Nothing Special   »   [go: up one dir, main page]

WO2015105260A1 - X-ray generator having anti-charging structure of triode electron emitting device - Google Patents

X-ray generator having anti-charging structure of triode electron emitting device Download PDF

Info

Publication number
WO2015105260A1
WO2015105260A1 PCT/KR2014/008991 KR2014008991W WO2015105260A1 WO 2015105260 A1 WO2015105260 A1 WO 2015105260A1 KR 2014008991 W KR2014008991 W KR 2014008991W WO 2015105260 A1 WO2015105260 A1 WO 2015105260A1
Authority
WO
WIPO (PCT)
Prior art keywords
cathode
emitting device
anode
electron emitting
electron
Prior art date
Application number
PCT/KR2014/008991
Other languages
French (fr)
Inventor
Dae-Jun Kim
Do-Yun Kim
Dong-Il Kim
Seung-Min YOU
Kwan-Soo Park
Seung-Wan SEO
Ji-Hye Park
Original Assignee
Vacuum Science & Instrument Co., Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Vacuum Science & Instrument Co., Ltd filed Critical Vacuum Science & Instrument Co., Ltd
Publication of WO2015105260A1 publication Critical patent/WO2015105260A1/en

Links

Images

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01JELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J35/00X-ray tubes
    • H01J35/02Details
    • H01J35/04Electrodes ; Mutual position thereof; Constructional adaptations therefor
    • H01J35/045Electrodes for controlling the current of the cathode ray, e.g. control grids
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01JELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J35/00X-ray tubes
    • H01J35/02Details
    • H01J35/04Electrodes ; Mutual position thereof; Constructional adaptations therefor
    • H01J35/06Cathodes
    • H01J35/065Field emission, photo emission or secondary emission cathodes
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01JELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J35/00X-ray tubes
    • H01J35/02Details
    • H01J35/14Arrangements for concentrating, focusing, or directing the cathode ray
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01JELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2201/00Electrodes common to discharge tubes
    • H01J2201/30Cold cathodes
    • H01J2201/304Field emission cathodes
    • H01J2201/30446Field emission cathodes characterised by the emitter material
    • H01J2201/30453Carbon types
    • H01J2201/30469Carbon nanotubes (CNTs)

Definitions

  • the present invention relates to an X-ray generator, and more particularly to a triode electron emitting structure capable of preventing electrical charge of insulator and a triode electron emitting device using the same.
  • the electron emitter using the cold cathode includes FEA (Field Emitter Array) type, SCE (Surface Conduction Emitter) type, MIM (Metal-Insulator-Metal) type or MIS (Metal-Insulator-Semiconductor) type and BSE (Ballisticel ectron Surface Emitter) type electron emitter.
  • FEA Field Emitter Array
  • SCE Surface Conduction Emitter
  • MIM Metal-Insulator-Metal
  • MIS Metal-Insulator-Semiconductor
  • BSE Billallisticel ectron Surface Emitter
  • the above electron emitters have different structure in detail, but generally include a structure for emitting electrons or electron emitting unit in a vacuum vessel and uses electrons emitted by the electron emitting unit. Additionally the above electron emitters include a fluorescent layer or an X-ray target material, which are disposed opposite to the electron emitting unit in the vacuum vessel, to show luminance operation or to generate X-ray.
  • the above electron emitters are embodied as a diode type with a cathode and an anode or a triode type with a cathode, an anode and a gate/grid, and an insulation layer with a specific thickness is formed between the electrodes.
  • electrons emitted by an electron source have a few eV of initial acceleration and speed (momentum) in case of the hot cathode type so that the trace of the electrons are adjusted only by electric field between the cathode and the anode.
  • electrons emitted by an electron source have a few keV of initial acceleration and speed (momentum) in case of the cold cathode type so that it is hard to adjust the trace of the electrons emitted in abnormal direction (or undesirable direction) even though a structure for inducing electron trace is included.
  • electrons emitted by a cathode of an electron emitter with normal electric field distribution are accumulated at an insulator for insulating each electrode before arriving at a target to deteriorate insulation between electrodes, to induce abnormal operation of the electron emitter, to destroy the electron emitter by arc discharge, and to induce malfunction of the electron emitter.
  • a spacer with metal pattern is used to discharge electron in order to prevent electric charging of a spacer used for the electron emitter, or high electric field is applied to a grid near the spacer to change trace of electron beam in order to prevent charging of the spacer.
  • the above solutions are only capable of preventing electric charging of the spacer but not capable of preventing electric charging of insulator between the cathode and gate/grid. Further, the above solutions are preventing for electric charging of the spacer so that it is hard to apply the above solutions to an electron emitter without the spacer. Furthermore, an additional electrode for preventing electrical charge of the spacer and an additional driving voltage are required to increase the number of components so that manufacturing cost is increased.
  • the present invention provides an electron emitter capable of preventing electrical charge of the insulator fundamentally by not exposing the insulator to electrons emitted by a cathode of the electron emitter and an electron trace.
  • the present invention for solving the above technical problem presents an electron emitting device with metal structure (subrack) having the same voltage as a cathode electrode, and the metal structure (subrack) supports and fastens an electrode structure having at least one bending portion, in electron emitting devices having an insulation substrate, cathode with electron source emitting electrons, electrode structure generating electric fields and a target part generating X-ray when receiving electrons.
  • An insulator is formed on the metal structure (subrack) supporing and fastening the electrode structure, and at least one of bending portion of the electrode structure bends toward the cathode.
  • An electron source emitting electrons comprises at least one of the group consisting of carbon nanotube, graphene, carbon, diamond liked carbon, fullerene and silicon nanowire.
  • An X-ray generator having an anti-charging structure of a triode electron emitting device includes: a cathode having an electron source emitting electrons; an anode disposed opposite to the cathode; a metal material formed at a center region of the anode to generate X-ray when the electrons are irradiated thereto; a carbon nanotube formed as a electron emitting device in a region of the cathode, which corresponds to a crossing of the cathode and the anode; a gate disposed between the cathode and the anode with spacing in order to control electrons emitted by the carbon nanotube; a pair of focusing electrodes bended to facilitate combination with both ends of the gate, respectively; subracks disposed between the cathode and the focusing electrodes, respectively, and connected to the cathode to have same electric potential as the cathode; and insulators disposed between the subracks and the focusing electrodes.
  • the pair of focusing electrodes extends toward the cathode electrode at a bending region.
  • the focusing electrode has a vertical portion and a horizontal portion with at least a ratio of about 1:1.5.
  • electron source emitting electrons comprises at least one of the group consisting of carbon nanotube, graphene, carbon, diamond liked carbon, fullerene and silicon nanowire.
  • the insulator near electron emitting device is prevented from being electrically charged through a structural characteristic of the metal structure and electrode structure to prevent problems induced by electric charging of the insulator by not disposing the insulator near the electron emitter by applying the metal structure near the electron emitting device in order not to expose the insulator to the electrons emitted by the electron emitting device and to the electron trance, and by not exposing the insulator for insulating the metal structure and the electrode structure of the cathode and the gate/grid, which is disposed on the metal structure, from each other to the electrons and the electron trace.
  • FIG. 1 is a schematic cross-sectional view showing an X-ray generator with a triode electron emitting device of anti-charging structure according to an embodiment of the present invention.
  • FIG. 2 is a schematic cross-sectional view showing an X-ray generator with a triode electron emitting device of anti-charging structure according to another embodiment of the present invention.
  • FIG. 3 is a perspective view showing main parts of an X-ray generator with a triode electron emitting device of anti-charging structure according to an embodiment of the present invention.
  • FIG. 4 is a cross-sectional view showing size and space of each components of an X-ray generator with a triode electron emitting device of anti-charging structure according to another embodiment of the present invention.
  • first, second, third etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, or section discussed below could be termed a second element, component, or section without departing from the teachings of the present invention.
  • FIG. 1 is a schematic cross-sectional view showing an electron emitter according to an embodiment of the present invention.
  • a cathode 21 with an electron emitting part 22 formed by CNT, etc. is formed on a substrate 20, and a metal structure (subrack) 23 connected onto the cathode 21 to be applied the same voltage with the cathode 21 is positioned.
  • a metal structure (subrack) 23 connected onto the cathode 21 to be applied the same voltage with the cathode 21 is positioned.
  • An electrode structure with a gate 25 and a grid 26 integrally formed with each other is disposed on the metal structure 23 to be supported and fixed by the metal structure 23.
  • the cathode 21 and the metal structure 23 are connected so that the same voltage is applied thereto, and a second voltage different from the cathode 21 is applied to the electrode structure 25 and 26.
  • An insulator 24 is disposed between the metal structure 23 and the electrode structure 25 and 26 to insulate them.
  • the metal structure 23 supports and fixes the electrode structure 25 and 26 disposed thereon and prevents the insulator from being electrically charged. As long as the metal structure 23 supports and fixes the electrode structure 25 and 26, the shape and form of the metal structure 23 are not specially limited.
  • the gate 25 and the grid 26 are integrally formed. A bending portion of the grid 26 is connected to the gate 25.
  • the metal structure 23, the insulator 24, the electrode structure 25 and 26 may be combined by a fastening means (not shown) such as a bolt, a clamp, etc., and a fastening method and the shape of the metal structure 23, which may be changed according to the fastening method, are not specially limited.
  • the cathode substrate 21, the metal structure 23, and insulator 24 and the electrode structure 25 and 26 are combined with each other to be one body, disposed in an outer case 20 and 21, and then an anode/target 27 is combined at the top portion of the outer case 20 and 21 to embody the electron emitter.
  • FIG. 2 is a figure showing another embodiment in which a bending portion and a position of an insulator are different.
  • the grid 26-1 in FIG. 1 extends upward so that focusing of electrons is enhanced to improve efficiency of the electron emitter through the extended portion 26-2 of the grid.
  • FIG. 3 is a perspective view showing main parts of an electron emitter according to an embodiment of the present invention.
  • a cathode substrate 31 is formed on an insulation substrate 30 such as glass, ceramic, etc., and a metal structure 33 having a rectangular frame shape with an opening for exposing electron emitting device is disposed on the cathode substrate 31.
  • An insulator 34 having a ring shape is disposed on the metal structure 33 along edges of the metal structure 33, and an electrode structure 36 with a gate 35 connected thereto is disposed on the insulator 34.
  • the electrode structure 36 has a bending portion, and the gate electrode 35 connected to an end portion of the bending portion is disposed in the opening of the metal structure 33, and the electrode structure 36 has a shoulder making contact with the insulator and edges of the metal structure 33.
  • the gate electrode 35 is spaced apart from the electron emitting device, and the gate electrode 35 is integrally formed to compose the electrode structure 36.
  • a bending surface 26-1 of the electrode structure 36 operates as a grid for focusing electron beams, and focuses electron beam emitted by the electron emitting part 22 to a target.
  • the metal structure 33 connected to the cathode 31, the insulator 34 and the electrode structure 36 may be combined through a plurality of clamps to be one body, but the fastening method is not only limited to the clamp fastening but various method such as bolt fastening may be used.
  • FIG. 4 shows size and space of each components of an X-ray generator of the present invention.
  • a space‘a’ is a space between the target (anode) and a grid, and the space‘a’ is not specially limited. But, the target does not make contact with the grid.
  • a space‘b’ is a height of a bending portion of the electrode structure.
  • the space‘b’ is in a range in which the electron emitting device and the anode electrode do not make contact with each other, and at least 2mm to improve focusing efficiency of electron beam.
  • a space‘c’ is a space between the bending portion and the metal structure.
  • the space‘c’ may be in a range of 10 ⁇ m ⁇ 3mm, and more preferably in a range of 200 ⁇ m ⁇ 1mm.
  • a space‘d’ is a width of a horizontal surface ( a surface parallel to the anode) of the electrode structure.
  • the space‘d’ may be equal to or greater than 3mm, and may be enlarged to outer case surface in maximum.
  • the ratio of the space‘b’ and the space‘d’ may be about 1:1.5 to effectively supporting and fastening of the electrode structure, but the ratio is not limited to that.
  • the triode electron emitting device in which the insulator is not exposed to prevent electrical charge of the insulator and to improve electron beam focusing and the X-ray generator having the same can be manufactured.

Landscapes

  • Cold Cathode And The Manufacture (AREA)

Abstract

A new structure of an electron emitting device, which is capable of preventing electrical charge of an insulator, and an X-ray generator using the same are presented. The present invention includes includes: a cathode having an electron source emitting electrons; an anode disposed opposite to the cathode; a metal material formed at a center region of the anode to generate X-ray when the electrons are irradiated thereto; a carbon nanotube formed as a electron emitting device in a region of the cathode, which corresponds to a crossing of the cathode and the anode; a gate disposed between the cathode and the anode with spacing in order to control electrons emitted by the carbon nanotube; a pair of focusing electrodes bended to facilitate combination with both ends of the gate, respectively; subracks disposed between the cathode and the focusing electrodes, respectively, and connected to the cathode to have same electric potential as the cathode; and insulators disposed between the subracks and the focusing electrodes. According to the triode electron emitting device of above structure, the insulator is not exposed to an electron emitter to solve the problems such as electric arc and device destroy, etc. Therefore, an X-ray generator stably generating X-ray can be manufactured.

Description

X-RAY GENERATOR HAVING ANTI-CHARGING STRUCTURE OF TRIODE ELECTRON EMITTING DEVICE
The present invention relates to an X-ray generator, and more particularly to a triode electron emitting structure capable of preventing electrical charge of insulator and a triode electron emitting device using the same.
In general, there are two types of electron emitter. One is a type using a hot cathode and the other is a type using a cold cathode as an electron source. The electron emitter using the cold cathode includes FEA (Field Emitter Array) type, SCE (Surface Conduction Emitter) type, MIM (Metal-Insulator-Metal) type or MIS (Metal-Insulator-Semiconductor) type and BSE (Ballisticel ectron Surface Emitter) type electron emitter.
The above electron emitters have different structure in detail, but generally include a structure for emitting electrons or electron emitting unit in a vacuum vessel and uses electrons emitted by the electron emitting unit. Additionally the above electron emitters include a fluorescent layer or an X-ray target material, which are disposed opposite to the electron emitting unit in the vacuum vessel, to show luminance operation or to generate X-ray.
The above electron emitters are embodied as a diode type with a cathode and an anode or a triode type with a cathode, an anode and a gate/grid, and an insulation layer with a specific thickness is formed between the electrodes.
According to a conventional X-ray generator, electrons emitted by an electron source (filament) have a few eV of initial acceleration and speed (momentum) in case of the hot cathode type so that the trace of the electrons are adjusted only by electric field between the cathode and the anode.
However, electrons emitted by an electron source have a few keV of initial acceleration and speed (momentum) in case of the cold cathode type so that it is hard to adjust the trace of the electrons emitted in abnormal direction (or undesirable direction) even though a structure for inducing electron trace is included. In detail, electrons emitted by a cathode of an electron emitter with normal electric field distribution are accumulated at an insulator for insulating each electrode before arriving at a target to deteriorate insulation between electrodes, to induce abnormal operation of the electron emitter, to destroy the electron emitter by arc discharge, and to induce malfunction of the electron emitter.
In order to solve above problem, a spacer with metal pattern is used to discharge electron in order to prevent electric charging of a spacer used for the electron emitter, or high electric field is applied to a grid near the spacer to change trace of electron beam in order to prevent charging of the spacer.
However, the above solutions are only capable of preventing electric charging of the spacer but not capable of preventing electric charging of insulator between the cathode and gate/grid. Further, the above solutions are preventing for electric charging of the spacer so that it is hard to apply the above solutions to an electron emitter without the spacer. Furthermore, an additional electrode for preventing electrical charge of the spacer and an additional driving voltage are required to increase the number of components so that manufacturing cost is increased.
Therefore, the present invention provides an electron emitter capable of preventing electrical charge of the insulator fundamentally by not exposing the insulator to electrons emitted by a cathode of the electron emitter and an electron trace.
The present invention for solving the above technical problem presents an electron emitting device with metal structure (subrack) having the same voltage as a cathode electrode, and the metal structure (subrack) supports and fastens an electrode structure having at least one bending portion, in electron emitting devices having an insulation substrate, cathode with electron source emitting electrons, electrode structure generating electric fields and a target part generating X-ray when receiving electrons.
An insulator is formed on the metal structure (subrack) supporing and fastening the electrode structure, and at least one of bending portion of the electrode structure bends toward the cathode.
An electron source emitting electrons comprises at least one of the group consisting of carbon nanotube, graphene, carbon, diamond liked carbon, fullerene and silicon nanowire.
An X-ray generator having an anti-charging structure of a triode electron emitting device according to the present invention, includes: a cathode having an electron source emitting electrons; an anode disposed opposite to the cathode; a metal material formed at a center region of the anode to generate X-ray when the electrons are irradiated thereto; a carbon nanotube formed as a electron emitting device in a region of the cathode, which corresponds to a crossing of the cathode and the anode; a gate disposed between the cathode and the anode with spacing in order to control electrons emitted by the carbon nanotube; a pair of focusing electrodes bended to facilitate combination with both ends of the gate, respectively; subracks disposed between the cathode and the focusing electrodes, respectively, and connected to the cathode to have same electric potential as the cathode; and insulators disposed between the subracks and the focusing electrodes.
The pair of focusing electrodes extends toward the cathode electrode at a bending region.
The focusing electrode has a vertical portion and a horizontal portion with at least a ratio of about 1:1.5.
Further, electron source emitting electrons comprises at least one of the group consisting of carbon nanotube, graphene, carbon, diamond liked carbon, fullerene and silicon nanowire.
According to the electron emitting device of the present invention, the insulator near electron emitting device is prevented from being electrically charged through a structural characteristic of the metal structure and electrode structure to prevent problems induced by electric charging of the insulator by not disposing the insulator near the electron emitter by applying the metal structure near the electron emitting device in order not to expose the insulator to the electrons emitted by the electron emitting device and to the electron trance, and by not exposing the insulator for insulating the metal structure and the electrode structure of the cathode and the gate/grid, which is disposed on the metal structure, from each other to the electrons and the electron trace.
FIG. 1 is a schematic cross-sectional view showing an X-ray generator with a triode electron emitting device of anti-charging structure according to an embodiment of the present invention.
FIG. 2 is a schematic cross-sectional view showing an X-ray generator with a triode electron emitting device of anti-charging structure according to another embodiment of the present invention.
FIG. 3 is a perspective view showing main parts of an X-ray generator with a triode electron emitting device of anti-charging structure according to an embodiment of the present invention.
FIG. 4 is a cross-sectional view showing size and space of each components of an X-ray generator with a triode electron emitting device of anti-charging structure according to another embodiment of the present invention.
The specification and cases below are for showing embodiments of the present invention but only for examples, and the present invention may, however, be embodied in many different forms and should not be construed as limited to the example embodiments set forth herein.
It will be understood that, although the terms first, second, third etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, or section discussed below could be termed a second element, component, or section without departing from the teachings of the present invention.
The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. As used herein, the singular forms "a," "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
Unless otherwise defined, all terms (including 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.
It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a schematic cross-sectional view showing an electron emitter according to an embodiment of the present invention. Referring to FIG. 1, according to the electron emitter of an embodiment of the present invention, a cathode 21 with an electron emitting part 22 formed by CNT, etc. is formed on a substrate 20, and a metal structure (subrack) 23 connected onto the cathode 21 to be applied the same voltage with the cathode 21 is positioned.
An electrode structure with a gate 25 and a grid 26 integrally formed with each other is disposed on the metal structure 23 to be supported and fixed by the metal structure 23.
In the above structure, the cathode 21 and the metal structure 23 are connected so that the same voltage is applied thereto, and a second voltage different from the cathode 21 is applied to the electrode structure 25 and 26. An insulator 24 is disposed between the metal structure 23 and the electrode structure 25 and 26 to insulate them.
The metal structure 23 supports and fixes the electrode structure 25 and 26 disposed thereon and prevents the insulator from being electrically charged. As long as the metal structure 23 supports and fixes the electrode structure 25 and 26, the shape and form of the metal structure 23 are not specially limited. In the electrode structure 25 and 26, the gate 25 and the grid 26 are integrally formed. A bending portion of the grid 26 is connected to the gate 25.
When the electron emitter is formed as described above, the metal structure 23, the insulator 24, the electrode structure 25 and 26 may be combined by a fastening means (not shown) such as a bolt, a clamp, etc., and a fastening method and the shape of the metal structure 23, which may be changed according to the fastening method, are not specially limited.
The cathode substrate 21, the metal structure 23, and insulator 24 and the electrode structure 25 and 26 are combined with each other to be one body, disposed in an outer case 20 and 21, and then an anode/target 27 is combined at the top portion of the outer case 20 and 21 to embody the electron emitter.
FIG. 2 is a figure showing another embodiment in which a bending portion and a position of an insulator are different. In the present embodiment, the grid 26-1 in FIG. 1 extends upward so that focusing of electrons is enhanced to improve efficiency of the electron emitter through the extended portion 26-2 of the grid.
FIG. 3 is a perspective view showing main parts of an electron emitter according to an embodiment of the present invention. A cathode substrate 31 is formed on an insulation substrate 30 such as glass, ceramic, etc., and a metal structure 33 having a rectangular frame shape with an opening for exposing electron emitting device is disposed on the cathode substrate 31.
An insulator 34 having a ring shape is disposed on the metal structure 33 along edges of the metal structure 33, and an electrode structure 36 with a gate 35 connected thereto is disposed on the insulator 34.
The electrode structure 36 has a bending portion, and the gate electrode 35 connected to an end portion of the bending portion is disposed in the opening of the metal structure 33, and the electrode structure 36 has a shoulder making contact with the insulator and edges of the metal structure 33.
The gate electrode 35 is spaced apart from the electron emitting device, and the gate electrode 35 is integrally formed to compose the electrode structure 36.
A bending surface 26-1 of the electrode structure 36 operates as a grid for focusing electron beams, and focuses electron beam emitted by the electron emitting part 22 to a target.
The metal structure 33 connected to the cathode 31, the insulator 34 and the electrode structure 36 may be combined through a plurality of clamps to be one body, but the fastening method is not only limited to the clamp fastening but various method such as bolt fastening may be used.
FIG. 4 shows size and space of each components of an X-ray generator of the present invention. A space‘a’ is a space between the target (anode) and a grid, and the space‘a’ is not specially limited. But, the target does not make contact with the grid.
A space‘b’ is a height of a bending portion of the electrode structure. The space‘b’ is in a range in which the electron emitting device and the anode electrode do not make contact with each other, and at least 2mm to improve focusing efficiency of electron beam.
A space‘c’ is a space between the bending portion and the metal structure. The space‘c’ may be in a range of 10μm ~ 3mm, and more preferably in a range of 200 μm ~ 1mm.
A space‘d’is a width of a horizontal surface ( a surface parallel to the anode) of the electrode structure. The space‘d’may be equal to or greater than 3mm, and may be enlarged to outer case surface in maximum.
The ratio of the space‘b’ and the space‘d’ may be about 1:1.5 to effectively supporting and fastening of the electrode structure, but the ratio is not limited to that.
Through the structure described above, the triode electron emitting device in which the insulator is not exposed to prevent electrical charge of the insulator and to improve electron beam focusing and the X-ray generator having the same can be manufactured.

Claims (4)

  1. An X-ray generator having an anti-charging structure of a triode electron emitting device, comprising:
    a cathode having an electron source emitting electrons;
    an anode disposed opposite to the cathode;
    a metal material formed at a center region of the anode to generate X-ray when the electrons are irradiated thereto;
    a carbon nanotube formed as a electron emitting device in a region of the cathode, which corresponds to a crossing of the cathode and the anode;
    a gate disposed between the cathode and the anode with spacing in order to control electrons emitted by the carbon nanotube;
    a pair of focusing electrodes bended to facilitate combination with both ends of the gate, respectively;
    subracks disposed between the cathode and the focusing electrodes, respectively, and connected to the cathode to have same electric potential as the cathode; and
    insulators disposed between the subracks and the focusing electrodes.
  2. The X-ray generator having an anti-charging structure of a triode electron emitting device of claim 1, wherein the pair of focusing electrodes extends toward the cathode electrode at a bending region.
  3. The X-ray generator having an anti-charging structure of a triode electron emitting device of claim 1, wherein the focusing electrode has a vertical portion and a horizontal portion with at least a ratio of about 1:1.5.
  4. The X-ray generator having an anti-charging structure of a triode electron emitting device of claim 1, wherein electron source emitting electrons comprises at least one of the group consisting of carbon nanotube, graphene, carbon, diamond liked carbon, fullerene and silicon nanowire.
PCT/KR2014/008991 2014-01-13 2014-09-26 X-ray generator having anti-charging structure of triode electron emitting device WO2015105260A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
KR1020140004224A KR20150084324A (en) 2014-01-13 2014-01-13 X-ray generator having anti-charging structure of triode electron emitting device
KR10-2014-0004224 2014-01-13

Publications (1)

Publication Number Publication Date
WO2015105260A1 true WO2015105260A1 (en) 2015-07-16

Family

ID=53524064

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/KR2014/008991 WO2015105260A1 (en) 2014-01-13 2014-09-26 X-ray generator having anti-charging structure of triode electron emitting device

Country Status (2)

Country Link
KR (1) KR20150084324A (en)
WO (1) WO2015105260A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105470078A (en) * 2015-12-29 2016-04-06 无锡吉仓纳米材料科技有限公司 Focused tripolar structured fully-packaged X-ray bulb tube based on carbon nanotube cold cathode
JP2017183028A (en) * 2016-03-30 2017-10-05 キヤノン株式会社 X-ray generating tube including electron gun and x-ray imaging apparatus
CN111081505A (en) * 2019-12-24 2020-04-28 中山大学 Nano cold cathode electron source with coplanar double-gate focusing structure and manufacturing method thereof

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001351507A (en) * 1991-05-13 2001-12-21 Seiko Epson Corp Field electron emission device and its manufacturing method
KR20070028000A (en) * 2005-08-30 2007-03-12 삼성에스디아이 주식회사 Electron emission device and electron emission display device using the same
KR20070043392A (en) * 2005-10-21 2007-04-25 삼성에스디아이 주식회사 Electron emission device, electron emission display device using the same and manufacturing method thereof
KR20120114585A (en) * 2011-04-07 2012-10-17 삼성전자주식회사 Apparatus of elecron beam generator and apparatus of x-ray generator

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001351507A (en) * 1991-05-13 2001-12-21 Seiko Epson Corp Field electron emission device and its manufacturing method
KR20070028000A (en) * 2005-08-30 2007-03-12 삼성에스디아이 주식회사 Electron emission device and electron emission display device using the same
KR20070043392A (en) * 2005-10-21 2007-04-25 삼성에스디아이 주식회사 Electron emission device, electron emission display device using the same and manufacturing method thereof
KR20120114585A (en) * 2011-04-07 2012-10-17 삼성전자주식회사 Apparatus of elecron beam generator and apparatus of x-ray generator

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105470078A (en) * 2015-12-29 2016-04-06 无锡吉仓纳米材料科技有限公司 Focused tripolar structured fully-packaged X-ray bulb tube based on carbon nanotube cold cathode
JP2017183028A (en) * 2016-03-30 2017-10-05 キヤノン株式会社 X-ray generating tube including electron gun and x-ray imaging apparatus
CN111081505A (en) * 2019-12-24 2020-04-28 中山大学 Nano cold cathode electron source with coplanar double-gate focusing structure and manufacturing method thereof

Also Published As

Publication number Publication date
KR20150084324A (en) 2015-07-22

Similar Documents

Publication Publication Date Title
EP3075000B1 (en) Electron emitting construct configured with ion bombardment resistant
EP0025221A1 (en) Flat display device
WO2015105275A1 (en) Cylindrical three-electrode field emission x-ray tube
KR20080059890A (en) Carbon nanotube field emitter and method for fabricating the same
EP1696465B1 (en) Electron emission device and method for manufacturing the same
WO2015105260A1 (en) X-ray generator having anti-charging structure of triode electron emitting device
US20120169212A1 (en) Field emission device and field emission display
US2223040A (en) Electron discharge device
KR20100123143A (en) Field emission device and field emission display device having the same
KR20180065861A (en) Field emission apparatus
US5793152A (en) Gated field-emitters with integrated planar lenses
KR100284539B1 (en) KAIST Field Emitter Display
CN102074441B (en) Field-emission cathode device and field-emission display
Choi et al. Carbon-nanotube (CNT)-based triode X-ray tube design by using computer simulation
US8901807B2 (en) Metal gate electrode and field emission display having same
US20070096619A1 (en) Electron emission source comprising carbon-based material and photoelectric element, method of preparing the same, electron emission device and electron emission display device comprising the electron emission source
KR0183174B1 (en) Field emission device
KR20070075659A (en) Method of manufacturing electron emission device, electron emission device prepared using the method, and backlight unit and electron emission display device adopting the electron emission device
US6376983B1 (en) Etched and formed extractor grid
JP4418813B2 (en) Electron emission display device
WO2020130642A1 (en) Cold cathode comprising graphene film, and electron gun using same
RU2524207C1 (en) Assembly of electrovacuum instrument with field-emission cathode
JPS6089041A (en) Plate type cathode ray tube
US7880383B2 (en) Electron emission display
KR100361502B1 (en) The apparatus of FED's spacer using elastic force

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 14877925

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

32PN Ep: public notification in the ep bulletin as address of the adressee cannot be established

Free format text: NOTING OF LOSS OF RIGHTS PURSUANT TO RULE 112(1) EPC (EPO FORM 1205A DATED 04.11.2016)

122 Ep: pct application non-entry in european phase

Ref document number: 14877925

Country of ref document: EP

Kind code of ref document: A1