WO2009128579A1

WO2009128579A1 - Oral irrigator having low-temperature plasma generating device

Info

Publication number: WO2009128579A1
Application number: PCT/KR2008/002608
Authority: WO
Inventors: Hee Woo Kim
Original assignee: Eco-From Co., Ltd.
Priority date: 2008-04-16
Filing date: 2008-05-09
Publication date: 2009-10-22
Also published as: KR100918474B1

Abstract

Disclosed herein is an oral irrigator having a low-temperature plasma generating device. The oral irrigator includes a low-temperature plasma generating unit, and a plasma fastening unit. The low-temperature plasma generating unit is mounted in a water tank or to a washing water supply conduit, and includes a first electrode, a spacer, a second electrode, and a first electrode element and a second electrode element. The second electrode is spaced apart from the first electrode by the spacer. The first and second electrode elements are electrically connected to the respective first and second electrodes. The plasma fastening unit is mounted in watertight space separated from the water tank or the washing water supply conduit, and includes nuts, packing rings, and a main body.

Description

ORAL IRRIGATOR HAVING LOW-TEMPERATURE PLASMA

GENERATING DEVICE

Technical Field

[1] The present invention relates, in general, to a oral irrigator having a low-temperature plasma generating device and, more particularly, to an oral irrigator, which realizes a function of sterilizing washing water, which is externally sprayed to clean teeth, using low-temperature plasma. Background Art

[2] Generally, tooth diseases, gum diseases and the like occur when cleaning of teeth is neglected after the intake of food. Accordingly, cleaning teeth within a predetermined period after eating food teeth is one of the most important and basic factors in maintaining healthy teeth and gums. In order to clean teeth and to maintain clean teeth, toothbrushes, toothpicks, dental floss and the like are used.

[3] Such a toothbrush may be easily used to remove foreign materials that are attached to the outer surfaces of teeth, but is disadvantage in that it cannot completely remove foreign materials that are tightly caught between the teeth, and in that all the surfaces of the teeth cannot be uniformly brushed. Such a toothpick may remove foreign material caught between teeth, but is disadvantage in that it is impossible to clean the overall surfaces of teeth, and in that it may cause gum diseases by deforming a set of teeth or damaging gums. The dental floss is known to dentist as the best method of cleaning teeth but the manipulation thereof is considered by unskilled users to be complicated, and thus only a very small number of users use it.

[4] In order to solve such disadvantages, an oral irrigator that is capable of removing foreign materials, which are caught between teeth and are attached to gums, using a powerful water pressure is used. Such an oral irrigator is a device that sprays water intermittently or continuously, and has various advantages in that it can remove foreign materials, which cannot be removed using typical toothbrushes, and in that it can also achieve an oral cleaning effect and a gum massage effect using the pressure of sprayed water. For these reasons, the number of users is gradually being increased.

[5] Such an oral irrigator generally includes a water tank 10, which is configured to store a predetermined amount of washing liquid and to supply the washing liquid at a predetermined pressure, a conduit or hose 40, which is configured such that one end thereof is connected to one side portion of the water tank 10 to supply the washing liquid, and a spraying nozzle 30, which is connected to the other end of the conduit or hose 40 to discharge the washing liquid, which is supplied from the water tank 10, to the outside. A motor 50 and a pump 60 are mounted to the water tank 10 or the conduit 40 so that the washing liquid can be supplied from the water tank 10 to the spraying nozzle 30 at the predetermined pressure.

[6] When a washing liquid, such as water, is charged in the oral irrigator water tank 10 and when power is supplied to the motor 50, the water in the water tank 10 is sprayed at the predetermined pressure to the outside via the spraying nozzle 30 due to the rotation of the motor 50. Accordingly, when a user adjusts the position and direction of the spraying nozzle 30 in an oral cavity in various ways, the position and direction in which the washing liquid reach teeth are changed, and thus foreign materials between the teeth and on gums can be removed using the spraying pressure of the washing liquid.

[7] The conventional oral irrigator, which is constructed as described above, has an excellent effect of removing foreign materials in an oral cavity using the above- described method of use, but is problematic in that the effect of preventing gum diseases from occurring due to the propagation of germs is negligible because it cannot kill germs in the oral cavity and cannot sterilize the oral cavity, in that contamination or the propagation of germs cannot be prevented because the washing liquid itself remains in the water tank 10 or in the conduit for supplying a washing liquid, and in that an inconvenient and burdensome method, such as using expensive distilled water rather than using general tap water, is used. Disclosure of Invention Technical Problem

[8] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and the present invention is directed to provide an oral irrigator, which not only can effectively remove foreign materials in an oral cavity using high-pressure washing water but can also kill germs in the oral cavity and sterilize the oral cavity, thus having an excellent effect of preventing gum diseases, attributable to the propagation of germs, from occurring, and which can sterilize washing water itself, such as general tap water, using a safe method that is harmless to the human body and the environment and can continue to conveniently supply the washing water for use thereof. Technical Solution [9] The present invention provides an oral irrigator having a low-temperature plasma generating device, the oral irrigator spraying washing water at a predetermined water pressure to remove foreign materials between teeth using high-pressure washing water, the oral irrigator including: a low-temperature plasma generating unit mounted in a water tank for storing the washing water or to a washing water supply conduit for supplying the washing water, and including: a first electrode, which is made of conductive material; a spacer, which is made of insulating material and is configured to have a predetermined thickness; a second electrode, which is spaced apart from the first electrode by the spacer; a grill and a grill base, which are coupled to contain the first electrode, the spacer and the second electrode, and are configured to have a plurality of through-holes through which the washing water can pass; and a first electrode element and a second electrode element, which are electrically connected to the respective first and second electrodes, and are configured to have bolt shapes; a plasma fastening unit mounted in watertight space separated from the water tank or the washing water supply conduit, and including: nuts, which are threadedly coupled with respective ends of the first and second electrode elements, and is used to fasten the low-temperature plasma generating unit to the structure of the oral irrigator; packing rings, which are inserted between the structure of the oral irrigator and the nuts so as to ensure the watertightness of the first and second electrode elements; and a main body, which is configured to support the nuts in the direction of the first and second electrode elements, and is fastened to the structure of the oral irrigator.

[10] It is preferred that the oral irrigator further include an auxiliary support unit including: a pressing bolt, which is mounted to the structure of the oral irrigator such that the bolt head thereof is in contact with the main body or/and nuts of the plasma fastening unit; an insertion part, which is mounted between the structure of the oral irrigator and the pressing bolt, and is configured to have a T-cylinder shape; and an elastic spring, which is mounted to elastically press the insertion part in the direction of the bolt head of the pressing bolt.

[11] Furthermore, it is preferred that the low- temperature plasma generating unit have the shape of a ring, the central portion of which is perforated, such that the conduit, which is used to supply the washing water to a spraying nozzle for spraying the washing water to an outside, can be mounted in the central portion of the bottom of the water tank, when connected to the water tank.

[12] Furthermore, it is preferred that each of the first and second electrodes of the low- temperature plasma generating unit have a mesh structure through which washing water can pass, and includes body through-holes, which are formed to a size such that only the bodes of the first and second electrode elements, each having a bolt shape, can pass therethrough, and bolt head through-holes, which are formed to have a diameter larger than that of the body through-holes such that the bolt heads of the first and second electrode elements can pass therethrough, the body through-holes and the bolt head through-holes being spaced apart from each other.

[13] Furthermore, it is preferred that the nuts of the plasma fastening unit include a power supply nut, which is connected to a power supply line to apply power to any one of the first and second electrode elements, and a ground nut, which is connected to a ground structure to ground a remaining electrode element, to which no power is applied.

Advantageous Effects

[14] The present invention, which is constructed as described above, can effectively remove foreign materials in an oral cavity using high-pressure washing water but can also kill germs in the oral cavity and sterilize the oral cavity using hydroxyl radicals having powerful oxidizing power and sterilizing power, which are generated by low- temperature plasma generated in water by the operation of the low-temperature plasma generating unit, thus effectively preventing gum diseases, attributable to the propagation of germs, from occurring.

[15] Furthermore, the present invention can sterilize washing water itself using a safe method that is harmless to the human body and the environment in response to the operation of the low-temperature plasma generating unit, thus enabling sanitary and convenient use of the washing water, such as general tap water, which is stored in the water tank, or which is continued to be directly supplied to the spraying nozzle via a tap water supply pipe, without entailing any additional cost. Brief Description of the Drawings

[16] The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[17] FIG. 1 is a perspective view showing a first embodiment of an oral irrigator having a low-temperature plasma generating device according to the present invention;

[18] FIG. 2 is an exploded perspective view of principal parts of FIG. 1 ;

[19] FIG. 3 is an exploded perspective view of a low- temperature plasma generating unit;

[20] FIG. 4 is a plan view of FIG. 1 ;

[21] FIG. 5 is a sectional view taken along line A-A of FIG. 4; [22] FIG. 6 is a sectional view taken along line B-B of FIG. 4;

[23] FIG. 7 is a sectional view taken along line C-C of FIG. 4; and

[24] FIG. 8 is a sectional view taken along line D-D of FIG. 4.

Best Mode for Carrying Out the Invention

[25] The present invention is described in detail with reference to the accompanying drawings below.

[26] FIG. 1 is a perspective view showing a first embodiment of an oral irrigator having a low-temperature plasma generating device according to the present invention, FIG. 2 is an exploded perspective view of principal parts of FIG. 1, FIG. 3 is an exploded perspective view of a low-temperature plasma generating unit, FIG. 4 is a plan view of FIG. 1, and FIGS. 5 to 8 are sectional views taken long respective lines A-A, B-B, C-C and D-D.

[27] The present invention relates to an oral irrigator having a low-temperature plasma generating device. The oral irrigator, which sprays washing water at a predetermined water pressure to remove foreign materials between teeth using high-pressure washing water, includes a low-temperature plasma generating unit 100, which is mounted in a water tank 10 for storing washing water or to a washing water supply conduit for supplying the washing water so that a function of sterilizing washing water can be realized by generating low-temperature plasma, and a plasma fastening unit 200, which is used to accurately fasten the low- temperature plasma generating unit 100 to the structure 20 of the oral irrigator in watertight space, which is formed to be separated from the water tank 10 or the washing water supply conduit.

[28] The low-temperature plasma generating unit 100 includes a first electrode 110, a spacer 120, a second electrode 130, a grill 140, a grill base 150, and electrode elements 160. The first and second electrodes 110 and 130 are spaced apart from each other by the spacer 120 and connected to the electrode elements 160 so as to be supplied with power necessary to generate low-temperature plasma or to enable connection to ground. Furthermore, the first and second electrodes 110 and 130 are covered by the grill 140 and the grill base 150 and installed to be exposed to a washing liquid.

[29] The first and second electrodes 110 and 130 may be formed to have a plurality of through-holes through which the washing water can pass, but it is preferred that each of the first and second electrodes 110 and 130 have a mesh structure that is made of conductive material. When manufactured to have the mesh structure, the first and second electrodes 110 and 130 are manufactured in such a way that unalloyed pure titanium (ASTM-B265 greed2/7/l l, ASME-SE greed4) having excellent corrosion- resistance, acid-resistance, heat-resistance, and mechanical tensile strength is drawn to have a wire diameter that is greater than 0.1 mm and is equal to or smaller than 0.5 mm in accordance with a mesh standard, and is formed to have a plain weave or mesh structure within a pitch that is greater than 16 mesh (0.15 mm) and is equal to or smaller 100 mesh (1.2 mm).

[30] Such pure titanium is material that has excellent acid-resistance and corrosion- resistance as in the case of platinum, is harmless to the human body even when a plated layer or a metal layer is separated due to use for a long time and is dissolved in a washing liquid, causes no concern about secondary environmental pollution, is cheaper than platinum wire, and has an electrical conductivity similar to that of Stainless 304, which is typically used as conventional electrode material but has more excellent corrosion-resistance and acid-resistance than stainless 304.

[31] The first and second electrodes 110 and 130 is finally completed by ion-plating the surface of the titanium mesh, which is manufactured to have a mesh structure as described above, with the platinum, having the most excellent corrosion-resistance, acid-resistance and heat-resistance, to a thickness 1 ~ 5 μm and electrodepositing it. In the case where a platinum-plated layer is separated due to use of the present invention for a long time and, thus, the efficiency of generation of low-temperature plasma is lowered, the first and second electrodes 110 and 130 can be permanently recycled by plating the above-described titanium mesh with platinum again.

[32] When current flows in the direction from a cathode electrode to an anode electrode, underwater discharge is generated, ionized impurities (organic material) and elec- trolyzed negative ions (inorganic material) are attached to the anode electrode and the cathode electrode, and thus a nucleus forming portion is formed. When a local electric field increase region is formed between the first and second electrodes 110 and 130, oxygen-based active species cluster ions are generated in the form of air bubbles.

[33] The generated air bubbles expand and, thus, an electric field is formed in the direction of the cathode electrode to the anode electrode. Accordingly, only when the gap between the first and second electrodes 110 and 130 is optimized according to the intensity of the electric field applied to the electrodes or according to the size of the electrodes, the loss of current can be minimized, and the efficiency of generation of ion cluster air bubbles can be maximized. For this purpose, the spacer 120 is made of insulting material, such as urethane, so as to optimize the spaced distance between the first and second electrodes 110 and 130 and to prevent the first and second electrodes 110 and 130 from being electrically connected to each other, and is installed between the first and second electrodes 110 and 130 to a predetermined thickness.

[34] The grill 140 and the grill base 150 contain the first electrode 110, the spacer 120, and the second electrode 130 therein and are coupled to each other by brazing welding or screw coupling, and thus the low- temperature plasma generating unit 100 is integrally formed. Furthermore, each of the grill 140 and the grill base 150 has a structure, in which a plurality of through-holes, through which the washing water can pass, is formed, or a mesh structure so that plasma and oxygen-based active species cluster ions, which are generated by the power applied to the first and second electrodes 110 and 130, can be easily mixed in the washing water.

[35] In the first embodiment of the present invention, the grill 140 has a cap-shaped longitudinal section in which the left and right ends thereof are bent downwards. The grill base 150 has upward engaging protrusions, which are formed to correspond to the respective inner surfaces of the downwardly bent ends of the grill 140. Accordingly, when the grill 140 is in contact with the grill base 150, the lateral movement of the grill 140 is restricted by the upward engaging protrusions, which are formed on the grill base 150, and thus the grill 140 can be coupled with the grill base 150 in the state in which the grill 140 is brought into accurate contact with the grill base 150.

[36] The electrode elements 160 are formed to have bolt shapes so as to pass through the first and second electrodes 110 and 130, and are made of conductive material such that power can be applied to the first or second electrode 110 or 130 or the first or such that second electrode 110 or 130 can be connected to ground. Furthermore, the electrode elements 160 are selectively connected to a power supply line or a ground structure in the state in which they are fastened by nut members, which are made of conductive material, such as brass or stainless, or in the state in which they are fastened by the grill 140 and the grill base 150, which are used to fasten the first and second electrodes 110 and 130.

[37] In the case where the electrode elements 160 are manufactured to have bolt shapes using pure titanium, which is the same material as that used to form the first and second electrodes 110 and 130, and then platinum plating is performed, the safety of the human body can be ensured and, in addition, environmental pollution can be prevented even when a plated layer is separated and dissolved due to use for a long time, as in the first and second electrodes 110 and 130.

[38] In the first embodiment of the present invention, the electrode elements 160 include a first electrode element 161 and a second electrode element 162. The first electrode element 161 is mounted such that the bolt head thereof is located above any of the through-holes that are formed in the grill 140 and such that the body thereof passes through the first electrode 110, the spacer 120, the second electrode 130, and the grill base 150. The second electrode element 162 is spaced apart from the first electrode element 161, and is mounted such that the bolt head hereof is located over the through- holes that are formed in the first and second electrodes 110 and the spacer 120 and such that the body thereof passes through the second electrode 130 and the grill base 150.

[39] The bolt heads of the respective first and second electrode elements 161 and 162 are coupled at different locations, so that the bolt head of the first electrode element 161 is in airtight contact with the first electrode 110, but the bolt head of the second electrode element 162 in airtight contact with the second electrode 130. Accordingly, the supply of power to the first or second electrode 110 or 130 and the connection to ground of the first or second electrode 110 or 130 can be achieved using the first and second electrode elements 161 and 162.

[40] Each of the first and second electrodes 110 and 130 has a mesh structure through which the washing water can pass, and includes body through-holes, which are formed to a size such that only the bodes of the first and second electrode elements 161 and 162, each having a bolt shape, can pass therethrough, and bolt head through-holes, which are formed to have a diameter larger than that of the body through-holes such that bolt heads of the first and second electrode elements 161 and 162 can pass therethrough, the body through-holes and the bolt head through-holes being spaced apart from each other. Accordingly, any one of the first and second electrodes 110 is connected to the first electrode element 161 to function as a power electrode, and the other electrode is connected to the second electrode element 162 to function as a ground electrode.

[41] When the low-temperature plasma generating unit 100 according to the present invention, which is constructed as described above, is coupled to the water tank 10 of the oral irrigator, it is preferred that the low- temperature plasma generating unit 100 have the shape of a ring, the central portion of which is perforated, such that the conduit 40, which is used to supply the washing water to a spraying nozzle 30 for spraying the washing water to the outside, is mounted in the central portion of the bottom of the water tank 10.

[42] The plasma fastening unit 200 includes ground nuts 210, which are threadedly coupled to the respective ends of the electrode elements 160 of the low-temperature plasma generating unit 100, packing rings 220, which are mounted to the respective nuts 210 to ensure the watertightness of the electrode elements 160, and a main body 230, which is configured to support the nuts 210 in the direction of the electrode elements 160 and is fastened to the structure 20 of the oral irrigator.

[43] The electrode elements 160 are formed to have bolt shapes, so that the low- temperature plasma generating unit 100 not only can be easily fastened using the nuts 210 but can also be conveniently separated from the nuts 210 by rotating the electrode elements 160 using a tool, such as a screw driver even when the low- temperature plasma generating unit 100 and the first and second electrodes 110 are replaced, with the result that the oral irrigator of the present invention can be completely recycled without causing damage thereto.

[44] Each of the nuts 210 is configured such that a part that is in contact with the main body 230 has a hemisphere shape that is convex downwards, and the main body 230 is configured such that parts that are in contact with the nuts 210 has a hemisphere that is concave downwards and the central portion thereof is perforated. Accordingly, the main body 230 can securely and accurately support the nuts 210 so that the nuts 210 are not twisted or moved in the side direction thereof.

[45] The nuts 210 include a power supply nut, which is connected to a power supply line to apply power to any one of the first and second electrode elements 161 and 162, and a ground nut, which is connected to a ground structure to ground the other electrode element, to which no power is applied. Accordingly, any one of the first and second electrodes 110 and 130 of the low- temperature plasma generating unit can functions as a power electrode, and the other electrode can function as a ground electrode.

[46] When the plasma operation switch, which is provided on the outside surface of the oral irrigator according to the present invention, is turned on, the operation is performed in order of power source unit → switching unit → pulse generating unit → connection unit → power switch → control unit → power source unit/switching unit → signal output unit in low-temperature plasma generating unit 100. When the switching unit and the signal output unit are operated, it is preferred that a power supply state or an operating state be indicated using a Light Emitting Dode (LED) or a Liquid Crystal Display (LCD) device so as to be viewed from the outside by a user.

[47] The power source unit is configured such that an AC voltage of 110 ~ 220 VAC, which is applied from a power source, is converted into a DC voltage of 3 ~ 47 VDC, and then an AC voltage is generated by a subsequent pulse circuit. The connection unit is a part to which the electrode elements 160 or the nuts 210, corresponding to connection terminals for transmitting current to the first electrode 110 and the second electrode 130, are connected. The switching unit is a part that turns on/off the supply of power to the power source unit in response to control signals from the control unit, and may be implemented using switching elements, such as PNP-type or NPN-type transistors and Field Effect Transistors (FETs), may be used for the switching unit.

[48] When the operation switch is turned on, the control unit causes DC power to be supplied from the source unit to the low-temperature plasma generator via the connection unit by applying an ON control signal to the switching unit, causes the supply of power to be interrupted by applying an OFF control signal to the switching unit after a preset operation period has elapsed, causes a positive voltage and a negative voltage to be alternately supplied within a range of one second to five minutes by controlling the switching unit and, thus, enables the polarities of the connection terminals to be altered whenever the power is alternately supplied, and controls the signal output unit and an operational LED.

[49] When current is applied to the device according to the present invention, described above, in the state in which it is installed in a water tank, or in a vessel, in which a liquid, such as general tap water, dirty water or waste water, is contained, low- temperature plasma is generated between the positive and negative electrodes of the device due to a water breakdown mechanism. Accordingly, water molecules (H2O) are decomposed into hydrogen ions and oxygen ions and are then diffused in the water as numerous minute air bubbles, which are kinds of ion clusters, and oxygen molecules (02) are created through bonding between oxygen atoms because the oxygen atoms each exhibit a property of attaining a stable state through bonding with other oxygen atoms.

[50] Negative ions are separated from the hydrogen atoms (H) by a strong electrochemical energy, which is caused by the above-described low-temperature plasma, and thus the hydrogen atoms (H) become positive hydrogen ions (H+). The oxygen molecules (02) are changed into negative oxygen ions by accepting surrounding negative ions, and parts of the oxygen molecules (02) are changed into 03. The above-described electrochemically dissociated state is generally restored to the original state within 2 - 5 hours in the atmosphere, or within about 48 hours in an airtight state, as in a refrigerator, and the water exhibits a moderately alkaline characteristic of about 7.4 Ph.

[51] The positive hydrogen ions (H+) and the negative oxygen ions (02-), which are generated as described above, react with surrounding water molecules (H2O), and thus hydroxyl radicals and various oxygen-based active species ions, such as negative ions, are generated in a cluster form. In this case, hydrogen peroxide, which is generated along with the ions, is evaporated upwards from the surface of the water, and the hydroxyl radicals function to be attached to germs and to decompose and remove the germs.

[52] The hydroxyl radicals, which enter a very unstable state in the characteristic of molecules, are restored again to water (H2O) by capturing hydrogen ions (H) present in the cell membranes of germs. In this case, the germs, from the cell membranes of which hydrogen ions (H) are removed, are changed into inactive and harmless materials when the cell membranes are destroyed. Due to the reaction of ozone (03), which is generated when the germs are changed, and is one oxygen-based active species, algae, such as mold and some kinds of moss, are also treated.

[53] Furthermore, a strong electric field is formed between minute underwater air bubbles, which are generated by a strong electric field between the cathode electrode and the anode electrode, and thus underwater germs and other organic and inorganic materials can be electrically removed. Oxygen-based active species ions, as wells as the hydroxyl radicals, which are generated in water by the low-temperature plasma, enter an unstable state, and thus they are converted to water within 2 - 5 hours in the normal atmosphere after reaction with germs, toxins or underwater organic or inorganic materials, therefore there is no problem of secondary pollution.

[54] In order to fasten the main body 230 to the structure 20 of the oral irrigator, hemisphere depression or protrusions are formed in or on the structure 20 of the oral irrigator, and hemisphere protrusions or depressions are formed at locations that correspond to the depression or protrusions of the structure 20. Accordingly, the main body 230 can be securely and accurately fastened to the structure 20, and the protrusions can also slide along the surfaces of the hemisphere depressions to be thus released depressions.

[55] In the first embodiment of the present invention, in order not only to more stably connect the plasma fastening unit 200 to the structure 20 of the oral irrigator and the plasma fastening unit 200 but also to stably maintain the connection even when vibration occurs due to the operation of the motor 50 during use of the present invention, the plasma fastening unit 200 is additionally provided with an auxiliary support unit 300 that comes into contact with and supports the main body 230 and the nuts 210 in the direction of the plasma fastening unit 200 and the electrode elements 160.

[56] The auxiliary support unit 300 includes a pressing bolt 310, an insertion part 320, and an elastic spring 330. The pressing bolt 310 is mounted to the structure 20 of the oral irrigator such that the bolt head thereof is in contact with the main body 230 or nuts 210 of the plasma fastening unit. The insertion part 320 is configured such that the upper end thereof is in contact with the lower end of the bolt head of the pressing bolt 310, is configured to have the shape of a T-cy Under, through which the body of the pressing bolt 210 can pass, and is mounted between the structure 29 of the oral irrigator and the pressing bolt 310. The elastic spring 330 is mounted to the insertion part 320 and the structure of the oral irrigator to elastically press the insertion part 320 in the direction of the bolt head of the pressing bolt 310. Industrial Applicability

[57] According to the present invention, the oral irrigator, having a low-temperature plasma generating device, not only can effectively remove foreign materials in an oral cavity using high-pressure washing water but can also kill germs in the oral cavity and sterilize the oral cavity using hydroxyl radicals having powerful oxidizing power and sterilizing power, which are generated by low-temperature plasma generated in water by the operation of the low- temperature plasma generating unit 100, thus effectively preventing gum diseases, attributable to the propagation of germs, from occurring.

[58] Furthermore, the oral irrigator can sterilize washing water itself using a safe method that is harmless to the human body and the environment in response to the operation of the low-temperature plasma generating unit, thus enabling sanitary and convenient use of the washing water, such as general tap water, which is stored in the water tank 10, or which is continued to be directly supplied to the spraying nozzle 30 via a tap water supply pipe (not shown), without entailing any additional cost.

[59] Although the preferred embodiment of the present invention has been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

[1] An oral irrigator having a low- temperature plasma generating device, the oral irrigator spraying washing water at a predetermined water pressure to remove foreign materials between teeth using high-pressure washing water, the oral irrigator comprising: a low-temperature plasma generating unit mounted in a water tank for storing the washing water or to a washing water supply conduit for supplying the washing water, and comprising: a first electrode, which is made of conductive material; a spacer, which is made of insulating material and is configured to have a predetermined thickness; a second electrode, which is spaced apart from the first electrode by the spacer; a grill and a grill base, which are coupled to contain the first electrode, the spacer and the second electrode, and are configured to have a plurality of through-holes through which the washing water can pass; and a first electrode element and a second electrode element, which are electrically connected to the respective first and second electrodes, and are configured to have bolt shapes; a plasma fastening unit mounted in watertight space separated from the water tank or the washing water supply conduit, and comprising: nuts, which are threadedly coupled with respective ends of the first and second electrode elements, and is used to fasten the low-temperature plasma generating unit to a structure of the oral irrigator; packing rings, which are inserted between the structure of the oral irrigator and the nuts so as to ensure watertightness of the first and second electrode elements; and a main body, which is configured to support the nuts in a direction of the first and second electrode elements, and is fastened to the structure of the oral irrigator.

[2] The oral irrigator according to claim 1, further comprising: an auxiliary support unit comprising: a pressing bolt, which is mounted to the structure of the oral irrigator such that a bolt head thereof is in contact with the main body or/and nuts of the plasma fastening unit; an insertion part, which is mounted between the structure of the oral irrigator and the pressing bolt, and is configured to have a T-cylinder shape; and an elastic spring, which is mounted to elastically press the insertion part in a direction of the bolt head of the pressing bolt.

[3] The oral irrigator according to claim 1, wherein the low- temperature plasma generating unit has a shape of a ring, a central portion of which is perforated, such that the conduit, which is used to supply the washing water to a spraying nozzle for spraying the washing water to an outside, can be mounted in a central portion of a bottom of the water tank, when connected to the water tank.

[4] The oral irrigator according to claim 1, wherein each of the first and second electrodes of the low-temperature plasma generating unit has a mesh structure through which washing water can pass, and comprises body through-holes, which are formed to a size such that only the bodes of the first and second electrode elements, each having a bolt shape, can pass therethrough, and bolt head through-holes, which are formed to have a diameter larger than that of the body through-holes such that bolt heads of the first and second electrode elements can pass therethrough, the body through-holes and the bolt head through-holes being spaced apart from each other.

[5] The oral irrigator according to claim 1, wherein the nuts of the plasma fastening unit comprise: a power supply nut, which is connected to a power supply line to apply power to any one of the first and second electrode elements; and a ground nut, which is connected to a ground structure to ground a remaining electrode element, to which no power is applied.