Electron beam generating source, electron beam irradiation device and X-ray irradiation device

Abstract

The electron beam generating source comprises: an electron emitting portion extending on a desired axis and emitting electrons; a supporting portion electrically connected to a power supply device for supplying power to the electron emitting portion; a tension holding portion connected between one end of the electron emitting portion and the supporting portion and maintaining tension of the electron emitting portion by a pressing force or a pulling force; and a power supply path portion, one end of which is electrically connected to the supporting portion and the other end of which is electrically connected to one end of the electron emitting portion. The resistance value of the tension holding portion is greater than the resistance value of the power supply path portion.

Description

Technical Field

[0001] The present invention relates to an electron beam generating source, an electron beam irradiating device and an X-ray irradiating device. Background Art

[0002] Patent Document 1 describes a fluorescent display tube that emits electrons from an electron emitting portion to a fluorescent body to cause the fluorescent body to emit light. In the electron beam generating source of the fluorescent display tube, a coil-shaped portion that forms the electron emitting portion into a coil shape is provided at a part of the linear electron emitting portion, and the tension of the electron emitting portion is maintained by the coil-shaped portion.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2002-93350 Summary of the invention

[0006] Problems to be solved by the invention

[0007] When a tension holding portion for holding the tension of the electron emitting portion is provided as in the coil-shaped portion of the fluorescent display tube described above, it is considered that the tension holding portion generates heat due to the flow of power in the tension holding portion, and the pressing force or the pulling force of the tension holding portion varies or deteriorates due to heat. When at least one of such variations and deteriorations in the pressing force etc. occurs, the tension holding portion cannot properly hold the tension of the electron emitting portion.

[0008] Therefore, an object of the present invention is to provide an electron beam generating source, an electron beam irradiating device, and an X-ray irradiating device capable of suppressing energization of a tension maintaining portion that maintains tension of an electron emitting portion and appropriately maintaining tension of the electron emitting portion.

[0009] Methods for solving problems

[0010] An electron beam generating source of one embodiment of the present invention comprises: an electron emitting portion, which extends on a desired axis and emits electrons; a supporting portion, which is electrically connected to a power supply device that supplies power to the electron emitting portion; a tension maintaining portion, which is connected between one end of the electron emitting portion and the supporting portion, and maintains the tension of the electron emitting portion by pressing force or stretching force; and a power supply path portion, one end of which is electrically connected to the supporting portion and the other end is electrically connected to one end of the electron emitting portion, and the resistance value of the tension maintaining portion is greater than the resistance value of the power supply path portion.

[0011] In the electron beam generating source, the tension of the electron emitting portion is maintained by the tension maintaining portion. In addition, in the electron beam generating source, two components, the tension maintaining portion and the power supply path portion, are connected between the supporting portion electrically connected to the power supply device and the electron emitting portion. The resistance value of the tension maintaining portion is greater than the resistance value of the power supply path portion. Therefore, the energization between the electron emitting portion and the supporting portion is not performed via the tension maintaining portion but via the power supply path portion. That is, the energization to the tension maintaining portion is suppressed. In this way, the electron beam generating source can suppress the energization to the tension maintaining portion that maintains the tension of the electron emitting portion, and appropriately maintain the tension of the electron emitting portion.

[0012] Alternatively, the electron beam generating source further includes a movable portion, which connects one end of the electron emitting portion to the other end of the tension holding portion and is movable along the axis, one end of the tension holding portion is connected to the supporting portion, and the other end of the power supply path portion and the other end of the tension holding portion are connected to the movable portion. In this case, the electron beam generating source can more reliably maintain the tension of the electron emitting portion and supply power via the movable portion connected to both the tension holding portion and the power supply path portion.

[0013] Alternatively, one end of the power supply path portion is connected to the support portion, and the length of the power supply path portion is longer than the length from the connection position between the power supply path portion and the support portion to the connection position between the power supply path portion and the movable portion. In this case, even when the movable portion moves, the electron beam generating source can more reliably supply power to the electron emitting portion because the power supply path portion can absorb the movement of the movable portion.

[0014] Alternatively, the power supply path may include a metal thin film portion whose thickness is smaller than its width. In this case, the power supply path can be easily bent to follow the movement of the movable portion, and power can be reliably supplied even when the movable portion moves.

[0015] The movable part may be formed of a conductive material. In this case, the electron beam generation source can more reliably electrically connect the electron emitting part and the power supply path part.

[0016] Alternatively, the support portion includes a housing portion having a storage space therein, and the connection portion between the power supply path portion and the movable portion and the connection portion between the tension holding portion and the movable portion are respectively located in the storage space. In this case, the electron beam generating source can protect the connection portions of these electrical connections from external factors through the housing portion, and can stably supply power to the connection portions.

[0017] The housing may support the movable part so that the movable part can move along the axis. In this case, the electron beam generation source can stably move the movable part, and the tension holding part can more reliably hold the tension on the electron emitting part.

[0018] Alternatively, the electron beam generating source further includes a movable portion, which is connected to one end of the electron emitting portion and is formed of a conductive material, the supporting portion includes a housing portion having a storage space therein, the housing portion includes a movable portion holding portion that holds the movable portion in a manner that the movable portion can move, and the other end of the power supply path portion is formed by electrically connecting the movable portion to the movable portion holding portion. In this case, the electron beam generating source can electrically connect the housing portion to the movable portion through the movable portion holding portion of the housing portion, and supply power to the electron emitting portion from the housing portion via the movable portion.

[0019] The tension holding portion may also be connected to the movable portion on the axis, and the tension of the electron emitting portion may be maintained via the movable portion by applying a tensile force to the movable portion. In this case, the electron beam generating source can easily make the tensile force of the tension holding portion act on the electron emitting portion via the movable portion along the axis direction, and the tension of the electron emitting portion can be easily maintained.

[0020] Alternatively, the support portion includes a housing portion, the housing portion includes an internal space for accommodating a tension holding portion, the tension holding portion being arranged between a movable portion tension bearing portion abutted by the tension holding portion in the movable portion and a housing tension bearing portion located closer to the electron emitting portion than the movable portion tension bearing portion in the housing portion, and the tension of the electron emitting portion is maintained via the movable portion by applying a pressing force to the movable portion. In this case, the electron beam generating source can easily maintain the tension of the electron emitting portion using the pressing force of the tension holding portion.

[0021] Alternatively, an insulating member made of a material having lower conductivity than the tension retaining portion may be provided between at least one of the tension retaining portion and the movable portion and between the tension retaining portion and the supporting portion. In this case, the electron beam generating source can further suppress the energization of the tension retaining portion and more reliably supply power to the electron emitting portion through the power supply path portion.

[0022] It is also possible to have an electron beam irradiation device including such an electron beam generating source, a main body for storing the electron beam generating source, and an electron extraction unit for extracting electrons from the electron beam generating source to the outside of the main body. In addition, it is also possible to have an X-ray irradiation device including such an electron beam generating source, a main body for storing the electron beam generating source, an X-ray generating unit for generating X-rays by incident electrons from the electron beam generating source, and an X-ray extraction unit for extracting X-rays to the outside of the main body. In this case, an electron beam irradiation device and an X-ray irradiation device capable of suppressing axial deviation of the electron emitting unit can be obtained.

[0023] Effects of the Invention

[0024] According to the present invention, it is possible to suppress the conduction of electricity to the tension maintaining portion that maintains the tension of the electron emitting portion, and to appropriately maintain the tension of the electron emitting portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a perspective view of the electron beam irradiation device according to the embodiment.

[0026] Figure 2 Yes means Figure 1 A partial cross-sectional view of the internal structure of an electron beam irradiation device.

[0027] Figure 3 It is along Figure 1 Cross-sectional view along line III-III.

[0028] Figure 4 It is a three-dimensional diagram of the filament unit.

[0029] Figure 5 is a cross-sectional view of the filament unit.

[0030] Figure 6 It is a cross-sectional perspective view of the tension holding unit.

[0031] Figure 7 is a cross-sectional view of the tension holding unit.

[0032] Figure 8 It is a cross-sectional perspective view of the tension maintaining unit according to the first modified example.

[0033] Fig. 9 It is a cross-sectional perspective view of a tension maintaining unit according to a second modified example.

[0034] Fig.10 It is a cross-sectional perspective view of a tension maintaining unit according to a third modified example.

[0035] Fig.11 It is a cross-sectional perspective view of a tension maintaining unit according to a fourth modified example.

[0036] Fig.12 It is a cross-sectional perspective view of a tension maintaining unit according to a fifth modified example.

[0037] Fig.13 It is a cross-sectional perspective view of a tension maintaining unit according to a sixth modified example.

[0038] Fig.14 It is a cross-sectional perspective view of a tension maintaining unit according to a seventh modified example.

[0039] Fig.15 This is a cross-sectional view showing an example of a structure for attaching a filament to a movable body. DETAILED DESCRIPTION

[0040] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings, the same or corresponding elements are denoted by the same reference numerals, and duplicate descriptions are omitted.

[0041] Figure 1 The electron beam irradiation device 1 shown is used to perform, for example, curing, sterilizing, or surface modification of the ink of the irradiation object by irradiating the irradiation object with an electron beam EB. In addition, the side irradiated with the electron beam EB by the electron beam irradiation device 1, that is, the electron beam emission side (window 9 side) is described as the "front side".

[0042] like Figure 1 to Figure 3 As shown, the electron beam irradiation device 1 includes a filament unit (electron beam generating source) 2, a vacuum container (main body) 3, a cathode holding member 4, a cathode holding member 5, a rail portion 6, a high voltage introduction insulating member 7, an insulating support member 8, and a window portion (electron extraction portion) 9. The filament unit 2 is an electron beam generating portion that generates an electron beam EB. In addition, the filament unit 2 is a long strip-shaped unit.

[0043] The vacuum container 3 is formed of a conductive material such as metal. The vacuum container 3 is substantially cylindrical. The vacuum container 3 forms a substantially cylindrical vacuum space R inside. The filament unit 2 is arranged inside the vacuum container 3 along the axial direction (long axis direction) of the substantially cylindrical vacuum space R. An opening 3a for connecting the vacuum space R with an external space is provided at a position on the front side of the filament unit 2 in the vacuum container 3. The window 9 is fixed to the opening 3a in a vacuum-tight manner.

[0044] The window portion 9 includes a window material 9a and a support body 9b. The window material 9a is formed into a thin film. As the material of the window material 9a, a material with excellent transmittance of the electron beam EB (such as beryllium, titanium, aluminum, etc.) is used. The support body 9b is arranged at a position closer to the vacuum space R side than the window material 9a, and supports the window material 9a. The support body 9b is a mesh-like component having a plurality of holes for allowing the electron beam EB to pass through.

[0045] An exhaust port 3b for exhausting the air in the vacuum container 3 is provided at a position behind the filament unit 2 in the vacuum container 3. A vacuum pump (not shown) is connected to the exhaust port 3b, and the air in the vacuum container 3 is exhausted by the vacuum pump. Thus, the interior of the vacuum container 3 becomes a vacuum space R. The openings 3c on the other side and the openings 3d on one side of the substantially cylindrical vacuum container 3 are closed by the flange 7a of the high voltage introduction insulating member 7 and the cover 3e, respectively.

[0046] A pair of cathode holding parts 4 and 5 that serve as cathode potential are respectively arranged in the vacuum container 3. Between the cathode holding part 4 on the other side and the cathode holding part 5 on one side, a rail part 6 that serves as cathode potential and also serves as a surrounding electrode that surrounds the filament unit 2 is provided. The rail part 6 is a conductive and elongated member with a roughly C-shaped cross section. The rail part 6 is configured so that the opening of the roughly C-shaped cross section faces the front side (window part 9 side). The rail part 6 holds the filament unit 2 in the inner part (inner space). For example, the filament unit 2 is inserted into the inner side of the rail part 6 through the insertion hole provided in the cathode holding part 5 and the insulating support part 8 in a state where the cover part 3e of the vacuum container 3 is removed, and is thereby held by the rail part 6.

[0047] The high voltage introduction insulating member 7 is provided at the end portion on the side of the opening 3c on the other side of the vacuum container 3. The other end portion of the high voltage introduction insulating member 7 protrudes to the outside of the vacuum container 3 through the opening 3c. The high voltage introduction insulating member 7 has a flange portion 7a extending outward in the radial direction thereof, and seals the opening 3c of the vacuum container 3. The high voltage introduction insulating member 7 is formed of an insulating material (for example, insulating resin such as epoxy resin, ceramic, etc.). The cathode holding member 4 holds one end portion of the high voltage introduction insulating member 7 in a state of being electrically insulated from the vacuum container 3 at the ground potential.

[0048] In addition, the high voltage introduction insulating component 7 is a high withstand voltage type connector for receiving a high voltage supply from a power supply device outside the electron beam irradiation device 1. A high voltage supply plug is inserted into the high voltage introduction insulating component 7 from a power supply device not shown. Internal wiring for supplying a high voltage supplied from the outside to the filament unit 2 and the like is provided inside the high voltage introduction insulating component 7. The internal wiring is covered with an insulating material constituting the high voltage introduction insulating component 7, and insulation from the vacuum container 3 is ensured.

[0049] The insulating support member 8 is provided at an end portion on the opening portion 3d side (end portion on the cover portion 3e side) of one side of the vacuum container 3. The insulating support member 8 is formed of an insulating material (for example, insulating resin such as epoxy resin, ceramic, etc.). The cathode holding member 5 holds the other end portion of the insulating support member 8 in a state of being electrically insulated from the vacuum container 3.

[0050] like Figure 3 to Figure 5 As shown, the filament unit 2 is configured as a unit in a manner that can be attached to and detached from the rail portion 6. The filament unit 2 includes a filament (electron emitting portion) 10, a main frame (frame portion) 11, a grid electrode 12, a sub-frame 13, a power supply line 14, a guide member 15, a terminal holding member 16, a filament fixing member 17, and a tension holding unit 20.

[0051] The main frame 11 is a long strip-shaped member with a substantially U-shaped (C-shaped) cross section. The main frame 11 is arranged so that the opening of the substantially U-shaped cross section faces the front side (window 9 side). A filament fixing member 17 is provided at the other end of the main frame 11 on the inner side (inner space) of the main frame 11. In addition, a tension holding unit 20 is provided at one end of the main frame 11 on the inner side (inner space) of the main frame 11.

[0052] The filament 10 is an electron emitting portion that is heated by power supply and emits electrons that become an electron beam EB. The filament 10 is a linear member that extends from one side to the other side and extends on a desired axis L. The filament 10 is formed of a high melting point metal material, such as a material containing tungsten as a main component. One end of the filament 10 is connected to a tension holding unit 20. The other end of the filament 10 is connected to a filament fixing member 17. In this way, the main frame 11 supports the tension holding unit 20 connected to one end of the filament 10 and the filament fixing member 17 connected to the other end of the filament 10, respectively.

[0053] The terminal holding member 16 is mounted on the other end of the main frame 11. The terminal holding member 16 holds the filament terminal T1 for supplying a current for the filament 10 to emit electrons, the high voltage terminal T2 for supplying a cathode potential to the filament unit 2, and the grid electrode terminal T3 for supplying an applied voltage to the grid electrode 12 in a mutually electrically insulated state. The filament terminal T1 is connected to the other end of the power supply line 14. The high voltage terminal T2 is electrically connected to the filament fixing member 17.

[0054] The sub-frame 13 is a long strip-shaped member with a substantially U-shaped cross section. The sub-frame 13 is arranged in parallel with the main frame 11. The power supply line 14 is connected to the tension holding unit 20 through the inner side (inner space) of the sub-frame 13 from the connection position with the filament terminal T1. The sub-frame 13 has a protection function for the power supply line 14. The main frame 11 and the sub-frame 13 are connected to each other by a plurality of guide members 15. The outer surface of the guide member 15 is in contact with the inner surface of the rail portion 6 in a slidable manner.

[0055] The grid electrode 12 is arranged in front of the filament 10 and supported by the guide member 15 via the insulating member 18. A plurality of holes are formed in the grid electrode 12 (see Figure 4 The grid electrode 12 is electrically connected to the grid electrode terminal T3 via wiring (not shown).

[0056] The tension holding unit 20 holds the tension of the filament 10. Here, the tension holding unit 20 can hold the tension of the filament 10 by pressing or pulling a movable body connected to one end of the filament 10 with a spring. In the present embodiment, the tension holding unit 20 holds the tension of the filament 10 by pulling the movable body with a spring. The tension holding unit 20 is mounted on the main frame 11 in a state of being electrically insulated from the main frame 11 via an insulating member or the like. One end of the power supply line 14 is connected to the tension holding unit 20. The tension holding unit 20 can supply power supplied via the power supply line 14 to the filament 10 while holding the tension of the filament 10.

[0057] The filament unit 2 is inserted and fixed to the inner side (inner space) of the rail portion 6 starting from the end on the other side where the filament terminal T1 and the like are provided, through the insertion holes provided in the cathode holding member 5 and the insulating support member 8. At the position where the filament unit 2 is inserted, the front ends of the filament terminal T1, the high voltage terminal T2, and the grid electrode terminal T3 are respectively in contact with the front ends of the three connection terminals provided in the high voltage introduction insulating member 7. Thus, the filament terminal T1 and the like are electrically connected to the connection terminals provided in the high voltage introduction insulating member 7.

[0058] The filament 10 emits electrons by applying a high negative voltage of tens of kV to hundreds of kV in a state where it is heated by being energized. A predetermined voltage is applied to the grid electrode 12. For example, a voltage of about 100V to 150V more positive than the negative voltage applied to the filament 10 may be applied to the grid electrode 12. The grid electrode 12 forms an electric field for extracting electrons and suppressing diffusion. As a result, the electrons emitted from the filament 10 are emitted to the front side from the holes provided in the grid electrode 12 as an electron beam EB.

[0059] Next, use Figure 6 and Figure 7 The tension holding unit 20 for holding the tension of the filament 10 is described in detail. In the following description, for convenience of description, the side (the other side) on which the filament 10 is provided with respect to the tension holding unit 20 is referred to as the "left side", and the side (one side) on which the tension holding unit 20 is provided with respect to the filament 10 is referred to as the "right side". That is, the left-right direction refers to the direction along the axis L extending from one side to the other side.

[0060] like Figure 6 and Figure 7As shown, the tension holding unit 20 includes a movable body (movable part) 21, a shell (support part, shell part) 22, a spring (tension holding part) 23 and a foil material (power supply path part) 24. The movable body 21 is connected to one end of the filament 10. The movable body 21 has a cylindrical part 21a and a connecting part 21b. The cylindrical part 21a is cylindrical and extends in the left-right direction. One end of the filament 10 is fixed to the end on the left side of the cylindrical part 21a. Various methods can be used to fix the cylindrical part 21a and the filament 10. The connecting part 21b is connected to the end on the right side of the cylindrical part 21a. The other end of the spring 23 and the other end of the foil material 24 are respectively connected to the connecting part 21b. The movable body 21 is formed of a conductive material. The movable body 21 is formed of materials such as stainless steel, copper, and copper alloy.

[0061] The movable body 21 is disposed on the axis L. In addition, the movable body 21 is disposed on the axis L, which means that the axis L is located inside the outer edge of the movable body 21 when viewed from the direction along the axis L. The same meaning applies to other components disposed on the axis L. In addition, the movable body 21 may be disposed in such a manner that the center of gravity of the movable body 21 is located on the axis L.

[0062] The housing 22 is a box having a storage space (internal space) S inside. The spring 23, the foil 24, and the right end of the movable body 21 are stored in the storage space S of the housing 22. The housing 22 can also be composed of a box portion 22a with one side opened and a cover portion 22b covering the opening of the box portion 22a, so that the spring 23 and the like can be stored in the storage space S. A guide hole (movable part holding portion) 22d is provided in the wall portion on the filament 10 side (the other side) of the housing 22, that is, the filament side wall portion 22c (the wall portion constituting the left side of the housing 22). The guide hole 22d extends along the axis L. In addition, the guide hole 22d is a cylindrical through hole extending along the axis L. The diameter of the guide hole 22d is larger than the diameter of the cylindrical portion 21a of the movable body 21 by a desired value. The guide hole 22d guides the cylindrical portion 21a of the movable body 21 so that it can move along the axis L. That is, the housing 22 holds the movable portion 21 such that the movable body 21 is movable along the axis L through the guide hole 22 d.

[0063] A power supply line connection portion 22f connected to one end of the power supply line 14 is provided on a wall portion on the side (one side) opposite to the filament 10 side in the housing 22, that is, a power supply side wall portion 22e (a wall portion constituting the right side of the housing 22). For example, the end of the power supply line 14 is electrically connected to the housing 22 at the power supply line connection portion 22f by a bolt. Thus, the housing 22 is electrically connected to a power supply device (power supply device) that supplies power to the filament 10 via the power supply line 14 and the like. The housing 22 is formed of a conductive material. The housing 22 is formed of, for example, stainless steel, copper, a copper alloy, or the like.

[0064] The spring 23 is stored in the storage space S of the housing 22. The spring 23 is set on the axis L. The other end of the spring 23 is connected to the end of the right side of the connecting portion 21b. The connection position of the spring 23 and the connecting portion 21b is located on the axis L. One end of the spring 23 is connected to the power supply side wall portion 22e of the housing 22. The housing 22 covers the spring 23 so that the spring 23 is not directly visible from the filament 10. The connection position (connection portion) of the spring 23 and the movable body 21 is located in the storage space S.

[0065] The spring 23 is a tension spring. The spring 23 applies a tension force to the movable body 21 in such a manner that the movable body 21 moves along the axis L. That is, the spring 23 pulls the movable body 21 from the connection position with the movable body 21 to one side direction along the axis L. The movable body 21 connects one end of the filament 10 to the other end of the spring 23. Thus, the spring 23 stretches the filament 10 via the movable body 21 by applying a tension force to the movable body 21, thereby maintaining the tension of the filament 10. The spring 23 is formed of materials such as stainless steel and Inconel. The spring 23 can be formed of a material different from that of the filament 10. The load of the spring 23 needs to be within the desired range during operation (when the filament 10 is energized). If it deviates from this range, the filament 10 may become loose, or plastically deform, or break, and other problems may occur. Therefore, if the load of the spring 23 is Fa, the allowable tensile load of the filament 10 is Fx, and the total weight of the movable body 21 and the friction force is Fy, the relationship of Fx+Fy>Fa must be established. Furthermore, due to the energization and heating of the filament 10, the allowable tensile load of the filament 10 is in the relationship of allowable tensile load Fx1 at room temperature>allowable tensile load Fx2 during heating, so it is necessary to pay attention. Therefore, the load of the spring 23 is preferably in the range of 0.01N to 1000N, more preferably in the range of 0.01N to 100N, and further preferably in the range of 0.1N to 10N.

[0066] The foil 24 is stored in the storage space S of the housing 22. The foil 24 serves as a power supply path for supplying the power supplied to the housing 22 via the power supply line 14 to the movable body 21. One end of the foil 24 is connected to the power supply side wall portion 22e of the housing 22, and the other end is connected to the connection portion 21b of the movable body 21. The connection portion between the foil 24 and the movable body 21 is located in the storage space S. Thus, the foil 24 is electrically connected to the filament 10 via the movable body 21. The foil 24 is formed of a material having better conductivity than the spring 23. That is, the resistance value of the spring 23 is greater than the resistance value of the foil 24. The foil 24 is formed of copper or the like as a material having good conductivity and good bendability. For example, the resistance of the spring 23 when formed of stainless steel is about 6Ω. For example, copper is used as the material of the foil 24, and its length is set to 50mm, for example. The resistivity of copper is 1.7×10-8Ω·m. Therefore, if the cross-sectional area of ​​the foil 24 is set to 1.4×10-2 mm 2 In the above manner, the resistance value of the foil 24 can be sufficiently reduced to 1 / 100 or less of the resistance value of the spring 23 formed of stainless steel.

[0067] The foil 24 is a thin film component (metal film portion) formed of metal. The thickness of the foil 24 is thinner than the width of the foil 24, and the width of the foil 24 is smaller than the length of the foil 24. The foil 24 extends from the power supply side wall portion 22e toward the movable body 21 side, and is fixed to the connecting portion 21b in a state where the front end portion is folded back into a U-shape. In this way, the foil 24 has a folded portion 24a folded back in a U-shape, and at its left end portion, it includes overlapping (double-layered) areas as a positional relationship along the axis L, and the areas are separated from each other in a direction perpendicular to the axis L. Therefore, the length of the foil 24 is longer than the spring 23, and is longer than the length (straight line length) from the connection position A of the foil 24 and the power supply side wall portion 22e to the connection position B of the foil 24 and the movable body 21. Thus, even when the movable body 21 moves along the axis L, the foil 24 can allow the movable body 21 to move by moving the position of the folded portion 24a in the foil 24 (making the doubled area larger or smaller) and maintain the state in which the power supply side wall portion 22e is connected to the movable body 21.

[0068] like Figure 7 As shown, the housing 22 may also include a partition 22g having one end fixed to the power supply side wall 22e and the other end extending toward the movable body 21. The partition 22g extends to a position to the left of the left end of the spring 23 in a manner that places the foil 24 when separated from the spring 23, thereby dividing the spring 23 and the foil 24. Thus, the foil 24 is prevented from contacting the spring 23.

[0069] Thus, in the tension holding unit 20, the tension of the filament 10 can be maintained by the tensile force of the spring 23. In addition, the length (free length) of the spring 23 is a length that can apply tensile force to the movable body 21 even when the filament 10 is lengthened due to thermal expansion. For example, when the material constituting the filament 10 is tungsten, if the filament 10 with a total length of 500 mm is heated to 2000°C, if the linear expansion coefficient of tungsten is set to 5.2×10 -6[1 / K](2000°C), it will lengthen by about 5mm due to thermal expansion. Therefore, in order to absorb the thermal expansion of the filament 10, it is necessary to enable the movable body 21 to move at least 5mm. In addition, it is more preferable to ensure a range of movement that also takes into account the thermal expansion of surrounding components (such as the main frame 11). Thus, even if the length of the filament 10 changes due to thermal expansion, the tension holding unit 20 can maintain the tension of the filament 10 by the tensile force of the spring 23. In this way, the filament 10 is maintained in a state of being stretched into a straight line by the tension holding unit 20.

[0070] In addition, in the tension holding unit 20, the power supply side wall portion 22e to which the power supply line 14 is connected and the movable body 21 to which the filament 10 is connected are connected via the spring 23 and the foil material 24, respectively. Here, the foil material 24 is formed of a material having a better conductivity than the spring 23. Thus, power is supplied from the power supply side wall portion 22e to the movable body 21 not via the spring 23 but mainly via the foil material 24. Thus, the heating of the spring 23 caused by the energization is suppressed, and the change or deterioration of the tensile force of the spring 23 due to the influence of heat is suppressed. In this way, the tension holding unit 20 can supply power to the filament 10 via the movable body 21 using the foil material 24 while maintaining the tension of the filament 10 using the spring 23. In more detail, the power supply to the filament 10 is via the movable body 21, so that the friction caused by the mechanical sliding action caused by the expansion and contraction of the spring 23 is borne by the movable body 21, so that mechanical damage to the filament 10 can be suppressed, and the maintenance of the tension of the filament 10 by the spring 23 and the influence of the foil 24 on the power supply to the filament 10 can be suppressed.

[0071] As described above, in the electron beam irradiation device 1 (filament unit 2), the tension of the filament 10 is maintained by the spring 23. In addition, in the electron beam irradiation device 1, since the resistance value of the spring 23 is larger than the resistance value of the foil 24, the energization of the spring 23 is suppressed. Thus, the deterioration of the spring 23 can be suppressed. In this way, the electron beam irradiation device 1 can suppress the energization of the spring 23 that maintains the tension of the filament 10, and appropriately maintain the tension of the filament 10.

[0072] The electron beam irradiation device 1 (filament unit 2) includes a movable body 21 that connects one end of the filament 10, the other end of the foil 24, and the other end of the spring 23. In this case, the electron beam irradiation device 1 can more reliably maintain the tension of the filament 10 and supply power via the movable body 21 connected to both the spring 23 and the foil 24. More specifically, the power supply to the filament 10 is via the movable body 21, and thus the friction caused by the mechanical sliding action caused by the expansion and contraction of the spring 23 is borne by the movable body 21. Therefore, mechanical damage to the filament 10 can be suppressed, and the influence of the spring 23 on the maintenance of the tension of the filament 10 and the foil 24 on the power supply to the filament 10 can be suppressed.

[0073] The length of the foil 24 is longer than the length (straight line length) from the connection position A between the foil 24 and the power supply side wall portion 22e to the connection position B between the foil 24 and the movable body 21. In this case, even if the movable body 21 moves due to thermal expansion of the filament 10, the foil 24 can absorb the movement of the movable body 21, so the filament 10 can be powered more reliably.

[0074] The thickness of the foil 24 is thinner than the width of the foil 24. In this case, the foil 24 can be easily bent following the movement of the movable body 21, and power can be reliably supplied even if the movable body 21 moves.

[0075] The movable body 21 is formed of a conductive material. In this case, the electron beam irradiation device 1 can more reliably electrically connect the filament 10 and the foil 24.

[0076] The connection portion between the spring 23 and the movable body 21 and the connection portion between the foil 24 and the movable body 21 are respectively located in the storage space S of the housing 22. In this case, the electron beam irradiation device 1 can protect these electrically connected connection portions from external factors through the housing 22, and can stably supply power to the connection portions.

[0077] The housing 22 supports the movable body 21 through the guide hole 22d so that the movable body 21 is movable along the axis L. In this case, the electron beam irradiation device 1 can stably move the movable body 21 and more reliably maintain the tension of the filament 10 by the spring 23.

[0078] The spring 23 is connected to the movable body 21 on the axis L, and the tension of the filament 10 is maintained via the movable body 21 by applying a tensile force to the movable body 21. In this case, the electron beam irradiation device 1 can easily make the tensile force of the spring 23 act on the filament 10 via the movable body 21 along the axis L direction, and can easily maintain the tension of the filament 10.

[0079] Next, various modifications will be described of the tension holding means provided in the electron beam irradiation device 1. The following description will focus on differences from the tension holding means 20 in the above-described embodiment and differences from the tension holding means in each modification.

[0080] (First Modification)

[0081] like Figure 8As shown, the tension holding unit 20A in the first variant includes a movable body 21A, a housing 22A, a spring 23 and an annular elastic body (power supply path portion) 25. The movable body 21A is cylindrical and extends in the left-right direction. One end of the filament 10 is fixed to the left end of the movable body 21A. The other end of the spring 23 is connected to the right end of the movable body 21A. The movable body 21A is set on the axis L. In addition, the movable body 21A is configured in such a way that the center of gravity of the movable body 21A is located on the axis L. The movable body 21A is formed of a conductive material. The movable body 21A is formed of, for example, a copper alloy, stainless steel, etc., which are materials with good conductivity.

[0082] The housing 22A is a box having a storage space S inside. The spring 23 is stored in the storage space S of the housing 22A. The housing 22A can also be composed of a box portion 22a with one side open so that the spring 23 can be stored in the storage space S. A guide hole 22d is provided in the filament side wall portion 22c of the housing 22A. The diameter of the guide hole 22d is larger than the diameter of the movable body 21A by a desired value. The length of the guide hole 22d in the direction of the axis L is longer than the length of the movable body 21A. The guide hole 22d guides the movable body 21A so that it can move along the axis L. That is, the housing 22A holds the movable body 21A through the guide hole 22d in a manner that the movable body 21A can move along the axis L. The housing 22A is formed of a conductive material. The housing 22A is formed of, for example, a copper alloy, stainless steel, or the like, which is a material with good conductivity.

[0083] The spring 23 is provided on the axis L. The other end of the spring 23 is connected to the end of the right side of the movable body 21A. The connection position of the spring 23 and the movable body 21A is located on the axis L. One end of the spring 23 is connected to the power supply side wall portion 22e of the housing 22A. The housing 22A covers the spring 23 so that the spring 23 is not directly visible from the filament 10.

[0084] The spring 23 applies a tensile force to the movable body 21A so as to move the movable body 21A along the axis L. That is, the spring 23 pulls the movable body 21A from the connection position with the movable body 21A to one side direction along the axis L. Thus, the spring 23 applies a tensile force to the movable body 21A to pull the filament 10 through the movable body 21A, thereby maintaining the tension of the filament 10.

[0085] The annular elastic body 25 is housed in the guide hole 22d of the housing 22A. The annular elastic body 25 serves as a power supply path for supplying the power supplied to the housing 22A via the power supply line 14 to the movable body 21A. The annular elastic body 25 is composed of an elastic member formed in an annular shape and having conductivity. The annular elastic body 25 is embedded in a recessed portion 21c extending over the entire circumferential area of ​​the outer peripheral surface of the cross section in a direction perpendicular to the axis L of the movable body 21A.

[0086] The radial (direction perpendicular to the axis L) outer peripheral portion (one end) of the annular elastic body 25 abuts against and is electrically connected to the inner peripheral surface of the guide hole 22d of the housing 22A. The radial inner peripheral portion (the other end) of the annular elastic body 25 abuts against and is electrically connected to the outer peripheral surface of the movable body 21A (the inner wall surface of the recess 21c). That is, when the annular elastic body 25 is embedded in the recess 21c, the diameter of its outer periphery is larger than the diameter of the outer periphery of the movable body 21A, and the diameter of its inner periphery is at least smaller than the diameter of the outer periphery of the movable body 21A. Thus, the annular elastic body 25 is electrically connected to the housing 22A, and is electrically connected to the filament 10 via the movable body 21A. The annular elastic body 25 is formed of a material with better electrical conductivity than the spring 23. That is, the resistance value of the spring 23 is greater than the resistance value of the annular elastic body 25. The annular elastic body 25 is formed of, for example, a copper alloy or the like, which is a material with good electrical conductivity.

[0087] In this way, in the tension holding unit 20A, similarly to the tension holding unit 20 in the embodiment, the tension of the filament 10 can be maintained by the tensile force of the spring 23. In addition, in the tension holding unit 20A, the housing 22A and the movable body 21A are connected by the spring 23 and the annular elastic body 25, respectively. In addition, the annular elastic body 25 is formed of a material with better conductivity than the spring 23. Thus, power is supplied from the housing 22A to the movable body 21A mainly through the annular elastic body 25, not through the spring 23. Thus, the heat generation of the spring 23 caused by the energization is suppressed, and the tensile force of the spring 23 is suppressed from changing or deteriorating due to the influence of heat. In this way, the tension holding unit 20A can supply power to the filament 10 through the annular elastic body 25 via the movable body 21A, while maintaining the tension of the filament 10 through the spring 23.

[0088] As described above, even when the electron beam irradiation device 1 includes the tension maintaining unit 20A, it is possible to achieve the same operational effects as when the electron beam irradiation device 1 includes the tension maintaining unit 20 in the embodiment.

[0089] Specifically, in the electron beam irradiation device 1 (filament unit 2), the tension of the filament 10 is maintained by the spring 23. In addition, in the tension holding unit 20A, since the resistance value of the spring 23 is larger than the resistance value of the annular elastic body 25, the power supply to the spring 23 is suppressed. Thus, the deterioration of the spring 23 can be suppressed. In this way, the electron beam irradiation device 1 including the tension holding unit 20A can suppress the power supply to the spring 23 that maintains the tension of the filament 10, and appropriately maintain the tension of the filament 10.

[0090] The electron beam irradiation device 1 (filament unit 2) includes a movable body 21A that connects one end of the filament 10 to one end of the spring 23 and the annular elastic body 25. In this case, the electron beam irradiation device 1 can more reliably maintain the tension of the filament 10 and supply power via the movable body 21A connected to both the spring 23 and the annular elastic body 25. In more detail, the power supply to the filament 10 is via the movable body 21A, and the friction caused by the mechanical sliding action caused by the expansion and contraction of the spring 23 is borne by the movable body 21A. Therefore, mechanical damage to the filament 10 can be suppressed, and the influence of the spring 23 on the maintenance of the tension of the filament 10 and the annular elastic body 25 on the power supply of the filament 10 can be suppressed.

[0091] The electron beam irradiation device 1 (filament unit 2) electrically connects the movable body 21A to the guide hole 22d of the housing 22A via the annular elastic body 25, thereby supplying power from the housing 22A to the filament 10. The annular elastic body 25 abuts against the inner circumference of the guide hole 22d and the outer circumference of the movable body 21A. Thus, the electron beam irradiation device 1 including the tension holding unit 20A electrically connects the housing 22A to the movable body 21A, and can supply power from the housing 22A to the filament 10 via the movable body 21A.

[0092] In this case, the electron beam irradiation device 1 including the tension holding unit 20A can easily hold the annular elastic body 25 by the recess 21c provided on the outer peripheral surface of the movable body 21A, and can more reliably supply power to the filament 10 through the annular elastic body 25.

[0093] The spring 23 is connected to the movable body 21A on the axis L, and the tension of the filament 10 is maintained via the movable body 21A by applying a tensile force to the movable body 21A. In this case, the electron beam irradiation device 1 including the tension maintaining unit 20A can easily make the tensile force of the spring 23 act on the filament 10 via the movable body 21A along the axis L direction, and can easily maintain the tension of the filament 10.

[0094] (Second Modification)

[0095] like Fig. 9As shown, the tension holding unit 20B in the second modified example includes a movable body 21B, a housing 22B, a spring (tension holding portion) 26, and a foil (power supply path portion) 27. The movable body 21B is connected to one end of the filament 10. The movable body 21B has a cylindrical portion 21a and a small-diameter cylindrical portion 21d. The small-diameter cylindrical portion 21d includes a main body 21d1 having a smaller diameter than the cylindrical portion 21a and a front end 21d2 having a smaller diameter than the main body 21d1. The main body 21d1 is connected to the left end of the cylindrical portion 21a, and the front end 21d2 is connected to the left end of the main body 21d1. One end of the filament 10 is fixed to the left end of the front end 21d2 of the small-diameter cylindrical portion 21d. The movable body 21B is set on the axis L. In addition, the movable body 21B is arranged in a manner that the center of gravity of the movable body 21B is located on the axis L. The movable body 21B is formed of a conductive material, such as stainless steel, copper, or a copper alloy.

[0096] The housing 22B is different from the housing 22A in the first modification (see Figure 8 ) also includes a housing spring receiving portion (housing tension bearing portion) 22h. The housing spring receiving portion 22h is provided on the surface of the filament side wall portion 22c on the filament 10 side (the other side). The housing spring receiving portion 22h is provided with a small diameter hole 22j through which the front end portion 21d2 of the small diameter cylindrical portion 21d of the movable body 21B can be inserted. The diameter of the small diameter hole 22j is smaller than the diameter of the guide hole 22d and larger than the diameter of the front end portion 21d2. The housing 22B is formed of a conductive material. The housing 22B is formed of materials such as stainless steel, copper, and copper alloy.

[0097] The spring 26 is accommodated in the guide hole 22d of the housing 22B. The spring 26 is arranged on the axis L. The main body 21d1 of the small diameter cylindrical portion 21d of the movable body 21B passes through the inner side of the spring 26. That is, the outer diameter of the spring 26 is smaller than the inner diameter of the guide hole 22d, and the inner diameter of the spring 26 is larger than the outer diameter of the main body 21d1 of the small diameter cylindrical portion 21d. One end of the spring 26 abuts against the end face on the left side of the cylindrical portion 21a of the movable body 21B. The other end of the spring 26 abuts against the right side surface of the housing spring receiving portion 22h. That is, the end face on the left side of the cylindrical portion 21a in the movable body 21B becomes the movable body spring receiving portion (movable part tension bearing portion) 21e abutted by the spring 26. The housing spring receiving portion 22h is located closer to the filament 10 side than the movable body spring receiving portion 21e. The spring 26 is disposed between the movable body spring receiving portion 21e and the case spring receiving portion 22h. The case spring receiving portion 22h covers the spring 26 so that the spring 26 cannot be directly seen from the filament 10 (the filament 10 and the spring 26 are separated).

[0098] The spring 26 is a compression spring. The spring 26 applies a pressing force to the movable body 21B so that the movable body 21B moves along the axis L. That is, the spring 26 presses the movable body 21B in one direction along the axis L from the contact position with the movable body 21B. The movable body 21B is connected to one end of the filament 10. Thus, the spring 26 applies a pressing force to the movable body 21B to pull the filament 10 in the right direction via the movable body 21B, thereby maintaining the tension of the filament 10. The spring 26 is formed of a material such as stainless steel or Inconel. The spring 26 may be formed of a material different from the filament 10.

[0099] The foil 27 is stored in the storage space S of the housing 22B. The foil 27 serves as a power supply path for supplying the power supplied to the housing 22B via the power supply line 14 to the movable body 21B. One end of the foil 27 is connected to the power supply side wall portion 22e of the housing 22B, and the other end is connected to the cylindrical portion 21a of the movable body 21B. Thus, the foil 27 is electrically connected to the filament 10 via the movable body 21B. The foil 27 is formed of a material having better electrical conductivity than the spring 26. That is, the resistance value of the spring 26 is greater than the resistance value of the foil 27. The foil 27 is formed of copper or the like as a material having good electrical conductivity and good flexibility.

[0100] The foil 27 is a thin film-shaped member (metal thin film portion) formed of metal. The thickness of the foil 27 is thinner than the width of the foil 27, and the width of the foil 27 is smaller than the length of the foil 27. The length of the foil 27 is longer than the length (the length of the straight line along the axis L) from the connection position A of the foil 27 and the power supply side wall portion 22e to the connection position B of the foil 27 and the movable body 21B. Thus, even when the movable body 21B moves along the axis L, the foil 24 can allow the movable body 21B to move and maintain the state in which the power supply side wall portion 22e is connected to the movable body 21B.

[0101] In this way, in the tension holding unit 20B, the tension of the filament 10 can be maintained by the pressing force of the spring 26. In addition, the length (free length) of the spring 26 is a length that can apply a pressing force to the movable body 21B even when the length of the filament 10 increases due to thermal expansion. Thus, the tension holding unit 20B can maintain the tension of the filament 10 by the pressing force of the spring 26 even when the length of the filament 10 changes due to thermal expansion. In this way, the filament 10 is maintained in a state of being stretched into a straight line by the tension holding unit 20B.

[0102] In addition, in the tension holding unit 20B, the housing 22B and the movable body 21B are connected by the spring 26 and the foil 27, respectively. Here, the foil 27 is formed of a material with better conductivity than the spring 26. Thus, power is supplied from the power supply side wall portion 22e to the movable body 21B not through the spring 26 but mainly through the foil 27. Thus, the heat generation of the spring 26 caused by the energization is suppressed, and the change in the pressing force of the spring 26 due to the influence of heat is suppressed. In this way, the tension holding unit 20B can supply power to the filament 10 via the movable body 21B using the foil 27, while maintaining the tension of the filament 10 using the spring 26.

[0103] As described above, even when the electron beam irradiation device 1 includes the tension maintaining unit 20B, it is possible to achieve the same operational effects as when the electron beam irradiation device 1 includes the tension maintaining unit 20 in the embodiment.

[0104] Here, in the tension holding unit 20B, a spring 26 is arranged between the movable body spring receiving portion 21e and the housing spring receiving portion 22h of the movable body 21B. The spring 26 applies a pressing force to the movable body 21B. In this case, the electron beam irradiation device 1 including the tension holding unit 20B can easily maintain the tension of the filament 10 using the pressing force of the spring 26.

[0105] (Third Modification)

[0106] like Fig.10 As shown, the tension holding unit 20C in the third modified example is configured to include the tension holding unit 20A in the first modified example (see Figure 8 ) is used to replace the tension holding unit 20B in the second modified example (see Fig. 9 ) in the structure. Specifically, the tension holding unit 20C includes a movable body 21C, a housing 22B, an annular elastic body (power supply path portion) 25, and a spring 26. A recess 21c is provided on the outer peripheral surface of the cylindrical portion 21a of the movable body 21C. The annular elastic body 25 is embedded in the recess 21c of the cylindrical portion 21a.

[0107] In the tension holding unit 20C, similarly to the tension holding unit 20B in the second variant, the tension of the filament 10 can be maintained by the pressing force of the spring 26. In addition, in the tension holding unit 20C, the housing 22B and the movable body 21C are connected respectively by the annular elastic body 25 and the spring 26. Here, the annular elastic body 25 is formed of a material with better conductivity than the spring 26. Thus, power is supplied from the housing 22B to the movable body 21C mainly through the annular elastic body 25, not through the spring 26. Thus, the heating of the spring 26 caused by the energization is suppressed, and the change of the pressing force of the spring 26 due to the influence of heat is suppressed. In this way, the tension holding unit 20C can supply power to the filament 10 via the movable body 21C using the annular elastic body 25, while maintaining the tension of the filament 10 using the spring 26.

[0108] As described above, even when the electron beam irradiation device 1 includes the tension maintaining unit 20C, it is possible to achieve the same operational effects as when the electron beam irradiation device 1 includes the tension maintaining unit 20B in the second modified example.

[0109] Here, in the tension holding unit 20C, a spring 26 is arranged between the movable body spring receiving portion 21e and the housing spring receiving portion 22h of the movable body 21C. The spring 26 applies a pressing force to the movable body 21C. In this case, the electron beam irradiation device 1 including the tension holding unit 20C can easily maintain the tension of the filament 10 using the pressing force of the spring 26.

[0110] (Fourth Modification)

[0111] like Fig.11 As shown, the tension holding unit 20D in the fourth modification is different from the tension holding unit 20B in the second modification (see Fig. 9 ) structure, and further includes an insulating ring (insulating member) 28 and an insulating ring (insulating member) 29. That is, the tension holding unit 20D includes a movable body 21B, a housing 22B, a spring 26, a foil material 27, an insulating ring 28 and an insulating ring 29.

[0112] The insulating ring 28 is arranged between the spring 26 and the housing spring receiving portion 22h. The insulating ring 28 electrically insulates the housing 22B from the spring 26. The insulating ring 28 is formed of a material having lower conductivity than the spring 26. The outer edge of the insulating ring 28 protrudes toward the spring 26 in the direction along the axis L in a manner of surrounding the outer periphery of the spring 26. Thus, the insulating ring 28 can prevent the outer periphery of the spring 26 from abutting against the inner periphery of the guide hole 22d. In addition, the inner periphery of the insulating ring 28 is also used to perform positioning in a direction perpendicular to the axis L of the spring 26, so that the contact between the spring 26 and the small-diameter cylindrical portion 21d of the movable body 21B is also suppressed.

[0113] Similarly, the insulating ring 29 is arranged between the movable body spring receiving portion 21e of the cylindrical portion 21a of the movable body 21B and the spring 26. The insulating ring 29 electrically insulates the movable body 21B from the spring 26. The insulating ring 29 is formed of a material having lower conductivity than the spring 26. The outer edge of the insulating ring 29 protrudes toward the side of the spring 26 along the axis L in a manner surrounding the outer peripheral portion of the spring 26. Thus, the insulating ring 29 can prevent the outer peripheral portion of the spring 26 from abutting against the inner peripheral surface of the guide hole 22d. In addition, positioning in a direction perpendicular to the axis L of the spring 26 is also performed by the inner peripheral portion of the insulating ring 29, so that the contact between the spring 26 and the small-diameter cylindrical portion 21d of the movable body 21B is also suppressed.

[0114] In addition, the tension maintaining unit 20D may be configured to include only one of the insulating ring 28 and the insulating ring 29 .

[0115] As described above, in the fourth modification, the tension holding unit 20D includes the insulating rings 28 and 29, thereby further suppressing the energization of the spring 26 and more reliably supplying power to the filament 10 using the foil 27. In addition, the tension holding unit 20D can further suppress the heating of the spring 26 caused by energization.

[0116] (Fifth Modification)

[0117] like Fig.12 As shown, the tension holding unit 20E in the fifth modification is different from the tension holding unit 20C in the third modification (see Fig.10 ) structure, and also includes an insulating ring (insulating component) 28 and an insulating ring (insulating component) 29. That is, the tension holding unit 20E includes a movable body 21C, a housing 22B, an annular elastic body 25, a spring 26, an insulating ring 28 and an insulating ring 29. The insulating rings 28 and 29 have the same structure as the insulating rings 28 and 29 in the fourth modified example.

[0118] As described above, in the fifth modification, the tension holding unit 20E includes the insulating rings 28 and 29, which can further suppress the current from flowing to the spring 26, and can more reliably supply power to the filament 10 by the annular elastic body 25. In addition, the tension holding unit 20E can further suppress the heating of the spring 26 caused by the energization.

[0119] Here, for example, when using Figure 6 and Figure 7 In the tension holding unit 20 in the embodiment described above, it is also possible to further suppress the flow of current to the spring 23. Specifically, Figure 6 and Figure 7The portion of the connection portion 21b of the tension holding unit 20 shown in the figure to which the spring 23 is connected (the portion to be hooked) may also be made of an insulating material (e.g., ceramic, etc.). Alternatively, the portion of the connection portion 21b to which the spring 23 is connected may be coated with an insulating coating. In addition, the spring 23 of the tension holding unit 20 may also be coated with an insulating coating. Similarly, for example, using Figure 8 The portion (hook portion) connected to the spring 23 in the movable body 21A of the tension holding unit 20A of the first modified example described may also be made of an insulating material (e.g., ceramics, etc.). Alternatively, an insulating coating may be applied to the portion of the movable body 21A connected to the spring 23. Furthermore, an insulating coating may be applied to the spring 23 of the tension holding unit 20A. Even in these cases, the tension holding units 20 and 20A can further suppress the flow of current to the spring 23, thereby further suppressing the heating of the spring 23 caused by the energization.

[0120] (Sixth Modification)

[0121] like Fig.13 As shown, the tension holding unit 20F in the sixth modification is obtained by dividing the housing 22 of the tension holding unit 20 in the embodiment into two. Specifically, the tension holding unit 20F includes a movable body 21, a housing 22F, a spring 23, and a foil 24. The housing 22F includes a first housing portion 22k and a second housing portion 22m.

[0122] The first housing portion 22k is provided with a guide hole 22d through which the cylindrical portion 21a of the movable body 21 passes. The second housing portion 22m has a storage space S for storing the spring 23 and the portion of the foil 24 on the power supply side wall portion 22e side. The first housing portion 22k and the second housing portion 22m are attached to the main frame 11 of the filament unit 2 via an insulator. That is, the first housing portion 22k and the second housing portion 22m are electrically insulated from each other.

[0123] As described above, the electron beam irradiation device 1 can achieve the same effect as the case of including the tension holding unit 20 in the embodiment even when the tension holding unit 20F is included. In addition, the tension holding unit 20F does not directly supply power to the movable body 21 from the inner peripheral surface of the guide hole 22d provided in the first housing portion 22k, but can supply power to the movable body 21 from the power supply side wall portion 22e via the foil material 24. In this way, since the tension holding unit 20F is not a structure in which power is supplied via mutually sliding parts, power can be supplied to the movable body 21 more reliably.

[0124] (Seventh Modification)

[0125] like Fig.14As shown in FIG. 1 , the tension holding unit 20G in the seventh modification is obtained by dividing the housing 22A of the tension holding unit 20A in the first modification into two parts. Specifically, the tension holding unit 20G includes a movable body 21A, a housing 22G, a spring 23, and an annular elastic body 25. The housing 22G includes a first housing portion 22n and a second housing portion 22p.

[0126] The first housing portion 22n is provided with a guide hole 22d through which the movable body 21A passes. One end of the spring 23 is connected to the right end of the movable body 21A. The other end of the spring 23 is connected to the second housing portion 22p. The first housing portion 22n and the second housing portion 22p are attached to the main frame 11 of the filament unit 2 via an insulator. That is, the first housing portion 22n and the second housing portion 22p are electrically insulated from each other.

[0127] The end of the power supply line 14 is connected to the first housing portion 22n. In the tension holding unit 20G, power is supplied from the first housing portion 22n to the filament 10 via the annular elastic body 25 and the movable body 21A. This suppresses the heating of the spring 23 caused by power supply, and suppresses the variation of the tensile force of the spring 23 due to the influence of heat. In this way, the tension holding unit 20G can supply power to the filament 10 via the annular elastic body 25 via the movable body 21A, while maintaining the tension of the filament 10 through the spring 23.

[0128] (An example of a method for fixing a filament)

[0129] Next, an example of a method for fixing the filament 10 to the front end portion of the movable body 21 of the tension holding unit 20 in the embodiment will be described. The method for fixing the filament 10 described below can also be applied to various modified examples of the tension holding unit described above. Fig.15 As shown, a bolt hole 21f extending along the axis L is provided on the front end face (the other end face) of the cylindrical portion 21a of the movable body 21. A filament fixing component 40 is mounted on the front end portion (one end side portion) of the filament 10. The filament fixing component 40 includes a barrel 41 and a flange 42. The front end portion of the filament 10 is fixed by passing through the barrel 41. Here, the barrel 41 may be mounted on the filament 10 by clamping the front end portion of the filament 10 on the inner circumferential surface by riveting. The flange 42 extends outward from the outer circumferential surface of the end portion of the barrel 41 on the movable body 21 side.

[0130] The filament fixing member 40 is fixed to the front end of the movable body 21 by means of a hole bolt 50. The hole bolt 50 is provided with a through hole 50a extending in the axial direction of the hole bolt 50. The barrel 41 of the filament fixing member 40 and a part of the filament 10 are passed through the through hole 50a in such a manner that the flange 42 abuts against the front end of the hole bolt 50. The hole bolt 50 is attached to the bolt hole 21f of the cylindrical portion 21a in a state where the barrel 41 and the like are passed through the through hole 50a. The filament fixing member 40 attached to the front end of the filament 10 is fixed to the front end of the cylindrical portion 21a by sandwiching the flange 42 between the front end of the hole bolt 50 and the bottom of the bolt hole 21f of the cylindrical portion 21a.

[0131] In this way, Fig.15 In the structure shown, the filament 10 can be easily attached and detached from the movable body 21 by using the bolt 50 with a hole. Therefore, in this structure, it is easy to replace the filament 10. In addition, according to this structure, the movable body 21 can suppress the axis deviation and can easily pull the filament 10 in the axis L direction.

[0132] The embodiments and various modifications of the present invention have been described above, but the present invention is not limited to the above-described embodiments and various modifications. In addition, the structure described below can be applied to all embodiments and various modifications as much as possible. For example, in the tension holding unit 20 of the embodiment, the movable body 21 may not be provided. In this case, the ends of the spring 23 and the foil 24 may also be directly connected to the ends of the filament 10.

[0133] In the tension maintaining unit 20 of the embodiment, the shapes of the movable body 21 and the guide hole 22d are not limited to the cylindrical shape extending along the axis L. The movable body 21 and the guide hole 22d may be shapes other than the cylindrical shape, for example, a polygonal shape.

[0134] In the tension maintaining unit 20A of the first modification, the annular elastic body 25 is not limited to being fitted into the recess 21c of the movable body 21A. For example, the annular elastic body 25 may be fitted into a recess extending over the entire circumferential area of ​​the inner peripheral surface of the guide hole 22d.

[0135] In the tension holding unit 20A of the first variant, the power supply path portion connecting the movable body 21A and the housing 22A includes an annular annular elastic body 25, but the power supply path portion may not be annular. In addition, the recessed portion 21c provided on the outer peripheral surface of the movable body 21A may not be provided over the entire circumferential area of ​​the outer peripheral surface of the movable body 21A. The recessed portion 21c may also be provided only on a portion of the outer peripheral surface of the movable body 21A. In this case, the power supply path portion connecting the movable body 21A and the housing 22A only needs to be in the shape of the recessed portion provided on the outer peripheral surface of the movable body 21A. Similarly, in the case where the power supply path portion connecting the movable body 21A and the housing 22A is embedded in the recessed portion provided in the guide hole 22d, the recessed portion provided in the guide hole 22d may not be provided over the entire circumferential area of ​​the inner peripheral surface of the guide hole 22d.

[0136] In addition, the filament unit 2 can also be used as an electron beam generating source provided in an X-ray irradiation device that irradiates X-rays. When the filament unit 2 is used as an electron beam generating source of an X-ray irradiation device, it includes: a main body that accommodates the filament unit 2; an X-ray target (such as tungsten, molybdenum, etc.) as an X-ray generating unit that generates X-rays by the incidence of electrons from the filament unit 2; and an X-ray extraction unit for extracting X-rays to the outside of the main body. In this case, as an example of the X-ray extraction unit, Figure 1 The window 9 shown may also be changed to a window for X-ray irradiation composed of a window material having high X-ray transmittance (e.g., beryllium, diamond, etc.) and an X-ray target disposed on the surface of the window material on the side of the vacuum space R. Thus, the electron beam EB emitted from the filament unit 2 can be incident on the X-ray target, and X-rays can be emitted from the X-ray target.

[0137] At least part of the above-described embodiments and various modifications may be arbitrarily combined.

[0138] Description of Reference Numerals

[0139] 1…Electron beam irradiation device

[0140] 2…Filament unit (electron beam generating source)

[0141] 10…Filament (electron emission part)

[0142] 20, 20A~20G…Tension holding unit

[0143] 21, 21A to 21C… movable body (movable part)

[0144] 21e…Movable body spring receiving portion (movable part tension receiving portion)

[0145] 22, 22A, 22B, 22F, 22G ... housing (supporting part housing part)

[0146] 22d...guide hole (movable part holding part)

[0147] 22h…Case spring receiving part (case tension receiving part)

[0148] 23, 26…Spring (tension retaining part)

[0149] 24, 27…Foil (power supply path, metal thin film)

[0150] 25…Annular elastic body (power supply path)

[0151] 28, 29…Insulating ring (insulating part)

[0152] L…Axis

[0153] S…Storage space (internal space).

Claims

1. An electron beam generating source, comprising: an electron emitting portion extending in a desired axis and emitting electrons; a support portion electrically connected to a power supply device for supplying power to the electron emitting portion; a tension holding portion connected between one end of the electron emitting portion and the supporting portion, and maintaining the tension of the electron emitting portion by a pressing force or a stretching force; and a power supply path portion, one end of which is electrically connected to the support portion, and the other end of which is electrically connected to the one end of the electron emitting portion, The resistance value of the tension holding portion is greater than the resistance value of the power supply path portion, The electron beam generating source further includes a movable portion, which is connected to one end of the electron emitting portion and is formed of a conductive material. The support portion includes a housing portion having a storage space therein. The housing portion includes a movable portion holding portion that holds the movable portion in a manner that allows the movable portion to move. The other end of the power supply path portion is configured to be electrically connected to the movable portion holding portion via the movable portion.

2. An electron beam generating source, comprising: an electron emitting portion extending in a desired axis and emitting electrons; a support portion electrically connected to a power supply device for supplying power to the electron emitting portion; a tension holding portion connected between one end of the electron emitting portion and the supporting portion, and maintaining the tension of the electron emitting portion by a pressing force or a stretching force; and a power supply path portion, one end of which is electrically connected to the support portion, and the other end of which is electrically connected to the one end of the electron emitting portion, The resistance value of the tension holding portion is greater than the resistance value of the power supply path portion, The electron beam generating source further includes a movable portion, the movable portion connecting the one end of the electron emitting portion and the other end of the tension holding portion and being movable along the axis. One end of the tension holding portion is connected to the support portion, and the other end of the power supply path portion and the other end of the tension holding portion are connected to the movable portion. The tension maintaining portion is connected to the movable portion on the axis, and maintains the tension of the electron emitting portion via the movable portion by applying the tensile force to the movable portion.

3. An electron beam generating source, comprising: an electron emitting portion extending in a desired axis and emitting electrons; a support portion electrically connected to a power supply device for supplying power to the electron emitting portion; a tension holding portion connected between one end of the electron emitting portion and the supporting portion, and maintaining the tension of the electron emitting portion by a pressing force or a stretching force; and a power supply path portion, one end of which is electrically connected to the support portion, and the other end of which is electrically connected to the one end of the electron emitting portion, The resistance value of the tension holding portion is greater than the resistance value of the power supply path portion, The electron beam generating source further includes a movable portion, the movable portion connecting the one end of the electron emitting portion and the other end of the tension holding portion and being movable along the axis. One end of the tension holding portion is connected to the support portion, and the other end of the power supply path portion and the other end of the tension holding portion are connected to the movable portion. The support portion includes a housing portion, the housing portion including an internal space for accommodating the tension maintaining portion therein. The tension maintaining portion is arranged between a movable portion tension bearing portion of the movable portion against which the tension maintaining portion abuts and a shell tension bearing portion of the shell portion located closer to the electron emitting portion than the movable portion tension bearing portion, and the tension of the electron emitting portion is maintained via the movable portion by applying the pressing force to the movable portion.

4. An electron beam generating source, comprising: an electron emitting portion extending in a desired axis and emitting electrons; a support portion electrically connected to a power supply device for supplying power to the electron emitting portion; a tension holding portion connected between one end of the electron emitting portion and the supporting portion, and maintaining the tension of the electron emitting portion by a pressing force or a stretching force; and a power supply path portion, one end of which is electrically connected to the support portion, and the other end of which is electrically connected to the one end of the electron emitting portion, The resistance value of the tension holding portion is greater than the resistance value of the power supply path portion, The electron beam generating source further includes a movable portion, the movable portion connecting the one end of the electron emitting portion and the other end of the tension holding portion and being movable along the axis. One end of the tension holding portion is connected to the support portion, and the other end of the power supply path portion and the other end of the tension holding portion are connected to the movable portion. An insulating member made of a material having lower conductivity than that of the tension maintaining portion is provided at least at one of a position between the tension maintaining portion and the movable portion and a position between the tension maintaining portion and the supporting portion.

5. The electron beam generating source according to any one of claims 2 to 4, wherein The one end of the power supply path portion is connected to the support portion, The length of the power supply path portion is longer than a length from a connection position between the power supply path portion and the support portion to a connection position between the power supply path portion and the movable portion.

6. The electron beam generating source according to claim 5, wherein: The power supply path portion has a metal thin film portion, The thickness of the metal thin film portion is smaller than the width of the metal thin film portion.

7. The electron beam generating source according to any one of claims 2 to 4, wherein The movable portion is formed of a conductive material.

8. The electron beam generating source according to claim 5, wherein: The movable portion is formed of a conductive material.

9. The electron beam generating source according to claim 6, wherein: The movable portion is formed of a conductive material.

10. The electron beam generating source according to any one of claims 2 to 4, wherein The support portion includes a housing portion having a storage space therein. A connection portion between the power supply path portion and the movable portion and a connection portion between the tension maintaining portion and the movable portion are respectively located in the storage space.

11. The electron beam generating source according to claim 5, wherein: The support portion includes a housing portion having a storage space therein. A connection portion between the power supply path portion and the movable portion and a connection portion between the tension maintaining portion and the movable portion are respectively located in the storage space.

12. The electron beam generating source according to claim 6, wherein: The support portion includes a housing portion having a storage space therein. A connection portion between the power supply path portion and the movable portion and a connection portion between the tension maintaining portion and the movable portion are respectively located in the storage space.

13. The electron beam generating source according to claim 7, wherein: The support portion includes a housing portion having a storage space therein. A connection portion between the power supply path portion and the movable portion and a connection portion between the tension maintaining portion and the movable portion are respectively located in the storage space.

14. The electron beam generating source according to claim 8, wherein: The support portion includes a housing portion having a storage space therein. A connection portion between the power supply path portion and the movable portion and a connection portion between the tension maintaining portion and the movable portion are respectively located in the storage space.

15. The electron beam generating source according to claim 9, wherein: The support portion includes a housing portion having a storage space therein. A connection portion between the power supply path portion and the movable portion and a connection portion between the tension maintaining portion and the movable portion are respectively located in the storage space.

16. The electron beam generating source according to claim 10, wherein: The housing portion supports the movable portion so that the movable portion is movable along the axis.

17. The electron beam generating source according to any one of claims 11 to 15, wherein The housing portion supports the movable portion so that the movable portion is movable along the axis.

18. An electron beam irradiation device, comprising: The electron beam generating source according to any one of claims 1 to 17; a main body portion, which accommodates the electron beam generating source; and The electron extraction portion is used to extract the electrons from the electron beam generation source to the outside of the main body portion.

19. An X-ray irradiation device, comprising: The electron beam generating source according to any one of claims 1 to 17; a main body portion, which accommodates the electron beam generating source; and An X-ray generating unit that generates X-rays by incident electrons from the electron beam generating source; and The X-ray extraction unit is used to extract the X-rays to the outside of the main body.

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