X-ray generating apparatus and x-ray imaging apparatus

Abstract

An X-ray generating device (100) includes: an X-ray generating tube (1) including an insulating tube (10), a cathode (30) including an electron emission portion (32), and an anode (20) including a target (23) that generates X-rays when electrons from the electron emission portion (32) collide; a driving circuit (40) configured to drive the X-ray generating tube (1); and a housing container (50) configured to house the X-ray generating tube (1) and the driving circuit (40), in which the housing container (50) has an open end (OP3) and the X-ray generating tube (1) is arranged to close the open end (OP3), the housing container (50) is filled with an insulating liquid (60) such that the insulating liquid contacts the insulating tube (10), the housing container (50) has a first space (SP1) and a second space (SP2), and the first space (SP1) and the second space (SP2) are spaced apart from each other. The first space (SP1) stores the driving circuit (40), the second space (SP2) protrudes from the first space (SP1) and stores the X-ray generating tube (1), the housing container (50) includes a protruding portion (520) surrounding the second space (SP2), and one end of the second space (SP2) forms an open end (OP3), the entire insulating tube (10) is stored in the second space (SP2), and the protruding portion (520) is made of an insulating material.

Description

Technical Field

[0001] This invention relates to X-ray generating apparatus and X-ray imaging apparatus. Background Technology

[0002] PTL 1 describes an X-ray generating apparatus including an X-ray generating tube, a tube driving circuit for driving the X-ray generating tube, and a housing container for housing the X-ray generating tube and the tube driving circuit. The housing container is filled with an insulating liquid, and the insulating liquid ensures insulation between the X-ray generating tube and the tube driving circuit.

[0003] PTL 2 describes a transmission-type X-ray generating apparatus in which the X-ray generating tube is stored in a protrusion provided to a receiving container.

[0004] Citation List

[0005] Patent documents

[0006] PTL 1: Japanese Patent Application Publication No. 2016-103451

[0007] PTL 2: Japanese Patent Application Publication No. 2018-073625 Summary of the Invention

[0008] When an X-ray generating device is used for extended periods, abnormal discharges sometimes occur within the X-ray generating tube. The inventors' research has revealed that these abnormal discharges occur between the cathode and anode of the X-ray generating tube via the outer surface of the insulating tube. These abnormal discharges can cause the X-ray generating device to stop or malfunction.

[0009] One aspect of the present invention provides an advantageous technique for suppressing the occurrence of abnormal discharges in X-ray generating apparatus.

[0010] A first aspect of the present invention relates to an X-ray generating apparatus, the X-ray generating apparatus comprising: an X-ray generating tube including an insulating tube, a cathode, and an anode, the cathode including an electron emitting portion, the anode including a target that generates X-rays upon collision with electrons from the electron emitting portion; a driving circuit configured to drive the X-ray generating tube; and a receiving container configured to receive the X-ray generating tube and the driving circuit, wherein the receiving container has an open end, and the X-ray generating tube is arranged to close the open end, the receiving container being filled with an insulating liquid such that the insulating liquid contacts the insulating tube, the receiving container having a first space and a second space, the first space storing the driving circuit, the second space protruding from the first space and storing the X-ray generating tube, the receiving container including a protruding portion surrounding the second space, and one end of the second space forming the open end, the entire insulating tube being stored in the second space, and the protruding portion being made of an insulating material.

[0011] A second aspect of the invention relates to an X-ray generating apparatus, comprising: an X-ray generating tube including an insulating tube, a cathode, and an anode, the cathode including an electron emitting portion, the anode including a target that generates X-rays upon collision with electrons from the electron emitting portion; a receiving container configured to receive the X-ray generating tube; and a driving circuit configured to drive the X-ray generating tube, wherein the receiving container has an open end, and the X-ray generating tube is arranged to close the open end, the receiving container being filled with an insulating liquid, the receiving container having a first space and a second space, the first space storing the driving circuit, the second space protruding from the first space and storing the X-ray generating tube, the receiving container including a protruding portion surrounding the second space, and one end of the second space forming the open end, the entire insulating tube being stored in the second space, and an insulating member being provided inside the protruding portion.

[0012] A third aspect of the invention relates to an X-ray imaging apparatus, the X-ray imaging apparatus comprising: an X-ray generating device as defined in the first or second aspect; and an X-ray detector configured to detect X-rays emitted from the X-ray generating device. Attached Figure Description

[0013] Figure 1 This is a schematic diagram illustrating the arrangement of a conventional X-ray generating apparatus to explain the basic arrangement of the X-ray generating apparatus according to this disclosure;

[0014] Figure 2 This is an illustrative and schematic diagram showing the arrangement of the X-ray generating apparatus according to the first embodiment;

[0015] Figure 3 This is an illustrative and schematic diagram showing the arrangement of the X-ray generating apparatus according to the second embodiment;

[0016] Figure 4 This is an illustrative and schematic diagram showing the arrangement of the X-ray generating apparatus according to the third embodiment;

[0017] Figure 5 This is an illustrative and schematic diagram showing the arrangement of the X-ray generating apparatus according to the fourth embodiment;

[0018] Figure 6 It is a schematic diagram illustrating the occurrence of abnormal discharge;

[0019] Figure 7 This is a diagram illustrating the triboelectric series in triboelectric charging with an insulating liquid;

[0020] Figure 8 This is a schematic diagram illustrating a problem with the X-ray generating apparatus in the fifth embodiment;

[0021] Figure 9 This is an illustrative and schematic diagram showing the arrangement of the X-ray generating apparatus according to the fifth embodiment;

[0022] Figure 10 This is a schematic diagram showing the arrangement of a first modification of the X-ray generating apparatus according to the fifth embodiment;

[0023] Figure 11 This is a schematic diagram showing the arrangement of a second modification of the X-ray generating apparatus according to the sixth embodiment;

[0024] Figure 12 This is a schematic diagram showing the arrangement of a third modification of the X-ray generating apparatus according to the sixth embodiment;

[0025] Figure 13 This is a schematic diagram showing the arrangement of a fourth modification of the X-ray generating apparatus according to the seventh embodiment;

[0026] Figure 14 This is a schematic diagram showing the arrangement of a fifth modification of the X-ray generating apparatus according to the eighth embodiment;

[0027] Figure 15This is a schematic diagram illustrating the arrangement of a sixth modification of the X-ray generating apparatus according to the eighth embodiment; and

[0028] Figure 16 This is a block diagram illustrating the arrangement of an X-ray imaging apparatus according to an embodiment. Detailed Implementation

[0029] In the following description, embodiments will be illustrated in detail with reference to the accompanying drawings. Note that the following embodiments are not intended to limit the scope of the claimed invention. Several features are described in the embodiments, but the invention is not limited to requiring all such features, and several such features may be suitably combined. Furthermore, in the drawings, the same or similar configurations are given the same reference numerals, and repeated descriptions thereof are omitted.

[0030] First, refer to Figure 1 The basic arrangement of an X-ray generating apparatus 100 according to this disclosure is described. The X-ray generating apparatus 100 may include an X-ray generating tube 1 and a receiving container 50 housing the X-ray generating tube 1. The X-ray generating apparatus 100 may also include a drive circuit 40 for driving the X-ray generating tube 1, and the drive circuit 40 is housed in the receiving container 50 and is connected to the X-ray generating tube 1 via a cable 42. A portion of the X-ray generating tube 1 (the anode 20, described later) may be exposed to the external space of the receiving container 50 (the external space of the X-ray generating apparatus 100). The internal space of the receiving container 50 is filled with an insulating liquid 60. From another perspective, the internal space of the receiving 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.) housed within it. The insulating liquid 60 may be, for example, an insulating oil such as mineral oil or a chemically synthesized oil. Alternatively, the insulating liquid 60 may be a liquid other than an insulating oil, such as a fluorinated inert liquid (e.g., Fluorinert). TM ).

[0031] X-ray generating tube 1 may include an insulating tube 10, a cathode 30, and an anode 20. A vacuum is maintained within the internal space of the X-ray generating tube 1. 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, primarily comprising alumina or zirconium oxide. Alternatively, the insulating tube 10 may be made of a glass material such as borosilicate glass.

[0032] The cathode 30 can be arranged to close the first open end OP1 of the insulating tube 10. The cathode 30 includes an electron emitting portion 32. The cathode 30 can be arranged to not contact the insulating liquid 60. The X-ray generating apparatus 100 can be configured such that a component having the same potential as the cathode 30 does not contact the insulating liquid 60. The anode 20 can be arranged to close the second open end OP2 of the insulating tube 10. The anode 20 can include a target 23 that generates X-rays when electrons from the electron emitting portion 32 collide with it. The anode 20 can 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 formed of a conductor and is electrically connected to the target 23 to apply a potential to the target 23. The anode 20 can be maintained at, for example, ground potential, but can be maintained at another potential. The target 23 can be made of a material with a high melting point and high X-ray generation efficiency, such as tungsten, tantalum, or molybdenum. The target holding plate 22 can be made of, for example, a material that can easily transmit X-rays, such as beryllium or diamond.

[0033] 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 the third open end OP3 of the container 50. In other words, the first portion 52 may include the third open end OP3. The second portion 53 is formed of a conductor and is electrically connected to the anode 20 of the X-ray generating tube 1. It is understood that the second portion 53 forms the anode together with the electrode 21. The second portion 53 may have an annular shape or a frame shape. The second portion 53 may be arranged to contact the insulating liquid 60. Alternatively, a conductive member including the electrode 21 and the second portion 53 may be arranged to contact the insulating liquid 60. The electrode 21 and the second portion 53 may be formed as a single component of the same material. The fourth portion 55 may have a tubular shape, such as a cylindrical shape or a rectangular tubular shape. The third portion 54 is connected to one end of the fourth portion 55 and may have an annular shape or a frame shape. The first part 52 can be connected to the third part 54 to protrude from the third part 54. The fifth part 56 can be connected to the other end of the fourth part 55. Alternatively, except for the joint portion with the first part 52, the third part 54, the fourth part 55 and the fifth part 56 can be integrated into a hollow spherical shape.

[0034] The insulating liquid 60 can induce convection within the internal space of the container 50. When the entire outer surface 14 of the insulating tube 10 comes into contact with the insulating liquid 60, both the insulating tube 10 and the insulating liquid 60 can become charged through friction between the insulating liquid 60 and the outer surface 14 of the insulating tube 10. This charging is called triboelectric charging. Generally, triboelectric charging refers to the phenomenon where friction between two different types of materials causes charges to move between the two types of materials, thus one material becomes positively charged and the other becomes negatively charged. The inventors conducted an experiment measuring the potential of the outer surface of the insulating tube using a surface potentiometer after leaving the insulating tube in convection of insulating oil (insulating liquid). As a result, it was confirmed that the outer surface of the insulating tube was positively charged and that the charge increased proportionally with time. The polarity of the charge induced by friction depends on the properties of the materials rubbed together. Examples of material properties include triboelectric series and relative permittivity. Figure 7 An example of triboelectric series relative to insulating oil is shown. The triboelectric series indicates the order in which the materials being rubbed are charged (positive or negative) and how easily they become charged. In the triboelectric series, materials on the positive side are more likely to become positively charged, and materials on the negative side are more likely to become negatively charged.

[0035] When the outer surface 14 of the insulating tube 10 is positively charged, the insulation performance between the cathode 30 and the anode 20 decreases. The insulation performance between the cathode 30 and the anode 20 depends on the potential difference between them, the resistance between them, and the distance between them. Experiments showed that when the insulating tube 10 is positively charged, as... Figure 6 The thick arrows in the diagram schematically indicate that the cathode 30 and anode 20 are short-circuited via the outer surface 14 of the insulating tube 10. Furthermore, as a result of the experiment, it was 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 prone to occur due to electron avalanche.

[0036] The following will be through Figure 2 , Figure 3 , Figure 4 and Figure 5 The various embodiments shown illustratively describe the X-ray generating apparatus 100 of this disclosure. Matters not mentioned below may be followed in the references. Figure 1 The basic layout described.

[0037] Figure 2An arrangement of an X-ray generating apparatus 100 according to a first embodiment is illustrated illustratively and schematically. A container 50 may be filled with an insulating liquid 60 to contact a portion of the anode (e.g., a 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 generating apparatus 100 of the first embodiment, at least a portion of the insulating tube 10 is surrounded by a member 72 to reduce abnormal discharge between the cathode 30 and the anode 20 via the insulating tube 10. The member 72 may be made of an insulating material. More specifically, in the X-ray generating apparatus 100 of the first embodiment, the entire area of ​​the outer surface 34 of the insulating tube 10 may be surrounded by the member 72. From another viewpoint, the entire area of ​​the outer surface 14 of the insulating tube 10 may be covered by the member 72. In addition to the entire area of ​​the outer surface 14 of the insulating tube 10, the entire area of ​​the outer surface 34 of the cathode 30 may also be covered by the member 72. The first embodiment is effective in avoiding the formation of a triple point by the outer surface 14 of the insulating tube 10, the cathode 30, and the insulating liquid 60, thereby enabling the reduction of abnormal discharge.

[0038] To reduce abnormal discharge between the cathode 30 and anode 20 via the insulating tube 10, the material of component 72 is determined such that frictional charging between component 72 and the insulating liquid 60 causes component 72 to become negatively charged and the insulating liquid 60 to become positively charged. When insulating oil is used as the insulating liquid 60, for example, it can be determined according to... Figure 7 The triboelectric sequence illustrated in the diagram selects the material of component 72 such that triboelectric charging between component 72 and the insulating oil causes component 72 to become negatively charged. For example, a material for component 72 is polytetrafluoroethylene (PTFE). TM PMMA (polymethyl methacrylate), epoxy resins, and fluororubber (e.g., Viton). TM It is preferred that component 72 is arranged to cover the entire area of ​​the outer surface 14 of the insulating tube 10 and the entire area of ​​the outer surface 34 of the cathode 30, and therefore, methods such as molding, spraying, and dipping can be applied.

[0039] To reduce abnormal discharge between the cathode 30 and anode 20 via the insulating tube 10, the material of component 72 can be determined such that the difference in relative permittivity between component 72 and the insulating liquid 60 is less than the difference in relative permittivity between component 72 and the insulating tube 10. For example, component 72 is made of Viton rubber with a relative permittivity of 3 or polytetrafluoroethylene with a relative permittivity of 2.1, and the insulating tube 10 is made of borosilicate glass with a relative permittivity of 4.9 or alumina with a relative permittivity of 9. The fact that the difference in relative permittivity between component 72 and the insulating liquid 60 is less than the difference in relative permittivity between component 72 and the insulating tube 10 can 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.

[0040] A preferred molding method for forming component 72 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 now be described. The material of component 72 (i.e., the covering material) is obtained by pre-kneading the main agent and curing aid using a kneading device to ensure it is free of air bubbles and can be maintained at a constant temperature to maintain proper flow. In the case of epoxy resins, the temperature is, for example, about 100°C, but can be appropriately determined depending on the material to be used. The covering material can be poured into a container larger than the X-ray generating tube 1 to be covered. At this time, the covering material can be rapidly cooled due to the temperature difference between the container and the covering material, thereby degrading the flowability of the covering material. To prevent this, it is desirable to preheat the container. After the covering material poured into the container overflows, the covering material can be cured at an appropriate cooling rate and temperature distribution to avoid problems such as shrinkage.

[0041] In the X-ray generating tube 1, a high voltage is applied between the anode 20 and the cathode 30. Therefore, if bubbles with a small dielectric constant are present in the component 72 made of the covering material, the electric field concentrates on the bubbles, thereby inducing abnormal discharge. To avoid this, the space in which the filling of the covering material is performed can be pre-emptively vented using a vacuum pump to obtain a vacuum level of approximately several hundred to several thousand Pa. Furthermore, to improve the adhesion between the covering material and the X-ray generating tube 1, the component 72 can be used to cover the X-ray generating tube 1 after applying a primer material to the surface of the X-ray generating tube 1 or after creating an uneven surface through sandblasting. From the viewpoint of heat dissipation of the X-ray generating tube 1, a small thickness of the component 72 is desirable. For example, the thickness of the component 72 is preferably 5 mm or less, and more preferably 3 mm or less. For example, the thickness of the component 72 is preferably 0.3 mm or more, and more preferably 0.5 mm or more.

[0042] Figure 3The arrangement of the X-ray generating apparatus 100 according to the second embodiment is illustrated illustratively and schematically. Matters not mentioned in the second embodiment may be followed in the first embodiment or referred to in the reference. Figure 1 The basic arrangement is described. Component 72 can be arranged to cover the contact portion C between the cathode 30 and the insulating tube 10. Furthermore, component 72 can be arranged to cover the cathode 30. The second embodiment is also effective in preventing the formation of a triple point between the outer surface 14 of the insulating tube 10, the cathode 30, and the insulating liquid 60, thereby reducing the occurrence of abnormal discharges.

[0043] Figure 4 The arrangement of the X-ray generating apparatus 100 according to the third embodiment is illustrated illustratively and schematically. Matters not mentioned in the third embodiment may be followed in the first or second embodiment or referred to in the reference. Figure 1 The basic arrangement is described. In the third embodiment, an intermediate layer 75 is provided between the member 72 and the insulating tube 10. The intermediate layer 75 can be made of an insulating material. The intermediate layer 75 can be configured to cover the insulating tube 10. The member 72 can be configured to cover the intermediate layer 75. The intermediate layer 75 can be made of, for example, Kovar glass, nylon, and at least one of a mixture containing a metal oxide with silicon dioxide as the main component. Providing the intermediate layer 75 is advantageous, for example, forming a smooth surface to cover the outer surface 14 of the insulating tube 10. Forming the intermediate layer 75 is advantageous in inhibiting foreign matter from entering between the particles forming 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 can prevent abnormal discharge, thereby increasing the lifespan of the X-ray generating apparatus 100.

[0044] Figure 5 The arrangement of the X-ray generating apparatus 100 according to the fourth embodiment is illustrated illustratively and schematically. Matters not mentioned in the fourth embodiment may be followed in the first to third embodiments or referred to in the following documents. Figure 1The basic arrangement is described. In the fourth embodiment, member 72 may include an annular portion. Alternatively, member 72 may be an annular portion. The annular portion may surround the entire circumference of a portion of the outer surface 14 of the insulating tube 10 in the axial direction (which is the axial direction of the insulating tube 10 and also the direction in which the electron beam is emitted from the electron emitting portion 32). The outer surface 14 of the insulating tube 10 may contact the insulating liquid 60 in the area other than the area surrounded by member 72. The shortest distance between member 72 and cathode 30 is preferably less than the shortest distance between member 72 and anode 20. The insulating tube 10 may be surrounded by a plurality of members 72 (annular portions). The plurality of members 72 may be arranged spaced apart from each other relative to the axial direction of the insulating tube 10. Member 72 may be formed of, for example, Vitronic rubber. Even if the outer surface 14 of the insulating tube 10 is positively charged, when member 72 is negatively charged, the positive charge on the entire outer surface 14 of the insulating tube 10 can be reduced. This can reduce the occurrence of abnormal discharge.

[0045] Figure 9 The arrangement of the X-ray generating apparatus 100 according to the fifth embodiment is illustrated illustratively and schematically. Matters not mentioned in the fifth embodiment may be followed in the first to fourth embodiments or referred to in the following embodiments. Figure 1 The basic arrangement is described. The X-ray generating tube 1 may include an insulating tube 10, a cathode 30 including an electron emitting portion 32, and an anode 20 including a target 23 that generates X-rays upon collision with electrons from the electron emitting portion 32. The insulating tube 10 may not have a first open end OP1. For example, when the insulating tube 10 is made of glass, it may not have a first open end OP1.

[0046] The receiving container 50 may define a first space SP1 for storing the drive circuit 40, and a second space SP2 protruding from the first space SP1 and storing the X-ray generating tube 1. More specifically, the third portion 54, the fourth portion 55, and the fifth portion 56 of the receiving container 50 may define the first space SP1. On the other hand, the first portion 520 and the second portion 53 of the receiving container 50 may define the second space SP2. One end of the second space SP2 may form a third opening end OP3. The first portion 520 may form a protrusion protruding from the third portion 54.

[0047] The insulating tube 10 can be arranged such that its entirety is situated within the second space SP2. In other words, in the direction D in which the electron beam is emitted from the electron emitting section 32, the length of the insulating tube 10 is less than the length of the first section 520. Furthermore, in other words, in the direction D in which the electron beam is emitted from the electron emitting section 32, the length of the insulating tube 10 is less than the length of the second space SP2. In this case, the cable 42 exists at the boundary between the first space SP1 and the second space SP2.

[0048] Here, when the first part 520 is made of a conductor, abnormal discharge can occur due to the small distance between the first part 520 and the cathode 30, the insulating tube 10, or the triple point (described later). According to one aspect of PTL 2, to prevent abnormal discharge, it is necessary to... Figure 8 The distance between the X-ray generating tube 1 and the first part 52 (protruding part) is increased as shown in the diagram.

[0049] exist Figure 9 In the X-ray generating apparatus 100 shown, the first portion 520 is made of an insulating material to reduce abnormal discharge between the first portion 520 and the cathode 30, the insulating tube 10, or the triple point. More specifically, in the X-ray generating apparatus 100 according to the fifth embodiment, the outer surface 34 of the insulating tube 10 is completely surrounded by the first portion 520 made of an insulating material. From another viewpoint, the entire area of ​​the X-ray generating tube 1 in contact with the insulating liquid 60 is surrounded by the first portion 520 made of an insulating material. For example, the first portion 520 may be made of, for example, polytetrafluoroethylene (PTFE). TM The first part 520 may be made of a resin such as borosilicate glass or PMMA (polymethyl methacrylate). Alternatively, the first part 520 may be made of a glass material such as borosilicate glass, a ceramic material, epoxy resin, or polycarbonate. For the first part 520 to function as a container 50, it is necessary to prevent the insulating liquid 60 from leaking from the interior of the container 50 to the exterior. To achieve this, O-rings may be arranged between the first part 520 and the second part 53 and / or between the first part 520 and the third part 54. Alternatively, if the second part 53 or the third part 54 is made of metal, a sealing structure can be achieved through dissimilar material joining processes (including brazing and adhesion using adhesives).

[0050] When the first portion 520 is made of insulating material, it does not provide the function of electrically connecting the second portion 53 to the third portion 54, the fourth portion 55, and the fifth portion 56. If the potential of the second portion 53, which forms the anode 20 together with the electrode 21, is unstable, it is difficult to generate X-rays stably. Therefore, the second portion 53 can be grounded via a component other than the first portion 520.

[0051] and Figure 8 Compared to the X-ray generating apparatus 100 shown, Figure 9 The X-ray generating apparatus 100 shown can improve the breakdown voltage performance between the protruding portion (first portion 520) and the cathode 30 or insulating tube 10, thereby preventing abnormal discharge. Furthermore, according to... Figure 9The X-ray generating apparatus 100 shown, unlike PTL 2, has no design limitations, allowing for a reduction in the distance between the X-ray generating tube 1 and the protrusion (first portion 520), thereby miniaturizing the X-ray generating apparatus 100. Furthermore, according to... Figure 9 The material of the protruding portion of the X-ray generating apparatus 100 shown can be reduced in weight, thereby reducing the overall weight of the X-ray generating apparatus 100.

[0052] Figure 10 A first modified arrangement of the X-ray generating apparatus 100 according to the fifth embodiment is schematically shown. The outer surface 34 of the cathode 30 may include a cylindrical side surface 35 and a circular bottom surface 36. At least the side surface 35 of the outer surface 34 may be completely surrounded by the member 72. 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 emitting section 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 orthogonal to the direction D in which the electron beam is emitted from the electron emitting section 32.

[0053] In the virtual plane including the direction D of electron beam emission ( Figure 10 In the X-ray generating apparatus 100 according to the first modification, the third portion 54 of the receiving container 50 may include a protrusion 90 projecting toward the interior of the receiving container 50. The protrusion 90 may have a ground potential different from that of the cathode 30. In the X-ray generating apparatus 100 according to the first modification, the entire side surface 35 of the cathode 30 may be surrounded by a member 72. This prevents abnormal discharge between the protrusion 90 and the cathode 30. The member 72 may be arranged to surround at least a portion or preferably the entire outer surface 14 of the insulating tube 10 in addition to surrounding the side surface 35 of the cathode 30. This prevents abnormal discharge between the cathode 30 and the protrusion 90, as well as abnormal discharge between the cathode 30 and the anode 20.

[0054] For example, if the tube voltage of the X-ray generating tube 1 is 100 keV, then the thickness of component 72 is preferably 15 mm or less; if the tube voltage is 300 keV, then the thickness of component 72 is preferably 50 mm or less, and more preferably 3 mm or less. For example, the thickness of component 72 is preferably 0.3 mm or more, and more preferably 0.5 mm or more.

[0055] Figure 11The arrangement of a second modification of the X-ray generating apparatus 100 according to the fifth embodiment is schematically shown. When the first portion 520 forming the protrusion is made of an insulating material, the first portion 520 forming the protrusion does not shield against X-rays. Therefore, in the second modification, the first portion 520 forming the protrusion is surrounded by an X-ray shielding member 521. The X-ray shielding member 521 may have a tubular shape. For example, the X-ray shielding member 521 may be integrally formed with the first portion 520, or it may be attached to the first portion 520.

[0056] X-ray transmittance decreases exponentially with increasing density and thickness of the shielding material. According to experiments conducted by the inventors, for X-ray generating apparatuses used for industrial non-destructive inspections (tube voltage approximately 50 to 300 keV), if the X-ray shielding member 521 is made of a metal such as SUS or lead, it only needs to have a thickness of 1 mm or greater, and preferably 3 mm or greater.

[0057] Figure 12 The arrangement of a third modification of the X-ray generating apparatus 100 according to the fifth embodiment is schematically shown. Figure 12 As illustrated, the X-ray shielding member 521 can be arranged to electrically connect the second portion 53 to the third portion 54, the fourth portion 55, and the fifth portion 56. The X-ray shielding member 521 can be secured to the receiving container 50 by providing grooves in the second portion 53 and the third portion 54 and engaging the X-ray shielding member 521 in the grooves. The first portion 520 can be reinforced by setting the thickness of the X-ray shielding member 521 to 5 mm or greater.

[0058] Figure 13 The arrangement of a fourth modification of the X-ray generating apparatus 100 according to the fifth embodiment is schematically shown. For example... Figure 13 As illustrated, instead of providing a first portion 520 made of insulating material, an insulating member 522 made of insulating material can be arranged inside the first portion 52 made of conductor. The insulating member 522 can be formed, for example, by molding to cover the inner surface of the first portion 52. This can prevent abnormal discharge between the X-ray generating tube 1 and the first portion 52 without changing the strength of the first portion 52.

[0059] Figure 14 The arrangement of a fifth modification of the X-ray generating apparatus 100 according to the fifth embodiment is schematically shown. Figure 14As illustrated, the first part 520, made of insulating material, and the X-ray shielding member 521 can be integrally formed by insert molding. The X-ray shielding member 521 can have a cylindrical shape. For example, the X-ray shielding member 521 can be formed using a cylindrical conductive material, and the first part 520 is formed by insert molding resin onto the outer and inner sides of the X-ray shielding member 521. In this case, by exposing the X-ray shielding member 521 from the upper and lower ends of the first part 520, the X-ray shielding member 521 can be electrically connected to the second part 53 and the third part 54. This allows for the electrical connection of the second part 53 and the third part 54 without increasing the number of components and reducing weight. High strength can be obtained by setting the thickness of the X-ray shielding member 521 to 5 mm or greater. The fifth modification can be understood as an example of a structure in which the first part 520 includes the X-ray shielding member 521.

[0060] Figure 15 The arrangement of a sixth modification of the X-ray generating apparatus 100 according to the fifth embodiment is schematically shown. For example... Figure 15 As illustrated, the resin can be inserted into the X-ray shielding member 521 only to form the first part 520. This arrangement is advantageous for reducing costs and increasing strength.

[0061] In the fifth embodiment, insulation measures may also be taken between the cathode 30 and the anode 20, as in the first and fourth embodiments.

[0062] Figure 16 An arrangement of an X-ray imaging apparatus 200 according to an embodiment is shown. The X-ray imaging apparatus 200 may include an X-ray generating apparatus 100 and an X-ray detection apparatus 110, which detects X-rays 104 emitted from the X-ray generating apparatus 100 and passing through an object 106. The X-ray imaging apparatus 200 may also include a control device 120 and a display device 130. The X-ray detection apparatus 110 may include an X-ray detector 112 and a signal processing unit 114. The control device 120 may control the X-ray generating apparatus 100 and the X-ray detection apparatus 110. The X-ray detector 112 detects or images the X-rays 104 emitted from the X-ray generating apparatus 100 and passing through the object 106. The signal processing unit 114 may process the signal output from the X-ray detector 112 and supply the processed signal to the control device 120. The control device 120 displays an image on the display device 130 based on the signal supplied from the signal processing unit 114.

[0063] This invention is not limited to the above embodiments, and various changes and modifications can be made within the spirit and scope of this invention. Therefore, the appended claims are presented to inform the public of the scope of this invention.

Claims

1. An X-ray generating apparatus, comprising: An X-ray generating tube includes an insulating tube, a cathode, and an anode. The cathode includes an electron emitting portion, and the anode includes a target that generates X-rays upon collision with electrons from the electron emitting portion. A driving circuit configured to drive the X-ray generating tube; as well as A receiving container configured to receive the X-ray generating tube and the driving circuitry. The container has an open end, and the X-ray generating tube is arranged to close the open end. The container is filled with an insulating liquid such that the insulating liquid comes into contact with the insulating tube. The container has a first space and a second space, the first space storing the drive circuit, and the second space protruding from the first space and storing the X-ray generating tube. The receiving container includes a protruding portion surrounding the second space, and one end of the second space forms the opening. The entire insulating tube is stored in the second space, and The protruding part is made of insulating material.

2. The X-ray generating apparatus according to claim 1, wherein... The protruding portion comes into contact with the insulating liquid.

3. The X-ray generating apparatus according to claim 1 or 2, wherein... The protruding portion is surrounded by an X-ray shielding component.

4. The X-ray generating apparatus according to claim 1 or 2, wherein... The protruding portion includes an X-ray shielding component.

5. The X-ray generating apparatus according to claim 3, wherein... The X-ray shielding member is attached to the protruding portion.

6. The X-ray generating apparatus according to claim 3 or 4, wherein The X-ray shielding component is an integral component with the protruding portion.

7. The X-ray generating apparatus according to any one of claims 3 to 6, wherein The X-ray shielding component is electrically connected to the anode.

8. The X-ray generating apparatus according to any one of claims 1 to 7, wherein The protruding portion is made of one of polytetrafluoroethylene, PMMA (polymethyl methacrylate), glass, ceramic, epoxy resin, and polycarbonate.

9. An X-ray generating apparatus, comprising: An X-ray generating tube includes an insulating tube, a cathode, and an anode. The cathode includes an electron emitting portion, and the anode includes a target that generates X-rays upon collision with electrons from the electron emitting portion. A container configured to house the X-ray generating tube; as well as A driving circuit, configured to drive the X-ray generating tube, The container has an open end, and the X-ray generating tube is arranged to close the open end. The container is filled with an insulating liquid. The container has a first space and a second space, the first space storing the drive circuit, and the second space protruding from the first space and storing the X-ray generating tube. The receiving container includes a protruding portion surrounding the second space, and one end of the second space forms the opening. The entire insulating tube is stored in the second space, and An insulating component is provided on the inside of the protrusion.

10. The X-ray generating apparatus according to claim 9, wherein... The insulating member is provided on the entire inner surface of the protrusion.

11. The X-ray generating apparatus according to claim 9 or 10, wherein The insulating component is formed by molding.

12. The X-ray generating apparatus according to any one of claims 9 to 11, wherein The protruding portion includes a conductor.

13. The X-ray generating apparatus according to any one of claims 1 to 12, wherein The insulating liquid is insulating oil.

14. The X-ray generating apparatus according to any one of claims 1 to 12, wherein The insulating liquid is a fluorine-based inert liquid.

15. The X-ray generating apparatus according to any one of claims 1 to 14, wherein At least the side surface of the cathode is completely surrounded by the component.

16. An X-ray imaging device, comprising: The X-ray generating apparatus as defined in any one of claims 1 to 15; as well as An X-ray detector configured to detect X-rays emitted from the X-ray generating device.

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