Disclosed is an electrostatic atomizer, which comprises a high-voltage applying section adapted to apply a high voltage between an atomizing electrode and a counter electrode so as to electrostatically atomize water supplied onto the atomizing electrode, wherein the high-voltage applying section is operable to set an absolute value of a voltage to be applied to the atomizing electrode smaller than an absolute value of a voltage to be applied to the counter electrode. This allows a physical object, such as an article stored in a mist-receiving space or an inner wall of a structural member defining the mist-receiving space to become less likely to be electrostatically charged, and makes it possible to avoid causing a problem about discomfort due to discharge of static charges when a user touches the physical object.

TECHNICAL FIELD

The present invention relates to an electrostatic atomizer adapted to generate nanometer-size charged fine water droplets by an electrostatic atomization phenomenon and supply fine water droplets to a mist-receiving space.

BACKGROUND ART

There has been proposed an electrostatic atomizer comprising an atomizing electrode, a counter electrode disposed in opposed relation to the atomizing electrode, and water supplier for supplying water onto the atomizing electrode, wherein a high-voltage is applied between the atomizing electrode and the counter electrode to atomize water held on the atomizing electrode so as to generate charged fine water droplets in a nanometer size range and in a high charge state (i.e., nanometer-size electrostatically charged or ionized misty droplets), as disclosed in the following Patent Publication 1.

Typically, this type of electrostatic atomizer disclosed in the Patent Publication 1 and others has been designed such that, after a potential of the counter electrode is set at a ground potential (zero V) as a precondition to applying an voltage in such a manner as to set a potential difference between the atomizing electrode and the counter electrode at a desired value for electrostatically atomizing water supplied onto the atomizing electrode, the voltage is applied to allow the atomizing electrode to have a potential of about minus 5 kV when it is intended to produce negatively-charged fine water droplets, or the voltage is applied to allow the atomizing electrode to have a potential of about plus 5 kV when it is intended to produce positively-charged fine water droplets.

This operation will be more specifically described with reference to a schematic diagram illustrated inFIG. 7. As shown inFIG. 7, when a voltage is applied between an atomizing electrode2and a counter electrode3to allow the atomizing electrode2and the counter electrode3to be set at +5 kV and a ground voltage (zero V), respectively, water W supplied onto the atomizing electrode2is electrostatically atomized to produce negatively-charged fine water droplets M and negative ions I.

In the above situation, the counter electrode is set at zero V, and a physical object C, such as an article stored in a mist-receiving space or an inner wall of a structural member defining the mist-receiving space, has an approximately zero V. Thus, most of the negative ions I produced and released into the mist-receiving space during the electrostatic atomization are likely to drift in the mist-receiving space without attaching onto the counter electrode3, and excessively attach onto the physical object C, causing the physical object C to become electrostatically charged. Particularly, in cases where the mist-receiving space is a small volume of closed space, such as a vegetable or cooling compartment of a refrigerator, a shoes storage, a clothes washer or a dishwasher, static electrification of a physical object C due to attachment of negative ions I drifting in the small volume of closed space becomes prominent. This causes a problem that, if a user touches the physical object C by his/her hand, the static charges will be discharged through the hand to make his/her feel uncomfortable.[Patent Publication 1] Japanese Unexamined Patent Publication No. 2006-68711

DISCLOSURE OF THE INVENTION

In view of the above problems of the prior art, it is an object of the present invention to provide an electrostatic atomizer which can make a physical object, such as an article stored in a mist-receiving space or an inner wall of a structural member defining the mist-receiving space, less likely to be electrostatically charged.

In order to achieve the above object, the present invention provides an electrostatic atomizer which comprises a high-voltage applying section adapted to apply a high voltage between an atomizing electrode and a counter electrode so as to electrostatically atomize water supplied onto the atomizing electrode. In this electrostatic atomizer, the high-voltage applying section is operable to set an absolute value of a voltage to be applied to the atomizing electrode smaller than an absolute value of a voltage to be applied to the counter electrode.

These and other objects, features, aspects, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments/examples with reference to the accompanying drawings.

BEST MODE FOR CARRYING OUT THE INVENTION

An electrostatic atomizer comprises an atomizing electrode2, a counter electrode3disposed in opposed relation to the atomizing electrode2, a water supplier15adapted to supply water onto the atomizing electrode2, and a high-voltage applying section9adapted to apply a high voltage between the atomizing electrode2and the counter electrode3.

It is contemplated to use various types of water supply systems as the water supplier15to supply water onto the atomizing electrode2. For example, the water supplier15may be designed to condense moisture in air so as to supply water onto the atomizing electrode2or may be designed to supply water from a water reservoir onto a tip end of the atomizing electrode2by means of a capillary phenomenon or using a force feed system (including force feed based on a pump).

Referring toFIGS. 1 to 3showing the electrostatic atomizer according to the embodiment, the water supplier15is designed to condense moisture in air so as to supply water onto the atomizing electrode2.

In the embodiment illustrated inFIGS. 1 to 3, an apparatus A using the electrostatic atomizer internally has a mist-receiving space1, and a cold space4disposed adjacent to the mist-receiving space1and kept at a temperature lower than that of the mist-receiving space1. The apparatus A is intended to supply nanometer-size charged fine water droplets produced by electrostatic atomization, to the mist-receiving space1. For example, the apparatus A having the mist-receiving space1and the cold space4may include a refrigerator and an air-conditioner.

Although the first embodiment illustrated inFIGS. 1 to 3will be described by taking a refrigerator A1as one example of the apparatus A having the mist-receiving space1and the cold space4, an apparatus suitable for applying the inventive electrostatic atomizer is not limited to the refrigerator A1.

FIG. 3is a schematic diagram showing an internal structure of the refrigerator A1. InFIG. 3, the refrigerator A1comprises a refrigerator housing20which is internally provided with a freezing compartment21, a vegetable compartment22, a cooling compartment23and a cold-air passage24. In an outer shell of the refrigerator housing20, each of the freezing compartment21, the vegetable compartment22, the cooling compartment23and the cold-air passage24is divided by a partition wall6. The partition wall6is made of a heat-insulating material. Further, an outer skin6aformed of a synthetic-resin molded product is integrally laminated on a surface of the partition wall6. Portion of the partition wall6dividing between the cold-air passage24and respective ones of the freezing compartment21, the vegetable compartment22and the cooling compartment23are formed, respectively, with communication holes27a,27b,27cfor providing fluid communication between the cold-air passage24and respective ones of the freezing compartment21, the vegetable compartment22and the cooling compartment23.

Each of the freezing compartment21, the vegetable compartment22and the cooling compartment23has an opening on a front side (inFIG. 3, left side) of the refrigerator A1. The front opening of the cooling compartment23is provided with a door25aattached thereto through a hinge in a swingably openable and closable manner. The freezing compartment21and the vegetable compartment22are provided, respectively, with drawer-type boxes26a,26bin an extractable and insertable manner. The drawer boxes26a,26bare integrally formed, respectively, with doors25b,25cat respective front ends thereof. Specifically, each of the drawer boxes26a,26bis adapted, when it is fully inserted and received into/in a corresponding one of the freezing compartment21and the vegetable compartment22, to close the front opening of the corresponding one of the freezing compartment21and the vegetable compartment22by the door (26a,26a) formed at the front end of the drawer box (26a,26b).

The cold-air passage24is internally provided with a cooling source28and a fan29. The cooling source29is operable to cooled air in the cold-air passage24(e.g., cool to about −20° C.), and the fan29is operable to supply the cooled air in the cold-air passage24to each of the freezing compartment21, the vegetable compartment22and the cooling compartment23through a corresponding one of the communication holes27a,27b,27c. Each of the freezing compartment21, the vegetable compartment22and the cooling compartment23is set at a desired temperature according to the cooled air supplied thereto. More specifically, each of the desired temperatures of the vegetable compartment22and the cooling compartment23is greater than the desired temperature of the freezing compartment21(e.g., the desired temperature of the vegetable compartment22is about 5° C.). Thus, each of the communication holes27b,27cis formed to have an opening area smaller than that of the communication hole27aso as to reduce a volume of cooled air from the cold-air passage into each of the vegetable compartment22and the cooling compartment23, as compared with the freezing compartment21.

Although not illustrated, each of the freezing compartment21, the vegetable compartment22and the cooling compartment23is provided with a return passage for returning air to an upstream side of the cold-air passage24relative to the cooling source28.

For example, in the above refrigerator A1, the vegetable compartment22and/or the cooling compartment23serve as the mist-receiving space1, and the cold-air passage24adjacent to the vegetable compartment22and the cooling compartment23through the partition wall6made of a heat-insulating material serves as the cold space4having a temperature lower than that of the mist-receiving space1(in the embodiment illustrated inFIGS. 1 to 3, the vegetable compartment22serves as the mist-receiving space1).

A main unit B of the electrostatic atomizer (hereinafter referred to simply as “atomizer main unit B”) according to the embodiment is mounted to a surface of the portion of the partition wall6dividing between the vegetable compartment22(i.e., the mist-receiving space1) and the cold-air passage24(i.e., the cold space4), on the side of the mist-receiving space1.

The atomizer main unit B comprises an atomizing electrode2, a counter electrode3, a high-voltage applying section9adapted to apply a high voltage between the atomizing electrode2and the counter electrode3, a control section10adapted to control an electrostatic atomization operation, and an atomizer housing11receiving therein the above components.

The atomizer housing11is divided into a receiving chamber11areceiving therein the high-voltage applying section9and the control section10, and a discharge chamber11b. The receiving chamber11areceiving therein the high-voltage applying section9and the control section10is formed as a closed (i.e., hermetically sealed) chamber designed to prevent foreign substances, such as water, from getting thereinto from outside. The atomizing electrode2and the counter electrode3are disposed in the discharge chamber11b. The counter electrode3is formed of a doughnut-shaped metal plate, and mounted to a portion of the discharge chamber11bon the front side of the refrigerator A1in such a manner as to be disposed inside the discharge chamber11band in opposed relation to a mist-releasing opening24formed in a front wall of the atomizer housing11. The atomizing electrode2is mounted to a rear wall of the discharge chamber11b. The atomizing electrode2is positioned to allow a pointed portion at a tip end thereof to be located coaxially with a center axis of a center hole of the doughnut-shaped counter electrode3. Each of the atomizing electrode2and the counter electrode3is electrically connected to the high-voltage applying section9through a high-voltage lead wire.

The atomizing electrode2is provided with a heat transfer member5made of a material having excellent heat conductivity, such as metal, and located at a rear end thereof to serve as one element of the water supplier15. The atomizing electrode2and the heat transfer member5may be integrally formed as a single piece. Alternatively, the heat transfer member5may be formed separately from the atomizing electrode2and then fixedly attached to the atomizing electrode2, or the heat transfer member5may be formed separately from the atomizing electrode2and then brought into contact with the atomizing electrode2. In either case, the atomizing electrode2and the heat transfer member5are formed in a structure which allows heat to be efficiently transferred therebetween.

The heat transfer member5is mounted to the atomizer housing11(in the embodiment, the heat transfer member5is mounted to a cap member11cforming a part of the rear wall of the atomizer housing11, as shown inFIGS. 1 and 2. The rear wall of the atomizer housing11is formed with a hole12(in the embodiment, the hole12is formed in the cap member11c, as shown inFIGS. 1 and 2). The heat transfer member5has a rear end facing the hole12. In the embodiment, the heat transfer member5is arranged such that the rear end thereof protrudes from the hole12, as shown inFIGS. 1 and 2. Alternatively, the heat transfer member5is arranged such that an end face thereof does not protrude rearwardly from the hole12.

The partition wall6has a portion7having higher heat conductivity than the remaining portion. For example, the highly heat-conductive portion7may be created by partly reducing a wall thickness of the partition wall6made of a heat-insulating material, or by making a part of the partition wall6from a material having a higher heat conductivity than of a material of the remaining part of the partition wall6, or by forming a communication hole providing fluid communication between the mist-receiving space1and the cold space4, in a part of the partition wall6made of a heat-insulating material, so as to increase heat conductivity.

In the structure where the partition wall6is partly thinned to form the highly heat-conductive portion7, a concave portion8may be formed in the partition wall6to partly thin the partition wall6in an easy manner. In this case, the concave portion8may be formed in a surface of the partition wall6on the side of the mist-receiving space1, or may be formed in a surface of the partition wall6on the side of the cold space4. Alternatively, the concave portion8may be formed in both the surfaces on the respective sides of the mist-receiving space1and the cold space4. In the embodiment, a hole is formed in a portion of the outer skin6acorresponding to around the highly heat-conductive portion7to allow the heat-insulating material to be exposed to the mist-receiving space1.

As above, the partition wall6is formed with the concave portion8to have the highly heat-conductive portion7with a reduced wall thickness. In an operation of mounting the atomizer housing11to the surface of the partition wall6on the side of the mist-receiving space1, the heat transfer member5is positioned to be in contact with the highly heat-conductive portion7, or positioned with a small distance relative to the highly heat-conductive portion7. While the rear end of the heat transfer member5in the embodiment is fitted in the concave portion8, as shown inFIG. 1, the present invention is not limited to this structure/arrangement, but may have any other suitable structure/arrangement capable of facilitating heat transfer in the partition wall6.

In the structure where the concave portion8is formed in the surface of the partition wall6on the side of the mist-receiving space1to form the highly heat-conductive portion7, the protruding portion5cof the heat transfer member5protruding from the hole12is inserted into the concave portion8, as shown inFIGS. 1 and 2. This makes it possible to more effectively perform the heat transfer between the heat transfer member5and the cold space4.

The heat transfer member5of the atomizing electrode2is disposed in opposed relation to the highly heat-conductive portion7formed in a part of the partition wall6, as mentioned above. Thus, even though the mist-receiving space1and the cold space4is thermally insulated from each other by the partition wall6made of a heat-insulating material, only the heat transfer member5can be cooled to a temperature lower than that of each region and each of the remaining components of the atomizer main unit B installed in the mist-receiving space1, so as to reduce the temperature of the atomizing electrode2while cooling moisture contained in air in the discharge chamber11b, to create condensed water on the atomizing electrode2. In this manner, water will be stably supplied onto the atomizing electrode2.

In the above state when water is supplied onto the atomizing electrode2, the high-voltage applying section9is operable to apply a voltage between the atomizing electrode2and the counter electrode3in such a manner as to allow a potential difference between the atomizing electrode2and the counter electrode3to be set at a given value. According to the high voltage applied between the atomizing electrode2and the counter electrode3, a Coulomb force acts between the counter electrode, and the water supplied on the tip end of the atomizing electrode2, to form a locally raised cone-shaped portion (Taylor cone) in a surface of the condensed water. Due to the formation of the Taylor cone, electric charges are concentrated in a tip of the Taylor cone to increase an electric field intensity and thereby increase the Coulomb force to be produced at the tip of the Taylor cone so as to accelerate growth of the Taylor cone. When electric charges are concentrated at the tip of the Taylor cone grown in this manner, to increase an electric charge density, large energy (repulsive force of the highly-desified electric charges) will be applied to a tip portion of Taylor cone-shaped water at a level greater than a surface tension of the water to cause repetitive breakup/scattering (Rayleigh breakup) of the water so as to produce a large amount of nanometer-size charged fine water droplets.

The nanometer-size charged fine water droplets produced in the above manner are released from the mist-releasing opening14formed in the front wall of the atomizer housing11, into the mist-receiving space1through the center hole of the counter electrode3. Each of the nanometer-size charged fine water droplets released into the mist-receiving space1has a nanometer-scale extremely small size, and therefore can drift in air for a long period of time with high diffusion capability. Thus, the nanometer-size charged fine water droplets will drift in every corner of the mist-receiving space1and attach onto a physical object C, such as an inner wall of a structural member defining the mist-receiving space1and an article stored in the mist-receiving space1. In addition, active species contained in the nanometer-size charged fine water droplets exist in such a manner as to be wrapped with water molecules so as to have a deodorizing effect, a sterilization effect on molds and bacteria, and a suppressive effect on propagation thereof. Thus, the nanometer-size charged fine water droplets attached onto a physical object C, such as an inner wall of a structural member defining the mist-receiving space1and an article stored in the mist-receiving space1, will exhibit the deodorizing effect, the sterilization effect on molds and bacteria, and the suppressive effect on propagation thereof. Further, the active species contained in the nanometer-size charged fine water droplets in such a manner as to be wrapped with water molecules have a longer life as compared with active species existing in the form of a free radical. This makes it possible to enhance the deodorizing effect, the sterilization effect on molds and bacteria, and the suppressive effect on propagation thereof. Furthermore, the nanometer-size charged fine water droplets have a moisturizing effect, and can effectively retain a moisture content of an article stored in the mist-receiving space1.

In the operation of applying a high voltage between the atomizing electrode2and the counter electrode3to electrostatically atomize water supplied onto the atomizing electrode2, the electrostatic atomizer according to the embodiment is operable to apply the voltage between the atomizing electrode2and the counter electrode3in such a manner as to allow a potential of the counter electrode3to become greater than that of the atomizing electrode2by about 5 kV. Further, in the operation of effectively electrostatically atomizing water supplied onto the tip end of the atomizing electrode2to produce nanometer-size charged fine water droplets, the electrostatic atomizer according to the embodiment is operable to allow an absolute value of a voltage of the counter electrode3to become greater than an absolute value of a voltage of the atomizing electrode2(i.e., to allow a potential of the atomizing electrode2to be set at a ground potential (zero V), or to allow the potential of the atomizing electrode2to be set at a value closer to a ground potential (zero V) than a potential of the counter electrode3).

With reference toFIG. 4, an operation of the electrostatic atomizer according to the embodiment will be made about one example where a given voltage (e.g., 5 kV) is applied between the atomizing electrode2and the counter electrode3in such a manner as to allow the potential of the atomizing electrode2to set at the ground potential (zero V), or to be set at a value closer to the ground potential (zero V) than the potential of the counter electrode3, and generate negative ions by the atomizing electrode2.

InFIG. 4, the potential of the counter electrode3is set at +5 kV, and the potential of the atomizing electrode2is set at zero V, by way of example. That is, the counter electrode3becomes a positive electrode. Thus, most of negative ions I generated by the atomizing electrode2will attach onto the counter electrode4, i.e., a positive electrode, to prevent the negative ions I generated during electrostatic atomization from excessively attaching onto the physical object C, such as an inner wall of a structural member defining the mist-receiving space1and an article stored in the mist-receiving space1. This allows the physical object C to become less likely to be electrostatically charged, and makes it possible to avoid causing discomfort due to static charges even if a user touches the physical object C by his/her hand.

Although not illustrated, in an operation of applying a voltage between the atomizing electrode2and the counter electrode3to generate positive ions by the atomizing electrode2, the counter electrode3becomes a negative electrode. Thus, most of positive ions generated by the atomizing electrode2will attach onto the counter electrode4, i.e., a negative electrode, to prevent the positive ions from excessively attaching onto the physical object C, such as an inner wall of a structural member defining the mist-receiving space1and an article stored in the mist-receiving space1. This allows the physical object C to become less likely to be electrostatically charged, and makes it possible to avoid causing discomfort due to static charges even if a user touches the physical object C by his/her hand.

In either case, while each of the negatively- or positively-charged fine water droplets has a nanometer-size extremely small size, it has a fairly greater mass than that of the negative ion I (or the positive ion). Thus, in response to a migration force given by an electric flux line F, the charged fine water droplets are inertially released into the mist-receiving space1. Then, the charged fine water droplets will attach onto the physical object C including not only an inner wall of a structural member defining the mist-receiving space1but also an article stored in the mist-receiving space1, while drifting in the mist-receiving space1. This makes it possible to effectively perform sterilization, antibacterial action, deodorization, moisturization, etc.

As described above, the electrostatic atomizer according to the embodiment can reduce an amount of negative ions (or positive ions) attaching onto the physical object C, such as an inner wall of a structural member defining the mist-receiving space1and an article stored in the mist-receiving space1, so as to prevent occurrence of troubles due to static electrification of the physical object C, and discomfort due to discharge of static charges. Thus, the electrostatic atomizer is suitable, particularly, for the operation of releasing charged fine water droplets M generated by electrostatic atomization, into a small volume of closed space, such as the vegetable or cooling compartment of the refrigerator1A, which would otherwise involve a problem about static electrification of the physical object C, such as an inner wall of a structural member defining the mist-receiving space1.

While the embodiment has been described based on one example where a voltage is applied to allow respective potentials of the atomizing electrode2and the counter electrode3to be set at zero V and +5 kV, respectively, the present invention is not limited to such an operation, but may be any other suitable operation to be performed on the assumption that a voltage is applied between the atomizing electrode2and the counter electrode3in such a manner as to allow a potential difference between the atomizing electrode2and the counter electrode3to be set at a given value for electrostatically atomizing water supplied onto the atomizing electrode2, wherein a potential of the atomizing electrode2is set at a ground potential (zero V) or at a value closer to the ground potential (zero V) than a potential of the counter electrode3. Preferably, a voltage is applied in such a manner that an absolute value of a voltage to be applied to the atomizing electrode2smaller than that of the counter electrode3is set within ±1 kV, and an absolute value of a voltage of the counter electrode3becomes greater than that of the atomizing electrode2. In this case, an effect of preventing electric shock due to an electrostatically charged physical object, can be obtained in addition to the aforementioned effect of reducing static electrification.

FIG. 5shows an electrostatic atomizer according to a second embodiment of the present invention, wherein the second embodiment is different from the previous first embodiment in a structure of water supplier15for condensing moisture in air and supply the condensed water to an atomizing electrode2.

In the second embodiment illustrated inFIG. 5, the water supplier15has a structure where the atomizing electrode2is thermally connected to a cooling section31of a Peltier unit30.

In the Peltier unit30, a pair of Peltier circuit boards32each comprising an electrical insulation substrate made of a material having high heat conductivity, such as alumina or aluminum nitride, and a circuit formed on one surface of the electrical insulation substrate, are disposed to allow the respective circuits to be located in opposed relation to each other. A large number of n-type and p-type BiTe-based thermoelectric elements34disposed in an alternate arrangement are sandwiched between the Peltier circuit boards32. Respective one ends of the adjacent thermoelectric elements34are electrically connected in series through a corresponding one of the opposed circuits. The Peltier unit30is adapted, in response to supplying a current to the thermoelectric elements34through a Peltier input lead wire33, to transfer heat from the side of one of the Peltier circuit boards32toward the other Peltier circuit board32. A cooling electrical insulation plate35made of a material having high heat conductivity and high electric resistance, such as alumina or aluminum nitride, is thermally connected to an upper surface of one (hereinafter referred to as “cooling-side Peltier circuit board”) of the Peltier circuit boards32. Further, a heat release plate36made of a material having high heat conductivity and high electric resistance, such as alumina or aluminum nitride, is thermally connected to a lower surface of the other Peltier circuit board32(hereinafter referred to as “heat release-side Peltier circuit board”).

In the second embodiment, the cooling section31is made up of the electrical insulation substrate of the cooling-side Peltier circuit board32, and the cooling electrical insulation plate35, and a heat release section37is made up of the electrical insulation substrate of the heat release-side Peltier circuit board32, and the heat release plate36, wherein heat is transferred from the side of the cooling section31toward the heat release section37through the thermoelectric elements34.

Thus, the water supplier15is adapted, in response to supplying a current to the Peltier unit30, to cool the atomizing electrode2thermally connected to the cooling section31so as to condense moisture in air to supply the condensed water onto the atomizing electrode2.

In an operation of applying a voltage between the atomizing electrode2and the counter electrode3in such a manner as to allow a potential difference between the atomizing electrode2and the counter electrode3to be set at a given value for electrostatically atomizing water supplied onto the atomizing electrode2, the electrostatic atomizer according to the second embodiment illustrated inFIG. 5is operable to allow a potential of the atomizing electrode2to be set at a ground potential or at a value closer to the ground voltage than that of a potential of the counter electrode3, in the same manner as that in the first embodiment.

Preferably, in the second embodiment, a voltage is applied in such a manner that an absolute value of a voltage to be applied to the atomizing electrode2smaller than that of a voltage of the counter electrode3is set within ±1 kV, and an absolute value of a voltage of the counter electrode3becomes greater than that of a voltage of the atomizing electrode2, as with the first embodiment.

FIG. 6shows an electrostatic atomizer according to a third embodiment of the present invention, wherein the third embodiment is different from the first and second embodiments in a structure of water supplier15for supplying water to an atomizing electrode2.

The water supplier15in the third embodiment illustrated inFIG. 6is adapted to store a liquid in a water reservoir40for reserving water (liquid) therein, and supply the water to a tip end of the atomizing electrode2by mans of a capillary phenomenon. In the embodiment, the atomizing electrode2is formed with a small hole or a porous portion to induce the capillary phenomenon so as to supply the water based on the capillary phenomenon. If the water reservoir40is located away from the atomizing electrode2, the water may be supplied from the water reservoir40to the atomizing electrode2through a water transport member capable of inducing a capillary phenomenon.

In an operation of applying a voltage between the atomizing electrode2and the counter electrode3in such a manner as to allow a potential difference between the atomizing electrode2and the counter electrode3to be set at a given value for electrostatically atomizing water supplied onto the atomizing electrode2, the electrostatic atomizer according to the third embodiment illustrated inFIG. 6is operable to allow a potential of the atomizing electrode2to be set at a ground potential or at a value closer to the ground voltage than that of a potential of the counter electrode3, in the same manner as that in the first and second embodiments.

Preferably, in the third embodiment, a voltage is applied in such a manner that an absolute value of a voltage to be applied to the atomizing electrode2smaller than that of a voltage of the counter electrode3is set within ±1 kV, and an absolute value of a voltage of the counter electrode3becomes greater than that of a voltage of the atomizing electrode2, as with the first and second embodiment.

Although not illustrated, when water is supplied onto the atomizing electrode2by means of force feed means, such as a pump or a water head, in an operation of applying a voltage between the atomizing electrode2and the counter electrode3in such a manner as to allow a potential difference between the atomizing electrode2and the counter electrode3to be set at a given value for electrostatically atomizing water supplied onto the atomizing electrode2, the electrostatic atomizer is operable to allow a potential of the atomizing electrode2to be set at a ground potential or at a value closer to the ground voltage than that of a potential of the counter electrode3, in the same manner as that in the aforementioned embodiments. Specifically, in the case of using a water head, the atomizing electrode comprises a tubular atomization nozzle having a taper-shaped tip end. This atomization nozzle has a rear end in fluid communication with a liquid reservoir. The liquid reservoir reserves a liquid (water), and the water is supplied onto the atomizing electrode based on a pressure caused by a water head difference therebetween. Alternatively, the liquid in the liquid reservoir may be forcedly supplied using a pump.

Preferably, in this case, a voltage is applied in such a manner that an absolute value of a voltage to be applied to the atomizing electrode2smaller than that of a voltage of the counter electrode3is set within ±1 kV, and an absolute value of a voltage of the counter electrode3becomes greater than that of a voltage of the atomizing electrode2, as with the aforementioned embodiments.

As described above, an inventive electrostatic atomizer comprises a high-voltage applying section adapted to apply a high voltage between an atomizing electrode and a counter electrode so as to electrostatically atomize water supplied onto the atomizing electrode. In this electrostatic atomizer, the high-voltage applying section is operable to set an absolute value of a voltage to be applied to the atomizing electrode smaller than an absolute value of a voltage to be applied to the counter electrode.

The voltage to be applied to the atomizing electrode may be preferably within ±1 kV.

Also, the voltage to be applied to the atomizing electrode may be preferably greater than the voltage to be applied to the counter electrode.

Further, the voltage to be applied to the atomizing electrode may be preferably smaller than the voltage to be applied to the counter electrode.

Moreover, the voltage to be applied to said atomizing electrode may be zero V.

In these constructions, when a voltage is applied between the atomizing electrode and the counter electrode to allow negative ions to be generated by the atomizing electrode during an operation of producing charged fine water droplets by electrostatic atomization, the counter electrode becomes a positive electrode, and therefore most of the negative ions generated by the atomizing electrode will be attached onto the counter electrode. Further, when a voltage is applied between the atomizing electrode and the counter electrode to allow positive ions to be generated by the atomizing electrode during the operation of producing charged fine water droplets by electrostatic atomization, the counter electrode becomes a negative electrode, and therefore most of the positive ions generated by the atomizing electrode will be attached onto the counter electrode. Thus, the negative ions (or the positive ions) never excessively attach onto a physical object, such as an inner wall of a structural member defining a mist-receiving space or an article stored in the mist-receiving space, and the physical object becomes less likely to be electrostatically charged. This makes it possible to avoid causing discomfort due to static charges even if a user touches the physical object by his/her hand.

In this specification, an element or component described in the form of means for achieving a certain function is not limited to a specific structure, configuration or arrangement disclosed in the specification to achieve such a function, but may include any other suitable structure, configuration or arrangement, such as a unit, a mechanism or a component, capable of achieving such a function.