TECHNICAL FIELD
[0001] The present disclosure relates to an X-ray source apparatus and a control method
of the X-ray source apparatus in which a cathode electrode and a gate electrode are
arranged in an array form to enable matrix control, and, thus, dose can be controlled
depending on the position on a subject.
BACKGROUND
[0002] Characteristics of an X-ray source are determined by the dose, energy, and focus
of X-rays. In order to obtain an X-ray source required for medical or industrial inspection,
a high-brightness and high-current electron emitter is needed. In this case, the brightness
is measured as characteristics of the electron emitter, and when high-density electrons
are emitted in a specific direction, the brightness increases.
[0003] In general, a cold cathode X-ray source attracts electron beams from a carbon nanotube
electron emitter by applying a voltage to a gate electrode and then focuses the electron
beams to high density through a focusing electrode and induces them to an anode electrode.
Further, if a high voltage is applied between a cathode electrode and the anode electrode,
electrons are accelerated toward the anode electrode and collide with the anode electrode,
and, thus, X-rays are generated from the anode electrode.
[0004] A conventional X-ray source operates by thermionic emission and uses a reflective
anode electrode. Thus, an X-ray is radially emitted from a point light source. Therefore,
it is difficult to control the dose of X-rays, and the intensity of X-rays is not
uniform.
[0005] Further, in the conventional cold cathode electron emitter, a carbon nanotube (CNT)
has mainly been used as a material of an electron emitter. The electron emitter has
been manufactured by mixing the CNT and a conductive organic material to a paste.
While the CNT paste electron emitter is manufactured, the CNT which serves as a field
emitter can be contaminated by unwanted organic material, and it is very difficult
to achieve vertical orientation of the CNT. Further, the CNT paste electron emitter
generates a gas caused by the organic material during field emission, and, thus, the
vacuum level in the device decreases, which may cause serious problems such as a sharp
decrease in the field emission efficiency and a reduction of the lifetime of the field
electron emitter.
[0006] Furthermore, in the conventional X-ray source, a thermionic emission-based point
light source has been used, and, thus, it is difficult to control the dose of X-rays.
Also, X-rays are radially generated, and, thus, the energy of X-rays is not uniform.
Further, electron beams colliding with the anode electrode have a large-sized focus,
and, thus, there is a limit in increasing the resolution of an X-ray image.
DISCLOSURE OF THE INVENTION
PROBLEMS TO BE SOLVED BY THE INVENTION
[0007] An exemplary embodiment of the present disclosure provides an X-ray source apparatus
and a control method of the X-ray source apparatus in which emitters are formed using
a CNT thin film, a graphene thin film, or a nanocarbon thin film to increase the field
emission efficiency, a transmission-type anode is used to enable X-rays to be emitted
in the form of a surface light source to a subject, and electron beams generated from
the emitters are driven by matrix control to irradiate X-rays at an optimum dose for
each position on the subject.
[0008] However, the problems to be solved by the present disclosure are not limited to the
above-described problems. There may be other problems to be solved by the present
disclosure.
MEANS FOR SOLVING THE PROBLEMS
[0009] As a technical means for solving the above-described problem, an X-ray source apparatus
that emits X-rays to a subject includes: emitters formed on upper surfaces of cathode
electrodes to emit electrons; an anode electrode arranged at a predetermined distance
from the cathode electrodes; gate electrodes positioned between the emitters and the
anode electrode and formed by transferring a graphene thin film on a metal electrode
having at least one or more openings; a focusing lens positioned between the gate
electrodes and the anode electrode and configured to focus electron beams emitted
from the emitters on the anode electrode; and a control module configured to adjust
the dose of X-rays for each position on the subject by performing two-dimensional
matrix control to the emitters and the gate electrodes. Herein, the emitters are arranged
in an array form in a first direction, the gate electrodes are arranged in an array
form in a second direction, the first direction and the second direction are perpendicular
to each other, and the control module determines the dose of X-rays depending on the
size of the array.
[0010] According to another aspect of the present disclosure, a control method of an X-ray
source apparatus which emits X-rays to a subject and in which emitters are arranged
on upper surfaces of cathode electrodes in an array form in a first direction and
gate electrodes are arranged between the emitters and an anode electrode in an array
form in a second direction perpendicular to the first direction includes: adjusting
the dose of X-rays for each position on the subject by performing two-dimensional
matrix control to the emitters and the gate electrodes arranged in an array form.
Herein, the dose of X-rays for each position on the subject is determined depending
on the size of the array.
EFFECTS OF THE INVENTION
[0011] According to the present disclosure, two-dimensional matrix control can be performed
to the cathode electrodes and the gate electrode, and, thus, it is possible to irradiate
X-rays at an optimum dose for each position on the subject. Therefore, it is possible
to suppress the irradiation of more X-rays than are needed to the subject. Also, it
is possible to obtain a high-resolution and high-quality X-ray image.
[0012] As such, according to the present disclosure, two-dimensional matrix control makes
it easy to control the dose of X-rays and makes it possible to uniformly irradiate
X-rays to the subject. Therefore, it is possible to manufacture a high-resolution
surface X-ray source with less dependence on the size of the focus of electron beams.
[0013] Further, according to the present disclosure, a CNT thin film is fabricated using
only a CNT material without containing an organic material by vacuum filtration and
then processed into a point shape or a line shape to manufacture the emitters or a
graphene thin film or a nanocarbon thin film is used to form the emitters. Then, the
emitters are arranged in an array form and used as cold cathode electron emitters.
Thus, it is possible to generate point or surface electron beams of various sizes.
Also, it is possible to adjust the magnitude of current to be emitted. Further, it
is possible to manufacture an X-ray source with high transmittance and high density
of electron beams.
[0014] In the present disclosure, a CNT thin film is used for the emitters instead of a
CNT paste cold cathode electron emitter. Therefore, high bonding force in the CNT
thin film which is a nanomaterial and high electrical/mechanical adhesion between
the CNT emitters and the cathode electrodes can be achieved without using an organic
material-containing paste or other adhesives. Accordingly, it is possible to overcome
a decrease in vacuum level caused by an organic material. Further, it is possible
to manufacture an X-ray source with high field emission efficiency and excellent lifetime.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015]
FIG. 1 is a diagram illustrating an X-ray source apparatus in accordance with an exemplary
embodiment of the present disclosure.
FIG. 2 is a diagram illustrating the X-ray source apparatus capable of performing two-dimensional
matrix control in accordance with an exemplary embodiment of the present disclosure.
FIG. 3 is a flowchart showing a control method of the X-ray source apparatus in accordance
with an exemplary embodiment of the present disclosure.
FIG. 4 is a flowchart showing a method of forming CNT emitters illustrated in FIG. 3.
FIG. 5 is a diagram illustrating a CNT thin film including a CNT network therein by the
method shown in FIG. 4.
FIG. 6 is a diagram illustrating a CNT thin film processed into a polygonal shape by the
method shown in FIG. 4.
FIG. 7 is a diagram illustrating various examples of the CNT emitters processed into a point
or surface shape by the method shown in FIG. 4.
FIG. 8 is a diagram illustrating the arrangement of the CNT emitter array formed by the
method shown in FIG. 7.
FIG. 9 is a flowchart showing a method of forming gate electrodes illustrated in FIG. 3.
FIG. 10 is a diagram provided to explain a process of transferring a graphene thin film on
a metal electrode as illustrated in FIG. 9.
FIG. 11 is a diagram illustrating an example of gate electrodes arranged in an array form
by the method shown in FIG. 9.
BEST MODE FOR CARRYING OUT THE INVENTION
[0016] Hereinafter, embodiments of the present disclosure will be described in detail with
reference to the accompanying drawings so that the present disclosure may be readily
implemented by a person with ordinary skill in the art. However, it is to be noted
that the present disclosure is not limited to the embodiments but can be embodied
in various other ways. In drawings, parts irrelevant to the description are omitted
for the simplicity of explanation, and like reference numerals denote like parts through
the whole document.
[0017] Through the whole document, the term "connected to" or "coupled to" that is used
to designate a connection or coupling of one element to another element includes both
a case that an element is "directly connected or coupled to" another element and a
case that an element is "electronically connected or coupled to" another element via
still another element. Further, it is to be understood that the term "comprises or
includes" and/or "comprising or including" used in the document means that one or
more other components, steps, operation and/or existence or addition of elements are
not excluded in addition to the described components, steps, operation and/or elements
unless context dictates otherwise and is not intended to preclude the possibility
that one or more other features, numbers, steps, operations, components, parts, or
combinations thereof may exist or may be added.
[0018] Through the whole document, the term "unit" or "module" includes a unit implemented
by hardware or software and a unit implemented by both of them. One unit may be implemented
by two or more pieces of hardware, and two or more units may be implemented by one
piece of hardware.
[0019] An exemplary embodiment of the present disclosure will be described in detail with
reference to the accompanying drawings.
[0020] FIG. 1 is a diagram illustrating an X-ray source apparatus in accordance with an exemplary
embodiment of the present disclosure, and
FIG. 2 is a diagram illustrating the X-ray source apparatus capable of performing two-dimensional
matrix control in accordance with an exemplary embodiment of the present disclosure.
[0021] Referring to
FIG. 1 and FIG. 2, an X-ray source apparatus 100 configured to emit X-rays to a subject includes cathode
electrodes 101, emitters 110, an anode electrode 120, gate electrodes 130, a focusing
lens 140, and an electron beam collimator 150.
[0022] The cathode electrodes 101, the anode electrode 120, and the gate electrodes 130
may be connected to an external power supply (not illustrated) to apply an electric
field. For example, the cathode electrodes 101 may be connected to a negative voltage
source or a positive voltage source, and the anode electrode 120 and the gate electrodes
130 may be connected to a voltage source that can apply a higher potential than a
potential of the voltage source connected to the cathode electrodes 101.
[0023] The emitters 110 are formed on the cathode electrodes 101 and used as cold cathode
electron emitters that emit electrons. That is, the emitters 110 may emit electrons
using an electric field formed by a voltage applied to the cathode electrodes 101,
the anode electrodes 120 and the gate electrodes 130. The emitters 110 manufactured
using a carbon nanotube (CNT) thin film can emit point or surface electron beams by
processing the CNT thin film into a point shape or a line shape.
[0024] Herein, the emitters 110 use the CNT thin film to provide a low threshold field and
a high field emission current density, but may also use a graphene thin film or a
nanocarbon thin film (e.g., nanographite thin film, etc.) instead of the CNT thin
film to form emitters with high field emission properties.
[0025] The anode electrode 120 is provided away from the cathode electrodes 101 at a predetermined
distance in an emission direction of an electron beam.
[0026] The gate electrodes 130 are positioned between the emitters 110 and the anode electrode
120 and provided away from and above the emitters 110. The gate electrodes 130 are
formed by transferring a graphene thin film including at least one or more layers
on an upper part of a metal electrode having at least one or more openings.
[0027] Further, the gate electrodes 130 may be formed by using a metal plate having a hole
or a polygonal metal mesh as a metal electrode, attaching a graphene thin film on
the metal electrode, or inserting at least one graphene thin film between two metal
electrodes.
[0028] Herein, the emitters 110 and the gate electrodes 130 may be arranged in an array
form. For example, the plurality of emitters 110 spaced in parallel to each other
is arranged in parallel in an array form at an equal distance in a first direction
and the gate electrodes 130 are arranged in parallel in an array form at an equal
distance in a second direction, and the first direction and the second direction may
be perpendicular to each other.
[0029] The focusing lens 140 is positioned between the gate electrodes 130 and the anode
electrode 120 and focuses electron beams emitted from the emitters 110 on the anode
electrode 120.
[0030] The electron beam collimator 150 is positioned between the focusing lens 140 and
the anode electrode 120 and allows the electron beams passing through the focusing
lens 140 to go straight and be focused on the anode electrode 120. The electron beam
collimator 150 can improve the linearity of the electron beams passing through the
focusing lens 140.
[0031] Meanwhile, as illustrated in
FIG. 2, the X-ray source apparatus 100 performs, through a control module 160, two-dimensional
matrix control to the emitters 110 and the gate electrodes 130 which are arranged
in an array form. Herein, the two-dimensional matrix control is to adjust a voltage
level between the emitters 110 and the gate electrodes 130 for each position and thus
adjust the generation density of electron beams for each body part. Since the density
of X-rays generated by the anode electrode 120 changes as the density of electron
beams changes, the two-dimensional matrix control makes it possible to adjust the
density of X-rays depending on the bone thickness of each body part.
[0032] The control module 160 adjusts the dose of X-rays to be suitable for each position
on a subject 200 to generate X-rays. The size of an X-ray source can be adjusted depending
on the size of an array, and, thus, a large-scale X-ray source can be implemented.
[0033] Meanwhile, the control module 160 may collect characteristics information of the
subject 200 such as gender, age, body information, and the like, and locally specify
emission information about the dose of X-rays depending on the area to be imaged,
the bone position, the bone thickness, and the like on the basis of the collected
characteristics information of the subject 200.
[0034] For example, since the bone position or the bone thickness distribution is different
for each user, a proper local dose of X-rays is set accordingly. To this end, the
control module 160 collects characteristics information of the subject 200 such as
gender, age, body information (height, weight, body type, etc.), and the like or additional
information for identifying each subject and anatomical information of each subject
200 such as the bone position or bone thickness and matches them respectively. If
characteristics information of the subject 200 is used, it is possible to estimate
anatomical information such as the bone position or bone thickness based on just characteristics
information of the subject 200 such as gender, age, body information, and the like
and then, it is possible to determine emission information about a proper dose of
X-rays for each position based on the estimated anatomical information such as the
bone position or bone thickness.
[0035] When the emission information about the dose of X-rays for each position is determined,
the control module 160 performs two-dimensional matrix control to the emitters 110
and the gate electrodes 130 to perform addressing to the X-ray source apparatus 100
and adjusts voltage levels to be applied to the cathode electrodes 101 and the gate
electrodes 130, respectively, to adjust the dose of X-rays from the emitters 110 for
each position.
[0036] Herein, the control module 160 configured as an intelligent device that supports
communication, auto-control, data processing, image data processing, and the like
may include all kinds of handheld wireless communication devices, such as a smartphone
and a tablet PCT, in which multiple application programs (
i.e., applications) desired by a user may be installed and executed, or may include wired
communication devices, such as a PC, which can access another device or server via
a network.
[0037] As such, in the X-ray source apparatus 100, the emitters 110 arranged in an array
form on the cathode electrodes 101, the gate electrodes 130 arranged in an array form,
the focusing lens 140, the electron beam collimator 150, and the anode electrode 120
are placed sequentially and vacuum packaged within a vacuum container made of any
one of a glass material, a ceramic material, or a metal material to implement a cold
cathode X-ray source that irradiates X-rays optimized for each position on the subject
200.
[0038] FIG. 3 is a flowchart showing a control method of the X-ray source apparatus in accordance
with an exemplary embodiment of the present disclosure.
[0039] Referring to
FIG. 3, the control method of the X-ray source apparatus is to generate X-rays with an adjusted
dose for each position on a subject by performing two-dimensional matrix control to
emitters and gate electrodes arranged in an array form.
[0040] To this end, when emitters without containing an organic material are formed on upper
surfaces of cathode electrodes by vacuum filtration to emit electrons (S110), the
X-ray source apparatus arranges the emitters in an array form in a first direction.
Herein, not only CNT emitters manufactured using a CNT thin film but also emitters
formed using any one of a graphene thin film or a nanocarbon thin film may be used.
[0041] An anode electrode is formed away from the cathode electrodes at a predetermined
distance (S120), and gate electrodes are formed using a graphene thin film including
at least one or more layers between the emitters and the anode electrode in a second
direction perpendicular to the first direction (S130). Herein, the anode electrode
is manufactured into a transmission type by depositing a tungsten thin film on a beryllium
metal plate. The manufactured transmission-type anode electrode can generate surface
X-rays.
[0042] A focusing lens provided between the gate electrodes and the anode electrode focuses
electron beams emitted from the emitters on the anode electrode (S140) and an electron
beam collimator is further provided between the focusing lens and the anode electrode
to improve the linearity of the electron beams passing through the focusing lens (S150).
Herein, the focusing lens may be manufactured into a hole shape or may be manufactured
by transferring one or more graphene layers on a lens. Further, one or two focusing
lenses may be used.
[0043] The X-ray source apparatus includes the emitters and the gate electrodes arranged
in an array form to cross perpendicular to each other, and the emitters and the gate
electrodes may be a large-size emitter and a large-size gate electrode, respectively,
to which two-dimensional matrix control can be performed.
[0044] The X-ray source apparatus collects characteristics information of the subject such
as gender, age, body information, and the like, and locally specifies emission information
about the dose of X-rays depending on the area to be imaged, the bone position, the
bone thickness, and the like on the basis of the collected characteristics information
of the subject and then outputs the emission information (S160). That is, when the
emission information about the dose of X-rays for each position is determined, the
X-ray source apparatus performs two-dimensional matrix control to the emitters and
the gate electrodes arranged in an array form to perform addressing, adjusts voltage
levels to be applied to the cathode electrodes and the gate electrodes, respectively,
to adjust the dose of X-rays from the emitters for each position, and emits X-rays
(S170).
[0045] FIG. 4 is a flowchart showing a method of forming CNT emitters illustrated in
FIG. 3, FIG. 5 is a diagram illustrating a CNT thin film including a CNT network therein by the
method shown in
FIG. 4, and
FIG. 6 is a diagram illustrating a CNT thin film processed into a polygonal shape by the
method shown in
FIG. 4. FIG. 7 is a diagram illustrating various examples of the CNT emitters processed into a point
or surface shape by the method shown in
FIG. 4, and
FIG. 8 is a diagram illustrating the arrangement of the CNT emitter array formed by the
method shown in
FIG. 7.
[0046] Referring to
FIG. 4 through
FIG. 8, a CNT-dispersed aqueous solution is prepared by dispersing 200 mg of sodium dodecyl
sulfate (SDS) and 4 mg of single-walled carbon nanotube in 200 ml of distilled (DI)
water (S410). After a sonication process for 65 minutes (S420) and a centrifugation
process for 40 minutes (S430), the CNT-dispersed aqueous solution is filtered through
an anodic aluminum oxide (AAO) membrane to allow only the DI water to pass through.
Then, CNTs remain unfiltered and deposited on the AAO membrane (S440).
[0047] As shown in
FIG. 5, the CNTs unfiltered on the AAO are strongly entangled to one another by van der Waals
forces. Then, when the AAO membrane is dissolved in a sodium hydroxide (NaOH) solution,
a CNT thin film including a CNT network therein is prepared (S450). In this case,
through a densification process, the CNT thin film is dipped in an isopropyl alcohol
solution (IPA) and then dried to make the CNTs more entangled to one another. After
the densification process, a scanning electron microscope image shows that a surface
of a CNT thin film 111 has a densely entangled CNT network.
[0048] As shown in
FIG. 6, the CNT thin film 111 is cut into a polygonal shape such as a triangle or a quadrangle
and pressed into a flat plate to manufacture an electron emitter, and the CNT emitters
110 are formed on upper surfaces of the cathode electrodes 101 (S460). Herein, a carbonization
process is performed for the CNT emitters 110 to more stably operate. When an organic
polymer material, i.e., carbon-based material, is coated on the CNT thin film 111
and annealed at a high temperature in a vacuum through the carbonization process,
the carbon-based material is inserted into an empty space between the CNTs in the
CNT network. Through this process, the bonding force between the CNTs can be further
increased.
[0049] As shown in
FIG. 7, the CNT thin film may be manufactured into a point- or line-shaped CNT emitters 110
depending on the cutting method. If the CNT thin film 111 is cut into a fan shape
or a triangular shape, an upper part of the cut portion may converge on a point, and
if the CNT thin film 111 is cut into a quadrangular shape, an upper part of the cut
portion may converge on a line.
[0050] Further, as shown in
FIG. 8, if a plurality of CNT thin films 111 is processed into a point shape or line shape
and then inserted in the cathode electrodes 101 to form the CNT emitters 110 arranged
in an array form, the CNT emitters can generate point or two dimensional electron
beams of various sizes depending on the cutting method of the CNT thin film.
[0051] FIG. 9 is a flowchart showing a method of forming gate electrodes illustrated in
FIG. 3, FIG. 10 is a diagram provided to explain a process of transferring a graphene thin film on
a metal electrode as illustrated in
FIG. 9, and
FIG. 11 is a diagram illustrating an example of gate electrodes arranged in an array form
by the method shown in
FIG. 9.
[0052] Referring to
FIG. 9 through
FIG. 11, the method of forming gate electrodes includes synthesizing graphene on a copper
foil by thermal chemical vapor deposition (CVD) and coating polymethylmethacrylate
(PMMA) on the graphene with a spin coater (①).
[0053] Then, the copper foil is etched using a copper etching solution (②), followed by
washing with DI water to remove the remaining copper foil (③). By repeating this process
several times, a graphene thin film including multiple laminated layers is prepared.
Then, as shown in
FIG. 10, a graphene thin film including one or more layers is transferred onto a metal electrode
(④, ⑤, ⑥, ⑦). In this case, the metal electrode may be a metal plate having circular
holes or a metal mesh having a quadrangular, circular, or hexagonal shape.
[0054] The graphene thin film 131 is transferred onto the metal electrode and then dipped
in an acetone solution and dried to remove the PMMA remaining on the graphene thin
film 131 and annealed at 300°C in a vacuum atmosphere of 10
-5 Torr or less to manufacture the gate electrodes 130 on which the graphene thin film
is stably transferred (⑧, ⑨). Further, as shown in
FIG. 11, the gate electrodes 130 arranged in an array form may be manufactured into a large-size
gate electrode, in which two-dimensional matrix control can be performed. Herein,
the gate electrodes may be manufactured by inserting a graphene thin film including
one or more layers between two metal electrodes.
[0055] The gate electrodes manufactured using the graphene thin film including at least
one layer can uniformly apply an electric field, and, thus, the linearity of electron
beams can be improved. Further, the graphene is an atomic scale mesh, and, thus, the
transmission efficiency of electron beams can be increased. Furthermore, due to the
graphene with very high heat transfer efficiency, heat caused by the collision of
electron beams can be effectively dispersed, and, thus, the thermal stability of the
gate electrodes can be improved.
[0056] Meanwhile, similar to the gate electrodes, the focusing lens may be manufactured
by transferring graphene including one or more layers onto a metal plate or a metal
mesh or inserting at least one graphene thin film into two focusing lens.
[0057] As described above, the X-ray source apparatus and the control method thereof according
to an exemplary embodiment of the present disclosure uses cold cathode electron emitters
using a CNT thin film and can irradiate X-rays with a two-dimensional area to a subject
through a transmission-type anode electrode and drive electron beams generated from
the CNT emitters by matrix control to irradiate X-rays at an optimum dose for each
position on the subject.
[0058] The fabricating method of the above-described X-ray source apparatus and the matrix
control method implemented by the X-ray source apparatus according to the exemplary
embodiments of the present disclosure can be embodied in a storage medium including
instruction codes executable by a computer such as a program module executed by the
computer. The storage medium includes a computer-readable medium, and the computer-readable
medium can be any usable medium which can be accessed by the computer and includes
all volatile/non-volatile and removable/non-removable media. Further, the computer-readable
medium may include all computer storage media. The computer storage media include
all volatile/non-volatile and removable/non-removable media embodied by a certain
method or technology for storing information such as computer-readable instruction
code, a data structure, a program module or other data.
[0059] The above description of the present disclosure is provided for the purpose of illustration,
and it would be understood by a person with ordinary skill in the art that various
changes and modifications may be made without changing technical conception and essential
features of the present disclosure. Thus, it is clear that the above-described embodiments
are illustrative in all aspects and do not limit the present disclosure. For example,
each component described to be of a single type can be implemented in a distributed
manner. Likewise, components described to be distributed can be implemented in a combined
manner.
[0060] Further, the method and system of the present disclosure have been explained in relation
to a specific embodiment, but their components or a part or all of their operations
can be embodied by using a computer system having general-purpose hardware architecture.
[0061] The scope of the present disclosure is defined by the following claims rather than
by the detailed description of the embodiment. It shall be understood that all modifications
and embodiments conceived from the meaning and scope of the claims and their equivalents
are included in the scope of the present disclosure.
1. An X-ray source apparatus that emits X-rays to a subject, comprising:
emitters formed on upper surfaces of cathode electrodes to emit electrons;
an anode electrode arranged at a predetermined distance from the cathode electrodes;
gate electrodes positioned between the emitters and the anode electrode and formed
by transferring a graphene thin film including at least one or more layers on an upper
part of a metal electrode having at least one or more openings;
a focusing lens positioned between the gate electrodes and the anode electrode and
configured to focus electron beams emitted from the emitters on the anode electrode;
and
a control module configured to adjust the dose of X-rays for each position on the
subject by performing two-dimensional matrix control to the emitters and the gate
electrodes,
wherein the emitters are arranged in an array form in a first direction, the gate
electrodes are arranged in an array form in a second direction and the first direction
and the second direction are perpendicular to each other, and
the control module determines the dose of X-rays depending on the size of the array.
2. The X-ray source apparatus of Claim 1,
wherein the control module performs two-dimensional matrix control to adjust a voltage
level between the emitters and the gate electrodes and thus adjust the generation
density of electron beams for each body part.
3. The X-ray source apparatus of Claim 1, further comprising:
an electron beam collimator positioned between the focusing lens and the anode electrode
and allowing the electron beams passing through the focusing lens to go straight and
be focused on the anode electrode.
4. The X-ray source apparatus of Claim 1,
wherein the emitters are manufactured using a CNT thin film which is formed by vacuum
filtration, and
the CNT thin film is formed by a densification process using an alcohol solution or
a carbonation process in which an organic polymer material is coated and then annealed
at a high temperature in a vacuum.
5. The X-ray source apparatus of Claim 4,
wherein the emitters are manufactured by processing the CNT thin film into a point
shape or line shape, and
at least one CNT thin film is cut into a polygonal shape, pressed into a flat plate
and then inserted in the cathode electrodes.
6. The X-ray source apparatus of Claim 1,
wherein the gate electrodes are formed by using a metal plate having a hole or a polygonal
metal mesh as a metal electrode, attaching a graphene thin film on the metal electrode,
or inserting at least one graphene thin film between two metal electrodes.
7. The X-ray source apparatus of Claim 1,
wherein the focusing lens is manufactured into a hole shape or manufactured by transferring
at least one graphene thin film.
8. The X-ray source apparatus of Claim 1,
wherein the emitters are formed using any one of a CNT thin film, a graphene thin
film, or a nanocarbon thin film.
9. The X-ray source apparatus of Claim 1,
wherein in the X-ray source apparatus, the emitters, the gate electrodes, the focusing
lens, and the anode electrode are placed sequentially within a vacuum container made
of any one of a glass material, a ceramic material, or a metal material.
10. The X-ray source apparatus of Claim 3,
wherein in the X-ray source apparatus, the emitters, the gate electrodes, the focusing
lens, the electron beam collimator, and the anode electrode are placed sequentially
within a vacuum container made of any one of a glass material, a ceramic material,
or a metal material.
11. A control method of an X-ray source apparatus which emits X-rays to a subject and
in which emitters are arranged on upper surfaces of cathode electrodes in an array
form in a first direction and gate electrodes are arranged between the emitters and
an anode electrode in an array form in a second direction perpendicular to the first
direction, the control method comprising:
adjusting the dose of X-rays for each position on the subject by performing two-dimensional
matrix control to the emitters and the gate electrodes arranged in an array form,
wherein the dose of X-rays for each position on the subject is determined depending
on the size of the array.
12. The control method of an X-ray source apparatus of Claim 11,
wherein the control module performs two-dimensional matrix control to adjust a voltage
level between the emitters and the gate electrodes and thus adjust the generation
density of electron beams for each body part.
13. The control method of an X-ray source apparatus of Claim 11,
wherein the emitters are point- or line-shaped electron emitters manufactured by cutting
any one of a CNT thin film, a graphene thin film, or a nanocarbon thin film into a
polygonal shape and pressing the cut polygonal thin film into a flat plate.
14. The control method of an X-ray source apparatus of Claim 11,
wherein in the X-ray source apparatus, the emitters, the gate electrodes, the focusing
lens, and the anode electrode are placed sequentially within a vacuum container made
of any one of a glass material, a ceramic material, or a metal material.
15. The control method of an X-ray source apparatus of Claim 11,
wherein if an electron beam collimator is further provided between the focusing lens
and the anode electrode to allow electron beams passing through the focusing lens
to go straight and be focused on the anode electrode,
the emitters, the gate electrodes, the focusing lens, the electron beam collimator,
and the anode electrode are placed sequentially within a vacuum container made of
any one of a glass material, a ceramic material, or a metal material in the X-ray
source apparatus.
16. A fabricating method of an X-ray source apparatus, comprising:
forming a plurality of emitters by cutting a CNT thin film, a graphene thin film,
or a nanocarbon thin film into a triangle or a quadrangle and processing an end portion
of the cut thin film into a point shape or a line shape;
combining, with a plurality of cathode electrodes, one or more of the plurality of
emitters which have been processed into the point shape or the line shape;
arranging the plurality of cathode electrodes combined with the plurality of emitters
in a two-dimensional array form;
forming openings in regions facing the respective cathode electrodes and forming,
at the respective openings, a plurality of gate electrodes combined with a graphene
thin film;
aligning the plurality of gate electrodes and the plurality of cathode electrodes
arranged in the two-dimensional array form in order for the openings for the respective
gate electrodes to face the respective cathode electrodes; and
placing an anode electrode in a two-dimensional array form at a predetermined distance
from the plurality of gate electrodes.
17. The fabricating method of an X-ray source apparatus of Claim 16, further comprising:
placing a focusing lens which is positioned between the cathode electrodes and the
anode electrode and configured to focus electron beams emitted from the plurality
of emitters on the anode electrode and an electron beam collimator which is positioned
between the focusing lens and the anode electrode and configured to allow the electron
beams passing through the focusing lens to go straight and be focused on the anode
electrode.
18. The fabricating method of an X-ray source apparatus of Claim 16,
wherein the combining of the processed CNT thin film with the cathode electrodes includes:
combining N columns of CNT thin films by combining the processed CNT thin film between
N+1 number of cathode electrode blocks which are separated from each other in parallel.
19. The fabricating method of an X-ray source apparatus of Claim 16,
wherein the forming of the gate electrodes includes:
forming, in main bodies of the gate electrodes, the openings in the regions facing
the respective cathode electrodes;
transferring a graphene thin film on the main bodies of the gate electrodes including
the openings; and
annealing the main bodies of the gate electrodes on which the graphene thin film has
been transferred.