X-ray tube and medical imaging device

Abstract

The present application relates to the field of medical equipment, and particularly to an X-ray tube and medical imaging equipment. The X-ray tube comprises a tube shell, a cathode assembly, an anode target disc and a bearing unit, the bearing unit and the anode target disc are arranged in the tube shell, the bearing unit is connected to the anode target disc, one end of the tube shell has a radiation window, the anode target disc can receive an electron beam emitted by the cathode assembly to generate X-rays, and the bearing unit is arranged perpendicularly to the radiation window. The present application has the advantages that the actual application area of generated X-rays can be increased, the radiation field of view is enlarged, the detector can receive more useful information, and the exposure area of the object to be detected is increased.

Description

Technical Field

[0001] This invention relates to the field of medical devices, and in particular to X-ray tubes and medical imaging equipment. Background Technology

[0002] In an X-ray tube, X-rays are generated by high-speed electrons striking an anode target. Because X-rays have advantages such as short wavelength, high energy, and strong penetrating power, they are widely used in medical imaging equipment.

[0003] In existing X-ray tubes, the bearing unit is set parallel to the X-ray window, and the target area bombarded by the cathode assembly has a large tilt angle with the X-ray window. When the detector probes from outside the X-ray window, the focal point of some areas cannot be detected, the focal point of some areas will be deformed, affecting the image quality, and the X-rays in some areas will be attenuated, thus reducing the radiation field of the X-ray tube. Summary of the Invention

[0004] Based on this, the present invention addresses the above-mentioned technical problems by providing an X-ray tube, the technical solution of which is as follows:

[0005] An X-ray tube includes a tube shell and a cathode assembly, an anode target disk and a bearing unit. The bearing unit and the anode target disk are disposed inside the tube shell. The bearing unit is connected to the anode target disk. One end of the tube shell has a radiation window. The anode target disk can receive an electron beam emitted by the cathode assembly to generate X-rays. The bearing unit is arranged perpendicular to the radiation window.

[0006] The X-ray tube provided by this invention, by vertically arranging the bearing unit with the X-ray window, reduces the tilt angle between the target area and the X-ray window, thereby increasing the practical application area for generating X-rays and expanding the radiation field of view. This allows the detector to receive more useful information, thus increasing the exposure area of ​​the object to be detected. Simultaneously, the vertically arranged bearing unit allows it to withstand less stress, extending its service life. This prevents the bearing unit from bearing the weight and torsional force of the anode target disk at one end when horizontally arranged, and also avoids the centrifugal force generated during rotation, which would affect its service life over long-term operation.

[0007] In one embodiment of the present invention, the end of the anode target disk facing the ray window has a target surface, the target surface including a target area for bombardment by the cathode assembly, and the angle between the surface where the target area is located and the ray window is less than or equal to 30°.

[0008] This setup increases the practical application area for generating X-rays and expands the radiation field of view.

[0009] In one embodiment of the present invention, the surface containing the target area is arranged parallel to the ray window.

[0010] This setup can further expand the practical application area and increase the radiation field of view.

[0011] In one embodiment of the present invention, the projection of the center of the ray window onto the target surface is located within the target area.

[0012] This configuration allows more X-rays to enter the radiation window, further increasing the radiation field of view.

[0013] In one embodiment of the present invention, the cathode assembly includes an emitter disposed within the housing, and the axis of the emitter is perpendicular to the plane containing the target region; or, the axis of the emitter is inclined relative to the plane containing the target region, and the emitting end of the emitter faces the target region.

[0014] This configuration allows the emitter to be installed in various ways without being restricted by its location, thus reducing X-ray attenuation and expanding its application scenarios.

[0015] In one embodiment of the present invention, the cathode assembly includes a control gate and an emitter disposed within the housing, the control gate being disposed around the emitter.

[0016] With this configuration, the control gate can be used to control the on / off state and emission level of the electron beam emitted by the transmitter. Furthermore, the control gate is arranged around the transmitter, which allows for more effective control of the electron beam.

[0017] In one embodiment of the present invention, the end face of the tube shell is provided with an opening, and the cathode assembly further includes a connecting cover, which is disposed on the opening, and the axis of the connecting cover is perpendicular to the plane where the target area is located.

[0018] In one embodiment of the present invention, an opening is provided on the side of the tube shell, and the cathode assembly further includes a connecting cover, which is disposed over the opening, and the axis of the connecting cover is inclined relative to the surface where the target area is located.

[0019] With this configuration, when a focal point is not required, an electron beam can be directly emitted towards the target area without needing to control the emission angle of the electron beam, resulting in a simple structure.

[0020] In one embodiment of the present invention, the cathode assembly further includes a deflection control element located between the target surface and the emitting end of the emitter to control the angle at which the emitter emits an electron beam.

[0021] With this configuration, the deflection control unit controls the launcher to bombard different positions of the target disk, achieving a focal point, thereby improving the utilization rate of the anode target disk. At the same time, it can avoid bombarding the same position on the target surface, which would cause the temperature of the target area to become too high and shorten the life of the anode target disk.

[0022] In one embodiment of the present invention, the target surface is a plane and the target surface is parallel to the ray window.

[0023] This design enhances heat dissipation from the target surface and prevents it from cracking due to high temperatures.

[0024] In one embodiment of the present invention, a heat dissipation coating is laid on the outer surface of the tube shell.

[0025] This configuration is intended to enhance heat dissipation from the casing.

[0026] In one embodiment of the present invention, the X-ray tube further includes a collecting component disposed within the tube shell, the collecting component being used to collect electrons and ions within the tube shell.

[0027] This configuration allows the tube to maintain a vacuum, ensuring that the electron beam can travel unimpeded and at high speed toward the target area.

[0028] This invention also provides the following technical solutions:

[0029] A medical imaging device, the medical imaging device comprising the above-described X-ray tube. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of an existing X-ray tube.

[0031] Figure 2 This is a map showing the X-ray distribution near the target area in an existing X-ray tube.

[0032] Figure 3 This is a schematic diagram of the focal deformation detected by the detector in an existing X-ray tube;

[0033] Figure 4 This is a schematic diagram of a detector probing the YZ plane in an existing X-ray tube.

[0034] Figure 5 This is a schematic diagram of a detector probing the YX plane in an existing X-ray tube;

[0035] Figure 6 This is a partial structural schematic diagram of the X-ray tube provided by the present invention;

[0036] Figure 7This is a schematic diagram of the structure of an X-ray tube according to Embodiment 1 of the present invention;

[0037] Figure 8 This is a schematic diagram of the structure of the X-ray tube according to Embodiment 2 of the present invention;

[0038] Figure 9 This is a schematic diagram of the structure of the X-ray tube according to Embodiment 3 of the present invention.

[0039] The symbols in the diagram represent the following meanings:

[0040] 100. X-ray tube; 10. Tube shell; 11. Lumen; 12. X-ray window; 13. Opening; 14. Groove; 20. Anode assembly; 21. Anode target plate; 211. Target surface; 2111. Target area; 2112. Angled area; 2113. Planar area; 22. Bearing unit; 221. Bushing; 23. Drive coil; 30. Cathode assembly; 31. Emitting element; 32. Control grid; 33. Deflection control element; 34. Connecting cover; 341. First part; 342. Second part; 40. Anode high-voltage socket; 41. Anode high-voltage cable; 50. Cathode high-voltage socket; 51. Cathode high-voltage cable; 200. Detector; 300. Object to be detected. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] It should be noted that when a component is said to be "attached" to another component, it can be directly on the other component or it can be in the middle of another component. When a component is said to be "set" to another component, it can be directly set to the other component or it may also be in the middle of another component. When a component is said to be "fixed" to another component, it can be directly fixed to the other component or it may also be in the middle of another component.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "or / and" as used herein includes any and all combinations of one or more of the associated listed items.

[0044] Please refer to the following: Figures 1 to 9 , Figure 1A schematic diagram of the existing X-ray tube 100'; Figure 2 The X-ray distribution near the target region 2111' in the existing X-ray tube 100'; Figure 3 This is a schematic diagram of the focal deformation detected by detector 200 in an existing X-ray tube 100'; Figure 4 This is a schematic diagram of detector 200 probing the YZ plane in an existing X-ray tube 100'; Figure 5 This is a schematic diagram of detector 200 probing the YX plane in an existing X-ray tube 100'; Figure 6 This is a partial structural schematic diagram of the X-ray tube 100 provided by the present invention; Figure 7 A schematic diagram of the structure of the X-ray tube 100 according to Embodiment 1 of the present invention; Figure 8 This is a schematic diagram of the structure of the X-ray tube 100 provided in this invention. Figure 9 This is a schematic diagram of the structure of the X-ray tube 100 according to Embodiment 3 of the present invention.

[0045] The present invention provides an X-ray tube 100 for emitting X-rays. Electrons in the X-ray tube 100 collide with a metal target at high energy and high speed. During the collision, part of the kinetic energy of the electrons is converted into radiation energy to emit X-rays.

[0046] In this embodiment, the X-ray tube 100 is used in medical imaging equipment as an X-ray source, such as in the X-ray generation system of a computed tomography (CT) scanner; it can also be used for X-ray emission in multimodal medical imaging equipment, such as positron emission tomography-computed tomography (PET-CT). This invention does not limit the X-ray tube 100 to applications only in medical imaging equipment; in other embodiments, the X-ray tube 100 can also be used in fields such as industrial flaw detection, security inspection, biomolecular analysis, and X-ray satellite navigation.

[0047] The X-ray tube 100 includes a tube shell 10, an anode assembly 20, and a cathode assembly 30. The tube shell 10 is hollow to form a cavity 11. The anode assembly 20 is disposed in the cavity 11. The anode high-voltage socket 40 applies high voltage to the anode assembly 20 through the anode high-voltage cable 41. The cathode assembly 30 is connected to the tube shell 10. The cathode high-voltage socket 50 applies high voltage to the cathode assembly 30 through the cathode high-voltage cable 51. A potential difference is formed between the anode assembly 20 and the cathode assembly 30, so that the cathode assembly 30 can emit an electron beam to the anode assembly 20, thereby generating X-rays.

[0048] The anode assembly 20 includes an anode target disk 21 disposed within the cavity 11. The cathode assembly 30 includes an emitter 31 capable of emitting an electron beam toward the anode target disk 21 to strike it. The emitter 31 may be made of tungsten, doped tungsten, tungsten alloy, or other materials capable of emitting electron beams, including but not limited to thermal emission hot cathodes and field emission cold cathodes. The shape of the emitter 31 may be a spiral coil, a flat plate, a D-shape, or other shapes. Preferably, in this embodiment, the material of the emitter 31 is tungsten, and the shape of the emitter 31 is a spiral coil.

[0049] The anode target disk 21 can be disc-shaped or cylindrical. The anode target disk 21 includes a target base (not shown in the figure) and a target surface 211. The target surface includes a target area 2111, and the emitter 31 emits an electron beam toward the target area 2111. Since the target surface 211 bears the bombardment of the electron beam, it will accumulate a large amount of heat. Therefore, the target surface 211 is preferably made of materials with high thermal conductivity and melting point, such as rhenium-tungsten alloy, iron, and aluminum.

[0050] The tube shell 10 has an X-ray window 12. The emitter 31 emits an electron beam toward the target surface 211 to generate X-rays. A portion of the X-rays exits from the X-ray window 12 and is directed toward the object to be detected 300. The detector 200 receives the X-rays that have passed through the object to be detected 300 to image the interior of the object to be detected 300. In this embodiment, the X-ray window 12 is made of beryllium, which has a filtering effect on X-rays, allowing the desired X-rays to exit. In other embodiments, the X-ray window 12 may also be made of lightweight glass. This invention does not limit the material of the X-ray window 12. It should be noted that the object to be detected 300 may be a human body, an animal body, or a phantom, etc. This invention does not limit the type of object to be detected 300, as long as it is a detectable object.

[0051] In this embodiment, a portion of the X-rays are emitted from the X-ray window 12. "A portion" refers to approximately 10% or less of the X-rays; of course, the exact amount will vary depending on the actual structure of the X-ray tube.

[0052] The anode assembly 20 also includes a bearing unit 22, one end of which is connected to the anode target disk 21 and the other end of which is connected to the shell 10.

[0053] In the rotating anode X-ray tube, the anode assembly 20 also includes a drive coil 23, which is sleeved outside the bearing unit 22. The drive coil 23 drives the bearing unit 22 to rotate, and the bearing unit 22 can drive the anode target disk 21 to rotate so that the target area 2111 forms an annular surface. The emitter 31 bombards the annular target area 2111. The heat generated by the high-speed electron beam bombarding the target surface 211 is evenly distributed on the rotating annular surface, which can improve the power of the X-ray tube 100.

[0054] Please continue to section 5. Figure 5 This is a schematic diagram of detector 200 detecting in the YX plane within an existing X-ray tube 100'. In the existing X-ray tube 100', the bearing unit 22' is arranged parallel to the X-ray window 12', and the emitter 31' bombards the target area 2111'. The tilt angle α between the target area 2111' and the X-ray window 12' is relatively large. It can be understood that the X-rays generated by the emitter 31' bombarding the target area 2111' are reflected to form an ineffective area A1, a usable area A2, a practical application area A3, and a heel effect area A4. The invalid region A1 is located above the XZ plane. X-rays from this region cannot enter the ray window 12' and will not be used in fluoroscopy. The usable region A2 is located above the XZ plane and in front of the XY plane. Some X-rays in the usable region A2 are emitted at an angle relative to the ray window 12', which will cause focal magnification and distortion, affecting the image quality and resolution, thereby reducing the radiation field of view. X-rays in the heel effect region A4 need to travel through a longer target path, and the amount of X-rays is significantly reduced. On the basis of the already small radiation field of view, the existence of the heel effect region A4 further reduces the radiation field of view and increases the impact of the heel effect region A4 on the radiation field of view.

[0055] This invention reduces the tilt angle b between the target area 2111 and the X-ray window 12 by perpendicularly aligning the bearing unit 22 with the X-ray window 12. This shrinks the ineffective area A1 and the usable area A2, increases the actual application area A3, and reduces the impact of the heel effect area A4 on the radiation field of view, thereby expanding the radiation field of view and increasing the exposure surface of the object under test 300. It should be noted that the target area 2111 is the area formed by the emission element 31 bombarding the target surface 211, and the surface containing the target area 2111 refers to the surface of the target surface 211 bombarded by the electron beam. The X-ray tube 100 of this invention can be a rotating anode X-ray tube or a fixed anode X-ray tube; this invention does not limit the type of X-ray tube 100.

[0056] Furthermore, in the rotating anode X-ray tube, the bearing unit 22 is vertically positioned relative to the X-ray window 12. That is, in the working state, the bearing unit 22 is vertically placed. Compared to the horizontally installed scheme, the bearing unit 22 bears less stress when the anode target plate 21 rotates, which can increase the service life of the bearing unit 22. It can be understood that when the bearing unit 22 is placed horizontally, one end of the bearing unit 22, due to its connection to the anode target plate 21, simultaneously bears the weight of the anode target plate 21 and the torque of the rotation of the anode target plate 21. At the same time, in applications such as CT, the bearing unit 22 generates a large centrifugal force when rotating. Under long-term operation, the above forces will cause significant damage to the bearing unit 22, resulting in wear and affecting the service life of the bearing unit 22.

[0057] Please see Figure 6, Figure 6 This is a partial structural schematic diagram of the X-ray tube 100 provided by the present invention. The inclination angle b between the surface containing the target region 2111 and the X-ray window 12 is less than or equal to 30°. That is, the target surface 211 includes an inclined area 2112 and a flat area 2113, the target region 2111 is disposed on the inclined area 2112, and the target angle b formed by the target region 2111 and the flat area 2113 is less than or equal to 30°. It can be understood that a smaller target angle b can increase the radiation field of view. In another embodiment, an entire target surface 211 can be set as an inclined surface, that is, the inclination angle b between the target surface 211 and the X-ray window 12 is less than or equal to 30°.

[0058] Furthermore, the surface containing the target area 2111 is set parallel to the X-ray window 12, that is, the tilt angle b between the surface containing the target area 2111 and the X-ray window 12 is 0°. It can be understood that the setting of no target angle b can further reduce the invalid area A1 and the usable area A2, increase the actual application area A3, thereby expanding the radiation field of view and increasing the exposure surface of the object to be detected 300.

[0059] Preferably, the projection of the center of the X-ray window 12 onto the target surface 211 is located within the target area 2111, so that as many X-rays generated in the target area 2111 as possible fall into the X-ray window 12 and exit, thereby further increasing the radiation field of view.

[0060] The target surface 211 is planar and is arranged parallel to the ray window 12. It is understood that the bombardment of the target area 2111 by the emitter 31 will generate a large amount of heat. The planar nature of the target surface 211 facilitates heat dissipation from the target area 2111, preventing excessively high temperatures in or near the target area 2111 that could cause cracking or damage to the target surface 211. Of course, in other embodiments, the target surface 211 can also be curved, etc., depending on actual needs.

[0061] The bearing unit 22 includes a bushing 221 and a bearing body (not shown). The bearing body is rotatably connected to the bushing. One end of the bushing 221 is connected to the anode target disk 21. The bearing body is fixedly connected to the shell 10. The bearing unit 22 realizes the connection between the anode target disk 21 and the shell 10. In this embodiment, the bearing body is a ball bearing. In other embodiments, the bearing body can also be a liquid metal bearing. The present invention does not limit the type of bearing body, as long as it enables the anode target disk 21 to be connected to the shell 10.

[0062] The axis of the transmitter 31 is perpendicular to the plane where the target area 2111 is located, or the axis of the transmitter 31 is inclined relative to the plane where the target area 2111 is located, and the transmitting end of the transmitter 31 faces the target area 2111. That is, the transmitter 31 can emit an electron beam at an inclination relative to the axis of the transmitter 31, or it can emit along the axis of the transmitter 31.

[0063] It is understandable that the emitter 31 can emit an electron beam at any angle, providing multiple possibilities for the installation position of the emitter 31, which facilitates installation. At the same time, the emitter 31 and the target surface 211 can have multiple installation methods to reduce the attenuation of X-rays and expand its application scenarios, so that more X-rays are emitted from the X-ray window 12 and the detector 200 receives more information.

[0064] like Figures 7 to 9 As shown, Figure 7 A schematic diagram of the structure of the X-ray tube 100 according to Embodiment 1 of the present invention; Figure 8 This is a schematic diagram of the structure of the X-ray tube 100 provided in this invention. Figure 9 This is a schematic diagram of the structure of the X-ray tube 100 according to Embodiment 3 of the present invention.

[0065] The cathode assembly 30 also includes a control grid 32, which is located within the housing 10 and between the emitter 31 and the anode target disk 21. The control grid 32 surrounds and is positioned close to the emitter 31. Since the electron velocity is low near the emitting end of the emitter 31, the proximity of the control grid 32 to the emitter 31 allows for better control of the electron beam. The control grid 32 is used to control the on / off state of the electron beam and the emission amount. Simultaneously, the control grid 32 has a focusing effect on the electron beam. The emitter 31, in conjunction with other devices, can form fan-shaped, cone-shaped, or pencil-shaped X-rays.

[0066] The cathode assembly 30 also includes a deflection control element 33, located between the target surface 211 and the emitter 31. The deflection control element 33 controls the angle at which the emitter 31 emits the electron beam. Under the action of the deflection control element 33, the electron beam bombards different positions on the target surface 211, causing the focal point to rapidly change between two different target regions 2111, achieving a fly-focal point. This configuration improves the utilization rate of the target surface 211, increases the area on the target surface 211 that can withstand high temperatures, thereby extending the lifespan of the anode target disk 21. Simultaneously, the electron beam bombarding different positions on the target surface 211 forms different focal points, which are detected by the detector 200 outside the X-ray window 12, allowing for the acquisition of more information.

[0067] Preferably, when a focal length shift is required, the focal point rapidly changes between two different target areas 2111, the center of the projection of these two different target areas 2111 onto the center of the X-ray window 12, so that more X-rays can be emitted from the X-ray window 12, thereby increasing the radiation field of view.

[0068] Furthermore, when the emitter 31 is disposed on the side of the tube shell 10 and is inclined relative to the side of the tube shell 10, the electron beam can be emitted along the axial direction of the emitter 31, and when a fly-focus is not required, the deflection control element 33 may not be provided. The deflection control element 33 may be a deflection electrode or a deflection coil, and the fly-focus is achieved by using electric field deflection or magnetic field deflection.

[0069] The deflection control element 33 can be located inside or outside the tube housing 10. The present invention does not limit the installation position of the deflection control element 33.

[0070] Example 1

[0071] Please see Figure 7 , Figure 7 A schematic diagram of the structure of the X-ray tube 100 according to Embodiment 1 of the present invention is shown. An opening 13 is provided on the end face of the tube shell 10. The cathode assembly 30 also includes a connecting cover 34, which covers the opening 13. The emitting element 31 is disposed inside the connecting cover 34, and the axis of the connecting cover 34 is perpendicular to the plane containing the target area 2111. The connecting cover 34 is made of ceramic or other insulating materials.

[0072] The end face of the tube shell 10 has a groove 14, and an opening 13 is formed on the bottom surface of the groove 14. The opening of the connecting cover 34 protrudes relative to the bottom surface of the groove 14. The emitting end of the emitter 31 is positioned close to the opening of the connecting cover 34 to increase the distance between the emitter 31 and the target area 2111, thereby better controlling the emission angle of the electron beam. If the distance between the emitter 31 and the target area 2111 is too close, the tilt angle of the electron beam emitted by the emitter 31 will be too large, making it difficult to control. The emitted electron beam will be blocked by the wall of the connecting cover 34. Raising the opening of the emitter 31 and the connecting cover 34 can prevent the emitted electron beam from being blocked by the side wall of the groove 14.

[0073] In this embodiment, since the emitting end of the emitter 31 extends into the housing 10, the deflection control element 33 is disposed inside the housing 10 and at the opening of the connecting cover 34. In other embodiments, the deflection control element 33 may also be disposed on the outer periphery of the connecting cover 34 inside the housing 10 or on the outer periphery of the control gate 32, as long as it is disposed between the target surface 211 and the emitter 31.

[0074] Example 2

[0075] Please see Figure 8 , Figure 8 This is a schematic diagram of the X-ray tube 100 according to Embodiment 2 of the present invention. The structure shown in this embodiment is basically the same as that in Embodiment 1, and the similar parts will not be described again here. The difference is that:

[0076] An opening 13 is provided on the end face of the tube shell 10, a connecting cover 34 is provided at the opening 13, the launching element 31 is provided inside the connecting cover 34, and the axis of the connecting cover 34 is perpendicular to the plane where the target area 2111 is located.

[0077] The deflection control element 33 is sleeved on the outer periphery of the connecting cover 34 or the outer periphery of the control gate 32.

[0078] Example 3

[0079] Please see Figure 9 , Figure 9 This is a schematic diagram of the X-ray tube 100 according to Embodiment 3 of the present invention. The structure shown in this embodiment is basically the same as that in Embodiment 1, and the similar parts will not be described again here. The difference is that:

[0080] An opening 13 is provided on the side of the tube shell 10 near the ray window 12, and a connecting cover 34 is provided over the opening 13. The axis of the connecting cover 34 is inclined relative to the plane where the target area 2111 is located. With this configuration, when the fly-focus is not required, the deflection control component 33 can be omitted, and the emitter 31 can directly emit an electron beam toward the target area 2111, saving costs.

[0081] The connecting cover 34 includes a first part 341 and a second part 342. The first part 341 is located near the anode target disk 21. The emitter 31 is located inside the second part 342, and the emitting end of the emitter 31 is located near the connection between the second part 342 and the first part 341. The outer diameter of the first part 341 is smaller than the outer diameter of the second part 342, so that the outer surface of the first part 341 forms a recess relative to the outer surface of the second part 342. The deflection control member 33 is located in the recess, which facilitates the installation of the deflection control member 33.

[0082] The outer surface of the tube shell 10 is covered with a heat dissipation coating (not shown in the figure). The heat dissipation coating can be a coating with high emissivity such as graphite or nickel oxide, which enhances the heat dissipation of the tube shell 10.

[0083] The X-ray tube 100 also includes an electron collecting assembly (not shown) and an ion collecting assembly (not shown), which are used to collect electrons or ions to maintain a vacuum inside the tube housing 10. The electron collecting assembly and the ion collecting assembly are respectively an electron collecting electrode and an ion pump, or electrons and ions inside the tube housing 10 can be absorbed by providing a getter.

[0084] The present invention also provides a medical imaging device, which includes the aforementioned X-ray tube 100. The medical imaging device may be a positron emission tomography-computed tomography (PET-CT), a computed radiography (CR) system, or a digital X-ray imaging system (DR), or other medical imaging devices.

[0085] The X-ray tube 100 provided by this invention reduces the target angle b and the tilt angle between the target area 2111 and the X-ray window 12 by vertically arranging the bearing unit 22 and the X-ray window 12. This increases the actual usable area A3, reduces the impact of the heel effect area A4 on the radiation field of view, and reduces the focal distortion problem. More effective X-rays are allowed to pass through the X-ray window 12, increasing the radiation field of view so that the detector 200 can receive more effective information and increasing the exposure surface of the object to be detected 300. Simultaneously, the vertical placement of the bearing unit 22 reduces the stress on the bearing unit 22 and increases its service life. The X-ray tube of this invention can achieve a flying focus by using electric or magnetic field deflection, allowing the electron beam to bombard multiple positions on the target surface 211, improving the utilization rate of the anode target disk 21, reducing the operating temperature of the target surface 211, and thus extending the life of the target surface 211. The collection component can absorb electrons and ions within the tube shell 10, alleviating defocusing problems. A heat dissipation coating is laid on the outer surface of the tube shell 10 to enhance heat dissipation.

[0086] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0087] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. An X-ray tube, comprising a tube shell (10), a cathode assembly (30), an anode target disk (21), a drive coil (23), and a bearing unit (22), wherein the bearing unit (22) and the anode target disk (21) are disposed inside the tube shell (10), the drive coil (23) is sleeved outside the bearing unit (22) for driving the bearing unit (22) to rotate, the bearing unit (22) is connected to the anode target disk (21), one end of the tube shell (10) has a X-ray window (12), and the anode target disk (21) is capable of receiving an electron beam emitted by the cathode assembly (30) to generate X-rays; Its features are, The bearing unit (22) is arranged perpendicularly to the ray window (12); The anode target disk (21) has a target surface (211) at one end facing the ray window (12), the target surface (211) including a target area (2111) for bombardment by the cathode assembly (30), and the angle between the surface of the target area (2111) and the ray window (12) is less than or equal to 30°.

2. The X-ray tube according to claim 1, characterized in that, The surface containing the target area (2111) is set parallel to the ray window (12).

3. The X-ray tube according to claim 1, characterized in that, The center of the ray window (12) is projected onto the target surface (211) within the target area (2111).

4. The X-ray tube according to claim 1, characterized in that, The cathode assembly (30) includes an emitter (31), which is disposed inside the housing (10), and the axis of the emitter (31) is perpendicular to the plane where the target area (2111) is located; Alternatively, the axis of the transmitter (31) is inclined relative to the plane where the target area (2111) is located, and the transmitting end of the transmitter (31) faces the target area (2111).

5. The X-ray tube according to claim 1, characterized in that, The cathode assembly (30) includes a control gate (32) and an emitter (31) disposed within the housing (10), the control gate (32) being arranged around the emitter (31).

6. The X-ray tube according to any one of claims 1-5, characterized in that, The end face of the tube shell (10) is provided with an opening (13), and the cathode assembly (30) also includes a connecting cover (34), which covers the opening (13), and the axis of the connecting cover (34) is perpendicular to the plane where the target area (2111) is located.

7. The X-ray tube according to any one of claims 1-5, characterized in that, The tube shell (10) has an opening (13) on its side. The cathode assembly (30) also includes a connecting cover (34), which is placed over the opening (13). The axis of the connecting cover (34) is inclined relative to the surface where the target area (2111) is located.

8. The X-ray tube according to claim 4 or 5, characterized in that, The cathode assembly (30) also includes a deflection control element (33) located between the target surface (211) and the emitting end of the emitter (31) to control the angle at which the emitter (31) emits an electron beam.

9. The X-ray tube according to any one of claims 1-5, characterized in that, The target surface (211) is a plane, and the target surface (211) is parallel to the ray window (12).

10. The X-ray tube according to any one of claims 1-5, characterized in that, The outer surface of the tube shell (10) is covered with a heat dissipation coating.

11. The X-ray tube according to any one of claims 1-5, characterized in that, The X-ray tube also includes a collection component disposed within the tube shell (10), the collection component being used to collect electrons and ions within the tube shell (10).

12. A medical imaging device, characterized in that, The medical imaging device includes an X-ray tube as described in any one of claims 1-11.

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