Cathode focusing cover, X-ray tube and X-ray imaging device

Abstract

The utility model discloses a cathode focusing cover, an X-ray tube and an X-ray imaging device, the cathode focusing cover is used for focusing an electron beam emitted by an electron emitter, the cathode focusing cover comprises a body, a first focusing groove is limited on the body, a second focusing groove is limited on the bottom surface of the first focusing groove, and the first focusing groove is communicated with the second focusing groove. The second focusing groove is used for accommodating the electron emitter, a notch communicated with the first focusing groove is defined in the edge, extending in the emitting direction of the electron beam, of the first focusing groove, and the notch is used for changing the size parameter of a focal spot formed by the electron beam in the set direction. According to the cathode focusing cover provided by the embodiment of the utility model, the notch is formed in the edge of the first focusing groove, so that the size adjustment of a focal spot in a set direction can be realized under the condition that the diameters of a ray tube and the cathode cover are not changed.

Description

Technical Field

[0001] This utility model belongs to the field of X-ray tube technology, specifically relating to a cathode focusing cover, an X-ray tube, and an X-ray imaging device. Background Technology

[0002] In an X-ray tube, the cathode emits an electron beam toward the anode, which then converges to form a focal spot. Smaller focal spots typically correspond to higher resolution; however, when the electron beam is focused on a very small target area, the increased electron density at that location can lead to excessive localized heat concentration at the anode, causing anode degradation and failure.

[0003] Therefore, when designing X-ray tubes, it is usually necessary to control the focal spot size within a reasonable range. Existing methods for adjusting the focal spot size can be broadly divided into mechanical adjustment and electronic adjustment. Electronic adjustment may involve the design and optimization of tube voltage, tube current, and control system, making the adjustment method relatively complex and costly. Mechanical adjustment can usually change the focal spot size by changing the width of the focusing groove. For example, the size parameters of the focal spot can be adjusted by increasing the radial dimension of the focusing groove in a certain direction. However, when the radial dimensions of the X-ray tube and cathode hood are limited, it is not possible to change the size of the focal spot by changing the radial dimension of the focusing groove. If other focusing structures are changed, it is also difficult to ensure that the size parameters of the focal spot in all directions meet the requirements. Summary of the Invention

[0004] The purpose of this utility model embodiment is to provide a cathode focusing hood, X-ray tube, and X-ray imaging device to solve the problem in the prior art that the focal spot size parameter is difficult to adjust when the diameter size parameters of the X-ray tube and cathode hood are limited.

[0005] According to a first aspect of the present invention, a cathode focusing hood is used to focus an electron beam emitted by an electron emitter, the cathode focusing hood comprising:

[0006] The body is defined with a first focusing groove, and the bottom surface of the first focusing groove is defined with a second focusing groove for accommodating the electron emitter. The edge of the first focusing groove extending along the electron beam emission direction is defined with a notch communicating with the first focusing groove. The notch is used to change the size parameters of the focal spot formed by the electron beam in a set direction.

[0007] Furthermore, the first focusing groove is formed as a square hole, a rectangular hole, a circular hole, or an oblong hole.

[0008] Furthermore, the second focusing groove is formed as an elongated hole, and the electron emitter is disposed in the second focusing groove extending along the length direction of the second focusing groove.

[0009] Furthermore, the first focusing groove defines two symmetrically arranged notches in the axial direction perpendicular to the electron emitter, and the notches are used to change the dimensional parameters of the focal spot in the axial direction perpendicular to the electron emitter.

[0010] Furthermore, the first focusing groove defines two symmetrically arranged notches in a direction parallel to the axial direction of the electron emitter, and the notches are used to change the dimensional parameters of the focal spot in the direction parallel to the axial direction of the electron emitter.

[0011] Furthermore, the width of the notch is greater than the width of the first focusing groove.

[0012] Furthermore, the notch is formed in the form of a trapezoid, rectangle, semicircle, or U-shape.

[0013] Furthermore, the body is a one-piece molded part.

[0014] According to a second aspect embodiment of the present invention, an X-ray tube includes:

[0015] The cathode focusing cover described in the above embodiments;

[0016] The electron emitter is located within the second focusing groove of the cathode focusing shroud;

[0017] An anode assembly includes an anode target for being bombarded by an electron beam emitted by the electron emitter to emit X-rays.

[0018] An X-ray imaging apparatus according to a third aspect embodiment of the present invention includes:

[0019] The X-ray tube described in the above embodiments;

[0020] An X-ray detection device detects X-rays emitted from the X-ray tube and passing through an object.

[0021] According to the embodiment of the present invention, by providing a notch along the edge of the first focusing groove, the size adjustment of the focal spot in the setting direction can be achieved without changing the diameter of the ray tube and the cathode cover. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of a cathode focusing cover in the prior art;

[0023] Figure 2 This is a schematic diagram of the electron beam trajectory in the prior art;

[0024] Figure 3 This is a schematic diagram of the electron beam trajectory in the X direction in the prior art;

[0025] Figure 4 This is a schematic diagram of the electron beam trajectory in the Y direction in the prior art;

[0026] Figure 5 This is a schematic diagram of the structure of the cathode focusing cover according to one embodiment of the present invention;

[0027] Figure 6 This is a schematic diagram of the structure of the cathode focusing cover according to another embodiment of the present invention;

[0028] Figure 7 This is a schematic diagram of the electron beam trajectory in the X direction according to an embodiment of the present invention;

[0029] Figure 8 This is a schematic diagram of the electron beam trajectory in the Y direction according to an embodiment of the present invention;

[0030] Figure 9 This is a schematic diagram of the structure of the cathode focusing cover according to another embodiment of the present invention;

[0031] Figure 10 This is a schematic diagram of the structure of the cathode focusing cover according to another embodiment of the present invention;

[0032] Figure 11 This is a schematic diagram of the structure of the cathode focusing cover according to another embodiment of the present invention.

[0033] Figure Labels

[0034] Cathode focusing cover 100; body 10; first focusing groove 11; second focusing groove 12; notch 13.

[0035] Electron beam 20. Detailed Implementation

[0036] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model.

[0037] The terms "first," "second," etc., used in the specification and claims of this utility model are used to distinguish similar objects and are not used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of this utility model can be implemented in orders other than those illustrated or described herein. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0038] In existing technologies, such as Figure 1 As shown, the edges of the focusing groove 1 extending towards the sun's extreme end are of equal height. Furthermore, as... Figure 2 As shown, filament 2 is located within focusing groove 1. To adjust the focal spot size parameters of electron beam 3, it is necessary to widen the focusing groove 1 in a certain radial direction. However, due to the limited diameter of the X-ray tube and cathode cover, the radial dimension of focusing groove 1 is also limited. Therefore, adjusting the focal spot size by adjusting the radial dimension of focusing groove 1 is not feasible under certain circumstances. Furthermore, changing other focusing structures also makes it difficult to ensure that the focal spot size meets the requirements in all directions, such as... Figure 4 As shown, although the size of the focal spot of electron beam 3 in the Y direction (i.e., the direction perpendicular to the axial direction of filament 2) meets the requirements, as... Figure 3 As shown, the size of the focal spot of electron beam 3 in the X direction (i.e., parallel to the filament axis) is too large. It can be seen from the figure that the focal spot has even exceeded the width of the anode target, which is obviously not in line with the requirements.

[0039] In view of the technical problems existing in the prior art, this utility model provides a cathode focusing cover 100.

[0040] The following is combined Figures 5 to 11 The cathode focusing cover 100 provided in this utility model embodiment will be described in detail through specific embodiments and application scenarios.

[0041] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0042] According to an embodiment of the present invention, the cathode focusing cover 100 is used to focus the electron beam 20 emitted by the electron emitter, such as... Figure 5 and Figure 6 As shown, the cathode focusing cover 100 includes a body 10, which defines a first focusing groove 11. The bottom surface of the first focusing groove 11 defines a second focusing groove 12, which is used to accommodate an electron emitter (not shown). The edge of the first focusing groove 11 extending along the emission direction of the electron beam 20 defines a notch 13 that communicates with the first focusing groove 11. The notch 13 is used to change the size parameters of the focal spot formed by the electron beam 20 in a set direction.

[0043] In other words, the cathode focusing cover 100 defines a first focusing groove 11 and a second focusing groove 12, wherein the first focusing groove 11 is a large focusing groove, and the second focusing groove 12 is a small focusing groove, with the electron emitter (filament) located within the small focusing groove. According to this embodiment, the height of the first focusing groove 11 in one direction is locally reduced to form a notch 13. The notch 13 can change the electric field distribution and adjust the trajectory of the electron beam 20, thereby causing the focal spot to be in the Y direction (e.g., ...). Figure 8 Dimensional parameters on (as shown) and X direction ( Figure 7 The dimensional parameters on the (shown) all meet the requirements. In other words, by setting notches 13 in one or both directions of the first focusing groove 11, the dimensional parameters of the focus spot in the corresponding one or both directions can be adjusted, wherein the shape and dimensional parameters of the notches 13 can be set according to specific needs.

[0044] Therefore, according to the embodiment of the present invention, the cathode focusing cover 100, by providing a notch 13 on the edge of the first focusing groove 11, can achieve dimensional adjustment of the focal spot setting direction without changing the diameter of the ray tube and the cathode cover.

[0045] Furthermore, the shape of the first focusing groove 11 also affects the size parameters of the focal spot. The first focusing groove can be a square hole, a rectangular hole, a circular hole, or an oblong hole, and is not limited to these. Specifically, Figure 5 The first focusing groove 11 is a square hole. Figure 6 The first focusing groove 12 is a circular hole. The notch 13 can be formed by reducing the height of the edge of the first focusing groove 11 in one direction or a portion of the edge in one direction, or it can be formed by reducing the height of the edge of the first focusing groove 11 in more than one direction.

[0046] In one embodiment of the present invention, the second focusing groove 12 is formed as an elongated hole, and the electron emitter is generally a filament, which is provided in the second focusing groove 12 along the length direction of the second focusing groove 12.

[0047] According to one embodiment of this utility model, the cathode focusing cover 100 has an axisymmetric structure. The first focusing groove 11 defines two symmetrically arranged notches 13 in the axial direction perpendicular to the electron emitter. The notches 13 are used to change the dimensional parameters of the focal spot in the axial direction perpendicular to the electron emitter. That is, the two notches 13 are located on both sides of the filament and are axisymmetric about the axis of the filament. The notches 13 are mainly used to change the dimensional parameters of the focal spot in the axial direction perpendicular to the filament.

[0048] Furthermore, the first focusing groove 11 defines two symmetrically arranged notches 13 in the axial direction parallel to the electron emitter. The notches 13 are used to change the dimensional parameters of the focal spot in the axial direction parallel to the electron emitter. That is, as... Figure 5 and Figure 6 As shown, the two notches 13 are located at both ends of the filament and on a line parallel to the filament axis. The notches 13 are mainly used to change the dimensional parameters of the focal spot in the direction parallel to the filament axis. The focal spot formed by the electron beam focused by the cathode focusing shroud 100 of this structure is as follows... Figure 7 and Figure 8 As shown, Figure 7 This is a schematic diagram of the focal spot parallel to the filament axis. Figure 8 This is a schematic diagram of the focal spot perpendicular to the filament axis. The dimensions of the focal spot in both directions meet the requirements.

[0049] Preferably, the width of the notch 13 is greater than the width of the first focusing groove 11, but it is not limited thereto. The width of the notch 13 can be adjusted according to the specific size parameters required by the focal spot.

[0050] Furthermore, the shape of the notch 13 can also affect the electric field distribution and the trajectory of the electron beam 20, thereby affecting the size of the focal spot of the electron beam 20. The notch 13 can be trapezoidal, rectangular, semi-circular, or U-shaped, and is not limited to these. Figure 9 As shown, the gap is U-shaped, as... Figure 10 As shown, gap 13 is rectangular, as... Figure 11 As shown, the notch is semi-circular.

[0051] Optionally, the body 10 is a one-piece molded part, that is, the cathode focusing groove with the notch 13 is directly machined. The one-piece molded part has a stable structure and is easy to process. In addition, the notch 13 can also be machined into the existing cathode focusing cover as needed.

[0052] According to a second aspect of the present invention, the X-ray tube includes a cathode focusing shroud 100, an electron emitter, and an anode assembly as described in the above embodiments. The electron emitter is located within the second focusing groove 12 of the cathode focusing shroud 100, and the anode assembly includes an anode target for being bombarded by an electron beam 20 emitted by the electron emitter to produce X-rays.

[0053] The X-ray tube according to the present invention includes the cathode focusing cover 100 described in the above embodiments. Since the cathode focusing cover 100 according to the present invention has the advantage of improving the focal spot size of the electron beam 20, the X-ray tube according to the present invention also has the above advantages.

[0054] Other structures and techniques of the X-ray tube according to the embodiments of this utility model are prior art and will not be described in detail here.

[0055] The X-ray imaging apparatus according to a third aspect embodiment of the present invention includes the X-ray tube described in the above embodiment. Since the X-ray tube according to the embodiment of the present invention has the advantage of improving the focal spot size of the electron beam 20, the X-ray imaging apparatus according to the embodiment of the present invention also has the above advantages.

[0056] Other structures and techniques of the X-ray imaging device according to the embodiments of this utility model are prior art and will not be described in detail here.

[0057] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the present invention.

Claims

1. A cathode focusing cup for focusing an electron beam emitted by an electron emitter, characterized in that, The cathode focusing cover includes: The body is defined with a first focusing groove, and the bottom surface of the first focusing groove is defined with a second focusing groove for accommodating the electron emitter. The edge of the first focusing groove extending along the electron beam emission direction is defined with a notch communicating with the first focusing groove. The notch is used to change the size parameters of the focal spot formed by the electron beam in a set direction.

2. The cathode focusing cup of claim 1, wherein, The first focusing groove is formed as a square hole, a rectangular hole, a circular hole, or an oblong hole.

3. The cathode focusing cover according to claim 2, characterized in that, The second focusing groove is formed as an elongated hole, and the electron emitter is disposed in the second focusing groove extending along the length direction of the second focusing groove.

4. The cathode focusing cover according to claim 3, characterized in that, The first focusing groove defines two symmetrically arranged notches in the axial direction perpendicular to the electron emitter, and the notches are used to change the dimensional parameters of the focal spot in the axial direction perpendicular to the electron emitter.

5. The cathode focusing cover according to claim 3, characterized in that, The first focusing groove defines two symmetrically arranged notches in a direction parallel to the axial direction of the electron emitter. The notches are used to change the dimensional parameters of the focal spot in the direction parallel to the axial direction of the electron emitter.

6. The cathode focusing cover according to claim 1, characterized in that, The width of the notch is greater than the width of the first focusing groove.

7. The cathode focusing cover according to claim 1, characterized in that, The notch is formed in the shape of a trapezoid, rectangle, semicircle or U.

8. The cathode focusing cover according to claim 1, characterized in that, The body is a one-piece molded part.

9. An X-ray tube, characterized in that, include: Cathode focusing cover as claimed in any one of claims 1-8; The electron emitter is located within the second focusing groove of the cathode focusing shroud; An anode assembly includes an anode target for being bombarded by an electron beam emitted by the electron emitter to emit X-rays.

10. An X-ray imaging device, characterized in that, include: The X-ray tube as described in claim 9; An X-ray detection device detects X-rays emitted from the X-ray tube and passing through an object.

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