WO2023188337A1

WO2023188337A1 - X-ray generation device, x-ray imaging device, and method for adjusting x-ray generation device

Info

Publication number: WO2023188337A1
Application number: PCT/JP2022/016710
Authority: WO
Inventors: 洋一安藤
Original assignee: キヤノンアネルバ株式会社
Priority date: 2022-03-31
Filing date: 2022-03-31
Publication date: 2023-10-05
Also published as: WO2023189735A1

Abstract

This X-ray generation device comprises: an X-ray generation tube including an electron gun and a target that generates X rays upon receiving an electron beam emitted from the electron gun; a support structure that supports the X-ray generation tube; and a deflector that deflects the electron beam. The support structure supports the X-ray generation tube so as to allow at least the target to rotate in a state where the deflector is fixed.

Description

X-ray generator, X-ray imaging device, and method for adjusting the X-ray generator

The present invention relates to an X-ray generation device, an X-ray imaging device, and a method for adjusting the X-ray generation device.

A transmission-type microfocus X-ray tube generates X-rays by irradiating a target with an electron beam. However, such an X-ray tube has a problem in that the target tends to deteriorate because heat is generated by irradiating the target with an electron beam.

Patent Document 1 discloses that a magnet section is arranged around the X-ray generating tube, and the irradiation position of the electron beam on the target is changed by rotating the magnet section, thereby extending the life of the X-ray generating tube. is listed. However, when the irradiation position of the electron beam on the target is changed by moving the magnet section as described in Patent Document 1, the irradiation position of the X-rays from the X-ray generator, that is, the focal position changes accordingly. Therefore, each time the magnet section is moved, that is, each time the focal position is changed, it is necessary to align the X-ray detector for detecting the X-rays emitted from the X-ray generator.

Patent No. 4309176

The present invention provides an advantageous technique for extending the life of the target or x-ray generating tube without changing the focal position.

One aspect of the present invention relates to an X-ray generator, and the X-ray generator includes an electron gun and a target that receives an electron beam emitted from the electron gun and generates X-rays. A tube, a support structure that supports the X-ray generating tube, and a deflector that deflects the electron beam, and the support structure is configured such that at least the target is rotated while the deflector is fixed. The X-ray generating tube is supported so as to allow the

A second aspect of the present invention provides an electron gun, an X-ray generation tube including a target that receives electron beams emitted from the electron gun and generates X-rays, and a support structure that supports the X-ray generation tube. and a deflector that deflects the electron beam, the adjusting method includes a rotation step of rotating at least the target while the deflector is fixed. .

FIG. 1 is a diagram schematically showing the configuration of an X-ray generator according to a first embodiment. FIG. 3 is a diagram schematically showing how an electron beam emitted from an electron gun collides with a target in the X-ray generator of the first embodiment. The figure which shows typically the adjustment method or the usage method of the X-ray generator of a comparative example. FIG. 1 is a diagram schematically showing a method of adjusting or using the X-ray generator according to the first embodiment. FIG. 3 is a diagram schematically showing the configuration of an X-ray generator according to a second embodiment. FIG. 7 is a diagram schematically showing the configuration of an X-ray generator according to a third embodiment. The figure which shows typically the structure of the X-ray generator of 4th Embodiment. FIG. 7 is a diagram schematically showing the configuration of an X-ray generator according to a fifth embodiment. FIG. 7 is a diagram schematically showing the configuration of an X-ray generator according to a sixth embodiment. FIG. 1 is a diagram schematically showing the configuration of an X-ray generator according to an embodiment. FIG. 1 is a diagram schematically showing the configuration of an X-ray imaging device according to an embodiment.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the claimed invention. Although a plurality of features are described in the embodiments, not all of these features are essential to the invention, and the plurality of features may be arbitrarily combined. Furthermore, in the accompanying drawings, the same or similar components are designated by the same reference numerals, and redundant description will be omitted.

FIG. 1 schematically shows the configuration of an X-ray generator 1 according to the first embodiment. The X-ray generator 1 can be configured as a transmission type X-ray generator. The X-ray generator 1 includes an X-ray generator tube XG. The X-ray generation tube XG may include an electron gun EG and a target 22 that receives an electron beam or electrons emitted from the electron gun EG and generates X-rays. In one example, the X-ray generating tube XG includes an insulated tube 10 having two open ends, an anode 20 that closes one of the two open ends of the insulated tube 10, and an anode 20 that closes the other of the two open ends of the insulated tube 10. A closing member 30 may be provided. The anode 20 may include a target 22, a target holding plate 21 that holds the target 22, and an electrode 23 that supports the target holding plate 21 and applies a potential to the target 22 via the target holding plate 21. The closing member 30 may be configured to hold the electron gun EG. The insulating tube 10, the anode 20, and the closing member 30 may constitute a container that defines a closed space. The sealed space is maintained at a vacuum or a high degree of vacuum.

The X-ray generator 1 may further include a tube support structure 60 that supports the X-ray generator tube XG, and a deflector 50 that deflects the electron beam emitted from the electron gun EG. The X-ray generator 1 may also include a deflector support structure 70 that supports the deflector 50. The tube support structure 60 can support the X-ray generating tube XG0 to allow at least the target 22 to be rotated while the deflector 50 is fixed. In another aspect, the tube support structure 60 may support the X-ray generating tube XG to allow the X-ray generating tube XG to be rotated with the deflector 50 fixed. In yet another aspect, the tube support structure 60 supports the X-ray generation tube XG0 to allow the X-ray generation tube XG to be rotated with the deflector 50 supported by the deflector support structure 70. sell. The tube support structure 60 and the deflector support structure 70 are structures that support the X-ray generating tube XG and the deflector 50 independently of each other. The X-ray generating tube XG may be rotated manually by an operator or the like, or may be rotated by a drive mechanism (not shown), for example.

The deflector 50 may be placed outside the X-ray generating tube XG. In the deflector 50, for example, a virtual plane VP3 that crosses the deflector 50 includes a virtual plane VP1 including the electron beam incident surface of the target 22 (the surface facing the electron gun EG) and the tip surface of the electron gun EG (the surface on the target 22 side). ) and a virtual plane VP2 including the virtual plane VP2. The virtual planes VP1, VP2, and VP3 may be defined as planes perpendicularly intersecting the central axis AX of the electron gun EG. The deflector 50 deflects the electron beam emitted from the electron gun EG by applying a magnetic field to the electron beam. By deflecting the electron beam with the deflector 50, the incident position of the electron beam on the target 22 can be adjusted or shifted.

The deflector 50 may be composed of a permanent magnet, an electromagnet, or a permanent magnet and an electromagnet. In one example, deflector 50 may include a first magnet and a second magnet. The first magnetic pole (for example, S pole) of the first magnet and the second magnetic pole (for example, N pole) of the second magnet may be arranged to face each other via the insulating tube 10 or the X-ray generating tube XG. . The deflector 50 may be composed of one magnet arranged so that its magnetic pole faces in the radial direction of the insulating tube 10 or the X-ray generating tube XG. Deflector 50 may be removably supported by deflector support structure 70. The deflector support structure 70 may include a drive mechanism that moves and/or rotates the deflector 50, or an adjustment mechanism that adjusts the position or attitude of the deflector 50. By providing such a drive mechanism or adjustment mechanism, it is possible to adjust the magnetic field that acts on the electron beam emitted from the X-ray generating tube XG.

The electrode 23 is electrically connected to the target 22 and applies a potential to the target 22. The target 22 generates X-rays when electrons from the electron gun EG collide with the target 22. The X-rays generated by the target 22 are transmitted through the target holding plate 21 and radiated to the outside of the X-ray generating tube XG. Anode 20 may be maintained at, for example, ground potential, but may also be maintained at other potentials. Target 22 is made of metal material. The target 22 is desirably made of a material with a high melting point, such as tungsten, tantalum, or molybdenum, and these materials are advantageous for improving the efficiency of generating X-rays. The target holding plate 21 may be made of, for example, a material that easily transmits X-rays, such as beryllium, diamond, or the like.

FIG. 2 schematically shows how the electron beam EB emitted from the electron gun EG collides with the target 22. In FIG. 2, the electron gun EG and the target 22 are shown close to each other, but the electron gun EG and the target 22 may be arranged further apart. The electron beam EB emitted from the electron gun EG is deflected by the magnetic field generated by the deflector 50, and then impinges on or collides with the target 22. The amount by which the electron beam EB is deflected, in other words, the incident position of the electron beam EB with respect to the target 22 may depend on the magnetic field generated by the deflector 50 and the accelerating voltage of the electron gun EG.

FIG. 3 schematically shows two states ST11 and ST12 of the X-ray generator in the comparative example. In both of the two states ST11 and ST12, the target 22 is shown as viewed from the electron gun EG side. In state ST11, the electron beam emitted from the electron gun EG is deflected by the magnetic field generated by the deflector 50, and the electron beam is incident on the target 22 at a position P1. State ST12 is a state in which the deflector 50 is rotated relative to the arrangement of the deflector 50 in state ST11. Therefore, the position P2 at which the electron beam is incident on the target 22 in state ST12 is a position obtained by rotating the position P1 at which the electron beam is incident on the target 22 in state ST11 around the central axis AX. That is, in the comparative example, the position at which the electron beam is incident on the target 22 is changed from position P1 to position P2 by rotating the deflector 50. In the comparative example, this makes it possible to extend the life of the target 22 or the X-ray generator 1. However, changing the position at which the electron beam is incident on the target 22 from position P1 to position P2 means that the position at which the X-ray is emitted from the target 22, that is, the focal position of the X-ray in the X-ray inspection apparatus, means to be changed. Therefore, in the comparative example, it is necessary to adjust the position of the X-ray detector in accordance with the change in the position where the electron beam is incident on the target 22 due to the rotation of the deflector 50.

FIG. 4 schematically shows two states ST21 and ST22 of the X-ray generator 1 in the first embodiment. In both of the two states ST21 and ST22, the target 22 is shown as viewed from the electron gun EG side. In state ST21, the electron beam emitted from the electron gun EG is deflected by the magnetic field generated by the deflector 50, and the electron beam is incident on the target 22 at the position P1. In state ST22, the X-ray generating tube XG (target 22) is rotated with respect to the orientation of the X-ray generating tube XG (target 22) in state ST21, and the electron beam is incident on position P2 of the target 22. In this example, the rotation angle of the target 22 is 90 degrees, but this rotation angle can be set arbitrarily. Here, reference numeral 25 is a virtual orientation mark given to the target 22. In the first embodiment, the X-ray generating tube XG (target 22) is rotated with the deflector 50 fixed. Therefore, in state ST21 and state ST22, the electron beam is incident on mutually different positions P1 and P2 of the target 22, but the positions P1 and P2 as seen from the X-ray detector, that is, the space where the X-ray generator 1 is arranged. Positions P1 and P2 in are the same positions. Thereby, the life of the target 22 or the X-ray generator 1 can be extended without changing the positions P1 and P2 in the space where the X-ray generator 1 is placed, that is, the focal position.

As is clear from the above description, the method for adjusting the X-ray generator 1 of one embodiment includes a rotation step of rotating the X-ray generation tube XG while the deflector 50 is fixed. The rotation process can be performed depending on the amount of use of the X-ray generator 1. The usage amount can be, for example, at least one of the usage time of the X-ray generator 1, the amount of electric power applied to the electrode 23, or the cumulative value of X-rays generated by the X-ray generator 1. Alternatively, the rotation process may be performed in response to changes in the X-rays generated by the X-ray generator 1. For example, the rotation step is executed in response to the fact that the X-rays generated by the X-ray generator 1 fall below a predetermined percentage of the intensity of the X-rays generated by the X-ray generator 1 immediately after execution of the last rotation step. can do.

The tube support structure 60 can support the X-ray generating tube XG so as to allow the X-ray generating tube XG to be rotated around a rotation axis that coincides with the central axis AX of the electron gun EG. The center axis AX of the electron gun EG may be arranged to pass through the center of the target 22. When the electron beam EB is not deflected by the deflector 50, the electron beam EB may be incident on the center of the target 22.

FIG. 5 schematically shows the configuration of the X-ray generator 1 of the second embodiment. Items not mentioned in the X-ray generator 1 of the second embodiment may follow the first embodiment. In the second embodiment, the tube support structure 60 includes a housing section 80 surrounding the X-ray generating tube XG. The housing part 80 can support the X-ray generating tube XG so as to allow the X-ray generating tube XG to be rotated with the deflector 50 fixed. The space between the X-ray generating tube XG and the accommodating portion 80 may be filled or disposed with an insulating fluid (for example, insulating oil). The X-ray generator 1 may include an O-ring 82, and the X-ray generator tube XG and the housing section 80 may have sealing surfaces facing each other via the O-ring 82.

The accommodating part 80 may include a sealing part 81. The seal portion 81 may include a recessed portion that covers a first surface 231 and a second surface 232 on opposite sides of the outer circumferential portion of the electrode 23 of the anode 20 and an end surface 233 of the outer circumferential portion. The O-ring 82 may be placed in contact with the end surface 233 or in a recess provided in the end surface 233. A deflector support structure 70 that supports the deflector 50 may be coupled to the housing part 80 .

FIG. 6 schematically shows the configuration of the X-ray generator 1 of the third embodiment. Items not mentioned in the X-ray generator 1 of the third embodiment may follow the first or second embodiment. In the third embodiment, the electrode 23 may be provided with a through hole 24 . An O-ring 82 may be disposed between the upper surface of the housing part 80 and the lower surface of the electrode 23. The electrode 23 (anode 20) can be fixed to the housing part 80 by a screw 83 passing through the through hole 24. The through hole 24 may be configured as a long hole, for example, to allow rotation of the X-ray generating tube XG with respect to the tube support structure 60. When loosening the screw 83 to rotate the X-ray generating tube XG, the torque can be managed so that the seal provided by the O-ring 82 is not lost. Alternatively, the rotation angle of the screw 83 may be limited within a predetermined angle so that the seal provided by the O-ring 82 is not lost when loosening the screw 83 to rotate the X-ray generating tube XG.

FIG. 7 schematically shows the configuration of the X-ray generator 1 of the fourth embodiment. Items not mentioned in the X-ray generator 1 of the fourth embodiment may follow the third embodiment. In the fourth embodiment, a regulating member 84 that regulates the position of the electrode 23 may be provided. The regulating member 84 may have a ring shape, for example. A through hole 85 may be provided in the regulating member 84 . An O-ring 82 may be disposed between the upper surface of the housing part 80 and the lower surface of the electrode 23. The regulating member 84 can be fixed to the accommodating portion 80 by the screw 83 passing through the through hole 85 so as to press the electrode 23 against the O-ring 82 . The through hole 85 may be configured as a long hole, for example, to allow rotation of the X-ray generating tube XG with respect to the tube support structure 60.

FIG. 8 schematically shows the configuration of the X-ray generator 1 of the fifth embodiment. Items not mentioned in the X-ray generator 1 of the fifth embodiment may follow the first to fourth embodiments. The X-ray generator 1 may have a mark 93 indicating the rotation angle of the X-ray generator tube XG with respect to the tube support structure 60. The X-ray generator 1 may include an engaging portion 91 that engages with a jig (not shown) for rotating the X-ray generating tube XG. The operator can rotate the X-ray generating tube XG by engaging a jig with the engaging portion 91 and operating the jig.

FIG. 9 schematically shows the configuration of an X-ray generator 1 according to the sixth embodiment. Items not mentioned in the X-ray generator 1 of the sixth embodiment may follow the first to fourth embodiments. The X-ray generator 1 may have a mark 93 indicating the rotation angle of the X-ray generator tube XG with respect to the tube support structure 60. The X-ray generator 1 may include an engaging portion 95 that engages with a jig (not shown) for rotating the X-ray generating tube XG. The operator can rotate the X-ray generating tube XG by engaging a jig with the engaging portion 95 and operating the jig.

FIG. 10 shows the configuration of an X-ray generator 1 according to one embodiment. The X-ray generator 1 may include a booster circuit 110 and a drive circuit 120 in addition to the above-mentioned X-ray generator tube XG. The booster circuit 110 can boost a voltage supplied from the outside to generate a boosted voltage, and supply the boosted voltage to the drive circuit 120. The drive circuit 120 can drive the X-ray generating tube XG based on the boosted voltage supplied from the booster circuit 110. The X-ray generating tube XG, the booster circuit 110, and the drive circuit 120 are housed in the housing part 80, and the space inside the housing part 80 can be filled with an insulating fluid.

FIG. 11 shows the configuration of an X-ray imaging device 200 according to one embodiment. The X-ray imaging device 200 can include an X-ray generation device 1 and an X-ray detection device 240 that detects X-rays XR emitted from the X-ray generation device 1 and transmitted through the object 230. The X-ray detection device 240 may further include a control device 210 and a display device 220. The X-ray detection device 240 may include an X-ray detector 242 and a signal processing section 244. Control device 210 can control X-ray generation device 1 and X-ray detection device 240. The X-ray detector 242 can detect or image the X-rays XR emitted from the X-ray generator 1 and transmitted through the object 230. The signal processing unit 244 may process the signal output from the X-ray detector 242 and provide the processed signal to the control device 210. The control device 210 causes the display device 220 to display an image based on the signal supplied from the signal processing section 244. The control device 210 determines whether or not it is necessary to execute the rotation process based on the usage amount of the X-ray generator 1 and/or changes in the X-rays generated by the X-ray generator 1, and determines whether it is necessary to perform the rotation process. If it is determined that this is the case, the display device 220 may be used to prompt the operator to perform the rotation process.

As described above, when the focal position of the X-rays emitted from the X-ray generator 1 (electron beam incident position) is changed, the X-ray detector 242 or the X-ray detector 240 is positioned accordingly. There is a need. According to the X-ray generating device 1 according to each of the embodiments described above, the life of the target or the X-ray generating tube can be extended without changing the focal position, so such alignment is unnecessary.

1: X-ray generator, EG: electron gun, 10: electron gun, 20: anode, 21: target holding plate, 22: target, 23: electrode, 30: closing member, 50: deflector, 60: tube support structure , 70: Deflector support structure, AX: Central axis, EB: Electron beam, 80: Accommodation part

Claims

an X-ray generation tube including an electron gun and a target that receives electron beams emitted from the electron gun and generates X-rays;
a support structure that supports the X-ray generating tube;
a deflector that deflects the electron beam,
The support structure supports the X-ray generating tube so as to allow at least the target to be rotated while the deflector is fixed.
An X-ray generator characterized by:
The support structure supports the X-ray generating tube so as to allow the X-ray generating tube to be rotated while the deflector is fixed.
The X-ray generator according to claim 1, characterized in that:
The support structure supports the X-ray generation tube to allow the X-ray generation tube to be rotated around a rotation axis that coincides with a central axis of the electron gun.
The X-ray generator according to claim 1 or 2, characterized in that:
a central axis of the electron gun passes through the center of the target;
The X-ray generator according to claim 3, characterized in that:
When the electron beam is not deflected by the deflector, the electron beam is incident on the center of the target.
The X-ray generator according to any one of claims 1 to 4, characterized in that:
The support structure includes a housing portion surrounding the X-ray generating tube,
The housing section supports the X-ray generating tube so as to allow the X-ray generating tube to be rotated while the deflector is fixed.
The X-ray generator according to any one of claims 1 to 5, characterized in that:
an insulating fluid is disposed in a space between the X-ray generating tube and the housing section;
The X-ray generator according to claim 6, characterized in that:
Further equipped with an O-ring,
The X-ray generating tube and the accommodating portion have sealing surfaces facing each other via the O-ring.
The X-ray generator according to claim 7, characterized in that:
The deflector includes a first magnet and a second magnet that are arranged to face each other through the housing part.
The X-ray generator according to any one of claims 6 to 8.
The X-ray generating tube has a mark indicating a rotation angle of the X-ray generating tube with respect to the support structure.
The X-ray generator according to any one of claims 1 to 9.
The X-ray generator according to any one of claims 1 to 10,
an X-ray detector that detects X-rays emitted from the X-ray generator;
An X-ray imaging device comprising:
an electron gun, an X-ray generation tube including a target that receives an electron beam emitted from the electron gun and generates X-rays, a support structure that supports the X-ray generation tube, and a deflector that deflects the electron beam. A method for adjusting an X-ray generator comprising:
a rotating step of rotating at least the target while the deflector is fixed;
A method for adjusting an X-ray generator, characterized in that:
In the rotating step, the X-ray generating tube is rotated while the deflector is fixed.
13. The method for adjusting an X-ray generator according to claim 12.
In the rotation step, the X-ray generating tube is rotated around a rotation axis that coincides with the central axis of the electron gun.
14. The method for adjusting an X-ray generator according to claim 12 or 13.
a central axis of the electron gun passes through the center of the target;
The method for adjusting an X-ray generator according to claim 14.
When the electron beam is not deflected by the deflector, the electron beam is incident on the center of the target.
The method for adjusting an X-ray generator according to any one of claims 12 to 15.
The support structure includes a housing portion surrounding the X-ray generating tube,
In the rotating step, the X-ray generating tube is rotated with the deflector and the housing section being fixed.
The method for adjusting an X-ray generator according to any one of claims 12 to 16.
The deflector includes a first magnet and a second magnet that are arranged to face each other through the housing part.
The method for adjusting an X-ray generator according to claim 17.
The rotation step is performed according to the amount of use of the X-ray generator,
The method for adjusting an X-ray generator according to any one of claims 12 to 18.
The rotation step is performed according to a change in X-rays generated by the X-ray generator.
The method for adjusting an X-ray generator according to any one of claims 12 to 18.