X-ray generator and X-ray imaging device

Abstract

This X-ray generation device comprises: an X-ray generating tube including an insulating tube having a first opening end and a second opening end, a cathode which is disposed so as to close the first opening end of the insulating tube and includes an electron-emitting portion, and an anode which is disposed so as to close the second opening end and includes a target that generates X-ray due to collision with electrons from the electron-emitting portion; and a housing container in which the X-ray generating tube is housed. The housing container has a third opening end, and the X-ray generating tube is disposed so as to close the third opening end. An insulating liquid is filled into the housing container so as to be in contact with part of the insulating tube. A first member disposed spaced apart from the second opening end is in contact with at least part of an outer surface of the insulating tube. The first member is sandwiched between a second member disposed spaced apart from the housing container and the insulating tube.

Description

[Technical field]

[0001] The present invention relates to an X-ray generating device and an X-ray imaging device. [Background technology]

[0002] Patent Document 1 describes an X-ray generating device that includes an X-ray generating tube, a tube drive circuit that drives the X-ray generating tube, and a container that houses the X-ray generating tube and the tube drive circuit. The container is filled with an insulating liquid that ensures insulation between the X-ray generating tube and the tube drive circuit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-103451 A Summary of the Invention

[0004] When an X-ray generating device is used for a long period of time, an abnormal discharge may occur in the X-ray generating tube. The inventor's research has revealed that an abnormal discharge occurs between the cathode and anode of the X-ray generating tube through the outer surface of the insulating tube. The abnormal discharge may cause the X-ray generating device to stop or break down.

[0005] One aspect of the present invention provides an advantageous technique for suppressing the occurrence of abnormal discharge in an X-ray generating device.

[0006] A first aspect of the present invention relates to an X-ray generating device comprising: an X-ray generating tube having an insulating tube having a first opening end and a second opening end; a cathode including an electron emitter, arranged to close the first opening end of the insulating tube; and an anode including a target that generates X-rays when electrons from the electron emitter collide with the target, arranged to close the second opening end; and a container for accommodating the X-ray generating tube, wherein the container has a third opening end, the X-ray generating tube is arranged to close the third opening end, an insulating liquid is filled in the container so as to be in contact with a part of the insulating tube, a first member arranged at a distance from the second opening end is in contact with at least a part of an outer surface of the insulating tube, and the first member is sandwiched between the insulating tube and a second member arranged at a distance from the container.

[0007] A second aspect of the present invention relates to an X-ray imaging device, the X-ray imaging device comprising the X-ray generator according to the first aspect, and an X-ray detector that detects X-rays emitted from the X-ray generator. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating a schematic configuration of a conventional X-ray generating device, for explaining the basic configuration of an X-ray generating device according to the present disclosure. [Diagram 2] FIG. 1 is a diagram exemplarily and diagrammatically illustrating the configuration of an X-ray generating device according to a first embodiment. [Diagram 3] FIG. 10 is a diagram exemplarily and diagrammatically illustrating the configuration of an X-ray generating device according to a second embodiment. [Figure 4] FIG. 11 is a diagram exemplarily and diagrammatically illustrating the configuration of an X-ray generating device according to a third embodiment. [Diagram 5] FIG. 13 is a diagram exemplarily and diagrammatically illustrating the configuration of an X-ray generating device according to a fourth embodiment. [Figure 6] FIG. 4 is a diagram showing the occurrence of abnormal discharge. [Figure 7] FIG. 1 is a diagram illustrating a triboelectric series in frictional electrification with an insulating liquid. [Figure 8] 13A to 13C are diagrams showing a problem in the X-ray generating device according to the fifth embodiment. [Figure 9] FIG. 13 is a diagram exemplarily and diagrammatically illustrating the configuration of an X-ray generating device according to a fifth embodiment. [Figure 10] FIG. 13 is a diagram illustrating a configuration of a first modified example of the X-ray generating device according to the fifth embodiment. [Figure 11] FIG. 13 is a diagram illustrating a configuration of a second modified example of the X-ray generation device according to the fifth embodiment. [Figure 12] FIG. 13 is a diagram illustrating a configuration of a third modified example of the X-ray generating device according to the fifth embodiment. [Figure 13] FIG. 13 is a diagram illustrating a configuration of a fourth modified example of the X-ray generator according to the fifth embodiment. [Figure 14] FIG. 1 is a diagram showing the configuration of an X-ray imaging apparatus according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe a number of features, not all of these features are essential to the invention, and the features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0010] First, a basic configuration of an X-ray generating device 100 in the present disclosure will be described with reference to FIG. 1. The X-ray generating device 100 may include an X-ray generating tube 1 and a container 50 that contains the X-ray generating tube 1. The X-ray generating device 100 may further include a driving circuit 40 that drives the X-ray generating tube 1, and the driving circuit 40 may be contained in the container 50 and connected to the X-ray generating tube 1 via a cable 42. A part of the X-ray generating tube 1 (an anode 20 described later) may be exposed to the external space of the container 50 (the external space of the X-ray generating device 100). An insulating liquid 60 is filled in the internal space of the container 50. In another respect, the internal space of the container 50 is filled with the insulating liquid 60, except for the space occupied by the components (X-ray generating tube 1, cable 42, etc.) contained in the container 50. The insulating liquid 60 may be, for example, an insulating oil such as a mineral oil or a chemically synthesized oil. Alternatively, the insulating liquid 60 may be a liquid other than insulating oil, for example, a fluorine-based inert liquid (for example, Fluorinert (trademark)).

[0011] The X-ray generating tube 1 may include an insulating tube 10, a cathode 30, and an anode 20. The internal space of the X-ray generating tube 1 is maintained in a vacuum. The insulating tube 10 may have a first open end OP1 and a second open end OP2. The insulating tube 10 may have a tubular shape, such as a cylindrical shape. The insulating tube 10 may be configured to provide vacuum tightness and insulation for the internal space of the insulating tube 10. The insulating tube 10 may be made of a ceramic material, for example, containing alumina or zirconia as a main component. Alternatively, the insulating tube 10 may be made of a glass material, such as borosilicate glass.

[0012] The cathode 30 may be disposed so as to close the first open end OP1 of the insulating tube 10. The cathode 30 includes an electron emitting portion 32. The anode 20 may be disposed so as to close the second open end OP2 of the insulating tube 10. The anode 20 may include a target 23 that generates X-rays when electrons from the electron emitting portion 32 collide with the target 23. The anode 20 may include a target holding plate 22 that holds the target 23, and an electrode 21 that supports the target holding plate 22. The electrode 21 is made of a conductor, is electrically connected to the target 23, and applies a potential to the target 23. The anode 20 and the container 50 may be maintained at, for example, a ground potential, but may be maintained at another potential. The target 23 may be made of a material that has a high melting point and a high X-ray generation efficiency, such as tungsten, tantalum, or molybdenum. The target holding plate 22 may be made of a material that is easily transparent to X-rays, such as beryllium, diamond, or the like.

[0013] The container 50 may have a third open end OP3. The container 50 may include, for example, a first portion 52, a second portion 53, a third portion 54, a fourth portion 55, and a fifth portion 56. The first portion 52 may have a tubular shape, such as a cylindrical shape. The first portion 52 may define a third open end OP3 of the container 50. In other words, the first portion 52 may have a third open end OP3. The second portion 53 is made of a conductor and is electrically connected to the anode 20 of the X-ray generating tube 1. The second portion 53 may be understood as constituting an anode together with the electrode 21. The second portion 53 may have a ring shape or a frame shape. The second portion 53 may be arranged so as to be in contact with the insulating liquid 60. Alternatively, the conductive member including the electrode 21 and the second portion 53 may be arranged so as to be in contact with the insulating liquid 60. The electrode 21 and the second portion 53 may be constructed as a single piece of the same material. The fourth portion 55 may have a tubular shape such as a cylindrical shape or a square tube shape. The third portion 54 may be connected to one end of the fourth portion 55 and may have a ring shape or a frame shape. The first portion 52 may be connected to the third portion 54 so as to protrude from the third portion 54. The fifth portion 56 may be connected to the other end of the fourth portion 55. Alternatively, the third portion 54, the fourth portion 55, and the fifth portion 56 may be integrated together to have a hollow spherical shape, except for the joint portion with the first portion 52.

[0014] The insulating liquid 60 can convect in the internal space of the container 50. The insulating tube 10 has an outer surface 14, an inner surface 15 facing the internal space (vacuum space) of the X-ray generating tube 1, and a contact surface 16 that contacts other members (e.g., the cathode 30 and the anode 20) that constitute the internal space (vacuum space) of the X-ray generating tube 1. The outer surface 14 is a surface of the entire surface of the insulating tube 10 that is neither the inner surface 15 nor the contact surface 16. When the entire outer surface 14 of the insulating tube 10 is in contact with the insulating liquid 60, the insulating tube 10 and the insulating liquid 60 can be charged by friction between the outer surface 14 of the insulating tube 10 and the insulating liquid 60. Such charging is called frictional charging. In general, frictional charging refers to a phenomenon in which charges are transferred between two different materials due to friction between the two materials, and one material is charged positively and the other material is charged negatively. The inventors conducted an experiment in which an insulating tube was left in convecting insulating oil (insulating liquid) and then the potential of the outer surface of the insulating tube was measured using a surface electrometer. As a result, it was confirmed that the outer surface of the insulating tube was positively charged, and that the amount of charge increased in proportion to time. The polarity of the charge caused by friction depends on the characteristics of the rubbing material. Examples of material characteristics include the triboelectric series and the relative dielectric constant. Figure 7 shows an example of the triboelectric series for insulating oil. The triboelectric series indicates whether the rubbed material will be charged to positive or negative polarity, and the order in which it is easily charged. In the triboelectric series, materials that are more positively charged are more likely to be charged to positive polarity, and materials that are more negatively charged are more likely to be charged to negative polarity.

[0015] When the outer surface 14 of the insulating tube 10 is positively charged, the insulating performance between the cathode 30 and the anode 20 may be reduced. The insulating performance between the cathode 30 and the anode 20 may depend on the potential difference between the cathode 30 and the anode 20, the resistance between the cathode 30 and the anode 20, the distance between the cathode 30 and the anode 20, and the like. As a result of the experiment, it was found that when the insulating tube 10 is positively charged, the cathode 30 and the anode 20 are short-circuited via the outer surface 14 of the insulating tube 10, as shown diagrammatically by the thick arrow in FIG. 6. In addition, as a result of the experiment, it was also found that when the outer surface 14 of the insulating tube 10, the cathode 30, and the insulating liquid 60 form a triple point, abnormal discharge is likely to occur due to electron avalanche.

[0016] Hereinafter, the X-ray generating device 100 of the present disclosure will be described by way of example through a number of embodiments shown in Figures 2, 3, 4, and 5. Items not mentioned below may follow the basic configuration described with reference to Figure 1.

[0017] FIG. 2 exemplarily and typically illustrates the configuration of the X-ray generator 100 of the first embodiment. The container 50 may be filled with an insulating liquid 60 so as to contact a portion of the anode (e.g., the second portion 53) and cover the outer surface 14 of the insulating tube 10 and the outer surface 34 of the cathode 30. In the X-ray generator 100 of the first embodiment, at least a portion of the insulating tube 10 is surrounded by a member 72 so as to reduce abnormal discharge between the cathode 30 and the anode 20 through the insulating tube 10. The member 72 may be made of an insulating material. More specifically, in the X-ray generator 100 of the first embodiment, the entire outer surface 34 of the insulating tube 10 may be surrounded by the member 72. In another respect, the entire outer surface 14 of the insulating tube 10 may be covered by the member 72. In addition to the entire outer surface 14 of the insulating tube 10, the entire outer surface 34 of the cathode 30 may be covered by the member 72. The first embodiment is effective in preventing the outer surface 14 of the insulating tube 10, the cathode 30, and the insulating liquid 60 from forming a triple point, which can reduce the occurrence of abnormal discharge.

[0018] In order to reduce abnormal discharge between the cathode 30 and the anode 20 through the insulating tube 10, the material of the member 72 may be determined so that the member 72 is negatively charged by frictional charging between the member 72 and the insulating liquid 60, and the insulating liquid 60 is positively charged. When insulating oil is used as the insulating liquid 60, the material of the member 72 may be selected so that the member 72 is negatively charged by frictional charging between the member 72 and the insulating oil, for example, according to the triboelectric series illustrated in FIG. 7. Suitable materials for the member 72 include, for example, polytetrafluoroethylene (Teflon (trademark)), PMMA (polymethylmethacrylate resin), epoxy, and fluororubber (for example, Viton (trademark)). The member 72 may be disposed so as to cover, for example, the entire outer surface 14 of the insulating tube 10 and the outer surface 34 of the cathode 30, and for this purpose, for example, a molding method, a spraying method, a dipping method, or the like may be applied.

[0019] In order to reduce abnormal discharge between the cathode 30 and the anode 20 via the insulating tube 10, the material of the member 72 may be determined so that the relative dielectric constant difference between the member 72 and the insulating liquid 60 is smaller than the relative dielectric constant difference between the member 72 and the insulating tube 10. For example, the member 72 is made of Viton with a relative dielectric constant of 3 or polytetrafluoroethylene with a relative dielectric constant of 2.1, and the insulating tube 10 is made of borosilicate glass with a relative dielectric constant of 4.9 or alumina with a relative dielectric constant of 9. Here, the fact that the relative dielectric constant difference between the member 72 and the insulating liquid 60 is smaller than the relative dielectric constant difference between the member 72 and the insulating tube 10 may be evaluated at the temperature at which X-rays are generated or at room temperature (e.g., 25°C). However, there is no significant difference between the former and the latter.

[0020] Here, a molding method suitable for forming the member 72 so as to cover the X-ray generating tube 1 (the outer surface 14 of the insulating tube 10, and the outer surface 34 of the cathode 30) will be described. The material of the member 72, i.e., the covering material, can be kneaded in advance by a kneading device with a base agent and a curing assistant so as to prevent air bubbles from being introduced, and can be kept at a constant temperature so as to maintain an appropriate flow. In the case of an epoxy resin, the temperature is, for example, around 100°C, but the temperature can be appropriately determined depending on the material used. The covering material can be poured into a container that is one size larger than the X-ray generating tube 1 to be covered. At that time, the covering material can be rapidly cooled due to the temperature difference between the container and the covering material, and the fluidity of the covering material can be reduced. To prevent this, it is desirable to heat the container in advance. After the covering material poured into the container overflows from the container, the amount of covering material can be solidified at an appropriate cooling rate and temperature distribution so as to prevent problems such as shrinkage from occurring.

[0021] In the X-ray generating tube 1, a high voltage is applied between the anode 20 and the cathode 30. If bubbles having a low dielectric constant are present in the member 72 made of the coating material, an electric field will concentrate there, which may induce abnormal discharge. To avoid this, the space in which the process of filling the coating material is performed can be evacuated in advance to a vacuum degree of about several hundred to several thousand Pa using a vacuum pump. In addition, in order to increase the adhesion between the coating material and the X-ray generating tube 1, a primer material may be applied to the surface of the X-ray generating tube 1, or unevenness may be formed by blasting, and then the coating with the member 72 may be performed. It is desirable that the thickness of the member 72 is thin from the viewpoint of heat dissipation of the X-ray generating tube 1. The thickness of the member 72 is, for example, preferably 5 mm or less, more preferably 3 mm or less. The thickness of the member 72 is, for example, preferably 0.3 mm or more, more preferably 0.5 mm or more.

[0022] FIG. 3 exemplarily and typically illustrates the configuration of an X-ray generator 100 according to a second embodiment. Matters not mentioned in the description of the second embodiment may follow the basic configuration described with reference to the first embodiment or FIG. 1. The member 72 may be arranged so as to cover the contact portion C between the cathode 30 and the insulating tube 10. The member 72 may also be arranged so as to cover the cathode 30. The second embodiment is also effective in preventing the outer surface 14 of the insulating tube 10, the cathode 30, and the insulating liquid 60 from forming a triple point, which may reduce the occurrence of abnormal discharge.

[0023] FIG. 4 exemplarily and typically illustrates the configuration of the X-ray generator 100 of the third embodiment. Matters not mentioned in the description of the third embodiment may follow the basic configuration described with reference to the first or second embodiment, or FIG. 1. In the third embodiment, an intermediate layer 75 is provided between the member 72 and the insulating tube 10. The intermediate layer 75 may be made of an insulating material. The intermediate layer 75 may be configured to cover the insulating tube 10. The member 72 may be configured to cover the intermediate layer 75. The intermediate layer 75 may be made of at least one of Kovar glass, nylon, and a mixture containing a metal oxide mainly composed of silica. Providing the intermediate layer 75 is advantageous for forming a smooth surface to cover the outer surface 14 of the insulating tube 10, for example. Forming the intermediate layer 75 is also advantageous for preventing foreign matter from entering between the particles that make up the insulating tube 10. As a result, the creepage withstand voltage on the surface of the member 72 arranged to cover the insulating tube 10 can be improved. This makes it possible to prevent abnormal discharge and extend the life of the X-ray generating device 100.

[0024] FIG. 5 exemplarily and typically illustrates the configuration of the X-ray generator 100 of the fourth embodiment. Matters not mentioned in the description of the fourth embodiment may follow the basic configuration described with reference to the first to third embodiments or FIG. 1. In the fourth embodiment, the member 72 may include a ring-shaped portion. Alternatively, the member 72 may be a ring-shaped portion. The ring-shaped portion may surround a part of the outer surface 14 of the insulating tube 10 in the axial direction (the axial direction of the insulating tube 10, which is also the direction in which the electron beam is emitted from the electron emitter 32) over the entire circumference. The outer surface 14 of the insulating tube 10 may come into contact with the insulating liquid 60 in a region other than the region surrounded by the member 72. It is preferable that the shortest distance between the member 72 and the cathode 30 is smaller than the shortest distance between the member 72 and the anode 20. The insulating tube 10 may be surrounded by a plurality of members 72 (ring-shaped portions). The plurality of members 72 may be arranged spaced apart from each other in the axial direction of the insulating tube 10. The member 72 may be made of, for example, Viton. Even if the outer surface 14 of the insulating tube 10 is charged to the positive polarity side, the member 72 is charged to the negative polarity side, so that the amount of charge to the positive polarity side on the entire outer surface 14 of the insulating tube 10 can be reduced. This can reduce the occurrence of abnormal discharge.

[0025] 9 exemplarily and diagrammatically illustrates the configuration of an X-ray generating device 100 according to a fifth embodiment. Matters not mentioned in the description of the fifth embodiment may follow the basic configuration described with reference to the fourth embodiment or FIG.

[0026] In order to improve the insulation between the anode 20 and the cathode 30, the insulating tube 10 may be provided with a protruding portion PP as shown in FIG. 8, or the axial length of the insulating tube 10 may be extended to lengthen the creepage distance of the outer surface 14 of the insulating tube 10 between the cathode 30 and the anode 20. However, when the protruding portion PP is provided integrally with the insulating tube 10, the insulating tube 10 has a complex shape, which increases the manufacturing cost of the insulating tube 10 and may reduce the yield. On the other hand, when the protruding portion PP is provided by a separate member, the creepage distance is not increased due to the gap between the insulating tube 10 and the protruding portion PP. Furthermore, when the axial length of the insulating tube 10 is extended, the X-ray generating device 100 becomes larger. Therefore, a measure to lengthen the creepage distance without increasing the size of the X-ray generating device 100 or changing the shape of the insulating tube 10 is required.

[0027] In the fifth embodiment, in order to increase the creepage distance between the cathode 30 and the anode 20, at least a part of the outer surface 14 of the insulating tube 10 is in contact with a first member 72 arranged at a distance from the second open end OP2 of the insulating tube 10. The outer surface 14 of the insulating tube 10 has a cylindrical outer side surface (cylindrical surface), and in the configuration example shown in Fig. 9, at least a part of the cylindrical outer side surface (cylindrical surface) of the outer surface 14 of the insulating tube 10 is surrounded by the first member 72 arranged at a distance from the second open end OP2 of the insulating tube 10. The first member 72 is sandwiched between the insulating tube 10 and a second member 73 arranged at a distance from the container 50.

[0028] The first member 72 may include a ring-shaped portion, similar to the member 72 in the fourth embodiment, and may be made of fluororubber such as Viton. The first member 72 may be pressed against the insulating tube 10 by the second member 73, thereby coming into close contact with the insulating tube 10. The first member 72 is desirably made of an elastic material such as a rubber material.

[0029] In the example shown in FIG. 9, a second member 73 is provided around a first member 72. The second member 73 may be a resin-impregnated glass cloth laminate (e.g., a laminated plate, a laminated pipe) that has been molded under heat and pressure. The resin-impregnated glass cloth laminate may be formed, for example, by laminating or winding a member (prepreg) in which a nonwoven glass fabric is impregnated with a resin such as an epoxy resin or a phenolic resin, and then performing molding under heat and pressure. The second member 73 may be made of, for example, glass epoxy. The second member 73 has a volume resistivity of 1×10 at 25° C. 5 It is preferable that the second member 73 has an insulating property of Ωm or more. The second member 73 may be made of insulating materials such as epoxy resin, polycarbonate, glass, ceramics, PEEK (polyether ether ketone), ABS (acrylonitrile-butadiene-styrene copolymer synthetic resin), polytetrafluoroethylene (Teflon (trademark)), PMMA (polymethyl methacrylate resin), and fluororubber (for example, Viton (trademark)).

[0030] The second member 73 may have, for example, a ring shape. The second member 73 may be composed of a plurality of divisible parts, or may be composed of a single piece. The second member 73 may also have the function of an insulating container that covers electrical components such as the drive circuit 40, as in the modified example shown in FIG. 10. The creepage distance between the cathode 30 and the anode 20 can also be increased in the modified example shown in FIG. 10. The first member 72 and the second member 73 may be provided on the outer surface 14 of the insulating tube 10 at a distance from the cathode 30, or may be provided at the contact portion (boundary) between the outer surface 14 of the insulating tube 10 and the cathode 30. In the latter case, the formation of a triple point by the outer surface 14 of the insulating tube 10, the cathode 30, and the insulating liquid 60 can be prevented.

[0031] Furthermore, the first member 72 and the second member 73 may be disposed between the outer surface 14 of the insulating tube 10 and the first portion 52, as in the modified example shown in FIG. 11. In the modified example shown in FIG. 11, the driving circuit 40 is disposed in a first space SP1 surrounded by the third portion 54, the fourth portion 55, and the fifth portion 56. In addition, in the modified example shown in FIG. 11, the second space SP2 surrounded by the first portion 52 and the second portion 53 protrudes from the first space SP1. The first portion 52 may be understood as a portion constituting a protruding portion. In the modified example shown in FIG. 11, the first member 72 and the second member 73 are disposed in the second space SP2. The entire insulating tube 10 may be disposed in the second space SP2, or a part of the insulating tube 10 may be disposed in the second space SP2.

[0032] As in the modified example shown in Fig. 12, a third member 74 may be provided between the X-ray generating tube 1 and the housing container 50 so as to surround a part of the X-ray generating tube 1. This makes it possible to prevent abnormal discharge between the housing container 50 and the X-ray generating tube 1. In this case, the second member 73 and the third member 74 may be integrated. Also, the third member 74 may have a function of an insulating container that covers electrical components such as the drive circuit 40, like the second member 73 in the modified example shown in Fig. 10.

[0033] As in the modified example shown in FIG. 13, the cathode 30 may be disposed so that its entirety fits within the second space SP2. The outer surface 34 of the cathode 30 may have a cylindrical side surface 35 and a circular bottom surface 36. The cylindrical side surface 35 has a non-zero dimension in the axial direction of the insulating tube 10 or in the direction D in which the electron beam is emitted from the electron emitter 32. The bottom surface 36 of the outer surface 34 of the cathode 30 may face the drive circuit 40. The bottom surface 36 has a non-zero dimension in the radial direction of the insulating tube 10 or in a direction perpendicular to the direction D in which the electron beam is emitted from the electron emitter 32. The insulating tube 10 may be disposed so as to surround the entire side surface 35 of the cathode 30. With this configuration, the insulation performance between the cathode 30 and the storage container 50 may be improved. In a cross section (FIG. 13) including the direction D in which the electron beam is emitted (the axis of the X-ray generating tube 1), the second portion 52 or the third portion 54 of the container 50 may have a protrusion 90 that protrudes toward the inside of the container 50.

[0034] Furthermore, the insulating tube 10 may extend so as to block at least a part of any imaginary line VL1 connecting the protrusion 90 and the outer surface 34 of the cathode 30. In this case, the third space SP3 may be defined so as to be surrounded by the outer surface 14 of the insulating tube 10 and the bottom surface 36 of the cathode 30. The first member 72 may be disposed in the third space SP3 so as to contact a surface ISS of the outer surface 14 of the insulating tube 10 that surrounds the third space SP3. The first member 72 is sandwiched between the insulating tube 10 and a second member 73 disposed away from the container 50. The first member 72 may include a ring-shaped portion. Such a configuration is effective for increasing the distance between the second member 73 and the first portion 52. In addition, in such a configuration, the second member 73 can block a part of the imaginary line VL1. The first member 72 may be disposed so as to cover a contact portion (boundary) between the cathode 30 and the insulating tube 10.

[0035] In the fifth embodiment illustrated in FIGS. 9, 10, 11, 12, and 13, insulation measures may also be taken between the cathode 30 and the anode 20, as in the first and fourth embodiments.

[0036] FIG. 14 shows a configuration of an X-ray imaging device 200 according to an embodiment. The X-ray imaging device 200 may include an X-ray generating device 100 and an X-ray detecting device 110 that detects X-rays 104 emitted from the X-ray generating device 100 and transmitted through an object 106. The X-ray imaging device 200 may further include a control device 120 and a display device 130. The X-ray detecting device 110 may include an X-ray detector 112 and a signal processing device 114. The control device 120 may control the X-ray generating device 100 and the X-ray detecting device 110. The X-ray detector 112 detects or captures the X-rays 104 emitted from the X-ray generating device 100 and transmitted through the object 106. The signal processing device 114 may process a signal output from the X-ray detector 112 and supply the processed signal to the control device 120. The control device 120 causes the display device 130 to display an image based on the signal supplied from the signal processing device 114.

[0037] The invention is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention.

Claims

1. an X-ray generating tube including: an insulating tube having a first open end and a second open end; a cathode arranged to close the first open end of the insulating tube and including an electron emitting portion; and an anode arranged to close the second open end and including a target that generates X-rays when electrons from the electron emitting portion collide with the target; a container that houses the X-ray generating tube, the container has a third open end, and the X-ray generating tube is disposed so as to close the third open end; The container is filled with an insulating liquid so as to be in contact with a part of the insulating tube, a first member that is disposed apart from the second opening end and that is in contact with at least a portion of an outer surface of the insulating tube; The first member is made of an insulating material, the first member is sandwiched between a second member disposed apart from the container and the insulating tube, The first member and the second member have a ring shape.

1. An X-ray generating device comprising:

2. the first member is disposed so as to cover a contact portion between the cathode and the insulating tube; 2. The X-ray generating device according to claim 1 .

3. an X-ray generating tube including: an insulating tube having a first open end and a second open end; a cathode arranged to close the first open end of the insulating tube and including an electron emitting portion; and an anode arranged to close the second open end and including a target that generates X-rays when electrons from the electron emitting portion collide with the target; a container that houses the X-ray generating tube, the container has a third open end, and the X-ray generating tube is disposed so as to close the third open end; The container is filled with an insulating liquid so as to be in contact with a part of the insulating tube, a first member that is disposed apart from the second open end and the cathode and that is in contact with at least a portion of an outer surface of the insulating tube; The first member includes a ring-shaped portion, the first member is sandwiched between a second member disposed apart from the container and the insulating tube, The second member has a ring shape.

1. An X-ray generating device comprising:

4. The first member is made of an insulating material.

4. The X-ray generating device according to claim 3.

5. the outer surface of the insulating tube includes a cylindrical outer surface, and at least a portion of the outer surface is surrounded by the first member.

2. The X-ray generating device according to claim 1 .

6. a space surrounded by the insulating tube is disposed inside the container and outside the X-ray generating tube; the outer surface of the insulating tube includes a surface surrounding the space from the outside thereof, the first member is disposed so as to be in contact with a surface of the outer surface of the insulating tube that surrounds the space from the outside.

2. The X-ray generating device according to claim 1 .

7. an X-ray generating tube including: an insulating tube having a first open end and a second open end; a cathode arranged to close the first open end of the insulating tube and including an electron emitting portion; and an anode arranged to close the second open end and including a target that generates X-rays when electrons from the electron emitting portion collide with the target; a container that houses the X-ray generating tube, the container has a third open end, and the X-ray generating tube is disposed so as to close the third open end; The container is filled with an insulating liquid so as to be in contact with a part of the insulating tube, a first member that is disposed apart from the second opening end and that is in contact with at least a portion of an outer surface of the insulating tube; The first member is made of an insulating material, the first member is sandwiched between a second member disposed apart from the container and the insulating tube, a space surrounded by the insulating tube is disposed inside the container and outside the X-ray generating tube; the outer surface of the insulating tube includes a surface surrounding the space from the outside thereof, the first member is disposed so as to be in contact with a surface of the outer surface of the insulating tube that surrounds the space from the outside.

1. An X-ray generating device comprising:

8. The first member is made of fluororubber.

2. The X-ray generating device according to claim 1 .

9. The second member is made of an insulating material.

2. The X-ray generating device according to claim 1 .

10. the second member is made of any one of polytetrafluoroethylene, PMMA (polymethyl methacrylate resin), epoxy resin, polycarbonate, glass, ceramics, PEEK (polyether ether ketone), ABS (acrylonitrile butadiene styrene copolymer synthetic resin), and fluororubber; 2. The X-ray generating device according to claim 1 .

11. an X-ray generating tube including: an insulating tube having a first open end and a second open end; a cathode arranged to close the first open end of the insulating tube and including an electron emitting portion; and an anode arranged to close the second open end and including a target that generates X-rays when electrons from the electron emitting portion collide with the target; A drive circuit for driving the X-ray generating tube; a container that houses the X-ray generating tube, the container has a third open end, and the X-ray generating tube is disposed so as to close the third open end; The container is filled with an insulating liquid so as to be in contact with a part of the insulating tube, a first member that is disposed apart from the second opening end and that is in contact with at least a portion of an outer surface of the insulating tube; The first member is made of an insulating material, the first member is sandwiched between a second member disposed apart from the container and the insulating tube, The second member is a part of an insulating container that covers the drive circuit in the housing container.

1. An X-ray generating device comprising:

12. an X-ray generating tube including: an insulating tube having a first open end and a second open end; a cathode arranged to close the first open end of the insulating tube and including an electron emitting portion; and an anode arranged to close the second open end and including a target that generates X-rays when electrons from the electron emitting portion collide with the target; A drive circuit for driving the X-ray generating tube; a container that houses the X-ray generating tube, the container has a third open end, and the X-ray generating tube is disposed so as to close the third open end; The container is filled with an insulating liquid so as to be in contact with a part of the insulating tube, a first member that is disposed apart from the second opening end and that is in contact with at least a portion of an outer surface of the insulating tube; The first member is made of an insulating material, the first member is sandwiched between a second member disposed apart from the container and the insulating tube, the container defines a first space for housing the drive circuit and a second space protruding from the first space, one end of the second space is defined by the third open end, and a part or the whole of the insulating tube is accommodated in the second space, the outer surface of the insulating tube has a portion that faces a portion of the container that defines the second space without the first member and the second member being interposed therebetween; 1. An X-ray generating device comprising:

13. The insulating liquid is an insulating oil.

13. An X-ray generating device according to claim 1, wherein the X-ray generating device is a casing.

14. The insulating liquid is a fluorine-based inert liquid.

13. An X-ray generating device according to claim 1, wherein the X-ray generating device is a casing.

15. An X-ray generating device according to any one of claims 1 to 12, an X-ray detector for detecting X-rays emitted from the X-ray generating device; An X-ray imaging device comprising:

16. The second member is spaced from the cathode in an axial direction of the insulating tube.

13. An X-ray generating device according to claim 1, wherein the X-ray generating device is a casing.

17. The second member is spaced from the anode in an axial direction of the insulating tube.

13. An X-ray generating device according to claim 1, wherein the X-ray generating device is a casing.

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