KR102775447B1 - X-ray source - Google Patents

Abstract

An X-ray tube according to the present invention comprises: a tube body made of an insulating material and having a predetermined space formed inside; an anode electrode disposed at one end of the tube body and having a target coupled thereto; a cathode electrode disposed at the other end of the tube body so as to face the anode electrode and having an emitter coupled thereto; and a sealing member that seals the lower part of the tube body, is made of an insulating material, and has an exhaust pipe terminal and at least one electrode terminal formed to penetrate therethrough, wherein an upper surface of the sealing member has a metal layer having a predetermined thickness laminated thereon, the exhaust pipe terminal is electrically connected to the metal layer, is sealed after vacuum treatment of the X-ray tube, and is used as a ground terminal, and at least one electrode terminal is electrically connected to the cathode electrode.

Description

X-Ray Tube{X-RAY SOURCE}

The present invention relates to an X-ray tube.

A typical X-ray generator consists of a cathode that generates an electron beam and an anode that generates X-rays when the electron beam from the cathode collides with it with high kinetic energy. In other words, the output of the X-ray generator is proportional to the current of the electron beam from the cathode (tube current) and the voltage applied between the cathode and the anode (tube voltage).

At this time, a target made of a metal material with a high atomic number such as tungsten, molybdenum, or copper is formed at the anode, and electrons that collide with the target are accelerated by electromagnetic interaction with the target atoms and emit X-ray radiation. Or, electrons bound to the target atoms exchange momentum and energy with electrons that collide with the target, and then when they are excited and return to the ground state, they emit electromagnetic radiation corresponding to the energy difference between the excited state and the ground state, thereby generating X-rays.

In general, sealed tubes require electrical connections between the inside and outside, and are manufactured by drilling a hole in a sealing member provided at the bottom, inserting a metal pin through the hole, and then filling the gap between the hole and the metal pin with filler.

In this regard, Korean Patent Publication No. 2017-0025065 (Title: Miniature X-ray tube having a tip-off tube and a manufacturing method thereof) discloses an ultra-miniature X-ray tube having a tip-off tube capable of preventing performance degradation of the ultra-miniature X-ray tube due to outgassing by forming a hole in a vacuum tube structure, installing an exhaust tube in the formed hole, removing outgassing, and fusing one end of the exhaust tube in a tip-off manner after the outgassing is completed.

In this way, the conventional sealed tube has the ground line and the vacuum exhaust pipe structurally and functionally separated. That is, since the sealed tube requires many electrical connections between the inside and the outside, it is required to make the sealing structure as simple as possible.

The present invention is intended to solve the above-mentioned problems, and has as a technical task the provision of an X-ray generating device that simplifies the sealing structure of an X-ray tube by using a sealed tube.

The technical problems to be solved by the present invention are not limited to the technical problems described above, and other technical problems of the present invention can be derived from the following description.

As a technical means for solving the above-described technical problem, an embodiment according to a first aspect of the present invention comprises: an X-ray tube comprising a tube body made of an insulating material and having a predetermined space formed therein; an anode electrode disposed at one end of the tube body and having a target coupled thereto; a cathode electrode disposed at the other end of the tube body so as to face the anode electrode and having an emitter coupled thereto; and a sealing member that seals the lower part of the tube body, is made of an insulating material, and is formed such that an exhaust pipe terminal and at least one electrode terminal penetrate through it, wherein an upper surface of the sealing member has a metal layer having a predetermined thickness laminated thereon, the exhaust pipe terminal is electrically connected to the metal layer, is sealed after vacuum treatment of the X-ray tube, and is used as a ground terminal, and the at least one electrode terminal is electrically connected to the cathode electrode.

According to the present invention, the existing electrical connection process of penetrating a metal pin into a hole formed in a lower sealing member of a sealed tube and then sealing the gap can be simplified.

In particular, by utilizing the exhaust pipe terminal for vacuum exhaust according to the present invention as a ground line, one ground pin can be reduced, and the hole processing process formed in the lower sealing member can be simplified, thereby lowering the production cost and improving the production yield.

In addition, a metal layer formed through a conductive coating on the upper surface of a sealing member formed of ceramic according to the present invention can be electrically connected to an exhaust pipe terminal penetrating the sealing member.

In addition, it is possible to prevent charge from accumulating on the upper surface of the sealing member made of insulating material through the exhaust pipe terminal connected to the metal layer, and to prevent change in the characteristics of the ceramic.

The effects of the present invention are not limited to the effects described above, and include all effects understood from the following description.

FIG. 1 is a perspective view of an X-ray tube according to an embodiment of the present invention.
Figure 2 is a cross-sectional view of the X-ray tube cut along the line BB shown in Figure 1.
FIG. 3 is a schematic cross-sectional view for explaining the electrical connection relationship between a ground terminal penetrating a sealing member and a metal layer laminated on an upper surface of the sealing member according to one embodiment of the present invention.
FIG. 4 is a drawing schematically illustrating a metal layer laminated on an upper surface of a sealing member according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to the attached drawings. However, the present invention can be implemented in various different forms and is not limited to the embodiments described herein. In addition, the attached drawings are only for easily understanding the embodiments disclosed in the present specification, and the technical ideas disclosed in the present specification are not limited by the attached drawings. In order to clearly describe the present invention in the drawings, parts that are not related to the description are omitted, and the size, shape, and shape of each component shown in the drawings can be variously modified. The same/similar drawing reference numerals are assigned to the same/similar parts throughout the specification.

The suffixes "module" and "part" used in the following description for components are given or used interchangeably only for the convenience of writing the specification, and do not have distinct meanings or roles in themselves. In addition, when describing the embodiments disclosed in this specification, if it is determined that a specific description of a related known technology may obscure the gist of the embodiments disclosed in this specification, the detailed description thereof has been omitted.

Throughout the specification, when a part is said to be "connected (connected, contacted or coupled)" with another part, this includes not only cases where it is "directly connected (connected, contacted or coupled)" but also cases where it is "indirectly connected (connected, contacted or coupled)" with another member in between. Also, when a part is said to "include (have or provide)" a component, this does not exclude other components unless specifically stated to the contrary, but rather means that it can "include (have or provide)" other components.

The terms indicating ordinal numbers, such as first, second, etc., used in this specification are used only for the purpose of distinguishing one component from another, and do not limit the order or relationship of the components. For example, the first component of the present invention may be named the second component, and similarly, the second component may also be named the first component.

FIG. 1 is a perspective view of an X-ray tube according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of the X-ray tube taken along line B-B shown in FIG. 1.

Referring to FIGS. 1 and 2, the X-ray tube includes a tube body (10), a sealing member (30), a cathode electrode (110), an anode electrode (120), a focusing lens (140), an electrode terminal (150), and an exhaust terminal (160).

For example, as illustrated in FIG. 2, the X-ray tube includes a tube body (10) made of an insulating material and having a predetermined space formed therein, an anode electrode (120) positioned at one end of the tube body (10) and having a target (125) coupled thereto, a cathode electrode (110) positioned at the other end of the tube body (10) so as to face the anode electrode (120) and having an emitter (115) coupled thereto, and a sealing member (30) that seals the lower part of the tube body (10), is made of an insulating material, and has an exhaust pipe terminal (160) and at least one electrode terminal (150) formed to penetrate therethrough. Here, the upper surface of the sealing member (30) is laminated with a metal layer (310) of a predetermined thickness, the exhaust pipe terminal (160) is electrically connected to the metal layer (310), sealed after vacuum treatment of the X-ray tube, and used as a ground terminal, and one or more electrode terminals (150) are electrically connected to the cathode electrode (110).

In this structure, if the exhaust pipe terminal (160) for vacuum exhaust is utilized as a ground terminal, the number of required electrode terminals (150) can be reduced by one. In addition, the number of holes formed in the sealing member (30) to insert the ground terminal can be reduced, thereby lowering the production cost of the X-ray tube and improving the production yield.

The cathode electrode (110) generates cathode electrons and includes an emitter (115) that emits cathode electrons to its upper surface.

For example, the emitter (115) may be configured as a field emitter array (FEA). Also, the present invention is not limited thereto, and the emitter (115) may include a conductive material configured as an electrode that controls the trajectory of emitted electrons, such as a metal or carbon-based material, such as a carbon nanotube (CNT), which is a nanomaterial.

Additionally, a focusing lens (140) may be formed on the cathode electrode (110) to focus an electron beam emitted from an emitter (115) onto the anode electrode (120).

For example, the focusing lens (140) may be manufactured using a general hole shape, or may be manufactured by transferring one or more layers of graphene onto the lens. Additionally, two or more focusing lenses (140) may be used.

The anode electrode (120) may be formed of a metal having high electrical conductivity and thermal conductivity. For example, the anode electrode (120) may be formed of a KOVAR alloy, and KOVAR may be formed of an iron-nickel-cobalt alloy.

Additionally, a target (125) may be formed at the electron beam impact site of the anode electrode (120) to be in contact with the anode electrode (120).

The target (125) may be formed of a material such as tungsten, which has a high melting point and a high atomic number, and thus can generate X-rays with high efficiency when an electron beam collides with it. For example, the target (125) may be formed as a transmission type or a reflection type.

For example, in the case of a reflective type, a window, which is an entrance/exit for X-rays emitted from the inside to the outside of the tube body (10), may be formed in one area of the tube body (10). For example, the window may be formed of a metal material such as beryllium or aluminum, or a glass material coated with a fluorescent material. When the window is formed of a metal material such as beryllium, it may be filtered so that only X-rays of a predetermined wavelength or less are emitted. In addition, when the window is formed of a glass material coated with a fluorescent material, visible light may be emitted through the window.

Referring to FIG. 2, the anode electrode (120) includes a flange (121) that is folded toward the outer surface of the tube body (10) around the circumference. Such a flange (121) may be formed of a material such as KOVAR having a thermal expansion coefficient similar to that of the material of the tube body (10). Therefore, even when the tube body (10) and the anode electrode (120) are joined through the flange (121), the integrity and vacuum tightness of the joint can be maintained even when the joint part experiences a wide temperature change between high and low temperatures.

Meanwhile, the anode electrode (120) may be formed as a rotating electrode. Specifically, the anode electrode (120) may be composed of a target (125) provided on the rotating electrode, a rotor (not shown) supporting the target, and a rotating shaft (not shown). Accordingly, when X-rays are generated, the target (125) rotates, so that the electron beam collision area is formed as a circular track, thereby generating high-output X-rays.

The tube body (10) and sealing member (30) constituting the X-ray tube are made of an insulating material and can be formed in a cylindrical shape with a predetermined space formed inside. At this time, the insulating material can be made of ceramic, but is not limited thereto, and can be made of an insulating material such as glass or silicon.

FIG. 3 is a schematic cross-sectional view for explaining an electrical connection relationship between a ground terminal penetrating a sealing member according to an embodiment of the present invention and a metal layer laminated on an upper surface of the sealing member, and FIG. 4 is a drawing schematically illustrating a metal layer laminated on an upper surface of a sealing member according to an embodiment of the present invention.

Referring to FIG. 3, the sealing member (30) includes a hole formed so that an exhaust pipe terminal (160) and at least one electrode terminal (150) pass through it.

Additionally, the sealing member (30) includes a metal layer (310) laminated to a predetermined thickness on the upper surface.

The exhaust terminal (160) may be electrically connected to the metal layer (310), and the electrode terminal (150) may be electrically insulated from the metal layer (310).

The exhaust pipe terminal (160) can be used as a ground terminal after the end is sealed by connecting a vacuum pump to evacuate the inside of the tube body (10). That is, the exhaust pipe terminal (160) can be electrically connected to the metal layer (310) to be used as a ground terminal.

As illustrated in FIG. 4, the metal layer (310) may be coated on the upper surface of the sealing member (30), except for the ring-shaped gap region around the hole through which the electrode terminal (150) penetrates. Such a metal layer (310) has an electrical connection function while being directly connected to the exhaust pipe terminal (160) and has a sealing function at the same time. In addition, the metal layer (310) can prevent a charging phenomenon in which charges generated inside the tube body (10) are accumulated on the upper surface of the sealing member (30). That is, charges accumulated on the metal layer (310) can be discharged to the outside through the exhaust pipe terminal (160) that is electrically connected to the metal layer (310).

In addition, the metal layer (310) has the effect of shielding a certain amount of X-rays emitted in the direction of the anode electrode and can prevent charging of the ceramic surface due to high-energy X-rays.

For example, the metal layer (310) can be electrically insulated from the electrode terminal (150) by an insulating ceramic material exposed through a ring-shaped gap region on the upper surface of the sealing member (30).

As another example, the metal layer (310) can be electrically insulated from the electrode terminal (150) by filling an additional insulator in the ring-shaped gap region of the upper surface of the sealing member (30).

Meanwhile, referring again to FIG. 2, the electrode terminal (150) can support and be electrically connected to the cathode electrode (110). In addition, the electrode terminal (150) can support and be electrically connected to the focusing lens (140) so that the area to be exposed by the hole of the focusing lens (140) and the cathode electrode (110) maintain a certain distance.

Those skilled in the art will understand that the present invention can be easily modified into other specific forms without changing the technical idea or essential features of the present invention based on the above description. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive. The scope of the present invention is indicated by the claims described below, and all changes or modified forms derived from the meaning and scope of the claims and the equivalent concepts thereof should be interpreted as being included in the scope of the present invention.

The scope of the present application is indicated by the claims described below rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present application.

10: Tube body
30: Sealing member
110: Cathode electrode
115: Emitter
120: Anode electrode
125: Target
140: Focusing lens
150: Electrode terminal
160: Exhaust pipe terminal
310: Metal layer

Claims (4)

In the x-ray tube,
A tube body made of insulating material and having a predetermined space formed inside;
An anode electrode positioned at one end of the above tube body and having a target coupled thereto;
A cathode electrode coupled to an emitter, positioned opposite the anode electrode at the other end of the tube body;
A sealing member is included that seals the lower part of the above tube body, is made of an insulating material, and is formed so that an exhaust pipe terminal and at least one electrode terminal penetrate through it.
The upper surface of the above sealing member is formed by laminating a metal layer of a predetermined thickness,
The above exhaust pipe terminal is electrically connected to the metal layer, sealed after vacuum treatment of the X-ray tube, and is used as a ground terminal.
The one or more electrode terminals support the cathode electrode and are electrically coupled to the cathode electrode,
An X-ray tube, wherein the metal layer is coated on the upper surface of the sealing member, except for a ring-shaped gap area around the hole through which the electrode terminal penetrates.
In the first paragraph,
An X-ray tube, wherein the electrode terminal is electrically insulated from the metal layer.
In the first paragraph,
An X-ray tube wherein the anode electrode is made of a KOVAR alloy.
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