CN111430204A

CN111430204A - X-ray tube and medical imaging apparatus

Info

Publication number: CN111430204A
Application number: CN202010389569.7A
Authority: CN
Inventors: 田佳甲; 张曦; 杜岩峰
Original assignee: Shanghai United Imaging Healthcare Co Ltd
Current assignee: Shanghai United Imaging Healthcare Co Ltd
Priority date: 2020-05-08
Filing date: 2020-05-08
Publication date: 2020-07-17

Abstract

The invention relates to the field of medical equipment, in particular to an X-ray tube and medical imaging equipment. An X-ray tube comprises a tube shell, a cathode assembly, an anode target disc and a bearing unit, wherein the bearing unit and the anode target disc are arranged in the tube shell, the bearing unit is connected with the anode target disc, one end of the tube shell is provided with a ray window, and the anode target disc can receive an electron beam emitted by the cathode assembly to generate X rays; the bearing unit is perpendicular to the ray window. The invention has the advantages that: the actual application area for generating X-rays can be increased, the radiation field of view is increased, so that the detector can receive more useful information, and the exposure surface of the object to be detected is increased.

Description

X-ray tube and medical imaging apparatus

Technical Field

The invention relates to the field of medical equipment, in particular to an X-ray tube and medical imaging equipment.

Background

In an X-ray tube, X-rays are generated by high-speed electrons striking an anode target disk, and the X-rays have the advantages of short wavelength, high energy, strong penetrating power and the like, so that the X-rays are widely applied to medical imaging equipment.

In the existing X-ray tube, a bearing unit is arranged in parallel with a ray window, a target area bombarded by a cathode assembly has a larger inclination angle with the ray window, when a detector detects from the outside of the ray window, the focus of a partial area cannot be detected, the focus of the partial area can deform to influence the image quality, and the X-ray of the partial area is attenuated, so that the radiation field of view of the X-ray tube is reduced.

Disclosure of Invention

Accordingly, the present invention provides an X-ray tube, which aims at the above technical problems, and the technical solution is as follows:

an X-ray tube comprises a tube shell, a cathode assembly, an anode target disc and a bearing unit, wherein the bearing unit and the anode target disc are arranged in the tube shell, the bearing unit is connected with the anode target disc, one end of the tube shell is provided with a ray window, and the anode target disc can receive an electron beam emitted by the cathode assembly to generate X rays; the bearing unit is perpendicular to the ray window.

According to the X-ray tube provided by the invention, the bearing unit is vertically arranged with the ray window, so that the inclination angle between the surface of the target area and the ray window is reduced, the actual application area for generating X-rays is increased, the radiation field is increased, the detector can receive more useful information, and the exposure surface of the body to be detected is increased; simultaneously, the bearing unit of vertical setting can make the bearing unit bears less stress, extension the life of bearing unit to when preventing the bearing unit transversely sets up, the one end of bearing unit bears the gravity and the torsional force of anode target dish, and at rotatory in-process, the bearing unit still can produce centrifugal force, in long-term working process, will influence the life of bearing unit.

In one embodiment of the invention, one end of the anode target disc facing the ray window is provided with a target surface, the target surface comprises a target area for bombardment of the cathode assembly, and the included angle between the surface of the target area and the ray window is less than or equal to 30 degrees.

By the arrangement, the actual application area for generating X-rays can be increased, and the radiation field of view is enlarged.

In one embodiment of the present invention, a plane of the target region is parallel to the radiation window.

By such arrangement, the actual application area can be further enlarged, and the radiation visual field is increased.

In one embodiment of the present invention, a projection of the center of the ray window on the target surface is located within the target region.

With such an arrangement, more X-rays can be incident on the radiation window, and the radiation field of view can be further increased.

In one embodiment of the invention, the cathode assembly comprises an emitting piece, the emitting piece is arranged in the tube shell, and the axis of the emitting piece is perpendicular to the surface of the target area; or the axis of the emitting piece is obliquely arranged relative to the surface of the target area, and the emitting end of the emitting piece faces the target area.

By the arrangement, the emitting piece is not limited by the installation position, and the emitting piece and the target surface can be installed in various ways, so that the attenuation of X-rays is reduced, and the application scene is enlarged.

In one embodiment of the present invention, the cathode assembly includes a control gate and an emitter disposed in the tube, and the control gate is disposed around the emitter.

By the arrangement, the control grid can control the on, off and emission quantity of the electron beam emitted by the emitting part, and the control grid is arranged around the emitting part, so that the electron beam can be more effectively controlled.

In one embodiment of the invention, an opening is formed in an end face of the tube shell, the cathode assembly further comprises a connecting cover, the connecting cover is covered at the opening, and an axis of the connecting cover is perpendicular to a plane where the target area is located.

In one embodiment of the present invention, an opening is opened on a side surface of the tube housing, the cathode assembly further includes a connection cover, the connection cover is covered at the opening, and an axis of the connection cover is inclined with respect to a surface of the target area.

By the arrangement, when the flying focus is not needed, the electron beam can be directly emitted to the target area, the emission angle of the electron beam needs to be controlled, and the structure is simple.

In one embodiment of the invention, the cathode assembly further comprises a deflection control member positioned between the target surface and the emission end of the emitter to control the angle at which the emitter emits the electron beam.

According to the arrangement, the deflection control part controls the emitting part to bombard different positions of the target disc to realize focus flying, so that the utilization rate of the anode target disc is improved, the phenomenon that the same position of the target surface is bombarded to cause the temperature of the target area to be too high can be avoided, and the service life of the anode target disc is shortened.

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

So set up, can strengthen the heat dissipation of target surface prevents that high temperature from causing the target surface fracture.

In one embodiment of the invention, the outer surface of the pipe shell is coated with a heat dissipation coating.

So set up to strengthen the shell heat dissipation.

In one embodiment of the present invention, the X-ray tube further comprises a collection assembly disposed within the envelope, the collection assembly being configured to collect electrons and ions within the envelope.

By the arrangement, the vacuum can be kept in the tube shell, and the electron beam can smoothly fly to the target area at high speed without resistance.

The invention also provides the following technical scheme:

a medical imaging device comprises the X-ray tube.

Drawings

Fig. 1 is a schematic structural view of a conventional X-ray tube;

FIG. 2 is a diagram of an X-ray distribution near a target area in a conventional X-ray tube;

FIG. 3 is a schematic view of a detector detecting a deformation of a focal spot in a conventional X-ray tube;

FIG. 4 is a schematic view of a detector in a prior art X-ray tube detecting in the Y-Z plane;

FIG. 5 is a schematic view of a detector in a prior art X-ray tube detecting in the Y-X plane;

FIG. 6 is a schematic view of a portion of the X-ray tube according to the present invention;

fig. 7 is a schematic structural diagram of an X-ray tube according to a first embodiment of the present invention;

fig. 8 is a schematic structural view of an X-ray tube according to a second embodiment of the present invention;

fig. 9 is a schematic structural diagram of an X-ray tube according to a third embodiment of the present invention.

The symbols in the drawings represent the following meanings:

100. an X-ray tube; 10. a pipe shell; 11. a lumen; 12. a ray window; 13. an opening; 14. a groove; 20. an anode assembly; 21. an anode target disk; 211. a target surface; 2111. a target area; 2112. a beveled region; 2113. a planar area; 22. a bearing unit; 221. a shaft sleeve; 23. a drive coil; 30. a cathode assembly; 31. a launch member; 32. a control gate; 33. a deflection control member; 34. a connecting cover; 341. a first part; 342. a second section; 40. an anode high voltage socket; 41. an anode high voltage cable; 50. a cathode high voltage socket; 51. a cathode high voltage cable; 200. a detector; 300. the body is to be detected.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It will be understood that when an element is referred to as being "mounted on" another element, it can be directly on the other element or intervening elements may also be present. When a component is referred to as being "disposed on" another component, it can be directly on the other component or intervening components may also be present. When an element is referred to as being "secured to" another element, it can be directly secured to the other element or intervening elements may also be present.

Unless defined otherwise, 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 belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "or/and" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1 to 9, fig. 1 is a schematic structural diagram of a conventional X-ray tube 100'; fig. 2 is an X-ray distribution diagram of a target region 2111 'in a conventional X-ray tube 100'; fig. 3 is a schematic view of a distortion of a focus detected by the detector 200 in the conventional X-ray tube 100'; fig. 4 is a schematic diagram of the detector 200 in a conventional X-ray tube 100' for detection in the Y-Z plane; fig. 5 is a schematic diagram of the detector 200 in a prior art X-ray tube 100' detecting in the Y-X plane; fig. 6 is a schematic view of a portion of the X-ray tube 100 according to the present invention; fig. 7 is a schematic structural diagram of an X-ray tube 100 according to a first embodiment of the present invention; fig. 8 is a schematic diagram of a two-X-ray tube 100 embodying the present invention; fig. 9 is a schematic structural diagram of an X-ray tube 100 according to a third embodiment of the present invention.

The present invention provides an X-ray tube 100, the X-ray tube 100 being used for emitting X-rays, electrons in the X-ray tube 100 striking a metal target in a high energy, high speed state, a part of kinetic energy of the electrons being converted into radiation energy during striking to emit X-rays.

In the present embodiment, the X-ray tube 100 is applied to a medical imaging apparatus as an X-ray source, for example, in an X-ray generation system of a Computed Tomography (CT); it can also be used for X-ray emission of multi-modality medical imaging devices, such as Positron emission Tomography (PET-CT) and the like. The invention does not limit the X-ray tube 100 to be applicable only to medical imaging devices; in other embodiments, the X-ray tube 100 may also be used in the fields of industrial inspection, security inspection, biomacromolecule analysis, X-ray satellite navigation, and the like.

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

The anode assembly 20 comprises an anode target disk 21, the anode target disk 21 being arranged in the tube cavity 11, the cathode assembly 30 comprises an emitter 31, the emitter 31 being capable of emitting an electron beam towards the anode target disk 21 to impinge on the anode target disk 21. 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 hot cathode for thermal emission, cold cathode for field emission, etc., and the shape of the emitter 31 may be spiral coil, flat plate, D-shaped or other shapes. Preferably, in the present embodiment, the material of the emitter 31 is tungsten, and the emitter 31 has a spiral coil shape.

The anode target disk 21 may have a disk shape or a cylindrical shape. The anode target disk 21 includes a target base (not shown) and a target surface 211 including a target region 2111, and the emitter 31 emits an electron beam toward the target region 2111. Since the target surface 211 bears the bombardment of the electron beam and collects a large amount of heat, the target surface 211 is preferably made of materials with high thermal conductivity and melting point, such as rhenium-tungsten alloy, iron, aluminum, and the like.

The housing 10 is opened with a radiation window 12, the emitter 31 emits an electron beam toward the target surface 211 to generate X-rays, a part of the X-rays are emitted from the radiation window 12 and emitted toward the object 300, and the detector 200 receives the X-rays passing through the object 300 to image the inside of the object 300. In this embodiment, the radiation window 12 is made of beryllium, and has a filtering function for the X-rays to emit the required X-rays, in other embodiments, the radiation window 12 may also be made of light glass, and the invention does not limit the material of the radiation window 12. It should be explained that the object 300 to be detected may be a human body, an animal body, a phantom, or the like, and the present invention is not limited to the type of the object 300 to be detected as long as the object can be detected.

In the present embodiment, a part of the X-rays is emitted from the radiation window 12, and a "part" means approximately 10% or less of the X-rays; of course, the specific number may vary depending on the actual structure of the X-ray tube.

The anode assembly 20 further comprises a bearing unit 22, one end of the bearing unit 22 is connected to the anode target disk 21, and the other end is connected to the case 10.

In the rotating anode X-ray tube, the anode assembly 20 further includes a driving coil 23, the driving coil 23 is sleeved outside the bearing unit 22, the driving coil 23 drives the bearing unit 22 to rotate, the bearing unit 22 can drive the anode target disk 21 to rotate, so that the target area 2111 forms a circular ring, the emitter 31 bombards the circular ring-shaped target area 2111, heat generated by the electron beam bombarding the target area 211 in high-speed motion is uniformly distributed on the rotating circular ring, and power of the X-ray tube 100 can be improved.

With continued reference to fig. 5, fig. 5 is a schematic diagram of the detector 200 in the conventional X-ray tube 100' for detecting in the Y-X plane. In the conventional X-ray tube 100', the bearing unit 22' is disposed parallel to the radiation window 12', the emitter 31' bombards the target region 2111', and the inclination angle a between the target region 2111' and the radiation window 12' is large. It will be appreciated that the emitter 31 'bombards the target region 2111' to generate X-rays which are reflected to form an inactive area a1, an available area a2, an actual application area A3 and a heel effect area a 4. The null area a1, which is located above the XZ plane, is not able to pass X-rays into the window 12' and is not used in fluoroscopy; the usable area A2 is positioned above the XZ plane and in front of the XY plane, and part of the X-rays in the usable area A2 are obliquely emitted relative to the ray window 12', so that the focus is enlarged and deformed, the quality and the resolution of the image are influenced, and the radiation field of view is reduced; the X-rays in the heel effect area A4 need to pass through a longer target path, the X-rays are obviously reduced, on the basis that the radiation visual field is not large, the radiation visual field is further reduced due to the heel effect area A4, and the influence of the heel effect area A4 on the radiation visual field is increased.

The bearing unit 22 is arranged perpendicular to the radiation window 12, so that the inclination angle b between the target region 2111 and the radiation window 12 is reduced, the invalid region A1 and the available region A2 are reduced, the practical application region A3 is enlarged, the influence of the heel effect region A4 on the radiation visual field is reduced, the radiation visual field is enlarged, and the exposure surface of the object 300 to be detected is enlarged. It should be noted that the target region 2111 is a region formed by the emitter 31 bombarding the target surface 211, and the surface where the target region 2111 is located refers to the surface of the target surface 211 bombarded by the electron beam. The X-ray tube 100 of the present invention may be a rotary anode X-ray tube or a fixed anode X-ray tube, and the present invention is not limited to the type of the X-ray tube 100.

In addition, in the rotary anode X-ray tube, the bearing unit 22 is vertically arranged relative to the radiation window 12, i.e. the bearing unit 22 is vertically arranged in the working state, and compared with the scheme of transversely installing, when the anode target disk 21 rotates, the bearing unit 22 bears smaller stress, and the service life of the bearing unit 22 can be prolonged. It can be understood that when the bearing unit 22 is horizontally placed, one end of the bearing unit 22 is connected to the anode target disk 21 and simultaneously bears the gravity of the anode target disk 21 and the torque force of the rotation of the anode target disk 21; meanwhile, in CT and other applications, the bearing unit 22 generates a large centrifugal force when rotating; in long-term operation, the above forces may cause great damage to the bearing unit 22, resulting in wear of the bearing unit 22 and affecting the service life of the bearing unit 22.

Referring to fig. 6, fig. 6 is a partial structural schematic view of an X-ray tube 100 according to the present invention. The inclination angle b between the plane of the target region 2111 and the ray window 12 is less than or equal to 30 °, that is, the target plane 211 comprises a slant region 2112 and a flat region 2113, the target region 2111 is disposed on the slant region 2112, and the target angle b formed by the target region 2111 and the flat region 2113 is less than or equal to 30 °. It will be appreciated that a smaller target angle b can increase the field of view of the radiation. In a further embodiment, an entire target surface 211 may be provided as a bevel, i.e. the angle of inclination b between the target surface 211 and the radiation window 12 is less than or equal to 30 °.

Further, the plane in which the target region 2111 is located is disposed parallel to the radiation window 12, i.e., the angle of inclination b between the plane in which the target region 2111 is located and the radiation window 12 is 0 °. It is understood that the arrangement of the non-target angle b can further narrow the invalid region a1 and the usable region a2, and enlarge the practical application region A3, thereby enlarging the radiation field of view and enlarging the exposure surface of the object 300 to be detected.

Preferably, the projection of the center of the radiation window 12 on the target surface 211 is located in the target region 2111, so that the X-rays generated in the target region 2111 fall into the radiation window 12 as much as possible and exit, and the radiation field of view can be further enlarged.

The target surface 211 is a plane, and the target surface 211 is arranged parallel to the radiation window 12. It will be appreciated that the bombardment of target area 2111 by emitter 31 will generate a significant amount of heat, and that the planarity of target surface 211 facilitates heat dissipation from target area 2111 to prevent cracking or damage to target surface 211 due to excessive temperatures in target area 2111 or in the vicinity of target area 2111. Of course, in other embodiments, the target surface 211 may also be a curved surface, etc., which may be set according to actual requirements.

The bearing unit 22 includes a shaft sleeve 221 and a bearing body (not shown), the bearing body is rotatably connected with the shaft sleeve, the anode target disk 21 is connected with one end of the shaft sleeve 221, the bearing body is fixedly connected with the tube housing 10, and the bearing unit 22 realizes the connection between the anode target disk 21 and the tube housing 10. In this embodiment, the bearing body is a ball bearing, in other embodiments, the bearing body may be a liquid metal bearing, and the invention is not limited to the type of bearing body as long as the anode target disk 21 can be connected to the case 10.

The axis of the emitter 31 is perpendicular to the surface of the target area 2111, or the axis of the emitter 31 is inclined with respect to the surface of the target area 2111, and the emitting end of the emitter 31 faces the target area 2111, that is, the emitter 31 can emit electron beams obliquely with respect to the axial direction of the emitter 31, and can also emit the electron beams along the axial direction of the emitter 31.

It can be understood that the emitter 31 can emit the electron beam at any angle, so as to provide various possibilities for the installation position of the emitter 31, thereby facilitating installation, and meanwhile, the emitter 31 and the target 211 can have various installation manners to reduce the attenuation of the X-ray and expand the application scene thereof, so that more X-rays can be emitted from the ray window 12, and the detector 200 can receive more information.

Fig. 7 to 9 are schematic structural diagrams of an X-ray tube 100 according to a first embodiment of the present invention in fig. 7; fig. 8 is a schematic diagram of a two-X-ray tube 100 embodying the present invention; fig. 9 is a schematic structural diagram of an X-ray tube 100 according to a third embodiment of the present invention.

The cathode assembly 30 further includes a control grid 32, the control grid 32 is located in the tube 10 and is disposed between the emitter 31 and the anode target 21, the control grid 32 surrounds the emitter 31 and is disposed close to the emitter 31, since the flight speed of electrons near the emitting end of the emitter 31 is low, the control grid 32 close to the emitter 31 can better control the electron beam, the control grid 32 is used for controlling the on/off of the electron beam and the emitting amount of the electron beam, and meanwhile, the control grid 32 has a condensing effect on the electron beam. The emitter 31 may be used to form fan, cone or pencil X-rays by cooperation with other devices.

The cathode assembly 30 further comprises a deflection control member 33, the deflection control member 33 is located between the target surface 211 and the emitter 31, the deflection control member 33 can control the angle of the electron beam emitted by the emitter 31, and the electron beam bombards different positions of the target surface 211 under the action of the deflection control member 33, so that the focus is rapidly changed in two different target areas 2111, and the flying focus is realized. By the arrangement, the utilization rate of the target surface 211 can be improved, and the area of the target surface 211 bearing high temperature is increased, so that the service life of the anode target disc 21 is prolonged; meanwhile, the electron beams bombard different positions of the target surface 211 to form different focal points, and are detected by the detector 200 outside the ray window 12, so that more information can be obtained.

Preferably, when a flying focus is required, the focus is rapidly shifted at two different target regions 2111, the center of projection between the two different target regions 2111 at the radiation window 12 being at the center of the radiation window 12, so that more X-rays can exit the radiation window 12, thereby increasing the radiation field of view.

Further, when the emitter 31 is provided on the side of the envelope 10 and is inclined with respect to the side of the envelope 10, the electron beam can be emitted in the axial direction of the emitter 31, and when the flying focus is not required, the deflection control member 33 may not be provided. The deflection control 33 may be a deflection electrode or a deflection coil, using electric field deflection or magnetic field deflection to achieve the flying focus.

The deflection control member 33 may be provided inside the cartridge 10 or outside the cartridge 10, and the present invention is not limited to the mounting position of the deflection control member 33.

Example one

Referring to fig. 7, fig. 7 is a schematic structural diagram of an X-ray tube 100 according to a first embodiment of the present invention. The end surface of the tube shell 10 is provided with an opening 13, the cathode assembly 30 further comprises a connecting cover 34, the connecting cover 34 is covered at the opening 13, the emitter 31 is arranged in the connecting cover 34, and the axis of the connecting cover 34 is perpendicular to the surface of the target area 2111. The connecting cover 34 is made of ceramic or other materials with insulating function.

The end face of the tube shell 10 is provided with a groove 14, the opening 13 is arranged on the bottom surface of the groove 14, the cover opening of the connecting cover 34 is arranged in a protruding mode relative to the bottom surface of the groove 14, and the emission end of the emission part 31 is arranged close to the cover opening of the connecting cover 34 so as to pull the distance between the emission part 31 and the target area 2111 and better control the emission angle of the electron beams. If the distance between the emitter 31 and the target region 2111 is too short, the inclination angle of the electron beam emitted from the emitter 31 is too large to be easily controlled, the emitted electron beam is blocked by the wall surface of the connection cover 34, and the openings of the emitter 31 and the connection cover 34 are lifted, so that the emitted electron beam is prevented from being blocked by the side wall of the groove 14.

In this embodiment, the deflection control member 33 is disposed in the envelope 10 at the bell mouth of the connecting bell 34, since the emitting end of the emitting member 31 projects into the envelope 10. In other embodiments, the deflection control member 33 may be disposed on the outer circumference of the connecting cap 34 or on the outer circumference of the control grid 32 in the package 10 as long as it is disposed between the target surface 211 and the emitter 31.

Example two

Referring to fig. 8, fig. 8 is a schematic structural diagram of an X-ray tube 100 according to a second embodiment of the present invention. The structure shown in this embodiment is substantially the same as that in the first embodiment, and the same parts are not described herein again, but the differences are as follows:

an opening 13 is formed in the end face of the tube shell 10, the connecting cover 34 covers the opening 13, the emitter 31 is arranged in the connecting cover 34, and the axis of the connecting cover 34 is perpendicular to the plane of the target area 2111.

The deflection yoke 33 is fitted around the outer circumference of the connecting cover 34 or the outer circumference of the control grid 32.

EXAMPLE III

Referring to fig. 9, fig. 9 is a schematic structural diagram of an X-ray tube 100 according to a third embodiment of the present invention. The structure shown in this embodiment is substantially the same as that in the first embodiment, and the same parts are not described herein again, but the differences are as follows:

the side of the tube shell 10 close to the ray window 12 is provided with an opening 13, the connecting cover 34 is covered on the opening 13, and the axis of the connecting cover 34 is arranged obliquely relative to the surface of the target region 2111. With this arrangement, when the flying focus is not required, the deflection control member 33 may not be provided, and the emitting member 31 may emit the electron beam directly toward the target region 2111, saving cost.

The connecting cover 34 includes a first portion 341 and a second portion 342, the first portion 341 is disposed near the anode target 21, the emitter 31 is disposed in the second portion 342, and the emitting end of the emitter 31 is disposed near the connection between the second portion 342 and the first portion 341, the outer diameter of the first portion 341 is smaller than that of the second portion 342, so that the outer side surface of the first portion 341 is recessed relative to the outer side surface of the second portion 342, and the deflection control member 33 is disposed in the recess, thereby facilitating the installation of the deflection control member 33.

A heat dissipation coating (not shown) is laid on the outer surface of the tube shell 10, and the heat dissipation coating may be a coating with high emissivity such as graphite, nickel oxide, etc., to enhance the heat dissipation of the tube shell 10.

The X-ray tube 100 further includes an electron collecting assembly (not shown) and an ion collecting assembly (not shown) for collecting electrons or ions to maintain a vacuum in the tube housing 10. The electron collecting element and the ion collecting element are an electron collector and an ion pump, respectively, or the electron and the ion in the envelope 10 are absorbed by providing a getter.

The present invention also provides a medical imaging apparatus comprising the above-described X-ray tube 100. The medical Imaging device may be a Positron Emission Computed Tomography (PET-CT) camera, a Computed Radiography (CR) System, or a Digital Radiography (DR) System.

According to the X-ray tube 100 provided by the invention, the bearing unit 22 is vertically arranged with the ray window 12, so that the target angle b is reduced, the inclination angle between the target region 2111 and the ray window 12 is reduced, the actual available region A3 can be increased, the influence of a heel effect region A4 on the radiation visual field is reduced, the problem of focal point deformation is reduced, more effective X-rays penetrate out of the ray window 12, the radiation visual field is increased, so that the detector 200 can receive more effective information, and the exposure surface of the object 300 to be detected is increased; meanwhile, the bearing unit 22 is vertically arranged, so that the stress borne by the bearing unit 22 can be reduced, and the service life of the bearing unit 22 is prolonged; the X-ray tube can realize focus flying by utilizing electric field deflection or magnetic field deflection, so that electron beams can bombard a plurality of positions of the target surface 211, the utilization rate of the anode target disk 21 is improved, the working temperature of the target surface 211 is reduced, and the service life of the target surface 211 is prolonged; the collecting component can absorb electrons and ions in the tube shell 10, and the defocusing problem is relieved; and a heat dissipation coating is paved on the outer surface of the pipe shell 10 to enhance heat dissipation.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. An X-ray tube comprises a tube shell (10), a cathode assembly (30), an anode target disc (21) and a bearing unit (22), wherein the bearing unit (22) and the anode target disc (21) are arranged in the tube shell (10), the bearing unit (22) is connected to the anode target disc (21), one end of the tube shell (10) is provided with a ray window (12), and the anode target disc (21) can receive an electron beam emitted by the cathode assembly (30) to generate X rays;

characterized in that the bearing unit (22) is arranged perpendicular to the radiation window (12).

2. The X-ray tube according to claim 1, characterized in that the anode target disk (21) has a target surface (211) at its end facing the radiation window (12), the target surface (211) comprising a target region (2111) for bombardment by the cathode assembly (30), the target region (2111) being located at a face which is at an angle of less than or equal to 30 ° to the radiation window (12).

3. The X-ray tube according to claim 2, characterized in that the face of the target region (2111) is arranged parallel to the radiation window (12).

4. The X-ray tube according to claim 2, characterized in that a projection of the center of the radiation window (12) onto the target surface (211) is located within the target region (2111).

5. The X-ray tube according to claim 2, wherein the cathode assembly (30) comprises an emitter (31), the emitter (31) being arranged within the envelope (10) with the axis of the emitter (31) perpendicular to the plane of the target area (2111);

alternatively, the axis of the emitting member (31) is disposed obliquely with respect to the plane of the target region (2111), and the emitting end of the emitting member (31) faces the target region (2111).

6. The X-ray tube according to claim 2, wherein the cathode assembly (30) comprises a control grid (32) and an emitter (31) arranged within the envelope (10), the control grid (32) being arranged around the emitter (31).

7. The X-ray tube according to any one of claims 2 to 6, wherein an opening (13) is provided in an end face of the tube housing (10), the cathode assembly (30) further comprises a connection cap (34), the connection cap (34) is disposed over the opening (13), and an axis of the connection cap (34) is perpendicular to a plane of the target area (2111).

8. The X-ray tube according to one of the claims 2 to 6, wherein the envelope (10) has an opening (13) in a side surface thereof, the cathode assembly (30) further comprising a connection cap (34), the connection cap (34) being disposed at the opening (13), an axis of the connection cap (34) being disposed obliquely with respect to a plane of the target area (2111).

9. The X-ray tube according to claim 5 or 6, wherein the cathode assembly (30) further comprises a deflection control (33), the deflection control (33) being located between the target surface (211) and an emission end of the emitter (31) to control an angle at which the emitter (31) emits the electron beam.

10. The X-ray tube according to any one of claims 2 to 6, wherein the target surface (211) is planar and the target surface (211) is parallel to the radiation window (12).

11. X-ray tube according to one of claims 1 to 6, characterized in that the outer surface of the envelope (10) is provided with a heat-dissipating coating.

12. The X-ray tube according to any one of claims 1 to 6, further comprising a collecting assembly disposed within the envelope (10), the collecting assembly for collecting electrons and ions within the envelope (10).

13. A medical imaging device, characterized in that it comprises an X-ray tube according to any one of claims 1-12.