Electron gun, x-ray tube, and inspection device

Abstract

The invention provides an electron gun, an X-ray tube, an inspection device, and a method for manufacturing the electron gun, which can inhibit the peeling of an insulating material on the surface of a filament. According to the embodiment, the electronic gun comprises a cylindrical shell, a first electrode, a second electrode, a third electrode and a fourth electrode, the first rod pin is arranged on the first end part side of the interior of the shell; a focus electrode provided on a second end side of the inside of the case, the second end side being located on the opposite side from the first end side; the near-heating type cathode is arranged on the focusing electrode, and the focusing electrode is arranged on the near-heating type cathode; the first terminal is arranged on one side, provided with the near-heating cathode, of the focusing electrode through an insulating part; a tab electrically connected to a lead wire of a heater provided to the side-heating cathode and the first terminal; and a first lead wire provided inside the housing, one end side of the first lead wire being electrically connected to the first pin, and the other end side of the first lead wire being electrically connected to the first terminal.

Description

Technical Field

[0001] Embodiments of the present invention relate to an electron gun, an X-ray tube, and an inspection apparatus. Background Art

[0002] There is an X-ray tube with a micro focus called a micro focus X-ray tube. The electron gun provided in such an X-ray tube includes a indirectly heated cathode that emits electrons, a focusing electrode that focuses electrons in an electric field, and a stem for electrically connecting the indirectly heated electrode and the focusing electrode to a control device or the like provided outside. In this case, a heater having a filament and a sleeve into which the filament of the heater is inserted are provided in the indirectly heated cathode. In addition, in order to electrically insulate the filament from the sleeve, an insulating material such as ceramics is coated on the surface of the filament.

[0003] Here, in order to electrically connect the heater of the indirectly heated cathode to the stem, the stem is connected to a tab connected to the lead of the heater. In this case, the stem is connected to the tab in a state where the filament of the heater is inserted into the sleeve. Therefore, force may be applied to the filament via the tab. If force is applied to the filament, sliding may occur between the filament and the sleeve, and the insulating material on the surface of the filament may peel off. For this reason, it is desired to develop a technique for suppressing peeling of the insulating material on the surface of the filament. Prior Art Documents Patent Documents

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2000-48746 Patent Document 2: Japanese Patent Application Laid-Open No. 2008-257956 Patent Document 3: Japanese Patent Application Laid-Open No. 2003-123661 Summary of the Invention Technical Problem to be Solved by the Invention

[0005] The problem to be solved by the present invention is to provide an electron gun, an X-ray tube, and an inspection apparatus that can suppress peeling of the insulating material on the surface of the filament. Technical Solution for Solving the Technical Problem

[0006] The electron gun according to the embodiment includes: a housing, the housing being cylindrical; a first rod pin, the first rod pin being disposed on the first end side inside the housing; a focusing electrode, the focusing electrode being disposed on the second end side inside the housing, which is on the side opposite to the first end side; an indirectly heated cathode, the indirectly heated cathode being disposed on the focusing electrode; a first terminal, the first terminal being disposed on the side of the focusing electrode where the indirectly heated cathode is disposed through an insulating portion; a tab, the tab being electrically connected to a lead of a heater disposed on the indirectly heated cathode and the first terminal; and a first wire, the first wire being disposed inside the housing, one end side of the first wire being electrically connected to the first rod pin, and the other end side of the first wire being electrically connected to the first terminal. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a schematic cross-sectional view for illustrating the electron gun of the present embodiment. Figure 2 is a schematic three-dimensional cross-sectional view of the electron gun. Figure 3 is a schematic partial cross-sectional view of the electron gun. Figure 4 is a schematic three-dimensional partial cross-sectional view of the electron gun. Figure 5 is a schematic cross-sectional view for illustrating the electron gun of the comparative example. Figure 6 is a schematic exploded cross-sectional view for illustrating the manufacturing steps of the module. Figure 7 is a schematic cross-sectional view for illustrating the X-ray tube of the present embodiment. Figure 8 is a schematic cross-sectional view for illustrating the X-ray tube of another embodiment. REFERENCE SIGNS 1 Electron gun; 1a Module; 2 Housing; 3 Focusing electrode; 4 Focusing electrode; 6 Rod pin; 6a Rod pin; 6b Rod pin; 7 Indirectly heated cathode; 7a Sleeve; 7c Heater; 7c1 Filament; 7c2 Lead; 8 Terminal; 8a Terminal; 8b Terminal; 9 Tab; 9a Tab plate; 10 Wire; 10a Wire; 10b Wire; 20 X-ray tube; 20a X-ray tube; 21 Package; 23 Target; 26 Package; 27 Target holder; 28 Target. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0008] Hereinafter, embodiments will be illustrated with reference to the drawings. In addition, in each drawing, the same reference signs are assigned to the same components, and detailed descriptions are appropriately omitted.

[0009] (Electron gun) Figure 1 FIG. Figure 1 is a schematic cross-sectional view for illustrating the electron gun 1 of the present embodiment. Figure 2 FIG. is a schematic three-dimensional cross-sectional view of the electron gun 1. Figure 3 FIG. Figure 2 is a schematic partial cross-sectional view of the electron gun 1. Figure 4 FIG. is a schematic three-dimensional partial cross-sectional view of the electron gun 1. As Figures 1 to 4 shown in FIG. Figure 3 , the electron gun 1 includes, for example, a housing 2, a focusing electrode 3, a focusing electrode 4, a holder 5, a rod pin 6, a indirectly heated cathode 7, a terminal 8, a tab 9, and a wire 10.

[0010] The housing 2 has a cylindrical shape and extends, for example, in one direction. The housing 2 can be provided as a cylinder having openings at both ends, for example. A hole 2a can be provided on the side surface of the housing 2. The hole 2a is used, for example, for aligning the position of the indirectly heated cathode 7 housed inside the housing 2, joining the wire 10, etc.

[0011] The focusing electrode 3 is provided at one opening of the housing 2. The focusing electrode 3 is formed of a conductive material such as metal and has, for example, a main body 3a and a flange 3b. The main body portion 3a and the flange 3b can be formed integrally. The main body portion 3a has a cylindrical shape, for example, and has a concave portion 3a1 that opens at an end on the side opposite to the indirectly heated cathode 7 side. A hole 3a2 that penetrates in the thickness direction is provided on the bottom surface of the concave portion 3a1. The flange 3b has a plate shape and is provided on the side surface of the main body portion 3a. The peripheral edge of the flange 3b is joined to the end of the housing 2.

[0012] The focusing electrode 4 is provided inside the housing 2. The focusing electrode 4 is provided on the flange 3b of the focusing electrode 3 through a spacer 11 formed of an insulating material such as ceramic, for example. The focusing electrode 4 faces the main body portion 3a of the focusing electrode 3. The focusing electrode 4 is formed of a conductive material such as metal and has a cylindrical shape, for example. The focusing electrode 4 has a concave portion 4b that opens at an end on the side opposite to the focusing electrode 3 side and a concave portion 4a that opens on the bottom surface of the concave portion 4b. A hole 4a1 that penetrates in the thickness direction is provided on the bottom surface of the concave portion 4a. The hole 3a2 of the focusing electrode 3 and the hole 4a1 of the focusing electrode 4 are provided, for example, substantially coaxially with the central axis of the indirectly heated cathode 7. The focusing electrodes 3 and 4 are provided on one end side (an example corresponding to the second end side) inside the housing 2.

[0013] Electrons released from the indirectly heated cathode 7 pass through the hole 4a1 of the focusing electrode 4 and the hole 3a2 of the focusing electrode 3 and are incident on the targets 23 and 28 described later. At this time, by controlling the voltage applied to the focusing electrode 4, the amount of electrons incident on the targets 23 and 28 can be increased or decreased. In addition, through the spacer 11, the distance between the hole 4a1 of the focusing electrode 4 and the hole 3a2 of the focusing electrode 3 is set to a prescribed focal length on the targets 23 and 28. That is, the focusing electrode 3 and the focusing electrode 4 constitute an electron lens that focuses the electrons released from the indirectly heated cathode 7. The X-ray tubes 20 and 20a including the electron gun 1 having such a structure can be, for example, microfocus X-ray tubes having a small focal spot.

[0014] The holding member 5 is provided, for example, inside the housing 2. The holding member 5 can be provided, for example, near the opening of the housing 2 on the side opposite to the side where the focusing electrode 3 is located. The holding member 5 is plate-shaped and is formed of an insulating material such as ceramic, for example.

[0015] The rod pins 6 are rod-shaped and are formed of a conductive material such as metal. A plurality of rod pins 6 can be provided. For example, a pair of rod pins 6a (equivalent to an example of the first rod pin) electrically connected to the indirectly heated cathode 7 and a pair of rod pins 6b (equivalent to an example of the second rod pin) electrically connected to the focusing electrode 3 and the focusing electrode 4 can be provided. The rod pins 6a and 6b are provided on the end side (equivalent to an example of the first end side) of the inside of the housing 2 on the side opposite to the side where the focusing electrodes 3 and 4 are provided. For example, the rod pins 6a and 6b can be fixed to the holding member 5 by brazing. The rod pins 6a and 6b extend, for example, in the direction along the central axis of the housing 2. One end of the rod pins 6a and 6b is provided inside the housing 2, and the other end of the rod pins 6a and 6b is provided outside the housing 2. A control device or the like provided in the inspection device 100 is electrically connected to the rod pins 6a and 6b.

[0016] The indirectly heated cathode 7 is provided, for example, inside the housing 2. The indirectly heated cathode 7 is provided on the focusing electrode 4 through a holding member 12 formed of a material having heat resistance and insulation such as ceramic, for example. In this case, the holding member 12 can be provided, for example, inside the concave portion 4b of the focusing electrode 4. Thus, it is easy to align the central axes of the hole 3a2 of the focusing electrode 3, the hole 4a1 of the focusing electrode 4, and the indirectly heated cathode 7.

[0017] The indirectly heated cathode 7 has, for example, a sleeve 7a, an emitter 7b, and a heater 7c. The sleeve 7a is cylindrical and is formed of metal or the like, for example. The emitter 7b is provided at the end of the sleeve 7a on the side closer to the focusing electrode 4. A layer containing an electron-emitting substance is provided on the surface of the emitter 7b on the side opposite to the side where the focusing electrode 4 is located. In addition, the emitter 7b can also be a so-called impregnated cathode or the like, for example.

[0018] The heater 7c is disposed inside the sleeve 7a. The heater 7c is formed of a conductive material such as metal, for example. The heater 7c has, for example, a filament 7c1 formed by winding a wire into a spiral shape and a pair of lead wires 7c2 connected to the ends of the filament 7c1. The filament 7c1 and the pair of lead wires 7c2 may be formed integrally. In this case, the filament 7c1 is disposed inside the sleeve 7a, and the ends of the pair of lead wires 7c2 on the side opposite to the filament 7c1 side are disposed outside the sleeve 7a. The pair of lead wires 7c2 extends, for example, in the direction along the central axis of the housing 2.

[0019] In addition, in order to electrically insulate the heater 7c from the sleeve 7a, a material having heat resistance and insulation is coated on the surface of the portion of the heater 7c disposed inside the sleeve 7a (for example, the filament 7c1). For example, ceramics such as alumina is coated on the surface of the filament 7c1.

[0020] The terminal 8 is, for example, rod-shaped and is formed of a conductive material such as metal. The terminal 8 extends, for example, in the direction along the central axis of the housing 2. A plurality of terminals 8 may be provided. For example, a pair of terminals 8a (an example of the first terminal) electrically connected to the heater 7c of the indirectly heated cathode 7 through the tab 9 and a pair of terminals 8b (an example of the second terminal) electrically connected to the focusing electrodes 3 and 4 may be provided. The pair of terminals 8a may be disposed, for example, at the end of the focusing electrode 4 on the side where the indirectly heated cathode 7 is provided through an insulating portion 13 formed of an insulating material such as ceramics. The pair of terminals 8b may be disposed, for example, at the end of the focusing electrode 4 on the side where the indirectly heated cathode 7 is provided.

[0021] The tab 9 is, for example, thin plate-shaped and is formed of a conductive material such as metal. A pair of tabs 9 may be provided. The pair of tabs 9 are respectively electrically connected to the lead wires 7c2 of the heater 7c provided on the indirectly heated cathode 7 and the terminal 8a.

[0022] The wire 10 is linear and is formed of a conductive material such as metal. For example, the wire 10 may be a nickel wire or the like having a wire diameter of about 0.5 mm. A plurality of wires 10 may be provided. The plurality of wires 10 are disposed inside the housing 2. For example, one end side of the wire 10a (an example of the first wire) is electrically connected to the stud 6a, and the other end side of the wire 10a is electrically connected to the terminal 8a. For example, one end side of the wire 10b (an example of the second wire) is electrically connected to the stud 6b, and the other end side of the wire 10b is electrically connected to the terminal 8b.

[0023] Here, the functions and effects of the terminal 8 and the wire 10 will be further described. Figure 5 It is a schematic cross-sectional view for illustrating the electron gun 300 of the comparative example. As Figure 5As shown, the electron gun 300 includes a housing 2, a focusing electrode 3, a focusing electrode 4, a holder 5, a rod pin 306, an indirectly heated cathode 7, and a tab 309.

[0024] The rod pins 306 are rod-shaped and a plurality of them are provided. For example, a pair of rod pins 306a electrically connected to the indirectly heated cathode 7 and a pair of rod pins 306b electrically connected to the focusing electrode 3 and the focusing electrode 4 are provided. The tabs 309 are thin plate-shaped and a pair of them are provided. The pair of tabs 309 respectively electrically connect the rod pins 306a to the heater 7c of the indirectly heated cathode 7. The rod pins 306b and the leads 7c2 of the heater 7c are electrically connected to each of the pair of tabs 309. That is, in the electron gun 300 of the comparative example, the aforementioned terminal 8a and the wire 10a are not provided, and the rod pin 306a is directly connected to the tab 309.

[0025] When electrically connecting the rod pin 306a and the tab 309, the electrical connection is made in a state where the filament 7c1 of the heater 7c is inserted into the sleeve 7a. In addition, the electrical connection is made in such a narrow space inside the housing 2. Therefore, when making the electrical connection, force is likely to be applied to the filament 7c1 through the tab 309. If force is applied to the filament 7c1, sliding may occur between the filament 7c1 and the sleeve 7a, and the insulating material on the surface of the filament 7c1 may sometimes peel off. If the insulating material on the surface of the filament 7c1 peels off, a short circuit may occur between the heater 7c and the sleeve 7a, which is a main factor causing the function of the electron gun 300 to decline and the electron gun 300 to malfunction.

[0026] In contrast, since the electron gun 1 of the present embodiment is provided with the terminals 8a, a module 1a having a focusing electrode 3, a focusing electrode 4, an indirectly heated cathode 7, terminals 8a, tabs 9, spacers 11, a holder 12, and an insulating portion 13 can be manufactured outside the housing 2. Then, the manufactured module 1a is inserted into the inside of the housing 2 from one end side of the housing 2, so that the module 1a can be fixed to one end of the housing 2. For example, the flange 3b of the focusing electrode 3 can be welded or brazed to the end of the housing 2.

[0027] Figure 6 It is a schematic exploded cross-sectional view for illustrating the manufacturing steps of the module 1a. First, a module 1a including a focusing electrode 3, a focusing electrode 4, an indirectly heated cathode 7, a pair of terminals 8a, and a tab plate 9a is manufactured.

[0028] For example, as Figure 6 shown, a pair of leads 7c2 of the heater 7c are electrically connected to the tab plate 9a. For example, a pair of leads 7c2 of the heater 7c can be welded or brazed to the tab plate 9a. In addition, the sleeve 7a provided with the emitter 7b is fixed to the inside of the hole of the holding member 12. The fixing of the sleeve 7a can be performed, for example, by brazing. In addition, the focusing electrode 3, the spacer 11, the focusing electrode 4, and the insulating portion 13 are stacked, and the terminal 8a is fixed to the insulating portion 13. These members can be fixed, for example, by brazing.

[0029] Next, the filament 7c1 of the heater 7c is inserted into the inside of the sleeve 7a. Then, in a state where the filament 7c1 is inserted into the sleeve 7a, the holding member 12 is fixed to the inside of the concave portion 4b of the focusing electrode 4. The fixing can be performed, for example, by brazing. Next, a pair of terminals 8a are electrically connected to the tab board 9a. For example, a pair of terminals 8a can be welded or brazed to the tab board 9a. That is, in the process of manufacturing the module 1a, a pair of leads 7c2 and a pair of terminals 8a of the heater 7c provided in the indirectly heated cathode 7 are electrically connected to the tab board 9a.

[0030] Next, the region of the tab board 9a to which one lead 7c2 and one terminal 8a are electrically connected is separated from the region of the tab board 9a to which the other lead 7c2 and the other terminal 8a are electrically connected. The tab board 9a is divided to form a pair of tabs 9. As described above, the module 1a having the focusing electrode 3, the focusing electrode 4, the indirectly heated cathode 7, the terminal 8, the tab 9, the spacer 11, the holding member 12, and the insulating portion 13 can be manufactured.

[0031] Here, as described above, before the filament 7c1 is inserted into the sleeve 7a, a pair of leads 7c2 of the heater 7c are electrically connected to the tab board 9a. Therefore, when a pair of leads 7c2 are electrically connected to the tab board 9a, peeling of the insulating material on the surface of the filament 7c1 can be suppressed.

[0032] In addition, before the tab board 9a is divided to form the tab 9, a pair of terminals 8a are electrically connected to the tab board 9a. That is, a pair of terminals 8a are electrically connected to the tab board 9a having a higher rigidity than the tab 9. Therefore, when connecting, force is not easily applied to the filament 7c1 through the tab board 9a. As a result, peeling of the insulating material on the surface of the filament 7c1 can be suppressed.

[0033] In addition, since the electrical connection of the leads 7c2 and the terminals 8a to the tab board 9a can be performed outside the housing 2, the workability can be improved. In addition, a welding jig or a brazing jig can be used as needed to fix the connection portion. Therefore, it becomes easier to suppress the application of force to the filament 7c1 during connection. As described above, since the terminal 8a is provided in the electron gun 1 of the present embodiment, it is possible to suppress the peeling of the insulating material on the surface of the filament 7c1.

[0034] (X-ray Tube and Inspection Apparatus) Next, the X-ray tube 20 will be exemplified. Figure 7 It is a schematic cross-sectional view for exemplifying the X-ray tube 20 of the present embodiment. As Figure 7 shown, the X-ray tube 20 includes, for example, an electron gun 1, an envelope 21, a holder 22, and a target 23.

[0035] The envelope 21 has, for example, an insulating portion 21a and a cover 21b. The insulating portion 21 is cylindrical with open ends on both sides. The insulating portion 21a can be formed of an insulating material such as glass or ceramic, for example. The cover 21b is provided at one end of the insulating portion 21a. A hole 21b1 is provided in the cover 21b. The cover 21b can be formed of metal or the like, for example. In this case, a high voltage is applied to the cover 21b (target 23) and the stem pin 6 of the electron gun 1. For example, the cover 21b (target 23) can be set as the anode, and the indirectly heated cathode 7 of the electron gun 1 can be set as the cathode.

[0036] The holder 22 has, for example, a cylindrical portion 22a and a flange 22b. The cylindrical portion 22a is a bottomed cylinder. A hole 22a1 is provided in the bottom surface of the cylindrical portion 22a. The electron gun 1 is provided inside the cylindrical portion 22a. In addition, the housing 2 of the electron gun 1 is joined to the inner wall of the cylindrical portion 22a in an airtight manner. The flange 22b is plate-shaped and provided on the side surface of the cylindrical portion 22a. The flange 22b is joined to the end of the insulating portion 21a on the side opposite to the side where the cover 21b is provided in an airtight manner.

[0037] The target 23 is plate-shaped and provided on the cover 21b. The target 23 closes the hole 21b1 of the cover 21b. The target 23 is joined to the cover 21b in an airtight manner. The target 23 has, for example, a plate material and a film provided on the surface of the plate material. The plate material includes a material that allows X-rays to penetrate. The material of the plate material is, for example, beryllium or the like. The thickness of the plate material is, for example, about 1 mm. The film provided on the surface of the plate material includes a material that generates X-rays when hot electrons collide. The material of the film is, for example, at least any one of Rh (rhodium), W (tungsten), Mo (molybdenum), and Cr (chromium). The thickness of the film is, for example, about 1 μm. The target 23 is a so-called transmission type target.

[0038] In addition, for example, the centers of the holes 22a1 in the cylindrical portion 22a and the holes 21b1 in the lid 21b may be set to overlap with the central axis of the electron gun 1. The internal space of the package 21 is in an environment that is decompressed compared to the atmospheric pressure (also referred to as a vacuum state).

[0039] When a voltage is applied to the indirectly heated cathode 7 (heater 7c) of the electron gun 1, the emitter 7b is heated to generate thermoelectrons 24. The generated thermoelectrons 24 are incident on the target 23. Since the thermoelectrons 24 are incident on the target 23, X-rays 25 are generated, and the generated X-rays 25 pass through the target 23 and are irradiated to the outside of the X-ray tube 20.

[0040] As Figure 7 shown, the X-ray tube 20 may be provided in the inspection device 100. For example, the X-ray tube 20 can be held by a holding member 101 provided in the inspection device 100. As described above, the X-ray tube 20 including the electron gun 1 may be a microfocus X-ray tube having a microfocus. Therefore, the X-ray tube 20 can be applied to, for example, an inspection device that magnifies a sample by high resolution for non-destructive inspection. For example, the inspection device 100 may be an X-ray penetration inspection device, an X-ray CT scanner, or the like. However, the use of the X-ray tube 20 is not limited to the above-exemplified uses.

[0041] Figure 8 is a schematic cross-sectional view for illustrating the X-ray tube 20a of another embodiment. As Figure 8 shown, the X-ray tube 20a includes, for example, an electron gun 1, a package 26, a holding member 22, a target holding member 27, and a target 28. The package 26 has, for example, an insulating portion 26a and a lid 26b. The insulating portion 26a may be set to be the same as the aforementioned insulating portion 21a, for example. The lid 26b may be set to be the same as the aforementioned lid 21b, for example.

[0042] The target holding member 27 is columnar and is joined to the lid 26b in an airtight manner. The target holding member 27 extends in the direction along the central axis of the package 26. One end of the target holding member 27 is provided inside the package 26 and faces the indirectly heated cathode 7 of the electron gun 1 with a predetermined distance therebetween. One end of the target holding member 27 is inclined with respect to the central axis of the electron gun 1. The other end of the target holding member 27 is exposed outside the package 26. The target holding member 27 may be formed of a conductive material such as metal. In this case, a high voltage is applied to the target holding member 27 and the stem pin 6 of the electron gun 1. For example, the target holding member 27 may be set as the anode, and the indirectly heated cathode 7 of the electron gun 1 may be set as the cathode.

[0043] The target 28 is plate-shaped and is disposed inside the package 26. The target 28 is disposed at an end of the target holder 27 that is inclined with respect to the central axis of the electron gun 1. Accordingly, the target 28 is inclined with respect to the central axis of the electron gun 1. The target 28 contains a material that generates X-rays when hot electrons 24 collide with it. The material of the target 28 is, for example, at least any one of Rh (rhodium), W (tungsten), Mo (molybdenum), and Cr (chromium). The target 28 is a so-called reflection-type target.

[0044] When a voltage is applied to the indirectly heated cathode 7 (heater 7c) of the electron gun 1, the emitter 7b is heated to generate hot electrons 24. The generated hot electrons 24 are incident on the target 28. Since the hot electrons 24 are incident on the target 28, X-rays 25 are generated, and the generated X-rays 25 are irradiated in a direction intersecting the central axis of the package 26. The irradiated X-rays 25 pass through the insulating portion 26a of the package 26 and are irradiated to the outside of the X-ray tube 20a.

[0045] Similar to the aforementioned X-ray tube 20, the X-ray tube 20a can be disposed in the inspection apparatus 100. For example, the X-ray tube 20a can be held by a holder 101 disposed in the inspection apparatus 100. The X-ray tube 20a including the electron gun 1 can also be a microfocus X-ray tube having a small focal spot. Accordingly, the X-ray tube 20a can also be used in an X-ray penetration inspection apparatus, an X-ray CT scanner, etc. However, the use of the X-ray tube 20a is not limited to the uses exemplified above.

[0046] (Method for manufacturing an electron gun) Next, an example of a method for manufacturing the electron gun 1 of the present embodiment will be illustrated. The method for manufacturing the electron gun 1 of the present embodiment can include, for example, the following steps. A step of manufacturing a module 1a having a focusing electrode 3, a focusing electrode 4, an indirectly heated cathode 7, a terminal 8, a tab 9, a spacer 11, a holder 12, and an insulating portion 13. A step of disposing the module 1a inside the housing 2 and fixing a plurality of rod pins 6 to the holder 5. A step of electrically connecting one end side of the wire 10 to the tab 9 and electrically connecting the other end side of the wire 10 to the rod pin 6.

[0047] The step of manufacturing the module 1a can be set to the same steps as those Figure 6 illustrated in, and thus, detailed description thereof is omitted. In addition, the step of disposing the module 1a and fixing a plurality of rod pins 6 to the holder 5 can apply known techniques, and thus, detailed description thereof is omitted.

[0048] Accordingly, hereinafter, the electrical connection between the wire 10 and the terminal 8 and the rod pin 6 will be described. The wire 10a can be welded or brazed to the terminal 8a and the stud 6a. The wire 10b can be welded or brazed to the terminal 8b and the stud 6b. In this case, the welding can be performed, for example, by laser welding or resistance welding.

[0049] As described above, in the manufacturing process of the module 1a, the terminal 8a is electrically connected to the tab 9. Therefore, one end of the wire 10a can be electrically connected to the terminal 8a. Thus, since force is not easily applied to the filament 7c1, peeling of the insulating material on the surface of the filament 7c1 can be suppressed.

[0050] In addition, preferably, when electrically connecting the wire 10a, after connecting one end of the wire 10a to the terminal 8a, the other end of the wire 10a is connected to the stud 6a. In this way, since the handling and deformation of the wire 10a become easier, force is even less likely to be applied to the filament 7c1. Therefore, peeling of the insulating material on the surface of the filament 7c1 can be further suppressed.

[0051] In addition, since the electrical connection of the wire 10b to the terminal 8b and the stud 6b has no direct influence on the force applied to the filament 7c1, the connection steps can be set arbitrarily.

[0052] Several embodiments of the present invention have been described above, but these embodiments are only examples and do not represent a limitation on the scope of the invention. Regarding the foregoing embodiments, as long as they have the features of the present invention, addition, deletion or design change of the constituent elements made by those skilled in the art, or addition, omission or condition change of the processes made in the art are all included in the scope of the present invention. In addition, the constituent elements included in the above-described respective embodiments can be combined as much as possible, and their combinations are also included in the scope of the present invention as long as they include the features of the present invention.

[0053] Hereinafter, remarks related to the foregoing embodiments are shown.

[0054] (Remark 1) An electron gun, comprising: A housing, the housing being cylindrical; A first stud, the first stud being provided on the first end side inside the housing; A focusing electrode, the focusing electrode being provided on the second end side inside the housing, which is on the side opposite to the first end side; An indirectly heated cathode, the indirectly heated cathode being provided on the focusing electrode; A first terminal, the first terminal being provided on the side of the focusing electrode where the indirectly heated cathode is provided through an insulating portion; A connecting piece, the connecting piece being electrically connected to a lead of a heater provided in the indirectly heated cathode and the first terminal; and A first wire, the first wire being provided inside the housing, one end side of the first wire being electrically connected to the first rod pin, and the other end side of the first wire being electrically connected to the first terminal.

[0055] (Supplementary Note 2) The electron gun according to Supplementary Note 1 further includes: A second terminal, the second terminal being provided on a side of the focusing electrode where the indirectly heated cathode is provided; A second rod pin, the second rod pin being provided on the first end side inside the housing; and A second wire, the second wire being provided inside the housing, One end side of the second wire being electrically connected to the second rod pin, and the other end side of the second wire being electrically connected to the second terminal.

[0056] (Supplementary Note 3) In the electron gun according to Supplementary Note 1 or 2, The indirectly heated cathode has a cylindrical sleeve for arranging the filament of the heater, A material with insulation property is coated on the surface of the filament.

[0057] (Supplementary Note 4) An X-ray tube, comprising: A package; The electron gun according to any one of Supplementary Notes 1 to 3, the electron gun being provided inside the package; and A target, the target generating X-rays due to the incidence of thermoelectrons from the electron gun.

[0058] (Supplementary Note 5) An inspection device, comprising the X-ray tube according to Supplementary Note 4.

Claims

1. An electron gun, characterized in that: include: A shell, the shell being in a cylindrical shape; a first lever pin disposed on a first end side of the interior of the housing; a focusing electrode disposed on a second end side of the housing opposite to the first end side; A heat-sensitive cathode, wherein the heat-sensitive cathode is disposed on the focusing electrode; a first terminal, the first terminal being disposed on a side of the focusing electrode where the heated cathode is disposed through an insulating portion; A contact piece, the contact piece being electrically connected to a lead of a heater provided on the heated cathode and the first terminal; as well as A first conductive wire is provided inside the housing, one end of the first conductive wire is electrically connected to the first lever pin, and the other end of the first conductive wire is electrically connected to the first terminal.

2. The electron gun according to claim 1, characterized in that Also includes: a second terminal, the second terminal being disposed on a side of the focusing electrode where the heated cathode is disposed; a second lever pin disposed on the first end side of the interior of the housing; as well as a second wire, the second wire being arranged inside the housing, One end of the second conductive wire is electrically connected to the second lever pin, and the other end of the second conductive wire is electrically connected to the second terminal.

3. The electron gun according to claim 1 or 2, characterized in that The heated cathode has a sleeve which is cylindrical and on which the filament of the heater is disposed. The surface of the filament is coated with an insulating material.

4. An X-ray tube, characterized in that: include: Encapsulation body; The electron gun according to claim 1 or 2, wherein the electron gun is arranged inside the package; as well as A target generates X-rays due to the incidence of thermal electrons from the electron gun.

5. An inspection device, characterized in that: The inspection device includes the X-ray tube according to claim 4.

Images