4, thereby moving at least a portion of the image of the object OJ to straddle the boundary between adjacent pixels 41 between the first and second states. In other words, the control unit 3 controls the incident position of the electron beam EB (X-ray focal position) such that at least a portion of the image of the object OJ is formed on a certain pixel 41 in the first state and on a different pixel 41 in the second state. 【0048】 Here, if the magnification is M, the distance from the X-ray source 2 (X-ray focal point) to the object OJ in direction D1 is FOD (Focus to Object Distance), and the distance from the X-ray source 2 (X-ray focal point) to the X-ray detection unit 4 in direction D1 is FDD (Focus to Detector Distance), then the magnification M can be calculated by FDD / FOD. The magnification M is, for example, between 1.1 and 100,000. By setting the magnification M to a relatively large value, a detailed X-ray image of a part of the object OJ can be obtained, and by setting the magnification M to a relatively small value, an X-ray image of the entire object OJ can be obtained. By setting the magnification M to 1.1 or higher, the image of the object OJ can be suitably moved between the first state and the second state. By setting the upper limit of the magnification M to 100,000, the object OJ can be imaged with sufficient magnification. From the viewpoint of preventing the X-ray image acquisition device 1 from becoming larger, the magnification M may be 10,000 or less, or 5,000 or less. 【0049】The control unit 3 determines the distance D between the first incident position Y1 and the second incident position Y2 based on the magnification ratio M. The distance D corresponds to the distance between the focal position of the X-ray in the first state and the focal position of the X-ray in the second state. As an example, the control unit 3 determines the distance D as follows: In the first state, X-rays L1 generated when the electron beam EB is incident at the first incident position Y1 are irradiated onto the object OJ. As a result, an image Z1 of the object OJ is formed on the pixel 41. In the second state, X-rays L2 generated when the electron beam EB is incident at the second incident position Y2 are irradiated onto the object OJ. As a result, an image Z2 of the object OJ is formed on the pixel 41. 【0050】 Here, if P is the size of each of the multiple pixels 41, and α is the ratio of the amount of movement of the image of the object OJ relative to the multiple pixels 41 between the first state and the second state (distance between image Z1 and image Z2 in direction D2) to the size P, then the distance D satisfies the following equation (1). The ratio α is any value, such as 1 / 3 or 1 / 2. The control unit 3 receives the size P, ratio α, and magnification M (FDD and FOD) as input and determines the distance D from the following equation (1). Note that the following equation (1) can also be transformed as follows, since M = FDD / FOD: P × α = (M - 1) × D ... (1) P × α = ((FDD - FOD) / FOD) × D ... (2) 【0051】 The value of the displacement amount P × α of the image of the object OJ can be set such that at least a portion of the image of the object OJ straddles the boundary between adjacent pixels 41 between the first state and the second state. Based on the above, the control unit 3 determines the distance D. Then, the control unit 3 controls the incident position of the electron beam EB between the first state and the second state so that the distance between the first incident position Y1 and the second incident position Y2 is the distance D. 【0052】In the example shown in Figure 5, the control unit 3 determined the distance D when the image of the object OJ moves along direction D2. However, the control unit 3 may also determine the distance traveled by the incident position of the electron beam EB when the image of the object OJ moves along direction D3. The control unit 3 may also determine the distance traveled by the incident position of the electron beam EB when the image of the object OJ moves along a direction that is inclined with respect to both direction D2 and direction D3. 【0053】 The control unit 3 may output the incident position of the electron beam EB (X-ray generation position) at the target 22. For example, the control unit 3 may store the control method and the incident position of the electron beam EB (X-ray generation position) in association, and output the incident position of the electron beam EB (X-ray generation position) based on this association and the control method at the time of detection. 【0054】 Next, an example of the electron beam EB incidence position will be explained with reference to Figure 6. Figure 6 is a diagram illustrating the attenuation of X-rays within the target 22. The electron beam EB, incident on the target 22 from the vacuum side, penetrates a certain distance, interacts with the internal atoms of the target 22, and is converted into X-rays. Here, if Tx is the minimum distance (self-absorption thickness) between the air-side surface of the target 22 and the position of the electrons that have penetrated the target 22 and been converted into X-rays, T is the thickness of the target 22, θ is the angle of the electron beam EB with respect to an axis perpendicular to the target 22 (an axis parallel to direction D1), and L is the maximum penetration depth of the electrons within the target 22, then Tx satisfies the following equation (3): Tx = T - L cos θ ... (3) 【0055】In equation (3) above, since the thickness T and the maximum penetration depth L are constant, the self-absorption thickness Tx depends on the angle θ. That is, if the angle θ (incident angle of the electron beam EB to the target 22 (90° - θ)) is the same in the first to fourth states, the value of the self-absorption thickness Tx will also be the same. As a result, the effect of X-ray self-absorption in the first to fourth states can be made the same (the quality of the X-rays can be made the same). By utilizing this point, for example, the control unit 3 can control the incident position of the electron beam EB so that the angle θ is the same between the first to fourth states, thereby suppressing changes in the image quality of the X-ray image. For example, in the examples of Figures 2(a) to (c), the control unit 3 can make the angle θ the same between the first and second states by making the distance between incident position Y0 and the first incident position Y1 the same as the distance between incident position Y0 and the second incident position Y2. [First example of X-ray image acquisition method] 【0056】 A first example of an X-ray image acquisition method using the X-ray image acquisition device 1 will be described with reference to Figures 7 and 8. Figure 7 is a flowchart illustrating the processes performed in the X-ray image acquisition device 1. Figure 8 is a diagram illustrating the composite image acquired by the processing unit 5. In the first example, a first image and a second image are acquired and these images are processed. 【0057】 In step S11, the control unit 3 receives as input the amount of movement P × α of the image of the object OJ relative to the multiple pixels 41 between the first state and the second state, and the magnification ratio M. The control unit 3 may also receive as input the size P, ratio α, FOD, and FDD, and obtain the amount of movement P × α and the magnification ratio M from these values. In the first example, the image of the object OJ moves P × α in direction D2 and P × α in direction D3 between the first state and the second state. 【0058】 In step S12, the control unit 3 obtains the distance D between the first incident position and the second incident position. For example, the control unit 3 obtains the distance D by substituting the amount of movement P × α and the magnification ratio M obtained in step S11 into the above formula (1). 【0059】In step S13, the electron gun 21 emits an electron beam EB toward the first incident position on the target 22, thereby irradiating the object OJ with X-rays (first step). 【0060】 In step S14, the X-ray detection unit 4 detects the X-rays that have passed through the object OJ in the first state and acquires a first image, which is an X-ray image of the object OJ, based on the X-ray detection result (second step). 【0061】 In step S15, the electron gun 21 emits an electron beam EB toward the second incident position on the target 22, thereby irradiating the object OJ with X-rays (third step). 【0062】 In step S16, the X-ray detection unit 4 detects the X-rays that have passed through the object OJ in the second state and acquires a second image, which is an X-ray image of the object OJ, based on the X-ray detection result (fourth step). 【0063】 In steps S13 and S15, the control unit 3 controls the incident position of the electron beam EB between the first state and the second state so that the distance between the first incident position and the second incident position becomes the distance D obtained in step S12. As a result, at least a portion of the image of the object OJ moves between the first state and the second state so that it crosses the boundary between adjacent pixels 41. 【0064】 In step S17, the processing unit 5 processes the first image and the second image (fifth step). The specific processing in step S17 will be explained with reference to Figure 8. In the example in Figure 8, α is 1 / 2. In Figure 8, the pixel values ​​of the first image are shown as A to G, and the pixel values ​​of the second image are shown as a to g. 【0065】The processing unit 5 can generate a composite image by known processing methods such as those described in the following references 1 and 2. In the example shown in Figure 8, the processing unit 5 composites the first image and the second image with a displacement of the image (horizontal displacement P × α in Figure 8 and vertical displacement P × α in Figure 8). Specifically, the processing unit 5 sets pixels divided into P / 2 size with the first image and the second image shifted relative to each other. Then, the processing unit 5 obtains the pixel value of the divided pixels by performing an averaging process (interpolation process) on the pixel value of the first image and the pixel value of the second image. As a result, the processing unit 5 generates a composite image in which the size of the pixels is P / 2. For example, if the pixel with pixel value A in the first image and the pixel with pixel value a in the second image correspond to a certain pixel in the composite image, the processing unit 5 obtains (A + a) / 2 as the pixel value of that certain pixel in the composite image. By generating a composite image in this manner, the sampling pitch of the object OJ can be substantially reduced (information between pixels 41 can be interpolated), and as a result, the effective resolution of the composite image can be increased. References: 1. Japanese Patent Publication No. 6-217330; 2. Japanese Patent Publication No. 9-271030 【0066】 Furthermore, when determining the pixel values ​​of the composite image, the processing unit 5 may perform interpolation using linear functions, polynomial functions, functions of degree two or higher, etc. Also, general-purpose image processing techniques may be used for the interpolation. Additionally, Lagrangian interpolation, spline interpolation, etc., may be used for the interpolation. The processing unit 5 may generate the composite image by known processing using matrices, such as those described in References 3 and 4 below. Reference 3: U.S. Patent Application Publication No. 2022 / 0005157; Reference 4: Japanese Patent Publication No. 2023-502302 [Second Example of X-ray Image Acquisition Method] 【0067】 A second example of an X-ray image acquisition method using the X-ray image acquisition device 1 will be described with reference to Figures 9 and 10. Figure 9 is a flowchart illustrating the processes performed in the X-ray image acquisition device 1. Figure 10 is a diagram illustrating the composite image acquired by the processing unit 5. In the second example, the first to fourth images are acquired and these images are processed. 【0068】In step S61, the control unit 3 receives the amount of movement P × α of the image of the object OJ and the magnification M as input. In the second example, the image of the object OJ moves P × α in direction D2 between the first state and the second state. Also, the image of the object OJ moves P × α in direction D3 between the first state and the third state. Furthermore, the image of the object OJ moves P × α in direction D2 and P × α in direction D3 between the first state and the fourth state. 【0069】 In step S62, the control unit 3 obtains the distance between the first to fourth incident positions (the amount of movement of the incident position of the electron beam EB). For example, the control unit 3 obtains this distance by substituting the amount of movement P × α and the magnification factor M obtained in step S61 into the above formula (1). 【0070】 In step S63, the electron gun 21 emits an electron beam EB toward the first incident position on the target 22, thereby irradiating the object OJ with X-rays. In step S64, the X-ray detection unit 4 acquires the first image. 【0071】 In step S65, the control unit 3 controls the incident position of the electron beam EB to the second incident position. Then, the electron gun 21 emits the electron beam EB toward the second incident position on the target 22, thereby irradiating the object OJ with X-rays. In step S66, the X-ray detection unit 4 acquires the second image. 【0072】 In step S67, the control unit 3 controls the incident position of the electron beam EB to the third incident position. The electron gun 21 then emits the electron beam EB toward the third incident position on the target 22, thereby irradiating the object OJ with X-rays. In step S68, the X-ray detection unit 4 acquires the third image. 【0073】 In step S69, the control unit 3 controls the incident position of the electron beam EB to the fourth incident position. The electron gun 21 then emits the electron beam EB toward the fourth incident position on the target 22, thereby irradiating the object OJ with X-rays. In step S70, the X-ray detection unit 4 acquires the fourth image. 【0074】In step S71, the processing unit 5 processes the first to fourth images. The specific processing in step S71 will be explained with reference to Figure 10. In the example in Figure 10, α is 1 / 2. In Figure 10, the pixel values ​​of the first image are shown as a1 to a7, the pixel values ​​of the second image are shown as b1 to b7, the pixel values ​​of the third image are shown as c1 to c7, and the pixel values ​​of the fourth image are shown as d1 to d7. 【0075】 The processing unit 5 may generate a composite image (the composite image shown in the upper right of Figure 10) by rearranging the positions of the pixels of the first to fourth images. Alternatively, the processing unit 5 may generate a composite image (the composite image shown in the lower right of Figure 10) by compositing the first to fourth images with each image shifted by the amount of image movement, similar to the process in step S17. For example, if the pixel with pixel value a1 of the first image, the pixel with pixel value b1 of the second image, the pixel with pixel value c1 of the third image, and the pixel with pixel value d1 of the fourth image all correspond to a certain pixel in the composite image, the processing unit 5 calculates (a1 + b1 + c1 + d1) / 4 as the pixel value of that certain pixel in the composite image. 【0076】 In the first example described above (the example in Figure 8), two X-ray images were used to generate a composite image, and in the second example (the example in Figure 10), four X-ray images were used to generate a composite image. However, it is sufficient to use two or more X-ray images to generate a composite image; for example, three X-ray images may be used. When using three X-ray images (first to third images), the image of the object OJ may move P × α in direction D2 and P × α in direction D3 between the first and second states. Alternatively, the image of the object OJ may move 2 × P × α in direction D2 and 2 × P × α in direction D3 between the first and third states. Here, α is 1 / 3. The processing unit 5 generates a composite image from the first to third images with a pixel size of P / 3. [Method for obtaining height information] 【0077】Referring to Figures 11 to 13, a method for acquiring height information of an object OJ using the X-ray image acquisition device 1 will be explained. Figure 11 is a flowchart illustrating the process performed in the X-ray image acquisition device 1. Figure 12 is a schematic diagram showing an example of X-ray irradiation of an object OJ when the process in Figure 11 is performed. Figure 13 is a schematic diagram showing the X-ray image of the object OJ in Figure 12. 【0078】 In step S81, the electron gun 21 emits an electron beam EB toward the first incident position, irradiating the object OJ with X-rays. Then, the X-ray detection unit 4 acquires the first image. 【0079】 In step S82, the control unit 3 controls the incident position of the electron beam EB to the second incident position. The electron gun 21 then emits the electron beam EB toward the second incident position, irradiating the object OJ with X-rays. The X-ray detection unit 4 then acquires the second image. 【0080】 In step S83, the X-ray detection unit 4 acquires the amount of movement of the object OJ image between the first image and the second image. The X-ray detection unit 4 acquires the amount of movement, for example, by analyzing each X-ray image to obtain the position of the edge of the object OJ image. 【0081】 In step S84, the X-ray detection unit 4 calculates the magnification ratio of the object OJ based on the distance between the first incident position and the second incident position and the amount of movement of the object OJ image acquired in step S83. In step S85, the processing unit 5 acquires the height information of the object OJ based on the magnification ratio. 【0082】 The object OJ shown in Figure 12 has cylindrical members A1 and A2 and a spherical member A3. Members A1 and A2 are located inside member A3. Member A1 is located closer to the X-ray source 2 (X-ray focal point) than member A2. 【0083】Comparing the first and second images shown in Figure 13, the displacement DA1 of the image ZA1 of member A1 is greater than the displacement DA2 of the image ZA2 of member A2. In other words, when the heights of two objects are different, the displacement of the image of the object placed closer to the X-ray source 2 (X-ray focal point) is relatively larger. Utilizing this point, the X-ray detection unit 4 calculates the magnification ratio of member A1 based on the distance between the first and second incident positions and the displacement DA1. The X-ray detection unit 4 also calculates the magnification ratio of member A2 based on the distance between the first and second incident positions and the displacement DA2. The processing unit 5 acquires height information of the object OJ based on the magnification ratio. The processing unit 5 may also color-code members A1 and A2. This allows height information to be acquired based on the first and second images even when the heights of members A1 and A2 are unknown in advance because they are placed inside member A3. 【0084】 Furthermore, the processing unit 5 may acquire a cross-sectional image based on the first and second images. By combining or back-projecting the first and second images, a laminography or CT image can be obtained, enabling more accurate detection of the object. [Function and Effects] 【0085】As described above, in the X-ray image acquisition apparatus 1 and X-ray image acquisition method, the control unit 3 controls the incident position of the electron beam EB between a first incident position and a second incident position based on the magnification ratio of the X-rays from the target object OJ to the X-ray detection unit 4, thereby moving at least a portion of the image of the target object OJ between the first and second states so as to straddle the boundary between adjacent pixels 41. As a result, even if the magnification ratio (the positional relationship between the X-ray source 2, the target object OJ, and the X-ray detection unit 4) changes each time the target object OJ is detected, the incident position is controlled based on the magnification ratio, so that at least a portion of the image of the target object OJ between the first and second states can straddle the boundary between adjacent pixels 41. By using the first and second images acquired in this way, the information between pixels 41 can be complemented to improve the effective resolution. Therefore, the X-ray image acquisition apparatus 1 and X-ray image acquisition method can accurately detect the target object OJ. For example, the X-ray image acquisition apparatus 1 can suitably detect minute objects such as microvias or silicon cracks. 【0086】 In the X-ray image acquisition device 1, the control unit 3 determines the distance D between the first incident position and the second incident position based on the above formula (1). This makes it possible to easily determine the distance D between the first incident position and the second incident position, which is necessary to achieve the amount of image movement P × α of the object OJ, based on the magnification ratio M. 【0087】 In the X-ray image acquisition device 1, the target 22 extends along direction D2 (a direction intersecting the optical axis of the X-ray), and a plurality of pixels 41 are arranged along direction D2. This allows the image of the object OJ to be suitably moved between the first state and the second state relative to the plurality of pixels 41. 【0088】 In the X-ray image acquisition device 1, the X-ray source 2 has deflection units 23A to 23D that deflect the electron beam EB, and the control unit 3 controls the incident position between a first incident position and a second incident position by deflecting the electron beam EB with the deflection units 23A to 23D. This makes it easy to control the incident position of the electron beam EB between the first incident position and the second incident position. 【0089】In the X-ray image acquisition device 1, the control unit 3 may output the X-ray generation position (the incident position of the electron beam EB) at the target 22. In this case, the user of the X-ray image acquisition device 1 can easily understand the position at which X-rays are generated at the target 22. 【0090】 In the X-ray image acquisition device 1, the X-ray source 2 or the control unit 3 outputs first information including the timing of emitting the electron beam EB toward the first incident position, and second information including the timing of emitting the electron beam EB toward the second incident position. The X-ray detection unit 4 controls the detection of X-rays based on the first and second information. This makes it possible, for example, to start the exposure of the pixels 41 of the X-ray detection unit 4 at the timing of emitting the electron beam EB toward the first incident position and the timing of emitting the electron beam EB toward the second incident position. As a result, X-rays can be detected efficiently. 【0091】 In the X-ray image acquisition device 1, the processing unit 5 acquires a composite image of the first image and the second image. This makes it possible to acquire a composite image that is substantially high resolution, and as a result, the target object can be detected with greater accuracy. 【0092】 In the X-ray image acquisition device 1, the processing unit 5 may acquire height information of the object OJ based on the first image and the second image. In this case, the height information of the object OJ can be acquired with high accuracy. 【0093】 In the X-ray image acquisition device 1, the X-ray detection unit 4 acquires a plurality of first images, each being a first image, and a plurality of second images, each being a second image. The X-ray detection unit 4 or the processing unit 5 may integrate at least one of the plurality of first images and the plurality of second images, and the processing unit 5 may process at least one of the integrated plurality of first images and the plurality of second images. In this case, the accuracy of detecting the object OJ in at least one of the plurality of first images and the plurality of second images can be improved. As a result, the object OJ can be detected with greater accuracy. 【0094】In the X-ray image acquisition device 1, the X-ray detection unit 4 or the processing unit 5 may generate multiple pairs, each consisting of a first image and a second image. In this case, the processing unit 5 can easily perform accurate detection of the target object OJ. 【0095】 In the X-ray image acquisition apparatus 1, the X-ray detection unit 4 may have a processing unit 5. In this case, the processing unit 5 can be configured by the X-ray detection unit 4. [Second Embodiment] 【0096】 Figures 14(a) and 14(b) are schematic diagrams showing the configuration of the X-ray source in the X-ray image acquisition apparatus 1 according to the second embodiment. The X-ray source 2A shown in Figures 14(a) and 14(b) mainly differs from the X-ray source 2 according to the first embodiment (see Figures 2(a) to 14(c) and Figures 3(a) to 14(c)) in that it does not have deflection sections 23A to 23D and has a first electron gun 21A and a second electron gun 21B. 【0097】 The first electron gun 21A and the second electron gun 21B each have the same configuration as the electron gun 21 of the first embodiment. The first electron gun 21A and the second electron gun 21B emit an electron beam EB toward the target 22 along direction D1. The first electron gun 21A emits an electron beam EB toward the first incident position Y1, and the second electron gun 21B emits an electron beam EB toward the second incident position Y2. The first electron gun 21A and the second electron gun 21B are spaced apart in direction D2, for example, such that the distance between the first incident position Y1 and the second incident position Y2 is the distance D determined by the above formula (1). 【0098】 In the second embodiment, the control unit 3 controls the incident position of the electron beam EB between a first incident position Y1 and a second incident position Y2 by switching the on / off state of at least one of the first electron gun 21A and the second electron gun 21B. Figure 14(a) shows the state in which the first electron gun 21A is on and the second electron gun 21B is off (first state). Figure 14(b) shows the state in which the first electron gun 21A is off and the second electron gun 21B is on (second state). 【0099】In this second embodiment, as in the first embodiment, the target object OJ can be detected with high accuracy. In the second embodiment, there were two electron guns, but the number of electron guns may be any number of three or more. In that case, the control unit 3 may select a combination of two electron guns from the three or more electron guns such that the distance between the first incident position Y1 and the second incident position Y2 is a desired distance, and switch the on / off state of the two electron guns. 【0100】 In the second embodiment described above, a plurality of electron guns may be arranged in a line in direction D3. In this case, the control unit 3 may move the incident position of the electron beam EB along direction D3 by switching the on / off states of the plurality of electron guns. [Third Embodiment] 【0101】 Figures 15(a) and 15(b) are schematic diagrams showing the configuration of the X-ray source in the X-ray image acquisition apparatus 1 according to the third embodiment. The X-ray source 2B shown in Figures 15(a) and 15(b) mainly differs from the X-ray source 2A according to the second embodiment (see Figures 14(a) and 15(b)) in that it has a first target 22A, a second target 22B, a target support section 24, a first ammeter 25A, and a second ammeter 25B. 【0102】 The first target 22A and the second target 22B each have the same configuration as the target 22 of the first embodiment. The electron beam EB from the first electron gun 21A is incident on the first target 22A, and the electron beam EB from the second electron gun 21B is incident on the second target 22B. The first target 22A and the second target 22B are spaced apart in direction D2. Figure 15(a) shows the state in which the first electron gun 21A is on and the second electron gun 21B is off (first state). Figure 15(b) shows the state in which the first electron gun 21A is off and the second electron gun 21B is on (second state). 【0103】The target support portion 24 supports the first target 22A and the second target 22B. The first target 22A is positioned on the target support portion 24 at a position corresponding to the first incident position Y1, and the second target 22B is positioned on the target support portion 24 at a position corresponding to the second incident position Y2. The combined area of ​​the first target 22A and the second target 22B, when viewed from direction D1, is smaller than, for example, the area of ​​the target support portion 24. This reduces the amount of material required to form each of the first target 22A and the second target 22B. 【0104】 The first ammeter 25A and the second ammeter 25B are connected to the first target 22A and the second target 22B, respectively. The first ammeter 25A measures the current generated by the electron beam EB flowing into the first target 22A. The second ammeter 25B measures the current generated by the electron beam EB flowing into the second target 22B. By using the measurements from the first ammeter 25A and the second ammeter 25B, it is possible to detect which of the first target 22A and the second target 22B the electron beam EB is incident on (i.e., which of the first target 22A and the second target 22B is generating X-rays). 【0105】 The control unit 3 is connected to the first ammeter 25A and the second ammeter 25B, respectively. In the control unit 3, the first target 22A and the second target 22B are associated with the first ammeter 25A and the second ammeter 25B, respectively. Based on this association and the measured values ​​from the first ammeter 25A and the second ammeter 25B, the control unit 3 outputs the incident position of the electron beam EB (the X-ray generation position). 【0106】In this third embodiment, as in the first embodiment, the target object OJ can be detected with high accuracy. Furthermore, in the first embodiment, the control unit 3 directly output the position where X-rays are generated on the target, but in the third embodiment, the control unit 3 outputs the position where X-rays are generated on the target based on the measured values ​​of the first ammeter 25A and the second ammeter 25B. Even with this configuration, the user of the X-ray image acquisition device 1 can easily grasp the position where X-rays are generated on the target. [Fourth Embodiment] 【0107】 Figure 16 is a schematic diagram showing the configuration of the X-ray source in the X-ray image acquisition apparatus 1 according to the fourth embodiment. The X-ray source 2C shown in Figure 16 differs from the X-ray source 2 according to the first embodiment (see Figures 2(a) to (c) and Figures 3(a) to (c)) in that it has a first target 22A and a second target 22B. 【0108】 The first target 22A and the second target 22B each generate X-rays when an electron beam EB is incident on them. The first target 22A and the second target 22B are each formed in a plate shape extending along a plane perpendicular to direction D1. The first target 22A and the second target 22B are, for example, connected to each other. 【0109】 Examples of constituent materials for the first target 22A and the second target 22B include tungsten, molybdenum, cobalt, copper, silver, iron, or rhodium. The second target 22B is formed from a different material than the first target 22A. As a result, the energy distributions of the X-rays generated in the first target 22A and the X-rays generated in the second target 22B are different. 【0110】The control unit 3 deflects the electron beam EB by controlling the potential applied to the first deflection unit 23A and the second deflection unit 23B, respectively. The control unit 3 controls the incident position of the electron beam EB on the first target 22A between the first incident position Y1 and the second incident position Y2. By switching the detection state of the first target 22A between the first state and the second state in this way, the X-ray detection unit 4 acquires the first image and the second image captured by the X-rays generated at the first target 22A. The processing unit 5 processes these first and second images. 【0111】 Similarly, the control unit 3 controls the incidence position of the electron beam EB on the second target 22B between the first incidence position Y1 and the second incidence position Y2. By switching the detection state with respect to the second target 22B between the first state and the second state in this way, the X-ray detection unit 4 acquires the first and second images captured by the X-rays generated at the second target 22B. The processing unit 5 processes these first and second images. 【0112】 In this fourth embodiment, as in the first embodiment, the target object OJ can be detected with high accuracy. Furthermore, in the fourth embodiment, by controlling the incidence position of the electron beam EB to the first target 22A and the second target 22B between the first incidence position Y1 and the second incidence position Y2, no change in X-ray quality occurs between the first state and the second state due to differences in the material of each target. In the fourth embodiment, it is possible to acquire a combination of the first and second images obtained by the emission of the electron beam EB to the first target 22A, and a combination of the first and second images obtained by the emission of the electron beam EB to the second target 22B, thereby enabling so-called dual-energy image acquisition. 【0113】In the fourth embodiment described above, similar to the first embodiment, the third deflection unit 23C and the fourth deflection unit 23D may be arranged so as to straddle the trajectory of the electron beam EB in direction D3. In this case, the control unit 3 may move the incident position of the electron beam EB along direction D3 in each of the first target 22A and the second target 22B. [Fifth Embodiment] 【0114】 Figure 17 is a schematic diagram showing the configuration of the X-ray source in the X-ray image acquisition apparatus 1 according to the fifth embodiment. The X-ray source 2D shown in Figure 17 differs from the X-ray source 2C according to the fourth embodiment (see Figure 16) in that it has a first electron gun 21A and a second electron gun 21B. 【0115】 The first electron gun 21A and the second electron gun 21B each have the same configuration as the electron gun 21 of the first embodiment. The first electron gun 21A emits an electron beam EB toward the first target 22A. The second electron gun 21B emits an electron beam EB toward the second target 22B. 【0116】 The first deflection unit 23A is positioned on one side in direction D2 with respect to the trajectory of the electron beam EB emitted by the first electron gun 21A. The second deflection unit 23B is positioned on the other side in direction D2 with respect to the trajectory of the electron beam EB emitted by the second electron gun 21B. 【0117】 In the fifth embodiment, the control unit 3 controls the potential applied to the first deflection unit 23A and the second deflection unit 23B to deflect the electron beam EB emitted by the first electron gun 21A. The control unit 3 controls the incident position of the electron beam EB emitted by the first electron gun 21A on the first target 22A between a first incident position Y1 and a second incident position Y2. 【0118】 Similarly, the control unit 3 deflects the electron beam EB emitted by the second electron gun 21B by controlling the potential applied to the first deflection unit 23A and the second deflection unit 23B. On the second target 22B, the control unit 3 controls the incident position of the electron beam EB emitted by the second electron gun 21B between the first incident position Y1 and the second incident position Y2. 【0119】In this fifth embodiment, as in the first embodiment, the target object OJ can be detected with high accuracy. Also, in the fifth embodiment, as in the fourth embodiment, so-called dual-energy image acquisition is possible. [Sixth Embodiment] 【0120】 Figures 18(a) and 18(b) are schematic diagrams showing the configuration of the X-ray source in the X-ray image acquisition apparatus 1 according to the sixth embodiment. The X-ray source 2E shown in Figures 18(a) and 18(b) mainly differs from the X-ray source 2A according to the second embodiment (see Figures 14(a) and 14(b)) in that it is a so-called reflective type X-ray source. 【0121】 The X-ray source 2E includes a first electron gun 21A, a second electron gun 21B, a target 22, a housing 26, and a window portion 27. The housing 26 houses the first electron gun 21A, the second electron gun 21B, and the target 22. The window portion 27 hermetically seals an opening formed in the housing 26. The window portion 27 is formed in the shape of a plate from an X-ray transparent material such as beryllium, aluminum, diamond, carbon, silicon, or glass. 【0122】 The target 22 is a reflective target and is formed in the shape of a rod extending along direction D1. The tip 22a of the target 22 is formed in the shape of a square pyramid. The tip 22a may also be formed in the shape of a cone. 【0123】The first electron gun 21A and the second electron gun 21B are arranged so as to sandwich the tip portion 22a in direction D2. Each of the first electron gun 21A and the second electron gun 21B emits an electron beam EB toward the tip portion 22a along direction D2. The first electron gun 21A emits an electron beam EB toward a first incident position Y1 on the tip portion 22a, and the second electron gun 21B emits an electron beam EB toward a second incident position Y2 on the tip portion 22a. The first electron gun 21A and the second electron gun 21B are arranged such that the first incident position Y1 and the second incident position Y2 are at the same height in direction D1. For example, the first electron gun 21A and the second electron gun 21B are arranged at the same height in direction D1. This makes it possible to make the effect of X-ray self-absorption in the first state and the second state the same (the quality of the X-rays is the same). 【0124】 Figure 18(a) shows the state in which the first electron gun 21A is ON and the second electron gun 21B is OFF (first state). Figure 18(b) shows the state in which the first electron gun 21A is OFF and the second electron gun 21B is ON (second state). The X-rays generated at the tip 22a of the target 22 travel along direction D1, pass through the window 27, and irradiate the object OJ. 【0125】 In this sixth embodiment, as in the first embodiment, the target object OJ can be detected with high accuracy. In the sixth embodiment, the two electron guns may be arranged so as to sandwich the tip portion 22a in direction D3. In this case, the control unit 3 may move the incident position of the electron beam EB along direction D3 by switching the on / off states of the two electron guns. [First example of correction method] 【0126】 Next, a first example of a correction method using the X-ray image acquisition apparatus 1 according to each of the above embodiments will be described. Figure 19 is a flowchart illustrating the first example of a correction method. 【0127】 In step S21, the control unit 3 controls the incident position of the electron beam EB to the first incident position while the object OJ is not placed on the imaging table. The control unit 3 outputs the first incident position as the incident position of the electron beam EB to the X-ray detection unit 4. 【0128】 In step S22, the X-ray detection unit 4 detects the X-rays incident on the X-ray detection unit 4 in the first state and acquires gain correction data for each pixel 41 to correct the brightness based on the X-ray detection result. The X-ray detection unit 4 also acquires dark correction data for each pixel 41 to correct the dark based on the dark signal acquired with the X-ray source 2 turned off. The X-ray detection unit 4 stores the correction data, including the gain correction data and the dark correction data, associated with the first incident position. 【0129】 In step S23, the control unit 3 controls the incident position of the electron beam EB to the second incident position while the object OJ is not placed on the imaging table. The control unit 3 outputs the second incident position as the incident position of the electron beam EB to the X-ray detection unit 4. 【0130】 In step S24, the X-ray detection unit 4 detects the X-rays incident on the X-ray detection unit 4 in the second state and acquires gain correction data for each pixel 41 to correct the brightness based on the X-ray detection result. The X-ray detection unit 4 also acquires dark correction data for each pixel 41 to correct the dark based on the dark signal acquired with the X-ray source 2 turned off. The X-ray detection unit 4 stores the correction data, including the gain correction data and the dark correction data, associated with the second incident position. 【0131】 The correction data obtained as described above is used, for example, as follows. In step S14 shown in Figure 7, the X-ray detection unit 4 corrects the detection results from the multiple pixels 41 with correction data corresponding to the first incident position (the X-ray generation position in the first state) output by the control unit 3. The X-ray detection unit 4 acquires a corrected first image based on the corrected detection results. 【0132】 In step S16, the X-ray detection unit 4 corrects the detection results from the multiple pixels 41 with correction data corresponding to the second incident position (the X-ray generation position in the second state) output by the control unit 3. The X-ray detection unit 4 then acquires a corrected second image based on the corrected detection results. 【0133】In step S17, the processing unit 5 processes the corrected first and second images. According to this X-ray image acquisition method, the first and second images can be suitably acquired by correcting the detection results from multiple pixels 41 based on the incident position of the electron beam EB (the position where X-rays are generated). As a result, the target object OJ can be detected with greater accuracy. [Second example of correction method] 【0134】 Next, a second example of a correction method using the X-ray image acquisition apparatus 1 according to each of the above embodiments will be described. Figures 20(a) to (c) and 21 are diagrams illustrating the second example of the correction method. In the following description, a correction method will be described in the case where the ratio α of the amount of movement of the image of the object OJ between the first state and the second state should be set to 0.5, but the ratio α actually obtained is 0.4. 【0135】 The X-ray detection unit 4 determines the ratio α based on the first and second incident positions output by the control unit 3. The X-ray detection unit 4 determines the ratio α using, for example, the above formula (1). If the ratio α is the desired value of 0.5, the signal shown in Figure 20(a) is acquired, and if the ratio α is 0.4, the signal shown in Figure 20(b) is acquired. 【0136】 In Figure 20(a), the signal detected by each pixel 41 in the first state is schematically shown as signal G1, and the signal detected by each pixel 41 in the second state (α = 0.5) is schematically shown as signal G2. Figure 20(a) shows the signal that should be acquired. 【0137】 In Figure 20(b), the signals detected at each pixel 41 in the second state (α = 0.4) are schematically shown as signal G21. In Figure 20(b), the signal G2 that should actually be acquired is virtually shown by a dotted line. 【0138】In (c) of FIG. 20, assuming that the signal G21 detected in the second state (α = 0.4) is the signal G2 detected in the second state (α = 0.5), the first image and the second image are synthesized. In this case, since the signal amount of the actually detected signal G21 is smaller than the signal amount of the signal G2 that should be originally detected, for example, it may affect the accuracy of the synthesized image. Therefore, the X-ray detection unit 4 corrects the signal amount of the signal G21. 【0139】 As shown in FIG. 21, let the signal amount of the signal G21 in each pixel 41 be P ｉ , ｉ－１ (i is an integer from 1 to N), and the signal amount of the corrected signal G22 be Q ｉ When this is the case, the X-ray detection unit 4 calculates the signal amount Q ｉ by, for example, the following formulas (4) and (5). Here, N is the number of the plurality of pixels 41, and P ｉ－１ , P ｉ , P ｉ＋１ are the signal amounts in each of three consecutively arranged pixels 41. Q ｉ－１ = 0.1P ｉ－１ + 0.9P ｉ …(4) Q ｉ = 0.1P ｉ + 0.9P ｉ＋１ …(5) 【0140】 That is, the X-ray detection unit 4 obtains the corrected signal amount Q ｉ , P ｉ－１ (P ｉ , P ｉ＋１ ) as the internal division point of two adjacent pixels 41. Thereby, a signal amount close to the signal amount of the signal G2 that should be originally acquired can be obtained. The signal amount correction method does not have to be the above-described linear interpolation, and may be, for example, spline interpolation, interpolation using a higher-order function, or interpolation using artificial intelligence (AI). 【0141】 ​​​​The X-ray detection unit 4 may determine whether the ratio α (e.g., 0.4) obtained based on the first and second incident positions is a desired value (e.g., 0.5) and output the determination result to the control unit 3. Based on the determination result, the control unit 3 may adjust the incident position of the electron beam EB (X-ray focal position) so that the ratio α becomes a desired value. The X-ray detection unit 4 may detect X-rays in the adjusted first or second state and acquire the adjusted first or second image. [Acquisition of X-ray focal position from X-ray image] 【0142】 In the X-ray image acquisition apparatus 1 according to each of the above embodiments, the control unit 3 outputs the incident position of the electron beam EB (the focal position of the X-ray). However, in the X-ray image acquisition apparatus 1 according to each of the above embodiments, the focal position of the X-ray may be obtained from the X-ray image. Figures 22 and 23 are diagrams illustrating a method for obtaining the focal position of the X-ray from an X-ray image. 【0143】 Figure 22 shows the imaging platform 8 of the X-ray image acquisition device 1. A reference section 81 is embedded in the imaging platform 8. The reference section 81 is formed of, for example, a material with high X-ray shielding performance (e.g., metal) or a material with low X-ray shielding performance. This increases the contrast between the reference section 81 and the parts of the X-ray image other than the reference section 81. Taking advantage of this, the X-ray detection unit 4 may acquire the amount of movement of the reference section 81 image between the first image and the second image. Based on this amount of movement, the X-ray detection unit 4 may acquire the X-ray focal position (incident position of the electron beam EB) in the first state and the second state, respectively. The control unit 3 may adjust the incident position of the electron beam EB (X-ray focal position) based on the acquired results. 【0144】 As shown in Figure 23, the reference portion 81 may be embedded in the object OJ. Alternatively, a characteristic part (for example, a microbump) that originally exists in the object OJ may be set as the reference portion 81. 【0145】In the X-ray image acquisition device 1 according to each of the above embodiments, the X-ray focal position may be acquired using the chart C. Figure 24 shows the state in which the chart C is arranged in the X-ray image acquisition device 1. Figure 25 is a flowchart illustrating a method for acquiring the X-ray focal position using the chart C. 【0146】 Chart C, shown in Figure 24, is a metal plate with multiple rectangular grooves of known widths. In the X-ray image acquisition device 1 shown in Figure 25, Chart C is imaged instead of the object OJ. 【0147】 In step S31 shown in Figure 25, the control unit 3 controls the incident position of the electron beam EB to the first incident position. The X-ray detection unit 4 detects the X-rays incident on it in the first state and acquires an X-ray image of chart C based on the X-ray detection result. In Figure 24, the image of chart C in the first state is shown as image Z3. 【0148】 In step S32, the X-ray detection unit 4 obtains the chart width of chart C in the X-ray image acquired in step S31. The X-ray detection unit 4 obtains the chart width by, for example, analyzing the X-ray image. 【0149】 In step S33, the X-ray detection unit 4 acquires the magnification ratio in the X-ray image acquisition device 1 based on the chart width acquired in step S32 and the actual chart width of chart C. 【0150】 In step S34, the control unit 3 controls the incident position of the electron beam EB to the second incident position. The X-ray detection unit 4 detects the X-rays incident on it in the second state and acquires an X-ray image of chart C based on the X-ray detection result. In Figure 24, the image of chart C in the second state is shown as image Z4. 【0151】 In step S35, the X-ray detection unit 4 obtains the amount of movement of the chart C image between the X-ray image acquired in step S31 and the X-ray image acquired in step S34. The X-ray detection unit 4 obtains the amount of movement, for example, by analyzing each X-ray image to obtain the position of the edge of the chart C image. 【0152】In step S36, the X-ray detection unit 4 acquires the first and second incident positions, i.e., the X-ray focal positions in the first and second states, based on the magnification acquired in step S33 and the amount of movement of the chart C image acquired in step S35. As a result, the X-ray detection unit 4 acquires calibration data for the first and second incident positions. The control unit 3 may adjust the incident position of the electron beam EB (X-ray focal position) based on the calibration data. 【0153】 In the X-ray image acquisition apparatus 1 according to each of the above embodiments, the focal position of the X-rays may be acquired using a mesh ME. Figure 26 is a diagram showing the X-ray image acquisition apparatus 1 with a mesh ME arranged therein. Figure 27 is a flowchart illustrating a method for acquiring the focal position of the X-rays using a mesh ME. In the X-ray image acquisition apparatus 1 shown in Figure 26, the mesh ME is imaged instead of the object OJ. 【0154】 In step S41 shown in Figure 27, the control unit 3 controls the incident position of the electron beam EB to the first incident position. The X-ray detection unit 4 detects the X-rays incident on the X-ray detection unit 4 in the first state and acquires an X-ray image of the mesh ME based on the X-ray detection result. 【0155】 In step S42, the X-ray detection unit 4 acquires the amount of image displacement of the mesh ME in the X-ray image acquired in step S41. Figure 28 is a diagram illustrating the amount of image displacement of the mesh ME in the X-ray image. As shown in Figure 28, when magnified imaging is performed, the peripheral part of the mesh ME may be distorted in the X-ray image. In Figure 28, the mesh ME0 in the case where distortion occurs is virtually shown as a dotted line relative to the mesh ME in the case where distortion occurs. The X-ray detection unit 4 analyzes the X-ray image to acquire the amount of image displacement of the mesh ME relative to each point of mesh ME0 in the X-ray image (for example, the amount of displacement shown as an arrow in Figure 28). 【0156】In step S43, the X-ray detection unit 4 acquires the coordinates of the first incident position, that is, the coordinates of the X-ray focal position in the first state, based on the amount of displacement of the mesh ME image acquired in step S42 and the positional relationship of each component in the X-ray image acquisition device 1 (FOD or FDD, etc.). 【0157】 In step S44, the control unit 3 controls the incident position of the electron beam EB to the second incident position. The X-ray detection unit 4 detects the X-rays incident on it in the second state and acquires an X-ray image of the mesh ME based on the X-ray detection result. 【0158】 In step S45, the X-ray detection unit 4 acquires the amount of image displacement of the mesh ME in the X-ray image acquired in step S44, similar to step S42. 【0159】 In step S46, the X-ray detection unit 4 acquires the coordinates of the second incident position, that is, the coordinates of the X-ray focal position in the second state, based on the amount of displacement of the mesh ME image acquired in step S45 and the positional relationship of each component in the X-ray image acquisition device 1 (FOD or FDD, etc.). 【0160】 In step S47, the X-ray detection unit 4 acquires the amount of movement of the incident position (the amount of movement of the X-ray focal position) between the first state and the second state, based on the first incident position acquired in step S43 and the second incident position acquired in step S46. As a result, the X-ray detection unit 4 acquires calibration data for the first incident position and the second incident position. The control unit 3 may adjust the incident position of the electron beam EB (the X-ray focal position) based on the calibration data. 【0161】 The X-ray detection unit 4 may also perform distortion correction on the first image acquired in the first state and the second image acquired in the second state using the amount of image displacement (distortion mapping data) of the mesh ME acquired in steps S42 and S45. 【0162】Furthermore, in the X-ray image acquisition device 1, calibration data for the first and second incident positions may be acquired using multiple pillar phantoms for calibration instead of a mesh ME. Each of the multiple pillar phantoms is, for example, a cylindrical member. [Modification] 【0163】 This disclosure is not limited to the embodiments described above. For example, the materials and shapes of each component are not limited to those described above, but can be made from a variety of materials and shapes. 【0164】 Figures 29 and 30 are schematic diagrams showing the configuration of an X-ray image acquisition device 1 according to a modified example. As shown in Figure 29, the X-ray detection unit 4 may be a multi-line sensor 4A having multiple pixel lines in which multiple pixels 41 are arranged in one dimension. In this case, the multi-line sensor 4A changes the line used for imaging for each of the first and second states. For example, the multi-line sensor 4A images using odd-numbered lines when the incident position (X-ray focal position) of the electron beam EB output from the control unit 3 is the first incident position, and images using even-numbered lines when the incident position (X-ray focal position) of the electron beam EB is the second incident position. In this way, the operation of the multi-line sensor 4A and the operation of the X-ray source 2 may be synchronized. 【0165】 As shown in Figure 30, the X-ray detection unit 4 may be a TDI (Time Delay Integration) camera 4B. When imaging with a TDI camera 4B, it is necessary to match (synchronize) the charge transfer rate within the TDI camera 4B with the movement rate of the X-ray focal point (the movement rate of the incident position of the electron beam EB). If the charge transfer rate and the movement rate of the X-ray focal point are not matched and fine adjustment of the movement rate of the X-ray focal point is necessary, the control unit 3 may adjust the movement rate by moving the incident position of the electron beam EB (the X-ray focal position) along direction D1. When the X-ray source is a reflective type X-ray source 2E shown in Figure 18, the control unit 3 can suitably move the incident position of the electron beam EB (the X-ray focal position) along direction D1. 【0166】Figure 31 shows an object OJ having a priority inspection area B1 and a simple inspection area B2 positioned in the X-ray image acquisition device 1. In the X-ray image acquisition device 1, the focus of the X-ray beam is switched to acquire the first and second images for the priority inspection area B1 of the object OJ, while a single X-ray image may be acquired for the simple inspection area B2 of the object OJ without switching the focus of the X-ray beam. In this case, for example, the control unit 3 may accept position information of the priority inspection area B1 and the simple inspection area B2 as input. Based on this position information, the control unit 3 may decide whether to switch the incident position of the electron beam EB (X-ray focal position). This allows for efficient inspection of the object OJ. 【0167】 In Figure 4, the X-ray detection unit 4 controlled the image so that the pixels 41 would not be exposed while the incident position of the electron beam EB (the focal position of the X-rays) was moving, based on the first and second information. However, as shown in Figure 32, the X-ray detection unit 4 may discard the detection results corresponding to the period while the incident position is moving, based on the first and second information. Figure 32 is a diagram showing the control of X-ray detection in the X-ray detection unit. In this case, the X-ray detection unit 4 acquires the first and second images based on the detection results that remain undiscarded. When the X-ray detection unit 4 controls X-ray detection by discarding detection results in this way, the X-ray source 2 may remain on, and the pixels 41 may remain exposed. 【0168】 In the X-ray image acquisition device 1, the charge generated in each pixel 41 in the first state and the charge generated in each pixel 41 in the second state may be read out at the same time. Figure 33 is a diagram illustrating the circuit diagram of a pixel 41. The pixel 41 includes a photodiode PD, a transistor T1, a first switch SW1, a second switch SW2, a first charge holding part H1, a second charge holding part H2, a first readout switch SW11, and a second readout switch SW12. The first charge holding part H1 has a holding capacitor element C1. The second charge holding part H2 has a holding capacitor element C2. One end of each of the holding capacitor elements C1 and C2 is grounded. 【0169】In the first state, the first switch SW1 is closed and the second switch SW2 is open. Also, both the first readout switch SW11 and the second readout switch SW12 are open. In this state, the charge generated by the photodiode PD is stored in the retaining capacitance element C1 via the first switch SW1. 【0170】 In the second state, the first switch SW1 is open and the second switch SW2 is closed. Also, both the first readout switch SW11 and the second readout switch SW12 are open. In this state, the charge generated by the photodiode PD is stored in the retaining capacitance element C2 via the second switch SW2. 【0171】 With charge accumulated in the respective retaining capacitance elements C1 and C2, closing both the first readout switch SW11 and the second readout switch SW12 may output the charge accumulated in each of the retaining capacitance elements C1 and C2 to the integrating circuit IC at once (the charge may be read out at once). The integrating circuit IC includes, for example, an amplifier AM, a capacitance element C3, and a transistor T2. 【0172】 In the X-ray image acquisition device 1, the control unit 3 may move the incident position of the electron beam EB (the focal position of the X-ray) in a spiral manner. 【0173】 The X-ray detection unit 4 may add information regarding the incident position of the electron beam EB (the focal position of the X-ray) to the headers of the first and second images, respectively. This facilitates processing of the first and second images. 【0174】In the X-ray image acquisition device 1, the object OJ may be inspected based on the first and second images. This inspection may be performed using artificial intelligence (AI). If the result of this inspection is unsatisfactory, the object OJ may be inspected again based on other first and second images. In this case, these other first and second images may be transferred between the X-ray detection unit 4 and the processing unit 5. In the X-ray image acquisition device 1, an inspection may be performed based on a single X-ray image acquired without switching the X-ray focal position, and if the result of this inspection is unsatisfactory, the first and second images may be acquired after switching the X-ray focal position in order to perform a more detailed inspection. 【0175】 In the X-ray image acquisition device 1, the positions of the X-ray source 2 and the X-ray detection unit 4 were fixed, but the X-ray source 2 and the X-ray detection unit 4 may be movable by a moving mechanism (not shown). In this case, the focal position of the X-rays may be roughly moved by the moving mechanism, and the focal position of the X-rays may be finely adjusted by the control unit 3. 【0176】 The X-ray detection unit 4 may output status information indicating that the next X-ray image can be acquired when it has finished acquiring one X-ray image. The X-ray source 2 or control unit 3 may control the timing of X-ray generation based on this status information. 【0177】 The X-ray detection unit 4 may binn (combine) multiple X-ray images. For example, the X-ray detection unit 4 may binn the (n-1)th X-ray image with the nth X-ray image, and then binn the nth X-ray image with the (n+1)th X-ray image. The X-ray detection unit 4 may further binn the two binned X-ray images. Here, n is any integer greater than or equal to 2. 【0178】The X-ray image acquisition device 1 may be a radiation image acquisition device capable of acquiring radiation images of an object using radiation other than X-rays (for example, electron beams, beta rays, or gamma rays). In this case, the X-ray source 2 may be a radiation source that generates radiation other than X-rays (for example, electron beams, beta rays, or gamma rays). These radiation sources do not need to have a radiation generating member; for example, in the case of an electron beam, the electron beam generated from the electron gun is directly irradiated onto the object. The X-ray detection unit 4 may be a radiation detection unit that detects radiation other than X-rays and acquires a radiation image of the object based on the detection result. 【0179】 In the X-ray image acquisition device 1, the control unit 3 controls the X-ray generation position (X-ray focal position) by controlling the incident position of the electron beam EB. However, as described above, if the radiation generating member is omitted from the radiation source, the control unit 3 may directly control the focal position of the radiation emitted from the radiation source between the first focal position and the second focal position. The processing unit 5 may process the first image acquired as a radiation image in the first state where the focal position is the first focal position, and the second image acquired as a radiation image in the second state where the focal position is the second focal position. The control unit 3 may move at least a part of the image of the object between the first state and the second state so as to straddle the boundary between adjacent pixels 41 by controlling the focal position between the first focal position and the second focal position based on the magnification ratio M. 【0180】 1...X-ray image acquisition device (radiation image acquisition device), 2, 2A to 2E...X-ray source (radiation source), 3...Control unit, 4...X-ray detection unit (radiation detection unit), 5...Processing unit, 21...Electron gun (beam emission unit), 21A...First electron gun, 21B...Second electron gun, 22...Target (radiation generating member), 23A...First deflection unit, 23B...Second deflection unit, 23C...Third deflection unit, 23D...Fourth deflection unit, 41...Pixel, D2...Direction (predetermined direction), EB...Electron beam, OJ...Object, Y1...First incident position, Y2...Second incident position.

Claims

1. A radiation source for irradiating an object with radiation, comprising: a beam emission unit for emitting a beam; and a radiation generating member for generating radiation when the beam is incident on it; a control unit for controlling the incident position of the beam in the radiation generating member between a first incident position and a second incident position; a radiation detection unit having a plurality of pixels for detecting the radiation that has passed through the object, and acquiring a radiation image of the object based on the radiation detection results by the plurality of pixels; and a processing unit for processing a first image acquired as the radiation image in a first state where the incident position is the first incident position, and a second image acquired as the radiation image in a second state where the incident position is the second incident position, wherein the control unit controls the incident position between the first incident position and the second incident position based on the magnification ratio of the radiation from the object to the radiation detection unit, thereby moving at least a portion of the image of the object between the first state and the second state so as to straddle the boundary between adjacent pixels.

2. The radiation image acquisition apparatus according to claim 1, wherein the control unit determines the distance D between the first incident position and the second incident position based on the following formula (1): P × α = (M - 1) × D ... (1) In the above formula (1), P is the size of each of the plurality of pixels, α is the ratio of the amount of movement of the image of the object to the plurality of pixels between the first state and the second state to the size, and M is the magnification factor.

3. The radiation image acquisition apparatus according to claim 1, wherein the radiation generating member extends along a predetermined direction intersecting the central axis of the radiation, and the plurality of pixels are arranged along the predetermined direction.

4. The radiation image acquisition apparatus according to claim 1, wherein the radiation source is an X-ray source that irradiates X-rays as radiation, the beam emission unit is an electron gun that emits an electron beam as the beam, and the radiation generating member is a target that generates X-rays when the electron beam is incident on it.

5. The radiation image acquisition apparatus according to claim 4, wherein the X-ray source further comprises a deflection unit for deflecting the electron beam, and the control unit controls the incident position between the first incident position and the second incident position by deflecting the electron beam with the deflection unit.

6. The radiation image acquisition apparatus according to claim 4, wherein the beam emission unit comprises a first electron gun that emits the electron beam toward the first incident position and a second electron gun that emits the electron beam toward the second incident position, and the control unit controls the incident position between the first incident position and the second incident position by switching the on / off state of at least one of the first electron gun and the second electron gun.

7. The radiation image acquisition apparatus according to claim 1, wherein the control unit outputs the position where the radiation is generated in the radiation generating member.

8. The radiation image acquisition apparatus according to claim 7, wherein the radiation detection unit corrects the detection result by the plurality of pixels based on the position where the radiation output by the control unit is generated, acquires the corrected first image and second image based on the corrected detection result, and the processing unit processes the corrected first image and second image.

9. The radiation image acquisition apparatus according to claim 1, wherein the radiation source or the control unit outputs first information including the timing for emitting the beam toward the first incident position and second information including the timing for emitting the beam toward the second incident position, and the radiation detection unit controls the detection of the radiation based on the first information and the second information.

10. The radiation image acquisition apparatus according to claim 1, wherein the processing unit acquires a composite image of the first image and the second image.

11. The radiation image acquisition apparatus according to claim 1, wherein the processing unit acquires height information of the object based on the first image and the second image.

12. The radiation image acquisition apparatus according to claim 1, wherein the radiation detection unit acquires a plurality of first images, each of which is the first image, and a plurality of second images, each of which is the second image; the radiation detection unit or the processing unit integrates at least one of the plurality of first images and the plurality of second images; and the processing unit processes at least one of the integrated plurality of first images and the plurality of second images.

13. The radiation image acquisition apparatus according to claim 1, wherein the radiation detection unit acquires a plurality of first images, each of which is the first image, and a plurality of second images, each of which is the second image, and the radiation detection unit or the processing unit generates a plurality of pairs, each composed of the first image and the second image.

14. The radiation image acquisition apparatus according to claim 1, wherein the radiation detection unit has the processing unit.

15. The device comprises: a first step of emitting a beam toward a first incidence position in a radiation generating member that generates radiation when a beam is incident on it, and irradiating an object with the radiation; a second step of using a radiation detection unit having a plurality of pixels for detecting the radiation to detect the radiation that has passed through the object in a first state where the incident position of the beam is the first incidence position, and acquiring a first image which is a radiation image of the object based on the radiation detection result; a third step of emitting a beam toward a second incidence position in the radiation generating member, and irradiating the object with the radiation; a fourth step of using the radiation detection unit to detect the radiation that has passed through the object in a second state where the incident position of the beam is the second incidence position, and acquiring a second image which is a radiation image of the object based on the radiation detection result; and a fifth step of processing the first image and the second image. A radiation image acquisition method comprising, in at least one of the first and third steps, controlling the incident position between a first incident position and a second incident position based on the magnification ratio of the radiation from the object to the radiation detection unit, thereby moving at least a portion of the image of the object between the first state and the second state so as to straddle the boundary between adjacent pixels.

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