Technical Field
[0001] The present invention relates to an atmospheric pressure plasma generating device
that emits plasma from an emission port.
Background Art
[0002] With an atmospheric pressure generating device, by emitting plasma from an emission
port towards a target body, plasma is applied to the target body such that processing
is performed. An example of a plasma generating device is disclosed in the patent
literature below.
Summary of Invention
Technical Problem
[0004] According to the atmospheric plasma generating device disclosed in the above patent
literature, it is possible to perform plasma processing on a target body. However,
because it is not possible to check plasma visually, there are cases in which plasma
is not applied appropriately to the target body. The present invention takes account
of such circumstances and an object thereof is to appropriately apply plasma to a
target body.
Solution to Problem
[0005] To solve the above problems, an atmospheric pressure plasma generating device disclosed
herein is provided with an emission port from which plasma is emitted, and an emitting
device that emits lights in the emission direction of the plasma from the emission
port.
Advantageous Effects
[0006] With the disclosed atmospheric pressure plasma generating device, light is emitted
in the emission direction of the plasma from the emission port. Accordingly, due to
the light, it is possible to visually check the plasma emission position, and it is
possible to appropriately apply plasma to a target body.
Brief Description of Drawings
[0007]
[Fig. 1]
Fig. 1 is a perspective view showing a plasma emitting device of a first embodiment.
[Fig. 2]
Fig. 2 is an exploded view of the plasma emitting device of fig. 1.
[Fig. 3]
Fig. 3 is a perspective view showing a plasma emitting device of a second embodiment.
[Fig. 4]
Fig. 4 is a cross section of line AA shown in fig. 3.
Description of Preferred Embodiments
[0008] The following describes in detail referring to the figures an example embodiment
of the present invention.
First embodiment
Configuration of plasma emitting device
[0009] Fig. 1 shows an embodiment of the present invention, plasma emitting device 10. Plasma
emitting device 10 is for emitting plasma to a target body. Plasma emitting device
10 is provided with main body section 12, pair of electrodes 14 and 16, glass pipe
18, gas supply device 20, and laser emitting device 22.
[0010] Main body section 12 is formed from sapphire glass and is configured from cylindrical
section 23 and bent section 24. Cylindrical section 23 is substantially a round tube.
Bent section 24 is bent into an L-shape, and an end section thereof is connected in
an upright state to an outer surface of cylindrical section 23 near the other end
of cylindrical section 23. Note that, the inside of cylindrical section 23 and the
inside of bent section 24 are linked.
[0011] Also, multiple electrical discharge sections 26 and 28 of the pair of electrodes
14 and 16 are vacuum deposited on the outer circumferential surface of cylindrical
section 23 of main body section 12 so as to be lined up alternately in an axis direction
of cylindrical section 23. In detail, as shown in fig. 2, electrode 14 includes multiple
electrical discharge sections 26 and connecting sections 30, and electrode 16 includes
multiple electrical discharge sections 28 and connecting sections 32. Note that, fig.
2 is a theoretical view showing electrodes 14 and 16 removed from cylindrical section
23.
[0012] The multiple electrical discharge sections 26 of electrode 14 are vacuum deposited
on the outer circumferential surface of cylindrical section 23 extending in the circumferential
direction, and are arranged at a specified interval lined up in the axis direction
of cylindrical section 23. Also, connecting sections 30 of electrode 14 are vacuum
deposited on the outer circumferential surface of cylindrical section 23 extending
in a line in the axis direction of cylindrical section 23, and are connected to the
multiple electrical discharge sections 26. Note that, from among the multiple electrical
discharge sections 26 of electrode 14, electrical discharge section 26 positioned
at one end is vacuum deposited around the entire circumference in the circumferential
direction of cylindrical section 23; the other electrical discharge sections 26 are
vacuum deposited extending in the circumferential direction of cylindrical section
23, except for a portion on the opposite side to connecting section 30. Also, current
passing section 36 is formed on the electrical discharge section 26 vacuum deposited
across the entire circumference in the circumferential direction of cylindrical section
23 protruding from an end of cylindrical section 23.
[0013] Further, the multiple electrical discharge sections 28 of electrode 16 are vacuum
deposited on the outer circumferential surface of cylindrical section 23 extending
in the circumferential direction, and are arranged lined up in the axis direction
of cylindrical section 23 so as to be positioned between the multiple electrical discharge
sections 26 of electrode 14. Note that, from among the multiple electrical discharge
sections 28 of electrode 16, electrical discharge sections 28 positioned between two
of the electrical discharge sections 26 of electrode 14 are vacuum deposited extending
in the circumferential direction of cylindrical section 23 excluding connecting section
30 of electrode 14; the remaining electrical discharge sections 28 positioned at the
ends are vacuum deposited across the entire circumference in the circumferential direction
of cylindrical section 23. Current passing section 38 is formed on the electrical
discharge section 28 vacuum deposited across the entire circumference in the circumferential
direction of cylindrical section 23 protruding from an end of cylindrical section
23. Also, connecting sections 32 of electrode 16 are vacuum deposited on the outer
circumferential surface of cylindrical section 23 extending in a line in the axis
direction of cylindrical section 23 at locations where electrical discharge sections
26 of electrode 14 are not vacuum deposited, and are connected to the multiple electrical
discharge sections 28. Thus, the pair of electrodes 14 and 16 have electrical discharge
sections 26 of electrode 14 and electrical discharge sections 28 of electrode 16 vacuum
deposited on the outer circumferential surface of cylindrical section 23 lined up
alternately with a specified gap between them.
[0014] As shown in fig. 1, glass tube 18 is arranged on the outer circumferential surface
of cylindrical section 23 of main body section 12 so as to entirely cover the pair
of electrodes 14 and 16 vacuum deposited on the outer circumferential surface of main
body section 12. By this, it is possible to prevent exposure of electrodes 14 and
16, through which high voltage is applied, thereby maintaining safety. Note that,
because electrodes 14 and 16 are encased by glass pipe 18, glass pipe 18 encroaches
in between electrical discharge sections 26 of electrode 14 and electrical discharge
sections 28 of electrode 16.
[0015] Gas supply device 20 supplies processing gas and is connected to an end of bent section
24 opposite to an end of bent section that is connected to cylindrical section 23.
Thus, processing gas is supplied inside cylindrical section 23 via bent section 24.
Note that, processing gas may be gas in which an inert gas such as nitrogen is mixed
with active gases in the air such as oxygen at a given ratio, or may be only an inert
gas, or only air. Also, gas supply device 20 may also be provided with a function
to heat or cool the processing gas, such that processing gas can be supplied at a
given temperature.
[0016] Laser emitting device 22 emits laser light and is substantially a short cylinder.
An end surface of laser emitting device 22 is axially connected to an end surface
of cylindrical section 23 at which bent section 24 is arranged. Note that, laser emitting
device 22 is removably attached to cylindrical section 23. Also, in a central portion
of the end surface of laser emitting device 22 connected to cylindrical section 23,
emitting hole 40 (refer to fig. 2) is formed, and laser emitting device 22 emits laser
light from emitting hole 40 in an axial direction of cylindrical section 23. Note
that, the laser light is laser light of long wavelength visible light and of an ultraviolet
region.
[0017] Also, as shown in fig. 2, laser emitting device 50 different to laser emitting device
22 is prepared. Laser emitting device 50 has the same dimensions as laser emitting
device 22, such that by removing laser emitting device 22 from cylindrical section
23, laser emitting device 50 can be connected to cylindrical section 23 instead of
laser emitting device 22. Note that, similar to laser emitting device 22, laser emitting
device 50 emits laser light, but the laser light emitted by laser emitting device
50 is long wavelength visible light that does not include ultraviolet light.
Emitting plasma using the plasma emitting device
[0018] According to the above configuration, plasma emitting device 10 emits plasma from
an end of cylindrical section 23, so as to apply plasma to a target body. In detail,
processing gas from gas supply device 20 is supplied inside cylindrical section 23
via bent section 24. Because the end of cylindrical section 23 on which bent section
24 is arranged is covered by laser emitting device 22, processing gas supplied to
cylindrical section 23 flows from that end towards the opposite end. That is, processing
gas flows towards the inside of cylindrical section 23 on which electrodes 14 and
16 are vacuum deposited.
[0019] Then, current passing sections 36 and 38 apply voltage to electrodes 14 and 16, such
that current flows through electrodes 14 and 16. By this, electrical discharge is
generated between electrical discharge sections 26 and 28 of the pair of electrodes
14 and 16. Here, because electrodes 14 and 16 are encased by glass pipe 18, which
is an insulating body, electrical discharge is generated inside cylindrical section
23 such that the processing gas flowing inside cylindrical section 23 is plasmarized.
Thus, plasma is emitted in an axial direction of cylindrical section 23 from an opening
(also referred to as an "emission port") of cylindrical section 23 formed in an end
surface of cylindrical section 23 opposite to an end of cylindrical section 23 to
which laser emitting device 22 is connected. Thus, plasma is applied to a target body
arranged along the line of the emission direction of the plasma.
[0020] However, because the wavelength of the plasma is in a vacuum ultraviolet range,
it cannot be checked visually. Therefore, there are cases in which plasma is not applied
appropriately to the target body. Considering this point, plasma emitting device 10
is provided with laser emitting device 22, and by the laser light emitted by laser
emitting device 22, the emission position of plasma can be checked.
[0021] In detail, as described above, laser emitting device 22 is connected to an end surface
of cylindrical section 23, and emits laser light in an axial direction of cylindrical
section 23. That is, laser emitting device 22 emits laser light axially to the emission
direction of plasma. Also, laser light is directional light that travels straight.
Thus, the laser light emitted from laser emitting device 22 passes through cylindrical
section 23 and is emitted from the emission port of cylindrical section 23 axially
to the emission direction of the plasma. Thus, the laser light is emitted at a location
at which plasma is applied to the target body. Because the wavelength of the laser
light applied to the target body includes a wavelength is a visible range, an operator
can visually check the laser light. Thus, due to the laser light, an operator can
check the emission position of the plasma to ensure that plasma is appropriately applied
to the target body.
[0022] Also, with plasma emitting device 10, laser emitting device 22 is arranged at an
upstream location to where the processing gas is plasmarized. In detail, processing
gas is supplied inside cylindrical section 23 from gas supply device 20 via bent section
24. And, processing gas supplied inside cylindrical section 23 flows towards the emission
port. Here, the processing gas is plasmarized between a location where bent section
24 is connected to cylindrical section 23 and the emission port. Laser emitting device
22 is connected to the end of cylindrical section 23 opposite to the emission port.
Thus, laser emitting device 22 is arranged at an upstream location to where the processing
gas is plasmarized. Therefore, laser emitting device 22 is exposed to processing gas,
but is not exposed to plasma. This prevents plasma being applied to laser emitting
device 22.
[0023] Note that, emitting of plasma by plasma emitting device 10 is performed after the
emission location is confirmed by laser light. In detail, first, laser light is emitted
by laser emitting device 22. Here, supply of processing gas from gas supply device
20 and applying of voltage to electrodes 14 and 16 are not being performed. Thereby,
an operator points the emission port of cylindrical section 23 towards the target
body to align the planned plasma emitting position with the laser light. Once the
planned plasma emitting position is aligned with the laser light, processing gas is
supplied by gas supply device 20, and voltage is supplied to electrodes 14 and 16.
By this, plasma can be suitably emitted to the planned plasma emission position.
[0024] Plasma includes reactive oxygen radicals, and the target body to which plasma is
applied is activated at the surface, such that plasma can be applied to a target body
for various purposes. In detail, for example, in a medical field, skin can be activated
by applying plasma to the skin for the purpose of generating the skin. Also, for example,
by applying plasma to bone, the surface of the bone becomes more hydrophilic, which
improves bonding strength of adhesive. Thus, plasma can be applied for the purpose
of bonding bone. Further, for example, in an industrial field, plasma can be applied
for the purposes of surface processing and surface improvement of metals or the like.
In this manner, technology for applying plasma is used in various fields.
[0025] Due to the above, the emission temperature of the plasma is adjusted depending on
the purpose of applying plasma. Specifically, for example, in a case of applying plasma
to regenerate skin, processing gas with a relatively low temperature is supplied by
gas processing device 20. Therefore, the emission temperature of the plasma can be
made appropriate for applying to skin. Also, for example, in a case of applying plasma
to bone, metal, or the like, processing gas with a relatively high temperature is
supplied by gas supply device 20. Thus, the emission temperature of the plasma is
high, and effective plasma processing can be performed.
[0026] Also, as described above, laser emitting device 22 emits laser light of long wavelength
visible light and of an ultraviolet region. Thus, the surface of the target body to
which the laser light is applied is activated by ultraviolet light. That is, the surface
of the target body is also activated by the laser light that is used for checking
the emission position of the plasma. By this, the surface of the target body can be
activated by the laser light and the plasma, such that effective surface processing
can be performed on the target body. However, there are target bodies to which it
is not desirable to apply ultraviolet light. Therefore, as described above, with plasma
emitting device 10, laser emitting device 50 can be attached to plasma emitting device
10 instead of laser emitting device 22. Laser emitting device 50 emits laser light
of long wavelength visible light that does not include does not include ultraviolet
light. Thus, it is possible apply laser light and to check the emission position of
plasma even for a target body to which it is not desirable to apply ultraviolet light.
Second embodiment
[0027] Figs. 3 and 4 show a second embodiment, plasma emitting device 70. Plasma emitting
device 70 is provided with main body section 72, earth plate 74, emitting nozzle 76,
pair of electrodes 78 and 80, and laser emitting device 82. Note that, in fig. 3,
the main sections of plasma emitting device 70 are shown as transparent, and fig.
4 is a cross section along the line A-A of fig. 3. Also, for clarity, laser emitting
device 82 is not shown in fig. 3.
[0028] Main body section 72 is approximately cuboid, and is formed from a ceramic. Reaction
chamber 86 is formed inside main body section 72. Four first flow paths 88 are formed
at a bottom surface of reaction chamber 86 extending down. Note that, first flow paths
88 do not open to the lower surface of main body section 72. Also, second flow paths
90 that open to the front surface of main body section 72 are formed in main body
72 from the lower end of first flow paths 88. The end of second flow paths 90 on the
front side of main body section 72 are blocked by plugs 96. Further, third flow paths
98 that pierce second flow paths 90 in a vertical direction between both ends of flow
paths 90 are formed in main body section 72. Note that, an upper end section of third
flow path 98 does not open at a top surface of main body section 72, but a lower end
of third flow path does open on a lower surface of main body section 72.
[0029] Earth plate 74 is formed from metal, and is fixed to a lower surface of main body
section 72. Four through-holes 100 that run in a vertical direction are formed in
earth plate 74, with through-holes 100 being connected to third flow paths 98 of main
body section 72 in a coaxial manner.
[0030] Emitting nozzle 76 is fixed to a lower surface of earth plate 74. Four nozzle holes
102 that run in a vertical direction are formed in emitting nozzle 76, with nozzle
holes 102 being connected to through-holes 100 of earth plate 74 in a coaxial manner.
[0031] The pair of electrodes 78 and 80 are rod shaped, and are inserted into reaction chamber
86 in a state separated from each other. Also, laser emitting device 82 is arranged
inside main body section 72 and is connected to an upper end of third flow path 98.
Laser emitting device 82 is a device for emitting laser light, and emits laser light
in an axial direction of third flow path 98.
[0032] According to such a construction, plasma emitting device 70 emits laser light from
an opening (also referred to as emission port) at the lower end of nozzle hole 102
of emitting nozzle 76, and that laser light is used to emit plasma to a planned plasma
emission position. In detail, first, laser light is emitted by laser emitting device
82 along an axial direction of third flow path 98. Thus, laser light is emitted from
the emission port via third flow path 98, through-hole 100, and nozzle hole 102. Thereby,
an operator points the emission port towards the target body to align the laser light
with the planned plasma emitting position.
[0033] Continuing, processing gas is supplied to reaction chamber 86, and voltage is applied
to the pair of electrodes 78 and 80. Thus, current flows between the pair of electrodes
78 and 80, an electrical discharge occurs, and the processing gas is plasmarized by
the electrical discharge. Then, the plasma is emitted from the emission port via first
flow path 88, second flow path 90, through-hole 100, and nozzle hole 102. Here, the
emission direction of the plasma is the axial direction of second flow path 90, through-hole
100, and nozzle hole 102. Thus, plasma is emitted towards the laser light being applied
to the target body. In this manner, with second embodiment plasma emitting device
70, too, similar to with first embodiment plasma emitting device 10, the plasma emission
position can be checked with the laser light, and plasma can be appropriately applied
to the planned plasma emission position.
[0034] Note that, plasma emitting device 10 is an example of an atmospheric pressure plasma
generator. Main body section 12 is an example of a flow path. Electrodes 14 and 16
are examples of an electrode. Gas supply device 20 is an example of a supply device.
Laser emitting device 22 is an example of an emitting device. Laser emitting device
50 is an example of an emitting device. Plasma emitting device 70 is an example of
an atmospheric pressure plasma device. Electrodes 78 and 80 are examples of an electrode.
Laser emitting device 82 is an example of an emitting device. First flow path 88,
second flow path 90, through-hole 100, and nozzle hole 102 are examples of a flow
path.
[0035] Further, the present invention is not limited to the above example embodiments, and
various changed or improved methods of embodiment are possible based on the knowledge
of someone skilled in the art. Specifically, for example, in an embodiment above,
laser light is used as a light emitted to the target body, but various types of light
may be used, so long as the light is visible. However, to appropriately check the
plasma emission position, it is desirable to use light with excellent straightness
and convergence properties, that is, so-called directional light.
Reference Signs List
[0036] 10: plasma emitting device (atmospheric pressure plasma generator); 12: main body
section (flow path); 14: electrode; 16: electrode; 20: gas supply device (supply device);
22: laser emitting device (emitting device); 50: laser emitting device (emitting device);70:
plasma emitting device (atmospheric pressure plasma generator); 78: electrode; 80:
electrode; 82: laser emitting device (emitting device); 88: first flow path (flow
path); 90: second flow path (flow path); 100: through-hole (flow path); 102: nozzle
hole (flow path)