U.S. patent application number 13/055187 was filed with the patent office on 2011-06-02 for electrostatic atomizing device and air conditioner using same.
This patent application is currently assigned to PANASONIC ELECTRIC WORKS CO., LTD.. Invention is credited to Atsushi Isaka, Kenji Obata, Yutaka Uratani, Takeshi Yano.
Application Number | 20110126551 13/055187 |
Document ID | / |
Family ID | 41211850 |
Filed Date | 2011-06-02 |
United States Patent
Application |
20110126551 |
Kind Code |
A1 |
Uratani; Yutaka ; et
al. |
June 2, 2011 |
ELECTROSTATIC ATOMIZING DEVICE AND AIR CONDITIONER USING SAME
Abstract
An electrostatic atomizing device includes an atomizing
electrode which generates charged fine water particles negatively
charged in the form of mist, by generating an electric field when a
high negative voltage is applied thereto in a state in which water
is supplied; a water supply portion which supplies the water to the
atomizing electrode; a discharge detection portion which detects
whether negative ion discharge, indicating discharge in which only
negative ions are generated without generating the charged fine
water particles, is occurring at the atomizing electrode or not;
and a control portion which reduces the electric field intensity of
the electric field generated by the atomizing electrode when the
discharge detection portion detects the occurrence of the negative
ion discharge.
Inventors: |
Uratani; Yutaka; (Hikone,
JP) ; Obata; Kenji; (Hikone, JP) ; Yano;
Takeshi; (Kyoto, JP) ; Isaka; Atsushi;
(Hikone, JP) |
Assignee: |
PANASONIC ELECTRIC WORKS CO.,
LTD.
Osaka
JP
|
Family ID: |
41211850 |
Appl. No.: |
13/055187 |
Filed: |
July 27, 2009 |
PCT Filed: |
July 27, 2009 |
PCT NO: |
PCT/JP2009/063709 |
371 Date: |
January 21, 2011 |
Current U.S.
Class: |
62/3.2 ;
239/690 |
Current CPC
Class: |
B05B 5/0533 20130101;
B05B 5/006 20130101; B05B 5/0255 20130101; B05B 5/057 20130101;
B05B 7/0075 20130101; B05B 5/053 20130101 |
Class at
Publication: |
62/3.2 ;
239/690 |
International
Class: |
F25B 21/02 20060101
F25B021/02; F23D 11/32 20060101 F23D011/32 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 28, 2008 |
JP |
2008-193944 |
Claims
1-16. (canceled)
17. An electrostatic atomizing device, comprising: an atomizing
electrode which generates charged fine water particles negatively
charged in the form of mist, by generating an electric field when a
high negative voltage is applied thereto in a state in which water
is supplied; a water supply portion which supplies the water to the
atomizing electrode; a discharge detection portion which detects
whether negative ion discharge, indicating discharge in which only
negative ions are generated without generating the charged fine
water particles, is occurring at the atomizing electrode or not by
detecting a discharge current value of a discharge current
occurring when the high negative voltage is applied to the
atomizing electrode and comparing the discharge current value
detected with a predetermined threshold value; and a control
portion which carries on reducing the electric field intensity of
the electric field generated by the atomizing electrode until the
occurrence of the negative ion discharge is no longer detected by
the discharge detection portion, if the discharge detection portion
detects the occurrence of the negative ion discharge.
18. The electrostatic atomizing device according to claim 17,
further comprising a high-voltage power supply circuit which
applies the high negative voltage to the atomizing electrode,
wherein the control portion is configured to cause the high-voltage
power supply circuit to apply the high negative voltage to the
atomizing electrode, the control portion halts the supply of the
water to the atomizing electrode by the water supply portion during
the period from when the high-voltage power supply circuit is
caused to apply the high negative voltage to the atomizing
electrode until a predetermined first time has elapsed, and when
the first time has elapsed after causing the high-voltage power
supply circuit to apply the high negative voltage to the atomizing
electrode, the control portion causes the discharge detection
portion to detect whether the negative ion discharge is occurring
or not.
19. The electrostatic atomizing device according to claim 18,
wherein, when the occurrence of the negative ion discharge is
detected by the discharge detection portion, the control portion
further causes the discharge detection portion to detect whether
the negative ion discharge is occurring or not during the period
from the detection of the occurrence of the negative ion discharge
until a predetermined second time has elapsed, and when the
occurrence of the negative ion discharge is detected by the
discharge detection portion during the period from the time of
detection of the occurrence of the negative ion discharge until the
second time has elapsed, the control portion reduces the electric
field intensity of the electric field generated by the atomizing
electrode.
20. The electrostatic atomizing device according to claim 17,
wherein the water supply portion is a Peltier element provided at
the base of the atomizing electrode.
21. The electrostatic atomizing device according to claim 19,
wherein the second time is 1 minute.
22. The electrostatic atomizing device according to claim 17,
further comprising a high-voltage power supply circuit which
applies the high negative voltage to the atomizing electrode,
wherein the control portion reduces the electric field intensity of
the electric field generated by the atomizing electrode by reducing
a voltage value of the high negative voltage applied to the
atomizing electrode by the high-voltage power supply circuit.
23. The electrostatic atomizing device according to claim 17,
further comprising a high-voltage power supply circuit which
applies the high negative voltage to the atomizing electrode,
wherein a plurality of voltage values are set in advance as voltage
values of the high negative voltage applied to the atomizing
electrode by the high-voltage power supply circuit, and the control
portion reduces in steps the voltage value of the high negative
voltage applied to the atomizing electrode by the high-voltage
power supply circuit, according to the discharge current value
detected by the discharge detection portion.
24. The electrostatic atomizing device according to claim 17,
further comprising a high-voltage power supply circuit which
applies the high negative voltage to the atomizing electrode,
wherein the control portion turns OFF and then turns ON the
high-voltage power supply circuit as well as reduces the voltage
value of the high negative voltage applied to the atomizing
electrode.
25. The electrostatic atomizing device according to claim 17,
further comprising a high-voltage power supply circuit which
applies the high negative voltage to the atomizing electrode,
wherein a plurality of voltage values are set in advance as voltage
values of the high negative voltage applied to the atomizing
electrode by the high-voltage power supply circuit, and the control
portion repeatedly turns OFF and then turns ON the high-voltage
power supply circuit as well as reduces in steps the voltage value
of the high negative voltage applied to the atomizing electrode,
until the occurrence of the negative ion discharge is no longer
detected by the discharge detection portion.
26. The electrostatic atomizing device according to claim 17,
further comprising a high-voltage power supply circuit which
applies the high negative voltage to the atomizing electrode,
wherein the control portion reduces the voltage value of the high
negative voltage applied to the atomizing electrode, and when as a
result the occurrence of the negative ion discharge is no longer
detected by the discharge detection portion, further reduces the
voltage value of the high negative voltage.
27. The electrostatic atomizing device according to claim 22,
further comprising a storage portion which stores the voltage value
of the high negative voltage obtained when the discharge detection
portion no longer detects the negative ion discharge, wherein the
control portion causes the storage portion to store the voltage
value of the high negative voltage obtained when the discharge
detection portion no longer detects the negative ion discharge, and
the control portion sets the voltage value stored in the storage
portion as a default voltage value.
28. The electrostatic atomizing device according to claim 17,
further comprising a high-voltage power supply circuit which
applies the high negative voltage to the atomizing electrode,
wherein the control portion halts the supply of the water to the
atomizing electrode by the water supply portion during the period
from when the high-voltage power supply circuit is caused to apply
the high negative voltage to the atomizing electrode until a
predetermined first time has elapsed, and when the first time has
elapsed after causing the high-voltage power supply circuit to
apply the high negative voltage to the atomizing electrode, the
control portion causes the discharge detection portion to detect
whether the negative ion discharge is occurring or not, and when
the discharge detection portion detects that the negative ion
discharge is occurring when the first time has elapsed after the
high-voltage power supply circuit is caused to apply the high
negative voltage to the atomizing electrode, until the occurrence
of the negative ion discharge is no longer detected by the
discharge detection portion, the control portion repeats processing
of judging the discharge current value detected by the discharge
detection portion, and reducing the voltage value applied to the
atomizing electrode as the high negative voltage by a first voltage
value when a discharge current value detected is less than a
predetermined threshold value, otherwise reducing the voltage value
applied to the atomizing electrode as the high negative voltage by
a second voltage value which is different from the first voltage
value when a discharge current value detected is equal to or
greater than the predetermined threshold value.
29. The electrostatic atomizing device according to claim 28,
wherein the first voltage value is smaller than the second voltage
value.
30. The electrostatic atomizing device according to claim 17,
further comprising an opposing electrode provided opposing the
atomizing electrode, wherein the control portion reduces the
electric field intensity of the electric field generated from the
atomizing electrode toward the opposing electrode by causing the
atomizing electrode and the opposing electrode to be moved
apart.
31. The electrostatic atomizing device according to claim 18,
wherein the first time is a time in the range from 5 seconds to 30
seconds.
32. An air conditioner, comprising: an electrostatic atomizing
device which includes; an atomizing electrode which generates
charged fine water particles negatively charged in the form of
mist, by generating an electric field when a high negative voltage
is applied thereto in a state in which water is supplied; a water
supply portion which supplies the water to the atomizing electrode;
a discharge detection portion which detects whether negative ion
discharge, indicating discharge in which only negative ions are
generated without generating the charged fine water particles, is
occurring at the atomizing electrode or not by detecting a
discharge current value of a discharge current occurring when the
high negative voltage is applied to the atomizing electrode and
comparing the discharge current value detected with a predetermined
threshold value; and a control portion which carries on reducing
the electric field intensity of the electric field generated by the
atomizing electrode until the occurrence of the negative ion
discharge is no longer detected by the discharge detection portion,
if the discharge detection portion detects the occurrence of the
negative ion discharge; and an air conditioning portion which
performs air conditioning.
Description
TECHNICAL FIELD
[0001] This invention relates to an electrostatic atomizing device,
and to an air conditioner using such an electrostatic atomizing
device.
BACKGROUND ART
[0002] An electrostatic atomizing device causes Rayleigh splitting
of water supplied to an atomizer electrode to cause atomization by
applying a high voltage across the atomizer electrode (discharge
electrode) and an opposing electrode and inducing discharge. As a
result, charged fine water particles of nanometer size (nano-size
mist) are obtained. Such an electrostatic atomizing device is for
example installed in a dryer, as in Patent Document 1 by the
present applicant, and has been favorably evaluated. Various
applications for such electrostatic atomizing devices are being
studied. In particular, the charged fine water particles contain OH
radicals, and have a long lifetime. Further, a large quantity of
charged fine water particles is dispersed into the air. Hence
charged fine water particles adhere can effectively act on
malodorous components adhering to wall surfaces, clothing,
curtains, and similar to effectively act on malodorous components,
and can deodorize.
[0003] For this reason, the use of electrostatic atomizing devices
in air conditioners to perform deodorizing is being studied. An air
conditioner comprising an electrostatic atomizing device is
particularly well-suited to automotive uses, employed in confined
spaces.
[0004] However, in such applications, there arises a problem which
is not present in dryers. This problem is that negative ion
discharge, in the initial state with no water droplets which is
effective in a dryer, has no effect for the above-described
deodorizing. Even though there is no deodorizing effect, the stage
in which negative ion discharge is occurring may be handled as a
transient stage from the time the dryer power is turned on until
electrostatic atomizing discharge is begun. However, negative ion
discharge imparts damage to the atomizing electrode, due to
sputtering phenomena and similar. Consequently, in an air
conditioner which is used for a much longer period of time than a
dryer, damage to the atomizing electrode affects the equipment
lifetime and so poses a problem. Further, there is also a desire to
be able to rapidly start electrostatic atomizing discharge and
obtain the deodorizing effect.
CITATION LIST
Patent Literature
[0005] [PTL 1] Japanese Patent Application Laid-open No.
2008-73291
SUMMARY OF INVENTION
[0006] This invention has as an object the provision of an
electrostatic atomizing device capable of suppressing negative ion
discharge, as well as an air conditioner using such a device.
[0007] In one mode of this invention, an electrostatic atomizing
device comprises:
[0008] an atomizing electrode which generates charged fine water
particles negatively charged in the form of mist, by generating an
electric field when a high negative voltage is applied thereto in a
state in which water is supplied;
[0009] a water supply portion which supplies the water to the
atomizing electrode;
[0010] a discharge detection portion which detects whether negative
ion discharge, indicating discharge in which only negative ions are
generated without generating the charged fine water particles, is
occurring at the atomizing electrode or not; and
[0011] a control portion which reduces the electric field intensity
of the electric field generated by the atomizing electrode when the
discharge detection portion detects the occurrence of the negative
ion discharge.
[0012] Negative ion discharge is unnecessary in applications to air
conditioners for the purpose of deodorization. And, negative ion
discharge imparts damage to the atomizing electrode. In this
configuration, when negative ion discharge is detected, negative
ion discharge halting control is executed, by lowering the electric
field intensity of the electric field generated by the atomizing
electrode. Hence negative ion discharge is suppressed in air
conditioners used over long periods of time, so that wear of the
atomizing electrode is suppressed, and the equipment lifetime can
be extended.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a block diagram showing the electrical
configuration of the electrostatic atomizing device in a first
embodiment of the invention;
[0014] FIG. 2 is a flowchart used to explain operation of the
electrostatic atomizing device in the first embodiment of the
invention;
[0015] FIG. 3 is a graph showing the relation between the voltage
value of the voltage applied to the atomizing electrode, and the
current value of the discharge current occurring due to application
of the applied voltage, to explain operation of the electrostatic
atomizing device of the first embodiment of the invention;
[0016] FIG. 4 is a cross-sectional view showing schematically the
structure of the atomizing electrode in an ion dryer;
[0017] FIG. 5 is a flowchart used to explain operation of the
electrostatic atomizing device in a second embodiment of the
invention;
[0018] FIG. 6 is a flowchart used to explain operation of the
electrostatic atomizing device in a third embodiment of the
invention;
[0019] FIG. 7 is a graph showing the relation between the voltage
value of the voltage applied to the atomizing electrode, and the
current value of the discharge current occurring due to application
of the applied voltage, to explain operation of the electrostatic
atomizing device in a fourth embodiment of the invention;
[0020] FIG. 8 is a flowchart used to explain operation of the
electrostatic atomizing device in the fourth embodiment of the
invention;
[0021] FIG. 9 is a graph showing the relation between the voltage
value of the voltage applied to the atomizing electrode, and the
current value of the discharge current occurring due to application
of the applied voltage, to explain operation of the electrostatic
atomizing device in a fifth embodiment of the invention;
[0022] FIG. 10 is a flowchart used to explain operation of the
electrostatic atomizing device in the fifth embodiment of the
invention;
[0023] FIG. 11 is a block diagram showing the electrical
configuration of the electrostatic atomizing device in a sixth
embodiment of the invention;
[0024] FIG. 12 is a block diagram showing the electrical
configuration of the electrostatic atomizing device in a seventh
embodiment of the invention; and
[0025] FIG. 13 is a cross-sectional view showing schematically an
example of the configuration of the air conditioner in one
embodiment e of the invention.
DESCRIPTION OF EMBODIMENTS
[0026] First, electrostatic atomizing devices of first to seventh
embodiments of the invention are explained, together with drawings.
And finally, an air conditioner of an embodiment of the invention
is explained, together with drawings.
Electrostatic Atomizing Devices
Embodiment 1
[0027] FIG. 1 is a block diagram showing the electrical
configuration of the electrostatic atomizing device 1 in a first
embodiment of the invention. This electrostatic atomizing device 1
comprises an atomizing block 2, high-voltage power supply circuit
3, Peltier power supply circuit 4, discharge current detection
circuit 5, high-voltage power supply voltage detection circuit 6,
and microcomputer (control portion) 7. This electrostatic atomizing
device 1 is provided on the downstream side in the direction of
flow of air from the filter 90 of an air conditioner 30 (see FIG.
13). For example, if the air conditioner is air cleaning equipment,
charged fine water particles (nano-size mist) leaving the
electrostatic atomizing device 1 by means of an ion wind generated
from an ion generation portion (not shown) is carried on the air
current of the air conditioner 30, and is dispersed within the
room.
[0028] The atomizing block 2 comprises an atomizing electrode 13
having a spherical body 12 on the tip of a column 11; an opposing
electrode 14 which opposes the atomizing electrode 13; and a
Peltier element 15 which cools the base of the atomizing electrode
13. The Peltier power supply circuit 4 comprises a DC/DC converter
16. This DC/DC converter 16 supplies a power supply voltage for
cooling to the Peltier element 15, and by this means the atomizing
electrode 13 is cooled. At this time, surrounding water vapor
adheres to the surface of the atomizing electrode 13, so that
condensed water is obtained on the atomizing electrode 13. The
Peltier power supply circuit 4 and Peltier element 15 form a water
supply portion.
[0029] The microcomputer 7 provides cooling control signals to the
Peltier power supply circuit 4, and by controlling the voltage
value of the voltage applied to the Peltier power supply circuit 4,
executes control such that a constant amount of water is obtained
from the Peltier element 15, as explained below. The microcomputer
7 provides ON/OFF control signals and voltage adjustment signals to
the high-voltage power supply circuit 3, and causes the
high-voltage power supply circuit 3 to assume the ON state, as well
as causing the high-voltage power supply circuit 3 to apply a high
voltage at a prescribed voltage value (a high negative voltage;
similarly below) to the atomizing electrode 13. At this time,
electrostatic atomizing discharge is performed across the atomizing
electrode 13 and the opposing electrode 14, and the charged fine
water particles (nano-size mist) are generated.
[0030] Here, through electrostatic atomizing discharge, a discharge
current flows from the atomizing electrode 13, via the opposing
electrode 14, discharge current detection circuit 5, and
high-voltage power supply circuit 3, to the atomizing electrode 13.
This discharge current is detected by the discharge current
detection circuit 5 which is electrically connected to the opposing
electrode 14. Also, the discharge current detection circuit 5
detects the discharge current value of the detected discharge
current as well.
[0031] The voltage value of the high voltage applied to the
atomizing electrode 13 is detected by the high-voltage power supply
voltage detection circuit 6 which is electrically connected to the
high-voltage power supply circuit 3. And, the discharge current
value of the discharge current detected by the discharge current
detection circuit 5, and the voltage value of the high voltage
detected by the high-voltage power supply voltage detection circuit
6, are fed back to the microcomputer 7. The microcomputer 7
reflects the fed-back discharge current value and voltage value in
the control of the Peltier power supply circuit 4 and high-voltage
power supply circuit 3, and executes control such that a constant
amount of charged fine water particles (nano-size mist) is
generated by the electrostatic atomizing discharge.
[0032] The discharge current detection circuit 5 detects the
discharge current value of the discharge current flowing from the
opposing electrode 14 to the discharge current detection circuit 5.
This discharge current detection circuit 5 comprises, for example,
a current-voltage conversion resistor provided in a state in series
in the current path, and an amplifier or similar which amplifies
the voltage obtained from the current-voltage conversion resistor.
When an opposing electrode 14 is not provided, it is preferable
that a discharge current detection circuit 5a provided between the
high-voltage power supply circuit 3 and the atomizing electrode 13
detects the discharge current flowing from the high-voltage power
supply circuit 3 to the atomizing electrode 13.
[0033] In the electrostatic atomizing device 1 configured as
described above, it should be noted that, in this embodiment, upon
detection by the discharge current detection circuit 5 of the
occurrence of the negative ion discharge not accompanied by
electrostatic atomization, the microcomputer 7 causes the setting
state of the voltage value of the voltage adjustment signal output
to the high-voltage power supply circuit 3 to be changed, thereby
lowering the absolute value of the voltage applied by the
high-voltage power supply circuit 3 to the atomizing electrode 13.
Hence the electric field intensity generated by the atomizing
electrode 13 can be lowered, and negative ion discharge can be
halted.
[0034] FIG. 2 is a flowchart used to explain control operation of
the microcomputer 7. The microcomputer 7 causes the high-voltage
power supply circuit 3 to start application of a high voltage to
the atomizing electrode 13 (step S1). At this time, the Peltier
power supply circuit 4 remains halted. Then, when a predetermined
first time has elapsed after the start of the processing indicated
in step S1, the microcomputer 7 advances to the processing of step
S3. It is desirable that this first time comprise at least the time
for the voltage applied by the high-voltage power supply circuit 3
to the atomizing electrode 13 to rise from the initial 0 V to reach
a prescribed target voltage. Further, it is preferable that the
first time be a time such that the high voltage applied by the
high-voltage power supply circuit 3 to the atomizing electrode 13
can assume a stable state. Also, it is preferable that the first
time be selected to be sufficiently long that any moisture adhering
to the atomizing electrode 13 is evaporated. From the above
conditions, it is preferable that the first time be between 5
seconds and 30 seconds approximately.
[0035] In step S3, the microcomputer 7 judges whether the discharge
current value detected by the discharge current detection circuit 5
is equal to or greater than a predetermined threshold value is not.
That is, in step S3, if the discharge current value of the
discharge current is equal to or greater than the threshold value
(YES in step S3), the microcomputer 7 judges that discharge is
occurring across the atomizing electrode 13 and opposing electrode
14. Here, as explained above, the Peltier power supply circuit 4
remains halted. Hence water is not being supplied to the atomizing
electrode 13, so that the discharge across the atomizing electrode
13 and opposing electrode 14 is negative ion discharge. Hence until
negative discharge is no longer detected by the discharge current
detection circuit 5, the microcomputer 7 repeats processing to
reduce the absolute value of the voltage value of the high voltage
applied by the high-voltage power supply circuit 3 to the atomizing
electrode (step S4) and processing to judge whether the discharge
current value of the discharge current detected by the discharge
current detection circuit 5 is equal to or greater than the
threshold value or not (step S5).
[0036] That is, as shown in FIG. 3, after executing control to
prevent negative ion discharge to repeatedly decrease the absolute
value of the voltage applied to the atomizing electrode 13 until a
discharge current with discharge current value equal to or greater
than the threshold value is no longer detected, the microcomputer 7
proceeds to the electrostatic atomizing control of step S6. Here,
in FIG. 3 the discharge current value used as the threshold value
is 0 .mu.A. Also, "electrostatic atomizing control" means control
in which, by at least causing supplying water and application of a
high voltage to the atomizing electrode 13 and causing generation
of electrostatic atomizing discharge, the computer 7 executes
control to cause generation of charged fine water particles at the
atomizing electrode 13.
[0037] Further, when in the judgment of step S3 the discharge
current value is less than the threshold value (NO in step S3), the
microcomputer 7 directly proceeds to the processing of step S6.
Here, the microcomputer 7 and discharge current detection circuit 5
form the discharge detection portion.
[0038] In electrostatic atomizing control, the Peltier power supply
circuit 4 is operated so as to supply a constant amount of water to
the atomizing electrode 13, as explained above. Here, the
resistance value of the water generated by condensation of moisture
in the air is small. Consequently if the voltage value of the high
voltage applied to the atomizing electrode 13 is constant at for
example -5 kV, then the greater the amount of water supplied to the
atomizing electrode 13 by condensation of moisture in the air due
to the Peltier element 15, the greater is the discharge current
flowing from the atomizing electrode 13 to the opposing electrode
14 (the discharge current value detected by the discharge current
detection circuit 5). Hence if a cooling control signal is output
to the Peltier power supply circuit 4 such that the discharge
current value represented by the discharge current signal is
constant, then a constant amount of water is supplied to the
atomizing electrode 13.
[0039] Through this configuration, upon detection of the negative
ion discharge by the discharge current detection circuit 5, which
is unnecessary in uses for the purpose of deodorizing and which
imparts damage to the atomizing electrode 13, the microcomputer 7
executes control to halt the negative ion discharge, so that wear
of the atomizing electrode 13 in an air conditioner used over a
long period of time is suppressed, and the equipment lifetime is
extended. Further, during the period until the first time has
elapsed, the microcomputer 7 lowers the voltage value of the high
voltage applied to the atomizing electrode 13 until a voltage value
is reached at which negative ion discharge does not occur. Hence
when the first time has elapsed, the voltage value of the high
voltage applied to the atomizing electrode 13 is a value such that
negative ion discharge does not occur, so that electrostatic
atomizing discharge can be started rapidly, and a deodorizing
effect can be obtained.
[0040] Here, it is easy to perform control so as to transition to
electrostatic atomizing discharge after performing negative ion
discharge for a time by supplying water, as in the above-described
dryer. However, if mainly electrostatic atomizing discharge is
performed without performing negative ion discharge, as in the
present embodiment, it is not sufficient to simply cause discharge
after waiting until an adequate amount of water has been supplied.
Hence for the reason described below, it is difficult to apply such
dryer control to control of the electrostatic atomizing device
1.
[0041] Specifically, as shown in FIG. 4, the atomizing electrode of
the dryer is configured with a sharp protrusion 102 formed on a
spherical body 101. And, an electric field is concentrated between
the protrusion 102 and the opposing electrode 103 to start the
negative ion discharge. When water is supplied to the protrusion
102 and the protrusion 102 is covered with water (Taylor cone 104),
there is switching to electrostatic atomizing discharge.
[0042] At this time, the more the water increases at the atomizing
electrode (the longer the Taylor cone 104), the lower is the
resistance value between the atomizing electrode comprising the
spherical body 101 and the opposing electrode 103, so that
electrostatic atomizing discharge is performed at a low voltage
value. Further, the longer the Taylor cone 104 at the atomizing
electrode, the lower is the resistance value between the atomizing
electrode and the opposing electrode 103, so that a discharge
current with a large discharge current value occurs at a low
voltage value. Thus it is seen that there is a proportional
relationship between the amount of water at the atomizing electrode
and the discharge current value.
[0043] So long as a high voltage with a constant voltage value is
being applied to the atomizing electrode, the amount of water
increases at the atomizing electrode (the Taylor cone 104
lengthens), and to this extent the resistance value between the
atomizing electrode comprising the spherical body 101 and the
opposing electrode 103 declines, so that the discharge current
value increases. In general, the quantity of charged fine water
particles (nano-size mist) is affected by the discharge current
value. Also, the quantity of water at the atomizing electrode and
the discharge current value are in a proportionality relationship,
as explained above. Hence it is seen that in order to adjust the
quantity of charged fine water particles, the quantity of water at
the atomizing electrode may be adjusted.
[0044] However, in an electrostatic atomizing device 1 which is to
be made to primarily perform electrostatic atomizing discharge, the
atomizing electrode 13 is formed using only a spherical body 12, as
shown in FIG. 1. The spherical body 12 does not comprise a
protrusion 102, as in the case of the spherical body 101 of the
dryer. Hence if a discharge current flows when a high voltage is
applied to the atomizing electrode 13 with a voltage value smaller
than the voltage value which initiates a discharge current (a
specified application voltage), the cause of the discharge current
is not known.
[0045] That is, the spherical body 12 of the atomizing electrode
does not comprise a protrusion 102, and so the microcomputer 7
cannot judge whether a discharge current has flowed due to the
occurrence of a Taylor cone of constant length in electrostatic
atomizing discharge, or whether a discharge current has flowed due
to the occurrence of the negative ion discharge due to foreign
matter adhering, with a protruding shape, to the atomizing
electrode 13. Hence the microcomputer 7 cannot ascertain whether
the currently occurring discharge is micro-ion discharge or is
electrostatic atomizing discharge.
[0046] In general, in micro-ion discharge only negative ions are
generated, and charged fine water particles are not generated.
Hence in a state in which the microcomputer 7 cannot ascertain
whether the discharge currently occurring is micro-ion discharge or
electrostatic atomizing discharge, of course the quantity of
charged fine water particles cannot be adjusted by merely adjusting
the discharge current value. Hence it is difficult to employ a
discharge current value control method such as is used in dryers to
an electrostatic atomizing device employed to primarily cause
electrostatic atomizing discharge.
[0047] Hence in this embodiment, the microcomputer 7 causes the
Peltier power supply circuit 4 to halt the supply of water for a
first time from the time at which application of the high voltage
to the atomizing electrode 13 by the high-voltage power supply
circuit 3 is started. Hence even when moisture adheres to the
atomizing electrode 13 before the start of use in a
high-temperature and high-humidity environment, or even when the
time elapsed from the end of the time the equipment was previously
used is short, so that moisture from the time of previous use
remains on the atomizing electrode 13, this moisture is evaporated
within this first time. Hence a state results in which no moisture
adheres to the atomizing electrode 13. Here, even when foreign
matter adheres to the spherical body 12 in the shape of a
protrusion 102, this is removed from the atomizing electrode 13 by
the ion wind due to negative ion discharge at the atomizing
electrode 13 by the time the first time has elapsed.
[0048] Then, in a state in which neither water nor foreign matter
adhere to the atomizing electrode 13, the microcomputer 7 causes
the discharge current detection circuit 5 to detect whether
negative ion discharge is occurring or not. To this end, in a state
in which there is the possibility of the occurrence of
electrostatic atomizing discharge, the microcomputer 7 can suspend
operation to detect whether discharge is negative ion discharge or
not, and can reliably detect negative ion discharge.
[0049] That is, in a state in water remains on the atomizing
electrode 13, and it cannot be ascertained whether a discharge
current is occurring due to negative ion discharge, or whether a
discharge current is occurring due to electrostatic atomizing
discharge, the microcomputer 7 does not detect whether negative ion
discharge is occurring or not. When a state occurs in which
moisture does not adhere to the atomizing electrode 13 (in the
state in which the first time has elapsed), the microcomputer 7
performs detection of whether negative ion discharge is occurring
or not.
[0050] After detection of the occurrence of the negative ion
discharge, upon detection of a discharge current when a high
voltage, with voltage level lowered such that negative ion
discharge does not occur, is applied to the atomizing electrode 13,
the microcomputer 7 detects the occurrence of electrostatic
atomizing discharge, rather than micro-ion discharge.
[0051] Further, the controller 7 performs feedback control, based
on the discharge current value of the discharge current detected
when a high voltage, lowered to a voltage value at which negative
ion discharge does not occur, is applied to the atomizing electrode
13. For example, the microcomputer 7 control the Peltier power
supply circuit 4 such that an amount of water corresponding to the
discharge current value is supplied to the atomizing electrode 13
by the Peltier element 15, in "a relation of proportionality of the
amount of water at the atomizing electrode 13 and the discharge
current value" (described above).
[0052] Further, as the water supply portion, a heat exchanger
employing the Peltier element 15 is used. In general, start-up and
shut-down of a Peltier element 15 are fast. For example, in 5
seconds a Peltier element 15 can cause condensed water to adhere to
the atomizing electrode 13. Hence satisfactory response
characteristics for starting and halting supply of water to the
atomizing electrode 13 can be obtained.
Embodiment 2
[0053] FIG. 5 is a flowchart used to explain operation of the
electrostatic atomizing device 1 in a second embodiment of the
invention. The configuration of the electrostatic atomizing device
1 shown in FIG. 1 can be used in the electrostatic atomizing device
1 of this embodiment. In the electrostatic atomizing device 1 of
this embodiment, operation of the microcomputer 7 differs between
in FIG. 2 and in FIG. 5. In FIG. 5, which is similar to FIG. 2, the
same step numbers are assigned to corresponding processing, and
explanations thereof are omitted. It should be noted that in this
embodiment, after halting supply of water and waiting for a first
time in step S2, upon detecting a discharge current value of the
discharge current equal to or greater than a threshold value in
step S3, no judgment of negative ion discharge is performed
immediately, and processing returns to step S3 until a
predetermined second time elapses, and after the second time has
elapsed, judgment of negative ion discharge is performed. Here, the
second time represents a time elapsed from the time of judgment in
step S3 that the discharge current value is equal to or greater
than the threshold value.
[0054] In this configuration, whether negative ion discharge is
occurring or not is again judged after a second time from the
previous judgment, for example, after one minute has elapsed. As a
result, the following advantageous results are obtained from the
second embodiment. That is, by shorting the first time to, for
example, the abovementioned 5 seconds, erroneous judgments may
occur in a state in which moisture adheres to the atomizing
electrode 13. However, in the second embodiment, the moisture
evaporates during the period from the erroneous judgment until the
second time has elapsed. As a result, accurate judgment is
performed the second time. Hence the time for initially judging
whether a negative ion discharge is occurring or not can be set
comparatively short, and therefore electrostatic atomizing
discharge can be performed rapidly.
[0055] In the second embodiment, when negative ion discharge is
continued even after the first and second times have elapsed (YES
in step S11), the voltage value of the voltage applied to the
atomizing electrode 13 is reduced in steps until a negative ion
discharge is no longer detected (steps S4 and S5).
Embodiment 3
[0056] FIG. 6 is a flowchart used to explain operation of the
electrostatic atomizing device 1 in a third embodiment of the
invention. The configuration of the electrostatic atomizing device
1 shown in FIG. 1 can be used in the electrostatic atomizing device
1 of this embodiment. In the electrostatic atomizing device 1 of
this embodiment, operation of the microcomputer 7 differs from that
in FIG. 2 above and in FIG. 6. It should be noted that in this
embodiment, the negative ion discharge detection processing
indicated in steps S2 and S3 of FIG. 2 is performed in step
S23.
[0057] That is, in the state in which the supply of water to the
atomizing electrode 13 is halted during the period of the first
time (step S2 in FIG. 2), the microcomputer 7 performs processing
to judge whether the discharge current value is equal to or exceeds
the threshold value (step S3 in FIG. 2). And, in step S3 in FIG. 2,
upon detection of negative ion discharge (YES in step S3 of FIG.
2), the microcomputer 7 decreases in steps the voltage value of the
high voltage applied by the high-voltage power supply circuit 3 to
the atomizing electrode 13.
[0058] Specifically, when in step S23 negative ion discharge is
detected, the microcomputer 7 judges the discharge current value
represented by the discharge current signal output from the
discharge current detection circuit 5 (step S24). And, in step S41
the microcomputer 7 compares the discharge current value with a
predetermined threshold value A, and when the discharge current
value is less than the threshold value A, in step S42 sets the
voltage applied to the atomizing electrode to a value smaller by a
comparatively small voltage reduction amount .DELTA.1. When on the
other hand the discharge current value is equal to or greater than
the threshold value A, in step S43 the voltage applied to the
atomizing electrode 13 is set to a value smaller by a comparatively
large voltage reduction amount .DELTA.2.
[0059] After the processing represented by these steps S42 and S43,
the microcomputer 7 judges whether negative ion discharge is
continuing or not (step S5), and if it is judged that negative ion
discharge is continuing (YES in step S5), the microcomputer 7
executes the processing of step S24. On the other hand, upon
judging that negative ion discharge is not continuing, the
microcomputer 7 performs the electrostatic atomizing control
indicated by step S6.
[0060] Here, during negative ion discharge, the higher the voltage
value of the high voltage applied to the atomizing electrode 13,
the greater the increase in the quantity of electrons emitted from
the atomizing electrode 13, so that the discharge current value is
increased. Hence by setting a plurality of voltage reduction
amounts .DELTA.1, .DELTA.2 as the amounts of reduction in the
voltage applied by the high-voltage power supply circuit 3 to the
atomizing electrode 13, and by using a larger reduction (.DELTA.2)
in the voltage value when the discharge current value is large,
according to the discharge current value when negative ion
discharge is occurring, and using a smaller reduction (.DELTA.1) in
the voltage value when the discharge current value is small,
negative ion discharge can be rapidly stopped. Also, after stopping
negative ion discharge, so long as there is no occurrence of the
negative ion discharge, by applying a borderline voltage so that
negative ion discharge does not occur, electrostatic atomizing can
be induced with stability.
Embodiment 4
[0061] FIG. 7 is a waveform diagram used to explain operation of
the electrostatic atomizing device 1 in a fourth embodiment of the
invention. The configuration of the electrostatic atomizing device
1 shown in FIG. 1 can be used in the electrostatic atomizing device
1 of this embodiment as well. In the electrostatic atomizing device
1 of this embodiment, operation of the microcomputer 7 differs from
the operation of the microcomputer 7 in the first embodiment. It
should be noted that in this embodiment, the microcomputer 7
repeatedly lowers the voltage applied by the high-voltage power
supply circuit 3 to the atomizing electrode 13. And, prior to
lowering the applied voltage, the microcomputer 7 always first
turns the high-voltage power supply circuit 3 OFF, using an ON/OFF
control signal. Also, after first turning OFF the high-voltage
power supply circuit 3 and lowering the applied voltage, the
microcomputer 7 always puts the high-voltage power supply circuit 3
into the ON state, using an ON/OFF control signal.
[0062] FIG. 8 is a flowchart used to explain the operation. In step
S23, the microcomputer 7 judges whether negative ion discharge is
occurring or not. At this time, if negative ion discharge is
occurring, the microcomputer 7 first turns OFF the high-voltage
power supply circuit 3 in step S44.
[0063] Then, together with control to lower the applied voltage in
step S45, the high-voltage power supply circuit 3 is turned ON.
That is, the microcomputer 7 turns ON the power supply of the
high-voltage power supply circuit 3 using an ON/OFF control signal.
And, the microcomputer 7 reduces the voltage value of the high
voltage applied by the high-voltage power supply circuit 3 by means
of a voltage adjustment signal (step S45). Then, if negative ion
discharge is not eliminated through voltage reduction control (YES
in step S5), processing by the microcomputer 7 returns from step S5
to step S44, and voltage reduction control is repeated by the
microcomputer 7 until negative ion discharge is eliminated.
[0064] When reducing the voltage applied by the high-voltage power
supply circuit 3 to the atomizing electrode 13 in this way, by
turning OFF the high-voltage power supply circuit 3, the
microcomputer 7 forcibly cancels the state of negative ion
discharge. Hence the microcomputer 7 causes negative ion discharge
to be discontinued, and so damage to the atomizing electrode 13 can
be suppressed.
[0065] Further, by reducing in steps the voltage applied to the
atomizing electrode 13, the microcomputer 7 reduces the voltage
value of the applied voltage to a voltage value at which negative
ion discharge does not occur. Hence the microcomputer 7 can cause
the high-voltage power supply circuit 3 to apply a high voltage to
induce electrostatic atomizing discharge with stability, without
causing negative ion discharge. In this fourth embodiment, when
detected negative ion discharge has been eliminated (NO in step
S5), electrostatic atomizing control is performed (step S6).
Embodiment 5
[0066] FIG. 9 is a waveform diagram used to explain operation of
the electrostatic atomizing device 1 in a fifth embodiment of the
invention. The configuration of the electrostatic atomizing device
1 shown in FIG. 1 can be used in the electrostatic atomizing device
1 of this embodiment as well. In the electrostatic atomizing device
1 of this embodiment, operation of the microcomputer 7 differs from
the operation of the microcomputer 7 in the first embodiment
described above. This embodiment is similar to the embodiment shown
in FIG. 7 and FIG. 8 above. It should be noted that in this
embodiment, when reducing the voltage applied by the high-voltage
power supply circuit 3 to the atomizing electrode 13, the
microcomputer 7 first turns OFF the high-voltage power supply
circuit 3, and after negative ion discharge is no longer detected,
and after further lowering by one step the applied voltage,
proceeds to electrostatic atomizing control. In the example of FIG.
9, the discharge voltage value of the discharge current falls below
the threshold value by lowering the voltage value in three steps,
set in advance in the electrostatic atomizing device 1. However,
the microcomputer 7 thereafter further lowers the voltage one step.
As a result, a discharge current no longer flows.
[0067] Here, as one example of a voltage value lowered one more
step in this embodiment, a voltage value "b" is shown which is in
the range from 2 to 5% of the voltage value "a" in the voltage
application cycle CY1 immediately before the relevant voltage
application cycle CY2. That is, in the relevant voltage application
cycle CY2, the high voltage "a"-"b" of the voltage value is applied
to the atomizing electrode 13. At this time, a discharge current is
no longer detected by the discharge current detection circuit
5.
[0068] FIG. 10 is a flowchart used to explain the operation. In
steps S44 and S45 and in step S5, the microcomputer 7 lowers in
steps the applied voltage. As a result, negative ion discharge is
no longer detected. However, in this embodiment, after negative ion
discharge is no longer detected, in step S46 once again the
high-voltage power supply circuit 3 is turned OFF similarly to step
S44, and in step S47 the applied voltage is lowered one step
similarly to step S45. Here, in step S47 the microcomputer 7 turns
ON the power supply of the high-voltage power supply circuit 3.
And, by means of a voltage adjustment signal, the microcomputer 7
further reduces the voltage value of the high voltage applied by
the high-voltage power supply circuit 3. And, in step S6 the
microcomputer 7 performs electrostatic atomizing control.
[0069] In general, after negative ion discharge has been eliminated
the applied voltage is in an unstable state. However, in this
embodiment the microcomputer 7 can reliably halt negative ion
discharge by lowering the voltage to a predetermined level below
the voltage value at which negative ion discharge no longer occurs,
such as for example to from 2 to 5% below the voltage value at
which negative ion discharge no longer occurs, and consequently
stable electrostatic atomizing can be performed.
Embodiment 6
[0070] FIG. 11 is a block diagram showing the electrical
configuration of the electrostatic atomizing device 1a in a sixth
embodiment of the invention. The electrostatic atomizing device 1a
is similar to the electrostatic atomizing device 1 shown in FIG. 1
above. It should be noted that in this electrostatic atomizing
device 1a, a register 7b, which is a storage portion, is provided
in the microcomputer 7a, and that a detection result (voltage value
of the high voltage) of the high-voltage power supply voltage
detection circuit 6 is stored as the default value in this register
7b at the time that an negative ion discharge is no longer
detected. The voltage value stored as a default value is set in the
high-voltage power supply circuit 3 as the voltage value of the
high voltage to be applied at the time of the next startup.
[0071] In this way, at the time of the next startup, the voltage
value of the high voltage at which the negative ion discharge was
no longer detected at the time of previous operation is used, so
that the time for adjustment to the optimum applied voltage
enabling prevention of negative ion discharge is shortened, and
consequently electrostatic atomizing can be started rapidly.
Embodiment 7
[0072] FIG. 12 is a block diagram showing the electrical
configuration of the electrostatic atomizing device 21 in a seventh
embodiment of the invention. This electrostatic atomizing device 21
is similar to the electrostatic atomizing device 1 shown in FIG. 1
above; corresponding portions are assigned the same reference
symbols, and explanations thereof are omitted. It should be noted
that in this electrostatic atomizing device 21, a displacement
device 22 is provided on the opposing electrode 14 which can change
the distance between the atomizing electrode 13 and the opposing
electrode 14, as indicated by the arrows 29. Upon detection of
negative ion discharge, the microcomputer 27 causes the opposing
electrode 14 to be moved in the axial direction of the atomizing
electrode 13 and so to be moved away from the atomizing electrode
13. As a result, the electric field intensity in the region between
the atomizing electrode 13 and the opposing electrode 14 is
reduced.
[0073] This displacement device 22 comprises a support member 23
which supports the opposing electrode 14; a rack member 24, on
which the support member 23 is mounted; a guide portion (not shown)
which guides the rack member 24; a pinion gear 25 which meshes with
the rack member 24; and a motor 26 which drives the pinion gear 25.
The motor 26 is driven by a driving circuit 28. The driving circuit
28 operates according to distance control signals from the
microcomputer 27. By means of this configuration also, negative ion
discharge can be prevented.
[0074] Air Conditioner
[0075] FIG. 13 is a cross-sectional view showing schematically an
example of the configuration of the air conditioner in one
embodiment of the invention. In FIG. 13, a heating/cooling type air
conditioner 30 is shown as an example.
[0076] In this air conditioner 30, an air suction opening 81 is
provided in the upper portion of the front face of the housing 82.
Air suctioned by the air suction opening 81 is passed through a
filter 90 to remove dust and similar, and flows into the housing
82. In the figure, the arrows indicate the direction of flow of air
within the housing 82 (hereafter called the direction D).
[0077] Air which has flowed into the housing 82 undergoes heat
exchange by a heat exchanger (air conditioning portion) 80, and as
a result warmed air or cooled air is generated. On the downstream
side in the direction D of the heat exchanger 80 are provided two
among the electrostatic atomizing devices 1, 1a, and 21.
[0078] The charged fine water particles M1 generated by any among
the electrostatic atomizing devices 1, 1a, 21 are carried on the
flow of air which has undergone heat exchange by the heat exchanger
80, and travels toward the air blow-out opening 87. Here, the flow
of air which has undergone heat exchange is formed by rotation of a
fan 83. The air blow-out opening 87 is provided with a louver 88.
Hence charged fine water particles M1 traveling toward the air
blow-out opening 87 are blown in the direction toward the louver
88. Here, the direction of orientation of the louver 88 is
determined by rotation of a motor 100.
[0079] Further, within the housing 82 is provided a wall 84 to form
an airflow path 85 from the air suction opening 81, through the fan
83, to the air blow-out opening 87. Here, the lower-rear portion in
the housing 82 is partitioned from the airflow path 85 by the wall
84, and is a dead space used to draw out an exhaust drain pipe 89
from the right edge or left edge of the housing 82 to the outside.
Any one among the above-described electrostatic atomizing devices
1, 1a, 21 is provided in the dead space. To any one among the
electrostatic atomizing devices 1, 1a, 21a delivery tube 86, to
deliver charged fine water particles M2 occurring in one among the
electrostatic atomizing devices 1, 1a, 21 from the dead space to
the interior of the housing 82, is connected.
[0080] Hence the charged fine water particles M2 occurring in one
among the electrostatic atomizing devices 1, 1a, 21 is delivered to
the interior of the housing 82, and consequently the charged fine
water particles M2 are carried on the flow of air in the housing
82, and travel toward the air blow-out opening 87. Hence the
charged fine water particles M2 are blown in the direction of the
orientation of the louver 88 in the air blow-out opening 87.
[0081] Any one among the microcomputers 7, 7a, 21 not only controls
any one among the electrostatic atomizing devices 1, 1a, 21, but
also executes overall control of the air conditioner 30. In the
figure, the dot-dash arrows represent control signals output from
the microcomputer 7, 7a, or 21.
[0082] The above-described specific embodiments mainly comprise
inventions having the following configurations.
[0083] The electrostatic atomizing device of a first mode of the
invention comprises:
[0084] an atomizing electrode which generates charged fine water
particles negatively charged in the form of mist, by generating an
electric field when a high negative voltage is applied thereto in a
state in which water is supplied;
[0085] a water supply portion which supplies the water to the
atomizing electrode;
[0086] a discharge detection portion which detects whether negative
ion discharge is occurring at the atomizing electrode or not,
representing discharge which generates only negative ions without
generating charged fine water particles; and
[0087] a control portion which, when the occurrence of the negative
ion discharge is detected by the discharge detection portion,
reduces the electric field intensity of the electric field
generated by the atomizing electrode.
[0088] In this configuration, in the preliminary stage of
electrostatic atomizing discharge in which discharge occurs between
a Taylor cone of water drops adhering to the atomizing electrode
and an opposing pole (an opposing electrode, a housing or similar
at GND potential accommodating the electrostatic atomizing device,
or another member having polarity opposite that of the atomizing
electrode), when the occurrence of the negative ion discharge, in
which direct discharge occurs between the atomizing electrode and
the opposing pole without being accompanied by electrostatic
atomizing, is detected by the discharge detection portion, the
control portion controls the high-voltage power supply circuit to
cause reduction of the voltage applied to the atomizing electrode,
or else withdraws the opposing pole from the atomizing electrode,
and so lowers the electric field intensity generated by the
atomizing electrode.
[0089] Hence when negative ion discharge, which is unnecessary when
used for deodorizing purposes and imparts damage to the atomizing
electrode, is detected by the discharge detection portion, the
control portion executes control to halt the negative ion
discharge, so that wear of the atomizing electrode is suppressed in
an air conditioner used for extended lengths of time, and the
equipment lifetime is extended.
[0090] In the above configuration, it is desirable that a
high-voltage power supply circuit which applies the high negative
voltage to the atomizing electrode be further comprised, that the
control portion be configured to cause the high-voltage power
supply circuit to apply the high negative voltage to the atomizing
electrode, that the control portion halt the supply of the water to
the atomizing electrode by the water supply portion during the
period from when the high-voltage power supply circuit is caused to
apply the high negative voltage to the atomizing electrode until a
predetermined first time has elapsed, and that, when the first time
has elapsed after causing the high-voltage power supply circuit to
apply the high negative voltage to the atomizing electrode, the
control portion cause the discharge detection portion to detect
whether negative ion discharge is occurring or not.
[0091] In this configuration, the control portion controls the
timing of the start of application of a high voltage by the
high-voltage power supply circuit and controls the supply of water
by the water supply portion, and in addition controls the timing of
detection by the discharge detection portion. And, the control
portion halts the supply of water by the water supply portion for a
predetermined first time from the start of application of the high
voltage. Hence even when moisture adheres to the atomizing
electrode prior to the start of use in a high-temperature,
high-humidity environment, or when the time elapsed from the end of
the previous use is short and moisture from the previous use
remains on the atomizing electrode, this moisture evaporates during
the first time. Thereafter, the control portion causes the
discharge detection portion to judge whether negative ion discharge
is occurring or not.
[0092] Hence in circumstances in which there is the possibility of
occurrence of electrostatic atomizing discharge, operation to
detect whether discharge is negative ion discharge is occurring or
not is stopped, and negative ion discharge can be reliably
detected. The first time is the time sufficient for evaporation
even when moisture adheres to the atomizing electrode as described
above, and is approximately 5 to 30 seconds.
[0093] In the above configuration, it is desirable that, when the
occurrence of the negative ion discharge is detected by the
discharge detection portion, the control portion further cause the
discharge detection portion to detect whether negative ion
discharge is occurring or not during the period from the detection
of the occurrence of the negative ion discharge until a
predetermined second time has elapsed, and when the occurrence of
the negative ion discharge is detected by the discharge detection
portion during the period from the time of detection of the
occurrence of the negative ion discharge until the second time has
elapsed, the control portion reduce the electric field intensity of
the electric field generated by the atomizing electrode.
[0094] By means of this configuration, whether negative ion
discharge is occurrence is again judged after a second time, such
as for example 1 minute, has elapsed from the previous judgment,
and so even if the first time is shortened to for example
approximately 5 seconds as described above, and erroneous judgement
of the state of adhesion of moisture to the atomizing electrode is
made, the moisture evaporates during the period in which the second
time elapses, so that accurate judgment can be performed.
[0095] Hence the first time until the initial judgment that there
is no negative ion discharge can be set to be comparatively short,
and switching to electrostatic atomizing discharge can be performed
rapidly.
[0096] In the above configuration, it is desirable that the water
supply portion be a Peltier element provided at the base of the
atomizing electrode.
[0097] In this configuration, water adhering to the atomizing
electrode, by cooling of the atomizing electrode by the Peltier
element, is used for atomizing. Hence startup of the Peltier
element can be performed rapidly, condensed water can be made to
adhere to the atomizing electrode in for example 5 seconds, and
satisfactory response for water supply startup and halting can be
obtained.
[0098] In the above configuration, it is desirable that the second
time be 1 minute.
[0099] In this configuration, the presence or absence of negative
ion discharge can be accurately judged during the period from an
erroneous judgement of negative ion discharge until 1 minute has
elapsed. Hence there is little tendency for damage to be imparted
to the atomizing electrode due to sputtering phenomena or
similar.
[0100] In the above configuration, it is desirable that a
high-voltage power supply circuit which applies the high negative
voltage to the atomizing electrode be comprised, and that the
control portion reduces the electric field intensity of the
electric field generated by the atomizing electrode by reducing a
voltage value of the high negative voltage applied to the atomizing
electrode by the high-voltage power supply circuit.
[0101] In general, when the voltage value of the high negative
voltage applied to the atomizing electrode is reduced, the electric
field intensity of the electric field generated by the atomizing
electrode declines. And when the electric field intensity of the
electric field declines, the discharge current flowing due to
negative ion discharge decreases. And when the discharge current
decreases, there is a tendency for the negative ion discharge to be
eliminated.
[0102] Hence in this configuration, by reducing the voltage value
of the high negative voltage applied to the atomizing electrode and
lowering the electric field intensity of the electric field
generated by the atomizing electrode, the discharge current due to
negative ion discharge is decreased. Hence negative ions can be
eliminated through simple control in which the voltage value of the
high negative voltage applied to the atomizing electrode is
reduced.
[0103] In the above configuration, it is desirable that a
high-voltage power supply circuit which applies the high negative
voltage to the atomizing electrode be further comprised, that a
plurality of voltage values be set in advance as voltage values for
the high negative voltage applied to the atomizing electrode by the
high-voltage power supply circuit, that the discharge detection
portion be configured to further detect the discharge current value
of the discharge current representing the current occurring due to
negative ion discharge, and that the control portion reduce in
steps the voltage value of the high negative voltage applied to the
atomizing electrode by the high-voltage power supply circuit,
according to the discharge current value detected by the discharge
detection portion.
[0104] In this configuration, the voltage value of the high
negative voltage applied to the atomizing electrode is reduced in
steps until the negative ion discharge is eliminated. Hence after
the negative ion discharge is eliminated, a borderline voltage so
that negative ion discharge does not occur can be applied to the
atomizing electrode, to induce electrostatic atomizing. Hence
electricity fees can be suppressed.
[0105] In the above configuration, it is desirable that a
high-voltage power supply circuit which applies the high negative
voltage to the atomizing electrode be further comprised, and that
the control portion turn OFF and then turn ON the high-voltage
power supply circuit as well as reduces the voltage value of the
high negative voltage applied to the atomizing electrode.
[0106] By means of this configuration, the state of negative ion
discharge can be forcibly eliminated, and damage to the atomizing
electrode can be suppressed without continuation of negative ion
discharge; in addition, a high voltage can be applied so as to
stably induce electrostatic atomizing discharge, without causing
negative ion discharge.
[0107] In the above configuration, it is desirable that a
high-voltage power supply circuit which applies the high negative
voltage to the atomizing electrode be further comprised, that a
plurality of voltage values be set in advance as voltage values for
the high negative voltage applied to the atomizing electrode by the
high-voltage power supply circuit, that the discharge detection
portion be configured to further detect the discharge current value
of the discharge current representing the current occurring due to
negative ion discharge, and that the control portion repeatedly
turn OFF and then turn ON the high-voltage power supply circuit as
well as reduce in steps the voltage value of the high negative
voltage applied to the atomizing electrode by the high-voltage
power supply circuit, until the occurrence of the negative ion
discharge is no longer detected by the discharge detection
portion.
[0108] By means of this configuration, in a state in which negative
ion discharge has been interrupted, the voltage value of the high
negative voltage applied to the atomizing electrode is set to a
voltage value at which negative ion discharge does not occur. Hence
damage to the atomizing electrode due to sputtering phenomena and
similar can be suppressed. Further, the voltage value of the high
negative voltage applied to the atomizing electrode is reduced in
steps until the negative ion discharge is eliminated. Hence after
elimination of the negative ion discharge, a high voltage at a
borderline voltage value at which negative ion discharge does not
occur can be applied to the atomizing electrode to cause
electrostatic atomizing. Hence electricity fees can be
suppressed.
[0109] In the above configuration, it is desirable that a
high-voltage power supply circuit which applies the high negative
voltage to the atomizing electrode be further comprised, and that
the control portion reduce the voltage value of the high negative
voltage applied to the atomizing electrode, and to this end, when
the discharge detection portion no longer detects the occurrence of
the negative ion discharge, further reduces the voltage value of
the high negative voltage.
[0110] In general, the application voltage is in an unstable state
after elimination of the negative ion discharge. Hence by means of
this configuration, by further reducing the voltage value to a
level determined in advance, for example 2 to 5% below the voltage
value at the time of elimination of the negative ion discharge,
stable electrostatic atomizing can be performed.
[0111] In the above configuration, it is desirable that a storage
portion which stores the voltage value of the high negative voltage
obtained when the discharge detection portion no longer detects the
negative ion discharge be comprised, that the control portion cause
the storage portion to store the voltage value of the high negative
voltage obtained when the discharge detection portion no longer
detects the negative ion discharge, and set the voltage value
stored in the storage portion as a default voltage value.
[0112] By means of this configuration, the voltage value stored as
the default value is set in the high-voltage power supply circuit
as the voltage value of the high voltage to be applied at the time
of the next startup. Hence at the time of the next startup the
voltage value of the high voltage at which negative ion discharge
was no longer detected during the preceding operation is used, so
that the time for adjustment to the optimum applied voltage at
which negative ion discharge can be prevented is shortened, and
consequently electrostatic atomizing can be started rapidly.
[0113] In the above configuration, it is desirable that a
high-voltage power supply circuit which applies the high negative
voltage to the atomizing electrode be further comprised, that the
discharge detection portion be configured to further detect the
discharge current value of a discharge current representing the
current occurring due to negative ion discharge, and that, when a
first time has elapsed after causing the high-voltage power supply
circuit to apply the high negative voltage to the atomizing
electrode, when the discharge detection portion detects the
occurrence of the negative ion discharge, the control portion
judges the discharge current value detected by the discharge
detection portion, and during the period between the time when the
discharge current value is less than a predetermined threshold
value and the time when the discharge current value is equal to or
greater than a predetermined threshold value, employs different
voltage value magnitudes for application to the atomizing electrode
as the high negative voltage.
[0114] In this configuration, the amount of reduction of the
voltage value of the high negative voltage applied to the atomizing
electrode differs according to the discharge current value during
negative ion discharge. Hence when for example the discharge
current value is large the amount of reduction of the voltage value
is made large, and when the discharge current value is small the
amount of reduction of the voltage value is made small, so that the
state of occurrence of the negative ion discharge can be ended
efficiently.
[0115] In the above configuration, it is desirable that the voltage
value applied as the high negative voltage when the discharge
current value is equal to or greater than a predetermined threshold
value be made greater than the voltage value applied as the high
voltage when the discharge current value is less than the threshold
value.
[0116] In this configuration, when the discharge current value
during negative ion discharge is large, the amount of reduction of
the voltage value is large, and when the discharge current value is
small the amount of reduction of the voltage value is small, so
that the state of occurrence of the negative ion discharge can be
ended rapidly.
[0117] In the above configuration, it is desirable that an opposing
electrode, provided in opposition to the atomizing electrode, be
further comprised, and that by causing the atomizing electrode and
the opposing electrode to be moved apart, the control portion
reduces the electric field intensity of the electric field
generated from the atomizing electrode toward the opposing
electrode.
[0118] In this configuration, negative ion discharge is easily
prevented without requiring processing such as reduction of the
voltage value of the high negative voltage applied to the atomizing
electrode.
[0119] In the above configuration, it is desirable that the first
time be a time in the range from 5 seconds to 30 seconds.
[0120] In this configuration, even if moisture adheres to the
atomizing electrode, the occurrence of the negative ion discharge
is detected after sufficient time for the moisture to evaporate has
elapsed. Hence the occurrence of the negative ion discharge can be
accurately detected.
[0121] Further, the air conditioner of another mode of the
invention comprises:
[0122] the electrostatic atomizing device according to the first
mode; and
[0123] an air conditioning portion which performs air
conditioning.
[0124] In this configuration, the electrostatic atomizing device
according to the first mode is comprised. Hence an air conditioner
from which the advantageous results of the first mode are obtained
is provided.
* * * * *