KR20150084324A - X-ray generator having anti-charging structure of triode electron emitting device - Google Patents

Abstract

The present invention relates to an X-ray tube having a triode electron emitting device with an anti-charging structure. According to the present invention, the X-ray tube having a triode electron emitting device with an anti-charging structure comprises: a cathode electrode with the source to discharge electrons; an anode electrode facing to the cathode electrode; metallic material sprayed to a center of the anode electrode to generate the X-ray by emitting electrons; a carbon nano tube formed as an electron emitting device on the cathode electrode that corresponds to an intersection of the cathode and the anode electrodes; a gate electrode placed between the cathode electrode and the anode electrode with a certain interval to control electrons discharged from the carbon nano tube; a pair of convergent electrodes attached in a way to facilitate a combination at the both ends of the gate electrode; sub racks located between the cathode electrode and the convergent electrodes and combining with the cathode electrode on one side to achieve the same potential as the cathode electrode; and insulators located between the sub racks and the convergent electrodes. In the electron emitting device with an anti-charging structure according to the present invention, the insulator is not exposed to the electron emitting device. Therefore, the issue of arching by insulator conduction, and device destruction can be resolved by using a triode electron emitting device that is used to manufacture an X-ray tube that generates X-rays reliably.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an X-ray generator having an anti-charging structure and a triode field emission device,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an X-ray generator, and more particularly, to a novel three-pole field emission structure capable of preventing electrification of an insulator and an X-ray tube using the same.

Generally, the electron emitting device has a method of using a hot cathode as an electron source and a method of using a cold cathode. Among these, electron emitters of a cold cathode type include a field emitter array (FEA) type, a surface conduction emitter (SCE) type, a metal insulator-metal (MIM) Type and BSE (Ballistic Electron Surface Emitter) type electron emitting devices are known.

Although the electron emission devices differ in their detailed structures according to their types, basically, a structure for emitting electrons, that is, an electron emission unit is provided in a vacuum container, and electrons emitted therefrom are used. A fluorescent layer or an X-ray target material is provided inside the vacuum chamber so as to emit a predetermined light emission / display action or an X-ray.

These electron emitting devices are implemented in a bipolar configuration composed of a bipolar or cathode electrode composed of a cathode electrode and an anode electrode, a triode configuration composed of an anode electrode and a gate / grid electrode, and between the electrodes, Respectively.

In the conventional X-ray generator apparatus, in the case of a structure in which electrons are emitted by a thermionic electron emission structure, that is, by heating of filaments, an initial acceleration force and a velocity of electrons emitted from an electron source (filament) (Momentum) is within a few eV, the trajectory of the electron moves only by the electric field applied between the anode and the electron source (cathode).

However, in the case of an electron emitting device (field emission device) using a cold cathode, since the initial acceleration force and speed (momentum) of electrons emitted from the electron source reach several keV, even if a structure for inducing an electron locus is provided It is not easy to control the trajectory of electrons emitted in an abnormal direction (undesired direction). In other words, before the electrons generated in the cathode of the electron emitting device in which the electric field distribution is normally formed enter the target, they are accumulated in the insulator for maintaining the insulated state of each electrode for the above reason, Resulting in abnormal operation of the electron emitting device, occurrence of an arcing phenomenon, or the like, resulting in failure of the electron emitting device, and inability to drive the electron emitting device.

In order to solve such a problem, a spacer used for a field emission device is provided with a spacer having a metal pattern formed thereon to prevent the accumulation of electric charges, thereby leaking a charged charge, or applying a high electric field to a grid electrode near the spacer, So as to prevent the charging of the spacer.

However, the above-described conventional technique does not provide a solution to the charging problem of the insulator provided between the cathode electrode and the gate / grid electrode, which is a technique for preventing only the charging of the spacer. , Which are difficult to apply to field emission devices that do not use spacers. In addition, since a separate electrode for preventing electrification of the spacer must be formed or a separate driving voltage must be provided, there is a problem that the manufacturing cost of the device is increased due to an increase in the number of components.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and it is an object of the present invention to provide a field emission device capable of preventing electric field from being charged in an insulator by realizing an insulator in a locus of electrons and electrons generated in a field- Device.

According to an aspect of the present invention, there is provided a plasma display device comprising an insulating substrate, a cathode electrode having an electron source for emitting electrons, an electrode structure for forming an electric field, and a target portion for generating X- In a field emission device, a metal structure (subleak) is formed so as to have a potential equal to that of the cathode electrode, and a metal structure (subleak) to provide.

An insulator is provided between the metal structures (subleaks) for supporting and fixing the electrode structures so as to be insulated and separated. At least one of the bent portions formed in the electrode structure is bent toward the cathode electrode.

The electron source that emits electrons may be embodied as at least one material selected from the group consisting of carbon nanotubes, graphene and graphite, diamond-like carbon, fullerene, and silicon nanowires.

An X-ray tube having a triode field emission device according to an aspect of the present invention includes: a cathode electrode having an electron source for emitting electrons; An anode electrode disposed opposite to the cathode electrode, a metal material applied to the center region of the anode electrode to irradiate the emitted electrons to generate X-rays, a cathode electrode corresponding to the intersection of the cathode electrode and the anode electrode, Carbon nanotubes formed as electron-emitting devices on a substrate,

A gate electrode disposed at a predetermined interval between the cathode electrode and the anode electrode to control electrons emitted from the carbon nanotube, a pair of focusing electrodes bent at both ends of the gate electrode so as to be easily engaged, Subleaks positioned between the cathode electrode and the focusing electrodes and having one side bonded to the cathode electrode so as to have the same potential as the cathode electrode, and insulators respectively disposed between the subleaks and the focusing electrodes.

And the pair of focusing electrodes are protruded in the direction of the cathode at a bent position.

The focusing electrode has a length ratio of a bent vertical portion to a horizontal portion of at least 1: 1.5.

Further, the electron source that emits the electrons is formed of at least one material selected from the group consisting of carbon nanotubes, graphene and graphite, diamond-like carbon, fullerene, and silicon nanowires.

The field emission device of the present invention can be realized by applying a metal structure around the field emission device so that the insulator is not located around the field emission device so that the insulator is not exposed to the locus of electrons and electrons generated in the field emission device, The present invention provides an electrode structure such as a cathode electrode and a gate / grid electrode above a structure, and an insulator for insulation between a metal structure and an electrode structure is not exposed to the trajectories of electrons and electrons, A structure and a manufacturing method for fabricating a field emission device capable of preventing a charge caused by electrification of an insulator from being generated in an insulator used through structural features of a metal structure and an electrode structure .

FIG. 1 is a cross-sectional view schematically showing an X-ray tube having a triode field emission device of an anti-charging structure according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view schematically showing another embodiment of an X-ray tube having an anti-charging structure triode field emission device according to an embodiment of the present invention.
FIG. 3 is a three-dimensional view showing a main portion of an X-ray tube having an anti-charging structure of a triode field emission device according to an embodiment of the present invention.
4 is a cross-sectional view showing the dimensions and spacing of each component of the X-ray tube having the triode field emission device of another anti-charging structure of the present invention.

It is to be understood that the following detailed description and examples are illustrative of preferred embodiments of the present invention but are for the purpose of illustration and are not to be construed as limiting the scope of the present invention.

The terms first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprising" or "having ", and the like, are intended to specify the presence of stated features, integers, steps, operations, elements, parts, or combinations thereof, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the meaning in the context of the relevant art and are to be interpreted as ideal or overly formal in meaning unless explicitly defined in the present application Do not.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

1, a field emission device according to an embodiment of the present invention includes CNTs (not shown) formed on a substrate 20, A cathode electrode 21 having a field emission portion 22 formed thereon is formed and a metal structure (a subregion 23) to which the same potential is applied by bonding with the cathode electrode 21 is located.

An electrode structure in which a gate electrode 25 and a grid electrode 26 are integrally formed on the metal structure 23 is positioned and supported on the metal structure 23.

In this structure, the cathode electrode 21 and the metal structure 23 are joined to each other to have the same potential, and a second potential different from that of the cathode electrode 21 is supplied to the electrode structures 25 and 26, The insulator 24 is interposed between the structure 23 and the electrode structures 25 and 26 so as to be insulated.

The metal structure 23 is a structure for preventing electrification of the insulator by supporting and fixing the upper electrode structures 25 and 26. The shape and the shape of the metal structure 23 are the same as those of the electrode structure 25, 26) can be carried out. In the electrode structures 25 and 26, the gate electrode 25 and the grid electrode 26 are integrally formed. One side of the grid electrode 26 that is bent is connected to the gate electrode 25.

When the metal structure 23 and the insulator 24 are formed by using the bolts or the fastening means such as clamps, the metal structure 23 and the insulator 24 electrode structures 25, 24, and the electrode structures 25, 26, and the shape of the metal structure 23 that is different depending on the fastening method and fastening method is not particularly limited.

The cathode substrate 21, the metal structure 23, the insulator 24 and the electrode structures 25 and 26 are fastened together and integrated into the outer case 20 and 21, And the anode / target 27 is bonded to the upper portion to realize the field emission device.

FIG. 2 is a view showing another embodiment according to the position of the bent portion and the insulator. FIG. 2 is a structure formed by extending the grid electrode 26-1 in FIG. ), It is possible to increase the efficiency of the field emission device by realizing a higher field concentration effect.

3 is a perspective view of a field emission device according to an embodiment of the present invention. A cathode substrate 31 is formed on an insulating substrate 30 such as glass or ceramic, and a field emission device A square-pillar-shaped metal structure 33 having a hollow portion at the center is positioned to expose the device.

A ring-shaped insulator 34 formed along the rim of the metal structure 33 is provided on the metal structure 33 so that the electrode structure 36 to which the gate electrode 35 is bonded is positioned on the insulator 34 do.

The electrode structure 36 is formed so that a gate electrode 35 connected to an end of the bending portion is formed in the hollow region of the metal structure 33. The metal structure 33 is connected to the outer periphery of the metal structure 33, A stepped portion is formed so as to be in contact with the contact surface.

The gate electrode 35 is formed to have a certain distance from the field emission device, and the gate electrode 35 is integrally formed to constitute the electrode structure 36.

The folded surface 26-1 of the electrode structure 36 serves as a grid electrode for focusing the electric field and is configured so that electrons generated in the field emission portion 22 can be focused on the target.

The metal structure 33 bonded to the cathode electrode 31 and the insulator 34 and the electrode structure 36 are bonded to the metal structure 33, the insulator 34 and the electrode structure 36 using a plurality of clamps However, the present invention is not limited to the clamp fixing method, but can be integrated by using other coupling methods such as bolt fastening.

FIG. 4 shows the dimensions and the spacing of the respective components of the field emission device of the present invention. The distance a indicates the distance between the target (anode) and the grid. The distance a is not particularly limited, It is possible to form it within a range not to be used.

The distance b represents the height of the bent portion of the electrode structure. The distance b can be formed in a range not contacting the field emission device and the anode electrode on the top, and the electron beam focusing efficiency can be increased by forming a height of 2 mm or more.

The distance c indicates the gap between the bent portion and the metal structure, and is preferably formed within a range of 10 mu m to 3 mm, more preferably 200 mu m or more and less than 1 mm.

The distance d represents the width of the horizontal plane of the electrode structure (plane parallel to the anode electrode).

The ratio of the distance b and the distance d may be set to be about 1: 1.5, which is advantageous for fixing the support / position of the electrode structure, but the ratio is not limited thereto.

A three-electrode field emission device in which an insulator is not exposed through the above-described structure, and a triode field emission device capable of preventing electrification of an insulator and enhancing electric field concentration effect through an X-ray tube having the same, and an X- Can be prepared.

20, 30:
21, 31: cathode electrode
22: Field emission part
23,33: Metal structures
24, 34: Insulator
25, 35: gate electrode
26, 36: grid electrode
27, 37: anode / target (metallic material)

Claims (4)

A cathode electrode having an electron source for emitting electrons;
An anode electrode disposed opposite to the cathode electrode;
A metal material applied to the anode electrode center region so that the emitted electrons are irradiated to generate X-rays;
A carbon nanotube formed as an electron emitting device on a cathode electrode corresponding to an intersection of the cathode electrode and the anode electrode;
A gate electrode disposed at a predetermined interval between the cathode electrode and the anode electrode to control electrons emitted from the carbon nanotube;
A pair of focusing electrodes bent at both ends of the gate electrode so as to easily engage with each other;
A plurality of focusing electrodes disposed on the cathode electrode and having a same potential as the cathode electrode; And
And an insulator positioned between the focusing electrode and the sub-electrodes and between the focusing electrodes and the focusing electrode. The method according to claim 1,
Wherein the pair of focusing electrodes are formed so as to protrude in the direction of the cathode at a position where the focusing electrodes are bent. The X-ray tube according to claim 1, wherein the X-ray tube is an anti-charging structure. The method according to claim 1,
Ray tube according to claim 1, wherein the focusing electrode has a length ratio of a bent vertical portion to a horizontal portion of at least 1: 1.5. The method according to claim 1,
Wherein the electron source that emits electrons is formed of at least one material selected from the group consisting of carbon nanotubes, graphene, and graphite, diamond-like carbon, fullerene, and silicon nanowires. An X-ray tube having a three-pole field emission device.

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