JP6945584B2 - X-ray tube - Google Patents

Description

The present invention relates to an X-ray tube.

An X-ray tube usually includes a cathode that emits electrons and an anode that receives electrons emitted by the cathode to generate X-rays in a vacuum tube such as a glass enclosure. X-rays are generated in all directions from the position where electrons collide, that is, the position where X-rays are generated (so-called focal point). However, in taking an X-ray image or the like, only the X-rays generated in a predetermined direction are used, and the X-rays generated in other directions are not used as unnecessary X-rays. Therefore, in the conventional X-ray tube, unnecessary X-rays are shielded by covering the outside of the X-ray tube with a housing using an X-ray shielding material such as lead.

Further, the X-ray tube described in Patent Document 1 uses an X-ray shielding material for a disk-shaped member for supporting the cathode in order to shield unnecessary X-rays, so that the X-ray tube is inside the X-ray tube. It shields some unnecessary X-rays. Similarly, in the X-ray tube described in Patent Document 2, a part of unnecessary X-rays is shielded inside the X-ray tube by arranging an X-ray shielding disk between the cathode and the anode.

Japanese Unexamined Patent Publication No. 2001-273998 Special Table 2006-523005

An object of the present invention is to provide a lightweight X-ray tube as compared with the case where a shielding member is installed only on the outside of an enclosure which is a housing for accommodating a cathode assembly including a cathode and an anode. do.

The X-ray tube of the present invention includes an enclosure that is a housing, a cathode assembly that emits electrons inside the enclosure, a first member that extends at least a part to the outside of the enclosure, and a first member. It has a second member that is perpendicular to the central axis of the member, is in contact with the first member, and has a higher X-ray shielding property than the first member, and emits electrons emitted by the cathode assembly. It comprises a target that receives and generates X-rays, and an anode that has the target, and the end of the first member including the target is inclined with respect to the central axis of the first member. It is a slope, and the end portion of the second member forms a plane flush with the slope . The plane passing through the slope of the end of the first member intersects the outer peripheral surface of the end of the second member or intersects the inside of the end of the second member.

The second member preferably has a higher specific density than the first member.

The first member preferably has a higher thermal conductivity than the second member.

It is preferable that the first member is made of copper or an alloy containing copper and molybdenum, and the second member is made of an alloy containing copper and molybdenum.

The second member preferably has a higher molybdenum content than the first member.

The second member includes a first content rate portion in which the molybdenum content is the first content rate, and a second content rate portion in which the molybdenum content rate is higher than the first content rate. However, the distance from the first member to the second content rate portion is preferably longer than the distance from the first member to the first content rate portion.

It is preferable that the second member has a higher molybdenum content as it is farther from the first member.

The anode preferably has a large-diameter portion having a second member in addition to the first member and a small-diameter portion composed of the first member and having no second member inside the enclosure.

The first member preferably has a diameter of 8 mm or more.

A tube wall that shields X-rays from at least a part of the surface of the enclosure belonging to the cathode side when dividing the cathode side part including the cathode assembly and the anode side part including the anode with a plane including the anode surface as a boundary. It is preferable to provide a shielding member.

Of the boundary surfaces between the portion having the pipe wall shielding member and the portion not having the pipe wall shielding member, the boundary surface closest to the plane including the anode surface is preferably parallel to the anode surface.

Of the boundary surfaces between the portion having the pipe wall shielding member and the portion not having the pipe wall shielding member, the boundary surface closest to the plane including the anode surface is on the intersection of the plane including the anode surface and the enclosure, or It is preferably located on the anode side.

Of the boundary surfaces of the portion having the pipe wall shielding member and the portion not having the pipe wall shielding member, the shape of the boundary line at the boundary surface closest to the plane including the anode surface is preferably a circle or an ellipse.

It is preferable to further provide an additional shielding member that shields X-rays between the second member and the surrounding device.

The additional shielding member is preferably partially joined to the second member.

When the pipe wall shielding member and the additional shielding member are provided, it is preferable that the pipe wall shielding member shields X-rays at least in a portion where the additional shielding member does not shield X-rays.

According to the present invention, it is possible to provide a lightweight X-ray tube as compared with the case where the X-ray shielding member is installed only on the outside of the enclosure, which is a housing that houses the cathode assembly including the cathode and the anode.

It is sectional drawing which shows the outline of the X-ray tube. It is sectional drawing which shows the structure of the shielding part. It is explanatory drawing which shows the relative size of a cathode assembly and a shielding part. It is explanatory drawing which shows the action by providing the shielding part. It is sectional drawing which shows the shielding part which separated the 1st shielding part and the 2nd shielding part. It is sectional drawing which shows the other shielding part which separated the 1st shielding part and the 2nd shielding part. It is sectional drawing of the shielding part which has the inclined first shielding part. It is sectional drawing of the shielding part which has the inclined 2nd shielding part. It is sectional drawing which shows the shielding part which separated the 1st shielding part and the 2nd shielding part. It is sectional drawing which shows the shielding part which separated the 1st shielding part and the 2nd shielding part. It is sectional drawing which shows the shielding part which made the anode surface and a part of the 2nd shielding part vertical. It is sectional drawing which shows the shielding part which made a part of the 2nd shielding part parallel to the X-ray detector. It is sectional drawing which shows the shielding part which deformed the 2nd shielding part. It is sectional drawing which shows the shielding part which deformed the 2nd shielding part. It is sectional drawing which shows the shielding part which deformed the 2nd shielding part. It is sectional drawing which shows the shielding part which deformed the 2nd shielding part. It is sectional drawing which shows the deformed shielding part. It is sectional drawing which shows the deformed shielding part. Further, it is sectional drawing of the shielding part provided with the shielding member. It is sectional drawing of the shielding part having an ellipsoidal shape. It is sectional drawing of the shielding part which the 2nd shielding part protruded to the anode side. It is sectional drawing of the shielding part which the 2nd shielding part protruded to the anode side. It is sectional drawing of the shielding part which electrically connected the 2nd shielding part with a 2nd electrode. It is sectional drawing of the shielding part which electrically connected the 1st shielding part with 1st electrode. It is sectional drawing of the shielding part which bonded the 1st shielding part and a cathode assembly. It is sectional drawing of the shielding part which bonded the 2nd shielding part and a cathode assembly. It is sectional drawing of the shielding part which bonded the 1st shielding part and 2nd shielding part, and a cathode assembly. It is explanatory drawing which shows the edge of the 1st shielding part and the 2nd shielding part. It is explanatory drawing which shows the rounded open end. It is explanatory drawing which shows the rounded connection part. It is explanatory drawing which shows the edge when the 1st shielding part and the 2nd shielding part are separated. It is sectional drawing of the X-ray tube provided with the tube wall shielding member. It is sectional drawing of the shielding part which formed the 1st shielding part and the 2nd shielding part by different materials. It is sectional drawing of the X-ray tube which has an anode composed of 1st member and 2nd member. It is explanatory drawing which shows the arrangement of the 2nd member. It is explanatory drawing which shows the structure of the 2nd member. It is explanatory drawing which shows the structure of the 2nd member. It is a graph which shows the content rate of molybdenum (Mo). It is a graph which shows the content rate of copper (Cu). It is a graph which shows the content rate of molybdenum (Mo). It is a graph which shows the content rate of molybdenum (Mo). It is explanatory drawing which shows the operation of the anode composed of the 1st member and the 2nd member. It is sectional drawing of the X-ray tube provided with the tube wall shielding member. It is explanatory drawing which shows the arrangement of the pipe wall shielding member. It is explanatory drawing which shows the arrangement of the pipe wall shielding member. It is sectional drawing of the X-ray tube provided with the additional shielding member. It is explanatory drawing which shows the shape of the additional shielding member. It is explanatory drawing which shows the shape of the additional shielding member. It is explanatory drawing which shows the joining spot of an additional shielding member. It is explanatory drawing which shows the arrangement of the pipe wall shielding member when the additional shielding member is provided. It is explanatory drawing which shows the arrangement of the pipe wall shielding member when the additional shielding member is provided. It is explanatory drawing which shows the arrangement of the pipe wall shielding member when the additional shielding member is provided. It is explanatory drawing which shows the arrangement of the pipe wall shielding member when the additional shielding member is provided. It is sectional drawing of the modified example in which the 2nd member extends to the outside of an enclosure. It is sectional drawing of the modified example in which the 2nd member extends to the outside of an enclosure. FIG. 5 is a cross-sectional view of an X-ray tube in which the reference line and the central axis of the anode are non-parallel.

[First Embodiment]
As shown in FIG. 1, the X-ray tube 10 includes a cathode assembly 11 including a cathode, an anode 12, and an enclosure 13. Further, the X-ray tube 10 and the housing 14 constitute an X-ray tube device.

The cathode assembly 11 emits electrons. In this embodiment, the cathode assembly 11 emits electrons toward the negative side in the X direction. In the present embodiment, the direction parallel to the central axis 31 of the anode 12 is the X direction, the direction perpendicular to the central axis 31 of the anode 12 and the in-paper direction of the drawing is the Z direction, and the directions perpendicular to the X direction and the Z direction. The Y direction. Further, the left direction of the paper surface of the drawing is the positive direction of the X direction, the upward direction of the paper surface is the positive direction of the Z direction, and the front direction of the paper surface is the positive direction of the Y direction.

The cathode assembly 11 includes at least the cathode. As the cathode, for example, a hot cathode such as a filament 21 or a cold cathode using CNT (carbon nanotube) or the like can be used. In this embodiment, the cathode assembly 11 includes, by way of example, a filament 21 and a first electrode 22. Further, in the cathode assembly 11, the wiring of the second electrode 23, the wiring of the second electrode 23 and the support member for the enclosure 13, the wiring of the filament 21 and the support member for the enclosure 13, the wiring of the first electrode 22 and the support member The support member for the outer enclosure 13 is not included. However, if necessary, a part of an insulating member for insulating the filament 21, the first electrode 22, and the second electrode 23 from each other, or a member for supporting or positioning them by connecting them to each other, or All are included in the cathode assembly 11.

The filament 21 emits electrons (thermions) by energizing and applying a tube voltage. The current that energizes the filament 21 is the filament current, and the amount of electrons emitted by the filament 21 is the tube current of the X-ray tube 10. The filament 21 is made of, for example, tungsten or the like.

The first electrode 22 is a so-called focusing cup. The first electrode 22 has, for example, a rectangular parallelepiped recess 22a, and the filament 21 is arranged in the recess 22a of the first electrode 22. The first electrode 22 contributes to the convergence of electrons. A predetermined voltage is applied to the first electrode 22. The predetermined voltage applied to the first electrode 22 is, for example, −50 kV or 0 V.

The second electrode 23 is a so-called grid electrode. The second electrode 23 is arranged between the cathode assembly 11 and the anode 12. A predetermined voltage such as −5 kV is applied to the second electrode 23. Hereinafter, when the other members and the like are illustrated, the second electrode 23 may be omitted. Even when the description of the second electrode 23 is omitted in the drawing, the X-ray tube 10 has the second electrode 23. However, in the actual X-ray tube 10, the second electrode 23 may not be provided. That is, the second electrode 23 is not essential in the X-ray tube 10. The second electrode 23 corrects the electron emission direction by an electric field, but the electron emission direction is determined by using a member that generates a magnetic field such as a coil instead of the second electrode 23 or together with the second electrode 23. It can be fixed.

The filament 21, the first electrode 22, and the second electrode 23 constitute an electron gun. That is, the flow of electrons (electron beam) emitted by the filament 21 forms a crossover having a smaller cross-sectional radius than the other portions at a predetermined position by the lenticular action of the first electrode 22 and the second electrode 23, and then the crossover is formed at a predetermined position. The target 33 on the anode 12 is reached in a state of being narrowed down to the diameter.

The anode 12 receives the electrons emitted by the cathode assembly 11 to generate X-rays. A predetermined voltage is applied to the anode 12 with respect to the cathode assembly 11. The predetermined voltage applied between the anode 12 and the cathode assembly 11 is the tube voltage of the X-ray tube 10. The anode 12 has, for example, a shape in which a cylinder is notched diagonally with respect to the central axis 31, and the slope 32 formed by the notch is arranged toward the cathode assembly 11. "Directing the slope 32 toward the cathode assembly 11" means that the electrons emitted by the cathode assembly 11 are oriented so that they can collide with the slope 32 of the anode 12. In this embodiment, the central axis 31 of the anode 12 is parallel to the X axis. The slope 32 has a relatively short distance from the cathode assembly 11 on the positive side in the Z direction and a relatively long distance from the cathode assembly 11 on the negative side of the central axis 31 cage in the Z direction.

The anode 12 includes a target 33 at a position on the slope 32 where the electrons emitted by the cathode assembly 11 collide. The target 33 is, for example, tungsten, which receives the electrons emitted by the cathode assembly 11 to generate X-rays. Therefore, the slope 32 is one surface of the anode 12 and includes the X-ray generation point 35 (the focal point of the electron beam emitted by the cathode assembly 11). The X-ray generation point 35 is a portion where the electron beam hits, that is, the focal point of the electron beam emitted by the cathode assembly 11. If the focal point of the electron beam emitted by the cathode assembly 11 has a non-negligible magnitude (range), it is the entire range. Hereinafter, the slope 32 which is the “surface of the anode 12 including the X-ray generation point 35” is referred to as an anode surface 32. When the anode 12 is referred to as the "tip", it means the end including the anode surface 32, and when the anode 12 is referred to as the "base end", it means the end outside the enclosure 13. The anode 12 is made of a material having good thermal conductivity, such as copper. This is because the heat generated in the target 33 when X-rays are generated is exhausted or dissipated through the anode 12.

X-rays are generated from the generation point 35 in all directions. In the X-ray tube 10, X-rays generated from a predetermined X-ray generation point 35 as a starting point (hereinafter referred to as a usage direction) 36 are used for X-ray photography and the like. Therefore, the X-rays generated in directions other than the usage direction 36 are unnecessary X-rays that are not used for X-ray photography or the like. In order to avoid unnecessary exposure, unnecessary X-rays are shielded by using an X-ray shielding member such as lead.

The outer enclosure 13 is a housing including the cathode assembly 11 and the anode 12 inside. When the enclosure 13 "contains" the cathode assembly 11 "inside", it means that at least the filament 21, which is the generation point of electrons, is inside the enclosure 13. In the present embodiment, since the cathode assembly 11 includes the first electrode 22 in addition to the filament 21, the filament 21 and the first electrode 22 are in the enclosure 13. However, the wiring 38 for energizing the filament 21, the wiring for applying a voltage to the first electrode 22 (not shown), the wiring for applying a voltage to the second electrode 23 (not shown), and the like are included. It extends to the outside of the outer enclosure 13. Each of these wirings 38 and the like also serves as a support member for supporting the filament 21 and the like with respect to the enclosure 13. Further, the phrase "the enclosure 13 includes the anode 12 inside" means that at least the anode surface 32 of the anode 12 is inside the enclosure 13. In this embodiment, the anode 12 extends to the outside of the enclosure 13.

The outer enclosure 13 is, for example, a vacuum tube made of glass or the like. The inside of the outer enclosure 13 is evacuated so that at least the electrons emitted by the cathode assembly 11 (filament 21) can reach the anode 12. The outer enclosure 13 transmits X-rays at least within the range of the usage direction 36.

The housing 14 insulates the enclosure 13 by covering almost the entire enclosure 13, cools the enclosure 13 with a cooling medium, and / or shields unwanted X-rays. However, the range of the usage direction 36 has an X-ray transmission window (not shown) that transmits X-rays.

In addition to the above, the X-ray tube 10 further includes a shielding portion 40 in the outer enclosure 13. The shielding portion 40 includes an X-ray shielding member such as lead, and shields unnecessary X-rays at the rear of the cathode assembly 11 and on the side of the cathode assembly 11. The rear of the cathode assembly 11 refers to the space between the enclosure 13 and the cathode assembly 11 on the opposite side of the anode 12. The side of the cathode assembly 11 refers to the space between the cathode assembly 11 and the enclosure 13 in the direction perpendicular to the reference line 50 shown in FIG. Further, the front of the cathode assembly 11 means a space between the cathode assembly 11 and the anode 12. In the present embodiment, the shielding portion 40 has a cylindrical shape (cup type) with a bottom, but the outer shape may be a prismatic shape or the like. The shielding portion 40 is supported with respect to the outer enclosure 13 by using the supporting portion 39. The support portion 39 extends to the outside of the outer enclosure 13.

As shown in FIG. 2, the shielding portion 40 includes a first shielding portion 41 and a second shielding portion 42. That is, the X-ray tube 10 includes a first shielding portion 41 and a second shielding portion 42 in the enclosure 13.

The first shielding portion 41 shields unnecessary X-rays between the enclosure 13 on the reference line 50 and the cathode assembly 11. That is, the first shielding portion 41 is a portion of the shielding portion 40 that shields unnecessary X-rays behind the cathode assembly 11.

The reference line 50 is a straight line (half straight line) connecting the center 51 of the electron generation point and the center of the X-ray generation point, starting from the center 51 of the electron generation point. In this embodiment, the reference line 50 is a center line passing through the center of the cathode assembly 11. The electron generation point is a portion of the filament 21 that can emit electrons with heat by energization and application of voltage, and the filament 21 is sufficiently small in relation to other members and the like and can be regarded as one point. The electron generation point is the entire filament 21. The center 51 of the electron generation point is substantially the center of the filament 21 (the center when considering the three-dimensional size). In the present embodiment, the center 51 of the electron generation point is the center of the filament 21. The center of the X-ray generation point 35 is the X-ray generation point 35 itself when the X-ray generation point 35 is sufficiently small, and the X-ray generation point 35 has a size (range) that cannot be ignored. In some cases, it is the center (the center when considering the three-dimensional size). In the present embodiment, the X-ray generation point 35 is sufficiently small so that its size can be ignored. Therefore, in the present embodiment, the center of the X-ray generation point 35 is synonymous with the X-ray generation point 35.

The reference line 50 intersects the enclosure at the intersection 52. Further, the reference line 50 intersects the first shielding portion 41 at an intersection 53. That is, the first shielding portion 41 is at least a point (intersection point 53) on the reference line 50 outside the cathode assembly 11 (including the surface of the cathode assembly 11) as a whole and between the cathode assembly 11 and the intersection 52. ) To block unnecessary X-rays. If there is a hole or notch in the portion corresponding to the intersection 53 due to wiring or other reasons, the portion corresponding to the intersection 53 does not have the second shielding portion 42. In this case, "shielding unnecessary X-rays at the intersection 53" corresponds to the intersection 53 when the first shielding portion 41 in which a hole or notch for wiring or the like is filled with an X-ray shielding member is used. It means that unnecessary X-rays can be shielded in the part to be used.

The second shielding unit 42 shields unnecessary X-rays between the enclosure 13 and the cathode assembly 11 in the direction perpendicular to the reference line 50 from the center 51 of the electron generation point. That is, the second shielding portion 42 is a portion of the shielding portion 40 that shields unnecessary X-rays on the side of the cathode assembly 11. When the plane that passes through the center 51 of the electron generation point and is perpendicular to the reference line 50 is the reference plane 56, the reference plane 56 (line in FIG. 2) is the enclosure at the intersection line 57 (point in FIG. 2). Crosses 13. Further, in the present embodiment, the reference surface 56 intersects with the second shielding portion 42 at the line of intersection 58 (point in FIG. 2). That is, the second shielding portion 42 is at least a point outside the cathode assembly 11 as a whole and between the center 51 of the electron generation point and the enclosure 13 (at least a part of the points on the line of intersection 57). Shields unnecessary X-rays. If there is a hole or notch in the portion corresponding to the line of intersection 57 due to wiring or other reasons, there is no second shielding portion 42 in that portion. In this case, "shielding unnecessary X-rays on the line of intersection 58" means a portion corresponding to the line of intersection 58 when the second shielding portion 42 in which a hole or a notch is filled with an X-ray shielding member is used. It means that unnecessary X-rays can be shielded.

As shown in FIG. 3, the first shield 41 is longer than the cathode assembly 11 in the direction perpendicular to the reference line 50. When the length of the cathode assembly 11 in the YZ in-plane direction (for example, the Z-axis direction) is "L1c" and the length of the first shielding portion 41 in the YZ in-plane direction is "L1s", L1c <L1s. be. Further, in the direction parallel to the reference line 50, the second shielding portion 42 is longer than the cathode assembly 11. When the length of the cathode assembly 11 in the XY in-plane direction (for example, the X-axis direction) is "L2c" and the length of the second shielding portion 42 in the XY in-plane direction is "L2s", L2c <L2s. be. In the present embodiment, the angle α formed by the first shielding portion 41 and the second shielding portion 42 is 90 degrees, and the angle β formed by the reference line 50 and the first shielding portion 41 is 90 degrees.

As described above, the X-ray tube 10 includes a shielding portion 40 including a first shielding portion 41 and a second shielding portion 42 inside. Therefore, the X-ray tube 10 can reduce the amount (weight) of the X-ray shielding member used as compared with the case where the X-ray shielding member is installed only on the outside of the outer enclosure 13, and as a result, the X-ray tube 10 can be used. Can be made lighter. For example, as shown in FIG. 4, the shielding unit 40 shields unnecessary X-rays generated from the X-ray generation point 35 toward a predetermined direction Ac including the cathode assembly 11 in the vicinity of the X-ray generation point 35. can. Therefore, the amount (weight) of the X-ray shielding member used can be small as compared with the shielding portion 61 required for shielding in the housing 14. Similarly, the amount of the X-ray shielding member used can be small as compared with the shielding portion 62 required when shielding unnecessary X-rays generated toward the direction Ac in the vicinity of the outer surface of the enclosure 13. ..

In the first embodiment, the first shielding portion 41 and the second shielding portion 42 are joined to form an integrated shielding portion 40, but the first shielding portion 41 and the second shielding portion 42 are separated. Can be kept. For example, as shown in FIG. 5, the angle α formed by the first shielding portion 41 and the second shielding portion 42 remains at 90 degrees, and the angle β formed by the reference line 50 and the first shielding portion 41 remains at 90 degrees. , The first shielding portion 41 and the second shielding portion 42 can be separated. In this case, the second shielding portion 42 preferably protrudes behind the first shielding portion 41. “Back of the first shield 41” means the space between the cathode assembly 11 and the enclosure 13 on the enclosure 13 side of the plane 66 including the intersection of the reference line 50 and the first shield 41. say. When the second shielding portion 42 is projected to the rear of the first shielding portion 41, unnecessary X-rays passing between the first shielding portion 41 and the second shielding portion 42 are emitted from the second shielding portion 41 as shown by an arrow 67. It can be shielded by using the shielding unit 42.

Further, when the first shielding portion 41 and the second shielding portion 42 are separated, instead of projecting the second shielding portion 42 to the rear of the first shielding portion 41, as shown in FIG. 6, the first shielding portion The 41 can be configured to protrude from the second shielding portion 42. "The first shielding portion 41 projects more than the second shielding portion 42" means that the first shielding portion 41 is closer to the outer enclosure 13 than the extension line of the inner surface of the second shielding portion 42, as shown by an arrow 68. It means that is continuing. As described above, assuming that the shielding portion 40 is configured such that the first shielding portion 41 protrudes from the second shielding portion 42, it passes between the first shielding portion 41 and the second shielding portion 42 as shown by an arrow 67. Unnecessary X-rays can be shielded by using the first shielding unit 41. In FIG. 6, the angle α formed by the first shielding portion 41 and the second shielding portion 42 is 90 degrees, and the angle β formed by the reference line 50 and the first shielding portion 41 is 90 degrees.

In the first embodiment and the modified example, the angle β formed by the reference line 50 and the first shielding portion 41 is 90 degrees, but as shown in FIG. 7, the shielding portion 40 is based on the first shielding portion 41. It may be configured to be inclined with respect to the line 50. The same applies to the case where the first shielding portion 41 and the second shielding portion 42 are separated. In this case, the angle β formed by the reference line 50 and the first shielding portion 41 is smaller than 90 degrees. Further, when the second shielding portion 42 is parallel to the reference line 50, the angle α formed by the first shielding portion 41 and the second shielding portion 42 is not constant, and is formed by the first shielding portion 41 and the second shielding portion 42. The maximum value α _M of the angle α is larger than 90 degrees and less than 180 degrees. _{Further, the minimum value α m} of the angle α formed by the first shielding portion 41 and the second shielding portion 42 is smaller than 90 degrees.

In the above modification, the first shielding portion 41 is tilted with respect to the reference line 50, but as shown in FIG. 8, the shielding portion 40 tilts the second shielding portion 42 with respect to the reference line 50. It may be configured as a new type. "Inclining the second shielding portion 42 with respect to the reference line 50" means that a part or all of the second shielding portion 42 is non-parallel to the reference line 50. In FIG. 8, the second shielding portion 42 has a horn shape in which the opening uniformly widens toward the X-ray generation point 35 (anode 12). Therefore, the plane 71 extending the inner surface (the surface facing the cathode assembly 11) of the second shielding portion 42 in FIG. 8 converges to one point on the reference line 50, and its central angle γ is larger than 0 degrees. .. In FIG. 8, the angle α formed by the first shielding portion 41 and the second shielding portion 42 is larger than 90 degrees and less than 180 degrees. Further, the angle β formed by the first shielding portion 41 and the reference line 50 is 90 degrees. Of course, the opening of the second shielding portion 42 does not have to be widened or narrowed uniformly.

As described above, in both the case where the first shielding portion 41 is inclined with respect to the reference line 50 and the case where a part or all of the second shielding portion 42 is inclined with respect to the reference line 50. The shielding portion 40 may have a configuration in which the first shielding portion 41 and the second shielding portion 42 are separated from each other. For example, as shown in FIG. 9, the shielding portion 40 can have a configuration in which the first shielding portion 41 perpendicular to the reference line 50 and the second shielding portion 42 having a horn shape are separated. In this case, it is preferable that the second shielding portion 42 protrudes behind the first shielding portion 41. This is because, as shown by the arrow 67, unnecessary X-rays passing between the first shielding portion 41 and the second shielding portion 42 can be shielded by using the second shielding portion 42. In FIG. 9, the angle α formed by the first shielding portion 41 and the second shielding portion 42 is larger than 90 degrees and less than 180 degrees. Further, the angle β formed by the first shielding portion 41 and the reference line 50 is 90 degrees.

As shown in FIG. 10, when the first shielding portion 41 perpendicular to the reference line 50 and the horn-shaped second shielding portion 42 are separated, the first shielding portion 41 is the second shielding portion. The configuration may be such that it protrudes from 42. In this case, as shown by the arrow 67, unnecessary X-rays passing between the first shielding portion 41 and the second shielding portion 42 can be shielded by using the first shielding portion 41.

When the second shielding portion 42 has a horn shape or a shape having a portion non-parallel to the reference line 50, at least a part of the second shielding portion 42 is substantially perpendicular to the plane extending the anode surface 32. It is preferable to have. Almost vertical means an angle close to 90 degrees (for example, 80 or more and 100 degrees or less) in addition to being 90 degrees.

For example, as shown in FIG. 11, since the anode surface 32 is inclined with respect to the reference line 50, when the second shielding portion 42 is formed into a horn shape, the plane 71 is an extension of the inner surface of the second shielding portion 42. _{The maximum value δ M} of the angle δ formed by the plane 76 extending the anode surface 32 can be, for example, larger than 90 degrees and less than 180 degrees. Further, the minimum value δ _m of the angle δ is smaller than 90 degrees. In this case, for example, if the angle δ _M is set to 90 degrees, unnecessary X-rays generated toward a predetermined direction Ac including the cathode assembly 11 can be efficiently shielded. Therefore, the weight of the second shielding portion 42 and, by extension, the entire shielding portion 40 can be reduced. As a result, the weight of the X-ray tube 10 can also be reduced.

As described above, in at least a part of the second shielding portion 42, the angle δ formed by the plane 71 extending the inner surface of the second shielding portion 42 and the plane 76 extending the anode surface 32 is set to be approximately 90 degrees. In this case, the position where the angle δ is approximately 90 degrees is preferably the side opposite to the external device that uses X-rays such as an X-ray detection panel. That is, it is preferable that the portion opposite to the usage direction 36 includes a portion where the angle δ is approximately 90 degrees. The portion on the opposite side of the usage direction 36 means a portion within a range formed by extending the broken line indicating the usage direction 36 (see FIG. 1 and the like) to the enclosure 13 side facing the usage direction 36.

In FIG. 11, in at least a part of the second shielding portion 42, the plane 71 on which the inner surface of the second shielding portion 42 is extended and the plane 76 on which the anode surface 32 is extended are substantially perpendicular to each other. The reference may be the outer surface of the second shielding portion 42 (the surface facing the outer enclosure 13). That is, in at least a part of the second shielding portion 42, the plane on which the outer surface of the second shielding portion 42 is extended and the plane 76 on which the anode surface 32 is extended may be substantially perpendicular to each other.

Further, when the second shielding portion 42 has a horn shape or a shape having a portion non-parallel to the reference line 50, at least a part of the second shielding portion 42 is substantially parallel to the X-ray detector. Is preferable. For example, as shown in FIG. 12, the X-ray detection panel 73 for photographing a subject using X-rays is a flat plate-shaped X-ray detection device, and the photographing surface 73A (for example, a photoelectric conversion surface or the like) is a flat surface. The X-ray detection panel 73 shall be used in a substantially predetermined position and orientation with respect to the X-ray tube 10. In this case, it is preferable that at least a part of the second shielding portion 42 or the plane 71 extending the inner surface of the second shielding portion 42 is substantially parallel to the photographing surface 73A. More specifically, it is preferable that, for example, the portion of the second shielding portion 42 on the negative side in the Z direction is substantially parallel to the photographing surface 73A. This is because the portion of the second shielding portion 42 on the negative side in the Z direction can be made substantially the shortest, and as a result, the shielding portion 40 and the X-ray tube 10 can be reduced in weight.

In addition to the above-mentioned first embodiment and modification, the second shielding portion 42 can be variously modified. For example, as shown in FIG. 13, of the second shielding portion 42, the portion on the X-ray generation point 35 side (anode 12 side) has a horn shape, and the portion on the cathode assembly 11 side is relatively the reference line 50. It may be parallel. In the shielding portion 40 shown in FIG. 12, the angle α formed by the first shielding portion 41 (β = 90 degrees) perpendicular to the reference line 50 and the second shielding portion 42 is 90 degrees.

Further, as shown in FIG. 14, of the second shielding portion 42, the portion on the X-ray generation point 35 side (anode 12 side) has an inverted horn shape, and the portion relatively on the cathode assembly 11 side is the reference line 50. May be parallel to. The inverted horn shape is a shape in which the opening is uniformly narrowed toward the X-ray generation point 35. In the shielding portion 40 shown in FIG. 13, the angle α formed by the first shielding portion 41 (β = 90 degrees) perpendicular to the reference line 50 and the second shielding portion 42 is 90 degrees.

As shown in FIG. 15, of the second shielding portion 42, the portion on the cathode assembly 11 side has an inverted horn shape, and the portion on the X-ray generation point 35 side (anode 12 side) is parallel to the reference line 50. It may be. As shown in FIG. 16, the entire second shielding portion 42 may have an inverted horn shape. In these cases, the angle α formed by the first shielding portion 41 (β = 90 degrees) perpendicular to the reference line 50 and the second shielding portion 42 is less than 90 degrees.

As described above, even when a part or all of the second shielding portion 42 has an inverted horn shape, the first shielding portion 41 and the second shielding portion 42 can be separated to form the shielding portion 40. In this case, as shown in FIG. 17, the second shielding portion 42 is projected to the rear of the first shielding portion 41, or as shown in FIG. 18, the first shielding portion 41 protrudes from the second shielding portion 42. It is preferable to have a configuration. This is because unnecessary X-rays passing between the first shielding portion 41 and the second shielding portion 42 are shielded by the first shielding portion 41 or the second shielding portion 42.

In the first embodiment and the modified example, the shielding portion 40 is configured by using the first shielding portion 41 and the second shielding portion 42, but the shielding portion 40 may include other shielding members. can. For example, as shown in FIG. 19, an X-ray shielding member 78 can be additionally provided between the first shielding portion 41 and the cathode assembly 11. In this case, unnecessary X-rays can be more reliably shielded behind the cathode assembly 11. Similarly, a shielding member may be further provided between the second shielding portion 42 and the cathode assembly 11.

In the first embodiment and the modified example, the first shielding portion 41 and the second shielding portion 42 can be clearly distinguished from each other in the shielding portion 40, but the shielding portion 40 is the first shielding portion 41 and the first shielding portion 41. 2 The boundary of the shielding portion 42 may be ambiguous. For example, as shown in FIG. 20, the shielding portion 40 can have a shape such as a part of an ellipsoid, a hyperboloid, or a hemisphere. In this case, the portion behind the cathode assembly 11, that is, the portion closer to the enclosure 13 than the broken line 81 is the first shielding portion 41, and the remaining portion is the second shielding portion 42.

Although the shielding portions 40 having various shapes are shown in the first embodiment and the modified examples, in each case, it is preferable that the second shielding portion 42 protrudes toward the anode 12 side from the cathode assembly 11. "Protruding toward the anode 12 side from the cathode assembly 11" means that, as shown in FIG. 21, a part or all of the end portion of the second shielding portion 42 on the anode 12 side is the most anode 12 of the cathode assembly 11. It means that the surface or tip of the member on the side is included and continues to the anode 12 side of the plane 82 perpendicular to the reference line 50.

As described above, when the second shielding portion 42 is projected toward the anode 12 side from the cathode assembly 11, a part of the second shielding portion 42 on the anode 12 side or the entire second shielding portion 42 is shown in FIG. 22. It is preferable to have a horn shape as shown in. This is because it is easy to secure a distance between the second shielding portion 42 and the anode 12, so that discharge between the second shielding portion 42 and the anode 12 is unlikely to occur. Further, even if the weight of the second shielding portion 42 is reduced, unnecessary X-rays can be shielded in a wide range, so that the shielding portion 40 and the X-ray tube 10 can be efficiently reduced in weight.

In the shielding portion 40 of the first embodiment and the modified example, the angle α formed by the first shielding portion 41 and the second shielding portion 42 is preferably 90 degrees. When the angle α formed by the first shielding portion 41 and the second shielding portion 42 is not uniform, a part or all of the angle α formed by the first shielding portion 41 and the second shielding portion 42 is 90 degrees. Is preferable. This is because it is easy to manufacture. Further, the angle α formed by the first shielding portion 41 and the second shielding portion 42 may be larger than 90 degrees and less than 180 degrees. When the angle α formed by the first shielding portion 41 and the second shielding portion 42 is not uniform, a part or all of the angle α formed by the first shielding portion 41 and the second shielding portion 42 is 90 degrees. It is preferably larger and less than 180 degrees. This is because the second shielding portion 42 can be easily made smaller, and as a result, the shielding portion 40 and the X-ray tube 10 can be made lighter. Of course, as in the shielding portion 40 shown in FIG. 15 and the like, the angle α formed by the first shielding portion 41 and the second shielding portion 42 may be less than 90 degrees. When the angle α formed by the first shielding portion 41 and the second shielding portion 42 is not uniform, a part or all of the angle α may be less than 90 degrees. When the angle α formed by the first shielding portion 41 and the second shielding portion 42 is less than 90 degrees, the angle α can be reduced within the range in which the X-ray tube 10 functions. In this case, it may be easy to manufacture while avoiding physical or electrical interference. For example, the limit angle α at which the X-ray tube 10 fails due to physical or electrical interference, or other practical reasons, is the angle α between the first shield 41 and the second shield 42. It is the lower limit. The lower limit of the angle α is, for example, about 30 to 60 degrees.

When the angle α formed by the first shielding portion 41 and the second shielding portion 42 is not uniform, the angle α has a portion of 90 degrees and a portion larger than 90 degrees and less than 180 degrees. May be good. In this case, the effect of facilitating manufacturing and the effect of making the second shielding portion 42 smaller easily, and as a result, the effect of reducing the weight of the shielding portion 40 and the X-ray tube 10 can be achieved at the same time.

Further, when the angle α formed by the first shielding portion 41 and the second shielding portion 42 is not uniform, the angle α may have a portion of 90 degrees and a portion of less than 90 degrees. In this case, manufacturing can be facilitated while avoiding physical interference with other members and the like.

Further, when the angle α formed by the first shielding portion 41 and the second shielding portion 42 is not uniform, the angle α includes a portion larger than 90 degrees and less than 180 degrees and a portion less than 90 degrees. You may be doing it. In this case, the second shielding portion 42 can be easily made smaller, and as a result, the shielding portion 40 and the X-ray tube 10 can be made lighter, and the effect of avoiding physical interference with other members or the like can be avoided. Can be compatible.

Further, when the angle α formed by the first shielding portion 41 and the second shielding portion 42 is not uniform, the angle α is a portion of 90 degrees, a portion larger than 90 degrees and less than 180 degrees, and a portion of less than 90 degrees. And may have. In this case, the effect of facilitating manufacturing, the effect of making the second shielding portion 42 smaller, and as a result, the effect of reducing the weight of the shielding portion 40 and the X-ray tube 10 and physical interference with other members and the like are exhibited. There are some effects that can be avoided and some that can be obtained.

[Second Embodiment]
In the first embodiment and the modified example, the first electrode 22 and the second electrode 23 are not electrically connected to the first shielding portion 41 and the second shielding portion 42, but the first shielding portion 41 or the second shielding portion 41 or the second. The shielding portion 42 can be electrically connected to the first electrode 22 or the second electrode 23. That is, the X-ray tube 10 can include an electrode electrically connected to the first shielding portion 41 or the second shielding portion 42. For example, as shown in FIG. 23, the second shielding portion 42 is electrically connected to the second electrode 23. In this case, the second electrode 23 is an electrode electrically connected to the second shielding portion 42. Further, in FIG. 23, since the first shielding portion 41 and the second shielding portion 42 are joined and electrically connected, the second electrode 23 electrically connected to the second shielding portion 42 is It is also an electrode electrically connected to the first shielding portion 41. Of course, the first shielding portion 41 and the second electrode 23 may be directly and electrically connected. The same applies to the case of the shielding portion 40 in which the first shielding portion 41 and the second shielding portion 42 are separated.

As shown in FIG. 24, the first shielding portion 41 may be electrically connected to the first electrode 22. In this case, the first electrode 22 is an electrode electrically connected to the first shielding portion 41. When the first shielding portion 41 and the second shielding portion 42 are also electrically connected, the first electrode 22 electrically connected to the first shielding portion 41 is electrically connected to the second shielding portion 42. It is also a connected electrode. Of course, the second shielding portion 42 and the first electrode 22 may be directly and electrically connected. The same applies to the case of the shielding portion 40 in which the first shielding portion 41 and the second shielding portion 42 are separated.

As described above, when the first electrode 22 or the second electrode 23 is electrically connected to the first shielding portion 41 or the second shielding portion 42, the first shielding portion 41 or the second shielding portion 42 is used to obtain a second electrode 22 or the second electrode 23. A predetermined voltage can be applied to the 1st electrode 22 or the 2nd electrode 23 to form a necessary electric field on or near the orbit of an electron. Further, there is an advantage that the wiring of the support portion 39 of the shielding portion 40 (first shielding portion 41 or the second shielding portion 42) and the wiring of the first electrode 22 or the second electrode 23 can be shared.

In addition, an electrode different from the first electrode 22 and the second electrode 23 may be connected to the first shielding portion 41 or the second shielding portion 42. Further, in the case of the shielding portion 40 in which the first shielding portion 41 and the second shielding portion 42 are separated, different electrodes can be connected to the first shielding portion 41 and the second shielding portion 42, respectively. For example, the first electrode 22 is electrically connected to the first shielding portion 41, and the second electrode 23 is electrically connected to the second shielding portion 42.

[Third Embodiment]
In the first embodiment, the second embodiment, and the modified example, the first shielding portion 41 and the second shielding portion 42 are not adhered to the cathode assembly 11, but the first shielding portion 41 and / or the second shielding portion 41 and / or the second. A part or all of the shielding portion 42 can be adhered to the cathode assembly 11. In the present embodiment, the term "adhesive" means not only joining using an adhesive but also welding, fitting, or other forms of contact to substantially fix the mutual positional relationship. For example, as shown in FIG. 25, the first shielding portion 41 and the cathode assembly 11 can be adhered to each other. Further, as shown in FIG. 26, the second shielding portion 42 and the cathode assembly 11 can be adhered to each other. Further, as shown in FIG. 27, the first shielding portion 41 and the second shielding portion 42 and the cathode assembly 11 can be adhered to each other. By adhering the first shielding portion 41 and / or the second shielding portion 42 and the cathode assembly 11 in this way, the supporting portion 39 of the first shielding portion 41 and / or the second shielding portion 42 can be eliminated. Easy to manufacture. The same applies when the first shielding portion 41 and the second shielding portion 42 are separated.

When the first shielding portion 41 or the second shielding portion 42 and the first electrode 22 or the second electrode 23 are electrically connected as in the second embodiment, they are insulated at necessary positions. It takes that.

[Fourth Embodiment]
The edges of the first shielding portion 41 and / or the second shielding portion 42 are preferably rounded. As shown in FIG. 28, the edges of the first shielding portion 41 and / or the second shielding portion 42 are the opening end E1 formed by the second shielding portion 42, or the first shielding portion 41 and the second shielding portion 42. Connection part E2. "Rounded" means that it is formed by a generally smooth curved surface, and the connection angle of two or more planes forming ridges, vertices, or valleys by chamfering or the like is made larger than 90 degrees. Including cases. For example, as shown in FIGS. 29 and 30, the opening end E1 and / or the connecting portion E2 is preferably a smooth curved surface having a predetermined curvature. This is because the discharge due to the concentration of the electric field can be suppressed. Normally, when an abnormal discharge is detected, the X-ray tube 10 makes an emergency stop or the like for safety, and it takes time and effort to generate X-rays again. Further, since the shielding portion 40 is conductive and is inside the surrounding device 13, an abnormal discharge is likely to occur as compared with the case where the X-ray shielding member is provided only outside the surrounding device 13. However, as described above, if the edges of the first shielding portion 41 and / or the second shielding portion 42 are rounded, the lightweight shielding portion 40 has an unnecessary X-ray shielding effect and suppresses abnormal discharge. And can be compatible.

When there are edges at a plurality of positions of the first shielding portion 41 and / or the second shielding portion 42, one or more of these edges may have a rounded shape. This is because at least for rounded edges, discharge due to electric field concentration can be suppressed. Further, one edge of the first shielding portion 41 and / or the second shielding portion 42 does not have to be entirely rounded, and may be partially rounded. This is because the discharge due to the electric field concentration can be suppressed at least in the rounded portion. Taken together, it is sufficient that at least a part of the edges of the first shielding portion 41 and / or the second shielding portion 42 is rounded. A part of the edges of the first shield 41 and / or the second shield 42 is a part of one of the edges of the first shield 41 or one of the edges of the second shield 42. It is part of one edge.

When the first shielding portion 41 and the second shielding portion 42 are separated, the edge of the first shielding portion 41 and / or the second shielding portion 42 is the end portion of the first shielding portion 41 and / or the first. 2 It is an end portion of the shielding portion 42. For example, as shown in FIG. 31, when the first shielding portion 41 and the second shielding portion 42 are separated, the second shielding portion 42 has an edge E3 forming an opening on the anode 12 side and a cathode assembly. There are two types of edges, an edge E4 forming an opening on the side where the first shielding portion 41 is located with respect to 11, and one type of edge E5 in the first shielding portion 41. In this case, it is particularly preferable that at least the edge E3 has a rounded shape. This is because it is close to the anode 12 having a particularly large potential difference with respect to the edge E3, so that a discharge is likely to occur between the edge E5 and the anode 12. Next, it is preferable that the edge E5 has a rounded shape. This is because a discharge is likely to occur between the edge E5 and the second shielding portion 42 depending on the distance between the edge E5 of the first shielding portion 41 and the second shielding portion 42, the state of insulation, and the like.

[Fifth Embodiment]
When the shielding portion 40 of each of the above-described embodiments and modifications is provided, a shielding member that shields X-rays (hereinafter referred to as a pipe wall shielding member) reaches a portion of the outer enclosure 13 where X-rays (unnecessary X-rays) reach. It is preferable to provide (). This is because unnecessary X-rays that cannot be shielded by the shielding portion 40 are shielded on the inner surface or the outer surface of the outer enclosure 13. If the tube wall shielding member is provided, the weight of the X-ray tube 10 can be reduced as compared with the case where the X-ray shielding member for the same purpose is provided in the housing 14.

Specifically, as shown in FIG. 32, the pipe wall shielding member 91 is provided at least in a portion on the enclosure 13 where the first shielding portion 41 and the second shielding portion 42 do not shield unnecessary X-rays. The portion on the enclosure 13 in which the first shielding portion 41 and the second shielding portion 42 do not shield unnecessary X-rays is a predetermined orientation Ac including the cathode assembly 11 from the X-ray generation point 35 and the usage orientation. Part or all of the inner surface or the outer surface of the enclosure 13 not included in 36. The pipe wall shielding member 91 is formed with an opening 92 (X-ray transmission window), a notch, or the like in a portion included in the usage direction 36. This is because it does not interfere with the use of X-rays. Further, the pipe wall shielding member 91 is preferably provided at least at a portion 93 where the flat surface 76 having the anode surface 32 extended and the outer enclosure 13 intersect. That is, it is preferable that the pipe wall shielding member 91 is provided on the enclosure 13 in a manner of straddling (overlapping) a part or all of the flat surface 76 having the anode surface 32 extended. This is because the portion 93 is the portion where it is most difficult for the shielding portion 40 to shield unnecessary X-rays when a certain distance is secured between the shielding portion 40 and the anode 12 to avoid discharge.

[Sixth Embodiment]
As shown in FIG. 33, the first shielding portion 41 and the second shielding portion 42 can be formed of different materials. Another material refers to a material having different constituent elements (or a combination of elements), or a material having the same combination of elements but a different composition ratio. Further, when the first shielding portion 41 and the second shielding portion 42 are joined, a material different from that of the first shielding portion 41 and / or the second shielding portion 42 can be used for the joining portion 96.

For example, when the first shielding portion 41 and the second shielding portion 42 are formed of different materials, the first shielding portion 41 shields X-rays even if it is hard and relatively difficult to process, such as molybdenum or tungsten. It is preferable to use a material having high properties. This is because the first shielding portion 41 has a shape such as a disk shape that can be easily processed, so that the X-ray shielding property can be emphasized rather than the processability. On the other hand, the second shielding portion 42 is preferably formed of a material that is easier to process than the first shielding portion 41. This is because the second shielding portion 42 is processed into a complicated shape such as a cylindrical shape or a horn shape as compared with the first shielding portion 41. Ease of work means that the difficulty of cutting, spreading, cutting, bending, polishing, surface coating, or other shape processing or surface processing is low.

For the joint portion 96, it is preferable to select a material that can easily connect the first shielding portion 41 and the second shielding portion 42 in consideration of each material. When molybdenum or tungsten is used for the first shielding portion 41 and molybdenum is used for the second shielding portion 42, for example, an alloy of copper and molybdenum is used for the joint portion 96. This is because it is easy to weld the first shielding portion 41 and the second shielding portion 42. Further, when the first shielding portion 41, the second shielding portion 42, and the joining portion 96 are formed of an alloy of copper and molybdenum, the first shielding portion 41 has the highest molybdenum content to cause X-rays. Increase the shielding property. Then, it is assumed that the second shielding portion 42 has a higher copper content than the first shielding portion 41 to achieve both X-ray shielding and workability. In this case, the melting point of the joint portion 96 is lowered by increasing the copper content among them. This facilitates welding of the first shielding portion 41 and the second shielding portion 42 using the joint portion 96.

[7th Embodiment]
In the X-ray tubes 10 of the first to sixth embodiments and the modified examples, the shielding portion 40 is provided inside the enclosure 13, but instead of providing the shielding portion 40, or the shielding portion 40 is provided. Further, by devising the structure of the anode 12, the weight of the X-ray tube can be reduced.

As shown in FIG. 34, the X-ray tube 110 of the present embodiment emits electrons in the enclosure 13 which is a housing and the enclosure 13 like the X-ray tube 10 of the first embodiment and the like. The cathode assembly 11 is provided. Similarly, the outer enclosure 13 is covered with the housing 14. On the other hand, the X-ray tube 110 includes an anode 112 that receives electrons emitted by the cathode assembly 11 to generate X-rays, and the anode 112 of the X-ray tube 110 includes a first member 116 and a second member 117. , Has at least two types of members.

The first member 116 is the central portion of the anode 112, and at least a part thereof extends to the outside of the enclosure 13. Of the ends of the first member 116, the end inside the enclosure 13 is inclined with respect to the central axis 131 of the anode 112, and the target 33 is arranged on this slope. Therefore, the slope at the tip of the anode 112 constitutes at least a part of the surface of the anode 112 including the X-ray generation point 35, that is, the anode surface 132.

The first member 116 is made of a material having good thermal conductivity, such as copper or an alloy containing copper and molybdenum. This is because the heat generated in the target 33 when X-rays are generated is exhausted or dissipated through the anode 112. Compared with the second member 117, the first member 116 has a higher thermal conductivity than the second member 117. Further, although it depends on the dose of X-rays generated in the X-ray tube 110 and the like, the diameter of the first member 116 is preferably 8 mm or more for exhaust heat or heat dissipation.

The first member 116 has an X-ray shielding property, at least due to its length. In particular, when the first member 116 contains molybdenum or the like, it has an X-ray shielding property due to molybdenum. That is, the first member 116 can shield at least a part of unnecessary X-rays.

The second member 117 is in a direction perpendicular to the central axis 131 of the first member 116 and is in contact with the first member 116. The direction perpendicular to the central axis 131 of the first member 116 is between the central axis 131 and the outer enclosure 13, and is lateral to the first member 116. Further, in the present embodiment, the second member 117 is integrated with the first member 116. That is, the second member 117 is directly bonded, joined, fitted, or otherwise fixed to the first member 116 in a positional relationship with each other.

The second member 117 includes a material having an X-ray shielding property such as lead, tungsten, or molybdenum. In the present embodiment, the second member 117 is made of an alloy containing copper and molybdenum, and has a higher molybdenum content than the first member 116. Further, even when the first member 116 is an alloy containing copper and molybdenum, the second member 117 has a higher molybdenum content than the first member 116. Therefore, the second member 117 has a higher specific density than the first member 116. Further, the second member 117 has an X-ray shielding property, and has a higher X-ray shielding property than the first member 116.

Of the second member 117, the end on the cathode assembly 11 side reaches the slope at the tip of the first member 116, and at least a part of the surface of the second member 117 is the tip of the first member 116. Form a flush plane with the slope in. Therefore, a part of the surface of the second member 117 constitutes the anode surface 132 together with the slope of the first member 116.

The second member 117 is not provided on the entire side of the first member 116 in the outer enclosure 13, but is provided on a part of the first member 116 on the cathode assembly 11 side. That is, as shown in FIG. 35, the anode 112 has a large-diameter portion 122 and a small-diameter portion 123 inside the outer enclosure 13, and an extension portion 124 outside the outer enclosure 13. Has. The large diameter portion 122 is a portion inside the outer enclosure 13 that has a second member 117 in addition to the first member 116. The small diameter portion 123 is a portion inside the outer enclosure 13 that is composed of the first member 116 and does not have the second member 117. The extending portion 124 is a portion where the first member 116 extends to the outside of the outer enclosure 13. In FIG. 35, the diameter of the large diameter portion 122 is “D2”, and the diameter of the small diameter portion 123 and the diameter of the extending portion 124 are “D1” (D1 <D2). By balancing the first member 116 and the second member 117 constituting the anode 112 as described above, the second member 117, which contributes to shielding unnecessary X-rays, is made smaller and lighter (and thus the entire X-ray tube 110). While forming (lightweight), the heat generated in the target 33 when X-rays are generated can be efficiently exhausted or dissipated.

As shown in FIG. 36, the second member 117 has a first content rate portion 133 in which the molybdenum content is the first content rate, and a second content rate in which the molybdenum content rate is higher than the first content rate. It has a second content rate portion 134 and. The distance d2 from the first member 116 to the second content rate portion 134 is longer than the distance d1 from the first member 116 to the first content rate portion 133 (d1 <d2). In the present embodiment, the distance from the first member 116 is, for convenience, the distance from the central axis 131 to the boundary surface of the first content rate portion 133 or the second content rate portion 134 on the first member 116 side. There is. The distance from the first member 116 may be measured from the interface between the first member 116 and the second member 117. Further, the distance from the first member 116 to the first content rate portion 133 may be measured as the distance to the boundary surface on the outer device 13 side of the first content rate section 133, and is the center of the first content rate section 133. Etc., the distance to a predetermined position may be measured. The same applies to the distance from the first member 116 to the second content rate portion 134.

In FIG. 36, the first content rate section 133 and the second content rate section 134 are both a part of the second member 117, and the second member 117 is the first content rate section 133 and the second content rate section. Both of 134 may contain portions having different molybdenum contents. However, as shown in FIG. 37, the second member 117 may be composed of two parts, a first content rate part 133 and a second content rate part 134.

The content of the X-ray shielding material of the second member 117 may increase according to the distance from the first member 116. That is, the second member 117 can be configured to have a higher molybdenum content as it is farther from the first member 116. For example, when the first member 116 is formed of copper (Cu) and the second member 117 is formed of an alloy of copper (Cu) and molybdenum (Mo) which is an X-ray shielding material, as shown in FIG. 38, The second member 117 can be configured such that the molybdenum content (Mo content) increases linearly according to the distance from the first member 116. In this case, as shown in FIG. 39, the copper content (Cu content) of the second member 117 decreases linearly according to the distance from the first member 116. Further, for example, as shown in FIG. 40, the second member 117 can be configured such that the Mo content increases according to the distance from the first member 116 and according to an arbitrary curve. As shown in FIG. 41, the second member 117 may be configured such that the Mo content rate gradually increases according to the distance from the first member 116.

As described above, since the anode 112 is formed of the first member 116 and the second member 117, the X-ray tube 110 emits unnecessary X-rays by the anode 112 itself including the X-ray generation point 35. Can be shielded. Specifically, X-rays are generated from the X-ray generation point 35 in all directions, and as shown in FIG. 42, the plane 176 behind the anode surface 132, that is, the plane 176 extending the anode surface 132 is used as a reference. The anode 112 itself shields the unnecessary X-rays generated toward the range including the anode 112 by the first member 116 or the second member 117. Compared with the X-ray shielding member 141 provided on the outer enclosure 13 to shield unnecessary X-rays generated toward the rear of the anode surface 132, or the X-ray shielding member 142 provided on the housing 14, the anode 112 has an anode 112. A small amount of X-ray shielding material can shield unnecessary X-rays generated toward the rear of the anode surface 132. As a result, the weight of the X-ray tube 110 can be reduced.

In addition, by making the specific gravity of the second member 117 larger than the specific gravity of the first member 116, the X-ray tube 110 efficiently generates unnecessary X-rays toward the rear of the anode surface 132 with a small weight. Can be shielded. By making the thermal conductivity of the first member 116 higher than the thermal conductivity of the second member 117, the X-ray tube 110 can efficiently exhaust heat and dissipate heat generated together with X-rays.

When the first member 116 is formed of copper or an alloy containing copper and molybdenum, and the second member 117 is formed of an alloy containing copper and molybdenum, the X-ray tube 110 generates heat generated with X-rays. It is easy to achieve both exhaust heat and heat dissipation from the above and shielding unnecessary X-rays. By increasing the content of the X-ray shielding material of the second member 117 more than that of the first member 116, the X-ray tube 110 can exhaust and dissipate heat generated with X-rays and shield unnecessary X-rays. , Can be compatible.

By providing the first content rate section 133 and the second content rate section 134 on the second member 117, increasing the content rate of the X-ray shielding material toward the outside of the anode 112, and the like, X-rays are emitted from the central axis 131 to the outside of the anode 112. The X-ray tube 110 can efficiently shield unnecessary X-rays with a particularly small amount of X-ray shielding material, and can provide exhaust heat or heat dissipation and an X-ray shielding effect. It is compatible.

In particular, when the second member 117 has a configuration including a first content rate portion 133 and a second content rate section 134 (see FIG. 36), the amount of the X-ray shielding material used is reduced (weight reduction). , X-ray shielding effect (unnecessary X-ray shielding rate) can be achieved in a well-balanced manner with a simple structure. For example, it is lighter than the case where the content of the X-ray shielding material is constant in the entire second member 117, and the X-ray shielding can be maintained at the same level or more.

Further, when the second member 117 is composed of two parts, the first content rate part 133 and the second content rate part 134 (see FIG. 37), the amount of the X-ray shielding material used is reduced (weight reduction), and X In addition to having a good balance between the line shielding effect (unnecessary X-ray shielding rate), there is an advantage that the second member 117 is easy to manufacture. This is because there are only two parts constituting the second member 117, the first content rate part 133 and the second content rate part 134.

Further, when the second member 117 is configured to have a higher content of the X-ray shielding material toward the outside away from the first member 116 (see FIG. 39 and the like), the amount of the X-ray shielding material used is reduced (lightening). And, there is an advantage that the X-ray shielding effect (unnecessary X-ray shielding rate) can be optimized.

Since the anode 112 is provided with the large diameter portion 122 and the small diameter portion 123 inside the outer enclosure 13, the large diameter portion 122 enhances the X-ray shielding property and the small diameter portion 123 provides heat dissipation. Can be enhanced. Therefore, since the anode 112 has the large diameter portion 122 and the small diameter portion 123, both heat dissipation and X-ray shielding can be achieved at the same time.

[8th Embodiment]
The X-ray tube 110 of the seventh embodiment preferably includes a tube wall shielding member that shields X-rays at a portion of the outer enclosure 13 where X-rays (unnecessary X-rays) reach. This is to shield unnecessary X-rays that cannot be shielded by the anode 112 on the inner surface or the outer surface of the enclosure 13. If the tube wall shielding member is provided, the weight of the X-ray tube 10 can be reduced as compared with the case where the X-ray shielding member for the same purpose is provided in the housing 14.

Specifically, as shown in FIG. 43, the anode surface 132, which is the surface of the anode 112 including the X-ray generation point 35, is a flat surface. The term "planar" with respect to the anode surface 132 means that it is substantially and globally flat. Even if there is unevenness in the surface of the anode including the X-ray generation point 35, if it is flat at least in the vicinity of the X-ray generation point 35 (for example, at least the portion where the target 35 is arranged), the flatness is maintained. The surface (flat portion) is the anode surface 132. Further, when the surface of the anode including the X-ray generation point 35 is not flat in the vicinity of the X-ray generation point 35, such as having a curvature that cannot be ignored in relation to the size of other members, the anode surface 132 Is a tangent plane at the X-ray generation point 35. When the X-ray generation point 35 or its vicinity is uneven, the surface of the X-ray generation point 35 or its vicinity is naturally smoothed to determine the tangent plane. In any case, the anode surface 132 is roughly the range (part) where the X-rays that have passed through the anode 112 reach and the X-rays that pass through the anode 112 when the anode 112 transmits all the X-rays. It is a surface that separates the range (part) that can be reached without.

The X-ray tube 110 (enclosure 13) is divided into a cathode side portion 181 including the cathode assembly 11 and an anode side portion 182 including the anode 112 with a plane 176 including the anode surface 132 as a boundary. In this case, the tube wall shielding member 185 is provided on at least a part of the surface of the enclosure 13 belonging to the cathode side portion 181. The pipe wall shielding member 185 is formed with an opening 189 (X-ray transmission window), a notch, or the like in a portion included in the usage direction 36. This is to transmit the X-rays used.

In the present embodiment, it is assumed that the boundary between the portion having the pipe wall shielding member 185 and the portion not having the pipe wall shielding member 185 is a flat surface. In this case, of the boundary surface 191A and the boundary surface 191B between the portion having the pipe wall shielding member 185 and the portion not having the pipe wall shielding member 185, the boundary surface 191A closest to the plane 176 including the anode surface 132 is the anode surface. It is parallel to 132. In this way, when the boundary surface 191A closest to the plane 176 including the anode surface 132 is made parallel to the anode surface 132, the amount (weight, volume, and area) of the pipe wall shielding member 185 is reduced, and the efficiency is increased. Unnecessary X-rays that cannot be shielded by the anode 112 can be shielded.

Further, as shown in FIG. 44, of the boundary surface 191A and the boundary surface 191B of the portion having the pipe wall shielding member 185 and the portion not having the pipe wall shielding member 185, the boundary surface closest to the plane 176 including the anode surface 132. 191A may be on the line of intersection 193 between the plane 176 including the anode surface 132 and the enclosure 13. That is, the tube wall shielding member 185 is provided at least on the cathode assembly 11 side of the plane 176 on which the anode surface 132 is extended, and the end portion of the tube wall shielding member 185 is a plane 176 on which the anode surface 132 is extended. , On the line of intersection 193 with the anode 13. In this case, the anode 112 shields unnecessary X-rays generated toward the anode side portion 182, and the tube wall shielding member 185 shields unnecessary X-rays generated toward the cathode side portion 181. The anode 112 and the tube wall shielding member 185 inside the enclosure 13 can almost completely shield unnecessary X-rays.

As shown in FIG. 45, of the boundary surface 191A and the boundary surface 191B, the boundary surface 191A closest to the plane 176 including the anode surface 132 may be located on the anode side portion 182. In this case, since the range in which the tube wall shielding member 185 shields unnecessary X-rays and the range in which the anode 112 shields unnecessary X-rays partially overlap, unnecessary X-rays can be shielded more reliably.

The shape of the boundary line at the boundary surface 191A closest to the plane 176 including the anode surface 132 (the cross-sectional shape of the pipe wall shielding member 185 by the boundary surface 191A) is preferably a circle or an ellipse. In this case, the pipe wall shielding member 185 can be formed small while reliably shielding unnecessary X-rays.

[9th Embodiment]
It is preferable that the X-ray tube 110 of the seventh embodiment and the eighth embodiment further includes an additional shielding member that shields unnecessary X-rays between the second member 117 and the surrounding device 13. The additional shielding member is, for example, an X-ray shielding material containing lead, tungsten, molybdenum and the like.

Specifically, as shown in FIG. 46, between the second member 117 in the direction perpendicular to the central axis 131 of the first member 116 (anode 112) (in the YZ plane) and the outer enclosure 13. , An additional shielding member 201A is provided. Further, in the present embodiment, the second member 117 is in the direction parallel to the first member 116 and is on the side where the first member 116 extends to the outside of the outer enclosure 13 (small diameter portion 123 side). An additional shielding member 201B is provided between the enclosure 13 and the enclosure 13. That is, except for the portion where the anode surface 132 is located, the large diameter portion 122 is surrounded by the additional shielding member 201A and the additional shielding member 201B. As described above, when the additional shielding member 201A and / or the additional shielding member 201B is provided, the anode 112 and the additional shielding member 201A and / or the additional shielding member 201B surely do not require X as compared with the case of the anode 112 alone. Can shield the line.

As shown in FIG. 47, the entire additional shielding member 201A and the additional shielding member 201B have, for example, a hollow square prism shape with the additional shielding member 201B as the bottom surface and cut diagonally with respect to the central axis 131. As described above, when the additional shielding member 201A and the additional shielding member 201B have a prismatic shape cut diagonally, the additional shielding member 201A and the additional shielding member 201B can be easily manufactured. Therefore, it is easy to use a material having good X-ray shielding property for the additional shielding member 201A and the additional shielding member 201B, although it is difficult to process due to reasons such as hardness.

Further, as shown in FIG. 48, the entire additional shielding member 201A and the additional shielding member 201B are, for example, a hollow cylinder having the additional shielding member 201B as the bottom surface and the cathode assembly 11 side cut diagonally with respect to the central axis 131. It may be shaped. When the anode 112 is substantially cylindrical, if the additional shielding member 201A and the additional shielding member 201B have a cylindrical shape cut diagonally, the amount (weight, volume, and area) of the additional shielding member 201A and the additional shielding member 201B). Can be minimized. Therefore, the additional shielding member 201A and the additional shielding member 201B can be provided at the lightest weight. In addition, the shape of the additional shielding member is arbitrary.

The additional shielding member 201A and the additional shielding member 201B can be joined to the second member 117. In this case, it is preferable that the additional shielding member 201A and the additional shielding member 201B are partially joined to the second member 117. For example, as shown in FIG. 49, the additional shielding member 201A and the additional shielding member 201B are welded, bonded, engaged, at one or more joint spots 202 that are part of the additional shielding member 201A and the additional shielding member 201B. Join by screwing or other methods. In this way, when additional shielding members such as the additional shielding member 201A and the additional shielding member 201B are provided, if they are partially joined to the second member 117, the additional shielding member can be supported by the anode 112 (second member 117). , It is not necessary to provide another support portion for fixing to the anode 13. Further, when the second member 117 is partially joined, the joining itself is easy. Therefore, when the additional shielding member is provided, if it is partially joined to the second member 117, the manufacturing suitability is improved.

As described above, when the additional shielding member 201A and / or the additional shielding member 201B is provided on the X-ray tube 110, it is preferable to provide the tube wall shielding member 185 as shown in FIG. However, it is sufficient that the pipe wall shielding member 185 shields unnecessary X-rays at least in a portion where the additional shielding member 201A and / or the additional shielding member 201B does not shield unnecessary X-rays. Therefore, for example, when the opening of the additional shielding member 201A on the cathode assembly 11 side is a plane 206, the pipe wall shielding member 185 may be up to the line of intersection 207 between the plane 206 and the enclosure 13.

As shown in FIG. 51, the pipe wall shielding member 185 may protrude toward the anode 112 side from the plane 206. In this case, unnecessary X-rays can be shielded more reliably. Further, as shown in FIG. 52, even when the additional shielding member 201A and / or the additional shielding member 201B is provided, the range in which the pipe wall shielding member 185 is provided is the plane 176 including the anode surface 132 and the enclosure 13. It may be up to the line of intersection 193 with. Even in this case, unnecessary X-rays can be blocked. This is because the anode 112 itself has an X-ray shielding action. In addition, as shown in FIG. 53, when the additional shielding member 201A and / or the additional shielding member 201B and the pipe wall shielding member 185 are provided, a part of the pipe wall shielding member 185 is outside the flat surface 206. It may be provided up to the position of the line of intersection 207 with the enclosure 13, and in the other part of the pipe wall shielding member 185, it may be provided up to the position of the line of intersection 193 between the plane 176 including the anode surface 132 and the outer device 13. ..

In the seventh embodiment, the eighth embodiment, and the ninth embodiment, the anode 112 has only the first member 116 extending to the outside of the enclosure 13 (extending portion 124), and the second member. All 117 are inside the anode 13. However, for example, as shown in FIG. 54, the anode 112 may have a configuration in which a part of the second member 117 extends to the outside of the enclosure 13. In this case, the anode 112 has a large diameter portion 222 and a small diameter portion 223. The large diameter portion 222 is a portion formed by the first member 116 and the second member 117, and extends from the inside of the outer enclosure 13 to the outside. The small diameter portion 223 is a portion formed by the first member 116 (a portion having no second member 117), and is all outside the enclosure 13. Further, the portion 222A of the large diameter portion 222 extending to the outside of the outer enclosure 13 and the small diameter portion 223 constitute an extending portion 224 which is a portion of the anode 112 extending to the outside of the outer enclosure 13. do.

When a part of the second member 117 is extended to the outside of the outer enclosure 13 in this way, the anode 112 can be connected to the outer enclosure 13 in the large diameter portion 222, which has an advantage of being easy to manufacture. Further, by extending a part of the second member 117 to the outside of the outer enclosure 13, when the large diameter portion 222 is exposed to the outside of the outer enclosure 13, the surface area of the anode 112 in contact with the outside air increases. There is an advantage that the efficiency of exhaust heat or heat dissipation is improved.

The amount of the second member 117 extending to the outside of the outer enclosure 13 (the length along the first member 116 or the central axis 131) is arbitrary. Therefore, the above effect can be obtained even when the amount of the second member 117 extending to the outside of the outer enclosure 13 is “zero”. That is, the above effect can be obtained if the second member 117 is exposed to the outside of the enclosure 13 at least on the surface of the enclosure 13. Therefore, the state in which the second member 117 extends to the outside of the surrounding device 13 includes the state in which the second member 117 is exposed to the outside of the surrounding device 13 on the surface of the surrounding device 13. ..

Further, for example, as shown in FIG. 55, the outer enclosure 213 may be deformed to form a recess 213A at the connection portion with the anode 112, and the anode 112 may have a second recess depending on the depth of the recess 213A or the like. A part of the member 117 extends to the anode 13. In this case, similarly to the above, the anode 112 has a large diameter portion 222 and a small diameter portion 223. Further, the portion 222A of the large diameter portion 222 extending to the outside of the outer enclosure 13 and the small diameter portion 223 constitute an extending portion 224 which is a portion of the anode 112 extending to the outside of the outer enclosure 13. do. The action and the like are the same as in the above example.

The X-ray tubes 10 of the first to sixth embodiments and their modified examples shield unnecessary X-rays by using the shielding portion 40, and the seventh to ninth embodiments and their modifications are made. The X-ray tube 110 of the example uses an anode 112 to shield unnecessary X-rays, which can be combined arbitrarily.

Further, in the X-ray tubes 10 of the first to sixth embodiments and modified examples thereof, the reference line 50 and the central axis 31 of the anode 12 are parallel to each other, and the seventh to ninth embodiments and these. In the X-ray tube 110 of the modified example of, the reference line 50 and the central axis 131 of the anode 112 are parallel. However, the central axis 31 of the anode 12 (in the case of the anode 112, the central axis 131; the same applies hereinafter) may be non-parallel. For example, as shown in FIG. 54, in the X-ray tube 310, the reference line 50 and the central axis 331 of the anode 312 are perpendicular to each other. As shown in FIG. 54, it is preferable that the X-ray tube 310 is also provided with the shielding portion 40 in the same manner as the X-ray tubes 10 of the first to sixth embodiments and the modified examples thereof. Further, instead of providing the shielding portion 40, or after providing the shielding portion 40, the X-ray tube 310 has an anode similar to that of the X-ray tube 110 of the seventh to ninth embodiments and modified examples thereof. 112 may be provided. The same applies to the pipe wall shielding member 185, the additional shielding member 201A, and the additional shielding member 201B.

10 X-ray tube 11 Cathode 12, 112, 312 Anode 13 Surrounder 14 Housing 21 Filament 22 First electrode 22a, 213A Recess 23 Second electrode 31 Central axis 32 Anode surface (slope)
33 Target 35 X-ray generation point 36 Direction of use 38 Wiring 39 Support part 40 Shielding part 41 1st Shielding part 42 2nd Shielding part 50 Reference line 51 Center 52, 53 Intersection 56 Reference surface 57, 58 Crossing line 61, 62 Shielding Part 66, 71 Flat 67, 68 Arrow 73 X-ray detection panel 73A Imaging surface 76, 82, 176, 206 Flat 78 X-ray shielding member 81 Broken line 91 Tube wall shielding member 92, 189 Opening 93 Part 96 Joint 110 X-ray tube 116 1st member 117 2nd member 122 Large diameter part 123 Small diameter part 124 Extension part 131 Central axis 132 Anode surface 133 1st content rate part 134 2nd content rate part 141, 142 X-ray shielding member 181 Cone side part 182 Anode side part 185 Tube wall shielding member 191A, 191B Boundary surface 193, 207 Intersection line 201A, 201B Additional shielding member 202 Joint spot 310 X-ray tube 331 Central axis Ac Orientation Cu Copper d1, d2 Distance E1 Open end E2 Connection part E3, E4, E5 Edge Mo Molybdenum

Claims (16)

The outer enclosure, which is the housing,
A cathode assembly that emits electrons in the enclosure and
At least a part of the first member extending to the outside of the enclosure is in a direction perpendicular to the central axis of the first member, is in contact with the first member, and is from the first member. Also comprises an anode having a second member having a high X-ray shielding property and a target that receives electrons emitted by the cathode assembly to generate X-rays.
The target is provided on the first member, and the target is provided.
The end of the first member including the target is a slope inclined with respect to the central axis of the first member, and the end of the second member forms a plane flush with the slope. tube. The X-ray tube according to claim 1, wherein the second member has a larger specific gravity than the first member. The X-ray tube according to claim 1 or 2, wherein the first member has a higher thermal conductivity than the second member. The first member is made of copper or an alloy containing copper and molybdenum, and
The X-ray tube according to any one of claims 1 to 3, wherein the second member is made of an alloy containing copper and molybdenum. The X-ray tube according to claim 4, wherein the second member has a higher molybdenum content than the first member. The second member includes a first content portion in which the molybdenum content is the first content, a second content portion in which the molybdenum content is higher than the first content, and a second content portion. Have,
The X-ray tube according to claim 4 or 5, wherein the distance from the first member to the second content rate portion is longer than the distance from the first member to the first content rate portion. The X-ray tube according to any one of claims 4 to 6, wherein the second member has a higher molybdenum content toward the outside away from the first member. Inside the enclosure, the anode includes a large-diameter portion having the second member in addition to the first member, and a small-diameter portion composed of the first member and not having the second member. The X-ray tube according to any one of claims 1 to 7. The X-ray tube according to any one of claims 1 to 8, wherein the first member has a diameter of 8 mm or more. When the plane including the anode surface is used as a boundary to divide the cathode side portion including the cathode assembly and the anode side portion including the anode side, X-rays are emitted to at least a part of the surface of the enclosure belonging to the cathode side portion. The X-ray tube according to any one of claims 1 to 9, further comprising a tube wall shielding member for shielding. The tenth aspect of claim 10, wherein of the boundary surface between the portion having the pipe wall shielding member and the portion not having the pipe wall shielding member, the boundary surface closest to the plane including the anode surface is parallel to the anode surface. X-ray tube. Of the boundary surfaces of the portion having the tube wall shielding member and the portion not having the tube wall shielding member, the boundary surface closest to the plane including the anode surface is the plane including the anode surface and the enclosure. The X-ray tube according to claim 10 or 11, which is on the intersection or on the anode side portion. 10. The shape of the boundary line at the boundary surface closest to the plane including the anode surface among the boundary surfaces of the portion having the pipe wall shielding member and the portion not having the pipe wall shielding member is a circle or an ellipse. The X-ray tube according to any one of 12 to 12. The X-ray tube according to any one of claims 1 to 12, further comprising an additional shielding member that shields the X-ray between the second member and the surrounding device. The X-ray tube according to claim 14, wherein the additional shielding member is partially joined to the second member. In claim 14, which cites claim 10.
The tube wall shielding member is an X-ray tube that shields the X-ray at least in a portion where the additional shielding member does not shield the X-ray.

Images